MFC r236228:

[FreeBSD/stable/8.git] / sys / cam / scsi / scsi_xpt.c

/*-
 * Implementation of the SCSI Transport
 *
 * Copyright (c) 1997, 1998, 1999 Justin T. Gibbs.
 * Copyright (c) 1997, 1998, 1999 Kenneth D. Merry.
 * 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,
 *    without modification, immediately at the beginning of the file.
 * 2. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

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

#include <sys/param.h>
#include <sys/bus.h>
#include <sys/systm.h>
#include <sys/types.h>
#include <sys/malloc.h>
#include <sys/kernel.h>
#include <sys/time.h>
#include <sys/conf.h>
#include <sys/fcntl.h>
#include <sys/md5.h>
#include <sys/interrupt.h>
#include <sys/sbuf.h>

#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/sysctl.h>

#include <cam/cam.h>
#include <cam/cam_ccb.h>
#include <cam/cam_queue.h>
#include <cam/cam_periph.h>
#include <cam/cam_sim.h>
#include <cam/cam_xpt.h>
#include <cam/cam_xpt_sim.h>
#include <cam/cam_xpt_periph.h>
#include <cam/cam_xpt_internal.h>
#include <cam/cam_debug.h>

#include <cam/scsi/scsi_all.h>
#include <cam/scsi/scsi_message.h>
#include <cam/scsi/scsi_pass.h>
#include <machine/stdarg.h>     /* for xpt_print below */
#include "opt_cam.h"

struct scsi_quirk_entry {
        struct scsi_inquiry_pattern inq_pat;
        u_int8_t quirks;
#define CAM_QUIRK_NOLUNS        0x01
#define CAM_QUIRK_NOSERIAL      0x02
#define CAM_QUIRK_HILUNS        0x04
#define CAM_QUIRK_NOHILUNS      0x08
#define CAM_QUIRK_NORPTLUNS     0x10
        u_int mintags;
        u_int maxtags;
};
#define SCSI_QUIRK(dev) ((struct scsi_quirk_entry *)((dev)->quirk))

static int cam_srch_hi = 0;
TUNABLE_INT("kern.cam.cam_srch_hi", &cam_srch_hi);
static int sysctl_cam_search_luns(SYSCTL_HANDLER_ARGS);
SYSCTL_PROC(_kern_cam, OID_AUTO, cam_srch_hi, CTLTYPE_INT|CTLFLAG_RW, 0, 0,
    sysctl_cam_search_luns, "I",
    "allow search above LUN 7 for SCSI3 and greater devices");

#define CAM_SCSI2_MAXLUN        8
#define CAM_CAN_GET_SIMPLE_LUN(x, i)                            \
        ((((x)->luns[i].lundata[0] & RPL_LUNDATA_ATYP_MASK) ==  \
        RPL_LUNDATA_ATYP_PERIPH) ||                             \
        (((x)->luns[i].lundata[0] & RPL_LUNDATA_ATYP_MASK) ==   \
        RPL_LUNDATA_ATYP_FLAT))
#define CAM_GET_SIMPLE_LUN(lp, i, lval)                                 \
        if (((lp)->luns[(i)].lundata[0] & RPL_LUNDATA_ATYP_MASK) ==     \
            RPL_LUNDATA_ATYP_PERIPH) {                                  \
                (lval) = (lp)->luns[(i)].lundata[1];                    \
        } else {                                                        \
                (lval) = (lp)->luns[(i)].lundata[0];                    \
                (lval) &= RPL_LUNDATA_FLAT_LUN_MASK;                    \
                (lval) <<= 8;                                           \
                (lval) |=  (lp)->luns[(i)].lundata[1];                  \
        }
/*
 * If we're not quirked to search <= the first 8 luns
 * and we are either quirked to search above lun 8,
 * or we're > SCSI-2 and we've enabled hilun searching,
 * or we're > SCSI-2 and the last lun was a success,
 * we can look for luns above lun 8.
 */
#define CAN_SRCH_HI_SPARSE(dv)                                  \
  (((SCSI_QUIRK(dv)->quirks & CAM_QUIRK_NOHILUNS) == 0)         \
  && ((SCSI_QUIRK(dv)->quirks & CAM_QUIRK_HILUNS)               \
  || (SID_ANSI_REV(&dv->inq_data) > SCSI_REV_2 && cam_srch_hi)))

#define CAN_SRCH_HI_DENSE(dv)                                   \
  (((SCSI_QUIRK(dv)->quirks & CAM_QUIRK_NOHILUNS) == 0)         \
  && ((SCSI_QUIRK(dv)->quirks & CAM_QUIRK_HILUNS)               \
  || (SID_ANSI_REV(&dv->inq_data) > SCSI_REV_2)))

static periph_init_t probe_periph_init;

static struct periph_driver probe_driver =
{
        probe_periph_init, "probe",
        TAILQ_HEAD_INITIALIZER(probe_driver.units), /* generation */ 0,
        CAM_PERIPH_DRV_EARLY
};

PERIPHDRIVER_DECLARE(probe, probe_driver);

typedef enum {
        PROBE_TUR,
        PROBE_INQUIRY,  /* this counts as DV0 for Basic Domain Validation */
        PROBE_FULL_INQUIRY,
        PROBE_REPORT_LUNS,
        PROBE_MODE_SENSE,
        PROBE_SERIAL_NUM_0,
        PROBE_SERIAL_NUM_1,
        PROBE_TUR_FOR_NEGOTIATION,
        PROBE_INQUIRY_BASIC_DV1,
        PROBE_INQUIRY_BASIC_DV2,
        PROBE_DV_EXIT,
        PROBE_INVALID
} probe_action;

static char *probe_action_text[] = {
        "PROBE_TUR",
        "PROBE_INQUIRY",
        "PROBE_FULL_INQUIRY",
        "PROBE_REPORT_LUNS",
        "PROBE_MODE_SENSE",
        "PROBE_SERIAL_NUM_0",
        "PROBE_SERIAL_NUM_1",
        "PROBE_TUR_FOR_NEGOTIATION",
        "PROBE_INQUIRY_BASIC_DV1",
        "PROBE_INQUIRY_BASIC_DV2",
        "PROBE_DV_EXIT",
        "PROBE_INVALID"
};

#define PROBE_SET_ACTION(softc, newaction)      \
do {                                                                    \
        char **text;                                                    \
        text = probe_action_text;                                       \
        CAM_DEBUG((softc)->periph->path, CAM_DEBUG_INFO,                \
            ("Probe %s to %s\n", text[(softc)->action],                 \
            text[(newaction)]));                                        \
        (softc)->action = (newaction);                                  \
} while(0)

typedef enum {
        PROBE_INQUIRY_CKSUM     = 0x01,
        PROBE_SERIAL_CKSUM      = 0x02,
        PROBE_NO_ANNOUNCE       = 0x04
} probe_flags;

typedef struct {
        TAILQ_HEAD(, ccb_hdr) request_ccbs;
        probe_action    action;
        union ccb       saved_ccb;
        probe_flags     flags;
        MD5_CTX         context;
        u_int8_t        digest[16];
        struct cam_periph *periph;
} probe_softc;

static const char quantum[] = "QUANTUM";
static const char sony[] = "SONY";
static const char west_digital[] = "WDIGTL";
static const char samsung[] = "SAMSUNG";
static const char seagate[] = "SEAGATE";
static const char microp[] = "MICROP";

static struct scsi_quirk_entry scsi_quirk_table[] =
{
        {
                /* Reports QUEUE FULL for temporary resource shortages */
                { T_DIRECT, SIP_MEDIA_FIXED, quantum, "XP39100*", "*" },
                /*quirks*/0, /*mintags*/24, /*maxtags*/32
        },
        {
                /* Reports QUEUE FULL for temporary resource shortages */
                { T_DIRECT, SIP_MEDIA_FIXED, quantum, "XP34550*", "*" },
                /*quirks*/0, /*mintags*/24, /*maxtags*/32
        },
        {
                /* Reports QUEUE FULL for temporary resource shortages */
                { T_DIRECT, SIP_MEDIA_FIXED, quantum, "XP32275*", "*" },
                /*quirks*/0, /*mintags*/24, /*maxtags*/32
        },
        {
                /* Broken tagged queuing drive */
                { T_DIRECT, SIP_MEDIA_FIXED, microp, "4421-07*", "*" },
                /*quirks*/0, /*mintags*/0, /*maxtags*/0
        },
        {
                /* Broken tagged queuing drive */
                { T_DIRECT, SIP_MEDIA_FIXED, "HP", "C372*", "*" },
                /*quirks*/0, /*mintags*/0, /*maxtags*/0
        },
        {
                /* Broken tagged queuing drive */
                { T_DIRECT, SIP_MEDIA_FIXED, microp, "3391*", "x43h" },
                /*quirks*/0, /*mintags*/0, /*maxtags*/0
        },
        {
                /*
                 * Unfortunately, the Quantum Atlas III has the same
                 * problem as the Atlas II drives above.
                 * Reported by: "Johan Granlund" <johan@granlund.nu>
                 *
                 * For future reference, the drive with the problem was:
                 * QUANTUM QM39100TD-SW N1B0
                 *
                 * It's possible that Quantum will fix the problem in later
                 * firmware revisions.  If that happens, the quirk entry
                 * will need to be made specific to the firmware revisions
                 * with the problem.
                 *
                 */
                /* Reports QUEUE FULL for temporary resource shortages */
                { T_DIRECT, SIP_MEDIA_FIXED, quantum, "QM39100*", "*" },
                /*quirks*/0, /*mintags*/24, /*maxtags*/32
        },
        {
                /*
                 * 18 Gig Atlas III, same problem as the 9G version.
                 * Reported by: Andre Albsmeier
                 *              <andre.albsmeier@mchp.siemens.de>
                 *
                 * For future reference, the drive with the problem was:
                 * QUANTUM QM318000TD-S N491
                 */
                /* Reports QUEUE FULL for temporary resource shortages */
                { T_DIRECT, SIP_MEDIA_FIXED, quantum, "QM318000*", "*" },
                /*quirks*/0, /*mintags*/24, /*maxtags*/32
        },
        {
                /*
                 * Broken tagged queuing drive
                 * Reported by: Bret Ford <bford@uop.cs.uop.edu>
                 *         and: Martin Renters <martin@tdc.on.ca>
                 */
                { T_DIRECT, SIP_MEDIA_FIXED, seagate, "ST410800*", "71*" },
                /*quirks*/0, /*mintags*/0, /*maxtags*/0
        },
                /*
                 * The Seagate Medalist Pro drives have very poor write
                 * performance with anything more than 2 tags.
                 *
                 * Reported by:  Paul van der Zwan <paulz@trantor.xs4all.nl>
                 * Drive:  <SEAGATE ST36530N 1444>
                 *
                 * Reported by:  Jeremy Lea <reg@shale.csir.co.za>
                 * Drive:  <SEAGATE ST34520W 1281>
                 *
                 * No one has actually reported that the 9G version
                 * (ST39140*) of the Medalist Pro has the same problem, but
                 * we're assuming that it does because the 4G and 6.5G
                 * versions of the drive are broken.
                 */
        {
                { T_DIRECT, SIP_MEDIA_FIXED, seagate, "ST34520*", "*"},
                /*quirks*/0, /*mintags*/2, /*maxtags*/2
        },
        {
                { T_DIRECT, SIP_MEDIA_FIXED, seagate, "ST36530*", "*"},
                /*quirks*/0, /*mintags*/2, /*maxtags*/2
        },
        {
                { T_DIRECT, SIP_MEDIA_FIXED, seagate, "ST39140*", "*"},
                /*quirks*/0, /*mintags*/2, /*maxtags*/2
        },
        {
                /*
                 * Slow when tagged queueing is enabled.  Write performance
                 * steadily drops off with more and more concurrent
                 * transactions.  Best sequential write performance with
                 * tagged queueing turned off and write caching turned on.
                 *
                 * PR:  kern/10398
                 * Submitted by:  Hideaki Okada <hokada@isl.melco.co.jp>
                 * Drive:  DCAS-34330 w/ "S65A" firmware.
                 *
                 * The drive with the problem had the "S65A" firmware
                 * revision, and has also been reported (by Stephen J.
                 * Roznowski <sjr@home.net>) for a drive with the "S61A"
                 * firmware revision.
                 *
                 * Although no one has reported problems with the 2 gig
                 * version of the DCAS drive, the assumption is that it
                 * has the same problems as the 4 gig version.  Therefore
                 * this quirk entries disables tagged queueing for all
                 * DCAS drives.
                 */
                { T_DIRECT, SIP_MEDIA_FIXED, "IBM", "DCAS*", "*" },
                /*quirks*/0, /*mintags*/0, /*maxtags*/0
        },
        {
                /* Broken tagged queuing drive */
                { T_DIRECT, SIP_MEDIA_REMOVABLE, "iomega", "jaz*", "*" },
                /*quirks*/0, /*mintags*/0, /*maxtags*/0
        },
        {
                /* Broken tagged queuing drive */
                { T_DIRECT, SIP_MEDIA_FIXED, "CONNER", "CFP2107*", "*" },
                /*quirks*/0, /*mintags*/0, /*maxtags*/0
        },
        {
                /* This does not support other than LUN 0 */
                { T_DIRECT, SIP_MEDIA_FIXED, "VMware*", "*", "*" },
                CAM_QUIRK_NOLUNS, /*mintags*/2, /*maxtags*/255
        },
        {
                /*
                 * Broken tagged queuing drive.
                 * Submitted by:
                 * NAKAJI Hiroyuki <nakaji@zeisei.dpri.kyoto-u.ac.jp>
                 * in PR kern/9535
                 */
                { T_DIRECT, SIP_MEDIA_FIXED, samsung, "WN34324U*", "*" },
                /*quirks*/0, /*mintags*/0, /*maxtags*/0
        },
        {
                /*
                 * Slow when tagged queueing is enabled. (1.5MB/sec versus
                 * 8MB/sec.)
                 * Submitted by: Andrew Gallatin <gallatin@cs.duke.edu>
                 * Best performance with these drives is achieved with
                 * tagged queueing turned off, and write caching turned on.
                 */
                { T_DIRECT, SIP_MEDIA_FIXED, west_digital, "WDE*", "*" },
                /*quirks*/0, /*mintags*/0, /*maxtags*/0
        },
        {
                /*
                 * Slow when tagged queueing is enabled. (1.5MB/sec versus
                 * 8MB/sec.)
                 * Submitted by: Andrew Gallatin <gallatin@cs.duke.edu>
                 * Best performance with these drives is achieved with
                 * tagged queueing turned off, and write caching turned on.
                 */
                { T_DIRECT, SIP_MEDIA_FIXED, west_digital, "ENTERPRISE", "*" },
                /*quirks*/0, /*mintags*/0, /*maxtags*/0
        },
        {
                /*
                 * Doesn't handle queue full condition correctly,
                 * so we need to limit maxtags to what the device
                 * can handle instead of determining this automatically.
                 */
                { T_DIRECT, SIP_MEDIA_FIXED, samsung, "WN321010S*", "*" },
                /*quirks*/0, /*mintags*/2, /*maxtags*/32
        },
        {
                /* Really only one LUN */
                { T_ENCLOSURE, SIP_MEDIA_FIXED, "SUN", "SENA", "*" },
                CAM_QUIRK_NOLUNS, /*mintags*/0, /*maxtags*/0
        },
        {
                /* I can't believe we need a quirk for DPT volumes. */
                { T_ANY, SIP_MEDIA_FIXED|SIP_MEDIA_REMOVABLE, "DPT", "*", "*" },
                CAM_QUIRK_NOLUNS,
                /*mintags*/0, /*maxtags*/255
        },
        {
                /*
                 * Many Sony CDROM drives don't like multi-LUN probing.
                 */
                { T_CDROM, SIP_MEDIA_REMOVABLE, sony, "CD-ROM CDU*", "*" },
                CAM_QUIRK_NOLUNS, /*mintags*/0, /*maxtags*/0
        },
        {
                /*
                 * This drive doesn't like multiple LUN probing.
                 * Submitted by:  Parag Patel <parag@cgt.com>
                 */
                { T_WORM, SIP_MEDIA_REMOVABLE, sony, "CD-R   CDU9*", "*" },
                CAM_QUIRK_NOLUNS, /*mintags*/0, /*maxtags*/0
        },
        {
                { T_WORM, SIP_MEDIA_REMOVABLE, "YAMAHA", "CDR100*", "*" },
                CAM_QUIRK_NOLUNS, /*mintags*/0, /*maxtags*/0
        },
        {
                /*
                 * The 8200 doesn't like multi-lun probing, and probably
                 * don't like serial number requests either.
                 */
                {
                        T_SEQUENTIAL, SIP_MEDIA_REMOVABLE, "EXABYTE",
                        "EXB-8200*", "*"
                },
                CAM_QUIRK_NOLUNS, /*mintags*/0, /*maxtags*/0
        },
        {
                /*
                 * Let's try the same as above, but for a drive that says
                 * it's an IPL-6860 but is actually an EXB 8200.
                 */
                {
                        T_SEQUENTIAL, SIP_MEDIA_REMOVABLE, "EXABYTE",
                        "IPL-6860*", "*"
                },
                CAM_QUIRK_NOLUNS, /*mintags*/0, /*maxtags*/0
        },
        {
                /*
                 * These Hitachi drives don't like multi-lun probing.
                 * The PR submitter has a DK319H, but says that the Linux
                 * kernel has a similar work-around for the DK312 and DK314,
                 * so all DK31* drives are quirked here.
                 * PR:            misc/18793
                 * Submitted by:  Paul Haddad <paul@pth.com>
                 */
                { T_DIRECT, SIP_MEDIA_FIXED, "HITACHI", "DK31*", "*" },
                CAM_QUIRK_NOLUNS, /*mintags*/2, /*maxtags*/255
        },
        {
                /*
                 * The Hitachi CJ series with J8A8 firmware apparantly has
                 * problems with tagged commands.
                 * PR: 23536
                 * Reported by: amagai@nue.org
                 */
                { T_DIRECT, SIP_MEDIA_FIXED, "HITACHI", "DK32CJ*", "J8A8" },
                CAM_QUIRK_NOLUNS, /*mintags*/0, /*maxtags*/0
        },
        {
                /*
                 * These are the large storage arrays.
                 * Submitted by:  William Carrel <william.carrel@infospace.com>
                 */
                { T_DIRECT, SIP_MEDIA_FIXED, "HITACHI", "OPEN*", "*" },
                CAM_QUIRK_HILUNS, 2, 1024
        },
        {
                /*
                 * This old revision of the TDC3600 is also SCSI-1, and
                 * hangs upon serial number probing.
                 */
                {
                        T_SEQUENTIAL, SIP_MEDIA_REMOVABLE, "TANDBERG",
                        " TDC 3600", "U07:"
                },
                CAM_QUIRK_NOSERIAL, /*mintags*/0, /*maxtags*/0
        },
        {
                /*
                 * Would repond to all LUNs if asked for.
                 */
                {
                        T_SEQUENTIAL, SIP_MEDIA_REMOVABLE, "CALIPER",
                        "CP150", "*"
                },
                CAM_QUIRK_NOLUNS, /*mintags*/0, /*maxtags*/0
        },
        {
                /*
                 * Would repond to all LUNs if asked for.
                 */
                {
                        T_SEQUENTIAL, SIP_MEDIA_REMOVABLE, "KENNEDY",
                        "96X2*", "*"
                },
                CAM_QUIRK_NOLUNS, /*mintags*/0, /*maxtags*/0
        },
        {
                /* Submitted by: Matthew Dodd <winter@jurai.net> */
                { T_PROCESSOR, SIP_MEDIA_FIXED, "Cabletrn", "EA41*", "*" },
                CAM_QUIRK_NOLUNS, /*mintags*/0, /*maxtags*/0
        },
        {
                /* Submitted by: Matthew Dodd <winter@jurai.net> */
                { T_PROCESSOR, SIP_MEDIA_FIXED, "CABLETRN", "EA41*", "*" },
                CAM_QUIRK_NOLUNS, /*mintags*/0, /*maxtags*/0
        },
        {
                /* TeraSolutions special settings for TRC-22 RAID */
                { T_DIRECT, SIP_MEDIA_FIXED, "TERASOLU", "TRC-22", "*" },
                  /*quirks*/0, /*mintags*/55, /*maxtags*/255
        },
        {
                /* Veritas Storage Appliance */
                { T_DIRECT, SIP_MEDIA_FIXED, "VERITAS", "*", "*" },
                  CAM_QUIRK_HILUNS, /*mintags*/2, /*maxtags*/1024
        },
        {
                /*
                 * Would respond to all LUNs.  Device type and removable
                 * flag are jumper-selectable.
                 */
                { T_ANY, SIP_MEDIA_REMOVABLE|SIP_MEDIA_FIXED, "MaxOptix",
                  "Tahiti 1", "*"
                },
                CAM_QUIRK_NOLUNS, /*mintags*/0, /*maxtags*/0
        },
        {
                /* EasyRAID E5A aka. areca ARC-6010 */
                { T_DIRECT, SIP_MEDIA_FIXED, "easyRAID", "*", "*" },
                  CAM_QUIRK_NOHILUNS, /*mintags*/2, /*maxtags*/255
        },
        {
                { T_ENCLOSURE, SIP_MEDIA_FIXED, "DP", "BACKPLANE", "*" },
                CAM_QUIRK_NOLUNS, /*mintags*/0, /*maxtags*/0
        },
        {
                { T_DIRECT, SIP_MEDIA_REMOVABLE, "Garmin", "*", "*" },
                CAM_QUIRK_NORPTLUNS, /*mintags*/2, /*maxtags*/255
        },
        {
                /* Default tagged queuing parameters for all devices */
                {
                  T_ANY, SIP_MEDIA_REMOVABLE|SIP_MEDIA_FIXED,
                  /*vendor*/"*", /*product*/"*", /*revision*/"*"
                },
                /*quirks*/0, /*mintags*/2, /*maxtags*/255
        },
};

static const int scsi_quirk_table_size =
        sizeof(scsi_quirk_table) / sizeof(*scsi_quirk_table);

static cam_status       proberegister(struct cam_periph *periph,
                                      void *arg);
static void      probeschedule(struct cam_periph *probe_periph);
static void      probestart(struct cam_periph *periph, union ccb *start_ccb);
static void      proberequestdefaultnegotiation(struct cam_periph *periph);
static int       proberequestbackoff(struct cam_periph *periph,
                                     struct cam_ed *device);
static void      probedone(struct cam_periph *periph, union ccb *done_ccb);
static int       probe_strange_rpl_data(struct scsi_report_luns_data *rp,
                                        uint32_t maxlun);
static void      probe_purge_old(struct cam_path *path,
                                 struct scsi_report_luns_data *new);
static void      probecleanup(struct cam_periph *periph);
static void      scsi_find_quirk(struct cam_ed *device);
static void      scsi_scan_bus(struct cam_periph *periph, union ccb *ccb);
static void      scsi_scan_lun(struct cam_periph *periph,
                               struct cam_path *path, cam_flags flags,
                               union ccb *ccb);
static void      xptscandone(struct cam_periph *periph, union ccb *done_ccb);
static struct cam_ed *
                 scsi_alloc_device(struct cam_eb *bus, struct cam_et *target,
                                   lun_id_t lun_id);
static void      scsi_devise_transport(struct cam_path *path);
static void      scsi_set_transfer_settings(struct ccb_trans_settings *cts,
                                            struct cam_ed *device,
                                            int async_update);
static void      scsi_toggle_tags(struct cam_path *path);
static void      scsi_dev_async(u_int32_t async_code,
                                struct cam_eb *bus,
                                struct cam_et *target,
                                struct cam_ed *device,
                                void *async_arg);
static void      scsi_action(union ccb *start_ccb);
static void      scsi_announce_periph(struct cam_periph *periph);

static struct xpt_xport scsi_xport = {
        .alloc_device = scsi_alloc_device,
        .action = scsi_action,
        .async = scsi_dev_async,
        .announce = scsi_announce_periph,
};

struct xpt_xport *
scsi_get_xport(void)
{
        return (&scsi_xport);
}

static void
probe_periph_init()
{
}

static cam_status
proberegister(struct cam_periph *periph, void *arg)
{
        union ccb *request_ccb; /* CCB representing the probe request */
        cam_status status;
        probe_softc *softc;

        request_ccb = (union ccb *)arg;
        if (periph == NULL) {
                printf("proberegister: periph was NULL!!\n");
                return(CAM_REQ_CMP_ERR);
        }

        if (request_ccb == NULL) {
                printf("proberegister: no probe CCB, "
                       "can't register device\n");
                return(CAM_REQ_CMP_ERR);
        }

        softc = (probe_softc *)malloc(sizeof(*softc), M_CAMXPT, M_NOWAIT);

        if (softc == NULL) {
                printf("proberegister: Unable to probe new device. "
                       "Unable to allocate softc\n");
                return(CAM_REQ_CMP_ERR);
        }
        TAILQ_INIT(&softc->request_ccbs);
        TAILQ_INSERT_TAIL(&softc->request_ccbs, &request_ccb->ccb_h,
                          periph_links.tqe);
        softc->flags = 0;
        periph->softc = softc;
        softc->periph = periph;
        softc->action = PROBE_INVALID;
        status = cam_periph_acquire(periph);
        if (status != CAM_REQ_CMP) {
                return (status);
        }


        /*
         * Ensure we've waited at least a bus settle
         * delay before attempting to probe the device.
         * For HBAs that don't do bus resets, this won't make a difference.
         */
        cam_periph_freeze_after_event(periph, &periph->path->bus->last_reset,
                                      scsi_delay);
        /*
         * Ensure nobody slip in until probe finish.
         */
        cam_freeze_devq_arg(periph->path,
            RELSIM_RELEASE_RUNLEVEL, CAM_RL_XPT + 1);
        probeschedule(periph);
        return(CAM_REQ_CMP);
}

static void
probeschedule(struct cam_periph *periph)
{
        struct ccb_pathinq cpi;
        union ccb *ccb;
        probe_softc *softc;

        softc = (probe_softc *)periph->softc;
        ccb = (union ccb *)TAILQ_FIRST(&softc->request_ccbs);

        xpt_setup_ccb(&cpi.ccb_h, periph->path, CAM_PRIORITY_NONE);
        cpi.ccb_h.func_code = XPT_PATH_INQ;
        xpt_action((union ccb *)&cpi);

        /*
         * If a device has gone away and another device, or the same one,
         * is back in the same place, it should have a unit attention
         * condition pending.  It will not report the unit attention in
         * response to an inquiry, which may leave invalid transfer
         * negotiations in effect.  The TUR will reveal the unit attention
         * condition.  Only send the TUR for lun 0, since some devices
         * will get confused by commands other than inquiry to non-existent
         * luns.  If you think a device has gone away start your scan from
         * lun 0.  This will insure that any bogus transfer settings are
         * invalidated.
         *
         * If we haven't seen the device before and the controller supports
         * some kind of transfer negotiation, negotiate with the first
         * sent command if no bus reset was performed at startup.  This
         * ensures that the device is not confused by transfer negotiation
         * settings left over by loader or BIOS action.
         */
        if (((ccb->ccb_h.path->device->flags & CAM_DEV_UNCONFIGURED) == 0)
         && (ccb->ccb_h.target_lun == 0)) {
                PROBE_SET_ACTION(softc, PROBE_TUR);
        } else if ((cpi.hba_inquiry & (PI_WIDE_32|PI_WIDE_16|PI_SDTR_ABLE)) != 0
              && (cpi.hba_misc & PIM_NOBUSRESET) != 0) {
                proberequestdefaultnegotiation(periph);
                PROBE_SET_ACTION(softc, PROBE_INQUIRY);
        } else {
                PROBE_SET_ACTION(softc, PROBE_INQUIRY);
        }

        if (ccb->crcn.flags & CAM_EXPECT_INQ_CHANGE)
                softc->flags |= PROBE_NO_ANNOUNCE;
        else
                softc->flags &= ~PROBE_NO_ANNOUNCE;

        xpt_schedule(periph, CAM_PRIORITY_XPT);
}

static void
probestart(struct cam_periph *periph, union ccb *start_ccb)
{
        /* Probe the device that our peripheral driver points to */
        struct ccb_scsiio *csio;
        probe_softc *softc;

        CAM_DEBUG(start_ccb->ccb_h.path, CAM_DEBUG_TRACE, ("probestart\n"));

        softc = (probe_softc *)periph->softc;
        csio = &start_ccb->csio;
again:

        switch (softc->action) {
        case PROBE_TUR:
        case PROBE_TUR_FOR_NEGOTIATION:
        case PROBE_DV_EXIT:
        {
                scsi_test_unit_ready(csio,
                                     /*retries*/10,
                                     probedone,
                                     MSG_SIMPLE_Q_TAG,
                                     SSD_FULL_SIZE,
                                     /*timeout*/60000);
                break;
        }
        case PROBE_INQUIRY:
        case PROBE_FULL_INQUIRY:
        case PROBE_INQUIRY_BASIC_DV1:
        case PROBE_INQUIRY_BASIC_DV2:
        {
                u_int inquiry_len;
                struct scsi_inquiry_data *inq_buf;

                inq_buf = &periph->path->device->inq_data;

                /*
                 * If the device is currently configured, we calculate an
                 * MD5 checksum of the inquiry data, and if the serial number
                 * length is greater than 0, add the serial number data
                 * into the checksum as well.  Once the inquiry and the
                 * serial number check finish, we attempt to figure out
                 * whether we still have the same device.
                 */
                if ((periph->path->device->flags & CAM_DEV_UNCONFIGURED) == 0) {

                        MD5Init(&softc->context);
                        MD5Update(&softc->context, (unsigned char *)inq_buf,
                                  sizeof(struct scsi_inquiry_data));
                        softc->flags |= PROBE_INQUIRY_CKSUM;
                        if (periph->path->device->serial_num_len > 0) {
                                MD5Update(&softc->context,
                                          periph->path->device->serial_num,
                                          periph->path->device->serial_num_len);
                                softc->flags |= PROBE_SERIAL_CKSUM;
                        }
                        MD5Final(softc->digest, &softc->context);
                }

                if (softc->action == PROBE_INQUIRY)
                        inquiry_len = SHORT_INQUIRY_LENGTH;
                else
                        inquiry_len = SID_ADDITIONAL_LENGTH(inq_buf);

                /*
                 * Some parallel SCSI devices fail to send an
                 * ignore wide residue message when dealing with
                 * odd length inquiry requests.  Round up to be
                 * safe.
                 */
                inquiry_len = roundup2(inquiry_len, 2);

                if (softc->action == PROBE_INQUIRY_BASIC_DV1
                 || softc->action == PROBE_INQUIRY_BASIC_DV2) {
                        inq_buf = malloc(inquiry_len, M_CAMXPT, M_NOWAIT);
                }
                if (inq_buf == NULL) {
                        xpt_print(periph->path, "malloc failure- skipping Basic"
                            "Domain Validation\n");
                        PROBE_SET_ACTION(softc, PROBE_DV_EXIT);
                        scsi_test_unit_ready(csio,
                                             /*retries*/4,
                                             probedone,
                                             MSG_SIMPLE_Q_TAG,
                                             SSD_FULL_SIZE,
                                             /*timeout*/60000);
                        break;
                }
                scsi_inquiry(csio,
                             /*retries*/4,
                             probedone,
                             MSG_SIMPLE_Q_TAG,
                             (u_int8_t *)inq_buf,
                             inquiry_len,
                             /*evpd*/FALSE,
                             /*page_code*/0,
                             SSD_MIN_SIZE,
                             /*timeout*/60 * 1000);
                break;
        }
        case PROBE_REPORT_LUNS:
        {
                void *rp;

                rp = malloc(periph->path->target->rpl_size,
                    M_CAMXPT, M_NOWAIT | M_ZERO);
                if (rp == NULL) {
                        struct scsi_inquiry_data *inq_buf;
                        inq_buf = &periph->path->device->inq_data;
                        xpt_print(periph->path,
                            "Unable to alloc report luns storage\n");
                        if (INQ_DATA_TQ_ENABLED(inq_buf))
                                PROBE_SET_ACTION(softc, PROBE_MODE_SENSE);
                        else
                                PROBE_SET_ACTION(softc, PROBE_SERIAL_NUM_0);
                        goto again;
                }
                scsi_report_luns(csio, 5, probedone, MSG_SIMPLE_Q_TAG,
                    RPL_REPORT_DEFAULT, rp, periph->path->target->rpl_size,
                    SSD_FULL_SIZE, 60000); break;
                break;
        }
        case PROBE_MODE_SENSE:
        {
                void  *mode_buf;
                int    mode_buf_len;

                mode_buf_len = sizeof(struct scsi_mode_header_6)
                             + sizeof(struct scsi_mode_blk_desc)
                             + sizeof(struct scsi_control_page);
                mode_buf = malloc(mode_buf_len, M_CAMXPT, M_NOWAIT);
                if (mode_buf != NULL) {
                        scsi_mode_sense(csio,
                                        /*retries*/4,
                                        probedone,
                                        MSG_SIMPLE_Q_TAG,
                                        /*dbd*/FALSE,
                                        SMS_PAGE_CTRL_CURRENT,
                                        SMS_CONTROL_MODE_PAGE,
                                        mode_buf,
                                        mode_buf_len,
                                        SSD_FULL_SIZE,
                                        /*timeout*/60000);
                        break;
                }
                xpt_print(periph->path, "Unable to mode sense control page - "
                    "malloc failure\n");
                PROBE_SET_ACTION(softc, PROBE_SERIAL_NUM_0);
        }
        /* FALLTHROUGH */
        case PROBE_SERIAL_NUM_0:
        {
                struct scsi_vpd_supported_page_list *vpd_list = NULL;
                struct cam_ed *device;

                device = periph->path->device;
                if ((SCSI_QUIRK(device)->quirks & CAM_QUIRK_NOSERIAL) == 0) {
                        vpd_list = malloc(sizeof(*vpd_list), M_CAMXPT,
                            M_NOWAIT | M_ZERO);
                }

                if (vpd_list != NULL) {
                        scsi_inquiry(csio,
                                     /*retries*/4,
                                     probedone,
                                     MSG_SIMPLE_Q_TAG,
                                     (u_int8_t *)vpd_list,
                                     sizeof(*vpd_list),
                                     /*evpd*/TRUE,
                                     SVPD_SUPPORTED_PAGE_LIST,
                                     SSD_MIN_SIZE,
                                     /*timeout*/60 * 1000);
                        break;
                }
                /*
                 * We'll have to do without, let our probedone
                 * routine finish up for us.
                 */
                start_ccb->csio.data_ptr = NULL;
                probedone(periph, start_ccb);
                return;
        }
        case PROBE_SERIAL_NUM_1:
        {
                struct scsi_vpd_unit_serial_number *serial_buf;
                struct cam_ed* device;

                serial_buf = NULL;
                device = periph->path->device;
                if (device->serial_num != NULL) {
                        free(device->serial_num, M_CAMXPT);
                        device->serial_num = NULL;
                        device->serial_num_len = 0;
                }

                serial_buf = (struct scsi_vpd_unit_serial_number *)
                        malloc(sizeof(*serial_buf), M_CAMXPT, M_NOWAIT|M_ZERO);

                if (serial_buf != NULL) {
                        scsi_inquiry(csio,
                                     /*retries*/4,
                                     probedone,
                                     MSG_SIMPLE_Q_TAG,
                                     (u_int8_t *)serial_buf,
                                     sizeof(*serial_buf),
                                     /*evpd*/TRUE,
                                     SVPD_UNIT_SERIAL_NUMBER,
                                     SSD_MIN_SIZE,
                                     /*timeout*/60 * 1000);
                        break;
                }
                /*
                 * We'll have to do without, let our probedone
                 * routine finish up for us.
                 */
                start_ccb->csio.data_ptr = NULL;
                probedone(periph, start_ccb);
                return;
        }
        case PROBE_INVALID:
                CAM_DEBUG(start_ccb->ccb_h.path, CAM_DEBUG_INFO,
                    ("probestart: invalid action state\n"));
        default:
                break;
        }
        xpt_action(start_ccb);
}

static void
proberequestdefaultnegotiation(struct cam_periph *periph)
{
        struct ccb_trans_settings cts;

        xpt_setup_ccb(&cts.ccb_h, periph->path, CAM_PRIORITY_NONE);
        cts.ccb_h.func_code = XPT_GET_TRAN_SETTINGS;
        cts.type = CTS_TYPE_USER_SETTINGS;
        xpt_action((union ccb *)&cts);
        if ((cts.ccb_h.status & CAM_STATUS_MASK) != CAM_REQ_CMP) {
                return;
        }
        cts.ccb_h.func_code = XPT_SET_TRAN_SETTINGS;
        cts.type = CTS_TYPE_CURRENT_SETTINGS;
        xpt_action((union ccb *)&cts);
}

/*
 * Backoff Negotiation Code- only pertinent for SPI devices.
 */
static int
proberequestbackoff(struct cam_periph *periph, struct cam_ed *device)
{
        struct ccb_trans_settings cts;
        struct ccb_trans_settings_spi *spi;

        memset(&cts, 0, sizeof (cts));
        xpt_setup_ccb(&cts.ccb_h, periph->path, CAM_PRIORITY_NONE);
        cts.ccb_h.func_code = XPT_GET_TRAN_SETTINGS;
        cts.type = CTS_TYPE_CURRENT_SETTINGS;
        xpt_action((union ccb *)&cts);
        if ((cts.ccb_h.status & CAM_STATUS_MASK) != CAM_REQ_CMP) {
                if (bootverbose) {
                        xpt_print(periph->path,
                            "failed to get current device settings\n");
                }
                return (0);
        }
        if (cts.transport != XPORT_SPI) {
                if (bootverbose) {
                        xpt_print(periph->path, "not SPI transport\n");
                }
                return (0);
        }
        spi = &cts.xport_specific.spi;

        /*
         * We cannot renegotiate sync rate if we don't have one.
         */
        if ((spi->valid & CTS_SPI_VALID_SYNC_RATE) == 0) {
                if (bootverbose) {
                        xpt_print(periph->path, "no sync rate known\n");
                }
                return (0);
        }

        /*
         * We'll assert that we don't have to touch PPR options- the
         * SIM will see what we do with period and offset and adjust
         * the PPR options as appropriate.
         */

        /*
         * A sync rate with unknown or zero offset is nonsensical.
         * A sync period of zero means Async.
         */
        if ((spi->valid & CTS_SPI_VALID_SYNC_OFFSET) == 0
         || spi->sync_offset == 0 || spi->sync_period == 0) {
                if (bootverbose) {
                        xpt_print(periph->path, "no sync rate available\n");
                }
                return (0);
        }

        if (device->flags & CAM_DEV_DV_HIT_BOTTOM) {
                CAM_DEBUG(periph->path, CAM_DEBUG_INFO,
                    ("hit async: giving up on DV\n"));
                return (0);
        }


        /*
         * Jump sync_period up by one, but stop at 5MHz and fall back to Async.
         * We don't try to remember 'last' settings to see if the SIM actually
         * gets into the speed we want to set. We check on the SIM telling
         * us that a requested speed is bad, but otherwise don't try and
         * check the speed due to the asynchronous and handshake nature
         * of speed setting.
         */
        spi->valid = CTS_SPI_VALID_SYNC_RATE | CTS_SPI_VALID_SYNC_OFFSET;
        for (;;) {
                spi->sync_period++;
                if (spi->sync_period >= 0xf) {
                        spi->sync_period = 0;
                        spi->sync_offset = 0;
                        CAM_DEBUG(periph->path, CAM_DEBUG_INFO,
                            ("setting to async for DV\n"));
                        /*
                         * Once we hit async, we don't want to try
                         * any more settings.
                         */
                        device->flags |= CAM_DEV_DV_HIT_BOTTOM;
                } else if (bootverbose) {
                        CAM_DEBUG(periph->path, CAM_DEBUG_INFO,
                            ("DV: period 0x%x\n", spi->sync_period));
                        printf("setting period to 0x%x\n", spi->sync_period);
                }
                cts.ccb_h.func_code = XPT_SET_TRAN_SETTINGS;
                cts.type = CTS_TYPE_CURRENT_SETTINGS;
                xpt_action((union ccb *)&cts);
                if ((cts.ccb_h.status & CAM_STATUS_MASK) == CAM_REQ_CMP) {
                        break;
                }
                CAM_DEBUG(periph->path, CAM_DEBUG_INFO,
                    ("DV: failed to set period 0x%x\n", spi->sync_period));
                if (spi->sync_period == 0) {
                        return (0);
                }
        }
        return (1);
}

static void
probedone(struct cam_periph *periph, union ccb *done_ccb)
{
        probe_softc *softc;
        struct cam_path *path;
        u_int32_t  priority;

        CAM_DEBUG(done_ccb->ccb_h.path, CAM_DEBUG_TRACE, ("probedone\n"));

        softc = (probe_softc *)periph->softc;
        path = done_ccb->ccb_h.path;
        priority = done_ccb->ccb_h.pinfo.priority;

        switch (softc->action) {
        case PROBE_TUR:
        {
                if ((done_ccb->ccb_h.status & CAM_STATUS_MASK) != CAM_REQ_CMP) {

                        if (cam_periph_error(done_ccb, 0,
                                             SF_NO_PRINT, NULL) == ERESTART)
                                return;
                        else if ((done_ccb->ccb_h.status & CAM_DEV_QFRZN) != 0)
                                /* Don't wedge the queue */
                                xpt_release_devq(done_ccb->ccb_h.path,
                                                 /*count*/1,
                                                 /*run_queue*/TRUE);
                }
                PROBE_SET_ACTION(softc, PROBE_INQUIRY);
                xpt_release_ccb(done_ccb);
                xpt_schedule(periph, priority);
                return;
        }
        case PROBE_INQUIRY:
        case PROBE_FULL_INQUIRY:
        {
                if ((done_ccb->ccb_h.status & CAM_STATUS_MASK) == CAM_REQ_CMP) {
                        struct scsi_inquiry_data *inq_buf;
                        u_int8_t periph_qual;

                        path->device->flags |= CAM_DEV_INQUIRY_DATA_VALID;
                        inq_buf = &path->device->inq_data;

                        periph_qual = SID_QUAL(inq_buf);

                        if (periph_qual == SID_QUAL_LU_CONNECTED) {
                                u_int8_t len;

                                /*
                                 * We conservatively request only
                                 * SHORT_INQUIRY_LEN bytes of inquiry
                                 * information during our first try
                                 * at sending an INQUIRY. If the device
                                 * has more information to give,
                                 * perform a second request specifying
                                 * the amount of information the device
                                 * is willing to give.
                                 */
                                len = inq_buf->additional_length
                                    + offsetof(struct scsi_inquiry_data,
                                               additional_length) + 1;
                                if (softc->action == PROBE_INQUIRY
                                    && len > SHORT_INQUIRY_LENGTH) {
                                        PROBE_SET_ACTION(softc, PROBE_FULL_INQUIRY);
                                        xpt_release_ccb(done_ccb);
                                        xpt_schedule(periph, priority);
                                        return;
                                }

                                scsi_find_quirk(path->device);

                                scsi_devise_transport(path);

                                if (path->device->lun_id == 0 &&
                                    SID_ANSI_REV(inq_buf) > SCSI_REV_SPC2 &&
                                    (SCSI_QUIRK(path->device)->quirks &
                                     CAM_QUIRK_NORPTLUNS) == 0) {
                                        PROBE_SET_ACTION(softc,
                                            PROBE_REPORT_LUNS);
                                        /*
                                         * Start with room for *one* lun.
                                         */
                                        periph->path->target->rpl_size = 16;
                                } else if (INQ_DATA_TQ_ENABLED(inq_buf))
                                        PROBE_SET_ACTION(softc,
                                            PROBE_MODE_SENSE);
                                else
                                        PROBE_SET_ACTION(softc,
                                            PROBE_SERIAL_NUM_0);

                                if (path->device->flags & CAM_DEV_UNCONFIGURED) {
                                        path->device->flags &= ~CAM_DEV_UNCONFIGURED;
                                        xpt_acquire_device(path->device);
                                }
                                xpt_release_ccb(done_ccb);
                                xpt_schedule(periph, priority);
                                return;
                        } else if (path->device->lun_id == 0 &&
                            SID_ANSI_REV(inq_buf) > SCSI_REV_SPC2 &&
                            (SCSI_QUIRK(path->device)->quirks &
                             CAM_QUIRK_NORPTLUNS) == 0) {
                                if (path->device->flags &
                                    CAM_DEV_UNCONFIGURED) {
                                        path->device->flags &=
                                            ~CAM_DEV_UNCONFIGURED;
                                        xpt_acquire_device(path->device);
                                }
                                PROBE_SET_ACTION(softc, PROBE_REPORT_LUNS);
                                periph->path->target->rpl_size = 16;
                                xpt_release_ccb(done_ccb);
                                xpt_schedule(periph, priority);
                                return;
                        }
                } else if (cam_periph_error(done_ccb, 0,
                                            done_ccb->ccb_h.target_lun > 0
                                            ? SF_RETRY_UA|SF_QUIET_IR
                                            : SF_RETRY_UA,
                                            &softc->saved_ccb) == ERESTART) {
                        return;
                } else if ((done_ccb->ccb_h.status & CAM_DEV_QFRZN) != 0) {
                        /* Don't wedge the queue */
                        xpt_release_devq(done_ccb->ccb_h.path, /*count*/1,
                                         /*run_queue*/TRUE);
                }
                /*
                 * If we get to this point, we got an error status back
                 * from the inquiry and the error status doesn't require
                 * automatically retrying the command.  Therefore, the
                 * inquiry failed.  If we had inquiry information before
                 * for this device, but this latest inquiry command failed,
                 * the device has probably gone away.  If this device isn't
                 * already marked unconfigured, notify the peripheral
                 * drivers that this device is no more.
                 */
                if ((path->device->flags & CAM_DEV_UNCONFIGURED) == 0)
                        /* Send the async notification. */
                        xpt_async(AC_LOST_DEVICE, path, NULL);

                xpt_release_ccb(done_ccb);
                break;
        }
        case PROBE_REPORT_LUNS:
        {
                struct ccb_scsiio *csio;
                struct scsi_report_luns_data *lp;
                u_int nlun, maxlun;

                csio = &done_ccb->csio;

                lp = (struct scsi_report_luns_data *)csio->data_ptr;
                nlun = scsi_4btoul(lp->length) / 8;
                maxlun = (csio->dxfer_len / 8) - 1;

                if ((done_ccb->ccb_h.status & CAM_STATUS_MASK) != CAM_REQ_CMP) {
                        if (cam_periph_error(done_ccb, 0,
                            done_ccb->ccb_h.target_lun > 0 ?
                            SF_RETRY_UA|SF_QUIET_IR : SF_RETRY_UA,
                            &softc->saved_ccb) == ERESTART) {
                                return;
                        }
                        if ((done_ccb->ccb_h.status & CAM_DEV_QFRZN) != 0) {
                                xpt_release_devq(done_ccb->ccb_h.path, 1,
                                    TRUE);
                        }
                        free(lp, M_CAMXPT);
                        lp = NULL;
                } else if (nlun > maxlun) {
                        /*
                         * Reallocate and retry to cover all luns
                         */
                        CAM_DEBUG_PATH_PRINT(CAM_DEBUG_PROBE, path,
                            ("reallocating REPORT_LUNS for %u luns\n", nlun));
                        free(lp, M_CAMXPT);
                        path->target->rpl_size = (nlun << 3) + 8;
                        xpt_release_ccb(done_ccb);
                        xpt_schedule(periph, priority);
                        return;
                } else if (nlun == 0) {
                        /*
                         * If there don't appear to be any luns, bail.
                         */
                        free(lp, M_CAMXPT);
                        lp = NULL;
                } else if (probe_strange_rpl_data(lp, maxlun)) {
                        /*
                         * If we can't understand the lun format
                         * of any entry, bail.
                         */
                        free(lp, M_CAMXPT);
                        lp = NULL;
                } else {
                        lun_id_t lun;
                        int idx;

                        CAM_DEBUG_PATH_PRINT(CAM_DEBUG_PROBE, path,
                           ("%u luns reported\n", nlun));

                        CAM_GET_SIMPLE_LUN(lp, 0, lun);
                        /*
                         * If the first lun is not lun 0, then either there
                         * is no lun 0 in the list, or the list is unsorted.
                         */
                        if (lun != 0) {
                                for (idx = 0; idx < nlun; idx++) {
                                        CAM_GET_SIMPLE_LUN(lp, idx, lun);
                                        if (lun == 0) {
                                                break;
                                        }
                                }
                                if (idx != nlun) {
                                        uint8_t tlun[8];
                                        memcpy(tlun,
                                            lp->luns[0].lundata, 8);
                                        memcpy(lp->luns[0].lundata,
                                            lp->luns[idx].lundata, 8);
                                        memcpy(lp->luns[idx].lundata,
                                            tlun, 8);
                                        CAM_DEBUG_PATH_PRINT(CAM_DEBUG_PROBE,
                                            path, ("lun 0 in position %u\n", idx));
                                } else {
                                        /*
                                         * There is no lun 0 in our list. Destroy
                                         * the validity of the inquiry data so we
                                         * bail here and now.
                                         */
                                        path->device->flags &=
                                            ~CAM_DEV_INQUIRY_DATA_VALID;
                                }
                        }
                        /*
                         * If we have an old lun list, We can either
                         * retest luns that appear to have been dropped,
                         * or just nuke them.  We'll opt for the latter.
                         * This function will also install the new list
                         * in the target structure.
                         */
                        probe_purge_old(path, lp);
                        lp = NULL;
                }
                if (path->device->flags & CAM_DEV_INQUIRY_DATA_VALID) {
                        struct scsi_inquiry_data *inq_buf;
                        inq_buf = &path->device->inq_data;
                        if (INQ_DATA_TQ_ENABLED(inq_buf))
                                PROBE_SET_ACTION(softc, PROBE_MODE_SENSE);
                        else
                                PROBE_SET_ACTION(softc, PROBE_SERIAL_NUM_0);
                        xpt_release_ccb(done_ccb);
                        xpt_schedule(periph, priority);
                        return;
                }
                if (lp) {
                        free(lp, M_CAMXPT);
                }
                break;
        }
        case PROBE_MODE_SENSE:
        {
                struct ccb_scsiio *csio;
                struct scsi_mode_header_6 *mode_hdr;

                csio = &done_ccb->csio;
                mode_hdr = (struct scsi_mode_header_6 *)csio->data_ptr;
                if ((csio->ccb_h.status & CAM_STATUS_MASK) == CAM_REQ_CMP) {
                        struct scsi_control_page *page;
                        u_int8_t *offset;

                        offset = ((u_int8_t *)&mode_hdr[1])
                            + mode_hdr->blk_desc_len;
                        page = (struct scsi_control_page *)offset;
                        path->device->queue_flags = page->queue_flags;
                } else if (cam_periph_error(done_ccb, 0,
                                            SF_RETRY_UA|SF_NO_PRINT,
                                            &softc->saved_ccb) == ERESTART) {
                        return;
                } else if ((done_ccb->ccb_h.status & CAM_DEV_QFRZN) != 0) {
                        /* Don't wedge the queue */
                        xpt_release_devq(done_ccb->ccb_h.path,
                                         /*count*/1, /*run_queue*/TRUE);
                }
                xpt_release_ccb(done_ccb);
                free(mode_hdr, M_CAMXPT);
                PROBE_SET_ACTION(softc, PROBE_SERIAL_NUM_0);
                xpt_schedule(periph, priority);
                return;
        }
        case PROBE_SERIAL_NUM_0:
        {
                struct ccb_scsiio *csio;
                struct scsi_vpd_supported_page_list *page_list;
                int length, serialnum_supported, i;

                serialnum_supported = 0;
                csio = &done_ccb->csio;
                page_list =
                    (struct scsi_vpd_supported_page_list *)csio->data_ptr;

                if (page_list == NULL) {
                        /*
                         * Don't process the command as it was never sent
                         */
                } else if ((csio->ccb_h.status & CAM_STATUS_MASK) == CAM_REQ_CMP
                    && (page_list->length > 0)) {
                        length = min(page_list->length,
                            SVPD_SUPPORTED_PAGES_SIZE);
                        for (i = 0; i < length; i++) {
                                if (page_list->list[i] ==
                                    SVPD_UNIT_SERIAL_NUMBER) {
                                        serialnum_supported = 1;
                                        break;
                                }
                        }
                } else if (cam_periph_error(done_ccb, 0,
                                            SF_RETRY_UA|SF_NO_PRINT,
                                            &softc->saved_ccb) == ERESTART) {
                        return;
                } else if ((done_ccb->ccb_h.status & CAM_DEV_QFRZN) != 0) {
                        /* Don't wedge the queue */
                        xpt_release_devq(done_ccb->ccb_h.path, /*count*/1,
                                         /*run_queue*/TRUE);
                }

                if (page_list != NULL)
                        free(page_list, M_CAMXPT);

                if (serialnum_supported) {
                        xpt_release_ccb(done_ccb);
                        PROBE_SET_ACTION(softc, PROBE_SERIAL_NUM_1);
                        xpt_schedule(periph, priority);
                        return;
                }

                csio->data_ptr = NULL;
                /* FALLTHROUGH */
        }

        case PROBE_SERIAL_NUM_1:
        {
                struct ccb_scsiio *csio;
                struct scsi_vpd_unit_serial_number *serial_buf;
                u_int32_t  priority;
                int changed;
                int have_serialnum;

                changed = 1;
                have_serialnum = 0;
                csio = &done_ccb->csio;
                priority = done_ccb->ccb_h.pinfo.priority;
                serial_buf =
                    (struct scsi_vpd_unit_serial_number *)csio->data_ptr;

                /* Clean up from previous instance of this device */
                if (path->device->serial_num != NULL) {
                        free(path->device->serial_num, M_CAMXPT);
                        path->device->serial_num = NULL;
                        path->device->serial_num_len = 0;
                }

                if (serial_buf == NULL) {
                        /*
                         * Don't process the command as it was never sent
                         */
                } else if ((csio->ccb_h.status & CAM_STATUS_MASK) == CAM_REQ_CMP
                        && (serial_buf->length > 0)) {

                        have_serialnum = 1;
                        path->device->serial_num =
                                (u_int8_t *)malloc((serial_buf->length + 1),
                                                   M_CAMXPT, M_NOWAIT);
                        if (path->device->serial_num != NULL) {
                                bcopy(serial_buf->serial_num,
                                      path->device->serial_num,
                                      serial_buf->length);
                                path->device->serial_num_len =
                                    serial_buf->length;
                                path->device->serial_num[serial_buf->length]
                                    = '\0';
                        }
                } else if (cam_periph_error(done_ccb, 0,
                                            SF_RETRY_UA|SF_NO_PRINT,
                                            &softc->saved_ccb) == ERESTART) {
                        return;
                } else if ((done_ccb->ccb_h.status & CAM_DEV_QFRZN) != 0) {
                        /* Don't wedge the queue */
                        xpt_release_devq(done_ccb->ccb_h.path, /*count*/1,
                                         /*run_queue*/TRUE);
                }

                /*
                 * Let's see if we have seen this device before.
                 */
                if ((softc->flags & PROBE_INQUIRY_CKSUM) != 0) {
                        MD5_CTX context;
                        u_int8_t digest[16];

                        MD5Init(&context);

                        MD5Update(&context,
                                  (unsigned char *)&path->device->inq_data,
                                  sizeof(struct scsi_inquiry_data));

                        if (have_serialnum)
                                MD5Update(&context, serial_buf->serial_num,
                                          serial_buf->length);

                        MD5Final(digest, &context);
                        if (bcmp(softc->digest, digest, 16) == 0)
                                changed = 0;

                        /*
                         * XXX Do we need to do a TUR in order to ensure
                         *     that the device really hasn't changed???
                         */
                        if ((changed != 0)
                         && ((softc->flags & PROBE_NO_ANNOUNCE) == 0))
                                xpt_async(AC_LOST_DEVICE, path, NULL);
                }
                if (serial_buf != NULL)
                        free(serial_buf, M_CAMXPT);

                if (changed != 0) {
                        /*
                         * Now that we have all the necessary
                         * information to safely perform transfer
                         * negotiations... Controllers don't perform
                         * any negotiation or tagged queuing until
                         * after the first XPT_SET_TRAN_SETTINGS ccb is
                         * received.  So, on a new device, just retrieve
                         * the user settings, and set them as the current
                         * settings to set the device up.
                         */
                        proberequestdefaultnegotiation(periph);
                        xpt_release_ccb(done_ccb);

                        /*
                         * Perform a TUR to allow the controller to
                         * perform any necessary transfer negotiation.
                         */
                        PROBE_SET_ACTION(softc, PROBE_TUR_FOR_NEGOTIATION);
                        xpt_schedule(periph, priority);
                        return;
                }
                xpt_release_ccb(done_ccb);
                break;
        }
        case PROBE_TUR_FOR_NEGOTIATION:
                if ((done_ccb->ccb_h.status & CAM_STATUS_MASK) != CAM_REQ_CMP) {
                        DELAY(500000);
                        if (cam_periph_error(done_ccb, 0, SF_RETRY_UA,
                            NULL) == ERESTART)
                                return;
                }
        /* FALLTHROUGH */
        case PROBE_DV_EXIT:
                if ((done_ccb->ccb_h.status & CAM_DEV_QFRZN) != 0) {
                        /* Don't wedge the queue */
                        xpt_release_devq(done_ccb->ccb_h.path, /*count*/1,
                                         /*run_queue*/TRUE);
                }
                /*
                 * Do Domain Validation for lun 0 on devices that claim
                 * to support Synchronous Transfer modes.
                 */
                if (softc->action == PROBE_TUR_FOR_NEGOTIATION
                 && done_ccb->ccb_h.target_lun == 0
                 && (path->device->inq_data.flags & SID_Sync) != 0
                 && (path->device->flags & CAM_DEV_IN_DV) == 0) {
                        CAM_DEBUG(periph->path, CAM_DEBUG_INFO,
                            ("Begin Domain Validation\n"));
                        path->device->flags |= CAM_DEV_IN_DV;
                        xpt_release_ccb(done_ccb);
                        PROBE_SET_ACTION(softc, PROBE_INQUIRY_BASIC_DV1);
                        xpt_schedule(periph, priority);
                        return;
                }
                if (softc->action == PROBE_DV_EXIT) {
                        CAM_DEBUG(periph->path, CAM_DEBUG_INFO,
                            ("Leave Domain Validation\n"));
                }
                if (path->device->flags & CAM_DEV_UNCONFIGURED) {
                        path->device->flags &= ~CAM_DEV_UNCONFIGURED;
                        xpt_acquire_device(path->device);
                }
                path->device->flags &=
                    ~(CAM_DEV_IN_DV|CAM_DEV_DV_HIT_BOTTOM);
                if ((softc->flags & PROBE_NO_ANNOUNCE) == 0) {
                        /* Inform the XPT that a new device has been found */
                        done_ccb->ccb_h.func_code = XPT_GDEV_TYPE;
                        xpt_action(done_ccb);
                        xpt_async(AC_FOUND_DEVICE, done_ccb->ccb_h.path,
                                  done_ccb);
                }
                xpt_release_ccb(done_ccb);
                break;
        case PROBE_INQUIRY_BASIC_DV1:
        case PROBE_INQUIRY_BASIC_DV2:
        {
                struct scsi_inquiry_data *nbuf;
                struct ccb_scsiio *csio;

                if ((done_ccb->ccb_h.status & CAM_DEV_QFRZN) != 0) {
                        /* Don't wedge the queue */
                        xpt_release_devq(done_ccb->ccb_h.path, /*count*/1,
                                         /*run_queue*/TRUE);
                }
                csio = &done_ccb->csio;
                nbuf = (struct scsi_inquiry_data *)csio->data_ptr;
                if (bcmp(nbuf, &path->device->inq_data, SHORT_INQUIRY_LENGTH)) {
                        xpt_print(path,
                            "inquiry data fails comparison at DV%d step\n",
                            softc->action == PROBE_INQUIRY_BASIC_DV1 ? 1 : 2);
                        if (proberequestbackoff(periph, path->device)) {
                                path->device->flags &= ~CAM_DEV_IN_DV;
                                PROBE_SET_ACTION(softc, PROBE_TUR_FOR_NEGOTIATION);
                        } else {
                                /* give up */
                                PROBE_SET_ACTION(softc, PROBE_DV_EXIT);
                        }
                        free(nbuf, M_CAMXPT);
                        xpt_release_ccb(done_ccb);
                        xpt_schedule(periph, priority);
                        return;
                }
                free(nbuf, M_CAMXPT);
                if (softc->action == PROBE_INQUIRY_BASIC_DV1) {
                        PROBE_SET_ACTION(softc, PROBE_INQUIRY_BASIC_DV2);
                        xpt_release_ccb(done_ccb);
                        xpt_schedule(periph, priority);
                        return;
                }
                if (softc->action == PROBE_INQUIRY_BASIC_DV2) {
                        CAM_DEBUG(periph->path, CAM_DEBUG_INFO,
                            ("Leave Domain Validation Successfully\n"));
                }
                if (path->device->flags & CAM_DEV_UNCONFIGURED) {
                        path->device->flags &= ~CAM_DEV_UNCONFIGURED;
                        xpt_acquire_device(path->device);
                }
                path->device->flags &=
                    ~(CAM_DEV_IN_DV|CAM_DEV_DV_HIT_BOTTOM);
                if ((softc->flags & PROBE_NO_ANNOUNCE) == 0) {
                        /* Inform the XPT that a new device has been found */
                        done_ccb->ccb_h.func_code = XPT_GDEV_TYPE;
                        xpt_action(done_ccb);
                        xpt_async(AC_FOUND_DEVICE, done_ccb->ccb_h.path,
                                  done_ccb);
                }
                xpt_release_ccb(done_ccb);
                break;
        }
        case PROBE_INVALID:
                CAM_DEBUG(done_ccb->ccb_h.path, CAM_DEBUG_INFO,
                    ("probedone: invalid action state\n"));
        default:
                break;
        }
        done_ccb = (union ccb *)TAILQ_FIRST(&softc->request_ccbs);
        TAILQ_REMOVE(&softc->request_ccbs, &done_ccb->ccb_h, periph_links.tqe);
        done_ccb->ccb_h.status = CAM_REQ_CMP;
        xpt_done(done_ccb);
        if (TAILQ_FIRST(&softc->request_ccbs) == NULL) {
                cam_periph_invalidate(periph);
                cam_release_devq(periph->path,
                    RELSIM_RELEASE_RUNLEVEL, 0, CAM_RL_XPT + 1, FALSE);
                cam_periph_release_locked(periph);
        } else {
                probeschedule(periph);
        }
}

static int
probe_strange_rpl_data(struct scsi_report_luns_data *rp, uint32_t maxlun)
{
        uint32_t idx;
        uint32_t nlun = MIN(maxlun, (scsi_4btoul(rp->length) / 8));

        for (idx = 0; idx < nlun; idx++) {
                if (!CAM_CAN_GET_SIMPLE_LUN(rp, idx)) {
                        return (-1);
                }
        }
        return (0);
}

static void
probe_purge_old(struct cam_path *path, struct scsi_report_luns_data *new)
{
        struct cam_path *tp;
        struct scsi_report_luns_data *old;
        u_int idx1, idx2, nlun_old, nlun_new, this_lun;
        u_int8_t *ol, *nl;

        if (path->target == NULL) {
                return;
        }
        if (path->target->luns == NULL) {
                path->target->luns = new;
                return;
        }
        old = path->target->luns;
        nlun_old = scsi_4btoul(old->length) / 8;
        nlun_new = scsi_4btoul(new->length) / 8;

        /*
         * We are not going to assume sorted lists. Deal.
         */
        for (idx1 = 0; idx1 < nlun_old; idx1++) {
                ol = old->luns[idx1].lundata;
                for (idx2 = 0; idx2 < nlun_new; idx2++) {
                        nl = new->luns[idx2].lundata;
                        if (memcmp(nl, ol, 8) == 0) {
                                break;
                        }
                }
                if (idx2 < nlun_new) {
                        continue;
                }
                /*
                 * An 'old' item not in the 'new' list.
                 * Nuke it. Except that if it is lun 0,
                 * that would be what the probe state
                 * machine is currently working on,
                 * so we won't do that.
                 *
                 * We also cannot nuke it if it is
                 * not in a lun format we understand.
                 */
                if (!CAM_CAN_GET_SIMPLE_LUN(old, idx1)) {
                        continue;
                }
                CAM_GET_SIMPLE_LUN(old, idx1, this_lun);
                if (this_lun == 0) {
                        continue;
                }
                if (xpt_create_path(&tp, NULL, xpt_path_path_id(path),
                    xpt_path_target_id(path), this_lun) == CAM_REQ_CMP) {
                        xpt_async(AC_LOST_DEVICE, tp, NULL);
                        xpt_free_path(tp);
                }
        }
        free(old, M_CAMXPT);
        path->target->luns = new;
}

static void
probecleanup(struct cam_periph *periph)
{
        free(periph->softc, M_CAMXPT);
}

static void
scsi_find_quirk(struct cam_ed *device)
{
        struct scsi_quirk_entry *quirk;
        caddr_t match;

        match = cam_quirkmatch((caddr_t)&device->inq_data,
                               (caddr_t)scsi_quirk_table,
                               sizeof(scsi_quirk_table) /
                               sizeof(*scsi_quirk_table),
                               sizeof(*scsi_quirk_table), scsi_inquiry_match);

        if (match == NULL)
                panic("xpt_find_quirk: device didn't match wildcard entry!!");

        quirk = (struct scsi_quirk_entry *)match;
        device->quirk = quirk;
        device->mintags = quirk->mintags;
        device->maxtags = quirk->maxtags;
}

static int
sysctl_cam_search_luns(SYSCTL_HANDLER_ARGS)
{
        int error, val;

        val = cam_srch_hi;
        error = sysctl_handle_int(oidp, &val, 0, req);
        if (error != 0 || req->newptr == NULL)
                return (error);
        if (val == 0 || val == 1) {
                cam_srch_hi = val;
                return (0);
        } else {
                return (EINVAL);
        }
}

typedef struct {
        union   ccb *request_ccb;
        struct  ccb_pathinq *cpi;
        int     counter;
        int     lunindex[0];
} scsi_scan_bus_info;

/*
 * To start a scan, request_ccb is an XPT_SCAN_BUS ccb.
 * As the scan progresses, scsi_scan_bus is used as the
 * callback on completion function.
 */
static void
scsi_scan_bus(struct cam_periph *periph, union ccb *request_ccb)
{
        CAM_DEBUG(request_ccb->ccb_h.path, CAM_DEBUG_TRACE,
                  ("scsi_scan_bus\n"));
        switch (request_ccb->ccb_h.func_code) {
        case XPT_SCAN_BUS:
        case XPT_SCAN_TGT:
        {
                scsi_scan_bus_info *scan_info;
                union   ccb *work_ccb, *reset_ccb;
                struct  cam_path *path;
                u_int   i;
                u_int   low_target, max_target;
                u_int   initiator_id;

                /* Find out the characteristics of the bus */
                work_ccb = xpt_alloc_ccb_nowait();
                if (work_ccb == NULL) {
                        request_ccb->ccb_h.status = CAM_RESRC_UNAVAIL;
                        xpt_done(request_ccb);
                        return;
                }
                xpt_setup_ccb(&work_ccb->ccb_h, request_ccb->ccb_h.path,
                              request_ccb->ccb_h.pinfo.priority);
                work_ccb->ccb_h.func_code = XPT_PATH_INQ;
                xpt_action(work_ccb);
                if (work_ccb->ccb_h.status != CAM_REQ_CMP) {
                        request_ccb->ccb_h.status = work_ccb->ccb_h.status;
                        xpt_free_ccb(work_ccb);
                        xpt_done(request_ccb);
                        return;
                }

                if ((work_ccb->cpi.hba_misc & PIM_NOINITIATOR) != 0) {
                        /*
                         * Can't scan the bus on an adapter that
                         * cannot perform the initiator role.
                         */
                        request_ccb->ccb_h.status = CAM_REQ_CMP;
                        xpt_free_ccb(work_ccb);
                        xpt_done(request_ccb);
                        return;
                }

                /* We may need to reset bus first, if we haven't done it yet. */
                if ((work_ccb->cpi.hba_inquiry &
                    (PI_WIDE_32|PI_WIDE_16|PI_SDTR_ABLE)) &&
                    !(work_ccb->cpi.hba_misc & PIM_NOBUSRESET) &&
                    !timevalisset(&request_ccb->ccb_h.path->bus->last_reset)) {
                        reset_ccb = xpt_alloc_ccb_nowait();
                        xpt_setup_ccb(&reset_ccb->ccb_h, request_ccb->ccb_h.path,
                              CAM_PRIORITY_NONE);
                        reset_ccb->ccb_h.func_code = XPT_RESET_BUS;
                        xpt_action(reset_ccb);
                        if (reset_ccb->ccb_h.status != CAM_REQ_CMP) {
                                request_ccb->ccb_h.status = reset_ccb->ccb_h.status;
                                xpt_free_ccb(reset_ccb);
                                xpt_free_ccb(work_ccb);
                                xpt_done(request_ccb);
                                return;
                        }
                        xpt_free_ccb(reset_ccb);
                }

                /* Save some state for use while we probe for devices */
                scan_info = (scsi_scan_bus_info *) malloc(sizeof(scsi_scan_bus_info) +
                    (work_ccb->cpi.max_target * sizeof (u_int)), M_CAMXPT, M_ZERO|M_NOWAIT);
                if (scan_info == NULL) {
                        request_ccb->ccb_h.status = CAM_RESRC_UNAVAIL;
                        xpt_done(request_ccb);
                        return;
                }
                CAM_DEBUG_PATH_PRINT(CAM_DEBUG_PROBE, request_ccb->ccb_h.path,
                   ("SCAN start for %p\n", scan_info));
                scan_info->request_ccb = request_ccb;
                scan_info->cpi = &work_ccb->cpi;

                /* Cache on our stack so we can work asynchronously */
                max_target = scan_info->cpi->max_target;
                low_target = 0;
                initiator_id = scan_info->cpi->initiator_id;


                /*
                 * We can scan all targets in parallel, or do it sequentially.
                 */

                if (request_ccb->ccb_h.func_code == XPT_SCAN_TGT) {
                        max_target = low_target = request_ccb->ccb_h.target_id;
                        scan_info->counter = 0;
                } else if (scan_info->cpi->hba_misc & PIM_SEQSCAN) {
                        max_target = 0;
                        scan_info->counter = 0;
                } else {
                        scan_info->counter = scan_info->cpi->max_target + 1;
                        if (scan_info->cpi->initiator_id < scan_info->counter) {
                                scan_info->counter--;
                        }
                }

                for (i = low_target; i <= max_target; i++) {
                        cam_status status;
                        if (i == initiator_id)
                                continue;

                        status = xpt_create_path(&path, xpt_periph,
                                                 request_ccb->ccb_h.path_id,
                                                 i, 0);
                        if (status != CAM_REQ_CMP) {
                                printf("scsi_scan_bus: xpt_create_path failed"
                                       " with status %#x, bus scan halted\n",
                                       status);
                                free(scan_info, M_CAMXPT);
                                request_ccb->ccb_h.status = status;
                                xpt_free_ccb(work_ccb);
                                xpt_done(request_ccb);
                                break;
                        }
                        work_ccb = xpt_alloc_ccb_nowait();
                        if (work_ccb == NULL) {
                                xpt_free_ccb((union ccb *)scan_info->cpi);
                                free(scan_info, M_CAMXPT);
                                xpt_free_path(path);
                                request_ccb->ccb_h.status = CAM_RESRC_UNAVAIL;
                                xpt_done(request_ccb);
                                break;
                        }
                        xpt_setup_ccb(&work_ccb->ccb_h, path,
                                      request_ccb->ccb_h.pinfo.priority);
                        work_ccb->ccb_h.func_code = XPT_SCAN_LUN;
                        work_ccb->ccb_h.cbfcnp = scsi_scan_bus;
                        work_ccb->ccb_h.ppriv_ptr0 = scan_info;
                        work_ccb->crcn.flags = request_ccb->crcn.flags;
                        xpt_action(work_ccb);
                }
                break;
        }
        case XPT_SCAN_LUN:
        {
                cam_status status;
                struct cam_path *path, *oldpath;
                scsi_scan_bus_info *scan_info;
                struct cam_et *target;
                struct cam_ed *device;
                int next_target;
                path_id_t path_id;
                target_id_t target_id;
                lun_id_t lun_id;

                oldpath = request_ccb->ccb_h.path;

                status = request_ccb->ccb_h.status & CAM_STATUS_MASK;
                /* Reuse the same CCB to query if a device was really found */
                scan_info = (scsi_scan_bus_info *)request_ccb->ccb_h.ppriv_ptr0;
                xpt_setup_ccb(&request_ccb->ccb_h, request_ccb->ccb_h.path,
                              request_ccb->ccb_h.pinfo.priority);
                request_ccb->ccb_h.func_code = XPT_GDEV_TYPE;


                path_id = request_ccb->ccb_h.path_id;
                target_id = request_ccb->ccb_h.target_id;
                lun_id = request_ccb->ccb_h.target_lun;
                xpt_action(request_ccb);

                target = request_ccb->ccb_h.path->target;
                next_target = 1;

                if (target->luns) {
                        uint32_t first;
                        u_int nluns = scsi_4btoul(target->luns->length) / 8;

                        /*
                         * Make sure we skip over lun 0 if it's the first member
                         * of the list as we've actually just finished probing
                         * it.
                         */
                        CAM_GET_SIMPLE_LUN(target->luns, 0, first);
                        if (first == 0 && scan_info->lunindex[target_id] == 0) {
                                scan_info->lunindex[target_id]++;
                        } 

                        if (scan_info->lunindex[target_id] < nluns) {
                                CAM_GET_SIMPLE_LUN(target->luns,
                                    scan_info->lunindex[target_id], lun_id);
                                next_target = 0;
                                CAM_DEBUG_PATH_PRINT(CAM_DEBUG_PROBE,
                                    request_ccb->ccb_h.path,
                                   ("next lun to try at index %u is %u\n",
                                   scan_info->lunindex[target_id], lun_id));
                                scan_info->lunindex[target_id]++;
                        } else {
                                /*
                                 * We're done with scanning all luns.
                                 *
                                 * Nuke the bogus device for lun 0 if lun 0
                                 * wasn't on the list.
                                 */
                                if (first != 0) {
                                        TAILQ_FOREACH(device,
                                            &target->ed_entries, links) {
                                                if (device->lun_id == 0) {
                                                        break;
                                                }
                                        }
                                        if (device) {
                                                xpt_release_device(device);
                                        }
                                }
                        }
                } else if (request_ccb->ccb_h.status != CAM_REQ_CMP) {
                        int phl;

                        /*
                         * If we already probed lun 0 successfully, or
                         * we have additional configured luns on this
                         * target that might have "gone away", go onto
                         * the next lun.
                         */
                        /*
                         * We may touch devices that we don't
                         * hold references too, so ensure they
                         * don't disappear out from under us.
                         * The target above is referenced by the
                         * path in the request ccb.
                         */
                        phl = 0;
                        device = TAILQ_FIRST(&target->ed_entries);
                        if (device != NULL) {
                                phl = CAN_SRCH_HI_SPARSE(device);
                                if (device->lun_id == 0)
                                        device = TAILQ_NEXT(device, links);
                        }
                        if ((lun_id != 0) || (device != NULL)) {
                                if (lun_id < (CAM_SCSI2_MAXLUN-1) || phl) {
                                        lun_id++;
                                        next_target = 0;
                                }
                        }
                        if (lun_id == request_ccb->ccb_h.target_lun
                            || lun_id > scan_info->cpi->max_lun)
                                next_target = 1;
                } else {

                        device = request_ccb->ccb_h.path->device;

                        if ((SCSI_QUIRK(device)->quirks &
                            CAM_QUIRK_NOLUNS) == 0) {
                                /* Try the next lun */
                                if (lun_id < (CAM_SCSI2_MAXLUN-1)
                                  || CAN_SRCH_HI_DENSE(device)) {
                                        lun_id++;
                                        next_target = 0;
                                }
                        }
                        if (lun_id == request_ccb->ccb_h.target_lun
                            || lun_id > scan_info->cpi->max_lun)
                                next_target = 1;
                }

                /*
                 * Check to see if we scan any further luns.
                 */
                if (next_target) {
                        int done;

                        /*
                         * Free the current request path- we're done with it.
                         */
                        xpt_free_path(oldpath);
 hop_again:
                        done = 0;
                        if (scan_info->request_ccb->ccb_h.func_code == XPT_SCAN_TGT) {
                                done = 1;
                        } else if (scan_info->cpi->hba_misc & PIM_SEQSCAN) {
                                scan_info->counter++;
                                if (scan_info->counter ==
                                    scan_info->cpi->initiator_id) {
                                        scan_info->counter++;
                                }
                                if (scan_info->counter >=
                                    scan_info->cpi->max_target+1) {
                                        done = 1;
                                }
                        } else {
                                scan_info->counter--;
                                if (scan_info->counter == 0) {
                                        done = 1;
                                }
                        }
                        if (done) {
                                xpt_free_ccb(request_ccb);
                                xpt_free_ccb((union ccb *)scan_info->cpi);
                                request_ccb = scan_info->request_ccb;
                                CAM_DEBUG_PATH_PRINT(CAM_DEBUG_PROBE,
                                    request_ccb->ccb_h.path,
                                   ("SCAN done for %p\n", scan_info));
                                free(scan_info, M_CAMXPT);
                                request_ccb->ccb_h.status = CAM_REQ_CMP;
                                xpt_done(request_ccb);
                                break;
                        }

                        if ((scan_info->cpi->hba_misc & PIM_SEQSCAN) == 0) {
                                xpt_free_ccb(request_ccb);
                                break;
                        }
                        status = xpt_create_path(&path, xpt_periph,
                            scan_info->request_ccb->ccb_h.path_id,
                            scan_info->counter, 0);
                        if (status != CAM_REQ_CMP) {
                                printf("scsi_scan_bus: xpt_create_path failed"
                                    " with status %#x, bus scan halted\n",
                                    status);
                                xpt_free_ccb(request_ccb);
                                xpt_free_ccb((union ccb *)scan_info->cpi);
                                request_ccb = scan_info->request_ccb;
                                free(scan_info, M_CAMXPT);
                                request_ccb->ccb_h.status = status;
                                xpt_done(request_ccb);
                                break;
                        }
                        xpt_setup_ccb(&request_ccb->ccb_h, path,
                            request_ccb->ccb_h.pinfo.priority);
                        request_ccb->ccb_h.func_code = XPT_SCAN_LUN;
                        request_ccb->ccb_h.cbfcnp = scsi_scan_bus;
                        request_ccb->ccb_h.ppriv_ptr0 = scan_info;
                        request_ccb->crcn.flags =
                            scan_info->request_ccb->crcn.flags;
                } else {
                        status = xpt_create_path(&path, xpt_periph,
                                                 path_id, target_id, lun_id);
                        /*
                         * Free the old request path- we're done with it. We
                         * do this *after* creating the new path so that
                         * we don't remove a target that has our lun list
                         * in the case that lun 0 is not present.
                         */
                        xpt_free_path(oldpath);
                        if (status != CAM_REQ_CMP) {
                                printf("scsi_scan_bus: xpt_create_path failed "
                                       "with status %#x, halting LUN scan\n",
                                       status);
                                goto hop_again;
                        }
                        xpt_setup_ccb(&request_ccb->ccb_h, path,
                                      request_ccb->ccb_h.pinfo.priority);
                        request_ccb->ccb_h.func_code = XPT_SCAN_LUN;
                        request_ccb->ccb_h.cbfcnp = scsi_scan_bus;
                        request_ccb->ccb_h.ppriv_ptr0 = scan_info;
                        request_ccb->crcn.flags =
                                scan_info->request_ccb->crcn.flags;
                }
                xpt_action(request_ccb);
                break;
        }
        default:
                break;
        }
}

static void
scsi_scan_lun(struct cam_periph *periph, struct cam_path *path,
             cam_flags flags, union ccb *request_ccb)
{
        struct ccb_pathinq cpi;
        cam_status status;
        struct cam_path *new_path;
        struct cam_periph *old_periph;

        CAM_DEBUG(path, CAM_DEBUG_TRACE, ("scsi_scan_lun\n"));

        xpt_setup_ccb(&cpi.ccb_h, path, CAM_PRIORITY_NONE);
        cpi.ccb_h.func_code = XPT_PATH_INQ;
        xpt_action((union ccb *)&cpi);

        if (cpi.ccb_h.status != CAM_REQ_CMP) {
                if (request_ccb != NULL) {
                        request_ccb->ccb_h.status = cpi.ccb_h.status;
                        xpt_done(request_ccb);
                }
                return;
        }

        if ((cpi.hba_misc & PIM_NOINITIATOR) != 0) {
                /*
                 * Can't scan the bus on an adapter that
                 * cannot perform the initiator role.
                 */
                if (request_ccb != NULL) {
                        request_ccb->ccb_h.status = CAM_REQ_CMP;
                        xpt_done(request_ccb);
                }
                return;
        }

        if (request_ccb == NULL) {
                request_ccb = malloc(sizeof(union ccb), M_CAMXPT, M_NOWAIT);
                if (request_ccb == NULL) {
                        xpt_print(path, "scsi_scan_lun: can't allocate CCB, "
                            "can't continue\n");
                        return;
                }
                new_path = malloc(sizeof(*new_path), M_CAMXPT, M_NOWAIT);
                if (new_path == NULL) {
                        xpt_print(path, "scsi_scan_lun: can't allocate path, "
                            "can't continue\n");
                        free(request_ccb, M_CAMXPT);
                        return;
                }
                status = xpt_compile_path(new_path, xpt_periph,
                                          path->bus->path_id,
                                          path->target->target_id,
                                          path->device->lun_id);

                if (status != CAM_REQ_CMP) {
                        xpt_print(path, "scsi_scan_lun: can't compile path, "
                            "can't continue\n");
                        free(request_ccb, M_CAMXPT);
                        free(new_path, M_CAMXPT);
                        return;
                }
                xpt_setup_ccb(&request_ccb->ccb_h, new_path, CAM_PRIORITY_XPT);
                request_ccb->ccb_h.cbfcnp = xptscandone;
                request_ccb->ccb_h.func_code = XPT_SCAN_LUN;
                request_ccb->crcn.flags = flags;
        }

        if ((old_periph = cam_periph_find(path, "probe")) != NULL) {
                if ((old_periph->flags & CAM_PERIPH_INVALID) == 0) {
                        probe_softc *softc;

                        softc = (probe_softc *)old_periph->softc;
                        TAILQ_INSERT_TAIL(&softc->request_ccbs,
                            &request_ccb->ccb_h, periph_links.tqe);
                } else {
                        request_ccb->ccb_h.status = CAM_REQ_CMP_ERR;
                        xpt_done(request_ccb);
                }
        } else {
                status = cam_periph_alloc(proberegister, NULL, probecleanup,
                                          probestart, "probe",
                                          CAM_PERIPH_BIO,
                                          request_ccb->ccb_h.path, NULL, 0,
                                          request_ccb);

                if (status != CAM_REQ_CMP) {
                        xpt_print(path, "scsi_scan_lun: cam_alloc_periph "
                            "returned an error, can't continue probe\n");
                        request_ccb->ccb_h.status = status;
                        xpt_done(request_ccb);
                }
        }
}

static void
xptscandone(struct cam_periph *periph, union ccb *done_ccb)
{
        xpt_release_path(done_ccb->ccb_h.path);
        free(done_ccb->ccb_h.path, M_CAMXPT);
        free(done_ccb, M_CAMXPT);
}

static struct cam_ed *
scsi_alloc_device(struct cam_eb *bus, struct cam_et *target, lun_id_t lun_id)
{
        struct cam_path path;
        struct scsi_quirk_entry *quirk;
        struct cam_ed *device;
        struct cam_ed *cur_device;

        device = xpt_alloc_device(bus, target, lun_id);
        if (device == NULL)
                return (NULL);

        /*
         * Take the default quirk entry until we have inquiry
         * data and can determine a better quirk to use.
         */
        quirk = &scsi_quirk_table[scsi_quirk_table_size - 1];
        device->quirk = (void *)quirk;
        device->mintags = quirk->mintags;
        device->maxtags = quirk->maxtags;
        bzero(&device->inq_data, sizeof(device->inq_data));
        device->inq_flags = 0;
        device->queue_flags = 0;
        device->serial_num = NULL;
        device->serial_num_len = 0;

        /*
         * XXX should be limited by number of CCBs this bus can
         * do.
         */
        bus->sim->max_ccbs += device->ccbq.devq_openings;
        /* Insertion sort into our target's device list */
        cur_device = TAILQ_FIRST(&target->ed_entries);
        while (cur_device != NULL && cur_device->lun_id < lun_id)
                cur_device = TAILQ_NEXT(cur_device, links);
        if (cur_device != NULL) {
                TAILQ_INSERT_BEFORE(cur_device, device, links);
        } else {
                TAILQ_INSERT_TAIL(&target->ed_entries, device, links);
        }
        target->generation++;
        if (lun_id != CAM_LUN_WILDCARD) {
                xpt_compile_path(&path,
                                 NULL,
                                 bus->path_id,
                                 target->target_id,
                                 lun_id);
                scsi_devise_transport(&path);
                xpt_release_path(&path);
        }

        return (device);
}

static void
scsi_devise_transport(struct cam_path *path)
{
        struct ccb_pathinq cpi;
        struct ccb_trans_settings cts;
        struct scsi_inquiry_data *inq_buf;

        /* Get transport information from the SIM */
        xpt_setup_ccb(&cpi.ccb_h, path, CAM_PRIORITY_NONE);
        cpi.ccb_h.func_code = XPT_PATH_INQ;
        xpt_action((union ccb *)&cpi);

        inq_buf = NULL;
        if ((path->device->flags & CAM_DEV_INQUIRY_DATA_VALID) != 0)
                inq_buf = &path->device->inq_data;
        path->device->protocol = PROTO_SCSI;
        path->device->protocol_version =
            inq_buf != NULL ? SID_ANSI_REV(inq_buf) : cpi.protocol_version;
        path->device->transport = cpi.transport;
        path->device->transport_version = cpi.transport_version;

        /*
         * Any device not using SPI3 features should
         * be considered SPI2 or lower.
         */
        if (inq_buf != NULL) {
                if (path->device->transport == XPORT_SPI
                 && (inq_buf->spi3data & SID_SPI_MASK) == 0
                 && path->device->transport_version > 2)
                        path->device->transport_version = 2;
        } else {
                struct cam_ed* otherdev;

                for (otherdev = TAILQ_FIRST(&path->target->ed_entries);
                     otherdev != NULL;
                     otherdev = TAILQ_NEXT(otherdev, links)) {
                        if (otherdev != path->device)
                                break;
                }

                if (otherdev != NULL) {
                        /*
                         * Initially assume the same versioning as
                         * prior luns for this target.
                         */
                        path->device->protocol_version =
                            otherdev->protocol_version;
                        path->device->transport_version =
                            otherdev->transport_version;
                } else {
                        /* Until we know better, opt for safty */
                        path->device->protocol_version = 2;
                        if (path->device->transport == XPORT_SPI)
                                path->device->transport_version = 2;
                        else
                                path->device->transport_version = 0;
                }
        }

        /*
         * XXX
         * For a device compliant with SPC-2 we should be able
         * to determine the transport version supported by
         * scrutinizing the version descriptors in the
         * inquiry buffer.
         */

        /* Tell the controller what we think */
        xpt_setup_ccb(&cts.ccb_h, path, CAM_PRIORITY_NONE);
        cts.ccb_h.func_code = XPT_SET_TRAN_SETTINGS;
        cts.type = CTS_TYPE_CURRENT_SETTINGS;
        cts.transport = path->device->transport;
        cts.transport_version = path->device->transport_version;
        cts.protocol = path->device->protocol;
        cts.protocol_version = path->device->protocol_version;
        cts.proto_specific.valid = 0;
        cts.xport_specific.valid = 0;
        xpt_action((union ccb *)&cts);
}

static void
scsi_action(union ccb *start_ccb)
{

        switch (start_ccb->ccb_h.func_code) {
        case XPT_SET_TRAN_SETTINGS:
        {
                scsi_set_transfer_settings(&start_ccb->cts,
                                           start_ccb->ccb_h.path->device,
                                           /*async_update*/FALSE);
                break;
        }
        case XPT_SCAN_BUS:
        case XPT_SCAN_TGT:
                scsi_scan_bus(start_ccb->ccb_h.path->periph, start_ccb);
                break;
        case XPT_SCAN_LUN:
                scsi_scan_lun(start_ccb->ccb_h.path->periph,
                              start_ccb->ccb_h.path, start_ccb->crcn.flags,
                              start_ccb);
                break;
        case XPT_GET_TRAN_SETTINGS:
        {
                struct cam_sim *sim;

                sim = start_ccb->ccb_h.path->bus->sim;
                (*(sim->sim_action))(sim, start_ccb);
                break;
        }
        default:
                xpt_action_default(start_ccb);
                break;
        }
}

static void
scsi_set_transfer_settings(struct ccb_trans_settings *cts, struct cam_ed *device,
                           int async_update)
{
        struct  ccb_pathinq cpi;
        struct  ccb_trans_settings cur_cts;
        struct  ccb_trans_settings_scsi *scsi;
        struct  ccb_trans_settings_scsi *cur_scsi;
        struct  cam_sim *sim;
        struct  scsi_inquiry_data *inq_data;

        if (device == NULL) {
                cts->ccb_h.status = CAM_PATH_INVALID;
                xpt_done((union ccb *)cts);
                return;
        }

        if (cts->protocol == PROTO_UNKNOWN
         || cts->protocol == PROTO_UNSPECIFIED) {
                cts->protocol = device->protocol;
                cts->protocol_version = device->protocol_version;
        }

        if (cts->protocol_version == PROTO_VERSION_UNKNOWN
         || cts->protocol_version == PROTO_VERSION_UNSPECIFIED)
                cts->protocol_version = device->protocol_version;

        if (cts->protocol != device->protocol) {
                xpt_print(cts->ccb_h.path, "Uninitialized Protocol %x:%x?\n",
                       cts->protocol, device->protocol);
                cts->protocol = device->protocol;
        }

        if (cts->protocol_version > device->protocol_version) {
                if (bootverbose) {
                        xpt_print(cts->ccb_h.path, "Down reving Protocol "
                            "Version from %d to %d?\n", cts->protocol_version,
                            device->protocol_version);
                }
                cts->protocol_version = device->protocol_version;
        }

        if (cts->transport == XPORT_UNKNOWN
         || cts->transport == XPORT_UNSPECIFIED) {
                cts->transport = device->transport;
                cts->transport_version = device->transport_version;
        }

        if (cts->transport_version == XPORT_VERSION_UNKNOWN
         || cts->transport_version == XPORT_VERSION_UNSPECIFIED)
                cts->transport_version = device->transport_version;

        if (cts->transport != device->transport) {
                xpt_print(cts->ccb_h.path, "Uninitialized Transport %x:%x?\n",
                    cts->transport, device->transport);
                cts->transport = device->transport;
        }

        if (cts->transport_version > device->transport_version) {
                if (bootverbose) {
                        xpt_print(cts->ccb_h.path, "Down reving Transport "
                            "Version from %d to %d?\n", cts->transport_version,
                            device->transport_version);
                }
                cts->transport_version = device->transport_version;
        }

        sim = cts->ccb_h.path->bus->sim;

        /*
         * Nothing more of interest to do unless
         * this is a device connected via the
         * SCSI protocol.
         */
        if (cts->protocol != PROTO_SCSI) {
                if (async_update == FALSE)
                        (*(sim->sim_action))(sim, (union ccb *)cts);
                return;
        }

        inq_data = &device->inq_data;
        scsi = &cts->proto_specific.scsi;
        xpt_setup_ccb(&cpi.ccb_h, cts->ccb_h.path, CAM_PRIORITY_NONE);
        cpi.ccb_h.func_code = XPT_PATH_INQ;
        xpt_action((union ccb *)&cpi);

        /* SCSI specific sanity checking */
        if ((cpi.hba_inquiry & PI_TAG_ABLE) == 0
         || (INQ_DATA_TQ_ENABLED(inq_data)) == 0
         || (device->queue_flags & SCP_QUEUE_DQUE) != 0
         || (device->mintags == 0)) {
                /*
                 * Can't tag on hardware that doesn't support tags,
                 * doesn't have it enabled, or has broken tag support.
                 */
                scsi->flags &= ~CTS_SCSI_FLAGS_TAG_ENB;
        }

        if (async_update == FALSE) {
                /*
                 * Perform sanity checking against what the
                 * controller and device can do.
                 */
                xpt_setup_ccb(&cur_cts.ccb_h, cts->ccb_h.path, CAM_PRIORITY_NONE);
                cur_cts.ccb_h.func_code = XPT_GET_TRAN_SETTINGS;
                cur_cts.type = cts->type;
                xpt_action((union ccb *)&cur_cts);
                if ((cur_cts.ccb_h.status & CAM_STATUS_MASK) != CAM_REQ_CMP) {
                        return;
                }
                cur_scsi = &cur_cts.proto_specific.scsi;
                if ((scsi->valid & CTS_SCSI_VALID_TQ) == 0) {
                        scsi->flags &= ~CTS_SCSI_FLAGS_TAG_ENB;
                        scsi->flags |= cur_scsi->flags & CTS_SCSI_FLAGS_TAG_ENB;
                }
                if ((cur_scsi->valid & CTS_SCSI_VALID_TQ) == 0)
                        scsi->flags &= ~CTS_SCSI_FLAGS_TAG_ENB;
        }

        /* SPI specific sanity checking */
        if (cts->transport == XPORT_SPI && async_update == FALSE) {
                u_int spi3caps;
                struct ccb_trans_settings_spi *spi;
                struct ccb_trans_settings_spi *cur_spi;

                spi = &cts->xport_specific.spi;

                cur_spi = &cur_cts.xport_specific.spi;

                /* Fill in any gaps in what the user gave us */
                if ((spi->valid & CTS_SPI_VALID_SYNC_RATE) == 0)
                        spi->sync_period = cur_spi->sync_period;
                if ((cur_spi->valid & CTS_SPI_VALID_SYNC_RATE) == 0)
                        spi->sync_period = 0;
                if ((spi->valid & CTS_SPI_VALID_SYNC_OFFSET) == 0)
                        spi->sync_offset = cur_spi->sync_offset;
                if ((cur_spi->valid & CTS_SPI_VALID_SYNC_OFFSET) == 0)
                        spi->sync_offset = 0;
                if ((spi->valid & CTS_SPI_VALID_PPR_OPTIONS) == 0)
                        spi->ppr_options = cur_spi->ppr_options;
                if ((cur_spi->valid & CTS_SPI_VALID_PPR_OPTIONS) == 0)
                        spi->ppr_options = 0;
                if ((spi->valid & CTS_SPI_VALID_BUS_WIDTH) == 0)
                        spi->bus_width = cur_spi->bus_width;
                if ((cur_spi->valid & CTS_SPI_VALID_BUS_WIDTH) == 0)
                        spi->bus_width = 0;
                if ((spi->valid & CTS_SPI_VALID_DISC) == 0) {
                        spi->flags &= ~CTS_SPI_FLAGS_DISC_ENB;
                        spi->flags |= cur_spi->flags & CTS_SPI_FLAGS_DISC_ENB;
                }
                if ((cur_spi->valid & CTS_SPI_VALID_DISC) == 0)
                        spi->flags &= ~CTS_SPI_FLAGS_DISC_ENB;
                if (((device->flags & CAM_DEV_INQUIRY_DATA_VALID) != 0
                  && (inq_data->flags & SID_Sync) == 0
                  && cts->type == CTS_TYPE_CURRENT_SETTINGS)
                 || ((cpi.hba_inquiry & PI_SDTR_ABLE) == 0)) {
                        /* Force async */
                        spi->sync_period = 0;
                        spi->sync_offset = 0;
                }

                switch (spi->bus_width) {
                case MSG_EXT_WDTR_BUS_32_BIT:
                        if (((device->flags & CAM_DEV_INQUIRY_DATA_VALID) == 0
                          || (inq_data->flags & SID_WBus32) != 0
                          || cts->type == CTS_TYPE_USER_SETTINGS)
                         && (cpi.hba_inquiry & PI_WIDE_32) != 0)
                                break;
                        /* Fall Through to 16-bit */
                case MSG_EXT_WDTR_BUS_16_BIT:
                        if (((device->flags & CAM_DEV_INQUIRY_DATA_VALID) == 0
                          || (inq_data->flags & SID_WBus16) != 0
                          || cts->type == CTS_TYPE_USER_SETTINGS)
                         && (cpi.hba_inquiry & PI_WIDE_16) != 0) {
                                spi->bus_width = MSG_EXT_WDTR_BUS_16_BIT;
                                break;
                        }
                        /* Fall Through to 8-bit */
                default: /* New bus width?? */
                case MSG_EXT_WDTR_BUS_8_BIT:
                        /* All targets can do this */
                        spi->bus_width = MSG_EXT_WDTR_BUS_8_BIT;
                        break;
                }

                spi3caps = cpi.xport_specific.spi.ppr_options;
                if ((device->flags & CAM_DEV_INQUIRY_DATA_VALID) != 0
                 && cts->type == CTS_TYPE_CURRENT_SETTINGS)
                        spi3caps &= inq_data->spi3data;

                if ((spi3caps & SID_SPI_CLOCK_DT) == 0)
                        spi->ppr_options &= ~MSG_EXT_PPR_DT_REQ;

                if ((spi3caps & SID_SPI_IUS) == 0)
                        spi->ppr_options &= ~MSG_EXT_PPR_IU_REQ;

                if ((spi3caps & SID_SPI_QAS) == 0)
                        spi->ppr_options &= ~MSG_EXT_PPR_QAS_REQ;

                /* No SPI Transfer settings are allowed unless we are wide */
                if (spi->bus_width == 0)
                        spi->ppr_options = 0;

                if ((spi->valid & CTS_SPI_VALID_DISC)
                 && ((spi->flags & CTS_SPI_FLAGS_DISC_ENB) == 0)) {
                        /*
                         * Can't tag queue without disconnection.
                         */
                        scsi->flags &= ~CTS_SCSI_FLAGS_TAG_ENB;
                        scsi->valid |= CTS_SCSI_VALID_TQ;
                }

                /*
                 * If we are currently performing tagged transactions to
                 * this device and want to change its negotiation parameters,
                 * go non-tagged for a bit to give the controller a chance to
                 * negotiate unhampered by tag messages.
                 */
                if (cts->type == CTS_TYPE_CURRENT_SETTINGS
                 && (device->inq_flags & SID_CmdQue) != 0
                 && (scsi->flags & CTS_SCSI_FLAGS_TAG_ENB) != 0
                 && (spi->flags & (CTS_SPI_VALID_SYNC_RATE|
                                   CTS_SPI_VALID_SYNC_OFFSET|
                                   CTS_SPI_VALID_BUS_WIDTH)) != 0)
                        scsi_toggle_tags(cts->ccb_h.path);
        }

        if (cts->type == CTS_TYPE_CURRENT_SETTINGS
         && (scsi->valid & CTS_SCSI_VALID_TQ) != 0) {
                int device_tagenb;

                /*
                 * If we are transitioning from tags to no-tags or
                 * vice-versa, we need to carefully freeze and restart
                 * the queue so that we don't overlap tagged and non-tagged
                 * commands.  We also temporarily stop tags if there is
                 * a change in transfer negotiation settings to allow
                 * "tag-less" negotiation.
                 */
                if ((device->flags & CAM_DEV_TAG_AFTER_COUNT) != 0
                 || (device->inq_flags & SID_CmdQue) != 0)
                        device_tagenb = TRUE;
                else
                        device_tagenb = FALSE;

                if (((scsi->flags & CTS_SCSI_FLAGS_TAG_ENB) != 0
                  && device_tagenb == FALSE)
                 || ((scsi->flags & CTS_SCSI_FLAGS_TAG_ENB) == 0
                  && device_tagenb == TRUE)) {

                        if ((scsi->flags & CTS_SCSI_FLAGS_TAG_ENB) != 0) {
                                /*
                                 * Delay change to use tags until after a
                                 * few commands have gone to this device so
                                 * the controller has time to perform transfer
                                 * negotiations without tagged messages getting
                                 * in the way.
                                 */
                                device->tag_delay_count = CAM_TAG_DELAY_COUNT;
                                device->flags |= CAM_DEV_TAG_AFTER_COUNT;
                        } else {
                                xpt_stop_tags(cts->ccb_h.path);
                        }
                }
        }
        if (async_update == FALSE)
                (*(sim->sim_action))(sim, (union ccb *)cts);
}

static void
scsi_toggle_tags(struct cam_path *path)
{
        struct cam_ed *dev;

        /*
         * Give controllers a chance to renegotiate
         * before starting tag operations.  We
         * "toggle" tagged queuing off then on
         * which causes the tag enable command delay
         * counter to come into effect.
         */
        dev = path->device;
        if ((dev->flags & CAM_DEV_TAG_AFTER_COUNT) != 0
         || ((dev->inq_flags & SID_CmdQue) != 0
          && (dev->inq_flags & (SID_Sync|SID_WBus16|SID_WBus32)) != 0)) {
                struct ccb_trans_settings cts;

                xpt_setup_ccb(&cts.ccb_h, path, CAM_PRIORITY_NONE);
                cts.protocol = PROTO_SCSI;
                cts.protocol_version = PROTO_VERSION_UNSPECIFIED;
                cts.transport = XPORT_UNSPECIFIED;
                cts.transport_version = XPORT_VERSION_UNSPECIFIED;
                cts.proto_specific.scsi.flags = 0;
                cts.proto_specific.scsi.valid = CTS_SCSI_VALID_TQ;
                scsi_set_transfer_settings(&cts, path->device,
                                          /*async_update*/TRUE);
                cts.proto_specific.scsi.flags = CTS_SCSI_FLAGS_TAG_ENB;
                scsi_set_transfer_settings(&cts, path->device,
                                          /*async_update*/TRUE);
        }
}

/*
 * Handle any per-device event notifications that require action by the XPT.
 */
static void
scsi_dev_async(u_int32_t async_code, struct cam_eb *bus, struct cam_et *target,
              struct cam_ed *device, void *async_arg)
{
        cam_status status;
        struct cam_path newpath;

        /*
         * We only need to handle events for real devices.
         */
        if (target->target_id == CAM_TARGET_WILDCARD
         || device->lun_id == CAM_LUN_WILDCARD)
                return;

        /*
         * We need our own path with wildcards expanded to
         * handle certain types of events.
         */
        if ((async_code == AC_SENT_BDR)
         || (async_code == AC_BUS_RESET)
         || (async_code == AC_INQ_CHANGED))
                status = xpt_compile_path(&newpath, NULL,
                                          bus->path_id,
                                          target->target_id,
                                          device->lun_id);
        else
                status = CAM_REQ_CMP_ERR;

        if (status == CAM_REQ_CMP) {

                /*
                 * Allow transfer negotiation to occur in a
                 * tag free environment and after settle delay.
                 */
                if (async_code == AC_SENT_BDR
                 || async_code == AC_BUS_RESET) {
                        cam_freeze_devq(&newpath); 
                        cam_release_devq(&newpath,
                                RELSIM_RELEASE_AFTER_TIMEOUT,
                                /*reduction*/0,
                                /*timeout*/scsi_delay,
                                /*getcount_only*/0);
                        scsi_toggle_tags(&newpath);
                }

                if (async_code == AC_INQ_CHANGED) {
                        /*
                         * We've sent a start unit command, or
                         * something similar to a device that
                         * may have caused its inquiry data to
                         * change. So we re-scan the device to
                         * refresh the inquiry data for it.
                         */
                        scsi_scan_lun(newpath.periph, &newpath,
                                     CAM_EXPECT_INQ_CHANGE, NULL);
                }
                xpt_release_path(&newpath);
        } else if (async_code == AC_LOST_DEVICE &&
            (device->flags & CAM_DEV_UNCONFIGURED) == 0) {
                device->flags |= CAM_DEV_UNCONFIGURED;
                xpt_release_device(device);
        } else if (async_code == AC_TRANSFER_NEG) {
                struct ccb_trans_settings *settings;

                settings = (struct ccb_trans_settings *)async_arg;
                scsi_set_transfer_settings(settings, device,
                                          /*async_update*/TRUE);
        }
}

static void
scsi_announce_periph(struct cam_periph *periph)
{
        struct  ccb_pathinq cpi;
        struct  ccb_trans_settings cts;
        struct  cam_path *path = periph->path;
        u_int   speed;
        u_int   freq;
        u_int   mb;

        mtx_assert(periph->sim->mtx, MA_OWNED);

        xpt_setup_ccb(&cts.ccb_h, path, CAM_PRIORITY_NORMAL);
        cts.ccb_h.func_code = XPT_GET_TRAN_SETTINGS;
        cts.type = CTS_TYPE_CURRENT_SETTINGS;
        xpt_action((union ccb*)&cts);
        if ((cts.ccb_h.status & CAM_STATUS_MASK) != CAM_REQ_CMP)
                return;
        /* Ask the SIM for its base transfer speed */
        xpt_setup_ccb(&cpi.ccb_h, path, CAM_PRIORITY_NORMAL);
        cpi.ccb_h.func_code = XPT_PATH_INQ;
        xpt_action((union ccb *)&cpi);
        /* Report connection speed */ 
        speed = cpi.base_transfer_speed;
        freq = 0;
        if (cts.ccb_h.status == CAM_REQ_CMP && cts.transport == XPORT_SPI) {
                struct  ccb_trans_settings_spi *spi =
                    &cts.xport_specific.spi;

                if ((spi->valid & CTS_SPI_VALID_SYNC_OFFSET) != 0
                  && spi->sync_offset != 0) {
                        freq = scsi_calc_syncsrate(spi->sync_period);
                        speed = freq;
                }
                if ((spi->valid & CTS_SPI_VALID_BUS_WIDTH) != 0)
                        speed *= (0x01 << spi->bus_width);
        }
        if (cts.ccb_h.status == CAM_REQ_CMP && cts.transport == XPORT_FC) {
                struct  ccb_trans_settings_fc *fc =
                    &cts.xport_specific.fc;

                if (fc->valid & CTS_FC_VALID_SPEED)
                        speed = fc->bitrate;
        }
        if (cts.ccb_h.status == CAM_REQ_CMP && cts.transport == XPORT_SAS) {
                struct  ccb_trans_settings_sas *sas =
                    &cts.xport_specific.sas;

                if (sas->valid & CTS_SAS_VALID_SPEED)
                        speed = sas->bitrate;
        }
        mb = speed / 1000;
        if (mb > 0)
                printf("%s%d: %d.%03dMB/s transfers",
                       periph->periph_name, periph->unit_number,
                       mb, speed % 1000);
        else
                printf("%s%d: %dKB/s transfers", periph->periph_name,
                       periph->unit_number, speed);
        /* Report additional information about SPI connections */
        if (cts.ccb_h.status == CAM_REQ_CMP && cts.transport == XPORT_SPI) {
                struct  ccb_trans_settings_spi *spi;

                spi = &cts.xport_specific.spi;
                if (freq != 0) {
                        printf(" (%d.%03dMHz%s, offset %d", freq / 1000,
                               freq % 1000,
                               (spi->ppr_options & MSG_EXT_PPR_DT_REQ) != 0
                             ? " DT" : "",
                               spi->sync_offset);
                }
                if ((spi->valid & CTS_SPI_VALID_BUS_WIDTH) != 0
                 && spi->bus_width > 0) {
                        if (freq != 0) {
                                printf(", ");
                        } else {
                                printf(" (");
                        }
                        printf("%dbit)", 8 * (0x01 << spi->bus_width));
                } else if (freq != 0) {
                        printf(")");
                }
        }
        if (cts.ccb_h.status == CAM_REQ_CMP && cts.transport == XPORT_FC) {
                struct  ccb_trans_settings_fc *fc;

                fc = &cts.xport_specific.fc;
                if (fc->valid & CTS_FC_VALID_WWNN)
                        printf(" WWNN 0x%llx", (long long) fc->wwnn);
                if (fc->valid & CTS_FC_VALID_WWPN)
                        printf(" WWPN 0x%llx", (long long) fc->wwpn);
                if (fc->valid & CTS_FC_VALID_PORT)
                        printf(" PortID 0x%x", fc->port);
        }
        printf("\n");
}