xref: /netbsd-src/sys/arch/hp300/dev/mt.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /*	$NetBSD: mt.c,v 1.50 2009/12/05 22:34:43 pooka 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 1.50 2009/12/05 22:34:43 pooka 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 	mtopen, mtclose, mtstrategy, mtioctl, nodump, nosize, D_TAPE
146 };
147 
148 const struct cdevsw mt_cdevsw = {
149 	mtopen, mtclose, mtread, mtwrite, mtioctl,
150 	nostop, notty, nopoll, nommap, nokqfilter, D_TAPE
151 };
152 
153 static int	mtident(struct mt_softc *, struct hpibbus_attach_args *);
154 static void	mtustart(struct mt_softc *);
155 static int	mtreaddsj(struct mt_softc *, int);
156 static int	mtcommand(dev_t, int, int);
157 static void	spl_mtintr(void *);
158 static void	spl_mtstart(void *);
159 
160 static void	mtstart(void *);
161 static void	mtgo(void *);
162 static void	mtintr(void *);
163 
164 static int
165 mtmatch(device_t parent, cfdata_t cf, void *aux)
166 {
167 	struct hpibbus_attach_args *ha = aux;
168 
169 	return mtident(NULL, ha);
170 }
171 
172 static void
173 mtattach(device_t parent, device_t self, void *aux)
174 {
175 	struct mt_softc *sc = device_private(self);
176 	struct hpibbus_attach_args *ha = aux;
177 	int unit, hpibno, slave;
178 
179 	sc->sc_dev = self;
180 	if (mtident(sc, ha) == 0) {
181 		aprint_error(": impossible!\n");
182 		return;
183 	}
184 
185 	unit = device_unit(self);
186 	hpibno = device_unit(parent);
187 	slave = ha->ha_slave;
188 
189 	bufq_alloc(&sc->sc_tab, "fcfs", 0);
190 	callout_init(&sc->sc_start_ch, 0);
191 	callout_init(&sc->sc_intr_ch, 0);
192 
193 	sc->sc_hpibno = hpibno;
194 	sc->sc_slave = slave;
195 	sc->sc_flags = MTF_EXISTS;
196 
197 	/* Initialize hpib job queue entry. */
198 	sc->sc_hq.hq_softc = sc;
199 	sc->sc_hq.hq_slave = sc->sc_slave;
200 	sc->sc_hq.hq_start = mtstart;
201 	sc->sc_hq.hq_go = mtgo;
202 	sc->sc_hq.hq_intr = mtintr;
203 }
204 
205 static int
206 mtident(struct mt_softc *sc, struct hpibbus_attach_args *ha)
207 {
208 	int i;
209 
210 	for (i = 0; i < nmtinfo; i++) {
211 		if (ha->ha_id == mtinfo[i].hwid) {
212 			if (sc != NULL) {
213 				sc->sc_type = mtinfo[i].hwid;
214 				aprint_normal(": %s tape\n", mtinfo[i].desc);
215 			}
216 			return 1;
217 		}
218 	}
219 	return 0;
220 }
221 
222 /*
223  * Perform a read of "Device Status Jump" register and update the
224  * status if necessary.  If status is read, the given "ecmd" is also
225  * performed, unless "ecmd" is zero.  Returns DSJ value, -1 on failure
226  * and -2 on "temporary" failure.
227  */
228 static int
229 mtreaddsj(struct mt_softc *sc, int ecmd)
230 {
231 	int retval;
232 
233 	if (sc->sc_flags & MTF_STATTIMEO)
234 		goto getstats;
235 	retval = hpibrecv(sc->sc_hpibno,
236 	    (sc->sc_flags & MTF_DSJTIMEO) ? -1 : sc->sc_slave,
237 	    MTT_DSJ, &(sc->sc_lastdsj), 1);
238 	sc->sc_flags &= ~MTF_DSJTIMEO;
239 	if (retval != 1) {
240 		dlog(LOG_DEBUG, "%s can't hpibrecv DSJ",
241 		    device_xname(sc->sc_dev));
242 		if (sc->sc_recvtimeo == 0)
243 			sc->sc_recvtimeo = hz;
244 		if (--sc->sc_recvtimeo == 0)
245 			return -1;
246 		if (retval == 0)
247 			sc->sc_flags |= MTF_DSJTIMEO;
248 		return -2;
249 	}
250 	sc->sc_recvtimeo = 0;
251 	sc->sc_statindex = 0;
252 	dlog(LOG_DEBUG, "%s readdsj: 0x%x", device_xname(sc->sc_dev),
253 	    sc->sc_lastdsj);
254 	sc->sc_lastecmd = ecmd;
255 	switch (sc->sc_lastdsj) {
256 	    case 0:
257 		if (ecmd & MTE_DSJ_FORCE)
258 			break;
259 		return 0;
260 
261 	    case 2:
262 		sc->sc_lastecmd = MTE_COMPLETE;
263 	    case 1:
264 		break;
265 
266 	    default:
267 		log(LOG_ERR, "%s readdsj: DSJ 0x%x\n", device_xname(sc->sc_dev),
268 		    sc->sc_lastdsj);
269 		return -1;
270 	}
271  getstats:
272 	retval = hpibrecv(sc->sc_hpibno,
273 	    (sc->sc_flags & MTF_STATCONT) ? -1 : sc->sc_slave,
274 	    MTT_STAT, ((char *)&(sc->sc_stat)) + sc->sc_statindex,
275 	    sizeof(sc->sc_stat) - sc->sc_statindex);
276 	sc->sc_flags &= ~(MTF_STATTIMEO | MTF_STATCONT);
277 	if (retval != sizeof(sc->sc_stat) - sc->sc_statindex) {
278 		if (sc->sc_recvtimeo == 0)
279 			sc->sc_recvtimeo = hz;
280 		if (--sc->sc_recvtimeo != 0) {
281 			if (retval >= 0) {
282 				sc->sc_statindex += retval;
283 				sc->sc_flags |= MTF_STATCONT;
284 			}
285 			sc->sc_flags |= MTF_STATTIMEO;
286 			return -2;
287 		}
288 		log(LOG_ERR, "%s readdsj: can't read status",
289 		    device_xname(sc->sc_dev));
290 		return -1;
291 	}
292 	sc->sc_recvtimeo = 0;
293 	sc->sc_statindex = 0;
294 	dlog(LOG_DEBUG, "%s readdsj: status is %x %x %x %x %x %x",
295 	    device_xname(sc->sc_dev),
296 	    sc->sc_stat1, sc->sc_stat2, sc->sc_stat3,
297 	    sc->sc_stat4, sc->sc_stat5, sc->sc_stat6);
298 	if (sc->sc_lastecmd)
299 		(void) hpibsend(sc->sc_hpibno, sc->sc_slave,
300 		    MTL_ECMD, &(sc->sc_lastecmd), 1);
301 	return (int)sc->sc_lastdsj;
302 }
303 
304 static int
305 mtopen(dev_t dev, int flag, int mode, struct lwp *l)
306 {
307 	struct mt_softc *sc;
308 	int req_den;
309 	int error;
310 
311 	sc = device_lookup_private(&mt_cd, UNIT(dev));
312 	if (sc == NULL)
313 		return ENXIO;
314 
315 	if ((sc->sc_flags & MTF_EXISTS) == 0)
316 		return ENXIO;
317 
318 	dlog(LOG_DEBUG, "%s open: flags 0x%x", device_xname(sc->sc_dev),
319 	    sc->sc_flags);
320 	if (sc->sc_flags & MTF_OPEN)
321 		return EBUSY;
322 	sc->sc_flags |= MTF_OPEN;
323 	sc->sc_ttyp = tprintf_open(l->l_proc);
324 	if ((sc->sc_flags & MTF_ALIVE) == 0) {
325 		error = mtcommand(dev, MTRESET, 0);
326 		if (error != 0 || (sc->sc_flags & MTF_ALIVE) == 0)
327 			goto errout;
328 		if ((sc->sc_stat1 & (SR1_BOT | SR1_ONLINE)) == SR1_ONLINE)
329 			(void) mtcommand(dev, MTREW, 0);
330 	}
331 	for (;;) {
332 		if ((error = mtcommand(dev, MTNOP, 0)) != 0)
333 			goto errout;
334 		if (!(sc->sc_flags & MTF_REW))
335 			break;
336 		error = kpause("mt", true, hz, NULL);
337 		if (error != 0 && error != EWOULDBLOCK) {
338 			error = EINTR;
339 			goto errout;
340 		}
341 	}
342 	if ((flag & FWRITE) && (sc->sc_stat1 & SR1_RO)) {
343 		error = EROFS;
344 		goto errout;
345 	}
346 	if (!(sc->sc_stat1 & SR1_ONLINE)) {
347 		uprintf("%s: not online\n", device_xname(sc->sc_dev));
348 		error = EIO;
349 		goto errout;
350 	}
351 	/*
352 	 * Select density:
353 	 *  - find out what density the drive is set to
354 	 *	(i.e. the density of the current tape)
355 	 *  - if we are going to write
356 	 *    - if we're not at the beginning of the tape
357 	 *      - complain if we want to change densities
358 	 *    - otherwise, select the mtcommand to set the density
359 	 *
360 	 * If the drive doesn't support it then don't change the recorded
361 	 * density.
362 	 *
363 	 * The original MOREbsd code had these additional conditions
364 	 * for the mid-tape change
365 	 *
366 	 *	req_den != T_BADBPI &&
367 	 *	sc->sc_density != T_6250BPI
368 	 *
369 	 * which suggests that it would be possible to write multiple
370 	 * densities if req_den == T_BAD_BPI or the current tape
371 	 * density was 6250.  Testing of our 7980 suggests that the
372 	 * device cannot change densities mid-tape.
373 	 *
374 	 * ajv@comp.vuw.ac.nz
375 	 */
376 	sc->sc_density = (sc->sc_stat2 & SR2_6250) ? T_6250BPI : (
377 			 (sc->sc_stat3 & SR3_1600) ? T_1600BPI : (
378 			 (sc->sc_stat3 & SR3_800) ? T_800BPI : -1));
379 	req_den = (dev & T_DENSEL);
380 
381 	if (flag & FWRITE) {
382 		if (!(sc->sc_stat1 & SR1_BOT)) {
383 			if (sc->sc_density != req_den) {
384 				uprintf("%s: can't change density mid-tape\n",
385 				    device_xname(sc->sc_dev));
386 				error = EIO;
387 				goto errout;
388 			}
389 		}
390 		else {
391 			int mtset_density =
392 			    (req_den == T_800BPI  ? MTSET800BPI : (
393 			     req_den == T_1600BPI ? MTSET1600BPI : (
394 			     req_den == T_6250BPI ? MTSET6250BPI : (
395 			     sc->sc_type == MT7980ID
396 						  ? MTSET6250DC
397 						  : MTSET6250BPI))));
398 			if (mtcommand(dev, mtset_density, 0) == 0)
399 				sc->sc_density = req_den;
400 		}
401 	}
402 	return 0;
403 errout:
404 	sc->sc_flags &= ~MTF_OPEN;
405 	return error;
406 }
407 
408 static int
409 mtclose(dev_t dev, int flag, int fmt, struct lwp *l)
410 {
411 	struct mt_softc *sc = device_lookup_private(&mt_cd,UNIT(dev));
412 
413 	if (sc->sc_flags & MTF_WRT) {
414 		(void) mtcommand(dev, MTWEOF, 2);
415 		(void) mtcommand(dev, MTBSF, 0);
416 	}
417 	if ((minor(dev) & T_NOREWIND) == 0)
418 		(void) mtcommand(dev, MTREW, 0);
419 	sc->sc_flags &= ~MTF_OPEN;
420 	tprintf_close(sc->sc_ttyp);
421 	return 0;
422 }
423 
424 static int
425 mtcommand(dev_t dev, int cmd, int cnt)
426 {
427 	int error = 0;
428 	buf_t *bp;
429 
430 	bp = getiobuf(NULL, true);
431 	bp->b_cmd = cmd;
432 	bp->b_dev = dev;
433 	do {
434 		bp->b_cflags = BC_BUSY;
435 		bp->b_flags = B_CMD;
436 		bp->b_oflags = 0;
437 		mtstrategy(bp);
438 		biowait(bp);
439 		if (bp->b_error != 0) {
440 			error = bp->b_error;
441 			break;
442 		}
443 	} while (--cnt > 0);
444 	putiobuf(bp);
445 
446 	return error;
447 }
448 
449 /*
450  * Only thing to check here is for legal record lengths (writes only).
451  */
452 static void
453 mtstrategy(struct buf *bp)
454 {
455 	struct mt_softc *sc;
456 	int s;
457 
458 	sc = device_lookup_private(&mt_cd,UNIT(bp->b_dev));
459 	dlog(LOG_DEBUG, "%s strategy", device_xname(sc->sc_dev));
460 	if ((bp->b_flags & (B_CMD | B_READ)) == 0) {
461 #define WRITE_BITS_IGNORED	8
462 #if 0
463 		if (bp->b_bcount & ((1 << WRITE_BITS_IGNORED) - 1)) {
464 			tprintf(sc->sc_ttyp,
465 			    "%s: write record must be multiple of %d\n",
466 			    device_xname(sc->sc_dev), 1 << WRITE_BITS_IGNORED);
467 			goto error;
468 		}
469 #endif
470 		s = 16 * 1024;
471 		if (sc->sc_stat2 & SR2_LONGREC) {
472 			switch (sc->sc_density) {
473 			    case T_1600BPI:
474 				s = 32 * 1024;
475 				break;
476 
477 			    case T_6250BPI:
478 			    case T_BADBPI:
479 				s = 60 * 1024;
480 				break;
481 			}
482 		}
483 		if (bp->b_bcount > s) {
484 			tprintf(sc->sc_ttyp,
485 			    "%s: write record (%d) too big: limit (%d)\n",
486 			    device_xname(sc->sc_dev), bp->b_bcount, s);
487 #if 0 /* XXX see above */
488 	    error:
489 #endif
490 			bp->b_error = EIO;
491 			biodone(bp);
492 			return;
493 		}
494 	}
495 	s = splbio();
496 	bufq_put(sc->sc_tab, bp);
497 	if (sc->sc_active == 0) {
498 		sc->sc_active = 1;
499 		mtustart(sc);
500 	}
501 	splx(s);
502 }
503 
504 static void
505 mtustart(struct mt_softc *sc)
506 {
507 
508 	dlog(LOG_DEBUG, "%s ustart", device_xname(sc->sc_dev));
509 	if (hpibreq(device_parent(sc->sc_dev), &sc->sc_hq))
510 		mtstart(sc);
511 }
512 
513 static void
514 spl_mtintr(void *arg)
515 {
516 	struct mt_softc *sc = arg;
517 	int s = splbio();
518 
519 	hpibppclear(sc->sc_hpibno);
520 	mtintr(sc);
521 	splx(s);
522 }
523 
524 static void
525 spl_mtstart(void *arg)
526 {
527 	int s = splbio();
528 
529 	mtstart(arg);
530 	splx(s);
531 }
532 
533 static void
534 mtstart(void *arg)
535 {
536 	struct mt_softc *sc = arg;
537 	struct buf *bp;
538 	short	cmdcount = 1;
539 	u_char	cmdbuf[2];
540 
541 	dlog(LOG_DEBUG, "%s start", device_xname(sc->sc_dev));
542 	sc->sc_flags &= ~MTF_WRT;
543 	bp = bufq_peek(sc->sc_tab);
544 	if ((sc->sc_flags & MTF_ALIVE) == 0 &&
545 	    ((bp->b_flags & B_CMD) == 0 || bp->b_cmd != MTRESET))
546 		goto fatalerror;
547 
548 	if (sc->sc_flags & MTF_REW) {
549 		if (!hpibpptest(sc->sc_hpibno, sc->sc_slave))
550 			goto stillrew;
551 		switch (mtreaddsj(sc, MTE_DSJ_FORCE|MTE_COMPLETE|MTE_IDLE)) {
552 		    case 0:
553 		    case 1:
554 		stillrew:
555 			if ((sc->sc_stat1 & SR1_BOT) ||
556 			    !(sc->sc_stat1 & SR1_ONLINE)) {
557 				sc->sc_flags &= ~MTF_REW;
558 				break;
559 			}
560 		    case -2:
561 			/*
562 			 * -2 means "timeout" reading DSJ, which is probably
563 			 * temporary.  This is considered OK when doing a NOP,
564 			 * but not otherwise.
565 			 */
566 			if (sc->sc_flags & (MTF_DSJTIMEO | MTF_STATTIMEO)) {
567 				callout_reset(&sc->sc_start_ch, hz >> 5,
568 				    spl_mtstart, sc);
569 				return;
570 			}
571 		    case 2:
572 			if (bp->b_cmd != MTNOP || !(bp->b_flags & B_CMD)) {
573 				bp->b_error = EBUSY;
574 				goto done;
575 			}
576 			goto done;
577 
578 		    default:
579 			goto fatalerror;
580 		}
581 	}
582 	if (bp->b_flags & B_CMD) {
583 		if (sc->sc_flags & MTF_PASTEOT) {
584 			switch(bp->b_cmd) {
585 			    case MTFSF:
586 			    case MTWEOF:
587 			    case MTFSR:
588 				bp->b_error = ENOSPC;
589 				goto done;
590 
591 			    case MTBSF:
592 			    case MTOFFL:
593 			    case MTBSR:
594 			    case MTREW:
595 				sc->sc_flags &= ~(MTF_PASTEOT | MTF_ATEOT);
596 				break;
597 			}
598 		}
599 		switch(bp->b_cmd) {
600 		    case MTFSF:
601 			if (sc->sc_flags & MTF_HITEOF)
602 				goto done;
603 			cmdbuf[0] = MTTC_FSF;
604 			break;
605 
606 		    case MTBSF:
607 			if (sc->sc_flags & MTF_HITBOF)
608 				goto done;
609 			cmdbuf[0] = MTTC_BSF;
610 			break;
611 
612 		    case MTOFFL:
613 			sc->sc_flags |= MTF_REW;
614 			cmdbuf[0] = MTTC_REWOFF;
615 			break;
616 
617 		    case MTWEOF:
618 			cmdbuf[0] = MTTC_WFM;
619 			break;
620 
621 		    case MTBSR:
622 			cmdbuf[0] = MTTC_BSR;
623 			break;
624 
625 		    case MTFSR:
626 			cmdbuf[0] = MTTC_FSR;
627 			break;
628 
629 		    case MTREW:
630 			sc->sc_flags |= MTF_REW;
631 			cmdbuf[0] = MTTC_REW;
632 			break;
633 
634 		    case MTNOP:
635 			/*
636 			 * NOP is supposed to set status bits.
637 			 * Force readdsj to do it.
638 			 */
639 			switch (mtreaddsj(sc,
640 			  MTE_DSJ_FORCE | MTE_COMPLETE | MTE_IDLE)) {
641 			    default:
642 				goto done;
643 
644 			    case -1:
645 				/*
646 				 * If this fails, perform a device clear
647 				 * to fix any protocol problems and (most
648 				 * likely) get the status.
649 				 */
650 				bp->b_cmd = MTRESET;
651 				break;
652 
653 			    case -2:
654 				callout_reset(&sc->sc_start_ch, hz >> 5,
655 				    spl_mtstart, sc);
656 				return;
657 			}
658 
659 		    case MTRESET:
660 			/*
661 			 * 1) selected device clear (send with "-2" secondary)
662 			 * 2) set timeout, then wait for "service request"
663 			 * 3) interrupt will read DSJ (and END COMPLETE-IDLE)
664 			 */
665 			if (hpibsend(sc->sc_hpibno, sc->sc_slave, -2, NULL, 0)){
666 				log(LOG_ERR, "%s can't reset",
667 				    device_xname(sc->sc_dev));
668 				goto fatalerror;
669 			}
670 			callout_reset(&sc->sc_intr_ch, 4 * hz, spl_mtintr, sc);
671 			hpibawait(sc->sc_hpibno);
672 			return;
673 
674 		    case MTSET800BPI:
675 			cmdbuf[0] = MTTC_800;
676 			break;
677 
678 		    case MTSET1600BPI:
679 			cmdbuf[0] = MTTC_1600;
680 			break;
681 
682 		    case MTSET6250BPI:
683 			cmdbuf[0] = MTTC_6250;
684 			break;
685 
686 		    case MTSET6250DC:
687 			cmdbuf[0] = MTTC_DC6250;
688 			break;
689 		}
690 	} else {
691 		if (sc->sc_flags & MTF_PASTEOT) {
692 			bp->b_error = ENOSPC;
693 			goto done;
694 		}
695 		if (bp->b_flags & B_READ) {
696 			sc->sc_flags |= MTF_IO;
697 			cmdbuf[0] = MTTC_READ;
698 		} else {
699 			sc->sc_flags |= MTF_WRT | MTF_IO;
700 			cmdbuf[0] = MTTC_WRITE;
701 			cmdbuf[1] = (bp->b_bcount + ((1 << WRITE_BITS_IGNORED) - 1)) >> WRITE_BITS_IGNORED;
702 			cmdcount = 2;
703 		}
704 	}
705 	if (hpibsend(sc->sc_hpibno, sc->sc_slave, MTL_TCMD, cmdbuf, cmdcount)
706 	    == cmdcount) {
707 		if (sc->sc_flags & MTF_REW)
708 			goto done;
709 		hpibawait(sc->sc_hpibno);
710 		return;
711 	}
712 fatalerror:
713 	/*
714 	 * If anything fails, the drive is probably hosed, so mark it not
715 	 * "ALIVE" (but it EXISTS and is OPEN or we wouldn't be here, and
716 	 * if, last we heard, it was REWinding, remember that).
717 	 */
718 	sc->sc_flags &= MTF_EXISTS | MTF_OPEN | MTF_REW;
719 	bp->b_error = EIO;
720 done:
721 	sc->sc_flags &= ~(MTF_HITEOF | MTF_HITBOF);
722 	(void)bufq_get(sc->sc_tab);
723 	biodone(bp);
724 	hpibfree(device_parent(sc->sc_dev), &sc->sc_hq);
725 	if ((bp = bufq_peek(sc->sc_tab)) == NULL)
726 		sc->sc_active = 0;
727 	else
728 		mtustart(sc);
729 }
730 
731 /*
732  * The Utah code had a bug which meant that the driver was unable to read.
733  * "rw" was initialized to bp->b_flags & B_READ before "bp" was initialized.
734  *   -- ajv@comp.vuw.ac.nz
735  */
736 static void
737 mtgo(void *arg)
738 {
739 	struct mt_softc *sc = arg;
740 	struct buf *bp;
741 	int rw;
742 
743 	dlog(LOG_DEBUG, "%s go", device_xname(sc->sc_dev));
744 	bp = bufq_peek(sc->sc_tab);
745 	rw = bp->b_flags & B_READ;
746 	hpibgo(sc->sc_hpibno, sc->sc_slave, rw ? MTT_READ : MTL_WRITE,
747 	    bp->b_data, bp->b_bcount, rw, rw != 0);
748 }
749 
750 static void
751 mtintr(void *arg)
752 {
753 	struct mt_softc *sc = arg;
754 	struct buf *bp;
755 	int i;
756 	u_char cmdbuf[4];
757 
758 	bp = bufq_peek(sc->sc_tab);
759 	if (bp == NULL) {
760 		log(LOG_ERR, "%s intr: bp == NULL", device_xname(sc->sc_dev));
761 		return;
762 	}
763 
764 	dlog(LOG_DEBUG, "%s intr", device_xname(sc->sc_dev));
765 
766 	/*
767 	 * Some operation completed.  Read status bytes and report errors.
768 	 * Clear EOF flags here `cause they're set once on specific conditions
769 	 * below when a command succeeds.
770 	 * A DSJ of 2 always means keep waiting.  If the command was READ
771 	 * (and we're in data DMA phase) stop data transfer first.
772 	 */
773 	sc->sc_flags &= ~(MTF_HITEOF | MTF_HITBOF);
774 	if ((bp->b_flags & (B_CMD|B_READ)) == B_READ &&
775 	    !(sc->sc_flags & (MTF_IO | MTF_STATTIMEO | MTF_DSJTIMEO))){
776 		cmdbuf[0] = MTE_STOP;
777 		(void) hpibsend(sc->sc_hpibno, sc->sc_slave, MTL_ECMD,cmdbuf,1);
778 	}
779 	switch (mtreaddsj(sc, 0)) {
780 	    case 0:
781 		break;
782 
783 	    case 1:
784 		/*
785 		 * If we're in the middle of a READ/WRITE and have yet to
786 		 * start the data transfer, a DSJ of one should terminate it.
787 		 */
788 		sc->sc_flags &= ~MTF_IO;
789 		break;
790 
791 	    case 2:
792 		(void) hpibawait(sc->sc_hpibno);
793 		return;
794 
795 	    case -2:
796 		/*
797 		 * -2 means that the drive failed to respond quickly enough
798 		 * to the request for DSJ.  It's probably just "busy" figuring
799 		 * it out and will know in a little bit...
800 		 */
801 		callout_reset(&sc->sc_intr_ch, hz >> 5, spl_mtintr, sc);
802 		return;
803 
804 	    default:
805 		log(LOG_ERR, "%s intr: can't get drive stat",
806 		    device_xname(sc->sc_dev));
807 		goto error;
808 	}
809 	if (sc->sc_stat1 & (SR1_ERR | SR1_REJECT)) {
810 		i = sc->sc_stat4 & SR4_ERCLMASK;
811 		log(LOG_ERR, "%s: %s error, retry %d, SR2/3 %x/%x, code %d",
812 			device_xname(sc->sc_dev), i == SR4_DEVICE ? "device" :
813 			(i == SR4_PROTOCOL ? "protocol" :
814 			(i == SR4_SELFTEST ? "selftest" : "unknown")),
815 			sc->sc_stat4 & SR4_RETRYMASK, sc->sc_stat2,
816 			sc->sc_stat3, sc->sc_stat5);
817 
818 		if ((bp->b_flags & B_CMD) && bp->b_cmd == MTRESET)
819 			callout_stop(&sc->sc_intr_ch);
820 		if (sc->sc_stat3 & SR3_POWERUP)
821 			sc->sc_flags &= MTF_OPEN | MTF_EXISTS;
822 		goto error;
823 	}
824 	/*
825 	 * Report and clear any soft errors.
826 	 */
827 	if (sc->sc_stat1 & SR1_SOFTERR) {
828 		log(LOG_WARNING, "%s: soft error, retry %d\n",
829 		    device_xname(sc->sc_dev), sc->sc_stat4 & SR4_RETRYMASK);
830 		sc->sc_stat1 &= ~SR1_SOFTERR;
831 	}
832 	/*
833 	 * We've initiated a read or write, but haven't actually started to
834 	 * DMA the data yet.  At this point, the drive's ready.
835 	 */
836 	if (sc->sc_flags & MTF_IO) {
837 		sc->sc_flags &= ~MTF_IO;
838 		if (hpibustart(sc->sc_hpibno))
839 			mtgo(sc);
840 		return;
841 	}
842 	/*
843 	 * Check for End Of Tape - we're allowed to hit EOT and then write (or
844 	 * read) one more record.  If we get here and have not already hit EOT,
845 	 * return ENOSPC to inform the process that it's hit it.  If we get
846 	 * here and HAVE already hit EOT, don't allow any more operations that
847 	 * move the tape forward.
848 	 */
849 	if (sc->sc_stat1 & SR1_EOT) {
850 		if (sc->sc_flags & MTF_ATEOT)
851 			sc->sc_flags |= MTF_PASTEOT;
852 		else {
853 			bp->b_error = ENOSPC;
854 			sc->sc_flags |= MTF_ATEOT;
855 		}
856 	}
857 	/*
858 	 * If a motion command was being executed, check for Tape Marks.
859 	 * If we were doing data, make sure we got the right amount, and
860 	 * check for hitting tape marks on reads.
861 	 */
862 	if (bp->b_flags & B_CMD) {
863 		if (sc->sc_stat1 & SR1_EOF) {
864 			if (bp->b_cmd == MTFSR)
865 				sc->sc_flags |= MTF_HITEOF;
866 			if (bp->b_cmd == MTBSR)
867 				sc->sc_flags |= MTF_HITBOF;
868 		}
869 		if (bp->b_cmd == MTRESET) {
870 			callout_stop(&sc->sc_intr_ch);
871 			sc->sc_flags |= MTF_ALIVE;
872 		}
873 	} else {
874 		i = hpibrecv(sc->sc_hpibno, sc->sc_slave, MTT_BCNT, cmdbuf, 2);
875 		if (i != 2) {
876 			log(LOG_ERR, "%s intr: can't get xfer length\n",
877 			    device_xname(sc->sc_dev));
878 			goto error;
879 		}
880 		i = (int) *((u_short *) cmdbuf);
881 		if (i <= bp->b_bcount) {
882 			if (i == 0)
883 				sc->sc_flags |= MTF_HITEOF;
884 			bp->b_resid = bp->b_bcount - i;
885 			dlog(LOG_DEBUG, "%s intr: bcount %d, resid %d",
886 			    device_xname(sc->sc_dev), bp->b_bcount,
887 			    bp->b_resid);
888 		} else {
889 			tprintf(sc->sc_ttyp,
890 				"%s: record (%d) larger than wanted (%d)\n",
891 				device_xname(sc->sc_dev), i, bp->b_bcount);
892  error:
893 			sc->sc_flags &= ~MTF_IO;
894 			bp->b_error = EIO;
895 		}
896 	}
897 	/*
898 	 * The operation is completely done.
899 	 * Let the drive know with an END command.
900 	 */
901 	cmdbuf[0] = MTE_COMPLETE | MTE_IDLE;
902 	(void) hpibsend(sc->sc_hpibno, sc->sc_slave, MTL_ECMD, cmdbuf, 1);
903 	bp->b_flags &= ~B_CMD;
904 	(void)bufq_get(sc->sc_tab);
905 	biodone(bp);
906 	hpibfree(device_parent(sc->sc_dev), &sc->sc_hq);
907 	if (bufq_peek(sc->sc_tab) == NULL)
908 		sc->sc_active = 0;
909 	else
910 		mtustart(sc);
911 }
912 
913 static int
914 mtread(dev_t dev, struct uio *uio, int flags)
915 {
916 
917 	return physio(mtstrategy, NULL, dev, B_READ, minphys, uio);
918 }
919 
920 static int
921 mtwrite(dev_t dev, struct uio *uio, int flags)
922 {
923 
924 	return physio(mtstrategy, NULL, dev, B_WRITE, minphys, uio);
925 }
926 
927 static int
928 mtioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
929 {
930 	struct mtop *op;
931 	int cnt;
932 
933 	switch (cmd) {
934 	    case MTIOCTOP:
935 		op = (struct mtop *)data;
936 		switch(op->mt_op) {
937 		    case MTWEOF:
938 		    case MTFSF:
939 		    case MTBSR:
940 		    case MTBSF:
941 		    case MTFSR:
942 			cnt = op->mt_count;
943 			break;
944 
945 		    case MTOFFL:
946 		    case MTREW:
947 		    case MTNOP:
948 			cnt = 0;
949 			break;
950 
951 		    default:
952 			return EINVAL;
953 		}
954 		return mtcommand(dev, op->mt_op, cnt);
955 
956 	    case MTIOCGET:
957 		break;
958 
959 	    default:
960 		return EINVAL;
961 	}
962 	return 0;
963 }
964