xref: /netbsd-src/sys/arch/hp300/dev/mt.c (revision 2a399c6883d870daece976daec6ffa7bb7f934ce)
1 /*	$NetBSD: mt.c,v 1.9 1997/10/04 10:00:17 thorpej Exp $	*/
2 
3 /*-
4  * Copyright (c) 1996, 1997 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Jason R. Thorpe.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the NetBSD
21  *	Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 /*
40  * Copyright (c) 1992, The University of Utah and
41  * the Computer Systems Laboratory at the University of Utah (CSL).
42  * All rights reserved.
43  *
44  * Permission to use, copy, modify and distribute this software is hereby
45  * granted provided that (1) source code retains these copyright, permission,
46  * and disclaimer notices, and (2) redistributions including binaries
47  * reproduce the notices in supporting documentation, and (3) all advertising
48  * materials mentioning features or use of this software display the following
49  * acknowledgement: ``This product includes software developed by the
50  * Computer Systems Laboratory at the University of Utah.''
51  *
52  * THE UNIVERSITY OF UTAH AND CSL ALLOW FREE USE OF THIS SOFTWARE IN ITS "AS
53  * IS" CONDITION.  THE UNIVERSITY OF UTAH AND CSL DISCLAIM ANY LIABILITY OF
54  * ANY KIND FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
55  *
56  * CSL requests users of this software to return to csl-dist@cs.utah.edu any
57  * improvements that they make and grant CSL redistribution rights.
58  *
59  *	Utah $Hdr: mt.c 1.8 95/09/12$
60  */
61 /*	@(#)mt.c	3.9	90/07/10	mt Xinu
62  *
63  * Magnetic tape driver (7974a, 7978a/b, 7979a, 7980a, 7980xc)
64  * Original version contributed by Mt. Xinu.
65  * Modified for 4.4BSD by Mark Davies and Andrew Vignaux, Department of
66  * Computer Science, Victoria University of Wellington
67  */
68 
69 #include <sys/param.h>
70 #include <sys/systm.h>
71 #include <sys/buf.h>
72 #include <sys/ioctl.h>
73 #include <sys/mtio.h>
74 #include <sys/file.h>
75 #include <sys/proc.h>
76 #include <sys/errno.h>
77 #include <sys/syslog.h>
78 #include <sys/tty.h>
79 #include <sys/kernel.h>
80 #include <sys/tprintf.h>
81 #include <sys/device.h>
82 #include <sys/conf.h>
83 
84 #include <hp300/dev/hpibvar.h>
85 
86 #include <hp300/dev/mtreg.h>
87 
88 struct	mtinfo {
89 	u_short	hwid;
90 	char	*desc;
91 } mtinfo[] = {
92 	{ MT7978ID,	"7978"	},
93 	{ MT7979AID,	"7979A"	},
94 	{ MT7980ID,	"7980"	},
95 	{ MT7974AID,	"7974A"	},
96 };
97 int	nmtinfo = sizeof(mtinfo) / sizeof(mtinfo[0]);
98 
99 struct	mt_softc {
100 	struct	device sc_dev;
101 	int	sc_hpibno;	/* logical HPIB this slave it attached to */
102 	int	sc_slave;	/* HPIB slave address (0-6) */
103 	short	sc_flags;	/* see below */
104 	u_char	sc_lastdsj;	/* place for DSJ in mtreaddsj() */
105 	u_char	sc_lastecmd;	/* place for End Command in mtreaddsj() */
106 	short	sc_recvtimeo;	/* count of hpibsend timeouts to prevent hang */
107 	short	sc_statindex;	/* index for next sc_stat when MTF_STATTIMEO */
108 	struct	mt_stat sc_stat;/* status bytes last read from device */
109 	short	sc_density;	/* current density of tape (mtio.h format) */
110 	short	sc_type;	/* tape drive model (hardware IDs) */
111 	struct	hpibqueue sc_hq; /* HPIB device queue member */
112 	tpr_t	sc_ttyp;
113 	struct buf sc_tab;	/* buf queue */
114 	struct buf sc_bufstore;	/* XXX buffer storage */
115 };
116 
117 #ifdef DEBUG
118 int	mtdebug = 0;
119 #define	dlog	if (mtdebug) log
120 #else
121 #define	dlog	if (0) log
122 #endif
123 
124 #define	UNIT(x)		(minor(x) & 3)
125 
126 #define B_CMD		B_XXX		/* command buf instead of data */
127 #define	b_cmd		b_blkno		/* blkno holds cmd when B_CMD */
128 
129 int	mtmatch __P((struct device *, struct cfdata *, void *));
130 void	mtattach __P((struct device *, struct device *, void *));
131 
132 struct cfattach mt_ca = {
133 	sizeof(struct mt_softc), mtmatch, mtattach
134 };
135 
136 struct cfdriver mt_cd = {
137 	NULL, "mt", DV_TAPE
138 };
139 
140 int	mtident __P((struct mt_softc *, struct hpibbus_attach_args *));
141 void	mtustart __P((struct mt_softc *));
142 int	mtreaddsj __P((struct mt_softc *, int));
143 int	mtcommand __P((dev_t, int, int));
144 void	spl_mtintr __P((void *));
145 void	spl_mtstart __P((void *));
146 
147 void	mtstart __P((void *));
148 void	mtgo __P((void *));
149 void	mtintr __P((void *));
150 
151 bdev_decl(mt);
152 cdev_decl(mt);
153 
154 int
155 mtmatch(parent, match, aux)
156 	struct device *parent;
157 	struct cfdata *match;
158 	void *aux;
159 {
160 	struct hpibbus_attach_args *ha = aux;
161 
162 	return (mtident(NULL, ha));
163 }
164 
165 void
166 mtattach(parent, self, aux)
167 	struct device *parent, *self;
168 	void *aux;
169 {
170 	struct mt_softc *sc = (struct mt_softc *)self;
171 	struct hpibbus_attach_args *ha = aux;
172 	int unit, hpibno, slave;
173 
174 	if (mtident(sc, ha) == 0) {
175 		printf("\n%s: impossible!\n", sc->sc_dev.dv_xname);
176 		return;
177 	}
178 
179 	unit = self->dv_unit;
180 	hpibno = parent->dv_unit;
181 	slave = ha->ha_slave;
182 
183 	sc->sc_tab.b_actb = &sc->sc_tab.b_actf;
184 
185 	sc->sc_hpibno = hpibno;
186 	sc->sc_slave = slave;
187 	sc->sc_flags = MTF_EXISTS;
188 
189 	/* Initialize hpib job queue entry. */
190 	sc->sc_hq.hq_softc = sc;
191 	sc->sc_hq.hq_slave = sc->sc_slave;
192 	sc->sc_hq.hq_start = mtstart;
193 	sc->sc_hq.hq_go = mtgo;
194 	sc->sc_hq.hq_intr = mtintr;
195 }
196 
197 int
198 mtident(sc, ha)
199 	struct mt_softc *sc;
200 	struct hpibbus_attach_args *ha;
201 {
202 	int i;
203 
204 	for (i = 0; i < nmtinfo; i++) {
205 		if (ha->ha_id == mtinfo[i].hwid) {
206 			if (sc != NULL) {
207 				sc->sc_type = mtinfo[i].hwid;
208 				printf(": %s tape\n", mtinfo[i].desc);
209 			}
210 			return (1);
211 		}
212 	}
213 	return (0);
214 }
215 
216 /*
217  * Perform a read of "Device Status Jump" register and update the
218  * status if necessary.  If status is read, the given "ecmd" is also
219  * performed, unless "ecmd" is zero.  Returns DSJ value, -1 on failure
220  * and -2 on "temporary" failure.
221  */
222 int
223 mtreaddsj(sc, ecmd)
224 	struct mt_softc *sc;
225 	int ecmd;
226 {
227 	int retval;
228 
229 	if (sc->sc_flags & MTF_STATTIMEO)
230 		goto getstats;
231 	retval = hpibrecv(sc->sc_hpibno,
232 	    (sc->sc_flags & MTF_DSJTIMEO) ? -1 : sc->sc_slave,
233 	    MTT_DSJ, &(sc->sc_lastdsj), 1);
234 	sc->sc_flags &= ~MTF_DSJTIMEO;
235 	if (retval != 1) {
236 		dlog(LOG_DEBUG, "%s can't hpibrecv DSJ",
237 		    sc->sc_dev.dv_xname);
238 		if (sc->sc_recvtimeo == 0)
239 			sc->sc_recvtimeo = hz;
240 		if (--sc->sc_recvtimeo == 0)
241 			return (-1);
242 		if (retval == 0)
243 			sc->sc_flags |= MTF_DSJTIMEO;
244 		return (-2);
245 	}
246 	sc->sc_recvtimeo = 0;
247 	sc->sc_statindex = 0;
248 	dlog(LOG_DEBUG, "%s readdsj: 0x%x", sc->sc_dev.dv_xname,
249 	    sc->sc_lastdsj);
250 	sc->sc_lastecmd = ecmd;
251 	switch (sc->sc_lastdsj) {
252 	    case 0:
253 		if (ecmd & MTE_DSJ_FORCE)
254 			break;
255 		return (0);
256 
257 	    case 2:
258 		sc->sc_lastecmd = MTE_COMPLETE;
259 	    case 1:
260 		break;
261 
262 	    default:
263 		log(LOG_ERR, "%s readdsj: DSJ 0x%x\n", sc->sc_dev.dv_xname,
264 		    sc->sc_lastdsj);
265 		return (-1);
266 	}
267     getstats:
268 	retval = hpibrecv(sc->sc_hpibno,
269 	    (sc->sc_flags & MTF_STATCONT) ? -1 : sc->sc_slave,
270 	    MTT_STAT, ((char *)&(sc->sc_stat)) + sc->sc_statindex,
271 	    sizeof(sc->sc_stat) - sc->sc_statindex);
272 	sc->sc_flags &= ~(MTF_STATTIMEO | MTF_STATCONT);
273 	if (retval != sizeof(sc->sc_stat) - sc->sc_statindex) {
274 		if (sc->sc_recvtimeo == 0)
275 			sc->sc_recvtimeo = hz;
276 		if (--sc->sc_recvtimeo != 0) {
277 			if (retval >= 0) {
278 				sc->sc_statindex += retval;
279 				sc->sc_flags |= MTF_STATCONT;
280 			}
281 			sc->sc_flags |= MTF_STATTIMEO;
282 			return (-2);
283 		}
284 		log(LOG_ERR, "%s readdsj: can't read status",
285 		    sc->sc_dev.dv_xname);
286 		return (-1);
287 	}
288 	sc->sc_recvtimeo = 0;
289 	sc->sc_statindex = 0;
290 	dlog(LOG_DEBUG, "%s readdsj: status is %x %x %x %x %x %x",
291 	    sc->sc_dev.dv_xname,
292 	    sc->sc_stat1, sc->sc_stat2, sc->sc_stat3,
293 	    sc->sc_stat4, sc->sc_stat5, sc->sc_stat6);
294 	if (sc->sc_lastecmd)
295 		(void) hpibsend(sc->sc_hpibno, sc->sc_slave,
296 		    MTL_ECMD, &(sc->sc_lastecmd), 1);
297 	return ((int) sc->sc_lastdsj);
298 }
299 
300 int
301 mtopen(dev, flag, mode, p)
302 	dev_t dev;
303 	int flag, mode;
304 	struct proc *p;
305 {
306 	int unit = UNIT(dev);
307 	struct mt_softc *sc;
308 	int req_den;
309 	int error;
310 
311 	if (unit >= mt_cd.cd_ndevs ||
312 	    (sc = mt_cd.cd_devs[unit]) == NULL ||
313 	    (sc->sc_flags & MTF_EXISTS) == 0)
314 		return (ENXIO);
315 
316 	dlog(LOG_DEBUG, "%s open: flags 0x%x", sc->sc_dev.dv_xname,
317 	    sc->sc_flags);
318 	if (sc->sc_flags & MTF_OPEN)
319 		return (EBUSY);
320 	sc->sc_flags |= MTF_OPEN;
321 	sc->sc_ttyp = tprintf_open(p);
322 	if ((sc->sc_flags & MTF_ALIVE) == 0) {
323 		error = mtcommand(dev, MTRESET, 0);
324 		if (error != 0 || (sc->sc_flags & MTF_ALIVE) == 0)
325 			goto errout;
326 		if ((sc->sc_stat1 & (SR1_BOT | SR1_ONLINE)) == SR1_ONLINE)
327 			(void) mtcommand(dev, MTREW, 0);
328 	}
329 	for (;;) {
330 		if ((error = mtcommand(dev, MTNOP, 0)) != 0)
331 			goto errout;
332 		if (!(sc->sc_flags & MTF_REW))
333 			break;
334 		if (tsleep((caddr_t) &lbolt, PCATCH | (PZERO + 1),
335 		    "mt", 0) != 0) {
336 			error = EINTR;
337 			goto errout;
338 		}
339 	}
340 	if ((flag & FWRITE) && (sc->sc_stat1 & SR1_RO)) {
341 		error = EROFS;
342 		goto errout;
343 	}
344 	if (!(sc->sc_stat1 & SR1_ONLINE)) {
345 		uprintf("%s: not online\n", sc->sc_dev.dv_xname);
346 		error = EIO;
347 		goto errout;
348 	}
349 	/*
350 	 * Select density:
351 	 *  - find out what density the drive is set to
352 	 *	(i.e. the density of the current tape)
353 	 *  - if we are going to write
354 	 *    - if we're not at the beginning of the tape
355 	 *      - complain if we want to change densities
356 	 *    - otherwise, select the mtcommand to set the density
357 	 *
358 	 * If the drive doesn't support it then don't change the recorded
359 	 * density.
360 	 *
361 	 * The original MOREbsd code had these additional conditions
362 	 * for the mid-tape change
363 	 *
364 	 *	req_den != T_BADBPI &&
365 	 *	sc->sc_density != T_6250BPI
366 	 *
367 	 * which suggests that it would be possible to write multiple
368 	 * densities if req_den == T_BAD_BPI or the current tape
369 	 * density was 6250.  Testing of our 7980 suggests that the
370 	 * device cannot change densities mid-tape.
371 	 *
372 	 * ajv@comp.vuw.ac.nz
373 	 */
374 	sc->sc_density = (sc->sc_stat2 & SR2_6250) ? T_6250BPI : (
375 			 (sc->sc_stat3 & SR3_1600) ? T_1600BPI : (
376 			 (sc->sc_stat3 & SR3_800) ? T_800BPI : -1));
377 	req_den = (dev & T_DENSEL);
378 
379 	if (flag & FWRITE) {
380 		if (!(sc->sc_stat1 & SR1_BOT)) {
381 			if (sc->sc_density != req_den) {
382 				uprintf("%s: can't change density mid-tape\n",
383 				    sc->sc_dev.dv_xname);
384 				error = EIO;
385 				goto errout;
386 			}
387 		}
388 		else {
389 			int mtset_density =
390 			    (req_den == T_800BPI  ? MTSET800BPI : (
391 			     req_den == T_1600BPI ? MTSET1600BPI : (
392 			     req_den == T_6250BPI ? MTSET6250BPI : (
393 			     sc->sc_type == MT7980ID
394 						  ? MTSET6250DC
395 						  : MTSET6250BPI))));
396 			if (mtcommand(dev, mtset_density, 0) == 0)
397 				sc->sc_density = req_den;
398 		}
399 	}
400 	return (0);
401 errout:
402 	sc->sc_flags &= ~MTF_OPEN;
403 	return (error);
404 }
405 
406 int
407 mtclose(dev, flag, fmt, p)
408 	dev_t dev;
409 	int flag, fmt;
410 	struct proc *p;
411 {
412 	struct mt_softc *sc = mt_cd.cd_devs[UNIT(dev)];
413 
414 	if (sc->sc_flags & MTF_WRT) {
415 		(void) mtcommand(dev, MTWEOF, 2);
416 		(void) mtcommand(dev, MTBSF, 0);
417 	}
418 	if ((minor(dev) & T_NOREWIND) == 0)
419 		(void) mtcommand(dev, MTREW, 0);
420 	sc->sc_flags &= ~MTF_OPEN;
421 	tprintf_close(sc->sc_ttyp);
422 	return (0);
423 }
424 
425 int
426 mtcommand(dev, cmd, cnt)
427 	dev_t dev;
428 	int cmd;
429 	int cnt;
430 {
431 	struct mt_softc *sc = mt_cd.cd_devs[UNIT(dev)];
432 	struct buf *bp = &sc->sc_bufstore;
433 	int error = 0;
434 
435 #if 1
436 	if (bp->b_flags & B_BUSY)
437 		return (EBUSY);
438 #endif
439 	bp->b_cmd = cmd;
440 	bp->b_dev = dev;
441 	do {
442 		bp->b_flags = B_BUSY | B_CMD;
443 		mtstrategy(bp);
444 		iowait(bp);
445 		if (bp->b_flags & B_ERROR) {
446 			error = (int) (unsigned) bp->b_error;
447 			break;
448 		}
449 	} while (--cnt > 0);
450 #if 0
451 	bp->b_flags = 0 /*&= ~B_BUSY*/;
452 #else
453 	bp->b_flags &= ~B_BUSY;
454 #endif
455 	return (error);
456 }
457 
458 /*
459  * Only thing to check here is for legal record lengths (writes only).
460  */
461 void
462 mtstrategy(bp)
463 	struct buf *bp;
464 {
465 	struct mt_softc *sc;
466 	struct buf *dp;
467 	int unit;
468 	int s;
469 
470 	unit = UNIT(bp->b_dev);
471 	sc = mt_cd.cd_devs[unit];
472 	dlog(LOG_DEBUG, "%s strategy", sc->sc_dev.dv_xname);
473 	if ((bp->b_flags & (B_CMD | B_READ)) == 0) {
474 #define WRITE_BITS_IGNORED	8
475 #if 0
476 		if (bp->b_bcount & ((1 << WRITE_BITS_IGNORED) - 1)) {
477 			tprintf(sc->sc_ttyp,
478 				"%s: write record must be multiple of %d\n",
479 				sc->sc_dev.dv_xname, 1 << WRITE_BITS_IGNORED);
480 			goto error;
481 		}
482 #endif
483 		s = 16 * 1024;
484 		if (sc->sc_stat2 & SR2_LONGREC) {
485 			switch (sc->sc_density) {
486 			    case T_1600BPI:
487 				s = 32 * 1024;
488 				break;
489 
490 			    case T_6250BPI:
491 			    case T_BADBPI:
492 				s = 60 * 1024;
493 				break;
494 			}
495 		}
496 		if (bp->b_bcount > s) {
497 			tprintf(sc->sc_ttyp,
498 				"%s: write record (%ld) too big: limit (%d)\n",
499 				sc->sc_dev.dv_xname, bp->b_bcount, s);
500 #if 0 /* XXX see above */
501 	    error:
502 #endif
503 			bp->b_flags |= B_ERROR;
504 			bp->b_error = EIO;
505 			iodone(bp);
506 			return;
507 		}
508 	}
509 	dp = &sc->sc_tab;
510 	bp->b_actf = NULL;
511 	s = splbio();
512 	bp->b_actb = dp->b_actb;
513 	*dp->b_actb = bp;
514 	dp->b_actb = &bp->b_actf;
515 	if (dp->b_active == 0) {
516 		dp->b_active = 1;
517 		mtustart(sc);
518 	}
519 	splx(s);
520 }
521 
522 void
523 mtustart(sc)
524 	struct mt_softc *sc;
525 {
526 
527 	dlog(LOG_DEBUG, "%s ustart", sc->sc_dev.dv_xname);
528 	if (hpibreq(sc->sc_dev.dv_parent, &sc->sc_hq))
529 		mtstart(sc);
530 }
531 
532 void
533 spl_mtintr(arg)
534 	void *arg;
535 {
536 	struct mt_softc *sc = arg;
537 	int s = splbio();
538 
539 	hpibppclear(sc->sc_hpibno);
540 	mtintr(sc);
541 	(void) splx(s);
542 }
543 
544 void
545 spl_mtstart(arg)
546 	void *arg;
547 {
548 	int s = splbio();
549 
550 	mtstart(arg);
551 	(void) splx(s);
552 }
553 
554 void
555 mtstart(arg)
556 	void *arg;
557 {
558 	struct mt_softc *sc = arg;
559 	struct buf *bp, *dp;
560 	short	cmdcount = 1;
561 	u_char	cmdbuf[2];
562 
563 	dlog(LOG_DEBUG, "%s start", sc->sc_dev.dv_xname);
564 	sc->sc_flags &= ~MTF_WRT;
565 	bp = sc->sc_tab.b_actf;
566 	if ((sc->sc_flags & MTF_ALIVE) == 0 &&
567 	    ((bp->b_flags & B_CMD) == 0 || bp->b_cmd != MTRESET))
568 		goto fatalerror;
569 
570 	if (sc->sc_flags & MTF_REW) {
571 		if (!hpibpptest(sc->sc_hpibno, sc->sc_slave))
572 			goto stillrew;
573 		switch (mtreaddsj(sc, MTE_DSJ_FORCE|MTE_COMPLETE|MTE_IDLE)) {
574 		    case 0:
575 		    case 1:
576 		stillrew:
577 			if ((sc->sc_stat1 & SR1_BOT) ||
578 			    !(sc->sc_stat1 & SR1_ONLINE)) {
579 				sc->sc_flags &= ~MTF_REW;
580 				break;
581 			}
582 		    case -2:
583 			/*
584 			 * -2 means "timeout" reading DSJ, which is probably
585 			 * temporary.  This is considered OK when doing a NOP,
586 			 * but not otherwise.
587 			 */
588 			if (sc->sc_flags & (MTF_DSJTIMEO | MTF_STATTIMEO)) {
589 				timeout(spl_mtstart, sc, hz >> 5);
590 				return;
591 			}
592 		    case 2:
593 			if (bp->b_cmd != MTNOP || !(bp->b_flags & B_CMD)) {
594 				bp->b_error = EBUSY;
595 				goto errdone;
596 			}
597 			goto done;
598 
599 		    default:
600 			goto fatalerror;
601 		}
602 	}
603 	if (bp->b_flags & B_CMD) {
604 		if (sc->sc_flags & MTF_PASTEOT) {
605 			switch(bp->b_cmd) {
606 			    case MTFSF:
607 			    case MTWEOF:
608 			    case MTFSR:
609 				bp->b_error = ENOSPC;
610 				goto errdone;
611 
612 			    case MTBSF:
613 			    case MTOFFL:
614 			    case MTBSR:
615 			    case MTREW:
616 				sc->sc_flags &= ~(MTF_PASTEOT | MTF_ATEOT);
617 				break;
618 			}
619 		}
620 		switch(bp->b_cmd) {
621 		    case MTFSF:
622 			if (sc->sc_flags & MTF_HITEOF)
623 				goto done;
624 			cmdbuf[0] = MTTC_FSF;
625 			break;
626 
627 		    case MTBSF:
628 			if (sc->sc_flags & MTF_HITBOF)
629 				goto done;
630 			cmdbuf[0] = MTTC_BSF;
631 			break;
632 
633 		    case MTOFFL:
634 			sc->sc_flags |= MTF_REW;
635 			cmdbuf[0] = MTTC_REWOFF;
636 			break;
637 
638 		    case MTWEOF:
639 			cmdbuf[0] = MTTC_WFM;
640 			break;
641 
642 		    case MTBSR:
643 			cmdbuf[0] = MTTC_BSR;
644 			break;
645 
646 		    case MTFSR:
647 			cmdbuf[0] = MTTC_FSR;
648 			break;
649 
650 		    case MTREW:
651 			sc->sc_flags |= MTF_REW;
652 			cmdbuf[0] = MTTC_REW;
653 			break;
654 
655 		    case MTNOP:
656 			/*
657 			 * NOP is supposed to set status bits.
658 			 * Force readdsj to do it.
659 			 */
660 			switch (mtreaddsj(sc,
661 			  MTE_DSJ_FORCE | MTE_COMPLETE | MTE_IDLE)) {
662 			    default:
663 				goto done;
664 
665 			    case -1:
666 				/*
667 				 * If this fails, perform a device clear
668 				 * to fix any protocol problems and (most
669 				 * likely) get the status.
670 				 */
671 				bp->b_cmd = MTRESET;
672 				break;
673 
674 			    case -2:
675 				timeout(spl_mtstart, sc, hz >> 5);
676 				return;
677 			}
678 
679 		    case MTRESET:
680 			/*
681 			 * 1) selected device clear (send with "-2" secondary)
682 			 * 2) set timeout, then wait for "service request"
683 			 * 3) interrupt will read DSJ (and END COMPLETE-IDLE)
684 			 */
685 			if (hpibsend(sc->sc_hpibno, sc->sc_slave, -2, NULL, 0)){
686 				log(LOG_ERR, "%s can't reset",
687 				    sc->sc_dev.dv_xname);
688 				goto fatalerror;
689 			}
690 			timeout(spl_mtintr, sc, 4 * hz);
691 			hpibawait(sc->sc_hpibno);
692 			return;
693 
694 		    case MTSET800BPI:
695 			cmdbuf[0] = MTTC_800;
696 			break;
697 
698 		    case MTSET1600BPI:
699 			cmdbuf[0] = MTTC_1600;
700 			break;
701 
702 		    case MTSET6250BPI:
703 			cmdbuf[0] = MTTC_6250;
704 			break;
705 
706 		    case MTSET6250DC:
707 			cmdbuf[0] = MTTC_DC6250;
708 			break;
709 		}
710 	} else {
711 		if (sc->sc_flags & MTF_PASTEOT) {
712 			bp->b_error = ENOSPC;
713 			goto errdone;
714 		}
715 		if (bp->b_flags & B_READ) {
716 			sc->sc_flags |= MTF_IO;
717 			cmdbuf[0] = MTTC_READ;
718 		} else {
719 			sc->sc_flags |= MTF_WRT | MTF_IO;
720 			cmdbuf[0] = MTTC_WRITE;
721 			cmdbuf[1] = (bp->b_bcount + ((1 << WRITE_BITS_IGNORED) - 1)) >> WRITE_BITS_IGNORED;
722 			cmdcount = 2;
723 		}
724 	}
725 	if (hpibsend(sc->sc_hpibno, sc->sc_slave, MTL_TCMD, cmdbuf, cmdcount)
726 	    == cmdcount) {
727 		if (sc->sc_flags & MTF_REW)
728 			goto done;
729 		hpibawait(sc->sc_hpibno);
730 		return;
731 	}
732 fatalerror:
733 	/*
734 	 * If anything fails, the drive is probably hosed, so mark it not
735 	 * "ALIVE" (but it EXISTS and is OPEN or we wouldn't be here, and
736 	 * if, last we heard, it was REWinding, remember that).
737 	 */
738 	sc->sc_flags &= MTF_EXISTS | MTF_OPEN | MTF_REW;
739 	bp->b_error = EIO;
740 errdone:
741 	bp->b_flags |= B_ERROR;
742 done:
743 	sc->sc_flags &= ~(MTF_HITEOF | MTF_HITBOF);
744 	iodone(bp);
745 	if ((dp = bp->b_actf))
746 		dp->b_actb = bp->b_actb;
747 	else
748 		sc->sc_tab.b_actb = bp->b_actb;
749 	*bp->b_actb = dp;
750 	hpibfree(sc->sc_dev.dv_parent, &sc->sc_hq);
751 	if ((bp = dp) == NULL)
752 		sc->sc_tab.b_active = 0;
753 	else
754 		mtustart(sc);
755 }
756 
757 /*
758  * The Utah code had a bug which meant that the driver was unable to read.
759  * "rw" was initialized to bp->b_flags & B_READ before "bp" was initialized.
760  *   -- ajv@comp.vuw.ac.nz
761  */
762 void
763 mtgo(arg)
764 	void *arg;
765 {
766 	struct mt_softc *sc = arg;
767 	struct buf *bp;
768 	int rw;
769 
770 	dlog(LOG_DEBUG, "%s go", sc->sc_dev.dv_xname);
771 	bp = sc->sc_tab.b_actf;
772 	rw = bp->b_flags & B_READ;
773 	hpibgo(sc->sc_hpibno, sc->sc_slave, rw ? MTT_READ : MTL_WRITE,
774 	    bp->b_un.b_addr, bp->b_bcount, rw, rw != 0);
775 }
776 
777 void
778 mtintr(arg)
779 	void *arg;
780 {
781 	struct mt_softc *sc = arg;
782 	struct buf *bp, *dp;
783 	int i;
784 	u_char cmdbuf[4];
785 
786 	bp = sc->sc_tab.b_actf;
787 	if (bp == NULL) {
788 		log(LOG_ERR, "%s intr: bp == NULL", sc->sc_dev.dv_xname);
789 		return;
790 	}
791 
792 	dlog(LOG_DEBUG, "%s intr", sc->sc_dev.dv_xname);
793 
794 	/*
795 	 * Some operation completed.  Read status bytes and report errors.
796 	 * Clear EOF flags here `cause they're set once on specific conditions
797 	 * below when a command succeeds.
798 	 * A DSJ of 2 always means keep waiting.  If the command was READ
799 	 * (and we're in data DMA phase) stop data transfer first.
800 	 */
801 	sc->sc_flags &= ~(MTF_HITEOF | MTF_HITBOF);
802 	if ((bp->b_flags & (B_CMD|B_READ)) == B_READ &&
803 	    !(sc->sc_flags & (MTF_IO | MTF_STATTIMEO | MTF_DSJTIMEO))){
804 		cmdbuf[0] = MTE_STOP;
805 		(void) hpibsend(sc->sc_hpibno, sc->sc_slave, MTL_ECMD,cmdbuf,1);
806 	}
807 	switch (mtreaddsj(sc, 0)) {
808 	    case 0:
809 		break;
810 
811 	    case 1:
812 		/*
813 		 * If we're in the middle of a READ/WRITE and have yet to
814 		 * start the data transfer, a DSJ of one should terminate it.
815 		 */
816 		sc->sc_flags &= ~MTF_IO;
817 		break;
818 
819 	    case 2:
820 		(void) hpibawait(sc->sc_hpibno);
821 		return;
822 
823 	    case -2:
824 		/*
825 		 * -2 means that the drive failed to respond quickly enough
826 		 * to the request for DSJ.  It's probably just "busy" figuring
827 		 * it out and will know in a little bit...
828 		 */
829 		timeout(spl_mtintr, sc, hz >> 5);
830 		return;
831 
832 	    default:
833 		log(LOG_ERR, "%s intr: can't get drive stat",
834 		    sc->sc_dev.dv_xname);
835 		goto error;
836 	}
837 	if (sc->sc_stat1 & (SR1_ERR | SR1_REJECT)) {
838 		i = sc->sc_stat4 & SR4_ERCLMASK;
839 		log(LOG_ERR, "%s: %s error, retry %d, SR2/3 %x/%x, code %d",
840 			sc->sc_dev.dv_xname, i == SR4_DEVICE ? "device" :
841 			(i == SR4_PROTOCOL ? "protocol" :
842 			(i == SR4_SELFTEST ? "selftest" : "unknown")),
843 			sc->sc_stat4 & SR4_RETRYMASK, sc->sc_stat2,
844 			sc->sc_stat3, sc->sc_stat5);
845 
846 		if ((bp->b_flags & B_CMD) && bp->b_cmd == MTRESET)
847 			untimeout(spl_mtintr, sc);
848 		if (sc->sc_stat3 & SR3_POWERUP)
849 			sc->sc_flags &= MTF_OPEN | MTF_EXISTS;
850 		goto error;
851 	}
852 	/*
853 	 * Report and clear any soft errors.
854 	 */
855 	if (sc->sc_stat1 & SR1_SOFTERR) {
856 		log(LOG_WARNING, "%s: soft error, retry %d\n",
857 			sc->sc_dev.dv_xname, sc->sc_stat4 & SR4_RETRYMASK);
858 		sc->sc_stat1 &= ~SR1_SOFTERR;
859 	}
860 	/*
861 	 * We've initiated a read or write, but haven't actually started to
862 	 * DMA the data yet.  At this point, the drive's ready.
863 	 */
864 	if (sc->sc_flags & MTF_IO) {
865 		sc->sc_flags &= ~MTF_IO;
866 		if (hpibustart(sc->sc_hpibno))
867 			mtgo(sc);
868 		return;
869 	}
870 	/*
871 	 * Check for End Of Tape - we're allowed to hit EOT and then write (or
872 	 * read) one more record.  If we get here and have not already hit EOT,
873 	 * return ENOSPC to inform the process that it's hit it.  If we get
874 	 * here and HAVE already hit EOT, don't allow any more operations that
875 	 * move the tape forward.
876 	 */
877 	if (sc->sc_stat1 & SR1_EOT) {
878 		if (sc->sc_flags & MTF_ATEOT)
879 			sc->sc_flags |= MTF_PASTEOT;
880 		else {
881 			bp->b_flags |= B_ERROR;
882 			bp->b_error = ENOSPC;
883 			sc->sc_flags |= MTF_ATEOT;
884 		}
885 	}
886 	/*
887 	 * If a motion command was being executed, check for Tape Marks.
888 	 * If we were doing data, make sure we got the right amount, and
889 	 * check for hitting tape marks on reads.
890 	 */
891 	if (bp->b_flags & B_CMD) {
892 		if (sc->sc_stat1 & SR1_EOF) {
893 			if (bp->b_cmd == MTFSR)
894 				sc->sc_flags |= MTF_HITEOF;
895 			if (bp->b_cmd == MTBSR)
896 				sc->sc_flags |= MTF_HITBOF;
897 		}
898 		if (bp->b_cmd == MTRESET) {
899 			untimeout(spl_mtintr, sc);
900 			sc->sc_flags |= MTF_ALIVE;
901 		}
902 	} else {
903 		i = hpibrecv(sc->sc_hpibno, sc->sc_slave, MTT_BCNT, cmdbuf, 2);
904 		if (i != 2) {
905 			log(LOG_ERR, "%s intr: can't get xfer length\n",
906 			    sc->sc_dev.dv_xname);
907 			goto error;
908 		}
909 		i = (int) *((u_short *) cmdbuf);
910 		if (i <= bp->b_bcount) {
911 			if (i == 0)
912 				sc->sc_flags |= MTF_HITEOF;
913 			bp->b_resid = bp->b_bcount - i;
914 			dlog(LOG_DEBUG, "%s intr: bcount %ld, resid %ld",
915 			    sc->sc_dev.dv_xname, bp->b_bcount, bp->b_resid);
916 		} else {
917 			tprintf(sc->sc_ttyp,
918 				"%s: record (%d) larger than wanted (%ld)\n",
919 				sc->sc_dev.dv_xname, i, bp->b_bcount);
920     error:
921 			sc->sc_flags &= ~MTF_IO;
922 			bp->b_error = EIO;
923 			bp->b_flags |= B_ERROR;
924 		}
925 	}
926 	/*
927 	 * The operation is completely done.
928 	 * Let the drive know with an END command.
929 	 */
930 	cmdbuf[0] = MTE_COMPLETE | MTE_IDLE;
931 	(void) hpibsend(sc->sc_hpibno, sc->sc_slave, MTL_ECMD, cmdbuf, 1);
932 	bp->b_flags &= ~B_CMD;
933 	iodone(bp);
934 	if ((dp = bp->b_actf))
935 		dp->b_actb = bp->b_actb;
936 	else
937 		sc->sc_tab.b_actb = bp->b_actb;
938 	*bp->b_actb = dp;
939 	hpibfree(sc->sc_dev.dv_parent, &sc->sc_hq);
940 #if 0
941 	if (bp /*sc->sc_tab.b_actf*/ == NULL)
942 #else
943 	if (sc->sc_tab.b_actf == NULL)
944 #endif
945 		sc->sc_tab.b_active = 0;
946 	else
947 		mtustart(sc);
948 }
949 
950 int
951 mtread(dev, uio, flags)
952 	dev_t dev;
953 	struct uio *uio;
954 	int flags;
955 {
956 	struct mt_softc *sc = mt_cd.cd_devs[UNIT(dev)];
957 
958 	return(physio(mtstrategy, &sc->sc_bufstore,
959 	    dev, B_READ, minphys, uio));
960 }
961 
962 int
963 mtwrite(dev, uio, flags)
964 	dev_t dev;
965 	struct uio *uio;
966 	int flags;
967 {
968 	struct mt_softc *sc = mt_cd.cd_devs[UNIT(dev)];
969 
970 	return(physio(mtstrategy, &sc->sc_bufstore,
971 	    dev, B_WRITE, minphys, uio));
972 }
973 
974 int
975 mtioctl(dev, cmd, data, flag, p)
976 	dev_t dev;
977 	u_long cmd;
978 	caddr_t data;
979 	int flag;
980 	struct proc *p;
981 {
982 	struct mtop *op;
983 	int cnt;
984 
985 	switch (cmd) {
986 	    case MTIOCTOP:
987 		op = (struct mtop *)data;
988 		switch(op->mt_op) {
989 		    case MTWEOF:
990 		    case MTFSF:
991 		    case MTBSR:
992 		    case MTBSF:
993 		    case MTFSR:
994 			cnt = op->mt_count;
995 			break;
996 
997 		    case MTOFFL:
998 		    case MTREW:
999 		    case MTNOP:
1000 			cnt = 0;
1001 			break;
1002 
1003 		    default:
1004 			return (EINVAL);
1005 		}
1006 		return (mtcommand(dev, op->mt_op, cnt));
1007 
1008 	    case MTIOCGET:
1009 		break;
1010 
1011 	    default:
1012 		return (EINVAL);
1013 	}
1014 	return (0);
1015 }
1016 
1017 /*ARGSUSED*/
1018 int
1019 mtdump(dev, blkno, va, size)
1020 	dev_t dev;
1021 	daddr_t blkno;
1022 	caddr_t va;
1023 	size_t size;
1024 {
1025 	return (ENODEV);
1026 }
1027