MFV r245512:

[FreeBSD/FreeBSD.git] / sys / powerpc / booke / pmap.c

/*-
 * Copyright (C) 2007-2009 Semihalf, Rafal Jaworowski <raj@semihalf.com>
 * Copyright (C) 2006 Semihalf, Marian Balakowicz <m8@semihalf.com>
 * All rights reserved.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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.
 *
 * Some hw specific parts of this pmap were derived or influenced
 * by NetBSD's ibm4xx pmap module. More generic code is shared with
 * a few other pmap modules from the FreeBSD tree.
 */

 /*
  * VM layout notes:
  *
  * Kernel and user threads run within one common virtual address space
  * defined by AS=0.
  *
  * Virtual address space layout:
  * -----------------------------
  * 0x0000_0000 - 0xafff_ffff   : user process
  * 0xb000_0000 - 0xbfff_ffff   : pmap_mapdev()-ed area (PCI/PCIE etc.)
  * 0xc000_0000 - 0xc0ff_ffff   : kernel reserved
  *   0xc000_0000 - data_end    : kernel code+data, env, metadata etc.
  * 0xc100_0000 - 0xfeef_ffff   : KVA
  *   0xc100_0000 - 0xc100_3fff : reserved for page zero/copy
  *   0xc100_4000 - 0xc200_3fff : reserved for ptbl bufs
  *   0xc200_4000 - 0xc200_8fff : guard page + kstack0
  *   0xc200_9000 - 0xfeef_ffff : actual free KVA space
  * 0xfef0_0000 - 0xffff_ffff   : I/O devices region
  */

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

#include <sys/param.h>
#include <sys/malloc.h>
#include <sys/ktr.h>
#include <sys/proc.h>
#include <sys/user.h>
#include <sys/queue.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/linker.h>
#include <sys/msgbuf.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/rwlock.h>
#include <sys/sched.h>
#include <sys/smp.h>
#include <sys/vmmeter.h>

#include <vm/vm.h>
#include <vm/vm_page.h>
#include <vm/vm_kern.h>
#include <vm/vm_pageout.h>
#include <vm/vm_extern.h>
#include <vm/vm_object.h>
#include <vm/vm_param.h>
#include <vm/vm_map.h>
#include <vm/vm_pager.h>
#include <vm/uma.h>

#include <machine/cpu.h>
#include <machine/pcb.h>
#include <machine/platform.h>

#include <machine/tlb.h>
#include <machine/spr.h>
#include <machine/md_var.h>
#include <machine/mmuvar.h>
#include <machine/pmap.h>
#include <machine/pte.h>

#include "mmu_if.h"

#ifdef  DEBUG
#define debugf(fmt, args...) printf(fmt, ##args)
#else
#define debugf(fmt, args...)
#endif

#define TODO                    panic("%s: not implemented", __func__);

extern struct mtx sched_lock;

extern int dumpsys_minidump;

extern unsigned char _etext[];
extern unsigned char _end[];

extern uint32_t *bootinfo;

#ifdef SMP
extern uint32_t bp_ntlb1s;
#endif

vm_paddr_t ccsrbar_pa;
vm_paddr_t kernload;
vm_offset_t kernstart;
vm_size_t kernsize;

/* Message buffer and tables. */
static vm_offset_t data_start;
static vm_size_t data_end;

/* Phys/avail memory regions. */
static struct mem_region *availmem_regions;
static int availmem_regions_sz;
static struct mem_region *physmem_regions;
static int physmem_regions_sz;

/* Reserved KVA space and mutex for mmu_booke_zero_page. */
static vm_offset_t zero_page_va;
static struct mtx zero_page_mutex;

static struct mtx tlbivax_mutex;

/*
 * Reserved KVA space for mmu_booke_zero_page_idle. This is used
 * by idle thred only, no lock required.
 */
static vm_offset_t zero_page_idle_va;

/* Reserved KVA space and mutex for mmu_booke_copy_page. */
static vm_offset_t copy_page_src_va;
static vm_offset_t copy_page_dst_va;
static struct mtx copy_page_mutex;

/**************************************************************************/
/* PMAP */
/**************************************************************************/

static void mmu_booke_enter_locked(mmu_t, pmap_t, vm_offset_t, vm_page_t,
    vm_prot_t, boolean_t);

unsigned int kptbl_min;         /* Index of the first kernel ptbl. */
unsigned int kernel_ptbls;      /* Number of KVA ptbls. */

/*
 * If user pmap is processed with mmu_booke_remove and the resident count
 * drops to 0, there are no more pages to remove, so we need not continue.
 */
#define PMAP_REMOVE_DONE(pmap) \
        ((pmap) != kernel_pmap && (pmap)->pm_stats.resident_count == 0)

extern void tid_flush(tlbtid_t);

/**************************************************************************/
/* TLB and TID handling */
/**************************************************************************/

/* Translation ID busy table */
static volatile pmap_t tidbusy[MAXCPU][TID_MAX + 1];

/*
 * TLB0 capabilities (entry, way numbers etc.). These can vary between e500
 * core revisions and should be read from h/w registers during early config.
 */
uint32_t tlb0_entries;
uint32_t tlb0_ways;
uint32_t tlb0_entries_per_way;

#define TLB0_ENTRIES            (tlb0_entries)
#define TLB0_WAYS               (tlb0_ways)
#define TLB0_ENTRIES_PER_WAY    (tlb0_entries_per_way)

#define TLB1_ENTRIES 16

/* In-ram copy of the TLB1 */
static tlb_entry_t tlb1[TLB1_ENTRIES];

/* Next free entry in the TLB1 */
static unsigned int tlb1_idx;

static tlbtid_t tid_alloc(struct pmap *);

static void tlb_print_entry(int, uint32_t, uint32_t, uint32_t, uint32_t);

static int tlb1_set_entry(vm_offset_t, vm_offset_t, vm_size_t, uint32_t);
static void tlb1_write_entry(unsigned int);
static int tlb1_iomapped(int, vm_paddr_t, vm_size_t, vm_offset_t *);
static vm_size_t tlb1_mapin_region(vm_offset_t, vm_paddr_t, vm_size_t);

static vm_size_t tsize2size(unsigned int);
static unsigned int size2tsize(vm_size_t);
static unsigned int ilog2(unsigned int);

static void set_mas4_defaults(void);

static inline void tlb0_flush_entry(vm_offset_t);
static inline unsigned int tlb0_tableidx(vm_offset_t, unsigned int);

/**************************************************************************/
/* Page table management */
/**************************************************************************/

static struct rwlock_padalign pvh_global_lock;

/* Data for the pv entry allocation mechanism */
static uma_zone_t pvzone;
static struct vm_object pvzone_obj;
static int pv_entry_count = 0, pv_entry_max = 0, pv_entry_high_water = 0;

#define PV_ENTRY_ZONE_MIN       2048    /* min pv entries in uma zone */

#ifndef PMAP_SHPGPERPROC
#define PMAP_SHPGPERPROC        200
#endif

static void ptbl_init(void);
static struct ptbl_buf *ptbl_buf_alloc(void);
static void ptbl_buf_free(struct ptbl_buf *);
static void ptbl_free_pmap_ptbl(pmap_t, pte_t *);

static pte_t *ptbl_alloc(mmu_t, pmap_t, unsigned int);
static void ptbl_free(mmu_t, pmap_t, unsigned int);
static void ptbl_hold(mmu_t, pmap_t, unsigned int);
static int ptbl_unhold(mmu_t, pmap_t, unsigned int);

static vm_paddr_t pte_vatopa(mmu_t, pmap_t, vm_offset_t);
static pte_t *pte_find(mmu_t, pmap_t, vm_offset_t);
static void pte_enter(mmu_t, pmap_t, vm_page_t, vm_offset_t, uint32_t);
static int pte_remove(mmu_t, pmap_t, vm_offset_t, uint8_t);

static pv_entry_t pv_alloc(void);
static void pv_free(pv_entry_t);
static void pv_insert(pmap_t, vm_offset_t, vm_page_t);
static void pv_remove(pmap_t, vm_offset_t, vm_page_t);

/* Number of kva ptbl buffers, each covering one ptbl (PTBL_PAGES). */
#define PTBL_BUFS               (128 * 16)

struct ptbl_buf {
        TAILQ_ENTRY(ptbl_buf) link;     /* list link */
        vm_offset_t kva;                /* va of mapping */
};

/* ptbl free list and a lock used for access synchronization. */
static TAILQ_HEAD(, ptbl_buf) ptbl_buf_freelist;
static struct mtx ptbl_buf_freelist_lock;

/* Base address of kva space allocated fot ptbl bufs. */
static vm_offset_t ptbl_buf_pool_vabase;

/* Pointer to ptbl_buf structures. */
static struct ptbl_buf *ptbl_bufs;

void pmap_bootstrap_ap(volatile uint32_t *);

/*
 * Kernel MMU interface
 */
static void             mmu_booke_change_wiring(mmu_t, pmap_t, vm_offset_t, boolean_t);
static void             mmu_booke_clear_modify(mmu_t, vm_page_t);
static void             mmu_booke_clear_reference(mmu_t, vm_page_t);
static void             mmu_booke_copy(mmu_t, pmap_t, pmap_t, vm_offset_t,
    vm_size_t, vm_offset_t);
static void             mmu_booke_copy_page(mmu_t, vm_page_t, vm_page_t);
static void             mmu_booke_enter(mmu_t, pmap_t, vm_offset_t, vm_page_t,
    vm_prot_t, boolean_t);
static void             mmu_booke_enter_object(mmu_t, pmap_t, vm_offset_t, vm_offset_t,
    vm_page_t, vm_prot_t);
static void             mmu_booke_enter_quick(mmu_t, pmap_t, vm_offset_t, vm_page_t,
    vm_prot_t);
static vm_paddr_t       mmu_booke_extract(mmu_t, pmap_t, vm_offset_t);
static vm_page_t        mmu_booke_extract_and_hold(mmu_t, pmap_t, vm_offset_t,
    vm_prot_t);
static void             mmu_booke_init(mmu_t);
static boolean_t        mmu_booke_is_modified(mmu_t, vm_page_t);
static boolean_t        mmu_booke_is_prefaultable(mmu_t, pmap_t, vm_offset_t);
static boolean_t        mmu_booke_is_referenced(mmu_t, vm_page_t);
static int              mmu_booke_ts_referenced(mmu_t, vm_page_t);
static vm_offset_t      mmu_booke_map(mmu_t, vm_offset_t *, vm_paddr_t, vm_paddr_t,
    int);
static int              mmu_booke_mincore(mmu_t, pmap_t, vm_offset_t,
    vm_paddr_t *);
static void             mmu_booke_object_init_pt(mmu_t, pmap_t, vm_offset_t,
    vm_object_t, vm_pindex_t, vm_size_t);
static boolean_t        mmu_booke_page_exists_quick(mmu_t, pmap_t, vm_page_t);
static void             mmu_booke_page_init(mmu_t, vm_page_t);
static int              mmu_booke_page_wired_mappings(mmu_t, vm_page_t);
static void             mmu_booke_pinit(mmu_t, pmap_t);
static void             mmu_booke_pinit0(mmu_t, pmap_t);
static void             mmu_booke_protect(mmu_t, pmap_t, vm_offset_t, vm_offset_t,
    vm_prot_t);
static void             mmu_booke_qenter(mmu_t, vm_offset_t, vm_page_t *, int);
static void             mmu_booke_qremove(mmu_t, vm_offset_t, int);
static void             mmu_booke_release(mmu_t, pmap_t);
static void             mmu_booke_remove(mmu_t, pmap_t, vm_offset_t, vm_offset_t);
static void             mmu_booke_remove_all(mmu_t, vm_page_t);
static void             mmu_booke_remove_write(mmu_t, vm_page_t);
static void             mmu_booke_zero_page(mmu_t, vm_page_t);
static void             mmu_booke_zero_page_area(mmu_t, vm_page_t, int, int);
static void             mmu_booke_zero_page_idle(mmu_t, vm_page_t);
static void             mmu_booke_activate(mmu_t, struct thread *);
static void             mmu_booke_deactivate(mmu_t, struct thread *);
static void             mmu_booke_bootstrap(mmu_t, vm_offset_t, vm_offset_t);
static void             *mmu_booke_mapdev(mmu_t, vm_paddr_t, vm_size_t);
static void             mmu_booke_unmapdev(mmu_t, vm_offset_t, vm_size_t);
static vm_paddr_t       mmu_booke_kextract(mmu_t, vm_offset_t);
static void             mmu_booke_kenter(mmu_t, vm_offset_t, vm_paddr_t);
static void             mmu_booke_kremove(mmu_t, vm_offset_t);
static boolean_t        mmu_booke_dev_direct_mapped(mmu_t, vm_paddr_t, vm_size_t);
static void             mmu_booke_sync_icache(mmu_t, pmap_t, vm_offset_t,
    vm_size_t);
static vm_offset_t      mmu_booke_dumpsys_map(mmu_t, struct pmap_md *,
    vm_size_t, vm_size_t *);
static void             mmu_booke_dumpsys_unmap(mmu_t, struct pmap_md *,
    vm_size_t, vm_offset_t);
static struct pmap_md   *mmu_booke_scan_md(mmu_t, struct pmap_md *);

static mmu_method_t mmu_booke_methods[] = {
        /* pmap dispatcher interface */
        MMUMETHOD(mmu_change_wiring,    mmu_booke_change_wiring),
        MMUMETHOD(mmu_clear_modify,     mmu_booke_clear_modify),
        MMUMETHOD(mmu_clear_reference,  mmu_booke_clear_reference),
        MMUMETHOD(mmu_copy,             mmu_booke_copy),
        MMUMETHOD(mmu_copy_page,        mmu_booke_copy_page),
        MMUMETHOD(mmu_enter,            mmu_booke_enter),
        MMUMETHOD(mmu_enter_object,     mmu_booke_enter_object),
        MMUMETHOD(mmu_enter_quick,      mmu_booke_enter_quick),
        MMUMETHOD(mmu_extract,          mmu_booke_extract),
        MMUMETHOD(mmu_extract_and_hold, mmu_booke_extract_and_hold),
        MMUMETHOD(mmu_init,             mmu_booke_init),
        MMUMETHOD(mmu_is_modified,      mmu_booke_is_modified),
        MMUMETHOD(mmu_is_prefaultable,  mmu_booke_is_prefaultable),
        MMUMETHOD(mmu_is_referenced,    mmu_booke_is_referenced),
        MMUMETHOD(mmu_ts_referenced,    mmu_booke_ts_referenced),
        MMUMETHOD(mmu_map,              mmu_booke_map),
        MMUMETHOD(mmu_mincore,          mmu_booke_mincore),
        MMUMETHOD(mmu_object_init_pt,   mmu_booke_object_init_pt),
        MMUMETHOD(mmu_page_exists_quick,mmu_booke_page_exists_quick),
        MMUMETHOD(mmu_page_init,        mmu_booke_page_init),
        MMUMETHOD(mmu_page_wired_mappings, mmu_booke_page_wired_mappings),
        MMUMETHOD(mmu_pinit,            mmu_booke_pinit),
        MMUMETHOD(mmu_pinit0,           mmu_booke_pinit0),
        MMUMETHOD(mmu_protect,          mmu_booke_protect),
        MMUMETHOD(mmu_qenter,           mmu_booke_qenter),
        MMUMETHOD(mmu_qremove,          mmu_booke_qremove),
        MMUMETHOD(mmu_release,          mmu_booke_release),
        MMUMETHOD(mmu_remove,           mmu_booke_remove),
        MMUMETHOD(mmu_remove_all,       mmu_booke_remove_all),
        MMUMETHOD(mmu_remove_write,     mmu_booke_remove_write),
        MMUMETHOD(mmu_sync_icache,      mmu_booke_sync_icache),
        MMUMETHOD(mmu_zero_page,        mmu_booke_zero_page),
        MMUMETHOD(mmu_zero_page_area,   mmu_booke_zero_page_area),
        MMUMETHOD(mmu_zero_page_idle,   mmu_booke_zero_page_idle),
        MMUMETHOD(mmu_activate,         mmu_booke_activate),
        MMUMETHOD(mmu_deactivate,       mmu_booke_deactivate),

        /* Internal interfaces */
        MMUMETHOD(mmu_bootstrap,        mmu_booke_bootstrap),
        MMUMETHOD(mmu_dev_direct_mapped,mmu_booke_dev_direct_mapped),
        MMUMETHOD(mmu_mapdev,           mmu_booke_mapdev),
        MMUMETHOD(mmu_kenter,           mmu_booke_kenter),
        MMUMETHOD(mmu_kextract,         mmu_booke_kextract),
/*      MMUMETHOD(mmu_kremove,          mmu_booke_kremove),     */
        MMUMETHOD(mmu_unmapdev,         mmu_booke_unmapdev),

        /* dumpsys() support */
        MMUMETHOD(mmu_dumpsys_map,      mmu_booke_dumpsys_map),
        MMUMETHOD(mmu_dumpsys_unmap,    mmu_booke_dumpsys_unmap),
        MMUMETHOD(mmu_scan_md,          mmu_booke_scan_md),

        { 0, 0 }
};

MMU_DEF(booke_mmu, MMU_TYPE_BOOKE, mmu_booke_methods, 0);

static inline void
tlb_miss_lock(void)
{
#ifdef SMP
        struct pcpu *pc;

        if (!smp_started)
                return;

        STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
                if (pc != pcpup) {

                        CTR3(KTR_PMAP, "%s: tlb miss LOCK of CPU=%d, "
                            "tlb_lock=%p", __func__, pc->pc_cpuid, pc->pc_booke_tlb_lock);

                        KASSERT((pc->pc_cpuid != PCPU_GET(cpuid)),
                            ("tlb_miss_lock: tried to lock self"));

                        tlb_lock(pc->pc_booke_tlb_lock);

                        CTR1(KTR_PMAP, "%s: locked", __func__);
                }
        }
#endif
}

static inline void
tlb_miss_unlock(void)
{
#ifdef SMP
        struct pcpu *pc;

        if (!smp_started)
                return;

        STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
                if (pc != pcpup) {
                        CTR2(KTR_PMAP, "%s: tlb miss UNLOCK of CPU=%d",
                            __func__, pc->pc_cpuid);

                        tlb_unlock(pc->pc_booke_tlb_lock);

                        CTR1(KTR_PMAP, "%s: unlocked", __func__);
                }
        }
#endif
}

/* Return number of entries in TLB0. */
static __inline void
tlb0_get_tlbconf(void)
{
        uint32_t tlb0_cfg;

        tlb0_cfg = mfspr(SPR_TLB0CFG);
        tlb0_entries = tlb0_cfg & TLBCFG_NENTRY_MASK;
        tlb0_ways = (tlb0_cfg & TLBCFG_ASSOC_MASK) >> TLBCFG_ASSOC_SHIFT;
        tlb0_entries_per_way = tlb0_entries / tlb0_ways;
}

/* Initialize pool of kva ptbl buffers. */
static void
ptbl_init(void)
{
        int i;

        CTR3(KTR_PMAP, "%s: s (ptbl_bufs = 0x%08x size 0x%08x)", __func__,
            (uint32_t)ptbl_bufs, sizeof(struct ptbl_buf) * PTBL_BUFS);
        CTR3(KTR_PMAP, "%s: s (ptbl_buf_pool_vabase = 0x%08x size = 0x%08x)",
            __func__, ptbl_buf_pool_vabase, PTBL_BUFS * PTBL_PAGES * PAGE_SIZE);

        mtx_init(&ptbl_buf_freelist_lock, "ptbl bufs lock", NULL, MTX_DEF);
        TAILQ_INIT(&ptbl_buf_freelist);

        for (i = 0; i < PTBL_BUFS; i++) {
                ptbl_bufs[i].kva = ptbl_buf_pool_vabase + i * PTBL_PAGES * PAGE_SIZE;
                TAILQ_INSERT_TAIL(&ptbl_buf_freelist, &ptbl_bufs[i], link);
        }
}

/* Get a ptbl_buf from the freelist. */
static struct ptbl_buf *
ptbl_buf_alloc(void)
{
        struct ptbl_buf *buf;

        mtx_lock(&ptbl_buf_freelist_lock);
        buf = TAILQ_FIRST(&ptbl_buf_freelist);
        if (buf != NULL)
                TAILQ_REMOVE(&ptbl_buf_freelist, buf, link);
        mtx_unlock(&ptbl_buf_freelist_lock);

        CTR2(KTR_PMAP, "%s: buf = %p", __func__, buf);

        return (buf);
}

/* Return ptbl buff to free pool. */
static void
ptbl_buf_free(struct ptbl_buf *buf)
{

        CTR2(KTR_PMAP, "%s: buf = %p", __func__, buf);

        mtx_lock(&ptbl_buf_freelist_lock);
        TAILQ_INSERT_TAIL(&ptbl_buf_freelist, buf, link);
        mtx_unlock(&ptbl_buf_freelist_lock);
}

/*
 * Search the list of allocated ptbl bufs and find on list of allocated ptbls
 */
static void
ptbl_free_pmap_ptbl(pmap_t pmap, pte_t *ptbl)
{
        struct ptbl_buf *pbuf;

        CTR2(KTR_PMAP, "%s: ptbl = %p", __func__, ptbl);

        PMAP_LOCK_ASSERT(pmap, MA_OWNED);

        TAILQ_FOREACH(pbuf, &pmap->pm_ptbl_list, link)
                if (pbuf->kva == (vm_offset_t)ptbl) {
                        /* Remove from pmap ptbl buf list. */
                        TAILQ_REMOVE(&pmap->pm_ptbl_list, pbuf, link);

                        /* Free corresponding ptbl buf. */
                        ptbl_buf_free(pbuf);
                        break;
                }
}

/* Allocate page table. */
static pte_t *
ptbl_alloc(mmu_t mmu, pmap_t pmap, unsigned int pdir_idx)
{
        vm_page_t mtbl[PTBL_PAGES];
        vm_page_t m;
        struct ptbl_buf *pbuf;
        unsigned int pidx;
        pte_t *ptbl;
        int i;

        CTR4(KTR_PMAP, "%s: pmap = %p su = %d pdir_idx = %d", __func__, pmap,
            (pmap == kernel_pmap), pdir_idx);

        KASSERT((pdir_idx <= (VM_MAXUSER_ADDRESS / PDIR_SIZE)),
            ("ptbl_alloc: invalid pdir_idx"));
        KASSERT((pmap->pm_pdir[pdir_idx] == NULL),
            ("pte_alloc: valid ptbl entry exists!"));

        pbuf = ptbl_buf_alloc();
        if (pbuf == NULL)
                panic("pte_alloc: couldn't alloc kernel virtual memory");
                
        ptbl = (pte_t *)pbuf->kva;

        CTR2(KTR_PMAP, "%s: ptbl kva = %p", __func__, ptbl);

        /* Allocate ptbl pages, this will sleep! */
        for (i = 0; i < PTBL_PAGES; i++) {
                pidx = (PTBL_PAGES * pdir_idx) + i;
                while ((m = vm_page_alloc(NULL, pidx,
                    VM_ALLOC_NOOBJ | VM_ALLOC_WIRED)) == NULL) {

                        PMAP_UNLOCK(pmap);
                        rw_wunlock(&pvh_global_lock);
                        VM_WAIT;
                        rw_wlock(&pvh_global_lock);
                        PMAP_LOCK(pmap);
                }
                mtbl[i] = m;
        }

        /* Map allocated pages into kernel_pmap. */
        mmu_booke_qenter(mmu, (vm_offset_t)ptbl, mtbl, PTBL_PAGES);

        /* Zero whole ptbl. */
        bzero((caddr_t)ptbl, PTBL_PAGES * PAGE_SIZE);

        /* Add pbuf to the pmap ptbl bufs list. */
        TAILQ_INSERT_TAIL(&pmap->pm_ptbl_list, pbuf, link);

        return (ptbl);
}

/* Free ptbl pages and invalidate pdir entry. */
static void
ptbl_free(mmu_t mmu, pmap_t pmap, unsigned int pdir_idx)
{
        pte_t *ptbl;
        vm_paddr_t pa;
        vm_offset_t va;
        vm_page_t m;
        int i;

        CTR4(KTR_PMAP, "%s: pmap = %p su = %d pdir_idx = %d", __func__, pmap,
            (pmap == kernel_pmap), pdir_idx);

        KASSERT((pdir_idx <= (VM_MAXUSER_ADDRESS / PDIR_SIZE)),
            ("ptbl_free: invalid pdir_idx"));

        ptbl = pmap->pm_pdir[pdir_idx];

        CTR2(KTR_PMAP, "%s: ptbl = %p", __func__, ptbl);

        KASSERT((ptbl != NULL), ("ptbl_free: null ptbl"));

        /*
         * Invalidate the pdir entry as soon as possible, so that other CPUs
         * don't attempt to look up the page tables we are releasing.
         */
        mtx_lock_spin(&tlbivax_mutex);
        tlb_miss_lock();
        
        pmap->pm_pdir[pdir_idx] = NULL;

        tlb_miss_unlock();
        mtx_unlock_spin(&tlbivax_mutex);

        for (i = 0; i < PTBL_PAGES; i++) {
                va = ((vm_offset_t)ptbl + (i * PAGE_SIZE));
                pa = pte_vatopa(mmu, kernel_pmap, va);
                m = PHYS_TO_VM_PAGE(pa);
                vm_page_free_zero(m);
                atomic_subtract_int(&cnt.v_wire_count, 1);
                mmu_booke_kremove(mmu, va);
        }

        ptbl_free_pmap_ptbl(pmap, ptbl);
}

/*
 * Decrement ptbl pages hold count and attempt to free ptbl pages.
 * Called when removing pte entry from ptbl.
 *
 * Return 1 if ptbl pages were freed.
 */
static int
ptbl_unhold(mmu_t mmu, pmap_t pmap, unsigned int pdir_idx)
{
        pte_t *ptbl;
        vm_paddr_t pa;
        vm_page_t m;
        int i;

        CTR4(KTR_PMAP, "%s: pmap = %p su = %d pdir_idx = %d", __func__, pmap,
            (pmap == kernel_pmap), pdir_idx);

        KASSERT((pdir_idx <= (VM_MAXUSER_ADDRESS / PDIR_SIZE)),
            ("ptbl_unhold: invalid pdir_idx"));
        KASSERT((pmap != kernel_pmap),
            ("ptbl_unhold: unholding kernel ptbl!"));

        ptbl = pmap->pm_pdir[pdir_idx];

        //debugf("ptbl_unhold: ptbl = 0x%08x\n", (u_int32_t)ptbl);
        KASSERT(((vm_offset_t)ptbl >= VM_MIN_KERNEL_ADDRESS),
            ("ptbl_unhold: non kva ptbl"));

        /* decrement hold count */
        for (i = 0; i < PTBL_PAGES; i++) {
                pa = pte_vatopa(mmu, kernel_pmap,
                    (vm_offset_t)ptbl + (i * PAGE_SIZE));
                m = PHYS_TO_VM_PAGE(pa);
                m->wire_count--;
        }

        /*
         * Free ptbl pages if there are no pte etries in this ptbl.
         * wire_count has the same value for all ptbl pages, so check the last
         * page.
         */
        if (m->wire_count == 0) {
                ptbl_free(mmu, pmap, pdir_idx);

                //debugf("ptbl_unhold: e (freed ptbl)\n");
                return (1);
        }

        return (0);
}

/*
 * Increment hold count for ptbl pages. This routine is used when a new pte
 * entry is being inserted into the ptbl.
 */
static void
ptbl_hold(mmu_t mmu, pmap_t pmap, unsigned int pdir_idx)
{
        vm_paddr_t pa;
        pte_t *ptbl;
        vm_page_t m;
        int i;

        CTR3(KTR_PMAP, "%s: pmap = %p pdir_idx = %d", __func__, pmap,
            pdir_idx);

        KASSERT((pdir_idx <= (VM_MAXUSER_ADDRESS / PDIR_SIZE)),
            ("ptbl_hold: invalid pdir_idx"));
        KASSERT((pmap != kernel_pmap),
            ("ptbl_hold: holding kernel ptbl!"));

        ptbl = pmap->pm_pdir[pdir_idx];

        KASSERT((ptbl != NULL), ("ptbl_hold: null ptbl"));

        for (i = 0; i < PTBL_PAGES; i++) {
                pa = pte_vatopa(mmu, kernel_pmap,
                    (vm_offset_t)ptbl + (i * PAGE_SIZE));
                m = PHYS_TO_VM_PAGE(pa);
                m->wire_count++;
        }
}

/* Allocate pv_entry structure. */
pv_entry_t
pv_alloc(void)
{
        pv_entry_t pv;

        pv_entry_count++;
        if (pv_entry_count > pv_entry_high_water)
                pagedaemon_wakeup();
        pv = uma_zalloc(pvzone, M_NOWAIT);

        return (pv);
}

/* Free pv_entry structure. */
static __inline void
pv_free(pv_entry_t pve)
{

        pv_entry_count--;
        uma_zfree(pvzone, pve);
}


/* Allocate and initialize pv_entry structure. */
static void
pv_insert(pmap_t pmap, vm_offset_t va, vm_page_t m)
{
        pv_entry_t pve;

        //int su = (pmap == kernel_pmap);
        //debugf("pv_insert: s (su = %d pmap = 0x%08x va = 0x%08x m = 0x%08x)\n", su,
        //      (u_int32_t)pmap, va, (u_int32_t)m);

        pve = pv_alloc();
        if (pve == NULL)
                panic("pv_insert: no pv entries!");

        pve->pv_pmap = pmap;
        pve->pv_va = va;

        /* add to pv_list */
        PMAP_LOCK_ASSERT(pmap, MA_OWNED);
        rw_assert(&pvh_global_lock, RA_WLOCKED);

        TAILQ_INSERT_TAIL(&m->md.pv_list, pve, pv_link);

        //debugf("pv_insert: e\n");
}

/* Destroy pv entry. */
static void
pv_remove(pmap_t pmap, vm_offset_t va, vm_page_t m)
{
        pv_entry_t pve;

        //int su = (pmap == kernel_pmap);
        //debugf("pv_remove: s (su = %d pmap = 0x%08x va = 0x%08x)\n", su, (u_int32_t)pmap, va);

        PMAP_LOCK_ASSERT(pmap, MA_OWNED);
        rw_assert(&pvh_global_lock, RA_WLOCKED);

        /* find pv entry */
        TAILQ_FOREACH(pve, &m->md.pv_list, pv_link) {
                if ((pmap == pve->pv_pmap) && (va == pve->pv_va)) {
                        /* remove from pv_list */
                        TAILQ_REMOVE(&m->md.pv_list, pve, pv_link);
                        if (TAILQ_EMPTY(&m->md.pv_list))
                                vm_page_aflag_clear(m, PGA_WRITEABLE);

                        /* free pv entry struct */
                        pv_free(pve);
                        break;
                }
        }

        //debugf("pv_remove: e\n");
}

/*
 * Clean pte entry, try to free page table page if requested.
 *
 * Return 1 if ptbl pages were freed, otherwise return 0.
 */
static int
pte_remove(mmu_t mmu, pmap_t pmap, vm_offset_t va, uint8_t flags)
{
        unsigned int pdir_idx = PDIR_IDX(va);
        unsigned int ptbl_idx = PTBL_IDX(va);
        vm_page_t m;
        pte_t *ptbl;
        pte_t *pte;

        //int su = (pmap == kernel_pmap);
        //debugf("pte_remove: s (su = %d pmap = 0x%08x va = 0x%08x flags = %d)\n",
        //              su, (u_int32_t)pmap, va, flags);

        ptbl = pmap->pm_pdir[pdir_idx];
        KASSERT(ptbl, ("pte_remove: null ptbl"));

        pte = &ptbl[ptbl_idx];

        if (pte == NULL || !PTE_ISVALID(pte))
                return (0);

        if (PTE_ISWIRED(pte))
                pmap->pm_stats.wired_count--;

        /* Handle managed entry. */
        if (PTE_ISMANAGED(pte)) {
                /* Get vm_page_t for mapped pte. */
                m = PHYS_TO_VM_PAGE(PTE_PA(pte));

                if (PTE_ISMODIFIED(pte))
                        vm_page_dirty(m);

                if (PTE_ISREFERENCED(pte))
                        vm_page_aflag_set(m, PGA_REFERENCED);

                pv_remove(pmap, va, m);
        }

        mtx_lock_spin(&tlbivax_mutex);
        tlb_miss_lock();

        tlb0_flush_entry(va);
        pte->flags = 0;
        pte->rpn = 0;

        tlb_miss_unlock();
        mtx_unlock_spin(&tlbivax_mutex);

        pmap->pm_stats.resident_count--;

        if (flags & PTBL_UNHOLD) {
                //debugf("pte_remove: e (unhold)\n");
                return (ptbl_unhold(mmu, pmap, pdir_idx));
        }

        //debugf("pte_remove: e\n");
        return (0);
}

/*
 * Insert PTE for a given page and virtual address.
 */
static void
pte_enter(mmu_t mmu, pmap_t pmap, vm_page_t m, vm_offset_t va, uint32_t flags)
{
        unsigned int pdir_idx = PDIR_IDX(va);
        unsigned int ptbl_idx = PTBL_IDX(va);
        pte_t *ptbl, *pte;

        CTR4(KTR_PMAP, "%s: su = %d pmap = %p va = %p", __func__,
            pmap == kernel_pmap, pmap, va);

        /* Get the page table pointer. */
        ptbl = pmap->pm_pdir[pdir_idx];

        if (ptbl == NULL) {
                /* Allocate page table pages. */
                ptbl = ptbl_alloc(mmu, pmap, pdir_idx);
        } else {
                /*
                 * Check if there is valid mapping for requested
                 * va, if there is, remove it.
                 */
                pte = &pmap->pm_pdir[pdir_idx][ptbl_idx];
                if (PTE_ISVALID(pte)) {
                        pte_remove(mmu, pmap, va, PTBL_HOLD);
                } else {
                        /*
                         * pte is not used, increment hold count
                         * for ptbl pages.
                         */
                        if (pmap != kernel_pmap)
                                ptbl_hold(mmu, pmap, pdir_idx);
                }
        }

        /*
         * Insert pv_entry into pv_list for mapped page if part of managed
         * memory.
         */
        if ((m->oflags & VPO_UNMANAGED) == 0) {
                flags |= PTE_MANAGED;

                /* Create and insert pv entry. */
                pv_insert(pmap, va, m);
        }

        pmap->pm_stats.resident_count++;
        
        mtx_lock_spin(&tlbivax_mutex);
        tlb_miss_lock();

        tlb0_flush_entry(va);
        if (pmap->pm_pdir[pdir_idx] == NULL) {
                /*
                 * If we just allocated a new page table, hook it in
                 * the pdir.
                 */
                pmap->pm_pdir[pdir_idx] = ptbl;
        }
        pte = &(pmap->pm_pdir[pdir_idx][ptbl_idx]);
        pte->rpn = VM_PAGE_TO_PHYS(m) & ~PTE_PA_MASK;
        pte->flags |= (PTE_VALID | flags);

        tlb_miss_unlock();
        mtx_unlock_spin(&tlbivax_mutex);
}

/* Return the pa for the given pmap/va. */
static vm_paddr_t
pte_vatopa(mmu_t mmu, pmap_t pmap, vm_offset_t va)
{
        vm_paddr_t pa = 0;
        pte_t *pte;

        pte = pte_find(mmu, pmap, va);
        if ((pte != NULL) && PTE_ISVALID(pte))
                pa = (PTE_PA(pte) | (va & PTE_PA_MASK));
        return (pa);
}

/* Get a pointer to a PTE in a page table. */
static pte_t *
pte_find(mmu_t mmu, pmap_t pmap, vm_offset_t va)
{
        unsigned int pdir_idx = PDIR_IDX(va);
        unsigned int ptbl_idx = PTBL_IDX(va);

        KASSERT((pmap != NULL), ("pte_find: invalid pmap"));

        if (pmap->pm_pdir[pdir_idx])
                return (&(pmap->pm_pdir[pdir_idx][ptbl_idx]));

        return (NULL);
}

/**************************************************************************/
/* PMAP related */
/**************************************************************************/

/*
 * This is called during booke_init, before the system is really initialized.
 */
static void
mmu_booke_bootstrap(mmu_t mmu, vm_offset_t start, vm_offset_t kernelend)
{
        vm_offset_t phys_kernelend;
        struct mem_region *mp, *mp1;
        int cnt, i, j;
        u_int s, e, sz;
        u_int phys_avail_count;
        vm_size_t physsz, hwphyssz, kstack0_sz;
        vm_offset_t kernel_pdir, kstack0, va;
        vm_paddr_t kstack0_phys;
        void *dpcpu;
        pte_t *pte;

        debugf("mmu_booke_bootstrap: entered\n");

        /* Initialize invalidation mutex */
        mtx_init(&tlbivax_mutex, "tlbivax", NULL, MTX_SPIN);

        /* Read TLB0 size and associativity. */
        tlb0_get_tlbconf();

        /*
         * Align kernel start and end address (kernel image).
         * Note that kernel end does not necessarily relate to kernsize.
         * kernsize is the size of the kernel that is actually mapped.
         * Also note that "start - 1" is deliberate. With SMP, the
         * entry point is exactly a page from the actual load address.
         * As such, trunc_page() has no effect and we're off by a page.
         * Since we always have the ELF header between the load address
         * and the entry point, we can safely subtract 1 to compensate.
         */
        kernstart = trunc_page(start - 1);
        data_start = round_page(kernelend);
        data_end = data_start;

        /*
         * Addresses of preloaded modules (like file systems) use
         * physical addresses. Make sure we relocate those into
         * virtual addresses.
         */
        preload_addr_relocate = kernstart - kernload;

        /* Allocate the dynamic per-cpu area. */
        dpcpu = (void *)data_end;
        data_end += DPCPU_SIZE;

        /* Allocate space for the message buffer. */
        msgbufp = (struct msgbuf *)data_end;
        data_end += msgbufsize;
        debugf(" msgbufp at 0x%08x end = 0x%08x\n", (uint32_t)msgbufp,
            data_end);

        data_end = round_page(data_end);

        /* Allocate space for ptbl_bufs. */
        ptbl_bufs = (struct ptbl_buf *)data_end;
        data_end += sizeof(struct ptbl_buf) * PTBL_BUFS;
        debugf(" ptbl_bufs at 0x%08x end = 0x%08x\n", (uint32_t)ptbl_bufs,
            data_end);

        data_end = round_page(data_end);

        /* Allocate PTE tables for kernel KVA. */
        kernel_pdir = data_end;
        kernel_ptbls = (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS +
            PDIR_SIZE - 1) / PDIR_SIZE;
        data_end += kernel_ptbls * PTBL_PAGES * PAGE_SIZE;
        debugf(" kernel ptbls: %d\n", kernel_ptbls);
        debugf(" kernel pdir at 0x%08x end = 0x%08x\n", kernel_pdir, data_end);

        debugf(" data_end: 0x%08x\n", data_end);
        if (data_end - kernstart > kernsize) {
                kernsize += tlb1_mapin_region(kernstart + kernsize,
                    kernload + kernsize, (data_end - kernstart) - kernsize);
        }
        data_end = kernstart + kernsize;
        debugf(" updated data_end: 0x%08x\n", data_end);

        /*
         * Clear the structures - note we can only do it safely after the
         * possible additional TLB1 translations are in place (above) so that
         * all range up to the currently calculated 'data_end' is covered.
         */
        dpcpu_init(dpcpu, 0);
        memset((void *)ptbl_bufs, 0, sizeof(struct ptbl_buf) * PTBL_SIZE);
        memset((void *)kernel_pdir, 0, kernel_ptbls * PTBL_PAGES * PAGE_SIZE);

        /*******************************************************/
        /* Set the start and end of kva. */
        /*******************************************************/
        virtual_avail = round_page(data_end);
        virtual_end = VM_MAX_KERNEL_ADDRESS;

        /* Allocate KVA space for page zero/copy operations. */
        zero_page_va = virtual_avail;
        virtual_avail += PAGE_SIZE;
        zero_page_idle_va = virtual_avail;
        virtual_avail += PAGE_SIZE;
        copy_page_src_va = virtual_avail;
        virtual_avail += PAGE_SIZE;
        copy_page_dst_va = virtual_avail;
        virtual_avail += PAGE_SIZE;
        debugf("zero_page_va = 0x%08x\n", zero_page_va);
        debugf("zero_page_idle_va = 0x%08x\n", zero_page_idle_va);
        debugf("copy_page_src_va = 0x%08x\n", copy_page_src_va);
        debugf("copy_page_dst_va = 0x%08x\n", copy_page_dst_va);

        /* Initialize page zero/copy mutexes. */
        mtx_init(&zero_page_mutex, "mmu_booke_zero_page", NULL, MTX_DEF);
        mtx_init(&copy_page_mutex, "mmu_booke_copy_page", NULL, MTX_DEF);

        /* Allocate KVA space for ptbl bufs. */
        ptbl_buf_pool_vabase = virtual_avail;
        virtual_avail += PTBL_BUFS * PTBL_PAGES * PAGE_SIZE;
        debugf("ptbl_buf_pool_vabase = 0x%08x end = 0x%08x\n",
            ptbl_buf_pool_vabase, virtual_avail);

        /* Calculate corresponding physical addresses for the kernel region. */
        phys_kernelend = kernload + kernsize;
        debugf("kernel image and allocated data:\n");
        debugf(" kernload    = 0x%08x\n", kernload);
        debugf(" kernstart   = 0x%08x\n", kernstart);
        debugf(" kernsize    = 0x%08x\n", kernsize);

        if (sizeof(phys_avail) / sizeof(phys_avail[0]) < availmem_regions_sz)
                panic("mmu_booke_bootstrap: phys_avail too small");

        /*
         * Remove kernel physical address range from avail regions list. Page
         * align all regions.  Non-page aligned memory isn't very interesting
         * to us.  Also, sort the entries for ascending addresses.
         */

        /* Retrieve phys/avail mem regions */
        mem_regions(&physmem_regions, &physmem_regions_sz,
            &availmem_regions, &availmem_regions_sz);
        sz = 0;
        cnt = availmem_regions_sz;
        debugf("processing avail regions:\n");
        for (mp = availmem_regions; mp->mr_size; mp++) {
                s = mp->mr_start;
                e = mp->mr_start + mp->mr_size;
                debugf(" %08x-%08x -> ", s, e);
                /* Check whether this region holds all of the kernel. */
                if (s < kernload && e > phys_kernelend) {
                        availmem_regions[cnt].mr_start = phys_kernelend;
                        availmem_regions[cnt++].mr_size = e - phys_kernelend;
                        e = kernload;
                }
                /* Look whether this regions starts within the kernel. */
                if (s >= kernload && s < phys_kernelend) {
                        if (e <= phys_kernelend)
                                goto empty;
                        s = phys_kernelend;
                }
                /* Now look whether this region ends within the kernel. */
                if (e > kernload && e <= phys_kernelend) {
                        if (s >= kernload)
                                goto empty;
                        e = kernload;
                }
                /* Now page align the start and size of the region. */
                s = round_page(s);
                e = trunc_page(e);
                if (e < s)
                        e = s;
                sz = e - s;
                debugf("%08x-%08x = %x\n", s, e, sz);

                /* Check whether some memory is left here. */
                if (sz == 0) {
                empty:
                        memmove(mp, mp + 1,
                            (cnt - (mp - availmem_regions)) * sizeof(*mp));
                        cnt--;
                        mp--;
                        continue;
                }

                /* Do an insertion sort. */
                for (mp1 = availmem_regions; mp1 < mp; mp1++)
                        if (s < mp1->mr_start)
                                break;
                if (mp1 < mp) {
                        memmove(mp1 + 1, mp1, (char *)mp - (char *)mp1);
                        mp1->mr_start = s;
                        mp1->mr_size = sz;
                } else {
                        mp->mr_start = s;
                        mp->mr_size = sz;
                }
        }
        availmem_regions_sz = cnt;

        /*******************************************************/
        /* Steal physical memory for kernel stack from the end */
        /* of the first avail region                           */
        /*******************************************************/
        kstack0_sz = KSTACK_PAGES * PAGE_SIZE;
        kstack0_phys = availmem_regions[0].mr_start +
            availmem_regions[0].mr_size;
        kstack0_phys -= kstack0_sz;
        availmem_regions[0].mr_size -= kstack0_sz;

        /*******************************************************/
        /* Fill in phys_avail table, based on availmem_regions */
        /*******************************************************/
        phys_avail_count = 0;
        physsz = 0;
        hwphyssz = 0;
        TUNABLE_ULONG_FETCH("hw.physmem", (u_long *) &hwphyssz);

        debugf("fill in phys_avail:\n");
        for (i = 0, j = 0; i < availmem_regions_sz; i++, j += 2) {

                debugf(" region: 0x%08x - 0x%08x (0x%08x)\n",
                    availmem_regions[i].mr_start,
                    availmem_regions[i].mr_start +
                        availmem_regions[i].mr_size,
                    availmem_regions[i].mr_size);

                if (hwphyssz != 0 &&
                    (physsz + availmem_regions[i].mr_size) >= hwphyssz) {
                        debugf(" hw.physmem adjust\n");
                        if (physsz < hwphyssz) {
                                phys_avail[j] = availmem_regions[i].mr_start;
                                phys_avail[j + 1] =
                                    availmem_regions[i].mr_start +
                                    hwphyssz - physsz;
                                physsz = hwphyssz;
                                phys_avail_count++;
                        }
                        break;
                }

                phys_avail[j] = availmem_regions[i].mr_start;
                phys_avail[j + 1] = availmem_regions[i].mr_start +
                    availmem_regions[i].mr_size;
                phys_avail_count++;
                physsz += availmem_regions[i].mr_size;
        }
        physmem = btoc(physsz);

        /* Calculate the last available physical address. */
        for (i = 0; phys_avail[i + 2] != 0; i += 2)
                ;
        Maxmem = powerpc_btop(phys_avail[i + 1]);

        debugf("Maxmem = 0x%08lx\n", Maxmem);
        debugf("phys_avail_count = %d\n", phys_avail_count);
        debugf("physsz = 0x%08x physmem = %ld (0x%08lx)\n", physsz, physmem,
            physmem);

        /*******************************************************/
        /* Initialize (statically allocated) kernel pmap. */
        /*******************************************************/
        PMAP_LOCK_INIT(kernel_pmap);
        kptbl_min = VM_MIN_KERNEL_ADDRESS / PDIR_SIZE;

        debugf("kernel_pmap = 0x%08x\n", (uint32_t)kernel_pmap);
        debugf("kptbl_min = %d, kernel_ptbls = %d\n", kptbl_min, kernel_ptbls);
        debugf("kernel pdir range: 0x%08x - 0x%08x\n",
            kptbl_min * PDIR_SIZE, (kptbl_min + kernel_ptbls) * PDIR_SIZE - 1);

        /* Initialize kernel pdir */
        for (i = 0; i < kernel_ptbls; i++)
                kernel_pmap->pm_pdir[kptbl_min + i] =
                    (pte_t *)(kernel_pdir + (i * PAGE_SIZE * PTBL_PAGES));

        for (i = 0; i < MAXCPU; i++) {
                kernel_pmap->pm_tid[i] = TID_KERNEL;
                
                /* Initialize each CPU's tidbusy entry 0 with kernel_pmap */
                tidbusy[i][0] = kernel_pmap;
        }

        /*
         * Fill in PTEs covering kernel code and data. They are not required
         * for address translation, as this area is covered by static TLB1
         * entries, but for pte_vatopa() to work correctly with kernel area
         * addresses.
         */
        for (va = kernstart; va < data_end; va += PAGE_SIZE) {
                pte = &(kernel_pmap->pm_pdir[PDIR_IDX(va)][PTBL_IDX(va)]);
                pte->rpn = kernload + (va - kernstart);
                pte->flags = PTE_M | PTE_SR | PTE_SW | PTE_SX | PTE_WIRED |
                    PTE_VALID;
        }
        /* Mark kernel_pmap active on all CPUs */
        CPU_FILL(&kernel_pmap->pm_active);

        /*
         * Initialize the global pv list lock.
         */
        rw_init(&pvh_global_lock, "pmap pv global");

        /*******************************************************/
        /* Final setup */
        /*******************************************************/

        /* Enter kstack0 into kernel map, provide guard page */
        kstack0 = virtual_avail + KSTACK_GUARD_PAGES * PAGE_SIZE;
        thread0.td_kstack = kstack0;
        thread0.td_kstack_pages = KSTACK_PAGES;

        debugf("kstack_sz = 0x%08x\n", kstack0_sz);
        debugf("kstack0_phys at 0x%08x - 0x%08x\n",
            kstack0_phys, kstack0_phys + kstack0_sz);
        debugf("kstack0 at 0x%08x - 0x%08x\n", kstack0, kstack0 + kstack0_sz);
        
        virtual_avail += KSTACK_GUARD_PAGES * PAGE_SIZE + kstack0_sz;
        for (i = 0; i < KSTACK_PAGES; i++) {
                mmu_booke_kenter(mmu, kstack0, kstack0_phys);
                kstack0 += PAGE_SIZE;
                kstack0_phys += PAGE_SIZE;
        }
        
        debugf("virtual_avail = %08x\n", virtual_avail);
        debugf("virtual_end   = %08x\n", virtual_end);

        debugf("mmu_booke_bootstrap: exit\n");
}

void
pmap_bootstrap_ap(volatile uint32_t *trcp __unused)
{
        int i;

        /*
         * Finish TLB1 configuration: the BSP already set up its TLB1 and we
         * have the snapshot of its contents in the s/w tlb1[] table, so use
         * these values directly to (re)program AP's TLB1 hardware.
         */
        for (i = bp_ntlb1s; i < tlb1_idx; i++) {
                /* Skip invalid entries */
                if (!(tlb1[i].mas1 & MAS1_VALID))
                        continue;

                tlb1_write_entry(i);
        }

        set_mas4_defaults();
}

/*
 * Get the physical page address for the given pmap/virtual address.
 */
static vm_paddr_t
mmu_booke_extract(mmu_t mmu, pmap_t pmap, vm_offset_t va)
{
        vm_paddr_t pa;

        PMAP_LOCK(pmap);
        pa = pte_vatopa(mmu, pmap, va);
        PMAP_UNLOCK(pmap);

        return (pa);
}

/*
 * Extract the physical page address associated with the given
 * kernel virtual address.
 */
static vm_paddr_t
mmu_booke_kextract(mmu_t mmu, vm_offset_t va)
{

        return (pte_vatopa(mmu, kernel_pmap, va));
}

/*
 * Initialize the pmap module.
 * Called by vm_init, to initialize any structures that the pmap
 * system needs to map virtual memory.
 */
static void
mmu_booke_init(mmu_t mmu)
{
        int shpgperproc = PMAP_SHPGPERPROC;

        /*
         * Initialize the address space (zone) for the pv entries.  Set a
         * high water mark so that the system can recover from excessive
         * numbers of pv entries.
         */
        pvzone = uma_zcreate("PV ENTRY", sizeof(struct pv_entry), NULL, NULL,
            NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_VM | UMA_ZONE_NOFREE);

        TUNABLE_INT_FETCH("vm.pmap.shpgperproc", &shpgperproc);
        pv_entry_max = shpgperproc * maxproc + cnt.v_page_count;

        TUNABLE_INT_FETCH("vm.pmap.pv_entries", &pv_entry_max);
        pv_entry_high_water = 9 * (pv_entry_max / 10);

        uma_zone_set_obj(pvzone, &pvzone_obj, pv_entry_max);

        /* Pre-fill pvzone with initial number of pv entries. */
        uma_prealloc(pvzone, PV_ENTRY_ZONE_MIN);

        /* Initialize ptbl allocation. */
        ptbl_init();
}

/*
 * Map a list of wired pages into kernel virtual address space.  This is
 * intended for temporary mappings which do not need page modification or
 * references recorded.  Existing mappings in the region are overwritten.
 */
static void
mmu_booke_qenter(mmu_t mmu, vm_offset_t sva, vm_page_t *m, int count)
{
        vm_offset_t va;

        va = sva;
        while (count-- > 0) {
                mmu_booke_kenter(mmu, va, VM_PAGE_TO_PHYS(*m));
                va += PAGE_SIZE;
                m++;
        }
}

/*
 * Remove page mappings from kernel virtual address space.  Intended for
 * temporary mappings entered by mmu_booke_qenter.
 */
static void
mmu_booke_qremove(mmu_t mmu, vm_offset_t sva, int count)
{
        vm_offset_t va;

        va = sva;
        while (count-- > 0) {
                mmu_booke_kremove(mmu, va);
                va += PAGE_SIZE;
        }
}

/*
 * Map a wired page into kernel virtual address space.
 */
static void
mmu_booke_kenter(mmu_t mmu, vm_offset_t va, vm_paddr_t pa)
{
        unsigned int pdir_idx = PDIR_IDX(va);
        unsigned int ptbl_idx = PTBL_IDX(va);
        uint32_t flags;
        pte_t *pte;

        KASSERT(((va >= VM_MIN_KERNEL_ADDRESS) &&
            (va <= VM_MAX_KERNEL_ADDRESS)), ("mmu_booke_kenter: invalid va"));

        flags = PTE_M | PTE_SR | PTE_SW | PTE_SX | PTE_WIRED | PTE_VALID;

        pte = &(kernel_pmap->pm_pdir[pdir_idx][ptbl_idx]);

        mtx_lock_spin(&tlbivax_mutex);
        tlb_miss_lock();
        
        if (PTE_ISVALID(pte)) {
        
                CTR1(KTR_PMAP, "%s: replacing entry!", __func__);

                /* Flush entry from TLB0 */
                tlb0_flush_entry(va);
        }

        pte->rpn = pa & ~PTE_PA_MASK;
        pte->flags = flags;

        //debugf("mmu_booke_kenter: pdir_idx = %d ptbl_idx = %d va=0x%08x "
        //              "pa=0x%08x rpn=0x%08x flags=0x%08x\n",
        //              pdir_idx, ptbl_idx, va, pa, pte->rpn, pte->flags);

        /* Flush the real memory from the instruction cache. */
        if ((flags & (PTE_I | PTE_G)) == 0) {
                __syncicache((void *)va, PAGE_SIZE);
        }

        tlb_miss_unlock();
        mtx_unlock_spin(&tlbivax_mutex);
}

/*
 * Remove a page from kernel page table.
 */
static void
mmu_booke_kremove(mmu_t mmu, vm_offset_t va)
{
        unsigned int pdir_idx = PDIR_IDX(va);
        unsigned int ptbl_idx = PTBL_IDX(va);
        pte_t *pte;

//      CTR2(KTR_PMAP,("%s: s (va = 0x%08x)\n", __func__, va));

        KASSERT(((va >= VM_MIN_KERNEL_ADDRESS) &&
            (va <= VM_MAX_KERNEL_ADDRESS)),
            ("mmu_booke_kremove: invalid va"));

        pte = &(kernel_pmap->pm_pdir[pdir_idx][ptbl_idx]);

        if (!PTE_ISVALID(pte)) {
        
                CTR1(KTR_PMAP, "%s: invalid pte", __func__);

                return;
        }

        mtx_lock_spin(&tlbivax_mutex);
        tlb_miss_lock();

        /* Invalidate entry in TLB0, update PTE. */
        tlb0_flush_entry(va);
        pte->flags = 0;
        pte->rpn = 0;

        tlb_miss_unlock();
        mtx_unlock_spin(&tlbivax_mutex);
}

/*
 * Initialize pmap associated with process 0.
 */
static void
mmu_booke_pinit0(mmu_t mmu, pmap_t pmap)
{

        mmu_booke_pinit(mmu, pmap);
        PCPU_SET(curpmap, pmap);
}

/*
 * Initialize a preallocated and zeroed pmap structure,
 * such as one in a vmspace structure.
 */
static void
mmu_booke_pinit(mmu_t mmu, pmap_t pmap)
{
        int i;

        CTR4(KTR_PMAP, "%s: pmap = %p, proc %d '%s'", __func__, pmap,
            curthread->td_proc->p_pid, curthread->td_proc->p_comm);

        KASSERT((pmap != kernel_pmap), ("pmap_pinit: initializing kernel_pmap"));

        PMAP_LOCK_INIT(pmap);
        for (i = 0; i < MAXCPU; i++)
                pmap->pm_tid[i] = TID_NONE;
        CPU_ZERO(&kernel_pmap->pm_active);
        bzero(&pmap->pm_stats, sizeof(pmap->pm_stats));
        bzero(&pmap->pm_pdir, sizeof(pte_t *) * PDIR_NENTRIES);
        TAILQ_INIT(&pmap->pm_ptbl_list);
}

/*
 * Release any resources held by the given physical map.
 * Called when a pmap initialized by mmu_booke_pinit is being released.
 * Should only be called if the map contains no valid mappings.
 */
static void
mmu_booke_release(mmu_t mmu, pmap_t pmap)
{

        KASSERT(pmap->pm_stats.resident_count == 0,
            ("pmap_release: pmap resident count %ld != 0",
            pmap->pm_stats.resident_count));

        PMAP_LOCK_DESTROY(pmap);
}

/*
 * Insert the given physical page at the specified virtual address in the
 * target physical map with the protection requested. If specified the page
 * will be wired down.
 */
static void
mmu_booke_enter(mmu_t mmu, pmap_t pmap, vm_offset_t va, vm_page_t m,
    vm_prot_t prot, boolean_t wired)
{

        rw_wlock(&pvh_global_lock);
        PMAP_LOCK(pmap);
        mmu_booke_enter_locked(mmu, pmap, va, m, prot, wired);
        rw_wunlock(&pvh_global_lock);
        PMAP_UNLOCK(pmap);
}

static void
mmu_booke_enter_locked(mmu_t mmu, pmap_t pmap, vm_offset_t va, vm_page_t m,
    vm_prot_t prot, boolean_t wired)
{
        pte_t *pte;
        vm_paddr_t pa;
        uint32_t flags;
        int su, sync;

        pa = VM_PAGE_TO_PHYS(m);
        su = (pmap == kernel_pmap);
        sync = 0;

        //debugf("mmu_booke_enter_locked: s (pmap=0x%08x su=%d tid=%d m=0x%08x va=0x%08x "
        //              "pa=0x%08x prot=0x%08x wired=%d)\n",
        //              (u_int32_t)pmap, su, pmap->pm_tid,
        //              (u_int32_t)m, va, pa, prot, wired);

        if (su) {
                KASSERT(((va >= virtual_avail) &&
                    (va <= VM_MAX_KERNEL_ADDRESS)),
                    ("mmu_booke_enter_locked: kernel pmap, non kernel va"));
        } else {
                KASSERT((va <= VM_MAXUSER_ADDRESS),
                    ("mmu_booke_enter_locked: user pmap, non user va"));
        }
        KASSERT((m->oflags & (VPO_UNMANAGED | VPO_BUSY)) != 0 ||
            VM_OBJECT_LOCKED(m->object),
            ("mmu_booke_enter_locked: page %p is not busy", m));

        PMAP_LOCK_ASSERT(pmap, MA_OWNED);

        /*
         * If there is an existing mapping, and the physical address has not
         * changed, must be protection or wiring change.
         */
        if (((pte = pte_find(mmu, pmap, va)) != NULL) &&
            (PTE_ISVALID(pte)) && (PTE_PA(pte) == pa)) {
            
                /*
                 * Before actually updating pte->flags we calculate and
                 * prepare its new value in a helper var.
                 */
                flags = pte->flags;
                flags &= ~(PTE_UW | PTE_UX | PTE_SW | PTE_SX | PTE_MODIFIED);

                /* Wiring change, just update stats. */
                if (wired) {
                        if (!PTE_ISWIRED(pte)) {
                                flags |= PTE_WIRED;
                                pmap->pm_stats.wired_count++;
                        }
                } else {
                        if (PTE_ISWIRED(pte)) {
                                flags &= ~PTE_WIRED;
                                pmap->pm_stats.wired_count--;
                        }
                }

                if (prot & VM_PROT_WRITE) {
                        /* Add write permissions. */
                        flags |= PTE_SW;
                        if (!su)
                                flags |= PTE_UW;

                        if ((flags & PTE_MANAGED) != 0)
                                vm_page_aflag_set(m, PGA_WRITEABLE);
                } else {
                        /* Handle modified pages, sense modify status. */

                        /*
                         * The PTE_MODIFIED flag could be set by underlying
                         * TLB misses since we last read it (above), possibly
                         * other CPUs could update it so we check in the PTE
                         * directly rather than rely on that saved local flags
                         * copy.
                         */
                        if (PTE_ISMODIFIED(pte))
                                vm_page_dirty(m);
                }

                if (prot & VM_PROT_EXECUTE) {
                        flags |= PTE_SX;
                        if (!su)
                                flags |= PTE_UX;

                        /*
                         * Check existing flags for execute permissions: if we
                         * are turning execute permissions on, icache should
                         * be flushed.
                         */
                        if ((pte->flags & (PTE_UX | PTE_SX)) == 0)
                                sync++;
                }

                flags &= ~PTE_REFERENCED;

                /*
                 * The new flags value is all calculated -- only now actually
                 * update the PTE.
                 */
                mtx_lock_spin(&tlbivax_mutex);
                tlb_miss_lock();

                tlb0_flush_entry(va);
                pte->flags = flags;

                tlb_miss_unlock();
                mtx_unlock_spin(&tlbivax_mutex);

        } else {
                /*
                 * If there is an existing mapping, but it's for a different
                 * physical address, pte_enter() will delete the old mapping.
                 */
                //if ((pte != NULL) && PTE_ISVALID(pte))
                //      debugf("mmu_booke_enter_locked: replace\n");
                //else
                //      debugf("mmu_booke_enter_locked: new\n");

                /* Now set up the flags and install the new mapping. */
                flags = (PTE_SR | PTE_VALID);
                flags |= PTE_M;

                if (!su)
                        flags |= PTE_UR;

                if (prot & VM_PROT_WRITE) {
                        flags |= PTE_SW;
                        if (!su)
                                flags |= PTE_UW;

                        if ((m->oflags & VPO_UNMANAGED) == 0)
                                vm_page_aflag_set(m, PGA_WRITEABLE);
                }

                if (prot & VM_PROT_EXECUTE) {
                        flags |= PTE_SX;
                        if (!su)
                                flags |= PTE_UX;
                }

                /* If its wired update stats. */
                if (wired) {
                        pmap->pm_stats.wired_count++;
                        flags |= PTE_WIRED;
                }

                pte_enter(mmu, pmap, m, va, flags);

                /* Flush the real memory from the instruction cache. */
                if (prot & VM_PROT_EXECUTE)
                        sync++;
        }

        if (sync && (su || pmap == PCPU_GET(curpmap))) {
                __syncicache((void *)va, PAGE_SIZE);
                sync = 0;
        }
}

/*
 * Maps a sequence of resident pages belonging to the same object.
 * The sequence begins with the given page m_start.  This page is
 * mapped at the given virtual address start.  Each subsequent page is
 * mapped at a virtual address that is offset from start by the same
 * amount as the page is offset from m_start within the object.  The
 * last page in the sequence is the page with the largest offset from
 * m_start that can be mapped at a virtual address less than the given
 * virtual address end.  Not every virtual page between start and end
 * is mapped; only those for which a resident page exists with the
 * corresponding offset from m_start are mapped.
 */
static void
mmu_booke_enter_object(mmu_t mmu, pmap_t pmap, vm_offset_t start,
    vm_offset_t end, vm_page_t m_start, vm_prot_t prot)
{
        vm_page_t m;
        vm_pindex_t diff, psize;

        psize = atop(end - start);
        m = m_start;
        rw_wlock(&pvh_global_lock);
        PMAP_LOCK(pmap);
        while (m != NULL && (diff = m->pindex - m_start->pindex) < psize) {
                mmu_booke_enter_locked(mmu, pmap, start + ptoa(diff), m,
                    prot & (VM_PROT_READ | VM_PROT_EXECUTE), FALSE);
                m = TAILQ_NEXT(m, listq);
        }
        rw_wunlock(&pvh_global_lock);
        PMAP_UNLOCK(pmap);
}

static void
mmu_booke_enter_quick(mmu_t mmu, pmap_t pmap, vm_offset_t va, vm_page_t m,
    vm_prot_t prot)
{

        rw_wlock(&pvh_global_lock);
        PMAP_LOCK(pmap);
        mmu_booke_enter_locked(mmu, pmap, va, m,
            prot & (VM_PROT_READ | VM_PROT_EXECUTE), FALSE);
        rw_wunlock(&pvh_global_lock);
        PMAP_UNLOCK(pmap);
}

/*
 * Remove the given range of addresses from the specified map.
 *
 * It is assumed that the start and end are properly rounded to the page size.
 */
static void
mmu_booke_remove(mmu_t mmu, pmap_t pmap, vm_offset_t va, vm_offset_t endva)
{
        pte_t *pte;
        uint8_t hold_flag;

        int su = (pmap == kernel_pmap);

        //debugf("mmu_booke_remove: s (su = %d pmap=0x%08x tid=%d va=0x%08x endva=0x%08x)\n",
        //              su, (u_int32_t)pmap, pmap->pm_tid, va, endva);

        if (su) {
                KASSERT(((va >= virtual_avail) &&
                    (va <= VM_MAX_KERNEL_ADDRESS)),
                    ("mmu_booke_remove: kernel pmap, non kernel va"));
        } else {
                KASSERT((va <= VM_MAXUSER_ADDRESS),
                    ("mmu_booke_remove: user pmap, non user va"));
        }

        if (PMAP_REMOVE_DONE(pmap)) {
                //debugf("mmu_booke_remove: e (empty)\n");
                return;
        }

        hold_flag = PTBL_HOLD_FLAG(pmap);
        //debugf("mmu_booke_remove: hold_flag = %d\n", hold_flag);

        rw_wlock(&pvh_global_lock);
        PMAP_LOCK(pmap);
        for (; va < endva; va += PAGE_SIZE) {
                pte = pte_find(mmu, pmap, va);
                if ((pte != NULL) && PTE_ISVALID(pte))
                        pte_remove(mmu, pmap, va, hold_flag);
        }
        PMAP_UNLOCK(pmap);
        rw_wunlock(&pvh_global_lock);

        //debugf("mmu_booke_remove: e\n");
}

/*
 * Remove physical page from all pmaps in which it resides.
 */
static void
mmu_booke_remove_all(mmu_t mmu, vm_page_t m)
{
        pv_entry_t pv, pvn;
        uint8_t hold_flag;

        rw_wlock(&pvh_global_lock);
        for (pv = TAILQ_FIRST(&m->md.pv_list); pv != NULL; pv = pvn) {
                pvn = TAILQ_NEXT(pv, pv_link);

                PMAP_LOCK(pv->pv_pmap);
                hold_flag = PTBL_HOLD_FLAG(pv->pv_pmap);
                pte_remove(mmu, pv->pv_pmap, pv->pv_va, hold_flag);
                PMAP_UNLOCK(pv->pv_pmap);
        }
        vm_page_aflag_clear(m, PGA_WRITEABLE);
        rw_wunlock(&pvh_global_lock);
}

/*
 * Map a range of physical addresses into kernel virtual address space.
 */
static vm_offset_t
mmu_booke_map(mmu_t mmu, vm_offset_t *virt, vm_paddr_t pa_start,
    vm_paddr_t pa_end, int prot)
{
        vm_offset_t sva = *virt;
        vm_offset_t va = sva;

        //debugf("mmu_booke_map: s (sva = 0x%08x pa_start = 0x%08x pa_end = 0x%08x)\n",
        //              sva, pa_start, pa_end);

        while (pa_start < pa_end) {
                mmu_booke_kenter(mmu, va, pa_start);
                va += PAGE_SIZE;
                pa_start += PAGE_SIZE;
        }
        *virt = va;

        //debugf("mmu_booke_map: e (va = 0x%08x)\n", va);
        return (sva);
}

/*
 * The pmap must be activated before it's address space can be accessed in any
 * way.
 */
static void
mmu_booke_activate(mmu_t mmu, struct thread *td)
{
        pmap_t pmap;
        u_int cpuid;

        pmap = &td->td_proc->p_vmspace->vm_pmap;

        CTR5(KTR_PMAP, "%s: s (td = %p, proc = '%s', id = %d, pmap = 0x%08x)",
            __func__, td, td->td_proc->p_comm, td->td_proc->p_pid, pmap);

        KASSERT((pmap != kernel_pmap), ("mmu_booke_activate: kernel_pmap!"));

        mtx_lock_spin(&sched_lock);

        cpuid = PCPU_GET(cpuid);
        CPU_SET_ATOMIC(cpuid, &pmap->pm_active);
        PCPU_SET(curpmap, pmap);
        
        if (pmap->pm_tid[cpuid] == TID_NONE)
                tid_alloc(pmap);

        /* Load PID0 register with pmap tid value. */
        mtspr(SPR_PID0, pmap->pm_tid[cpuid]);
        __asm __volatile("isync");

        mtx_unlock_spin(&sched_lock);

        CTR3(KTR_PMAP, "%s: e (tid = %d for '%s')", __func__,
            pmap->pm_tid[PCPU_GET(cpuid)], td->td_proc->p_comm);
}

/*
 * Deactivate the specified process's address space.
 */
static void
mmu_booke_deactivate(mmu_t mmu, struct thread *td)
{
        pmap_t pmap;

        pmap = &td->td_proc->p_vmspace->vm_pmap;
        
        CTR5(KTR_PMAP, "%s: td=%p, proc = '%s', id = %d, pmap = 0x%08x",
            __func__, td, td->td_proc->p_comm, td->td_proc->p_pid, pmap);

        CPU_CLR_ATOMIC(PCPU_GET(cpuid), &pmap->pm_active);
        PCPU_SET(curpmap, NULL);
}

/*
 * Copy the range specified by src_addr/len
 * from the source map to the range dst_addr/len
 * in the destination map.
 *
 * This routine is only advisory and need not do anything.
 */
static void
mmu_booke_copy(mmu_t mmu, pmap_t dst_pmap, pmap_t src_pmap,
    vm_offset_t dst_addr, vm_size_t len, vm_offset_t src_addr)
{

}

/*
 * Set the physical protection on the specified range of this map as requested.
 */
static void
mmu_booke_protect(mmu_t mmu, pmap_t pmap, vm_offset_t sva, vm_offset_t eva,
    vm_prot_t prot)
{
        vm_offset_t va;
        vm_page_t m;
        pte_t *pte;

        if ((prot & VM_PROT_READ) == VM_PROT_NONE) {
                mmu_booke_remove(mmu, pmap, sva, eva);
                return;
        }

        if (prot & VM_PROT_WRITE)
                return;

        PMAP_LOCK(pmap);
        for (va = sva; va < eva; va += PAGE_SIZE) {
                if ((pte = pte_find(mmu, pmap, va)) != NULL) {
                        if (PTE_ISVALID(pte)) {
                                m = PHYS_TO_VM_PAGE(PTE_PA(pte));

                                mtx_lock_spin(&tlbivax_mutex);
                                tlb_miss_lock();

                                /* Handle modified pages. */
                                if (PTE_ISMODIFIED(pte) && PTE_ISMANAGED(pte))
                                        vm_page_dirty(m);

                                tlb0_flush_entry(va);
                                pte->flags &= ~(PTE_UW | PTE_SW | PTE_MODIFIED);

                                tlb_miss_unlock();
                                mtx_unlock_spin(&tlbivax_mutex);
                        }
                }
        }
        PMAP_UNLOCK(pmap);
}

/*
 * Clear the write and modified bits in each of the given page's mappings.
 */
static void
mmu_booke_remove_write(mmu_t mmu, vm_page_t m)
{
        pv_entry_t pv;
        pte_t *pte;

        KASSERT((m->oflags & VPO_UNMANAGED) == 0,
            ("mmu_booke_remove_write: page %p is not managed", m));

        /*
         * If the page is not VPO_BUSY, then PGA_WRITEABLE cannot be set by
         * another thread while the object is locked.  Thus, if PGA_WRITEABLE
         * is clear, no page table entries need updating.
         */
        VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED);
        if ((m->oflags & VPO_BUSY) == 0 &&
            (m->aflags & PGA_WRITEABLE) == 0)
                return;
        rw_wlock(&pvh_global_lock);
        TAILQ_FOREACH(pv, &m->md.pv_list, pv_link) {
                PMAP_LOCK(pv->pv_pmap);
                if ((pte = pte_find(mmu, pv->pv_pmap, pv->pv_va)) != NULL) {
                        if (PTE_ISVALID(pte)) {
                                m = PHYS_TO_VM_PAGE(PTE_PA(pte));

                                mtx_lock_spin(&tlbivax_mutex);
                                tlb_miss_lock();

                                /* Handle modified pages. */
                                if (PTE_ISMODIFIED(pte))
                                        vm_page_dirty(m);

                                /* Flush mapping from TLB0. */
                                pte->flags &= ~(PTE_UW | PTE_SW | PTE_MODIFIED);

                                tlb_miss_unlock();
                                mtx_unlock_spin(&tlbivax_mutex);
                        }
                }
                PMAP_UNLOCK(pv->pv_pmap);
        }
        vm_page_aflag_clear(m, PGA_WRITEABLE);
        rw_wunlock(&pvh_global_lock);
}

static void
mmu_booke_sync_icache(mmu_t mmu, pmap_t pm, vm_offset_t va, vm_size_t sz)
{
        pte_t *pte;
        pmap_t pmap;
        vm_page_t m;
        vm_offset_t addr;
        vm_paddr_t pa;
        int active, valid;
 
        va = trunc_page(va);
        sz = round_page(sz);

        rw_wlock(&pvh_global_lock);
        pmap = PCPU_GET(curpmap);
        active = (pm == kernel_pmap || pm == pmap) ? 1 : 0;
        while (sz > 0) {
                PMAP_LOCK(pm);
                pte = pte_find(mmu, pm, va);
                valid = (pte != NULL && PTE_ISVALID(pte)) ? 1 : 0;
                if (valid)
                        pa = PTE_PA(pte);
                PMAP_UNLOCK(pm);
                if (valid) {
                        if (!active) {
                                /* Create a mapping in the active pmap. */
                                addr = 0;
                                m = PHYS_TO_VM_PAGE(pa);
                                PMAP_LOCK(pmap);
                                pte_enter(mmu, pmap, m, addr,
                                    PTE_SR | PTE_VALID | PTE_UR);
                                __syncicache((void *)addr, PAGE_SIZE);
                                pte_remove(mmu, pmap, addr, PTBL_UNHOLD);
                                PMAP_UNLOCK(pmap);
                        } else
                                __syncicache((void *)va, PAGE_SIZE);
                }
                va += PAGE_SIZE;
                sz -= PAGE_SIZE;
        }
        rw_wunlock(&pvh_global_lock);
}

/*
 * Atomically extract and hold the physical page with the given
 * pmap and virtual address pair if that mapping permits the given
 * protection.
 */
static vm_page_t
mmu_booke_extract_and_hold(mmu_t mmu, pmap_t pmap, vm_offset_t va,
    vm_prot_t prot)
{
        pte_t *pte;
        vm_page_t m;
        uint32_t pte_wbit;
        vm_paddr_t pa;
        
        m = NULL;
        pa = 0; 
        PMAP_LOCK(pmap);
retry:
        pte = pte_find(mmu, pmap, va);
        if ((pte != NULL) && PTE_ISVALID(pte)) {
                if (pmap == kernel_pmap)
                        pte_wbit = PTE_SW;
                else
                        pte_wbit = PTE_UW;

                if ((pte->flags & pte_wbit) || ((prot & VM_PROT_WRITE) == 0)) {
                        if (vm_page_pa_tryrelock(pmap, PTE_PA(pte), &pa))
                                goto retry;
                        m = PHYS_TO_VM_PAGE(PTE_PA(pte));
                        vm_page_hold(m);
                }
        }

        PA_UNLOCK_COND(pa);
        PMAP_UNLOCK(pmap);
        return (m);
}

/*
 * Initialize a vm_page's machine-dependent fields.
 */
static void
mmu_booke_page_init(mmu_t mmu, vm_page_t m)
{

        TAILQ_INIT(&m->md.pv_list);
}

/*
 * mmu_booke_zero_page_area zeros the specified hardware page by
 * mapping it into virtual memory and using bzero to clear
 * its contents.
 *
 * off and size must reside within a single page.
 */
static void
mmu_booke_zero_page_area(mmu_t mmu, vm_page_t m, int off, int size)
{
        vm_offset_t va;

        /* XXX KASSERT off and size are within a single page? */

        mtx_lock(&zero_page_mutex);
        va = zero_page_va;

        mmu_booke_kenter(mmu, va, VM_PAGE_TO_PHYS(m));
        bzero((caddr_t)va + off, size);
        mmu_booke_kremove(mmu, va);

        mtx_unlock(&zero_page_mutex);
}

/*
 * mmu_booke_zero_page zeros the specified hardware page.
 */
static void
mmu_booke_zero_page(mmu_t mmu, vm_page_t m)
{

        mmu_booke_zero_page_area(mmu, m, 0, PAGE_SIZE);
}

/*
 * mmu_booke_copy_page copies the specified (machine independent) page by
 * mapping the page into virtual memory and using memcopy to copy the page,
 * one machine dependent page at a time.
 */
static void
mmu_booke_copy_page(mmu_t mmu, vm_page_t sm, vm_page_t dm)
{
        vm_offset_t sva, dva;

        sva = copy_page_src_va;
        dva = copy_page_dst_va;

        mtx_lock(&copy_page_mutex);
        mmu_booke_kenter(mmu, sva, VM_PAGE_TO_PHYS(sm));
        mmu_booke_kenter(mmu, dva, VM_PAGE_TO_PHYS(dm));
        memcpy((caddr_t)dva, (caddr_t)sva, PAGE_SIZE);
        mmu_booke_kremove(mmu, dva);
        mmu_booke_kremove(mmu, sva);
        mtx_unlock(&copy_page_mutex);
}

/*
 * mmu_booke_zero_page_idle zeros the specified hardware page by mapping it
 * into virtual memory and using bzero to clear its contents. This is intended
 * to be called from the vm_pagezero process only and outside of Giant. No
 * lock is required.
 */
static void
mmu_booke_zero_page_idle(mmu_t mmu, vm_page_t m)
{
        vm_offset_t va;

        va = zero_page_idle_va;
        mmu_booke_kenter(mmu, va, VM_PAGE_TO_PHYS(m));
        bzero((caddr_t)va, PAGE_SIZE);
        mmu_booke_kremove(mmu, va);
}

/*
 * Return whether or not the specified physical page was modified
 * in any of physical maps.
 */
static boolean_t
mmu_booke_is_modified(mmu_t mmu, vm_page_t m)
{
        pte_t *pte;
        pv_entry_t pv;
        boolean_t rv;

        KASSERT((m->oflags & VPO_UNMANAGED) == 0,
            ("mmu_booke_is_modified: page %p is not managed", m));
        rv = FALSE;

        /*
         * If the page is not VPO_BUSY, then PGA_WRITEABLE cannot be
         * concurrently set while the object is locked.  Thus, if PGA_WRITEABLE
         * is clear, no PTEs can be modified.
         */
        VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED);
        if ((m->oflags & VPO_BUSY) == 0 &&
            (m->aflags & PGA_WRITEABLE) == 0)
                return (rv);
        rw_wlock(&pvh_global_lock);
        TAILQ_FOREACH(pv, &m->md.pv_list, pv_link) {
                PMAP_LOCK(pv->pv_pmap);
                if ((pte = pte_find(mmu, pv->pv_pmap, pv->pv_va)) != NULL &&
                    PTE_ISVALID(pte)) {
                        if (PTE_ISMODIFIED(pte))
                                rv = TRUE;
                }
                PMAP_UNLOCK(pv->pv_pmap);
                if (rv)
                        break;
        }
        rw_wunlock(&pvh_global_lock);
        return (rv);
}

/*
 * Return whether or not the specified virtual address is eligible
 * for prefault.
 */
static boolean_t
mmu_booke_is_prefaultable(mmu_t mmu, pmap_t pmap, vm_offset_t addr)
{

        return (FALSE);
}

/*
 * Return whether or not the specified physical page was referenced
 * in any physical maps.
 */
static boolean_t
mmu_booke_is_referenced(mmu_t mmu, vm_page_t m)
{
        pte_t *pte;
        pv_entry_t pv;
        boolean_t rv;

        KASSERT((m->oflags & VPO_UNMANAGED) == 0,
            ("mmu_booke_is_referenced: page %p is not managed", m));
        rv = FALSE;
        rw_wlock(&pvh_global_lock);
        TAILQ_FOREACH(pv, &m->md.pv_list, pv_link) {
                PMAP_LOCK(pv->pv_pmap);
                if ((pte = pte_find(mmu, pv->pv_pmap, pv->pv_va)) != NULL &&
                    PTE_ISVALID(pte)) {
                        if (PTE_ISREFERENCED(pte))
                                rv = TRUE;
                }
                PMAP_UNLOCK(pv->pv_pmap);
                if (rv)
                        break;
        }
        rw_wunlock(&pvh_global_lock);
        return (rv);
}

/*
 * Clear the modify bits on the specified physical page.
 */
static void
mmu_booke_clear_modify(mmu_t mmu, vm_page_t m)
{
        pte_t *pte;
        pv_entry_t pv;

        KASSERT((m->oflags & VPO_UNMANAGED) == 0,
            ("mmu_booke_clear_modify: page %p is not managed", m));
        VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED);
        KASSERT((m->oflags & VPO_BUSY) == 0,
            ("mmu_booke_clear_modify: page %p is busy", m));

        /*
         * If the page is not PG_AWRITEABLE, then no PTEs can be modified.
         * If the object containing the page is locked and the page is not
         * VPO_BUSY, then PG_AWRITEABLE cannot be concurrently set.
         */
        if ((m->aflags & PGA_WRITEABLE) == 0)
                return;
        rw_wlock(&pvh_global_lock);
        TAILQ_FOREACH(pv, &m->md.pv_list, pv_link) {
                PMAP_LOCK(pv->pv_pmap);
                if ((pte = pte_find(mmu, pv->pv_pmap, pv->pv_va)) != NULL &&
                    PTE_ISVALID(pte)) {
                        mtx_lock_spin(&tlbivax_mutex);
                        tlb_miss_lock();
                        
                        if (pte->flags & (PTE_SW | PTE_UW | PTE_MODIFIED)) {
                                tlb0_flush_entry(pv->pv_va);
                                pte->flags &= ~(PTE_SW | PTE_UW | PTE_MODIFIED |
                                    PTE_REFERENCED);
                        }

                        tlb_miss_unlock();
                        mtx_unlock_spin(&tlbivax_mutex);
                }
                PMAP_UNLOCK(pv->pv_pmap);
        }
        rw_wunlock(&pvh_global_lock);
}

/*
 * Return a count of reference bits for a page, clearing those bits.
 * It is not necessary for every reference bit to be cleared, but it
 * is necessary that 0 only be returned when there are truly no
 * reference bits set.
 *
 * XXX: The exact number of bits to check and clear is a matter that
 * should be tested and standardized at some point in the future for
 * optimal aging of shared pages.
 */
static int
mmu_booke_ts_referenced(mmu_t mmu, vm_page_t m)
{
        pte_t *pte;
        pv_entry_t pv;
        int count;

        KASSERT((m->oflags & VPO_UNMANAGED) == 0,
            ("mmu_booke_ts_referenced: page %p is not managed", m));
        count = 0;
        rw_wlock(&pvh_global_lock);
        TAILQ_FOREACH(pv, &m->md.pv_list, pv_link) {
                PMAP_LOCK(pv->pv_pmap);
                if ((pte = pte_find(mmu, pv->pv_pmap, pv->pv_va)) != NULL &&
                    PTE_ISVALID(pte)) {
                        if (PTE_ISREFERENCED(pte)) {
                                mtx_lock_spin(&tlbivax_mutex);
                                tlb_miss_lock();

                                tlb0_flush_entry(pv->pv_va);
                                pte->flags &= ~PTE_REFERENCED;

                                tlb_miss_unlock();
                                mtx_unlock_spin(&tlbivax_mutex);

                                if (++count > 4) {
                                        PMAP_UNLOCK(pv->pv_pmap);
                                        break;
                                }
                        }
                }
                PMAP_UNLOCK(pv->pv_pmap);
        }
        rw_wunlock(&pvh_global_lock);
        return (count);
}

/*
 * Clear the reference bit on the specified physical page.
 */
static void
mmu_booke_clear_reference(mmu_t mmu, vm_page_t m)
{
        pte_t *pte;
        pv_entry_t pv;

        KASSERT((m->oflags & VPO_UNMANAGED) == 0,
            ("mmu_booke_clear_reference: page %p is not managed", m));
        rw_wlock(&pvh_global_lock);
        TAILQ_FOREACH(pv, &m->md.pv_list, pv_link) {
                PMAP_LOCK(pv->pv_pmap);
                if ((pte = pte_find(mmu, pv->pv_pmap, pv->pv_va)) != NULL &&
                    PTE_ISVALID(pte)) {
                        if (PTE_ISREFERENCED(pte)) {
                                mtx_lock_spin(&tlbivax_mutex);
                                tlb_miss_lock();
                                
                                tlb0_flush_entry(pv->pv_va);
                                pte->flags &= ~PTE_REFERENCED;

                                tlb_miss_unlock();
                                mtx_unlock_spin(&tlbivax_mutex);
                        }
                }
                PMAP_UNLOCK(pv->pv_pmap);
        }
        rw_wunlock(&pvh_global_lock);
}

/*
 * Change wiring attribute for a map/virtual-address pair.
 */
static void
mmu_booke_change_wiring(mmu_t mmu, pmap_t pmap, vm_offset_t va, boolean_t wired)
{
        pte_t *pte;

        PMAP_LOCK(pmap);
        if ((pte = pte_find(mmu, pmap, va)) != NULL) {
                if (wired) {
                        if (!PTE_ISWIRED(pte)) {
                                pte->flags |= PTE_WIRED;
                                pmap->pm_stats.wired_count++;
                        }
                } else {
                        if (PTE_ISWIRED(pte)) {
                                pte->flags &= ~PTE_WIRED;
                                pmap->pm_stats.wired_count--;
                        }
                }
        }
        PMAP_UNLOCK(pmap);
}

/*
 * Return true if the pmap's pv is one of the first 16 pvs linked to from this
 * page.  This count may be changed upwards or downwards in the future; it is
 * only necessary that true be returned for a small subset of pmaps for proper
 * page aging.
 */
static boolean_t
mmu_booke_page_exists_quick(mmu_t mmu, pmap_t pmap, vm_page_t m)
{
        pv_entry_t pv;
        int loops;
        boolean_t rv;

        KASSERT((m->oflags & VPO_UNMANAGED) == 0,
            ("mmu_booke_page_exists_quick: page %p is not managed", m));
        loops = 0;
        rv = FALSE;
        rw_wlock(&pvh_global_lock);
        TAILQ_FOREACH(pv, &m->md.pv_list, pv_link) {
                if (pv->pv_pmap == pmap) {
                        rv = TRUE;
                        break;
                }
                if (++loops >= 16)
                        break;
        }
        rw_wunlock(&pvh_global_lock);
        return (rv);
}

/*
 * Return the number of managed mappings to the given physical page that are
 * wired.
 */
static int
mmu_booke_page_wired_mappings(mmu_t mmu, vm_page_t m)
{
        pv_entry_t pv;
        pte_t *pte;
        int count = 0;

        if ((m->oflags & VPO_UNMANAGED) != 0)
                return (count);
        rw_wlock(&pvh_global_lock);
        TAILQ_FOREACH(pv, &m->md.pv_list, pv_link) {
                PMAP_LOCK(pv->pv_pmap);
                if ((pte = pte_find(mmu, pv->pv_pmap, pv->pv_va)) != NULL)
                        if (PTE_ISVALID(pte) && PTE_ISWIRED(pte))
                                count++;
                PMAP_UNLOCK(pv->pv_pmap);
        }
        rw_wunlock(&pvh_global_lock);
        return (count);
}

static int
mmu_booke_dev_direct_mapped(mmu_t mmu, vm_paddr_t pa, vm_size_t size)
{
        int i;
        vm_offset_t va;

        /*
         * This currently does not work for entries that
         * overlap TLB1 entries.
         */
        for (i = 0; i < tlb1_idx; i ++) {
                if (tlb1_iomapped(i, pa, size, &va) == 0)
                        return (0);
        }

        return (EFAULT);
}

vm_offset_t
mmu_booke_dumpsys_map(mmu_t mmu, struct pmap_md *md, vm_size_t ofs,
    vm_size_t *sz)
{
        vm_paddr_t pa, ppa;
        vm_offset_t va;
        vm_size_t gran;

        /* Raw physical memory dumps don't have a virtual address. */
        if (md->md_vaddr == ~0UL) {
                /* We always map a 256MB page at 256M. */
                gran = 256 * 1024 * 1024;
                pa = md->md_paddr + ofs;
                ppa = pa & ~(gran - 1);
                ofs = pa - ppa;
                va = gran;
                tlb1_set_entry(va, ppa, gran, _TLB_ENTRY_IO);
                if (*sz > (gran - ofs))
                        *sz = gran - ofs;
                return (va + ofs);
        }

        /* Minidumps are based on virtual memory addresses. */
        va = md->md_vaddr + ofs;
        if (va >= kernstart + kernsize) {
                gran = PAGE_SIZE - (va & PAGE_MASK);
                if (*sz > gran)
                        *sz = gran;
        }
        return (va);
}

void
mmu_booke_dumpsys_unmap(mmu_t mmu, struct pmap_md *md, vm_size_t ofs,
    vm_offset_t va)
{

        /* Raw physical memory dumps don't have a virtual address. */
        if (md->md_vaddr == ~0UL) {
                tlb1_idx--;
                tlb1[tlb1_idx].mas1 = 0;
                tlb1[tlb1_idx].mas2 = 0;
                tlb1[tlb1_idx].mas3 = 0;
                tlb1_write_entry(tlb1_idx);
                return;
        }
 
        /* Minidumps are based on virtual memory addresses. */
        /* Nothing to do... */
}

struct pmap_md *
mmu_booke_scan_md(mmu_t mmu, struct pmap_md *prev)
{
        static struct pmap_md md;
        pte_t *pte;
        vm_offset_t va;
 
        if (dumpsys_minidump) {
                md.md_paddr = ~0UL;     /* Minidumps use virtual addresses. */
                if (prev == NULL) {
                        /* 1st: kernel .data and .bss. */
                        md.md_index = 1;
                        md.md_vaddr = trunc_page((uintptr_t)_etext);
                        md.md_size = round_page((uintptr_t)_end) - md.md_vaddr;
                        return (&md);
                }
                switch (prev->md_index) {
                case 1:
                        /* 2nd: msgbuf and tables (see pmap_bootstrap()). */
                        md.md_index = 2;
                        md.md_vaddr = data_start;
                        md.md_size = data_end - data_start;
                        break;
                case 2:
                        /* 3rd: kernel VM. */
                        va = prev->md_vaddr + prev->md_size;
                        /* Find start of next chunk (from va). */
                        while (va < virtual_end) {
                                /* Don't dump the buffer cache. */
                                if (va >= kmi.buffer_sva &&
                                    va < kmi.buffer_eva) {
                                        va = kmi.buffer_eva;
                                        continue;
                                }
                                pte = pte_find(mmu, kernel_pmap, va);
                                if (pte != NULL && PTE_ISVALID(pte))
                                        break;
                                va += PAGE_SIZE;
                        }
                        if (va < virtual_end) {
                                md.md_vaddr = va;
                                va += PAGE_SIZE;
                                /* Find last page in chunk. */
                                while (va < virtual_end) {
                                        /* Don't run into the buffer cache. */
                                        if (va == kmi.buffer_sva)
                                                break;
                                        pte = pte_find(mmu, kernel_pmap, va);
                                        if (pte == NULL || !PTE_ISVALID(pte))
                                                break;
                                        va += PAGE_SIZE;
                                }
                                md.md_size = va - md.md_vaddr;
                                break;
                        }
                        md.md_index = 3;
                        /* FALLTHROUGH */
                default:
                        return (NULL);
                }
        } else { /* minidumps */
                mem_regions(&physmem_regions, &physmem_regions_sz,
                    &availmem_regions, &availmem_regions_sz);

                if (prev == NULL) {
                        /* first physical chunk. */
                        md.md_paddr = physmem_regions[0].mr_start;
                        md.md_size = physmem_regions[0].mr_size;
                        md.md_vaddr = ~0UL;
                        md.md_index = 1;
                } else if (md.md_index < physmem_regions_sz) {
                        md.md_paddr = physmem_regions[md.md_index].mr_start;
                        md.md_size = physmem_regions[md.md_index].mr_size;
                        md.md_vaddr = ~0UL;
                        md.md_index++;
                } else {
                        /* There's no next physical chunk. */
                        return (NULL);
                }
        }

        return (&md);
}

/*
 * Map a set of physical memory pages into the kernel virtual address space.
 * Return a pointer to where it is mapped. This routine is intended to be used
 * for mapping device memory, NOT real memory.
 */
static void *
mmu_booke_mapdev(mmu_t mmu, vm_paddr_t pa, vm_size_t size)
{
        void *res;
        uintptr_t va;
        vm_size_t sz;

        /*
         * CCSR is premapped. Note that (pa + size - 1) is there to make sure
         * we don't wrap around. Devices on the local bus typically extend all
         * the way up to and including 0xffffffff. In that case (pa + size)
         * would be 0. This creates a false positive (i.e. we think it's
         * within the CCSR) and not create a mapping.
         */
        if (pa >= ccsrbar_pa && (pa + size - 1) < (ccsrbar_pa + CCSRBAR_SIZE)) {
                va = CCSRBAR_VA + (pa - ccsrbar_pa);
                return ((void *)va);
        }

        va = (pa >= 0x80000000) ? pa : (0xe2000000 + pa);
        res = (void *)va;

        do {
                sz = 1 << (ilog2(size) & ~1);
                if (bootverbose)
                        printf("Wiring VA=%x to PA=%x (size=%x), "
                            "using TLB1[%d]\n", va, pa, sz, tlb1_idx);
                tlb1_set_entry(va, pa, sz, _TLB_ENTRY_IO);
                size -= sz;
                pa += sz;
                va += sz;
        } while (size > 0);

        return (res);
}

/*
 * 'Unmap' a range mapped by mmu_booke_mapdev().
 */
static void
mmu_booke_unmapdev(mmu_t mmu, vm_offset_t va, vm_size_t size)
{
        vm_offset_t base, offset;

        /*
         * Unmap only if this is inside kernel virtual space.
         */
        if ((va >= VM_MIN_KERNEL_ADDRESS) && (va <= VM_MAX_KERNEL_ADDRESS)) {
                base = trunc_page(va);
                offset = va & PAGE_MASK;
                size = roundup(offset + size, PAGE_SIZE);
                kmem_free(kernel_map, base, size);
        }
}

/*
 * mmu_booke_object_init_pt preloads the ptes for a given object into the
 * specified pmap. This eliminates the blast of soft faults on process startup
 * and immediately after an mmap.
 */
static void
mmu_booke_object_init_pt(mmu_t mmu, pmap_t pmap, vm_offset_t addr,
    vm_object_t object, vm_pindex_t pindex, vm_size_t size)
{

        VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
        KASSERT(object->type == OBJT_DEVICE || object->type == OBJT_SG,
            ("mmu_booke_object_init_pt: non-device object"));
}

/*
 * Perform the pmap work for mincore.
 */
static int
mmu_booke_mincore(mmu_t mmu, pmap_t pmap, vm_offset_t addr,
    vm_paddr_t *locked_pa)
{

        TODO;
        return (0);
}

/**************************************************************************/
/* TID handling */
/**************************************************************************/

/*
 * Allocate a TID. If necessary, steal one from someone else.
 * The new TID is flushed from the TLB before returning.
 */
static tlbtid_t
tid_alloc(pmap_t pmap)
{
        tlbtid_t tid;
        int thiscpu;

        KASSERT((pmap != kernel_pmap), ("tid_alloc: kernel pmap"));

        CTR2(KTR_PMAP, "%s: s (pmap = %p)", __func__, pmap);

        thiscpu = PCPU_GET(cpuid);

        tid = PCPU_GET(tid_next);
        if (tid > TID_MAX)
                tid = TID_MIN;
        PCPU_SET(tid_next, tid + 1);

        /* If we are stealing TID then clear the relevant pmap's field */
        if (tidbusy[thiscpu][tid] != NULL) {

                CTR2(KTR_PMAP, "%s: warning: stealing tid %d", __func__, tid);
                
                tidbusy[thiscpu][tid]->pm_tid[thiscpu] = TID_NONE;

                /* Flush all entries from TLB0 matching this TID. */
                tid_flush(tid);
        }

        tidbusy[thiscpu][tid] = pmap;
        pmap->pm_tid[thiscpu] = tid;
        __asm __volatile("msync; isync");

        CTR3(KTR_PMAP, "%s: e (%02d next = %02d)", __func__, tid,
            PCPU_GET(tid_next));

        return (tid);
}

/**************************************************************************/
/* TLB0 handling */
/**************************************************************************/

static void
tlb_print_entry(int i, uint32_t mas1, uint32_t mas2, uint32_t mas3,
    uint32_t mas7)
{
        int as;
        char desc[3];
        tlbtid_t tid;
        vm_size_t size;
        unsigned int tsize;

        desc[2] = '\0';
        if (mas1 & MAS1_VALID)
                desc[0] = 'V';
        else
                desc[0] = ' ';

        if (mas1 & MAS1_IPROT)
                desc[1] = 'P';
        else
                desc[1] = ' ';

        as = (mas1 & MAS1_TS_MASK) ? 1 : 0;
        tid = MAS1_GETTID(mas1);

        tsize = (mas1 & MAS1_TSIZE_MASK) >> MAS1_TSIZE_SHIFT;
        size = 0;
        if (tsize)
                size = tsize2size(tsize);

        debugf("%3d: (%s) [AS=%d] "
            "sz = 0x%08x tsz = %d tid = %d mas1 = 0x%08x "
            "mas2(va) = 0x%08x mas3(pa) = 0x%08x mas7 = 0x%08x\n",
            i, desc, as, size, tsize, tid, mas1, mas2, mas3, mas7);
}

/* Convert TLB0 va and way number to tlb0[] table index. */
static inline unsigned int
tlb0_tableidx(vm_offset_t va, unsigned int way)
{
        unsigned int idx;

        idx = (way * TLB0_ENTRIES_PER_WAY);
        idx += (va & MAS2_TLB0_ENTRY_IDX_MASK) >> MAS2_TLB0_ENTRY_IDX_SHIFT;
        return (idx);
}

/*
 * Invalidate TLB0 entry.
 */
static inline void
tlb0_flush_entry(vm_offset_t va)
{

        CTR2(KTR_PMAP, "%s: s va=0x%08x", __func__, va);

        mtx_assert(&tlbivax_mutex, MA_OWNED);

        __asm __volatile("tlbivax 0, %0" :: "r"(va & MAS2_EPN_MASK));
        __asm __volatile("isync; msync");
        __asm __volatile("tlbsync; msync");

        CTR1(KTR_PMAP, "%s: e", __func__);
}

/* Print out contents of the MAS registers for each TLB0 entry */
void
tlb0_print_tlbentries(void)
{
        uint32_t mas0, mas1, mas2, mas3, mas7;
        int entryidx, way, idx;

        debugf("TLB0 entries:\n");
        for (way = 0; way < TLB0_WAYS; way ++)
                for (entryidx = 0; entryidx < TLB0_ENTRIES_PER_WAY; entryidx++) {

                        mas0 = MAS0_TLBSEL(0) | MAS0_ESEL(way);
                        mtspr(SPR_MAS0, mas0);
                        __asm __volatile("isync");

                        mas2 = entryidx << MAS2_TLB0_ENTRY_IDX_SHIFT;
                        mtspr(SPR_MAS2, mas2);

                        __asm __volatile("isync; tlbre");

                        mas1 = mfspr(SPR_MAS1);
                        mas2 = mfspr(SPR_MAS2);
                        mas3 = mfspr(SPR_MAS3);
                        mas7 = mfspr(SPR_MAS7);

                        idx = tlb0_tableidx(mas2, way);
                        tlb_print_entry(idx, mas1, mas2, mas3, mas7);
                }
}

/**************************************************************************/
/* TLB1 handling */
/**************************************************************************/

/*
 * TLB1 mapping notes:
 *
 * TLB1[0]      CCSRBAR
 * TLB1[1]      Kernel text and data.
 * TLB1[2-15]   Additional kernel text and data mappings (if required), PCI
 *              windows, other devices mappings.
 */

/*
 * Write given entry to TLB1 hardware.
 * Use 32 bit pa, clear 4 high-order bits of RPN (mas7).
 */
static void
tlb1_write_entry(unsigned int idx)
{
        uint32_t mas0, mas7;

        //debugf("tlb1_write_entry: s\n");

        /* Clear high order RPN bits */
        mas7 = 0;

        /* Select entry */
        mas0 = MAS0_TLBSEL(1) | MAS0_ESEL(idx);
        //debugf("tlb1_write_entry: mas0 = 0x%08x\n", mas0);

        mtspr(SPR_MAS0, mas0);
        __asm __volatile("isync");
        mtspr(SPR_MAS1, tlb1[idx].mas1);
        __asm __volatile("isync");
        mtspr(SPR_MAS2, tlb1[idx].mas2);
        __asm __volatile("isync");
        mtspr(SPR_MAS3, tlb1[idx].mas3);
        __asm __volatile("isync");
        mtspr(SPR_MAS7, mas7);
        __asm __volatile("isync; tlbwe; isync; msync");

        //debugf("tlb1_write_entry: e\n");
}

/*
 * Return the largest uint value log such that 2^log <= num.
 */
static unsigned int
ilog2(unsigned int num)
{
        int lz;

        __asm ("cntlzw %0, %1" : "=r" (lz) : "r" (num));
        return (31 - lz);
}

/*
 * Convert TLB TSIZE value to mapped region size.
 */
static vm_size_t
tsize2size(unsigned int tsize)
{

        /*
         * size = 4^tsize KB
         * size = 4^tsize * 2^10 = 2^(2 * tsize - 10)
         */

        return ((1 << (2 * tsize)) * 1024);
}

/*
 * Convert region size (must be power of 4) to TLB TSIZE value.
 */
static unsigned int
size2tsize(vm_size_t size)
{

        return (ilog2(size) / 2 - 5);
}

/*
 * Register permanent kernel mapping in TLB1.
 *
 * Entries are created starting from index 0 (current free entry is
 * kept in tlb1_idx) and are not supposed to be invalidated.
 */
static int
tlb1_set_entry(vm_offset_t va, vm_offset_t pa, vm_size_t size,
    uint32_t flags)
{
        uint32_t ts, tid;
        int tsize;
        
        if (tlb1_idx >= TLB1_ENTRIES) {
                printf("tlb1_set_entry: TLB1 full!\n");
                return (-1);
        }

        /* Convert size to TSIZE */
        tsize = size2tsize(size);

        tid = (TID_KERNEL << MAS1_TID_SHIFT) & MAS1_TID_MASK;
        /* XXX TS is hard coded to 0 for now as we only use single address space */
        ts = (0 << MAS1_TS_SHIFT) & MAS1_TS_MASK;

        /* XXX LOCK tlb1[] */

        tlb1[tlb1_idx].mas1 = MAS1_VALID | MAS1_IPROT | ts | tid;
        tlb1[tlb1_idx].mas1 |= ((tsize << MAS1_TSIZE_SHIFT) & MAS1_TSIZE_MASK);
        tlb1[tlb1_idx].mas2 = (va & MAS2_EPN_MASK) | flags;

        /* Set supervisor RWX permission bits */
        tlb1[tlb1_idx].mas3 = (pa & MAS3_RPN) | MAS3_SR | MAS3_SW | MAS3_SX;

        tlb1_write_entry(tlb1_idx++);

        /* XXX UNLOCK tlb1[] */

        /*
         * XXX in general TLB1 updates should be propagated between CPUs,
         * since current design assumes to have the same TLB1 set-up on all
         * cores.
         */
        return (0);
}

/*
 * Map in contiguous RAM region into the TLB1 using maximum of
 * KERNEL_REGION_MAX_TLB_ENTRIES entries.
 *
 * If necessary round up last entry size and return total size
 * used by all allocated entries.
 */
vm_size_t
tlb1_mapin_region(vm_offset_t va, vm_paddr_t pa, vm_size_t size)
{
        vm_size_t pgs[KERNEL_REGION_MAX_TLB_ENTRIES];
        vm_size_t mapped, pgsz, base, mask;
        int idx, nents;

        /* Round up to the next 1M */
        size = (size + (1 << 20) - 1) & ~((1 << 20) - 1);

        mapped = 0;
        idx = 0;
        base = va;
        pgsz = 64*1024*1024;
        while (mapped < size) {
                while (mapped < size && idx < KERNEL_REGION_MAX_TLB_ENTRIES) {
                        while (pgsz > (size - mapped))
                                pgsz >>= 2;
                        pgs[idx++] = pgsz;
                        mapped += pgsz;
                }

                /* We under-map. Correct for this. */
                if (mapped < size) {
                        while (pgs[idx - 1] == pgsz) {
                                idx--;
                                mapped -= pgsz;
                        }
                        /* XXX We may increase beyond out starting point. */
                        pgsz <<= 2;
                        pgs[idx++] = pgsz;
                        mapped += pgsz;
                }
        }

        nents = idx;
        mask = pgs[0] - 1;
        /* Align address to the boundary */
        if (va & mask) {
                va = (va + mask) & ~mask;
                pa = (pa + mask) & ~mask;
        }

        for (idx = 0; idx < nents; idx++) {
                pgsz = pgs[idx];
                debugf("%u: %x -> %x, size=%x\n", idx, pa, va, pgsz);
                tlb1_set_entry(va, pa, pgsz, _TLB_ENTRY_MEM);
                pa += pgsz;
                va += pgsz;
        }

        mapped = (va - base);
        debugf("mapped size 0x%08x (wasted space 0x%08x)\n",
            mapped, mapped - size);
        return (mapped);
}

/*
 * TLB1 initialization routine, to be called after the very first
 * assembler level setup done in locore.S.
 */
void
tlb1_init(vm_offset_t ccsrbar)
{
        uint32_t mas0, mas1, mas3;
        uint32_t tsz;
        u_int i;

        ccsrbar_pa = ccsrbar;

        if (bootinfo != NULL && bootinfo[0] != 1) {
                tlb1_idx = *((uint16_t *)(bootinfo + 8));
        } else
                tlb1_idx = 1;

        /* The first entry/entries are used to map the kernel. */
        for (i = 0; i < tlb1_idx; i++) {
                mas0 = MAS0_TLBSEL(1) | MAS0_ESEL(i);
                mtspr(SPR_MAS0, mas0);
                __asm __volatile("isync; tlbre");

                mas1 = mfspr(SPR_MAS1);
                if ((mas1 & MAS1_VALID) == 0)
                        continue;

                mas3 = mfspr(SPR_MAS3);

                tlb1[i].mas1 = mas1;
                tlb1[i].mas2 = mfspr(SPR_MAS2);
                tlb1[i].mas3 = mas3;

                if (i == 0)
                        kernload = mas3 & MAS3_RPN;

                tsz = (mas1 & MAS1_TSIZE_MASK) >> MAS1_TSIZE_SHIFT;
                kernsize += (tsz > 0) ? tsize2size(tsz) : 0;
        }

        /* Map in CCSRBAR. */
        tlb1_set_entry(CCSRBAR_VA, ccsrbar, CCSRBAR_SIZE, _TLB_ENTRY_IO);

#ifdef SMP
        bp_ntlb1s = tlb1_idx;
#endif

        /* Purge the remaining entries */
        for (i = tlb1_idx; i < TLB1_ENTRIES; i++)
                tlb1_write_entry(i);

        /* Setup TLB miss defaults */
        set_mas4_defaults();
}

/*
 * Setup MAS4 defaults.
 * These values are loaded to MAS0-2 on a TLB miss.
 */
static void
set_mas4_defaults(void)
{
        uint32_t mas4;

        /* Defaults: TLB0, PID0, TSIZED=4K */
        mas4 = MAS4_TLBSELD0;
        mas4 |= (TLB_SIZE_4K << MAS4_TSIZED_SHIFT) & MAS4_TSIZED_MASK;
#ifdef SMP
        mas4 |= MAS4_MD;
#endif
        mtspr(SPR_MAS4, mas4);
        __asm __volatile("isync");
}

/*
 * Print out contents of the MAS registers for each TLB1 entry
 */
void
tlb1_print_tlbentries(void)
{
        uint32_t mas0, mas1, mas2, mas3, mas7;
        int i;

        debugf("TLB1 entries:\n");
        for (i = 0; i < TLB1_ENTRIES; i++) {

                mas0 = MAS0_TLBSEL(1) | MAS0_ESEL(i);
                mtspr(SPR_MAS0, mas0);

                __asm __volatile("isync; tlbre");

                mas1 = mfspr(SPR_MAS1);
                mas2 = mfspr(SPR_MAS2);
                mas3 = mfspr(SPR_MAS3);
                mas7 = mfspr(SPR_MAS7);

                tlb_print_entry(i, mas1, mas2, mas3, mas7);
        }
}

/*
 * Print out contents of the in-ram tlb1 table.
 */
void
tlb1_print_entries(void)
{
        int i;

        debugf("tlb1[] table entries:\n");
        for (i = 0; i < TLB1_ENTRIES; i++)
                tlb_print_entry(i, tlb1[i].mas1, tlb1[i].mas2, tlb1[i].mas3, 0);
}

/*
 * Return 0 if the physical IO range is encompassed by one of the
 * the TLB1 entries, otherwise return related error code.
 */
static int
tlb1_iomapped(int i, vm_paddr_t pa, vm_size_t size, vm_offset_t *va)
{
        uint32_t prot;
        vm_paddr_t pa_start;
        vm_paddr_t pa_end;
        unsigned int entry_tsize;
        vm_size_t entry_size;

        *va = (vm_offset_t)NULL;

        /* Skip invalid entries */
        if (!(tlb1[i].mas1 & MAS1_VALID))
                return (EINVAL);

        /*
         * The entry must be cache-inhibited, guarded, and r/w
         * so it can function as an i/o page
         */
        prot = tlb1[i].mas2 & (MAS2_I | MAS2_G);
        if (prot != (MAS2_I | MAS2_G))
                return (EPERM);

        prot = tlb1[i].mas3 & (MAS3_SR | MAS3_SW);
        if (prot != (MAS3_SR | MAS3_SW))
                return (EPERM);

        /* The address should be within the entry range. */
        entry_tsize = (tlb1[i].mas1 & MAS1_TSIZE_MASK) >> MAS1_TSIZE_SHIFT;
        KASSERT((entry_tsize), ("tlb1_iomapped: invalid entry tsize"));

        entry_size = tsize2size(entry_tsize);
        pa_start = tlb1[i].mas3 & MAS3_RPN;
        pa_end = pa_start + entry_size - 1;

        if ((pa < pa_start) || ((pa + size) > pa_end))
                return (ERANGE);

        /* Return virtual address of this mapping. */
        *va = (tlb1[i].mas2 & MAS2_EPN_MASK) + (pa - pa_start);
        return (0);
}