xref: /netbsd-src/sys/arch/hp300/dev/mt.c (revision cd22f25e6f6d1cc1f197fe8c5468a80f51d1c4e1)
1 /*	$NetBSD: mt.c,v 1.43 2008/04/28 20:23:19 martin 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 1.43 2008/04/28 20:23:19 martin 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 	struct buf sc_bufstore;	/* XXX buffer storage */
118 };
119 
120 #ifdef DEBUG
121 int	mtdebug = 0;
122 #define	dlog	if (mtdebug) log
123 #else
124 #define	dlog	if (0) log
125 #endif
126 
127 #define	UNIT(x)		(minor(x) & 3)
128 
129 #define B_CMD		B_DEVPRIVATE	/* command buf instead of data */
130 #define	b_cmd		b_blkno		/* blkno holds cmd when B_CMD */
131 
132 static int	mtmatch(device_t, cfdata_t, void *);
133 static void	mtattach(device_t, device_t, void *);
134 
135 CFATTACH_DECL_NEW(mt, sizeof(struct mt_softc),
136     mtmatch, mtattach, NULL, NULL);
137 
138 static dev_type_open(mtopen);
139 static dev_type_close(mtclose);
140 static dev_type_read(mtread);
141 static dev_type_write(mtwrite);
142 static dev_type_ioctl(mtioctl);
143 static dev_type_strategy(mtstrategy);
144 
145 const struct bdevsw mt_bdevsw = {
146 	mtopen, mtclose, mtstrategy, mtioctl, nodump, nosize, D_TAPE
147 };
148 
149 const struct cdevsw mt_cdevsw = {
150 	mtopen, mtclose, mtread, mtwrite, mtioctl,
151 	nostop, notty, nopoll, nommap, nokqfilter, D_TAPE
152 };
153 
154 static int	mtident(struct mt_softc *, struct hpibbus_attach_args *);
155 static void	mtustart(struct mt_softc *);
156 static int	mtreaddsj(struct mt_softc *, int);
157 static int	mtcommand(dev_t, int, int);
158 static void	spl_mtintr(void *);
159 static void	spl_mtstart(void *);
160 
161 static void	mtstart(void *);
162 static void	mtgo(void *);
163 static void	mtintr(void *);
164 
165 static int
166 mtmatch(device_t parent, cfdata_t cf, void *aux)
167 {
168 	struct hpibbus_attach_args *ha = aux;
169 
170 	return mtident(NULL, ha);
171 }
172 
173 static void
174 mtattach(device_t parent, device_t self, void *aux)
175 {
176 	struct mt_softc *sc = device_private(self);
177 	struct hpibbus_attach_args *ha = aux;
178 	int unit, hpibno, slave;
179 
180 	sc->sc_dev = self;
181 	if (mtident(sc, ha) == 0) {
182 		aprint_error(": impossible!\n");
183 		return;
184 	}
185 
186 	unit = device_unit(self);
187 	hpibno = device_unit(parent);
188 	slave = ha->ha_slave;
189 
190 	bufq_alloc(&sc->sc_tab, "fcfs", 0);
191 	callout_init(&sc->sc_start_ch, 0);
192 	callout_init(&sc->sc_intr_ch, 0);
193 
194 	sc->sc_hpibno = hpibno;
195 	sc->sc_slave = slave;
196 	sc->sc_flags = MTF_EXISTS;
197 
198 	/* Initialize hpib job queue entry. */
199 	sc->sc_hq.hq_softc = sc;
200 	sc->sc_hq.hq_slave = sc->sc_slave;
201 	sc->sc_hq.hq_start = mtstart;
202 	sc->sc_hq.hq_go = mtgo;
203 	sc->sc_hq.hq_intr = mtintr;
204 }
205 
206 static int
207 mtident(struct mt_softc *sc, struct hpibbus_attach_args *ha)
208 {
209 	int i;
210 
211 	for (i = 0; i < nmtinfo; i++) {
212 		if (ha->ha_id == mtinfo[i].hwid) {
213 			if (sc != NULL) {
214 				sc->sc_type = mtinfo[i].hwid;
215 				aprint_normal(": %s tape\n", mtinfo[i].desc);
216 			}
217 			return 1;
218 		}
219 	}
220 	return 0;
221 }
222 
223 /*
224  * Perform a read of "Device Status Jump" register and update the
225  * status if necessary.  If status is read, the given "ecmd" is also
226  * performed, unless "ecmd" is zero.  Returns DSJ value, -1 on failure
227  * and -2 on "temporary" failure.
228  */
229 static int
230 mtreaddsj(struct mt_softc *sc, int ecmd)
231 {
232 	int retval;
233 
234 	if (sc->sc_flags & MTF_STATTIMEO)
235 		goto getstats;
236 	retval = hpibrecv(sc->sc_hpibno,
237 	    (sc->sc_flags & MTF_DSJTIMEO) ? -1 : sc->sc_slave,
238 	    MTT_DSJ, &(sc->sc_lastdsj), 1);
239 	sc->sc_flags &= ~MTF_DSJTIMEO;
240 	if (retval != 1) {
241 		dlog(LOG_DEBUG, "%s can't hpibrecv DSJ",
242 		    device_xname(sc->sc_dev));
243 		if (sc->sc_recvtimeo == 0)
244 			sc->sc_recvtimeo = hz;
245 		if (--sc->sc_recvtimeo == 0)
246 			return -1;
247 		if (retval == 0)
248 			sc->sc_flags |= MTF_DSJTIMEO;
249 		return -2;
250 	}
251 	sc->sc_recvtimeo = 0;
252 	sc->sc_statindex = 0;
253 	dlog(LOG_DEBUG, "%s readdsj: 0x%x", device_xname(sc->sc_dev),
254 	    sc->sc_lastdsj);
255 	sc->sc_lastecmd = ecmd;
256 	switch (sc->sc_lastdsj) {
257 	    case 0:
258 		if (ecmd & MTE_DSJ_FORCE)
259 			break;
260 		return 0;
261 
262 	    case 2:
263 		sc->sc_lastecmd = MTE_COMPLETE;
264 	    case 1:
265 		break;
266 
267 	    default:
268 		log(LOG_ERR, "%s readdsj: DSJ 0x%x\n", device_xname(sc->sc_dev),
269 		    sc->sc_lastdsj);
270 		return -1;
271 	}
272  getstats:
273 	retval = hpibrecv(sc->sc_hpibno,
274 	    (sc->sc_flags & MTF_STATCONT) ? -1 : sc->sc_slave,
275 	    MTT_STAT, ((char *)&(sc->sc_stat)) + sc->sc_statindex,
276 	    sizeof(sc->sc_stat) - sc->sc_statindex);
277 	sc->sc_flags &= ~(MTF_STATTIMEO | MTF_STATCONT);
278 	if (retval != sizeof(sc->sc_stat) - sc->sc_statindex) {
279 		if (sc->sc_recvtimeo == 0)
280 			sc->sc_recvtimeo = hz;
281 		if (--sc->sc_recvtimeo != 0) {
282 			if (retval >= 0) {
283 				sc->sc_statindex += retval;
284 				sc->sc_flags |= MTF_STATCONT;
285 			}
286 			sc->sc_flags |= MTF_STATTIMEO;
287 			return -2;
288 		}
289 		log(LOG_ERR, "%s readdsj: can't read status",
290 		    device_xname(sc->sc_dev));
291 		return -1;
292 	}
293 	sc->sc_recvtimeo = 0;
294 	sc->sc_statindex = 0;
295 	dlog(LOG_DEBUG, "%s readdsj: status is %x %x %x %x %x %x",
296 	    device_xname(sc->sc_dev),
297 	    sc->sc_stat1, sc->sc_stat2, sc->sc_stat3,
298 	    sc->sc_stat4, sc->sc_stat5, sc->sc_stat6);
299 	if (sc->sc_lastecmd)
300 		(void) hpibsend(sc->sc_hpibno, sc->sc_slave,
301 		    MTL_ECMD, &(sc->sc_lastecmd), 1);
302 	return (int)sc->sc_lastdsj;
303 }
304 
305 static int
306 mtopen(dev_t dev, int flag, int mode, struct lwp *l)
307 {
308 	int unit = UNIT(dev);
309 	struct mt_softc *sc;
310 	int req_den;
311 	int error;
312 
313 	if (unit >= mt_cd.cd_ndevs ||
314 	    (sc = device_private(mt_cd.cd_devs[unit])) == NULL ||
315 	    (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 		if (tsleep((void *) &lbolt, PCATCH | (PZERO + 1),
337 		    "mt", 0) != 0) {
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_private(mt_cd.cd_devs[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 	struct mt_softc *sc = device_private(mt_cd.cd_devs[UNIT(dev)]);
428 	struct buf *bp = &sc->sc_bufstore;
429 	int error = 0;
430 
431 #if 1
432 	if (bp->b_cflags & BC_BUSY)
433 		return EBUSY;
434 #endif
435 	bp->b_cmd = cmd;
436 	bp->b_dev = dev;
437 	do {
438 		bp->b_cflags = BC_BUSY;
439 		bp->b_flags = B_CMD;
440 		mtstrategy(bp);
441 		biowait(bp);
442 		if (bp->b_error != 0) {
443 			error = bp->b_error;
444 			break;
445 		}
446 	} while (--cnt > 0);
447 #if 0
448 	bp->b_flags = 0 /*&= ~BC_BUSY*/;
449 #else
450 	bp->b_flags &= ~BC_BUSY;
451 #endif
452 	return error;
453 }
454 
455 /*
456  * Only thing to check here is for legal record lengths (writes only).
457  */
458 static void
459 mtstrategy(struct buf *bp)
460 {
461 	struct mt_softc *sc;
462 	int unit;
463 	int s;
464 
465 	unit = UNIT(bp->b_dev);
466 	sc = device_private(mt_cd.cd_devs[unit]);
467 	dlog(LOG_DEBUG, "%s strategy", device_xname(sc->sc_dev));
468 	if ((bp->b_flags & (B_CMD | B_READ)) == 0) {
469 #define WRITE_BITS_IGNORED	8
470 #if 0
471 		if (bp->b_bcount & ((1 << WRITE_BITS_IGNORED) - 1)) {
472 			tprintf(sc->sc_ttyp,
473 			    "%s: write record must be multiple of %d\n",
474 			    device_xname(sc->sc_dev), 1 << WRITE_BITS_IGNORED);
475 			goto error;
476 		}
477 #endif
478 		s = 16 * 1024;
479 		if (sc->sc_stat2 & SR2_LONGREC) {
480 			switch (sc->sc_density) {
481 			    case T_1600BPI:
482 				s = 32 * 1024;
483 				break;
484 
485 			    case T_6250BPI:
486 			    case T_BADBPI:
487 				s = 60 * 1024;
488 				break;
489 			}
490 		}
491 		if (bp->b_bcount > s) {
492 			tprintf(sc->sc_ttyp,
493 			    "%s: write record (%d) too big: limit (%d)\n",
494 			    device_xname(sc->sc_dev), bp->b_bcount, s);
495 #if 0 /* XXX see above */
496 	    error:
497 #endif
498 			bp->b_error = EIO;
499 			biodone(bp);
500 			return;
501 		}
502 	}
503 	s = splbio();
504 	BUFQ_PUT(sc->sc_tab, bp);
505 	if (sc->sc_active == 0) {
506 		sc->sc_active = 1;
507 		mtustart(sc);
508 	}
509 	splx(s);
510 }
511 
512 static void
513 mtustart(struct mt_softc *sc)
514 {
515 
516 	dlog(LOG_DEBUG, "%s ustart", device_xname(sc->sc_dev));
517 	if (hpibreq(device_parent(sc->sc_dev), &sc->sc_hq))
518 		mtstart(sc);
519 }
520 
521 static void
522 spl_mtintr(void *arg)
523 {
524 	struct mt_softc *sc = arg;
525 	int s = splbio();
526 
527 	hpibppclear(sc->sc_hpibno);
528 	mtintr(sc);
529 	splx(s);
530 }
531 
532 static void
533 spl_mtstart(void *arg)
534 {
535 	int s = splbio();
536 
537 	mtstart(arg);
538 	splx(s);
539 }
540 
541 static void
542 mtstart(void *arg)
543 {
544 	struct mt_softc *sc = arg;
545 	struct buf *bp;
546 	short	cmdcount = 1;
547 	u_char	cmdbuf[2];
548 
549 	dlog(LOG_DEBUG, "%s start", device_xname(sc->sc_dev));
550 	sc->sc_flags &= ~MTF_WRT;
551 	bp = BUFQ_PEEK(sc->sc_tab);
552 	if ((sc->sc_flags & MTF_ALIVE) == 0 &&
553 	    ((bp->b_flags & B_CMD) == 0 || bp->b_cmd != MTRESET))
554 		goto fatalerror;
555 
556 	if (sc->sc_flags & MTF_REW) {
557 		if (!hpibpptest(sc->sc_hpibno, sc->sc_slave))
558 			goto stillrew;
559 		switch (mtreaddsj(sc, MTE_DSJ_FORCE|MTE_COMPLETE|MTE_IDLE)) {
560 		    case 0:
561 		    case 1:
562 		stillrew:
563 			if ((sc->sc_stat1 & SR1_BOT) ||
564 			    !(sc->sc_stat1 & SR1_ONLINE)) {
565 				sc->sc_flags &= ~MTF_REW;
566 				break;
567 			}
568 		    case -2:
569 			/*
570 			 * -2 means "timeout" reading DSJ, which is probably
571 			 * temporary.  This is considered OK when doing a NOP,
572 			 * but not otherwise.
573 			 */
574 			if (sc->sc_flags & (MTF_DSJTIMEO | MTF_STATTIMEO)) {
575 				callout_reset(&sc->sc_start_ch, hz >> 5,
576 				    spl_mtstart, sc);
577 				return;
578 			}
579 		    case 2:
580 			if (bp->b_cmd != MTNOP || !(bp->b_flags & B_CMD)) {
581 				bp->b_error = EBUSY;
582 				goto done;
583 			}
584 			goto done;
585 
586 		    default:
587 			goto fatalerror;
588 		}
589 	}
590 	if (bp->b_flags & B_CMD) {
591 		if (sc->sc_flags & MTF_PASTEOT) {
592 			switch(bp->b_cmd) {
593 			    case MTFSF:
594 			    case MTWEOF:
595 			    case MTFSR:
596 				bp->b_error = ENOSPC;
597 				goto done;
598 
599 			    case MTBSF:
600 			    case MTOFFL:
601 			    case MTBSR:
602 			    case MTREW:
603 				sc->sc_flags &= ~(MTF_PASTEOT | MTF_ATEOT);
604 				break;
605 			}
606 		}
607 		switch(bp->b_cmd) {
608 		    case MTFSF:
609 			if (sc->sc_flags & MTF_HITEOF)
610 				goto done;
611 			cmdbuf[0] = MTTC_FSF;
612 			break;
613 
614 		    case MTBSF:
615 			if (sc->sc_flags & MTF_HITBOF)
616 				goto done;
617 			cmdbuf[0] = MTTC_BSF;
618 			break;
619 
620 		    case MTOFFL:
621 			sc->sc_flags |= MTF_REW;
622 			cmdbuf[0] = MTTC_REWOFF;
623 			break;
624 
625 		    case MTWEOF:
626 			cmdbuf[0] = MTTC_WFM;
627 			break;
628 
629 		    case MTBSR:
630 			cmdbuf[0] = MTTC_BSR;
631 			break;
632 
633 		    case MTFSR:
634 			cmdbuf[0] = MTTC_FSR;
635 			break;
636 
637 		    case MTREW:
638 			sc->sc_flags |= MTF_REW;
639 			cmdbuf[0] = MTTC_REW;
640 			break;
641 
642 		    case MTNOP:
643 			/*
644 			 * NOP is supposed to set status bits.
645 			 * Force readdsj to do it.
646 			 */
647 			switch (mtreaddsj(sc,
648 			  MTE_DSJ_FORCE | MTE_COMPLETE | MTE_IDLE)) {
649 			    default:
650 				goto done;
651 
652 			    case -1:
653 				/*
654 				 * If this fails, perform a device clear
655 				 * to fix any protocol problems and (most
656 				 * likely) get the status.
657 				 */
658 				bp->b_cmd = MTRESET;
659 				break;
660 
661 			    case -2:
662 				callout_reset(&sc->sc_start_ch, hz >> 5,
663 				    spl_mtstart, sc);
664 				return;
665 			}
666 
667 		    case MTRESET:
668 			/*
669 			 * 1) selected device clear (send with "-2" secondary)
670 			 * 2) set timeout, then wait for "service request"
671 			 * 3) interrupt will read DSJ (and END COMPLETE-IDLE)
672 			 */
673 			if (hpibsend(sc->sc_hpibno, sc->sc_slave, -2, NULL, 0)){
674 				log(LOG_ERR, "%s can't reset",
675 				    device_xname(sc->sc_dev));
676 				goto fatalerror;
677 			}
678 			callout_reset(&sc->sc_intr_ch, 4 * hz, spl_mtintr, sc);
679 			hpibawait(sc->sc_hpibno);
680 			return;
681 
682 		    case MTSET800BPI:
683 			cmdbuf[0] = MTTC_800;
684 			break;
685 
686 		    case MTSET1600BPI:
687 			cmdbuf[0] = MTTC_1600;
688 			break;
689 
690 		    case MTSET6250BPI:
691 			cmdbuf[0] = MTTC_6250;
692 			break;
693 
694 		    case MTSET6250DC:
695 			cmdbuf[0] = MTTC_DC6250;
696 			break;
697 		}
698 	} else {
699 		if (sc->sc_flags & MTF_PASTEOT) {
700 			bp->b_error = ENOSPC;
701 			goto done;
702 		}
703 		if (bp->b_flags & B_READ) {
704 			sc->sc_flags |= MTF_IO;
705 			cmdbuf[0] = MTTC_READ;
706 		} else {
707 			sc->sc_flags |= MTF_WRT | MTF_IO;
708 			cmdbuf[0] = MTTC_WRITE;
709 			cmdbuf[1] = (bp->b_bcount + ((1 << WRITE_BITS_IGNORED) - 1)) >> WRITE_BITS_IGNORED;
710 			cmdcount = 2;
711 		}
712 	}
713 	if (hpibsend(sc->sc_hpibno, sc->sc_slave, MTL_TCMD, cmdbuf, cmdcount)
714 	    == cmdcount) {
715 		if (sc->sc_flags & MTF_REW)
716 			goto done;
717 		hpibawait(sc->sc_hpibno);
718 		return;
719 	}
720 fatalerror:
721 	/*
722 	 * If anything fails, the drive is probably hosed, so mark it not
723 	 * "ALIVE" (but it EXISTS and is OPEN or we wouldn't be here, and
724 	 * if, last we heard, it was REWinding, remember that).
725 	 */
726 	sc->sc_flags &= MTF_EXISTS | MTF_OPEN | MTF_REW;
727 	bp->b_error = EIO;
728 done:
729 	sc->sc_flags &= ~(MTF_HITEOF | MTF_HITBOF);
730 	(void)BUFQ_GET(sc->sc_tab);
731 	biodone(bp);
732 	hpibfree(device_parent(sc->sc_dev), &sc->sc_hq);
733 	if ((bp = BUFQ_PEEK(sc->sc_tab)) == NULL)
734 		sc->sc_active = 0;
735 	else
736 		mtustart(sc);
737 }
738 
739 /*
740  * The Utah code had a bug which meant that the driver was unable to read.
741  * "rw" was initialized to bp->b_flags & B_READ before "bp" was initialized.
742  *   -- ajv@comp.vuw.ac.nz
743  */
744 static void
745 mtgo(void *arg)
746 {
747 	struct mt_softc *sc = arg;
748 	struct buf *bp;
749 	int rw;
750 
751 	dlog(LOG_DEBUG, "%s go", device_xname(sc->sc_dev));
752 	bp = BUFQ_PEEK(sc->sc_tab);
753 	rw = bp->b_flags & B_READ;
754 	hpibgo(sc->sc_hpibno, sc->sc_slave, rw ? MTT_READ : MTL_WRITE,
755 	    bp->b_data, bp->b_bcount, rw, rw != 0);
756 }
757 
758 static void
759 mtintr(void *arg)
760 {
761 	struct mt_softc *sc = arg;
762 	struct buf *bp;
763 	int i;
764 	u_char cmdbuf[4];
765 
766 	bp = BUFQ_PEEK(sc->sc_tab);
767 	if (bp == NULL) {
768 		log(LOG_ERR, "%s intr: bp == NULL", device_xname(sc->sc_dev));
769 		return;
770 	}
771 
772 	dlog(LOG_DEBUG, "%s intr", device_xname(sc->sc_dev));
773 
774 	/*
775 	 * Some operation completed.  Read status bytes and report errors.
776 	 * Clear EOF flags here `cause they're set once on specific conditions
777 	 * below when a command succeeds.
778 	 * A DSJ of 2 always means keep waiting.  If the command was READ
779 	 * (and we're in data DMA phase) stop data transfer first.
780 	 */
781 	sc->sc_flags &= ~(MTF_HITEOF | MTF_HITBOF);
782 	if ((bp->b_flags & (B_CMD|B_READ)) == B_READ &&
783 	    !(sc->sc_flags & (MTF_IO | MTF_STATTIMEO | MTF_DSJTIMEO))){
784 		cmdbuf[0] = MTE_STOP;
785 		(void) hpibsend(sc->sc_hpibno, sc->sc_slave, MTL_ECMD,cmdbuf,1);
786 	}
787 	switch (mtreaddsj(sc, 0)) {
788 	    case 0:
789 		break;
790 
791 	    case 1:
792 		/*
793 		 * If we're in the middle of a READ/WRITE and have yet to
794 		 * start the data transfer, a DSJ of one should terminate it.
795 		 */
796 		sc->sc_flags &= ~MTF_IO;
797 		break;
798 
799 	    case 2:
800 		(void) hpibawait(sc->sc_hpibno);
801 		return;
802 
803 	    case -2:
804 		/*
805 		 * -2 means that the drive failed to respond quickly enough
806 		 * to the request for DSJ.  It's probably just "busy" figuring
807 		 * it out and will know in a little bit...
808 		 */
809 		callout_reset(&sc->sc_intr_ch, hz >> 5, spl_mtintr, sc);
810 		return;
811 
812 	    default:
813 		log(LOG_ERR, "%s intr: can't get drive stat",
814 		    device_xname(sc->sc_dev));
815 		goto error;
816 	}
817 	if (sc->sc_stat1 & (SR1_ERR | SR1_REJECT)) {
818 		i = sc->sc_stat4 & SR4_ERCLMASK;
819 		log(LOG_ERR, "%s: %s error, retry %d, SR2/3 %x/%x, code %d",
820 			device_xname(sc->sc_dev), i == SR4_DEVICE ? "device" :
821 			(i == SR4_PROTOCOL ? "protocol" :
822 			(i == SR4_SELFTEST ? "selftest" : "unknown")),
823 			sc->sc_stat4 & SR4_RETRYMASK, sc->sc_stat2,
824 			sc->sc_stat3, sc->sc_stat5);
825 
826 		if ((bp->b_flags & B_CMD) && bp->b_cmd == MTRESET)
827 			callout_stop(&sc->sc_intr_ch);
828 		if (sc->sc_stat3 & SR3_POWERUP)
829 			sc->sc_flags &= MTF_OPEN | MTF_EXISTS;
830 		goto error;
831 	}
832 	/*
833 	 * Report and clear any soft errors.
834 	 */
835 	if (sc->sc_stat1 & SR1_SOFTERR) {
836 		log(LOG_WARNING, "%s: soft error, retry %d\n",
837 		    device_xname(sc->sc_dev), sc->sc_stat4 & SR4_RETRYMASK);
838 		sc->sc_stat1 &= ~SR1_SOFTERR;
839 	}
840 	/*
841 	 * We've initiated a read or write, but haven't actually started to
842 	 * DMA the data yet.  At this point, the drive's ready.
843 	 */
844 	if (sc->sc_flags & MTF_IO) {
845 		sc->sc_flags &= ~MTF_IO;
846 		if (hpibustart(sc->sc_hpibno))
847 			mtgo(sc);
848 		return;
849 	}
850 	/*
851 	 * Check for End Of Tape - we're allowed to hit EOT and then write (or
852 	 * read) one more record.  If we get here and have not already hit EOT,
853 	 * return ENOSPC to inform the process that it's hit it.  If we get
854 	 * here and HAVE already hit EOT, don't allow any more operations that
855 	 * move the tape forward.
856 	 */
857 	if (sc->sc_stat1 & SR1_EOT) {
858 		if (sc->sc_flags & MTF_ATEOT)
859 			sc->sc_flags |= MTF_PASTEOT;
860 		else {
861 			bp->b_error = ENOSPC;
862 			sc->sc_flags |= MTF_ATEOT;
863 		}
864 	}
865 	/*
866 	 * If a motion command was being executed, check for Tape Marks.
867 	 * If we were doing data, make sure we got the right amount, and
868 	 * check for hitting tape marks on reads.
869 	 */
870 	if (bp->b_flags & B_CMD) {
871 		if (sc->sc_stat1 & SR1_EOF) {
872 			if (bp->b_cmd == MTFSR)
873 				sc->sc_flags |= MTF_HITEOF;
874 			if (bp->b_cmd == MTBSR)
875 				sc->sc_flags |= MTF_HITBOF;
876 		}
877 		if (bp->b_cmd == MTRESET) {
878 			callout_stop(&sc->sc_intr_ch);
879 			sc->sc_flags |= MTF_ALIVE;
880 		}
881 	} else {
882 		i = hpibrecv(sc->sc_hpibno, sc->sc_slave, MTT_BCNT, cmdbuf, 2);
883 		if (i != 2) {
884 			log(LOG_ERR, "%s intr: can't get xfer length\n",
885 			    device_xname(sc->sc_dev));
886 			goto error;
887 		}
888 		i = (int) *((u_short *) cmdbuf);
889 		if (i <= bp->b_bcount) {
890 			if (i == 0)
891 				sc->sc_flags |= MTF_HITEOF;
892 			bp->b_resid = bp->b_bcount - i;
893 			dlog(LOG_DEBUG, "%s intr: bcount %d, resid %d",
894 			    device_xname(sc->sc_dev), bp->b_bcount,
895 			    bp->b_resid);
896 		} else {
897 			tprintf(sc->sc_ttyp,
898 				"%s: record (%d) larger than wanted (%d)\n",
899 				device_xname(sc->sc_dev), i, bp->b_bcount);
900  error:
901 			sc->sc_flags &= ~MTF_IO;
902 			bp->b_error = EIO;
903 		}
904 	}
905 	/*
906 	 * The operation is completely done.
907 	 * Let the drive know with an END command.
908 	 */
909 	cmdbuf[0] = MTE_COMPLETE | MTE_IDLE;
910 	(void) hpibsend(sc->sc_hpibno, sc->sc_slave, MTL_ECMD, cmdbuf, 1);
911 	bp->b_flags &= ~B_CMD;
912 	(void)BUFQ_GET(sc->sc_tab);
913 	biodone(bp);
914 	hpibfree(device_parent(sc->sc_dev), &sc->sc_hq);
915 	if (BUFQ_PEEK(sc->sc_tab) == NULL)
916 		sc->sc_active = 0;
917 	else
918 		mtustart(sc);
919 }
920 
921 static int
922 mtread(dev_t dev, struct uio *uio, int flags)
923 {
924 	struct mt_softc *sc = device_private(mt_cd.cd_devs[UNIT(dev)]);
925 
926 	return physio(mtstrategy, &sc->sc_bufstore,
927 	    dev, B_READ, minphys, uio);
928 }
929 
930 static int
931 mtwrite(dev_t dev, struct uio *uio, int flags)
932 {
933 	struct mt_softc *sc = device_private(mt_cd.cd_devs[UNIT(dev)]);
934 
935 	return physio(mtstrategy, &sc->sc_bufstore,
936 	    dev, B_WRITE, minphys, uio);
937 }
938 
939 static int
940 mtioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
941 {
942 	struct mtop *op;
943 	int cnt;
944 
945 	switch (cmd) {
946 	    case MTIOCTOP:
947 		op = (struct mtop *)data;
948 		switch(op->mt_op) {
949 		    case MTWEOF:
950 		    case MTFSF:
951 		    case MTBSR:
952 		    case MTBSF:
953 		    case MTFSR:
954 			cnt = op->mt_count;
955 			break;
956 
957 		    case MTOFFL:
958 		    case MTREW:
959 		    case MTNOP:
960 			cnt = 0;
961 			break;
962 
963 		    default:
964 			return EINVAL;
965 		}
966 		return mtcommand(dev, op->mt_op, cnt);
967 
968 	    case MTIOCGET:
969 		break;
970 
971 	    default:
972 		return EINVAL;
973 	}
974 	return 0;
975 }
976