xref: /netbsd-src/sys/arch/hp300/dev/mt.c (revision aef5eb5f59cdfe8314f1b5f78ac04eb144e44010)
1 /*	$NetBSD: mt.c,v 1.55 2021/07/05 14:03:46 tsutsui 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  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 /*
33  * Copyright (c) 1992, The University of Utah and
34  * the Computer Systems Laboratory at the University of Utah (CSL).
35  * All rights reserved.
36  *
37  * Permission to use, copy, modify and distribute this software is hereby
38  * granted provided that (1) source code retains these copyright, permission,
39  * and disclaimer notices, and (2) redistributions including binaries
40  * reproduce the notices in supporting documentation, and (3) all advertising
41  * materials mentioning features or use of this software display the following
42  * acknowledgement: ``This product includes software developed by the
43  * Computer Systems Laboratory at the University of Utah.''
44  *
45  * THE UNIVERSITY OF UTAH AND CSL ALLOW FREE USE OF THIS SOFTWARE IN ITS "AS
46  * IS" CONDITION.  THE UNIVERSITY OF UTAH AND CSL DISCLAIM ANY LIABILITY OF
47  * ANY KIND FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
48  *
49  * CSL requests users of this software to return to csl-dist@cs.utah.edu any
50  * improvements that they make and grant CSL redistribution rights.
51  *
52  *	Utah $Hdr: mt.c 1.8 95/09/12$
53  */
54 /*	@(#)mt.c	3.9	90/07/10	mt Xinu
55  *
56  * Magnetic tape driver (7974a, 7978a/b, 7979a, 7980a, 7980xc)
57  * Original version contributed by Mt. Xinu.
58  * Modified for 4.4BSD by Mark Davies and Andrew Vignaux, Department of
59  * Computer Science, Victoria University of Wellington
60  */
61 
62 #include <sys/cdefs.h>
63 __KERNEL_RCSID(0, "$NetBSD: mt.c,v 1.55 2021/07/05 14:03:46 tsutsui Exp $");
64 
65 #include <sys/param.h>
66 #include <sys/systm.h>
67 #include <sys/callout.h>
68 #include <sys/buf.h>
69 #include <sys/bufq.h>
70 #include <sys/ioctl.h>
71 #include <sys/mtio.h>
72 #include <sys/file.h>
73 #include <sys/proc.h>
74 #include <sys/errno.h>
75 #include <sys/syslog.h>
76 #include <sys/tty.h>
77 #include <sys/kernel.h>
78 #include <sys/tprintf.h>
79 #include <sys/device.h>
80 #include <sys/conf.h>
81 
82 #include <hp300/dev/hpibvar.h>
83 
84 #include <hp300/dev/mtreg.h>
85 
86 #include "ioconf.h"
87 
88 static const struct mtinfo {
89 	u_short	hwid;
90 	const char *desc;
91 } mtinfo[] = {
92 	{ MT7978ID,	"7978"	},
93 	{ MT7979AID,	"7979A"	},
94 	{ MT7980ID,	"7980"	},
95 	{ MT7974AID,	"7974A"	},
96 };
97 static const int nmtinfo = sizeof(mtinfo) / sizeof(mtinfo[0]);
98 
99 struct	mt_softc {
100 	device_t sc_dev;
101 	struct	callout sc_start_ch;
102 	struct	callout sc_intr_ch;
103 	int	sc_hpibno;	/* logical HPIB this slave it attached to */
104 	int	sc_slave;	/* HPIB slave address (0-6) */
105 	short	sc_flags;	/* see below */
106 	u_char	sc_lastdsj;	/* place for DSJ in mtreaddsj() */
107 	u_char	sc_lastecmd;	/* place for End Command in mtreaddsj() */
108 	short	sc_recvtimeo;	/* count of hpibsend timeouts to prevent hang */
109 	short	sc_statindex;	/* index for next sc_stat when MTF_STATTIMEO */
110 	struct	mt_stat sc_stat;/* status bytes last read from device */
111 	short	sc_density;	/* current density of tape (mtio.h format) */
112 	short	sc_type;	/* tape drive model (hardware IDs) */
113 	struct	hpibqueue sc_hq; /* HPIB device queue member */
114 	tpr_t	sc_ttyp;
115 	struct bufq_state *sc_tab;/* buf queue */
116 	int	sc_active;
117 };
118 
119 #ifdef DEBUG
120 int	mtdebug = 0;
121 #define	dlog	if (mtdebug) log
122 #else
123 #define	dlog	if (0) log
124 #endif
125 
126 #define	UNIT(x)		(minor(x) & 3)
127 
128 #define B_CMD		B_DEVPRIVATE	/* command buf instead of data */
129 #define	b_cmd		b_blkno		/* blkno holds cmd when B_CMD */
130 
131 static int	mtmatch(device_t, cfdata_t, void *);
132 static void	mtattach(device_t, device_t, void *);
133 
134 CFATTACH_DECL_NEW(mt, sizeof(struct mt_softc),
135     mtmatch, mtattach, NULL, NULL);
136 
137 static dev_type_open(mtopen);
138 static dev_type_close(mtclose);
139 static dev_type_read(mtread);
140 static dev_type_write(mtwrite);
141 static dev_type_ioctl(mtioctl);
142 static dev_type_strategy(mtstrategy);
143 
144 const struct bdevsw mt_bdevsw = {
145 	.d_open = mtopen,
146 	.d_close = mtclose,
147 	.d_strategy = mtstrategy,
148 	.d_ioctl = mtioctl,
149 	.d_dump = nodump,
150 	.d_psize = nosize,
151 	.d_discard = nodiscard,
152 	.d_flag = D_TAPE
153 };
154 
155 const struct cdevsw mt_cdevsw = {
156 	.d_open = mtopen,
157 	.d_close = mtclose,
158 	.d_read = mtread,
159 	.d_write = mtwrite,
160 	.d_ioctl = mtioctl,
161 	.d_stop = nostop,
162 	.d_tty = notty,
163 	.d_poll = nopoll,
164 	.d_mmap = nommap,
165 	.d_kqfilter = nokqfilter,
166 	.d_discard = nodiscard,
167 	.d_flag = D_TAPE
168 };
169 
170 static int	mtident(struct mt_softc *, struct hpibbus_attach_args *);
171 static void	mtustart(struct mt_softc *);
172 static int	mtreaddsj(struct mt_softc *, int);
173 static int	mtcommand(dev_t, int, int);
174 static void	spl_mtintr(void *);
175 static void	spl_mtstart(void *);
176 
177 static void	mtstart(void *);
178 static void	mtgo(void *);
179 static void	mtintr(void *);
180 
181 static int
182 mtmatch(device_t parent, cfdata_t cf, void *aux)
183 {
184 	struct hpibbus_attach_args *ha = aux;
185 
186 	return mtident(NULL, ha);
187 }
188 
189 static void
190 mtattach(device_t parent, device_t self, void *aux)
191 {
192 	struct mt_softc *sc = device_private(self);
193 	struct hpibbus_attach_args *ha = aux;
194 	int hpibno, slave;
195 
196 	sc->sc_dev = self;
197 	if (mtident(sc, ha) == 0) {
198 		aprint_error(": impossible!\n");
199 		return;
200 	}
201 
202 	hpibno = device_unit(parent);
203 	slave = ha->ha_slave;
204 
205 	bufq_alloc(&sc->sc_tab, "fcfs", 0);
206 	callout_init(&sc->sc_start_ch, 0);
207 	callout_init(&sc->sc_intr_ch, 0);
208 
209 	sc->sc_hpibno = hpibno;
210 	sc->sc_slave = slave;
211 	sc->sc_flags = MTF_EXISTS;
212 
213 	/* Initialize hpib job queue entry. */
214 	sc->sc_hq.hq_softc = sc;
215 	sc->sc_hq.hq_slave = sc->sc_slave;
216 	sc->sc_hq.hq_start = mtstart;
217 	sc->sc_hq.hq_go = mtgo;
218 	sc->sc_hq.hq_intr = mtintr;
219 }
220 
221 static int
222 mtident(struct mt_softc *sc, struct hpibbus_attach_args *ha)
223 {
224 	int i;
225 
226 	for (i = 0; i < nmtinfo; i++) {
227 		if (ha->ha_id == mtinfo[i].hwid &&
228 		    ha->ha_punit == 0) {
229 			if (sc != NULL) {
230 				sc->sc_type = mtinfo[i].hwid;
231 				aprint_normal(": %s tape\n", mtinfo[i].desc);
232 			}
233 			return 1;
234 		}
235 	}
236 	return 0;
237 }
238 
239 /*
240  * Perform a read of "Device Status Jump" register and update the
241  * status if necessary.  If status is read, the given "ecmd" is also
242  * performed, unless "ecmd" is zero.  Returns DSJ value, -1 on failure
243  * and -2 on "temporary" failure.
244  */
245 static int
246 mtreaddsj(struct mt_softc *sc, int ecmd)
247 {
248 	int retval;
249 
250 	if (sc->sc_flags & MTF_STATTIMEO)
251 		goto getstats;
252 	retval = hpibrecv(sc->sc_hpibno,
253 	    (sc->sc_flags & MTF_DSJTIMEO) ? -1 : sc->sc_slave,
254 	    MTT_DSJ, &(sc->sc_lastdsj), 1);
255 	sc->sc_flags &= ~MTF_DSJTIMEO;
256 	if (retval != 1) {
257 		dlog(LOG_DEBUG, "%s can't hpibrecv DSJ",
258 		    device_xname(sc->sc_dev));
259 		if (sc->sc_recvtimeo == 0)
260 			sc->sc_recvtimeo = hz;
261 		if (--sc->sc_recvtimeo == 0)
262 			return -1;
263 		if (retval == 0)
264 			sc->sc_flags |= MTF_DSJTIMEO;
265 		return -2;
266 	}
267 	sc->sc_recvtimeo = 0;
268 	sc->sc_statindex = 0;
269 	dlog(LOG_DEBUG, "%s readdsj: 0x%x", device_xname(sc->sc_dev),
270 	    sc->sc_lastdsj);
271 	sc->sc_lastecmd = ecmd;
272 	switch (sc->sc_lastdsj) {
273 	    case 0:
274 		if (ecmd & MTE_DSJ_FORCE)
275 			break;
276 		return 0;
277 
278 	    case 2:
279 		sc->sc_lastecmd = MTE_COMPLETE;
280 	    case 1:
281 		break;
282 
283 	    default:
284 		log(LOG_ERR, "%s readdsj: DSJ 0x%x\n", device_xname(sc->sc_dev),
285 		    sc->sc_lastdsj);
286 		return -1;
287 	}
288  getstats:
289 	retval = hpibrecv(sc->sc_hpibno,
290 	    (sc->sc_flags & MTF_STATCONT) ? -1 : sc->sc_slave,
291 	    MTT_STAT, ((char *)&(sc->sc_stat)) + sc->sc_statindex,
292 	    sizeof(sc->sc_stat) - sc->sc_statindex);
293 	sc->sc_flags &= ~(MTF_STATTIMEO | MTF_STATCONT);
294 	if (retval != sizeof(sc->sc_stat) - sc->sc_statindex) {
295 		if (sc->sc_recvtimeo == 0)
296 			sc->sc_recvtimeo = hz;
297 		if (--sc->sc_recvtimeo != 0) {
298 			if (retval >= 0) {
299 				sc->sc_statindex += retval;
300 				sc->sc_flags |= MTF_STATCONT;
301 			}
302 			sc->sc_flags |= MTF_STATTIMEO;
303 			return -2;
304 		}
305 		log(LOG_ERR, "%s readdsj: can't read status",
306 		    device_xname(sc->sc_dev));
307 		return -1;
308 	}
309 	sc->sc_recvtimeo = 0;
310 	sc->sc_statindex = 0;
311 	dlog(LOG_DEBUG, "%s readdsj: status is %x %x %x %x %x %x",
312 	    device_xname(sc->sc_dev),
313 	    sc->sc_stat1, sc->sc_stat2, sc->sc_stat3,
314 	    sc->sc_stat4, sc->sc_stat5, sc->sc_stat6);
315 	if (sc->sc_lastecmd)
316 		(void) hpibsend(sc->sc_hpibno, sc->sc_slave,
317 		    MTL_ECMD, &(sc->sc_lastecmd), 1);
318 	return (int)sc->sc_lastdsj;
319 }
320 
321 static int
322 mtopen(dev_t dev, int flag, int mode, struct lwp *l)
323 {
324 	struct mt_softc *sc;
325 	int req_den;
326 	int error;
327 
328 	sc = device_lookup_private(&mt_cd, UNIT(dev));
329 	if (sc == NULL)
330 		return ENXIO;
331 
332 	if ((sc->sc_flags & MTF_EXISTS) == 0)
333 		return ENXIO;
334 
335 	dlog(LOG_DEBUG, "%s open: flags 0x%x", device_xname(sc->sc_dev),
336 	    sc->sc_flags);
337 	if (sc->sc_flags & MTF_OPEN)
338 		return EBUSY;
339 	sc->sc_flags |= MTF_OPEN;
340 	sc->sc_ttyp = tprintf_open(l->l_proc);
341 	if ((sc->sc_flags & MTF_ALIVE) == 0) {
342 		error = mtcommand(dev, MTRESET, 0);
343 		if (error != 0 || (sc->sc_flags & MTF_ALIVE) == 0)
344 			goto errout;
345 		if ((sc->sc_stat1 & (SR1_BOT | SR1_ONLINE)) == SR1_ONLINE)
346 			(void) mtcommand(dev, MTREW, 0);
347 	}
348 	for (;;) {
349 		if ((error = mtcommand(dev, MTNOP, 0)) != 0)
350 			goto errout;
351 		if (!(sc->sc_flags & MTF_REW))
352 			break;
353 		error = kpause("mt", true, hz, NULL);
354 		if (error != 0 && error != EWOULDBLOCK) {
355 			error = EINTR;
356 			goto errout;
357 		}
358 	}
359 	if ((flag & FWRITE) && (sc->sc_stat1 & SR1_RO)) {
360 		error = EROFS;
361 		goto errout;
362 	}
363 	if (!(sc->sc_stat1 & SR1_ONLINE)) {
364 		uprintf("%s: not online\n", device_xname(sc->sc_dev));
365 		error = EIO;
366 		goto errout;
367 	}
368 	/*
369 	 * Select density:
370 	 *  - find out what density the drive is set to
371 	 *	(i.e. the density of the current tape)
372 	 *  - if we are going to write
373 	 *    - if we're not at the beginning of the tape
374 	 *      - complain if we want to change densities
375 	 *    - otherwise, select the mtcommand to set the density
376 	 *
377 	 * If the drive doesn't support it then don't change the recorded
378 	 * density.
379 	 *
380 	 * The original MOREbsd code had these additional conditions
381 	 * for the mid-tape change
382 	 *
383 	 *	req_den != T_BADBPI &&
384 	 *	sc->sc_density != T_6250BPI
385 	 *
386 	 * which suggests that it would be possible to write multiple
387 	 * densities if req_den == T_BAD_BPI or the current tape
388 	 * density was 6250.  Testing of our 7980 suggests that the
389 	 * device cannot change densities mid-tape.
390 	 *
391 	 * ajv@comp.vuw.ac.nz
392 	 */
393 	sc->sc_density = (sc->sc_stat2 & SR2_6250) ? T_6250BPI : (
394 			 (sc->sc_stat3 & SR3_1600) ? T_1600BPI : (
395 			 (sc->sc_stat3 & SR3_800) ? T_800BPI : -1));
396 	req_den = (dev & T_DENSEL);
397 
398 	if (flag & FWRITE) {
399 		if (!(sc->sc_stat1 & SR1_BOT)) {
400 			if (sc->sc_density != req_den) {
401 				uprintf("%s: can't change density mid-tape\n",
402 				    device_xname(sc->sc_dev));
403 				error = EIO;
404 				goto errout;
405 			}
406 		}
407 		else {
408 			int mtset_density =
409 			    (req_den == T_800BPI  ? MTSET800BPI : (
410 			     req_den == T_1600BPI ? MTSET1600BPI : (
411 			     req_den == T_6250BPI ? MTSET6250BPI : (
412 			     sc->sc_type == MT7980ID
413 						  ? MTSET6250DC
414 						  : MTSET6250BPI))));
415 			if (mtcommand(dev, mtset_density, 0) == 0)
416 				sc->sc_density = req_den;
417 		}
418 	}
419 	return 0;
420 errout:
421 	sc->sc_flags &= ~MTF_OPEN;
422 	return error;
423 }
424 
425 static int
426 mtclose(dev_t dev, int flag, int fmt, struct lwp *l)
427 {
428 	struct mt_softc *sc = device_lookup_private(&mt_cd,UNIT(dev));
429 
430 	if (sc->sc_flags & MTF_WRT) {
431 		(void) mtcommand(dev, MTWEOF, 2);
432 		(void) mtcommand(dev, MTBSF, 0);
433 	}
434 	if ((minor(dev) & T_NOREWIND) == 0)
435 		(void) mtcommand(dev, MTREW, 0);
436 	sc->sc_flags &= ~MTF_OPEN;
437 	tprintf_close(sc->sc_ttyp);
438 	return 0;
439 }
440 
441 static int
442 mtcommand(dev_t dev, int cmd, int cnt)
443 {
444 	int error = 0;
445 	buf_t *bp;
446 
447 	bp = getiobuf(NULL, true);
448 	bp->b_cmd = cmd;
449 	bp->b_dev = dev;
450 	do {
451 		bp->b_cflags = BC_BUSY;
452 		bp->b_flags = B_CMD;
453 		bp->b_oflags = 0;
454 		mtstrategy(bp);
455 		biowait(bp);
456 		if (bp->b_error != 0) {
457 			error = bp->b_error;
458 			break;
459 		}
460 	} while (--cnt > 0);
461 	putiobuf(bp);
462 
463 	return error;
464 }
465 
466 /*
467  * Only thing to check here is for legal record lengths (writes only).
468  */
469 static void
470 mtstrategy(struct buf *bp)
471 {
472 	struct mt_softc *sc;
473 	int s;
474 
475 	sc = device_lookup_private(&mt_cd,UNIT(bp->b_dev));
476 	dlog(LOG_DEBUG, "%s strategy", device_xname(sc->sc_dev));
477 	if ((bp->b_flags & (B_CMD | B_READ)) == 0) {
478 #define WRITE_BITS_IGNORED	8
479 #if 0
480 		if (bp->b_bcount & ((1 << WRITE_BITS_IGNORED) - 1)) {
481 			tprintf(sc->sc_ttyp,
482 			    "%s: write record must be multiple of %d\n",
483 			    device_xname(sc->sc_dev), 1 << WRITE_BITS_IGNORED);
484 			goto error;
485 		}
486 #endif
487 		s = 16 * 1024;
488 		if (sc->sc_stat2 & SR2_LONGREC) {
489 			switch (sc->sc_density) {
490 			    case T_1600BPI:
491 				s = 32 * 1024;
492 				break;
493 
494 			    case T_6250BPI:
495 			    case T_BADBPI:
496 				s = 60 * 1024;
497 				break;
498 			}
499 		}
500 		if (bp->b_bcount > s) {
501 			tprintf(sc->sc_ttyp,
502 			    "%s: write record (%d) too big: limit (%d)\n",
503 			    device_xname(sc->sc_dev), bp->b_bcount, s);
504 #if 0 /* XXX see above */
505 	    error:
506 #endif
507 			bp->b_error = EIO;
508 			biodone(bp);
509 			return;
510 		}
511 	}
512 	s = splbio();
513 	bufq_put(sc->sc_tab, bp);
514 	if (sc->sc_active == 0) {
515 		sc->sc_active = 1;
516 		mtustart(sc);
517 	}
518 	splx(s);
519 }
520 
521 static void
522 mtustart(struct mt_softc *sc)
523 {
524 
525 	dlog(LOG_DEBUG, "%s ustart", device_xname(sc->sc_dev));
526 	if (hpibreq(device_parent(sc->sc_dev), &sc->sc_hq))
527 		mtstart(sc);
528 }
529 
530 static void
531 spl_mtintr(void *arg)
532 {
533 	struct mt_softc *sc = arg;
534 	int s = splbio();
535 
536 	hpibppclear(sc->sc_hpibno);
537 	mtintr(sc);
538 	splx(s);
539 }
540 
541 static void
542 spl_mtstart(void *arg)
543 {
544 	int s = splbio();
545 
546 	mtstart(arg);
547 	splx(s);
548 }
549 
550 static void
551 mtstart(void *arg)
552 {
553 	struct mt_softc *sc = arg;
554 	struct buf *bp;
555 	short	cmdcount = 1;
556 	u_char	cmdbuf[2];
557 
558 	dlog(LOG_DEBUG, "%s start", device_xname(sc->sc_dev));
559 	sc->sc_flags &= ~MTF_WRT;
560 	bp = bufq_peek(sc->sc_tab);
561 	if ((sc->sc_flags & MTF_ALIVE) == 0 &&
562 	    ((bp->b_flags & B_CMD) == 0 || bp->b_cmd != MTRESET))
563 		goto fatalerror;
564 
565 	if (sc->sc_flags & MTF_REW) {
566 		if (!hpibpptest(sc->sc_hpibno, sc->sc_slave))
567 			goto stillrew;
568 		switch (mtreaddsj(sc, MTE_DSJ_FORCE|MTE_COMPLETE|MTE_IDLE)) {
569 		    case 0:
570 		    case 1:
571 		stillrew:
572 			if ((sc->sc_stat1 & SR1_BOT) ||
573 			    !(sc->sc_stat1 & SR1_ONLINE)) {
574 				sc->sc_flags &= ~MTF_REW;
575 				break;
576 			}
577 		    case -2:
578 			/*
579 			 * -2 means "timeout" reading DSJ, which is probably
580 			 * temporary.  This is considered OK when doing a NOP,
581 			 * but not otherwise.
582 			 */
583 			if (sc->sc_flags & (MTF_DSJTIMEO | MTF_STATTIMEO)) {
584 				callout_reset(&sc->sc_start_ch, hz >> 5,
585 				    spl_mtstart, sc);
586 				return;
587 			}
588 		    case 2:
589 			if (bp->b_cmd != MTNOP || !(bp->b_flags & B_CMD)) {
590 				bp->b_error = EBUSY;
591 				goto done;
592 			}
593 			goto done;
594 
595 		    default:
596 			goto fatalerror;
597 		}
598 	}
599 	if (bp->b_flags & B_CMD) {
600 		if (sc->sc_flags & MTF_PASTEOT) {
601 			switch(bp->b_cmd) {
602 			    case MTFSF:
603 			    case MTWEOF:
604 			    case MTFSR:
605 				bp->b_error = ENOSPC;
606 				goto done;
607 
608 			    case MTBSF:
609 			    case MTOFFL:
610 			    case MTBSR:
611 			    case MTREW:
612 				sc->sc_flags &= ~(MTF_PASTEOT | MTF_ATEOT);
613 				break;
614 			}
615 		}
616 		switch(bp->b_cmd) {
617 		    case MTFSF:
618 			if (sc->sc_flags & MTF_HITEOF)
619 				goto done;
620 			cmdbuf[0] = MTTC_FSF;
621 			break;
622 
623 		    case MTBSF:
624 			if (sc->sc_flags & MTF_HITBOF)
625 				goto done;
626 			cmdbuf[0] = MTTC_BSF;
627 			break;
628 
629 		    case MTOFFL:
630 			sc->sc_flags |= MTF_REW;
631 			cmdbuf[0] = MTTC_REWOFF;
632 			break;
633 
634 		    case MTWEOF:
635 			cmdbuf[0] = MTTC_WFM;
636 			break;
637 
638 		    case MTBSR:
639 			cmdbuf[0] = MTTC_BSR;
640 			break;
641 
642 		    case MTFSR:
643 			cmdbuf[0] = MTTC_FSR;
644 			break;
645 
646 		    case MTREW:
647 			sc->sc_flags |= MTF_REW;
648 			cmdbuf[0] = MTTC_REW;
649 			break;
650 
651 		    case MTNOP:
652 			/*
653 			 * NOP is supposed to set status bits.
654 			 * Force readdsj to do it.
655 			 */
656 			switch (mtreaddsj(sc,
657 			  MTE_DSJ_FORCE | MTE_COMPLETE | MTE_IDLE)) {
658 			    default:
659 				goto done;
660 
661 			    case -1:
662 				/*
663 				 * If this fails, perform a device clear
664 				 * to fix any protocol problems and (most
665 				 * likely) get the status.
666 				 */
667 				bp->b_cmd = MTRESET;
668 				break;
669 
670 			    case -2:
671 				callout_reset(&sc->sc_start_ch, hz >> 5,
672 				    spl_mtstart, sc);
673 				return;
674 			}
675 
676 		    case MTRESET:
677 			/*
678 			 * 1) selected device clear (send with "-2" secondary)
679 			 * 2) set timeout, then wait for "service request"
680 			 * 3) interrupt will read DSJ (and END COMPLETE-IDLE)
681 			 */
682 			if (hpibsend(sc->sc_hpibno, sc->sc_slave, -2, NULL, 0)){
683 				log(LOG_ERR, "%s can't reset",
684 				    device_xname(sc->sc_dev));
685 				goto fatalerror;
686 			}
687 			callout_reset(&sc->sc_intr_ch, 4 * hz, spl_mtintr, sc);
688 			hpibawait(sc->sc_hpibno);
689 			return;
690 
691 		    case MTSET800BPI:
692 			cmdbuf[0] = MTTC_800;
693 			break;
694 
695 		    case MTSET1600BPI:
696 			cmdbuf[0] = MTTC_1600;
697 			break;
698 
699 		    case MTSET6250BPI:
700 			cmdbuf[0] = MTTC_6250;
701 			break;
702 
703 		    case MTSET6250DC:
704 			cmdbuf[0] = MTTC_DC6250;
705 			break;
706 		}
707 	} else {
708 		if (sc->sc_flags & MTF_PASTEOT) {
709 			bp->b_error = ENOSPC;
710 			goto done;
711 		}
712 		if (bp->b_flags & B_READ) {
713 			sc->sc_flags |= MTF_IO;
714 			cmdbuf[0] = MTTC_READ;
715 		} else {
716 			sc->sc_flags |= MTF_WRT | MTF_IO;
717 			cmdbuf[0] = MTTC_WRITE;
718 			cmdbuf[1] = (bp->b_bcount + ((1 << WRITE_BITS_IGNORED) - 1)) >> WRITE_BITS_IGNORED;
719 			cmdcount = 2;
720 		}
721 	}
722 	if (hpibsend(sc->sc_hpibno, sc->sc_slave, MTL_TCMD, cmdbuf, cmdcount)
723 	    == cmdcount) {
724 		if (sc->sc_flags & MTF_REW)
725 			goto done;
726 		hpibawait(sc->sc_hpibno);
727 		return;
728 	}
729 fatalerror:
730 	/*
731 	 * If anything fails, the drive is probably hosed, so mark it not
732 	 * "ALIVE" (but it EXISTS and is OPEN or we wouldn't be here, and
733 	 * if, last we heard, it was REWinding, remember that).
734 	 */
735 	sc->sc_flags &= MTF_EXISTS | MTF_OPEN | MTF_REW;
736 	bp->b_error = EIO;
737 done:
738 	sc->sc_flags &= ~(MTF_HITEOF | MTF_HITBOF);
739 	(void)bufq_get(sc->sc_tab);
740 	biodone(bp);
741 	hpibfree(device_parent(sc->sc_dev), &sc->sc_hq);
742 	if ((bp = bufq_peek(sc->sc_tab)) == NULL)
743 		sc->sc_active = 0;
744 	else
745 		mtustart(sc);
746 }
747 
748 /*
749  * The Utah code had a bug which meant that the driver was unable to read.
750  * "rw" was initialized to bp->b_flags & B_READ before "bp" was initialized.
751  *   -- ajv@comp.vuw.ac.nz
752  */
753 static void
754 mtgo(void *arg)
755 {
756 	struct mt_softc *sc = arg;
757 	struct buf *bp;
758 	int rw;
759 
760 	dlog(LOG_DEBUG, "%s go", device_xname(sc->sc_dev));
761 	bp = bufq_peek(sc->sc_tab);
762 	rw = bp->b_flags & B_READ;
763 	hpibgo(sc->sc_hpibno, sc->sc_slave, rw ? MTT_READ : MTL_WRITE,
764 	    bp->b_data, bp->b_bcount, rw, rw != 0);
765 }
766 
767 static void
768 mtintr(void *arg)
769 {
770 	struct mt_softc *sc = arg;
771 	struct buf *bp;
772 	int i;
773 	u_char cmdbuf[4];
774 
775 	bp = bufq_peek(sc->sc_tab);
776 	if (bp == NULL) {
777 		log(LOG_ERR, "%s intr: bp == NULL", device_xname(sc->sc_dev));
778 		return;
779 	}
780 
781 	dlog(LOG_DEBUG, "%s intr", device_xname(sc->sc_dev));
782 
783 	/*
784 	 * Some operation completed.  Read status bytes and report errors.
785 	 * Clear EOF flags here `cause they're set once on specific conditions
786 	 * below when a command succeeds.
787 	 * A DSJ of 2 always means keep waiting.  If the command was READ
788 	 * (and we're in data DMA phase) stop data transfer first.
789 	 */
790 	sc->sc_flags &= ~(MTF_HITEOF | MTF_HITBOF);
791 	if ((bp->b_flags & (B_CMD|B_READ)) == B_READ &&
792 	    !(sc->sc_flags & (MTF_IO | MTF_STATTIMEO | MTF_DSJTIMEO))){
793 		cmdbuf[0] = MTE_STOP;
794 		(void) hpibsend(sc->sc_hpibno, sc->sc_slave, MTL_ECMD,cmdbuf,1);
795 	}
796 	switch (mtreaddsj(sc, 0)) {
797 	    case 0:
798 		break;
799 
800 	    case 1:
801 		/*
802 		 * If we're in the middle of a READ/WRITE and have yet to
803 		 * start the data transfer, a DSJ of one should terminate it.
804 		 */
805 		sc->sc_flags &= ~MTF_IO;
806 		break;
807 
808 	    case 2:
809 		(void) hpibawait(sc->sc_hpibno);
810 		return;
811 
812 	    case -2:
813 		/*
814 		 * -2 means that the drive failed to respond quickly enough
815 		 * to the request for DSJ.  It's probably just "busy" figuring
816 		 * it out and will know in a little bit...
817 		 */
818 		callout_reset(&sc->sc_intr_ch, hz >> 5, spl_mtintr, sc);
819 		return;
820 
821 	    default:
822 		log(LOG_ERR, "%s intr: can't get drive stat",
823 		    device_xname(sc->sc_dev));
824 		goto error;
825 	}
826 	if (sc->sc_stat1 & (SR1_ERR | SR1_REJECT)) {
827 		i = sc->sc_stat4 & SR4_ERCLMASK;
828 		log(LOG_ERR, "%s: %s error, retry %d, SR2/3 %x/%x, code %d",
829 			device_xname(sc->sc_dev), i == SR4_DEVICE ? "device" :
830 			(i == SR4_PROTOCOL ? "protocol" :
831 			(i == SR4_SELFTEST ? "selftest" : "unknown")),
832 			sc->sc_stat4 & SR4_RETRYMASK, sc->sc_stat2,
833 			sc->sc_stat3, sc->sc_stat5);
834 
835 		if ((bp->b_flags & B_CMD) && bp->b_cmd == MTRESET)
836 			callout_stop(&sc->sc_intr_ch);
837 		if (sc->sc_stat3 & SR3_POWERUP)
838 			sc->sc_flags &= MTF_OPEN | MTF_EXISTS;
839 		goto error;
840 	}
841 	/*
842 	 * Report and clear any soft errors.
843 	 */
844 	if (sc->sc_stat1 & SR1_SOFTERR) {
845 		log(LOG_WARNING, "%s: soft error, retry %d\n",
846 		    device_xname(sc->sc_dev), sc->sc_stat4 & SR4_RETRYMASK);
847 		sc->sc_stat1 &= ~SR1_SOFTERR;
848 	}
849 	/*
850 	 * We've initiated a read or write, but haven't actually started to
851 	 * DMA the data yet.  At this point, the drive's ready.
852 	 */
853 	if (sc->sc_flags & MTF_IO) {
854 		sc->sc_flags &= ~MTF_IO;
855 		if (hpibustart(sc->sc_hpibno))
856 			mtgo(sc);
857 		return;
858 	}
859 	/*
860 	 * Check for End Of Tape - we're allowed to hit EOT and then write (or
861 	 * read) one more record.  If we get here and have not already hit EOT,
862 	 * return ENOSPC to inform the process that it's hit it.  If we get
863 	 * here and HAVE already hit EOT, don't allow any more operations that
864 	 * move the tape forward.
865 	 */
866 	if (sc->sc_stat1 & SR1_EOT) {
867 		if (sc->sc_flags & MTF_ATEOT)
868 			sc->sc_flags |= MTF_PASTEOT;
869 		else {
870 			bp->b_error = ENOSPC;
871 			sc->sc_flags |= MTF_ATEOT;
872 		}
873 	}
874 	/*
875 	 * If a motion command was being executed, check for Tape Marks.
876 	 * If we were doing data, make sure we got the right amount, and
877 	 * check for hitting tape marks on reads.
878 	 */
879 	if (bp->b_flags & B_CMD) {
880 		if (sc->sc_stat1 & SR1_EOF) {
881 			if (bp->b_cmd == MTFSR)
882 				sc->sc_flags |= MTF_HITEOF;
883 			if (bp->b_cmd == MTBSR)
884 				sc->sc_flags |= MTF_HITBOF;
885 		}
886 		if (bp->b_cmd == MTRESET) {
887 			callout_stop(&sc->sc_intr_ch);
888 			sc->sc_flags |= MTF_ALIVE;
889 		}
890 	} else {
891 		i = hpibrecv(sc->sc_hpibno, sc->sc_slave, MTT_BCNT, cmdbuf, 2);
892 		if (i != 2) {
893 			log(LOG_ERR, "%s intr: can't get xfer length\n",
894 			    device_xname(sc->sc_dev));
895 			goto error;
896 		}
897 		i = (int) *((u_short *) cmdbuf);
898 		if (i <= bp->b_bcount) {
899 			if (i == 0)
900 				sc->sc_flags |= MTF_HITEOF;
901 			bp->b_resid = bp->b_bcount - i;
902 			dlog(LOG_DEBUG, "%s intr: bcount %d, resid %d",
903 			    device_xname(sc->sc_dev), bp->b_bcount,
904 			    bp->b_resid);
905 		} else {
906 			tprintf(sc->sc_ttyp,
907 				"%s: record (%d) larger than wanted (%d)\n",
908 				device_xname(sc->sc_dev), i, bp->b_bcount);
909  error:
910 			sc->sc_flags &= ~MTF_IO;
911 			bp->b_error = EIO;
912 		}
913 	}
914 	/*
915 	 * The operation is completely done.
916 	 * Let the drive know with an END command.
917 	 */
918 	cmdbuf[0] = MTE_COMPLETE | MTE_IDLE;
919 	(void) hpibsend(sc->sc_hpibno, sc->sc_slave, MTL_ECMD, cmdbuf, 1);
920 	bp->b_flags &= ~B_CMD;
921 	(void)bufq_get(sc->sc_tab);
922 	biodone(bp);
923 	hpibfree(device_parent(sc->sc_dev), &sc->sc_hq);
924 	if (bufq_peek(sc->sc_tab) == NULL)
925 		sc->sc_active = 0;
926 	else
927 		mtustart(sc);
928 }
929 
930 static int
931 mtread(dev_t dev, struct uio *uio, int flags)
932 {
933 
934 	return physio(mtstrategy, NULL, dev, B_READ, minphys, uio);
935 }
936 
937 static int
938 mtwrite(dev_t dev, struct uio *uio, int flags)
939 {
940 
941 	return physio(mtstrategy, NULL, dev, B_WRITE, minphys, uio);
942 }
943 
944 static int
945 mtioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
946 {
947 	struct mtop *op;
948 	int cnt;
949 
950 	switch (cmd) {
951 	    case MTIOCTOP:
952 		op = (struct mtop *)data;
953 		switch(op->mt_op) {
954 		    case MTWEOF:
955 		    case MTFSF:
956 		    case MTBSR:
957 		    case MTBSF:
958 		    case MTFSR:
959 			cnt = op->mt_count;
960 			break;
961 
962 		    case MTOFFL:
963 		    case MTREW:
964 		    case MTNOP:
965 			cnt = 0;
966 			break;
967 
968 		    default:
969 			return EINVAL;
970 		}
971 		return mtcommand(dev, op->mt_op, cnt);
972 
973 	    case MTIOCGET:
974 		break;
975 
976 	    default:
977 		return EINVAL;
978 	}
979 	return 0;
980 }
981