/*-
 * Common functions for CAM "type" (peripheral) drivers.
 *
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 1997, 1998 Justin T. Gibbs.
 * Copyright (c) 1997, 1998, 1999, 2000 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/param.h>
#include <sys/systm.h>
#include <sys/types.h>
#include <sys/malloc.h>
#include <sys/kernel.h>
#include <sys/bio.h>
#include <sys/conf.h>
#include <sys/devctl.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/buf.h>
#include <sys/proc.h>
#include <sys/devicestat.h>
#include <sys/sbuf.h>
#include <sys/sysctl.h>
#include <vm/vm.h>
#include <vm/vm_extern.h>

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

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

static  u_int           camperiphnextunit(struct periph_driver *p_drv,
                                          u_int newunit, bool wired,
                                          path_id_t pathid, target_id_t target,
                                          lun_id_t lun);
static  u_int           camperiphunit(struct periph_driver *p_drv,
                                      path_id_t pathid, target_id_t target,
                                      lun_id_t lun,
                                      const char *sn);
static  void            camperiphdone(struct cam_periph *periph, 
                                        union ccb *done_ccb);
static  void            camperiphfree(struct cam_periph *periph);
static int              camperiphscsistatuserror(union ccb *ccb,
                                                union ccb **orig_ccb,
                                                 cam_flags camflags,
                                                 uint32_t sense_flags,
                                                 int *openings,
                                                 uint32_t *relsim_flags,
                                                 uint32_t *timeout,
                                                 uint32_t  *action,
                                                 const char **action_string);
static  int             camperiphscsisenseerror(union ccb *ccb,
                                                union ccb **orig_ccb,
                                                cam_flags camflags,
                                                uint32_t sense_flags,
                                                int *openings,
                                                uint32_t *relsim_flags,
                                                uint32_t *timeout,
                                                uint32_t *action,
                                                const char **action_string);
static void             cam_periph_devctl_notify(union ccb *ccb);

static int nperiph_drivers;
static int initialized = 0;
struct periph_driver **periph_drivers;

static MALLOC_DEFINE(M_CAMPERIPH, "CAM periph", "CAM peripheral buffers");

static int periph_selto_delay = 1000;
TUNABLE_INT("kern.cam.periph_selto_delay", &periph_selto_delay);
static int periph_noresrc_delay = 500;
TUNABLE_INT("kern.cam.periph_noresrc_delay", &periph_noresrc_delay);
static int periph_busy_delay = 500;
TUNABLE_INT("kern.cam.periph_busy_delay", &periph_busy_delay);

static u_int periph_mapmem_thresh = 65536;
SYSCTL_UINT(_kern_cam, OID_AUTO, mapmem_thresh, CTLFLAG_RWTUN,
    &periph_mapmem_thresh, 0, "Threshold for user-space buffer mapping");

void
periphdriver_register(void *data)
{
        struct periph_driver *drv = (struct periph_driver *)data;
        struct periph_driver **newdrivers, **old;
        int ndrivers;

again:
        ndrivers = nperiph_drivers + 2;
        newdrivers = malloc(sizeof(*newdrivers) * ndrivers, M_CAMPERIPH,
                            M_WAITOK);
        xpt_lock_buses();
        if (ndrivers != nperiph_drivers + 2) {
                /*
                 * Lost race against itself; go around.
                 */
                xpt_unlock_buses();
                free(newdrivers, M_CAMPERIPH);
                goto again;
        }
        if (periph_drivers)
                bcopy(periph_drivers, newdrivers,
                      sizeof(*newdrivers) * nperiph_drivers);
        newdrivers[nperiph_drivers] = drv;
        newdrivers[nperiph_drivers + 1] = NULL;
        old = periph_drivers;
        periph_drivers = newdrivers;
        nperiph_drivers++;
        xpt_unlock_buses();
        if (old)
                free(old, M_CAMPERIPH);
        /* If driver marked as early or it is late now, initialize it. */
        if (((drv->flags & CAM_PERIPH_DRV_EARLY) != 0 && initialized > 0) ||
            initialized > 1)
                (*drv->init)();
}

int
periphdriver_unregister(void *data)
{
        struct periph_driver *drv = (struct periph_driver *)data;
        int error, n;

        /* If driver marked as early or it is late now, deinitialize it. */
        if (((drv->flags & CAM_PERIPH_DRV_EARLY) != 0 && initialized > 0) ||
            initialized > 1) {
                if (drv->deinit == NULL) {
                        printf("CAM periph driver '%s' doesn't have deinit.\n",
                            drv->driver_name);
                        return (EOPNOTSUPP);
                }
                error = drv->deinit();
                if (error != 0)
                        return (error);
        }

        xpt_lock_buses();
        for (n = 0; n < nperiph_drivers && periph_drivers[n] != drv; n++)
                ;
        KASSERT(n < nperiph_drivers,
            ("Periph driver '%s' was not registered", drv->driver_name));
        for (; n + 1 < nperiph_drivers; n++)
                periph_drivers[n] = periph_drivers[n + 1];
        periph_drivers[n + 1] = NULL;
        nperiph_drivers--;
        xpt_unlock_buses();
        return (0);
}

void
periphdriver_init(int level)
{
        int     i, early;

        initialized = max(initialized, level);
        for (i = 0; periph_drivers[i] != NULL; i++) {
                early = (periph_drivers[i]->flags & CAM_PERIPH_DRV_EARLY) ? 1 : 2;
                if (early == initialized)
                        (*periph_drivers[i]->init)();
        }
}

cam_status
cam_periph_alloc(periph_ctor_t *periph_ctor,
                 periph_oninv_t *periph_oninvalidate,
                 periph_dtor_t *periph_dtor, periph_start_t *periph_start,
                 char *name, cam_periph_type type, struct cam_path *path,
                 ac_callback_t *ac_callback, ac_code code, void *arg)
{
        struct          periph_driver **p_drv;
        struct          cam_sim *sim;
        struct          cam_periph *periph;
        struct          cam_periph *cur_periph;
        path_id_t       path_id;
        target_id_t     target_id;
        lun_id_t        lun_id;
        cam_status      status;
        u_int           init_level;

        init_level = 0;
        /*
         * Handle Hot-Plug scenarios.  If there is already a peripheral
         * of our type assigned to this path, we are likely waiting for
         * final close on an old, invalidated, peripheral.  If this is
         * the case, queue up a deferred call to the peripheral's async
         * handler.  If it looks like a mistaken re-allocation, complain.
         */
        if ((periph = cam_periph_find(path, name)) != NULL) {
                if ((periph->flags & CAM_PERIPH_INVALID) != 0
                 && (periph->flags & CAM_PERIPH_NEW_DEV_FOUND) == 0) {
                        periph->flags |= CAM_PERIPH_NEW_DEV_FOUND;
                        periph->deferred_callback = ac_callback;
                        periph->deferred_ac = code;
                        return (CAM_REQ_INPROG);
                } else {
                        printf("cam_periph_alloc: attempt to re-allocate "
                               "valid device %s%d rejected flags %#x "
                               "refcount %d\n", periph->periph_name,
                               periph->unit_number, periph->flags,
                               periph->refcount);
                }
                return (CAM_REQ_INVALID);
        }

        periph = (struct cam_periph *)malloc(sizeof(*periph), M_CAMPERIPH,
                                             M_NOWAIT|M_ZERO);

        if (periph == NULL)
                return (CAM_RESRC_UNAVAIL);

        init_level++;

        sim = xpt_path_sim(path);
        path_id = xpt_path_path_id(path);
        target_id = xpt_path_target_id(path);
        lun_id = xpt_path_lun_id(path);
        periph->periph_start = periph_start;
        periph->periph_dtor = periph_dtor;
        periph->periph_oninval = periph_oninvalidate;
        periph->type = type;
        periph->periph_name = name;
        periph->scheduled_priority = CAM_PRIORITY_NONE;
        periph->immediate_priority = CAM_PRIORITY_NONE;
        periph->refcount = 1;           /* Dropped by invalidation. */
        periph->sim = sim;
        SLIST_INIT(&periph->ccb_list);
        status = xpt_create_path(&path, periph, path_id, target_id, lun_id);
        if (status != CAM_REQ_CMP)
                goto failure;
        periph->path = path;

        xpt_lock_buses();
        for (p_drv = periph_drivers; *p_drv != NULL; p_drv++) {
                if (strcmp((*p_drv)->driver_name, name) == 0)
                        break;
        }
        if (*p_drv == NULL) {
                printf("cam_periph_alloc: invalid periph name '%s'\n", name);
                xpt_unlock_buses();
                xpt_free_path(periph->path);
                free(periph, M_CAMPERIPH);
                return (CAM_REQ_INVALID);
        }
        periph->unit_number = camperiphunit(*p_drv, path_id, target_id, lun_id,
            path->device->serial_num);
        cur_periph = TAILQ_FIRST(&(*p_drv)->units);
        while (cur_periph != NULL
            && cur_periph->unit_number < periph->unit_number)
                cur_periph = TAILQ_NEXT(cur_periph, unit_links);
        if (cur_periph != NULL) {
                KASSERT(cur_periph->unit_number != periph->unit_number,
                    ("duplicate units on periph list"));
                TAILQ_INSERT_BEFORE(cur_periph, periph, unit_links);
        } else {
                TAILQ_INSERT_TAIL(&(*p_drv)->units, periph, unit_links);
                (*p_drv)->generation++;
        }
        xpt_unlock_buses();

        init_level++;

        status = xpt_add_periph(periph);
        if (status != CAM_REQ_CMP)
                goto failure;

        init_level++;
        CAM_DEBUG(periph->path, CAM_DEBUG_INFO, ("Periph created\n"));

        status = periph_ctor(periph, arg);

        if (status == CAM_REQ_CMP)
                init_level++;

failure:
        switch (init_level) {
        case 4:
                /* Initialized successfully */
                break;
        case 3:
                CAM_DEBUG(periph->path, CAM_DEBUG_INFO, ("Periph destroyed\n"));
                xpt_remove_periph(periph);
                /* FALLTHROUGH */
        case 2:
                xpt_lock_buses();
                TAILQ_REMOVE(&(*p_drv)->units, periph, unit_links);
                xpt_unlock_buses();
                xpt_free_path(periph->path);
                /* FALLTHROUGH */
        case 1:
                free(periph, M_CAMPERIPH);
                /* FALLTHROUGH */
        case 0:
                /* No cleanup to perform. */
                break;
        default:
                panic("%s: Unknown init level", __func__);
        }
        return(status);
}

/*
 * Find a peripheral structure with the specified path, target, lun, 
 * and (optionally) type.  If the name is NULL, this function will return
 * the first peripheral driver that matches the specified path.
 */
struct cam_periph *
cam_periph_find(struct cam_path *path, char *name)
{
        struct periph_driver **p_drv;
        struct cam_periph *periph;

        xpt_lock_buses();
        for (p_drv = periph_drivers; *p_drv != NULL; p_drv++) {
                if (name != NULL && (strcmp((*p_drv)->driver_name, name) != 0))
                        continue;

                TAILQ_FOREACH(periph, &(*p_drv)->units, unit_links) {
                        if (xpt_path_comp(periph->path, path) == 0) {
                                xpt_unlock_buses();
                                cam_periph_assert(periph, MA_OWNED);
                                return(periph);
                        }
                }
                if (name != NULL) {
                        xpt_unlock_buses();
                        return(NULL);
                }
        }
        xpt_unlock_buses();
        return(NULL);
}

/*
 * Find peripheral driver instances attached to the specified path.
 */
int
cam_periph_list(struct cam_path *path, struct sbuf *sb)
{
        struct sbuf local_sb;
        struct periph_driver **p_drv;
        struct cam_periph *periph;
        int count;
        int sbuf_alloc_len;

        sbuf_alloc_len = 16;
retry:
        sbuf_new(&local_sb, NULL, sbuf_alloc_len, SBUF_FIXEDLEN);
        count = 0;
        xpt_lock_buses();
        for (p_drv = periph_drivers; *p_drv != NULL; p_drv++) {
                TAILQ_FOREACH(periph, &(*p_drv)->units, unit_links) {
                        if (xpt_path_comp(periph->path, path) != 0)
                                continue;

                        if (sbuf_len(&local_sb) != 0)
                                sbuf_cat(&local_sb, ",");

                        sbuf_printf(&local_sb, "%s%d", periph->periph_name,
                                    periph->unit_number);

                        if (sbuf_error(&local_sb) == ENOMEM) {
                                sbuf_alloc_len *= 2;
                                xpt_unlock_buses();
                                sbuf_delete(&local_sb);
                                goto retry;
                        }
                        count++;
                }
        }
        xpt_unlock_buses();
        sbuf_finish(&local_sb);
        if (sbuf_len(sb) != 0)
                sbuf_cat(sb, ",");
        sbuf_cat(sb, sbuf_data(&local_sb));
        sbuf_delete(&local_sb);
        return (count);
}

int
cam_periph_acquire(struct cam_periph *periph)
{
        int status;

        if (periph == NULL)
                return (EINVAL);

        status = ENOENT;
        xpt_lock_buses();
        if ((periph->flags & CAM_PERIPH_INVALID) == 0) {
                periph->refcount++;
                status = 0;
        }
        xpt_unlock_buses();

        return (status);
}

void
cam_periph_doacquire(struct cam_periph *periph)
{

        xpt_lock_buses();
        KASSERT(periph->refcount >= 1,
            ("cam_periph_doacquire() with refcount == %d", periph->refcount));
        periph->refcount++;
        xpt_unlock_buses();
}

void
cam_periph_release_locked_buses(struct cam_periph *periph)
{

        cam_periph_assert(periph, MA_OWNED);
        KASSERT(periph->refcount >= 1, ("periph->refcount >= 1"));
        if (--periph->refcount == 0)
                camperiphfree(periph);
}

void
cam_periph_release_locked(struct cam_periph *periph)
{

        if (periph == NULL)
                return;

        xpt_lock_buses();
        cam_periph_release_locked_buses(periph);
        xpt_unlock_buses();
}

void
cam_periph_release(struct cam_periph *periph)
{
        struct mtx *mtx;

        if (periph == NULL)
                return;

        cam_periph_assert(periph, MA_NOTOWNED);
        mtx = cam_periph_mtx(periph);
        mtx_lock(mtx);
        cam_periph_release_locked(periph);
        mtx_unlock(mtx);
}

/*
 * hold/unhold act as mutual exclusion for sections of the code that
 * need to sleep and want to make sure that other sections that
 * will interfere are held off. This only protects exclusive sections
 * from each other.
 */
int
cam_periph_hold(struct cam_periph *periph, int priority)
{
        int error;

        /*
         * Increment the reference count on the peripheral
         * while we wait for our lock attempt to succeed
         * to ensure the peripheral doesn't disappear out
         * from user us while we sleep.
         */

        if (cam_periph_acquire(periph) != 0)
                return (ENXIO);

        cam_periph_assert(periph, MA_OWNED);
        while ((periph->flags & CAM_PERIPH_LOCKED) != 0) {
                periph->flags |= CAM_PERIPH_LOCK_WANTED;
                if ((error = cam_periph_sleep(periph, periph, priority,
                    "caplck", 0)) != 0) {
                        cam_periph_release_locked(periph);
                        return (error);
                }
                if (periph->flags & CAM_PERIPH_INVALID) {
                        cam_periph_release_locked(periph);
                        return (ENXIO);
                }
        }

        periph->flags |= CAM_PERIPH_LOCKED;
        return (0);
}

void
cam_periph_unhold(struct cam_periph *periph)
{

        cam_periph_assert(periph, MA_OWNED);

        periph->flags &= ~CAM_PERIPH_LOCKED;
        if ((periph->flags & CAM_PERIPH_LOCK_WANTED) != 0) {
                periph->flags &= ~CAM_PERIPH_LOCK_WANTED;
                wakeup(periph);
        }

        cam_periph_release_locked(periph);
}

void
cam_periph_hold_boot(struct cam_periph *periph)
{

        root_mount_hold_token(periph->periph_name, &periph->periph_rootmount);
}

void
cam_periph_release_boot(struct cam_periph *periph)
{

        root_mount_rel(&periph->periph_rootmount);
}

/*
 * Look for the next unit number that is not currently in use for this
 * peripheral type starting at "newunit".  Also exclude unit numbers that
 * are reserved by for future "hardwiring" unless we already know that this
 * is a potential wired device.  Only assume that the device is "wired" the
 * first time through the loop since after that we'll be looking at unit
 * numbers that did not match a wiring entry.
 */
static u_int
camperiphnextunit(struct periph_driver *p_drv, u_int newunit, bool wired,
                  path_id_t pathid, target_id_t target, lun_id_t lun)
{
        struct  cam_periph *periph;
        char    *periph_name;
        int     i, val, dunit, r;
        const char *dname, *strval;

        periph_name = p_drv->driver_name;
        for (;;newunit++) {
                for (periph = TAILQ_FIRST(&p_drv->units);
                     periph != NULL && periph->unit_number != newunit;
                     periph = TAILQ_NEXT(periph, unit_links))
                        ;

                if (periph != NULL && periph->unit_number == newunit) {
                        if (wired) {
                                xpt_print(periph->path, "Duplicate Wired "
                                    "Device entry!\n");
                                xpt_print(periph->path, "Second device (%s "
                                    "device at scbus%d target %d lun %d) will "
                                    "not be wired\n", periph_name, pathid,
                                    target, lun);
                                wired = false;
                        }
                        continue;
                }
                if (wired)
                        break;

                /*
                 * Don't allow the mere presence of any attributes of a device
                 * means that it is for a wired down entry. Instead, insist that
                 * one of the matching criteria from camperiphunit be present
                 * for the device.
                 */
                i = 0;
                dname = periph_name;
                for (;;) {
                        r = resource_find_dev(&i, dname, &dunit, NULL, NULL);
                        if (r != 0)
                                break;

                        if (newunit != dunit)
                                continue;
                        if (resource_string_value(dname, dunit, "sn", &strval) == 0 ||
                            resource_int_value(dname, dunit, "lun", &val) == 0 ||
                            resource_int_value(dname, dunit, "target", &val) == 0 ||
                            resource_string_value(dname, dunit, "at", &strval) == 0)
                                break;
                }
                if (r != 0)
                        break;
        }
        return (newunit);
}

static u_int
camperiphunit(struct periph_driver *p_drv, path_id_t pathid,
    target_id_t target, lun_id_t lun, const char *sn)
{
        bool    wired = false;
        u_int   unit;
        int     i, val, dunit;
        const char *dname, *strval;
        char    pathbuf[32], *periph_name;

        periph_name = p_drv->driver_name;
        snprintf(pathbuf, sizeof(pathbuf), "scbus%d", pathid);
        unit = 0;
        i = 0;
        dname = periph_name;

        for (wired = false; resource_find_dev(&i, dname, &dunit, NULL, NULL) == 0;
             wired = false) {
                if (resource_string_value(dname, dunit, "at", &strval) == 0) {
                        if (strcmp(strval, pathbuf) != 0)
                                continue;
                        wired = true;
                }
                if (resource_int_value(dname, dunit, "target", &val) == 0) {
                        if (val != target)
                                continue;
                        wired = true;
                }
                if (resource_int_value(dname, dunit, "lun", &val) == 0) {
                        if (val != lun)
                                continue;
                        wired = true;
                }
                if (resource_string_value(dname, dunit, "sn", &strval) == 0) {
                        if (sn == NULL || strcmp(strval, sn) != 0)
                                continue;
                        wired = true;
                }
                if (wired) {
                        unit = dunit;
                        break;
                }
        }

        /*
         * Either start from 0 looking for the next unit or from
         * the unit number given in the resource config.  This way,
         * if we have wildcard matches, we don't return the same
         * unit number twice.
         */
        unit = camperiphnextunit(p_drv, unit, wired, pathid, target, lun);

        return (unit);
}

void
cam_periph_invalidate(struct cam_periph *periph)
{

        cam_periph_assert(periph, MA_OWNED);
        /*
         * We only tear down the device the first time a peripheral is
         * invalidated.
         */
        if ((periph->flags & CAM_PERIPH_INVALID) != 0)
                return;

        CAM_DEBUG(periph->path, CAM_DEBUG_INFO, ("Periph invalidated\n"));
        if ((periph->flags & CAM_PERIPH_ANNOUNCED) && !rebooting) {
                struct sbuf sb;
                char buffer[160];

                sbuf_new(&sb, buffer, 160, SBUF_FIXEDLEN);
                xpt_denounce_periph_sbuf(periph, &sb);
                sbuf_finish(&sb);
                sbuf_putbuf(&sb);
        }
        periph->flags |= CAM_PERIPH_INVALID;
        periph->flags &= ~CAM_PERIPH_NEW_DEV_FOUND;
        if (periph->periph_oninval != NULL)
                periph->periph_oninval(periph);
        cam_periph_release_locked(periph);
}

static void
camperiphfree(struct cam_periph *periph)
{
        struct periph_driver **p_drv;
        struct periph_driver *drv;

        cam_periph_assert(periph, MA_OWNED);
        KASSERT(periph->periph_allocating == 0, ("%s%d: freed while allocating",
            periph->periph_name, periph->unit_number));
        for (p_drv = periph_drivers; *p_drv != NULL; p_drv++) {
                if (strcmp((*p_drv)->driver_name, periph->periph_name) == 0)
                        break;
        }
        if (*p_drv == NULL) {
                printf("camperiphfree: attempt to free non-existant periph\n");
                return;
        }
        /*
         * Cache a pointer to the periph_driver structure.  If a
         * periph_driver is added or removed from the array (see
         * periphdriver_register()) while we drop the toplogy lock
         * below, p_drv may change.  This doesn't protect against this
         * particular periph_driver going away.  That will require full
         * reference counting in the periph_driver infrastructure.
         */
        drv = *p_drv;

        /*
         * We need to set this flag before dropping the topology lock, to
         * let anyone who is traversing the list that this peripheral is
         * about to be freed, and there will be no more reference count
         * checks.
         */
        periph->flags |= CAM_PERIPH_FREE;

        /*
         * The peripheral destructor semantics dictate calling with only the
         * SIM mutex held.  Since it might sleep, it should not be called
         * with the topology lock held.
         */
        xpt_unlock_buses();

        /*
         * We need to call the peripheral destructor prior to removing the
         * peripheral from the list.  Otherwise, we risk running into a
         * scenario where the peripheral unit number may get reused
         * (because it has been removed from the list), but some resources
         * used by the peripheral are still hanging around.  In particular,
         * the devfs nodes used by some peripherals like the pass(4) driver
         * aren't fully cleaned up until the destructor is run.  If the
         * unit number is reused before the devfs instance is fully gone,
         * devfs will panic.
         */
        if (periph->periph_dtor != NULL)
                periph->periph_dtor(periph);

        /*
         * The peripheral list is protected by the topology lock. We have to
         * remove the periph from the drv list before we call deferred_ac. The
         * AC_FOUND_DEVICE callback won't create a new periph if it's still there.
         */
        xpt_lock_buses();

        TAILQ_REMOVE(&drv->units, periph, unit_links);
        drv->generation++;

        xpt_remove_periph(periph);

        xpt_unlock_buses();
        if ((periph->flags & CAM_PERIPH_ANNOUNCED) && !rebooting)
                xpt_print(periph->path, "Periph destroyed\n");
        else
                CAM_DEBUG(periph->path, CAM_DEBUG_INFO, ("Periph destroyed\n"));

        if (periph->flags & CAM_PERIPH_NEW_DEV_FOUND) {
                switch (periph->deferred_ac) {
                case AC_FOUND_DEVICE: {
                        struct ccb_getdev cgd;

                        xpt_gdev_type(&cgd, periph->path);
                        periph->deferred_callback(NULL, periph->deferred_ac,
                            periph->path, &cgd);
                        break;
                }
                case AC_PATH_REGISTERED: {
                        struct ccb_pathinq cpi;

                        xpt_path_inq(&cpi, periph->path);
                        periph->deferred_callback(NULL, periph->deferred_ac,
                            periph->path, &cpi);
                        break;
                }
                default:
                        periph->deferred_callback(NULL, periph->deferred_ac,
                            periph->path, NULL);
                        break;
                }
        }
        xpt_free_path(periph->path);
        free(periph, M_CAMPERIPH);
        xpt_lock_buses();
}

/*
 * Map user virtual pointers into kernel virtual address space, so we can
 * access the memory.  This is now a generic function that centralizes most
 * of the sanity checks on the data flags, if any.
 * This also only works for up to maxphys memory.  Since we use
 * buffers to map stuff in and out, we're limited to the buffer size.
 */
int
cam_periph_mapmem(union ccb *ccb, struct cam_periph_map_info *mapinfo,
    u_int maxmap)
{
        int numbufs, i;
        uint8_t **data_ptrs[CAM_PERIPH_MAXMAPS];
        uint32_t lengths[CAM_PERIPH_MAXMAPS];
        uint32_t dirs[CAM_PERIPH_MAXMAPS];

        bzero(mapinfo, sizeof(*mapinfo));
        if (maxmap == 0)
                maxmap = DFLTPHYS;      /* traditional default */
        else if (maxmap > maxphys)
                maxmap = maxphys;       /* for safety */
        switch(ccb->ccb_h.func_code) {
        case XPT_DEV_MATCH:
                if (ccb->cdm.match_buf_len == 0) {
                        printf("cam_periph_mapmem: invalid match buffer "
                               "length 0\n");
                        return(EINVAL);
                }
                if (ccb->cdm.pattern_buf_len > 0) {
                        data_ptrs[0] = (uint8_t **)&ccb->cdm.patterns;
                        lengths[0] = ccb->cdm.pattern_buf_len;
                        dirs[0] = CAM_DIR_OUT;
                        data_ptrs[1] = (uint8_t **)&ccb->cdm.matches;
                        lengths[1] = ccb->cdm.match_buf_len;
                        dirs[1] = CAM_DIR_IN;
                        numbufs = 2;
                } else {
                        data_ptrs[0] = (uint8_t **)&ccb->cdm.matches;
                        lengths[0] = ccb->cdm.match_buf_len;
                        dirs[0] = CAM_DIR_IN;
                        numbufs = 1;
                }
                /*
                 * This request will not go to the hardware, no reason
                 * to be so strict. vmapbuf() is able to map up to maxphys.
                 */
                maxmap = maxphys;
                break;
        case XPT_SCSI_IO:
        case XPT_CONT_TARGET_IO:
                if ((ccb->ccb_h.flags & CAM_DIR_MASK) == CAM_DIR_NONE)
                        return(0);
                if ((ccb->ccb_h.flags & CAM_DATA_MASK) != CAM_DATA_VADDR)
                        return (EINVAL);
                data_ptrs[0] = &ccb->csio.data_ptr;
                lengths[0] = ccb->csio.dxfer_len;
                dirs[0] = ccb->ccb_h.flags & CAM_DIR_MASK;
                numbufs = 1;
                break;
        case XPT_ATA_IO:
                if ((ccb->ccb_h.flags & CAM_DIR_MASK) == CAM_DIR_NONE)
                        return(0);
                if ((ccb->ccb_h.flags & CAM_DATA_MASK) != CAM_DATA_VADDR)
                        return (EINVAL);
                data_ptrs[0] = &ccb->ataio.data_ptr;
                lengths[0] = ccb->ataio.dxfer_len;
                dirs[0] = ccb->ccb_h.flags & CAM_DIR_MASK;
                numbufs = 1;
                break;
        case XPT_MMC_IO:
                if ((ccb->ccb_h.flags & CAM_DIR_MASK) == CAM_DIR_NONE)
                        return(0);
                /* Two mappings: one for cmd->data and one for cmd->data->data */
                data_ptrs[0] = (unsigned char **)&ccb->mmcio.cmd.data;
                lengths[0] = sizeof(struct mmc_data *);
                dirs[0] = ccb->ccb_h.flags & CAM_DIR_MASK;
                data_ptrs[1] = (unsigned char **)&ccb->mmcio.cmd.data->data;
                lengths[1] = ccb->mmcio.cmd.data->len;
                dirs[1] = ccb->ccb_h.flags & CAM_DIR_MASK;
                numbufs = 2;
                break;
        case XPT_SMP_IO:
                data_ptrs[0] = &ccb->smpio.smp_request;
                lengths[0] = ccb->smpio.smp_request_len;
                dirs[0] = CAM_DIR_OUT;
                data_ptrs[1] = &ccb->smpio.smp_response;
                lengths[1] = ccb->smpio.smp_response_len;
                dirs[1] = CAM_DIR_IN;
                numbufs = 2;
                break;
        case XPT_NVME_IO:
        case XPT_NVME_ADMIN:
                if ((ccb->ccb_h.flags & CAM_DIR_MASK) == CAM_DIR_NONE)
                        return (0);
                if ((ccb->ccb_h.flags & CAM_DATA_MASK) != CAM_DATA_VADDR)
                        return (EINVAL);
                data_ptrs[0] = &ccb->nvmeio.data_ptr;
                lengths[0] = ccb->nvmeio.dxfer_len;
                dirs[0] = ccb->ccb_h.flags & CAM_DIR_MASK;
                numbufs = 1;
                break;
        case XPT_DEV_ADVINFO:
                if (ccb->cdai.bufsiz == 0)
                        return (0);

                data_ptrs[0] = (uint8_t **)&ccb->cdai.buf;
                lengths[0] = ccb->cdai.bufsiz;
                dirs[0] = CAM_DIR_IN;
                numbufs = 1;

                /*
                 * This request will not go to the hardware, no reason
                 * to be so strict. vmapbuf() is able to map up to maxphys.
                 */
                maxmap = maxphys;
                break;
        default:
                return(EINVAL);
                break; /* NOTREACHED */
        }

        /*
         * Check the transfer length and permissions first, so we don't
         * have to unmap any previously mapped buffers.
         */
        for (i = 0; i < numbufs; i++) {
                if (lengths[i] > maxmap) {
                        printf("cam_periph_mapmem: attempt to map %lu bytes, "
                               "which is greater than %lu\n",
                               (long)(lengths[i]), (u_long)maxmap);
                        return (E2BIG);
                }
        }

        for (i = 0; i < numbufs; i++) {
                /* Save the user's data address. */
                mapinfo->orig[i] = *data_ptrs[i];

                /*
                 * For small buffers use malloc+copyin/copyout instead of
                 * mapping to KVA to avoid expensive TLB shootdowns.  For
                 * small allocations malloc is backed by UMA, and so much
                 * cheaper on SMP systems.
                 */
                if (lengths[i] <= periph_mapmem_thresh &&
                    ccb->ccb_h.func_code != XPT_MMC_IO) {
                        *data_ptrs[i] = malloc(lengths[i], M_CAMPERIPH,
                            M_WAITOK);
                        if (dirs[i] != CAM_DIR_IN) {
                                if (copyin(mapinfo->orig[i], *data_ptrs[i],
                                    lengths[i]) != 0) {
                                        free(*data_ptrs[i], M_CAMPERIPH);
                                        *data_ptrs[i] = mapinfo->orig[i];
                                        goto fail;
                                }
                        } else
                                bzero(*data_ptrs[i], lengths[i]);
                        continue;
                }

                /*
                 * Get the buffer.
                 */
                mapinfo->bp[i] = uma_zalloc(pbuf_zone, M_WAITOK);

                /* set the direction */
                mapinfo->bp[i]->b_iocmd = (dirs[i] == CAM_DIR_OUT) ?
                    BIO_WRITE : BIO_READ;

                /* Map the buffer into kernel memory. */
                if (vmapbuf(mapinfo->bp[i], *data_ptrs[i], lengths[i], 1) < 0) {
                        uma_zfree(pbuf_zone, mapinfo->bp[i]);
                        goto fail;
                }

                /* set our pointer to the new mapped area */
                *data_ptrs[i] = mapinfo->bp[i]->b_data;
        }

        /*
         * Now that we've gotten this far, change ownership to the kernel
         * of the buffers so that we don't run afoul of returning to user
         * space with locks (on the buffer) held.
         */
        for (i = 0; i < numbufs; i++) {
                if (mapinfo->bp[i])
                        BUF_KERNPROC(mapinfo->bp[i]);
        }

        mapinfo->num_bufs_used = numbufs;
        return(0);

fail:
        for (i--; i >= 0; i--) {
                if (mapinfo->bp[i]) {
                        vunmapbuf(mapinfo->bp[i]);
                        uma_zfree(pbuf_zone, mapinfo->bp[i]);
                } else
                        free(*data_ptrs[i], M_CAMPERIPH);
                *data_ptrs[i] = mapinfo->orig[i];
        }
        return(EACCES);
}

/*
 * Unmap memory segments mapped into kernel virtual address space by
 * cam_periph_mapmem().
 */
int
cam_periph_unmapmem(union ccb *ccb, struct cam_periph_map_info *mapinfo)
{
        int error, numbufs, i;
        uint8_t **data_ptrs[CAM_PERIPH_MAXMAPS];
        uint32_t lengths[CAM_PERIPH_MAXMAPS];
        uint32_t dirs[CAM_PERIPH_MAXMAPS];

        if (mapinfo->num_bufs_used <= 0) {
                /* nothing to free and the process wasn't held. */
                return (0);
        }

        switch (ccb->ccb_h.func_code) {
        case XPT_DEV_MATCH:
                if (ccb->cdm.pattern_buf_len > 0) {
                        data_ptrs[0] = (uint8_t **)&ccb->cdm.patterns;
                        lengths[0] = ccb->cdm.pattern_buf_len;
                        dirs[0] = CAM_DIR_OUT;
                        data_ptrs[1] = (uint8_t **)&ccb->cdm.matches;
                        lengths[1] = ccb->cdm.match_buf_len;
                        dirs[1] = CAM_DIR_IN;
                        numbufs = 2;
                } else {
                        data_ptrs[0] = (uint8_t **)&ccb->cdm.matches;
                        lengths[0] = ccb->cdm.match_buf_len;
                        dirs[0] = CAM_DIR_IN;
                        numbufs = 1;
                }
                break;
        case XPT_SCSI_IO:
        case XPT_CONT_TARGET_IO:
                data_ptrs[0] = &ccb->csio.data_ptr;
                lengths[0] = ccb->csio.dxfer_len;
                dirs[0] = ccb->ccb_h.flags & CAM_DIR_MASK;
                numbufs = 1;
                break;
        case XPT_ATA_IO:
                data_ptrs[0] = &ccb->ataio.data_ptr;
                lengths[0] = ccb->ataio.dxfer_len;
                dirs[0] = ccb->ccb_h.flags & CAM_DIR_MASK;
                numbufs = 1;
                break;
        case XPT_MMC_IO:
                data_ptrs[0] = (uint8_t **)&ccb->mmcio.cmd.data;
                lengths[0] = sizeof(struct mmc_data *);
                dirs[0] = ccb->ccb_h.flags & CAM_DIR_MASK;
                data_ptrs[1] = (uint8_t **)&ccb->mmcio.cmd.data->data;
                lengths[1] = ccb->mmcio.cmd.data->len;
                dirs[1] = ccb->ccb_h.flags & CAM_DIR_MASK;
                numbufs = 2;
                break;
        case XPT_SMP_IO:
                data_ptrs[0] = &ccb->smpio.smp_request;
                lengths[0] = ccb->smpio.smp_request_len;
                dirs[0] = CAM_DIR_OUT;
                data_ptrs[1] = &ccb->smpio.smp_response;
                lengths[1] = ccb->smpio.smp_response_len;
                dirs[1] = CAM_DIR_IN;
                numbufs = 2;
                break;
        case XPT_NVME_IO:
        case XPT_NVME_ADMIN:
                data_ptrs[0] = &ccb->nvmeio.data_ptr;
                lengths[0] = ccb->nvmeio.dxfer_len;
                dirs[0] = ccb->ccb_h.flags & CAM_DIR_MASK;
                numbufs = 1;
                break;
        case XPT_DEV_ADVINFO:
                data_ptrs[0] = (uint8_t **)&ccb->cdai.buf;
                lengths[0] = ccb->cdai.bufsiz;
                dirs[0] = CAM_DIR_IN;
                numbufs = 1;
                break;
        default:
                numbufs = 0;
                break;
        }

        error = 0;
        for (i = 0; i < numbufs; i++) {
                if (mapinfo->bp[i]) {
                        /* unmap the buffer */
                        vunmapbuf(mapinfo->bp[i]);

                        /* release the buffer */
                        uma_zfree(pbuf_zone, mapinfo->bp[i]);
                } else {
                        if (dirs[i] != CAM_DIR_OUT) {
                                int error1;

                                error1 = copyout(*data_ptrs[i], mapinfo->orig[i],
                                    lengths[i]);
                                if (error == 0)
                                        error = error1;
                        }
                        free(*data_ptrs[i], M_CAMPERIPH);
                }

                /* Set the user's pointer back to the original value */
                *data_ptrs[i] = mapinfo->orig[i];
        }

        return (error);
}

int
cam_periph_ioctl(struct cam_periph *periph, u_long cmd, caddr_t addr,
                 int (*error_routine)(union ccb *ccb, 
                                      cam_flags camflags,
                                      uint32_t sense_flags))
{
        union ccb            *ccb;
        int                  error;
        int                  found;

        error = found = 0;

        switch(cmd){
        case CAMGETPASSTHRU_0x19:
        case CAMGETPASSTHRU:
                ccb = cam_periph_getccb(periph, CAM_PRIORITY_NORMAL);
                xpt_setup_ccb(&ccb->ccb_h,
                              ccb->ccb_h.path,
                              CAM_PRIORITY_NORMAL);
                ccb->ccb_h.func_code = XPT_GDEVLIST;

                /*
                 * Basically, the point of this is that we go through
                 * getting the list of devices, until we find a passthrough
                 * device.  In the current version of the CAM code, the
                 * only way to determine what type of device we're dealing
                 * with is by its name.
                 */
                while (found == 0) {
                        ccb->cgdl.index = 0;
                        ccb->cgdl.status = CAM_GDEVLIST_MORE_DEVS;
                        while (ccb->cgdl.status == CAM_GDEVLIST_MORE_DEVS) {
                                /* we want the next device in the list */
                                xpt_action(ccb);
                                if (strncmp(ccb->cgdl.periph_name, 
                                    "pass", 4) == 0){
                                        found = 1;
                                        break;
                                }
                        }
                        if ((ccb->cgdl.status == CAM_GDEVLIST_LAST_DEVICE) &&
                            (found == 0)) {
                                ccb->cgdl.periph_name[0] = '\0';
                                ccb->cgdl.unit_number = 0;
                                break;
                        }
                }

                /* copy the result back out */  
                bcopy(ccb, addr, sizeof(union ccb));

                /* and release the ccb */
                xpt_release_ccb(ccb);

                break;
        default:
                error = ENOTTY;
                break;
        }
        return(error);
}

static void
cam_periph_done_panic(struct cam_periph *periph, union ccb *done_ccb)
{

        panic("%s: already done with ccb %p", __func__, done_ccb);
}

static void
cam_periph_done(struct cam_periph *periph, union ccb *done_ccb)
{

        /* Caller will release the CCB */
        xpt_path_assert(done_ccb->ccb_h.path, MA_OWNED);
        done_ccb->ccb_h.cbfcnp = cam_periph_done_panic;
        wakeup(&done_ccb->ccb_h.cbfcnp);
}

static void
cam_periph_ccbwait(union ccb *ccb)
{

        if ((ccb->ccb_h.func_code & XPT_FC_QUEUED) != 0) {
                while (ccb->ccb_h.cbfcnp != cam_periph_done_panic)
                        xpt_path_sleep(ccb->ccb_h.path, &ccb->ccb_h.cbfcnp,
                            PRIBIO, "cbwait", 0);
        }
        KASSERT(ccb->ccb_h.pinfo.index == CAM_UNQUEUED_INDEX &&
            (ccb->ccb_h.status & CAM_STATUS_MASK) != CAM_REQ_INPROG,
            ("%s: proceeding with incomplete ccb: ccb=%p, func_code=%#x, "
             "status=%#x, index=%d", __func__, ccb, ccb->ccb_h.func_code,
             ccb->ccb_h.status, ccb->ccb_h.pinfo.index));
}

/*
 * Dispatch a CCB and wait for it to complete.  If the CCB has set a
 * callback function (ccb->ccb_h.cbfcnp), it will be overwritten and lost.
 */
int
cam_periph_runccb(union ccb *ccb,
                  int (*error_routine)(union ccb *ccb,
                                       cam_flags camflags,
                                       uint32_t sense_flags),
                  cam_flags camflags, uint32_t sense_flags,
                  struct devstat *ds)
{
        struct bintime *starttime;
        struct bintime ltime;
        int error;
        bool must_poll;
        uint32_t timeout = 1;

        starttime = NULL;
        xpt_path_assert(ccb->ccb_h.path, MA_OWNED);
        KASSERT((ccb->ccb_h.flags & CAM_UNLOCKED) == 0,
            ("%s: ccb=%p, func_code=%#x, flags=%#x", __func__, ccb,
             ccb->ccb_h.func_code, ccb->ccb_h.flags));

        /*
         * If the user has supplied a stats structure, and if we understand
         * this particular type of ccb, record the transaction start.
         */
        if (ds != NULL &&
            (ccb->ccb_h.func_code == XPT_SCSI_IO ||
            ccb->ccb_h.func_code == XPT_ATA_IO ||
            ccb->ccb_h.func_code == XPT_NVME_IO)) {
                starttime = &ltime;
                binuptime(starttime);
                devstat_start_transaction(ds, starttime);
        }

        /*
         * We must poll the I/O while we're dumping. The scheduler is normally
         * stopped for dumping, except when we call doadump from ddb. While the
         * scheduler is running in this case, we still need to poll the I/O to
         * avoid sleeping waiting for the ccb to complete.
         *
         * A panic triggered dump stops the scheduler, any callback from the
         * shutdown_post_sync event will run with the scheduler stopped, but
         * before we're officially dumping. To avoid hanging in adashutdown
         * initiated commands (or other similar situations), we have to test for
         * either dumping or SCHEDULER_STOPPED() here.
         *
         * To avoid locking problems, dumping/polling callers must call
         * without a periph lock held.
         */
        must_poll = dumping || SCHEDULER_STOPPED();
        ccb->ccb_h.cbfcnp = cam_periph_done;

        /*
         * If we're polling, then we need to ensure that we have ample resources
         * in the periph.  cam_periph_error can reschedule the ccb by calling
         * xpt_action and returning ERESTART, so we have to effect the polling
         * in the do loop below.
         */
        if (must_poll) {
                if (cam_sim_pollable(ccb->ccb_h.path->bus->sim))
                        timeout = xpt_poll_setup(ccb);
                else
                        timeout = 0;
        }

        if (timeout == 0) {
                ccb->ccb_h.status = CAM_RESRC_UNAVAIL;
                error = EBUSY;
        } else {
                xpt_action(ccb);
                do {
                        if (must_poll) {
                                xpt_pollwait(ccb, timeout);
                                timeout = ccb->ccb_h.timeout * 10;
                        } else {
                                cam_periph_ccbwait(ccb);
                        }
                        if ((ccb->ccb_h.status & CAM_STATUS_MASK) == CAM_REQ_CMP)
                                error = 0;
                        else if (error_routine != NULL) {
                                /*
                                 * cbfcnp is modified by cam_periph_ccbwait so
                                 * reset it before we call the error routine
                                 * which may call xpt_done.
                                 */
                                ccb->ccb_h.cbfcnp = cam_periph_done;
                                error = (*error_routine)(ccb, camflags, sense_flags);
                        } else
                                error = 0;
                } while (error == ERESTART);
        }

        if ((ccb->ccb_h.status & CAM_DEV_QFRZN) != 0) {
                cam_release_devq(ccb->ccb_h.path,
                                 /* relsim_flags */0,
                                 /* openings */0,
                                 /* timeout */0,
                                 /* getcount_only */ FALSE);
                ccb->ccb_h.status &= ~CAM_DEV_QFRZN;
        }

        if (ds != NULL) {
                uint32_t bytes;
                devstat_tag_type tag;
                bool valid = true;

                if (ccb->ccb_h.func_code == XPT_SCSI_IO) {
                        bytes = ccb->csio.dxfer_len - ccb->csio.resid;
                        tag = (devstat_tag_type)(ccb->csio.tag_action & 0x3);
                } else if (ccb->ccb_h.func_code == XPT_ATA_IO) {
                        bytes = ccb->ataio.dxfer_len - ccb->ataio.resid;
                        tag = (devstat_tag_type)0;
                } else if (ccb->ccb_h.func_code == XPT_NVME_IO) {
                        bytes = ccb->nvmeio.dxfer_len; /* NB: resid no possible */
                        tag = (devstat_tag_type)0;
                } else {
                        valid = false;
                }
                if (valid)
                        devstat_end_transaction(ds, bytes, tag,
                            ((ccb->ccb_h.flags & CAM_DIR_MASK) == CAM_DIR_NONE) ?
                            DEVSTAT_NO_DATA : (ccb->ccb_h.flags & CAM_DIR_OUT) ?
                            DEVSTAT_WRITE : DEVSTAT_READ, NULL, starttime);
        }

        return(error);
}

void
cam_freeze_devq(struct cam_path *path)
{
        struct ccb_hdr ccb_h;

        CAM_DEBUG(path, CAM_DEBUG_TRACE, ("cam_freeze_devq\n"));
        memset(&ccb_h, 0, sizeof(ccb_h));
        xpt_setup_ccb(&ccb_h, path, /*priority*/1);
        ccb_h.func_code = XPT_NOOP;
        ccb_h.flags = CAM_DEV_QFREEZE;
        xpt_action((union ccb *)&ccb_h);
}

uint32_t
cam_release_devq(struct cam_path *path, uint32_t relsim_flags,
                 uint32_t openings, uint32_t arg,
                 int getcount_only)
{
        struct ccb_relsim crs;

        CAM_DEBUG(path, CAM_DEBUG_TRACE, ("cam_release_devq(%u, %u, %u, %d)\n",
            relsim_flags, openings, arg, getcount_only));
        memset(&crs, 0, sizeof(crs));
        xpt_setup_ccb(&crs.ccb_h, path, CAM_PRIORITY_NORMAL);
        crs.ccb_h.func_code = XPT_REL_SIMQ;
        crs.ccb_h.flags = getcount_only ? CAM_DEV_QFREEZE : 0;
        crs.release_flags = relsim_flags;
        crs.openings = openings;
        crs.release_timeout = arg;
        xpt_action((union ccb *)&crs);
        return (crs.qfrozen_cnt);
}

#define saved_ccb_ptr ppriv_ptr0
static void
camperiphdone(struct cam_periph *periph, union ccb *done_ccb)
{
        union ccb      *saved_ccb;
        cam_status      status;
        struct scsi_start_stop_unit *scsi_cmd;
        int             error = 0, error_code, sense_key, asc, ascq;
        uint16_t        done_flags;

        scsi_cmd = (struct scsi_start_stop_unit *)
            &done_ccb->csio.cdb_io.cdb_bytes;
        status = done_ccb->ccb_h.status;

        if ((status & CAM_STATUS_MASK) != CAM_REQ_CMP) {
                if (scsi_extract_sense_ccb(done_ccb,
                    &error_code, &sense_key, &asc, &ascq)) {
                        /*
                         * If the error is "invalid field in CDB",
                         * and the load/eject flag is set, turn the
                         * flag off and try again.  This is just in
                         * case the drive in question barfs on the
                         * load eject flag.  The CAM code should set
                         * the load/eject flag by default for
                         * removable media.
                         */
                        if ((scsi_cmd->opcode == START_STOP_UNIT) &&
                            ((scsi_cmd->how & SSS_LOEJ) != 0) &&
                             (asc == 0x24) && (ascq == 0x00)) {
                                scsi_cmd->how &= ~SSS_LOEJ;
                                if (status & CAM_DEV_QFRZN) {
                                        cam_release_devq(done_ccb->ccb_h.path,
                                            0, 0, 0, 0);
                                        done_ccb->ccb_h.status &=
                                            ~CAM_DEV_QFRZN;
                                }
                                xpt_action(done_ccb);
                                goto out;
                        }
                }
                error = cam_periph_error(done_ccb, 0,
                    SF_RETRY_UA | SF_NO_PRINT);
                if (error == ERESTART)
                        goto out;
                if (done_ccb->ccb_h.status & CAM_DEV_QFRZN) {
                        cam_release_devq(done_ccb->ccb_h.path, 0, 0, 0, 0);
                        done_ccb->ccb_h.status &= ~CAM_DEV_QFRZN;
                }
        } else {
                /*
                 * If we have successfully taken a device from the not
                 * ready to ready state, re-scan the device and re-get
                 * the inquiry information.  Many devices (mostly disks)
                 * don't properly report their inquiry information unless
                 * they are spun up.
                 */
                if (scsi_cmd->opcode == START_STOP_UNIT)
                        xpt_async(AC_INQ_CHANGED, done_ccb->ccb_h.path, NULL);
        }

        /* If we tried long wait and still failed, remember that. */
        if ((periph->flags & CAM_PERIPH_RECOVERY_WAIT) &&
            (done_ccb->csio.cdb_io.cdb_bytes[0] == TEST_UNIT_READY)) {
                periph->flags &= ~CAM_PERIPH_RECOVERY_WAIT;
                if (error != 0 && done_ccb->ccb_h.retry_count == 0)
                        periph->flags |= CAM_PERIPH_RECOVERY_WAIT_FAILED;
        }

        /*
         * After recovery action(s) completed, return to the original CCB.
         * If the recovery CCB has failed, considering its own possible
         * retries and recovery, assume we are back in state where we have
         * been originally, but without recovery hopes left.  In such case,
         * after the final attempt below, we cancel any further retries,
         * blocking by that also any new recovery attempts for this CCB,
         * and the result will be the final one returned to the CCB owher.
         */
        saved_ccb = (union ccb *)done_ccb->ccb_h.saved_ccb_ptr;
        KASSERT(saved_ccb->ccb_h.func_code == XPT_SCSI_IO,
            ("%s: saved_ccb func_code %#x != XPT_SCSI_IO",
             __func__, saved_ccb->ccb_h.func_code));
        KASSERT(done_ccb->ccb_h.func_code == XPT_SCSI_IO,
            ("%s: done_ccb func_code %#x != XPT_SCSI_IO",
             __func__, done_ccb->ccb_h.func_code));
        saved_ccb->ccb_h.periph_links = done_ccb->ccb_h.periph_links;
        done_flags = done_ccb->ccb_h.alloc_flags;
        bcopy(saved_ccb, done_ccb, sizeof(struct ccb_scsiio));
        done_ccb->ccb_h.alloc_flags = done_flags;
        xpt_free_ccb(saved_ccb);
        if (done_ccb->ccb_h.cbfcnp != camperiphdone)
                periph->flags &= ~CAM_PERIPH_RECOVERY_INPROG;
        if (error != 0)
                done_ccb->ccb_h.retry_count = 0;
        xpt_action(done_ccb);

out:
        /* Drop freeze taken due to CAM_DEV_QFREEZE flag set. */
        cam_release_devq(done_ccb->ccb_h.path, 0, 0, 0, 0);
}

/*
 * Generic Async Event handler.  Peripheral drivers usually
 * filter out the events that require personal attention,
 * and leave the rest to this function.
 */
void
cam_periph_async(struct cam_periph *periph, uint32_t code,
                 struct cam_path *path, void *arg)
{
        switch (code) {
        case AC_LOST_DEVICE:
                cam_periph_invalidate(periph);
                break; 
        default:
                break;
        }
}

void
cam_periph_bus_settle(struct cam_periph *periph, u_int bus_settle)
{
        struct ccb_getdevstats cgds;

        memset(&cgds, 0, sizeof(cgds));
        xpt_setup_ccb(&cgds.ccb_h, periph->path, CAM_PRIORITY_NORMAL);
        cgds.ccb_h.func_code = XPT_GDEV_STATS;
        xpt_action((union ccb *)&cgds);
        cam_periph_freeze_after_event(periph, &cgds.last_reset, bus_settle);
}

void
cam_periph_freeze_after_event(struct cam_periph *periph,
                              struct timeval* event_time, u_int duration_ms)
{
        struct timeval delta;
        struct timeval duration_tv;

        if (!timevalisset(event_time))
                return;

        microtime(&delta);
        timevalsub(&delta, event_time);
        duration_tv.tv_sec = duration_ms / 1000;
        duration_tv.tv_usec = (duration_ms % 1000) * 1000;
        if (timevalcmp(&delta, &duration_tv, <)) {
                timevalsub(&duration_tv, &delta);

                duration_ms = duration_tv.tv_sec * 1000;
                duration_ms += duration_tv.tv_usec / 1000;
                cam_freeze_devq(periph->path); 
                cam_release_devq(periph->path,
                                RELSIM_RELEASE_AFTER_TIMEOUT,
                                /*reduction*/0,
                                /*timeout*/duration_ms,
                                /*getcount_only*/0);
        }

}

static int
camperiphscsistatuserror(union ccb *ccb, union ccb **orig_ccb,
    cam_flags camflags, uint32_t sense_flags,
    int *openings, uint32_t *relsim_flags,
    uint32_t *timeout, uint32_t *action, const char **action_string)
{
        struct cam_periph *periph;
        int error;

        switch (ccb->csio.scsi_status) {
        case SCSI_STATUS_OK:
        case SCSI_STATUS_COND_MET:
        case SCSI_STATUS_INTERMED:
        case SCSI_STATUS_INTERMED_COND_MET:
                error = 0;
                break;
        case SCSI_STATUS_CMD_TERMINATED:
        case SCSI_STATUS_CHECK_COND:
                error = camperiphscsisenseerror(ccb, orig_ccb,
                                                camflags,
                                                sense_flags,
                                                openings,
                                                relsim_flags,
                                                timeout,
                                                action,
                                                action_string);
                break;
        case SCSI_STATUS_QUEUE_FULL:
        {
                /* no decrement */
                struct ccb_getdevstats cgds;

                /*
                 * First off, find out what the current
                 * transaction counts are.
                 */
                memset(&cgds, 0, sizeof(cgds));
                xpt_setup_ccb(&cgds.ccb_h,
                              ccb->ccb_h.path,
                              CAM_PRIORITY_NORMAL);
                cgds.ccb_h.func_code = XPT_GDEV_STATS;
                xpt_action((union ccb *)&cgds);

                /*
                 * If we were the only transaction active, treat
                 * the QUEUE FULL as if it were a BUSY condition.
                 */
                if (cgds.dev_active != 0) {
                        int total_openings;

                        /*
                         * Reduce the number of openings to
                         * be 1 less than the amount it took
                         * to get a queue full bounded by the
                         * minimum allowed tag count for this
                         * device.
                         */
                        total_openings = cgds.dev_active + cgds.dev_openings;
                        *openings = cgds.dev_active;
                        if (*openings < cgds.mintags)
                                *openings = cgds.mintags;
                        if (*openings < total_openings)
                                *relsim_flags = RELSIM_ADJUST_OPENINGS;
                        else {
                                /*
                                 * Some devices report queue full for
                                 * temporary resource shortages.  For
                                 * this reason, we allow a minimum
                                 * tag count to be entered via a
                                 * quirk entry to prevent the queue
                                 * count on these devices from falling
                                 * to a pessimisticly low value.  We
                                 * still wait for the next successful
                                 * completion, however, before queueing
                                 * more transactions to the device.
                                 */
                                *relsim_flags = RELSIM_RELEASE_AFTER_CMDCMPLT;
                        }
                        *timeout = 0;
                        error = ERESTART;
                        *action &= ~SSQ_PRINT_SENSE;
                        break;
                }
                /* FALLTHROUGH */
        }
        case SCSI_STATUS_BUSY:
                /*
                 * Restart the queue after either another
                 * command completes or a 1 second timeout.
                 */
                periph = xpt_path_periph(ccb->ccb_h.path);
                if (periph->flags & CAM_PERIPH_INVALID) {
                        error = ENXIO;
                        *action_string = "Periph was invalidated";
                } else if ((sense_flags & SF_RETRY_BUSY) != 0 ||
                    ccb->ccb_h.retry_count > 0) {
                        if ((sense_flags & SF_RETRY_BUSY) == 0)
                                ccb->ccb_h.retry_count--;
                        error = ERESTART;
                        *relsim_flags = RELSIM_RELEASE_AFTER_TIMEOUT
                                      | RELSIM_RELEASE_AFTER_CMDCMPLT;
                        *timeout = 1000;
                } else {
                        error = EIO;
                        *action_string = "Retries exhausted";
                }
                break;
        case SCSI_STATUS_RESERV_CONFLICT:
        default:
                error = EIO;
                break;
        }
        return (error);
}

static int
camperiphscsisenseerror(union ccb *ccb, union ccb **orig,
    cam_flags camflags, uint32_t sense_flags,
    int *openings, uint32_t *relsim_flags,
    uint32_t *timeout, uint32_t *action, const char **action_string)
{
        struct cam_periph *periph;
        union ccb *orig_ccb = ccb;
        int error, recoveryccb;
        uint16_t flags;

#if defined(BUF_TRACKING) || defined(FULL_BUF_TRACKING)
        if (ccb->ccb_h.func_code == XPT_SCSI_IO && ccb->csio.bio != NULL)
                biotrack(ccb->csio.bio, __func__);
#endif

        periph = xpt_path_periph(ccb->ccb_h.path);
        recoveryccb = (ccb->ccb_h.cbfcnp == camperiphdone);
        if ((periph->flags & CAM_PERIPH_RECOVERY_INPROG) && !recoveryccb) {
                /*
                 * If error recovery is already in progress, don't attempt
                 * to process this error, but requeue it unconditionally
                 * and attempt to process it once error recovery has
                 * completed.  This failed command is probably related to
                 * the error that caused the currently active error recovery
                 * action so our  current recovery efforts should also
                 * address this command.  Be aware that the error recovery
                 * code assumes that only one recovery action is in progress
                 * on a particular peripheral instance at any given time
                 * (e.g. only one saved CCB for error recovery) so it is
                 * imperitive that we don't violate this assumption.
                 */
                error = ERESTART;
                *action &= ~SSQ_PRINT_SENSE;
        } else {
                scsi_sense_action err_action;
                struct ccb_getdev cgd;

                /*
                 * Grab the inquiry data for this device.
                 */
                xpt_gdev_type(&cgd, ccb->ccb_h.path);

                err_action = scsi_error_action(&ccb->csio, &cgd.inq_data,
                    sense_flags);
                error = err_action & SS_ERRMASK;

                /*
                 * Do not autostart sequential access devices
                 * to avoid unexpected tape loading.
                 */
                if ((err_action & SS_MASK) == SS_START &&
                    SID_TYPE(&cgd.inq_data) == T_SEQUENTIAL) {
                        *action_string = "Will not autostart a "
                            "sequential access device";
                        goto sense_error_done;
                }

                /*
                 * Avoid recovery recursion if recovery action is the same.
                 */
                if ((err_action & SS_MASK) >= SS_START && recoveryccb) {
                        if (((err_action & SS_MASK) == SS_START &&
                             ccb->csio.cdb_io.cdb_bytes[0] == START_STOP_UNIT) ||
                            ((err_action & SS_MASK) == SS_TUR &&
                             (ccb->csio.cdb_io.cdb_bytes[0] == TEST_UNIT_READY))) {
                                err_action = SS_RETRY|SSQ_DECREMENT_COUNT|EIO;
                                *relsim_flags = RELSIM_RELEASE_AFTER_TIMEOUT;
                                *timeout = 500;
                        }
                }

                /*
                 * If the recovery action will consume a retry,
                 * make sure we actually have retries available.
                 */
                if ((err_action & SSQ_DECREMENT_COUNT) != 0) {
                        if (ccb->ccb_h.retry_count > 0 &&
                            (periph->flags & CAM_PERIPH_INVALID) == 0)
                                ccb->ccb_h.retry_count--;
                        else {
                                *action_string = "Retries exhausted";
                                goto sense_error_done;
                        }
                }

                if ((err_action & SS_MASK) >= SS_START) {
                        /*
                         * Do common portions of commands that
                         * use recovery CCBs.
                         */
                        orig_ccb = xpt_alloc_ccb_nowait();
                        if (orig_ccb == NULL) {
                                *action_string = "Can't allocate recovery CCB";
                                goto sense_error_done;
                        }
                        /*
                         * Clear freeze flag for original request here, as
                         * this freeze will be dropped as part of ERESTART.
                         */
                        ccb->ccb_h.status &= ~CAM_DEV_QFRZN;

                        KASSERT(ccb->ccb_h.func_code == XPT_SCSI_IO,
                            ("%s: ccb func_code %#x != XPT_SCSI_IO",
                             __func__, ccb->ccb_h.func_code));
                        flags = orig_ccb->ccb_h.alloc_flags;
                        bcopy(ccb, orig_ccb, sizeof(struct ccb_scsiio));
                        orig_ccb->ccb_h.alloc_flags = flags;
                }

                switch (err_action & SS_MASK) {
                case SS_NOP:
                        *action_string = "No recovery action needed";
                        error = 0;
                        break;
                case SS_RETRY:
                        *action_string = "Retrying command (per sense data)";
                        error = ERESTART;
                        break;
                case SS_FAIL:
                        *action_string = "Unretryable error";
                        break;
                case SS_START:
                {
                        int le;

                        /*
                         * Send a start unit command to the device, and
                         * then retry the command.
                         */
                        *action_string = "Attempting to start unit";
                        periph->flags |= CAM_PERIPH_RECOVERY_INPROG;

                        /*
                         * Check for removable media and set
                         * load/eject flag appropriately.
                         */
                        if (SID_IS_REMOVABLE(&cgd.inq_data))
                                le = TRUE;
                        else
                                le = FALSE;

                        scsi_start_stop(&ccb->csio,
                                        /*retries*/1,
                                        camperiphdone,
                                        MSG_SIMPLE_Q_TAG,
                                        /*start*/TRUE,
                                        /*load/eject*/le,
                                        /*immediate*/FALSE,
                                        SSD_FULL_SIZE,
                                        /*timeout*/50000);
                        break;
                }
                case SS_TUR:
                {
                        /*
                         * Send a Test Unit Ready to the device.
                         * If the 'many' flag is set, we send 120
                         * test unit ready commands, one every half 
                         * second.  Otherwise, we just send one TUR.
                         * We only want to do this if the retry 
                         * count has not been exhausted.
                         */
                        int retries;

                        if ((err_action & SSQ_MANY) != 0 && (periph->flags &
                             CAM_PERIPH_RECOVERY_WAIT_FAILED) == 0) {
                                periph->flags |= CAM_PERIPH_RECOVERY_WAIT;
                                *action_string = "Polling device for readiness";
                                retries = 120;
                        } else {
                                *action_string = "Testing device for readiness";
                                retries = 1;
                        }
                        periph->flags |= CAM_PERIPH_RECOVERY_INPROG;
                        scsi_test_unit_ready(&ccb->csio,
                                             retries,
                                             camperiphdone,
                                             MSG_SIMPLE_Q_TAG,
                                             SSD_FULL_SIZE,
                                             /*timeout*/5000);

                        /*
                         * Accomplish our 500ms delay by deferring
                         * the release of our device queue appropriately.
                         */
                        *relsim_flags = RELSIM_RELEASE_AFTER_TIMEOUT;
                        *timeout = 500;
                        break;
                }
                default:
                        panic("Unhandled error action %x", err_action);
                }
                
                if ((err_action & SS_MASK) >= SS_START) {
                        /*
                         * Drop the priority, so that the recovery
                         * CCB is the first to execute.  Freeze the queue
                         * after this command is sent so that we can
                         * restore the old csio and have it queued in
                         * the proper order before we release normal 
                         * transactions to the device.
                         */
                        ccb->ccb_h.pinfo.priority--;
                        ccb->ccb_h.flags |= CAM_DEV_QFREEZE;
                        ccb->ccb_h.saved_ccb_ptr = orig_ccb;
                        error = ERESTART;
                        *orig = orig_ccb;
                }

sense_error_done:
                *action = err_action;
        }
        return (error);
}

/*
 * Generic error handler.  Peripheral drivers usually filter
 * out the errors that they handle in a unique manner, then
 * call this function.
 */
int
cam_periph_error(union ccb *ccb, cam_flags camflags,
                 uint32_t sense_flags)
{
        struct cam_path *newpath;
        union ccb  *orig_ccb, *scan_ccb;
        struct cam_periph *periph;
        const char *action_string;
        cam_status  status;
        bool        frozen;
        int         error, openings, devctl_err;
        uint32_t   action, relsim_flags, timeout;

        action = SSQ_PRINT_SENSE;
        periph = xpt_path_periph(ccb->ccb_h.path);
        action_string = NULL;
        status = ccb->ccb_h.status;
        frozen = (status & CAM_DEV_QFRZN) != 0;
        status &= CAM_STATUS_MASK;
        devctl_err = openings = relsim_flags = timeout = 0;
        orig_ccb = ccb;

        /* Filter the errors that should be reported via devctl */
        switch (ccb->ccb_h.status & CAM_STATUS_MASK) {
        case CAM_CMD_TIMEOUT:
        case CAM_REQ_ABORTED:
        case CAM_REQ_CMP_ERR:
        case CAM_REQ_TERMIO:
        case CAM_UNREC_HBA_ERROR:
        case CAM_DATA_RUN_ERR:
        case CAM_SCSI_STATUS_ERROR:
        case CAM_ATA_STATUS_ERROR:
        case CAM_SMP_STATUS_ERROR:
        case CAM_DEV_NOT_THERE:
        case CAM_NVME_STATUS_ERROR:
                devctl_err++;
                break;
        default:
                break;
        }

        switch (status) {
        case CAM_REQ_CMP:
                error = 0;
                action &= ~SSQ_PRINT_SENSE;
                break;
        case CAM_SCSI_STATUS_ERROR:
                error = camperiphscsistatuserror(ccb, &orig_ccb,
                    camflags, sense_flags, &openings, &relsim_flags,
                    &timeout, &action, &action_string);
                break;
        case CAM_AUTOSENSE_FAIL:
                error = EIO;    /* we have to kill the command */
                break;
        case CAM_UA_ABORT:
        case CAM_UA_TERMIO:
        case CAM_MSG_REJECT_REC:
                /* XXX Don't know that these are correct */
                error = EIO;
                break;
        case CAM_SEL_TIMEOUT:
                if ((camflags & CAM_RETRY_SELTO) != 0) {
                        if (ccb->ccb_h.retry_count > 0 &&
                            (periph->flags & CAM_PERIPH_INVALID) == 0) {
                                ccb->ccb_h.retry_count--;
                                error = ERESTART;

                                /*
                                 * Wait a bit to give the device
                                 * time to recover before we try again.
                                 */
                                relsim_flags = RELSIM_RELEASE_AFTER_TIMEOUT;
                                timeout = periph_selto_delay;
                                break;
                        }
                        action_string = "Retries exhausted";
                }
                /* FALLTHROUGH */
        case CAM_DEV_NOT_THERE:
                error = ENXIO;
                action = SSQ_LOST;
                break;
        case CAM_REQ_INVALID:
        case CAM_PATH_INVALID:
        case CAM_NO_HBA:
        case CAM_PROVIDE_FAIL:
        case CAM_REQ_TOO_BIG:
        case CAM_LUN_INVALID:
        case CAM_TID_INVALID:
        case CAM_FUNC_NOTAVAIL:
                error = EINVAL;
                break;
        case CAM_SCSI_BUS_RESET:
        case CAM_BDR_SENT:
                /*
                 * Commands that repeatedly timeout and cause these
                 * kinds of error recovery actions, should return
                 * CAM_CMD_TIMEOUT, which allows us to safely assume
                 * that this command was an innocent bystander to
                 * these events and should be unconditionally
                 * retried.
                 */
        case CAM_REQUEUE_REQ:
                /* Unconditional requeue if device is still there */
                if (periph->flags & CAM_PERIPH_INVALID) {
                        action_string = "Periph was invalidated";
                        error = ENXIO;
                } else if (sense_flags & SF_NO_RETRY) {
                        error = EIO;
                        action_string = "Retry was blocked";
                } else {
                        error = ERESTART;
                        action &= ~SSQ_PRINT_SENSE;
                }
                break;
        case CAM_RESRC_UNAVAIL:
                /* Wait a bit for the resource shortage to abate. */
                timeout = periph_noresrc_delay;
                /* FALLTHROUGH */
        case CAM_BUSY:
                if (timeout == 0) {
                        /* Wait a bit for the busy condition to abate. */
                        timeout = periph_busy_delay;
                }
                relsim_flags = RELSIM_RELEASE_AFTER_TIMEOUT;
                /* FALLTHROUGH */
        case CAM_ATA_STATUS_ERROR:
        case CAM_NVME_STATUS_ERROR:
        case CAM_SMP_STATUS_ERROR:
        case CAM_REQ_CMP_ERR:
        case CAM_CMD_TIMEOUT:
        case CAM_UNEXP_BUSFREE:
        case CAM_UNCOR_PARITY:
        case CAM_DATA_RUN_ERR:
        default:
                if (periph->flags & CAM_PERIPH_INVALID) {
                        error = ENXIO;
                        action_string = "Periph was invalidated";
                } else if (ccb->ccb_h.retry_count == 0) {
                        error = EIO;
                        action_string = "Retries exhausted";
                } else if (sense_flags & SF_NO_RETRY) {
                        error = EIO;
                        action_string = "Retry was blocked";
                } else {
                        ccb->ccb_h.retry_count--;
                        error = ERESTART;
                }
                break;
        }

        if ((sense_flags & SF_PRINT_ALWAYS) ||
            CAM_DEBUGGED(ccb->ccb_h.path, CAM_DEBUG_INFO))
                action |= SSQ_PRINT_SENSE;
        else if (sense_flags & SF_NO_PRINT)
                action &= ~SSQ_PRINT_SENSE;
        if ((action & SSQ_PRINT_SENSE) != 0)
                cam_error_print(orig_ccb, CAM_ESF_ALL, CAM_EPF_ALL);
        if (error != 0 && (action & SSQ_PRINT_SENSE) != 0) {
                if (error != ERESTART) {
                        if (action_string == NULL)
                                action_string = "Unretryable error";
                        xpt_print(ccb->ccb_h.path, "Error %d, %s\n",
                            error, action_string);
                } else if (action_string != NULL)
                        xpt_print(ccb->ccb_h.path, "%s\n", action_string);
                else {
                        xpt_print(ccb->ccb_h.path,
                            "Retrying command, %d more tries remain\n",
                            ccb->ccb_h.retry_count);
                }
        }

        if (devctl_err && (error != 0 || (action & SSQ_PRINT_SENSE) != 0))
                cam_periph_devctl_notify(orig_ccb);

        if ((action & SSQ_LOST) != 0) {
                lun_id_t lun_id;

                /*
                 * For a selection timeout, we consider all of the LUNs on
                 * the target to be gone.  If the status is CAM_DEV_NOT_THERE,
                 * then we only get rid of the device(s) specified by the
                 * path in the original CCB.
                 */
                if (status == CAM_SEL_TIMEOUT)
                        lun_id = CAM_LUN_WILDCARD;
                else
                        lun_id = xpt_path_lun_id(ccb->ccb_h.path);

                /* Should we do more if we can't create the path?? */
                if (xpt_create_path(&newpath, periph,
                                    xpt_path_path_id(ccb->ccb_h.path),
                                    xpt_path_target_id(ccb->ccb_h.path),
                                    lun_id) == CAM_REQ_CMP) {
                        /*
                         * Let peripheral drivers know that this
                         * device has gone away.
                         */
                        xpt_async(AC_LOST_DEVICE, newpath, NULL);
                        xpt_free_path(newpath);
                }
        }

        /* Broadcast UNIT ATTENTIONs to all periphs. */
        if ((action & SSQ_UA) != 0)
                xpt_async(AC_UNIT_ATTENTION, orig_ccb->ccb_h.path, orig_ccb);

        /* Rescan target on "Reported LUNs data has changed" */
        if ((action & SSQ_RESCAN) != 0) {
                if (xpt_create_path(&newpath, NULL,
                                    xpt_path_path_id(ccb->ccb_h.path),
                                    xpt_path_target_id(ccb->ccb_h.path),
                                    CAM_LUN_WILDCARD) == CAM_REQ_CMP) {
                        scan_ccb = xpt_alloc_ccb_nowait();
                        if (scan_ccb != NULL) {
                                scan_ccb->ccb_h.path = newpath;
                                scan_ccb->ccb_h.func_code = XPT_SCAN_TGT;
                                scan_ccb->crcn.flags = 0;
                                xpt_rescan(scan_ccb);
                        } else {
                                xpt_print(newpath,
                                    "Can't allocate CCB to rescan target\n");
                                xpt_free_path(newpath);
                        }
                }
        }

        /* Attempt a retry */
        if (error == ERESTART || error == 0) {
                if (frozen)
                        ccb->ccb_h.status &= ~CAM_DEV_QFRZN;
                if (error == ERESTART)
                        xpt_action(ccb);
                if (frozen)
                        cam_release_devq(ccb->ccb_h.path,
                                         relsim_flags,
                                         openings,
                                         timeout,
                                         /*getcount_only*/0);
        }

        return (error);
}

#define CAM_PERIPH_DEVD_MSG_SIZE        1024

static void
cam_periph_devctl_notify(union ccb *ccb)
{
        struct cam_periph *periph;
        struct ccb_getdev *cgd;
        struct sbuf sb;
        char *sbmsg, *type;

        sbmsg = malloc(CAM_PERIPH_DEVD_MSG_SIZE, M_CAMPERIPH, M_NOWAIT);
        if (sbmsg == NULL)
                return;

        sbuf_new(&sb, sbmsg, CAM_PERIPH_DEVD_MSG_SIZE, SBUF_FIXEDLEN);

        periph = xpt_path_periph(ccb->ccb_h.path);
        sbuf_printf(&sb, "device=%s%d ", periph->periph_name,
            periph->unit_number);

        sbuf_cat(&sb, "serial=\"");
        if ((cgd = (struct ccb_getdev *)xpt_alloc_ccb_nowait()) != NULL) {
                xpt_gdev_type(cgd, ccb->ccb_h.path);
                if (cgd->ccb_h.status == CAM_REQ_CMP)
                        sbuf_bcat(&sb, cgd->serial_num, cgd->serial_num_len);
                xpt_free_ccb((union ccb *)cgd);
        }
        sbuf_cat(&sb, "\" ");
        sbuf_printf(&sb, "cam_status=\"0x%x\" ", ccb->ccb_h.status);

        switch (ccb->ccb_h.status & CAM_STATUS_MASK) {
        case CAM_CMD_TIMEOUT:
                sbuf_printf(&sb, "timeout=%d ", ccb->ccb_h.timeout);
                type = "timeout";
                break;
        case CAM_SCSI_STATUS_ERROR:
                scsi_format_sense_devd(&ccb->csio, &sb);
                type = "error";
                break;
        case CAM_ATA_STATUS_ERROR:
                sbuf_cat(&sb, "RES=\"");
                ata_res_sbuf(&ccb->ataio.res, &sb);
                sbuf_cat(&sb, "\" ");
                type = "error";
                break;
        case CAM_NVME_STATUS_ERROR:
        {
                struct ccb_nvmeio *n = &ccb->nvmeio;

                sbuf_printf(&sb, "sct=\"%02x\" sc=\"%02x\" cdw0=\"%08x\" ",
                    NVME_STATUS_GET_SCT(n->cpl.status),
                    NVME_STATUS_GET_SC(n->cpl.status), n->cpl.cdw0);
                type = "error";
                break;
        }
        default:
                type = "error";
                break;
        }


        switch (ccb->ccb_h.func_code) {
        case XPT_SCSI_IO:
                sbuf_cat(&sb, "CDB=\"");
                scsi_cdb_sbuf(scsiio_cdb_ptr(&ccb->csio), &sb);
                sbuf_cat(&sb, "\" ");
                break;
        case XPT_ATA_IO:
                sbuf_cat(&sb, "ACB=\"");
                ata_cmd_sbuf(&ccb->ataio.cmd, &sb);
                sbuf_cat(&sb, "\" ");
                break;
        case XPT_NVME_IO:
        case XPT_NVME_ADMIN:
        {
                struct ccb_nvmeio *n = &ccb->nvmeio;
                struct nvme_command *cmd = &n->cmd;

                // XXX Likely should be nvme_cmd_sbuf
                sbuf_printf(&sb, "opc=\"%02x\" fuse=\"%02x\" cid=\"%04x\" "
                    "nsid=\"%08x\" cdw10=\"%08x\" cdw11=\"%08x\" cdw12=\"%08x\" "
                    "cdw13=\"%08x\" cdw14=\"%08x\" cdw15=\"%08x\" ",
                    cmd->opc, cmd->fuse, cmd->cid, cmd->nsid, cmd->cdw10,
                    cmd->cdw11, cmd->cdw12, cmd->cdw13, cmd->cdw14, cmd->cdw15);
                break;
        }
        default:
                break;
        }

        if (sbuf_finish(&sb) == 0)
                devctl_notify("CAM", "periph", type, sbuf_data(&sb));
        sbuf_delete(&sb);
        free(sbmsg, M_CAMPERIPH);
}

/*
 * Sysctl to force an invalidation of the drive right now. Can be
 * called with CTLFLAG_MPSAFE since we take periph lock.
 */
int
cam_periph_invalidate_sysctl(SYSCTL_HANDLER_ARGS)
{
        struct cam_periph *periph;
        int error, value;

        periph = arg1;
        value = 0;
        error = sysctl_handle_int(oidp, &value, 0, req);
        if (error != 0 || req->newptr == NULL || value != 1)
                return (error);

        cam_periph_lock(periph);
        cam_periph_invalidate(periph);
        cam_periph_unlock(periph);

        return (0);
}