* Copyright (c) 1996, 1997 The NetBSD Foundation, Inc.

/* $NetBSD: mt.c,v 1.56 2022/11/26 00:25:36 tsutsui Exp $ */

/*-
* Copyright (c) 1996, 1997 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Jason R. Thorpe.
*
* 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.
*/

/*
* Copyright (c) 1992, The University of Utah and
* the Computer Systems Laboratory at the University of Utah (CSL).
* All rights reserved.
*
* Permission to use, copy, modify and distribute this software is hereby
* granted provided that (1) source code retains these copyright, permission,
* and disclaimer notices, and (2) redistributions including binaries
* reproduce the notices in supporting documentation, and (3) all advertising
* materials mentioning features or use of this software display the following
* acknowledgement: ``This product includes software developed by the
* Computer Systems Laboratory at the University of Utah.''
*
* THE UNIVERSITY OF UTAH AND CSL ALLOW FREE USE OF THIS SOFTWARE IN ITS "AS
* IS" CONDITION. THE UNIVERSITY OF UTAH AND CSL DISCLAIM ANY LIABILITY OF
* ANY KIND FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* CSL requests users of this software to return to [email protected] any
* improvements that they make and grant CSL redistribution rights.
*
* Utah $Hdr: mt.c 1.8 95/09/12$
*/
/* @(#)mt.c 3.9 90/07/10 mt Xinu
*
* Magnetic tape driver (7974a, 7978a/b, 7979a, 7980a, 7980xc)
* Original version contributed by Mt. Xinu.
* Modified for 4.4BSD by Mark Davies and Andrew Vignaux, Department of
* Computer Science, Victoria University of Wellington
*/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: mt.c,v 1.56 2022/11/26 00:25:36 tsutsui Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/callout.h>
#include <sys/buf.h>
#include <sys/bufq.h>
#include <sys/ioctl.h>
#include <sys/mtio.h>
#include <sys/file.h>
#include <sys/proc.h>
#include <sys/errno.h>
#include <sys/syslog.h>
#include <sys/tty.h>
#include <sys/kernel.h>
#include <sys/tprintf.h>
#include <sys/device.h>
#include <sys/conf.h>

#include <hp300/dev/hpibvar.h>

#include <hp300/dev/mtreg.h>

#include "ioconf.h"

static const struct mtinfo {
uint16_t hwid;
const char *desc;
} mtinfo[] = {
{ MT7978ID, "7978" },
{ MT7979AID, "7979A" },
{ MT7980ID, "7980" },
{ MT7974AID, "7974A" },
};
static const int nmtinfo = sizeof(mtinfo) / sizeof(mtinfo[0]);

struct mt_softc {
device_t sc_dev;
struct callout sc_start_ch;
struct callout sc_intr_ch;
int sc_hpibno; /* logical HPIB this slave it attached to */
int sc_slave; /* HPIB slave address (0-6) */
short sc_flags; /* see below */
uint8_t sc_lastdsj; /* place for DSJ in mtreaddsj() */
uint8_t sc_lastecmd; /* place for End Command in mtreaddsj() */
short sc_recvtimeo; /* count of hpibsend timeouts to prevent hang */
short sc_statindex; /* index for next sc_stat when MTF_STATTIMEO */
struct mt_stat sc_stat;/* status bytes last read from device */
short sc_density; /* current density of tape (mtio.h format) */
short sc_type; /* tape drive model (hardware IDs) */
struct hpibqueue sc_hq; /* HPIB device queue member */
tpr_t sc_ttyp;
struct bufq_state *sc_tab;/* buf queue */
int sc_active;
};

#ifdef DEBUG
int mtdebug = 0;
#define dlog if (mtdebug) log
#else
#define dlog if (0) log
#endif

#define UNIT(x) (minor(x) & 3)

#define B_CMD B_DEVPRIVATE /* command buf instead of data */
#define b_cmd b_blkno /* blkno holds cmd when B_CMD */

static int mtmatch(device_t, cfdata_t, void *);
static void mtattach(device_t, device_t, void *);

CFATTACH_DECL_NEW(mt, sizeof(struct mt_softc),
mtmatch, mtattach, NULL, NULL);

static dev_type_open(mtopen);
static dev_type_close(mtclose);
static dev_type_read(mtread);
static dev_type_write(mtwrite);
static dev_type_ioctl(mtioctl);
static dev_type_strategy(mtstrategy);

const struct bdevsw mt_bdevsw = {
.d_open = mtopen,
.d_close = mtclose,
.d_strategy = mtstrategy,
.d_ioctl = mtioctl,
.d_dump = nodump,
.d_psize = nosize,
.d_discard = nodiscard,
.d_flag = D_TAPE
};

const struct cdevsw mt_cdevsw = {
.d_open = mtopen,
.d_close = mtclose,
.d_read = mtread,
.d_write = mtwrite,
.d_ioctl = mtioctl,
.d_stop = nostop,
.d_tty = notty,
.d_poll = nopoll,
.d_mmap = nommap,
.d_kqfilter = nokqfilter,
.d_discard = nodiscard,
.d_flag = D_TAPE
};

static int mtident(struct mt_softc *, struct hpibbus_attach_args *);
static void mtustart(struct mt_softc *);
static int mtreaddsj(struct mt_softc *, int);
static int mtcommand(dev_t, int, int);
static void spl_mtintr(void *);
static void spl_mtstart(void *);

static void mtstart(void *);
static void mtgo(void *);
static void mtintr(void *);

static int
mtmatch(device_t parent, cfdata_t cf, void *aux)
{
struct hpibbus_attach_args *ha = aux;

return mtident(NULL, ha);
}

static void
mtattach(device_t parent, device_t self, void *aux)
{
struct mt_softc *sc = device_private(self);
struct hpibbus_attach_args *ha = aux;
int hpibno, slave;

sc->sc_dev = self;
if (mtident(sc, ha) == 0) {
aprint_error(": impossible!\n");
return;
}

hpibno = device_unit(parent);
slave = ha->ha_slave;

bufq_alloc(&sc->sc_tab, "fcfs", 0);
callout_init(&sc->sc_start_ch, 0);
callout_init(&sc->sc_intr_ch, 0);

sc->sc_hpibno = hpibno;
sc->sc_slave = slave;
sc->sc_flags = MTF_EXISTS;

/* Initialize hpib job queue entry. */
sc->sc_hq.hq_softc = sc;
sc->sc_hq.hq_slave = sc->sc_slave;
sc->sc_hq.hq_start = mtstart;
sc->sc_hq.hq_go = mtgo;
sc->sc_hq.hq_intr = mtintr;
}

static int
mtident(struct mt_softc *sc, struct hpibbus_attach_args *ha)
{
int i;

for (i = 0; i < nmtinfo; i++) {
if (ha->ha_id == mtinfo[i].hwid &&
ha->ha_punit == 0) {
if (sc != NULL) {
sc->sc_type = mtinfo[i].hwid;
aprint_normal(": %s tape\n", mtinfo[i].desc);
}
return 1;
}
}
return 0;
}

/*
* Perform a read of "Device Status Jump" register and update the
* status if necessary. If status is read, the given "ecmd" is also
* performed, unless "ecmd" is zero. Returns DSJ value, -1 on failure
* and -2 on "temporary" failure.
*/
static int
mtreaddsj(struct mt_softc *sc, int ecmd)
{
int retval;

if ((sc->sc_flags & MTF_STATTIMEO) != 0)
goto getstats;
retval = hpibrecv(sc->sc_hpibno,
(sc->sc_flags & MTF_DSJTIMEO) != 0 ? -1 : sc->sc_slave,
MTT_DSJ, &(sc->sc_lastdsj), 1);
sc->sc_flags &= ~MTF_DSJTIMEO;
if (retval != 1) {
dlog(LOG_DEBUG, "%s can't hpibrecv DSJ",
device_xname(sc->sc_dev));
if (sc->sc_recvtimeo == 0)
sc->sc_recvtimeo = hz;
if (--sc->sc_recvtimeo == 0)
return -1;
if (retval == 0)
sc->sc_flags |= MTF_DSJTIMEO;
return -2;
}
sc->sc_recvtimeo = 0;
sc->sc_statindex = 0;
dlog(LOG_DEBUG, "%s readdsj: 0x%x", device_xname(sc->sc_dev),
sc->sc_lastdsj);
sc->sc_lastecmd = ecmd;
switch (sc->sc_lastdsj) {
case 0:
if (ecmd & MTE_DSJ_FORCE)
break;
return 0;

case 2:
sc->sc_lastecmd = MTE_COMPLETE;
case 1:
break;

default:
log(LOG_ERR, "%s readdsj: DSJ 0x%x\n", device_xname(sc->sc_dev),
sc->sc_lastdsj);
return -1;
}
getstats:
retval = hpibrecv(sc->sc_hpibno,
(sc->sc_flags & MTF_STATCONT) != 0 ? -1 : sc->sc_slave,
MTT_STAT, ((char *)&(sc->sc_stat)) + sc->sc_statindex,
sizeof(sc->sc_stat) - sc->sc_statindex);
sc->sc_flags &= ~(MTF_STATTIMEO | MTF_STATCONT);
if (retval != sizeof(sc->sc_stat) - sc->sc_statindex) {
if (sc->sc_recvtimeo == 0)
sc->sc_recvtimeo = hz;
if (--sc->sc_recvtimeo != 0) {
if (retval >= 0) {
sc->sc_statindex += retval;
sc->sc_flags |= MTF_STATCONT;
}
sc->sc_flags |= MTF_STATTIMEO;
return -2;
}
log(LOG_ERR, "%s readdsj: can't read status",
device_xname(sc->sc_dev));
return -1;
}
sc->sc_recvtimeo = 0;
sc->sc_statindex = 0;
dlog(LOG_DEBUG, "%s readdsj: status is %x %x %x %x %x %x",
device_xname(sc->sc_dev),
sc->sc_stat1, sc->sc_stat2, sc->sc_stat3,
sc->sc_stat4, sc->sc_stat5, sc->sc_stat6);
if (sc->sc_lastecmd != 0)
(void) hpibsend(sc->sc_hpibno, sc->sc_slave,
MTL_ECMD, &sc->sc_lastecmd, 1);
return (int)sc->sc_lastdsj;
}

static int
mtopen(dev_t dev, int flag, int mode, struct lwp *l)
{
struct mt_softc *sc;
int req_den;
int error;

sc = device_lookup_private(&mt_cd, UNIT(dev));
if (sc == NULL)
return ENXIO;

if ((sc->sc_flags & MTF_EXISTS) == 0)
return ENXIO;

dlog(LOG_DEBUG, "%s open: flags 0x%x", device_xname(sc->sc_dev),
sc->sc_flags);
if ((sc->sc_flags & MTF_OPEN) != 0)
return EBUSY;
sc->sc_flags |= MTF_OPEN;
sc->sc_ttyp = tprintf_open(l->l_proc);
if ((sc->sc_flags & MTF_ALIVE) == 0) {
error = mtcommand(dev, MTRESET, 0);
if (error != 0 || (sc->sc_flags & MTF_ALIVE) == 0)
goto errout;
if ((sc->sc_stat1 & (SR1_BOT | SR1_ONLINE)) == SR1_ONLINE)
(void) mtcommand(dev, MTREW, 0);
}
for (;;) {
if ((error = mtcommand(dev, MTNOP, 0)) != 0)
goto errout;
if ((sc->sc_flags & MTF_REW) == 0)
break;
error = kpause("mt", true, hz, NULL);
if (error != 0 && error != EWOULDBLOCK) {
error = EINTR;
goto errout;
}
}
if ((flag & FWRITE) != 0 && (sc->sc_stat1 & SR1_RO) != 0) {
error = EROFS;
goto errout;
}
if ((sc->sc_stat1 & SR1_ONLINE) == 0) {
uprintf("%s: not online\n", device_xname(sc->sc_dev));
error = EIO;
goto errout;
}
/*
* Select density:
* - find out what density the drive is set to
* (i.e. the density of the current tape)
* - if we are going to write
* - if we're not at the beginning of the tape
* - complain if we want to change densities
* - otherwise, select the mtcommand to set the density
*
* If the drive doesn't support it then don't change the recorded
* density.
*
* The original MOREbsd code had these additional conditions
* for the mid-tape change
*
* req_den != T_BADBPI &&
* sc->sc_density != T_6250BPI
*
* which suggests that it would be possible to write multiple
* densities if req_den == T_BAD_BPI or the current tape
* density was 6250. Testing of our 7980 suggests that the
* device cannot change densities mid-tape.
*
* [email protected]
*/
sc->sc_density = (sc->sc_stat2 & SR2_6250) ? T_6250BPI : (
(sc->sc_stat3 & SR3_1600) ? T_1600BPI : (
(sc->sc_stat3 & SR3_800) ? T_800BPI : -1));
req_den = (dev & T_DENSEL);

if ((flag & FWRITE) != 0) {
if ((sc->sc_stat1 & SR1_BOT) == 0) {
if (sc->sc_density != req_den) {
uprintf("%s: can't change density mid-tape\n",
device_xname(sc->sc_dev));
error = EIO;
goto errout;
}
} else {
int mtset_density =
(req_den == T_800BPI ? MTSET800BPI : (
req_den == T_1600BPI ? MTSET1600BPI : (
req_den == T_6250BPI ? MTSET6250BPI : (
sc->sc_type == MT7980ID
? MTSET6250DC
: MTSET6250BPI))));
if (mtcommand(dev, mtset_density, 0) == 0)
sc->sc_density = req_den;
}
}
return 0;
errout:
sc->sc_flags &= ~MTF_OPEN;
return error;
}

static int
mtclose(dev_t dev, int flag, int fmt, struct lwp *l)
{
struct mt_softc *sc = device_lookup_private(&mt_cd,UNIT(dev));

if ((sc->sc_flags & MTF_WRT) != 0) {
(void)mtcommand(dev, MTWEOF, 2);
(void)mtcommand(dev, MTBSF, 0);
}
if ((minor(dev) & T_NOREWIND) == 0)
(void)mtcommand(dev, MTREW, 0);
sc->sc_flags &= ~MTF_OPEN;
tprintf_close(sc->sc_ttyp);
return 0;
}

static int
mtcommand(dev_t dev, int cmd, int cnt)
{
int error = 0;
buf_t *bp;

bp = getiobuf(NULL, true);
bp->b_cmd = cmd;
bp->b_dev = dev;
do {
bp->b_cflags = BC_BUSY;
bp->b_flags = B_CMD;
bp->b_oflags = 0;
mtstrategy(bp);
biowait(bp);
if (bp->b_error != 0) {
error = bp->b_error;
break;
}
} while (--cnt > 0);
putiobuf(bp);

return error;
}

/*
* Only thing to check here is for legal record lengths (writes only).
*/
static void
mtstrategy(struct buf *bp)
{
struct mt_softc *sc;
int s;

sc = device_lookup_private(&mt_cd,UNIT(bp->b_dev));
dlog(LOG_DEBUG, "%s strategy", device_xname(sc->sc_dev));
if ((bp->b_flags & (B_CMD | B_READ)) == 0) {
#define WRITE_BITS_IGNORED 8
#if 0
if (bp->b_bcount & ((1 << WRITE_BITS_IGNORED) - 1)) {
tprintf(sc->sc_ttyp,
"%s: write record must be multiple of %d\n",
device_xname(sc->sc_dev), 1 << WRITE_BITS_IGNORED);
goto error;
}
#endif
s = 16 * 1024;
if ((sc->sc_stat2 & SR2_LONGREC) != 0) {
switch (sc->sc_density) {
case T_1600BPI:
s = 32 * 1024;
break;

case T_6250BPI:
case T_BADBPI:
s = 60 * 1024;
break;
}
}
if (bp->b_bcount > s) {
tprintf(sc->sc_ttyp,
"%s: write record (%d) too big: limit (%d)\n",
device_xname(sc->sc_dev), bp->b_bcount, s);
#if 0 /* XXX see above */
error:
#endif
bp->b_error = EIO;
biodone(bp);
return;
}
}
s = splbio();
bufq_put(sc->sc_tab, bp);
if (sc->sc_active == 0) {
sc->sc_active = 1;
mtustart(sc);
}
splx(s);
}

static void
mtustart(struct mt_softc *sc)
{

dlog(LOG_DEBUG, "%s ustart", device_xname(sc->sc_dev));
if (hpibreq(device_parent(sc->sc_dev), &sc->sc_hq))
mtstart(sc);
}

static void
spl_mtintr(void *arg)
{
struct mt_softc *sc = arg;
int s = splbio();

hpibppclear(sc->sc_hpibno);
mtintr(sc);
splx(s);
}

static void
spl_mtstart(void *arg)
{
int s = splbio();

mtstart(arg);
splx(s);
}

static void
mtstart(void *arg)
{
struct mt_softc *sc = arg;
struct buf *bp;
short cmdcount = 1;
uint8_t cmdbuf[2];

dlog(LOG_DEBUG, "%s start", device_xname(sc->sc_dev));
sc->sc_flags &= ~MTF_WRT;
bp = bufq_peek(sc->sc_tab);
if ((sc->sc_flags & MTF_ALIVE) == 0 &&
((bp->b_flags & B_CMD) == 0 || bp->b_cmd != MTRESET))
goto fatalerror;

if ((sc->sc_flags & MTF_REW) != 0) {
if (!hpibpptest(sc->sc_hpibno, sc->sc_slave))
goto stillrew;
switch (mtreaddsj(sc, MTE_DSJ_FORCE|MTE_COMPLETE|MTE_IDLE)) {
case 0:
case 1:
stillrew:
if ((sc->sc_stat1 & SR1_BOT) != 0 ||
(sc->sc_stat1 & SR1_ONLINE) == 0) {
sc->sc_flags &= ~MTF_REW;
break;
}
case -2:
/*
* -2 means "timeout" reading DSJ, which is probably
* temporary. This is considered OK when doing a NOP,
* but not otherwise.
*/
if ((sc->sc_flags &
(MTF_DSJTIMEO | MTF_STATTIMEO)) != 0) {
callout_reset(&sc->sc_start_ch, hz >> 5,
spl_mtstart, sc);
return;
}
case 2:
if (bp->b_cmd != MTNOP || !(bp->b_flags & B_CMD)) {
bp->b_error = EBUSY;
goto done;
}
goto done;

default:
goto fatalerror;
}
}
if ((bp->b_flags & B_CMD) != 0) {
if ((sc->sc_flags & MTF_PASTEOT) != 0) {
switch(bp->b_cmd) {
case MTFSF:
case MTWEOF:
case MTFSR:
bp->b_error = ENOSPC;
goto done;

case MTBSF:
case MTOFFL:
case MTBSR:
case MTREW:
sc->sc_flags &= ~(MTF_PASTEOT | MTF_ATEOT);
break;
}
}
switch(bp->b_cmd) {
case MTFSF:
if ((sc->sc_flags & MTF_HITEOF) != 0)
goto done;
cmdbuf[0] = MTTC_FSF;
break;

case MTBSF:
if ((sc->sc_flags & MTF_HITBOF) != 0)
goto done;
cmdbuf[0] = MTTC_BSF;
break;

case MTOFFL:
sc->sc_flags |= MTF_REW;
cmdbuf[0] = MTTC_REWOFF;
break;

case MTWEOF:
cmdbuf[0] = MTTC_WFM;
break;

case MTBSR:
cmdbuf[0] = MTTC_BSR;
break;

case MTFSR:
cmdbuf[0] = MTTC_FSR;
break;

case MTREW:
sc->sc_flags |= MTF_REW;
cmdbuf[0] = MTTC_REW;
break;

case MTNOP:
/*
* NOP is supposed to set status bits.
* Force readdsj to do it.
*/
switch (mtreaddsj(sc,
MTE_DSJ_FORCE | MTE_COMPLETE | MTE_IDLE)) {
default:
goto done;

case -1:
/*
* If this fails, perform a device clear
* to fix any protocol problems and (most
* likely) get the status.
*/
bp->b_cmd = MTRESET;
break;

case -2:
callout_reset(&sc->sc_start_ch, hz >> 5,
spl_mtstart, sc);
return;
}

case MTRESET:
/*
* 1) selected device clear (send with "-2" secondary)
* 2) set timeout, then wait for "service request"
* 3) interrupt will read DSJ (and END COMPLETE-IDLE)
*/
if (hpibsend(sc->sc_hpibno, sc->sc_slave, -2,
NULL, 0)) {
log(LOG_ERR, "%s can't reset",
device_xname(sc->sc_dev));
goto fatalerror;
}
callout_reset(&sc->sc_intr_ch, 4 * hz, spl_mtintr, sc);
hpibawait(sc->sc_hpibno);
return;

case MTSET800BPI:
cmdbuf[0] = MTTC_800;
break;

case MTSET1600BPI:
cmdbuf[0] = MTTC_1600;
break;

case MTSET6250BPI:
cmdbuf[0] = MTTC_6250;
break;

case MTSET6250DC:
cmdbuf[0] = MTTC_DC6250;
break;
}
} else {
if ((sc->sc_flags & MTF_PASTEOT) != 0) {
bp->b_error = ENOSPC;
goto done;
}
if ((bp->b_flags & B_READ) != 0) {
sc->sc_flags |= MTF_IO;
cmdbuf[0] = MTTC_READ;
} else {
sc->sc_flags |= MTF_WRT | MTF_IO;
cmdbuf[0] = MTTC_WRITE;
cmdbuf[1] =
(bp->b_bcount + ((1 << WRITE_BITS_IGNORED) - 1))
>> WRITE_BITS_IGNORED;
cmdcount = 2;
}
}
if (hpibsend(sc->sc_hpibno, sc->sc_slave, MTL_TCMD, cmdbuf, cmdcount)
== cmdcount) {
if ((sc->sc_flags & MTF_REW) != 0)
goto done;
hpibawait(sc->sc_hpibno);
return;
}
fatalerror:
/*
* If anything fails, the drive is probably hosed, so mark it not
* "ALIVE" (but it EXISTS and is OPEN or we wouldn't be here, and
* if, last we heard, it was REWinding, remember that).
*/
sc->sc_flags &= MTF_EXISTS | MTF_OPEN | MTF_REW;
bp->b_error = EIO;
done:
sc->sc_flags &= ~(MTF_HITEOF | MTF_HITBOF);
(void)bufq_get(sc->sc_tab);
biodone(bp);
hpibfree(device_parent(sc->sc_dev), &sc->sc_hq);
if ((bp = bufq_peek(sc->sc_tab)) == NULL)
sc->sc_active = 0;
else
mtustart(sc);
}

/*
* The Utah code had a bug which meant that the driver was unable to read.
* "rw" was initialized to bp->b_flags & B_READ before "bp" was initialized.
* -- [email protected]
*/
static void
mtgo(void *arg)
{
struct mt_softc *sc = arg;
struct buf *bp;
int rw;

dlog(LOG_DEBUG, "%s go", device_xname(sc->sc_dev));
bp = bufq_peek(sc->sc_tab);
rw = bp->b_flags & B_READ;
hpibgo(sc->sc_hpibno, sc->sc_slave, rw ? MTT_READ : MTL_WRITE,
bp->b_data, bp->b_bcount, rw, rw != 0);
}

static void
mtintr(void *arg)
{
struct mt_softc *sc = arg;
struct buf *bp;
int i;
uint8_t cmdbuf[4];

bp = bufq_peek(sc->sc_tab);
if (bp == NULL) {
log(LOG_ERR, "%s intr: bp == NULL", device_xname(sc->sc_dev));
return;
}

dlog(LOG_DEBUG, "%s intr", device_xname(sc->sc_dev));

/*
* Some operation completed. Read status bytes and report errors.
* Clear EOF flags here `cause they're set once on specific conditions
* below when a command succeeds.
* A DSJ of 2 always means keep waiting. If the command was READ
* (and we're in data DMA phase) stop data transfer first.
*/
sc->sc_flags &= ~(MTF_HITEOF | MTF_HITBOF);
if ((bp->b_flags & (B_CMD|B_READ)) == B_READ &&
(sc->sc_flags & (MTF_IO | MTF_STATTIMEO | MTF_DSJTIMEO)) == 0){
cmdbuf[0] = MTE_STOP;
(void)hpibsend(sc->sc_hpibno, sc->sc_slave, MTL_ECMD,cmdbuf, 1);
}
switch (mtreaddsj(sc, 0)) {
case 0:
break;

case 1:
/*
* If we're in the middle of a READ/WRITE and have yet to
* start the data transfer, a DSJ of one should terminate it.
*/
sc->sc_flags &= ~MTF_IO;
break;

case 2:
(void)hpibawait(sc->sc_hpibno);
return;

case -2:
/*
* -2 means that the drive failed to respond quickly enough
* to the request for DSJ. It's probably just "busy" figuring
* it out and will know in a little bit...
*/
callout_reset(&sc->sc_intr_ch, hz >> 5, spl_mtintr, sc);
return;

default:
log(LOG_ERR, "%s intr: can't get drive stat",
device_xname(sc->sc_dev));
goto error;
}
if ((sc->sc_stat1 & (SR1_ERR | SR1_REJECT)) != 0) {
i = sc->sc_stat4 & SR4_ERCLMASK;
log(LOG_ERR, "%s: %s error, retry %d, SR2/3 %x/%x, code %d",
device_xname(sc->sc_dev), i == SR4_DEVICE ? "device" :
(i == SR4_PROTOCOL ? "protocol" :
(i == SR4_SELFTEST ? "selftest" : "unknown")),
sc->sc_stat4 & SR4_RETRYMASK, sc->sc_stat2,
sc->sc_stat3, sc->sc_stat5);

if ((bp->b_flags & B_CMD) != 0 && bp->b_cmd == MTRESET)
callout_stop(&sc->sc_intr_ch);
if ((sc->sc_stat3 & SR3_POWERUP) != 0)
sc->sc_flags &= MTF_OPEN | MTF_EXISTS;
goto error;
}
/*
* Report and clear any soft errors.
*/
if ((sc->sc_stat1 & SR1_SOFTERR) != 0) {
log(LOG_WARNING, "%s: soft error, retry %d\n",
device_xname(sc->sc_dev), sc->sc_stat4 & SR4_RETRYMASK);
sc->sc_stat1 &= ~SR1_SOFTERR;
}
/*
* We've initiated a read or write, but haven't actually started to
* DMA the data yet. At this point, the drive's ready.
*/
if ((sc->sc_flags & MTF_IO) != 0) {
sc->sc_flags &= ~MTF_IO;
if (hpibustart(sc->sc_hpibno))
mtgo(sc);
return;
}
/*
* Check for End Of Tape - we're allowed to hit EOT and then write (or
* read) one more record. If we get here and have not already hit EOT,
* return ENOSPC to inform the process that it's hit it. If we get
* here and HAVE already hit EOT, don't allow any more operations that
* move the tape forward.
*/
if ((sc->sc_stat1 & SR1_EOT) != 0) {
if ((sc->sc_flags & MTF_ATEOT) != 0)
sc->sc_flags |= MTF_PASTEOT;
else {
bp->b_error = ENOSPC;
sc->sc_flags |= MTF_ATEOT;
}
}
/*
* If a motion command was being executed, check for Tape Marks.
* If we were doing data, make sure we got the right amount, and
* check for hitting tape marks on reads.
*/
if ((bp->b_flags & B_CMD) != 0) {
if ((sc->sc_stat1 & SR1_EOF) != 0) {
if (bp->b_cmd == MTFSR)
sc->sc_flags |= MTF_HITEOF;
if (bp->b_cmd == MTBSR)
sc->sc_flags |= MTF_HITBOF;
}
if (bp->b_cmd == MTRESET) {
callout_stop(&sc->sc_intr_ch);
sc->sc_flags |= MTF_ALIVE;
}
} else {
i = hpibrecv(sc->sc_hpibno, sc->sc_slave, MTT_BCNT, cmdbuf, 2);
if (i != 2) {
log(LOG_ERR, "%s intr: can't get xfer length\n",
device_xname(sc->sc_dev));
goto error;
}
i = (int)*((uint16_t *)cmdbuf);
if (i <= bp->b_bcount) {
if (i == 0)
sc->sc_flags |= MTF_HITEOF;
bp->b_resid = bp->b_bcount - i;
dlog(LOG_DEBUG, "%s intr: bcount %d, resid %d",
device_xname(sc->sc_dev), bp->b_bcount,
bp->b_resid);
} else {
tprintf(sc->sc_ttyp,
"%s: record (%d) larger than wanted (%d)\n",
device_xname(sc->sc_dev), i, bp->b_bcount);
error:
sc->sc_flags &= ~MTF_IO;
bp->b_error = EIO;
}
}
/*
* The operation is completely done.
* Let the drive know with an END command.
*/
cmdbuf[0] = MTE_COMPLETE | MTE_IDLE;
(void)hpibsend(sc->sc_hpibno, sc->sc_slave, MTL_ECMD, cmdbuf, 1);
bp->b_flags &= ~B_CMD;
(void)bufq_get(sc->sc_tab);
biodone(bp);
hpibfree(device_parent(sc->sc_dev), &sc->sc_hq);
if (bufq_peek(sc->sc_tab) == NULL)
sc->sc_active = 0;
else
mtustart(sc);
}

static int
mtread(dev_t dev, struct uio *uio, int flags)
{

return physio(mtstrategy, NULL, dev, B_READ, minphys, uio);
}

static int
mtwrite(dev_t dev, struct uio *uio, int flags)
{

return physio(mtstrategy, NULL, dev, B_WRITE, minphys, uio);
}

static int
mtioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
{
struct mtop *op;
int cnt;

switch (cmd) {
case MTIOCTOP:
op = (struct mtop *)data;
switch(op->mt_op) {
case MTWEOF:
case MTFSF:
case MTBSR:
case MTBSF:
case MTFSR:
cnt = op->mt_count;
break;

case MTOFFL:
case MTREW:
case MTNOP:
cnt = 0;
break;

default:
return EINVAL;
}
return mtcommand(dev, op->mt_op, cnt);

case MTIOCGET:
break;

default:
return EINVAL;
}
return 0;
}