Update to bmake-20200710

[FreeBSD/FreeBSD.git] / sys / dev / sym / sym_hipd.c

/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 *  Device driver optimized for the Symbios/LSI 53C896/53C895A/53C1010
 *  PCI-SCSI controllers.
 *
 *  Copyright (C) 1999-2001  Gerard Roudier <groudier@free.fr>
 *
 *  This driver also supports the following Symbios/LSI PCI-SCSI chips:
 *      53C810A, 53C825A, 53C860, 53C875, 53C876, 53C885, 53C895,
 *      53C810,  53C815,  53C825 and the 53C1510D is 53C8XX mode.
 *
 *
 *  This driver for FreeBSD-CAM is derived from the Linux sym53c8xx driver.
 *  Copyright (C) 1998-1999  Gerard Roudier
 *
 *  The sym53c8xx driver is derived from the ncr53c8xx driver that had been
 *  a port of the FreeBSD ncr driver to Linux-1.2.13.
 *
 *  The original ncr driver has been written for 386bsd and FreeBSD by
 *          Wolfgang Stanglmeier        <wolf@cologne.de>
 *          Stefan Esser                <se@mi.Uni-Koeln.de>
 *  Copyright (C) 1994  Wolfgang Stanglmeier
 *
 *  The initialisation code, and part of the code that addresses
 *  FreeBSD-CAM services is based on the aic7xxx driver for FreeBSD-CAM
 *  written by Justin T. Gibbs.
 *
 *  Other major contributions:
 *
 *  NVRAM detection and reading.
 *  Copyright (C) 1997 Richard Waltham <dormouse@farsrobt.demon.co.uk>
 *
 *-----------------------------------------------------------------------------
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#define SYM_DRIVER_NAME "sym-1.6.5-20000902"

/* #define SYM_DEBUG_GENERIC_SUPPORT */

#include <sys/param.h>

/*
 *  Driver configuration options.
 */
#include "opt_sym.h"
#include <dev/sym/sym_conf.h>

#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/endian.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/module.h>
#include <sys/bus.h>

#include <sys/proc.h>

#include <dev/pci/pcireg.h>
#include <dev/pci/pcivar.h>

#include <machine/bus.h>
#include <machine/resource.h>
#include <machine/atomic.h>

#include <sys/rman.h>

#include <cam/cam.h>
#include <cam/cam_ccb.h>
#include <cam/cam_sim.h>
#include <cam/cam_xpt_sim.h>
#include <cam/cam_debug.h>

#include <cam/scsi/scsi_all.h>
#include <cam/scsi/scsi_message.h>

/* Short and quite clear integer types */
typedef int8_t    s8;
typedef int16_t   s16;
typedef int32_t   s32;
typedef u_int8_t  u8;
typedef u_int16_t u16;
typedef u_int32_t u32;

/*
 *  Driver definitions.
 */
#include <dev/sym/sym_defs.h>
#include <dev/sym/sym_fw.h>

/*
 *  IA32 architecture does not reorder STORES and prevents
 *  LOADS from passing STORES. It is called `program order'
 *  by Intel and allows device drivers to deal with memory
 *  ordering by only ensuring that the code is not reordered
 *  by the compiler when ordering is required.
 *  Other architectures implement a weaker ordering that
 *  requires memory barriers (and also IO barriers when they
 *  make sense) to be used.
 */
#if     defined __i386__ || defined __amd64__
#define MEMORY_BARRIER()        do { ; } while(0)
#elif   defined __powerpc__
#define MEMORY_BARRIER()        __asm__ volatile("eieio; sync" : : : "memory")
#elif   defined __arm__
#define MEMORY_BARRIER()        dmb()
#elif   defined __aarch64__
#define MEMORY_BARRIER()        dmb(sy)
#elif   defined __riscv
#define MEMORY_BARRIER()        fence()
#else
#error  "Not supported platform"
#endif

/*
 *  A la VMS/CAM-3 queue management.
 */
typedef struct sym_quehead {
        struct sym_quehead *flink;      /* Forward  pointer */
        struct sym_quehead *blink;      /* Backward pointer */
} SYM_QUEHEAD;

#define sym_que_init(ptr) do { \
        (ptr)->flink = (ptr); (ptr)->blink = (ptr); \
} while (0)

static __inline void __sym_que_add(struct sym_quehead * new,
        struct sym_quehead * blink,
        struct sym_quehead * flink)
{
        flink->blink    = new;
        new->flink      = flink;
        new->blink      = blink;
        blink->flink    = new;
}

static __inline void __sym_que_del(struct sym_quehead * blink,
        struct sym_quehead * flink)
{
        flink->blink = blink;
        blink->flink = flink;
}

static __inline int sym_que_empty(struct sym_quehead *head)
{
        return head->flink == head;
}

static __inline void sym_que_splice(struct sym_quehead *list,
        struct sym_quehead *head)
{
        struct sym_quehead *first = list->flink;

        if (first != list) {
                struct sym_quehead *last = list->blink;
                struct sym_quehead *at   = head->flink;

                first->blink = head;
                head->flink  = first;

                last->flink = at;
                at->blink   = last;
        }
}

#define sym_que_entry(ptr, type, member) \
        ((type *)((char *)(ptr)-(size_t)(&((type *)0)->member)))

#define sym_insque(new, pos)            __sym_que_add(new, pos, (pos)->flink)

#define sym_remque(el)                  __sym_que_del((el)->blink, (el)->flink)

#define sym_insque_head(new, head)      __sym_que_add(new, head, (head)->flink)

static __inline struct sym_quehead *sym_remque_head(struct sym_quehead *head)
{
        struct sym_quehead *elem = head->flink;

        if (elem != head)
                __sym_que_del(head, elem->flink);
        else
                elem = NULL;
        return elem;
}

#define sym_insque_tail(new, head)      __sym_que_add(new, (head)->blink, head)

/*
 *  This one may be useful.
 */
#define FOR_EACH_QUEUED_ELEMENT(head, qp) \
        for (qp = (head)->flink; qp != (head); qp = qp->flink)
/*
 *  FreeBSD does not offer our kind of queue in the CAM CCB.
 *  So, we have to cast.
 */
#define sym_qptr(p)     ((struct sym_quehead *) (p))

/*
 *  Simple bitmap operations.
 */
#define sym_set_bit(p, n)       (((u32 *)(p))[(n)>>5] |=  (1<<((n)&0x1f)))
#define sym_clr_bit(p, n)       (((u32 *)(p))[(n)>>5] &= ~(1<<((n)&0x1f)))
#define sym_is_bit(p, n)        (((u32 *)(p))[(n)>>5] &   (1<<((n)&0x1f)))

/*
 *  Number of tasks per device we want to handle.
 */
#if     SYM_CONF_MAX_TAG_ORDER > 8
#error  "more than 256 tags per logical unit not allowed."
#endif
#define SYM_CONF_MAX_TASK       (1<<SYM_CONF_MAX_TAG_ORDER)

/*
 *  Donnot use more tasks that we can handle.
 */
#ifndef SYM_CONF_MAX_TAG
#define SYM_CONF_MAX_TAG        SYM_CONF_MAX_TASK
#endif
#if     SYM_CONF_MAX_TAG > SYM_CONF_MAX_TASK
#undef  SYM_CONF_MAX_TAG
#define SYM_CONF_MAX_TAG        SYM_CONF_MAX_TASK
#endif

/*
 *    This one means 'NO TAG for this job'
 */
#define NO_TAG  (256)

/*
 *  Number of SCSI targets.
 */
#if     SYM_CONF_MAX_TARGET > 16
#error  "more than 16 targets not allowed."
#endif

/*
 *  Number of logical units per target.
 */
#if     SYM_CONF_MAX_LUN > 64
#error  "more than 64 logical units per target not allowed."
#endif

/*
 *    Asynchronous pre-scaler (ns). Shall be 40 for
 *    the SCSI timings to be compliant.
 */
#define SYM_CONF_MIN_ASYNC (40)

/*
 *  Number of entries in the START and DONE queues.
 *
 *  We limit to 1 PAGE in order to succeed allocation of
 *  these queues. Each entry is 8 bytes long (2 DWORDS).
 */
#ifdef  SYM_CONF_MAX_START
#define SYM_CONF_MAX_QUEUE (SYM_CONF_MAX_START+2)
#else
#define SYM_CONF_MAX_QUEUE (7*SYM_CONF_MAX_TASK+2)
#define SYM_CONF_MAX_START (SYM_CONF_MAX_QUEUE-2)
#endif

#if     SYM_CONF_MAX_QUEUE > PAGE_SIZE/8
#undef  SYM_CONF_MAX_QUEUE
#define SYM_CONF_MAX_QUEUE   PAGE_SIZE/8
#undef  SYM_CONF_MAX_START
#define SYM_CONF_MAX_START (SYM_CONF_MAX_QUEUE-2)
#endif

/*
 *  For this one, we want a short name :-)
 */
#define MAX_QUEUE       SYM_CONF_MAX_QUEUE

/*
 *  Active debugging tags and verbosity.
 */
#define DEBUG_ALLOC     (0x0001)
#define DEBUG_PHASE     (0x0002)
#define DEBUG_POLL      (0x0004)
#define DEBUG_QUEUE     (0x0008)
#define DEBUG_RESULT    (0x0010)
#define DEBUG_SCATTER   (0x0020)
#define DEBUG_SCRIPT    (0x0040)
#define DEBUG_TINY      (0x0080)
#define DEBUG_TIMING    (0x0100)
#define DEBUG_NEGO      (0x0200)
#define DEBUG_TAGS      (0x0400)
#define DEBUG_POINTER   (0x0800)

#if 0
static int sym_debug = 0;
        #define DEBUG_FLAGS sym_debug
#else
/*      #define DEBUG_FLAGS (0x0631) */
        #define DEBUG_FLAGS (0x0000)

#endif
#define sym_verbose     (np->verbose)

/*
 *  Insert a delay in micro-seconds and milli-seconds.
 */
static void UDELAY(int us) { DELAY(us); }
static void MDELAY(int ms) { while (ms--) UDELAY(1000); }

/*
 *  Simple power of two buddy-like allocator.
 *
 *  This simple code is not intended to be fast, but to
 *  provide power of 2 aligned memory allocations.
 *  Since the SCRIPTS processor only supplies 8 bit arithmetic,
 *  this allocator allows simple and fast address calculations
 *  from the SCRIPTS code. In addition, cache line alignment
 *  is guaranteed for power of 2 cache line size.
 *
 *  This allocator has been developed for the Linux sym53c8xx
 *  driver, since this O/S does not provide naturally aligned
 *  allocations.
 *  It has the advantage of allowing the driver to use private
 *  pages of memory that will be useful if we ever need to deal
 *  with IO MMUs for PCI.
 */
#define MEMO_SHIFT      4       /* 16 bytes minimum memory chunk */
#define MEMO_PAGE_ORDER 0       /* 1 PAGE  maximum */
#if 0
#define MEMO_FREE_UNUSED        /* Free unused pages immediately */
#endif
#define MEMO_WARN       1
#define MEMO_CLUSTER_SHIFT      (PAGE_SHIFT+MEMO_PAGE_ORDER)
#define MEMO_CLUSTER_SIZE       (1UL << MEMO_CLUSTER_SHIFT)
#define MEMO_CLUSTER_MASK       (MEMO_CLUSTER_SIZE-1)

#define get_pages()             malloc(MEMO_CLUSTER_SIZE, M_DEVBUF, M_NOWAIT)
#define free_pages(p)           free((p), M_DEVBUF)

typedef u_long m_addr_t;        /* Enough bits to bit-hack addresses */

typedef struct m_link {         /* Link between free memory chunks */
        struct m_link *next;
} m_link_s;

typedef struct m_vtob {         /* Virtual to Bus address translation */
        struct m_vtob   *next;
        bus_dmamap_t    dmamap; /* Map for this chunk */
        m_addr_t        vaddr;  /* Virtual address */
        m_addr_t        baddr;  /* Bus physical address */
} m_vtob_s;
/* Hash this stuff a bit to speed up translations */
#define VTOB_HASH_SHIFT         5
#define VTOB_HASH_SIZE          (1UL << VTOB_HASH_SHIFT)
#define VTOB_HASH_MASK          (VTOB_HASH_SIZE-1)
#define VTOB_HASH_CODE(m)       \
        ((((m_addr_t) (m)) >> MEMO_CLUSTER_SHIFT) & VTOB_HASH_MASK)

typedef struct m_pool {         /* Memory pool of a given kind */
        bus_dma_tag_t    dev_dmat;      /* Identifies the pool */
        bus_dma_tag_t    dmat;          /* Tag for our fixed allocations */
        m_addr_t (*getp)(struct m_pool *);
#ifdef  MEMO_FREE_UNUSED
        void (*freep)(struct m_pool *, m_addr_t);
#endif
#define M_GETP()                mp->getp(mp)
#define M_FREEP(p)              mp->freep(mp, p)
        int nump;
        m_vtob_s *(vtob[VTOB_HASH_SIZE]);
        struct m_pool *next;
        struct m_link h[MEMO_CLUSTER_SHIFT - MEMO_SHIFT + 1];
} m_pool_s;

static void *___sym_malloc(m_pool_s *mp, int size)
{
        int i = 0;
        int s = (1 << MEMO_SHIFT);
        int j;
        m_addr_t a;
        m_link_s *h = mp->h;

        if (size > MEMO_CLUSTER_SIZE)
                return NULL;

        while (size > s) {
                s <<= 1;
                ++i;
        }

        j = i;
        while (!h[j].next) {
                if (s == MEMO_CLUSTER_SIZE) {
                        h[j].next = (m_link_s *) M_GETP();
                        if (h[j].next)
                                h[j].next->next = NULL;
                        break;
                }
                ++j;
                s <<= 1;
        }
        a = (m_addr_t) h[j].next;
        if (a) {
                h[j].next = h[j].next->next;
                while (j > i) {
                        j -= 1;
                        s >>= 1;
                        h[j].next = (m_link_s *) (a+s);
                        h[j].next->next = NULL;
                }
        }
#ifdef DEBUG
        printf("___sym_malloc(%d) = %p\n", size, (void *) a);
#endif
        return (void *) a;
}

static void ___sym_mfree(m_pool_s *mp, void *ptr, int size)
{
        int i = 0;
        int s = (1 << MEMO_SHIFT);
        m_link_s *q;
        m_addr_t a, b;
        m_link_s *h = mp->h;

#ifdef DEBUG
        printf("___sym_mfree(%p, %d)\n", ptr, size);
#endif

        if (size > MEMO_CLUSTER_SIZE)
                return;

        while (size > s) {
                s <<= 1;
                ++i;
        }

        a = (m_addr_t) ptr;

        while (1) {
#ifdef MEMO_FREE_UNUSED
                if (s == MEMO_CLUSTER_SIZE) {
                        M_FREEP(a);
                        break;
                }
#endif
                b = a ^ s;
                q = &h[i];
                while (q->next && q->next != (m_link_s *) b) {
                        q = q->next;
                }
                if (!q->next) {
                        ((m_link_s *) a)->next = h[i].next;
                        h[i].next = (m_link_s *) a;
                        break;
                }
                q->next = q->next->next;
                a = a & b;
                s <<= 1;
                ++i;
        }
}

static void *__sym_calloc2(m_pool_s *mp, int size, char *name, int uflags)
{
        void *p;

        p = ___sym_malloc(mp, size);

        if (DEBUG_FLAGS & DEBUG_ALLOC)
                printf ("new %-10s[%4d] @%p.\n", name, size, p);

        if (p)
                bzero(p, size);
        else if (uflags & MEMO_WARN)
                printf ("__sym_calloc2: failed to allocate %s[%d]\n", name, size);

        return p;
}

#define __sym_calloc(mp, s, n)  __sym_calloc2(mp, s, n, MEMO_WARN)

static void __sym_mfree(m_pool_s *mp, void *ptr, int size, char *name)
{
        if (DEBUG_FLAGS & DEBUG_ALLOC)
                printf ("freeing %-10s[%4d] @%p.\n", name, size, ptr);

        ___sym_mfree(mp, ptr, size);

}

/*
 * Default memory pool we donnot need to involve in DMA.
 */
/*
 * With the `bus dma abstraction', we use a separate pool for
 * memory we donnot need to involve in DMA.
 */
static m_addr_t ___mp0_getp(m_pool_s *mp)
{
        m_addr_t m = (m_addr_t) get_pages();
        if (m)
                ++mp->nump;
        return m;
}

#ifdef  MEMO_FREE_UNUSED
static void ___mp0_freep(m_pool_s *mp, m_addr_t m)
{
        free_pages(m);
        --mp->nump;
}
#endif

#ifdef  MEMO_FREE_UNUSED
static m_pool_s mp0 = {0, 0, ___mp0_getp, ___mp0_freep};
#else
static m_pool_s mp0 = {0, 0, ___mp0_getp};
#endif

/*
 * Actual memory allocation routine for non-DMAed memory.
 */
static void *sym_calloc(int size, char *name)
{
        void *m;
        /* Lock */
        m = __sym_calloc(&mp0, size, name);
        /* Unlock */
        return m;
}

/*
 * Actual memory allocation routine for non-DMAed memory.
 */
static void sym_mfree(void *ptr, int size, char *name)
{
        /* Lock */
        __sym_mfree(&mp0, ptr, size, name);
        /* Unlock */
}

/*
 * DMAable pools.
 */
/*
 * With `bus dma abstraction', we use a separate pool per parent
 * BUS handle. A reverse table (hashed) is maintained for virtual
 * to BUS address translation.
 */
static void getbaddrcb(void *arg, bus_dma_segment_t *segs, int nseg __unused,
    int error)
{
        bus_addr_t *baddr;

        KASSERT(nseg == 1, ("%s: too many DMA segments (%d)", __func__, nseg));

        baddr = (bus_addr_t *)arg;
        if (error)
                *baddr = 0;
        else
                *baddr = segs->ds_addr;
}

static m_addr_t ___dma_getp(m_pool_s *mp)
{
        m_vtob_s *vbp;
        void *vaddr = NULL;
        bus_addr_t baddr = 0;

        vbp = __sym_calloc(&mp0, sizeof(*vbp), "VTOB");
        if (!vbp)
                goto out_err;

        if (bus_dmamem_alloc(mp->dmat, &vaddr,
                        BUS_DMA_COHERENT | BUS_DMA_WAITOK, &vbp->dmamap))
                goto out_err;
        bus_dmamap_load(mp->dmat, vbp->dmamap, vaddr,
                        MEMO_CLUSTER_SIZE, getbaddrcb, &baddr, BUS_DMA_NOWAIT);
        if (baddr) {
                int hc = VTOB_HASH_CODE(vaddr);
                vbp->vaddr = (m_addr_t) vaddr;
                vbp->baddr = (m_addr_t) baddr;
                vbp->next = mp->vtob[hc];
                mp->vtob[hc] = vbp;
                ++mp->nump;
                return (m_addr_t) vaddr;
        }
out_err:
        if (baddr)
                bus_dmamap_unload(mp->dmat, vbp->dmamap);
        if (vaddr)
                bus_dmamem_free(mp->dmat, vaddr, vbp->dmamap);
        if (vbp)
                __sym_mfree(&mp0, vbp, sizeof(*vbp), "VTOB");
        return 0;
}

#ifdef  MEMO_FREE_UNUSED
static void ___dma_freep(m_pool_s *mp, m_addr_t m)
{
        m_vtob_s **vbpp, *vbp;
        int hc = VTOB_HASH_CODE(m);

        vbpp = &mp->vtob[hc];
        while (*vbpp && (*vbpp)->vaddr != m)
                vbpp = &(*vbpp)->next;
        if (*vbpp) {
                vbp = *vbpp;
                *vbpp = (*vbpp)->next;
                bus_dmamap_unload(mp->dmat, vbp->dmamap);
                bus_dmamem_free(mp->dmat, (void *) vbp->vaddr, vbp->dmamap);
                __sym_mfree(&mp0, vbp, sizeof(*vbp), "VTOB");
                --mp->nump;
        }
}
#endif

static __inline m_pool_s *___get_dma_pool(bus_dma_tag_t dev_dmat)
{
        m_pool_s *mp;
        for (mp = mp0.next; mp && mp->dev_dmat != dev_dmat; mp = mp->next);
        return mp;
}

static m_pool_s *___cre_dma_pool(bus_dma_tag_t dev_dmat)
{
        m_pool_s *mp = NULL;

        mp = __sym_calloc(&mp0, sizeof(*mp), "MPOOL");
        if (mp) {
                mp->dev_dmat = dev_dmat;
                if (!bus_dma_tag_create(dev_dmat, 1, MEMO_CLUSTER_SIZE,
                               BUS_SPACE_MAXADDR_32BIT,
                               BUS_SPACE_MAXADDR,
                               NULL, NULL, MEMO_CLUSTER_SIZE, 1,
                               MEMO_CLUSTER_SIZE, 0,
                               NULL, NULL, &mp->dmat)) {
                        mp->getp = ___dma_getp;
#ifdef  MEMO_FREE_UNUSED
                        mp->freep = ___dma_freep;
#endif
                        mp->next = mp0.next;
                        mp0.next = mp;
                        return mp;
                }
        }
        if (mp)
                __sym_mfree(&mp0, mp, sizeof(*mp), "MPOOL");
        return NULL;
}

#ifdef  MEMO_FREE_UNUSED
static void ___del_dma_pool(m_pool_s *p)
{
        struct m_pool **pp = &mp0.next;

        while (*pp && *pp != p)
                pp = &(*pp)->next;
        if (*pp) {
                *pp = (*pp)->next;
                bus_dma_tag_destroy(p->dmat);
                __sym_mfree(&mp0, p, sizeof(*p), "MPOOL");
        }
}
#endif

static void *__sym_calloc_dma(bus_dma_tag_t dev_dmat, int size, char *name)
{
        struct m_pool *mp;
        void *m = NULL;

        /* Lock */
        mp = ___get_dma_pool(dev_dmat);
        if (!mp)
                mp = ___cre_dma_pool(dev_dmat);
        if (mp)
                m = __sym_calloc(mp, size, name);
#ifdef  MEMO_FREE_UNUSED
        if (mp && !mp->nump)
                ___del_dma_pool(mp);
#endif
        /* Unlock */

        return m;
}

static void
__sym_mfree_dma(bus_dma_tag_t dev_dmat, void *m, int size, char *name)
{
        struct m_pool *mp;

        /* Lock */
        mp = ___get_dma_pool(dev_dmat);
        if (mp)
                __sym_mfree(mp, m, size, name);
#ifdef  MEMO_FREE_UNUSED
        if (mp && !mp->nump)
                ___del_dma_pool(mp);
#endif
        /* Unlock */
}

static m_addr_t __vtobus(bus_dma_tag_t dev_dmat, void *m)
{
        m_pool_s *mp;
        int hc = VTOB_HASH_CODE(m);
        m_vtob_s *vp = NULL;
        m_addr_t a = ((m_addr_t) m) & ~MEMO_CLUSTER_MASK;

        /* Lock */
        mp = ___get_dma_pool(dev_dmat);
        if (mp) {
                vp = mp->vtob[hc];
                while (vp && (m_addr_t) vp->vaddr != a)
                        vp = vp->next;
        }
        /* Unlock */
        if (!vp)
                panic("sym: VTOBUS FAILED!\n");
        return vp ? vp->baddr + (((m_addr_t) m) - a) : 0;
}

/*
 * Verbs for DMAable memory handling.
 * The _uvptv_ macro avoids a nasty warning about pointer to volatile
 * being discarded.
 */
#define _uvptv_(p) ((void *)((vm_offset_t)(p)))
#define _sym_calloc_dma(np, s, n)       __sym_calloc_dma(np->bus_dmat, s, n)
#define _sym_mfree_dma(np, p, s, n)     \
                                __sym_mfree_dma(np->bus_dmat, _uvptv_(p), s, n)
#define sym_calloc_dma(s, n)            _sym_calloc_dma(np, s, n)
#define sym_mfree_dma(p, s, n)          _sym_mfree_dma(np, p, s, n)
#define _vtobus(np, p)                  __vtobus(np->bus_dmat, _uvptv_(p))
#define vtobus(p)                       _vtobus(np, p)

/*
 *  Print a buffer in hexadecimal format.
 */
static void sym_printb_hex (u_char *p, int n)
{
        while (n-- > 0)
                printf (" %x", *p++);
}

/*
 *  Same with a label at beginning and .\n at end.
 */
static void sym_printl_hex (char *label, u_char *p, int n)
{
        printf ("%s", label);
        sym_printb_hex (p, n);
        printf (".\n");
}

/*
 *  Return a string for SCSI BUS mode.
 */
static const char *sym_scsi_bus_mode(int mode)
{
        switch(mode) {
        case SMODE_HVD: return "HVD";
        case SMODE_SE:  return "SE";
        case SMODE_LVD: return "LVD";
        }
        return "??";
}

/*
 *  Some poor and bogus sync table that refers to Tekram NVRAM layout.
 */
#ifdef SYM_CONF_NVRAM_SUPPORT
static const u_char Tekram_sync[16] =
        {25,31,37,43, 50,62,75,125, 12,15,18,21, 6,7,9,10};
#endif

/*
 *  Union of supported NVRAM formats.
 */
struct sym_nvram {
        int type;
#define SYM_SYMBIOS_NVRAM       (1)
#define SYM_TEKRAM_NVRAM        (2)
#ifdef  SYM_CONF_NVRAM_SUPPORT
        union {
                Symbios_nvram Symbios;
                Tekram_nvram Tekram;
        } data;
#endif
};

/*
 *  This one is hopefully useless, but actually useful. :-)
 */
#ifndef assert
#define assert(expression) { \
        if (!(expression)) { \
                (void)panic( \
                        "assertion \"%s\" failed: file \"%s\", line %d\n", \
                        #expression, \
                        __FILE__, __LINE__); \
        } \
}
#endif

/*
 *  Some provision for a possible big endian mode supported by
 *  Symbios chips (never seen, by the way).
 *  For now, this stuff does not deserve any comments. :)
 */
#define sym_offb(o)     (o)
#define sym_offw(o)     (o)

/*
 *  Some provision for support for BIG ENDIAN CPU.
 */
#define cpu_to_scr(dw)  htole32(dw)
#define scr_to_cpu(dw)  le32toh(dw)

/*
 *  Access to the chip IO registers and on-chip RAM.
 *  We use the `bus space' interface under FreeBSD-4 and
 *  later kernel versions.
 */
#if defined(SYM_CONF_IOMAPPED)

#define INB_OFF(o)      bus_read_1(np->io_res, (o))
#define INW_OFF(o)      bus_read_2(np->io_res, (o))
#define INL_OFF(o)      bus_read_4(np->io_res, (o))

#define OUTB_OFF(o, v)  bus_write_1(np->io_res, (o), (v))
#define OUTW_OFF(o, v)  bus_write_2(np->io_res, (o), (v))
#define OUTL_OFF(o, v)  bus_write_4(np->io_res, (o), (v))

#else   /* Memory mapped IO */

#define INB_OFF(o)      bus_read_1(np->mmio_res, (o))
#define INW_OFF(o)      bus_read_2(np->mmio_res, (o))
#define INL_OFF(o)      bus_read_4(np->mmio_res, (o))

#define OUTB_OFF(o, v)  bus_write_1(np->mmio_res, (o), (v))
#define OUTW_OFF(o, v)  bus_write_2(np->mmio_res, (o), (v))
#define OUTL_OFF(o, v)  bus_write_4(np->mmio_res, (o), (v))

#endif  /* SYM_CONF_IOMAPPED */

#define OUTRAM_OFF(o, a, l)     \
        bus_write_region_1(np->ram_res, (o), (a), (l))

/*
 *  Common definitions for both bus space and legacy IO methods.
 */
#define INB(r)          INB_OFF(offsetof(struct sym_reg,r))
#define INW(r)          INW_OFF(offsetof(struct sym_reg,r))
#define INL(r)          INL_OFF(offsetof(struct sym_reg,r))

#define OUTB(r, v)      OUTB_OFF(offsetof(struct sym_reg,r), (v))
#define OUTW(r, v)      OUTW_OFF(offsetof(struct sym_reg,r), (v))
#define OUTL(r, v)      OUTL_OFF(offsetof(struct sym_reg,r), (v))

#define OUTONB(r, m)    OUTB(r, INB(r) | (m))
#define OUTOFFB(r, m)   OUTB(r, INB(r) & ~(m))
#define OUTONW(r, m)    OUTW(r, INW(r) | (m))
#define OUTOFFW(r, m)   OUTW(r, INW(r) & ~(m))
#define OUTONL(r, m)    OUTL(r, INL(r) | (m))
#define OUTOFFL(r, m)   OUTL(r, INL(r) & ~(m))

/*
 *  We normally want the chip to have a consistent view
 *  of driver internal data structures when we restart it.
 *  Thus these macros.
 */
#define OUTL_DSP(v)                             \
        do {                                    \
                MEMORY_BARRIER();               \
                OUTL (nc_dsp, (v));             \
        } while (0)

#define OUTONB_STD()                            \
        do {                                    \
                MEMORY_BARRIER();               \
                OUTONB (nc_dcntl, (STD|NOCOM)); \
        } while (0)

/*
 *  Command control block states.
 */
#define HS_IDLE         (0)
#define HS_BUSY         (1)
#define HS_NEGOTIATE    (2)     /* sync/wide data transfer*/
#define HS_DISCONNECT   (3)     /* Disconnected by target */
#define HS_WAIT         (4)     /* waiting for resource   */

#define HS_DONEMASK     (0x80)
#define HS_COMPLETE     (4|HS_DONEMASK)
#define HS_SEL_TIMEOUT  (5|HS_DONEMASK) /* Selection timeout      */
#define HS_UNEXPECTED   (6|HS_DONEMASK) /* Unexpected disconnect  */
#define HS_COMP_ERR     (7|HS_DONEMASK) /* Completed with error   */

/*
 *  Software Interrupt Codes
 */
#define SIR_BAD_SCSI_STATUS     (1)
#define SIR_SEL_ATN_NO_MSG_OUT  (2)
#define SIR_MSG_RECEIVED        (3)
#define SIR_MSG_WEIRD           (4)
#define SIR_NEGO_FAILED         (5)
#define SIR_NEGO_PROTO          (6)
#define SIR_SCRIPT_STOPPED      (7)
#define SIR_REJECT_TO_SEND      (8)
#define SIR_SWIDE_OVERRUN       (9)
#define SIR_SODL_UNDERRUN       (10)
#define SIR_RESEL_NO_MSG_IN     (11)
#define SIR_RESEL_NO_IDENTIFY   (12)
#define SIR_RESEL_BAD_LUN       (13)
#define SIR_TARGET_SELECTED     (14)
#define SIR_RESEL_BAD_I_T_L     (15)
#define SIR_RESEL_BAD_I_T_L_Q   (16)
#define SIR_ABORT_SENT          (17)
#define SIR_RESEL_ABORTED       (18)
#define SIR_MSG_OUT_DONE        (19)
#define SIR_COMPLETE_ERROR      (20)
#define SIR_DATA_OVERRUN        (21)
#define SIR_BAD_PHASE           (22)
#define SIR_MAX                 (22)

/*
 *  Extended error bit codes.
 *  xerr_status field of struct sym_ccb.
 */
#define XE_EXTRA_DATA   (1)     /* unexpected data phase         */
#define XE_BAD_PHASE    (1<<1)  /* illegal phase (4/5)           */
#define XE_PARITY_ERR   (1<<2)  /* unrecovered SCSI parity error */
#define XE_SODL_UNRUN   (1<<3)  /* ODD transfer in DATA OUT phase */
#define XE_SWIDE_OVRUN  (1<<4)  /* ODD transfer in DATA IN phase */

/*
 *  Negotiation status.
 *  nego_status field of struct sym_ccb.
 */
#define NS_SYNC         (1)
#define NS_WIDE         (2)
#define NS_PPR          (3)

/*
 *  A CCB hashed table is used to retrieve CCB address
 *  from DSA value.
 */
#define CCB_HASH_SHIFT          8
#define CCB_HASH_SIZE           (1UL << CCB_HASH_SHIFT)
#define CCB_HASH_MASK           (CCB_HASH_SIZE-1)
#define CCB_HASH_CODE(dsa)      (((dsa) >> 9) & CCB_HASH_MASK)

/*
 *  Device flags.
 */
#define SYM_DISC_ENABLED        (1)
#define SYM_TAGS_ENABLED        (1<<1)
#define SYM_SCAN_BOOT_DISABLED  (1<<2)
#define SYM_SCAN_LUNS_DISABLED  (1<<3)

/*
 *  Host adapter miscellaneous flags.
 */
#define SYM_AVOID_BUS_RESET     (1)
#define SYM_SCAN_TARGETS_HILO   (1<<1)

/*
 *  Device quirks.
 *  Some devices, for example the CHEETAH 2 LVD, disconnects without
 *  saving the DATA POINTER then reselects and terminates the IO.
 *  On reselection, the automatic RESTORE DATA POINTER makes the
 *  CURRENT DATA POINTER not point at the end of the IO.
 *  This behaviour just breaks our calculation of the residual.
 *  For now, we just force an AUTO SAVE on disconnection and will
 *  fix that in a further driver version.
 */
#define SYM_QUIRK_AUTOSAVE 1

/*
 *  Misc.
 */
#define SYM_LOCK()              mtx_lock(&np->mtx)
#define SYM_LOCK_ASSERT(_what)  mtx_assert(&np->mtx, (_what))
#define SYM_LOCK_DESTROY()      mtx_destroy(&np->mtx)
#define SYM_LOCK_INIT()         mtx_init(&np->mtx, "sym_lock", NULL, MTX_DEF)
#define SYM_LOCK_INITIALIZED()  mtx_initialized(&np->mtx)
#define SYM_UNLOCK()            mtx_unlock(&np->mtx)

#define SYM_SNOOP_TIMEOUT (10000000)
#define SYM_PCI_IO      PCIR_BAR(0)
#define SYM_PCI_MMIO    PCIR_BAR(1)
#define SYM_PCI_RAM     PCIR_BAR(2)
#define SYM_PCI_RAM64   PCIR_BAR(3)

/*
 *  Back-pointer from the CAM CCB to our data structures.
 */
#define sym_hcb_ptr     spriv_ptr0
/* #define sym_ccb_ptr  spriv_ptr1 */

/*
 *  We mostly have to deal with pointers.
 *  Thus these typedef's.
 */
typedef struct sym_tcb *tcb_p;
typedef struct sym_lcb *lcb_p;
typedef struct sym_ccb *ccb_p;
typedef struct sym_hcb *hcb_p;

/*
 *  Gather negotiable parameters value
 */
struct sym_trans {
        u8 scsi_version;
        u8 spi_version;
        u8 period;
        u8 offset;
        u8 width;
        u8 options;     /* PPR options */
};

struct sym_tinfo {
        struct sym_trans current;
        struct sym_trans goal;
        struct sym_trans user;
};

#define BUS_8_BIT       MSG_EXT_WDTR_BUS_8_BIT
#define BUS_16_BIT      MSG_EXT_WDTR_BUS_16_BIT

/*
 *  Global TCB HEADER.
 *
 *  Due to lack of indirect addressing on earlier NCR chips,
 *  this substructure is copied from the TCB to a global
 *  address after selection.
 *  For SYMBIOS chips that support LOAD/STORE this copy is
 *  not needed and thus not performed.
 */
struct sym_tcbh {
        /*
         *  Scripts bus addresses of LUN table accessed from scripts.
         *  LUN #0 is a special case, since multi-lun devices are rare,
         *  and we we want to speed-up the general case and not waste
         *  resources.
         */
        u32     luntbl_sa;      /* bus address of this table    */
        u32     lun0_sa;        /* bus address of LCB #0        */
        /*
         *  Actual SYNC/WIDE IO registers value for this target.
         *  'sval', 'wval' and 'uval' are read from SCRIPTS and
         *  so have alignment constraints.
         */
/*0*/   u_char  uval;           /* -> SCNTL4 register           */
/*1*/   u_char  sval;           /* -> SXFER  io register        */
/*2*/   u_char  filler1;
/*3*/   u_char  wval;           /* -> SCNTL3 io register        */
};

/*
 *  Target Control Block
 */
struct sym_tcb {
        /*
         *  TCB header.
         *  Assumed at offset 0.
         */
/*0*/   struct sym_tcbh head;

        /*
         *  LUN table used by the SCRIPTS processor.
         *  An array of bus addresses is used on reselection.
         */
        u32     *luntbl;        /* LCBs bus address table       */

        /*
         *  LUN table used by the C code.
         */
        lcb_p   lun0p;          /* LCB of LUN #0 (usual case)   */
#if SYM_CONF_MAX_LUN > 1
        lcb_p   *lunmp;         /* Other LCBs [1..MAX_LUN]      */
#endif

        /*
         *  Bitmap that tells about LUNs that succeeded at least
         *  1 IO and therefore assumed to be a real device.
         *  Avoid useless allocation of the LCB structure.
         */
        u32     lun_map[(SYM_CONF_MAX_LUN+31)/32];

        /*
         *  Bitmap that tells about LUNs that haven't yet an LCB
         *  allocated (not discovered or LCB allocation failed).
         */
        u32     busy0_map[(SYM_CONF_MAX_LUN+31)/32];

        /*
         *  Transfer capabilities (SIP)
         */
        struct sym_tinfo tinfo;

        /*
         * Keep track of the CCB used for the negotiation in order
         * to ensure that only 1 negotiation is queued at a time.
         */
        ccb_p   nego_cp;        /* CCB used for the nego                */

        /*
         *  Set when we want to reset the device.
         */
        u_char  to_reset;

        /*
         *  Other user settable limits and options.
         *  These limits are read from the NVRAM if present.
         */
        u_char  usrflags;
        u_short usrtags;
};

/*
 *  Assert some alignments required by the chip.
 */
CTASSERT(((offsetof(struct sym_reg, nc_sxfer) ^
    offsetof(struct sym_tcb, head.sval)) &3) == 0);
CTASSERT(((offsetof(struct sym_reg, nc_scntl3) ^
    offsetof(struct sym_tcb, head.wval)) &3) == 0);

/*
 *  Global LCB HEADER.
 *
 *  Due to lack of indirect addressing on earlier NCR chips,
 *  this substructure is copied from the LCB to a global
 *  address after selection.
 *  For SYMBIOS chips that support LOAD/STORE this copy is
 *  not needed and thus not performed.
 */
struct sym_lcbh {
        /*
         *  SCRIPTS address jumped by SCRIPTS on reselection.
         *  For not probed logical units, this address points to
         *  SCRIPTS that deal with bad LU handling (must be at
         *  offset zero of the LCB for that reason).
         */
/*0*/   u32     resel_sa;

        /*
         *  Task (bus address of a CCB) read from SCRIPTS that points
         *  to the unique ITL nexus allowed to be disconnected.
         */
        u32     itl_task_sa;

        /*
         *  Task table bus address (read from SCRIPTS).
         */
        u32     itlq_tbl_sa;
};

/*
 *  Logical Unit Control Block
 */
struct sym_lcb {
        /*
         *  TCB header.
         *  Assumed at offset 0.
         */
/*0*/   struct sym_lcbh head;

        /*
         *  Task table read from SCRIPTS that contains pointers to
         *  ITLQ nexuses. The bus address read from SCRIPTS is
         *  inside the header.
         */
        u32     *itlq_tbl;      /* Kernel virtual address       */

        /*
         *  Busy CCBs management.
         */
        u_short busy_itlq;      /* Number of busy tagged CCBs   */
        u_short busy_itl;       /* Number of busy untagged CCBs */

        /*
         *  Circular tag allocation buffer.
         */
        u_short ia_tag;         /* Tag allocation index         */
        u_short if_tag;         /* Tag release index            */
        u_char  *cb_tags;       /* Circular tags buffer         */

        /*
         *  Set when we want to clear all tasks.
         */
        u_char to_clear;

        /*
         *  Capabilities.
         */
        u_char  user_flags;
        u_char  current_flags;
};

/*
 *  Action from SCRIPTS on a task.
 *  Is part of the CCB, but is also used separately to plug
 *  error handling action to perform from SCRIPTS.
 */
struct sym_actscr {
        u32     start;          /* Jumped by SCRIPTS after selection    */
        u32     restart;        /* Jumped by SCRIPTS on relection       */
};

/*
 *  Phase mismatch context.
 *
 *  It is part of the CCB and is used as parameters for the
 *  DATA pointer. We need two contexts to handle correctly the
 *  SAVED DATA POINTER.
 */
struct sym_pmc {
        struct  sym_tblmove sg; /* Updated interrupted SG block */
        u32     ret;            /* SCRIPT return address        */
};

/*
 *  LUN control block lookup.
 *  We use a direct pointer for LUN #0, and a table of
 *  pointers which is only allocated for devices that support
 *  LUN(s) > 0.
 */
#if SYM_CONF_MAX_LUN <= 1
#define sym_lp(tp, lun) (!lun) ? (tp)->lun0p : 0
#else
#define sym_lp(tp, lun) \
        (!lun) ? (tp)->lun0p : (tp)->lunmp ? (tp)->lunmp[(lun)] : 0
#endif

/*
 *  Status are used by the host and the script processor.
 *
 *  The last four bytes (status[4]) are copied to the
 *  scratchb register (declared as scr0..scr3) just after the
 *  select/reselect, and copied back just after disconnecting.
 *  Inside the script the XX_REG are used.
 */

/*
 *  Last four bytes (script)
 */
#define  QU_REG scr0
#define  HS_REG scr1
#define  HS_PRT nc_scr1
#define  SS_REG scr2
#define  SS_PRT nc_scr2
#define  HF_REG scr3
#define  HF_PRT nc_scr3

/*
 *  Last four bytes (host)
 */
#define  actualquirks  phys.head.status[0]
#define  host_status   phys.head.status[1]
#define  ssss_status   phys.head.status[2]
#define  host_flags    phys.head.status[3]

/*
 *  Host flags
 */
#define HF_IN_PM0       1u
#define HF_IN_PM1       (1u<<1)
#define HF_ACT_PM       (1u<<2)
#define HF_DP_SAVED     (1u<<3)
#define HF_SENSE        (1u<<4)
#define HF_EXT_ERR      (1u<<5)
#define HF_DATA_IN      (1u<<6)
#ifdef SYM_CONF_IARB_SUPPORT
#define HF_HINT_IARB    (1u<<7)
#endif

/*
 *  Global CCB HEADER.
 *
 *  Due to lack of indirect addressing on earlier NCR chips,
 *  this substructure is copied from the ccb to a global
 *  address after selection (or reselection) and copied back
 *  before disconnect.
 *  For SYMBIOS chips that support LOAD/STORE this copy is
 *  not needed and thus not performed.
 */
struct sym_ccbh {
        /*
         *  Start and restart SCRIPTS addresses (must be at 0).
         */
/*0*/   struct sym_actscr go;

        /*
         *  SCRIPTS jump address that deal with data pointers.
         *  'savep' points to the position in the script responsible
         *  for the actual transfer of data.
         *  It's written on reception of a SAVE_DATA_POINTER message.
         */
        u32     savep;          /* Jump address to saved data pointer   */
        u32     lastp;          /* SCRIPTS address at end of data       */
        u32     goalp;          /* Not accessed for now from SCRIPTS    */

        /*
         *  Status fields.
         */
        u8      status[4];
};

/*
 *  Data Structure Block
 *
 *  During execution of a ccb by the script processor, the
 *  DSA (data structure address) register points to this
 *  substructure of the ccb.
 */
struct sym_dsb {
        /*
         *  CCB header.
         *  Also assumed at offset 0 of the sym_ccb structure.
         */
/*0*/   struct sym_ccbh head;

        /*
         *  Phase mismatch contexts.
         *  We need two to handle correctly the SAVED DATA POINTER.
         *  MUST BOTH BE AT OFFSET < 256, due to using 8 bit arithmetic
         *  for address calculation from SCRIPTS.
         */
        struct sym_pmc pm0;
        struct sym_pmc pm1;

        /*
         *  Table data for Script
         */
        struct sym_tblsel  select;
        struct sym_tblmove smsg;
        struct sym_tblmove smsg_ext;
        struct sym_tblmove cmd;
        struct sym_tblmove sense;
        struct sym_tblmove wresid;
        struct sym_tblmove data [SYM_CONF_MAX_SG];
};

/*
 *  Our Command Control Block
 */
struct sym_ccb {
        /*
         *  This is the data structure which is pointed by the DSA
         *  register when it is executed by the script processor.
         *  It must be the first entry.
         */
        struct sym_dsb phys;

        /*
         *  Pointer to CAM ccb and related stuff.
         */
        struct callout ch;      /* callout handle               */
        union ccb *cam_ccb;     /* CAM scsiio ccb               */
        u8      cdb_buf[16];    /* Copy of CDB                  */
        u8      *sns_bbuf;      /* Bounce buffer for sense data */
#define SYM_SNS_BBUF_LEN        sizeof(struct scsi_sense_data)
        int     data_len;       /* Total data length            */
        int     segments;       /* Number of SG segments        */

        /*
         *  Miscellaneous status'.
         */
        u_char  nego_status;    /* Negotiation status           */
        u_char  xerr_status;    /* Extended error flags         */
        u32     extra_bytes;    /* Extraneous bytes transferred */

        /*
         *  Message areas.
         *  We prepare a message to be sent after selection.
         *  We may use a second one if the command is rescheduled
         *  due to CHECK_CONDITION or COMMAND TERMINATED.
         *  Contents are IDENTIFY and SIMPLE_TAG.
         *  While negotiating sync or wide transfer,
         *  a SDTR or WDTR message is appended.
         */
        u_char  scsi_smsg [12];
        u_char  scsi_smsg2[12];

        /*
         *  Auto request sense related fields.
         */
        u_char  sensecmd[6];    /* Request Sense command        */
        u_char  sv_scsi_status; /* Saved SCSI status            */
        u_char  sv_xerr_status; /* Saved extended status        */
        int     sv_resid;       /* Saved residual               */

        /*
         *  Map for the DMA of user data.
         */
        void            *arg;   /* Argument for some callback   */
        bus_dmamap_t    dmamap; /* DMA map for user data        */
        u_char          dmamapped;
#define SYM_DMA_NONE    0
#define SYM_DMA_READ    1
#define SYM_DMA_WRITE   2
        /*
         *  Other fields.
         */
        u32     ccb_ba;         /* BUS address of this CCB      */
        u_short tag;            /* Tag for this transfer        */
                                /*  NO_TAG means no tag         */
        u_char  target;
        u_char  lun;
        ccb_p   link_ccbh;      /* Host adapter CCB hash chain  */
        SYM_QUEHEAD
                link_ccbq;      /* Link to free/busy CCB queue  */
        u32     startp;         /* Initial data pointer         */
        int     ext_sg;         /* Extreme data pointer, used   */
        int     ext_ofs;        /*  to calculate the residual.  */
        u_char  to_abort;       /* Want this IO to be aborted   */
};

#define CCB_BA(cp,lbl)  (cp->ccb_ba + offsetof(struct sym_ccb, lbl))

/*
 *  Host Control Block
 */
struct sym_hcb {
        struct mtx      mtx;

        /*
         *  Global headers.
         *  Due to poorness of addressing capabilities, earlier
         *  chips (810, 815, 825) copy part of the data structures
         *  (CCB, TCB and LCB) in fixed areas.
         */
#ifdef  SYM_CONF_GENERIC_SUPPORT
        struct sym_ccbh ccb_head;
        struct sym_tcbh tcb_head;
        struct sym_lcbh lcb_head;
#endif
        /*
         *  Idle task and invalid task actions and
         *  their bus addresses.
         */
        struct sym_actscr idletask, notask, bad_itl, bad_itlq;
        vm_offset_t idletask_ba, notask_ba, bad_itl_ba, bad_itlq_ba;

        /*
         *  Dummy lun table to protect us against target
         *  returning bad lun number on reselection.
         */
        u32     *badluntbl;     /* Table physical address       */
        u32     badlun_sa;      /* SCRIPT handler BUS address   */

        /*
         *  Bus address of this host control block.
         */
        u32     hcb_ba;

        /*
         *  Bit 32-63 of the on-chip RAM bus address in LE format.
         *  The START_RAM64 script loads the MMRS and MMWS from this
         *  field.
         */
        u32     scr_ram_seg;

        /*
         *  Chip and controller indentification.
         */
        device_t device;

        /*
         *  Initial value of some IO register bits.
         *  These values are assumed to have been set by BIOS, and may
         *  be used to probe adapter implementation differences.
         */
        u_char  sv_scntl0, sv_scntl3, sv_dmode, sv_dcntl, sv_ctest3, sv_ctest4,
                sv_ctest5, sv_gpcntl, sv_stest2, sv_stest4, sv_scntl4,
                sv_stest1;

        /*
         *  Actual initial value of IO register bits used by the
         *  driver. They are loaded at initialisation according to
         *  features that are to be enabled/disabled.
         */
        u_char  rv_scntl0, rv_scntl3, rv_dmode, rv_dcntl, rv_ctest3, rv_ctest4,
                rv_ctest5, rv_stest2, rv_ccntl0, rv_ccntl1, rv_scntl4;

        /*
         *  Target data.
         */
#ifdef __amd64__
        struct sym_tcb  *target;
#else
        struct sym_tcb  target[SYM_CONF_MAX_TARGET];
#endif

        /*
         *  Target control block bus address array used by the SCRIPT
         *  on reselection.
         */
        u32             *targtbl;
        u32             targtbl_ba;

        /*
         *  CAM SIM information for this instance.
         */
        struct          cam_sim  *sim;
        struct          cam_path *path;

        /*
         *  Allocated hardware resources.
         */
        struct resource *irq_res;
        struct resource *io_res;
        struct resource *mmio_res;
        struct resource *ram_res;
        int             ram_id;
        void *intr;

        /*
         *  Bus stuff.
         *
         *  My understanding of PCI is that all agents must share the
         *  same addressing range and model.
         *  But some hardware architecture guys provide complex and
         *  brain-deaded stuff that makes shit.
         *  This driver only support PCI compliant implementations and
         *  deals with part of the BUS stuff complexity only to fit O/S
         *  requirements.
         */

        /*
         *  DMA stuff.
         */
        bus_dma_tag_t   bus_dmat;       /* DMA tag from parent BUS      */
        bus_dma_tag_t   data_dmat;      /* DMA tag for user data        */
        /*
         *  BUS addresses of the chip
         */
        vm_offset_t     mmio_ba;        /* MMIO BUS address             */
        int             mmio_ws;        /* MMIO Window size             */

        vm_offset_t     ram_ba;         /* RAM BUS address              */
        int             ram_ws;         /* RAM window size              */

        /*
         *  SCRIPTS virtual and physical bus addresses.
         *  'script'  is loaded in the on-chip RAM if present.
         *  'scripth' stays in main memory for all chips except the
         *  53C895A, 53C896 and 53C1010 that provide 8K on-chip RAM.
         */
        u_char          *scripta0;      /* Copies of script and scripth */
        u_char          *scriptb0;      /* Copies of script and scripth */
        vm_offset_t     scripta_ba;     /* Actual script and scripth    */
        vm_offset_t     scriptb_ba;     /*  bus addresses.              */
        vm_offset_t     scriptb0_ba;
        u_short         scripta_sz;     /* Actual size of script A      */
        u_short         scriptb_sz;     /* Actual size of script B      */

        /*
         *  Bus addresses, setup and patch methods for
         *  the selected firmware.
         */
        struct sym_fwa_ba fwa_bas;      /* Useful SCRIPTA bus addresses */
        struct sym_fwb_ba fwb_bas;      /* Useful SCRIPTB bus addresses */
        void            (*fw_setup)(hcb_p np, const struct sym_fw *fw);
        void            (*fw_patch)(hcb_p np);
        const char      *fw_name;

        /*
         *  General controller parameters and configuration.
         */
        u_short device_id;      /* PCI device id                */
        u_char  revision_id;    /* PCI device revision id       */
        u_int   features;       /* Chip features map            */
        u_char  myaddr;         /* SCSI id of the adapter       */
        u_char  maxburst;       /* log base 2 of dwords burst   */
        u_char  maxwide;        /* Maximum transfer width       */
        u_char  minsync;        /* Min sync period factor (ST)  */
        u_char  maxsync;        /* Max sync period factor (ST)  */
        u_char  maxoffs;        /* Max scsi offset        (ST)  */
        u_char  minsync_dt;     /* Min sync period factor (DT)  */
        u_char  maxsync_dt;     /* Max sync period factor (DT)  */
        u_char  maxoffs_dt;     /* Max scsi offset        (DT)  */
        u_char  multiplier;     /* Clock multiplier (1,2,4)     */
        u_char  clock_divn;     /* Number of clock divisors     */
        u32     clock_khz;      /* SCSI clock frequency in KHz  */
        u32     pciclk_khz;     /* Estimated PCI clock  in KHz  */
        /*
         *  Start queue management.
         *  It is filled up by the host processor and accessed by the
         *  SCRIPTS processor in order to start SCSI commands.
         */
        volatile                /* Prevent code optimizations   */
        u32     *squeue;        /* Start queue virtual address  */
        u32     squeue_ba;      /* Start queue BUS address      */
        u_short squeueput;      /* Next free slot of the queue  */
        u_short actccbs;        /* Number of allocated CCBs     */

        /*
         *  Command completion queue.
         *  It is the same size as the start queue to avoid overflow.
         */
        u_short dqueueget;      /* Next position to scan        */
        volatile                /* Prevent code optimizations   */
        u32     *dqueue;        /* Completion (done) queue      */
        u32     dqueue_ba;      /* Done queue BUS address       */

        /*
         *  Miscellaneous buffers accessed by the scripts-processor.
         *  They shall be DWORD aligned, because they may be read or
         *  written with a script command.
         */
        u_char          msgout[8];      /* Buffer for MESSAGE OUT       */
        u_char          msgin [8];      /* Buffer for MESSAGE IN        */
        u32             lastmsg;        /* Last SCSI message sent       */
        u_char          scratch;        /* Scratch for SCSI receive     */

        /*
         *  Miscellaneous configuration and status parameters.
         */
        u_char          usrflags;       /* Miscellaneous user flags     */
        u_char          scsi_mode;      /* Current SCSI BUS mode        */
        u_char          verbose;        /* Verbosity for this controller*/
        u32             cache;          /* Used for cache test at init. */

        /*
         *  CCB lists and queue.
         */
        ccb_p ccbh[CCB_HASH_SIZE];      /* CCB hashed by DSA value      */
        SYM_QUEHEAD     free_ccbq;      /* Queue of available CCBs      */
        SYM_QUEHEAD     busy_ccbq;      /* Queue of busy CCBs           */

        /*
         *  During error handling and/or recovery,
         *  active CCBs that are to be completed with
         *  error or requeued are moved from the busy_ccbq
         *  to the comp_ccbq prior to completion.
         */
        SYM_QUEHEAD     comp_ccbq;

        /*
         *  CAM CCB pending queue.
         */
        SYM_QUEHEAD     cam_ccbq;

        /*
         *  IMMEDIATE ARBITRATION (IARB) control.
         *
         *  We keep track in 'last_cp' of the last CCB that has been
         *  queued to the SCRIPTS processor and clear 'last_cp' when
         *  this CCB completes. If last_cp is not zero at the moment
         *  we queue a new CCB, we set a flag in 'last_cp' that is
         *  used by the SCRIPTS as a hint for setting IARB.
         *  We donnot set more than 'iarb_max' consecutive hints for
         *  IARB in order to leave devices a chance to reselect.
         *  By the way, any non zero value of 'iarb_max' is unfair. :)
         */
#ifdef SYM_CONF_IARB_SUPPORT
        u_short         iarb_max;       /* Max. # consecutive IARB hints*/
        u_short         iarb_count;     /* Actual # of these hints      */
        ccb_p           last_cp;
#endif

        /*
         *  Command abort handling.
         *  We need to synchronize tightly with the SCRIPTS
         *  processor in order to handle things correctly.
         */
        u_char          abrt_msg[4];    /* Message to send buffer       */
        struct sym_tblmove abrt_tbl;    /* Table for the MOV of it      */
        struct sym_tblsel  abrt_sel;    /* Sync params for selection    */
        u_char          istat_sem;      /* Tells the chip to stop (SEM) */
};

#define HCB_BA(np, lbl)     (np->hcb_ba      + offsetof(struct sym_hcb, lbl))

/*
 *  Return the name of the controller.
 */
static __inline const char *sym_name(hcb_p np)
{
        return device_get_nameunit(np->device);
}

/*--------------------------------------------------------------------------*/
/*------------------------------ FIRMWARES ---------------------------------*/
/*--------------------------------------------------------------------------*/

/*
 *  This stuff will be moved to a separate source file when
 *  the driver will be broken into several source modules.
 */

/*
 *  Macros used for all firmwares.
 */
#define SYM_GEN_A(s, label)     ((short) offsetof(s, label)),
#define SYM_GEN_B(s, label)     ((short) offsetof(s, label)),
#define PADDR_A(label)          SYM_GEN_PADDR_A(struct SYM_FWA_SCR, label)
#define PADDR_B(label)          SYM_GEN_PADDR_B(struct SYM_FWB_SCR, label)

#ifdef  SYM_CONF_GENERIC_SUPPORT
/*
 *  Allocate firmware #1 script area.
 */
#define SYM_FWA_SCR             sym_fw1a_scr
#define SYM_FWB_SCR             sym_fw1b_scr
#include <dev/sym/sym_fw1.h>
static const struct sym_fwa_ofs sym_fw1a_ofs = {
        SYM_GEN_FW_A(struct SYM_FWA_SCR)
};
static const struct sym_fwb_ofs sym_fw1b_ofs = {
        SYM_GEN_FW_B(struct SYM_FWB_SCR)
};
#undef  SYM_FWA_SCR
#undef  SYM_FWB_SCR
#endif  /* SYM_CONF_GENERIC_SUPPORT */

/*
 *  Allocate firmware #2 script area.
 */
#define SYM_FWA_SCR             sym_fw2a_scr
#define SYM_FWB_SCR             sym_fw2b_scr
#include <dev/sym/sym_fw2.h>
static const struct sym_fwa_ofs sym_fw2a_ofs = {
        SYM_GEN_FW_A(struct SYM_FWA_SCR)
};
static const struct sym_fwb_ofs sym_fw2b_ofs = {
        SYM_GEN_FW_B(struct SYM_FWB_SCR)
        SYM_GEN_B(struct SYM_FWB_SCR, start64)
        SYM_GEN_B(struct SYM_FWB_SCR, pm_handle)
};
#undef  SYM_FWA_SCR
#undef  SYM_FWB_SCR

#undef  SYM_GEN_A
#undef  SYM_GEN_B
#undef  PADDR_A
#undef  PADDR_B

#ifdef  SYM_CONF_GENERIC_SUPPORT
/*
 *  Patch routine for firmware #1.
 */
static void
sym_fw1_patch(hcb_p np)
{
        struct sym_fw1a_scr *scripta0;
        struct sym_fw1b_scr *scriptb0;

        scripta0 = (struct sym_fw1a_scr *) np->scripta0;
        scriptb0 = (struct sym_fw1b_scr *) np->scriptb0;

        /*
         *  Remove LED support if not needed.
         */
        if (!(np->features & FE_LED0)) {
                scripta0->idle[0]       = cpu_to_scr(SCR_NO_OP);
                scripta0->reselected[0] = cpu_to_scr(SCR_NO_OP);
                scripta0->start[0]      = cpu_to_scr(SCR_NO_OP);
        }

#ifdef SYM_CONF_IARB_SUPPORT
        /*
         *    If user does not want to use IMMEDIATE ARBITRATION
         *    when we are reselected while attempting to arbitrate,
         *    patch the SCRIPTS accordingly with a SCRIPT NO_OP.
         */
        if (!SYM_CONF_SET_IARB_ON_ARB_LOST)
                scripta0->ungetjob[0] = cpu_to_scr(SCR_NO_OP);
#endif
        /*
         *  Patch some data in SCRIPTS.
         *  - start and done queue initial bus address.
         *  - target bus address table bus address.
         */
        scriptb0->startpos[0]   = cpu_to_scr(np->squeue_ba);
        scriptb0->done_pos[0]   = cpu_to_scr(np->dqueue_ba);
        scriptb0->targtbl[0]    = cpu_to_scr(np->targtbl_ba);
}
#endif  /* SYM_CONF_GENERIC_SUPPORT */

/*
 *  Patch routine for firmware #2.
 */
static void
sym_fw2_patch(hcb_p np)
{
        struct sym_fw2a_scr *scripta0;
        struct sym_fw2b_scr *scriptb0;

        scripta0 = (struct sym_fw2a_scr *) np->scripta0;
        scriptb0 = (struct sym_fw2b_scr *) np->scriptb0;

        /*
         *  Remove LED support if not needed.
         */
        if (!(np->features & FE_LED0)) {
                scripta0->idle[0]       = cpu_to_scr(SCR_NO_OP);
                scripta0->reselected[0] = cpu_to_scr(SCR_NO_OP);
                scripta0->start[0]      = cpu_to_scr(SCR_NO_OP);
        }

#ifdef SYM_CONF_IARB_SUPPORT
        /*
         *    If user does not want to use IMMEDIATE ARBITRATION
         *    when we are reselected while attempting to arbitrate,
         *    patch the SCRIPTS accordingly with a SCRIPT NO_OP.
         */
        if (!SYM_CONF_SET_IARB_ON_ARB_LOST)
                scripta0->ungetjob[0] = cpu_to_scr(SCR_NO_OP);
#endif
        /*
         *  Patch some variable in SCRIPTS.
         *  - start and done queue initial bus address.
         *  - target bus address table bus address.
         */
        scriptb0->startpos[0]   = cpu_to_scr(np->squeue_ba);
        scriptb0->done_pos[0]   = cpu_to_scr(np->dqueue_ba);
        scriptb0->targtbl[0]    = cpu_to_scr(np->targtbl_ba);

        /*
         *  Remove the load of SCNTL4 on reselection if not a C10.
         */
        if (!(np->features & FE_C10)) {
                scripta0->resel_scntl4[0] = cpu_to_scr(SCR_NO_OP);
                scripta0->resel_scntl4[1] = cpu_to_scr(0);
        }

        /*
         *  Remove a couple of work-arounds specific to C1010 if
         *  they are not desirable. See `sym_fw2.h' for more details.
         */
        if (!(np->device_id == PCI_ID_LSI53C1010_2 &&
              np->revision_id < 0x1 &&
              np->pciclk_khz < 60000)) {
                scripta0->datao_phase[0] = cpu_to_scr(SCR_NO_OP);
                scripta0->datao_phase[1] = cpu_to_scr(0);
        }
        if (!(np->device_id == PCI_ID_LSI53C1010 &&
              /* np->revision_id < 0xff */ 1)) {
                scripta0->sel_done[0] = cpu_to_scr(SCR_NO_OP);
                scripta0->sel_done[1] = cpu_to_scr(0);
        }

        /*
         *  Patch some other variables in SCRIPTS.
         *  These ones are loaded by the SCRIPTS processor.
         */
        scriptb0->pm0_data_addr[0] =
                cpu_to_scr(np->scripta_ba +
                           offsetof(struct sym_fw2a_scr, pm0_data));
        scriptb0->pm1_data_addr[0] =
                cpu_to_scr(np->scripta_ba +
                           offsetof(struct sym_fw2a_scr, pm1_data));
}

/*
 *  Fill the data area in scripts.
 *  To be done for all firmwares.
 */
static void
sym_fw_fill_data (u32 *in, u32 *out)
{
        int     i;

        for (i = 0; i < SYM_CONF_MAX_SG; i++) {
                *in++  = SCR_CHMOV_TBL ^ SCR_DATA_IN;
                *in++  = offsetof (struct sym_dsb, data[i]);
                *out++ = SCR_CHMOV_TBL ^ SCR_DATA_OUT;
                *out++ = offsetof (struct sym_dsb, data[i]);
        }
}

/*
 *  Setup useful script bus addresses.
 *  To be done for all firmwares.
 */
static void
sym_fw_setup_bus_addresses(hcb_p np, const struct sym_fw *fw)
{
        u32 *pa;
        const u_short *po;
        int i;

        /*
         *  Build the bus address table for script A
         *  from the script A offset table.
         */
        po = (const u_short *) fw->a_ofs;
        pa = (u32 *) &np->fwa_bas;
        for (i = 0 ; i < sizeof(np->fwa_bas)/sizeof(u32) ; i++)
                pa[i] = np->scripta_ba + po[i];

        /*
         *  Same for script B.
         */
        po = (const u_short *) fw->b_ofs;
        pa = (u32 *) &np->fwb_bas;
        for (i = 0 ; i < sizeof(np->fwb_bas)/sizeof(u32) ; i++)
                pa[i] = np->scriptb_ba + po[i];
}

#ifdef  SYM_CONF_GENERIC_SUPPORT
/*
 *  Setup routine for firmware #1.
 */
static void
sym_fw1_setup(hcb_p np, const struct sym_fw *fw)
{
        struct sym_fw1a_scr *scripta0;

        scripta0 = (struct sym_fw1a_scr *) np->scripta0;

        /*
         *  Fill variable parts in scripts.
         */
        sym_fw_fill_data(scripta0->data_in, scripta0->data_out);

        /*
         *  Setup bus addresses used from the C code..
         */
        sym_fw_setup_bus_addresses(np, fw);
}
#endif  /* SYM_CONF_GENERIC_SUPPORT */

/*
 *  Setup routine for firmware #2.
 */
static void
sym_fw2_setup(hcb_p np, const struct sym_fw *fw)
{
        struct sym_fw2a_scr *scripta0;

        scripta0 = (struct sym_fw2a_scr *) np->scripta0;

        /*
         *  Fill variable parts in scripts.
         */
        sym_fw_fill_data(scripta0->data_in, scripta0->data_out);

        /*
         *  Setup bus addresses used from the C code..
         */
        sym_fw_setup_bus_addresses(np, fw);
}

/*
 *  Allocate firmware descriptors.
 */
#ifdef  SYM_CONF_GENERIC_SUPPORT
static const struct sym_fw sym_fw1 = SYM_FW_ENTRY(sym_fw1, "NCR-generic");
#endif  /* SYM_CONF_GENERIC_SUPPORT */
static const struct sym_fw sym_fw2 = SYM_FW_ENTRY(sym_fw2, "LOAD/STORE-based");

/*
 *  Find the most appropriate firmware for a chip.
 */
static const struct sym_fw *
sym_find_firmware(const struct sym_pci_chip *chip)
{
        if (chip->features & FE_LDSTR)
                return &sym_fw2;
#ifdef  SYM_CONF_GENERIC_SUPPORT
        else if (!(chip->features & (FE_PFEN|FE_NOPM|FE_DAC)))
                return &sym_fw1;
#endif
        else
                return NULL;
}

/*
 *  Bind a script to physical addresses.
 */
static void sym_fw_bind_script (hcb_p np, u32 *start, int len)
{
        u32 opcode, new, old, tmp1, tmp2;
        u32 *end, *cur;
        int relocs;

        cur = start;
        end = start + len/4;

        while (cur < end) {

                opcode = *cur;

                /*
                 *  If we forget to change the length
                 *  in scripts, a field will be
                 *  padded with 0. This is an illegal
                 *  command.
                 */
                if (opcode == 0) {
                        printf ("%s: ERROR0 IN SCRIPT at %d.\n",
                                sym_name(np), (int) (cur-start));
                        MDELAY (10000);
                        ++cur;
                        continue;
                }

                /*
                 *  We use the bogus value 0xf00ff00f ;-)
                 *  to reserve data area in SCRIPTS.
                 */
                if (opcode == SCR_DATA_ZERO) {
                        *cur++ = 0;
                        continue;
                }

                if (DEBUG_FLAGS & DEBUG_SCRIPT)
                        printf ("%d:  <%x>\n", (int) (cur-start),
                                (unsigned)opcode);

                /*
                 *  We don't have to decode ALL commands
                 */
                switch (opcode >> 28) {
                case 0xf:
                        /*
                         *  LOAD / STORE DSA relative, don't relocate.
                         */
                        relocs = 0;
                        break;
                case 0xe:
                        /*
                         *  LOAD / STORE absolute.
                         */
                        relocs = 1;
                        break;
                case 0xc:
                        /*
                         *  COPY has TWO arguments.
                         */
                        relocs = 2;
                        tmp1 = cur[1];
                        tmp2 = cur[2];
                        if ((tmp1 ^ tmp2) & 3) {
                                printf ("%s: ERROR1 IN SCRIPT at %d.\n",
                                        sym_name(np), (int) (cur-start));
                                MDELAY (10000);
                        }
                        /*
                         *  If PREFETCH feature not enabled, remove
                         *  the NO FLUSH bit if present.
                         */
                        if ((opcode & SCR_NO_FLUSH) &&
                            !(np->features & FE_PFEN)) {
                                opcode = (opcode & ~SCR_NO_FLUSH);
                        }
                        break;
                case 0x0:
                        /*
                         *  MOVE/CHMOV (absolute address)
                         */
                        if (!(np->features & FE_WIDE))
                                opcode = (opcode | OPC_MOVE);
                        relocs = 1;
                        break;
                case 0x1:
                        /*
                         *  MOVE/CHMOV (table indirect)
                         */
                        if (!(np->features & FE_WIDE))
                                opcode = (opcode | OPC_MOVE);
                        relocs = 0;
                        break;
                case 0x8:
                        /*
                         *  JUMP / CALL
                         *  dont't relocate if relative :-)
                         */
                        if (opcode & 0x00800000)
                                relocs = 0;
                        else if ((opcode & 0xf8400000) == 0x80400000)/*JUMP64*/
                                relocs = 2;
                        else
                                relocs = 1;
                        break;
                case 0x4:
                case 0x5:
                case 0x6:
                case 0x7:
                        relocs = 1;
                        break;
                default:
                        relocs = 0;
                        break;
                }

                /*
                 *  Scriptify:) the opcode.
                 */
                *cur++ = cpu_to_scr(opcode);

                /*
                 *  If no relocation, assume 1 argument
                 *  and just scriptize:) it.
                 */
                if (!relocs) {
                        *cur = cpu_to_scr(*cur);
                        ++cur;
                        continue;
                }

                /*
                 *  Otherwise performs all needed relocations.
                 */
                while (relocs--) {
                        old = *cur;

                        switch (old & RELOC_MASK) {
                        case RELOC_REGISTER:
                                new = (old & ~RELOC_MASK) + np->mmio_ba;
                                break;
                        case RELOC_LABEL_A:
                                new = (old & ~RELOC_MASK) + np->scripta_ba;
                                break;
                        case RELOC_LABEL_B:
                                new = (old & ~RELOC_MASK) + np->scriptb_ba;
                                break;
                        case RELOC_SOFTC:
                                new = (old & ~RELOC_MASK) + np->hcb_ba;
                                break;
                        case 0:
                                /*
                                 *  Don't relocate a 0 address.
                                 *  They are mostly used for patched or
                                 *  script self-modified areas.
                                 */
                                if (old == 0) {
                                        new = old;
                                        break;
                                }
                                /* fall through */
                        default:
                                new = 0;
                                panic("sym_fw_bind_script: "
                                      "weird relocation %x\n", old);
                                break;
                        }

                        *cur++ = cpu_to_scr(new);
                }
        }
}

/*---------------------------------------------------------------------------*/
/*--------------------------- END OF FIRMWARES  -----------------------------*/
/*---------------------------------------------------------------------------*/

/*
 *  Function prototypes.
 */
static void sym_save_initial_setting (hcb_p np);
static int  sym_prepare_setting (hcb_p np, struct sym_nvram *nvram);
static int  sym_prepare_nego (hcb_p np, ccb_p cp, int nego, u_char *msgptr);
static void sym_put_start_queue (hcb_p np, ccb_p cp);
static void sym_chip_reset (hcb_p np);
static void sym_soft_reset (hcb_p np);
static void sym_start_reset (hcb_p np);
static int  sym_reset_scsi_bus (hcb_p np, int enab_int);
static int  sym_wakeup_done (hcb_p np);
static void sym_flush_busy_queue (hcb_p np, int cam_status);
static void sym_flush_comp_queue (hcb_p np, int cam_status);
static void sym_init (hcb_p np, int reason);
static int  sym_getsync(hcb_p np, u_char dt, u_char sfac, u_char *divp,
                        u_char *fakp);
static void sym_setsync (hcb_p np, ccb_p cp, u_char ofs, u_char per,
                         u_char div, u_char fak);
static void sym_setwide (hcb_p np, ccb_p cp, u_char wide);
static void sym_setpprot(hcb_p np, ccb_p cp, u_char dt, u_char ofs,
                         u_char per, u_char wide, u_char div, u_char fak);
static void sym_settrans(hcb_p np, ccb_p cp, u_char dt, u_char ofs,
                         u_char per, u_char wide, u_char div, u_char fak);
static void sym_log_hard_error (hcb_p np, u_short sist, u_char dstat);
static void sym_intr (void *arg);
static void sym_poll (struct cam_sim *sim);
static void sym_recover_scsi_int (hcb_p np, u_char hsts);
static void sym_int_sto (hcb_p np);
static void sym_int_udc (hcb_p np);
static void sym_int_sbmc (hcb_p np);
static void sym_int_par (hcb_p np, u_short sist);
static void sym_int_ma (hcb_p np);
static int  sym_dequeue_from_squeue(hcb_p np, int i, int target, int lun,
                                    int task);
static void sym_sir_bad_scsi_status (hcb_p np, ccb_p cp);
static int  sym_clear_tasks (hcb_p np, int status, int targ, int lun, int task);
static void sym_sir_task_recovery (hcb_p np, int num);
static int  sym_evaluate_dp (hcb_p np, ccb_p cp, u32 scr, int *ofs);
static void sym_modify_dp(hcb_p np, ccb_p cp, int ofs);
static int  sym_compute_residual (hcb_p np, ccb_p cp);
static int  sym_show_msg (u_char * msg);
static void sym_print_msg (ccb_p cp, char *label, u_char *msg);
static void sym_sync_nego (hcb_p np, tcb_p tp, ccb_p cp);
static void sym_ppr_nego (hcb_p np, tcb_p tp, ccb_p cp);
static void sym_wide_nego (hcb_p np, tcb_p tp, ccb_p cp);
static void sym_nego_default (hcb_p np, tcb_p tp, ccb_p cp);
static void sym_nego_rejected (hcb_p np, tcb_p tp, ccb_p cp);
static void sym_int_sir (hcb_p np);
static void sym_free_ccb (hcb_p np, ccb_p cp);
static ccb_p sym_get_ccb (hcb_p np, u_char tn, u_char ln, u_char tag_order);
static ccb_p sym_alloc_ccb (hcb_p np);
static ccb_p sym_ccb_from_dsa (hcb_p np, u32 dsa);
static lcb_p sym_alloc_lcb (hcb_p np, u_char tn, u_char ln);
static void sym_alloc_lcb_tags (hcb_p np, u_char tn, u_char ln);
static int  sym_snooptest (hcb_p np);
static void sym_selectclock(hcb_p np, u_char scntl3);
static void sym_getclock (hcb_p np, int mult);
static int  sym_getpciclock (hcb_p np);
static void sym_complete_ok (hcb_p np, ccb_p cp);
static void sym_complete_error (hcb_p np, ccb_p cp);
static void sym_callout (void *arg);
static int  sym_abort_scsiio (hcb_p np, union ccb *ccb, int timed_out);
static void sym_reset_dev (hcb_p np, union ccb *ccb);
static void sym_action (struct cam_sim *sim, union ccb *ccb);
static int  sym_setup_cdb (hcb_p np, struct ccb_scsiio *csio, ccb_p cp);
static void sym_setup_data_and_start (hcb_p np, struct ccb_scsiio *csio,
                                      ccb_p cp);
static int sym_fast_scatter_sg_physical(hcb_p np, ccb_p cp,
                                        bus_dma_segment_t *psegs, int nsegs);
static int sym_scatter_sg_physical (hcb_p np, ccb_p cp,
                                    bus_dma_segment_t *psegs, int nsegs);
static void sym_action2 (struct cam_sim *sim, union ccb *ccb);
static void sym_update_trans(hcb_p np, struct sym_trans *tip,
                              struct ccb_trans_settings *cts);
static void sym_update_dflags(hcb_p np, u_char *flags,
                              struct ccb_trans_settings *cts);

static const struct sym_pci_chip *sym_find_pci_chip (device_t dev);
static int  sym_pci_probe (device_t dev);
static int  sym_pci_attach (device_t dev);

static void sym_pci_free (hcb_p np);
static int  sym_cam_attach (hcb_p np);
static void sym_cam_free (hcb_p np);

static void sym_nvram_setup_host (hcb_p np, struct sym_nvram *nvram);
static void sym_nvram_setup_target (hcb_p np, int targ, struct sym_nvram *nvp);
static int sym_read_nvram (hcb_p np, struct sym_nvram *nvp);

/*
 *  Print something which allows to retrieve the controller type,
 *  unit, target, lun concerned by a kernel message.
 */
static void PRINT_TARGET (hcb_p np, int target)
{
        printf ("%s:%d:", sym_name(np), target);
}

static void PRINT_LUN(hcb_p np, int target, int lun)
{
        printf ("%s:%d:%d:", sym_name(np), target, lun);
}

static void PRINT_ADDR (ccb_p cp)
{
        if (cp && cp->cam_ccb)
                xpt_print_path(cp->cam_ccb->ccb_h.path);
}

/*
 *  Take into account this ccb in the freeze count.
 */
static void sym_freeze_cam_ccb(union ccb *ccb)
{
        if (!(ccb->ccb_h.flags & CAM_DEV_QFRZDIS)) {
                if (!(ccb->ccb_h.status & CAM_DEV_QFRZN)) {
                        ccb->ccb_h.status |= CAM_DEV_QFRZN;
                        xpt_freeze_devq(ccb->ccb_h.path, 1);
                }
        }
}

/*
 *  Set the status field of a CAM CCB.
 */
static __inline void sym_set_cam_status(union ccb *ccb, cam_status status)
{
        ccb->ccb_h.status &= ~CAM_STATUS_MASK;
        ccb->ccb_h.status |= status;
}

/*
 *  Get the status field of a CAM CCB.
 */
static __inline int sym_get_cam_status(union ccb *ccb)
{
        return ccb->ccb_h.status & CAM_STATUS_MASK;
}

/*
 *  Enqueue a CAM CCB.
 */
static void sym_enqueue_cam_ccb(ccb_p cp)
{
        hcb_p np;
        union ccb *ccb;

        ccb = cp->cam_ccb;
        np = (hcb_p) cp->arg;

        assert(!(ccb->ccb_h.status & CAM_SIM_QUEUED));
        ccb->ccb_h.status = CAM_REQ_INPROG;

        callout_reset_sbt(&cp->ch, SBT_1MS * ccb->ccb_h.timeout, 0, sym_callout,
            (caddr_t)ccb, 0);
        ccb->ccb_h.status |= CAM_SIM_QUEUED;
        ccb->ccb_h.sym_hcb_ptr = np;

        sym_insque_tail(sym_qptr(&ccb->ccb_h.sim_links), &np->cam_ccbq);
}

/*
 *  Complete a pending CAM CCB.
 */

static void sym_xpt_done(hcb_p np, union ccb *ccb, ccb_p cp)
{

        SYM_LOCK_ASSERT(MA_OWNED);

        if (ccb->ccb_h.status & CAM_SIM_QUEUED) {
                callout_stop(&cp->ch);
                sym_remque(sym_qptr(&ccb->ccb_h.sim_links));
                ccb->ccb_h.status &= ~CAM_SIM_QUEUED;
                ccb->ccb_h.sym_hcb_ptr = NULL;
        }
        xpt_done(ccb);
}

static void sym_xpt_done2(hcb_p np, union ccb *ccb, int cam_status)
{

        SYM_LOCK_ASSERT(MA_OWNED);

        sym_set_cam_status(ccb, cam_status);
        xpt_done(ccb);
}

/*
 *  SYMBIOS chip clock divisor table.
 *
 *  Divisors are multiplied by 10,000,000 in order to make
 *  calculations more simple.
 */
#define _5M 5000000
static const u32 div_10M[] =
        {2*_5M, 3*_5M, 4*_5M, 6*_5M, 8*_5M, 12*_5M, 16*_5M};

/*
 *  SYMBIOS chips allow burst lengths of 2, 4, 8, 16, 32, 64,
 *  128 transfers. All chips support at least 16 transfers
 *  bursts. The 825A, 875 and 895 chips support bursts of up
 *  to 128 transfers and the 895A and 896 support bursts of up
 *  to 64 transfers. All other chips support up to 16
 *  transfers bursts.
 *
 *  For PCI 32 bit data transfers each transfer is a DWORD.
 *  It is a QUADWORD (8 bytes) for PCI 64 bit data transfers.
 *
 *  We use log base 2 (burst length) as internal code, with
 *  value 0 meaning "burst disabled".
 */

/*
 *  Burst length from burst code.
 */
#define burst_length(bc) (!(bc))? 0 : 1 << (bc)

/*
 *  Burst code from io register bits.
 */
#define burst_code(dmode, ctest4, ctest5) \
        (ctest4) & 0x80? 0 : (((dmode) & 0xc0) >> 6) + ((ctest5) & 0x04) + 1

/*
 *  Set initial io register bits from burst code.
 */
static __inline void sym_init_burst(hcb_p np, u_char bc)
{
        np->rv_ctest4   &= ~0x80;
        np->rv_dmode    &= ~(0x3 << 6);
        np->rv_ctest5   &= ~0x4;

        if (!bc) {
                np->rv_ctest4   |= 0x80;
        }
        else {
                --bc;
                np->rv_dmode    |= ((bc & 0x3) << 6);
                np->rv_ctest5   |= (bc & 0x4);
        }
}

/*
 * Print out the list of targets that have some flag disabled by user.
 */
static void sym_print_targets_flag(hcb_p np, int mask, char *msg)
{
        int cnt;
        int i;

        for (cnt = 0, i = 0 ; i < SYM_CONF_MAX_TARGET ; i++) {
                if (i == np->myaddr)
                        continue;
                if (np->target[i].usrflags & mask) {
                        if (!cnt++)
                                printf("%s: %s disabled for targets",
                                        sym_name(np), msg);
                        printf(" %d", i);
                }
        }
        if (cnt)
                printf(".\n");
}

/*
 *  Save initial settings of some IO registers.
 *  Assumed to have been set by BIOS.
 *  We cannot reset the chip prior to reading the
 *  IO registers, since informations will be lost.
 *  Since the SCRIPTS processor may be running, this
 *  is not safe on paper, but it seems to work quite
 *  well. :)
 */
static void sym_save_initial_setting (hcb_p np)
{
        np->sv_scntl0   = INB(nc_scntl0) & 0x0a;
        np->sv_scntl3   = INB(nc_scntl3) & 0x07;
        np->sv_dmode    = INB(nc_dmode)  & 0xce;
        np->sv_dcntl    = INB(nc_dcntl)  & 0xa8;
        np->sv_ctest3   = INB(nc_ctest3) & 0x01;
        np->sv_ctest4   = INB(nc_ctest4) & 0x80;
        np->sv_gpcntl   = INB(nc_gpcntl);
        np->sv_stest1   = INB(nc_stest1);
        np->sv_stest2   = INB(nc_stest2) & 0x20;
        np->sv_stest4   = INB(nc_stest4);
        if (np->features & FE_C10) {    /* Always large DMA fifo + ultra3 */
                np->sv_scntl4   = INB(nc_scntl4);
                np->sv_ctest5   = INB(nc_ctest5) & 0x04;
        }
        else
                np->sv_ctest5   = INB(nc_ctest5) & 0x24;
}

/*
 *  Prepare io register values used by sym_init() according
 *  to selected and supported features.
 */
static int sym_prepare_setting(hcb_p np, struct sym_nvram *nvram)
{
        u_char  burst_max;
        u32     period;
        int i;

        /*
         *  Wide ?
         */
        np->maxwide     = (np->features & FE_WIDE)? 1 : 0;

        /*
         *  Get the frequency of the chip's clock.
         */
        if      (np->features & FE_QUAD)
                np->multiplier  = 4;
        else if (np->features & FE_DBLR)
                np->multiplier  = 2;
        else
                np->multiplier  = 1;

        np->clock_khz   = (np->features & FE_CLK80)? 80000 : 40000;
        np->clock_khz   *= np->multiplier;

        if (np->clock_khz != 40000)
                sym_getclock(np, np->multiplier);

        /*
         * Divisor to be used for async (timer pre-scaler).
         */
        i = np->clock_divn - 1;
        while (--i >= 0) {
                if (10ul * SYM_CONF_MIN_ASYNC * np->clock_khz > div_10M[i]) {
                        ++i;
                        break;
                }
        }
        np->rv_scntl3 = i+1;

        /*
         * The C1010 uses hardwired divisors for async.
         * So, we just throw away, the async. divisor.:-)
         */
        if (np->features & FE_C10)
                np->rv_scntl3 = 0;

        /*
         * Minimum synchronous period factor supported by the chip.
         * Btw, 'period' is in tenths of nanoseconds.
         */
        period = howmany(4 * div_10M[0], np->clock_khz);
        if      (period <= 250)         np->minsync = 10;
        else if (period <= 303)         np->minsync = 11;
        else if (period <= 500)         np->minsync = 12;
        else                            np->minsync = howmany(period, 40);

        /*
         * Check against chip SCSI standard support (SCSI-2,ULTRA,ULTRA2).
         */
        if      (np->minsync < 25 &&
                 !(np->features & (FE_ULTRA|FE_ULTRA2|FE_ULTRA3)))
                np->minsync = 25;
        else if (np->minsync < 12 &&
                 !(np->features & (FE_ULTRA2|FE_ULTRA3)))
                np->minsync = 12;

        /*
         * Maximum synchronous period factor supported by the chip.
         */
        period = (11 * div_10M[np->clock_divn - 1]) / (4 * np->clock_khz);
        np->maxsync = period > 2540 ? 254 : period / 10;

        /*
         * If chip is a C1010, guess the sync limits in DT mode.
         */
        if ((np->features & (FE_C10|FE_ULTRA3)) == (FE_C10|FE_ULTRA3)) {
                if (np->clock_khz == 160000) {
                        np->minsync_dt = 9;
                        np->maxsync_dt = 50;
                        np->maxoffs_dt = 62;
                }
        }

        /*
         *  64 bit addressing  (895A/896/1010) ?
         */
        if (np->features & FE_DAC)
#ifdef __LP64__
                np->rv_ccntl1   |= (XTIMOD | EXTIBMV);
#else
                np->rv_ccntl1   |= (DDAC);
#endif

        /*
         *  Phase mismatch handled by SCRIPTS (895A/896/1010) ?
         */
        if (np->features & FE_NOPM)
                np->rv_ccntl0   |= (ENPMJ);

        /*
         *  C1010 Errata.
         *  In dual channel mode, contention occurs if internal cycles
         *  are used. Disable internal cycles.
         */
        if (np->device_id == PCI_ID_LSI53C1010 &&
            np->revision_id < 0x2)
                np->rv_ccntl0   |=  DILS;

        /*
         *  Select burst length (dwords)
         */
        burst_max       = SYM_SETUP_BURST_ORDER;
        if (burst_max == 255)
                burst_max = burst_code(np->sv_dmode, np->sv_ctest4,
                                       np->sv_ctest5);
        if (burst_max > 7)
                burst_max = 7;
        if (burst_max > np->maxburst)
                burst_max = np->maxburst;

        /*
         *  DEL 352 - 53C810 Rev x11 - Part Number 609-0392140 - ITEM 2.
         *  This chip and the 860 Rev 1 may wrongly use PCI cache line
         *  based transactions on LOAD/STORE instructions. So we have
         *  to prevent these chips from using such PCI transactions in
         *  this driver. The generic ncr driver that does not use
         *  LOAD/STORE instructions does not need this work-around.
         */
        if ((np->device_id == PCI_ID_SYM53C810 &&
             np->revision_id >= 0x10 && np->revision_id <= 0x11) ||
            (np->device_id == PCI_ID_SYM53C860 &&
             np->revision_id <= 0x1))
                np->features &= ~(FE_WRIE|FE_ERL|FE_ERMP);

        /*
         *  Select all supported special features.
         *  If we are using on-board RAM for scripts, prefetch (PFEN)
         *  does not help, but burst op fetch (BOF) does.
         *  Disabling PFEN makes sure BOF will be used.
         */
        if (np->features & FE_ERL)
                np->rv_dmode    |= ERL;         /* Enable Read Line */
        if (np->features & FE_BOF)
                np->rv_dmode    |= BOF;         /* Burst Opcode Fetch */
        if (np->features & FE_ERMP)
                np->rv_dmode    |= ERMP;        /* Enable Read Multiple */
#if 1
        if ((np->features & FE_PFEN) && !np->ram_ba)
#else
        if (np->features & FE_PFEN)
#endif
                np->rv_dcntl    |= PFEN;        /* Prefetch Enable */
        if (np->features & FE_CLSE)
                np->rv_dcntl    |= CLSE;        /* Cache Line Size Enable */
        if (np->features & FE_WRIE)
                np->rv_ctest3   |= WRIE;        /* Write and Invalidate */
        if (np->features & FE_DFS)
                np->rv_ctest5   |= DFS;         /* Dma Fifo Size */

        /*
         *  Select some other
         */
        if (SYM_SETUP_PCI_PARITY)
                np->rv_ctest4   |= MPEE; /* Master parity checking */
        if (SYM_SETUP_SCSI_PARITY)
                np->rv_scntl0   |= 0x0a; /*  full arb., ena parity, par->ATN  */

        /*
         *  Get parity checking, host ID and verbose mode from NVRAM
         */
        np->myaddr = 255;
        sym_nvram_setup_host (np, nvram);

        /*
         *  Get SCSI addr of host adapter (set by bios?).
         */
        if (np->myaddr == 255) {
                np->myaddr = INB(nc_scid) & 0x07;
                if (!np->myaddr)
                        np->myaddr = SYM_SETUP_HOST_ID;
        }

        /*
         *  Prepare initial io register bits for burst length
         */
        sym_init_burst(np, burst_max);

        /*
         *  Set SCSI BUS mode.
         *  - LVD capable chips (895/895A/896/1010) report the
         *    current BUS mode through the STEST4 IO register.
         *  - For previous generation chips (825/825A/875),
         *    user has to tell us how to check against HVD,
         *    since a 100% safe algorithm is not possible.
         */
        np->scsi_mode = SMODE_SE;
        if (np->features & (FE_ULTRA2|FE_ULTRA3))
                np->scsi_mode = (np->sv_stest4 & SMODE);
        else if (np->features & FE_DIFF) {
                if (SYM_SETUP_SCSI_DIFF == 1) {
                        if (np->sv_scntl3) {
                                if (np->sv_stest2 & 0x20)
                                        np->scsi_mode = SMODE_HVD;
                        }
                        else if (nvram->type == SYM_SYMBIOS_NVRAM) {
                                if (!(INB(nc_gpreg) & 0x08))
                                        np->scsi_mode = SMODE_HVD;
                        }
                }
                else if (SYM_SETUP_SCSI_DIFF == 2)
                        np->scsi_mode = SMODE_HVD;
        }
        if (np->scsi_mode == SMODE_HVD)
                np->rv_stest2 |= 0x20;

        /*
         *  Set LED support from SCRIPTS.
         *  Ignore this feature for boards known to use a
         *  specific GPIO wiring and for the 895A, 896
         *  and 1010 that drive the LED directly.
         */
        if ((SYM_SETUP_SCSI_LED ||
             (nvram->type == SYM_SYMBIOS_NVRAM ||
              (nvram->type == SYM_TEKRAM_NVRAM &&
               np->device_id == PCI_ID_SYM53C895))) &&
            !(np->features & FE_LEDC) && !(np->sv_gpcntl & 0x01))
                np->features |= FE_LED0;

        /*
         *  Set irq mode.
         */
        switch(SYM_SETUP_IRQ_MODE & 3) {
        case 2:
                np->rv_dcntl    |= IRQM;
                break;
        case 1:
                np->rv_dcntl    |= (np->sv_dcntl & IRQM);
                break;
        default:
                break;
        }

        /*
         *  Configure targets according to driver setup.
         *  If NVRAM present get targets setup from NVRAM.
         */
        for (i = 0 ; i < SYM_CONF_MAX_TARGET ; i++) {
                tcb_p tp = &np->target[i];

                tp->tinfo.user.scsi_version = tp->tinfo.current.scsi_version= 2;
                tp->tinfo.user.spi_version  = tp->tinfo.current.spi_version = 2;
                tp->tinfo.user.period = np->minsync;
                if (np->features & FE_ULTRA3)
                        tp->tinfo.user.period = np->minsync_dt;
                tp->tinfo.user.offset = np->maxoffs;
                tp->tinfo.user.width  = np->maxwide ? BUS_16_BIT : BUS_8_BIT;
                tp->usrflags |= (SYM_DISC_ENABLED | SYM_TAGS_ENABLED);
                tp->usrtags = SYM_SETUP_MAX_TAG;

                sym_nvram_setup_target (np, i, nvram);

                /*
                 *  For now, guess PPR/DT support from the period
                 *  and BUS width.
                 */
                if (np->features & FE_ULTRA3) {
                        if (tp->tinfo.user.period <= 9  &&
                            tp->tinfo.user.width == BUS_16_BIT) {
                                tp->tinfo.user.options |= PPR_OPT_DT;
                                tp->tinfo.user.offset   = np->maxoffs_dt;
                                tp->tinfo.user.spi_version = 3;
                        }
                }

                if (!tp->usrtags)
                        tp->usrflags &= ~SYM_TAGS_ENABLED;
        }

        /*
         *  Let user know about the settings.
         */
        i = nvram->type;
        printf("%s: %s NVRAM, ID %d, Fast-%d, %s, %s\n", sym_name(np),
                i  == SYM_SYMBIOS_NVRAM ? "Symbios" :
                (i == SYM_TEKRAM_NVRAM  ? "Tekram" : "No"),
                np->myaddr,
                (np->features & FE_ULTRA3) ? 80 :
                (np->features & FE_ULTRA2) ? 40 :
                (np->features & FE_ULTRA)  ? 20 : 10,
                sym_scsi_bus_mode(np->scsi_mode),
                (np->rv_scntl0 & 0xa)   ? "parity checking" : "NO parity");
        /*
         *  Tell him more on demand.
         */
        if (sym_verbose) {
                printf("%s: %s IRQ line driver%s\n",
                        sym_name(np),
                        np->rv_dcntl & IRQM ? "totem pole" : "open drain",
                        np->ram_ba ? ", using on-chip SRAM" : "");
                printf("%s: using %s firmware.\n", sym_name(np), np->fw_name);
                if (np->features & FE_NOPM)
                        printf("%s: handling phase mismatch from SCRIPTS.\n",
                               sym_name(np));
        }
        /*
         *  And still more.
         */
        if (sym_verbose > 1) {
                printf ("%s: initial SCNTL3/DMODE/DCNTL/CTEST3/4/5 = "
                        "(hex) %02x/%02x/%02x/%02x/%02x/%02x\n",
                        sym_name(np), np->sv_scntl3, np->sv_dmode, np->sv_dcntl,
                        np->sv_ctest3, np->sv_ctest4, np->sv_ctest5);

                printf ("%s: final   SCNTL3/DMODE/DCNTL/CTEST3/4/5 = "
                        "(hex) %02x/%02x/%02x/%02x/%02x/%02x\n",
                        sym_name(np), np->rv_scntl3, np->rv_dmode, np->rv_dcntl,
                        np->rv_ctest3, np->rv_ctest4, np->rv_ctest5);
        }
        /*
         *  Let user be aware of targets that have some disable flags set.
         */
        sym_print_targets_flag(np, SYM_SCAN_BOOT_DISABLED, "SCAN AT BOOT");
        if (sym_verbose)
                sym_print_targets_flag(np, SYM_SCAN_LUNS_DISABLED,
                                       "SCAN FOR LUNS");

        return 0;
}

/*
 *  Prepare the next negotiation message if needed.
 *
 *  Fill in the part of message buffer that contains the
 *  negotiation and the nego_status field of the CCB.
 *  Returns the size of the message in bytes.
 */
static int sym_prepare_nego(hcb_p np, ccb_p cp, int nego, u_char *msgptr)
{
        tcb_p tp = &np->target[cp->target];
        int msglen = 0;

        /*
         *  Early C1010 chips need a work-around for DT
         *  data transfer to work.
         */
        if (!(np->features & FE_U3EN))
                tp->tinfo.goal.options = 0;
        /*
         *  negotiate using PPR ?
         */
        if (tp->tinfo.goal.options & PPR_OPT_MASK)
                nego = NS_PPR;
        /*
         *  negotiate wide transfers ?
         */
        else if (tp->tinfo.current.width != tp->tinfo.goal.width)
                nego = NS_WIDE;
        /*
         *  negotiate synchronous transfers?
         */
        else if (tp->tinfo.current.period != tp->tinfo.goal.period ||
                 tp->tinfo.current.offset != tp->tinfo.goal.offset)
                nego = NS_SYNC;

        switch (nego) {
        case NS_SYNC:
                msgptr[msglen++] = M_EXTENDED;
                msgptr[msglen++] = 3;
                msgptr[msglen++] = M_X_SYNC_REQ;
                msgptr[msglen++] = tp->tinfo.goal.period;
                msgptr[msglen++] = tp->tinfo.goal.offset;
                break;
        case NS_WIDE:
                msgptr[msglen++] = M_EXTENDED;
                msgptr[msglen++] = 2;
                msgptr[msglen++] = M_X_WIDE_REQ;
                msgptr[msglen++] = tp->tinfo.goal.width;
                break;
        case NS_PPR:
                msgptr[msglen++] = M_EXTENDED;
                msgptr[msglen++] = 6;
                msgptr[msglen++] = M_X_PPR_REQ;
                msgptr[msglen++] = tp->tinfo.goal.period;
                msgptr[msglen++] = 0;
                msgptr[msglen++] = tp->tinfo.goal.offset;
                msgptr[msglen++] = tp->tinfo.goal.width;
                msgptr[msglen++] = tp->tinfo.goal.options & PPR_OPT_DT;
                break;
        }

        cp->nego_status = nego;

        if (nego) {
                tp->nego_cp = cp; /* Keep track a nego will be performed */
                if (DEBUG_FLAGS & DEBUG_NEGO) {
                        sym_print_msg(cp, nego == NS_SYNC ? "sync msgout" :
                                          nego == NS_WIDE ? "wide msgout" :
                                          "ppr msgout", msgptr);
                }
        }

        return msglen;
}

/*
 *  Insert a job into the start queue.
 */
static void sym_put_start_queue(hcb_p np, ccb_p cp)
{
        u_short qidx;

#ifdef SYM_CONF_IARB_SUPPORT
        /*
         *  If the previously queued CCB is not yet done,
         *  set the IARB hint. The SCRIPTS will go with IARB
         *  for this job when starting the previous one.
         *  We leave devices a chance to win arbitration by
         *  not using more than 'iarb_max' consecutive
         *  immediate arbitrations.
         */
        if (np->last_cp && np->iarb_count < np->iarb_max) {
                np->last_cp->host_flags |= HF_HINT_IARB;
                ++np->iarb_count;
        }
        else
                np->iarb_count = 0;
        np->last_cp = cp;
#endif

        /*
         *  Insert first the idle task and then our job.
         *  The MB should ensure proper ordering.
         */
        qidx = np->squeueput + 2;
        if (qidx >= MAX_QUEUE*2) qidx = 0;

        np->squeue [qidx]          = cpu_to_scr(np->idletask_ba);
        MEMORY_BARRIER();
        np->squeue [np->squeueput] = cpu_to_scr(cp->ccb_ba);

        np->squeueput = qidx;

        if (DEBUG_FLAGS & DEBUG_QUEUE)
                printf ("%s: queuepos=%d.\n", sym_name (np), np->squeueput);

        /*
         *  Script processor may be waiting for reselect.
         *  Wake it up.
         */
        MEMORY_BARRIER();
        OUTB (nc_istat, SIGP|np->istat_sem);
}

/*
 *  Soft reset the chip.
 *
 *  Raising SRST when the chip is running may cause
 *  problems on dual function chips (see below).
 *  On the other hand, LVD devices need some delay
 *  to settle and report actual BUS mode in STEST4.
 */
static void sym_chip_reset (hcb_p np)
{
        OUTB (nc_istat, SRST);
        UDELAY (10);
        OUTB (nc_istat, 0);
        UDELAY(2000);   /* For BUS MODE to settle */
}

/*
 *  Soft reset the chip.
 *
 *  Some 896 and 876 chip revisions may hang-up if we set
 *  the SRST (soft reset) bit at the wrong time when SCRIPTS
 *  are running.
 *  So, we need to abort the current operation prior to
 *  soft resetting the chip.
 */
static void sym_soft_reset (hcb_p np)
{
        u_char istat;
        int i;

        OUTB (nc_istat, CABRT);
        for (i = 1000000 ; i ; --i) {
                istat = INB (nc_istat);
                if (istat & SIP) {
                        INW (nc_sist);
                        continue;
                }
                if (istat & DIP) {
                        OUTB (nc_istat, 0);
                        INB (nc_dstat);
                        break;
                }
        }
        if (!i)
                printf("%s: unable to abort current chip operation.\n",
                        sym_name(np));
        sym_chip_reset (np);
}

/*
 *  Start reset process.
 *
 *  The interrupt handler will reinitialize the chip.
 */
static void sym_start_reset(hcb_p np)
{
        (void) sym_reset_scsi_bus(np, 1);
}

static int sym_reset_scsi_bus(hcb_p np, int enab_int)
{
        u32 term;
        int retv = 0;

        sym_soft_reset(np);     /* Soft reset the chip */
        if (enab_int)
                OUTW (nc_sien, RST);
        /*
         *  Enable Tolerant, reset IRQD if present and
         *  properly set IRQ mode, prior to resetting the bus.
         */
        OUTB (nc_stest3, TE);
        OUTB (nc_dcntl, (np->rv_dcntl & IRQM));
        OUTB (nc_scntl1, CRST);
        UDELAY (200);

        if (!SYM_SETUP_SCSI_BUS_CHECK)
                goto out;
        /*
         *  Check for no terminators or SCSI bus shorts to ground.
         *  Read SCSI data bus, data parity bits and control signals.
         *  We are expecting RESET to be TRUE and other signals to be
         *  FALSE.
         */
        term =  INB(nc_sstat0);
        term =  ((term & 2) << 7) + ((term & 1) << 17); /* rst sdp0 */
        term |= ((INB(nc_sstat2) & 0x01) << 26) |       /* sdp1     */
                ((INW(nc_sbdl) & 0xff)   << 9)  |       /* d7-0     */
                ((INW(nc_sbdl) & 0xff00) << 10) |       /* d15-8    */
                INB(nc_sbcl);   /* req ack bsy sel atn msg cd io    */

        if (!(np->features & FE_WIDE))
                term &= 0x3ffff;

        if (term != (2<<7)) {
                printf("%s: suspicious SCSI data while resetting the BUS.\n",
                        sym_name(np));
                printf("%s: %sdp0,d7-0,rst,req,ack,bsy,sel,atn,msg,c/d,i/o = "
                        "0x%lx, expecting 0x%lx\n",
                        sym_name(np),
                        (np->features & FE_WIDE) ? "dp1,d15-8," : "",
                        (u_long)term, (u_long)(2<<7));
                if (SYM_SETUP_SCSI_BUS_CHECK == 1)
                        retv = 1;
        }
out:
        OUTB (nc_scntl1, 0);
        /* MDELAY(100); */
        return retv;
}

/*
 *  The chip may have completed jobs. Look at the DONE QUEUE.
 *
 *  On architectures that may reorder LOAD/STORE operations,
 *  a memory barrier may be needed after the reading of the
 *  so-called `flag' and prior to dealing with the data.
 */
static int sym_wakeup_done (hcb_p np)
{
        ccb_p cp;
        int i, n;
        u32 dsa;

        SYM_LOCK_ASSERT(MA_OWNED);

        n = 0;
        i = np->dqueueget;
        while (1) {
                dsa = scr_to_cpu(np->dqueue[i]);
                if (!dsa)
                        break;
                np->dqueue[i] = 0;
                if ((i = i+2) >= MAX_QUEUE*2)
                        i = 0;

                cp = sym_ccb_from_dsa(np, dsa);
                if (cp) {
                        MEMORY_BARRIER();
                        sym_complete_ok (np, cp);
                        ++n;
                }
                else
                        printf ("%s: bad DSA (%x) in done queue.\n",
                                sym_name(np), (u_int) dsa);
        }
        np->dqueueget = i;

        return n;
}

/*
 *  Complete all active CCBs with error.
 *  Used on CHIP/SCSI RESET.
 */
static void sym_flush_busy_queue (hcb_p np, int cam_status)
{
        /*
         *  Move all active CCBs to the COMP queue
         *  and flush this queue.
         */
        sym_que_splice(&np->busy_ccbq, &np->comp_ccbq);
        sym_que_init(&np->busy_ccbq);
        sym_flush_comp_queue(np, cam_status);
}

/*
 *  Start chip.
 *
 *  'reason' means:
 *     0: initialisation.
 *     1: SCSI BUS RESET delivered or received.
 *     2: SCSI BUS MODE changed.
 */
static void sym_init (hcb_p np, int reason)
{
        int     i;
        u32     phys;

        SYM_LOCK_ASSERT(MA_OWNED);

        /*
         *  Reset chip if asked, otherwise just clear fifos.
         */
        if (reason == 1)
                sym_soft_reset(np);
        else {
                OUTB (nc_stest3, TE|CSF);
                OUTONB (nc_ctest3, CLF);
        }

        /*
         *  Clear Start Queue
         */
        phys = np->squeue_ba;
        for (i = 0; i < MAX_QUEUE*2; i += 2) {
                np->squeue[i]   = cpu_to_scr(np->idletask_ba);
                np->squeue[i+1] = cpu_to_scr(phys + (i+2)*4);
        }
        np->squeue[MAX_QUEUE*2-1] = cpu_to_scr(phys);

        /*
         *  Start at first entry.
         */
        np->squeueput = 0;

        /*
         *  Clear Done Queue
         */
        phys = np->dqueue_ba;
        for (i = 0; i < MAX_QUEUE*2; i += 2) {
                np->dqueue[i]   = 0;
                np->dqueue[i+1] = cpu_to_scr(phys + (i+2)*4);
        }
        np->dqueue[MAX_QUEUE*2-1] = cpu_to_scr(phys);

        /*
         *  Start at first entry.
         */
        np->dqueueget = 0;

        /*
         *  Install patches in scripts.
         *  This also let point to first position the start
         *  and done queue pointers used from SCRIPTS.
         */
        np->fw_patch(np);

        /*
         *  Wakeup all pending jobs.
         */
        sym_flush_busy_queue(np, CAM_SCSI_BUS_RESET);

        /*
         *  Init chip.
         */
        OUTB (nc_istat,  0x00   );      /*  Remove Reset, abort */
        UDELAY (2000);  /* The 895 needs time for the bus mode to settle */

        OUTB (nc_scntl0, np->rv_scntl0 | 0xc0);
                                        /*  full arb., ena parity, par->ATN  */
        OUTB (nc_scntl1, 0x00);         /*  odd parity, and remove CRST!! */

        sym_selectclock(np, np->rv_scntl3);     /* Select SCSI clock */

        OUTB (nc_scid  , RRE|np->myaddr);       /* Adapter SCSI address */
        OUTW (nc_respid, 1ul<<np->myaddr);      /* Id to respond to */
        OUTB (nc_istat , SIGP   );              /*  Signal Process */
        OUTB (nc_dmode , np->rv_dmode);         /* Burst length, dma mode */
        OUTB (nc_ctest5, np->rv_ctest5);        /* Large fifo + large burst */

        OUTB (nc_dcntl , NOCOM|np->rv_dcntl);   /* Protect SFBR */
        OUTB (nc_ctest3, np->rv_ctest3);        /* Write and invalidate */
        OUTB (nc_ctest4, np->rv_ctest4);        /* Master parity checking */

        /* Extended Sreq/Sack filtering not supported on the C10 */
        if (np->features & FE_C10)
                OUTB (nc_stest2, np->rv_stest2);
        else
                OUTB (nc_stest2, EXT|np->rv_stest2);

        OUTB (nc_stest3, TE);                   /* TolerANT enable */
        OUTB (nc_stime0, 0x0c);                 /* HTH disabled  STO 0.25 sec */

        /*
         *  For now, disable AIP generation on C1010-66.
         */
        if (np->device_id == PCI_ID_LSI53C1010_2)
                OUTB (nc_aipcntl1, DISAIP);

        /*
         *  C10101 Errata.
         *  Errant SGE's when in narrow. Write bits 4 & 5 of
         *  STEST1 register to disable SGE. We probably should do
         *  that from SCRIPTS for each selection/reselection, but
         *  I just don't want. :)
         */
        if (np->device_id == PCI_ID_LSI53C1010 &&
            /* np->revision_id < 0xff */ 1)
                OUTB (nc_stest1, INB(nc_stest1) | 0x30);

        /*
         *  DEL 441 - 53C876 Rev 5 - Part Number 609-0392787/2788 - ITEM 2.
         *  Disable overlapped arbitration for some dual function devices,
         *  regardless revision id (kind of post-chip-design feature. ;-))
         */
        if (np->device_id == PCI_ID_SYM53C875)
                OUTB (nc_ctest0, (1<<5));
        else if (np->device_id == PCI_ID_SYM53C896)
                np->rv_ccntl0 |= DPR;

        /*
         *  Write CCNTL0/CCNTL1 for chips capable of 64 bit addressing
         *  and/or hardware phase mismatch, since only such chips
         *  seem to support those IO registers.
         */
        if (np->features & (FE_DAC|FE_NOPM)) {
                OUTB (nc_ccntl0, np->rv_ccntl0);
                OUTB (nc_ccntl1, np->rv_ccntl1);
        }

        /*
         *  If phase mismatch handled by scripts (895A/896/1010),
         *  set PM jump addresses.
         */
        if (np->features & FE_NOPM) {
                OUTL (nc_pmjad1, SCRIPTB_BA (np, pm_handle));
                OUTL (nc_pmjad2, SCRIPTB_BA (np, pm_handle));
        }

        /*
         *    Enable GPIO0 pin for writing if LED support from SCRIPTS.
         *    Also set GPIO5 and clear GPIO6 if hardware LED control.
         */
        if (np->features & FE_LED0)
                OUTB(nc_gpcntl, INB(nc_gpcntl) & ~0x01);
        else if (np->features & FE_LEDC)
                OUTB(nc_gpcntl, (INB(nc_gpcntl) & ~0x41) | 0x20);

        /*
         *      enable ints
         */
        OUTW (nc_sien , STO|HTH|MA|SGE|UDC|RST|PAR);
        OUTB (nc_dien , MDPE|BF|SSI|SIR|IID);

        /*
         *  For 895/6 enable SBMC interrupt and save current SCSI bus mode.
         *  Try to eat the spurious SBMC interrupt that may occur when
         *  we reset the chip but not the SCSI BUS (at initialization).
         */
        if (np->features & (FE_ULTRA2|FE_ULTRA3)) {
                OUTONW (nc_sien, SBMC);
                if (reason == 0) {
                        MDELAY(100);
                        INW (nc_sist);
                }
                np->scsi_mode = INB (nc_stest4) & SMODE;
        }

        /*
         *  Fill in target structure.
         *  Reinitialize usrsync.
         *  Reinitialize usrwide.
         *  Prepare sync negotiation according to actual SCSI bus mode.
         */
        for (i=0;i<SYM_CONF_MAX_TARGET;i++) {
                tcb_p tp = &np->target[i];

                tp->to_reset  = 0;
                tp->head.sval = 0;
                tp->head.wval = np->rv_scntl3;
                tp->head.uval = 0;

                tp->tinfo.current.period = 0;
                tp->tinfo.current.offset = 0;
                tp->tinfo.current.width  = BUS_8_BIT;
                tp->tinfo.current.options = 0;
        }

        /*
         *  Download SCSI SCRIPTS to on-chip RAM if present,
         *  and start script processor.
         */
        if (np->ram_ba) {
                if (sym_verbose > 1)
                        printf ("%s: Downloading SCSI SCRIPTS.\n",
                                sym_name(np));
                if (np->ram_ws == 8192) {
                        OUTRAM_OFF(4096, np->scriptb0, np->scriptb_sz);
                        OUTL (nc_mmws, np->scr_ram_seg);
                        OUTL (nc_mmrs, np->scr_ram_seg);
                        OUTL (nc_sfs,  np->scr_ram_seg);
                        phys = SCRIPTB_BA (np, start64);
                }
                else
                        phys = SCRIPTA_BA (np, init);
                OUTRAM_OFF(0, np->scripta0, np->scripta_sz);
        }
        else
                phys = SCRIPTA_BA (np, init);

        np->istat_sem = 0;

        OUTL (nc_dsa, np->hcb_ba);
        OUTL_DSP (phys);

        /*
         *  Notify the XPT about the RESET condition.
         */
        if (reason != 0)
                xpt_async(AC_BUS_RESET, np->path, NULL);
}

/*
 *  Get clock factor and sync divisor for a given
 *  synchronous factor period.
 */
static int
sym_getsync(hcb_p np, u_char dt, u_char sfac, u_char *divp, u_char *fakp)
{
        u32     clk = np->clock_khz;    /* SCSI clock frequency in kHz  */
        int     div = np->clock_divn;   /* Number of divisors supported */
        u32     fak;                    /* Sync factor in sxfer         */
        u32     per;                    /* Period in tenths of ns       */
        u32     kpc;                    /* (per * clk)                  */
        int     ret;

        /*
         *  Compute the synchronous period in tenths of nano-seconds
         */
        if (dt && sfac <= 9)    per = 125;
        else if (sfac <= 10)    per = 250;
        else if (sfac == 11)    per = 303;
        else if (sfac == 12)    per = 500;
        else                    per = 40 * sfac;
        ret = per;

        kpc = per * clk;
        if (dt)
                kpc <<= 1;

        /*
         *  For earliest C10 revision 0, we cannot use extra
         *  clocks for the setting of the SCSI clocking.
         *  Note that this limits the lowest sync data transfer
         *  to 5 Mega-transfers per second and may result in
         *  using higher clock divisors.
         */
#if 1
        if ((np->features & (FE_C10|FE_U3EN)) == FE_C10) {
                /*
                 *  Look for the lowest clock divisor that allows an
                 *  output speed not faster than the period.
                 */
                while (div > 0) {
                        --div;
                        if (kpc > (div_10M[div] << 2)) {
                                ++div;
                                break;
                        }
                }
                fak = 0;                        /* No extra clocks */
                if (div == np->clock_divn) {    /* Are we too fast ? */
                        ret = -1;
                }
                *divp = div;
                *fakp = fak;
                return ret;
        }
#endif

        /*
         *  Look for the greatest clock divisor that allows an
         *  input speed faster than the period.
         */
        while (div-- > 0)
                if (kpc >= (div_10M[div] << 2)) break;

        /*
         *  Calculate the lowest clock factor that allows an output
         *  speed not faster than the period, and the max output speed.
         *  If fak >= 1 we will set both XCLKH_ST and XCLKH_DT.
         *  If fak >= 2 we will also set XCLKS_ST and XCLKS_DT.
         */
        if (dt) {
                fak = (kpc - 1) / (div_10M[div] << 1) + 1 - 2;
                /* ret = ((2+fak)*div_10M[div])/np->clock_khz; */
        }
        else {
                fak = (kpc - 1) / div_10M[div] + 1 - 4;
                /* ret = ((4+fak)*div_10M[div])/np->clock_khz; */
        }

        /*
         *  Check against our hardware limits, or bugs :).
         */
        if (fak > 2)    {fak = 2; ret = -1;}

        /*
         *  Compute and return sync parameters.
         */
        *divp = div;
        *fakp = fak;

        return ret;
}

/*
 *  Tell the SCSI layer about the new transfer parameters.
 */
static void
sym_xpt_async_transfer_neg(hcb_p np, int target, u_int spi_valid)
{
        struct ccb_trans_settings cts;
        struct cam_path *path;
        int sts;
        tcb_p tp = &np->target[target];

        sts = xpt_create_path(&path, NULL, cam_sim_path(np->sim), target,
                              CAM_LUN_WILDCARD);
        if (sts != CAM_REQ_CMP)
                return;

        bzero(&cts, sizeof(cts));

#define cts__scsi (cts.proto_specific.scsi)
#define cts__spi  (cts.xport_specific.spi)

        cts.type      = CTS_TYPE_CURRENT_SETTINGS;
        cts.protocol  = PROTO_SCSI;
        cts.transport = XPORT_SPI;
        cts.protocol_version  = tp->tinfo.current.scsi_version;
        cts.transport_version = tp->tinfo.current.spi_version;

        cts__spi.valid = spi_valid;
        if (spi_valid & CTS_SPI_VALID_SYNC_RATE)
                cts__spi.sync_period = tp->tinfo.current.period;
        if (spi_valid & CTS_SPI_VALID_SYNC_OFFSET)
                cts__spi.sync_offset = tp->tinfo.current.offset;
        if (spi_valid & CTS_SPI_VALID_BUS_WIDTH)
                cts__spi.bus_width   = tp->tinfo.current.width;
        if (spi_valid & CTS_SPI_VALID_PPR_OPTIONS)
                cts__spi.ppr_options = tp->tinfo.current.options;
#undef cts__spi
#undef cts__scsi
        xpt_setup_ccb(&cts.ccb_h, path, /*priority*/1);
        xpt_async(AC_TRANSFER_NEG, path, &cts);
        xpt_free_path(path);
}

#define SYM_SPI_VALID_WDTR              \
        CTS_SPI_VALID_BUS_WIDTH |       \
        CTS_SPI_VALID_SYNC_RATE |       \
        CTS_SPI_VALID_SYNC_OFFSET
#define SYM_SPI_VALID_SDTR              \
        CTS_SPI_VALID_SYNC_RATE |       \
        CTS_SPI_VALID_SYNC_OFFSET
#define SYM_SPI_VALID_PPR               \
        CTS_SPI_VALID_PPR_OPTIONS |     \
        CTS_SPI_VALID_BUS_WIDTH |       \
        CTS_SPI_VALID_SYNC_RATE |       \
        CTS_SPI_VALID_SYNC_OFFSET

/*
 *  We received a WDTR.
 *  Let everything be aware of the changes.
 */
static void sym_setwide(hcb_p np, ccb_p cp, u_char wide)
{
        tcb_p tp = &np->target[cp->target];

        sym_settrans(np, cp, 0, 0, 0, wide, 0, 0);

        /*
         *  Tell the SCSI layer about the new transfer parameters.
         */
        tp->tinfo.goal.width = tp->tinfo.current.width = wide;
        tp->tinfo.current.offset = 0;
        tp->tinfo.current.period = 0;
        tp->tinfo.current.options = 0;

        sym_xpt_async_transfer_neg(np, cp->target, SYM_SPI_VALID_WDTR);
}

/*
 *  We received a SDTR.
 *  Let everything be aware of the changes.
 */
static void
sym_setsync(hcb_p np, ccb_p cp, u_char ofs, u_char per, u_char div, u_char fak)
{
        tcb_p tp = &np->target[cp->target];
        u_char wide = (cp->phys.select.sel_scntl3 & EWS) ? 1 : 0;

        sym_settrans(np, cp, 0, ofs, per, wide, div, fak);

        /*
         *  Tell the SCSI layer about the new transfer parameters.
         */
        tp->tinfo.goal.period   = tp->tinfo.current.period  = per;
        tp->tinfo.goal.offset   = tp->tinfo.current.offset  = ofs;
        tp->tinfo.goal.options  = tp->tinfo.current.options = 0;

        sym_xpt_async_transfer_neg(np, cp->target, SYM_SPI_VALID_SDTR);
}

/*
 *  We received a PPR.
 *  Let everything be aware of the changes.
 */
static void sym_setpprot(hcb_p np, ccb_p cp, u_char dt, u_char ofs,
                         u_char per, u_char wide, u_char div, u_char fak)
{
        tcb_p tp = &np->target[cp->target];

        sym_settrans(np, cp, dt, ofs, per, wide, div, fak);

        /*
         *  Tell the SCSI layer about the new transfer parameters.
         */
        tp->tinfo.goal.width    = tp->tinfo.current.width  = wide;
        tp->tinfo.goal.period   = tp->tinfo.current.period = per;
        tp->tinfo.goal.offset   = tp->tinfo.current.offset = ofs;
        tp->tinfo.goal.options  = tp->tinfo.current.options = dt;

        sym_xpt_async_transfer_neg(np, cp->target, SYM_SPI_VALID_PPR);
}

/*
 *  Switch trans mode for current job and it's target.
 */
static void sym_settrans(hcb_p np, ccb_p cp, u_char dt, u_char ofs,
                         u_char per, u_char wide, u_char div, u_char fak)
{
        SYM_QUEHEAD *qp;
        union   ccb *ccb;
        tcb_p tp;
        u_char target = INB (nc_sdid) & 0x0f;
        u_char sval, wval, uval;

        assert (cp);
        if (!cp) return;
        ccb = cp->cam_ccb;
        assert (ccb);
        if (!ccb) return;
        assert (target == (cp->target & 0xf));
        tp = &np->target[target];

        sval = tp->head.sval;
        wval = tp->head.wval;
        uval = tp->head.uval;

#if 0
        printf("XXXX sval=%x wval=%x uval=%x (%x)\n",
                sval, wval, uval, np->rv_scntl3);
#endif
        /*
         *  Set the offset.
         */
        if (!(np->features & FE_C10))
                sval = (sval & ~0x1f) | ofs;
        else
                sval = (sval & ~0x3f) | ofs;

        /*
         *  Set the sync divisor and extra clock factor.
         */
        if (ofs != 0) {
                wval = (wval & ~0x70) | ((div+1) << 4);
                if (!(np->features & FE_C10))
                        sval = (sval & ~0xe0) | (fak << 5);
                else {
                        uval = uval & ~(XCLKH_ST|XCLKH_DT|XCLKS_ST|XCLKS_DT);
                        if (fak >= 1) uval |= (XCLKH_ST|XCLKH_DT);
                        if (fak >= 2) uval |= (XCLKS_ST|XCLKS_DT);
                }
        }

        /*
         *  Set the bus width.
         */
        wval = wval & ~EWS;
        if (wide != 0)
                wval |= EWS;

        /*
         *  Set misc. ultra enable bits.
         */
        if (np->features & FE_C10) {
                uval = uval & ~(U3EN|AIPCKEN);
                if (dt) {
                        assert(np->features & FE_U3EN);
                        uval |= U3EN;
                }
        }
        else {
                wval = wval & ~ULTRA;
                if (per <= 12)  wval |= ULTRA;
        }

        /*
         *   Stop there if sync parameters are unchanged.
         */
        if (tp->head.sval == sval &&
            tp->head.wval == wval &&
            tp->head.uval == uval)
                return;
        tp->head.sval = sval;
        tp->head.wval = wval;
        tp->head.uval = uval;

        /*
         *  Disable extended Sreq/Sack filtering if per < 50.
         *  Not supported on the C1010.
         */
        if (per < 50 && !(np->features & FE_C10))
                OUTOFFB (nc_stest2, EXT);

        /*
         *  set actual value and sync_status
         */
        OUTB (nc_sxfer,  tp->head.sval);
        OUTB (nc_scntl3, tp->head.wval);

        if (np->features & FE_C10) {
                OUTB (nc_scntl4, tp->head.uval);
        }

        /*
         *  patch ALL busy ccbs of this target.
         */
        FOR_EACH_QUEUED_ELEMENT(&np->busy_ccbq, qp) {
                cp = sym_que_entry(qp, struct sym_ccb, link_ccbq);
                if (cp->target != target)
                        continue;
                cp->phys.select.sel_scntl3 = tp->head.wval;
                cp->phys.select.sel_sxfer  = tp->head.sval;
                if (np->features & FE_C10) {
                        cp->phys.select.sel_scntl4 = tp->head.uval;
                }
        }
}

/*
 *  log message for real hard errors
 *
 *  sym0 targ 0?: ERROR (ds:si) (so-si-sd) (sxfer/scntl3) @ name (dsp:dbc).
 *            reg: r0 r1 r2 r3 r4 r5 r6 ..... rf.
 *
 *  exception register:
 *      ds:     dstat
 *      si:     sist
 *
 *  SCSI bus lines:
 *      so:     control lines as driven by chip.
 *      si:     control lines as seen by chip.
 *      sd:     scsi data lines as seen by chip.
 *
 *  wide/fastmode:
 *      sxfer:  (see the manual)
 *      scntl3: (see the manual)
 *
 *  current script command:
 *      dsp:    script address (relative to start of script).
 *      dbc:    first word of script command.
 *
 *  First 24 register of the chip:
 *      r0..rf
 */
static void sym_log_hard_error(hcb_p np, u_short sist, u_char dstat)
{
        u32     dsp;
        int     script_ofs;
        int     script_size;
        char    *script_name;
        u_char  *script_base;
        int     i;

        dsp     = INL (nc_dsp);

        if      (dsp > np->scripta_ba &&
                 dsp <= np->scripta_ba + np->scripta_sz) {
                script_ofs      = dsp - np->scripta_ba;
                script_size     = np->scripta_sz;
                script_base     = (u_char *) np->scripta0;
                script_name     = "scripta";
        }
        else if (np->scriptb_ba < dsp &&
                 dsp <= np->scriptb_ba + np->scriptb_sz) {
                script_ofs      = dsp - np->scriptb_ba;
                script_size     = np->scriptb_sz;
                script_base     = (u_char *) np->scriptb0;
                script_name     = "scriptb";
        } else {
                script_ofs      = dsp;
                script_size     = 0;
                script_base     = NULL;
                script_name     = "mem";
        }

        printf ("%s:%d: ERROR (%x:%x) (%x-%x-%x) (%x/%x) @ (%s %x:%08x).\n",
                sym_name (np), (unsigned)INB (nc_sdid)&0x0f, dstat, sist,
                (unsigned)INB (nc_socl), (unsigned)INB (nc_sbcl),
                (unsigned)INB (nc_sbdl), (unsigned)INB (nc_sxfer),
                (unsigned)INB (nc_scntl3), script_name, script_ofs,
                (unsigned)INL (nc_dbc));

        if (((script_ofs & 3) == 0) &&
            (unsigned)script_ofs < script_size) {
                printf ("%s: script cmd = %08x\n", sym_name(np),
                        scr_to_cpu((int) *(u32 *)(script_base + script_ofs)));
        }

        printf ("%s: regdump:", sym_name(np));
        for (i=0; i<24;i++)
            printf (" %02x", (unsigned)INB_OFF(i));
        printf (".\n");

        /*
         *  PCI BUS error, read the PCI ststus register.
         */
        if (dstat & (MDPE|BF)) {
                u_short pci_sts;
                pci_sts = pci_read_config(np->device, PCIR_STATUS, 2);
                if (pci_sts & 0xf900) {
                        pci_write_config(np->device, PCIR_STATUS, pci_sts, 2);
                        printf("%s: PCI STATUS = 0x%04x\n",
                                sym_name(np), pci_sts & 0xf900);
                }
        }
}

/*
 *  chip interrupt handler
 *
 *  In normal situations, interrupt conditions occur one at
 *  a time. But when something bad happens on the SCSI BUS,
 *  the chip may raise several interrupt flags before
 *  stopping and interrupting the CPU. The additionnal
 *  interrupt flags are stacked in some extra registers
 *  after the SIP and/or DIP flag has been raised in the
 *  ISTAT. After the CPU has read the interrupt condition
 *  flag from SIST or DSTAT, the chip unstacks the other
 *  interrupt flags and sets the corresponding bits in
 *  SIST or DSTAT. Since the chip starts stacking once the
 *  SIP or DIP flag is set, there is a small window of time
 *  where the stacking does not occur.
 *
 *  Typically, multiple interrupt conditions may happen in
 *  the following situations:
 *
 *  - SCSI parity error + Phase mismatch  (PAR|MA)
 *    When a parity error is detected in input phase
 *    and the device switches to msg-in phase inside a
 *    block MOV.
 *  - SCSI parity error + Unexpected disconnect (PAR|UDC)
 *    When a stupid device does not want to handle the
 *    recovery of an SCSI parity error.
 *  - Some combinations of STO, PAR, UDC, ...
 *    When using non compliant SCSI stuff, when user is
 *    doing non compliant hot tampering on the BUS, when
 *    something really bad happens to a device, etc ...
 *
 *  The heuristic suggested by SYMBIOS to handle
 *  multiple interrupts is to try unstacking all
 *  interrupts conditions and to handle them on some
 *  priority based on error severity.
 *  This will work when the unstacking has been
 *  successful, but we cannot be 100 % sure of that,
 *  since the CPU may have been faster to unstack than
 *  the chip is able to stack. Hmmm ... But it seems that
 *  such a situation is very unlikely to happen.
 *
 *  If this happen, for example STO caught by the CPU
 *  then UDC happenning before the CPU have restarted
 *  the SCRIPTS, the driver may wrongly complete the
 *  same command on UDC, since the SCRIPTS didn't restart
 *  and the DSA still points to the same command.
 *  We avoid this situation by setting the DSA to an
 *  invalid value when the CCB is completed and before
 *  restarting the SCRIPTS.
 *
 *  Another issue is that we need some section of our
 *  recovery procedures to be somehow uninterruptible but
 *  the SCRIPTS processor does not provides such a
 *  feature. For this reason, we handle recovery preferently
 *  from the C code and check against some SCRIPTS critical
 *  sections from the C code.
 *
 *  Hopefully, the interrupt handling of the driver is now
 *  able to resist to weird BUS error conditions, but donnot
 *  ask me for any guarantee that it will never fail. :-)
 *  Use at your own decision and risk.
 */
static void sym_intr1 (hcb_p np)
{
        u_char  istat, istatc;
        u_char  dstat;
        u_short sist;

        SYM_LOCK_ASSERT(MA_OWNED);

        /*
         *  interrupt on the fly ?
         *
         *  A `dummy read' is needed to ensure that the
         *  clear of the INTF flag reaches the device
         *  before the scanning of the DONE queue.
         */
        istat = INB (nc_istat);
        if (istat & INTF) {
                OUTB (nc_istat, (istat & SIGP) | INTF | np->istat_sem);
                istat = INB (nc_istat);         /* DUMMY READ */
                if (DEBUG_FLAGS & DEBUG_TINY) printf ("F ");
                (void)sym_wakeup_done (np);
        }

        if (!(istat & (SIP|DIP)))
                return;

#if 0   /* We should never get this one */
        if (istat & CABRT)
                OUTB (nc_istat, CABRT);
#endif

        /*
         *  PAR and MA interrupts may occur at the same time,
         *  and we need to know of both in order to handle
         *  this situation properly. We try to unstack SCSI
         *  interrupts for that reason. BTW, I dislike a LOT
         *  such a loop inside the interrupt routine.
         *  Even if DMA interrupt stacking is very unlikely to
         *  happen, we also try unstacking these ones, since
         *  this has no performance impact.
         */
        sist    = 0;
        dstat   = 0;
        istatc  = istat;
        do {
                if (istatc & SIP)
                        sist  |= INW (nc_sist);
                if (istatc & DIP)
                        dstat |= INB (nc_dstat);
                istatc = INB (nc_istat);
                istat |= istatc;
        } while (istatc & (SIP|DIP));

        if (DEBUG_FLAGS & DEBUG_TINY)
                printf ("<%d|%x:%x|%x:%x>",
                        (int)INB(nc_scr0),
                        dstat,sist,
                        (unsigned)INL(nc_dsp),
                        (unsigned)INL(nc_dbc));
        /*
         *  On paper, a memory barrier may be needed here.
         *  And since we are paranoid ... :)
         */
        MEMORY_BARRIER();

        /*
         *  First, interrupts we want to service cleanly.
         *
         *  Phase mismatch (MA) is the most frequent interrupt
         *  for chip earlier than the 896 and so we have to service
         *  it as quickly as possible.
         *  A SCSI parity error (PAR) may be combined with a phase
         *  mismatch condition (MA).
         *  Programmed interrupts (SIR) are used to call the C code
         *  from SCRIPTS.
         *  The single step interrupt (SSI) is not used in this
         *  driver.
         */
        if (!(sist  & (STO|GEN|HTH|SGE|UDC|SBMC|RST)) &&
            !(dstat & (MDPE|BF|ABRT|IID))) {
                if      (sist & PAR)    sym_int_par (np, sist);
                else if (sist & MA)     sym_int_ma (np);
                else if (dstat & SIR)   sym_int_sir (np);
                else if (dstat & SSI)   OUTONB_STD ();
                else                    goto unknown_int;
                return;
        }

        /*
         *  Now, interrupts that donnot happen in normal
         *  situations and that we may need to recover from.
         *
         *  On SCSI RESET (RST), we reset everything.
         *  On SCSI BUS MODE CHANGE (SBMC), we complete all
         *  active CCBs with RESET status, prepare all devices
         *  for negotiating again and restart the SCRIPTS.
         *  On STO and UDC, we complete the CCB with the corres-
         *  ponding status and restart the SCRIPTS.
         */
        if (sist & RST) {
                xpt_print_path(np->path);
                printf("SCSI BUS reset detected.\n");
                sym_init (np, 1);
                return;
        }

        OUTB (nc_ctest3, np->rv_ctest3 | CLF);  /* clear dma fifo  */
        OUTB (nc_stest3, TE|CSF);               /* clear scsi fifo */

        if (!(sist  & (GEN|HTH|SGE)) &&
            !(dstat & (MDPE|BF|ABRT|IID))) {
                if      (sist & SBMC)   sym_int_sbmc (np);
                else if (sist & STO)    sym_int_sto (np);
                else if (sist & UDC)    sym_int_udc (np);
                else                    goto unknown_int;
                return;
        }

        /*
         *  Now, interrupts we are not able to recover cleanly.
         *
         *  Log message for hard errors.
         *  Reset everything.
         */

        sym_log_hard_error(np, sist, dstat);

        if ((sist & (GEN|HTH|SGE)) ||
                (dstat & (MDPE|BF|ABRT|IID))) {
                sym_start_reset(np);
                return;
        }

unknown_int:
        /*
         *  We just miss the cause of the interrupt. :(
         *  Print a message. The timeout will do the real work.
         */
        printf( "%s: unknown interrupt(s) ignored, "
                "ISTAT=0x%x DSTAT=0x%x SIST=0x%x\n",
                sym_name(np), istat, dstat, sist);
}

static void sym_intr(void *arg)
{
        hcb_p np = arg;

        SYM_LOCK();

        if (DEBUG_FLAGS & DEBUG_TINY) printf ("[");
        sym_intr1((hcb_p) arg);
        if (DEBUG_FLAGS & DEBUG_TINY) printf ("]");

        SYM_UNLOCK();
}

static void sym_poll(struct cam_sim *sim)
{
        sym_intr1(cam_sim_softc(sim));
}

/*
 *  generic recovery from scsi interrupt
 *
 *  The doc says that when the chip gets an SCSI interrupt,
 *  it tries to stop in an orderly fashion, by completing
 *  an instruction fetch that had started or by flushing
 *  the DMA fifo for a write to memory that was executing.
 *  Such a fashion is not enough to know if the instruction
 *  that was just before the current DSP value has been
 *  executed or not.
 *
 *  There are some small SCRIPTS sections that deal with
 *  the start queue and the done queue that may break any
 *  assomption from the C code if we are interrupted
 *  inside, so we reset if this happens. Btw, since these
 *  SCRIPTS sections are executed while the SCRIPTS hasn't
 *  started SCSI operations, it is very unlikely to happen.
 *
 *  All the driver data structures are supposed to be
 *  allocated from the same 4 GB memory window, so there
 *  is a 1 to 1 relationship between DSA and driver data
 *  structures. Since we are careful :) to invalidate the
 *  DSA when we complete a command or when the SCRIPTS
 *  pushes a DSA into a queue, we can trust it when it
 *  points to a CCB.
 */
static void sym_recover_scsi_int (hcb_p np, u_char hsts)
{
        u32     dsp     = INL (nc_dsp);
        u32     dsa     = INL (nc_dsa);
        ccb_p cp        = sym_ccb_from_dsa(np, dsa);

        /*
         *  If we haven't been interrupted inside the SCRIPTS
         *  critical paths, we can safely restart the SCRIPTS
         *  and trust the DSA value if it matches a CCB.
         */
        if ((!(dsp > SCRIPTA_BA (np, getjob_begin) &&
               dsp < SCRIPTA_BA (np, getjob_end) + 1)) &&
            (!(dsp > SCRIPTA_BA (np, ungetjob) &&
               dsp < SCRIPTA_BA (np, reselect) + 1)) &&
            (!(dsp > SCRIPTB_BA (np, sel_for_abort) &&
               dsp < SCRIPTB_BA (np, sel_for_abort_1) + 1)) &&
            (!(dsp > SCRIPTA_BA (np, done) &&
               dsp < SCRIPTA_BA (np, done_end) + 1))) {
                OUTB (nc_ctest3, np->rv_ctest3 | CLF);  /* clear dma fifo  */
                OUTB (nc_stest3, TE|CSF);               /* clear scsi fifo */
                /*
                 *  If we have a CCB, let the SCRIPTS call us back for
                 *  the handling of the error with SCRATCHA filled with
                 *  STARTPOS. This way, we will be able to freeze the
                 *  device queue and requeue awaiting IOs.
                 */
                if (cp) {
                        cp->host_status = hsts;
                        OUTL_DSP (SCRIPTA_BA (np, complete_error));
                }
                /*
                 *  Otherwise just restart the SCRIPTS.
                 */
                else {
                        OUTL (nc_dsa, 0xffffff);
                        OUTL_DSP (SCRIPTA_BA (np, start));
                }
        }
        else
                goto reset_all;

        return;

reset_all:
        sym_start_reset(np);
}

/*
 *  chip exception handler for selection timeout
 */
static void sym_int_sto (hcb_p np)
{
        u32 dsp = INL (nc_dsp);

        if (DEBUG_FLAGS & DEBUG_TINY) printf ("T");

        if (dsp == SCRIPTA_BA (np, wf_sel_done) + 8)
                sym_recover_scsi_int(np, HS_SEL_TIMEOUT);
        else
                sym_start_reset(np);
}

/*
 *  chip exception handler for unexpected disconnect
 */
static void sym_int_udc (hcb_p np)
{
        printf ("%s: unexpected disconnect\n", sym_name(np));
        sym_recover_scsi_int(np, HS_UNEXPECTED);
}

/*
 *  chip exception handler for SCSI bus mode change
 *
 *  spi2-r12 11.2.3 says a transceiver mode change must
 *  generate a reset event and a device that detects a reset
 *  event shall initiate a hard reset. It says also that a
 *  device that detects a mode change shall set data transfer
 *  mode to eight bit asynchronous, etc...
 *  So, just reinitializing all except chip should be enough.
 */
static void sym_int_sbmc (hcb_p np)
{
        u_char scsi_mode = INB (nc_stest4) & SMODE;

        /*
         *  Notify user.
         */
        xpt_print_path(np->path);
        printf("SCSI BUS mode change from %s to %s.\n",
                sym_scsi_bus_mode(np->scsi_mode), sym_scsi_bus_mode(scsi_mode));

        /*
         *  Should suspend command processing for a few seconds and
         *  reinitialize all except the chip.
         */
        sym_init (np, 2);
}

/*
 *  chip exception handler for SCSI parity error.
 *
 *  When the chip detects a SCSI parity error and is
 *  currently executing a (CH)MOV instruction, it does
 *  not interrupt immediately, but tries to finish the
 *  transfer of the current scatter entry before
 *  interrupting. The following situations may occur:
 *
 *  - The complete scatter entry has been transferred
 *    without the device having changed phase.
 *    The chip will then interrupt with the DSP pointing
 *    to the instruction that follows the MOV.
 *
 *  - A phase mismatch occurs before the MOV finished
 *    and phase errors are to be handled by the C code.
 *    The chip will then interrupt with both PAR and MA
 *    conditions set.
 *
 *  - A phase mismatch occurs before the MOV finished and
 *    phase errors are to be handled by SCRIPTS.
 *    The chip will load the DSP with the phase mismatch
 *    JUMP address and interrupt the host processor.
 */
static void sym_int_par (hcb_p np, u_short sist)
{
        u_char  hsts    = INB (HS_PRT);
        u32     dsp     = INL (nc_dsp);
        u32     dbc     = INL (nc_dbc);
        u32     dsa     = INL (nc_dsa);
        u_char  sbcl    = INB (nc_sbcl);
        u_char  cmd     = dbc >> 24;
        int phase       = cmd & 7;
        ccb_p   cp      = sym_ccb_from_dsa(np, dsa);

        printf("%s: SCSI parity error detected: SCR1=%d DBC=%x SBCL=%x\n",
                sym_name(np), hsts, dbc, sbcl);

        /*
         *  Check that the chip is connected to the SCSI BUS.
         */
        if (!(INB (nc_scntl1) & ISCON)) {
                sym_recover_scsi_int(np, HS_UNEXPECTED);
                return;
        }

        /*
         *  If the nexus is not clearly identified, reset the bus.
         *  We will try to do better later.
         */
        if (!cp)
                goto reset_all;

        /*
         *  Check instruction was a MOV, direction was INPUT and
         *  ATN is asserted.
         */
        if ((cmd & 0xc0) || !(phase & 1) || !(sbcl & 0x8))
                goto reset_all;

        /*
         *  Keep track of the parity error.
         */
        OUTONB (HF_PRT, HF_EXT_ERR);
        cp->xerr_status |= XE_PARITY_ERR;

        /*
         *  Prepare the message to send to the device.
         */
        np->msgout[0] = (phase == 7) ? M_PARITY : M_ID_ERROR;

        /*
         *  If the old phase was DATA IN phase, we have to deal with
         *  the 3 situations described above.
         *  For other input phases (MSG IN and STATUS), the device
         *  must resend the whole thing that failed parity checking
         *  or signal error. So, jumping to dispatcher should be OK.
         */
        if (phase == 1 || phase == 5) {
                /* Phase mismatch handled by SCRIPTS */
                if (dsp == SCRIPTB_BA (np, pm_handle))
                        OUTL_DSP (dsp);
                /* Phase mismatch handled by the C code */
                else if (sist & MA)
                        sym_int_ma (np);
                /* No phase mismatch occurred */
                else {
                        OUTL (nc_temp, dsp);
                        OUTL_DSP (SCRIPTA_BA (np, dispatch));
                }
        }
        else
                OUTL_DSP (SCRIPTA_BA (np, clrack));
        return;

reset_all:
        sym_start_reset(np);
}

/*
 *  chip exception handler for phase errors.
 *
 *  We have to construct a new transfer descriptor,
 *  to transfer the rest of the current block.
 */
static void sym_int_ma (hcb_p np)
{
        u32     dbc;
        u32     rest;
        u32     dsp;
        u32     dsa;
        u32     nxtdsp;
        u32     *vdsp;
        u32     oadr, olen;
        u32     *tblp;
        u32     newcmd;
        u_int   delta;
        u_char  cmd;
        u_char  hflags, hflags0;
        struct  sym_pmc *pm;
        ccb_p   cp;

        dsp     = INL (nc_dsp);
        dbc     = INL (nc_dbc);
        dsa     = INL (nc_dsa);

        cmd     = dbc >> 24;
        rest    = dbc & 0xffffff;
        delta   = 0;

        /*
         *  locate matching cp if any.
         */
        cp = sym_ccb_from_dsa(np, dsa);

        /*
         *  Donnot take into account dma fifo and various buffers in
         *  INPUT phase since the chip flushes everything before
         *  raising the MA interrupt for interrupted INPUT phases.
         *  For DATA IN phase, we will check for the SWIDE later.
         */
        if ((cmd & 7) != 1 && (cmd & 7) != 5) {
                u_char ss0, ss2;

                if (np->features & FE_DFBC)
                        delta = INW (nc_dfbc);
                else {
                        u32 dfifo;

                        /*
                         * Read DFIFO, CTEST[4-6] using 1 PCI bus ownership.
                         */
                        dfifo = INL(nc_dfifo);

                        /*
                         *  Calculate remaining bytes in DMA fifo.
                         *  (CTEST5 = dfifo >> 16)
                         */
                        if (dfifo & (DFS << 16))
                                delta = ((((dfifo >> 8) & 0x300) |
                                          (dfifo & 0xff)) - rest) & 0x3ff;
                        else
                                delta = ((dfifo & 0xff) - rest) & 0x7f;
                }

                /*
                 *  The data in the dma fifo has not been transferred to
                 *  the target -> add the amount to the rest
                 *  and clear the data.
                 *  Check the sstat2 register in case of wide transfer.
                 */
                rest += delta;
                ss0  = INB (nc_sstat0);
                if (ss0 & OLF) rest++;
                if (!(np->features & FE_C10))
                        if (ss0 & ORF) rest++;
                if (cp && (cp->phys.select.sel_scntl3 & EWS)) {
                        ss2 = INB (nc_sstat2);
                        if (ss2 & OLF1) rest++;
                        if (!(np->features & FE_C10))
                                if (ss2 & ORF1) rest++;
                }

                /*
                 *  Clear fifos.
                 */
                OUTB (nc_ctest3, np->rv_ctest3 | CLF);  /* dma fifo  */
                OUTB (nc_stest3, TE|CSF);               /* scsi fifo */
        }

        /*
         *  log the information
         */
        if (DEBUG_FLAGS & (DEBUG_TINY|DEBUG_PHASE))
                printf ("P%x%x RL=%d D=%d ", cmd&7, INB(nc_sbcl)&7,
                        (unsigned) rest, (unsigned) delta);

        /*
         *  try to find the interrupted script command,
         *  and the address at which to continue.
         */
        vdsp    = NULL;
        nxtdsp  = 0;
        if      (dsp >  np->scripta_ba &&
                 dsp <= np->scripta_ba + np->scripta_sz) {
                vdsp = (u32 *)((char*)np->scripta0 + (dsp-np->scripta_ba-8));
                nxtdsp = dsp;
        }
        else if (dsp >  np->scriptb_ba &&
                 dsp <= np->scriptb_ba + np->scriptb_sz) {
                vdsp = (u32 *)((char*)np->scriptb0 + (dsp-np->scriptb_ba-8));
                nxtdsp = dsp;
        }

        /*
         *  log the information
         */
        if (DEBUG_FLAGS & DEBUG_PHASE) {
                printf ("\nCP=%p DSP=%x NXT=%x VDSP=%p CMD=%x ",
                        cp, (unsigned)dsp, (unsigned)nxtdsp, vdsp, cmd);
        }

        if (!vdsp) {
                printf ("%s: interrupted SCRIPT address not found.\n",
                        sym_name (np));
                goto reset_all;
        }

        if (!cp) {
                printf ("%s: SCSI phase error fixup: CCB already dequeued.\n",
                        sym_name (np));
                goto reset_all;
        }

        /*
         *  get old startaddress and old length.
         */
        oadr = scr_to_cpu(vdsp[1]);

        if (cmd & 0x10) {       /* Table indirect */
                tblp = (u32 *) ((char*) &cp->phys + oadr);
                olen = scr_to_cpu(tblp[0]);
                oadr = scr_to_cpu(tblp[1]);
        } else {
                tblp = (u32 *) 0;
                olen = scr_to_cpu(vdsp[0]) & 0xffffff;
        }

        if (DEBUG_FLAGS & DEBUG_PHASE) {
                printf ("OCMD=%x\nTBLP=%p OLEN=%x OADR=%x\n",
                        (unsigned) (scr_to_cpu(vdsp[0]) >> 24),
                        tblp,
                        (unsigned) olen,
                        (unsigned) oadr);
        }

        /*
         *  check cmd against assumed interrupted script command.
         *  If dt data phase, the MOVE instruction hasn't bit 4 of
         *  the phase.
         */
        if (((cmd & 2) ? cmd : (cmd & ~4)) != (scr_to_cpu(vdsp[0]) >> 24)) {
                PRINT_ADDR(cp);
                printf ("internal error: cmd=%02x != %02x=(vdsp[0] >> 24)\n",
                        (unsigned)cmd, (unsigned)scr_to_cpu(vdsp[0]) >> 24);

                goto reset_all;
        }

        /*
         *  if old phase not dataphase, leave here.
         */
        if (cmd & 2) {
                PRINT_ADDR(cp);
                printf ("phase change %x-%x %d@%08x resid=%d.\n",
                        cmd&7, INB(nc_sbcl)&7, (unsigned)olen,
                        (unsigned)oadr, (unsigned)rest);
                goto unexpected_phase;
        }

        /*
         *  Choose the correct PM save area.
         *
         *  Look at the PM_SAVE SCRIPT if you want to understand
         *  this stuff. The equivalent code is implemented in
         *  SCRIPTS for the 895A, 896 and 1010 that are able to
         *  handle PM from the SCRIPTS processor.
         */
        hflags0 = INB (HF_PRT);
        hflags = hflags0;

        if (hflags & (HF_IN_PM0 | HF_IN_PM1 | HF_DP_SAVED)) {
                if (hflags & HF_IN_PM0)
                        nxtdsp = scr_to_cpu(cp->phys.pm0.ret);
                else if (hflags & HF_IN_PM1)
                        nxtdsp = scr_to_cpu(cp->phys.pm1.ret);

                if (hflags & HF_DP_SAVED)
                        hflags ^= HF_ACT_PM;
        }

        if (!(hflags & HF_ACT_PM)) {
                pm = &cp->phys.pm0;
                newcmd = SCRIPTA_BA (np, pm0_data);
        }
        else {
                pm = &cp->phys.pm1;
                newcmd = SCRIPTA_BA (np, pm1_data);
        }

        hflags &= ~(HF_IN_PM0 | HF_IN_PM1 | HF_DP_SAVED);
        if (hflags != hflags0)
                OUTB (HF_PRT, hflags);

        /*
         *  fillin the phase mismatch context
         */
        pm->sg.addr = cpu_to_scr(oadr + olen - rest);
        pm->sg.size = cpu_to_scr(rest);
        pm->ret     = cpu_to_scr(nxtdsp);

        /*
         *  If we have a SWIDE,
         *  - prepare the address to write the SWIDE from SCRIPTS,
         *  - compute the SCRIPTS address to restart from,
         *  - move current data pointer context by one byte.
         */
        nxtdsp = SCRIPTA_BA (np, dispatch);
        if ((cmd & 7) == 1 && cp && (cp->phys.select.sel_scntl3 & EWS) &&
            (INB (nc_scntl2) & WSR)) {
                u32 tmp;

                /*
                 *  Set up the table indirect for the MOVE
                 *  of the residual byte and adjust the data
                 *  pointer context.
                 */
                tmp = scr_to_cpu(pm->sg.addr);
                cp->phys.wresid.addr = cpu_to_scr(tmp);
                pm->sg.addr = cpu_to_scr(tmp + 1);
                tmp = scr_to_cpu(pm->sg.size);
                cp->phys.wresid.size = cpu_to_scr((tmp&0xff000000) | 1);
                pm->sg.size = cpu_to_scr(tmp - 1);

                /*
                 *  If only the residual byte is to be moved,
                 *  no PM context is needed.
                 */
                if ((tmp&0xffffff) == 1)
                        newcmd = pm->ret;

                /*
                 *  Prepare the address of SCRIPTS that will
                 *  move the residual byte to memory.
                 */
                nxtdsp = SCRIPTB_BA (np, wsr_ma_helper);
        }

        if (DEBUG_FLAGS & DEBUG_PHASE) {
                PRINT_ADDR(cp);
                printf ("PM %x %x %x / %x %x %x.\n",
                        hflags0, hflags, newcmd,
                        (unsigned)scr_to_cpu(pm->sg.addr),
                        (unsigned)scr_to_cpu(pm->sg.size),
                        (unsigned)scr_to_cpu(pm->ret));
        }

        /*
         *  Restart the SCRIPTS processor.
         */
        OUTL (nc_temp, newcmd);
        OUTL_DSP (nxtdsp);
        return;

        /*
         *  Unexpected phase changes that occurs when the current phase
         *  is not a DATA IN or DATA OUT phase are due to error conditions.
         *  Such event may only happen when the SCRIPTS is using a
         *  multibyte SCSI MOVE.
         *
         *  Phase change                Some possible cause
         *
         *  COMMAND  --> MSG IN SCSI parity error detected by target.
         *  COMMAND  --> STATUS Bad command or refused by target.
         *  MSG OUT  --> MSG IN     Message rejected by target.
         *  MSG OUT  --> COMMAND    Bogus target that discards extended
         *                      negotiation messages.
         *
         *  The code below does not care of the new phase and so
         *  trusts the target. Why to annoy it ?
         *  If the interrupted phase is COMMAND phase, we restart at
         *  dispatcher.
         *  If a target does not get all the messages after selection,
         *  the code assumes blindly that the target discards extended
         *  messages and clears the negotiation status.
         *  If the target does not want all our response to negotiation,
         *  we force a SIR_NEGO_PROTO interrupt (it is a hack that avoids
         *  bloat for such a should_not_happen situation).
         *  In all other situation, we reset the BUS.
         *  Are these assumptions reasonnable ? (Wait and see ...)
         */
unexpected_phase:
        dsp -= 8;
        nxtdsp = 0;

        switch (cmd & 7) {
        case 2: /* COMMAND phase */
                nxtdsp = SCRIPTA_BA (np, dispatch);
                break;
#if 0
        case 3: /* STATUS  phase */
                nxtdsp = SCRIPTA_BA (np, dispatch);
                break;
#endif
        case 6: /* MSG OUT phase */
                /*
                 *  If the device may want to use untagged when we want
                 *  tagged, we prepare an IDENTIFY without disc. granted,
                 *  since we will not be able to handle reselect.
                 *  Otherwise, we just don't care.
                 */
                if      (dsp == SCRIPTA_BA (np, send_ident)) {
                        if (cp->tag != NO_TAG && olen - rest <= 3) {
                                cp->host_status = HS_BUSY;
                                np->msgout[0] = M_IDENTIFY | cp->lun;
                                nxtdsp = SCRIPTB_BA (np, ident_break_atn);
                        }
                        else
                                nxtdsp = SCRIPTB_BA (np, ident_break);
                }
                else if (dsp == SCRIPTB_BA (np, send_wdtr) ||
                         dsp == SCRIPTB_BA (np, send_sdtr) ||
                         dsp == SCRIPTB_BA (np, send_ppr)) {
                        nxtdsp = SCRIPTB_BA (np, nego_bad_phase);
                }
                break;
#if 0
        case 7: /* MSG IN  phase */
                nxtdsp = SCRIPTA_BA (np, clrack);
                break;
#endif
        }

        if (nxtdsp) {
                OUTL_DSP (nxtdsp);
                return;
        }

reset_all:
        sym_start_reset(np);
}

/*
 *  Dequeue from the START queue all CCBs that match
 *  a given target/lun/task condition (-1 means all),
 *  and move them from the BUSY queue to the COMP queue
 *  with CAM_REQUEUE_REQ status condition.
 *  This function is used during error handling/recovery.
 *  It is called with SCRIPTS not running.
 */
static int
sym_dequeue_from_squeue(hcb_p np, int i, int target, int lun, int task)
{
        int j;
        ccb_p cp;

        /*
         *  Make sure the starting index is within range.
         */
        assert((i >= 0) && (i < 2*MAX_QUEUE));

        /*
         *  Walk until end of START queue and dequeue every job
         *  that matches the target/lun/task condition.
         */
        j = i;
        while (i != np->squeueput) {
                cp = sym_ccb_from_dsa(np, scr_to_cpu(np->squeue[i]));
                assert(cp);
#ifdef SYM_CONF_IARB_SUPPORT
                /* Forget hints for IARB, they may be no longer relevant */
                cp->host_flags &= ~HF_HINT_IARB;
#endif
                if ((target == -1 || cp->target == target) &&
                    (lun    == -1 || cp->lun    == lun)    &&
                    (task   == -1 || cp->tag    == task)) {
                        sym_set_cam_status(cp->cam_ccb, CAM_REQUEUE_REQ);
                        sym_remque(&cp->link_ccbq);
                        sym_insque_tail(&cp->link_ccbq, &np->comp_ccbq);
                }
                else {
                        if (i != j)
                                np->squeue[j] = np->squeue[i];
                        if ((j += 2) >= MAX_QUEUE*2) j = 0;
                }
                if ((i += 2) >= MAX_QUEUE*2) i = 0;
        }
        if (i != j)             /* Copy back the idle task if needed */
                np->squeue[j] = np->squeue[i];
        np->squeueput = j;      /* Update our current start queue pointer */

        return (i - j) / 2;
}

/*
 *  Complete all CCBs queued to the COMP queue.
 *
 *  These CCBs are assumed:
 *  - Not to be referenced either by devices or
 *    SCRIPTS-related queues and datas.
 *  - To have to be completed with an error condition
 *    or requeued.
 *
 *  The device queue freeze count is incremented
 *  for each CCB that does not prevent this.
 *  This function is called when all CCBs involved
 *  in error handling/recovery have been reaped.
 */
static void
sym_flush_comp_queue(hcb_p np, int cam_status)
{
        SYM_QUEHEAD *qp;
        ccb_p cp;

        while ((qp = sym_remque_head(&np->comp_ccbq)) != NULL) {
                union ccb *ccb;
                cp = sym_que_entry(qp, struct sym_ccb, link_ccbq);
                sym_insque_tail(&cp->link_ccbq, &np->busy_ccbq);
                /* Leave quiet CCBs waiting for resources */
                if (cp->host_status == HS_WAIT)
                        continue;
                ccb = cp->cam_ccb;
                if (cam_status)
                        sym_set_cam_status(ccb, cam_status);
                sym_freeze_cam_ccb(ccb);
                sym_xpt_done(np, ccb, cp);
                sym_free_ccb(np, cp);
        }
}

/*
 *  chip handler for bad SCSI status condition
 *
 *  In case of bad SCSI status, we unqueue all the tasks
 *  currently queued to the controller but not yet started
 *  and then restart the SCRIPTS processor immediately.
 *
 *  QUEUE FULL and BUSY conditions are handled the same way.
 *  Basically all the not yet started tasks are requeued in
 *  device queue and the queue is frozen until a completion.
 *
 *  For CHECK CONDITION and COMMAND TERMINATED status, we use
 *  the CCB of the failed command to prepare a REQUEST SENSE
 *  SCSI command and queue it to the controller queue.
 *
 *  SCRATCHA is assumed to have been loaded with STARTPOS
 *  before the SCRIPTS called the C code.
 */
static void sym_sir_bad_scsi_status(hcb_p np, ccb_p cp)
{
        tcb_p tp        = &np->target[cp->target];
        u32             startp;
        u_char          s_status = cp->ssss_status;
        u_char          h_flags  = cp->host_flags;
        int             msglen;
        int             nego;
        int             i;

        SYM_LOCK_ASSERT(MA_OWNED);

        /*
         *  Compute the index of the next job to start from SCRIPTS.
         */
        i = (INL (nc_scratcha) - np->squeue_ba) / 4;

        /*
         *  The last CCB queued used for IARB hint may be
         *  no longer relevant. Forget it.
         */
#ifdef SYM_CONF_IARB_SUPPORT
        if (np->last_cp)
                np->last_cp = NULL;
#endif

        /*
         *  Now deal with the SCSI status.
         */
        switch(s_status) {
        case S_BUSY:
        case S_QUEUE_FULL:
                if (sym_verbose >= 2) {
                        PRINT_ADDR(cp);
                        printf (s_status == S_BUSY ? "BUSY" : "QUEUE FULL\n");
                }
        default:        /* S_INT, S_INT_COND_MET, S_CONFLICT */
                sym_complete_error (np, cp);
                break;
        case S_TERMINATED:
        case S_CHECK_COND:
                /*
                 *  If we get an SCSI error when requesting sense, give up.
                 */
                if (h_flags & HF_SENSE) {
                        sym_complete_error (np, cp);
                        break;
                }

                /*
                 *  Dequeue all queued CCBs for that device not yet started,
                 *  and restart the SCRIPTS processor immediately.
                 */
                (void) sym_dequeue_from_squeue(np, i, cp->target, cp->lun, -1);
                OUTL_DSP (SCRIPTA_BA (np, start));

                /*
                 *  Save some info of the actual IO.
                 *  Compute the data residual.
                 */
                cp->sv_scsi_status = cp->ssss_status;
                cp->sv_xerr_status = cp->xerr_status;
                cp->sv_resid = sym_compute_residual(np, cp);

                /*
                 *  Prepare all needed data structures for
                 *  requesting sense data.
                 */

                /*
                 *  identify message
                 */
                cp->scsi_smsg2[0] = M_IDENTIFY | cp->lun;
                msglen = 1;

                /*
                 *  If we are currently using anything different from
                 *  async. 8 bit data transfers with that target,
                 *  start a negotiation, since the device may want
                 *  to report us a UNIT ATTENTION condition due to
                 *  a cause we currently ignore, and we donnot want
                 *  to be stuck with WIDE and/or SYNC data transfer.
                 *
                 *  cp->nego_status is filled by sym_prepare_nego().
                 */
                cp->nego_status = 0;
                nego = 0;
                if      (tp->tinfo.current.options & PPR_OPT_MASK)
                        nego = NS_PPR;
                else if (tp->tinfo.current.width != BUS_8_BIT)
                        nego = NS_WIDE;
                else if (tp->tinfo.current.offset != 0)
                        nego = NS_SYNC;
                if (nego)
                        msglen +=
                        sym_prepare_nego (np,cp, nego, &cp->scsi_smsg2[msglen]);
                /*
                 *  Message table indirect structure.
                 */
                cp->phys.smsg.addr      = cpu_to_scr(CCB_BA (cp, scsi_smsg2));
                cp->phys.smsg.size      = cpu_to_scr(msglen);

                /*
                 *  sense command
                 */
                cp->phys.cmd.addr       = cpu_to_scr(CCB_BA (cp, sensecmd));
                cp->phys.cmd.size       = cpu_to_scr(6);

                /*
                 *  patch requested size into sense command
                 */
                cp->sensecmd[0]         = 0x03;
                cp->sensecmd[1]         = cp->lun << 5;
                if (tp->tinfo.current.scsi_version > 2 || cp->lun > 7)
                        cp->sensecmd[1] = 0;
                cp->sensecmd[4]         = SYM_SNS_BBUF_LEN;
                cp->data_len            = SYM_SNS_BBUF_LEN;

                /*
                 *  sense data
                 */
                bzero(cp->sns_bbuf, SYM_SNS_BBUF_LEN);
                cp->phys.sense.addr     = cpu_to_scr(vtobus(cp->sns_bbuf));
                cp->phys.sense.size     = cpu_to_scr(SYM_SNS_BBUF_LEN);

                /*
                 *  requeue the command.
                 */
                startp = SCRIPTB_BA (np, sdata_in);

                cp->phys.head.savep     = cpu_to_scr(startp);
                cp->phys.head.goalp     = cpu_to_scr(startp + 16);
                cp->phys.head.lastp     = cpu_to_scr(startp);
                cp->startp      = cpu_to_scr(startp);

                cp->actualquirks = SYM_QUIRK_AUTOSAVE;
                cp->host_status = cp->nego_status ? HS_NEGOTIATE : HS_BUSY;
                cp->ssss_status = S_ILLEGAL;
                cp->host_flags  = (HF_SENSE|HF_DATA_IN);
                cp->xerr_status = 0;
                cp->extra_bytes = 0;

                cp->phys.head.go.start = cpu_to_scr(SCRIPTA_BA (np, select));

                /*
                 *  Requeue the command.
                 */
                sym_put_start_queue(np, cp);

                /*
                 *  Give back to upper layer everything we have dequeued.
                 */
                sym_flush_comp_queue(np, 0);
                break;
        }
}

/*
 *  After a device has accepted some management message
 *  as BUS DEVICE RESET, ABORT TASK, etc ..., or when
 *  a device signals a UNIT ATTENTION condition, some
 *  tasks are thrown away by the device. We are required
 *  to reflect that on our tasks list since the device
 *  will never complete these tasks.
 *
 *  This function move from the BUSY queue to the COMP
 *  queue all disconnected CCBs for a given target that
 *  match the following criteria:
 *  - lun=-1  means any logical UNIT otherwise a given one.
 *  - task=-1 means any task, otherwise a given one.
 */
static int
sym_clear_tasks(hcb_p np, int cam_status, int target, int lun, int task)
{
        SYM_QUEHEAD qtmp, *qp;
        int i = 0;
        ccb_p cp;

        /*
         *  Move the entire BUSY queue to our temporary queue.
         */
        sym_que_init(&qtmp);
        sym_que_splice(&np->busy_ccbq, &qtmp);
        sym_que_init(&np->busy_ccbq);

        /*
         *  Put all CCBs that matches our criteria into
         *  the COMP queue and put back other ones into
         *  the BUSY queue.
         */
        while ((qp = sym_remque_head(&qtmp)) != NULL) {
                union ccb *ccb;
                cp = sym_que_entry(qp, struct sym_ccb, link_ccbq);
                ccb = cp->cam_ccb;
                if (cp->host_status != HS_DISCONNECT ||
                    cp->target != target             ||
                    (lun  != -1 && cp->lun != lun)   ||
                    (task != -1 &&
                        (cp->tag != NO_TAG && cp->scsi_smsg[2] != task))) {
                        sym_insque_tail(&cp->link_ccbq, &np->busy_ccbq);
                        continue;
                }
                sym_insque_tail(&cp->link_ccbq, &np->comp_ccbq);

                /* Preserve the software timeout condition */
                if (sym_get_cam_status(ccb) != CAM_CMD_TIMEOUT)
                        sym_set_cam_status(ccb, cam_status);
                ++i;
#if 0
printf("XXXX TASK @%p CLEARED\n", cp);
#endif
        }
        return i;
}

/*
 *  chip handler for TASKS recovery
 *
 *  We cannot safely abort a command, while the SCRIPTS
 *  processor is running, since we just would be in race
 *  with it.
 *
 *  As long as we have tasks to abort, we keep the SEM
 *  bit set in the ISTAT. When this bit is set, the
 *  SCRIPTS processor interrupts (SIR_SCRIPT_STOPPED)
 *  each time it enters the scheduler.
 *
 *  If we have to reset a target, clear tasks of a unit,
 *  or to perform the abort of a disconnected job, we
 *  restart the SCRIPTS for selecting the target. Once
 *  selected, the SCRIPTS interrupts (SIR_TARGET_SELECTED).
 *  If it loses arbitration, the SCRIPTS will interrupt again
 *  the next time it will enter its scheduler, and so on ...
 *
 *  On SIR_TARGET_SELECTED, we scan for the more
 *  appropriate thing to do:
 *
 *  - If nothing, we just sent a M_ABORT message to the
 *    target to get rid of the useless SCSI bus ownership.
 *    According to the specs, no tasks shall be affected.
 *  - If the target is to be reset, we send it a M_RESET
 *    message.
 *  - If a logical UNIT is to be cleared , we send the
 *    IDENTIFY(lun) + M_ABORT.
 *  - If an untagged task is to be aborted, we send the
 *    IDENTIFY(lun) + M_ABORT.
 *  - If a tagged task is to be aborted, we send the
 *    IDENTIFY(lun) + task attributes + M_ABORT_TAG.
 *
 *  Once our 'kiss of death' :) message has been accepted
 *  by the target, the SCRIPTS interrupts again
 *  (SIR_ABORT_SENT). On this interrupt, we complete
 *  all the CCBs that should have been aborted by the
 *  target according to our message.
 */
static void sym_sir_task_recovery(hcb_p np, int num)
{
        SYM_QUEHEAD *qp;
        ccb_p cp;
        tcb_p tp;
        int target=-1, lun=-1, task;
        int i, k;

        switch(num) {
        /*
         *  The SCRIPTS processor stopped before starting
         *  the next command in order to allow us to perform
         *  some task recovery.
         */
        case SIR_SCRIPT_STOPPED:
                /*
                 *  Do we have any target to reset or unit to clear ?
                 */
                for (i = 0 ; i < SYM_CONF_MAX_TARGET ; i++) {
                        tp = &np->target[i];
                        if (tp->to_reset ||
                            (tp->lun0p && tp->lun0p->to_clear)) {
                                target = i;
                                break;
                        }
                        if (!tp->lunmp)
                                continue;
                        for (k = 1 ; k < SYM_CONF_MAX_LUN ; k++) {
                                if (tp->lunmp[k] && tp->lunmp[k]->to_clear) {
                                        target  = i;
                                        break;
                                }
                        }
                        if (target != -1)
                                break;
                }

                /*
                 *  If not, walk the busy queue for any
                 *  disconnected CCB to be aborted.
                 */
                if (target == -1) {
                        FOR_EACH_QUEUED_ELEMENT(&np->busy_ccbq, qp) {
                                cp = sym_que_entry(qp,struct sym_ccb,link_ccbq);
                                if (cp->host_status != HS_DISCONNECT)
                                        continue;
                                if (cp->to_abort) {
                                        target = cp->target;
                                        break;
                                }
                        }
                }

                /*
                 *  If some target is to be selected,
                 *  prepare and start the selection.
                 */
                if (target != -1) {
                        tp = &np->target[target];
                        np->abrt_sel.sel_id     = target;
                        np->abrt_sel.sel_scntl3 = tp->head.wval;
                        np->abrt_sel.sel_sxfer  = tp->head.sval;
                        OUTL(nc_dsa, np->hcb_ba);
                        OUTL_DSP (SCRIPTB_BA (np, sel_for_abort));
                        return;
                }

                /*
                 *  Now look for a CCB to abort that haven't started yet.
                 *  Btw, the SCRIPTS processor is still stopped, so
                 *  we are not in race.
                 */
                i = 0;
                cp = NULL;
                FOR_EACH_QUEUED_ELEMENT(&np->busy_ccbq, qp) {
                        cp = sym_que_entry(qp, struct sym_ccb, link_ccbq);
                        if (cp->host_status != HS_BUSY &&
                            cp->host_status != HS_NEGOTIATE)
                                continue;
                        if (!cp->to_abort)
                                continue;
#ifdef SYM_CONF_IARB_SUPPORT
                        /*
                         *    If we are using IMMEDIATE ARBITRATION, we donnot
                         *    want to cancel the last queued CCB, since the
                         *    SCRIPTS may have anticipated the selection.
                         */
                        if (cp == np->last_cp) {
                                cp->to_abort = 0;
                                continue;
                        }
#endif
                        i = 1;  /* Means we have found some */
                        break;
                }
                if (!i) {
                        /*
                         *  We are done, so we donnot need
                         *  to synchronize with the SCRIPTS anylonger.
                         *  Remove the SEM flag from the ISTAT.
                         */
                        np->istat_sem = 0;
                        OUTB (nc_istat, SIGP);
                        break;
                }
                /*
                 *  Compute index of next position in the start
                 *  queue the SCRIPTS intends to start and dequeue
                 *  all CCBs for that device that haven't been started.
                 */
                i = (INL (nc_scratcha) - np->squeue_ba) / 4;
                i = sym_dequeue_from_squeue(np, i, cp->target, cp->lun, -1);

                /*
                 *  Make sure at least our IO to abort has been dequeued.
                 */
                assert(i && sym_get_cam_status(cp->cam_ccb) == CAM_REQUEUE_REQ);

                /*
                 *  Keep track in cam status of the reason of the abort.
                 */
                if (cp->to_abort == 2)
                        sym_set_cam_status(cp->cam_ccb, CAM_CMD_TIMEOUT);
                else
                        sym_set_cam_status(cp->cam_ccb, CAM_REQ_ABORTED);

                /*
                 *  Complete with error everything that we have dequeued.
                 */
                sym_flush_comp_queue(np, 0);
                break;
        /*
         *  The SCRIPTS processor has selected a target
         *  we may have some manual recovery to perform for.
         */
        case SIR_TARGET_SELECTED:
                target = (INB (nc_sdid) & 0xf);
                tp = &np->target[target];

                np->abrt_tbl.addr = cpu_to_scr(vtobus(np->abrt_msg));

                /*
                 *  If the target is to be reset, prepare a
                 *  M_RESET message and clear the to_reset flag
                 *  since we donnot expect this operation to fail.
                 */
                if (tp->to_reset) {
                        np->abrt_msg[0] = M_RESET;
                        np->abrt_tbl.size = 1;
                        tp->to_reset = 0;
                        break;
                }

                /*
                 *  Otherwise, look for some logical unit to be cleared.
                 */
                if (tp->lun0p && tp->lun0p->to_clear)
                        lun = 0;
                else if (tp->lunmp) {
                        for (k = 1 ; k < SYM_CONF_MAX_LUN ; k++) {
                                if (tp->lunmp[k] && tp->lunmp[k]->to_clear) {
                                        lun = k;
                                        break;
                                }
                        }
                }

                /*
                 *  If a logical unit is to be cleared, prepare
                 *  an IDENTIFY(lun) + ABORT MESSAGE.
                 */
                if (lun != -1) {
                        lcb_p lp = sym_lp(tp, lun);
                        lp->to_clear = 0; /* We donnot expect to fail here */
                        np->abrt_msg[0] = M_IDENTIFY | lun;
                        np->abrt_msg[1] = M_ABORT;
                        np->abrt_tbl.size = 2;
                        break;
                }

                /*
                 *  Otherwise, look for some disconnected job to
                 *  abort for this target.
                 */
                i = 0;
                cp = NULL;
                FOR_EACH_QUEUED_ELEMENT(&np->busy_ccbq, qp) {
                        cp = sym_que_entry(qp, struct sym_ccb, link_ccbq);
                        if (cp->host_status != HS_DISCONNECT)
                                continue;
                        if (cp->target != target)
                                continue;
                        if (!cp->to_abort)
                                continue;
                        i = 1;  /* Means we have some */
                        break;
                }

                /*
                 *  If we have none, probably since the device has
                 *  completed the command before we won abitration,
                 *  send a M_ABORT message without IDENTIFY.
                 *  According to the specs, the device must just
                 *  disconnect the BUS and not abort any task.
                 */
                if (!i) {
                        np->abrt_msg[0] = M_ABORT;
                        np->abrt_tbl.size = 1;
                        break;
                }

                /*
                 *  We have some task to abort.
                 *  Set the IDENTIFY(lun)
                 */
                np->abrt_msg[0] = M_IDENTIFY | cp->lun;

                /*
                 *  If we want to abort an untagged command, we
                 *  will send an IDENTIFY + M_ABORT.
                 *  Otherwise (tagged command), we will send
                 *  an IDENTIFY + task attributes + ABORT TAG.
                 */
                if (cp->tag == NO_TAG) {
                        np->abrt_msg[1] = M_ABORT;
                        np->abrt_tbl.size = 2;
                }
                else {
                        np->abrt_msg[1] = cp->scsi_smsg[1];
                        np->abrt_msg[2] = cp->scsi_smsg[2];
                        np->abrt_msg[3] = M_ABORT_TAG;
                        np->abrt_tbl.size = 4;
                }
                /*
                 *  Keep track of software timeout condition, since the
                 *  peripheral driver may not count retries on abort
                 *  conditions not due to timeout.
                 */
                if (cp->to_abort == 2)
                        sym_set_cam_status(cp->cam_ccb, CAM_CMD_TIMEOUT);
                cp->to_abort = 0; /* We donnot expect to fail here */
                break;

        /*
         *  The target has accepted our message and switched
         *  to BUS FREE phase as we expected.
         */
        case SIR_ABORT_SENT:
                target = (INB (nc_sdid) & 0xf);
                tp = &np->target[target];

                /*
                **  If we didn't abort anything, leave here.
                */
                if (np->abrt_msg[0] == M_ABORT)
                        break;

                /*
                 *  If we sent a M_RESET, then a hardware reset has
                 *  been performed by the target.
                 *  - Reset everything to async 8 bit
                 *  - Tell ourself to negotiate next time :-)
                 *  - Prepare to clear all disconnected CCBs for
                 *    this target from our task list (lun=task=-1)
                 */
                lun = -1;
                task = -1;
                if (np->abrt_msg[0] == M_RESET) {
                        tp->head.sval = 0;
                        tp->head.wval = np->rv_scntl3;
                        tp->head.uval = 0;
                        tp->tinfo.current.period = 0;
                        tp->tinfo.current.offset = 0;
                        tp->tinfo.current.width  = BUS_8_BIT;
                        tp->tinfo.current.options = 0;
                }

                /*
                 *  Otherwise, check for the LUN and TASK(s)
                 *  concerned by the cancellation.
                 *  If it is not ABORT_TAG then it is CLEAR_QUEUE
                 *  or an ABORT message :-)
                 */
                else {
                        lun = np->abrt_msg[0] & 0x3f;
                        if (np->abrt_msg[1] == M_ABORT_TAG)
                                task = np->abrt_msg[2];
                }

                /*
                 *  Complete all the CCBs the device should have
                 *  aborted due to our 'kiss of death' message.
                 */
                i = (INL (nc_scratcha) - np->squeue_ba) / 4;
                (void) sym_dequeue_from_squeue(np, i, target, lun, -1);
                (void) sym_clear_tasks(np, CAM_REQ_ABORTED, target, lun, task);
                sym_flush_comp_queue(np, 0);

                /*
                 *  If we sent a BDR, make uper layer aware of that.
                 */
                if (np->abrt_msg[0] == M_RESET)
                        xpt_async(AC_SENT_BDR, np->path, NULL);
                break;
        }

        /*
         *  Print to the log the message we intend to send.
         */
        if (num == SIR_TARGET_SELECTED) {
                PRINT_TARGET(np, target);
                sym_printl_hex("control msgout:", np->abrt_msg,
                              np->abrt_tbl.size);
                np->abrt_tbl.size = cpu_to_scr(np->abrt_tbl.size);
        }

        /*
         *  Let the SCRIPTS processor continue.
         */
        OUTONB_STD ();
}

/*
 *  Gerard's alchemy:) that deals with with the data
 *  pointer for both MDP and the residual calculation.
 *
 *  I didn't want to bloat the code by more than 200
 *  lignes for the handling of both MDP and the residual.
 *  This has been achieved by using a data pointer
 *  representation consisting in an index in the data
 *  array (dp_sg) and a negative offset (dp_ofs) that
 *  have the following meaning:
 *
 *  - dp_sg = SYM_CONF_MAX_SG
 *    we are at the end of the data script.
 *  - dp_sg < SYM_CONF_MAX_SG
 *    dp_sg points to the next entry of the scatter array
 *    we want to transfer.
 *  - dp_ofs < 0
 *    dp_ofs represents the residual of bytes of the
 *    previous entry scatter entry we will send first.
 *  - dp_ofs = 0
 *    no residual to send first.
 *
 *  The function sym_evaluate_dp() accepts an arbitray
 *  offset (basically from the MDP message) and returns
 *  the corresponding values of dp_sg and dp_ofs.
 */
static int sym_evaluate_dp(hcb_p np, ccb_p cp, u32 scr, int *ofs)
{
        u32     dp_scr;
        int     dp_ofs, dp_sg, dp_sgmin;
        int     tmp;
        struct sym_pmc *pm;

        /*
         *  Compute the resulted data pointer in term of a script
         *  address within some DATA script and a signed byte offset.
         */
        dp_scr = scr;
        dp_ofs = *ofs;
        if      (dp_scr == SCRIPTA_BA (np, pm0_data))
                pm = &cp->phys.pm0;
        else if (dp_scr == SCRIPTA_BA (np, pm1_data))
                pm = &cp->phys.pm1;
        else
                pm = NULL;

        if (pm) {
                dp_scr  = scr_to_cpu(pm->ret);
                dp_ofs -= scr_to_cpu(pm->sg.size);
        }

        /*
         *  If we are auto-sensing, then we are done.
         */
        if (cp->host_flags & HF_SENSE) {
                *ofs = dp_ofs;
                return 0;
        }

        /*
         *  Deduce the index of the sg entry.
         *  Keep track of the index of the first valid entry.
         *  If result is dp_sg = SYM_CONF_MAX_SG, then we are at the
         *  end of the data.
         */
        tmp = scr_to_cpu(cp->phys.head.goalp);
        dp_sg = SYM_CONF_MAX_SG;
        if (dp_scr != tmp)
                dp_sg -= (tmp - 8 - (int)dp_scr) / (2*4);
        dp_sgmin = SYM_CONF_MAX_SG - cp->segments;

        /*
         *  Move to the sg entry the data pointer belongs to.
         *
         *  If we are inside the data area, we expect result to be:
         *
         *  Either,
         *      dp_ofs = 0 and dp_sg is the index of the sg entry
         *      the data pointer belongs to (or the end of the data)
         *  Or,
         *      dp_ofs < 0 and dp_sg is the index of the sg entry
         *      the data pointer belongs to + 1.
         */
        if (dp_ofs < 0) {
                int n;
                while (dp_sg > dp_sgmin) {
                        --dp_sg;
                        tmp = scr_to_cpu(cp->phys.data[dp_sg].size);
                        n = dp_ofs + (tmp & 0xffffff);
                        if (n > 0) {
                                ++dp_sg;
                                break;
                        }
                        dp_ofs = n;
                }
        }
        else if (dp_ofs > 0) {
                while (dp_sg < SYM_CONF_MAX_SG) {
                        tmp = scr_to_cpu(cp->phys.data[dp_sg].size);
                        dp_ofs -= (tmp & 0xffffff);
                        ++dp_sg;
                        if (dp_ofs <= 0)
                                break;
                }
        }

        /*
         *  Make sure the data pointer is inside the data area.
         *  If not, return some error.
         */
        if      (dp_sg < dp_sgmin || (dp_sg == dp_sgmin && dp_ofs < 0))
                goto out_err;
        else if (dp_sg > SYM_CONF_MAX_SG ||
                 (dp_sg == SYM_CONF_MAX_SG && dp_ofs > 0))
                goto out_err;

        /*
         *  Save the extreme pointer if needed.
         */
        if (dp_sg > cp->ext_sg ||
            (dp_sg == cp->ext_sg && dp_ofs > cp->ext_ofs)) {
                cp->ext_sg  = dp_sg;
                cp->ext_ofs = dp_ofs;
        }

        /*
         *  Return data.
         */
        *ofs = dp_ofs;
        return dp_sg;

out_err:
        return -1;
}

/*
 *  chip handler for MODIFY DATA POINTER MESSAGE
 *
 *  We also call this function on IGNORE WIDE RESIDUE
 *  messages that do not match a SWIDE full condition.
 *  Btw, we assume in that situation that such a message
 *  is equivalent to a MODIFY DATA POINTER (offset=-1).
 */
static void sym_modify_dp(hcb_p np, ccb_p cp, int ofs)
{
        int dp_ofs      = ofs;
        u32     dp_scr  = INL (nc_temp);
        u32     dp_ret;
        u32     tmp;
        u_char  hflags;
        int     dp_sg;
        struct  sym_pmc *pm;

        /*
         *  Not supported for auto-sense.
         */
        if (cp->host_flags & HF_SENSE)
                goto out_reject;

        /*
         *  Apply our alchemy:) (see comments in sym_evaluate_dp()),
         *  to the resulted data pointer.
         */
        dp_sg = sym_evaluate_dp(np, cp, dp_scr, &dp_ofs);
        if (dp_sg < 0)
                goto out_reject;

        /*
         *  And our alchemy:) allows to easily calculate the data
         *  script address we want to return for the next data phase.
         */
        dp_ret = cpu_to_scr(cp->phys.head.goalp);
        dp_ret = dp_ret - 8 - (SYM_CONF_MAX_SG - dp_sg) * (2*4);

        /*
         *  If offset / scatter entry is zero we donnot need
         *  a context for the new current data pointer.
         */
        if (dp_ofs == 0) {
                dp_scr = dp_ret;
                goto out_ok;
        }

        /*
         *  Get a context for the new current data pointer.
         */
        hflags = INB (HF_PRT);

        if (hflags & HF_DP_SAVED)
                hflags ^= HF_ACT_PM;

        if (!(hflags & HF_ACT_PM)) {
                pm  = &cp->phys.pm0;
                dp_scr = SCRIPTA_BA (np, pm0_data);
        }
        else {
                pm = &cp->phys.pm1;
                dp_scr = SCRIPTA_BA (np, pm1_data);
        }

        hflags &= ~(HF_DP_SAVED);

        OUTB (HF_PRT, hflags);

        /*
         *  Set up the new current data pointer.
         *  ofs < 0 there, and for the next data phase, we
         *  want to transfer part of the data of the sg entry
         *  corresponding to index dp_sg-1 prior to returning
         *  to the main data script.
         */
        pm->ret = cpu_to_scr(dp_ret);
        tmp  = scr_to_cpu(cp->phys.data[dp_sg-1].addr);
        tmp += scr_to_cpu(cp->phys.data[dp_sg-1].size) + dp_ofs;
        pm->sg.addr = cpu_to_scr(tmp);
        pm->sg.size = cpu_to_scr(-dp_ofs);

out_ok:
        OUTL (nc_temp, dp_scr);
        OUTL_DSP (SCRIPTA_BA (np, clrack));
        return;

out_reject:
        OUTL_DSP (SCRIPTB_BA (np, msg_bad));
}

/*
 *  chip calculation of the data residual.
 *
 *  As I used to say, the requirement of data residual
 *  in SCSI is broken, useless and cannot be achieved
 *  without huge complexity.
 *  But most OSes and even the official CAM require it.
 *  When stupidity happens to be so widely spread inside
 *  a community, it gets hard to convince.
 *
 *  Anyway, I don't care, since I am not going to use
 *  any software that considers this data residual as
 *  a relevant information. :)
 */
static int sym_compute_residual(hcb_p np, ccb_p cp)
{
        int dp_sg, dp_sgmin, resid = 0;
        int dp_ofs = 0;

        /*
         *  Check for some data lost or just thrown away.
         *  We are not required to be quite accurate in this
         *  situation. Btw, if we are odd for output and the
         *  device claims some more data, it may well happen
         *  than our residual be zero. :-)
         */
        if (cp->xerr_status & (XE_EXTRA_DATA|XE_SODL_UNRUN|XE_SWIDE_OVRUN)) {
                if (cp->xerr_status & XE_EXTRA_DATA)
                        resid -= cp->extra_bytes;
                if (cp->xerr_status & XE_SODL_UNRUN)
                        ++resid;
                if (cp->xerr_status & XE_SWIDE_OVRUN)
                        --resid;
        }

        /*
         *  If all data has been transferred,
         *  there is no residual.
         */
        if (cp->phys.head.lastp == cp->phys.head.goalp)
                return resid;

        /*
         *  If no data transfer occurs, or if the data
         *  pointer is weird, return full residual.
         */
        if (cp->startp == cp->phys.head.lastp ||
            sym_evaluate_dp(np, cp, scr_to_cpu(cp->phys.head.lastp),
                            &dp_ofs) < 0) {
                return cp->data_len;
        }

        /*
         *  If we were auto-sensing, then we are done.
         */
        if (cp->host_flags & HF_SENSE) {
                return -dp_ofs;
        }

        /*
         *  We are now full comfortable in the computation
         *  of the data residual (2's complement).
         */
        dp_sgmin = SYM_CONF_MAX_SG - cp->segments;
        resid = -cp->ext_ofs;
        for (dp_sg = cp->ext_sg; dp_sg < SYM_CONF_MAX_SG; ++dp_sg) {
                u_int tmp = scr_to_cpu(cp->phys.data[dp_sg].size);
                resid += (tmp & 0xffffff);
        }

        /*
         *  Hopefully, the result is not too wrong.
         */
        return resid;
}

/*
 *  Print out the content of a SCSI message.
 */
static int sym_show_msg (u_char * msg)
{
        u_char i;
        printf ("%x",*msg);
        if (*msg==M_EXTENDED) {
                for (i=1;i<8;i++) {
                        if (i-1>msg[1]) break;
                        printf ("-%x",msg[i]);
                }
                return (i+1);
        } else if ((*msg & 0xf0) == 0x20) {
                printf ("-%x",msg[1]);
                return (2);
        }
        return (1);
}

static void sym_print_msg (ccb_p cp, char *label, u_char *msg)
{
        PRINT_ADDR(cp);
        if (label)
                printf ("%s: ", label);

        (void) sym_show_msg (msg);
        printf (".\n");
}

/*
 *  Negotiation for WIDE and SYNCHRONOUS DATA TRANSFER.
 *
 *  When we try to negotiate, we append the negotiation message
 *  to the identify and (maybe) simple tag message.
 *  The host status field is set to HS_NEGOTIATE to mark this
 *  situation.
 *
 *  If the target doesn't answer this message immediately
 *  (as required by the standard), the SIR_NEGO_FAILED interrupt
 *  will be raised eventually.
 *  The handler removes the HS_NEGOTIATE status, and sets the
 *  negotiated value to the default (async / nowide).
 *
 *  If we receive a matching answer immediately, we check it
 *  for validity, and set the values.
 *
 *  If we receive a Reject message immediately, we assume the
 *  negotiation has failed, and fall back to standard values.
 *
 *  If we receive a negotiation message while not in HS_NEGOTIATE
 *  state, it's a target initiated negotiation. We prepare a
 *  (hopefully) valid answer, set our parameters, and send back
 *  this answer to the target.
 *
 *  If the target doesn't fetch the answer (no message out phase),
 *  we assume the negotiation has failed, and fall back to default
 *  settings (SIR_NEGO_PROTO interrupt).
 *
 *  When we set the values, we adjust them in all ccbs belonging
 *  to this target, in the controller's register, and in the "phys"
 *  field of the controller's struct sym_hcb.
 */

/*
 *  chip handler for SYNCHRONOUS DATA TRANSFER REQUEST (SDTR) message.
 */
static void sym_sync_nego(hcb_p np, tcb_p tp, ccb_p cp)
{
        u_char  chg, ofs, per, fak, div;
        int     req = 1;

        /*
         *  Synchronous request message received.
         */
        if (DEBUG_FLAGS & DEBUG_NEGO) {
                sym_print_msg(cp, "sync msgin", np->msgin);
        }

        /*
         * request or answer ?
         */
        if (INB (HS_PRT) == HS_NEGOTIATE) {
                OUTB (HS_PRT, HS_BUSY);
                if (cp->nego_status && cp->nego_status != NS_SYNC)
                        goto reject_it;
                req = 0;
        }

        /*
         *  get requested values.
         */
        chg = 0;
        per = np->msgin[3];
        ofs = np->msgin[4];

        /*
         *  check values against our limits.
         */
        if (ofs) {
                if (ofs > np->maxoffs)
                        {chg = 1; ofs = np->maxoffs;}
                if (req) {
                        if (ofs > tp->tinfo.user.offset)
                                {chg = 1; ofs = tp->tinfo.user.offset;}
                }
        }

        if (ofs) {
                if (per < np->minsync)
                        {chg = 1; per = np->minsync;}
                if (req) {
                        if (per < tp->tinfo.user.period)
                                {chg = 1; per = tp->tinfo.user.period;}
                }
        }

        div = fak = 0;
        if (ofs && sym_getsync(np, 0, per, &div, &fak) < 0)
                goto reject_it;

        if (DEBUG_FLAGS & DEBUG_NEGO) {
                PRINT_ADDR(cp);
                printf ("sdtr: ofs=%d per=%d div=%d fak=%d chg=%d.\n",
                        ofs, per, div, fak, chg);
        }

        /*
         *  This was an answer message
         */
        if (req == 0) {
                if (chg)        /* Answer wasn't acceptable. */
                        goto reject_it;
                sym_setsync (np, cp, ofs, per, div, fak);
                OUTL_DSP (SCRIPTA_BA (np, clrack));
                return;
        }

        /*
         *  It was a request. Set value and
         *  prepare an answer message
         */
        sym_setsync (np, cp, ofs, per, div, fak);

        np->msgout[0] = M_EXTENDED;
        np->msgout[1] = 3;
        np->msgout[2] = M_X_SYNC_REQ;
        np->msgout[3] = per;
        np->msgout[4] = ofs;

        cp->nego_status = NS_SYNC;

        if (DEBUG_FLAGS & DEBUG_NEGO) {
                sym_print_msg(cp, "sync msgout", np->msgout);
        }

        np->msgin [0] = M_NOOP;

        OUTL_DSP (SCRIPTB_BA (np, sdtr_resp));
        return;
reject_it:
        sym_setsync (np, cp, 0, 0, 0, 0);
        OUTL_DSP (SCRIPTB_BA (np, msg_bad));
}

/*
 *  chip handler for PARALLEL PROTOCOL REQUEST (PPR) message.
 */
static void sym_ppr_nego(hcb_p np, tcb_p tp, ccb_p cp)
{
        u_char  chg, ofs, per, fak, dt, div, wide;
        int     req = 1;

        /*
         * Synchronous request message received.
         */
        if (DEBUG_FLAGS & DEBUG_NEGO) {
                sym_print_msg(cp, "ppr msgin", np->msgin);
        }

        /*
         *  get requested values.
         */
        chg  = 0;
        per  = np->msgin[3];
        ofs  = np->msgin[5];
        wide = np->msgin[6];
        dt   = np->msgin[7] & PPR_OPT_DT;

        /*
         * request or answer ?
         */
        if (INB (HS_PRT) == HS_NEGOTIATE) {
                OUTB (HS_PRT, HS_BUSY);
                if (cp->nego_status && cp->nego_status != NS_PPR)
                        goto reject_it;
                req = 0;
        }

        /*
         *  check values against our limits.
         */
        if (wide > np->maxwide)
                {chg = 1; wide = np->maxwide;}
        if (!wide || !(np->features & FE_ULTRA3))
                dt &= ~PPR_OPT_DT;
        if (req) {
                if (wide > tp->tinfo.user.width)
                        {chg = 1; wide = tp->tinfo.user.width;}
        }

        if (!(np->features & FE_U3EN))  /* Broken U3EN bit not supported */
                dt &= ~PPR_OPT_DT;

        if (dt != (np->msgin[7] & PPR_OPT_MASK)) chg = 1;

        if (ofs) {
                if (dt) {
                        if (ofs > np->maxoffs_dt)
                                {chg = 1; ofs = np->maxoffs_dt;}
                }
                else if (ofs > np->maxoffs)
                        {chg = 1; ofs = np->maxoffs;}
                if (req) {
                        if (ofs > tp->tinfo.user.offset)
                                {chg = 1; ofs = tp->tinfo.user.offset;}
                }
        }

        if (ofs) {
                if (dt) {
                        if (per < np->minsync_dt)
                                {chg = 1; per = np->minsync_dt;}
                }
                else if (per < np->minsync)
                        {chg = 1; per = np->minsync;}
                if (req) {
                        if (per < tp->tinfo.user.period)
                                {chg = 1; per = tp->tinfo.user.period;}
                }
        }

        div = fak = 0;
        if (ofs && sym_getsync(np, dt, per, &div, &fak) < 0)
                goto reject_it;

        if (DEBUG_FLAGS & DEBUG_NEGO) {
                PRINT_ADDR(cp);
                printf ("ppr: "
                        "dt=%x ofs=%d per=%d wide=%d div=%d fak=%d chg=%d.\n",
                        dt, ofs, per, wide, div, fak, chg);
        }

        /*
         *  It was an answer.
         */
        if (req == 0) {
                if (chg)        /* Answer wasn't acceptable */
                        goto reject_it;
                sym_setpprot (np, cp, dt, ofs, per, wide, div, fak);
                OUTL_DSP (SCRIPTA_BA (np, clrack));
                return;
        }

        /*
         *  It was a request. Set value and
         *  prepare an answer message
         */
        sym_setpprot (np, cp, dt, ofs, per, wide, div, fak);

        np->msgout[0] = M_EXTENDED;
        np->msgout[1] = 6;
        np->msgout[2] = M_X_PPR_REQ;
        np->msgout[3] = per;
        np->msgout[4] = 0;
        np->msgout[5] = ofs;
        np->msgout[6] = wide;
        np->msgout[7] = dt;

        cp->nego_status = NS_PPR;

        if (DEBUG_FLAGS & DEBUG_NEGO) {
                sym_print_msg(cp, "ppr msgout", np->msgout);
        }

        np->msgin [0] = M_NOOP;

        OUTL_DSP (SCRIPTB_BA (np, ppr_resp));
        return;
reject_it:
        sym_setpprot (np, cp, 0, 0, 0, 0, 0, 0);
        OUTL_DSP (SCRIPTB_BA (np, msg_bad));
        /*
         *  If it was a device response that should result in
         *  ST, we may want to try a legacy negotiation later.
         */
        if (!req && !dt) {
                tp->tinfo.goal.options = 0;
                tp->tinfo.goal.width   = wide;
                tp->tinfo.goal.period  = per;
                tp->tinfo.goal.offset  = ofs;
        }
}

/*
 *  chip handler for WIDE DATA TRANSFER REQUEST (WDTR) message.
 */
static void sym_wide_nego(hcb_p np, tcb_p tp, ccb_p cp)
{
        u_char  chg, wide;
        int     req = 1;

        /*
         *  Wide request message received.
         */
        if (DEBUG_FLAGS & DEBUG_NEGO) {
                sym_print_msg(cp, "wide msgin", np->msgin);
        }

        /*
         * Is it a request from the device?
         */
        if (INB (HS_PRT) == HS_NEGOTIATE) {
                OUTB (HS_PRT, HS_BUSY);
                if (cp->nego_status && cp->nego_status != NS_WIDE)
                        goto reject_it;
                req = 0;
        }

        /*
         *  get requested values.
         */
        chg  = 0;
        wide = np->msgin[3];

        /*
         *  check values against driver limits.
         */
        if (wide > np->maxwide)
                {chg = 1; wide = np->maxwide;}
        if (req) {
                if (wide > tp->tinfo.user.width)
                        {chg = 1; wide = tp->tinfo.user.width;}
        }

        if (DEBUG_FLAGS & DEBUG_NEGO) {
                PRINT_ADDR(cp);
                printf ("wdtr: wide=%d chg=%d.\n", wide, chg);
        }

        /*
         * This was an answer message
         */
        if (req == 0) {
                if (chg)        /*  Answer wasn't acceptable. */
                        goto reject_it;
                sym_setwide (np, cp, wide);

                /*
                 * Negotiate for SYNC immediately after WIDE response.
                 * This allows to negotiate for both WIDE and SYNC on
                 * a single SCSI command (Suggested by Justin Gibbs).
                 */
                if (tp->tinfo.goal.offset) {
                        np->msgout[0] = M_EXTENDED;
                        np->msgout[1] = 3;
                        np->msgout[2] = M_X_SYNC_REQ;
                        np->msgout[3] = tp->tinfo.goal.period;
                        np->msgout[4] = tp->tinfo.goal.offset;

                        if (DEBUG_FLAGS & DEBUG_NEGO) {
                                sym_print_msg(cp, "sync msgout", np->msgout);
                        }

                        cp->nego_status = NS_SYNC;
                        OUTB (HS_PRT, HS_NEGOTIATE);
                        OUTL_DSP (SCRIPTB_BA (np, sdtr_resp));
                        return;
                }

                OUTL_DSP (SCRIPTA_BA (np, clrack));
                return;
        }

        /*
         *  It was a request, set value and
         *  prepare an answer message
         */
        sym_setwide (np, cp, wide);

        np->msgout[0] = M_EXTENDED;
        np->msgout[1] = 2;
        np->msgout[2] = M_X_WIDE_REQ;
        np->msgout[3] = wide;

        np->msgin [0] = M_NOOP;

        cp->nego_status = NS_WIDE;

        if (DEBUG_FLAGS & DEBUG_NEGO) {
                sym_print_msg(cp, "wide msgout", np->msgout);
        }

        OUTL_DSP (SCRIPTB_BA (np, wdtr_resp));
        return;
reject_it:
        OUTL_DSP (SCRIPTB_BA (np, msg_bad));
}

/*
 *  Reset SYNC or WIDE to default settings.
 *
 *  Called when a negotiation does not succeed either
 *  on rejection or on protocol error.
 *
 *  If it was a PPR that made problems, we may want to
 *  try a legacy negotiation later.
 */
static void sym_nego_default(hcb_p np, tcb_p tp, ccb_p cp)
{
        /*
         *  any error in negotiation:
         *  fall back to default mode.
         */
        switch (cp->nego_status) {
        case NS_PPR:
#if 0
                sym_setpprot (np, cp, 0, 0, 0, 0, 0, 0);
#else
                tp->tinfo.goal.options = 0;
                if (tp->tinfo.goal.period < np->minsync)
                        tp->tinfo.goal.period = np->minsync;
                if (tp->tinfo.goal.offset > np->maxoffs)
                        tp->tinfo.goal.offset = np->maxoffs;
#endif
                break;
        case NS_SYNC:
                sym_setsync (np, cp, 0, 0, 0, 0);
                break;
        case NS_WIDE:
                sym_setwide (np, cp, 0);
                break;
        }
        np->msgin [0] = M_NOOP;
        np->msgout[0] = M_NOOP;
        cp->nego_status = 0;
}

/*
 *  chip handler for MESSAGE REJECT received in response to
 *  a WIDE or SYNCHRONOUS negotiation.
 */
static void sym_nego_rejected(hcb_p np, tcb_p tp, ccb_p cp)
{
        sym_nego_default(np, tp, cp);
        OUTB (HS_PRT, HS_BUSY);
}

/*
 *  chip exception handler for programmed interrupts.
 */
static void sym_int_sir (hcb_p np)
{
        u_char  num     = INB (nc_dsps);
        u32     dsa     = INL (nc_dsa);
        ccb_p   cp      = sym_ccb_from_dsa(np, dsa);
        u_char  target  = INB (nc_sdid) & 0x0f;
        tcb_p   tp      = &np->target[target];
        int     tmp;

        SYM_LOCK_ASSERT(MA_OWNED);

        if (DEBUG_FLAGS & DEBUG_TINY) printf ("I#%d", num);

        switch (num) {
        /*
         *  Command has been completed with error condition
         *  or has been auto-sensed.
         */
        case SIR_COMPLETE_ERROR:
                sym_complete_error(np, cp);
                return;
        /*
         *  The C code is currently trying to recover from something.
         *  Typically, user want to abort some command.
         */
        case SIR_SCRIPT_STOPPED:
        case SIR_TARGET_SELECTED:
        case SIR_ABORT_SENT:
                sym_sir_task_recovery(np, num);
                return;
        /*
         *  The device didn't go to MSG OUT phase after having
         *  been selected with ATN. We donnot want to handle
         *  that.
         */
        case SIR_SEL_ATN_NO_MSG_OUT:
                printf ("%s:%d: No MSG OUT phase after selection with ATN.\n",
                        sym_name (np), target);
                goto out_stuck;
        /*
         *  The device didn't switch to MSG IN phase after
         *  having reseleted the initiator.
         */
        case SIR_RESEL_NO_MSG_IN:
                printf ("%s:%d: No MSG IN phase after reselection.\n",
                        sym_name (np), target);
                goto out_stuck;
        /*
         *  After reselection, the device sent a message that wasn't
         *  an IDENTIFY.
         */
        case SIR_RESEL_NO_IDENTIFY:
                printf ("%s:%d: No IDENTIFY after reselection.\n",
                        sym_name (np), target);
                goto out_stuck;
        /*
         *  The device reselected a LUN we donnot know about.
         */
        case SIR_RESEL_BAD_LUN:
                np->msgout[0] = M_RESET;
                goto out;
        /*
         *  The device reselected for an untagged nexus and we
         *  haven't any.
         */
        case SIR_RESEL_BAD_I_T_L:
                np->msgout[0] = M_ABORT;
                goto out;
        /*
         *  The device reselected for a tagged nexus that we donnot
         *  have.
         */
        case SIR_RESEL_BAD_I_T_L_Q:
                np->msgout[0] = M_ABORT_TAG;
                goto out;
        /*
         *  The SCRIPTS let us know that the device has grabbed
         *  our message and will abort the job.
         */
        case SIR_RESEL_ABORTED:
                np->lastmsg = np->msgout[0];
                np->msgout[0] = M_NOOP;
                printf ("%s:%d: message %x sent on bad reselection.\n",
                        sym_name (np), target, np->lastmsg);
                goto out;
        /*
         *  The SCRIPTS let us know that a message has been
         *  successfully sent to the device.
         */
        case SIR_MSG_OUT_DONE:
                np->lastmsg = np->msgout[0];
                np->msgout[0] = M_NOOP;
                /* Should we really care of that */
                if (np->lastmsg == M_PARITY || np->lastmsg == M_ID_ERROR) {
                        if (cp) {
                                cp->xerr_status &= ~XE_PARITY_ERR;
                                if (!cp->xerr_status)
                                        OUTOFFB (HF_PRT, HF_EXT_ERR);
                        }
                }
                goto out;
        /*
         *  The device didn't send a GOOD SCSI status.
         *  We may have some work to do prior to allow
         *  the SCRIPTS processor to continue.
         */
        case SIR_BAD_SCSI_STATUS:
                if (!cp)
                        goto out;
                sym_sir_bad_scsi_status(np, cp);
                return;
        /*
         *  We are asked by the SCRIPTS to prepare a
         *  REJECT message.
         */
        case SIR_REJECT_TO_SEND:
                sym_print_msg(cp, "M_REJECT to send for ", np->msgin);
                np->msgout[0] = M_REJECT;
                goto out;
        /*
         *  We have been ODD at the end of a DATA IN
         *  transfer and the device didn't send a
         *  IGNORE WIDE RESIDUE message.
         *  It is a data overrun condition.
         */
        case SIR_SWIDE_OVERRUN:
                if (cp) {
                        OUTONB (HF_PRT, HF_EXT_ERR);
                        cp->xerr_status |= XE_SWIDE_OVRUN;
                }
                goto out;
        /*
         *  We have been ODD at the end of a DATA OUT
         *  transfer.
         *  It is a data underrun condition.
         */
        case SIR_SODL_UNDERRUN:
                if (cp) {
                        OUTONB (HF_PRT, HF_EXT_ERR);
                        cp->xerr_status |= XE_SODL_UNRUN;
                }
                goto out;
        /*
         *  The device wants us to transfer more data than
         *  expected or in the wrong direction.
         *  The number of extra bytes is in scratcha.
         *  It is a data overrun condition.
         */
        case SIR_DATA_OVERRUN:
                if (cp) {
                        OUTONB (HF_PRT, HF_EXT_ERR);
                        cp->xerr_status |= XE_EXTRA_DATA;
                        cp->extra_bytes += INL (nc_scratcha);
                }
                goto out;
        /*
         *  The device switched to an illegal phase (4/5).
         */
        case SIR_BAD_PHASE:
                if (cp) {
                        OUTONB (HF_PRT, HF_EXT_ERR);
                        cp->xerr_status |= XE_BAD_PHASE;
                }
                goto out;
        /*
         *  We received a message.
         */
        case SIR_MSG_RECEIVED:
                if (!cp)
                        goto out_stuck;
                switch (np->msgin [0]) {
                /*
                 *  We received an extended message.
                 *  We handle MODIFY DATA POINTER, SDTR, WDTR
                 *  and reject all other extended messages.
                 */
                case M_EXTENDED:
                        switch (np->msgin [2]) {
                        case M_X_MODIFY_DP:
                                if (DEBUG_FLAGS & DEBUG_POINTER)
                                        sym_print_msg(cp,"modify DP",np->msgin);
                                tmp = (np->msgin[3]<<24) + (np->msgin[4]<<16) +
                                      (np->msgin[5]<<8)  + (np->msgin[6]);
                                sym_modify_dp(np, cp, tmp);
                                return;
                        case M_X_SYNC_REQ:
                                sym_sync_nego(np, tp, cp);
                                return;
                        case M_X_PPR_REQ:
                                sym_ppr_nego(np, tp, cp);
                                return;
                        case M_X_WIDE_REQ:
                                sym_wide_nego(np, tp, cp);
                                return;
                        default:
                                goto out_reject;
                        }
                        break;
                /*
                 *  We received a 1/2 byte message not handled from SCRIPTS.
                 *  We are only expecting MESSAGE REJECT and IGNORE WIDE
                 *  RESIDUE messages that haven't been anticipated by
                 *  SCRIPTS on SWIDE full condition. Unanticipated IGNORE
                 *  WIDE RESIDUE messages are aliased as MODIFY DP (-1).
                 */
                case M_IGN_RESIDUE:
                        if (DEBUG_FLAGS & DEBUG_POINTER)
                                sym_print_msg(cp,"ign wide residue", np->msgin);
                        sym_modify_dp(np, cp, -1);
                        return;
                case M_REJECT:
                        if (INB (HS_PRT) == HS_NEGOTIATE)
                                sym_nego_rejected(np, tp, cp);
                        else {
                                PRINT_ADDR(cp);
                                printf ("M_REJECT received (%x:%x).\n",
                                        scr_to_cpu(np->lastmsg), np->msgout[0]);
                        }
                        goto out_clrack;
                        break;
                default:
                        goto out_reject;
                }
                break;
        /*
         *  We received an unknown message.
         *  Ignore all MSG IN phases and reject it.
         */
        case SIR_MSG_WEIRD:
                sym_print_msg(cp, "WEIRD message received", np->msgin);
                OUTL_DSP (SCRIPTB_BA (np, msg_weird));
                return;
        /*
         *  Negotiation failed.
         *  Target does not send us the reply.
         *  Remove the HS_NEGOTIATE status.
         */
        case SIR_NEGO_FAILED:
                OUTB (HS_PRT, HS_BUSY);
        /*
         *  Negotiation failed.
         *  Target does not want answer message.
         */
        case SIR_NEGO_PROTO:
                sym_nego_default(np, tp, cp);
                goto out;
        }

out:
        OUTONB_STD ();
        return;
out_reject:
        OUTL_DSP (SCRIPTB_BA (np, msg_bad));
        return;
out_clrack:
        OUTL_DSP (SCRIPTA_BA (np, clrack));
        return;
out_stuck:
        return;
}

/*
 *  Acquire a control block
 */
static  ccb_p sym_get_ccb (hcb_p np, u_char tn, u_char ln, u_char tag_order)
{
        tcb_p tp = &np->target[tn];
        lcb_p lp = sym_lp(tp, ln);
        u_short tag = NO_TAG;
        SYM_QUEHEAD *qp;
        ccb_p cp = (ccb_p) NULL;

        /*
         *  Look for a free CCB
         */
        if (sym_que_empty(&np->free_ccbq))
                goto out;
        qp = sym_remque_head(&np->free_ccbq);
        if (!qp)
                goto out;
        cp = sym_que_entry(qp, struct sym_ccb, link_ccbq);

        /*
         *  If the LCB is not yet available and the LUN
         *  has been probed ok, try to allocate the LCB.
         */
        if (!lp && sym_is_bit(tp->lun_map, ln)) {
                lp = sym_alloc_lcb(np, tn, ln);
                if (!lp)
                        goto out_free;
        }

        /*
         *  If the LCB is not available here, then the
         *  logical unit is not yet discovered. For those
         *  ones only accept 1 SCSI IO per logical unit,
         *  since we cannot allow disconnections.
         */
        if (!lp) {
                if (!sym_is_bit(tp->busy0_map, ln))
                        sym_set_bit(tp->busy0_map, ln);
                else
                        goto out_free;
        } else {
                /*
                 *  If we have been asked for a tagged command.
                 */
                if (tag_order) {
                        /*
                         *  Debugging purpose.
                         */
                        assert(lp->busy_itl == 0);
                        /*
                         *  Allocate resources for tags if not yet.
                         */
                        if (!lp->cb_tags) {
                                sym_alloc_lcb_tags(np, tn, ln);
                                if (!lp->cb_tags)
                                        goto out_free;
                        }
                        /*
                         *  Get a tag for this SCSI IO and set up
                         *  the CCB bus address for reselection,
                         *  and count it for this LUN.
                         *  Toggle reselect path to tagged.
                         */
                        if (lp->busy_itlq < SYM_CONF_MAX_TASK) {
                                tag = lp->cb_tags[lp->ia_tag];
                                if (++lp->ia_tag == SYM_CONF_MAX_TASK)
                                        lp->ia_tag = 0;
                                lp->itlq_tbl[tag] = cpu_to_scr(cp->ccb_ba);
                                ++lp->busy_itlq;
                                lp->head.resel_sa =
                                        cpu_to_scr(SCRIPTA_BA (np, resel_tag));
                        }
                        else
                                goto out_free;
                }
                /*
                 *  This command will not be tagged.
                 *  If we already have either a tagged or untagged
                 *  one, refuse to overlap this untagged one.
                 */
                else {
                        /*
                         *  Debugging purpose.
                         */
                        assert(lp->busy_itl == 0 && lp->busy_itlq == 0);
                        /*
                         *  Count this nexus for this LUN.
                         *  Set up the CCB bus address for reselection.
                         *  Toggle reselect path to untagged.
                         */
                        if (++lp->busy_itl == 1) {
                                lp->head.itl_task_sa = cpu_to_scr(cp->ccb_ba);
                                lp->head.resel_sa =
                                      cpu_to_scr(SCRIPTA_BA (np, resel_no_tag));
                        }
                        else
                                goto out_free;
                }
        }
        /*
         *  Put the CCB into the busy queue.
         */
        sym_insque_tail(&cp->link_ccbq, &np->busy_ccbq);

        /*
         *  Remember all informations needed to free this CCB.
         */
        cp->to_abort = 0;
        cp->tag    = tag;
        cp->target = tn;
        cp->lun    = ln;

        if (DEBUG_FLAGS & DEBUG_TAGS) {
                PRINT_LUN(np, tn, ln);
                printf ("ccb @%p using tag %d.\n", cp, tag);
        }

out:
        return cp;
out_free:
        sym_insque_head(&cp->link_ccbq, &np->free_ccbq);
        return NULL;
}

/*
 *  Release one control block
 */
static void sym_free_ccb(hcb_p np, ccb_p cp)
{
        tcb_p tp = &np->target[cp->target];
        lcb_p lp = sym_lp(tp, cp->lun);

        if (DEBUG_FLAGS & DEBUG_TAGS) {
                PRINT_LUN(np, cp->target, cp->lun);
                printf ("ccb @%p freeing tag %d.\n", cp, cp->tag);
        }

        /*
         *  If LCB available,
         */
        if (lp) {
                /*
                 *  If tagged, release the tag, set the relect path
                 */
                if (cp->tag != NO_TAG) {
                        /*
                         *  Free the tag value.
                         */
                        lp->cb_tags[lp->if_tag] = cp->tag;
                        if (++lp->if_tag == SYM_CONF_MAX_TASK)
                                lp->if_tag = 0;
                        /*
                         *  Make the reselect path invalid,
                         *  and uncount this CCB.
                         */
                        lp->itlq_tbl[cp->tag] = cpu_to_scr(np->bad_itlq_ba);
                        --lp->busy_itlq;
                } else {        /* Untagged */
                        /*
                         *  Make the reselect path invalid,
                         *  and uncount this CCB.
                         */
                        lp->head.itl_task_sa = cpu_to_scr(np->bad_itl_ba);
                        --lp->busy_itl;
                }
                /*
                 *  If no JOB active, make the LUN reselect path invalid.
                 */
                if (lp->busy_itlq == 0 && lp->busy_itl == 0)
                        lp->head.resel_sa =
                                cpu_to_scr(SCRIPTB_BA (np, resel_bad_lun));
        }
        /*
         *  Otherwise, we only accept 1 IO per LUN.
         *  Clear the bit that keeps track of this IO.
         */
        else
                sym_clr_bit(tp->busy0_map, cp->lun);

        /*
         *  We donnot queue more than 1 ccb per target
         *  with negotiation at any time. If this ccb was
         *  used for negotiation, clear this info in the tcb.
         */
        if (cp == tp->nego_cp)
                tp->nego_cp = NULL;

#ifdef SYM_CONF_IARB_SUPPORT
        /*
         *  If we just complete the last queued CCB,
         *  clear this info that is no longer relevant.
         */
        if (cp == np->last_cp)
                np->last_cp = NULL;
#endif

        /*
         *  Unmap user data from DMA map if needed.
         */
        if (cp->dmamapped) {
                bus_dmamap_unload(np->data_dmat, cp->dmamap);
                cp->dmamapped = 0;
        }

        /*
         *  Make this CCB available.
         */
        cp->cam_ccb = NULL;
        cp->host_status = HS_IDLE;
        sym_remque(&cp->link_ccbq);
        sym_insque_head(&cp->link_ccbq, &np->free_ccbq);
}

/*
 *  Allocate a CCB from memory and initialize its fixed part.
 */
static ccb_p sym_alloc_ccb(hcb_p np)
{
        ccb_p cp = NULL;
        int hcode;

        SYM_LOCK_ASSERT(MA_NOTOWNED);

        /*
         *  Prevent from allocating more CCBs than we can
         *  queue to the controller.
         */
        if (np->actccbs >= SYM_CONF_MAX_START)
                return NULL;

        /*
         *  Allocate memory for this CCB.
         */
        cp = sym_calloc_dma(sizeof(struct sym_ccb), "CCB");
        if (!cp)
                return NULL;

        /*
         *  Allocate a bounce buffer for sense data.
         */
        cp->sns_bbuf = sym_calloc_dma(SYM_SNS_BBUF_LEN, "SNS_BBUF");
        if (!cp->sns_bbuf)
                goto out_free;

        /*
         *  Allocate a map for the DMA of user data.
         */
        if (bus_dmamap_create(np->data_dmat, 0, &cp->dmamap))
                goto out_free;
        /*
         *  Count it.
         */
        np->actccbs++;

        /*
         * Initialize the callout.
         */
        callout_init(&cp->ch, 1);

        /*
         *  Compute the bus address of this ccb.
         */
        cp->ccb_ba = vtobus(cp);

        /*
         *  Insert this ccb into the hashed list.
         */
        hcode = CCB_HASH_CODE(cp->ccb_ba);
        cp->link_ccbh = np->ccbh[hcode];
        np->ccbh[hcode] = cp;

        /*
         *  Initialize the start and restart actions.
         */
        cp->phys.head.go.start   = cpu_to_scr(SCRIPTA_BA (np, idle));
        cp->phys.head.go.restart = cpu_to_scr(SCRIPTB_BA (np, bad_i_t_l));

        /*
         *  Initilialyze some other fields.
         */
        cp->phys.smsg_ext.addr = cpu_to_scr(HCB_BA(np, msgin[2]));

        /*
         *  Chain into free ccb queue.
         */
        sym_insque_head(&cp->link_ccbq, &np->free_ccbq);

        return cp;
out_free:
        if (cp->sns_bbuf)
                sym_mfree_dma(cp->sns_bbuf, SYM_SNS_BBUF_LEN, "SNS_BBUF");
        sym_mfree_dma(cp, sizeof(*cp), "CCB");
        return NULL;
}

/*
 *  Look up a CCB from a DSA value.
 */
static ccb_p sym_ccb_from_dsa(hcb_p np, u32 dsa)
{
        int hcode;
        ccb_p cp;

        hcode = CCB_HASH_CODE(dsa);
        cp = np->ccbh[hcode];
        while (cp) {
                if (cp->ccb_ba == dsa)
                        break;
                cp = cp->link_ccbh;
        }

        return cp;
}

/*
 *  Lun control block allocation and initialization.
 */
static lcb_p sym_alloc_lcb (hcb_p np, u_char tn, u_char ln)
{
        tcb_p tp = &np->target[tn];
        lcb_p lp = sym_lp(tp, ln);

        /*
         *  Already done, just return.
         */
        if (lp)
                return lp;
        /*
         *  Check against some race.
         */
        assert(!sym_is_bit(tp->busy0_map, ln));

        /*
         *  Allocate the LCB bus address array.
         *  Compute the bus address of this table.
         */
        if (ln && !tp->luntbl) {
                int i;

                tp->luntbl = sym_calloc_dma(256, "LUNTBL");
                if (!tp->luntbl)
                        goto fail;
                for (i = 0 ; i < 64 ; i++)
                        tp->luntbl[i] = cpu_to_scr(vtobus(&np->badlun_sa));
                tp->head.luntbl_sa = cpu_to_scr(vtobus(tp->luntbl));
        }

        /*
         *  Allocate the table of pointers for LUN(s) > 0, if needed.
         */
        if (ln && !tp->lunmp) {
                tp->lunmp = sym_calloc(SYM_CONF_MAX_LUN * sizeof(lcb_p),
                                   "LUNMP");
                if (!tp->lunmp)
                        goto fail;
        }

        /*
         *  Allocate the lcb.
         *  Make it available to the chip.
         */
        lp = sym_calloc_dma(sizeof(struct sym_lcb), "LCB");
        if (!lp)
                goto fail;
        if (ln) {
                tp->lunmp[ln] = lp;
                tp->luntbl[ln] = cpu_to_scr(vtobus(lp));
        }
        else {
                tp->lun0p = lp;
                tp->head.lun0_sa = cpu_to_scr(vtobus(lp));
        }

        /*
         *  Let the itl task point to error handling.
         */
        lp->head.itl_task_sa = cpu_to_scr(np->bad_itl_ba);

        /*
         *  Set the reselect pattern to our default. :)
         */
        lp->head.resel_sa = cpu_to_scr(SCRIPTB_BA (np, resel_bad_lun));

        /*
         *  Set user capabilities.
         */
        lp->user_flags = tp->usrflags & (SYM_DISC_ENABLED | SYM_TAGS_ENABLED);

fail:
        return lp;
}

/*
 *  Allocate LCB resources for tagged command queuing.
 */
static void sym_alloc_lcb_tags (hcb_p np, u_char tn, u_char ln)
{
        tcb_p tp = &np->target[tn];
        lcb_p lp = sym_lp(tp, ln);
        int i;

        /*
         *  If LCB not available, try to allocate it.
         */
        if (!lp && !(lp = sym_alloc_lcb(np, tn, ln)))
                return;

        /*
         *  Allocate the task table and and the tag allocation
         *  circular buffer. We want both or none.
         */
        lp->itlq_tbl = sym_calloc_dma(SYM_CONF_MAX_TASK*4, "ITLQ_TBL");
        if (!lp->itlq_tbl)
                return;
        lp->cb_tags = sym_calloc(SYM_CONF_MAX_TASK, "CB_TAGS");
        if (!lp->cb_tags) {
                sym_mfree_dma(lp->itlq_tbl, SYM_CONF_MAX_TASK*4, "ITLQ_TBL");
                lp->itlq_tbl = NULL;
                return;
        }

        /*
         *  Initialize the task table with invalid entries.
         */
        for (i = 0 ; i < SYM_CONF_MAX_TASK ; i++)
                lp->itlq_tbl[i] = cpu_to_scr(np->notask_ba);

        /*
         *  Fill up the tag buffer with tag numbers.
         */
        for (i = 0 ; i < SYM_CONF_MAX_TASK ; i++)
                lp->cb_tags[i] = i;

        /*
         *  Make the task table available to SCRIPTS,
         *  And accept tagged commands now.
         */
        lp->head.itlq_tbl_sa = cpu_to_scr(vtobus(lp->itlq_tbl));
}

/*
 *  Test the pci bus snoop logic :-(
 *
 *  Has to be called with interrupts disabled.
 */
#ifndef SYM_CONF_IOMAPPED
static int sym_regtest (hcb_p np)
{
        register volatile u32 data;
        /*
         *  chip registers may NOT be cached.
         *  write 0xffffffff to a read only register area,
         *  and try to read it back.
         */
        data = 0xffffffff;
        OUTL_OFF(offsetof(struct sym_reg, nc_dstat), data);
        data = INL_OFF(offsetof(struct sym_reg, nc_dstat));
#if 1
        if (data == 0xffffffff) {
#else
        if ((data & 0xe2f0fffd) != 0x02000080) {
#endif
                printf ("CACHE TEST FAILED: reg dstat-sstat2 readback %x.\n",
                        (unsigned) data);
                return (0x10);
        }
        return (0);
}
#endif

static int sym_snooptest (hcb_p np)
{
        u32     sym_rd, sym_wr, sym_bk, host_rd, host_wr, pc, dstat;
        int     i, err=0;
#ifndef SYM_CONF_IOMAPPED
        err |= sym_regtest (np);
        if (err) return (err);
#endif
restart_test:
        /*
         *  Enable Master Parity Checking as we intend
         *  to enable it for normal operations.
         */
        OUTB (nc_ctest4, (np->rv_ctest4 & MPEE));
        /*
         *  init
         */
        pc  = SCRIPTB0_BA (np, snooptest);
        host_wr = 1;
        sym_wr  = 2;
        /*
         *  Set memory and register.
         */
        np->cache = cpu_to_scr(host_wr);
        OUTL (nc_temp, sym_wr);
        /*
         *  Start script (exchange values)
         */
        OUTL (nc_dsa, np->hcb_ba);
        OUTL_DSP (pc);
        /*
         *  Wait 'til done (with timeout)
         */
        for (i=0; i<SYM_SNOOP_TIMEOUT; i++)
                if (INB(nc_istat) & (INTF|SIP|DIP))
                        break;
        if (i>=SYM_SNOOP_TIMEOUT) {
                printf ("CACHE TEST FAILED: timeout.\n");
                return (0x20);
        }
        /*
         *  Check for fatal DMA errors.
         */
        dstat = INB (nc_dstat);
#if 1   /* Band aiding for broken hardwares that fail PCI parity */
        if ((dstat & MDPE) && (np->rv_ctest4 & MPEE)) {
                printf ("%s: PCI DATA PARITY ERROR DETECTED - "
                        "DISABLING MASTER DATA PARITY CHECKING.\n",
                        sym_name(np));
                np->rv_ctest4 &= ~MPEE;
                goto restart_test;
        }
#endif
        if (dstat & (MDPE|BF|IID)) {
                printf ("CACHE TEST FAILED: DMA error (dstat=0x%02x).", dstat);
                return (0x80);
        }
        /*
         *  Save termination position.
         */
        pc = INL (nc_dsp);
        /*
         *  Read memory and register.
         */
        host_rd = scr_to_cpu(np->cache);
        sym_rd  = INL (nc_scratcha);
        sym_bk  = INL (nc_temp);

        /*
         *  Check termination position.
         */
        if (pc != SCRIPTB0_BA (np, snoopend)+8) {
                printf ("CACHE TEST FAILED: script execution failed.\n");
                printf ("start=%08lx, pc=%08lx, end=%08lx\n",
                        (u_long) SCRIPTB0_BA (np, snooptest), (u_long) pc,
                        (u_long) SCRIPTB0_BA (np, snoopend) +8);
                return (0x40);
        }
        /*
         *  Show results.
         */
        if (host_wr != sym_rd) {
                printf ("CACHE TEST FAILED: host wrote %d, chip read %d.\n",
                        (int) host_wr, (int) sym_rd);
                err |= 1;
        }
        if (host_rd != sym_wr) {
                printf ("CACHE TEST FAILED: chip wrote %d, host read %d.\n",
                        (int) sym_wr, (int) host_rd);
                err |= 2;
        }
        if (sym_bk != sym_wr) {
                printf ("CACHE TEST FAILED: chip wrote %d, read back %d.\n",
                        (int) sym_wr, (int) sym_bk);
                err |= 4;
        }

        return (err);
}

/*
 *  Determine the chip's clock frequency.
 *
 *  This is essential for the negotiation of the synchronous
 *  transfer rate.
 *
 *  Note: we have to return the correct value.
 *  THERE IS NO SAFE DEFAULT VALUE.
 *
 *  Most NCR/SYMBIOS boards are delivered with a 40 Mhz clock.
 *  53C860 and 53C875 rev. 1 support fast20 transfers but
 *  do not have a clock doubler and so are provided with a
 *  80 MHz clock. All other fast20 boards incorporate a doubler
 *  and so should be delivered with a 40 MHz clock.
 *  The recent fast40 chips (895/896/895A/1010) use a 40 Mhz base
 *  clock and provide a clock quadrupler (160 Mhz).
 */

/*
 *  Select SCSI clock frequency
 */
static void sym_selectclock(hcb_p np, u_char scntl3)
{
        /*
         *  If multiplier not present or not selected, leave here.
         */
        if (np->multiplier <= 1) {
                OUTB(nc_scntl3, scntl3);
                return;
        }

        if (sym_verbose >= 2)
                printf ("%s: enabling clock multiplier\n", sym_name(np));

        OUTB(nc_stest1, DBLEN);    /* Enable clock multiplier             */
        /*
         *  Wait for the LCKFRQ bit to be set if supported by the chip.
         *  Otherwise wait 20 micro-seconds.
         */
        if (np->features & FE_LCKFRQ) {
                int i = 20;
                while (!(INB(nc_stest4) & LCKFRQ) && --i > 0)
                        UDELAY (20);
                if (!i)
                        printf("%s: the chip cannot lock the frequency\n",
                                sym_name(np));
        } else
                UDELAY (20);
        OUTB(nc_stest3, HSC);           /* Halt the scsi clock          */
        OUTB(nc_scntl3, scntl3);
        OUTB(nc_stest1, (DBLEN|DBLSEL));/* Select clock multiplier      */
        OUTB(nc_stest3, 0x00);          /* Restart scsi clock           */
}

/*
 *  calculate SCSI clock frequency (in KHz)
 */
static unsigned getfreq (hcb_p np, int gen)
{
        unsigned int ms = 0;
        unsigned int f;

        /*
         * Measure GEN timer delay in order
         * to calculate SCSI clock frequency
         *
         * This code will never execute too
         * many loop iterations (if DELAY is
         * reasonably correct). It could get
         * too low a delay (too high a freq.)
         * if the CPU is slow executing the
         * loop for some reason (an NMI, for
         * example). For this reason we will
         * if multiple measurements are to be
         * performed trust the higher delay
         * (lower frequency returned).
         */
        OUTW (nc_sien , 0);     /* mask all scsi interrupts */
        (void) INW (nc_sist);   /* clear pending scsi interrupt */
        OUTB (nc_dien , 0);     /* mask all dma interrupts */
        (void) INW (nc_sist);   /* another one, just to be sure :) */
        OUTB (nc_scntl3, 4);    /* set pre-scaler to divide by 3 */
        OUTB (nc_stime1, 0);    /* disable general purpose timer */
        OUTB (nc_stime1, gen);  /* set to nominal delay of 1<<gen * 125us */
        while (!(INW(nc_sist) & GEN) && ms++ < 100000)
                UDELAY (1000);  /* count ms */
        OUTB (nc_stime1, 0);    /* disable general purpose timer */
        /*
         * set prescaler to divide by whatever 0 means
         * 0 ought to choose divide by 2, but appears
         * to set divide by 3.5 mode in my 53c810 ...
         */
        OUTB (nc_scntl3, 0);

        /*
         * adjust for prescaler, and convert into KHz
         */
        f = ms ? ((1 << gen) * 4340) / ms : 0;

        if (sym_verbose >= 2)
                printf ("%s: Delay (GEN=%d): %u msec, %u KHz\n",
                        sym_name(np), gen, ms, f);

        return f;
}

static unsigned sym_getfreq (hcb_p np)
{
        u_int f1, f2;
        int gen = 11;

        (void) getfreq (np, gen);       /* throw away first result */
        f1 = getfreq (np, gen);
        f2 = getfreq (np, gen);
        if (f1 > f2) f1 = f2;           /* trust lower result   */
        return f1;
}

/*
 *  Get/probe chip SCSI clock frequency
 */
static void sym_getclock (hcb_p np, int mult)
{
        unsigned char scntl3 = np->sv_scntl3;
        unsigned char stest1 = np->sv_stest1;
        unsigned f1;

        /*
         *  For the C10 core, assume 40 MHz.
         */
        if (np->features & FE_C10) {
                np->multiplier = mult;
                np->clock_khz = 40000 * mult;
                return;
        }

        np->multiplier = 1;
        f1 = 40000;
        /*
         *  True with 875/895/896/895A with clock multiplier selected
         */
        if (mult > 1 && (stest1 & (DBLEN+DBLSEL)) == DBLEN+DBLSEL) {
                if (sym_verbose >= 2)
                        printf ("%s: clock multiplier found\n", sym_name(np));
                np->multiplier = mult;
        }

        /*
         *  If multiplier not found or scntl3 not 7,5,3,
         *  reset chip and get frequency from general purpose timer.
         *  Otherwise trust scntl3 BIOS setting.
         */
        if (np->multiplier != mult || (scntl3 & 7) < 3 || !(scntl3 & 1)) {
                OUTB (nc_stest1, 0);            /* make sure doubler is OFF */
                f1 = sym_getfreq (np);

                if (sym_verbose)
                        printf ("%s: chip clock is %uKHz\n", sym_name(np), f1);

                if      (f1 <   45000)          f1 =  40000;
                else if (f1 <   55000)          f1 =  50000;
                else                            f1 =  80000;

                if (f1 < 80000 && mult > 1) {
                        if (sym_verbose >= 2)
                                printf ("%s: clock multiplier assumed\n",
                                        sym_name(np));
                        np->multiplier  = mult;
                }
        } else {
                if      ((scntl3 & 7) == 3)     f1 =  40000;
                else if ((scntl3 & 7) == 5)     f1 =  80000;
                else                            f1 = 160000;

                f1 /= np->multiplier;
        }

        /*
         *  Compute controller synchronous parameters.
         */
        f1              *= np->multiplier;
        np->clock_khz   = f1;
}

/*
 *  Get/probe PCI clock frequency
 */
static int sym_getpciclock (hcb_p np)
{
        int f = 0;

        /*
         *  For the C1010-33, this doesn't work.
         *  For the C1010-66, this will be tested when I'll have
         *  such a beast to play with.
         */
        if (!(np->features & FE_C10)) {
                OUTB (nc_stest1, SCLK); /* Use the PCI clock as SCSI clock */
                f = (int) sym_getfreq (np);
                OUTB (nc_stest1, 0);
        }
        np->pciclk_khz = f;

        return f;
}

/*============= DRIVER ACTION/COMPLETION ====================*/

/*
 *  Print something that tells about extended errors.
 */
static void sym_print_xerr(ccb_p cp, int x_status)
{
        if (x_status & XE_PARITY_ERR) {
                PRINT_ADDR(cp);
                printf ("unrecovered SCSI parity error.\n");
        }
        if (x_status & XE_EXTRA_DATA) {
                PRINT_ADDR(cp);
                printf ("extraneous data discarded.\n");
        }
        if (x_status & XE_BAD_PHASE) {
                PRINT_ADDR(cp);
                printf ("illegal scsi phase (4/5).\n");
        }
        if (x_status & XE_SODL_UNRUN) {
                PRINT_ADDR(cp);
                printf ("ODD transfer in DATA OUT phase.\n");
        }
        if (x_status & XE_SWIDE_OVRUN) {
                PRINT_ADDR(cp);
                printf ("ODD transfer in DATA IN phase.\n");
        }
}

/*
 *  Choose the more appropriate CAM status if
 *  the IO encountered an extended error.
 */
static int sym_xerr_cam_status(int cam_status, int x_status)
{
        if (x_status) {
                if      (x_status & XE_PARITY_ERR)
                        cam_status = CAM_UNCOR_PARITY;
                else if (x_status &(XE_EXTRA_DATA|XE_SODL_UNRUN|XE_SWIDE_OVRUN))
                        cam_status = CAM_DATA_RUN_ERR;
                else if (x_status & XE_BAD_PHASE)
                        cam_status = CAM_REQ_CMP_ERR;
                else
                        cam_status = CAM_REQ_CMP_ERR;
        }
        return cam_status;
}

/*
 *  Complete execution of a SCSI command with extented
 *  error, SCSI status error, or having been auto-sensed.
 *
 *  The SCRIPTS processor is not running there, so we
 *  can safely access IO registers and remove JOBs from
 *  the START queue.
 *  SCRATCHA is assumed to have been loaded with STARTPOS
 *  before the SCRIPTS called the C code.
 */
static void sym_complete_error (hcb_p np, ccb_p cp)
{
        struct ccb_scsiio *csio;
        u_int cam_status;
        int i, sense_returned;

        SYM_LOCK_ASSERT(MA_OWNED);

        /*
         *  Paranoid check. :)
         */
        if (!cp || !cp->cam_ccb)
                return;

        if (DEBUG_FLAGS & (DEBUG_TINY|DEBUG_RESULT)) {
                printf ("CCB=%lx STAT=%x/%x/%x DEV=%d/%d\n", (unsigned long)cp,
                        cp->host_status, cp->ssss_status, cp->host_flags,
                        cp->target, cp->lun);
                MDELAY(100);
        }

        /*
         *  Get CAM command pointer.
         */
        csio = &cp->cam_ccb->csio;

        /*
         *  Check for extended errors.
         */
        if (cp->xerr_status) {
                if (sym_verbose)
                        sym_print_xerr(cp, cp->xerr_status);
                if (cp->host_status == HS_COMPLETE)
                        cp->host_status = HS_COMP_ERR;
        }

        /*
         *  Calculate the residual.
         */
        csio->sense_resid = 0;
        csio->resid = sym_compute_residual(np, cp);

        if (!SYM_CONF_RESIDUAL_SUPPORT) {/* If user does not want residuals */
                csio->resid  = 0;       /* throw them away. :)             */
                cp->sv_resid = 0;
        }

        if (cp->host_flags & HF_SENSE) {                /* Auto sense     */
                csio->scsi_status = cp->sv_scsi_status; /* Restore status */
                csio->sense_resid = csio->resid;        /* Swap residuals */
                csio->resid       = cp->sv_resid;
                cp->sv_resid      = 0;
                if (sym_verbose && cp->sv_xerr_status)
                        sym_print_xerr(cp, cp->sv_xerr_status);
                if (cp->host_status == HS_COMPLETE &&
                    cp->ssss_status == S_GOOD &&
                    cp->xerr_status == 0) {
                        cam_status = sym_xerr_cam_status(CAM_SCSI_STATUS_ERROR,
                                                         cp->sv_xerr_status);
                        cam_status |= CAM_AUTOSNS_VALID;
                        /*
                         *  Bounce back the sense data to user and
                         *  fix the residual.
                         */
                        bzero(&csio->sense_data, sizeof(csio->sense_data));
                        sense_returned = SYM_SNS_BBUF_LEN - csio->sense_resid;
                        if (sense_returned < csio->sense_len)
                                csio->sense_resid = csio->sense_len -
                                    sense_returned;
                        else
                                csio->sense_resid = 0;
                        bcopy(cp->sns_bbuf, &csio->sense_data,
                            MIN(csio->sense_len, sense_returned));
#if 0
                        /*
                         *  If the device reports a UNIT ATTENTION condition
                         *  due to a RESET condition, we should consider all
                         *  disconnect CCBs for this unit as aborted.
                         */
                        if (1) {
                                u_char *p;
                                p  = (u_char *) csio->sense_data;
                                if (p[0]==0x70 && p[2]==0x6 && p[12]==0x29)
                                        sym_clear_tasks(np, CAM_REQ_ABORTED,
                                                        cp->target,cp->lun, -1);
                        }
#endif
                }
                else
                        cam_status = CAM_AUTOSENSE_FAIL;
        }
        else if (cp->host_status == HS_COMPLETE) {      /* Bad SCSI status */
                csio->scsi_status = cp->ssss_status;
                cam_status = CAM_SCSI_STATUS_ERROR;
        }
        else if (cp->host_status == HS_SEL_TIMEOUT)     /* Selection timeout */
                cam_status = CAM_SEL_TIMEOUT;
        else if (cp->host_status == HS_UNEXPECTED)      /* Unexpected BUS FREE*/
                cam_status = CAM_UNEXP_BUSFREE;
        else {                                          /* Extended error */
                if (sym_verbose) {
                        PRINT_ADDR(cp);
                        printf ("COMMAND FAILED (%x %x %x).\n",
                                cp->host_status, cp->ssss_status,
                                cp->xerr_status);
                }
                csio->scsi_status = cp->ssss_status;
                /*
                 *  Set the most appropriate value for CAM status.
                 */
                cam_status = sym_xerr_cam_status(CAM_REQ_CMP_ERR,
                                                 cp->xerr_status);
        }

        /*
         *  Dequeue all queued CCBs for that device
         *  not yet started by SCRIPTS.
         */
        i = (INL (nc_scratcha) - np->squeue_ba) / 4;
        (void) sym_dequeue_from_squeue(np, i, cp->target, cp->lun, -1);

        /*
         *  Restart the SCRIPTS processor.
         */
        OUTL_DSP (SCRIPTA_BA (np, start));

        /*
         *  Synchronize DMA map if needed.
         */
        if (cp->dmamapped) {
                bus_dmamap_sync(np->data_dmat, cp->dmamap,
                        (cp->dmamapped == SYM_DMA_READ ?
                                BUS_DMASYNC_POSTREAD : BUS_DMASYNC_POSTWRITE));
        }
        /*
         *  Add this one to the COMP queue.
         *  Complete all those commands with either error
         *  or requeue condition.
         */
        sym_set_cam_status((union ccb *) csio, cam_status);
        sym_remque(&cp->link_ccbq);
        sym_insque_head(&cp->link_ccbq, &np->comp_ccbq);
        sym_flush_comp_queue(np, 0);
}

/*
 *  Complete execution of a successful SCSI command.
 *
 *  Only successful commands go to the DONE queue,
 *  since we need to have the SCRIPTS processor
 *  stopped on any error condition.
 *  The SCRIPTS processor is running while we are
 *  completing successful commands.
 */
static void sym_complete_ok (hcb_p np, ccb_p cp)
{
        struct ccb_scsiio *csio;
        tcb_p tp;
        lcb_p lp;

        SYM_LOCK_ASSERT(MA_OWNED);

        /*
         *  Paranoid check. :)
         */
        if (!cp || !cp->cam_ccb)
                return;
        assert (cp->host_status == HS_COMPLETE);

        /*
         *  Get command, target and lun pointers.
         */
        csio = &cp->cam_ccb->csio;
        tp = &np->target[cp->target];
        lp = sym_lp(tp, cp->lun);

        /*
         *  Assume device discovered on first success.
         */
        if (!lp)
                sym_set_bit(tp->lun_map, cp->lun);

        /*
         *  If all data have been transferred, given than no
         *  extended error did occur, there is no residual.
         */
        csio->resid = 0;
        if (cp->phys.head.lastp != cp->phys.head.goalp)
                csio->resid = sym_compute_residual(np, cp);

        /*
         *  Wrong transfer residuals may be worse than just always
         *  returning zero. User can disable this feature from
         *  sym_conf.h. Residual support is enabled by default.
         */
        if (!SYM_CONF_RESIDUAL_SUPPORT)
                csio->resid  = 0;

        /*
         *  Synchronize DMA map if needed.
         */
        if (cp->dmamapped) {
                bus_dmamap_sync(np->data_dmat, cp->dmamap,
                        (cp->dmamapped == SYM_DMA_READ ?
                                BUS_DMASYNC_POSTREAD : BUS_DMASYNC_POSTWRITE));
        }
        /*
         *  Set status and complete the command.
         */
        csio->scsi_status = cp->ssss_status;
        sym_set_cam_status((union ccb *) csio, CAM_REQ_CMP);
        sym_xpt_done(np, (union ccb *) csio, cp);
        sym_free_ccb(np, cp);
}

/*
 *  Our callout handler
 */
static void sym_callout(void *arg)
{
        union ccb *ccb = (union ccb *) arg;
        hcb_p np = ccb->ccb_h.sym_hcb_ptr;

        /*
         *  Check that the CAM CCB is still queued.
         */
        if (!np)
                return;

        SYM_LOCK();

        switch(ccb->ccb_h.func_code) {
        case XPT_SCSI_IO:
                (void) sym_abort_scsiio(np, ccb, 1);
                break;
        default:
                break;
        }

        SYM_UNLOCK();
}

/*
 *  Abort an SCSI IO.
 */
static int sym_abort_scsiio(hcb_p np, union ccb *ccb, int timed_out)
{
        ccb_p cp;
        SYM_QUEHEAD *qp;

        SYM_LOCK_ASSERT(MA_OWNED);

        /*
         *  Look up our CCB control block.
         */
        cp = NULL;
        FOR_EACH_QUEUED_ELEMENT(&np->busy_ccbq, qp) {
                ccb_p cp2 = sym_que_entry(qp, struct sym_ccb, link_ccbq);
                if (cp2->cam_ccb == ccb) {
                        cp = cp2;
                        break;
                }
        }
        if (!cp || cp->host_status == HS_WAIT)
                return -1;

        /*
         *  If a previous abort didn't succeed in time,
         *  perform a BUS reset.
         */
        if (cp->to_abort) {
                sym_reset_scsi_bus(np, 1);
                return 0;
        }

        /*
         *  Mark the CCB for abort and allow time for.
         */
        cp->to_abort = timed_out ? 2 : 1;
        callout_reset(&cp->ch, 10 * hz, sym_callout, (caddr_t) ccb);

        /*
         *  Tell the SCRIPTS processor to stop and synchronize with us.
         */
        np->istat_sem = SEM;
        OUTB (nc_istat, SIGP|SEM);
        return 0;
}

/*
 *  Reset a SCSI device (all LUNs of a target).
 */
static void sym_reset_dev(hcb_p np, union ccb *ccb)
{
        tcb_p tp;
        struct ccb_hdr *ccb_h = &ccb->ccb_h;

        SYM_LOCK_ASSERT(MA_OWNED);

        if (ccb_h->target_id   == np->myaddr ||
            ccb_h->target_id   >= SYM_CONF_MAX_TARGET ||
            ccb_h->target_lun  >= SYM_CONF_MAX_LUN) {
                sym_xpt_done2(np, ccb, CAM_DEV_NOT_THERE);
                return;
        }

        tp = &np->target[ccb_h->target_id];

        tp->to_reset = 1;
        sym_xpt_done2(np, ccb, CAM_REQ_CMP);

        np->istat_sem = SEM;
        OUTB (nc_istat, SIGP|SEM);
}

/*
 *  SIM action entry point.
 */
static void sym_action(struct cam_sim *sim, union ccb *ccb)
{
        hcb_p   np;
        tcb_p   tp;
        lcb_p   lp;
        ccb_p   cp;
        int     tmp;
        u_char  idmsg, *msgptr;
        u_int   msglen;
        struct  ccb_scsiio *csio;
        struct  ccb_hdr  *ccb_h;

        CAM_DEBUG(ccb->ccb_h.path, CAM_DEBUG_TRACE, ("sym_action\n"));

        /*
         *  Retrieve our controller data structure.
         */
        np = (hcb_p) cam_sim_softc(sim);

        SYM_LOCK_ASSERT(MA_OWNED);

        /*
         *  The common case is SCSI IO.
         *  We deal with other ones elsewhere.
         */
        if (ccb->ccb_h.func_code != XPT_SCSI_IO) {
                sym_action2(sim, ccb);
                return;
        }
        csio  = &ccb->csio;
        ccb_h = &csio->ccb_h;

        /*
         *  Work around races.
         */
        if ((ccb_h->status & CAM_STATUS_MASK) != CAM_REQ_INPROG) {
                xpt_done(ccb);
                return;
        }

        /*
         *  Minimal checkings, so that we will not
         *  go outside our tables.
         */
        if (ccb_h->target_id   == np->myaddr ||
            ccb_h->target_id   >= SYM_CONF_MAX_TARGET ||
            ccb_h->target_lun  >= SYM_CONF_MAX_LUN) {
                sym_xpt_done2(np, ccb, CAM_DEV_NOT_THERE);
                return;
        }

        /*
         *  Retrieve the target and lun descriptors.
         */
        tp = &np->target[ccb_h->target_id];
        lp = sym_lp(tp, ccb_h->target_lun);

        /*
         *  Complete the 1st INQUIRY command with error
         *  condition if the device is flagged NOSCAN
         *  at BOOT in the NVRAM. This may speed up
         *  the boot and maintain coherency with BIOS
         *  device numbering. Clearing the flag allows
         *  user to rescan skipped devices later.
         *  We also return error for devices not flagged
         *  for SCAN LUNS in the NVRAM since some mono-lun
         *  devices behave badly when asked for some non
         *  zero LUN. Btw, this is an absolute hack.:-)
         */
        if (!(ccb_h->flags & CAM_CDB_PHYS) &&
            (0x12 == ((ccb_h->flags & CAM_CDB_POINTER) ?
                  csio->cdb_io.cdb_ptr[0] : csio->cdb_io.cdb_bytes[0]))) {
                if ((tp->usrflags & SYM_SCAN_BOOT_DISABLED) ||
                    ((tp->usrflags & SYM_SCAN_LUNS_DISABLED) &&
                     ccb_h->target_lun != 0)) {
                        tp->usrflags &= ~SYM_SCAN_BOOT_DISABLED;
                        sym_xpt_done2(np, ccb, CAM_DEV_NOT_THERE);
                        return;
                }
        }

        /*
         *  Get a control block for this IO.
         */
        tmp = ((ccb_h->flags & CAM_TAG_ACTION_VALID) != 0);
        cp = sym_get_ccb(np, ccb_h->target_id, ccb_h->target_lun, tmp);
        if (!cp) {
                sym_xpt_done2(np, ccb, CAM_RESRC_UNAVAIL);
                return;
        }

        /*
         *  Keep track of the IO in our CCB.
         */
        cp->cam_ccb = ccb;

        /*
         *  Build the IDENTIFY message.
         */
        idmsg = M_IDENTIFY | cp->lun;
        if (cp->tag != NO_TAG || (lp && (lp->current_flags & SYM_DISC_ENABLED)))
                idmsg |= 0x40;

        msgptr = cp->scsi_smsg;
        msglen = 0;
        msgptr[msglen++] = idmsg;

        /*
         *  Build the tag message if present.
         */
        if (cp->tag != NO_TAG) {
                u_char order = csio->tag_action;

                switch(order) {
                case M_ORDERED_TAG:
                        break;
                case M_HEAD_TAG:
                        break;
                default:
                        order = M_SIMPLE_TAG;
                }
                msgptr[msglen++] = order;

                /*
                 *  For less than 128 tags, actual tags are numbered
                 *  1,3,5,..2*MAXTAGS+1,since we may have to deal
                 *  with devices that have problems with #TAG 0 or too
                 *  great #TAG numbers. For more tags (up to 256),
                 *  we use directly our tag number.
                 */
#if SYM_CONF_MAX_TASK > (512/4)
                msgptr[msglen++] = cp->tag;
#else
                msgptr[msglen++] = (cp->tag << 1) + 1;
#endif
        }

        /*
         *  Build a negotiation message if needed.
         *  (nego_status is filled by sym_prepare_nego())
         */
        cp->nego_status = 0;
        if (tp->tinfo.current.width   != tp->tinfo.goal.width  ||
            tp->tinfo.current.period  != tp->tinfo.goal.period ||
            tp->tinfo.current.offset  != tp->tinfo.goal.offset ||
            tp->tinfo.current.options != tp->tinfo.goal.options) {
                if (!tp->nego_cp && lp)
                        msglen += sym_prepare_nego(np, cp, 0, msgptr + msglen);
        }

        /*
         *  Fill in our ccb
         */

        /*
         *  Startqueue
         */
        cp->phys.head.go.start   = cpu_to_scr(SCRIPTA_BA (np, select));
        cp->phys.head.go.restart = cpu_to_scr(SCRIPTA_BA (np, resel_dsa));

        /*
         *  select
         */
        cp->phys.select.sel_id          = cp->target;
        cp->phys.select.sel_scntl3      = tp->head.wval;
        cp->phys.select.sel_sxfer       = tp->head.sval;
        cp->phys.select.sel_scntl4      = tp->head.uval;

        /*
         *  message
         */
        cp->phys.smsg.addr      = cpu_to_scr(CCB_BA (cp, scsi_smsg));
        cp->phys.smsg.size      = cpu_to_scr(msglen);

        /*
         *  command
         */
        if (sym_setup_cdb(np, csio, cp) < 0) {
                sym_xpt_done(np, ccb, cp);
                sym_free_ccb(np, cp);
                return;
        }

        /*
         *  status
         */
#if     0       /* Provision */
        cp->actualquirks        = tp->quirks;
#endif
        cp->actualquirks        = SYM_QUIRK_AUTOSAVE;
        cp->host_status         = cp->nego_status ? HS_NEGOTIATE : HS_BUSY;
        cp->ssss_status         = S_ILLEGAL;
        cp->xerr_status         = 0;
        cp->host_flags          = 0;
        cp->extra_bytes         = 0;

        /*
         *  extreme data pointer.
         *  shall be positive, so -1 is lower than lowest.:)
         */
        cp->ext_sg  = -1;
        cp->ext_ofs = 0;

        /*
         *  Build the data descriptor block
         *  and start the IO.
         */
        sym_setup_data_and_start(np, csio, cp);
}

/*
 *  Setup buffers and pointers that address the CDB.
 *  I bet, physical CDBs will never be used on the planet,
 *  since they can be bounced without significant overhead.
 */
static int sym_setup_cdb(hcb_p np, struct ccb_scsiio *csio, ccb_p cp)
{
        struct ccb_hdr *ccb_h;
        u32     cmd_ba;
        int     cmd_len;

        SYM_LOCK_ASSERT(MA_OWNED);

        ccb_h = &csio->ccb_h;

        /*
         *  CDB is 16 bytes max.
         */
        if (csio->cdb_len > sizeof(cp->cdb_buf)) {
                sym_set_cam_status(cp->cam_ccb, CAM_REQ_INVALID);
                return -1;
        }
        cmd_len = csio->cdb_len;

        if (ccb_h->flags & CAM_CDB_POINTER) {
                /* CDB is a pointer */
                if (!(ccb_h->flags & CAM_CDB_PHYS)) {
                        /* CDB pointer is virtual */
                        bcopy(csio->cdb_io.cdb_ptr, cp->cdb_buf, cmd_len);
                        cmd_ba = CCB_BA (cp, cdb_buf[0]);
                } else {
                        /* CDB pointer is physical */
#if 0
                        cmd_ba = ((u32)csio->cdb_io.cdb_ptr) & 0xffffffff;
#else
                        sym_set_cam_status(cp->cam_ccb, CAM_REQ_INVALID);
                        return -1;
#endif
                }
        } else {
                /* CDB is in the CAM ccb (buffer) */
                bcopy(csio->cdb_io.cdb_bytes, cp->cdb_buf, cmd_len);
                cmd_ba = CCB_BA (cp, cdb_buf[0]);
        }

        cp->phys.cmd.addr       = cpu_to_scr(cmd_ba);
        cp->phys.cmd.size       = cpu_to_scr(cmd_len);

        return 0;
}

/*
 *  Set up data pointers used by SCRIPTS.
 */
static void __inline
sym_setup_data_pointers(hcb_p np, ccb_p cp, int dir)
{
        u32 lastp, goalp;

        SYM_LOCK_ASSERT(MA_OWNED);

        /*
         *  No segments means no data.
         */
        if (!cp->segments)
                dir = CAM_DIR_NONE;

        /*
         *  Set the data pointer.
         */
        switch(dir) {
        case CAM_DIR_OUT:
                goalp = SCRIPTA_BA (np, data_out2) + 8;
                lastp = goalp - 8 - (cp->segments * (2*4));
                break;
        case CAM_DIR_IN:
                cp->host_flags |= HF_DATA_IN;
                goalp = SCRIPTA_BA (np, data_in2) + 8;
                lastp = goalp - 8 - (cp->segments * (2*4));
                break;
        case CAM_DIR_NONE:
        default:
                lastp = goalp = SCRIPTB_BA (np, no_data);
                break;
        }

        cp->phys.head.lastp = cpu_to_scr(lastp);
        cp->phys.head.goalp = cpu_to_scr(goalp);
        cp->phys.head.savep = cpu_to_scr(lastp);
        cp->startp          = cp->phys.head.savep;
}

/*
 *  Call back routine for the DMA map service.
 *  If bounce buffers are used (why ?), we may sleep and then
 *  be called there in another context.
 */
static void
sym_execute_ccb(void *arg, bus_dma_segment_t *psegs, int nsegs, int error)
{
        ccb_p   cp;
        hcb_p   np;
        union   ccb *ccb;

        cp  = (ccb_p) arg;
        ccb = cp->cam_ccb;
        np  = (hcb_p) cp->arg;

        SYM_LOCK_ASSERT(MA_OWNED);

        /*
         *  Deal with weird races.
         */
        if (sym_get_cam_status(ccb) != CAM_REQ_INPROG)
                goto out_abort;

        /*
         *  Deal with weird errors.
         */
        if (error) {
                cp->dmamapped = 0;
                sym_set_cam_status(cp->cam_ccb, CAM_REQ_ABORTED);
                goto out_abort;
        }

        /*
         *  Build the data descriptor for the chip.
         */
        if (nsegs) {
                int retv;
                /* 896 rev 1 requires to be careful about boundaries */
                if (np->device_id == PCI_ID_SYM53C896 && np->revision_id <= 1)
                        retv = sym_scatter_sg_physical(np, cp, psegs, nsegs);
                else
                        retv = sym_fast_scatter_sg_physical(np,cp, psegs,nsegs);
                if (retv < 0) {
                        sym_set_cam_status(cp->cam_ccb, CAM_REQ_TOO_BIG);
                        goto out_abort;
                }
        }

        /*
         *  Synchronize the DMA map only if we have
         *  actually mapped the data.
         */
        if (cp->dmamapped) {
                bus_dmamap_sync(np->data_dmat, cp->dmamap,
                        (cp->dmamapped == SYM_DMA_READ ?
                                BUS_DMASYNC_PREREAD : BUS_DMASYNC_PREWRITE));
        }

        /*
         *  Set host status to busy state.
         *  May have been set back to HS_WAIT to avoid a race.
         */
        cp->host_status = cp->nego_status ? HS_NEGOTIATE : HS_BUSY;

        /*
         *  Set data pointers.
         */
        sym_setup_data_pointers(np, cp,  (ccb->ccb_h.flags & CAM_DIR_MASK));

        /*
         *  Enqueue this IO in our pending queue.
         */
        sym_enqueue_cam_ccb(cp);

        /*
         *  When `#ifed 1', the code below makes the driver
         *  panic on the first attempt to write to a SCSI device.
         *  It is the first test we want to do after a driver
         *  change that does not seem obviously safe. :)
         */
#if 0
        switch (cp->cdb_buf[0]) {
        case 0x0A: case 0x2A: case 0xAA:
                panic("XXXXXXXXXXXXX WRITE NOT YET ALLOWED XXXXXXXXXXXXXX\n");
                MDELAY(10000);
                break;
        default:
                break;
        }
#endif
        /*
         *  Activate this job.
         */
        sym_put_start_queue(np, cp);
        return;
out_abort:
        sym_xpt_done(np, ccb, cp);
        sym_free_ccb(np, cp);
}

/*
 *  How complex it gets to deal with the data in CAM.
 *  The Bus Dma stuff makes things still more complex.
 */
static void
sym_setup_data_and_start(hcb_p np, struct ccb_scsiio *csio, ccb_p cp)
{
        struct ccb_hdr *ccb_h;
        int dir, retv;

        SYM_LOCK_ASSERT(MA_OWNED);

        ccb_h = &csio->ccb_h;

        /*
         *  Now deal with the data.
         */
        cp->data_len = csio->dxfer_len;
        cp->arg      = np;

        /*
         *  No direction means no data.
         */
        dir = (ccb_h->flags & CAM_DIR_MASK);
        if (dir == CAM_DIR_NONE) {
                sym_execute_ccb(cp, NULL, 0, 0);
                return;
        }

        cp->dmamapped = (dir == CAM_DIR_IN) ?  SYM_DMA_READ : SYM_DMA_WRITE;
        retv = bus_dmamap_load_ccb(np->data_dmat, cp->dmamap,
                               (union ccb *)csio, sym_execute_ccb, cp, 0);
        if (retv == EINPROGRESS) {
                cp->host_status = HS_WAIT;
                xpt_freeze_simq(np->sim, 1);
                csio->ccb_h.status |= CAM_RELEASE_SIMQ;
        }
}

/*
 *  Move the scatter list to our data block.
 */
static int
sym_fast_scatter_sg_physical(hcb_p np, ccb_p cp,
                             bus_dma_segment_t *psegs, int nsegs)
{
        struct sym_tblmove *data;
        bus_dma_segment_t *psegs2;

        SYM_LOCK_ASSERT(MA_OWNED);

        if (nsegs > SYM_CONF_MAX_SG)
                return -1;

        data   = &cp->phys.data[SYM_CONF_MAX_SG-1];
        psegs2 = &psegs[nsegs-1];
        cp->segments = nsegs;

        while (1) {
                data->addr = cpu_to_scr(psegs2->ds_addr);
                data->size = cpu_to_scr(psegs2->ds_len);
                if (DEBUG_FLAGS & DEBUG_SCATTER) {
                        printf ("%s scatter: paddr=%lx len=%ld\n",
                                sym_name(np), (long) psegs2->ds_addr,
                                (long) psegs2->ds_len);
                }
                if (psegs2 != psegs) {
                        --data;
                        --psegs2;
                        continue;
                }
                break;
        }
        return 0;
}

/*
 *  Scatter a SG list with physical addresses into bus addressable chunks.
 */
static int
sym_scatter_sg_physical(hcb_p np, ccb_p cp, bus_dma_segment_t *psegs, int nsegs)
{
        u_long  ps, pe, pn;
        u_long  k;
        int s, t;

        SYM_LOCK_ASSERT(MA_OWNED);

        s  = SYM_CONF_MAX_SG - 1;
        t  = nsegs - 1;
        ps = psegs[t].ds_addr;
        pe = ps + psegs[t].ds_len;

        while (s >= 0) {
                pn = rounddown2(pe - 1, SYM_CONF_DMA_BOUNDARY);
                if (pn <= ps)
                        pn = ps;
                k = pe - pn;
                if (DEBUG_FLAGS & DEBUG_SCATTER) {
                        printf ("%s scatter: paddr=%lx len=%ld\n",
                                sym_name(np), pn, k);
                }
                cp->phys.data[s].addr = cpu_to_scr(pn);
                cp->phys.data[s].size = cpu_to_scr(k);
                --s;
                if (pn == ps) {
                        if (--t < 0)
                                break;
                        ps = psegs[t].ds_addr;
                        pe = ps + psegs[t].ds_len;
                }
                else
                        pe = pn;
        }

        cp->segments = SYM_CONF_MAX_SG - 1 - s;

        return t >= 0 ? -1 : 0;
}

/*
 *  SIM action for non performance critical stuff.
 */
static void sym_action2(struct cam_sim *sim, union ccb *ccb)
{
        union ccb *abort_ccb;
        struct ccb_hdr *ccb_h;
        struct ccb_pathinq *cpi;
        struct ccb_trans_settings *cts;
        struct sym_trans *tip;
        hcb_p   np;
        tcb_p   tp;
        lcb_p   lp;
        u_char dflags;

        /*
         *  Retrieve our controller data structure.
         */
        np = (hcb_p) cam_sim_softc(sim);

        SYM_LOCK_ASSERT(MA_OWNED);

        ccb_h = &ccb->ccb_h;

        switch (ccb_h->func_code) {
        case XPT_SET_TRAN_SETTINGS:
                cts  = &ccb->cts;
                tp = &np->target[ccb_h->target_id];

                /*
                 *  Update SPI transport settings in TARGET control block.
                 *  Update SCSI device settings in LUN control block.
                 */
                lp = sym_lp(tp, ccb_h->target_lun);
                if (cts->type == CTS_TYPE_CURRENT_SETTINGS) {
                        sym_update_trans(np, &tp->tinfo.goal, cts);
                        if (lp)
                                sym_update_dflags(np, &lp->current_flags, cts);
                }
                if (cts->type == CTS_TYPE_USER_SETTINGS) {
                        sym_update_trans(np, &tp->tinfo.user, cts);
                        if (lp)
                                sym_update_dflags(np, &lp->user_flags, cts);
                }

                sym_xpt_done2(np, ccb, CAM_REQ_CMP);
                break;
        case XPT_GET_TRAN_SETTINGS:
                cts = &ccb->cts;
                tp = &np->target[ccb_h->target_id];
                lp = sym_lp(tp, ccb_h->target_lun);

#define cts__scsi (&cts->proto_specific.scsi)
#define cts__spi  (&cts->xport_specific.spi)
                if (cts->type == CTS_TYPE_CURRENT_SETTINGS) {
                        tip = &tp->tinfo.current;
                        dflags = lp ? lp->current_flags : 0;
                }
                else {
                        tip = &tp->tinfo.user;
                        dflags = lp ? lp->user_flags : tp->usrflags;
                }

                cts->protocol  = PROTO_SCSI;
                cts->transport = XPORT_SPI;
                cts->protocol_version  = tip->scsi_version;
                cts->transport_version = tip->spi_version;

                cts__spi->sync_period = tip->period;
                cts__spi->sync_offset = tip->offset;
                cts__spi->bus_width   = tip->width;
                cts__spi->ppr_options = tip->options;

                cts__spi->valid = CTS_SPI_VALID_SYNC_RATE
                                | CTS_SPI_VALID_SYNC_OFFSET
                                | CTS_SPI_VALID_BUS_WIDTH
                                | CTS_SPI_VALID_PPR_OPTIONS;

                cts__spi->flags &= ~CTS_SPI_FLAGS_DISC_ENB;
                if (dflags & SYM_DISC_ENABLED)
                        cts__spi->flags |= CTS_SPI_FLAGS_DISC_ENB;
                cts__spi->valid |= CTS_SPI_VALID_DISC;

                cts__scsi->flags &= ~CTS_SCSI_FLAGS_TAG_ENB;
                if (dflags & SYM_TAGS_ENABLED)
                        cts__scsi->flags |= CTS_SCSI_FLAGS_TAG_ENB;
                cts__scsi->valid |= CTS_SCSI_VALID_TQ;
#undef  cts__spi
#undef  cts__scsi
                sym_xpt_done2(np, ccb, CAM_REQ_CMP);
                break;
        case XPT_CALC_GEOMETRY:
                cam_calc_geometry(&ccb->ccg, /*extended*/1);
                sym_xpt_done2(np, ccb, CAM_REQ_CMP);
                break;
        case XPT_PATH_INQ:
                cpi = &ccb->cpi;
                cpi->version_num = 1;
                cpi->hba_inquiry = PI_MDP_ABLE|PI_SDTR_ABLE|PI_TAG_ABLE;
                if ((np->features & FE_WIDE) != 0)
                        cpi->hba_inquiry |= PI_WIDE_16;
                cpi->target_sprt = 0;
                cpi->hba_misc = PIM_UNMAPPED;
                if (np->usrflags & SYM_SCAN_TARGETS_HILO)
                        cpi->hba_misc |= PIM_SCANHILO;
                if (np->usrflags & SYM_AVOID_BUS_RESET)
                        cpi->hba_misc |= PIM_NOBUSRESET;
                cpi->hba_eng_cnt = 0;
                cpi->max_target = (np->features & FE_WIDE) ? 15 : 7;
                /* Semantic problem:)LUN number max = max number of LUNs - 1 */
                cpi->max_lun = SYM_CONF_MAX_LUN-1;
                if (SYM_SETUP_MAX_LUN < SYM_CONF_MAX_LUN)
                        cpi->max_lun = SYM_SETUP_MAX_LUN-1;
                cpi->bus_id = cam_sim_bus(sim);
                cpi->initiator_id = np->myaddr;
                cpi->base_transfer_speed = 3300;
                strlcpy(cpi->sim_vid, "FreeBSD", SIM_IDLEN);
                strlcpy(cpi->hba_vid, "Symbios", HBA_IDLEN);
                strlcpy(cpi->dev_name, cam_sim_name(sim), DEV_IDLEN);
                cpi->unit_number = cam_sim_unit(sim);

                cpi->protocol = PROTO_SCSI;
                cpi->protocol_version = SCSI_REV_2;
                cpi->transport = XPORT_SPI;
                cpi->transport_version = 2;
                cpi->xport_specific.spi.ppr_options = SID_SPI_CLOCK_ST;
                if (np->features & FE_ULTRA3) {
                        cpi->transport_version = 3;
                        cpi->xport_specific.spi.ppr_options =
                            SID_SPI_CLOCK_DT_ST;
                }
                cpi->maxio = SYM_CONF_MAX_SG * PAGE_SIZE;
                sym_xpt_done2(np, ccb, CAM_REQ_CMP);
                break;
        case XPT_ABORT:
                abort_ccb = ccb->cab.abort_ccb;
                switch(abort_ccb->ccb_h.func_code) {
                case XPT_SCSI_IO:
                        if (sym_abort_scsiio(np, abort_ccb, 0) == 0) {
                                sym_xpt_done2(np, ccb, CAM_REQ_CMP);
                                break;
                        }
                default:
                        sym_xpt_done2(np, ccb, CAM_UA_ABORT);
                        break;
                }
                break;
        case XPT_RESET_DEV:
                sym_reset_dev(np, ccb);
                break;
        case XPT_RESET_BUS:
                sym_reset_scsi_bus(np, 0);
                if (sym_verbose) {
                        xpt_print_path(np->path);
                        printf("SCSI BUS reset delivered.\n");
                }
                sym_init (np, 1);
                sym_xpt_done2(np, ccb, CAM_REQ_CMP);
                break;
        case XPT_TERM_IO:
        default:
                sym_xpt_done2(np, ccb, CAM_REQ_INVALID);
                break;
        }
}

/*
 *  Asynchronous notification handler.
 */
static void
sym_async(void *cb_arg, u32 code, struct cam_path *path, void *args __unused)
{
        hcb_p np;
        struct cam_sim *sim;
        u_int tn;
        tcb_p tp;

        sim = (struct cam_sim *) cb_arg;
        np  = (hcb_p) cam_sim_softc(sim);

        SYM_LOCK_ASSERT(MA_OWNED);

        switch (code) {
        case AC_LOST_DEVICE:
                tn = xpt_path_target_id(path);
                if (tn >= SYM_CONF_MAX_TARGET)
                        break;

                tp = &np->target[tn];

                tp->to_reset  = 0;
                tp->head.sval = 0;
                tp->head.wval = np->rv_scntl3;
                tp->head.uval = 0;

                tp->tinfo.current.period  = tp->tinfo.goal.period = 0;
                tp->tinfo.current.offset  = tp->tinfo.goal.offset = 0;
                tp->tinfo.current.width   = tp->tinfo.goal.width  = BUS_8_BIT;
                tp->tinfo.current.options = tp->tinfo.goal.options = 0;

                break;
        default:
                break;
        }
}

/*
 *  Update transfer settings of a target.
 */
static void sym_update_trans(hcb_p np, struct sym_trans *tip,
    struct ccb_trans_settings *cts)
{

        SYM_LOCK_ASSERT(MA_OWNED);

        /*
         *  Update the infos.
         */
#define cts__spi (&cts->xport_specific.spi)
        if ((cts__spi->valid & CTS_SPI_VALID_BUS_WIDTH) != 0)
                tip->width = cts__spi->bus_width;
        if ((cts__spi->valid & CTS_SPI_VALID_SYNC_OFFSET) != 0)
                tip->offset = cts__spi->sync_offset;
        if ((cts__spi->valid & CTS_SPI_VALID_SYNC_RATE) != 0)
                tip->period = cts__spi->sync_period;
        if ((cts__spi->valid & CTS_SPI_VALID_PPR_OPTIONS) != 0)
                tip->options = (cts__spi->ppr_options & PPR_OPT_DT);
        if (cts->protocol_version != PROTO_VERSION_UNSPECIFIED &&
            cts->protocol_version != PROTO_VERSION_UNKNOWN)
                tip->scsi_version = cts->protocol_version;
        if (cts->transport_version != XPORT_VERSION_UNSPECIFIED &&
            cts->transport_version != XPORT_VERSION_UNKNOWN)
                tip->spi_version = cts->transport_version;
#undef cts__spi
        /*
         *  Scale against driver configuration limits.
         */
        if (tip->width  > SYM_SETUP_MAX_WIDE) tip->width  = SYM_SETUP_MAX_WIDE;
        if (tip->period && tip->offset) {
                if (tip->offset > SYM_SETUP_MAX_OFFS) tip->offset = SYM_SETUP_MAX_OFFS;
                if (tip->period < SYM_SETUP_MIN_SYNC) tip->period = SYM_SETUP_MIN_SYNC;
        } else {
                tip->offset = 0;
                tip->period = 0;
        }

        /*
         *  Scale against actual controller BUS width.
         */
        if (tip->width > np->maxwide)
                tip->width  = np->maxwide;

        /*
         *  Only accept DT if controller supports and SYNC/WIDE asked.
         */
        if (!((np->features & (FE_C10|FE_ULTRA3)) == (FE_C10|FE_ULTRA3)) ||
            !(tip->width == BUS_16_BIT && tip->offset)) {
                tip->options &= ~PPR_OPT_DT;
        }

        /*
         *  Scale period factor and offset against controller limits.
         */
        if (tip->offset && tip->period) {
                if (tip->options & PPR_OPT_DT) {
                        if (tip->period < np->minsync_dt)
                                tip->period = np->minsync_dt;
                        if (tip->period > np->maxsync_dt)
                                tip->period = np->maxsync_dt;
                        if (tip->offset > np->maxoffs_dt)
                                tip->offset = np->maxoffs_dt;
                }
                else {
                        if (tip->period < np->minsync)
                                tip->period = np->minsync;
                        if (tip->period > np->maxsync)
                                tip->period = np->maxsync;
                        if (tip->offset > np->maxoffs)
                                tip->offset = np->maxoffs;
                }
        }
}

/*
 *  Update flags for a device (logical unit).
 */
static void
sym_update_dflags(hcb_p np, u_char *flags, struct ccb_trans_settings *cts)
{

        SYM_LOCK_ASSERT(MA_OWNED);

#define cts__scsi (&cts->proto_specific.scsi)
#define cts__spi  (&cts->xport_specific.spi)
        if ((cts__spi->valid & CTS_SPI_VALID_DISC) != 0) {
                if ((cts__spi->flags & CTS_SPI_FLAGS_DISC_ENB) != 0)
                        *flags |= SYM_DISC_ENABLED;
                else
                        *flags &= ~SYM_DISC_ENABLED;
        }

        if ((cts__scsi->valid & CTS_SCSI_VALID_TQ) != 0) {
                if ((cts__scsi->flags & CTS_SCSI_FLAGS_TAG_ENB) != 0)
                        *flags |= SYM_TAGS_ENABLED;
                else
                        *flags &= ~SYM_TAGS_ENABLED;
        }
#undef  cts__spi
#undef  cts__scsi
}

/*============= DRIVER INITIALISATION ==================*/

static device_method_t sym_pci_methods[] = {
        DEVMETHOD(device_probe,  sym_pci_probe),
        DEVMETHOD(device_attach, sym_pci_attach),
        DEVMETHOD_END
};

static driver_t sym_pci_driver = {
        "sym",
        sym_pci_methods,
        1       /* no softc */
};

static devclass_t sym_devclass;

DRIVER_MODULE(sym, pci, sym_pci_driver, sym_devclass, NULL, NULL);
MODULE_DEPEND(sym, cam, 1, 1, 1);
MODULE_DEPEND(sym, pci, 1, 1, 1);

static const struct sym_pci_chip sym_pci_dev_table[] = {
 {PCI_ID_SYM53C810, 0x0f, "810", 4, 8, 4, 64,
 FE_ERL}
 ,
#ifdef SYM_DEBUG_GENERIC_SUPPORT
 {PCI_ID_SYM53C810, 0xff, "810a", 4,  8, 4, 1,
 FE_BOF}
 ,
#else
 {PCI_ID_SYM53C810, 0xff, "810a", 4,  8, 4, 1,
 FE_CACHE_SET|FE_LDSTR|FE_PFEN|FE_BOF}
 ,
#endif
 {PCI_ID_SYM53C815, 0xff, "815", 4,  8, 4, 64,
 FE_BOF|FE_ERL}
 ,
 {PCI_ID_SYM53C825, 0x0f, "825", 6,  8, 4, 64,
 FE_WIDE|FE_BOF|FE_ERL|FE_DIFF}
 ,
 {PCI_ID_SYM53C825, 0xff, "825a", 6,  8, 4, 2,
 FE_WIDE|FE_CACHE0_SET|FE_BOF|FE_DFS|FE_LDSTR|FE_PFEN|FE_RAM|FE_DIFF}
 ,
 {PCI_ID_SYM53C860, 0xff, "860", 4,  8, 5, 1,
 FE_ULTRA|FE_CLK80|FE_CACHE_SET|FE_BOF|FE_LDSTR|FE_PFEN}
 ,
 {PCI_ID_SYM53C875, 0x01, "875", 6, 16, 5, 2,
 FE_WIDE|FE_ULTRA|FE_CLK80|FE_CACHE0_SET|FE_BOF|FE_DFS|FE_LDSTR|FE_PFEN|
 FE_RAM|FE_DIFF}
 ,
 {PCI_ID_SYM53C875, 0xff, "875", 6, 16, 5, 2,
 FE_WIDE|FE_ULTRA|FE_DBLR|FE_CACHE0_SET|FE_BOF|FE_DFS|FE_LDSTR|FE_PFEN|
 FE_RAM|FE_DIFF}
 ,
 {PCI_ID_SYM53C875_2, 0xff, "875", 6, 16, 5, 2,
 FE_WIDE|FE_ULTRA|FE_DBLR|FE_CACHE0_SET|FE_BOF|FE_DFS|FE_LDSTR|FE_PFEN|
 FE_RAM|FE_DIFF}
 ,
 {PCI_ID_SYM53C885, 0xff, "885", 6, 16, 5, 2,
 FE_WIDE|FE_ULTRA|FE_DBLR|FE_CACHE0_SET|FE_BOF|FE_DFS|FE_LDSTR|FE_PFEN|
 FE_RAM|FE_DIFF}
 ,
#ifdef SYM_DEBUG_GENERIC_SUPPORT
 {PCI_ID_SYM53C895, 0xff, "895", 6, 31, 7, 2,
 FE_WIDE|FE_ULTRA2|FE_QUAD|FE_CACHE_SET|FE_BOF|FE_DFS|
 FE_RAM|FE_LCKFRQ}
 ,
#else
 {PCI_ID_SYM53C895, 0xff, "895", 6, 31, 7, 2,
 FE_WIDE|FE_ULTRA2|FE_QUAD|FE_CACHE_SET|FE_BOF|FE_DFS|FE_LDSTR|FE_PFEN|
 FE_RAM|FE_LCKFRQ}
 ,
#endif
 {PCI_ID_SYM53C896, 0xff, "896", 6, 31, 7, 4,
 FE_WIDE|FE_ULTRA2|FE_QUAD|FE_CACHE_SET|FE_BOF|FE_DFS|FE_LDSTR|FE_PFEN|
 FE_RAM|FE_RAM8K|FE_64BIT|FE_DAC|FE_IO256|FE_NOPM|FE_LEDC|FE_LCKFRQ}
 ,
 {PCI_ID_SYM53C895A, 0xff, "895a", 6, 31, 7, 4,
 FE_WIDE|FE_ULTRA2|FE_QUAD|FE_CACHE_SET|FE_BOF|FE_DFS|FE_LDSTR|FE_PFEN|
 FE_RAM|FE_RAM8K|FE_DAC|FE_IO256|FE_NOPM|FE_LEDC|FE_LCKFRQ}
 ,
 {PCI_ID_LSI53C1010, 0x00, "1010-33", 6, 31, 7, 8,
 FE_WIDE|FE_ULTRA3|FE_QUAD|FE_CACHE_SET|FE_BOF|FE_DFBC|FE_LDSTR|FE_PFEN|
 FE_RAM|FE_RAM8K|FE_64BIT|FE_DAC|FE_IO256|FE_NOPM|FE_LEDC|FE_CRC|
 FE_C10}
 ,
 {PCI_ID_LSI53C1010, 0xff, "1010-33", 6, 31, 7, 8,
 FE_WIDE|FE_ULTRA3|FE_QUAD|FE_CACHE_SET|FE_BOF|FE_DFBC|FE_LDSTR|FE_PFEN|
 FE_RAM|FE_RAM8K|FE_64BIT|FE_DAC|FE_IO256|FE_NOPM|FE_LEDC|FE_CRC|
 FE_C10|FE_U3EN}
 ,
 {PCI_ID_LSI53C1010_2, 0xff, "1010-66", 6, 31, 7, 8,
 FE_WIDE|FE_ULTRA3|FE_QUAD|FE_CACHE_SET|FE_BOF|FE_DFBC|FE_LDSTR|FE_PFEN|
 FE_RAM|FE_RAM8K|FE_64BIT|FE_DAC|FE_IO256|FE_NOPM|FE_LEDC|FE_66MHZ|FE_CRC|
 FE_C10|FE_U3EN}
 ,
 {PCI_ID_LSI53C1510D, 0xff, "1510d", 6, 31, 7, 4,
 FE_WIDE|FE_ULTRA2|FE_QUAD|FE_CACHE_SET|FE_BOF|FE_DFS|FE_LDSTR|FE_PFEN|
 FE_RAM|FE_IO256|FE_LEDC}
};

/*
 *  Look up the chip table.
 *
 *  Return a pointer to the chip entry if found,
 *  zero otherwise.
 */
static const struct sym_pci_chip *
sym_find_pci_chip(device_t dev)
{
        const struct    sym_pci_chip *chip;
        int     i;
        u_short device_id;
        u_char  revision;

        if (pci_get_vendor(dev) != PCI_VENDOR_NCR)
                return NULL;

        device_id = pci_get_device(dev);
        revision  = pci_get_revid(dev);

        for (i = 0; i < nitems(sym_pci_dev_table); i++) {
                chip = &sym_pci_dev_table[i];
                if (device_id != chip->device_id)
                        continue;
                if (revision > chip->revision_id)
                        continue;
                return chip;
        }

        return NULL;
}

/*
 *  Tell upper layer if the chip is supported.
 */
static int
sym_pci_probe(device_t dev)
{
        const struct    sym_pci_chip *chip;

        chip = sym_find_pci_chip(dev);
        if (chip && sym_find_firmware(chip)) {
                device_set_desc(dev, chip->name);
                return BUS_PROBE_DEFAULT;
        }
        return ENXIO;
}

/*
 *  Attach a sym53c8xx device.
 */
static int
sym_pci_attach(device_t dev)
{
        const struct    sym_pci_chip *chip;
        u_short command;
        u_char  cachelnsz;
        struct  sym_hcb *np = NULL;
        struct  sym_nvram nvram;
        const struct    sym_fw *fw = NULL;
        int     i;
        bus_dma_tag_t   bus_dmat;

        bus_dmat = bus_get_dma_tag(dev);

        /*
         *  Only probed devices should be attached.
         *  We just enjoy being paranoid. :)
         */
        chip = sym_find_pci_chip(dev);
        if (chip == NULL || (fw = sym_find_firmware(chip)) == NULL)
                return (ENXIO);

        /*
         *  Allocate immediately the host control block,
         *  since we are only expecting to succeed. :)
         *  We keep track in the HCB of all the resources that
         *  are to be released on error.
         */
        np = __sym_calloc_dma(bus_dmat, sizeof(*np), "HCB");
        if (np)
                np->bus_dmat = bus_dmat;
        else
                return (ENXIO);
        device_set_softc(dev, np);

        SYM_LOCK_INIT();

        /*
         *  Copy some useful infos to the HCB.
         */
        np->hcb_ba       = vtobus(np);
        np->verbose      = bootverbose;
        np->device       = dev;
        np->device_id    = pci_get_device(dev);
        np->revision_id  = pci_get_revid(dev);
        np->features     = chip->features;
        np->clock_divn   = chip->nr_divisor;
        np->maxoffs      = chip->offset_max;
        np->maxburst     = chip->burst_max;
        np->scripta_sz   = fw->a_size;
        np->scriptb_sz   = fw->b_size;
        np->fw_setup     = fw->setup;
        np->fw_patch     = fw->patch;
        np->fw_name      = fw->name;

#ifdef __amd64__
        np->target = sym_calloc_dma(SYM_CONF_MAX_TARGET * sizeof(*(np->target)),
                        "TARGET");
        if (!np->target)
                goto attach_failed;
#endif

        /*
         *  Initialize the CCB free and busy queues.
         */
        sym_que_init(&np->free_ccbq);
        sym_que_init(&np->busy_ccbq);
        sym_que_init(&np->comp_ccbq);
        sym_que_init(&np->cam_ccbq);

        /*
         *  Allocate a tag for the DMA of user data.
         */
        if (bus_dma_tag_create(np->bus_dmat, 1, SYM_CONF_DMA_BOUNDARY,
            BUS_SPACE_MAXADDR_32BIT, BUS_SPACE_MAXADDR, NULL, NULL,
            BUS_SPACE_MAXSIZE_32BIT, SYM_CONF_MAX_SG, SYM_CONF_DMA_BOUNDARY,
            0, busdma_lock_mutex, &np->mtx, &np->data_dmat)) {
                device_printf(dev, "failed to create DMA tag.\n");
                goto attach_failed;
        }

        /*
         *  Read and apply some fix-ups to the PCI COMMAND
         *  register. We want the chip to be enabled for:
         *  - BUS mastering
         *  - PCI parity checking (reporting would also be fine)
         *  - Write And Invalidate.
         */
        command = pci_read_config(dev, PCIR_COMMAND, 2);
        command |= PCIM_CMD_BUSMASTEREN | PCIM_CMD_PERRESPEN |
            PCIM_CMD_MWRICEN;
        pci_write_config(dev, PCIR_COMMAND, command, 2);

        /*
         *  Let the device know about the cache line size,
         *  if it doesn't yet.
         */
        cachelnsz = pci_read_config(dev, PCIR_CACHELNSZ, 1);
        if (!cachelnsz) {
                cachelnsz = 8;
                pci_write_config(dev, PCIR_CACHELNSZ, cachelnsz, 1);
        }

        /*
         *  Alloc/get/map/retrieve everything that deals with MMIO.
         */
        i = SYM_PCI_MMIO;
        np->mmio_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &i,
            RF_ACTIVE);
        if (!np->mmio_res) {
                device_printf(dev, "failed to allocate MMIO resources\n");
                goto attach_failed;
        }
        np->mmio_ba = rman_get_start(np->mmio_res);

        /*
         *  Allocate the IRQ.
         */
        i = 0;
        np->irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &i,
                                             RF_ACTIVE | RF_SHAREABLE);
        if (!np->irq_res) {
                device_printf(dev, "failed to allocate IRQ resource\n");
                goto attach_failed;
        }

#ifdef  SYM_CONF_IOMAPPED
        /*
         *  User want us to use normal IO with PCI.
         *  Alloc/get/map/retrieve everything that deals with IO.
         */
        i = SYM_PCI_IO;
        np->io_res = bus_alloc_resource_any(dev, SYS_RES_IOPORT, &i, RF_ACTIVE);
        if (!np->io_res) {
                device_printf(dev, "failed to allocate IO resources\n");
                goto attach_failed;
        }

#endif /* SYM_CONF_IOMAPPED */

        /*
         *  If the chip has RAM.
         *  Alloc/get/map/retrieve the corresponding resources.
         */
        if (np->features & (FE_RAM|FE_RAM8K)) {
                int regs_id = SYM_PCI_RAM;
                if (np->features & FE_64BIT)
                        regs_id = SYM_PCI_RAM64;
                np->ram_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY,
                                                     &regs_id, RF_ACTIVE);
                if (!np->ram_res) {
                        device_printf(dev,"failed to allocate RAM resources\n");
                        goto attach_failed;
                }
                np->ram_id  = regs_id;
                np->ram_ba = rman_get_start(np->ram_res);
        }

        /*
         *  Save setting of some IO registers, so we will
         *  be able to probe specific implementations.
         */
        sym_save_initial_setting (np);

        /*
         *  Reset the chip now, since it has been reported
         *  that SCSI clock calibration may not work properly
         *  if the chip is currently active.
         */
        sym_chip_reset (np);

        /*
         *  Try to read the user set-up.
         */
        (void) sym_read_nvram(np, &nvram);

        /*
         *  Prepare controller and devices settings, according
         *  to chip features, user set-up and driver set-up.
         */
        (void) sym_prepare_setting(np, &nvram);

        /*
         *  Check the PCI clock frequency.
         *  Must be performed after prepare_setting since it destroys
         *  STEST1 that is used to probe for the clock doubler.
         */
        i = sym_getpciclock(np);
        if (i > 37000)
                device_printf(dev, "PCI BUS clock seems too high: %u KHz.\n",i);

        /*
         *  Allocate the start queue.
         */
        np->squeue = (u32 *) sym_calloc_dma(sizeof(u32)*(MAX_QUEUE*2),"SQUEUE");
        if (!np->squeue)
                goto attach_failed;
        np->squeue_ba = vtobus(np->squeue);

        /*
         *  Allocate the done queue.
         */
        np->dqueue = (u32 *) sym_calloc_dma(sizeof(u32)*(MAX_QUEUE*2),"DQUEUE");
        if (!np->dqueue)
                goto attach_failed;
        np->dqueue_ba = vtobus(np->dqueue);

        /*
         *  Allocate the target bus address array.
         */
        np->targtbl = (u32 *) sym_calloc_dma(256, "TARGTBL");
        if (!np->targtbl)
                goto attach_failed;
        np->targtbl_ba = vtobus(np->targtbl);

        /*
         *  Allocate SCRIPTS areas.
         */
        np->scripta0 = sym_calloc_dma(np->scripta_sz, "SCRIPTA0");
        np->scriptb0 = sym_calloc_dma(np->scriptb_sz, "SCRIPTB0");
        if (!np->scripta0 || !np->scriptb0)
                goto attach_failed;

        /*
         *  Allocate the CCBs. We need at least ONE.
         */
        for (i = 0; sym_alloc_ccb(np) != NULL; i++)
                ;
        if (i < 1)
                goto attach_failed;

        /*
         *  Calculate BUS addresses where we are going
         *  to load the SCRIPTS.
         */
        np->scripta_ba  = vtobus(np->scripta0);
        np->scriptb_ba  = vtobus(np->scriptb0);
        np->scriptb0_ba = np->scriptb_ba;

        if (np->ram_ba) {
                np->scripta_ba  = np->ram_ba;
                if (np->features & FE_RAM8K) {
                        np->ram_ws = 8192;
                        np->scriptb_ba = np->scripta_ba + 4096;
#ifdef __LP64__
                        np->scr_ram_seg = cpu_to_scr(np->scripta_ba >> 32);
#endif
                }
                else
                        np->ram_ws = 4096;
        }

        /*
         *  Copy scripts to controller instance.
         */
        bcopy(fw->a_base, np->scripta0, np->scripta_sz);
        bcopy(fw->b_base, np->scriptb0, np->scriptb_sz);

        /*
         *  Setup variable parts in scripts and compute
         *  scripts bus addresses used from the C code.
         */
        np->fw_setup(np, fw);

        /*
         *  Bind SCRIPTS with physical addresses usable by the
         *  SCRIPTS processor (as seen from the BUS = BUS addresses).
         */
        sym_fw_bind_script(np, (u32 *) np->scripta0, np->scripta_sz);
        sym_fw_bind_script(np, (u32 *) np->scriptb0, np->scriptb_sz);

#ifdef SYM_CONF_IARB_SUPPORT
        /*
         *    If user wants IARB to be set when we win arbitration
         *    and have other jobs, compute the max number of consecutive
         *    settings of IARB hints before we leave devices a chance to
         *    arbitrate for reselection.
         */
#ifdef  SYM_SETUP_IARB_MAX
        np->iarb_max = SYM_SETUP_IARB_MAX;
#else
        np->iarb_max = 4;
#endif
#endif

        /*
         *  Prepare the idle and invalid task actions.
         */
        np->idletask.start      = cpu_to_scr(SCRIPTA_BA (np, idle));
        np->idletask.restart    = cpu_to_scr(SCRIPTB_BA (np, bad_i_t_l));
        np->idletask_ba         = vtobus(&np->idletask);

        np->notask.start        = cpu_to_scr(SCRIPTA_BA (np, idle));
        np->notask.restart      = cpu_to_scr(SCRIPTB_BA (np, bad_i_t_l));
        np->notask_ba           = vtobus(&np->notask);

        np->bad_itl.start       = cpu_to_scr(SCRIPTA_BA (np, idle));
        np->bad_itl.restart     = cpu_to_scr(SCRIPTB_BA (np, bad_i_t_l));
        np->bad_itl_ba          = vtobus(&np->bad_itl);

        np->bad_itlq.start      = cpu_to_scr(SCRIPTA_BA (np, idle));
        np->bad_itlq.restart    = cpu_to_scr(SCRIPTB_BA (np,bad_i_t_l_q));
        np->bad_itlq_ba         = vtobus(&np->bad_itlq);

        /*
         *  Allocate and prepare the lun JUMP table that is used
         *  for a target prior the probing of devices (bad lun table).
         *  A private table will be allocated for the target on the
         *  first INQUIRY response received.
         */
        np->badluntbl = sym_calloc_dma(256, "BADLUNTBL");
        if (!np->badluntbl)
                goto attach_failed;

        np->badlun_sa = cpu_to_scr(SCRIPTB_BA (np, resel_bad_lun));
        for (i = 0 ; i < 64 ; i++)      /* 64 luns/target, no less */
                np->badluntbl[i] = cpu_to_scr(vtobus(&np->badlun_sa));

        /*
         *  Prepare the bus address array that contains the bus
         *  address of each target control block.
         *  For now, assume all logical units are wrong. :)
         */
        for (i = 0 ; i < SYM_CONF_MAX_TARGET ; i++) {
                np->targtbl[i] = cpu_to_scr(vtobus(&np->target[i]));
                np->target[i].head.luntbl_sa =
                                cpu_to_scr(vtobus(np->badluntbl));
                np->target[i].head.lun0_sa =
                                cpu_to_scr(vtobus(&np->badlun_sa));
        }

        /*
         *  Now check the cache handling of the pci chipset.
         */
        if (sym_snooptest (np)) {
                device_printf(dev, "CACHE INCORRECTLY CONFIGURED.\n");
                goto attach_failed;
        }

        /*
         *  Now deal with CAM.
         *  Hopefully, we will succeed with that one.:)
         */
        if (!sym_cam_attach(np))
                goto attach_failed;

        /*
         *  Sigh! we are done.
         */
        return 0;

        /*
         *  We have failed.
         *  We will try to free all the resources we have
         *  allocated, but if we are a boot device, this
         *  will not help that much.;)
         */
attach_failed:
        if (np)
                sym_pci_free(np);
        return ENXIO;
}

/*
 *  Free everything that have been allocated for this device.
 */
static void sym_pci_free(hcb_p np)
{
        SYM_QUEHEAD *qp;
        ccb_p cp;
        tcb_p tp;
        lcb_p lp;
        int target, lun;

        /*
         *  First free CAM resources.
         */
        sym_cam_free(np);

        /*
         *  Now every should be quiet for us to
         *  free other resources.
         */
        if (np->ram_res)
                bus_release_resource(np->device, SYS_RES_MEMORY,
                                     np->ram_id, np->ram_res);
        if (np->mmio_res)
                bus_release_resource(np->device, SYS_RES_MEMORY,
                                     SYM_PCI_MMIO, np->mmio_res);
        if (np->io_res)
                bus_release_resource(np->device, SYS_RES_IOPORT,
                                     SYM_PCI_IO, np->io_res);
        if (np->irq_res)
                bus_release_resource(np->device, SYS_RES_IRQ,
                                     0, np->irq_res);

        if (np->scriptb0)
                sym_mfree_dma(np->scriptb0, np->scriptb_sz, "SCRIPTB0");
        if (np->scripta0)
                sym_mfree_dma(np->scripta0, np->scripta_sz, "SCRIPTA0");
        if (np->squeue)
                sym_mfree_dma(np->squeue, sizeof(u32)*(MAX_QUEUE*2), "SQUEUE");
        if (np->dqueue)
                sym_mfree_dma(np->dqueue, sizeof(u32)*(MAX_QUEUE*2), "DQUEUE");

        while ((qp = sym_remque_head(&np->free_ccbq)) != NULL) {
                cp = sym_que_entry(qp, struct sym_ccb, link_ccbq);
                bus_dmamap_destroy(np->data_dmat, cp->dmamap);
                sym_mfree_dma(cp->sns_bbuf, SYM_SNS_BBUF_LEN, "SNS_BBUF");
                sym_mfree_dma(cp, sizeof(*cp), "CCB");
        }

        if (np->badluntbl)
                sym_mfree_dma(np->badluntbl, 256,"BADLUNTBL");

        for (target = 0; target < SYM_CONF_MAX_TARGET ; target++) {
                tp = &np->target[target];
                for (lun = 0 ; lun < SYM_CONF_MAX_LUN ; lun++) {
                        lp = sym_lp(tp, lun);
                        if (!lp)
                                continue;
                        if (lp->itlq_tbl)
                                sym_mfree_dma(lp->itlq_tbl, SYM_CONF_MAX_TASK*4,
                                       "ITLQ_TBL");
                        if (lp->cb_tags)
                                sym_mfree(lp->cb_tags, SYM_CONF_MAX_TASK,
                                       "CB_TAGS");
                        sym_mfree_dma(lp, sizeof(*lp), "LCB");
                }
#if SYM_CONF_MAX_LUN > 1
                if (tp->lunmp)
                        sym_mfree(tp->lunmp, SYM_CONF_MAX_LUN*sizeof(lcb_p),
                               "LUNMP");
#endif
        }
#ifdef __amd64__
        if (np->target)
                sym_mfree_dma(np->target,
                        SYM_CONF_MAX_TARGET * sizeof(*(np->target)), "TARGET");
#endif
        if (np->targtbl)
                sym_mfree_dma(np->targtbl, 256, "TARGTBL");
        if (np->data_dmat)
                bus_dma_tag_destroy(np->data_dmat);
        if (SYM_LOCK_INITIALIZED() != 0)
                SYM_LOCK_DESTROY();
        device_set_softc(np->device, NULL);
        sym_mfree_dma(np, sizeof(*np), "HCB");
}

/*
 *  Allocate CAM resources and register a bus to CAM.
 */
static int sym_cam_attach(hcb_p np)
{
        struct cam_devq *devq = NULL;
        struct cam_sim *sim = NULL;
        struct cam_path *path = NULL;
        int err;

        /*
         *  Establish our interrupt handler.
         */
        err = bus_setup_intr(np->device, np->irq_res,
                        INTR_ENTROPY | INTR_MPSAFE | INTR_TYPE_CAM,
                        NULL, sym_intr, np, &np->intr);
        if (err) {
                device_printf(np->device, "bus_setup_intr() failed: %d\n",
                              err);
                goto fail;
        }

        /*
         *  Create the device queue for our sym SIM.
         */
        devq = cam_simq_alloc(SYM_CONF_MAX_START);
        if (!devq)
                goto fail;

        /*
         *  Construct our SIM entry.
         */
        sim = cam_sim_alloc(sym_action, sym_poll, "sym", np,
                        device_get_unit(np->device),
                        &np->mtx, 1, SYM_SETUP_MAX_TAG, devq);
        if (!sim)
                goto fail;

        SYM_LOCK();

        if (xpt_bus_register(sim, np->device, 0) != CAM_SUCCESS)
                goto fail;
        np->sim = sim;
        sim = NULL;

        if (xpt_create_path(&path, NULL,
                            cam_sim_path(np->sim), CAM_TARGET_WILDCARD,
                            CAM_LUN_WILDCARD) != CAM_REQ_CMP) {
                goto fail;
        }
        np->path = path;

        /*
         *  Establish our async notification handler.
         */
        if (xpt_register_async(AC_LOST_DEVICE, sym_async, np->sim, path) !=
            CAM_REQ_CMP)
                goto fail;

        /*
         *  Start the chip now, without resetting the BUS, since
         *  it seems that this must stay under control of CAM.
         *  With LVD/SE capable chips and BUS in SE mode, we may
         *  get a spurious SMBC interrupt.
         */
        sym_init (np, 0);

        SYM_UNLOCK();

        return 1;
fail:
        if (sim)
                cam_sim_free(sim, FALSE);
        if (devq)
                cam_simq_free(devq);

        SYM_UNLOCK();

        sym_cam_free(np);

        return 0;
}

/*
 *  Free everything that deals with CAM.
 */
static void sym_cam_free(hcb_p np)
{

        SYM_LOCK_ASSERT(MA_NOTOWNED);

        if (np->intr) {
                bus_teardown_intr(np->device, np->irq_res, np->intr);
                np->intr = NULL;
        }

        SYM_LOCK();

        if (np->sim) {
                xpt_bus_deregister(cam_sim_path(np->sim));
                cam_sim_free(np->sim, /*free_devq*/ TRUE);
                np->sim = NULL;
        }
        if (np->path) {
                xpt_free_path(np->path);
                np->path = NULL;
        }

        SYM_UNLOCK();
}

/*============ OPTIONNAL NVRAM SUPPORT =================*/

/*
 *  Get host setup from NVRAM.
 */
static void sym_nvram_setup_host (hcb_p np, struct sym_nvram *nvram)
{
#ifdef SYM_CONF_NVRAM_SUPPORT
        /*
         *  Get parity checking, host ID, verbose mode
         *  and miscellaneous host flags from NVRAM.
         */
        switch(nvram->type) {
        case SYM_SYMBIOS_NVRAM:
                if (!(nvram->data.Symbios.flags & SYMBIOS_PARITY_ENABLE))
                        np->rv_scntl0  &= ~0x0a;
                np->myaddr = nvram->data.Symbios.host_id & 0x0f;
                if (nvram->data.Symbios.flags & SYMBIOS_VERBOSE_MSGS)
                        np->verbose += 1;
                if (nvram->data.Symbios.flags1 & SYMBIOS_SCAN_HI_LO)
                        np->usrflags |= SYM_SCAN_TARGETS_HILO;
                if (nvram->data.Symbios.flags2 & SYMBIOS_AVOID_BUS_RESET)
                        np->usrflags |= SYM_AVOID_BUS_RESET;
                break;
        case SYM_TEKRAM_NVRAM:
                np->myaddr = nvram->data.Tekram.host_id & 0x0f;
                break;
        default:
                break;
        }
#endif
}

/*
 *  Get target setup from NVRAM.
 */
#ifdef SYM_CONF_NVRAM_SUPPORT
static void sym_Symbios_setup_target(hcb_p np,int target, Symbios_nvram *nvram);
static void sym_Tekram_setup_target(hcb_p np,int target, Tekram_nvram *nvram);
#endif

static void
sym_nvram_setup_target (hcb_p np, int target, struct sym_nvram *nvp)
{
#ifdef SYM_CONF_NVRAM_SUPPORT
        switch(nvp->type) {
        case SYM_SYMBIOS_NVRAM:
                sym_Symbios_setup_target (np, target, &nvp->data.Symbios);
                break;
        case SYM_TEKRAM_NVRAM:
                sym_Tekram_setup_target (np, target, &nvp->data.Tekram);
                break;
        default:
                break;
        }
#endif
}

#ifdef SYM_CONF_NVRAM_SUPPORT
/*
 *  Get target set-up from Symbios format NVRAM.
 */
static void
sym_Symbios_setup_target(hcb_p np, int target, Symbios_nvram *nvram)
{
        tcb_p tp = &np->target[target];
        Symbios_target *tn = &nvram->target[target];

        tp->tinfo.user.period = tn->sync_period ? (tn->sync_period + 3) / 4 : 0;
        tp->tinfo.user.width  = tn->bus_width == 0x10 ? BUS_16_BIT : BUS_8_BIT;
        tp->usrtags =
                (tn->flags & SYMBIOS_QUEUE_TAGS_ENABLED)? SYM_SETUP_MAX_TAG : 0;

        if (!(tn->flags & SYMBIOS_DISCONNECT_ENABLE))
                tp->usrflags &= ~SYM_DISC_ENABLED;
        if (!(tn->flags & SYMBIOS_SCAN_AT_BOOT_TIME))
                tp->usrflags |= SYM_SCAN_BOOT_DISABLED;
        if (!(tn->flags & SYMBIOS_SCAN_LUNS))
                tp->usrflags |= SYM_SCAN_LUNS_DISABLED;
}

/*
 *  Get target set-up from Tekram format NVRAM.
 */
static void
sym_Tekram_setup_target(hcb_p np, int target, Tekram_nvram *nvram)
{
        tcb_p tp = &np->target[target];
        struct Tekram_target *tn = &nvram->target[target];
        int i;

        if (tn->flags & TEKRAM_SYNC_NEGO) {
                i = tn->sync_index & 0xf;
                tp->tinfo.user.period = Tekram_sync[i];
        }

        tp->tinfo.user.width =
                (tn->flags & TEKRAM_WIDE_NEGO) ? BUS_16_BIT : BUS_8_BIT;

        if (tn->flags & TEKRAM_TAGGED_COMMANDS) {
                tp->usrtags = 2 << nvram->max_tags_index;
        }

        if (tn->flags & TEKRAM_DISCONNECT_ENABLE)
                tp->usrflags |= SYM_DISC_ENABLED;

        /* If any device does not support parity, we will not use this option */
        if (!(tn->flags & TEKRAM_PARITY_CHECK))
                np->rv_scntl0  &= ~0x0a; /* SCSI parity checking disabled */
}

#ifdef  SYM_CONF_DEBUG_NVRAM
/*
 *  Dump Symbios format NVRAM for debugging purpose.
 */
static void sym_display_Symbios_nvram(hcb_p np, Symbios_nvram *nvram)
{
        int i;

        /* display Symbios nvram host data */
        printf("%s: HOST ID=%d%s%s%s%s%s%s\n",
                sym_name(np), nvram->host_id & 0x0f,
                (nvram->flags  & SYMBIOS_SCAM_ENABLE)   ? " SCAM"       :"",
                (nvram->flags  & SYMBIOS_PARITY_ENABLE) ? " PARITY"     :"",
                (nvram->flags  & SYMBIOS_VERBOSE_MSGS)  ? " VERBOSE"    :"",
                (nvram->flags  & SYMBIOS_CHS_MAPPING)   ? " CHS_ALT"    :"",
                (nvram->flags2 & SYMBIOS_AVOID_BUS_RESET)?" NO_RESET"   :"",
                (nvram->flags1 & SYMBIOS_SCAN_HI_LO)    ? " HI_LO"      :"");

        /* display Symbios nvram drive data */
        for (i = 0 ; i < 15 ; i++) {
                struct Symbios_target *tn = &nvram->target[i];
                printf("%s-%d:%s%s%s%s WIDTH=%d SYNC=%d TMO=%d\n",
                sym_name(np), i,
                (tn->flags & SYMBIOS_DISCONNECT_ENABLE) ? " DISC"       : "",
                (tn->flags & SYMBIOS_SCAN_AT_BOOT_TIME) ? " SCAN_BOOT"  : "",
                (tn->flags & SYMBIOS_SCAN_LUNS)         ? " SCAN_LUNS"  : "",
                (tn->flags & SYMBIOS_QUEUE_TAGS_ENABLED)? " TCQ"        : "",
                tn->bus_width,
                tn->sync_period / 4,
                tn->timeout);
        }
}

/*
 *  Dump TEKRAM format NVRAM for debugging purpose.
 */
static const u_char Tekram_boot_delay[7] = {3, 5, 10, 20, 30, 60, 120};
static void sym_display_Tekram_nvram(hcb_p np, Tekram_nvram *nvram)
{
        int i, tags, boot_delay;
        char *rem;

        /* display Tekram nvram host data */
        tags = 2 << nvram->max_tags_index;
        boot_delay = 0;
        if (nvram->boot_delay_index < 6)
                boot_delay = Tekram_boot_delay[nvram->boot_delay_index];
        switch((nvram->flags & TEKRAM_REMOVABLE_FLAGS) >> 6) {
        default:
        case 0: rem = "";                       break;
        case 1: rem = " REMOVABLE=boot device"; break;
        case 2: rem = " REMOVABLE=all";         break;
        }

        printf("%s: HOST ID=%d%s%s%s%s%s%s%s%s%s BOOT DELAY=%d tags=%d\n",
                sym_name(np), nvram->host_id & 0x0f,
                (nvram->flags1 & SYMBIOS_SCAM_ENABLE)   ? " SCAM"       :"",
                (nvram->flags & TEKRAM_MORE_THAN_2_DRIVES) ? " >2DRIVES"        :"",
                (nvram->flags & TEKRAM_DRIVES_SUP_1GB)  ? " >1GB"       :"",
                (nvram->flags & TEKRAM_RESET_ON_POWER_ON) ? " RESET"    :"",
                (nvram->flags & TEKRAM_ACTIVE_NEGATION) ? " ACT_NEG"    :"",
                (nvram->flags & TEKRAM_IMMEDIATE_SEEK)  ? " IMM_SEEK"   :"",
                (nvram->flags & TEKRAM_SCAN_LUNS)       ? " SCAN_LUNS"  :"",
                (nvram->flags1 & TEKRAM_F2_F6_ENABLED)  ? " F2_F6"      :"",
                rem, boot_delay, tags);

        /* display Tekram nvram drive data */
        for (i = 0; i <= 15; i++) {
                int sync, j;
                struct Tekram_target *tn = &nvram->target[i];
                j = tn->sync_index & 0xf;
                sync = Tekram_sync[j];
                printf("%s-%d:%s%s%s%s%s%s PERIOD=%d\n",
                sym_name(np), i,
                (tn->flags & TEKRAM_PARITY_CHECK)       ? " PARITY"     : "",
                (tn->flags & TEKRAM_SYNC_NEGO)          ? " SYNC"       : "",
                (tn->flags & TEKRAM_DISCONNECT_ENABLE)  ? " DISC"       : "",
                (tn->flags & TEKRAM_START_CMD)          ? " START"      : "",
                (tn->flags & TEKRAM_TAGGED_COMMANDS)    ? " TCQ"        : "",
                (tn->flags & TEKRAM_WIDE_NEGO)          ? " WIDE"       : "",
                sync);
        }
}
#endif  /* SYM_CONF_DEBUG_NVRAM */
#endif  /* SYM_CONF_NVRAM_SUPPORT */

/*
 *  Try reading Symbios or Tekram NVRAM
 */
#ifdef SYM_CONF_NVRAM_SUPPORT
static int sym_read_Symbios_nvram (hcb_p np, Symbios_nvram *nvram);
static int sym_read_Tekram_nvram  (hcb_p np, Tekram_nvram *nvram);
#endif

static int sym_read_nvram(hcb_p np, struct sym_nvram *nvp)
{
#ifdef SYM_CONF_NVRAM_SUPPORT
        /*
         *  Try to read SYMBIOS nvram.
         *  Try to read TEKRAM nvram if Symbios nvram not found.
         */
        if      (SYM_SETUP_SYMBIOS_NVRAM &&
                 !sym_read_Symbios_nvram (np, &nvp->data.Symbios)) {
                nvp->type = SYM_SYMBIOS_NVRAM;
#ifdef SYM_CONF_DEBUG_NVRAM
                sym_display_Symbios_nvram(np, &nvp->data.Symbios);
#endif
        }
        else if (SYM_SETUP_TEKRAM_NVRAM &&
                 !sym_read_Tekram_nvram (np, &nvp->data.Tekram)) {
                nvp->type = SYM_TEKRAM_NVRAM;
#ifdef SYM_CONF_DEBUG_NVRAM
                sym_display_Tekram_nvram(np, &nvp->data.Tekram);
#endif
        }
        else
                nvp->type = 0;
#else
        nvp->type = 0;
#endif
        return nvp->type;
}

#ifdef SYM_CONF_NVRAM_SUPPORT
/*
 *  24C16 EEPROM reading.
 *
 *  GPOI0 - data in/data out
 *  GPIO1 - clock
 *  Symbios NVRAM wiring now also used by Tekram.
 */

#define SET_BIT 0
#define CLR_BIT 1
#define SET_CLK 2
#define CLR_CLK 3

/*
 *  Set/clear data/clock bit in GPIO0
 */
static void S24C16_set_bit(hcb_p np, u_char write_bit, u_char *gpreg,
                          int bit_mode)
{
        UDELAY (5);
        switch (bit_mode){
        case SET_BIT:
                *gpreg |= write_bit;
                break;
        case CLR_BIT:
                *gpreg &= 0xfe;
                break;
        case SET_CLK:
                *gpreg |= 0x02;
                break;
        case CLR_CLK:
                *gpreg &= 0xfd;
                break;

        }
        OUTB (nc_gpreg, *gpreg);
        UDELAY (5);
}

/*
 *  Send START condition to NVRAM to wake it up.
 */
static void S24C16_start(hcb_p np, u_char *gpreg)
{
        S24C16_set_bit(np, 1, gpreg, SET_BIT);
        S24C16_set_bit(np, 0, gpreg, SET_CLK);
        S24C16_set_bit(np, 0, gpreg, CLR_BIT);
        S24C16_set_bit(np, 0, gpreg, CLR_CLK);
}

/*
 *  Send STOP condition to NVRAM - puts NVRAM to sleep... ZZzzzz!!
 */
static void S24C16_stop(hcb_p np, u_char *gpreg)
{
        S24C16_set_bit(np, 0, gpreg, SET_CLK);
        S24C16_set_bit(np, 1, gpreg, SET_BIT);
}

/*
 *  Read or write a bit to the NVRAM,
 *  read if GPIO0 input else write if GPIO0 output
 */
static void S24C16_do_bit(hcb_p np, u_char *read_bit, u_char write_bit,
                         u_char *gpreg)
{
        S24C16_set_bit(np, write_bit, gpreg, SET_BIT);
        S24C16_set_bit(np, 0, gpreg, SET_CLK);
        if (read_bit)
                *read_bit = INB (nc_gpreg);
        S24C16_set_bit(np, 0, gpreg, CLR_CLK);
        S24C16_set_bit(np, 0, gpreg, CLR_BIT);
}

/*
 *  Output an ACK to the NVRAM after reading,
 *  change GPIO0 to output and when done back to an input
 */
static void S24C16_write_ack(hcb_p np, u_char write_bit, u_char *gpreg,
                            u_char *gpcntl)
{
        OUTB (nc_gpcntl, *gpcntl & 0xfe);
        S24C16_do_bit(np, 0, write_bit, gpreg);
        OUTB (nc_gpcntl, *gpcntl);
}

/*
 *  Input an ACK from NVRAM after writing,
 *  change GPIO0 to input and when done back to an output
 */
static void S24C16_read_ack(hcb_p np, u_char *read_bit, u_char *gpreg,
                           u_char *gpcntl)
{
        OUTB (nc_gpcntl, *gpcntl | 0x01);
        S24C16_do_bit(np, read_bit, 1, gpreg);
        OUTB (nc_gpcntl, *gpcntl);
}

/*
 *  WRITE a byte to the NVRAM and then get an ACK to see it was accepted OK,
 *  GPIO0 must already be set as an output
 */
static void S24C16_write_byte(hcb_p np, u_char *ack_data, u_char write_data,
                             u_char *gpreg, u_char *gpcntl)
{
        int x;

        for (x = 0; x < 8; x++)
                S24C16_do_bit(np, 0, (write_data >> (7 - x)) & 0x01, gpreg);

        S24C16_read_ack(np, ack_data, gpreg, gpcntl);
}

/*
 *  READ a byte from the NVRAM and then send an ACK to say we have got it,
 *  GPIO0 must already be set as an input
 */
static void S24C16_read_byte(hcb_p np, u_char *read_data, u_char ack_data,
                            u_char *gpreg, u_char *gpcntl)
{
        int x;
        u_char read_bit;

        *read_data = 0;
        for (x = 0; x < 8; x++) {
                S24C16_do_bit(np, &read_bit, 1, gpreg);
                *read_data |= ((read_bit & 0x01) << (7 - x));
        }

        S24C16_write_ack(np, ack_data, gpreg, gpcntl);
}

/*
 *  Read 'len' bytes starting at 'offset'.
 */
static int sym_read_S24C16_nvram (hcb_p np, int offset, u_char *data, int len)
{
        u_char  gpcntl, gpreg;
        u_char  old_gpcntl, old_gpreg;
        u_char  ack_data;
        int     retv = 1;
        int     x;

        /* save current state of GPCNTL and GPREG */
        old_gpreg       = INB (nc_gpreg);
        old_gpcntl      = INB (nc_gpcntl);
        gpcntl          = old_gpcntl & 0x1c;

        /* set up GPREG & GPCNTL to set GPIO0 and GPIO1 in to known state */
        OUTB (nc_gpreg,  old_gpreg);
        OUTB (nc_gpcntl, gpcntl);

        /* this is to set NVRAM into a known state with GPIO0/1 both low */
        gpreg = old_gpreg;
        S24C16_set_bit(np, 0, &gpreg, CLR_CLK);
        S24C16_set_bit(np, 0, &gpreg, CLR_BIT);

        /* now set NVRAM inactive with GPIO0/1 both high */
        S24C16_stop(np, &gpreg);

        /* activate NVRAM */
        S24C16_start(np, &gpreg);

        /* write device code and random address MSB */
        S24C16_write_byte(np, &ack_data,
                0xa0 | ((offset >> 7) & 0x0e), &gpreg, &gpcntl);
        if (ack_data & 0x01)
                goto out;

        /* write random address LSB */
        S24C16_write_byte(np, &ack_data,
                offset & 0xff, &gpreg, &gpcntl);
        if (ack_data & 0x01)
                goto out;

        /* regenerate START state to set up for reading */
        S24C16_start(np, &gpreg);

        /* rewrite device code and address MSB with read bit set (lsb = 0x01) */
        S24C16_write_byte(np, &ack_data,
                0xa1 | ((offset >> 7) & 0x0e), &gpreg, &gpcntl);
        if (ack_data & 0x01)
                goto out;

        /* now set up GPIO0 for inputting data */
        gpcntl |= 0x01;
        OUTB (nc_gpcntl, gpcntl);

        /* input all requested data - only part of total NVRAM */
        for (x = 0; x < len; x++)
                S24C16_read_byte(np, &data[x], (x == (len-1)), &gpreg, &gpcntl);

        /* finally put NVRAM back in inactive mode */
        gpcntl &= 0xfe;
        OUTB (nc_gpcntl, gpcntl);
        S24C16_stop(np, &gpreg);
        retv = 0;
out:
        /* return GPIO0/1 to original states after having accessed NVRAM */
        OUTB (nc_gpcntl, old_gpcntl);
        OUTB (nc_gpreg,  old_gpreg);

        return retv;
}

#undef SET_BIT /* 0 */
#undef CLR_BIT /* 1 */
#undef SET_CLK /* 2 */
#undef CLR_CLK /* 3 */

/*
 *  Try reading Symbios NVRAM.
 *  Return 0 if OK.
 */
static int sym_read_Symbios_nvram (hcb_p np, Symbios_nvram *nvram)
{
        static u_char Symbios_trailer[6] = {0xfe, 0xfe, 0, 0, 0, 0};
        u_char *data = (u_char *) nvram;
        int len  = sizeof(*nvram);
        u_short csum;
        int x;

        /* probe the 24c16 and read the SYMBIOS 24c16 area */
        if (sym_read_S24C16_nvram (np, SYMBIOS_NVRAM_ADDRESS, data, len))
                return 1;

        /* check valid NVRAM signature, verify byte count and checksum */
        if (nvram->type != 0 ||
            bcmp(nvram->trailer, Symbios_trailer, 6) ||
            nvram->byte_count != len - 12)
                return 1;

        /* verify checksum */
        for (x = 6, csum = 0; x < len - 6; x++)
                csum += data[x];
        if (csum != nvram->checksum)
                return 1;

        return 0;
}

/*
 *  93C46 EEPROM reading.
 *
 *  GPOI0 - data in
 *  GPIO1 - data out
 *  GPIO2 - clock
 *  GPIO4 - chip select
 *
 *  Used by Tekram.
 */

/*
 *  Pulse clock bit in GPIO0
 */
static void T93C46_Clk(hcb_p np, u_char *gpreg)
{
        OUTB (nc_gpreg, *gpreg | 0x04);
        UDELAY (2);
        OUTB (nc_gpreg, *gpreg);
}

/*
 *  Read bit from NVRAM
 */
static void T93C46_Read_Bit(hcb_p np, u_char *read_bit, u_char *gpreg)
{
        UDELAY (2);
        T93C46_Clk(np, gpreg);
        *read_bit = INB (nc_gpreg);
}

/*
 *  Write bit to GPIO0
 */
static void T93C46_Write_Bit(hcb_p np, u_char write_bit, u_char *gpreg)
{
        if (write_bit & 0x01)
                *gpreg |= 0x02;
        else
                *gpreg &= 0xfd;

        *gpreg |= 0x10;

        OUTB (nc_gpreg, *gpreg);
        UDELAY (2);

        T93C46_Clk(np, gpreg);
}

/*
 *  Send STOP condition to NVRAM - puts NVRAM to sleep... ZZZzzz!!
 */
static void T93C46_Stop(hcb_p np, u_char *gpreg)
{
        *gpreg &= 0xef;
        OUTB (nc_gpreg, *gpreg);
        UDELAY (2);

        T93C46_Clk(np, gpreg);
}

/*
 *  Send read command and address to NVRAM
 */
static void T93C46_Send_Command(hcb_p np, u_short write_data,
                                u_char *read_bit, u_char *gpreg)
{
        int x;

        /* send 9 bits, start bit (1), command (2), address (6)  */
        for (x = 0; x < 9; x++)
                T93C46_Write_Bit(np, (u_char) (write_data >> (8 - x)), gpreg);

        *read_bit = INB (nc_gpreg);
}

/*
 *  READ 2 bytes from the NVRAM
 */
static void T93C46_Read_Word(hcb_p np, u_short *nvram_data, u_char *gpreg)
{
        int x;
        u_char read_bit;

        *nvram_data = 0;
        for (x = 0; x < 16; x++) {
                T93C46_Read_Bit(np, &read_bit, gpreg);

                if (read_bit & 0x01)
                        *nvram_data |=  (0x01 << (15 - x));
                else
                        *nvram_data &= ~(0x01 << (15 - x));
        }
}

/*
 *  Read Tekram NvRAM data.
 */
static int T93C46_Read_Data(hcb_p np, u_short *data,int len,u_char *gpreg)
{
        u_char  read_bit;
        int     x;

        for (x = 0; x < len; x++)  {

                /* output read command and address */
                T93C46_Send_Command(np, 0x180 | x, &read_bit, gpreg);
                if (read_bit & 0x01)
                        return 1; /* Bad */
                T93C46_Read_Word(np, &data[x], gpreg);
                T93C46_Stop(np, gpreg);
        }

        return 0;
}

/*
 *  Try reading 93C46 Tekram NVRAM.
 */
static int sym_read_T93C46_nvram (hcb_p np, Tekram_nvram *nvram)
{
        u_char gpcntl, gpreg;
        u_char old_gpcntl, old_gpreg;
        int retv = 1;

        /* save current state of GPCNTL and GPREG */
        old_gpreg       = INB (nc_gpreg);
        old_gpcntl      = INB (nc_gpcntl);

        /* set up GPREG & GPCNTL to set GPIO0/1/2/4 in to known state, 0 in,
           1/2/4 out */
        gpreg = old_gpreg & 0xe9;
        OUTB (nc_gpreg, gpreg);
        gpcntl = (old_gpcntl & 0xe9) | 0x09;
        OUTB (nc_gpcntl, gpcntl);

        /* input all of NVRAM, 64 words */
        retv = T93C46_Read_Data(np, (u_short *) nvram,
                                sizeof(*nvram) / sizeof(short), &gpreg);

        /* return GPIO0/1/2/4 to original states after having accessed NVRAM */
        OUTB (nc_gpcntl, old_gpcntl);
        OUTB (nc_gpreg,  old_gpreg);

        return retv;
}

/*
 *  Try reading Tekram NVRAM.
 *  Return 0 if OK.
 */
static int sym_read_Tekram_nvram (hcb_p np, Tekram_nvram *nvram)
{
        u_char *data = (u_char *) nvram;
        int len = sizeof(*nvram);
        u_short csum;
        int x;

        switch (np->device_id) {
        case PCI_ID_SYM53C885:
        case PCI_ID_SYM53C895:
        case PCI_ID_SYM53C896:
                x = sym_read_S24C16_nvram(np, TEKRAM_24C16_NVRAM_ADDRESS,
                                          data, len);
                break;
        case PCI_ID_SYM53C875:
                x = sym_read_S24C16_nvram(np, TEKRAM_24C16_NVRAM_ADDRESS,
                                          data, len);
                if (!x)
                        break;
        default:
                x = sym_read_T93C46_nvram(np, nvram);
                break;
        }
        if (x)
                return 1;

        /* verify checksum */
        for (x = 0, csum = 0; x < len - 1; x += 2)
                csum += data[x] + (data[x+1] << 8);
        if (csum != 0x1234)
                return 1;

        return 0;
}

#endif  /* SYM_CONF_NVRAM_SUPPORT */