initial import of NetBSD tree

1 files changed, 850 insertions, 0 deletions

diff --git a/sys/arch/pmax/dev/tz.c b/sys/arch/pmax/dev/tz.c
new file mode 100644
index 00000000000..b556191ad11
--- /dev/null
+++ b/sys/arch/pmax/dev/tz.c
@@ -0,0 +1,850 @@
+/*	$NetBSD: tz.c,v 1.8 1995/09/18 03:04:55 jonathan Exp $	*/
+
+/*
+ * Copyright (c) 1992, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Ralph Campbell.
+ *
+ * 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.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
+ *
+ *	@(#)tz.c	8.4 (Berkeley) 1/11/94
+ *
+ * from: Header: /sprite/src/kernel/dev/RCS/devSCSITape.c,
+ *	v 8.14 89/07/31 17:26:13 mendel Exp  SPRITE (Berkeley)
+ */
+
+/*
+ * SCSI CCS (Command Command Set) tape driver.
+ */
+#include "tz.h"
+#if NTZ > 0
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/buf.h>
+#include <sys/errno.h>
+#include <sys/file.h>
+#include <sys/ioctl.h>
+#include <sys/mtio.h>
+#include <sys/syslog.h>
+#include <sys/tprintf.h>
+
+#include <pmax/dev/device.h>
+#include <pmax/dev/scsi.h>
+
+int	tzprobe();
+void	tzstart(), tzdone();
+
+struct	pmax_driver tzdriver = {
+	"tz", tzprobe, tzstart, tzdone,
+};
+
+struct	tz_softc {
+	struct	pmax_scsi_device *sc_sd;	/* physical unit info */
+	int	sc_flags;		/* see below */
+	int	sc_tapeid;		/* tape drive id */
+	int	sc_blklen;		/* 0 = variable len records */
+	long	sc_numblks;		/* number of blocks on tape */
+	tpr_t	sc_ctty;		/* terminal for error messages */
+	struct	buf sc_tab;		/* queue of pending operations */
+	struct	buf sc_buf;		/* buf for doing I/O */
+	struct	buf sc_errbuf;		/* buf for doing REQUEST_SENSE */
+	struct	ScsiCmd sc_cmd;		/* command for controller */
+	ScsiGroup0Cmd sc_rwcmd;		/* SCSI cmd for read/write */
+	struct	scsi_fmt_cdb sc_cdb;	/* SCSI cmd if not read/write */
+	struct	scsi_fmt_sense sc_sense;	/* sense data from last cmd */
+	struct	ScsiTapeModeSelectHdr sc_mode;	/* SCSI_MODE_SENSE data */
+	char	sc_modelen;		/* SCSI_MODE_SENSE data length */
+} tz_softc[NTZ];
+
+/* sc_flags values */
+#define	TZF_ALIVE		0x01	/* drive found and ready */
+#define	TZF_SENSEINPROGRESS	0x02	/* REQUEST_SENSE command in progress */
+#define	TZF_ALTCMD		0x04	/* alternate command in progress */
+#define	TZF_WRITTEN		0x08	/* tape has been written to */
+#define	TZF_OPEN		0x10	/* device is open */
+#define	TZF_WAIT		0x20	/* waiting for sc_tab to drain */
+#define TZF_SEENEOF		0x40	/* seen file mark on read */
+
+/* bits in minor device */
+#define	tzunit(x)	(minor(x) >> 4)	/* tz%d unit number */
+#define TZ_NOREWIND	0x01		/* don't rewind on close */
+#define TZ_HIDENSITY	0x02
+#define TZ_EXSFMK	0x04
+#define TZ_FIXEDBLK	0x08
+
+#ifdef DEBUG
+int	tzdebug = 0;
+#endif
+
+void tzstrategy __P((register struct buf *bp));
+
+/*
+ * Test to see if device is present.
+ * Return true if found and initialized ok.
+ */
+tzprobe(sd)
+	struct pmax_scsi_device *sd;
+{
+	register struct tz_softc *sc = &tz_softc[sd->sd_unit];
+	register int i;
+	ScsiInquiryData inqbuf;
+	ScsiClass7Sense *sp;
+
+	/* init some parameters that don't change */
+	sc->sc_sd = sd;
+	sc->sc_cmd.sd = sd;
+	sc->sc_cmd.unit = sd->sd_unit;
+	sc->sc_cmd.flags = 0;
+	sc->sc_rwcmd.unitNumber = sd->sd_slave;
+
+	/* try to find out what type of device this is */
+	sc->sc_flags = TZF_ALTCMD;	/* force use of sc_cdb */
+	sc->sc_cdb.len = sizeof(ScsiGroup0Cmd);
+	scsiGroup0Cmd(SCSI_INQUIRY, sd->sd_slave, 0, sizeof(inqbuf),
+		(ScsiGroup0Cmd *)sc->sc_cdb.cdb);
+	sc->sc_buf.b_flags = B_BUSY | B_READ;
+	sc->sc_buf.b_bcount = sizeof(inqbuf);
+	sc->sc_buf.b_un.b_addr = (caddr_t)&inqbuf;
+	sc->sc_buf.b_actf = (struct buf *)0;
+	sc->sc_buf.b_actb = &sc->sc_tab.b_actf;
+	sc->sc_tab.b_actf = &sc->sc_buf;
+	sc->sc_tab.b_actb = &sc->sc_buf.b_actf;
+	tzstart(sd->sd_unit);
+	if (biowait(&sc->sc_buf) ||
+	    (i = sizeof(inqbuf) - sc->sc_buf.b_resid) < 5)
+		goto bad;
+	if (inqbuf.type != SCSI_TAPE_TYPE || !inqbuf.rmb)
+		goto bad;
+
+	/* check for device ready to clear UNIT_ATTN */
+	sc->sc_cdb.len = sizeof(ScsiGroup0Cmd);
+	scsiGroup0Cmd(SCSI_TEST_UNIT_READY, sd->sd_slave, 0, 0,
+		(ScsiGroup0Cmd *)sc->sc_cdb.cdb);
+	sc->sc_buf.b_flags = B_BUSY | B_READ;
+	sc->sc_buf.b_bcount = 0;
+	sc->sc_buf.b_un.b_addr = (caddr_t)0;
+	sc->sc_buf.b_actf = (struct buf *)0;
+	sc->sc_buf.b_actb = &sc->sc_tab.b_actf;
+	sc->sc_tab.b_actf = &sc->sc_buf;
+	sc->sc_tab.b_actb = &sc->sc_buf.b_actf;
+	tzstart(sd->sd_unit);
+	(void) biowait(&sc->sc_buf);
+
+	sc->sc_flags = TZF_ALIVE;
+	sc->sc_modelen = 12;
+	sc->sc_buf.b_flags = 0;
+	printf("tz%d at %s%d drive %d slave %d", sd->sd_unit,
+		sd->sd_cdriver->d_name, sd->sd_ctlr, sd->sd_drive,
+		sd->sd_slave);
+	if (i == 5 && inqbuf.version == 1 && inqbuf.qualifier == 0x50) {
+		printf(" TK50\n");
+		sc->sc_tapeid = MT_ISTK50;
+	} else if (i >= 5 && inqbuf.version == 1 && inqbuf.qualifier == 0 &&
+	    inqbuf.length == 0) {
+		/* assume Emultex MT02 controller */
+		printf(" MT02\n");
+		sc->sc_tapeid = MT_ISMT02;
+	} else if (inqbuf.version > 2 || i < 36) {
+		printf(" GENERIC SCSI tape device: qual 0x%x, ver %d\n",
+			inqbuf.qualifier, inqbuf.version);
+		sc->sc_tapeid = 0;
+	} else {
+		char vid[9], pid[17], revl[5];
+
+		bcopy((caddr_t)inqbuf.vendorID, (caddr_t)vid, 8);
+		bcopy((caddr_t)inqbuf.productID, (caddr_t)pid, 16);
+		bcopy((caddr_t)inqbuf.revLevel, (caddr_t)revl, 4);
+		for (i = 8; --i > 0; )
+			if (vid[i] != ' ')
+				break;
+		vid[i+1] = 0;
+		for (i = 16; --i > 0; )
+			if (pid[i] != ' ')
+				break;
+		pid[i+1] = 0;
+		for (i = 4; --i > 0; )
+			if (revl[i] != ' ')
+				break;
+		revl[i+1] = 0;
+		printf(" %s %s rev %s\n", vid, pid, revl);
+
+		if (bcmp("EXB-8200", pid, 8) == 0) {
+			sc->sc_tapeid = MT_ISEXABYTE;
+			sc->sc_modelen = 17;
+		} else if (bcmp("VIPER 150", pid, 9) == 0) {
+			sc->sc_tapeid = MT_ISVIPER1;
+		} else if (bcmp("Python 25501", pid, 12) == 0) {
+			sc->sc_tapeid = MT_ISPYTHON;
+		} else if (bcmp("HP35450A", pid, 8) == 0) {
+#if 0
+			/* XXX "extra" stat makes the HP drive happy at boot time */
+			stat = scsi_test_unit_rdy(ctlr, slave, unit);
+#endif
+			sc->sc_tapeid = MT_ISHPDAT;
+		} else if (bcmp("123107 SCSI", pid, 11) == 0) {
+			sc->sc_tapeid = MT_ISMFOUR;
+		} else {
+			printf("tz%d: assuming GENERIC SCSI tape device\n",
+				sd->sd_unit,
+				inqbuf.type, inqbuf.qualifier, inqbuf.version);
+			sc->sc_tapeid = 0;
+		}
+	}
+	return (1);
+
+bad:
+	/* doesn't exist or not a CCS device */
+	sc->sc_flags = 0;
+	sc->sc_buf.b_flags = 0;
+	return (0);
+}
+
+/*
+ * Perform a special tape command on a SCSI Tape drive.
+ */
+tzcommand(dev, command, code, count, data)
+	dev_t dev;
+	int command;
+	int code;
+	int count;
+	caddr_t data;
+{
+	register struct tz_softc *sc = &tz_softc[tzunit(dev)];
+	register ScsiGroup0Cmd *c;
+	int s, error;
+
+	s = splbio();
+	/* wait for pending operations to finish */
+	while (sc->sc_tab.b_actf) {
+		sc->sc_flags |= TZF_WAIT;
+		sleep(&sc->sc_flags, PZERO);
+	}
+	sc->sc_flags |= TZF_ALTCMD;	/* force use of sc_cdb */
+	sc->sc_cdb.len = sizeof(ScsiGroup0Cmd);
+	c = (ScsiGroup0Cmd *)sc->sc_cdb.cdb;
+	c->command = command;
+	c->unitNumber = sc->sc_sd->sd_slave;
+	c->highAddr = code;
+	c->midAddr = count >> 16;
+	c->lowAddr = count >> 8;
+	c->blockCount = count;
+	c->control = 0;
+	if (command == SCSI_MODE_SELECT)
+		sc->sc_buf.b_flags = B_BUSY;
+	else {
+		sc->sc_buf.b_flags = B_BUSY | B_READ;
+#if 0
+		/* this seems to work but doesn't give us a speed advantage */
+		if (command == SCSI_TEST_UNIT_READY)
+			sc->sc_cmd.flags |= SCSICMD_USE_SYNC;
+#endif
+	}
+	sc->sc_buf.b_bcount = data ? count : 0;
+	sc->sc_buf.b_un.b_addr = data;
+	sc->sc_buf.b_actf = (struct buf *)0;
+	sc->sc_buf.b_actb = &sc->sc_tab.b_actf;
+	sc->sc_tab.b_actf = &sc->sc_buf;
+	sc->sc_tab.b_actb = &sc->sc_buf.b_actf;
+	tzstart(sc->sc_sd->sd_unit);
+	error = biowait(&sc->sc_buf);
+	sc->sc_flags &= ~TZF_ALTCMD;	/* force use of sc_cdb */
+	sc->sc_buf.b_flags = 0;
+	sc->sc_cmd.flags = 0;
+	if (sc->sc_buf.b_resid)
+		printf("tzcommand: resid %d\n", sc->sc_buf.b_resid); /* XXX */
+	if (error == 0)
+		switch (command) {
+		case SCSI_SPACE:
+		case SCSI_WRITE_EOF:
+		case SCSI_REWIND:
+			sc->sc_flags &= ~TZF_SEENEOF;
+		}
+	splx(s);
+	return (error);
+}
+
+void
+tzstart(unit)
+	int unit;
+{
+	register struct tz_softc *sc = &tz_softc[unit];
+	register struct buf *bp = sc->sc_tab.b_actf;
+	register int n;
+
+	sc->sc_cmd.buf = bp->b_un.b_addr;
+	sc->sc_cmd.buflen = bp->b_bcount;
+
+	if (sc->sc_flags & (TZF_SENSEINPROGRESS | TZF_ALTCMD)) {
+		if (bp->b_flags & B_READ)
+			sc->sc_cmd.flags &= ~SCSICMD_DATA_TO_DEVICE;
+		else
+			sc->sc_cmd.flags |= SCSICMD_DATA_TO_DEVICE;
+		sc->sc_cmd.cmd = sc->sc_cdb.cdb;
+		sc->sc_cmd.cmdlen = sc->sc_cdb.len;
+	} else {
+		if (bp->b_flags & B_READ) {
+			sc->sc_cmd.flags = 0;
+			sc->sc_rwcmd.command = SCSI_READ;
+			sc->sc_flags &= ~TZF_WRITTEN;
+		} else {
+			sc->sc_cmd.flags = SCSICMD_DATA_TO_DEVICE;
+			sc->sc_rwcmd.command = SCSI_WRITE;
+			sc->sc_flags |= TZF_WRITTEN;
+		}
+		sc->sc_cmd.cmd = (u_char *)&sc->sc_rwcmd;
+		sc->sc_cmd.cmdlen = sizeof(sc->sc_rwcmd);
+		if (sc->sc_blklen) {
+			/* fixed sized records */
+			n = bp->b_bcount / sc->sc_blklen;
+			if (bp->b_bcount % sc->sc_blklen) {
+				tprintf(sc->sc_ctty,
+					"tz%d: I/O not block aligned %d/%ld\n",
+					unit, sc->sc_blklen, bp->b_bcount);
+				tzdone(unit, EIO, bp->b_bcount, 0);
+			}
+			sc->sc_rwcmd.highAddr = 1;
+		} else {
+			/* variable sized records */
+			n = bp->b_bcount;
+			sc->sc_rwcmd.highAddr = 0;
+		}
+		sc->sc_rwcmd.midAddr = n >> 16;
+		sc->sc_rwcmd.lowAddr = n >> 8;
+		sc->sc_rwcmd.blockCount = n;
+	}
+
+	/* tell controller to start this command */
+	(*sc->sc_sd->sd_cdriver->d_start)(&sc->sc_cmd);
+}
+
+/*
+ * This is called by the controller driver when the command is done.
+ */
+void
+tzdone(unit, error, resid, status)
+	int unit;
+	int error;		/* error number from errno.h */
+	int resid;		/* amount not transfered */
+	int status;		/* SCSI status byte */
+{
+	register struct tz_softc *sc = &tz_softc[unit];
+	register struct buf *bp = sc->sc_tab.b_actf;
+	register struct buf *dp;
+	extern int cold;
+
+	if (bp == NULL) {
+		printf("tz%d: bp == NULL\n", unit);
+		return;
+	}
+	if (sc->sc_flags & TZF_SENSEINPROGRESS) {
+		sc->sc_flags &= ~TZF_SENSEINPROGRESS;
+		*bp->b_actb = dp = bp->b_actf;	/* remove sc_errbuf */
+#ifdef DIAGNOSTIC
+		if (!dp)
+			panic("tzdone");
+#endif
+		dp->b_actb = bp->b_actb;
+		bp = dp;
+
+		if (error || (status & SCSI_STATUS_CHECKCOND)) {
+			printf("tz%d: error reading sense data: error %d scsi status 0x%x\n",
+				unit, error, status);
+			/*
+			 * We got an error during the REQUEST_SENSE,
+			 * fill in no sense for data.
+			 */
+			sc->sc_sense.sense[0] = 0x70;
+			sc->sc_sense.sense[2] = SCSI_CLASS7_NO_SENSE;
+		} else if (!cold) {
+			ScsiClass7Sense *sp;
+			long resid;
+
+			sp = (ScsiClass7Sense *)sc->sc_sense.sense;
+			if (sp->error7 != 0x70)
+				goto prerr;
+			if (sp->valid) {
+				resid = (sp->info1 << 24) | (sp->info2 << 16) |
+					(sp->info3 << 8) | sp->info4;
+				if (sc->sc_blklen)
+					resid *= sc->sc_blklen;
+			} else
+				resid = 0;
+			switch (sp->key) {
+			case SCSI_CLASS7_NO_SENSE:
+				/*
+				 * Hit a filemark, end of media, or
+				 * end of record.
+				 * Fixed length blocks, an error.
+				 */
+				if (sp->endOfMedia) {
+					bp->b_error = ENOSPC;
+					bp->b_resid = resid;
+					break;
+				}
+				if (sc->sc_blklen && sp->badBlockLen) {
+					tprintf(sc->sc_ctty,
+						"tz%d: Incorrect Block Length, expected %d got %d\n",
+						unit, sc->sc_blklen, resid);
+					break;
+				}
+				if (resid < 0) {
+					/*
+					 * Variable length records but
+					 * attempted to read less than a
+					 * full record.
+					 */
+					tprintf(sc->sc_ctty,
+						"tz%d: Partial Read of Variable Length Tape Block, expected %d read %d\n",
+						unit, bp->b_bcount - resid,
+						bp->b_bcount);
+					bp->b_resid = 0;
+					break;
+				}
+				if (sp->fileMark)
+					sc->sc_flags |= TZF_SEENEOF;
+				/*
+				 * Attempting to read more than a record is
+				 * OK. Just record how much was actually read.
+				 */
+				bp->b_flags &= ~B_ERROR;
+				bp->b_error = 0;
+				bp->b_resid = resid;
+				break;
+
+			case SCSI_CLASS7_UNIT_ATTN:
+				if (!(sc->sc_flags & TZF_OPEN))
+					break;
+
+			default:
+			prerr:
+				printf("tz%d: ", unit);
+				scsiPrintSense((ScsiClass7Sense *)
+					sc->sc_sense.sense,
+					sizeof(sc->sc_sense.sense) - resid);
+			}
+		}
+	} else if (error || (status & SCSI_STATUS_CHECKCOND)) {
+#ifdef DEBUG
+		if (!cold && tzdebug)
+			printf("tz%d: error %d scsi status 0x%x\n",
+				unit, error, status);
+#endif
+		/* save error info */
+		sc->sc_sense.status = status;
+		bp->b_flags |= B_ERROR;
+		bp->b_error = error;
+		bp->b_resid = resid;
+
+		if (status & SCSI_STATUS_CHECKCOND) {
+			/*
+			 * Start a REQUEST_SENSE command.
+			 * Since we are called at interrupt time, we can't
+			 * wait for the command to finish; that's why we use
+			 * the sc_flags field.
+			 */
+			sc->sc_flags |= TZF_SENSEINPROGRESS;
+			sc->sc_cdb.len = sizeof(ScsiGroup0Cmd);
+			scsiGroup0Cmd(SCSI_REQUEST_SENSE, sc->sc_sd->sd_slave,
+				0, sizeof(sc->sc_sense.sense),
+				(ScsiGroup0Cmd *)sc->sc_cdb.cdb);
+			sc->sc_errbuf.b_flags = B_BUSY | B_PHYS | B_READ;
+			sc->sc_errbuf.b_bcount = sizeof(sc->sc_sense.sense);
+			sc->sc_errbuf.b_un.b_addr = (caddr_t)sc->sc_sense.sense;
+			sc->sc_errbuf.b_actf = bp;
+			sc->sc_errbuf.b_actb = bp->b_actb;
+			*bp->b_actb = &sc->sc_errbuf;
+			bp->b_actb = &sc->sc_errbuf.b_actf;
+			tzstart(unit);
+			return;
+		}
+	} else {
+		sc->sc_sense.status = status;
+		bp->b_resid = resid;
+	}
+
+	if (dp = bp->b_actf)
+		dp->b_actb = bp->b_actb;
+	else
+		sc->sc_tab.b_actb = bp->b_actb;
+	*bp->b_actb = dp;
+	biodone(bp);
+	if (sc->sc_tab.b_actf)
+		tzstart(unit);
+	else {
+		sc->sc_tab.b_active = 0;
+		if (sc->sc_flags & TZF_WAIT) {
+			sc->sc_flags &= ~TZF_WAIT;
+			wakeup(&sc->sc_flags);
+		}
+	}
+}
+
+/* ARGSUSED */
+tzopen(dev, flags, type, p)
+	dev_t dev;
+	int flags, type;
+	struct proc *p;
+{
+	register int unit = tzunit(dev);
+	register struct tz_softc *sc = &tz_softc[unit];
+	int error;
+
+	if (unit >= NTZ || sc->sc_sd == NULL)
+		return (ENXIO);
+	if (!(sc->sc_flags & TZF_ALIVE)) {
+		/* check again, tape may have been turned off at boot time */
+		if (!tzprobe(sc->sc_sd))
+			return (ENXIO);
+	}
+	if (sc->sc_flags & TZF_OPEN)
+		return (EBUSY);
+
+	/* clear UNIT_ATTENTION */
+	error = tzcommand(dev, SCSI_TEST_UNIT_READY, 0, 0, 0);
+	while (error) {
+		ScsiClass7Sense *sp = (ScsiClass7Sense *)sc->sc_sense.sense;
+
+		/* return error if last error was not UNIT_ATTENTION */
+		if (!(sc->sc_sense.status & SCSI_STATUS_CHECKCOND) ||
+		    sp->error7 != 0x70 || sp->key != SCSI_CLASS7_UNIT_ATTN)
+			return (error);
+
+		/*
+		 * Try it again just to be sure and
+		 * try to negotiate synchonous transfers.
+		 */
+		error = tzcommand(dev, SCSI_TEST_UNIT_READY, 0, 0, 0);
+	}
+
+	/* get the current mode settings */
+	error = tzcommand(dev, SCSI_MODE_SENSE, 0,
+		sc->sc_modelen, (caddr_t)&sc->sc_mode);
+	if (error)
+		return (error);
+
+	/* check for write protected tape */
+	if ((flags & FWRITE) && sc->sc_mode.writeprot) {
+		uprintf("tz%d: write protected\n", unit);
+		return (EACCES);
+	}
+
+	/* set record length */
+	switch (sc->sc_tapeid) {
+	case MT_ISAR:
+	case MT_ISHPDAT:
+	case MT_ISVIPER1:
+		sc->sc_blklen = 512;
+		break;
+
+	case MT_ISEXABYTE:
+#if 0
+		if (minor(dev) & TZ_FIXEDBLK)
+			sc->sc_blklen = 1024;
+		else
+			sc->sc_blklen = st_exblklen;
+#endif
+		break;
+
+	case MT_ISPYTHON:
+	case MT_ISMFOUR:
+	case MT_ISTK50:
+		sc->sc_blklen = 0;
+		break;
+
+	default:
+		sc->sc_blklen = (sc->sc_mode.block_size2 << 16) |
+			(sc->sc_mode.block_size1 << 8) | sc->sc_mode.block_size0;
+	}
+
+	/* save total number of blocks on tape */
+	sc->sc_numblks = (sc->sc_mode.blocks_2 << 16) |
+		(sc->sc_mode.blocks_1 << 8) | sc->sc_mode.blocks_0;
+
+	/* setup for mode select */
+	sc->sc_mode.len = 0;
+	sc->sc_mode.media = 0;
+	sc->sc_mode.bufferedMode = 1;
+	sc->sc_mode.blocks_0 = 0;
+	sc->sc_mode.blocks_1 = 0;
+	sc->sc_mode.blocks_2 = 0;
+	sc->sc_mode.block_size0 = sc->sc_blklen >> 16;
+	sc->sc_mode.block_size1 = sc->sc_blklen >> 8;
+	sc->sc_mode.block_size2 = sc->sc_blklen;
+
+	/* check for tape density changes */
+	switch (sc->sc_tapeid) {
+	case MT_ISAR:
+		if (minor(dev) & TZ_HIDENSITY)
+			sc->sc_mode.density = 0x5;
+		else {
+			if (flags & FWRITE) {
+				uprintf("Can only write QIC-24\n");
+				return (EIO);
+			}
+			sc->sc_mode.density = 0x4;
+		}
+		break;
+
+	case MT_ISMT02:
+		/*
+		 * The tape density is set automatically when the tape
+		 * is loaded. We only need to change it if we are writing.
+		 */
+		if (flags & FWRITE) {
+			if (minor(dev) & TZ_HIDENSITY)
+				sc->sc_mode.density = 0;
+			else
+				sc->sc_mode.density = 0x4;
+		}
+		break;
+
+	case MT_ISEXABYTE:
+#if 0
+		if (minor(dev) & TZ_HIDENSITY)
+			uprintf("EXB-8200 density support only\n");
+		sc->sc_mode.vupb = (u_char)st_exvup;
+		sc->sc_mode.rsvd5 = 0;
+		sc->sc_mode.p5 = 0;
+		sc->sc_mode.motionthres = (u_char)st_exmotthr;
+		sc->sc_mode.reconthres = (u_char)st_exreconthr;
+		sc->sc_mode.gapthres = (u_char)st_exgapthr;
+#endif
+		break;
+
+	case MT_ISHPDAT:
+	case MT_ISVIPER1:
+	case MT_ISPYTHON:
+	case MT_ISTK50:
+		if (minor(dev) & TZ_HIDENSITY)
+			uprintf("tz%d: Only one density supported\n", unit);
+		break;
+
+	case MT_ISMFOUR:
+		break;		/* XXX could do density select? */
+	}
+
+	/* set the current mode settings */
+	error = tzcommand(dev, SCSI_MODE_SELECT, 0,
+		sc->sc_modelen, (caddr_t)&sc->sc_mode);
+	if (error)
+		return (error);
+
+	sc->sc_ctty = tprintf_open(p);
+	sc->sc_flags = TZF_ALIVE | TZF_OPEN;
+	return (0);
+}
+
+tzclose(dev, flag)
+	dev_t dev;
+	int flag;
+{
+	register struct tz_softc *sc = &tz_softc[tzunit(dev)];
+	int error = 0;
+
+	if (!(sc->sc_flags & TZF_OPEN))
+		return (0);
+	if (flag == FWRITE ||
+	    ((flag & FWRITE) && (sc->sc_flags & TZF_WRITTEN))) {
+		error = tzcommand(dev, SCSI_WRITE_EOF, 0, 1, 0);
+#if 0
+		/*
+		 * Cartridge tapes don't do double EOFs on EOT.
+		 */
+		switch (sc->sc_tapeid) {
+		case MT_ISAR:
+		case MT_ISMT02:
+			break;
+
+		default:
+			error = tzcommand(dev, SCSI_WRITE_EOF, 0, 1, 0);
+			if (minor(dev) & TZ_NOREWIND)
+				(void) tzcommand(dev, SCSI_SPACE, 0, -1, 0);
+		}
+#endif
+	}
+	if ((minor(dev) & TZ_NOREWIND) == 0)
+		(void) tzcommand(dev, SCSI_REWIND, 0, 0, 0);
+	sc->sc_flags &= ~(TZF_OPEN | TZF_WRITTEN);
+	tprintf_close(sc->sc_ctty);
+	return (error);
+}
+
+int
+tzread(dev, uio)
+	dev_t dev;
+	struct uio *uio;
+{
+	register struct tz_softc *sc = &tz_softc[tzunit(dev)];
+
+	/*XXX*/ /* check for hardware write-protect? */
+#if 0
+	if (sc->sc_type == SCSI_ROM_TYPE)
+		return (EROFS);
+
+	if (sc->sc_format_pid && sc->sc_format_pid != curproc->p_pid)
+		return (EPERM);
+#endif
+
+	return (physio(tzstrategy, (struct buf *)0, dev,
+		B_READ, minphys, uio));
+}
+
+int
+tzwrite(dev, uio)
+	dev_t dev;
+	struct uio *uio;
+{
+	register struct tz_softc *sc = &tz_softc[tzunit(dev)];
+
+#if 0
+	if (sc->sc_format_pid && sc->sc_format_pid != curproc->p_pid)
+		return (EPERM);
+#endif
+
+	return (physio(tzstrategy, (struct buf *)0, dev,
+		B_WRITE, minphys, uio));
+}
+
+int
+tzioctl(dev, cmd, data, flag)
+	dev_t dev;
+	int cmd;
+	caddr_t data;
+	int flag;
+{
+	register struct tz_softc *sc = &tz_softc[tzunit(dev)];
+	register struct buf *bp = &sc->sc_buf;
+	struct mtop *mtop;
+	struct mtget *mtget;
+	int code, count;
+	static tzops[] = {
+		SCSI_WRITE_EOF, SCSI_SPACE, SCSI_SPACE, SCSI_SPACE, SCSI_SPACE,
+		SCSI_REWIND, SCSI_REWIND, SCSI_TEST_UNIT_READY
+	};
+
+	switch (cmd) {
+
+	case MTIOCTOP:	/* tape operation */
+		mtop = (struct mtop *)data;
+		if ((unsigned)mtop->mt_op < MTREW && mtop->mt_count <= 0)
+			return (EINVAL);
+		switch (mtop->mt_op) {
+
+		case MTWEOF:
+			code = 0;
+			count = mtop->mt_count;
+			break;
+
+		case MTFSF:
+			code = 1;
+			count = mtop->mt_count;
+			break;
+
+		case MTBSF:
+			code = 1;
+			count = -mtop->mt_count;
+			break;
+
+		case MTFSR:
+			code = 0;
+			count = mtop->mt_count;
+			break;
+
+		case MTBSR:
+			code = 0;
+			count = -mtop->mt_count;
+			break;
+
+		case MTREW:
+		case MTOFFL:
+		case MTNOP:
+			code = 0;
+			count = 0;
+			break;
+
+		default:
+			return (EINVAL);
+		}
+		return (tzcommand(dev, tzops[mtop->mt_op], code, count, 0));
+
+	case MTIOCGET:
+		mtget = (struct mtget *)data;
+		mtget->mt_dsreg = 0;
+		mtget->mt_erreg = sc->sc_sense.status;
+		mtget->mt_resid = 0;
+		mtget->mt_type = 0;
+		break;
+
+	default:
+		return (EINVAL);
+	}
+	return (0);
+}
+
+void
+tzstrategy(bp)
+	register struct buf *bp;
+{
+	register int unit = tzunit(bp->b_dev);
+	register struct tz_softc *sc = &tz_softc[unit];
+	register struct buf *dp;
+	register int s;
+
+	if (sc->sc_flags & TZF_SEENEOF) {
+		bp->b_resid = bp->b_bcount;
+		biodone(bp);
+		return;
+	}
+	bp->b_actf = NULL;
+	dp = &sc->sc_tab;
+	s = splbio();
+	bp->b_actb = dp->b_actb;
+	*dp->b_actb = bp;
+	dp->b_actb = &bp->b_actf;
+	if (dp->b_active == 0) {
+		dp->b_active = 1;
+		tzstart(unit);
+	}
+	splx(s);
+}
+
+/*
+ * Non-interrupt driven, non-dma dump routine.
+ */
+int
+tzdump(dev)
+	dev_t dev;
+{
+	/* Not implemented. */
+	return (ENXIO);
+}
+#endif