/*      $OpenBSD: sd.c,v 1.341 2025/11/17 14:27:43 jsg Exp $    */
/*      $NetBSD: sd.c,v 1.111 1997/04/02 02:29:41 mycroft Exp $ */

/*-
 * Copyright (c) 1998, 2003, 2004 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Charles M. Hannum.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
 */

/*
 * Originally written by Julian Elischer (julian@dialix.oz.au)
 * for TRW Financial Systems for use under the MACH(2.5) operating system.
 *
 * TRW Financial Systems, in accordance with their agreement with Carnegie
 * Mellon University, makes this software available to CMU to distribute
 * or use in any manner that they see fit as long as this message is kept with
 * the software. For this reason TFS also grants any other persons or
 * organisations permission to use or modify this software.
 *
 * TFS supplies this software to be publicly redistributed
 * on the understanding that TFS is not responsible for the correct
 * functioning of this software in any circumstances.
 *
 * Ported to run under 386BSD by Julian Elischer (julian@dialix.oz.au) Sept 1992
 */

#include <sys/stdint.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/timeout.h>
#include <sys/fcntl.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/mtio.h>
#include <sys/mutex.h>
#include <sys/buf.h>
#include <sys/uio.h>
#include <sys/malloc.h>
#include <sys/pool.h>
#include <sys/errno.h>
#include <sys/device.h>
#include <sys/disklabel.h>
#include <sys/disk.h>
#include <sys/conf.h>
#include <sys/scsiio.h>
#include <sys/dkio.h>
#include <sys/reboot.h>

#include <scsi/scsi_all.h>
#include <scsi/scsi_debug.h>
#include <scsi/scsi_disk.h>
#include <scsi/scsiconf.h>
#include <scsi/sdvar.h>

#include <ufs/ffs/fs.h>                 /* for BBSIZE and SBSIZE */

#include <sys/vnode.h>

int     sdmatch(struct device *, void *, void *);
void    sdattach(struct device *, struct device *, void *);
int     sdactivate(struct device *, int);
int     sddetach(struct device *, int);

void    sdminphys(struct buf *);
int     sdgetdisklabel(dev_t, struct sd_softc *, struct disklabel *, int);
void    sdstart(struct scsi_xfer *);
int     sd_interpret_sense(struct scsi_xfer *);
int     sd_read_cap_10(struct sd_softc *, int);
int     sd_read_cap_16(struct sd_softc *, int);
int     sd_read_cap(struct sd_softc *, int);
int     sd_thin_pages(struct sd_softc *, int);
int     sd_vpd_block_limits(struct sd_softc *, int);
int     sd_vpd_thin(struct sd_softc *, int);
int     sd_thin_params(struct sd_softc *, int);
int     sd_get_parms(struct sd_softc *, int);
int     sd_flush(struct sd_softc *, int);

void    viscpy(u_char *, u_char *, int);

int     sd_ioctl_inquiry(struct sd_softc *, struct dk_inquiry *);
int     sd_ioctl_cache(struct sd_softc *, long, struct dk_cache *);

int     sd_cmd_rw6(struct scsi_generic *, int, u_int64_t, u_int32_t);
int     sd_cmd_rw10(struct scsi_generic *, int, u_int64_t, u_int32_t);
int     sd_cmd_rw12(struct scsi_generic *, int, u_int64_t, u_int32_t);
int     sd_cmd_rw16(struct scsi_generic *, int, u_int64_t, u_int32_t);

void    sd_buf_done(struct scsi_xfer *);

const struct cfattach sd_ca = {
        sizeof(struct sd_softc), sdmatch, sdattach,
        sddetach, sdactivate
};

struct cfdriver sd_cd = {
        NULL, "sd", DV_DISK, CD_COCOVM
};

const struct scsi_inquiry_pattern sd_patterns[] = {
        {T_DIRECT, T_FIXED,
         "",         "",                 ""},
        {T_DIRECT, T_REMOV,
         "",         "",                 ""},
        {T_RDIRECT, T_FIXED,
         "",         "",                 ""},
        {T_RDIRECT, T_REMOV,
         "",         "",                 ""},
        {T_OPTICAL, T_FIXED,
         "",         "",                 ""},
        {T_OPTICAL, T_REMOV,
         "",         "",                 ""},
};

#define sdlookup(unit) (struct sd_softc *)disk_lookup(&sd_cd, (unit))

int
sdmatch(struct device *parent, void *match, void *aux)
{
        struct scsi_attach_args         *sa = aux;
        struct scsi_inquiry_data        *inq = &sa->sa_sc_link->inqdata;
        int                              priority;

        (void)scsi_inqmatch(inq, sd_patterns, nitems(sd_patterns),
            sizeof(sd_patterns[0]), &priority);

        return priority;
}

/*
 * The routine called by the low level scsi routine when it discovers
 * a device suitable for this driver.
 */
void
sdattach(struct device *parent, struct device *self, void *aux)
{
        struct dk_cache                  dkc;
        struct sd_softc                 *sc = (struct sd_softc *)self;
        struct scsi_attach_args         *sa = aux;
        struct disk_parms               *dp = &sc->params;
        struct scsi_link                *link = sa->sa_sc_link;
        int                              error, sd_autoconf;
        int                              sortby = BUFQ_DEFAULT;

        SC_DEBUG(link, SDEV_DB2, ("sdattach:\n"));

        sd_autoconf = scsi_autoconf | SCSI_SILENT |
            SCSI_IGNORE_ILLEGAL_REQUEST | SCSI_IGNORE_MEDIA_CHANGE;

        /*
         * Store information needed to contact our base driver.
         */
        sc->sc_link = link;
        link->interpret_sense = sd_interpret_sense;
        link->device_softc = sc;

        if (ISSET(link->flags, SDEV_ATAPI) && ISSET(link->flags,
            SDEV_REMOVABLE))
                SET(link->quirks, SDEV_NOSYNCCACHE);

        /*
         * Use the subdriver to request information regarding the drive. We
         * cannot use interrupts yet, so the request must specify this.
         */
        printf("\n");

        scsi_xsh_set(&sc->sc_xsh, link, sdstart);

        /* Spin up non-UMASS devices ready or not. */
        if (!ISSET(link->flags, SDEV_UMASS))
                scsi_start(link, SSS_START, sd_autoconf);

        /*
         * Some devices (e.g. BlackBerry Pearl) won't admit they have
         * media loaded unless its been locked in.
         */
        if (ISSET(link->flags, SDEV_REMOVABLE))
                scsi_prevent(link, PR_PREVENT, sd_autoconf);

        /* Check that it is still responding and ok. */
        error = scsi_test_unit_ready(sc->sc_link, TEST_READY_RETRIES * 3,
            sd_autoconf);
        if (error == 0)
                error = sd_get_parms(sc, sd_autoconf);

        if (ISSET(link->flags, SDEV_REMOVABLE))
                scsi_prevent(link, PR_ALLOW, sd_autoconf);

        if (error == 0) {
                printf("%s: %lluMB, %u bytes/sector, %llu sectors",
                    sc->sc_dev.dv_xname,
                    dp->disksize / (1048576 / dp->secsize), dp->secsize,
                    dp->disksize);
                if (ISSET(sc->flags, SDF_THIN)) {
                        sortby = BUFQ_FIFO;
                        printf(", thin");
                }
                if (ISSET(link->flags, SDEV_READONLY))
                        printf(", readonly");
                printf("\n");
        }

        /*
         * Initialize disk structures.
         */
        sc->sc_dk.dk_name = sc->sc_dev.dv_xname;
        bufq_init(&sc->sc_bufq, sortby);

        /*
         * Enable write cache by default.
         */
        memset(&dkc, 0, sizeof(dkc));
        if (sd_ioctl_cache(sc, DIOCGCACHE, &dkc) == 0 && dkc.wrcache == 0) {
                dkc.wrcache = 1;
                sd_ioctl_cache(sc, DIOCSCACHE, &dkc);
        }

        /* Attach disk. */
        disk_attach(&sc->sc_dev, &sc->sc_dk);
}

int
sdactivate(struct device *self, int act)
{
        struct scsi_link                *link;
        struct sd_softc                 *sc = (struct sd_softc *)self;

        if (ISSET(sc->flags, SDF_DYING))
                return ENXIO;
        link = sc->sc_link;

        switch (act) {
        case DVACT_SUSPEND:
                /*
                 * We flush the cache, since we our next step before
                 * DVACT_POWERDOWN might be a hibernate operation.
                 */
                if (ISSET(sc->flags, SDF_DIRTY))
                        sd_flush(sc, SCSI_AUTOCONF);
                break;
        case DVACT_POWERDOWN:
                /*
                 * Stop the disk.  Stopping the disk should flush the
                 * cache, but we are paranoid so we flush the cache
                 * first.  We're cold at this point, so we poll for
                 * completion.
                 */
                if (ISSET(sc->flags, SDF_DIRTY))
                        sd_flush(sc, SCSI_AUTOCONF);
                if (ISSET(boothowto, RB_POWERDOWN))
                        scsi_start(link, SSS_STOP,
                            SCSI_IGNORE_ILLEGAL_REQUEST |
                            SCSI_IGNORE_NOT_READY | SCSI_AUTOCONF);
                break;
        case DVACT_RESUME:
                scsi_start(link, SSS_START,
                    SCSI_IGNORE_ILLEGAL_REQUEST | SCSI_AUTOCONF);
                break;
        case DVACT_DEACTIVATE:
                SET(sc->flags, SDF_DYING);
                scsi_xsh_del(&sc->sc_xsh);
                break;
        }
        return 0;
}

int
sddetach(struct device *self, int flags)
{
        struct sd_softc *sc = (struct sd_softc *)self;

        bufq_drain(&sc->sc_bufq);

        disk_gone(sdopen, self->dv_unit);

        /* Detach disk. */
        bufq_destroy(&sc->sc_bufq);
        disk_detach(&sc->sc_dk);

        return 0;
}

/*
 * Open the device. Make sure the partition info is as up-to-date as can be.
 */
int
sdopen(dev_t dev, int flag, int fmt, struct proc *p)
{
        struct scsi_link                *link;
        struct sd_softc                 *sc;
        int                              error = 0, part, rawopen, unit;

        unit = DISKUNIT(dev);
        part = DISKPART(dev);

        rawopen = (part == RAW_PART) && (fmt == S_IFCHR);

        sc = sdlookup(unit);
        if (sc == NULL)
                return ENXIO;
        if (ISSET(sc->flags, SDF_DYING)) {
                device_unref(&sc->sc_dev);
                return ENXIO;
        }
        link = sc->sc_link;

        SC_DEBUG(link, SDEV_DB1,
            ("sdopen: dev=0x%x (unit %d (of %d), partition %d)\n", dev, unit,
            sd_cd.cd_ndevs, part));

        if (ISSET(flag, FWRITE) && ISSET(link->flags, SDEV_READONLY)) {
                device_unref(&sc->sc_dev);
                return EACCES;
        }
        if ((error = disk_lock(&sc->sc_dk)) != 0) {
                device_unref(&sc->sc_dev);
                return error;
        }
        if (ISSET(sc->flags, SDF_DYING)) {
                error = ENXIO;
                goto die;
        }

        if (sc->sc_dk.dk_openmask != 0) {
                /*
                 * If any partition is open, but the disk has been invalidated,
                 * disallow further opens of non-raw partition.
                 */
                if (!ISSET(link->flags, SDEV_MEDIA_LOADED)) {
                        if (rawopen)
                                goto out;
                        error = EIO;
                        goto bad;
                }
        } else {
                /* Spin up non-UMASS devices ready or not. */
                if (!ISSET(link->flags, SDEV_UMASS))
                        scsi_start(link, SSS_START, (rawopen ? SCSI_SILENT :
                            0) | SCSI_IGNORE_ILLEGAL_REQUEST |
                            SCSI_IGNORE_MEDIA_CHANGE);

                /*
                 * Use sd_interpret_sense() for sense errors.
                 *
                 * But only after spinning the disk up! Just in case a broken
                 * device returns "Initialization command required." and causes
                 * a loop of scsi_start() calls.
                 */
                if (ISSET(sc->flags, SDF_DYING)) {
                        error = ENXIO;
                        goto die;
                }
                SET(link->flags, SDEV_OPEN);

                /*
                 * Try to prevent the unloading of a removable device while
                 * it's open. But allow the open to proceed if the device can't
                 * be locked in.
                 */
                if (ISSET(link->flags, SDEV_REMOVABLE)) {
                        scsi_prevent(link, PR_PREVENT, SCSI_SILENT |
                            SCSI_IGNORE_ILLEGAL_REQUEST |
                            SCSI_IGNORE_MEDIA_CHANGE);
                }

                /* Check that it is still responding and ok. */
                if (ISSET(sc->flags, SDF_DYING)) {
                        error = ENXIO;
                        goto die;
                }
                error = scsi_test_unit_ready(link,
                    TEST_READY_RETRIES, SCSI_SILENT |
                    SCSI_IGNORE_ILLEGAL_REQUEST | SCSI_IGNORE_MEDIA_CHANGE);
                if (error) {
                        if (rawopen) {
                                error = 0;
                                goto out;
                        } else
                                goto bad;
                }

                /* Load the physical device parameters. */
                if (ISSET(sc->flags, SDF_DYING)) {
                        error = ENXIO;
                        goto die;
                }
                SET(link->flags, SDEV_MEDIA_LOADED);
                if (sd_get_parms(sc, (rawopen ? SCSI_SILENT : 0)) == -1) {
                        if (ISSET(sc->flags, SDF_DYING)) {
                                error = ENXIO;
                                goto die;
                        }
                        CLR(link->flags, SDEV_MEDIA_LOADED);
                        error = ENXIO;
                        goto bad;
                }
                SC_DEBUG(link, SDEV_DB3, ("Params loaded\n"));

                /* Load the partition info if not already loaded. */
                error = sdgetdisklabel(dev, sc, sc->sc_dk.dk_label, 0);
                if (error == EIO || error == ENXIO)
                        goto bad;
                SC_DEBUG(link, SDEV_DB3, ("Disklabel loaded\n"));
        }

out:
        if ((error = disk_openpart(&sc->sc_dk, part, fmt, 1)) != 0)
                goto bad;

        SC_DEBUG(link, SDEV_DB3, ("open complete\n"));

        /* It's OK to fall through because dk_openmask is now non-zero. */
bad:
        if (sc->sc_dk.dk_openmask == 0) {
                if (ISSET(sc->flags, SDF_DYING)) {
                        error = ENXIO;
                        goto die;
                }
                if (ISSET(link->flags, SDEV_REMOVABLE))
                        scsi_prevent(link, PR_ALLOW, SCSI_SILENT |
                            SCSI_IGNORE_ILLEGAL_REQUEST |
                            SCSI_IGNORE_MEDIA_CHANGE);
                if (ISSET(sc->flags, SDF_DYING)) {
                        error = ENXIO;
                        goto die;
                }
                CLR(link->flags, SDEV_OPEN | SDEV_MEDIA_LOADED);
        }

die:
        disk_unlock(&sc->sc_dk);
        device_unref(&sc->sc_dev);
        return error;
}

/*
 * Close the device. Only called if we are the last occurrence of an open
 * device.  Convenient now but usually a pain.
 */
int
sdclose(dev_t dev, int flag, int fmt, struct proc *p)
{
        struct scsi_link                *link;
        struct sd_softc                 *sc;
        int                              part = DISKPART(dev);
        int                              error = 0;

        sc = sdlookup(DISKUNIT(dev));
        if (sc == NULL)
                return ENXIO;
        if (ISSET(sc->flags, SDF_DYING)) {
                device_unref(&sc->sc_dev);
                return ENXIO;
        }
        link = sc->sc_link;

        disk_lock_nointr(&sc->sc_dk);

        disk_closepart(&sc->sc_dk, part, fmt);

        if ((ISSET(flag, FWRITE) || sc->sc_dk.dk_openmask == 0) &&
            ISSET(sc->flags, SDF_DIRTY))
                sd_flush(sc, 0);

        if (sc->sc_dk.dk_openmask == 0) {
                if (ISSET(sc->flags, SDF_DYING)) {
                        error = ENXIO;
                        goto die;
                }
                if (ISSET(link->flags, SDEV_REMOVABLE))
                        scsi_prevent(link, PR_ALLOW,
                            SCSI_IGNORE_ILLEGAL_REQUEST |
                            SCSI_IGNORE_NOT_READY | SCSI_SILENT);
                if (ISSET(sc->flags, SDF_DYING)) {
                        error = ENXIO;
                        goto die;
                }
                CLR(link->flags, SDEV_OPEN | SDEV_MEDIA_LOADED);

                if (ISSET(link->flags, SDEV_EJECTING)) {
                        scsi_start(link, SSS_STOP|SSS_LOEJ, 0);
                        if (ISSET(sc->flags, SDF_DYING)) {
                                error = ENXIO;
                                goto die;
                        }
                        CLR(link->flags, SDEV_EJECTING);
                }

                scsi_xsh_del(&sc->sc_xsh);
        }

die:
        disk_unlock(&sc->sc_dk);
        device_unref(&sc->sc_dev);
        return error;
}

/*
 * Actually translate the requested transfer into one the physical driver
 * can understand.  The transfer is described by a buf and will include
 * only one physical transfer.
 */
void
sdstrategy(struct buf *bp)
{
        struct scsi_link                *link;
        struct sd_softc                 *sc;
        int                              s;

        sc = sdlookup(DISKUNIT(bp->b_dev));
        if (sc == NULL) {
                bp->b_error = ENXIO;
                goto bad;
        }
        if (ISSET(sc->flags, SDF_DYING)) {
                bp->b_error = ENXIO;
                goto bad;
        }
        link = sc->sc_link;

        SC_DEBUG(link, SDEV_DB2, ("sdstrategy: %ld bytes @ blk %lld\n",
            bp->b_bcount, (long long)bp->b_blkno));
        /*
         * If the device has been made invalid, error out.
         */
        if (!ISSET(link->flags, SDEV_MEDIA_LOADED)) {
                if (ISSET(link->flags, SDEV_OPEN))
                        bp->b_error = EIO;
                else
                        bp->b_error = ENODEV;
                goto bad;
        }

        /* Validate the request. */
        if (bounds_check_with_label(bp, sc->sc_dk.dk_label) == -1)
                goto done;

        /* Place it in the queue of disk activities for this disk. */
        bufq_queue(&sc->sc_bufq, bp);

        /*
         * Tell the device to get going on the transfer if it's
         * not doing anything, otherwise just wait for completion
         */
        scsi_xsh_add(&sc->sc_xsh);

        device_unref(&sc->sc_dev);
        return;

bad:
        SET(bp->b_flags, B_ERROR);
        bp->b_resid = bp->b_bcount;
done:
        s = splbio();
        biodone(bp);
        splx(s);
        if (sc != NULL)
                device_unref(&sc->sc_dev);
}

int
sd_cmd_rw6(struct scsi_generic *generic, int read, u_int64_t secno,
    u_int32_t nsecs)
{
        struct scsi_rw *cmd = (struct scsi_rw *)generic;

        cmd->opcode = read ? READ_COMMAND : WRITE_COMMAND;
        _lto3b(secno, cmd->addr);
        cmd->length = nsecs;

        return sizeof(*cmd);
}

int
sd_cmd_rw10(struct scsi_generic *generic, int read, u_int64_t secno,
    u_int32_t nsecs)
{
        struct scsi_rw_10 *cmd = (struct scsi_rw_10 *)generic;

        cmd->opcode = read ? READ_10 : WRITE_10;
        _lto4b(secno, cmd->addr);
        _lto2b(nsecs, cmd->length);

        return sizeof(*cmd);
}

int
sd_cmd_rw12(struct scsi_generic *generic, int read, u_int64_t secno,
    u_int32_t nsecs)
{
        struct scsi_rw_12 *cmd = (struct scsi_rw_12 *)generic;

        cmd->opcode = read ? READ_12 : WRITE_12;
        _lto4b(secno, cmd->addr);
        _lto4b(nsecs, cmd->length);

        return sizeof(*cmd);
}

int
sd_cmd_rw16(struct scsi_generic *generic, int read, u_int64_t secno,
    u_int32_t nsecs)
{
        struct scsi_rw_16 *cmd = (struct scsi_rw_16 *)generic;

        cmd->opcode = read ? READ_16 : WRITE_16;
        _lto8b(secno, cmd->addr);
        _lto4b(nsecs, cmd->length);

        return sizeof(*cmd);
}

/*
 * sdstart looks to see if there is a buf waiting for the device
 * and that the device is not already busy. If both are true,
 * It dequeues the buf and creates a scsi command to perform the
 * transfer in the buf. The transfer request will call scsi_done
 * on completion, which will in turn call this routine again
 * so that the next queued transfer is performed.
 * The bufs are queued by the strategy routine (sdstrategy)
 *
 * This routine is also called after other non-queued requests
 * have been made of the scsi driver, to ensure that the queue
 * continues to be drained.
 */
void
sdstart(struct scsi_xfer *xs)
{
        struct scsi_link                *link = xs->sc_link;
        struct sd_softc                 *sc = link->device_softc;
        struct buf                      *bp;
        struct partition                *p;
        u_int64_t                        secno;
        u_int32_t                        nsecs;
        int                              read;

        if (ISSET(sc->flags, SDF_DYING)) {
                scsi_xs_put(xs);
                return;
        }
        if (!ISSET(link->flags, SDEV_MEDIA_LOADED)) {
                bufq_drain(&sc->sc_bufq);
                scsi_xs_put(xs);
                return;
        }

        bp = bufq_dequeue(&sc->sc_bufq);
        if (bp == NULL) {
                scsi_xs_put(xs);
                return;
        }
        read = ISSET(bp->b_flags, B_READ);

        SET(xs->flags, (read ? SCSI_DATA_IN : SCSI_DATA_OUT));
        xs->timeout = 60000;
        xs->data = bp->b_data;
        xs->datalen = bp->b_bcount;
        xs->done = sd_buf_done;
        xs->cookie = bp;
        xs->bp = bp;

        p = &sc->sc_dk.dk_label->d_partitions[DISKPART(bp->b_dev)];
        secno = DL_GETPOFFSET(p) + DL_BLKTOSEC(sc->sc_dk.dk_label, bp->b_blkno);
        nsecs = howmany(bp->b_bcount, sc->sc_dk.dk_label->d_secsize);

        if (!ISSET(link->flags, SDEV_ATAPI | SDEV_UMASS) &&
            (SID_ANSII_REV(&link->inqdata) < SCSI_REV_2) &&
            ((secno & 0x1fffff) == secno) &&
            ((nsecs & 0xff) == nsecs))
                xs->cmdlen = sd_cmd_rw6(&xs->cmd, read, secno, nsecs);

        else if (sc->params.disksize > UINT32_MAX)
                xs->cmdlen = sd_cmd_rw16(&xs->cmd, read, secno, nsecs);

        else if (nsecs <= UINT16_MAX)
                xs->cmdlen = sd_cmd_rw10(&xs->cmd, read, secno, nsecs);

        else
                xs->cmdlen = sd_cmd_rw12(&xs->cmd, read, secno, nsecs);

        disk_busy(&sc->sc_dk);
        if (!read)
                SET(sc->flags, SDF_DIRTY);
        scsi_xs_exec(xs);

        /* Move onto the next io. */
        if (bufq_peek(&sc->sc_bufq))
                scsi_xsh_add(&sc->sc_xsh);
}

void
sd_buf_done(struct scsi_xfer *xs)
{
        struct sd_softc                 *sc = xs->sc_link->device_softc;
        struct buf                      *bp = xs->cookie;
        int                              error, s;

        switch (xs->error) {
        case XS_NOERROR:
                bp->b_error = 0;
                CLR(bp->b_flags, B_ERROR);
                bp->b_resid = xs->resid;
                break;

        case XS_SENSE:
        case XS_SHORTSENSE:
                SC_DEBUG_SENSE(xs);
                error = sd_interpret_sense(xs);
                if (error == 0) {
                        bp->b_error = 0;
                        CLR(bp->b_flags, B_ERROR);
                        bp->b_resid = xs->resid;
                        break;
                }
                if (error != ERESTART) {
                        bp->b_error = error;
                        SET(bp->b_flags, B_ERROR);
                        xs->retries = 0;
                }
                goto retry;

        case XS_BUSY:
                if (xs->retries) {
                        if (scsi_delay(xs, 1) != ERESTART)
                                xs->retries = 0;
                }
                goto retry;

        case XS_TIMEOUT:
retry:
                if (xs->retries--) {
                        scsi_xs_exec(xs);
                        return;
                }
                /* FALLTHROUGH */

        default:
                if (bp->b_error == 0)
                        bp->b_error = EIO;
                SET(bp->b_flags, B_ERROR);
                bp->b_resid = bp->b_bcount;
                break;
        }

        disk_unbusy(&sc->sc_dk, bp->b_bcount - xs->resid, bp->b_blkno,
            bp->b_flags & B_READ);

        s = splbio();
        biodone(bp);
        splx(s);
        scsi_xs_put(xs);
}

void
sdminphys(struct buf *bp)
{
        struct scsi_link                *link;
        struct sd_softc                 *sc;
        long                             max;

        sc = sdlookup(DISKUNIT(bp->b_dev));
        if (sc == NULL)
                return;  /* XXX - right way to fail this? */
        if (ISSET(sc->flags, SDF_DYING)) {
                device_unref(&sc->sc_dev);
                return;
        }
        link = sc->sc_link;

        /*
         * If the device is ancient, we want to make sure that
         * the transfer fits into a 6-byte cdb.
         *
         * XXX Note that the SCSI-I spec says that 256-block transfers
         * are allowed in a 6-byte read/write, and are specified
         * by setting the "length" to 0.  However, we're conservative
         * here, allowing only 255-block transfers in case an
         * ancient device gets confused by length == 0.  A length of 0
         * in a 10-byte read/write actually means 0 blocks.
         */
        if (!ISSET(link->flags, SDEV_ATAPI | SDEV_UMASS) &&
            SID_ANSII_REV(&link->inqdata) < SCSI_REV_2) {
                max = sc->sc_dk.dk_label->d_secsize * 0xff;

                if (bp->b_bcount > max)
                        bp->b_bcount = max;
        }

        if (link->bus->sb_adapter->dev_minphys != NULL)
                (*link->bus->sb_adapter->dev_minphys)(bp, link);
        else
                minphys(bp);

        device_unref(&sc->sc_dev);
}

int
sdread(dev_t dev, struct uio *uio, int ioflag)
{
        return physio(sdstrategy, dev, B_READ, sdminphys, uio);
}

int
sdwrite(dev_t dev, struct uio *uio, int ioflag)
{
        return physio(sdstrategy, dev, B_WRITE, sdminphys, uio);
}

/*
 * Perform special action on behalf of the user. Knows about the internals of
 * this device
 */
int
sdioctl(dev_t dev, u_long cmd, caddr_t addr, int flag, struct proc *p)
{
        struct scsi_link                *link;
        struct sd_softc                 *sc;
        struct disklabel                *lp;
        int                              error = 0;
        int                              part = DISKPART(dev);

        sc = sdlookup(DISKUNIT(dev));
        if (sc == NULL)
                return ENXIO;
        if (ISSET(sc->flags, SDF_DYING)) {
                device_unref(&sc->sc_dev);
                return ENXIO;
        }
        link = sc->sc_link;

        SC_DEBUG(link, SDEV_DB2, ("sdioctl 0x%lx\n", cmd));

        /*
         * If the device is not valid, abandon ship.
         */
        if (!ISSET(link->flags, SDEV_MEDIA_LOADED)) {
                switch (cmd) {
                case DIOCLOCK:
                case DIOCEJECT:
                case SCIOCIDENTIFY:
                case SCIOCCOMMAND:
                case SCIOCDEBUG:
                        if (part == RAW_PART)
                                break;
                /* FALLTHROUGH */
                default:
                        if (!ISSET(link->flags, SDEV_OPEN)) {
                                error = ENODEV;
                                goto exit;
                        } else {
                                error = EIO;
                                goto exit;
                        }
                }
        }

        switch (cmd) {
        case DIOCRLDINFO:
                lp = malloc(sizeof(*lp), M_TEMP, M_WAITOK);
                sdgetdisklabel(dev, sc, lp, 0);
                memcpy(sc->sc_dk.dk_label, lp, sizeof(*lp));
                free(lp, M_TEMP, sizeof(*lp));
                goto exit;

        case DIOCGPDINFO:
                sdgetdisklabel(dev, sc, (struct disklabel *)addr, 1);
                goto exit;

        case DIOCGDINFO:
                *(struct disklabel *)addr = *(sc->sc_dk.dk_label);
                goto exit;

        /* XXX temporary to support the transition to more partitions */
        case O_DIOCGDINFO:
                /* truncate the buffer, good enough */
                bcopy(sc->sc_dk.dk_label, addr, O_disklabel);
                goto exit;

        case DIOCGPART:
                ((struct partinfo *)addr)->disklab = sc->sc_dk.dk_label;
                ((struct partinfo *)addr)->part =
                    &sc->sc_dk.dk_label->d_partitions[DISKPART(dev)];
                goto exit;

        case DIOCWDINFO:
        case DIOCSDINFO:
                if (!ISSET(flag, FWRITE)) {
                        error = EBADF;
                        goto exit;
                }

                if ((error = disk_lock(&sc->sc_dk)) != 0)
                        goto exit;

                error = setdisklabel(sc->sc_dk.dk_label,
                    (struct disklabel *)addr, sc->sc_dk.dk_openmask);
                if (error == 0) {
                        if (cmd == DIOCWDINFO)
                                error = writedisklabel(DISKLABELDEV(dev),
                                    sdstrategy, sc->sc_dk.dk_label);
                }

                disk_unlock(&sc->sc_dk);
                goto exit;

        case DIOCLOCK:
                error = scsi_prevent(link,
                    (*(int *)addr) ? PR_PREVENT : PR_ALLOW, 0);
                goto exit;

        case MTIOCTOP:
                if (((struct mtop *)addr)->mt_op != MTOFFL) {
                        error = EIO;
                        goto exit;
                }
                /* FALLTHROUGH */
        case DIOCEJECT:
                if (!ISSET(link->flags, SDEV_REMOVABLE)) {
                        error = ENOTTY;
                        goto exit;
                }
                SET(link->flags, SDEV_EJECTING);
                goto exit;

        case DIOCINQ:
                error = scsi_do_ioctl(link, cmd, addr, flag);
                if (error == ENOTTY)
                        error = sd_ioctl_inquiry(sc,
                            (struct dk_inquiry *)addr);
                goto exit;

        case DIOCSCACHE:
                if (!ISSET(flag, FWRITE)) {
                        error = EBADF;
                        goto exit;
                }
                /* FALLTHROUGH */
        case DIOCGCACHE:
                error = sd_ioctl_cache(sc, cmd, (struct dk_cache *)addr);
                goto exit;

        case DIOCCACHESYNC:
                if (!ISSET(flag, FWRITE)) {
                        error = EBADF;
                        goto exit;
                }
                if (ISSET(sc->flags, SDF_DIRTY) || *(int *)addr != 0)
                        error = sd_flush(sc, 0);
                goto exit;

        default:
                if (part != RAW_PART) {
                        error = ENOTTY;
                        goto exit;
                }
                error = scsi_do_ioctl(link, cmd, addr, flag);
        }

 exit:
        device_unref(&sc->sc_dev);
        return error;
}

int
sd_ioctl_inquiry(struct sd_softc *sc, struct dk_inquiry *di)
{
        struct scsi_link                *link;
        struct scsi_vpd_serial          *vpd;

        vpd = dma_alloc(sizeof(*vpd), PR_WAITOK | PR_ZERO);

        if (ISSET(sc->flags, SDF_DYING)) {
                dma_free(vpd, sizeof(*vpd));
                return ENXIO;
        }
        link = sc->sc_link;

        bzero(di, sizeof(struct dk_inquiry));
        scsi_strvis(di->vendor, link->inqdata.vendor,
            sizeof(link->inqdata.vendor));
        scsi_strvis(di->product, link->inqdata.product,
            sizeof(link->inqdata.product));
        scsi_strvis(di->revision, link->inqdata.revision,
            sizeof(link->inqdata.revision));

        /* the serial vpd page is optional */
        if (scsi_inquire_vpd(link, vpd, sizeof(*vpd), SI_PG_SERIAL, 0) == 0)
                scsi_strvis(di->serial, vpd->serial, sizeof(vpd->serial));
        else
                strlcpy(di->serial, "(unknown)", sizeof(vpd->serial));

        dma_free(vpd, sizeof(*vpd));
        return 0;
}

int
sd_ioctl_cache(struct sd_softc *sc, long cmd, struct dk_cache *dkc)
{
        struct scsi_link                *link;
        union scsi_mode_sense_buf       *buf;
        struct page_caching_mode        *mode = NULL;
        u_int                            wrcache, rdcache;
        int                              big, rv;

        if (ISSET(sc->flags, SDF_DYING))
                return ENXIO;
        link = sc->sc_link;

        if (ISSET(link->flags, SDEV_UMASS))
                return EOPNOTSUPP;

        /* See if the adapter has special handling. */
        rv = scsi_do_ioctl(link, cmd, (caddr_t)dkc, 0);
        if (rv != ENOTTY)
                return rv;

        buf = dma_alloc(sizeof(*buf), PR_WAITOK);
        if (buf == NULL)
                return ENOMEM;

        if (ISSET(sc->flags, SDF_DYING)) {
                rv = ENXIO;
                goto done;
        }
        rv = scsi_do_mode_sense(link, PAGE_CACHING_MODE, buf, (void **)&mode,
            sizeof(*mode) - 4, scsi_autoconf | SCSI_SILENT, &big);
        if (rv == 0 && mode == NULL)
                rv = EIO;
        if (rv != 0)
                goto done;

        wrcache = (ISSET(mode->flags, PG_CACHE_FL_WCE) ? 1 : 0);
        rdcache = (ISSET(mode->flags, PG_CACHE_FL_RCD) ? 0 : 1);

        switch (cmd) {
        case DIOCGCACHE:
                dkc->wrcache = wrcache;
                dkc->rdcache = rdcache;
                break;

        case DIOCSCACHE:
                if (dkc->wrcache == wrcache && dkc->rdcache == rdcache)
                        break;

                if (dkc->wrcache)
                        SET(mode->flags, PG_CACHE_FL_WCE);
                else
                        CLR(mode->flags, PG_CACHE_FL_WCE);

                if (dkc->rdcache)
                        CLR(mode->flags, PG_CACHE_FL_RCD);
                else
                        SET(mode->flags, PG_CACHE_FL_RCD);

                if (ISSET(sc->flags, SDF_DYING)) {
                        rv = ENXIO;
                        goto done;
                }
                if (big) {
                        rv = scsi_mode_select_big(link, SMS_PF,
                            &buf->hdr_big, scsi_autoconf | SCSI_SILENT, 20000);
                } else {
                        rv = scsi_mode_select(link, SMS_PF,
                            &buf->hdr, scsi_autoconf | SCSI_SILENT, 20000);
                }
                break;
        }

done:
        dma_free(buf, sizeof(*buf));
        return rv;
}

/*
 * Load the label information on the named device.
 */
int
sdgetdisklabel(dev_t dev, struct sd_softc *sc, struct disklabel *lp,
    int spoofonly)
{
        char                             packname[sizeof(lp->d_packname) + 1];
        char                             product[17], vendor[9];
        struct scsi_link                *link;
        size_t                           len;

        if (ISSET(sc->flags, SDF_DYING))
                return ENXIO;
        link = sc->sc_link;

        bzero(lp, sizeof(struct disklabel));

        lp->d_secsize = sc->params.secsize;
        lp->d_ntracks = sc->params.heads;
        lp->d_nsectors = sc->params.sectors;
        lp->d_ncylinders = sc->params.cyls;
        lp->d_secpercyl = lp->d_ntracks * lp->d_nsectors;
        if (lp->d_secpercyl == 0) {
                lp->d_secpercyl = 100;
                /* As long as it's not 0 - readdisklabel divides by it. */
        }

        if (ISSET(link->flags, SDEV_UFI)) {
                lp->d_type = DTYPE_FLOPPY;
                strncpy(lp->d_typename, "USB floppy disk",
                    sizeof(lp->d_typename));
        } else {
                lp->d_type = DTYPE_SCSI;
                if ((link->inqdata.device & SID_TYPE) == T_OPTICAL)
                        strncpy(lp->d_typename, "SCSI optical",
                            sizeof(lp->d_typename));
                else
                        strncpy(lp->d_typename, "SCSI disk",
                            sizeof(lp->d_typename));
        }

        /*
         * Try to fit '<vendor> <product>' into d_packname. If that doesn't fit
         * then leave out '<vendor> ' and use only as much of '<product>' as
         * does fit.
         */
        viscpy(vendor, link->inqdata.vendor, 8);
        viscpy(product, link->inqdata.product, 16);
        len = snprintf(packname, sizeof(packname), "%s %s", vendor, product);
        if (len > sizeof(lp->d_packname)) {
                strlcpy(packname, product, sizeof(packname));
                len = strlen(packname);
        }
        /*
         * It is safe to use len as the count of characters to copy because
         * packname is sizeof(lp->d_packname)+1, the string in packname is
         * always null terminated and len does not count the terminating null.
         * d_packname is not a null terminated string.
         */
        memcpy(lp->d_packname, packname, len);

        DL_SETDSIZE(lp, sc->params.disksize);
        lp->d_version = 1;

        lp->d_magic = DISKMAGIC;
        lp->d_magic2 = DISKMAGIC;
        lp->d_checksum = dkcksum(lp);

        /*
         * Call the generic disklabel extraction routine.
         */
        return readdisklabel(DISKLABELDEV(dev), sdstrategy, lp, spoofonly);
}


/*
 * Check Errors.
 */
int
sd_interpret_sense(struct scsi_xfer *xs)
{
        struct scsi_sense_data          *sense = &xs->sense;
        struct scsi_link                *link = xs->sc_link;
        int                              retval;
        u_int8_t                         serr = sense->error_code & SSD_ERRCODE;

        /*
         * Let the generic code handle everything except a few categories of
         * LUN not ready errors on open devices.
         */
        if ((!ISSET(link->flags, SDEV_OPEN)) ||
            (serr != SSD_ERRCODE_CURRENT && serr != SSD_ERRCODE_DEFERRED) ||
            ((sense->flags & SSD_KEY) != SKEY_NOT_READY) ||
            (sense->extra_len < 6))
                return scsi_interpret_sense(xs);

        if (ISSET(xs->flags, SCSI_IGNORE_NOT_READY))
                return 0;

        switch (ASC_ASCQ(sense)) {
        case SENSE_NOT_READY_BECOMING_READY:
                SC_DEBUG(link, SDEV_DB1, ("becoming ready.\n"));
                retval = scsi_delay(xs, 5);
                break;

        case SENSE_NOT_READY_INIT_REQUIRED:
                SC_DEBUG(link, SDEV_DB1, ("spinning up\n"));
                retval = scsi_start(link, SSS_START,
                    SCSI_IGNORE_ILLEGAL_REQUEST | SCSI_NOSLEEP);
                if (retval == 0)
                        retval = ERESTART;
                else if (retval == ENOMEM)
                        /* Can't issue the command. Fall back on a delay. */
                        retval = scsi_delay(xs, 5);
                else
                        SC_DEBUG(link, SDEV_DB1, ("spin up failed (%#x)\n",
                            retval));
                break;

        default:
                retval = scsi_interpret_sense(xs);
                break;
        }

        return retval;
}

daddr_t
sdsize(dev_t dev)
{
        struct disklabel                *lp;
        struct sd_softc                 *sc;
        daddr_t                          size;
        int                              part;
        uint64_t                         omask;

        sc = sdlookup(DISKUNIT(dev));
        if (sc == NULL)
                return -1;
        if (ISSET(sc->flags, SDF_DYING)) {
                size = -1;
                goto exit;
        }

        part = DISKPART(dev);
        omask = sc->sc_dk.dk_openmask & (1ULL << part);

        if (omask == 0 && sdopen(dev, 0, S_IFBLK, NULL) != 0) {
                size = -1;
                goto exit;
        }

        lp = sc->sc_dk.dk_label;
        if (ISSET(sc->flags, SDF_DYING)) {
                size = -1;
                goto exit;
        }
        if (!ISSET(sc->sc_link->flags, SDEV_MEDIA_LOADED))
                size = -1;
        else if (lp->d_partitions[part].p_fstype != FS_SWAP)
                size = -1;
        else
                size = DL_SECTOBLK(lp, DL_GETPSIZE(&lp->d_partitions[part]));
        if (omask == 0 && sdclose(dev, 0, S_IFBLK, NULL) != 0)
                size = -1;

 exit:
        device_unref(&sc->sc_dev);
        return size;
}

/* #define SD_DUMP_NOT_TRUSTED if you just want to watch. */
static int sddoingadump;

/*
 * Dump all of physical memory into the partition specified, starting
 * at offset 'dumplo' into the partition.
 */
int
sddump(dev_t dev, daddr_t blkno, caddr_t va, size_t size)
{
        struct sd_softc                 *sc;
        struct disklabel                *lp;
        struct scsi_xfer                *xs;
        u_int64_t                        nsects;        /* partition sectors */
        u_int64_t                        sectoff;       /* partition offset */
        u_int64_t                        totwrt;        /* sectors left */
        int                              part, rv, unit;
        u_int32_t                        sectorsize;
        u_int32_t                        nwrt;          /* sectors to write */

        /* Check if recursive dump; if so, punt. */
        if (sddoingadump)
                return EFAULT;
        if (blkno < 0)
                return EINVAL;

        /* Mark as active early. */
        sddoingadump = 1;

        unit = DISKUNIT(dev);   /* Decompose unit & partition. */
        part = DISKPART(dev);

        /* Check for acceptable drive number. */
        if (unit >= sd_cd.cd_ndevs || (sc = sd_cd.cd_devs[unit]) == NULL)
                return ENXIO;

        /*
         * XXX Can't do this check, since the media might have been
         * XXX marked `invalid' by successful unmounting of all
         * XXX filesystems.
         */
#if 0
        /* Make sure it was initialized. */
        if (!ISSET(sc->sc_link->flags, SDEV_MEDIA_LOADED))
                return ENXIO;
#endif /* 0 */

        /* Convert to disk sectors. Request must be a multiple of size. */
        lp = sc->sc_dk.dk_label;
        sectorsize = lp->d_secsize;
        if ((size % sectorsize) != 0)
                return EFAULT;
        if ((blkno % DL_BLKSPERSEC(lp)) != 0)
                return EFAULT;
        totwrt = size / sectorsize;
        blkno = DL_BLKTOSEC(lp, blkno);

        nsects = DL_GETPSIZE(&lp->d_partitions[part]);
        sectoff = DL_GETPOFFSET(&lp->d_partitions[part]);

        /* Check transfer bounds against partition size. */
        if ((blkno + totwrt) > nsects)
                return EINVAL;

        /* Offset block number to start of partition. */
        blkno += sectoff;

        while (totwrt > 0) {
                if (totwrt > UINT32_MAX)
                        nwrt = UINT32_MAX;
                else
                        nwrt = totwrt;

#ifndef SD_DUMP_NOT_TRUSTED
                xs = scsi_xs_get(sc->sc_link, SCSI_NOSLEEP | SCSI_DATA_OUT);
                if (xs == NULL)
                        return ENOMEM;

                xs->timeout = 10000;
                xs->data = va;
                xs->datalen = nwrt * sectorsize;

                xs->cmdlen = sd_cmd_rw10(&xs->cmd, 0, blkno, nwrt); /* XXX */

                rv = scsi_xs_sync(xs);
                scsi_xs_put(xs);
                if (rv != 0)
                        return ENXIO;
#else   /* SD_DUMP_NOT_TRUSTED */
                /* Let's just talk about this first. */
                printf("sd%d: dump addr 0x%x, blk %lld\n", unit, va,
                    (long long)blkno);
                delay(500 * 1000);      /* 1/2 a second */
#endif  /* ~SD_DUMP_NOT_TRUSTED */

                /* Update block count. */
                totwrt -= nwrt;
                blkno += nwrt;
                va += sectorsize * nwrt;
        }

        sddoingadump = 0;

        return 0;
}

/*
 * Copy up to len chars from src to dst, ignoring non-printables.
 * Must be room for len+1 chars in dst so we can write the NUL.
 * Does not assume src is NUL-terminated.
 */
void
viscpy(u_char *dst, u_char *src, int len)
{
        while (len > 0 && *src != '\0') {
                if (*src < 0x20 || *src >= 0x80) {
                        src++;
                        continue;
                }
                *dst++ = *src++;
                len--;
        }
        *dst = '\0';
}

int
sd_read_cap_10(struct sd_softc *sc, int flags)
{
        struct scsi_read_cap_data       *rdcap;
        int                              rv;

        rdcap = dma_alloc(sizeof(*rdcap), (ISSET(flags, SCSI_NOSLEEP) ?
            PR_NOWAIT : PR_WAITOK) | PR_ZERO);
        if (rdcap == NULL)
                return -1;

        if (ISSET(sc->flags, SDF_DYING)) {
                rv = -1;
                goto done;
        }

        rv = scsi_read_cap_10(sc->sc_link, rdcap, flags);
        if (rv == 0) {
                if (_4btol(rdcap->addr) == 0) {
                        rv = -1;
                        goto done;
                }
                sc->params.disksize = _4btol(rdcap->addr) + 1ll;
                sc->params.secsize = _4btol(rdcap->length);
                CLR(sc->flags, SDF_THIN);
        }

done:
        dma_free(rdcap, sizeof(*rdcap));
        return rv;
}

int
sd_read_cap_16(struct sd_softc *sc, int flags)
{
        struct scsi_read_cap_data_16    *rdcap;
        int                              rv;

        rdcap = dma_alloc(sizeof(*rdcap), (ISSET(flags, SCSI_NOSLEEP) ?
            PR_NOWAIT : PR_WAITOK) | PR_ZERO);
        if (rdcap == NULL)
                return -1;

        if (ISSET(sc->flags, SDF_DYING)) {
                rv = -1;
                goto done;
        }

        rv = scsi_read_cap_16(sc->sc_link, rdcap, flags);
        if (rv == 0) {
                if (_8btol(rdcap->addr) == 0) {
                        rv = -1;
                        goto done;
                }
                sc->params.disksize = _8btol(rdcap->addr) + 1ll;
                sc->params.secsize = _4btol(rdcap->length);
                if (ISSET(_2btol(rdcap->lowest_aligned), READ_CAP_16_TPE))
                        SET(sc->flags, SDF_THIN);
                else
                        CLR(sc->flags, SDF_THIN);
        }

done:
        dma_free(rdcap, sizeof(*rdcap));
        return rv;
}

int
sd_read_cap(struct sd_softc *sc, int flags)
{
        int rv;

        CLR(flags, SCSI_IGNORE_ILLEGAL_REQUEST);

        /*
         * post-SPC2 (i.e. post-SCSI-3) devices can start with 16 byte
         * read capacity commands. Older devices start with the 10 byte
         * version and move up to the 16 byte version if the device
         * says it has more sectors than can be reported via the 10 byte
         * read capacity.
         */
        if (SID_ANSII_REV(&sc->sc_link->inqdata) > SCSI_REV_SPC2) {
                rv = sd_read_cap_16(sc, flags);
                if (rv != 0)
                        rv = sd_read_cap_10(sc, flags);
        } else {
                rv = sd_read_cap_10(sc, flags);
                if (rv == 0 && sc->params.disksize == 0x100000000ll)
                        rv = sd_read_cap_16(sc, flags);
        }

        return rv;
}

int
sd_thin_pages(struct sd_softc *sc, int flags)
{
        struct scsi_vpd_hdr             *pg;
        u_int8_t                        *pages;
        size_t                           len = 0;
        int                              i, rv, score = 0;

        pg = dma_alloc(sizeof(*pg), (ISSET(flags, SCSI_NOSLEEP) ?
            PR_NOWAIT : PR_WAITOK) | PR_ZERO);
        if (pg == NULL)
                return ENOMEM;

        if (ISSET(sc->flags, SDF_DYING)) {
                rv = ENXIO;
                goto done;
        }
        rv = scsi_inquire_vpd(sc->sc_link, pg, sizeof(*pg),
            SI_PG_SUPPORTED, flags);
        if (rv != 0)
                goto done;

        len = _2btol(pg->page_length);

        dma_free(pg, sizeof(*pg));
        pg = dma_alloc(sizeof(*pg) + len, (ISSET(flags, SCSI_NOSLEEP) ?
            PR_NOWAIT : PR_WAITOK) | PR_ZERO);
        if (pg == NULL)
                return ENOMEM;

        if (ISSET(sc->flags, SDF_DYING)) {
                rv = ENXIO;
                goto done;
        }
        rv = scsi_inquire_vpd(sc->sc_link, pg, sizeof(*pg) + len,
            SI_PG_SUPPORTED, flags);
        if (rv != 0)
                goto done;

        pages = (u_int8_t *)(pg + 1);
        if (pages[0] != SI_PG_SUPPORTED) {
                rv = EIO;
                goto done;
        }

        for (i = 1; i < len; i++) {
                switch (pages[i]) {
                case SI_PG_DISK_LIMITS:
                case SI_PG_DISK_THIN:
                        score++;
                        break;
                }
        }

        if (score < 2)
                rv = EOPNOTSUPP;

done:
        dma_free(pg, sizeof(*pg) + len);
        return rv;
}

int
sd_vpd_block_limits(struct sd_softc *sc, int flags)
{
        struct scsi_vpd_disk_limits     *pg;
        int                              rv;

        pg = dma_alloc(sizeof(*pg), (ISSET(flags, SCSI_NOSLEEP) ?
            PR_NOWAIT : PR_WAITOK) | PR_ZERO);
        if (pg == NULL)
                return ENOMEM;

        if (ISSET(sc->flags, SDF_DYING)) {
                rv = ENXIO;
                goto done;
        }
        rv = scsi_inquire_vpd(sc->sc_link, pg, sizeof(*pg),
            SI_PG_DISK_LIMITS, flags);
        if (rv != 0)
                goto done;

        if (_2btol(pg->hdr.page_length) == SI_PG_DISK_LIMITS_LEN_THIN) {
                sc->params.unmap_sectors = _4btol(pg->max_unmap_lba_count);
                sc->params.unmap_descs = _4btol(pg->max_unmap_desc_count);
        } else
                rv = EOPNOTSUPP;

done:
        dma_free(pg, sizeof(*pg));
        return rv;
}

int
sd_vpd_thin(struct sd_softc *sc, int flags)
{
        struct scsi_vpd_disk_thin       *pg;
        int                              rv;

        pg = dma_alloc(sizeof(*pg), (ISSET(flags, SCSI_NOSLEEP) ?
            PR_NOWAIT : PR_WAITOK) | PR_ZERO);
        if (pg == NULL)
                return ENOMEM;

        if (ISSET(sc->flags, SDF_DYING)) {
                rv = ENXIO;
                goto done;
        }
        rv = scsi_inquire_vpd(sc->sc_link, pg, sizeof(*pg),
            SI_PG_DISK_THIN, flags);
        if (rv != 0)
                goto done;

#ifdef notyet
        if (ISSET(pg->flags, VPD_DISK_THIN_TPU))
                sc->sc_delete = sd_unmap;
        else if (ISSET(pg->flags, VPD_DISK_THIN_TPWS)) {
                sc->sc_delete = sd_write_same_16;
                sc->params.unmap_descs = 1; /* WRITE SAME 16 only does one */
        } else
                rv = EOPNOTSUPP;
#endif /* notyet */

done:
        dma_free(pg, sizeof(*pg));
        return rv;
}

int
sd_thin_params(struct sd_softc *sc, int flags)
{
        int rv;

        rv = sd_thin_pages(sc, flags);
        if (rv != 0)
                return rv;

        rv = sd_vpd_block_limits(sc, flags);
        if (rv != 0)
                return rv;

        rv = sd_vpd_thin(sc, flags);
        if (rv != 0)
                return rv;

        return 0;
}

/*
 * Fill out the disk parameter structure. Return 0 if the structure is correctly
 * filled in, otherwise return -1.
 *
 * The caller is responsible for clearing the SDEV_MEDIA_LOADED flag if the
 * structure cannot be completed.
 */
int
sd_get_parms(struct sd_softc *sc, int flags)
{
        struct disk_parms                dp;
        struct scsi_link                *link = sc->sc_link;
        union scsi_mode_sense_buf       *buf = NULL;
        struct page_rigid_geometry      *rigid = NULL;
        struct page_flex_geometry       *flex = NULL;
        struct page_reduced_geometry    *reduced = NULL;
        u_char                          *page0 = NULL;
        int                              big, err = 0;

        if (sd_read_cap(sc, flags) != 0)
                return -1;

        if (ISSET(sc->flags, SDF_THIN) && sd_thin_params(sc, flags) != 0) {
                /* we don't know the unmap limits, so we can't use this shizz */
                CLR(sc->flags, SDF_THIN);
        }

        /*
         * Work on a copy of the values initialized by sd_read_cap() and
         * sd_thin_params().
         */
        dp = sc->params;

        buf = dma_alloc(sizeof(*buf), PR_NOWAIT);
        if (buf == NULL)
                goto validate;

        if (ISSET(sc->flags, SDF_DYING))
                goto die;

        /*
         * Ask for page 0 (vendor specific) mode sense data to find
         * READONLY info. The only thing USB devices will ask for.
         *
         * page0 == NULL is a valid situation.
         */
        err = scsi_do_mode_sense(link, 0, buf, (void **)&page0, 1,
            flags | SCSI_SILENT, &big);
        if (ISSET(sc->flags, SDF_DYING))
                goto die;
        if (err == 0) {
                if (big && buf->hdr_big.dev_spec & SMH_DSP_WRITE_PROT)
                        SET(link->flags, SDEV_READONLY);
                else if (!big && buf->hdr.dev_spec & SMH_DSP_WRITE_PROT)
                        SET(link->flags, SDEV_READONLY);
                else
                        CLR(link->flags, SDEV_READONLY);
        }

        /*
         * Many UMASS devices choke when asked about their geometry. Most
         * don't have a meaningful geometry anyway, so just fake it if
         * sd_read_cap() worked.
         */
        if (ISSET(link->flags, SDEV_UMASS) && dp.disksize > 0)
                goto validate;

        switch (link->inqdata.device & SID_TYPE) {
        case T_OPTICAL:
                /* No more information needed or available. */
                break;

        case T_RDIRECT:
                /* T_RDIRECT supports only PAGE_REDUCED_GEOMETRY (6). */
                err = scsi_do_mode_sense(link, PAGE_REDUCED_GEOMETRY, buf,
                    (void **)&reduced, sizeof(*reduced), flags | SCSI_SILENT,
                    &big);
                if (err == 0) {
                        scsi_parse_blkdesc(link, buf, big, NULL, NULL,
                            &dp.secsize);
                        if (reduced != NULL) {
                                if (dp.disksize == 0)
                                        dp.disksize = _5btol(reduced->sectors);
                                if (dp.secsize == 0)
                                        dp.secsize = _2btol(reduced->bytes_s);
                        }
                }
                break;

        default:
                /*
                 * NOTE: Some devices leave off the last four bytes of
                 * PAGE_RIGID_GEOMETRY and PAGE_FLEX_GEOMETRY mode sense pages.
                 * The only information in those four bytes is RPM information
                 * so accept the page. The extra bytes will be zero and RPM will
                 * end up with the default value of 3600.
                 */
                err = 0;
                if (!ISSET(link->flags, SDEV_ATAPI) ||
                    !ISSET(link->flags, SDEV_REMOVABLE))
                        err = scsi_do_mode_sense(link, PAGE_RIGID_GEOMETRY, buf,
                            (void **)&rigid, sizeof(*rigid) - 4,
                            flags | SCSI_SILENT, &big);
                if (err == 0) {
                        scsi_parse_blkdesc(link, buf, big, NULL, NULL,
                            &dp.secsize);
                        if (rigid != NULL) {
                                dp.heads = rigid->nheads;
                                dp.cyls = _3btol(rigid->ncyl);
                                if (dp.heads * dp.cyls > 0)
                                        dp.sectors = dp.disksize / (dp.heads *
                                            dp.cyls);
                        }
                } else {
                        if (ISSET(sc->flags, SDF_DYING))
                                goto die;
                        err = scsi_do_mode_sense(link, PAGE_FLEX_GEOMETRY, buf,
                            (void **)&flex, sizeof(*flex) - 4,
                            flags | SCSI_SILENT, &big);
                        if (err == 0) {
                                scsi_parse_blkdesc(link, buf, big, NULL, NULL,
                                    &dp.secsize);
                                if (flex != NULL) {
                                        dp.sectors = flex->ph_sec_tr;
                                        dp.heads = flex->nheads;
                                        dp.cyls = _2btol(flex->ncyl);
                                        if (dp.secsize == 0)
                                                dp.secsize =
                                                    _2btol(flex->bytes_s);
                                        if (dp.disksize == 0)
                                                dp.disksize =
                                                    (u_int64_t)dp.cyls *
                                                    dp.heads * dp.sectors;
                                }
                        }
                }
                break;
        }

validate:
        if (buf) {
                dma_free(buf, sizeof(*buf));
                buf = NULL;
        }

        if (dp.disksize == 0)
                return -1;

        /*
         * Restrict secsize values to powers of two between 512 and 64k.
         */
        switch (dp.secsize) {
        case 0:
                dp.secsize = DEV_BSIZE;
                break;
        case 0x200:     /* == 512, == DEV_BSIZE on all architectures. */
        case 0x400:
        case 0x800:
        case 0x1000:
        case 0x2000:
        case 0x4000:
        case 0x8000:
        case 0x10000:
                break;
        default:
                SC_DEBUG(sc->sc_link, SDEV_DB1,
                    ("sd_get_parms: bad secsize: %#x\n", dp.secsize));
                return -1;
        }

        /*
         * XXX THINK ABOUT THIS!!  Using values such that sectors * heads *
         * cyls is <= disk_size can lead to wasted space. We need a more
         * careful calculation/validation to make everything work out
         * optimally.
         */
        if (dp.disksize > 0xffffffff && (dp.heads * dp.sectors) < 0xffff) {
                dp.heads = 511;
                dp.sectors = 255;
                dp.cyls = 0;
        }

        /*
         * Use standard geometry values for anything we still don't
         * know.
         */
        if (dp.heads == 0)
                dp.heads = 255;
        if (dp.sectors == 0)
                dp.sectors = 63;
        if (dp.cyls == 0) {
                dp.cyls = dp.disksize / (dp.heads * dp.sectors);
                if (dp.cyls == 0) {
                        /* Put everything into one cylinder. */
                        dp.heads = dp.cyls = 1;
                        dp.sectors = dp.disksize;
                }
        }

#ifdef SCSIDEBUG
        if (dp.disksize != (u_int64_t)dp.cyls * dp.heads * dp.sectors) {
                sc_print_addr(sc->sc_link);
                printf("disksize (%llu) != cyls (%u) * heads (%u) * "
                    "sectors/track (%u) (%llu)\n", dp.disksize, dp.cyls,
                    dp.heads, dp.sectors,
                    (u_int64_t)dp.cyls * dp.heads * dp.sectors);
        }
#endif /* SCSIDEBUG */

        sc->params = dp;
        return 0;

die:
        dma_free(buf, sizeof(*buf));
        return -1;
}

int
sd_flush(struct sd_softc *sc, int flags)
{
        struct scsi_link                *link;
        struct scsi_xfer                *xs;
        struct scsi_synchronize_cache   *cmd;
        int                              error;

        if (ISSET(sc->flags, SDF_DYING))
                return ENXIO;
        link = sc->sc_link;

        if (ISSET(link->quirks, SDEV_NOSYNCCACHE))
                return 0;

        /*
         * Issue a SYNCHRONIZE CACHE. Address 0, length 0 means "all remaining
         * blocks starting at address 0". Ignore ILLEGAL REQUEST in the event
         * that the command is not supported by the device.
         */

        xs = scsi_xs_get(link, flags | SCSI_IGNORE_ILLEGAL_REQUEST);
        if (xs == NULL) {
                SC_DEBUG(link, SDEV_DB1, ("cache sync failed to get xs\n"));
                return EIO;
        }

        cmd = (struct scsi_synchronize_cache *)&xs->cmd;
        cmd->opcode = SYNCHRONIZE_CACHE;

        xs->cmdlen = sizeof(*cmd);
        xs->timeout = 100000;

        error = scsi_xs_sync(xs);

        scsi_xs_put(xs);

        if (error)
                SC_DEBUG(link, SDEV_DB1, ("cache sync failed\n"));
        else
                CLR(sc->flags, SDF_DIRTY);

        return error;
}