/*      $NetBSD: sd.c,v 1.345 2025/04/13 14:01:00 jakllsch 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 ([email protected])
* 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 ([email protected])
* Sept 1992
*/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: sd.c,v 1.345 2025/04/13 14:01:00 jakllsch Exp $");

#ifdef _KERNEL_OPT
#include "opt_scsi.h"
#endif

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/scsiio.h>
#include <sys/buf.h>
#include <sys/bufq.h>
#include <sys/uio.h>
#include <sys/malloc.h>
#include <sys/errno.h>
#include <sys/device.h>
#include <sys/disklabel.h>
#include <sys/disk.h>
#include <sys/proc.h>
#include <sys/conf.h>
#include <sys/vnode.h>

#include <dev/scsipi/scsi_spc.h>
#include <dev/scsipi/scsipi_all.h>
#include <dev/scsipi/scsi_all.h>
#include <dev/scsipi/scsipi_disk.h>
#include <dev/scsipi/scsi_disk.h>
#include <dev/scsipi/scsiconf.h>
#include <dev/scsipi/scsipi_base.h>
#include <dev/scsipi/sdvar.h>

#include <prop/proplib.h>

#define SDUNIT(dev)                     DISKUNIT(dev)
#define SDPART(dev)                     DISKPART(dev)
#define SDMINOR(unit, part)             DISKMINOR(unit, part)
#define MAKESDDEV(maj, unit, part)      MAKEDISKDEV(maj, unit, part)

#define SDLABELDEV(dev) (MAKESDDEV(major(dev), SDUNIT(dev), RAW_PART))

#define SD_DEFAULT_BLKSIZE      512

static void     sdminphys(struct buf *);
static void     sdstart(struct scsipi_periph *);
static void     sdrestart(void *);
static void     sddone(struct scsipi_xfer *, int);
static bool     sd_suspend(device_t, const pmf_qual_t *);
static bool     sd_shutdown(device_t, int);
static int      sd_interpret_sense(struct scsipi_xfer *);
static int      sd_diskstart(device_t, struct buf *);
static int      sd_dumpblocks(device_t, void *, daddr_t, int);
static void     sd_iosize(device_t, int *);
static int      sd_lastclose(device_t);
static int      sd_firstopen(device_t, dev_t, int, int);
static void     sd_label(device_t, struct disklabel *);
static int      sd_discard(device_t, off_t, off_t);

static int      sd_mode_sense(struct sd_softc *, u_int8_t, void *, size_t, int,
                   int, int *);
static int      sd_mode_select(struct sd_softc *, u_int8_t, void *, size_t,
                   int, int);
static int      sd_validate_blksize(struct scsipi_periph *, int);
static u_int64_t sd_read_capacity(struct sd_softc *, int *, int flags);
static int      sd_get_simplifiedparms(struct sd_softc *, struct disk_parms *,
                   int);
static int      sd_get_capacity(struct sd_softc *, struct disk_parms *, int);
static int      sd_get_parms(struct sd_softc *, struct disk_parms *, int);
static int      sd_get_parms_page4(struct sd_softc *, struct disk_parms *,
                   int);
static int      sd_get_parms_page5(struct sd_softc *, struct disk_parms *,
                   int);

static int      sd_flush(struct sd_softc *, int);
static int      sd_getcache(struct sd_softc *, int *);
static int      sd_setcache(struct sd_softc *, int);

static int      sdmatch(device_t, cfdata_t, void *);
static void     sdattach(device_t, device_t, void *);
static int      sddetach(device_t, int);
static void     sd_set_geometry(struct sd_softc *);

CFATTACH_DECL3_NEW(sd, sizeof(struct sd_softc), sdmatch, sdattach, sddetach,
   NULL, NULL, NULL, DVF_DETACH_SHUTDOWN);

extern struct cfdriver sd_cd;

static const struct scsipi_inquiry_pattern sd_patterns[] = {
       {T_DIRECT, T_FIXED,
        "",         "",                 ""},
       {T_DIRECT, T_REMOV,
        "",         "",                 ""},
       {T_OPTICAL, T_FIXED,
        "",         "",                 ""},
       {T_OPTICAL, T_REMOV,
        "",         "",                 ""},
       {T_SIMPLE_DIRECT, T_FIXED,
        "",         "",                 ""},
       {T_SIMPLE_DIRECT, T_REMOV,
        "",         "",                 ""},
};

static dev_type_open(sdopen);
static dev_type_close(sdclose);
static dev_type_read(sdread);
static dev_type_write(sdwrite);
static dev_type_ioctl(sdioctl);
static dev_type_strategy(sdstrategy);
static dev_type_dump(sddump);
static dev_type_size(sdsize);
static dev_type_discard(sddiscard);

const struct bdevsw sd_bdevsw = {
       .d_open = sdopen,
       .d_close = sdclose,
       .d_strategy = sdstrategy,
       .d_ioctl = sdioctl,
       .d_dump = sddump,
       .d_psize = sdsize,
       .d_discard = sddiscard,
       .d_cfdriver = &sd_cd,
       .d_devtounit = disklabel_dev_unit,
       .d_flag = D_DISK | D_MPSAFE
};

const struct cdevsw sd_cdevsw = {
       .d_open = sdopen,
       .d_close = sdclose,
       .d_read = sdread,
       .d_write = sdwrite,
       .d_ioctl = sdioctl,
       .d_stop = nostop,
       .d_tty = notty,
       .d_poll = nopoll,
       .d_mmap = nommap,
       .d_kqfilter = nokqfilter,
       .d_discard = sddiscard,
       .d_cfdriver = &sd_cd,
       .d_devtounit = disklabel_dev_unit,
       .d_flag = D_DISK | D_MPSAFE
};

static const struct dkdriver sddkdriver = {
       .d_open = sdopen,
       .d_close = sdclose,
       .d_strategy = sdstrategy,
       .d_minphys = sdminphys,
       .d_diskstart = sd_diskstart,
       .d_dumpblocks = sd_dumpblocks,
       .d_iosize = sd_iosize,
       .d_firstopen = sd_firstopen,
       .d_lastclose = sd_lastclose,
       .d_label = sd_label,
       .d_discard = sd_discard,
};

static const struct scsipi_periphsw sd_switch = {
       sd_interpret_sense,     /* check our error handler first */
       sdstart,                /* have a queue, served by this */
       NULL,                   /* have no async handler */
       sddone,                 /* deal with stats at interrupt time */
};

struct sd_mode_sense_data {
       /*
        * XXX
        * We are not going to parse this as-is -- it just has to be large
        * enough.
        */
       union {
               struct scsi_mode_parameter_header_6 small;
               struct scsi_mode_parameter_header_10 big;
       } header;
       struct scsi_general_block_descriptor blk_desc;
       union scsi_disk_pages pages;
};

/*
* The routine called by the low level scsi routine when it discovers
* A device suitable for this driver
*/
static int
sdmatch(device_t parent, cfdata_t match,
   void *aux)
{
       struct scsipibus_attach_args *sa = aux;
       int priority;

       (void)scsipi_inqmatch(&sa->sa_inqbuf,
           sd_patterns, sizeof(sd_patterns) / sizeof(sd_patterns[0]),
           sizeof(sd_patterns[0]), &priority);

       return (priority);
}

/*
* Attach routine common to atapi & scsi.
*/
static void
sdattach(device_t parent, device_t self, void *aux)
{
       struct sd_softc *sd = device_private(self);
       struct dk_softc *dksc = &sd->sc_dksc;
       struct scsipibus_attach_args *sa = aux;
       struct scsipi_periph *periph = sa->sa_periph;
       int error, result, dtype;
       struct disk_parms *dp = &sd->params;
       char pbuf[9];

       SC_DEBUG(periph, SCSIPI_DB2, ("sdattach: "));

       sd->type = (sa->sa_inqbuf.type & SID_TYPE);
       memcpy(sd->name, sa->sa_inqbuf.product, uimin(16, sizeof(sd->name)));
       memcpy(sd->typename, sa->sa_inqbuf.product,
           uimin(16, sizeof(sd->typename)));

       if (sd->type == T_SIMPLE_DIRECT) {
               periph->periph_quirks |= PQUIRK_ONLYBIG;
               periph->periph_quirks |= PQUIRK_NOBIGMODESENSE;
       }

       switch (SCSIPI_BUSTYPE_TYPE(scsipi_periph_bustype(sa->sa_periph))) {
       case SCSIPI_BUSTYPE_SCSI:
               dtype = DKTYPE_SCSI;
               if (periph->periph_version == 0)
                       sd->flags |= SDF_ANCIENT;
               break;
       case SCSIPI_BUSTYPE_ATAPI:
               dtype = DKTYPE_ATAPI;
               break;
       default:
               dtype = DKTYPE_UNKNOWN;
               break;
       }

       /* Initialize dk and disk structure. */
       dk_init(dksc, self, dtype);
       disk_init(&dksc->sc_dkdev, dksc->sc_xname, &sddkdriver);

       /* Attach dk and disk subsystems */
       dk_attach(dksc);
       disk_attach(&dksc->sc_dkdev);

       bufq_alloc(&dksc->sc_bufq, BUFQ_DISK_DEFAULT_STRAT,
           BUFQ_SORT_RAWBLOCK);

       callout_init(&sd->sc_callout, 0);

       /*
        * Store information needed to contact our base driver
        */
       sd->sc_periph = periph;

       periph->periph_dev = dksc->sc_dev;
       periph->periph_switch = &sd_switch;

       /*
        * Increase our openings to the maximum-per-periph
        * supported by the adapter.  This will either be
        * clamped down or grown by the adapter if necessary.
        */
       periph->periph_openings =
           SCSIPI_CHAN_MAX_PERIPH(periph->periph_channel);
       periph->periph_flags |= PERIPH_GROW_OPENINGS;

       /*
        * Use the subdriver to request information regarding the drive.
        */
       aprint_naive("\n");
       aprint_normal("\n");

       if (periph->periph_quirks & PQUIRK_START)
               (void)scsipi_start(periph, SSS_START, XS_CTL_SILENT);

       error = scsipi_test_unit_ready(periph,
           XS_CTL_DISCOVERY | XS_CTL_IGNORE_ILLEGAL_REQUEST |
           XS_CTL_IGNORE_MEDIA_CHANGE | XS_CTL_SILENT_NODEV);
       if (error)
               result = SDGP_RESULT_OFFLINE;
       else
               result = sd_get_parms(sd, &sd->params, XS_CTL_DISCOVERY);

       aprint_normal_dev(dksc->sc_dev, "");
       switch (result) {
       case SDGP_RESULT_OK:
               format_bytes(pbuf, sizeof(pbuf),
                   (u_int64_t)dp->disksize * dp->blksize);
               aprint_normal("%s, %ld cyl, %ld head, %ld sec, %ld bytes/sect"
                   " x %llu sectors",
                   pbuf, dp->cyls, dp->heads, dp->sectors, dp->blksize,
                   (unsigned long long)dp->disksize);
               if (dp->lbppbe) {
                       aprint_normal(" (%lu bytes/physsect", dp->blksize <<
                           dp->lbppbe);
                       if (dp->lalba)
                               aprint_normal("; first aligned sector %u",
                                   dp->lalba);
                       aprint_normal(")");
               }
               break;

       case SDGP_RESULT_OFFLINE:
               aprint_normal("drive offline");
               break;

       case SDGP_RESULT_UNFORMATTED:
               aprint_normal("unformatted media");
               break;

#ifdef DIAGNOSTIC
       default:
               panic("sdattach: unknown result from get_parms");
               break;
#endif
       }
       aprint_normal("\n");

       /* Discover wedges on this disk if it is online */
       if (result == SDGP_RESULT_OK)
               dkwedge_discover(&dksc->sc_dkdev);

       /*
        * Establish a shutdown hook so that we can ensure that
        * our data has actually made it onto the platter at
        * shutdown time.  Note that this relies on the fact
        * that the shutdown hooks at the "leaves" of the device tree
        * are run, first (thus guaranteeing that our hook runs before
        * our ancestors').
        */
       if (!pmf_device_register1(self, sd_suspend, NULL, sd_shutdown))
               aprint_error_dev(self, "couldn't establish power handler\n");
}

static int
sddetach(device_t self, int flags)
{
       struct sd_softc *sd = device_private(self);
       struct dk_softc *dksc = &sd->sc_dksc;
       struct scsipi_periph *periph = sd->sc_periph;
       struct scsipi_channel *chan = periph->periph_channel;
       int bmaj, cmaj, i, mn, rc;

       rc = disk_begindetach(&dksc->sc_dkdev, sd_lastclose, self, flags);
       if (rc)
               return rc;

       /* locate the major number */
       bmaj = bdevsw_lookup_major(&sd_bdevsw);
       cmaj = cdevsw_lookup_major(&sd_cdevsw);

       /* Nuke the vnodes for any open instances */
       for (i = 0; i < MAXPARTITIONS; i++) {
               mn = SDMINOR(device_unit(self), i);
               vdevgone(bmaj, mn, mn, VBLK);
               vdevgone(cmaj, mn, mn, VCHR);
       }

       /* kill any pending restart */
       callout_halt(&sd->sc_callout, NULL);

       dk_drain(dksc);

       /* Kill off any pending commands. */
       mutex_enter(chan_mtx(chan));
       scsipi_kill_pending(periph);
       mutex_exit(chan_mtx(chan));

       bufq_free(dksc->sc_bufq);

       /* Delete all of our wedges. */
       dkwedge_delall(&dksc->sc_dkdev);

       /* Detach from the disk list. */
       disk_detach(&dksc->sc_dkdev);
       disk_destroy(&dksc->sc_dkdev);

       dk_detach(dksc);

       callout_destroy(&sd->sc_callout);

       pmf_device_deregister(self);

       return (0);
}

/*
* Serialized by caller
*/
static int
sd_firstopen(device_t self, dev_t dev, int flag, int fmt)
{
       struct sd_softc *sd = device_private(self);
       struct scsipi_periph *periph = sd->sc_periph;
       struct scsipi_adapter *adapt = periph->periph_channel->chan_adapter;
       int error, silent;
       int part, removable;

       part = SDPART(dev);

       error = scsipi_adapter_addref(adapt);
       if (error)
               return error;

       if ((part == RAW_PART && fmt == S_IFCHR) || (flag & FSILENT))
               silent = XS_CTL_SILENT;
       else
               silent = 0;

       /* Check that it is still responding and ok. */
       error = scsipi_test_unit_ready(periph,
           XS_CTL_IGNORE_ILLEGAL_REQUEST | XS_CTL_IGNORE_MEDIA_CHANGE |
           silent);

       /*
        * Start the pack spinning if necessary. Always allow the
        * raw partition to be opened, for raw IOCTLs. Data transfers
        * will check for SDEV_MEDIA_LOADED.
        */
       if (error == EIO) {
               error = scsipi_start(periph, SSS_START, silent);
               if (error == EINVAL)
                       error = EIO;
       }
       if (error)
               goto bad;

       removable = (periph->periph_flags & PERIPH_REMOVABLE) != 0;
       if (removable) {
               /* Lock the pack in. */
               error = scsipi_prevent(periph, SPAMR_PREVENT_DT,
                   XS_CTL_IGNORE_ILLEGAL_REQUEST |
                   XS_CTL_IGNORE_MEDIA_CHANGE |
                   XS_CTL_SILENT);
               if (error)
                       goto bad;
       }

       if ((periph->periph_flags & PERIPH_MEDIA_LOADED) == 0) {
               int param_error;

               /*
                * Load the physical device parameters.
                *
                * Note that if media is present but unformatted,
                * we allow the open (so that it can be formatted!).
                * The drive should refuse real I/O, if the media is
                * unformatted.
                */
               param_error = sd_get_parms(sd, &sd->params, 0);
               if (param_error == SDGP_RESULT_OFFLINE) {
                       error = ENXIO;
                       goto bad2;
               }
               periph->periph_flags |= PERIPH_MEDIA_LOADED;

               SC_DEBUG(periph, SCSIPI_DB3, ("Params loaded "));
       }

       periph->periph_flags |= PERIPH_OPEN;
       return 0;

bad2:
       if (removable)
               scsipi_prevent(periph, SPAMR_ALLOW,
                   XS_CTL_IGNORE_ILLEGAL_REQUEST |
                   XS_CTL_IGNORE_MEDIA_CHANGE |
                   XS_CTL_SILENT);

bad:
       scsipi_adapter_delref(adapt);
       return error;
}

/*
* open the device. Make sure the partition info is a up-to-date as can be.
*/
static int
sdopen(dev_t dev, int flag, int fmt, struct lwp *l)
{
       struct sd_softc *sd;
       struct dk_softc *dksc;
       struct scsipi_periph *periph;
       int unit, part;
       int error;

       unit = SDUNIT(dev);
       sd = device_lookup_private(&sd_cd, unit);
       if (sd == NULL)
               return (ENXIO);
       dksc = &sd->sc_dksc;

       if (!device_is_active(dksc->sc_dev))
               return (ENODEV);

       periph = sd->sc_periph;
       part = SDPART(dev);

       SC_DEBUG(periph, SCSIPI_DB1,
           ("sdopen: dev=0x%"PRIx64" (unit %d (of %d), partition %d)\n",
           dev, unit, sd_cd.cd_ndevs, SDPART(dev)));

       /*
        * If any partition is open, but the disk has been invalidated,
        * disallow further opens of non-raw partition
        */
       if ((periph->periph_flags & (PERIPH_OPEN | PERIPH_MEDIA_LOADED)) ==
           PERIPH_OPEN) {
               if (part != RAW_PART || fmt != S_IFCHR)
                       return EIO;
       }

       error = dk_open(dksc, dev, flag, fmt, l);

       SC_DEBUG(periph, SCSIPI_DB3, ("open complete\n"));

       return error;
}

/*
* Serialized by caller
*/
static int
sd_lastclose(device_t self)
{
       struct sd_softc *sd = device_private(self);
       struct dk_softc *dksc = &sd->sc_dksc;
       struct scsipi_periph *periph = sd->sc_periph;
       struct scsipi_adapter *adapt = periph->periph_channel->chan_adapter;

       /*
        * If the disk cache needs flushing, and the disk supports
        * it, do it now.
        */
       if ((sd->flags & SDF_DIRTY) != 0) {
               if (sd_flush(sd, 0)) {
                       aprint_error_dev(dksc->sc_dev,
                               "cache synchronization failed\n");
                       sd->flags &= ~SDF_FLUSHING;
               } else
                       sd->flags &= ~(SDF_FLUSHING|SDF_DIRTY);
       }

       scsipi_wait_drain(periph);

       if (periph->periph_flags & PERIPH_REMOVABLE)
               scsipi_prevent(periph, SPAMR_ALLOW,
                   XS_CTL_IGNORE_ILLEGAL_REQUEST |
                   XS_CTL_IGNORE_NOT_READY |
                   XS_CTL_SILENT);
       periph->periph_flags &= ~PERIPH_OPEN;

       scsipi_wait_drain(periph);

       scsipi_adapter_delref(adapt);

       return 0;
}

/*
* close the device.. only called if we are the LAST occurrence of an open
* device.  Convenient now but usually a pain.
*/
static int
sdclose(dev_t dev, int flag, int fmt, struct lwp *l)
{
       struct sd_softc *sd;
       struct dk_softc *dksc;
       int unit;

       unit = SDUNIT(dev);
       sd = device_lookup_private(&sd_cd, unit);
       dksc = &sd->sc_dksc;

       return dk_close(dksc, dev, flag, fmt, l);
}

/*
* 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.
*/
static void
sdstrategy(struct buf *bp)
{
       struct sd_softc *sd = device_lookup_private(&sd_cd, SDUNIT(bp->b_dev));
       struct dk_softc *dksc = &sd->sc_dksc;
       struct scsipi_periph *periph = sd->sc_periph;

       SC_DEBUG(sd->sc_periph, SCSIPI_DB2, ("sdstrategy "));
       SC_DEBUG(sd->sc_periph, SCSIPI_DB1,
           ("%d bytes @ blk %" PRId64 "\n", bp->b_bcount, bp->b_blkno));

       /*
        * If the device has been made invalid, error out
        */
       if ((periph->periph_flags & PERIPH_MEDIA_LOADED) == 0 ||
           !device_is_active(dksc->sc_dev)) {
               if (periph->periph_flags & PERIPH_OPEN)
                       bp->b_error = EIO;
               else
                       bp->b_error = ENODEV;

               bp->b_resid = bp->b_bcount;
               biodone(bp);
               return;
       }

       dk_strategy(dksc, bp);
}

/*
* Issue single I/O command
*
* Called from dk_start and implicitly from dk_strategy
*/
static int
sd_diskstart(device_t dev, struct buf *bp)
{
       struct sd_softc *sd = device_private(dev);
       struct scsipi_periph *periph = sd->sc_periph;
       struct scsipi_channel *chan = periph->periph_channel;
       struct scsipi_rw_16 cmd16;
       struct scsipi_rw_10 cmd_big;
       struct scsi_rw_6 cmd_small;
       struct scsipi_generic *cmdp;
       struct scsipi_xfer *xs;
       int error, flags, nblks, cmdlen;
       int cdb_flags;
       bool havefua = !(periph->periph_quirks & PQUIRK_NOFUA);

       mutex_enter(chan_mtx(chan));

       if (periph->periph_active >= periph->periph_openings) {
               error = EAGAIN;
               goto out;
       }

       /*
        * there is excess capacity, but a special waits
        * It'll need the adapter as soon as we clear out of the
        * way and let it run (user level wait).
        */
       if (periph->periph_flags & PERIPH_WAITING) {
               periph->periph_flags &= ~PERIPH_WAITING;
               cv_broadcast(periph_cv_periph(periph));
               error = EAGAIN;
               goto out;
       }

       /*
        * If the device has become invalid, abort all the
        * reads and writes until all files have been closed and
        * re-opened.
        */
       if (__predict_false(
           (periph->periph_flags & PERIPH_MEDIA_LOADED) == 0)) {
               error = EIO;
               goto out;
       }

       /*
        * Mark the disk dirty so that the cache will be
        * flushed on close.
        */
       if ((bp->b_flags & B_READ) == 0)
               sd->flags |= SDF_DIRTY;

       if (sd->params.blksize == DEV_BSIZE)
               nblks = bp->b_bcount >> DEV_BSHIFT;
       else
               nblks = howmany(bp->b_bcount, sd->params.blksize);

       /*
        * Pass FUA and/or DPO if requested. Must be done before CDB
        * selection, as 6-byte CDB doesn't support the flags.
        */
       cdb_flags = 0;
       if (havefua) {
               if (bp->b_flags & B_MEDIA_FUA)
                       cdb_flags |= SRWB_FUA;

               if (bp->b_flags & B_MEDIA_DPO)
                       cdb_flags |= SRWB_DPO;
       }

       /*
        * Fill out the scsi command.  Use the smallest CDB possible
        * (6-byte, 10-byte, or 16-byte). If we need FUA or DPO,
        * need to use 10-byte or bigger, as the 6-byte doesn't support
        * the flags.
        */
       if (((bp->b_rawblkno & 0x1fffff) == bp->b_rawblkno) &&
           ((nblks & 0xff) == nblks) &&
           !(periph->periph_quirks & PQUIRK_ONLYBIG) &&
           !cdb_flags) {
               /* 6-byte CDB */
               memset(&cmd_small, 0, sizeof(cmd_small));
               cmd_small.opcode = (bp->b_flags & B_READ) ?
                   SCSI_READ_6_COMMAND : SCSI_WRITE_6_COMMAND;
               _lto3b(bp->b_rawblkno, cmd_small.addr);
               cmd_small.length = nblks & 0xff;
               cmdlen = sizeof(cmd_small);
               cmdp = (struct scsipi_generic *)&cmd_small;
       } else if ((bp->b_rawblkno & 0xffffffff) == bp->b_rawblkno) {
               /* 10-byte CDB */
               memset(&cmd_big, 0, sizeof(cmd_big));
               cmd_big.opcode = (bp->b_flags & B_READ) ?
                   READ_10 : WRITE_10;
               _lto4b(bp->b_rawblkno, cmd_big.addr);
               _lto2b(nblks, cmd_big.length);
               cmdlen = sizeof(cmd_big);
               cmdp = (struct scsipi_generic *)&cmd_big;
       } else {
               /* 16-byte CDB */
               memset(&cmd16, 0, sizeof(cmd16));
               cmd16.opcode = (bp->b_flags & B_READ) ?
                   READ_16 : WRITE_16;
               _lto8b(bp->b_rawblkno, cmd16.addr);
               _lto4b(nblks, cmd16.length);
               cmdlen = sizeof(cmd16);
               cmdp = (struct scsipi_generic *)&cmd16;
       }

       if (cdb_flags)
               cmdp->bytes[0] = cdb_flags;

       /*
        * Figure out what flags to use.
        */
       flags = XS_CTL_NOSLEEP|XS_CTL_ASYNC|XS_CTL_SIMPLE_TAG;
       if (bp->b_flags & B_READ)
               flags |= XS_CTL_DATA_IN;
       else
               flags |= XS_CTL_DATA_OUT;

       /*
        * Call the routine that chats with the adapter.
        * Note: we cannot sleep as we may be an interrupt
        */
       xs = scsipi_make_xs_locked(periph, cmdp, cmdlen,
           (u_char *)bp->b_data, bp->b_bcount,
           SDRETRIES, SD_IO_TIMEOUT, bp, flags);
       if (__predict_false(xs == NULL)) {
               /*
                * out of memory. Keep this buffer in the queue, and
                * retry later.
                */
               callout_reset(&sd->sc_callout, hz / 2, sdrestart, sd);
               error = EAGAIN;
               goto out;
       }

       error = scsipi_execute_xs(xs);
       /* with a scsipi_xfer preallocated, scsipi_command can't fail */
       KASSERT(error == 0);

out:
       mutex_exit(chan_mtx(chan));

       return error;
}

/*
* Recover I/O request after memory shortage
*
* Called from callout
*/
static void
sdrestart(void *v)
{
       struct sd_softc *sd = v;
       struct dk_softc *dksc = &sd->sc_dksc;

       dk_start(dksc, NULL);
}

/*
* Recover I/O request after memory shortage
*
* Called from scsipi midlayer when resources have been freed
* with channel lock held
*/
static void
sdstart(struct scsipi_periph *periph)
{
       struct sd_softc *sd = device_private(periph->periph_dev);
       struct dk_softc *dksc = &sd->sc_dksc;
       struct scsipi_channel *chan = periph->periph_channel;

       /*
        * release channel lock as dk_start may need to acquire
        * other locks
        *
        * sdstart is called from scsipi_put_xs and all its callers
        * release the lock afterwards. So releasing it here
        * doesn't matter.
        */
       mutex_exit(chan_mtx(chan));

       dk_start(dksc, NULL);

       mutex_enter(chan_mtx(chan));
}

static void
sddone(struct scsipi_xfer *xs, int error)
{
       struct sd_softc *sd = device_private(xs->xs_periph->periph_dev);
       struct dk_softc *dksc = &sd->sc_dksc;
       struct buf *bp = xs->bp;

       if (sd->flags & SDF_FLUSHING) {
               /* Flush completed, no longer dirty. */
               sd->flags &= ~(SDF_FLUSHING|SDF_DIRTY);
       }

       if (bp) {
               bp->b_error = error;
               bp->b_resid = xs->resid;
               if (error) {
                       /* on a read/write error bp->b_resid is zero, so fix */
                       bp->b_resid = bp->b_bcount;
               }

               dk_done(dksc, bp);
               /* dk_start is called from scsipi_complete */
       }
}

static void
sdminphys(struct buf *bp)
{
       struct sd_softc *sd = device_lookup_private(&sd_cd, SDUNIT(bp->b_dev));
       struct dk_softc *dksc = &sd->sc_dksc;
       long xmax;

       /*
        * 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 ((sd->flags & SDF_ANCIENT) &&
           ((sd->sc_periph->periph_flags &
           (PERIPH_REMOVABLE | PERIPH_MEDIA_LOADED)) != PERIPH_REMOVABLE)) {
               xmax = dksc->sc_dkdev.dk_geom.dg_secsize * 0xff;

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

       scsipi_adapter_minphys(sd->sc_periph->periph_channel, bp);
}

static void
sd_iosize(device_t dev, int *count)
{
       struct buf B;
       int bmaj;

       bmaj       = bdevsw_lookup_major(&sd_bdevsw);
       B.b_dev    = MAKESDDEV(bmaj,device_unit(dev),RAW_PART);
       B.b_bcount = *count;

       sdminphys(&B);

       *count = B.b_bcount;
}

static int
sdread(dev_t dev, struct uio *uio, int ioflag)
{

       return (physio(sdstrategy, NULL, dev, B_READ, sdminphys, uio));
}

static int
sdwrite(dev_t dev, struct uio *uio, int ioflag)
{

       return (physio(sdstrategy, NULL, dev, B_WRITE, sdminphys, uio));
}

/*
* Perform special action on behalf of the user
* Knows about the internals of this device
*/
static int
sdioctl(dev_t dev, u_long cmd, void *addr, int flag, struct lwp *l)
{
       struct sd_softc *sd = device_lookup_private(&sd_cd, SDUNIT(dev));
       struct dk_softc *dksc = &sd->sc_dksc;
       struct scsipi_periph *periph = sd->sc_periph;

       int part = SDPART(dev);
       int error;

       SC_DEBUG(sd->sc_periph, SCSIPI_DB2, ("sdioctl 0x%lx ", cmd));

       /*
        * If the device is not valid, some IOCTLs can still be
        * handled on the raw partition. Check this here.
        */
       if ((periph->periph_flags & PERIPH_MEDIA_LOADED) == 0 &&
           part != RAW_PART)
               return (EIO);

       switch (cmd) {
       case DIOCLOCK:
               if (periph->periph_flags & PERIPH_REMOVABLE)
                       return (scsipi_prevent(periph,
                           (*(int *)addr) ?
                           SPAMR_PREVENT_DT : SPAMR_ALLOW, 0));
               else
                       return (ENOTTY);

       case DIOCEJECT:
               if ((periph->periph_flags & PERIPH_REMOVABLE) == 0)
                       return (ENOTTY);
               if (*(int *)addr == 0) {
                       int pmask = __BIT(part);
                       /*
                        * Don't force eject: check that we are the only
                        * partition open. If so, unlock it.
                        */
                       if (DK_BUSY(dksc, pmask) == 0) {
                               error = scsipi_prevent(periph, SPAMR_ALLOW,
                                   XS_CTL_IGNORE_NOT_READY);
                               if (error)
                                       return (error);
                       } else {
                               return (EBUSY);
                       }
               }
               /* FALLTHROUGH */
       case ODIOCEJECT:
               return ((periph->periph_flags & PERIPH_REMOVABLE) == 0 ?
                   ENOTTY : scsipi_start(periph, SSS_STOP|SSS_LOEJ, 0));

       case DIOCGCACHE:
               return (sd_getcache(sd, (int *) addr));

       case DIOCSCACHE:
               if ((flag & FWRITE) == 0)
                       return (EBADF);
               return (sd_setcache(sd, *(int *) addr));

       case DIOCCACHESYNC:
               /*
                * XXX Do we really need to care about having a writable
                * file descriptor here?
                */
               if ((flag & FWRITE) == 0)
                       return (EBADF);
               if (((sd->flags & SDF_DIRTY) != 0 || *(int *)addr != 0)) {
                       error = sd_flush(sd, 0);
                       if (error) {
                               sd->flags &= ~SDF_FLUSHING;
                               return (error);
                       }
                       sd->flags &= ~(SDF_FLUSHING|SDF_DIRTY);
               }
               return (0);

       default:
               error = dk_ioctl(dksc, dev, cmd, addr, flag, l);
               if (error == ENOTTY) {
                       error = scsipi_do_ioctl(periph, dev, cmd, addr, flag,
                           l);
               }
               return (error);
       }

#ifdef DIAGNOSTIC
       panic("sdioctl: impossible");
#endif
}

static void
sd_label(device_t self, struct disklabel *lp)
{
       struct sd_softc *sd = device_private(self);

       strncpy(lp->d_typename, sd->name, 16);
       lp->d_rpm = sd->params.rot_rate;
       if (sd->sc_periph->periph_flags & PERIPH_REMOVABLE)
               lp->d_flags |= D_REMOVABLE;
}

static int
sd_unmap(struct sd_softc *sd, off_t pos, off_t len)
{
       struct scsi_unmap_10 cmd;
       struct scsi_unmap_10_data data;
       int flags = 0;
       uint64_t bno;
       uint32_t size;

       /* round the start up and the end down */
       bno = (pos + sd->params.blksize - 1) / sd->params.blksize;
       size = ((pos + len) / sd->params.blksize) - bno;

       if (size == 0)
               return 0;

       memset(&data, 0, sizeof(data));
       _lto2b(sizeof(data) - 2, data.unmap_data_length);
       _lto2b(sizeof(data) - 8, data.unmap_block_descriptor_data_length);
       _lto8b(bno, data.unmap_block_descriptor[0].addr);
       _lto4b(size, data.unmap_block_descriptor[0].len);

       memset(&cmd, 0, sizeof(cmd));
       cmd.opcode = UNMAP_10;
       cmd.byte2 = 0;
       _lto2b(sizeof(data), cmd.length);

       scsipi_command(sd->sc_periph,
           (void *)&cmd, sizeof(cmd), (void *)&data, sizeof(data),
           SDRETRIES, 2000000, NULL,
           flags | XS_CTL_DATA_OUT);

       return 0;
}

static int
sd_discard(device_t self, off_t pos, off_t len)
{
       struct sd_softc *sd = device_private(self);
       if (sd->flags & SDF_LBPU) {
               return sd_unmap(sd, pos, len);
       }
       return ENODEV;
}

static bool
sd_shutdown(device_t self, int how)
{
       struct sd_softc *sd = device_private(self);
       struct dk_softc *dksc = &sd->sc_dksc;

       /*
        * If the disk cache needs to be flushed, and the disk supports
        * it, flush it.  We're cold at this point, so we poll for
        * completion.
        */
       if ((sd->flags & SDF_DIRTY) != 0) {
               if (sd_flush(sd, XS_CTL_NOSLEEP|XS_CTL_POLL)) {
                       aprint_error_dev(dksc->sc_dev,
                               "cache synchronization failed\n");
                       sd->flags &= ~SDF_FLUSHING;
               } else
                       sd->flags &= ~(SDF_FLUSHING|SDF_DIRTY);
       }
       return true;
}

static bool
sd_suspend(device_t dv, const pmf_qual_t *qual)
{
       return sd_shutdown(dv, boothowto); /* XXX no need to poll */
}

/*
* Check Errors
*/
static int
sd_interpret_sense(struct scsipi_xfer *xs)
{
       struct scsipi_periph *periph = xs->xs_periph;
       struct scsipi_channel *chan = periph->periph_channel;
       struct scsi_sense_data *sense = &xs->sense.scsi_sense;
       struct sd_softc *sd = device_private(periph->periph_dev);
       struct dk_softc *dksc = &sd->sc_dksc;
       int error, retval = EJUSTRETURN;

       /*
        * If the periph is already recovering, just do the normal
        * error processing.
        */
       if (periph->periph_flags & PERIPH_RECOVERING)
               return (retval);

       /*
        * Ignore errors from accessing illegal fields (e.g. trying to
        * lock the door of a digicam, which doesn't have a door that
        * can be locked) for the SCSI_PREVENT_ALLOW_MEDIUM_REMOVAL command.
        */
       if (xs->cmd->opcode == SCSI_PREVENT_ALLOW_MEDIUM_REMOVAL &&
           SSD_SENSE_KEY(sense->flags) == SKEY_ILLEGAL_REQUEST &&
           sense->asc == 0x24 &&
           sense->ascq == 0x00) { /* Illegal field in CDB */
               if (!(xs->xs_control & XS_CTL_SILENT)) {
                       scsipi_printaddr(periph);
                       printf("no door lock\n");
               }
               xs->xs_control |= XS_CTL_IGNORE_ILLEGAL_REQUEST;
               return (retval);
       }

       /*
        * If it isn't a extended or extended/deferred error, let
        * the generic code handle it.
        */
       if (SSD_RCODE(sense->response_code) != SSD_RCODE_CURRENT &&
           SSD_RCODE(sense->response_code) != SSD_RCODE_DEFERRED)
               return (retval);

       if (SSD_SENSE_KEY(sense->flags) == SKEY_NOT_READY &&
           sense->asc == 0x4) {
               if (sense->ascq == 0x01)        {
                       /*
                        * Unit In The Process Of Becoming Ready.
                        */
                       printf("%s: waiting for pack to spin up...\n",
                           dksc->sc_xname);
                       if (!callout_pending(&periph->periph_callout))
                               scsipi_periph_freeze(periph, 1);
                       callout_reset(&periph->periph_callout,
                           5 * hz, scsipi_periph_timed_thaw, periph);
                       retval = ERESTART;
               } else if (sense->ascq == 0x02) {
                       printf("%s: pack is stopped, restarting...\n",
                           dksc->sc_xname);
                       mutex_enter(chan_mtx(chan));
                       periph->periph_flags |= PERIPH_RECOVERING;
                       mutex_exit(chan_mtx(chan));
                       error = scsipi_start(periph, SSS_START,
                           XS_CTL_URGENT|XS_CTL_HEAD_TAG|
                           XS_CTL_THAW_PERIPH|XS_CTL_FREEZE_PERIPH);
                       if (error) {
                               aprint_error_dev(dksc->sc_dev,
                                       "unable to restart pack\n");
                               retval = error;
                       } else
                               retval = ERESTART;
                       mutex_enter(chan_mtx(chan));
                       periph->periph_flags &= ~PERIPH_RECOVERING;
                       mutex_exit(chan_mtx(chan));
               }
       }
       if (SSD_SENSE_KEY(sense->flags) == SKEY_MEDIUM_ERROR &&
           sense->asc == 0x31 &&
           sense->ascq == 0x00)        { /* maybe for any asq ? */
               /* Medium Format Corrupted */
               retval = EFTYPE;
       }
       return (retval);
}


static int
sdsize(dev_t dev)
{
       struct sd_softc *sd;
       struct dk_softc *dksc;
       int unit;

       unit = SDUNIT(dev);
       sd = device_lookup_private(&sd_cd, unit);
       if (sd == NULL)
               return (-1);
       dksc = &sd->sc_dksc;

       if (!device_is_active(dksc->sc_dev))
               return (-1);

       return dk_size(dksc, dev);
}

/* #define SD_DUMP_NOT_TRUSTED if you just want to watch */
static struct scsipi_xfer sx;

/*
* dump all of physical memory into the partition specified, starting
* at offset 'dumplo' into the partition.
*/
static int
sddump(dev_t dev, daddr_t blkno, void *va, size_t size)
{
       struct sd_softc *sd;
       struct dk_softc *dksc;
       struct scsipi_periph *periph;
       int unit;

       unit = SDUNIT(dev);
       if ((sd = device_lookup_private(&sd_cd, unit)) == NULL)
               return (ENXIO);
       dksc = &sd->sc_dksc;

       if (!device_is_active(dksc->sc_dev))
               return (ENODEV);

       periph = sd->sc_periph;

       /* Make sure it was initialized. */
       if ((periph->periph_flags & PERIPH_MEDIA_LOADED) == 0)
               return (ENXIO);

       return dk_dump(dksc, dev, blkno, va, size, 0);
}

static int
sd_dumpblocks(device_t dev, void *va, daddr_t blkno, int nblk)
{
       struct sd_softc *sd = device_private(dev);
       struct dk_softc *dksc = &sd->sc_dksc;
       struct disk_geom *dg = &dksc->sc_dkdev.dk_geom;
       struct scsipi_rw_10 cmd;        /* write command */
       struct scsipi_rw_16 cmd16;      /* write command */
       struct scsipi_generic *cmdp;
       struct scsipi_xfer *xs;         /* ... convenience */
       struct scsipi_periph *periph;
       struct scsipi_channel *chan;
       size_t sectorsize;
       int cmdlen;

       periph = sd->sc_periph;
       chan = periph->periph_channel;

       sectorsize = dg->dg_secsize;

       xs = &sx;

#ifndef SD_DUMP_NOT_TRUSTED
       /*
        *  Fill out the scsi command
        */
       if ((blkno & 0xffffffff) == blkno) {
               memset(&cmd, 0, sizeof(cmd));
               cmd.opcode = WRITE_10;
               _lto4b(blkno, cmd.addr);
               _lto2b(nblk, cmd.length);
               cmdlen = sizeof(cmd);
               cmdp = (struct scsipi_generic *)&cmd;
       } else {
               memset(&cmd16, 0, sizeof(cmd16));
               cmd16.opcode = WRITE_16;
               _lto8b(blkno, cmd16.addr);
               _lto4b(nblk, cmd16.length);
               cmdlen = sizeof(cmd16);
               cmdp = (struct scsipi_generic *)&cmd16;
       }

       /*
        * Fill out the scsipi_xfer structure
        *    Note: we cannot sleep as we may be an interrupt
        * don't use scsipi_command() as it may want to wait
        * for an xs.
        */
       memset(xs, 0, sizeof(sx));
       xs->xs_control |= XS_CTL_NOSLEEP | XS_CTL_POLL |
           XS_CTL_DATA_OUT;
       xs->xs_status = 0;
       xs->xs_periph = periph;
       xs->xs_retries = SDRETRIES;
       xs->timeout = 10000;    /* 10000 millisecs for a disk ! */
       xs->cmd = cmdp;
       xs->cmdlen = cmdlen;
       xs->resid = nblk * sectorsize;
       xs->error = XS_NOERROR;
       xs->bp = 0;
       xs->data = va;
       xs->datalen = nblk * sectorsize;
       callout_init(&xs->xs_callout, 0);

       /*
        * Pass all this info to the scsi driver.
        */
       scsipi_adapter_request(chan, ADAPTER_REQ_RUN_XFER, xs);
       if ((xs->xs_status & XS_STS_DONE) == 0 ||
           xs->error != XS_NOERROR)
               return (EIO);
#else   /* SD_DUMP_NOT_TRUSTED */
       /* Let's just talk about this first... */
       printf("sd%d: dump addr 0x%x, blk %d\n", unit, va, blkno);
       delay(500 * 1000);      /* half a second */
#endif  /* SD_DUMP_NOT_TRUSTED */

       return (0);
}

static int
sd_mode_sense(struct sd_softc *sd, u_int8_t byte2, void *sense, size_t size,
   int page, int flags, int *big)
{

       if ((sd->sc_periph->periph_quirks & PQUIRK_ONLYBIG) &&
           !(sd->sc_periph->periph_quirks & PQUIRK_NOBIGMODESENSE)) {
               *big = 1;
               return scsipi_mode_sense_big(sd->sc_periph, byte2, page, sense,
                   size + sizeof(struct scsi_mode_parameter_header_10),
                   flags, SDRETRIES, 6000);
       } else {
               *big = 0;
               return scsipi_mode_sense(sd->sc_periph, byte2, page, sense,
                   size + sizeof(struct scsi_mode_parameter_header_6),
                   flags, SDRETRIES, 6000);
       }
}

static int
sd_mode_select(struct sd_softc *sd, u_int8_t byte2, void *sense, size_t size,
   int flags, int big)
{

       if (big) {
               struct scsi_mode_parameter_header_10 *header = sense;

               _lto2b(0, header->data_length);
               return scsipi_mode_select_big(sd->sc_periph, byte2, sense,
                   size + sizeof(struct scsi_mode_parameter_header_10),
                   flags, SDRETRIES, 6000);
       } else {
               struct scsi_mode_parameter_header_6 *header = sense;

               header->data_length = 0;
               return scsipi_mode_select(sd->sc_periph, byte2, sense,
                   size + sizeof(struct scsi_mode_parameter_header_6),
                   flags, SDRETRIES, 6000);
       }
}

/*
* sd_validate_blksize:
*
*      Validate the block size.  Print error if periph is specified,
*/
static int
sd_validate_blksize(struct scsipi_periph *periph, int len)
{

       if (len >= 256 && powerof2(len) && len <= MAXPHYS) {
               return 1;
       }

       if (periph) {
               scsipi_printaddr(periph);
               printf("%s sector size: 0x%x.  Defaulting to %d bytes.\n",
                   !powerof2(len) ?
                   "preposterous" : "unsupported",
                   len, SD_DEFAULT_BLKSIZE);
       }

       return 0;
}

/*
* sd_read_capacity:
*
*      Find out from the device what its capacity is.
*/
static u_int64_t
sd_read_capacity(struct sd_softc *sd, int *blksize, int flags)
{
       struct scsipi_periph *periph = sd->sc_periph;
       union {
               struct scsipi_read_capacity_10 cmd;
               struct scsipi_read_capacity_16 cmd16;
       } cmd;
       union {
               struct scsipi_read_capacity_10_data data;
               struct scsipi_read_capacity_16_data data16;
       } *datap;
       uint64_t rv;

       sd->params.lbppbe = 0;
       sd->params.lalba = 0;

       memset(&cmd, 0, sizeof(cmd));
       cmd.cmd.opcode = READ_CAPACITY_10;

       /*
        * Don't allocate data buffer on stack;
        * The lower driver layer might use the same stack and
        * if it uses region which is in the same cacheline,
        * cache flush ops against the data buffer won't work properly.
        */
       datap = malloc(sizeof(*datap), M_TEMP, M_WAITOK);
       if (datap == NULL)
               return 0;

       if (periph->periph_version >= 5) /* SPC-3 */
               goto rc16;

       /*
        * If the command works, interpret the result as a 4 byte
        * number of blocks
        */
       rv = 0;
       memset(datap, 0, sizeof(datap->data));
       if (scsipi_command(periph, (void *)&cmd.cmd, sizeof(cmd.cmd),
           (void *)datap, sizeof(datap->data), SCSIPIRETRIES, 20000, NULL,
           flags | XS_CTL_DATA_IN | XS_CTL_SILENT) != 0)
               goto out;

       if (_4btol(datap->data.addr) != 0xffffffff) {
               *blksize = _4btol(datap->data.length);
               rv = _4btol(datap->data.addr) + 1;
               goto out;
       }

       /*
        * Device is larger than can be reflected by READ CAPACITY (10).
        * Try READ CAPACITY (16).
        */

rc16:
       memset(&cmd, 0, sizeof(cmd));
       cmd.cmd16.opcode = READ_CAPACITY_16;
       cmd.cmd16.byte2 = SRC16_SERVICE_ACTION;
       _lto4b(sizeof(datap->data16), cmd.cmd16.len);

       memset(datap, 0, sizeof(datap->data16));
       if (scsipi_command(periph, (void *)&cmd.cmd16, sizeof(cmd.cmd16),
           (void *)datap, sizeof(datap->data16), SCSIPIRETRIES, 20000, NULL,
           flags | XS_CTL_DATA_IN | XS_CTL_SILENT) != 0)
               goto out;

       *blksize = _4btol(datap->data16.length);
       rv = _8btol(datap->data16.addr) + 1;
       sd->params.lbppbe = datap->data16.byte14 & SRC16D_LBPPB_EXPONENT;
       sd->params.lalba = _2btol(datap->data16.lowest_aligned) & SRC16D_LALBA;
       if (_2btol(datap->data16.lowest_aligned) & SRC16D_LBPME) {
               sd->flags |= SDF_LBPME;
       } else {
               sd->flags &= ~SDF_LBPME;
       }

out:
       free(datap, M_TEMP);
       return rv;
}

static int
sd_get_simplifiedparms(struct sd_softc *sd, struct disk_parms *dp, int flags)
{
       struct {
               struct scsi_mode_parameter_header_6 header;
               /* no block descriptor */
               u_int8_t pg_code; /* page code (should be 6) */
               u_int8_t pg_length; /* page length (should be 11) */
               u_int8_t wcd; /* bit0: cache disable */
               u_int8_t lbs[2]; /* logical block size */
               u_int8_t size[5]; /* number of log. blocks */
               u_int8_t pp; /* power/performance */
               u_int8_t flags;
               u_int8_t resvd;
       } scsipi_sense;
       u_int64_t blocks;
       int error, blksize;

       /*
        * sd_read_capacity (ie "read capacity") and mode sense page 6
        * give the same information. Do both for now, and check
        * for consistency.
        * XXX probably differs for removable media
        */
       dp->blksize = SD_DEFAULT_BLKSIZE;
       if ((blocks = sd_read_capacity(sd, &blksize, flags)) == 0)
               return (SDGP_RESULT_OFFLINE);           /* XXX? */

       error = scsipi_mode_sense(sd->sc_periph, SMS_DBD, 6,
           &scsipi_sense.header, sizeof(scsipi_sense),
           flags, SDRETRIES, 6000);

       if (error != 0)
               return (SDGP_RESULT_OFFLINE);           /* XXX? */

       dp->blksize = blksize;
       if (!sd_validate_blksize(NULL, dp->blksize))
               dp->blksize = _2btol(scsipi_sense.lbs);
       if (!sd_validate_blksize(sd->sc_periph, dp->blksize))
               dp->blksize = SD_DEFAULT_BLKSIZE;

       /*
        * Create a pseudo-geometry.
        */
       dp->heads = 64;
       dp->sectors = 32;
       dp->cyls = blocks / (dp->heads * dp->sectors);
       dp->disksize = _5btol(scsipi_sense.size);
       if (dp->disksize <= UINT32_MAX && dp->disksize != blocks) {
               printf("RBC size: mode sense=%llu, get cap=%llu\n",
                      (unsigned long long)dp->disksize,
                      (unsigned long long)blocks);
               dp->disksize = blocks;
       }
       dp->disksize512 = (dp->disksize * dp->blksize) / DEV_BSIZE;

       return (SDGP_RESULT_OK);
}

/*
* Get the scsi driver to send a full inquiry to the * device and use the
* results to fill out the disk parameter structure.
*/
static int
sd_get_capacity(struct sd_softc *sd, struct disk_parms *dp, int flags)
{
       u_int64_t blocks;
       int error, blksize;
#if 0
       int i;
       u_int8_t *p;
#endif

       dp->disksize = blocks = sd_read_capacity(sd, &blksize, flags);
       if (blocks == 0) {
               struct scsipi_read_format_capacities cmd;
               struct {
                       struct scsipi_capacity_list_header header;
                       struct scsipi_capacity_descriptor desc;
               } __packed data;

               memset(&cmd, 0, sizeof(cmd));
               memset(&data, 0, sizeof(data));
               cmd.opcode = READ_FORMAT_CAPACITIES;
               _lto2b(sizeof(data), cmd.length);

               error = scsipi_command(sd->sc_periph,
                   (void *)&cmd, sizeof(cmd), (void *)&data, sizeof(data),
                   SDRETRIES, 20000, NULL,
                   flags | XS_CTL_DATA_IN);
               if (error == EFTYPE) {
                       /* Medium Format Corrupted, handle as not formatted */
                       return (SDGP_RESULT_UNFORMATTED);
               }
               if (error || data.header.length == 0)
                       return (SDGP_RESULT_OFFLINE);

#if 0
printf("rfc: length=%d\n", data.header.length);
printf("rfc result:"); for (i = sizeof(struct scsipi_capacity_list_header) + data.header.length, p = (void *)&data; i; i--, p++) printf(" %02x", *p); printf("\n");
#endif
               switch (data.desc.byte5 & SCSIPI_CAP_DESC_CODE_MASK) {
               case SCSIPI_CAP_DESC_CODE_RESERVED:
               case SCSIPI_CAP_DESC_CODE_FORMATTED:
                       break;

               case SCSIPI_CAP_DESC_CODE_UNFORMATTED:
                       return (SDGP_RESULT_UNFORMATTED);

               case SCSIPI_CAP_DESC_CODE_NONE:
                       return (SDGP_RESULT_OFFLINE);
               }

               dp->disksize = blocks = _4btol(data.desc.nblks);
               if (blocks == 0)
                       return (SDGP_RESULT_OFFLINE);           /* XXX? */

               blksize = _3btol(data.desc.blklen);

       } else if (!sd_validate_blksize(NULL, blksize)) {
               struct sd_mode_sense_data scsipi_sense;
               int big, bsize;
               struct scsi_general_block_descriptor *bdesc;

               memset(&scsipi_sense, 0, sizeof(scsipi_sense));
               error = sd_mode_sense(sd, 0, &scsipi_sense,
                   sizeof(scsipi_sense.blk_desc), 0, flags | XS_CTL_SILENT,
                   &big);
               if (error)
                       goto next;
               if (big) {
                       bdesc = (void *)(&scsipi_sense.header.big + 1);
                       bsize = _2btol(scsipi_sense.header.big.blk_desc_len);
               } else {
                       bdesc = (void *)(&scsipi_sense.header.small + 1);
                       bsize = scsipi_sense.header.small.blk_desc_len;
               }

#if 0
printf("page 0 sense:"); for (i = sizeof(scsipi_sense), p = (void *)&scsipi_sense; i; i--, p++) printf(" %02x", *p); printf("\n");
printf("page 0 bsize=%d\n", bsize);
printf("page 0 ok\n");
#endif

               if (bsize >= 8) {
                       blksize = _3btol(bdesc->blklen);
               }
       }
next:
       if (!sd_validate_blksize(sd->sc_periph, blksize))
               blksize = SD_DEFAULT_BLKSIZE;

       dp->blksize = blksize;
       dp->disksize512 = (blocks * dp->blksize) / DEV_BSIZE;

       if ((sd->flags & SDF_LBPME) == 0)
               goto end;
       struct scsipi_inquiry cmd;
       struct scsi_vpd_logical_block_provisioning vpdbuf;
       memset(&cmd, 0, sizeof(cmd));
       cmd.opcode = INQUIRY;
       cmd.length = sizeof(vpdbuf);
       cmd.byte2 |= SINQ_EVPD;
       cmd.pagecode = SINQ_VPD_LOGICAL_PROV;

       sd->flags &= ~SDF_LBPU;
       if (scsipi_command(sd->sc_periph, (void *)&cmd, sizeof(cmd),
               (void *)&vpdbuf, sizeof(vpdbuf),
               SDRETRIES, 100000, NULL,
               flags | XS_CTL_DATA_IN | XS_CTL_IGNORE_ILLEGAL_REQUEST))
               goto end;

       if (vpdbuf.flags & VPD_LBP_LBPU)
               sd->flags |= SDF_LBPU;

end:
       return (0);
}

static int
sd_get_parms_page4(struct sd_softc *sd, struct disk_parms *dp, int flags)
{
       struct sd_mode_sense_data scsipi_sense;
       int error;
       int big, byte2;
       size_t poffset;
       union scsi_disk_pages *pages;

       byte2 = SMS_DBD;
again:
       memset(&scsipi_sense, 0, sizeof(scsipi_sense));
       error = sd_mode_sense(sd, byte2, &scsipi_sense,
           (byte2 ? 0 : sizeof(scsipi_sense.blk_desc)) +
           sizeof(scsipi_sense.pages.rigid_geometry), 4,
           flags | XS_CTL_SILENT, &big);
       if (error) {
               if (byte2 == SMS_DBD) {
                       /* No result; try once more with DBD off */
                       byte2 = 0;
                       goto again;
               }
               return (error);
       }

       if (big) {
               poffset = sizeof scsipi_sense.header.big;
               poffset += _2btol(scsipi_sense.header.big.blk_desc_len);
       } else {
               poffset = sizeof scsipi_sense.header.small;
               poffset += scsipi_sense.header.small.blk_desc_len;
       }

       if (poffset > sizeof(scsipi_sense) - sizeof(pages->rigid_geometry))
               return ERESTART;

       pages = (void *)((u_long)&scsipi_sense + poffset);
#if 0
       {
               size_t i;
               u_int8_t *p;

               printf("page 4 sense:");
               for (i = sizeof(scsipi_sense), p = (void *)&scsipi_sense; i;
                   i--, p++)
                       printf(" %02x", *p);
               printf("\n");
               printf("page 4 pg_code=%d sense=%p/%p\n",
                   pages->rigid_geometry.pg_code, &scsipi_sense, pages);
       }
#endif

       if ((pages->rigid_geometry.pg_code & PGCODE_MASK) != 4)
               return (ERESTART);

       SC_DEBUG(sd->sc_periph, SCSIPI_DB3,
           ("%d cyls, %d heads, %d precomp, %d red_write, %d land_zone\n",
           _3btol(pages->rigid_geometry.ncyl),
           pages->rigid_geometry.nheads,
           _2btol(pages->rigid_geometry.st_cyl_wp),
           _2btol(pages->rigid_geometry.st_cyl_rwc),
           _2btol(pages->rigid_geometry.land_zone)));

       /*
        * KLUDGE!! (for zone recorded disks)
        * give a number of sectors so that sec * trks * cyls
        * is <= disk_size
        * can lead to wasted space! THINK ABOUT THIS !
        */
       dp->heads = pages->rigid_geometry.nheads;
       dp->cyls = _3btol(pages->rigid_geometry.ncyl);
       if (dp->heads == 0 || dp->cyls == 0)
               return (ERESTART);
       dp->sectors = dp->disksize / (dp->heads * dp->cyls);    /* XXX */

       dp->rot_rate = _2btol(pages->rigid_geometry.rpm);
       if (dp->rot_rate == 0)
               dp->rot_rate = 3600;

#if 0
printf("page 4 ok\n");
#endif
       return (0);
}

static int
sd_get_parms_page5(struct sd_softc *sd, struct disk_parms *dp, int flags)
{
       struct sd_mode_sense_data scsipi_sense;
       int error;
       int big, byte2;
       size_t poffset;
       union scsi_disk_pages *pages;

       byte2 = SMS_DBD;
again:
       memset(&scsipi_sense, 0, sizeof(scsipi_sense));
       error = sd_mode_sense(sd, 0, &scsipi_sense,
           (byte2 ? 0 : sizeof(scsipi_sense.blk_desc)) +
           sizeof(scsipi_sense.pages.flex_geometry), 5,
           flags | XS_CTL_SILENT, &big);
       if (error) {
               if (byte2 == SMS_DBD) {
                       /* No result; try once more with DBD off */
                       byte2 = 0;
                       goto again;
               }
               return (error);
       }

       if (big) {
               poffset = sizeof scsipi_sense.header.big;
               poffset += _2btol(scsipi_sense.header.big.blk_desc_len);
       } else {
               poffset = sizeof scsipi_sense.header.small;
               poffset += scsipi_sense.header.small.blk_desc_len;
       }

       if (poffset > sizeof(scsipi_sense) - sizeof(pages->flex_geometry))
               return ERESTART;

       pages = (void *)((u_long)&scsipi_sense + poffset);
#if 0
       {
               size_t i;
               u_int8_t *p;

               printf("page 5 sense:");
               for (i = sizeof(scsipi_sense), p = (void *)&scsipi_sense; i;
                   i--, p++)
                       printf(" %02x", *p);
               printf("\n");
               printf("page 5 pg_code=%d sense=%p/%p\n",
                   pages->flex_geometry.pg_code, &scsipi_sense, pages);
       }
#endif

       if ((pages->flex_geometry.pg_code & PGCODE_MASK) != 5)
               return (ERESTART);

       SC_DEBUG(sd->sc_periph, SCSIPI_DB3,
           ("%d cyls, %d heads, %d sec, %d bytes/sec\n",
           _3btol(pages->flex_geometry.ncyl),
           pages->flex_geometry.nheads,
           pages->flex_geometry.ph_sec_tr,
           _2btol(pages->flex_geometry.bytes_s)));

       dp->heads = pages->flex_geometry.nheads;
       dp->cyls = _2btol(pages->flex_geometry.ncyl);
       dp->sectors = pages->flex_geometry.ph_sec_tr;
       if (dp->heads == 0 || dp->cyls == 0 || dp->sectors == 0)
               return (ERESTART);

       dp->rot_rate = _2btol(pages->rigid_geometry.rpm);
       if (dp->rot_rate == 0)
               dp->rot_rate = 3600;

#if 0
printf("page 5 ok\n");
#endif
       return (0);
}

static int
sd_get_parms(struct sd_softc *sd, struct disk_parms *dp, int flags)
{
       struct dk_softc *dksc = &sd->sc_dksc;
       int error;

       /*
        * If offline, the SDEV_MEDIA_LOADED flag will be
        * cleared by the caller if necessary.
        */
       if (sd->type == T_SIMPLE_DIRECT) {
               error = sd_get_simplifiedparms(sd, dp, flags);
               if (!error)
                       goto setprops;
               return (error);
       }

       error = sd_get_capacity(sd, dp, flags);
       if (error)
               return (error);

       if (sd->type == T_OPTICAL)
               goto page0;

       if (sd->sc_periph->periph_flags & PERIPH_REMOVABLE) {
               if (!sd_get_parms_page5(sd, dp, flags) ||
                   !sd_get_parms_page4(sd, dp, flags))
                       goto setprops;
       } else {
               if (!sd_get_parms_page4(sd, dp, flags) ||
                   !sd_get_parms_page5(sd, dp, flags))
                       goto setprops;
       }

page0:
       printf("%s: fabricating a geometry\n", dksc->sc_xname);
       /* Try calling driver's method for figuring out geometry. */
       if (!sd->sc_periph->periph_channel->chan_adapter->adapt_getgeom ||
           !(*sd->sc_periph->periph_channel->chan_adapter->adapt_getgeom)
               (sd->sc_periph, dp, dp->disksize)) {
               /*
                * Use adaptec standard fictitious geometry
                * this depends on which controller (e.g. 1542C is
                * different. but we have to put SOMETHING here..)
                */
               dp->heads = 64;
               dp->sectors = 32;
               dp->cyls = dp->disksize / (64 * 32);
       }
       dp->rot_rate = 3600;

setprops:
       sd_set_geometry(sd);

       return (SDGP_RESULT_OK);
}

static int
sd_flush(struct sd_softc *sd, int flags)
{
       struct scsipi_periph *periph = sd->sc_periph;
       struct scsi_synchronize_cache_10 cmd;

       /*
        * If the device is SCSI-2, issue a SYNCHRONIZE CACHE.
        * We issue with address 0 length 0, which should be
        * interpreted by the device as "all remaining blocks
        * starting at address 0".  We ignore ILLEGAL REQUEST
        * in the event that the command is not supported by
        * the device, and poll for completion so that we know
        * that the cache has actually been flushed.
        *
        * Unless, that is, the device can't handle the SYNCHRONIZE CACHE
        * command, as indicated by our quirks flags.
        *
        * XXX What about older devices?
        */
       if (periph->periph_version < 2 ||
           (periph->periph_quirks & PQUIRK_NOSYNCCACHE))
               return (0);

       sd->flags |= SDF_FLUSHING;
       memset(&cmd, 0, sizeof(cmd));
       cmd.opcode = SCSI_SYNCHRONIZE_CACHE_10;

       return (scsipi_command(periph, (void *)&cmd, sizeof(cmd), 0, 0,
           SDRETRIES, 100000, NULL, flags | XS_CTL_IGNORE_ILLEGAL_REQUEST));
}

static int
sd_getcache(struct sd_softc *sd, int *bitsp)
{
       struct scsipi_periph *periph = sd->sc_periph;
       struct sd_mode_sense_data scsipi_sense;
       int error, bits = 0;
       int big;
       union scsi_disk_pages *pages;
       uint8_t dev_spec;

       /* only SCSI-2 and later supported */
       if (periph->periph_version < 2)
               return (EOPNOTSUPP);

       memset(&scsipi_sense, 0, sizeof(scsipi_sense));
       error = sd_mode_sense(sd, SMS_DBD, &scsipi_sense,
           sizeof(scsipi_sense.pages.caching_params), 8, XS_CTL_SILENT, &big);
       if (error)
               return (error);

       if (big) {
               pages = (void *)(&scsipi_sense.header.big + 1);
               dev_spec = scsipi_sense.header.big.dev_spec;
       } else {
               pages = (void *)(&scsipi_sense.header.small + 1);
               dev_spec = scsipi_sense.header.small.dev_spec;
       }

       if ((pages->caching_params.flags & CACHING_RCD) == 0)
               bits |= DKCACHE_READ;
       if (pages->caching_params.flags & CACHING_WCE)
               bits |= DKCACHE_WRITE;
       if (pages->caching_params.pg_code & PGCODE_PS)
               bits |= DKCACHE_SAVE;

       /*
        * Support for FUA/DPO, defined starting with SCSI-2. Use only
        * if device claims to support it, according to the MODE SENSE.
        */
       if (!(periph->periph_quirks & PQUIRK_NOFUA) &&
           ISSET(dev_spec, SMH_DSP_DPOFUA))
               bits |= DKCACHE_FUA | DKCACHE_DPO;

       memset(&scsipi_sense, 0, sizeof(scsipi_sense));
       error = sd_mode_sense(sd, SMS_DBD, &scsipi_sense,
           sizeof(scsipi_sense.pages.caching_params),
           SMS_PCTRL_CHANGEABLE|8, XS_CTL_SILENT, &big);
       if (error == 0) {
               if (big)
                       pages = (void *)(&scsipi_sense.header.big + 1);
               else
                       pages = (void *)(&scsipi_sense.header.small + 1);

               if (pages->caching_params.flags & CACHING_RCD)
                       bits |= DKCACHE_RCHANGE;
               if (pages->caching_params.flags & CACHING_WCE)
                       bits |= DKCACHE_WCHANGE;
       }

       *bitsp = bits;

       return (0);
}

static int
sd_setcache(struct sd_softc *sd, int bits)
{
       struct scsipi_periph *periph = sd->sc_periph;
       struct sd_mode_sense_data scsipi_sense;
       int error;
       uint8_t oflags, byte2 = 0;
       int big;
       union scsi_disk_pages *pages;

       if (periph->periph_version < 2)
               return (EOPNOTSUPP);

       memset(&scsipi_sense, 0, sizeof(scsipi_sense));
       error = sd_mode_sense(sd, SMS_DBD, &scsipi_sense,
           sizeof(scsipi_sense.pages.caching_params), 8, 0, &big);
       if (error)
               return (error);

       if (big)
               pages = (void *)(&scsipi_sense.header.big + 1);
       else
               pages = (void *)(&scsipi_sense.header.small + 1);

       oflags = pages->caching_params.flags;

       if (bits & DKCACHE_READ)
               pages->caching_params.flags &= ~CACHING_RCD;
       else
               pages->caching_params.flags |= CACHING_RCD;

       if (bits & DKCACHE_WRITE)
               pages->caching_params.flags |= CACHING_WCE;
       else
               pages->caching_params.flags &= ~CACHING_WCE;

       if (oflags == pages->caching_params.flags)
               return (0);

       pages->caching_params.pg_code &= PGCODE_MASK;

       if (bits & DKCACHE_SAVE)
               byte2 |= SMS_SP;

       return (sd_mode_select(sd, byte2|SMS_PF, &scsipi_sense,
           sizeof(struct scsi_mode_page_header) +
           pages->caching_params.pg_length, 0, big));
}

static void
sd_set_geometry(struct sd_softc *sd)
{
       struct dk_softc *dksc = &sd->sc_dksc;
       struct disk_geom *dg = &dksc->sc_dkdev.dk_geom;

       memset(dg, 0, sizeof(*dg));

       dg->dg_secperunit = sd->params.disksize;
       dg->dg_secsize = sd->params.blksize;
       dg->dg_nsectors = sd->params.sectors;
       dg->dg_ntracks = sd->params.heads;
       dg->dg_ncylinders = sd->params.cyls;
       dg->dg_physsecsize = dg->dg_secsize << sd->params.lbppbe;
       dg->dg_alignedsec = sd->params.lalba;

       disk_set_info(dksc->sc_dev, &dksc->sc_dkdev, sd->typename);
}

static int
sddiscard(dev_t dev, off_t pos, off_t len)
{
       struct sd_softc *sd;
       int unit;

       unit = SDUNIT(dev);
       sd = device_lookup_private(&sd_cd, unit);

       return dk_discard(&sd->sc_dksc, dev, pos, len);
}