* Copyright (c) 1998, 2004 The NetBSD Foundation, Inc.

/* $NetBSD: st.c,v 1.231 2017/06/17 22:35:50 mlelstv Exp $ */

/*-
* Copyright (c) 1998, 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
* major changes by Julian Elischer ([email protected]) May 1993
*
* A lot of rewhacking done by mjacob ([email protected]).
*/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: st.c,v 1.231 2017/06/17 22:35:50 mlelstv Exp $");

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

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/fcntl.h>
#include <sys/errno.h>
#include <sys/ioctl.h>
#include <sys/malloc.h>
#include <sys/buf.h>
#include <sys/bufq.h>
#include <sys/proc.h>
#include <sys/mtio.h>
#include <sys/device.h>
#include <sys/conf.h>
#include <sys/kernel.h>
#include <sys/vnode.h>
#include <sys/iostat.h>
#include <sys/sysctl.h>

#include <dev/scsipi/scsi_spc.h>
#include <dev/scsipi/scsipi_all.h>
#include <dev/scsipi/scsi_all.h>
#include <dev/scsipi/scsi_tape.h>
#include <dev/scsipi/scsipiconf.h>
#include <dev/scsipi/scsipi_base.h>
#include <dev/scsipi/stvar.h>

/* Defines for device specific stuff */
#define DEF_FIXED_BSIZE 512

#define STMODE(z) ( minor(z) & 0x03)
#define STDSTY(z) ((minor(z) >> 2) & 0x03)
#define STUNIT(z) ((minor(z) >> 4) )
#define STNMINOR 16

#define NORMAL_MODE 0
#define NOREW_MODE 1
#define EJECT_MODE 2
#define CTRL_MODE 3

#ifndef ST_MOUNT_DELAY
#define ST_MOUNT_DELAY 0
#endif

static dev_type_open(stopen);
static dev_type_close(stclose);
static dev_type_read(stread);
static dev_type_write(stwrite);
static dev_type_ioctl(stioctl);
static dev_type_strategy(ststrategy);
static dev_type_dump(stdump);

const struct bdevsw st_bdevsw = {
.d_open = stopen,
.d_close = stclose,
.d_strategy = ststrategy,
.d_ioctl = stioctl,
.d_dump = stdump,
.d_psize = nosize,
.d_discard = nodiscard,
.d_flag = D_TAPE | D_MPSAFE
};

const struct cdevsw st_cdevsw = {
.d_open = stopen,
.d_close = stclose,
.d_read = stread,
.d_write = stwrite,
.d_ioctl = stioctl,
.d_stop = nostop,
.d_tty = notty,
.d_poll = nopoll,
.d_mmap = nommap,
.d_kqfilter = nokqfilter,
.d_discard = nodiscard,
.d_flag = D_TAPE | D_MPSAFE
};

/*
* Define various devices that we know mis-behave in some way,
* and note how they are bad, so we can correct for them
*/

static const struct st_quirk_inquiry_pattern st_quirk_patterns[] = {
{{T_SEQUENTIAL, T_REMOV,
" ", " ", " "}, {0, 0, {
{ST_Q_FORCE_BLKSIZE, 512, 0}, /* minor 0-3 */
{ST_Q_FORCE_BLKSIZE, 512, QIC_24}, /* minor 4-7 */
{ST_Q_FORCE_BLKSIZE, 0, HALFINCH_1600}, /* minor 8-11 */
{ST_Q_FORCE_BLKSIZE, 0, HALFINCH_6250} /* minor 12-15 */
}}},
{{T_SEQUENTIAL, T_REMOV,
"TANDBERG", " TDC 3600 ", ""}, {0, 12, {
{0, 0, 0}, /* minor 0-3 */
{ST_Q_FORCE_BLKSIZE, 0, QIC_525}, /* minor 4-7 */
{0, 0, QIC_150}, /* minor 8-11 */
{0, 0, QIC_120} /* minor 12-15 */
}}},
{{T_SEQUENTIAL, T_REMOV,
"TANDBERG", " TDC 3800 ", ""}, {0, 0, {
{ST_Q_FORCE_BLKSIZE, 512, 0}, /* minor 0-3 */
{0, 0, QIC_525}, /* minor 4-7 */
{0, 0, QIC_150}, /* minor 8-11 */
{0, 0, QIC_120} /* minor 12-15 */
}}},
{{T_SEQUENTIAL, T_REMOV,
"TANDBERG", " SLR5 4/8GB ", ""}, {0, 0, {
{ST_Q_FORCE_BLKSIZE, 1024, 0}, /* minor 0-3 */
{0, 0, 0}, /* minor 4-7 */
{0, 0, 0}, /* minor 8-11 */
{0, 0, 0} /* minor 12-15 */
}}},
/*
* lacking a manual for the 4200, it's not clear what the
* specific density codes should be- the device is a 2.5GB
* capable QIC drive, those density codes aren't readily
* availabel. The 'default' will just have to do.
*/
{{T_SEQUENTIAL, T_REMOV,
"TANDBERG", " TDC 4200 ", ""}, {0, 0, {
{ST_Q_FORCE_BLKSIZE, 512, 0}, /* minor 0-3 */
{0, 0, QIC_525}, /* minor 4-7 */
{0, 0, QIC_150}, /* minor 8-11 */
{0, 0, QIC_120} /* minor 12-15 */
}}},
/*
* At least -005 and -007 need this. I'll assume they all do unless I
* hear otherwise. - mycroft, 31MAR1994
*/
{{T_SEQUENTIAL, T_REMOV,
"ARCHIVE ", "VIPER 2525 25462", ""}, {0, 0, {
{ST_Q_SENSE_HELP, 0, 0}, /* minor 0-3 */
{ST_Q_SENSE_HELP, 0, QIC_525}, /* minor 4-7 */
{0, 0, QIC_150}, /* minor 8-11 */
{0, 0, QIC_120} /* minor 12-15 */
}}},
/*
* One user reports that this works for his tape drive. It probably
* needs more work. - mycroft, 09APR1994
*/
{{T_SEQUENTIAL, T_REMOV,
"SANKYO ", "CP525 ", ""}, {0, 0, {
{ST_Q_FORCE_BLKSIZE, 512, 0}, /* minor 0-3 */
{ST_Q_FORCE_BLKSIZE, 512, QIC_525}, /* minor 4-7 */
{0, 0, QIC_150}, /* minor 8-11 */
{0, 0, QIC_120} /* minor 12-15 */
}}},
{{T_SEQUENTIAL, T_REMOV,
"ANRITSU ", "DMT780 ", ""}, {0, 0, {
{ST_Q_FORCE_BLKSIZE, 512, 0}, /* minor 0-3 */
{ST_Q_FORCE_BLKSIZE, 512, QIC_525}, /* minor 4-7 */
{0, 0, QIC_150}, /* minor 8-11 */
{0, 0, QIC_120} /* minor 12-15 */
}}},
{{T_SEQUENTIAL, T_REMOV,
"ARCHIVE ", "VIPER 150 21247", ""}, {ST_Q_ERASE_NOIMM, 12, {
{ST_Q_SENSE_HELP, 0, 0}, /* minor 0-3 */
{0, 0, QIC_150}, /* minor 4-7 */
{0, 0, QIC_120}, /* minor 8-11 */
{0, 0, QIC_24} /* minor 12-15 */
}}},
{{T_SEQUENTIAL, T_REMOV,
"ARCHIVE ", "VIPER 150 21531", ""}, {ST_Q_ERASE_NOIMM, 12, {
{ST_Q_SENSE_HELP, 0, 0}, /* minor 0-3 */
{0, 0, QIC_150}, /* minor 4-7 */
{0, 0, QIC_120}, /* minor 8-11 */
{0, 0, QIC_24} /* minor 12-15 */
}}},
{{T_SEQUENTIAL, T_REMOV,
"WANGTEK ", "5099ES SCSI", ""}, {0, 0, {
{ST_Q_FORCE_BLKSIZE, 512, 0}, /* minor 0-3 */
{0, 0, QIC_11}, /* minor 4-7 */
{0, 0, QIC_24}, /* minor 8-11 */
{0, 0, QIC_24} /* minor 12-15 */
}}},
{{T_SEQUENTIAL, T_REMOV,
"WANGTEK ", "5150ES SCSI", ""}, {0, 0, {
{ST_Q_FORCE_BLKSIZE, 512, 0}, /* minor 0-3 */
{0, 0, QIC_24}, /* minor 4-7 */
{0, 0, QIC_120}, /* minor 8-11 */
{0, 0, QIC_150} /* minor 12-15 */
}}},
{{T_SEQUENTIAL, T_REMOV,
"WANGTEK ", "5525ES SCSI REV7", ""}, {0, 0, {
{0, 0, 0}, /* minor 0-3 */
{ST_Q_BLKSIZE, 0, QIC_525}, /* minor 4-7 */
{0, 0, QIC_150}, /* minor 8-11 */
{0, 0, QIC_120} /* minor 12-15 */
}}},
{{T_SEQUENTIAL, T_REMOV,
"WangDAT ", "Model 1300 ", ""}, {0, 0, {
{0, 0, 0}, /* minor 0-3 */
{ST_Q_FORCE_BLKSIZE, 512, DDS}, /* minor 4-7 */
{ST_Q_FORCE_BLKSIZE, 1024, DDS}, /* minor 8-11 */
{ST_Q_FORCE_BLKSIZE, 0, DDS} /* minor 12-15 */
}}},
{{T_SEQUENTIAL, T_REMOV,
"EXABYTE ", "EXB-8200 ", "263H"}, {0, 5, {
{0, 0, 0}, /* minor 0-3 */
{0, 0, 0}, /* minor 4-7 */
{0, 0, 0}, /* minor 8-11 */
{0, 0, 0} /* minor 12-15 */
}}},
{{T_SEQUENTIAL, T_REMOV,
"STK", "9490", ""},
{ST_Q_FORCE_BLKSIZE, 0, {
{0, 0, 0}, /* minor 0-3 */
{0, 0, 0}, /* minor 4-7 */
{0, 0, 0}, /* minor 8-11 */
{0, 0, 0} /* minor 12-15 */
}}},
{{T_SEQUENTIAL, T_REMOV,
"STK", "SD-3", ""},
{ST_Q_FORCE_BLKSIZE, 0, {
{0, 0, 0}, /* minor 0-3 */
{0, 0, 0}, /* minor 4-7 */
{0, 0, 0}, /* minor 8-11 */
{0, 0, 0} /* minor 12-15 */
}}},
{{T_SEQUENTIAL, T_REMOV,
"IBM", "03590", ""}, {ST_Q_IGNORE_LOADS, 0, {
{0, 0, 0}, /* minor 0-3 */
{0, 0, 0}, /* minor 4-7 */
{0, 0, 0}, /* minor 8-11 */
{0, 0, 0} /* minor 12-15 */
}}},
{{T_SEQUENTIAL, T_REMOV,
"HP ", "T4000s ", ""}, {ST_Q_UNIMODAL, 0, {
{0, 0, QIC_3095}, /* minor 0-3 */
{0, 0, QIC_3095}, /* minor 4-7 */
{0, 0, QIC_3095}, /* minor 8-11 */
{0, 0, QIC_3095}, /* minor 12-15 */
}}},
#if 0
{{T_SEQUENTIAL, T_REMOV,
"EXABYTE ", "EXB-8200 ", ""}, {0, 12, {
{0, 0, 0}, /* minor 0-3 */
{0, 0, 0}, /* minor 4-7 */
{0, 0, 0}, /* minor 8-11 */
{0, 0, 0} /* minor 12-15 */
}}},
#endif
{{T_SEQUENTIAL, T_REMOV,
"TEAC ", "MT-2ST/N50 ", ""}, {ST_Q_IGNORE_LOADS, 0, {
{0, 0, 0}, /* minor 0-3 */
{0, 0, 0}, /* minor 4-7 */
{0, 0, 0}, /* minor 8-11 */
{0, 0, 0} /* minor 12-15 */
}}},
{{T_SEQUENTIAL, T_REMOV,
"OnStream", "ADR50 Drive", ""}, {ST_Q_UNIMODAL, 0, {
{ST_Q_FORCE_BLKSIZE, 512, 0}, /* minor 0-3 */
{ST_Q_FORCE_BLKSIZE, 512, 0}, /* minor 4-7 */
{ST_Q_FORCE_BLKSIZE, 512, 0}, /* minor 8-11 */
{ST_Q_FORCE_BLKSIZE, 512, 0}, /* minor 12-15 */
}}},
{{T_SEQUENTIAL, T_REMOV,
"OnStream DI-30", "", "1.0"}, {ST_Q_NOFILEMARKS, 0, {
{0, 0, 0}, /* minor 0-3 */
{0, 0, 0}, /* minor 4-7 */
{0, 0, 0}, /* minor 8-11 */
{0, 0, 0} /* minor 12-15 */
}}},
{{T_SEQUENTIAL, T_REMOV,
"NCR H621", "0-STD-03-46F880 ", ""}, {ST_Q_NOPREVENT, 0, {
{0, 0, 0}, /* minor 0-3 */
{0, 0, 0}, /* minor 4-7 */
{0, 0, 0}, /* minor 8-11 */
{0, 0, 0} /* minor 12-15 */
}}},
{{T_SEQUENTIAL, T_REMOV,
"Seagate STT3401A", "hp0atxa", ""}, {0, 0, {
{ST_Q_FORCE_BLKSIZE, 512, 0}, /* minor 0-3 */
{ST_Q_FORCE_BLKSIZE, 1024, 0}, /* minor 4-7 */
{ST_Q_FORCE_BLKSIZE, 512, 0}, /* minor 8-11 */
{ST_Q_FORCE_BLKSIZE, 512, 0} /* minor 12-15 */
}}},
};

#define NOEJECT 0
#define EJECT 1

static void st_identify_drive(struct st_softc *,
struct scsipi_inquiry_pattern *);
static void st_loadquirks(struct st_softc *);
static int st_mount_tape(dev_t, int);
static void st_unmount(struct st_softc *, boolean);
static int st_decide_mode(struct st_softc *, boolean);
static void ststart(struct scsipi_periph *);
static int ststart1(struct scsipi_periph *, struct buf *);
static void strestart(void *);
static void stdone(struct scsipi_xfer *, int);
static int st_read(struct st_softc *, char *, int, int);
static int st_space(struct st_softc *, int, u_int, int);
static int st_write_filemarks(struct st_softc *, int, int);
static int st_check_eod(struct st_softc *, boolean, int *, int);
static int st_load(struct st_softc *, u_int, int);
static int st_rewind(struct st_softc *, u_int, int);
static int st_interpret_sense(struct scsipi_xfer *);
static int st_touch_tape(struct st_softc *);
static int st_erase(struct st_softc *, int full, int flags);
static int st_rdpos(struct st_softc *, int, uint32_t *);
static int st_setpos(struct st_softc *, int, uint32_t *);

static const struct scsipi_periphsw st_switch = {
st_interpret_sense,
ststart,
NULL,
stdone
};

#if defined(ST_ENABLE_EARLYWARN)
#define ST_INIT_FLAGS ST_EARLYWARN
#else
#define ST_INIT_FLAGS 0
#endif

/*
* The routine called by the low level scsi routine when it discovers
* A device suitable for this driver
*/
void
stattach(device_t parent, device_t self, void *aux)
{
struct st_softc *st = device_private(self);
struct scsipibus_attach_args *sa = aux;
struct scsipi_periph *periph = sa->sa_periph;

SC_DEBUG(periph, SCSIPI_DB2, ("stattach: "));
st->sc_dev = self;

/* Store information needed to contact our base driver */
st->sc_periph = periph;
periph->periph_dev = st->sc_dev;
periph->periph_switch = &st_switch;

/* Set initial flags */
st->flags = ST_INIT_FLAGS;

/* Set up the buf queues for this device */
bufq_alloc(&st->buf_queue, "fcfs", 0);
bufq_alloc(&st->buf_defer, "fcfs", 0);
callout_init(&st->sc_callout, 0);
mutex_init(&st->sc_iolock, MUTEX_DEFAULT, IPL_VM);

/*
* Check if the drive is a known criminal and take
* Any steps needed to bring it into line
*/
st_identify_drive(st, &sa->sa_inqbuf);
aprint_naive("\n");
aprint_normal("\n");
/* Use the subdriver to request information regarding the drive. */
aprint_normal_dev(self, "%s", st->quirkdata ? "quirks apply, " : "");
if (scsipi_test_unit_ready(periph,
XS_CTL_DISCOVERY | XS_CTL_SILENT | XS_CTL_IGNORE_MEDIA_CHANGE) ||
st->ops(st, ST_OPS_MODESENSE,
XS_CTL_DISCOVERY | XS_CTL_SILENT | XS_CTL_IGNORE_MEDIA_CHANGE))
aprint_normal("drive empty\n");
else {
aprint_normal("density code %d, ", st->media_density);
if (st->media_blksize > 0)
aprint_normal("%d-byte", st->media_blksize);
else
aprint_normal("variable");
aprint_normal(" blocks, write-%s\n",
(st->flags & ST_READONLY) ? "protected" : "enabled");
}

st->stats = iostat_alloc(IOSTAT_TAPE, parent,
device_xname(st->sc_dev));

rnd_attach_source(&st->rnd_source, device_xname(st->sc_dev),
RND_TYPE_TAPE, RND_FLAG_DEFAULT);
}

int
stdetach(device_t self, int flags)
{
struct st_softc *st = device_private(self);
struct scsipi_periph *periph = st->sc_periph;
struct scsipi_channel *chan = periph->periph_channel;
int bmaj, cmaj, mn;

/* locate the major number */
bmaj = bdevsw_lookup_major(&st_bdevsw);
cmaj = cdevsw_lookup_major(&st_cdevsw);

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

mutex_enter(chan_mtx(chan));

/* Kill off any queued buffers. */
bufq_drain(st->buf_defer);
bufq_drain(st->buf_queue);

/* Kill off any pending commands. */
scsipi_kill_pending(st->sc_periph);

mutex_exit(chan_mtx(chan));

bufq_free(st->buf_defer);
bufq_free(st->buf_queue);
mutex_destroy(&st->sc_iolock);

/* Nuke the vnodes for any open instances */
mn = STUNIT(device_unit(self));
vdevgone(bmaj, mn, mn+STNMINOR-1, VBLK);
vdevgone(cmaj, mn, mn+STNMINOR-1, VCHR);

iostat_free(st->stats);

/* Unhook the entropy source. */
rnd_detach_source(&st->rnd_source);

return 0;
}

/*
* Use the inquiry routine in 'scsi_base' to get drive info so we can
* Further tailor our behaviour.
*/
static void
st_identify_drive(struct st_softc *st, struct scsipi_inquiry_pattern *inqbuf)
{
const struct st_quirk_inquiry_pattern *finger;
int priority;

finger = scsipi_inqmatch(inqbuf,
st_quirk_patterns,
sizeof(st_quirk_patterns) / sizeof(st_quirk_patterns[0]),
sizeof(st_quirk_patterns[0]), &priority);
if (priority != 0) {
st->quirkdata = &finger->quirkdata;
st->drive_quirks = finger->quirkdata.quirks;
st->quirks = finger->quirkdata.quirks; /* start value */
st->page_0_size = finger->quirkdata.page_0_size;
KASSERT(st->page_0_size <= MAX_PAGE_0_SIZE);
st_loadquirks(st);
}
}

/*
* initialise the subdevices to the default (QUIRK) state.
* this will remove any setting made by the system operator or previous
* operations.
*/
static void
st_loadquirks(struct st_softc *st)
{
const struct modes *mode;
struct modes *mode2;
int i;

mode = st->quirkdata->modes;
mode2 = st->modes;
for (i = 0; i < 4; i++) {
memset(mode2, 0, sizeof(struct modes));
st->modeflags[i] &= ~(BLKSIZE_SET_BY_QUIRK |
DENSITY_SET_BY_QUIRK | BLKSIZE_SET_BY_USER |
DENSITY_SET_BY_USER);
if ((mode->quirks | st->drive_quirks) & ST_Q_FORCE_BLKSIZE) {
mode2->blksize = mode->blksize;
st->modeflags[i] |= BLKSIZE_SET_BY_QUIRK;
}
if (mode->density) {
mode2->density = mode->density;
st->modeflags[i] |= DENSITY_SET_BY_QUIRK;
}
mode2->quirks |= mode->quirks;
mode++;
mode2++;
}
}

/* open the device. */
static int
stopen(dev_t dev, int flags, int mode, struct lwp *l)
{
u_int stmode, dsty;
int error, sflags, unit, tries, ntries;
struct st_softc *st;
struct scsipi_periph *periph;
struct scsipi_adapter *adapt;

unit = STUNIT(dev);
st = device_lookup_private(&st_cd, unit);
if (st == NULL)
return ENXIO;

stmode = STMODE(dev);
dsty = STDSTY(dev);

periph = st->sc_periph;
adapt = periph->periph_channel->chan_adapter;

SC_DEBUG(periph, SCSIPI_DB1,
("open: dev=0x%"PRIx64" (unit %d (of %d))\n", dev, unit,
st_cd.cd_ndevs));

/* Only allow one at a time */
if (periph->periph_flags & PERIPH_OPEN) {
aprint_error_dev(st->sc_dev, "already open\n");
return EBUSY;
}

if ((error = scsipi_adapter_addref(adapt)) != 0)
return error;

/* clear any latched errors. */
st->mt_resid = 0;
st->mt_erreg = 0;
st->asc = 0;
st->ascq = 0;

/*
* Catch any unit attention errors. Be silent about this
* unless we're already mounted. We ignore media change
* if we're in control mode or not mounted yet.
*/
if ((st->flags & ST_MOUNTED) == 0 || stmode == CTRL_MODE) {
#ifdef SCSIDEBUG
sflags = XS_CTL_IGNORE_MEDIA_CHANGE;
#else
sflags = XS_CTL_SILENT|XS_CTL_IGNORE_MEDIA_CHANGE;
#endif
} else
sflags = 0;

/*
* If we're already mounted or we aren't configured for
* a mount delay, only try a test unit ready once. Otherwise,
* try up to ST_MOUNT_DELAY times with a rest interval of
* one second between each try.
*/
if ((st->flags & ST_MOUNTED) || ST_MOUNT_DELAY == 0)
ntries = 1;
else
ntries = ST_MOUNT_DELAY;

for (error = tries = 0; tries < ntries; tries++) {
int slpintr, oflags;

/*
* If we had no error, or we're opening the control mode
* device, we jump out right away.
*/
error = scsipi_test_unit_ready(periph, sflags);
if (error == 0 || stmode == CTRL_MODE)
break;

/*
* We had an error.
*
* If we're already mounted or we aren't configured for
* a mount delay, or the error isn't a NOT READY error,
* skip to the error exit now.
*/
if ((st->flags & ST_MOUNTED) || ST_MOUNT_DELAY == 0 ||
(st->mt_key != SKEY_NOT_READY)) {
device_printf(st->sc_dev, "mount error (key=%d)\n",
st->mt_key);
goto bad;
}

/* clear any latched errors. */
st->mt_resid = 0;
st->mt_erreg = 0;
st->asc = 0;
st->ascq = 0;

/*
* Fake that we have the device open so
* we block other apps from getting in.
*/
oflags = periph->periph_flags;
periph->periph_flags |= PERIPH_OPEN;

slpintr = kpause("stload", true, hz, NULL);

periph->periph_flags = oflags; /* restore flags */
if (slpintr != 0 && slpintr != EWOULDBLOCK) {
device_printf(st->sc_dev, "load interrupted\n");
goto bad;
}
}

/*
* If the mode is 3 (e.g. minor = 3,7,11,15) then the device has
* been opened to set defaults and perform other, usually non-I/O
* related, operations. In this case, do a quick check to see
* whether the unit actually had a tape loaded (this will be known
* as to whether or not we got a NOT READY for the above
* unit attention). If a tape is there, go do a mount sequence.
*/
if (stmode == CTRL_MODE &&
st->mt_key != SKEY_NO_SENSE &&
st->mt_key != SKEY_UNIT_ATTENTION) {
periph->periph_flags |= PERIPH_OPEN;
return 0;
}

/*
* If we get this far and had an error set, that means we failed
* to pass the 'test unit ready' test for the non-controlmode device,
* so we bounce the open.
*/
if (error)
return error;

/* Else, we're now committed to saying we're open. */
periph->periph_flags |= PERIPH_OPEN; /* unit attn are now errors */

/*
* If it's a different mode, or if the media has been
* invalidated, unmount the tape from the previous
* session but continue with open processing
*/
if (st->last_dsty != dsty ||
(periph->periph_flags & PERIPH_MEDIA_LOADED) == 0)
st_unmount(st, NOEJECT);

/*
* If we are not mounted, then we should start a new
* mount session.
*/
if (!(st->flags & ST_MOUNTED)) {
if ((error = st_mount_tape(dev, flags)) != 0)
goto bad;
st->last_dsty = dsty;
}
if (!(st->quirks & ST_Q_NOPREVENT)) {
scsipi_prevent(periph, SPAMR_PREVENT_DT,
XS_CTL_IGNORE_ILLEGAL_REQUEST | XS_CTL_IGNORE_NOT_READY);
}

SC_DEBUG(periph, SCSIPI_DB2, ("open complete\n"));
return 0;

bad:
st_unmount(st, NOEJECT);
scsipi_adapter_delref(adapt);
periph->periph_flags &= ~PERIPH_OPEN;
return error;
}

static int
stclose(dev_t dev, int flags, int mode, struct lwp *l)
{
int stxx, error = 0;
struct st_softc *st = device_lookup_private(&st_cd, STUNIT(dev));
struct scsipi_periph *periph = st->sc_periph;
struct scsipi_adapter *adapt = periph->periph_channel->chan_adapter;

SC_DEBUG(st->sc_periph, SCSIPI_DB1, ("closing\n"));

/*
* Make sure that a tape opened in write-only mode will have
* file marks written on it when closed, even if not written to.
*
* This is for SUN compatibility. Actually, the Sun way of
* things is to:
*
* only write filemarks if there are fmks to be written and
* - open for write (possibly read/write)
* - the last operation was a write
* or:
* - opened for wronly
* - no data was written (including filemarks)
*/

stxx = st->flags & (ST_WRITTEN | ST_FM_WRITTEN);
if (((flags & FWRITE) && stxx == ST_WRITTEN) ||
((flags & O_ACCMODE) == FWRITE && stxx == 0)) {
int nm;
error = st_check_eod(st, FALSE, &nm, 0);
}

/* Allow robots to eject tape if needed. */
scsipi_prevent(periph, SPAMR_ALLOW,
XS_CTL_IGNORE_ILLEGAL_REQUEST | XS_CTL_IGNORE_NOT_READY);

switch (STMODE(dev)) {
case NORMAL_MODE:
st_unmount(st, NOEJECT);
break;
case NOREW_MODE:
case CTRL_MODE:
/*
* Leave mounted unless media seems to have been removed.
*
* Otherwise, if we're to terminate a tape with more than one
* filemark [ and because we're not rewinding here ], backspace
* one filemark so that later appends will see an unbroken
* sequence of:
*
* file - FMK - file - FMK ... file - FMK FMK (EOM)
*/
if ((periph->periph_flags & PERIPH_MEDIA_LOADED) == 0) {
st_unmount(st, NOEJECT);
} else if (error == 0) {
/*
* ST_WRITTEN was preserved from above.
*
* All we need to know here is:
*
* Were we writing this tape and was the last
* operation a write?
*
* Are there supposed to be 2FM at EOD?
*
* If both statements are true, then we backspace
* one filemark.
*/
stxx |= (st->flags & ST_2FM_AT_EOD);
if ((flags & FWRITE) != 0 &&
(stxx == (ST_2FM_AT_EOD|ST_WRITTEN))) {
error = st_space(st, -1, SP_FILEMARKS, 0);
}
}
break;
case EJECT_MODE:
st_unmount(st, EJECT);
break;
}

scsipi_wait_drain(periph);

scsipi_adapter_delref(adapt);
periph->periph_flags &= ~PERIPH_OPEN;

return error;
}

/*
* Start a new mount session.
* Copy in all the default parameters from the selected device mode.
* and try guess any that seem to be defaulted.
*/
static int
st_mount_tape(dev_t dev, int flags)
{
int unit;
u_int dsty;
struct st_softc *st;
struct scsipi_periph *periph;
int error = 0;

unit = STUNIT(dev);
dsty = STDSTY(dev);
st = device_lookup_private(&st_cd, unit);
periph = st->sc_periph;

if (st->flags & ST_MOUNTED)
return 0;

SC_DEBUG(periph, SCSIPI_DB1, ("mounting\n "));
st->flags |= ST_NEW_MOUNT;
st->quirks = st->drive_quirks | st->modes[dsty].quirks;
/*
* If the media is new, then make sure we give it a chance to
* to do a 'load' instruction. (We assume it is new.)
*/
if ((error = st_load(st, LD_LOAD, XS_CTL_SILENT)) != 0)
return error;
/*
* Throw another dummy instruction to catch
* 'Unit attention' errors. Many drives give
* these after doing a Load instruction (with
* the MEDIUM MAY HAVE CHANGED asc/ascq).
*/
scsipi_test_unit_ready(periph, XS_CTL_SILENT); /* XXX */

/*
* Some devices can't tell you much until they have been
* asked to look at the media. This quirk does this.
*/
if (st->quirks & ST_Q_SENSE_HELP)
if ((error = st_touch_tape(st)) != 0)
return error;
/*
* Load the physical device parameters
* loads: blkmin, blkmax
*/
if ((error = st->ops(st, ST_OPS_RBL, 0)) != 0)
return error;
/*
* Load the media dependent parameters
* includes: media_blksize,media_density,numblks
* As we have a tape in, it should be reflected here.
* If not you may need the "quirk" above.
*/
if ((error = st->ops(st, ST_OPS_MODESENSE, 0)) != 0)
return error;
/*
* If we have gained a permanent density from somewhere,
* then use it in preference to the one supplied by
* default by the driver.
*/
if (st->modeflags[dsty] & (DENSITY_SET_BY_QUIRK | DENSITY_SET_BY_USER))
st->density = st->modes[dsty].density;
else
st->density = st->media_density;
/*
* If we have gained a permanent blocksize
* then use it in preference to the one supplied by
* default by the driver.
*/
st->flags &= ~ST_FIXEDBLOCKS;
if (st->modeflags[dsty] &
(BLKSIZE_SET_BY_QUIRK | BLKSIZE_SET_BY_USER)) {
st->blksize = st->modes[dsty].blksize;
if (st->blksize)
st->flags |= ST_FIXEDBLOCKS;
} else {
if ((error = st_decide_mode(st, FALSE)) != 0)
return error;
}
if ((error = st->ops(st, ST_OPS_MODESELECT, 0)) != 0) {
/* ATAPI will return ENODEV for this, and this may be OK */
if (error != ENODEV) {
aprint_error_dev(st->sc_dev,
"cannot set selected mode\n");
return error;
}
}
st->flags &= ~ST_NEW_MOUNT;
st->flags |= ST_MOUNTED;
periph->periph_flags |= PERIPH_MEDIA_LOADED; /* move earlier? */
st->blkno = st->fileno = (daddr_t) 0;
return 0;
}

/*
* End the present mount session.
* Rewind, and optionally eject the tape.
* Reset various flags to indicate that all new
* operations require another mount operation
*/
static void
st_unmount(struct st_softc *st, boolean eject)
{
struct scsipi_periph *periph = st->sc_periph;
int nmarks;

if ((st->flags & ST_MOUNTED) == 0)
return;
SC_DEBUG(periph, SCSIPI_DB1, ("unmounting\n"));
st_check_eod(st, FALSE, &nmarks, XS_CTL_IGNORE_NOT_READY);
st_rewind(st, 0, XS_CTL_IGNORE_NOT_READY);

/*
* Section 9.3.3 of the SCSI specs states that a device shall return
* the density value specified in the last succesfull MODE SELECT
* after an unload operation, in case it is not able to
* automatically determine the density of the new medium.
*
* So we instruct the device to use the default density, which will
* prevent the use of stale density values (in particular,
* in st_touch_tape().
*/
st->density = 0;
if (st->ops(st, ST_OPS_MODESELECT, 0) != 0) {
aprint_error_dev(st->sc_dev,
"WARNING: cannot revert to default density\n");
}

if (eject) {
if (!(st->quirks & ST_Q_NOPREVENT)) {
scsipi_prevent(periph, SPAMR_ALLOW,
XS_CTL_IGNORE_ILLEGAL_REQUEST |
XS_CTL_IGNORE_NOT_READY);
}
st_load(st, LD_UNLOAD, XS_CTL_IGNORE_NOT_READY);
st->blkno = st->fileno = (daddr_t) -1;
} else {
st->blkno = st->fileno = (daddr_t) 0;
}
st->flags &= ~(ST_MOUNTED | ST_NEW_MOUNT);
periph->periph_flags &= ~PERIPH_MEDIA_LOADED;
}

/*
* Given all we know about the device, media, mode, 'quirks' and
* initial operation, make a decision as to how we should be set
* to run (regarding blocking and EOD marks)
*/
int
st_decide_mode(struct st_softc *st, boolean first_read)
{

SC_DEBUG(st->sc_periph, SCSIPI_DB2, ("starting block mode decision\n"));

/*
* If the drive can only handle fixed-length blocks and only at
* one size, perhaps we should just do that.
*/
if (st->blkmin && (st->blkmin == st->blkmax)) {
st->flags |= ST_FIXEDBLOCKS;
st->blksize = st->blkmin;
SC_DEBUG(st->sc_periph, SCSIPI_DB3,
("blkmin == blkmax of %d\n", st->blkmin));
goto done;
}
/*
* If the tape density mandates (or even suggests) use of fixed
* or variable-length blocks, comply.
*/
switch (st->density) {
case HALFINCH_800:
case HALFINCH_1600:
case HALFINCH_6250:
case DDS:
st->flags &= ~ST_FIXEDBLOCKS;
st->blksize = 0;
SC_DEBUG(st->sc_periph, SCSIPI_DB3,
("density specified variable\n"));
goto done;
case QIC_11:
case QIC_24:
case QIC_120:
case QIC_150:
case QIC_525:
case QIC_1320:
case QIC_3095:
case QIC_3220:
st->flags |= ST_FIXEDBLOCKS;
if (st->media_blksize > 0)
st->blksize = st->media_blksize;
else
st->blksize = DEF_FIXED_BSIZE;
SC_DEBUG(st->sc_periph, SCSIPI_DB3,
("density specified fixed\n"));
goto done;
}
/*
* If we're about to read the tape, perhaps we should choose
* fixed or variable-length blocks and block size according to
* what the drive found on the tape.
*/
if (first_read &&
(!(st->quirks & ST_Q_BLKSIZE) || (st->media_blksize == 0) ||
(st->media_blksize == DEF_FIXED_BSIZE) ||
(st->media_blksize == 1024))) {
if (st->media_blksize > 0)
st->flags |= ST_FIXEDBLOCKS;
else
st->flags &= ~ST_FIXEDBLOCKS;
st->blksize = st->media_blksize;
SC_DEBUG(st->sc_periph, SCSIPI_DB3,
("Used media_blksize of %d\n", st->media_blksize));
goto done;
}
/*
* We're getting no hints from any direction. Choose variable-
* length blocks arbitrarily.
*/
st->flags &= ~ST_FIXEDBLOCKS;
st->blksize = 0;
SC_DEBUG(st->sc_periph, SCSIPI_DB3,
("Give up and default to variable mode\n"));

done:
/*
* Decide whether or not to write two file marks to signify end-
* of-data. Make the decision as a function of density. If
* the decision is not to use a second file mark, the SCSI BLANK
* CHECK condition code will be recognized as end-of-data when
* first read.
* (I think this should be a by-product of fixed/variable..julian)
*/
switch (st->density) {
/* case 8 mm: What is the SCSI density code for 8 mm, anyway? */
case QIC_11:
case QIC_24:
case QIC_120:
case QIC_150:
case QIC_525:
case QIC_1320:
case QIC_3095:
case QIC_3220:
st->flags &= ~ST_2FM_AT_EOD;
break;
default:
st->flags |= ST_2FM_AT_EOD;
}
return 0;
}

/*
* 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
ststrategy(struct buf *bp)
{
struct st_softc *st = device_lookup_private(&st_cd, STUNIT(bp->b_dev));
struct scsipi_periph *periph = st->sc_periph;
struct scsipi_channel *chan = periph->periph_channel;

SC_DEBUG(periph, SCSIPI_DB1,
("ststrategy %d bytes @ blk %" PRId64 "\n", bp->b_bcount,
bp->b_blkno));
/* If it's a null transfer, return immediately */
if (bp->b_bcount == 0)
goto abort;

/* If offset is negative, error */
if (bp->b_blkno < 0) {
bp->b_error = EINVAL;
goto abort;
}

/* Odd sized request on fixed drives are verboten */
if (st->flags & ST_FIXEDBLOCKS) {
if (bp->b_bcount % st->blksize) {
aprint_error_dev(st->sc_dev, "bad request, must be multiple of %d\n",
st->blksize);
bp->b_error = EIO;
goto abort;
}
}
/* as are out-of-range requests on variable drives. */
else if (bp->b_bcount < st->blkmin ||
(st->blkmax && bp->b_bcount > st->blkmax)) {
aprint_error_dev(st->sc_dev, "bad request, must be between %d and %d\n",
st->blkmin, st->blkmax);
bp->b_error = EIO;
goto abort;
}
mutex_enter(chan_mtx(chan));

/*
* Place it in the queue of activities for this tape
* at the end (a bit silly because we only have on user..
* (but it could fork()))
*/
bufq_put(st->buf_queue, bp);

/*
* Tell the device to get going on the transfer if it's
* not doing anything, otherwise just wait for completion
* (All a bit silly if we're only allowing 1 open but..)
*/
ststart(periph);

mutex_exit(chan_mtx(chan));
return;
abort:
/*
* Reset the residue because we didn't do anything,
* and send the buffer back as done.
*/
bp->b_resid = bp->b_bcount;
biodone(bp);
return;
}

/*
* ststart 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 required. The transfer request will call scsipi_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 (ststrategy)
*
* 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.
* ststart() is called with channel lock held
*/
static int
ststart1(struct scsipi_periph *periph, struct buf *bp)
{
struct st_softc *st = device_private(periph->periph_dev);
struct scsipi_channel *chan = periph->periph_channel;
struct scsi_rw_tape cmd;
struct scsipi_xfer *xs;
int flags, error;

SC_DEBUG(periph, SCSIPI_DB2, ("ststart1 "));

mutex_enter(chan_mtx(chan));

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

/* if a special awaits, let it proceed first */
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 been unmounted by the user
* then throw away all requests until done.
*/
if (__predict_false((st->flags & ST_MOUNTED) == 0 ||
(periph->periph_flags & PERIPH_MEDIA_LOADED) == 0)) {
error = EIO;
goto out;
}

/*
* only FIXEDBLOCK devices have pending I/O or space operations.
*/
if (st->flags & ST_FIXEDBLOCKS) {
/*
* If we are at a filemark but have not reported it yet
* then we should report it now
*/
if (st->flags & ST_AT_FILEMARK) {
if ((bp->b_flags & B_READ) == B_WRITE) {
/*
* Handling of ST_AT_FILEMARK in
* st_space will fill in the right file
* mark count.
* Back up over filemark
*/
if (st_space(st, 0, SP_FILEMARKS, 0)) {
error = EIO;
goto out;
}
} else {
bp->b_resid = bp->b_bcount;
error = 0;
st->flags &= ~ST_AT_FILEMARK;
goto out;
}
}
}
/*
* If we are at EOM but have not reported it
* yet then we should report it now.
*/
if (st->flags & (ST_EOM_PENDING|ST_EIO_PENDING)) {
error = EIO;
goto out;
}

/* Fill out the scsi command */
memset(&cmd, 0, sizeof(cmd));
flags = XS_CTL_NOSLEEP | XS_CTL_ASYNC;
if ((bp->b_flags & B_READ) == B_WRITE) {
cmd.opcode = WRITE;
st->flags &= ~ST_FM_WRITTEN;
flags |= XS_CTL_DATA_OUT;
} else {
cmd.opcode = READ;
flags |= XS_CTL_DATA_IN;
}

/*
* Handle "fixed-block-mode" tape drives by using the
* block count instead of the length.
*/
if (st->flags & ST_FIXEDBLOCKS) {
cmd.byte2 |= SRW_FIXED;
_lto3b(bp->b_bcount / st->blksize, cmd.len);
} else
_lto3b(bp->b_bcount, cmd.len);

/* Clear 'position updated' indicator */
st->flags &= ~ST_POSUPDATED;

/* go ask the adapter to do all this for us */
xs = scsipi_make_xs_locked(periph,
(struct scsipi_generic *)&cmd, sizeof(cmd),
(u_char *)bp->b_data, bp->b_bcount,
0, ST_IO_TIME, bp, flags);
if (__predict_false(xs == NULL)) {
/*
* out of memory. Keep this buffer in the queue, and
* retry later.
*/
callout_reset(&st->sc_callout, hz / 2, strestart,
periph);
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;
}

static void
ststart(struct scsipi_periph *periph)
{
struct st_softc *st = device_private(periph->periph_dev);
struct scsipi_channel *chan = periph->periph_channel;
struct buf *bp;
int error;

SC_DEBUG(periph, SCSIPI_DB2, ("ststart "));

mutex_exit(chan_mtx(chan));
mutex_enter(&st->sc_iolock);

while ((bp = bufq_get(st->buf_defer)) != NULL
|| (bp = bufq_get(st->buf_queue)) != NULL) {

iostat_busy(st->stats);
mutex_exit(&st->sc_iolock);

error = ststart1(periph, bp);

mutex_enter(&st->sc_iolock);
if (error != 0)
iostat_unbusy(st->stats, 0,
((bp->b_flags & B_READ) == B_READ));
if (error == EAGAIN) {
bufq_put(st->buf_defer, bp);
break;
}
mutex_exit(&st->sc_iolock);

if (error != 0) {
bp->b_error = error;
bp->b_resid = bp->b_bcount;
biodone(bp);
}

mutex_enter(&st->sc_iolock);
}

mutex_exit(&st->sc_iolock);
mutex_enter(chan_mtx(chan));
}

static void
strestart(void *v)
{
struct scsipi_periph *periph = (struct scsipi_periph *)v;
struct scsipi_channel *chan = periph->periph_channel;

mutex_enter(chan_mtx(chan));
ststart((struct scsipi_periph *)v);
mutex_exit(chan_mtx(chan));
}

static void
stdone(struct scsipi_xfer *xs, int error)
{
struct st_softc *st = device_private(xs->xs_periph->periph_dev);
struct buf *bp = xs->bp;

if (bp) {
bp->b_error = error;
bp->b_resid = xs->resid;
/*
* buggy device ? A SDLT320 can report an info
* field of 0x3de8000 on a Media Error/Write Error
* for this CBD: 0x0a 00 00 80 00 00
*/
if (bp->b_resid > bp->b_bcount || bp->b_resid < 0)
bp->b_resid = bp->b_bcount;

if ((bp->b_flags & B_READ) == B_WRITE)
st->flags |= ST_WRITTEN;
else
st->flags &= ~ST_WRITTEN;

mutex_enter(&st->sc_iolock);
iostat_unbusy(st->stats, bp->b_bcount,
((bp->b_flags & B_READ) == B_READ));
mutex_exit(&st->sc_iolock);

rnd_add_uint32(&st->rnd_source, bp->b_blkno);

if ((st->flags & ST_POSUPDATED) == 0) {
if (error) {
st->fileno = st->blkno = -1;
} else if (st->blkno != -1) {
if (st->flags & ST_FIXEDBLOCKS)
st->blkno +=
(bp->b_bcount / st->blksize);
else
st->blkno++;
}
}
biodone(bp);
}
}

static int
stread(dev_t dev, struct uio *uio, int iomode)
{
struct st_softc *st = device_lookup_private(&st_cd, STUNIT(dev));

return physio(ststrategy, NULL, dev, B_READ,
st->sc_periph->periph_channel->chan_adapter->adapt_minphys, uio);
}

static int
stwrite(dev_t dev, struct uio *uio, int iomode)
{
struct st_softc *st = device_lookup_private(&st_cd, STUNIT(dev));

return physio(ststrategy, NULL, dev, B_WRITE,
st->sc_periph->periph_channel->chan_adapter->adapt_minphys, uio);
}

/*
* Perform special action on behalf of the user;
* knows about the internals of this device
*/
static int
stioctl(dev_t dev, u_long cmd, void *arg, int flag, struct lwp *l)
{
int error = 0;
int unit;
int number, nmarks, dsty;
int flags;
struct st_softc *st;
int hold_blksize;
uint8_t hold_density;
struct mtop *mt = (struct mtop *) arg;

/* Find the device that the user is talking about */
flags = 0; /* give error messages, act on errors etc. */
unit = STUNIT(dev);
dsty = STDSTY(dev);
st = device_lookup_private(&st_cd, unit);
hold_blksize = st->blksize;
hold_density = st->density;

switch ((u_int)cmd) {
case MTIOCGET: {
struct mtget *g = (struct mtget *) arg;
/*
* (to get the current state of READONLY)
*/
error = st->ops(st, ST_OPS_MODESENSE, XS_CTL_SILENT);
if (error) {
/*
* Ignore the error if in control mode;
* this is mandated by st(4).
*/
if (STMODE(dev) != CTRL_MODE)
break;
error = 0;
}
SC_DEBUG(st->sc_periph, SCSIPI_DB1, ("[ioctl: get status]\n"));
memset(g, 0, sizeof(struct mtget));
g->mt_type = MT_ISAR; /* Ultrix compat *//*? */
g->mt_blksiz = st->blksize;
g->mt_density = st->density;
g->mt_mblksiz[0] = st->modes[0].blksize;
g->mt_mblksiz[1] = st->modes[1].blksize;
g->mt_mblksiz[2] = st->modes[2].blksize;
g->mt_mblksiz[3] = st->modes[3].blksize;
g->mt_mdensity[0] = st->modes[0].density;
g->mt_mdensity[1] = st->modes[1].density;
g->mt_mdensity[2] = st->modes[2].density;
g->mt_mdensity[3] = st->modes[3].density;
g->mt_fileno = st->fileno;
g->mt_blkno = st->blkno;
if (st->flags & ST_READONLY)
g->mt_dsreg |= MT_DS_RDONLY;
if (st->flags & ST_MOUNTED)
g->mt_dsreg |= MT_DS_MOUNTED;
g->mt_resid = st->mt_resid;
g->mt_erreg = st->mt_erreg;
/*
* clear latched errors.
*/
st->mt_resid = 0;
st->mt_erreg = 0;
st->asc = 0;
st->ascq = 0;
break;
}
case MTIOCTOP: {
SC_DEBUG(st->sc_periph, SCSIPI_DB1,
("[ioctl: op=0x%x count=0x%x]\n", mt->mt_op,
mt->mt_count));

/* compat: in U*x it is a short */
number = mt->mt_count;
switch ((short) (mt->mt_op)) {
case MTWEOF: /* write an end-of-file record */
error = st_write_filemarks(st, number, flags);
break;
case MTBSF: /* backward space file */
number = -number;
case MTFSF: /* forward space file */
error = st_check_eod(st, FALSE, &nmarks, flags);
if (!error)
error = st_space(st, number - nmarks,
SP_FILEMARKS, flags);
break;
case MTBSR: /* backward space record */
number = -number;
case MTFSR: /* forward space record */
error = st_check_eod(st, true, &nmarks, flags);
if (!error)
error = st_space(st, number, SP_BLKS, flags);
break;
case MTREW: /* rewind */
error = st_rewind(st, 0, flags);
break;
case MTOFFL: /* rewind and put the drive offline */
st_unmount(st, EJECT);
break;
case MTNOP: /* no operation, sets status only */
break;
case MTRETEN: /* retension the tape */
error = st_load(st, LD_RETENSION, flags);
if (!error)
error = st_load(st, LD_LOAD, flags);
break;
case MTEOM: /* forward space to end of media */
error = st_check_eod(st, FALSE, &nmarks, flags);
if (!error)
error = st_space(st, 1, SP_EOM, flags);
break;
case MTCACHE: /* enable controller cache */
st->flags &= ~ST_DONTBUFFER;
goto try_new_value;
case MTNOCACHE: /* disable controller cache */
st->flags |= ST_DONTBUFFER;
goto try_new_value;
case MTERASE: /* erase volume */
error = st_erase(st, number, flags);
break;
case MTSETBSIZ: /* Set block size for device */
#ifdef NOTYET
if (!(st->flags & ST_NEW_MOUNT)) {
uprintf("re-mount tape before changing "
"blocksize");
error = EINVAL;
break;
}
#endif
if (number == 0)
st->flags &= ~ST_FIXEDBLOCKS;
else {
if ((st->blkmin || st->blkmax) &&
(number < st->blkmin ||
number > st->blkmax)) {
error = EINVAL;
break;
}
st->flags |= ST_FIXEDBLOCKS;
}
st->blksize = number;
st->flags |= ST_BLOCK_SET; /*XXX */
goto try_new_value;
case MTSETDNSTY: /* Set density for device and mode */
/*
* Any number >= 0 and <= 0xff is legal. Numbers
* above 0x80 are 'vendor unique'.
*/
if (number < 0 || number > 255) {
error = EINVAL;
break;
} else
st->density = number;
goto try_new_value;
case MTCMPRESS:
error = st->ops(st, (number == 0) ?
ST_OPS_CMPRSS_OFF : ST_OPS_CMPRSS_ON,
XS_CTL_SILENT);
break;
case MTEWARN:
if (number)
st->flags |= ST_EARLYWARN;
else
st->flags &= ~ST_EARLYWARN;
break;

default:
error = EINVAL;
}
break;
}
case MTIOCIEOT:
case MTIOCEEOT:
break;
case MTIOCRDSPOS:
error = st_rdpos(st, 0, (uint32_t *)arg);
break;
case MTIOCRDHPOS:
error = st_rdpos(st, 1, (uint32_t *)arg);
break;
case MTIOCSLOCATE:
error = st_setpos(st, 0, (uint32_t *)arg);
break;
case MTIOCHLOCATE:
error = st_setpos(st, 1, (uint32_t *)arg);
break;
default:
error = scsipi_do_ioctl(st->sc_periph, dev, cmd, arg, flag, l);
break;
}
return error;

try_new_value:
/*
* Check that the mode being asked for is aggreeable to the
* drive. If not, put it back the way it was.
*
* If in control mode, we can make (persistent) mode changes
* even if no medium is loaded (see st(4)).
*/
if ((STMODE(dev) != CTRL_MODE || (st->flags & ST_MOUNTED) != 0) &&
(error = st->ops(st, ST_OPS_MODESELECT, 0)) != 0) {
/* put it back as it was */
aprint_error_dev(st->sc_dev, "cannot set selected mode\n");
st->density = hold_density;
st->blksize = hold_blksize;
if (st->blksize)
st->flags |= ST_FIXEDBLOCKS;
else
st->flags &= ~ST_FIXEDBLOCKS;
return error;
}
/*
* As the drive liked it, if we are setting a new default,
* set it into the structures as such.
*
* The means for deciding this are not finalised yet- but
* if the device was opened in Control Mode, the values
* are persistent now across mounts.
*/
if (STMODE(dev) == CTRL_MODE) {
switch ((short) (mt->mt_op)) {
case MTSETBSIZ:
st->modes[dsty].blksize = st->blksize;
st->modeflags[dsty] |= BLKSIZE_SET_BY_USER;
break;
case MTSETDNSTY:
st->modes[dsty].density = st->density;
st->modeflags[dsty] |= DENSITY_SET_BY_USER;
break;
}
}
return 0;
}

/* Do a synchronous read. */
static int
st_read(struct st_softc *st, char *bf, int size, int flags)
{
struct scsi_rw_tape cmd;

/* If it's a null transfer, return immediatly */
if (size == 0)
return 0;
memset(&cmd, 0, sizeof(cmd));
cmd.opcode = READ;
if (st->flags & ST_FIXEDBLOCKS) {
cmd.byte2 |= SRW_FIXED;
_lto3b(size / (st->blksize ? st->blksize : DEF_FIXED_BSIZE),
cmd.len);
} else
_lto3b(size, cmd.len);
return scsipi_command(st->sc_periph,
(void *)&cmd, sizeof(cmd), (void *)bf, size, 0, ST_IO_TIME, NULL,
flags | XS_CTL_DATA_IN);
}

/* issue an erase command */
static int
st_erase(struct st_softc *st, int full, int flags)
{
int tmo;
struct scsi_erase cmd;

/*
* Full erase means set LONG bit in erase command, which asks
* the drive to erase the entire unit. Without this bit, we're
* asking the drive to write an erase gap.
*/
memset(&cmd, 0, sizeof(cmd));
cmd.opcode = ERASE;
if (full) {
cmd.byte2 = SE_LONG;
tmo = ST_SPC_TIME;
} else
tmo = ST_IO_TIME;

/*
* XXX We always do this asynchronously, for now, unless the device
* has the ST_Q_ERASE_NOIMM quirk. How long should we wait if we
* want to (eventually) to it synchronously?
*/
if ((st->quirks & ST_Q_ERASE_NOIMM) == 0)
cmd.byte2 |= SE_IMMED;

return scsipi_command(st->sc_periph, (void *)&cmd, sizeof(cmd), 0, 0,
ST_RETRIES, tmo, NULL, flags);
}

/* skip N blocks/filemarks/seq filemarks/eom */
static int
st_space(struct st_softc *st, int number, u_int what, int flags)
{
struct scsi_space cmd;
int error;

switch (what) {
case SP_BLKS:
if (st->flags & ST_PER_ACTION) {
if (number > 0) {
st->flags &= ~ST_PER_ACTION;
return EIO;
} else if (number < 0) {
if (st->flags & ST_AT_FILEMARK) {
/*
* Handling of ST_AT_FILEMARK
* in st_space will fill in the
* right file mark count.
*/
error = st_space(st, 0, SP_FILEMARKS,
flags);
if (error)
return error;
}
if (st->flags & ST_BLANK_READ) {
st->flags &= ~ST_BLANK_READ;
return EIO;
}
st->flags &= ~(ST_EIO_PENDING|ST_EOM_PENDING);
}
}
break;
case SP_FILEMARKS:
if (st->flags & ST_EIO_PENDING) {
if (number > 0) {
/* pretend we just discovered the error */
st->flags &= ~ST_EIO_PENDING;
return EIO;
} else if (number < 0) {
/* back away from the error */
st->flags &= ~ST_EIO_PENDING;
}
}
if (st->flags & ST_AT_FILEMARK) {
st->flags &= ~ST_AT_FILEMARK;
number--;
}
if ((st->flags & ST_BLANK_READ) && (number < 0)) {
/* back away from unwritten tape */
st->flags &= ~ST_BLANK_READ;
number++; /* XXX dubious */
}
break;
case SP_EOM:
if (st->flags & ST_EOM_PENDING) {
/* we're already there */
st->flags &= ~ST_EOM_PENDING;
return 0;
}
if (st->flags & ST_EIO_PENDING) {
/* pretend we just discovered the error */
st->flags &= ~ST_EIO_PENDING;
return EIO;
}
if (st->flags & ST_AT_FILEMARK)
st->flags &= ~ST_AT_FILEMARK;
break;
}
if (number == 0)
return 0;

memset(&cmd, 0, sizeof(cmd));
cmd.opcode = SPACE;
cmd.byte2 = what;
_lto3b(number, cmd.number);

st->flags &= ~ST_POSUPDATED;
st->last_ctl_resid = 0;
error = scsipi_command(st->sc_periph, (void *)&cmd, sizeof(cmd), 0, 0,
0, ST_SPC_TIME, NULL, flags);

if (error == 0 && (st->flags & ST_POSUPDATED) == 0) {
number = number - st->last_ctl_resid;
if (what == SP_BLKS) {
if (st->blkno != -1)
st->blkno += number;
} else if (what == SP_FILEMARKS) {
if (st->fileno != -1) {
st->fileno += number;
if (number > 0)
st->blkno = 0;
else if (number < 0)
st->blkno = -1;
}
} else if (what == SP_EOM) {
/* This loses us relative position. */
st->fileno = st->blkno = -1;
}
}
return error;
}

/*
* write N filemarks
*/
static int
st_write_filemarks(struct st_softc *st, int number, int flags)
{
int error;
struct scsi_write_filemarks cmd;

/*
* It's hard to write a negative number of file marks.
* Don't try.
*/
if (number < 0)
return EINVAL;
switch (number) {
case 0: /* really a command to sync the drive's buffers */
break;
case 1:
if (st->flags & ST_FM_WRITTEN) /* already have one down */
st->flags &= ~ST_WRITTEN;
else
st->flags |= ST_FM_WRITTEN;
st->flags &= ~ST_PER_ACTION;
break;
default:
st->flags &= ~(ST_PER_ACTION | ST_WRITTEN);
}

memset(&cmd, 0, sizeof(cmd));
cmd.opcode = WRITE_FILEMARKS;
if (SCSIPI_BUSTYPE_TYPE(scsipi_periph_bustype(st->sc_periph)) ==
SCSIPI_BUSTYPE_ATAPI)
cmd.byte2 = SR_IMMED;
/*
* The ATAPI Onstream DI-30 doesn't support writing filemarks, but
* WRITE_FILEMARKS is still used to flush the buffer
*/
if ((st->quirks & ST_Q_NOFILEMARKS) == 0)
_lto3b(number, cmd.number);

/* XXX WE NEED TO BE ABLE TO GET A RESIDIUAL XXX */
error = scsipi_command(st->sc_periph, (void *)&cmd, sizeof(cmd), 0, 0,
0, ST_IO_TIME * 4, NULL, flags);
if (error == 0 && st->fileno != -1)
st->fileno += number;
return error;
}

/*
* Make sure the right number of file marks is on tape if the
* tape has been written. If the position argument is true,
* leave the tape positioned where it was originally.
*
* nmarks returns the number of marks to skip (or, if position
* true, which were skipped) to get back original position.
*/
static int
st_check_eod(struct st_softc *st, boolean position, int *nmarks, int flags)
{
int error;

switch (st->flags & (ST_WRITTEN | ST_FM_WRITTEN | ST_2FM_AT_EOD)) {
default:
*nmarks = 0;
return 0;
case ST_WRITTEN:
case ST_WRITTEN | ST_FM_WRITTEN | ST_2FM_AT_EOD:
*nmarks = 1;
break;
case ST_WRITTEN | ST_2FM_AT_EOD:
*nmarks = 2;
}
error = st_write_filemarks(st, *nmarks, flags);
if (position && !error)
error = st_space(st, -*nmarks, SP_FILEMARKS, flags);
return error;
}

/* load/unload/retension */
static int
st_load(struct st_softc *st, u_int type, int flags)
{
int error;
struct scsi_load cmd;

if (type != LD_LOAD) {
int nmarks;

error = st_check_eod(st, FALSE, &nmarks, flags);
if (error) {
aprint_error_dev(st->sc_dev,
"failed to write closing filemarks at "
"unload, errno=%d\n", error);
return error;
}
}
if (st->quirks & ST_Q_IGNORE_LOADS) {
if (type == LD_LOAD)
/*
* If we ignore loads, at least we should try a rewind.
*/
return st_rewind(st, 0, flags);
/* otherwise, we should do what's asked of us */
}

memset(&cmd, 0, sizeof(cmd));
cmd.opcode = LOAD;
if (SCSIPI_BUSTYPE_TYPE(scsipi_periph_bustype(st->sc_periph)) ==
SCSIPI_BUSTYPE_ATAPI)
cmd.byte2 = SR_IMMED;
cmd.how = type;

error = scsipi_command(st->sc_periph, (void *)&cmd, sizeof(cmd), 0, 0,
ST_RETRIES, ST_SPC_TIME, NULL, flags);
if (error) {
aprint_error_dev(st->sc_dev, "error %d in st_load (op %d)\n",
error, type);
}
return error;
}

/* Rewind the device */
static int
st_rewind(struct st_softc *st, u_int immediate, int flags)
{
struct scsi_rewind cmd;
int error;
int nmarks;
int timeout;

error = st_check_eod(st, FALSE, &nmarks, flags);
if (error) {
aprint_error_dev(st->sc_dev,
"failed to write closing filemarks at "
"rewind, errno=%d\n", error);
return error;
}
st->flags &= ~ST_PER_ACTION;

/* If requestor asked for immediate response, set a short timeout */
timeout = immediate ? ST_CTL_TIME : ST_SPC_TIME;

/* ATAPI tapes always need immediate to be set */
if (scsipi_periph_bustype(st->sc_periph) == SCSIPI_BUSTYPE_ATAPI)
immediate = SR_IMMED;

memset(&cmd, 0, sizeof(cmd));
cmd.opcode = REWIND;
cmd.byte2 = immediate;

error = scsipi_command(st->sc_periph, (void *)&cmd, sizeof(cmd), 0, 0,
ST_RETRIES, timeout, NULL, flags);
if (error) {
aprint_error_dev(st->sc_dev, "error %d trying to rewind\n",
error);
/* lost position */
st->fileno = st->blkno = -1;
} else
st->fileno = st->blkno = 0;
return error;
}

static int
st_rdpos(struct st_softc *st, int hard, uint32_t *blkptr)
{
int error;
uint8_t posdata[20];
struct scsi_tape_read_position cmd;

/*
* We try and flush any buffered writes here if we were writing
* and we're trying to get hardware block position. It eats
* up performance substantially, but I'm wary of drive firmware.
*
* I think that *logical* block position is probably okay-
* but hardware block position might have to wait for data
* to hit media to be valid. Caveat Emptor.
*/

if (hard && (st->flags & ST_WRITTEN)) {
/* First flush any pending writes... */
error = st_write_filemarks(st, 0, XS_CTL_SILENT);
/*
* The latter case is for 'write protected' tapes
* which are too stupid to recognize a zero count
* for writing filemarks as a no-op.
*/
if (error != 0 && error != EACCES && error != EROFS)
return error;
}

memset(&cmd, 0, sizeof(cmd));
memset(&posdata, 0, sizeof(posdata));
cmd.opcode = READ_POSITION;
if (hard)
cmd.byte1 = 1;

error = scsipi_command(st->sc_periph, (void *)&cmd, sizeof(cmd),
(void *)&posdata, sizeof(posdata), ST_RETRIES, ST_CTL_TIME, NULL,
XS_CTL_SILENT | XS_CTL_DATA_IN);

if (error == 0) {
#if 0
printf("posdata:");
for (hard = 0; hard < sizeof(posdata); hard++)
printf("%02x ", posdata[hard] & 0xff);
printf("\n");
#endif
if (posdata[0] & 0x4) /* Block Position Unknown */
error = EINVAL;
else
*blkptr = _4btol(&posdata[4]);
}
return error;
}

static int
st_setpos(struct st_softc *st, int hard, uint32_t *blkptr)
{
int error;
struct scsi_tape_locate cmd;

/*
* We used to try and flush any buffered writes here.
* Now we push this onto user applications to either
* flush the pending writes themselves (via a zero count
* WRITE FILEMARKS command) or they can trust their tape
* drive to do this correctly for them.
*
* There are very ugly performance limitations otherwise.
*/

memset(&cmd, 0, sizeof(cmd));
cmd.opcode = LOCATE;
if (hard)
cmd.byte2 = 1 << 2;
_lto4b(*blkptr, cmd.blkaddr);
error = scsipi_command(st->sc_periph, (void *)&cmd, sizeof(cmd), 0, 0,
ST_RETRIES, ST_SPC_TIME, NULL, 0);
/*
* Note file && block number position now unknown (if
* these things ever start being maintained in this driver)
*/
st->fileno = st->blkno = -1;
return error;
}

/*
* Look at the returned sense and act on the error and determine
* the unix error number to pass back..., 0 (== report no error),
* -1 = retry the operation, -2 continue error processing.
*/
static int
st_interpret_sense(struct scsipi_xfer *xs)
{
struct scsipi_periph *periph = xs->xs_periph;
struct scsi_sense_data *sense = &xs->sense.scsi_sense;
struct buf *bp = xs->bp;
struct st_softc *st = device_private(periph->periph_dev);
int retval = EJUSTRETURN;
int doprint = ((xs->xs_control & XS_CTL_SILENT) == 0);
uint8_t key;
int32_t info;

/*
* 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 (sense->response_code & SSD_RCODE_VALID)
info = _4btol(sense->info);
else
info = (st->flags & ST_FIXEDBLOCKS) ?
xs->datalen / st->blksize : xs->datalen;
key = SSD_SENSE_KEY(sense->flags);
st->mt_erreg = key;
st->asc = sense->asc;
st->ascq = sense->ascq;
st->mt_resid = (short) info;

if (key == SKEY_NOT_READY && st->asc == 0x4 && st->ascq == 0x1) {
/* Not Ready, Logical Unit Is in Process Of Becoming Ready */
if (!callout_pending(&periph->periph_callout))
scsipi_periph_freeze(periph, 1);
callout_reset(&periph->periph_callout,
hz, scsipi_periph_timed_thaw, periph);
return ERESTART;
}

/* If the device is not open yet, let generic handle */
if ((periph->periph_flags & PERIPH_OPEN) == 0)
return retval;

xs->resid = info;
if (st->flags & ST_FIXEDBLOCKS) {
if (bp) {
xs->resid *= st->blksize;
st->last_io_resid = xs->resid;
} else
st->last_ctl_resid = xs->resid;
if (key == SKEY_VOLUME_OVERFLOW) {
st->flags |= ST_EIO_PENDING;
if (bp)
bp->b_resid = xs->resid;
} else if (sense->flags & SSD_EOM) {
if ((st->flags & ST_EARLYWARN) == 0)
st->flags |= ST_EIO_PENDING;
st->flags |= ST_EOM_PENDING;
if (bp) {
#if 0
bp->b_resid = xs->resid;
#else
/*
* Grotesque as it seems, the few times
* I've actually seen a non-zero resid,
* the tape drive actually lied and had
* written all the data!
*/
bp->b_resid = 0;
#endif
}
}
if (sense->flags & SSD_FILEMARK) {
st->flags |= ST_AT_FILEMARK;
if (bp)
bp->b_resid = xs->resid;
if (st->fileno != (daddr_t) -1) {
st->fileno++;
st->blkno = 0;
st->flags |= ST_POSUPDATED;
}
}
if (sense->flags & SSD_ILI) {
st->flags |= ST_EIO_PENDING;
if (bp)
bp->b_resid = xs->resid;
if (sense->response_code & SSD_RCODE_VALID &&
(xs->xs_control & XS_CTL_SILENT) == 0)
aprint_error_dev(st->sc_dev,
"block wrong size, %d blocks residual\n",
info);

/*
* This quirk code helps the drive read
* the first tape block, regardless of
* format. That is required for these
* drives to return proper MODE SENSE
* information.
*/
if ((st->quirks & ST_Q_SENSE_HELP) &&
(periph->periph_flags & PERIPH_MEDIA_LOADED) == 0)
st->blksize -= 512;
else if ((st->flags & ST_POSUPDATED) == 0) {
if (st->blkno != (daddr_t) -1) {
st->blkno +=
(xs->datalen / st->blksize);
st->flags |= ST_POSUPDATED;
}
}
}
/*
* If data wanted and no data was transferred, do it immediately
*/
if (xs->datalen && xs->resid >= xs->datalen) {
if (st->flags & ST_EIO_PENDING)
return EIO;
if (st->flags & ST_AT_FILEMARK) {
if (bp)
bp->b_resid = xs->resid;
return 0;
}
}
} else { /* must be variable mode */
if (bp)
st->last_io_resid = xs->resid;
else
st->last_ctl_resid = xs->resid;
if (sense->flags & SSD_EOM) {
/*
* The current semantics of this
* driver requires EOM detection
* to return EIO unless early
* warning detection is enabled
* for variable mode (this is always
* on for fixed block mode).
*/
if (st->flags & ST_EARLYWARN) {
st->flags |= ST_EOM_PENDING;
retval = 0;
} else {
retval = EIO;
/*
* If we return an error we can't claim to
* have transfered all data.
*/
if (xs->resid == 0)
xs->resid = xs->datalen;
}

/*
* If it's an unadorned EOM detection,
* suppress printing an error.
*/
if (key == SKEY_NO_SENSE) {
doprint = 0;
}
} else if (sense->flags & SSD_FILEMARK) {
retval = 0;
if (st->fileno != (daddr_t) -1) {
st->fileno++;
st->blkno = 0;
st->flags |= ST_POSUPDATED;
}
} else if (sense->flags & SSD_ILI) {
if (info < 0) {
/*
* The tape record was bigger than the read
* we issued.
*/
if ((xs->xs_control & XS_CTL_SILENT) == 0) {
aprint_error_dev(st->sc_dev,
"%d-byte tape record too big"
" for %d-byte user buffer\n",
xs->datalen - info, xs->datalen);
}
retval = EIO;
} else {
retval = 0;
if (st->blkno != (daddr_t) -1) {
st->blkno++;
st->flags |= ST_POSUPDATED;
}
}
}
if (bp)
bp->b_resid = xs->resid;
}

#ifndef SCSIPI_DEBUG
if (retval == 0 && key == SKEY_NO_SENSE)
doprint = 0;
#endif
if (key == SKEY_BLANK_CHECK) {
/*
* This quirk code helps the drive read the
* first tape block, regardless of format. That
* is required for these drives to return proper
* MODE SENSE information.
*/
if ((st->quirks & ST_Q_SENSE_HELP) &&
(periph->periph_flags & PERIPH_MEDIA_LOADED) == 0) {
/* still starting */
st->blksize -= 512;
} else if (!(st->flags & (ST_2FM_AT_EOD | ST_BLANK_READ))) {
st->flags |= ST_BLANK_READ;
xs->resid = xs->datalen;
if (bp) {
bp->b_resid = xs->resid;
/* return an EOF */
}
retval = 0;
/* lost position */
st->fileno = st->blkno = -1;
}
}

/*
* If generic sense processing will continue, we should not
* print sense info here.
*/
if (retval == EJUSTRETURN)
doprint = 0;

if (doprint) {
/* Print verbose sense info if possible */
if (scsipi_print_sense(xs, 0) != 0)
return retval;

/* Print less-verbose sense info */
scsipi_printaddr(periph);
printf("Sense Key 0x%02x", key);
if ((sense->response_code & SSD_RCODE_VALID) != 0) {
switch (key) {
case SKEY_NOT_READY:
case SKEY_ILLEGAL_REQUEST:
case SKEY_UNIT_ATTENTION:
case SKEY_DATA_PROTECT:
break;
case SKEY_VOLUME_OVERFLOW:
case SKEY_BLANK_CHECK:
printf(", requested size: %d (decimal)", info);
break;
case SKEY_ABORTED_COMMAND:
if (xs->xs_retries)
printf(", retrying");
printf(", cmd 0x%x, info 0x%x",
xs->cmd->opcode, info);
break;
default:
printf(", info = %d (decimal)", info);
}
}
if (sense->extra_len != 0) {
int n;
printf(", data =");
for (n = 0; n < sense->extra_len; n++)
printf(" %02x", sense->csi[n]);
}
printf("\n");
}
return retval;
}

/*
* The quirk here is that the drive returns some value to st_mode_sense
* incorrectly until the tape has actually passed by the head.
*
* The method is to set the drive to large fixed-block state (user-specified
* density and 1024-byte blocks), then read and rewind to get it to sense the
* tape. If that doesn't work, try 512-byte fixed blocks. If that doesn't
* work, as a last resort, try variable- length blocks. The result will be
* the ability to do an accurate st_mode_sense.
*
* We know we can do a rewind because we just did a load, which implies rewind.
* Rewind seems preferable to space backward if we have a virgin tape.
*
* The rest of the code for this quirk is in ILI processing and BLANK CHECK
* error processing, both part of st_interpret_sense.
*/
static int
st_touch_tape(struct st_softc *st)
{
char *bf;
int readsize;
int error;

bf = malloc(1024, M_TEMP, M_NOWAIT);
if (bf == NULL)
return ENOMEM;

if ((error = st->ops(st, ST_OPS_MODESENSE, 0)) != 0)
goto bad;

/*
* If the block size is already known from the
* sense data, use it. Else start probing at 1024.
*/
if (st->media_blksize > 0)
st->blksize = st->media_blksize;
else
st->blksize = 1024;

do {
switch (st->blksize) {
case 512:
case 1024:
readsize = st->blksize;
st->flags |= ST_FIXEDBLOCKS;
break;
default:
readsize = 1;
st->flags &= ~ST_FIXEDBLOCKS;
}
if ((error = st->ops(st, ST_OPS_MODESELECT, XS_CTL_SILENT))
!= 0) {
/*
* The device did not agree with the proposed
* block size. If we exhausted our options,
* return failure, else try another.
*/
if (readsize == 1)
goto bad;
st->blksize -= 512;
continue;
}
st_read(st, bf, readsize, XS_CTL_SILENT); /* XXX */
if ((error = st_rewind(st, 0, 0)) != 0) {
bad: free(bf, M_TEMP);
return error;
}
} while (readsize != 1 && readsize > st->blksize);

free(bf, M_TEMP);
return 0;
}

static int
stdump(dev_t dev, daddr_t blkno, void *va, size_t size)
{
/* Not implemented. */
return ENXIO;
}

/*
* Send a filled out parameter structure to the drive to
* set it into the desire modes etc.
*/
int
st_mode_select(struct st_softc *st, int flags)
{
u_int select_len;
struct select {
struct scsi_mode_parameter_header_6 header;
struct scsi_general_block_descriptor blk_desc;
u_char sense_data[MAX_PAGE_0_SIZE];
} select;
struct scsipi_periph *periph = st->sc_periph;

select_len = sizeof(select.header) + sizeof(select.blk_desc) +
st->page_0_size;

/*
* This quirk deals with drives that have only one valid mode
* and think this gives them license to reject all mode selects,
* even if the selected mode is the one that is supported.
*/
if (st->quirks & ST_Q_UNIMODAL) {
SC_DEBUG(periph, SCSIPI_DB3,
("not setting density 0x%x blksize 0x%x\n",
st->density, st->blksize));
return 0;
}

/* Set up for a mode select */
memset(&select, 0, sizeof(select));
select.header.blk_desc_len = sizeof(struct
scsi_general_block_descriptor);
select.header.dev_spec &= ~SMH_DSP_BUFF_MODE;
select.blk_desc.density = st->density;
if (st->flags & ST_DONTBUFFER)
select.header.dev_spec |= SMH_DSP_BUFF_MODE_OFF;
else
select.header.dev_spec |= SMH_DSP_BUFF_MODE_ON;
if (st->flags & ST_FIXEDBLOCKS)
_lto3b(st->blksize, select.blk_desc.blklen);
if (st->page_0_size)
memcpy(select.sense_data, st->sense_data, st->page_0_size);

/* do the command */
return scsipi_mode_select(periph, 0, &select.header, select_len,
flags, ST_RETRIES, ST_CTL_TIME);
}