xref: /netbsd-src/sys/dev/scsipi/st.c (revision 9573504567626934c7ee01c7dce0c4bb1dfe7403)
1 /*	$NetBSD: st.c,v 1.55 1995/11/30 10:12:04 pk Exp $	*/
2 
3 /*
4  * Copyright (c) 1994 Charles Hannum.  All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. All advertising materials mentioning features or use of this software
15  *    must display the following acknowledgement:
16  *	This product includes software developed by Charles Hannum.
17  * 4. The name of the author may not be used to endorse or promote products
18  *    derived from this software without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
21  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
22  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
23  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
24  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
25  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
29  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 /*
33  * Originally written by Julian Elischer (julian@tfs.com)
34  * for TRW Financial Systems for use under the MACH(2.5) operating system.
35  *
36  * TRW Financial Systems, in accordance with their agreement with Carnegie
37  * Mellon University, makes this software available to CMU to distribute
38  * or use in any manner that they see fit as long as this message is kept with
39  * the software. For this reason TFS also grants any other persons or
40  * organisations permission to use or modify this software.
41  *
42  * TFS supplies this software to be publicly redistributed
43  * on the understanding that TFS is not responsible for the correct
44  * functioning of this software in any circumstances.
45  *
46  * Ported to run under 386BSD by Julian Elischer (julian@tfs.com) Sept 1992
47  * major changes by Julian Elischer (julian@jules.dialix.oz.au) May 1993
48  */
49 
50 /*
51  * To do:
52  * work out some better way of guessing what a good timeout is going
53  * to be depending on whether we expect to retension or not.
54  */
55 
56 #include <sys/types.h>
57 #include <sys/param.h>
58 #include <sys/systm.h>
59 #include <sys/fcntl.h>
60 #include <sys/errno.h>
61 #include <sys/ioctl.h>
62 #include <sys/malloc.h>
63 #include <sys/buf.h>
64 #include <sys/proc.h>
65 #include <sys/user.h>
66 #include <sys/mtio.h>
67 #include <sys/device.h>
68 
69 #include <scsi/scsi_all.h>
70 #include <scsi/scsi_tape.h>
71 #include <scsi/scsiconf.h>
72 
73 /* Defines for device specific stuff */
74 #define DEF_FIXED_BSIZE  512
75 #define	ST_RETRIES	4	/* only on non IO commands */
76 
77 #define STMODE(z)	( minor(z)       & 0x03)
78 #define STDSTY(z)	((minor(z) >> 2) & 0x03)
79 #define STUNIT(z)	((minor(z) >> 4)       )
80 #define CTLMODE	3
81 
82 #define SCSI_2_MAX_DENSITY_CODE	0x17	/* maximum density code specified
83 					 * in SCSI II spec. */
84 /*
85  * Define various devices that we know mis-behave in some way,
86  * and note how they are bad, so we can correct for them
87  */
88 struct modes {
89 	u_int quirks;			/* same definitions as in quirkdata */
90 	int blksize;
91 	u_int8_t density;
92 };
93 
94 struct quirkdata {
95 	u_int quirks;
96 #define	ST_Q_FORCE_BLKSIZE	0x0001
97 #define	ST_Q_SENSE_HELP		0x0002	/* must do READ for good MODE SENSE */
98 #define	ST_Q_IGNORE_LOADS	0x0004
99 #define	ST_Q_BLKSIZE		0x0008	/* variable-block media_blksize > 0 */
100 	u_int page_0_size;
101 #define	MAX_PAGE_0_SIZE	64
102 	struct modes modes[4];
103 };
104 
105 struct st_quirk_inquiry_pattern {
106 	struct scsi_inquiry_pattern pattern;
107 	struct quirkdata quirkdata;
108 };
109 
110 struct st_quirk_inquiry_pattern st_quirk_patterns[] = {
111 	{T_SEQUENTIAL, T_REMOV,
112 	 "        ", "                ", "    ", 0, 0, {
113 		ST_Q_FORCE_BLKSIZE, 512, 0,		/* minor 0-3 */
114 		ST_Q_FORCE_BLKSIZE, 512, QIC_24,	/* minor 4-7 */
115 		ST_Q_FORCE_BLKSIZE, 0, HALFINCH_1600,	/* minor 8-11 */
116 		ST_Q_FORCE_BLKSIZE, 0, HALFINCH_6250	/* minor 12-15 */
117 	}},
118 	{T_SEQUENTIAL, T_REMOV,
119 	 "TANDBERG", " TDC 3600       ", "",     0, 12, {
120 		0, 0, 0,				/* minor 0-3 */
121 		ST_Q_FORCE_BLKSIZE, 0, QIC_525,		/* minor 4-7 */
122 		0, 0, QIC_150,				/* minor 8-11 */
123 		0, 0, QIC_120				/* minor 12-15 */
124 	}},
125 	{T_SEQUENTIAL, T_REMOV,
126 	 "TANDBERG", " TDC 3800       ", "",     0, 0, {
127 		ST_Q_FORCE_BLKSIZE, 512, 0,		/* minor 0-3 */
128 		0, 0, QIC_525,				/* minor 4-7 */
129 		0, 0, QIC_150,				/* minor 8-11 */
130 		0, 0, QIC_120				/* minor 12-15 */
131 	}},
132 	/*
133 	 * At least -005 and -007 need this.  I'll assume they all do unless I
134 	 * hear otherwise.  - mycroft, 31MAR1994
135 	 */
136 	{T_SEQUENTIAL, T_REMOV,
137 	 "ARCHIVE ", "VIPER 2525 25462", "",     0, 0, {
138 		ST_Q_SENSE_HELP, 0, 0,			/* minor 0-3 */
139 		ST_Q_SENSE_HELP, 0, QIC_525,		/* minor 4-7 */
140 		0, 0, QIC_150,				/* minor 8-11 */
141 		0, 0, QIC_120				/* minor 12-15 */
142 	}},
143 	/*
144 	 * One user reports that this works for his tape drive.  It probably
145 	 * needs more work.  - mycroft, 09APR1994
146 	 */
147 	{T_SEQUENTIAL, T_REMOV,
148 	 "SANKYO  ", "CP525           ", "",     0, 0, {
149 		ST_Q_FORCE_BLKSIZE, 512, 0,		/* minor 0-3 */
150 		ST_Q_FORCE_BLKSIZE, 512, QIC_525,	/* minor 4-7 */
151 		0, 0, QIC_150,				/* minor 8-11 */
152 		0, 0, QIC_120				/* minor 12-15 */
153 	}},
154 	{T_SEQUENTIAL, T_REMOV,
155 	 "ANRITSU ", "DMT780          ", "",     0, 0, {
156 		ST_Q_FORCE_BLKSIZE, 512, 0,		/* minor 0-3 */
157 		ST_Q_FORCE_BLKSIZE, 512, QIC_525,	/* minor 4-7 */
158 		0, 0, QIC_150,				/* minor 8-11 */
159 		0, 0, QIC_120				/* minor 12-15 */
160 	}},
161 	{T_SEQUENTIAL, T_REMOV,
162 	 "ARCHIVE ", "VIPER 150  21247", "",     0, 12, {
163 		0, 0, 0,				/* minor 0-3 */
164 		0, 0, QIC_150,				/* minor 4-7 */
165 		0, 0, QIC_120,				/* minor 8-11 */
166 		0, 0, QIC_24				/* minor 12-15 */
167 	}},
168 	{T_SEQUENTIAL, T_REMOV,
169 	 "WANGTEK ", "5099ES SCSI", "",          0, 0, {
170 		ST_Q_FORCE_BLKSIZE, 512, 0,		/* minor 0-3 */
171 		0, 0, QIC_11,				/* minor 4-7 */
172 		0, 0, QIC_24,				/* minor 8-11 */
173 		0, 0, QIC_24,				/* minor 12-15 */
174 	}},
175 	{T_SEQUENTIAL, T_REMOV,
176 	 "WANGTEK ", "5150ES SCSI", "",          0, 0, {
177 		ST_Q_FORCE_BLKSIZE, 512, 0,		/* minor 0-3 */
178 		0, 0, QIC_24,				/* minor 4-7 */
179 		0, 0, QIC_120,				/* minor 8-11 */
180 		0, 0, QIC_150				/* minor 12-15 */
181 	}},
182 	{T_SEQUENTIAL, T_REMOV,
183 	 "WANGTEK ", "5525ES SCSI REV7", "",     0, 0, {
184 		0, 0, 0,				/* minor 0-3 */
185 		ST_Q_BLKSIZE, 0, QIC_525,		/* minor 4-7 */
186 		0, 0, QIC_150,				/* minor 8-11 */
187 		0, 0, QIC_120				/* minor 12-15 */
188 	}},
189 	{T_SEQUENTIAL, T_REMOV,
190 	 "WangDAT ", "Model 1300      ", "",     0, 0, {
191 		0, 0, 0,				/* minor 0-3 */
192 		ST_Q_FORCE_BLKSIZE, 512, DDS,		/* minor 4-7 */
193 		ST_Q_FORCE_BLKSIZE, 1024, DDS,		/* minor 8-11 */
194 		ST_Q_FORCE_BLKSIZE, 0, DDS		/* minor 12-15 */
195 	}},
196 	{T_SEQUENTIAL, T_REMOV,
197 	 "EXABYTE ", "EXB-8200        ", "263H", 0, 5, {
198 		0, 0, 0,				/* minor 0-3 */
199 		0, 0, 0,				/* minor 4-7 */
200 		0, 0, 0,				/* minor 8-11 */
201 		0, 0, 0					/* minor 12-15 */
202 	}},
203 #if 0
204 	{T_SEQUENTIAL, T_REMOV,
205 	 "EXABYTE ", "EXB-8200        ", "",     0, 12, {
206 		0, 0, 0,				/* minor 0-3 */
207 		0, 0, 0,				/* minor 4-7 */
208 		0, 0, 0,				/* minor 8-11 */
209 		0, 0, 0					/* minor 12-15 */
210 	}},
211 #endif
212 };
213 
214 #define NOEJECT 0
215 #define EJECT 1
216 
217 struct st_softc {
218 	struct device sc_dev;
219 /*--------------------present operating parameters, flags etc.----------------*/
220 	int flags;		/* see below                          */
221 	u_int quirks;		/* quirks for the open mode           */
222 	int blksize;		/* blksize we are using                */
223 	u_int8_t density;	/* present density                    */
224 	u_int page_0_size;	/* size of page 0 data		      */
225 	u_int last_dsty;	/* last density opened               */
226 /*--------------------device/scsi parameters----------------------------------*/
227 	struct scsi_link *sc_link;	/* our link to the adpter etc.        */
228 /*--------------------parameters reported by the device ----------------------*/
229 	int blkmin;		/* min blk size                       */
230 	int blkmax;		/* max blk size                       */
231 	struct quirkdata *quirkdata;	/* if we have a rogue entry           */
232 /*--------------------parameters reported by the device for this media--------*/
233 	u_long numblks;		/* nominal blocks capacity            */
234 	int media_blksize;	/* 0 if not ST_FIXEDBLOCKS            */
235 	u_int8_t media_density;	/* this is what it said when asked    */
236 /*--------------------quirks for the whole drive------------------------------*/
237 	u_int drive_quirks;	/* quirks of this drive               */
238 /*--------------------How we should set up when opening each minor device----*/
239 	struct modes modes[4];	/* plus more for each mode            */
240 	u_int8_t  modeflags[4];	/* flags for the modes                */
241 #define DENSITY_SET_BY_USER	0x01
242 #define DENSITY_SET_BY_QUIRK	0x02
243 #define BLKSIZE_SET_BY_USER	0x04
244 #define BLKSIZE_SET_BY_QUIRK	0x08
245 /*--------------------storage for sense data returned by the drive------------*/
246 	u_char sense_data[MAX_PAGE_0_SIZE];	/*
247 						 * additional sense data needed
248 						 * for mode sense/select.
249 						 */
250 	struct buf buf_queue;		/* the queue of pending IO operations */
251 };
252 
253 int stmatch __P((struct device *, void *, void *));
254 void stattach __P((struct device *, struct device *, void *));
255 
256 struct cfdriver stcd = {
257 	NULL, "st", stmatch, stattach, DV_TAPE, sizeof(struct st_softc)
258 };
259 
260 int	st_space __P((struct st_softc *, int number, u_int what, int flags));
261 int	st_rewind __P((struct st_softc *, u_int immediate, int flags));
262 int	st_mode_sense __P((struct st_softc *, int flags));
263 int	st_decide_mode __P((struct st_softc *, boolean first_read));
264 int	st_read_block_limits __P((struct st_softc *, int flags));
265 int	st_touch_tape __P((struct st_softc *));
266 int	st_write_filemarks __P((struct st_softc *, int number, int flags));
267 int	st_load __P((struct st_softc *, u_int type, int flags));
268 int	st_mode_select __P((struct st_softc *, int flags));
269 void    ststrategy();
270 int	st_check_eod();
271 void    ststart();
272 void	st_unmount();
273 int	st_mount_tape();
274 void	st_loadquirks();
275 void	st_identify_drive();
276 int	st_interpret_sense();
277 
278 struct scsi_device st_switch = {
279 	st_interpret_sense,
280 	ststart,
281 	NULL,
282 	NULL,
283 };
284 
285 #define	ST_INFO_VALID	0x0001
286 #define	ST_BLOCK_SET	0x0002	/* block size, mode set by ioctl      */
287 #define	ST_WRITTEN	0x0004	/* data have been written, EOD needed */
288 #define	ST_FIXEDBLOCKS	0x0008
289 #define	ST_AT_FILEMARK	0x0010
290 #define	ST_EIO_PENDING	0x0020	/* we couldn't report it then (had data) */
291 #define	ST_NEW_MOUNT	0x0040	/* still need to decide mode              */
292 #define	ST_READONLY	0x0080	/* st_mode_sense says write protected */
293 #define	ST_FM_WRITTEN	0x0100	/*
294 				 * EOF file mark written  -- used with
295 				 * ~ST_WRITTEN to indicate that multiple file
296 				 * marks have been written
297 				 */
298 #define	ST_BLANK_READ	0x0200	/* BLANK CHECK encountered already */
299 #define	ST_2FM_AT_EOD	0x0400	/* write 2 file marks at EOD */
300 #define	ST_MOUNTED	0x0800	/* Device is presently mounted */
301 
302 #define	ST_PER_ACTION	(ST_AT_FILEMARK | ST_EIO_PENDING | ST_BLANK_READ)
303 #define	ST_PER_MOUNT	(ST_INFO_VALID | ST_BLOCK_SET | ST_WRITTEN | \
304 			 ST_FIXEDBLOCKS | ST_READONLY | ST_FM_WRITTEN | \
305 			 ST_2FM_AT_EOD | ST_PER_ACTION)
306 
307 struct scsi_inquiry_pattern st_patterns[] = {
308 	{T_SEQUENTIAL, T_REMOV,
309 	 "",         "",                 ""},
310 };
311 
312 int
313 stmatch(parent, match, aux)
314 	struct device *parent;
315 	void *match, *aux;
316 {
317 	struct cfdata *cf = match;
318 	struct scsibus_attach_args *sa = aux;
319 	int priority;
320 
321 	(void)scsi_inqmatch(sa->sa_inqbuf,
322 	    (caddr_t)st_patterns, sizeof(st_patterns)/sizeof(st_patterns[0]),
323 	    sizeof(st_patterns[0]), &priority);
324 	return (priority);
325 }
326 
327 /*
328  * The routine called by the low level scsi routine when it discovers
329  * A device suitable for this driver
330  */
331 void
332 stattach(parent, self, aux)
333 	struct device *parent, *self;
334 	void *aux;
335 {
336 	struct st_softc *st = (void *)self;
337 	struct scsibus_attach_args *sa = aux;
338 	struct scsi_link *sc_link = sa->sa_sc_link;
339 
340 	SC_DEBUG(sc_link, SDEV_DB2, ("stattach: "));
341 
342 	/*
343 	 * Store information needed to contact our base driver
344 	 */
345 	st->sc_link = sc_link;
346 	sc_link->device = &st_switch;
347 	sc_link->device_softc = st;
348 	sc_link->openings = 1;
349 
350 	/*
351 	 * Check if the drive is a known criminal and take
352 	 * Any steps needed to bring it into line
353 	 */
354 	st_identify_drive(st, sa->sa_inqbuf);
355 
356 	/*
357 	 * Use the subdriver to request information regarding
358 	 * the drive. We cannot use interrupts yet, so the
359 	 * request must specify this.
360 	 */
361 	printf(": %s", st->quirkdata ? "rogue, " : "");
362 	if (scsi_test_unit_ready(sc_link,
363 	    SCSI_AUTOCONF | SCSI_SILENT | SCSI_IGNORE_MEDIA_CHANGE) ||
364 	    st_mode_sense(st,
365 	    SCSI_AUTOCONF | SCSI_SILENT | SCSI_IGNORE_MEDIA_CHANGE))
366 		printf("drive empty\n");
367 	else {
368 		printf("density code 0x%x, ", st->media_density);
369 		if (st->media_blksize > 0)
370 			printf("%d-byte", st->media_blksize);
371 		else
372 			printf("variable");
373 		printf(" blocks, write-%s\n",
374 		    (st->flags & ST_READONLY) ? "protected" : "enabled");
375 	}
376 
377 	/*
378 	 * Set up the buf queue for this device
379 	 */
380 	st->buf_queue.b_active = 0;
381 	st->buf_queue.b_actf = 0;
382 	st->buf_queue.b_actb = &st->buf_queue.b_actf;
383 }
384 
385 /*
386  * Use the inquiry routine in 'scsi_base' to get drive info so we can
387  * Further tailor our behaviour.
388  */
389 void
390 st_identify_drive(st, inqbuf)
391 	struct st_softc *st;
392 	struct scsi_inquiry_data *inqbuf;
393 {
394 	struct st_quirk_inquiry_pattern *finger;
395 	int priority;
396 
397 	finger = (struct st_quirk_inquiry_pattern *)scsi_inqmatch(inqbuf,
398 	    (caddr_t)st_quirk_patterns,
399 	    sizeof(st_quirk_patterns)/sizeof(st_quirk_patterns[0]),
400 	    sizeof(st_quirk_patterns[0]), &priority);
401 	if (priority != 0) {
402 		st->quirkdata = &finger->quirkdata;
403 		st->drive_quirks = finger->quirkdata.quirks;
404 		st->quirks = finger->quirkdata.quirks;	/* start value */
405 		st->page_0_size = finger->quirkdata.page_0_size;
406 		st_loadquirks(st);
407 	}
408 }
409 
410 /*
411  * initialise the subdevices to the default (QUIRK) state.
412  * this will remove any setting made by the system operator or previous
413  * operations.
414  */
415 void
416 st_loadquirks(st)
417 	struct st_softc *st;
418 {
419 	int i;
420 	struct	modes *mode;
421 	struct	modes *mode2;
422 
423 	mode = st->quirkdata->modes;
424 	mode2 = st->modes;
425 	for (i = 0; i < 4; i++) {
426 		bzero(mode2, sizeof(struct modes));
427 		st->modeflags[i] &= ~(BLKSIZE_SET_BY_QUIRK |
428 		    DENSITY_SET_BY_QUIRK | BLKSIZE_SET_BY_USER |
429 		    DENSITY_SET_BY_USER);
430 		if ((mode->quirks | st->drive_quirks) & ST_Q_FORCE_BLKSIZE) {
431 			mode2->blksize = mode->blksize;
432 			st->modeflags[i] |= BLKSIZE_SET_BY_QUIRK;
433 		}
434 		if (mode->density) {
435 			mode2->density = mode->density;
436 			st->modeflags[i] |= DENSITY_SET_BY_QUIRK;
437 		}
438 		mode++;
439 		mode2++;
440 	}
441 }
442 
443 /*
444  * open the device.
445  */
446 int
447 stopen(dev, flags)
448 	dev_t dev;
449 	int flags;
450 {
451 	int unit;
452 	u_int mode, dsty;
453 	int error = 0;
454 	struct st_softc *st;
455 	struct scsi_link *sc_link;
456 
457 	unit = STUNIT(dev);
458 	if (unit >= stcd.cd_ndevs)
459 		return ENXIO;
460 	st = stcd.cd_devs[unit];
461 	if (!st)
462 		return ENXIO;
463 
464 	mode = STMODE(dev);
465 	dsty = STDSTY(dev);
466 	sc_link = st->sc_link;
467 
468 	SC_DEBUG(sc_link, SDEV_DB1, ("open: dev=0x%x (unit %d (of %d))\n", dev,
469 	    unit, stcd.cd_ndevs));
470 
471 	/*
472 	 * Only allow one at a time
473 	 */
474 	if (sc_link->flags & SDEV_OPEN) {
475 		printf("%s: already open\n", st->sc_dev.dv_xname);
476 		return EBUSY;
477 	}
478 
479 	/*
480 	 * Catch any unit attention errors.
481 	 */
482 	if (error = scsi_test_unit_ready(sc_link,
483 	    SCSI_IGNORE_MEDIA_CHANGE | (mode == CTLMODE ? SCSI_IGNORE_NOT_READY : 0)))
484 		goto bad;
485 
486 	sc_link->flags |= SDEV_OPEN;	/* unit attn are now errors */
487 
488 	/*
489 	 * If the mode is 3 (e.g. minor = 3,7,11,15)
490 	 * then the device has been opened to set defaults
491 	 * This mode does NOT ALLOW I/O, only ioctls
492 	 */
493 	if (mode == CTLMODE)
494 		return 0;
495 
496 	/*
497 	 * if it's a different mode, or if the media has been
498 	 * invalidated, unmount the tape from the previous
499 	 * session but continue with open processing
500 	 */
501 	if (st->last_dsty != dsty || !(sc_link->flags & SDEV_MEDIA_LOADED))
502 		st_unmount(st, NOEJECT);
503 
504 	/*
505 	 * If we are not mounted, then we should start a new
506 	 * mount session.
507 	 */
508 	if (!(st->flags & ST_MOUNTED)) {
509 		st_mount_tape(dev, flags);
510 		st->last_dsty = dsty;
511 	}
512 
513 	/*
514 	 * Make sure that a tape opened in write-only mode will have
515 	 * file marks written on it when closed, even if not written to.
516 	 * This is for SUN compatibility
517 	 */
518 	if ((flags & O_ACCMODE) == FWRITE)
519 		st->flags |= ST_WRITTEN;
520 
521 	SC_DEBUG(sc_link, SDEV_DB2, ("open complete\n"));
522 	return 0;
523 
524 bad:
525 	st_unmount(st, NOEJECT);
526 	sc_link->flags &= ~SDEV_OPEN;
527 	return error;
528 }
529 
530 /*
531  * close the device.. only called if we are the LAST
532  * occurence of an open device
533  */
534 int
535 stclose(dev)
536 	dev_t dev;
537 {
538 	struct st_softc *st = stcd.cd_devs[STUNIT(dev)];
539 
540 	SC_DEBUG(st->sc_link, SDEV_DB1, ("closing\n"));
541 	if ((st->flags & (ST_WRITTEN | ST_FM_WRITTEN)) == ST_WRITTEN)
542 		st_write_filemarks(st, 1, 0);
543 	switch (STMODE(dev)) {
544 	case 0:
545 	case 3:		/* for now */
546 		st_unmount(st, NOEJECT);
547 		break;
548 	case 1:
549 		/* leave mounted unless media seems to have been removed */
550 		if (!(st->sc_link->flags & SDEV_MEDIA_LOADED))
551 			st_unmount(st, NOEJECT);
552 		break;
553 	case 2:
554 		st_unmount(st, EJECT);
555 		break;
556 	}
557 	st->sc_link->flags &= ~SDEV_OPEN;
558 
559 	return 0;
560 }
561 
562 /*
563  * Start a new mount session.
564  * Copy in all the default parameters from the selected device mode.
565  * and try guess any that seem to be defaulted.
566  */
567 int
568 st_mount_tape(dev, flags)
569 	dev_t dev;
570 	int flags;
571 {
572 	int unit;
573 	u_int mode, dsty;
574 	struct st_softc *st;
575 	struct scsi_link *sc_link;
576 	int error = 0;
577 
578 	unit = STUNIT(dev);
579 	mode = STMODE(dev);
580 	dsty = STDSTY(dev);
581 	st = stcd.cd_devs[unit];
582 	sc_link = st->sc_link;
583 
584 	if (st->flags & ST_MOUNTED)
585 		return 0;
586 
587 	SC_DEBUG(sc_link, SDEV_DB1, ("mounting\n "));
588 	st->flags |= ST_NEW_MOUNT;
589 	st->quirks = st->drive_quirks | st->modes[dsty].quirks;
590 	/*
591 	 * If the media is new, then make sure we give it a chance to
592 	 * to do a 'load' instruction.  (We assume it is new.)
593 	 */
594 	if (error = st_load(st, LD_LOAD, 0))
595 		return error;
596 	/*
597 	 * Throw another dummy instruction to catch
598 	 * 'Unit attention' errors. Some drives appear to give
599 	 * these after doing a Load instruction.
600 	 * (noteably some DAT drives)
601 	 */
602 	scsi_test_unit_ready(sc_link, SCSI_SILENT);	/* XXX */
603 
604 	/*
605 	 * Some devices can't tell you much until they have been
606 	 * asked to look at the media. This quirk does this.
607 	 */
608 	if (st->quirks & ST_Q_SENSE_HELP)
609 		if (error = st_touch_tape(st))
610 			return error;
611 	/*
612 	 * Load the physical device parameters
613 	 * loads: blkmin, blkmax
614 	 */
615 	if (error = st_read_block_limits(st, 0))
616 		return error;
617 	/*
618 	 * Load the media dependent parameters
619 	 * includes: media_blksize,media_density,numblks
620 	 * As we have a tape in, it should be reflected here.
621 	 * If not you may need the "quirk" above.
622 	 */
623 	if (error = st_mode_sense(st, 0))
624 		return error;
625 	/*
626 	 * If we have gained a permanent density from somewhere,
627 	 * then use it in preference to the one supplied by
628 	 * default by the driver.
629 	 */
630 	if (st->modeflags[dsty] & (DENSITY_SET_BY_QUIRK | DENSITY_SET_BY_USER))
631 		st->density = st->modes[dsty].density;
632 	else
633 		st->density = st->media_density;
634 	/*
635 	 * If we have gained a permanent blocksize
636 	 * then use it in preference to the one supplied by
637 	 * default by the driver.
638 	 */
639 	st->flags &= ~ST_FIXEDBLOCKS;
640 	if (st->modeflags[dsty] & (BLKSIZE_SET_BY_QUIRK | BLKSIZE_SET_BY_USER)) {
641 		st->blksize = st->modes[dsty].blksize;
642 		if (st->blksize)
643 			st->flags |= ST_FIXEDBLOCKS;
644 	} else {
645 		if (error = st_decide_mode(st, FALSE))
646 			return error;
647 	}
648 	if (error = st_mode_select(st, 0)) {
649 		printf("%s: cannot set selected mode\n", st->sc_dev.dv_xname);
650 		return error;
651 	}
652 	scsi_prevent(sc_link, PR_PREVENT,
653 	    SCSI_IGNORE_ILLEGAL_REQUEST | SCSI_IGNORE_NOT_READY);
654 	st->flags &= ~ST_NEW_MOUNT;
655 	st->flags |= ST_MOUNTED;
656 	sc_link->flags |= SDEV_MEDIA_LOADED;	/* move earlier? */
657 
658 	return 0;
659 }
660 
661 /*
662  * End the present mount session.
663  * Rewind, and optionally eject the tape.
664  * Reset various flags to indicate that all new
665  * operations require another mount operation
666  */
667 void
668 st_unmount(st, eject)
669 	struct st_softc *st;
670 	boolean eject;
671 {
672 	struct scsi_link *sc_link = st->sc_link;
673 	int nmarks;
674 
675 	if (!(st->flags & ST_MOUNTED))
676 		return;
677 	SC_DEBUG(sc_link, SDEV_DB1, ("unmounting\n"));
678 	st_check_eod(st, FALSE, &nmarks, SCSI_IGNORE_NOT_READY);
679 	st_rewind(st, 0, SCSI_IGNORE_NOT_READY);
680 	scsi_prevent(sc_link, PR_ALLOW,
681 	    SCSI_IGNORE_ILLEGAL_REQUEST | SCSI_IGNORE_NOT_READY);
682 	if (eject)
683 		st_load(st, LD_UNLOAD, SCSI_IGNORE_NOT_READY);
684 	st->flags &= ~(ST_MOUNTED | ST_NEW_MOUNT);
685 	sc_link->flags &= ~SDEV_MEDIA_LOADED;
686 }
687 
688 /*
689  * Given all we know about the device, media, mode, 'quirks' and
690  * initial operation, make a decision as to how we should be set
691  * to run (regarding blocking and EOD marks)
692  */
693 int
694 st_decide_mode(st, first_read)
695 	struct st_softc *st;
696 	boolean	first_read;
697 {
698 #ifdef SCSIDEBUG
699 	struct scsi_link *sc_link = st->sc_link;
700 #endif
701 
702 	SC_DEBUG(sc_link, SDEV_DB2, ("starting block mode decision\n"));
703 
704 	/*
705 	 * If the drive can only handle fixed-length blocks and only at
706 	 * one size, perhaps we should just do that.
707 	 */
708 	if (st->blkmin && (st->blkmin == st->blkmax)) {
709 		st->flags |= ST_FIXEDBLOCKS;
710 		st->blksize = st->blkmin;
711 		SC_DEBUG(sc_link, SDEV_DB3,
712 		    ("blkmin == blkmax of %d\n", st->blkmin));
713 		goto done;
714 	}
715 	/*
716 	 * If the tape density mandates (or even suggests) use of fixed
717 	 * or variable-length blocks, comply.
718 	 */
719 	switch (st->density) {
720 	case HALFINCH_800:
721 	case HALFINCH_1600:
722 	case HALFINCH_6250:
723 	case DDS:
724 		st->flags &= ~ST_FIXEDBLOCKS;
725 		st->blksize = 0;
726 		SC_DEBUG(sc_link, SDEV_DB3, ("density specified variable\n"));
727 		goto done;
728 	case QIC_11:
729 	case QIC_24:
730 	case QIC_120:
731 	case QIC_150:
732 	case QIC_525:
733 	case QIC_1320:
734 		st->flags |= ST_FIXEDBLOCKS;
735 		if (st->media_blksize > 0)
736 			st->blksize = st->media_blksize;
737 		else
738 			st->blksize = DEF_FIXED_BSIZE;
739 		SC_DEBUG(sc_link, SDEV_DB3, ("density specified fixed\n"));
740 		goto done;
741 	}
742 	/*
743 	 * If we're about to read the tape, perhaps we should choose
744 	 * fixed or variable-length blocks and block size according to
745 	 * what the drive found on the tape.
746 	 */
747 	if (first_read &&
748 	    (!(st->quirks & ST_Q_BLKSIZE) || (st->media_blksize == 0) ||
749 	    (st->media_blksize == DEF_FIXED_BSIZE) ||
750 	    (st->media_blksize == 1024))) {
751 		if (st->media_blksize > 0)
752 			st->flags |= ST_FIXEDBLOCKS;
753 		else
754 			st->flags &= ~ST_FIXEDBLOCKS;
755 		st->blksize = st->media_blksize;
756 		SC_DEBUG(sc_link, SDEV_DB3,
757 		    ("Used media_blksize of %d\n", st->media_blksize));
758 		goto done;
759 	}
760 	/*
761 	 * We're getting no hints from any direction.  Choose variable-
762 	 * length blocks arbitrarily.
763 	 */
764 	st->flags &= ~ST_FIXEDBLOCKS;
765 	st->blksize = 0;
766 	SC_DEBUG(sc_link, SDEV_DB3,
767 	    ("Give up and default to variable mode\n"));
768 
769 done:
770 	/*
771 	 * Decide whether or not to write two file marks to signify end-
772 	 * of-data.  Make the decision as a function of density.  If
773 	 * the decision is not to use a second file mark, the SCSI BLANK
774 	 * CHECK condition code will be recognized as end-of-data when
775 	 * first read.
776 	 * (I think this should be a by-product of fixed/variable..julian)
777 	 */
778 	switch (st->density) {
779 /*      case 8 mm:   What is the SCSI density code for 8 mm, anyway? */
780 	case QIC_11:
781 	case QIC_24:
782 	case QIC_120:
783 	case QIC_150:
784 	case QIC_525:
785 	case QIC_1320:
786 		st->flags &= ~ST_2FM_AT_EOD;
787 		break;
788 	default:
789 		st->flags |= ST_2FM_AT_EOD;
790 	}
791 	return 0;
792 }
793 
794 /*
795  * Actually translate the requested transfer into
796  * one the physical driver can understand
797  * The transfer is described by a buf and will include
798  * only one physical transfer.
799  */
800 void
801 ststrategy(bp)
802 	struct buf *bp;
803 {
804 	struct st_softc *st = stcd.cd_devs[STUNIT(bp->b_dev)];
805 	struct buf *dp;
806 	int s;
807 
808 	SC_DEBUG(st->sc_link, SDEV_DB1,
809 	    ("ststrategy %d bytes @ blk %d\n", bp->b_bcount, bp->b_blkno));
810 	/*
811 	 * If it's a null transfer, return immediatly
812 	 */
813 	if (bp->b_bcount == 0)
814 		goto done;
815 	/*
816 	 * Odd sized request on fixed drives are verboten
817 	 */
818 	if (st->flags & ST_FIXEDBLOCKS) {
819 		if (bp->b_bcount % st->blksize) {
820 			printf("%s: bad request, must be multiple of %d\n",
821 			    st->sc_dev.dv_xname, st->blksize);
822 			bp->b_error = EIO;
823 			goto bad;
824 		}
825 	}
826 	/*
827 	 * as are out-of-range requests on variable drives.
828 	 */
829 	else if (bp->b_bcount < st->blkmin ||
830 		 (st->blkmax && bp->b_bcount > st->blkmax)) {
831 		printf("%s: bad request, must be between %d and %d\n",
832 		    st->sc_dev.dv_xname, st->blkmin, st->blkmax);
833 		bp->b_error = EIO;
834 		goto bad;
835 	}
836 	s = splbio();
837 
838 	/*
839 	 * Place it in the queue of activities for this tape
840 	 * at the end (a bit silly because we only have on user..
841 	 * (but it could fork()))
842 	 */
843 	dp = &st->buf_queue;
844 	bp->b_actf = NULL;
845 	bp->b_actb = dp->b_actb;
846 	*dp->b_actb = bp;
847 	dp->b_actb = &bp->b_actf;
848 
849 	/*
850 	 * Tell the device to get going on the transfer if it's
851 	 * not doing anything, otherwise just wait for completion
852 	 * (All a bit silly if we're only allowing 1 open but..)
853 	 */
854 	ststart(st);
855 
856 	splx(s);
857 	return;
858 bad:
859 	bp->b_flags |= B_ERROR;
860 done:
861 	/*
862 	 * Correctly set the buf to indicate a completed xfer
863 	 */
864 	iodone(bp);
865 	return;
866 }
867 
868 /*
869  * ststart looks to see if there is a buf waiting for the device
870  * and that the device is not already busy. If both are true,
871  * It dequeues the buf and creates a scsi command to perform the
872  * transfer required. The transfer request will call scsi_done
873  * on completion, which will in turn call this routine again
874  * so that the next queued transfer is performed.
875  * The bufs are queued by the strategy routine (ststrategy)
876  *
877  * This routine is also called after other non-queued requests
878  * have been made of the scsi driver, to ensure that the queue
879  * continues to be drained.
880  * ststart() is called at splbio
881  */
882 void
883 ststart(st)
884 	struct st_softc *st;
885 {
886 	struct scsi_link *sc_link = st->sc_link;
887 	register struct buf *bp, *dp;
888 	struct scsi_rw_tape cmd;
889 	int flags;
890 
891 	SC_DEBUG(sc_link, SDEV_DB2, ("ststart "));
892 	/*
893 	 * See if there is a buf to do and we are not already
894 	 * doing one
895 	 */
896 	while (sc_link->openings > 0) {
897 		/* if a special awaits, let it proceed first */
898 		if (sc_link->flags & SDEV_WAITING) {
899 			sc_link->flags &= ~SDEV_WAITING;
900 			wakeup((caddr_t)sc_link);
901 			return;
902 		}
903 
904 		bp = st->buf_queue.b_actf;
905 		if (!bp)
906 			return;	/* no work to bother with */
907 		if (dp = bp->b_actf)
908 			dp->b_actb = bp->b_actb;
909 		else
910 			st->buf_queue.b_actb = bp->b_actb;
911 		*bp->b_actb = dp;
912 
913 		/*
914 		 * if the device has been unmounted byt the user
915 		 * then throw away all requests until done
916 		 */
917 		if (!(st->flags & ST_MOUNTED) ||
918 		    !(sc_link->flags & SDEV_MEDIA_LOADED)) {
919 			/* make sure that one implies the other.. */
920 			sc_link->flags &= ~SDEV_MEDIA_LOADED;
921 			bp->b_flags |= B_ERROR;
922 			bp->b_error = EIO;
923 			biodone(bp);
924 			continue;
925 		}
926 		/*
927 		 * only FIXEDBLOCK devices have pending operations
928 		 */
929 		if (st->flags & ST_FIXEDBLOCKS) {
930 			/*
931 			 * If we are at a filemark but have not reported it yet
932 			 * then we should report it now
933 			 */
934 			if (st->flags & ST_AT_FILEMARK) {
935 				if ((bp->b_flags & B_READ) == B_WRITE) {
936 					/*
937 					 * Handling of ST_AT_FILEMARK in
938 					 * st_space will fill in the right file
939 					 * mark count.
940 					 * Back up over filemark
941 					 */
942 					if (st_space(st, 0, SP_FILEMARKS, 0)) {
943 						bp->b_flags |= B_ERROR;
944 						bp->b_error = EIO;
945 						biodone(bp);
946 						continue;
947 					}
948 				} else {
949 					bp->b_resid = bp->b_bcount;
950 					bp->b_error = 0;
951 					bp->b_flags &= ~B_ERROR;
952 					st->flags &= ~ST_AT_FILEMARK;
953 					biodone(bp);
954 					continue;	/* seek more work */
955 				}
956 			}
957 			/*
958 			 * If we are at EIO (e.g. EOM) but have not reported it
959 			 * yet then we should report it now
960 			 */
961 			if (st->flags & ST_EIO_PENDING) {
962 				bp->b_resid = bp->b_bcount;
963 				bp->b_error = EIO;
964 				bp->b_flags |= B_ERROR;
965 				st->flags &= ~ST_EIO_PENDING;
966 				biodone(bp);
967 				continue;	/* seek more work */
968 			}
969 		}
970 
971 		/*
972 		 *  Fill out the scsi command
973 		 */
974 		bzero(&cmd, sizeof(cmd));
975 		if ((bp->b_flags & B_READ) == B_WRITE) {
976 			cmd.opcode = WRITE;
977 			st->flags &= ~ST_FM_WRITTEN;
978 			st->flags |= ST_WRITTEN;
979 			flags = SCSI_DATA_OUT;
980 		} else {
981 			cmd.opcode = READ;
982 			flags = SCSI_DATA_IN;
983 		}
984 
985 		/*
986 		 * Handle "fixed-block-mode" tape drives by using the
987 		 * block count instead of the length.
988 		 */
989 		if (st->flags & ST_FIXEDBLOCKS) {
990 			cmd.byte2 |= SRW_FIXED;
991 			lto3b(bp->b_bcount / st->blksize, cmd.len);
992 		} else
993 			lto3b(bp->b_bcount, cmd.len);
994 
995 		/*
996 		 * go ask the adapter to do all this for us
997 		 */
998 		if (scsi_scsi_cmd(sc_link, (struct scsi_generic *) &cmd,
999 		    sizeof(cmd), (u_char *) bp->b_data, bp->b_bcount, 0,
1000 		    100000, bp, flags | SCSI_NOSLEEP))
1001 			printf("%s: not queued\n", st->sc_dev.dv_xname);
1002 	} /* go back and see if we can cram more work in.. */
1003 }
1004 
1005 int
1006 stread(dev, uio)
1007 	dev_t dev;
1008 	struct uio *uio;
1009 {
1010 	struct st_softc *st = stcd.cd_devs[STUNIT(dev)];
1011 
1012 	return (physio(ststrategy, NULL, dev, B_READ,
1013 		       st->sc_link->adapter->scsi_minphys, uio));
1014 }
1015 
1016 int
1017 stwrite(dev, uio)
1018 	dev_t dev;
1019 	struct uio *uio;
1020 {
1021 	struct st_softc *st = stcd.cd_devs[STUNIT(dev)];
1022 
1023 	return (physio(ststrategy, NULL, dev, B_WRITE,
1024 		       st->sc_link->adapter->scsi_minphys, uio));
1025 }
1026 
1027 /*
1028  * Perform special action on behalf of the user;
1029  * knows about the internals of this device
1030  */
1031 int
1032 stioctl(dev, cmd, arg, flag, p)
1033 	dev_t dev;
1034 	u_long cmd;
1035 	caddr_t arg;
1036 	int flag;
1037 	struct proc *p;
1038 {
1039 	int error = 0;
1040 	int unit;
1041 	int number, nmarks, dsty;
1042 	int flags;
1043 	struct st_softc *st;
1044 	int hold_blksize;
1045 	u_int8_t hold_density;
1046 	struct mtop *mt = (struct mtop *) arg;
1047 
1048 	/*
1049 	 * Find the device that the user is talking about
1050 	 */
1051 	flags = 0;		/* give error messages, act on errors etc. */
1052 	unit = STUNIT(dev);
1053 	dsty = STDSTY(dev);
1054 	st = stcd.cd_devs[unit];
1055 	hold_blksize = st->blksize;
1056 	hold_density = st->density;
1057 
1058 	switch (cmd) {
1059 
1060 	case MTIOCGET: {
1061 		struct mtget *g = (struct mtget *) arg;
1062 
1063 		SC_DEBUG(st->sc_link, SDEV_DB1, ("[ioctl: get status]\n"));
1064 		bzero(g, sizeof(struct mtget));
1065 		g->mt_type = 0x7;	/* Ultrix compat *//*? */
1066 		g->mt_blksiz = st->blksize;
1067 		g->mt_density = st->density;
1068 		g->mt_mblksiz[0] = st->modes[0].blksize;
1069 		g->mt_mblksiz[1] = st->modes[1].blksize;
1070 		g->mt_mblksiz[2] = st->modes[2].blksize;
1071 		g->mt_mblksiz[3] = st->modes[3].blksize;
1072 		g->mt_mdensity[0] = st->modes[0].density;
1073 		g->mt_mdensity[1] = st->modes[1].density;
1074 		g->mt_mdensity[2] = st->modes[2].density;
1075 		g->mt_mdensity[3] = st->modes[3].density;
1076 		break;
1077 	}
1078 	case MTIOCTOP: {
1079 
1080 		SC_DEBUG(st->sc_link, SDEV_DB1,
1081 		    ("[ioctl: op=0x%x count=0x%x]\n", mt->mt_op, mt->mt_count));
1082 
1083 		/* compat: in U*x it is a short */
1084 		number = mt->mt_count;
1085 		switch ((short) (mt->mt_op)) {
1086 		case MTWEOF:	/* write an end-of-file record */
1087 			error = st_write_filemarks(st, number, flags);
1088 			break;
1089 		case MTBSF:	/* backward space file */
1090 			number = -number;
1091 		case MTFSF:	/* forward space file */
1092 			error = st_check_eod(st, FALSE, &nmarks, flags);
1093 			if (!error)
1094 				error = st_space(st, number - nmarks,
1095 				    SP_FILEMARKS, flags);
1096 			break;
1097 		case MTBSR:	/* backward space record */
1098 			number = -number;
1099 		case MTFSR:	/* forward space record */
1100 			error = st_check_eod(st, TRUE, &nmarks, flags);
1101 			if (!error)
1102 				error = st_space(st, number, SP_BLKS, flags);
1103 			break;
1104 		case MTREW:	/* rewind */
1105 			error = st_rewind(st, 0, flags);
1106 			break;
1107 		case MTOFFL:	/* rewind and put the drive offline */
1108 			st_unmount(st, EJECT);
1109 			break;
1110 		case MTNOP:	/* no operation, sets status only */
1111 			break;
1112 		case MTRETEN:	/* retension the tape */
1113 			error = st_load(st, LD_RETENSION, flags);
1114 			if (!error)
1115 				error = st_load(st, LD_LOAD, flags);
1116 			break;
1117 		case MTEOM:	/* forward space to end of media */
1118 			error = st_check_eod(st, FALSE, &nmarks, flags);
1119 			if (!error)
1120 				error = st_space(st, 1, SP_EOM, flags);
1121 			break;
1122 		case MTCACHE:	/* enable controller cache */
1123 		case MTNOCACHE:	/* disable controller cache */
1124 			break;
1125 		case MTSETBSIZ:	/* Set block size for device */
1126 #ifdef	NOTYET
1127 			if (!(st->flags & ST_NEW_MOUNT)) {
1128 				uprintf("re-mount tape before changing blocksize");
1129 				error = EINVAL;
1130 				break;
1131 			}
1132 #endif
1133 			if (number == 0) {
1134 				st->flags &= ~ST_FIXEDBLOCKS;
1135 			} else {
1136 				if ((st->blkmin || st->blkmax) &&
1137 				    (number < st->blkmin ||
1138 				    number > st->blkmax)) {
1139 					error = EINVAL;
1140 					break;
1141 				}
1142 				st->flags |= ST_FIXEDBLOCKS;
1143 			}
1144 			st->blksize = number;
1145 			st->flags |= ST_BLOCK_SET;	/*XXX */
1146 			goto try_new_value;
1147 
1148 		case MTSETDNSTY:	/* Set density for device and mode */
1149 			if (number > SCSI_2_MAX_DENSITY_CODE)
1150 				error = EINVAL;
1151 			else
1152 				st->density = number;
1153 			goto try_new_value;
1154 
1155 		default:
1156 			error = EINVAL;
1157 		}
1158 		break;
1159 	}
1160 	case MTIOCIEOT:
1161 	case MTIOCEEOT:
1162 		break;
1163 	default:
1164 		if (STMODE(dev) == CTLMODE)
1165 			error = scsi_do_ioctl(st->sc_link, dev, cmd, arg, flag, p);
1166 		else
1167 			error = ENOTTY;
1168 		break;
1169 	}
1170 	return error;
1171 /*-----------------------------*/
1172 try_new_value:
1173 	/*
1174 	 * Check that the mode being asked for is aggreeable to the
1175 	 * drive. If not, put it back the way it was.
1176 	 */
1177 	if (error = st_mode_select(st, 0)) {	/* put it back as it was */
1178 		printf("%s: cannot set selected mode\n", st->sc_dev.dv_xname);
1179 		st->density = hold_density;
1180 		st->blksize = hold_blksize;
1181 		if (st->blksize)
1182 			st->flags |= ST_FIXEDBLOCKS;
1183 		else
1184 			st->flags &= ~ST_FIXEDBLOCKS;
1185 		return error;
1186 	}
1187 	/*
1188 	 * As the drive liked it, if we are setting a new default,
1189 	 * set it into the structures as such.
1190 	 *
1191 	 * The means for deciding this are not finalised yet
1192 	 */
1193 	if (STMODE(dev) == 0x03) {
1194 		/* special mode */
1195 		/* XXX */
1196 		switch ((short) (mt->mt_op)) {
1197 		case MTSETBSIZ:
1198 			st->modes[dsty].blksize = st->blksize;
1199 			st->modeflags[dsty] |= BLKSIZE_SET_BY_USER;
1200 			break;
1201 		case MTSETDNSTY:
1202 			st->modes[dsty].density = st->density;
1203 			st->modeflags[dsty] |= DENSITY_SET_BY_USER;
1204 			break;
1205 		}
1206 	}
1207 	return 0;
1208 }
1209 
1210 /*
1211  * Do a synchronous read.
1212  */
1213 int
1214 st_read(st, buf, size, flags)
1215 	struct st_softc *st;
1216 	int size;
1217 	int flags;
1218 	char *buf;
1219 {
1220 	struct scsi_rw_tape cmd;
1221 
1222 	/*
1223 	 * If it's a null transfer, return immediatly
1224 	 */
1225 	if (size == 0)
1226 		return 0;
1227 	bzero(&cmd, sizeof(cmd));
1228 	cmd.opcode = READ;
1229 	if (st->flags & ST_FIXEDBLOCKS) {
1230 		cmd.byte2 |= SRW_FIXED;
1231 		lto3b(size / (st->blksize ? st->blksize : DEF_FIXED_BSIZE),
1232 		    cmd.len);
1233 	} else
1234 		lto3b(size, cmd.len);
1235 	return scsi_scsi_cmd(st->sc_link, (struct scsi_generic *) &cmd,
1236 	    sizeof(cmd), (u_char *) buf, size, 0, 100000, NULL,
1237 	    flags | SCSI_DATA_IN);
1238 }
1239 
1240 #ifdef	__STDC__
1241 #define b2tol(a)	(((unsigned)(a##_1) << 8) + (unsigned)a##_0)
1242 #else
1243 #define b2tol(a)	(((unsigned)(a/**/_1) << 8) + (unsigned)a/**/_0)
1244 #endif
1245 
1246 /*
1247  * Ask the drive what it's min and max blk sizes are.
1248  */
1249 int
1250 st_read_block_limits(st, flags)
1251 	struct st_softc *st;
1252 	int flags;
1253 {
1254 	struct scsi_block_limits cmd;
1255 	struct scsi_block_limits_data block_limits;
1256 	struct scsi_link *sc_link = st->sc_link;
1257 	int error;
1258 
1259 	/*
1260 	 * First check if we have it all loaded
1261 	 */
1262 	if ((sc_link->flags & SDEV_MEDIA_LOADED))
1263 		return 0;
1264 
1265 	/*
1266 	 * do a 'Read Block Limits'
1267 	 */
1268 	bzero(&cmd, sizeof(cmd));
1269 	cmd.opcode = READ_BLOCK_LIMITS;
1270 
1271 	/*
1272 	 * do the command, update the global values
1273 	 */
1274 	if (error = scsi_scsi_cmd(sc_link, (struct scsi_generic *) &cmd,
1275 	    sizeof(cmd), (u_char *) &block_limits, sizeof(block_limits),
1276 	    ST_RETRIES, 5000, NULL, flags | SCSI_DATA_IN))
1277 		return error;
1278 
1279 	st->blkmin = b2tol(block_limits.min_length);
1280 	st->blkmax = _3btol(&block_limits.max_length_2);
1281 
1282 	SC_DEBUG(sc_link, SDEV_DB3,
1283 	    ("(%d <= blksize <= %d)\n", st->blkmin, st->blkmax));
1284 	return 0;
1285 }
1286 
1287 /*
1288  * Get the scsi driver to send a full inquiry to the
1289  * device and use the results to fill out the global
1290  * parameter structure.
1291  *
1292  * called from:
1293  * attach
1294  * open
1295  * ioctl (to reset original blksize)
1296  */
1297 int
1298 st_mode_sense(st, flags)
1299 	struct st_softc *st;
1300 	int flags;
1301 {
1302 	u_int scsi_sense_len;
1303 	int error;
1304 	struct scsi_mode_sense cmd;
1305 	struct scsi_sense {
1306 		struct scsi_mode_header header;
1307 		struct scsi_blk_desc blk_desc;
1308 		u_char sense_data[MAX_PAGE_0_SIZE];
1309 	} scsi_sense;
1310 	struct scsi_link *sc_link = st->sc_link;
1311 
1312 	scsi_sense_len = 12 + st->page_0_size;
1313 
1314 	/*
1315 	 * Set up a mode sense
1316 	 */
1317 	bzero(&cmd, sizeof(cmd));
1318 	cmd.opcode = MODE_SENSE;
1319 	cmd.length = scsi_sense_len;
1320 
1321 	/*
1322 	 * do the command, but we don't need the results
1323 	 * just print them for our interest's sake, if asked,
1324 	 * or if we need it as a template for the mode select
1325 	 * store it away.
1326 	 */
1327 	if (error = scsi_scsi_cmd(sc_link, (struct scsi_generic *) &cmd,
1328 	    sizeof(cmd), (u_char *) &scsi_sense, scsi_sense_len,
1329 	    ST_RETRIES, 5000, NULL, flags | SCSI_DATA_IN))
1330 		return error;
1331 
1332 	st->numblks = _3btol(scsi_sense.blk_desc.nblocks);
1333 	st->media_blksize = _3btol(scsi_sense.blk_desc.blklen);
1334 	st->media_density = scsi_sense.blk_desc.density;
1335 	if (scsi_sense.header.dev_spec & SMH_DSP_WRITE_PROT)
1336 		st->flags |= ST_READONLY;
1337 	SC_DEBUG(sc_link, SDEV_DB3,
1338 	    ("density code 0x%x, %d-byte blocks, write-%s, ",
1339 	    st->media_density, st->media_blksize,
1340 	    st->flags & ST_READONLY ? "protected" : "enabled"));
1341 	SC_DEBUG(sc_link, SDEV_DB3,
1342 	    ("%sbuffered\n",
1343 	    scsi_sense.header.dev_spec & SMH_DSP_BUFF_MODE ? "" : "un"));
1344 	if (st->page_0_size)
1345 		bcopy(scsi_sense.sense_data, st->sense_data, st->page_0_size);
1346 	sc_link->flags |= SDEV_MEDIA_LOADED;
1347 	return 0;
1348 }
1349 
1350 /*
1351  * Send a filled out parameter structure to the drive to
1352  * set it into the desire modes etc.
1353  */
1354 int
1355 st_mode_select(st, flags)
1356 	struct st_softc *st;
1357 	int flags;
1358 {
1359 	u_int scsi_select_len;
1360 	int error;
1361 	struct scsi_mode_select cmd;
1362 	struct scsi_select {
1363 		struct scsi_mode_header header;
1364 		struct scsi_blk_desc blk_desc;
1365 		u_char sense_data[MAX_PAGE_0_SIZE];
1366 	} scsi_select;
1367 	struct scsi_link *sc_link = st->sc_link;
1368 
1369 	scsi_select_len = 12 + st->page_0_size;
1370 
1371 	/*
1372 	 * Set up for a mode select
1373 	 */
1374 	bzero(&cmd, sizeof(cmd));
1375 	cmd.opcode = MODE_SELECT;
1376 	cmd.length = scsi_select_len;
1377 
1378 	bzero(&scsi_select, scsi_select_len);
1379 	scsi_select.header.blk_desc_len = sizeof(struct scsi_blk_desc);
1380 	scsi_select.header.dev_spec |= SMH_DSP_BUFF_MODE_ON;
1381 	scsi_select.blk_desc.density = st->density;
1382 	if (st->flags & ST_FIXEDBLOCKS)
1383 		lto3b(st->blksize, scsi_select.blk_desc.blklen);
1384 	if (st->page_0_size)
1385 		bcopy(st->sense_data, scsi_select.sense_data, st->page_0_size);
1386 
1387 	/*
1388 	 * do the command
1389 	 */
1390 	return scsi_scsi_cmd(sc_link, (struct scsi_generic *) &cmd,
1391 	    sizeof(cmd), (u_char *) &scsi_select, scsi_select_len,
1392 	    ST_RETRIES, 5000, NULL, flags | SCSI_DATA_OUT);
1393 }
1394 
1395 /*
1396  * skip N blocks/filemarks/seq filemarks/eom
1397  */
1398 int
1399 st_space(st, number, what, flags)
1400 	struct st_softc *st;
1401 	u_int what;
1402 	int flags;
1403 	int number;
1404 {
1405 	struct scsi_space cmd;
1406 	int error;
1407 
1408 	switch (what) {
1409 	case SP_BLKS:
1410 		if (st->flags & ST_PER_ACTION) {
1411 			if (number > 0) {
1412 				st->flags &= ~ST_PER_ACTION;
1413 				return EIO;
1414 			} else if (number < 0) {
1415 				if (st->flags & ST_AT_FILEMARK) {
1416 					/*
1417 					 * Handling of ST_AT_FILEMARK
1418 					 * in st_space will fill in the
1419 					 * right file mark count.
1420 					 */
1421 					error = st_space(st, 0, SP_FILEMARKS,
1422 						flags);
1423 					if (error)
1424 						return error;
1425 				}
1426 				if (st->flags & ST_BLANK_READ) {
1427 					st->flags &= ~ST_BLANK_READ;
1428 					return EIO;
1429 				}
1430 				st->flags &= ~ST_EIO_PENDING;
1431 			}
1432 		}
1433 		break;
1434 	case SP_FILEMARKS:
1435 		if (st->flags & ST_EIO_PENDING) {
1436 			if (number > 0) {
1437 				/* pretend we just discovered the error */
1438 				st->flags &= ~ST_EIO_PENDING;
1439 				return EIO;
1440 			} else if (number < 0) {
1441 				/* back away from the error */
1442 				st->flags &= ~ST_EIO_PENDING;
1443 			}
1444 		}
1445 		if (st->flags & ST_AT_FILEMARK) {
1446 			st->flags &= ~ST_AT_FILEMARK;
1447 			number--;
1448 		}
1449 		if ((st->flags & ST_BLANK_READ) && (number < 0)) {
1450 			/* back away from unwritten tape */
1451 			st->flags &= ~ST_BLANK_READ;
1452 			number++;	/* XXX dubious */
1453 		}
1454 		break;
1455 	case SP_EOM:
1456 		if (st->flags & ST_EIO_PENDING) {
1457 			/* pretend we just discovered the error */
1458 			st->flags &= ~ST_EIO_PENDING;
1459 			return EIO;
1460 		}
1461 		if (st->flags & ST_AT_FILEMARK)
1462 			st->flags &= ~ST_AT_FILEMARK;
1463 		break;
1464 	}
1465 	if (number == 0)
1466 		return 0;
1467 
1468 	bzero(&cmd, sizeof(cmd));
1469 	cmd.opcode = SPACE;
1470 	cmd.byte2 = what;
1471 	lto3b(number, cmd.number);
1472 
1473 	return scsi_scsi_cmd(st->sc_link, (struct scsi_generic *) &cmd,
1474 	    sizeof(cmd), 0, 0, 0, 900000, NULL, flags);
1475 }
1476 
1477 /*
1478  * write N filemarks
1479  */
1480 int
1481 st_write_filemarks(st, number, flags)
1482 	struct st_softc *st;
1483 	int flags;
1484 	int number;
1485 {
1486 	struct scsi_write_filemarks cmd;
1487 
1488 	/*
1489 	 * It's hard to write a negative number of file marks.
1490 	 * Don't try.
1491 	 */
1492 	if (number < 0)
1493 		return EINVAL;
1494 	switch (number) {
1495 	case 0:		/* really a command to sync the drive's buffers */
1496 		break;
1497 	case 1:
1498 		if (st->flags & ST_FM_WRITTEN)	/* already have one down */
1499 			st->flags &= ~ST_WRITTEN;
1500 		else
1501 			st->flags |= ST_FM_WRITTEN;
1502 		st->flags &= ~ST_PER_ACTION;
1503 		break;
1504 	default:
1505 		st->flags &= ~(ST_PER_ACTION | ST_WRITTEN);
1506 	}
1507 
1508 	bzero(&cmd, sizeof(cmd));
1509 	cmd.opcode = WRITE_FILEMARKS;
1510 	lto3b(number, cmd.number);
1511 
1512 	return scsi_scsi_cmd(st->sc_link, (struct scsi_generic *) &cmd,
1513 	    sizeof(cmd), 0, 0, 0, 100000, NULL, flags);
1514 }
1515 
1516 /*
1517  * Make sure the right number of file marks is on tape if the
1518  * tape has been written.  If the position argument is true,
1519  * leave the tape positioned where it was originally.
1520  *
1521  * nmarks returns the number of marks to skip (or, if position
1522  * true, which were skipped) to get back original position.
1523  */
1524 int
1525 st_check_eod(st, position, nmarks, flags)
1526 	struct st_softc *st;
1527 	boolean position;
1528 	int *nmarks;
1529 	int flags;
1530 {
1531 	int error;
1532 
1533 	switch (st->flags & (ST_WRITTEN | ST_FM_WRITTEN | ST_2FM_AT_EOD)) {
1534 	default:
1535 		*nmarks = 0;
1536 		return 0;
1537 	case ST_WRITTEN:
1538 	case ST_WRITTEN | ST_FM_WRITTEN | ST_2FM_AT_EOD:
1539 		*nmarks = 1;
1540 		break;
1541 	case ST_WRITTEN | ST_2FM_AT_EOD:
1542 		*nmarks = 2;
1543 	}
1544 	error = st_write_filemarks(st, *nmarks, flags);
1545 	if (position && !error)
1546 		error = st_space(st, -*nmarks, SP_FILEMARKS, flags);
1547 	return error;
1548 }
1549 
1550 /*
1551  * load/unload/retension
1552  */
1553 int
1554 st_load(st, type, flags)
1555 	struct st_softc *st;
1556 	u_int type;
1557 	int flags;
1558 {
1559 	struct scsi_load cmd;
1560 
1561 	if (type != LD_LOAD) {
1562 		int error;
1563 		int nmarks;
1564 
1565 		error = st_check_eod(st, FALSE, &nmarks, flags);
1566 		if (error)
1567 			return error;
1568 	}
1569 	if (st->quirks & ST_Q_IGNORE_LOADS)
1570 		return 0;
1571 
1572 	bzero(&cmd, sizeof(cmd));
1573 	cmd.opcode = LOAD;
1574 	cmd.how = type;
1575 
1576 	return scsi_scsi_cmd(st->sc_link, (struct scsi_generic *) &cmd,
1577 	    sizeof(cmd), 0, 0, ST_RETRIES, 300000, NULL, flags);
1578 }
1579 
1580 /*
1581  *  Rewind the device
1582  */
1583 int
1584 st_rewind(st, immediate, flags)
1585 	struct st_softc *st;
1586 	u_int immediate;
1587 	int flags;
1588 {
1589 	struct scsi_rewind cmd;
1590 	int error;
1591 	int nmarks;
1592 
1593 	error = st_check_eod(st, FALSE, &nmarks, flags);
1594 	if (error)
1595 		return error;
1596 	st->flags &= ~ST_PER_ACTION;
1597 
1598 	bzero(&cmd, sizeof(cmd));
1599 	cmd.opcode = REWIND;
1600 	cmd.byte2 = immediate;
1601 
1602 	return scsi_scsi_cmd(st->sc_link, (struct scsi_generic *) &cmd,
1603 	    sizeof(cmd), 0, 0, ST_RETRIES, immediate ? 5000 : 300000, NULL,
1604 	    flags);
1605 }
1606 
1607 /*
1608  * Look at the returned sense and act on the error and detirmine
1609  * The unix error number to pass back... (0 = report no error)
1610  *                            (-1 = continue processing)
1611  */
1612 int
1613 st_interpret_sense(xs)
1614 	struct scsi_xfer *xs;
1615 {
1616 	struct scsi_link *sc_link = xs->sc_link;
1617 	struct scsi_sense_data *sense = &xs->sense;
1618 	struct buf *bp = xs->bp;
1619 	struct st_softc *st = sc_link->device_softc;
1620 	u_int8_t key;
1621 	u_int32_t info;
1622 
1623 	/*
1624 	 * Get the sense fields and work out what code
1625 	 */
1626 	if (sense->error_code & SSD_ERRCODE_VALID) {
1627 		bcopy(sense->extended_info, &info, sizeof info);
1628 		info = ntohl(info);
1629 	} else
1630 		info = xs->datalen;	/* bad choice if fixed blocks */
1631 	if ((sense->error_code & SSD_ERRCODE) != 0x70)
1632 		return -1;	/* let the generic code handle it */
1633 	if (st->flags & ST_FIXEDBLOCKS) {
1634 		xs->resid = info * st->blksize;
1635 		if (sense->extended_flags & SSD_EOM) {
1636 			st->flags |= ST_EIO_PENDING;
1637 			if (bp)
1638 				bp->b_resid = xs->resid;
1639 		}
1640 		if (sense->extended_flags & SSD_FILEMARK) {
1641 			st->flags |= ST_AT_FILEMARK;
1642 			if (bp)
1643 				bp->b_resid = xs->resid;
1644 		}
1645 		if (sense->extended_flags & SSD_ILI) {
1646 			st->flags |= ST_EIO_PENDING;
1647 			if (bp)
1648 				bp->b_resid = xs->resid;
1649 			if (sense->error_code & SSD_ERRCODE_VALID &&
1650 			    (xs->flags & SCSI_SILENT) == 0)
1651 				printf("%s: block wrong size, %d blocks residual\n",
1652 				    st->sc_dev.dv_xname, info);
1653 
1654 			/*
1655 			 * This quirk code helps the drive read
1656 			 * the first tape block, regardless of
1657 			 * format.  That is required for these
1658 			 * drives to return proper MODE SENSE
1659 			 * information.
1660 			 */
1661 			if ((st->quirks & ST_Q_SENSE_HELP) &&
1662 			    !(sc_link->flags & SDEV_MEDIA_LOADED))
1663 				st->blksize -= 512;
1664 		}
1665 		/*
1666 		 * If no data was tranfered, do it immediatly
1667 		 */
1668 		if (xs->resid >= xs->datalen) {
1669 			if (st->flags & ST_EIO_PENDING)
1670 				return EIO;
1671 			if (st->flags & ST_AT_FILEMARK) {
1672 				if (bp)
1673 					bp->b_resid = xs->resid;
1674 				return 0;
1675 			}
1676 		}
1677 	} else {		/* must be variable mode */
1678 		xs->resid = xs->datalen;	/* to be sure */
1679 		if (sense->extended_flags & SSD_EOM)
1680 			return EIO;
1681 		if (sense->extended_flags & SSD_FILEMARK) {
1682 			if (bp)
1683 				bp->b_resid = bp->b_bcount;
1684 			return 0;
1685 		}
1686 		if (sense->extended_flags & SSD_ILI) {
1687 			if (info < 0) {
1688 				/*
1689 				 * the record was bigger than the read
1690 				 */
1691 				if ((xs->flags & SCSI_SILENT) == 0)
1692 					printf("%s: %d-byte record too big\n",
1693 					    st->sc_dev.dv_xname,
1694 					    xs->datalen - info);
1695 				return EIO;
1696 			}
1697 			xs->resid = info;
1698 			if (bp)
1699 				bp->b_resid = info;
1700 		}
1701 	}
1702 	key = sense->extended_flags & SSD_KEY;
1703 
1704 	if (key == 0x8) {
1705 		/*
1706 		 * This quirk code helps the drive read the
1707 		 * first tape block, regardless of format.  That
1708 		 * is required for these drives to return proper
1709 		 * MODE SENSE information.
1710 		 */
1711 		if ((st->quirks & ST_Q_SENSE_HELP) &&
1712 		    !(sc_link->flags & SDEV_MEDIA_LOADED)) {
1713 			/* still starting */
1714 			st->blksize -= 512;
1715 		} else if (!(st->flags & (ST_2FM_AT_EOD | ST_BLANK_READ))) {
1716 			st->flags |= ST_BLANK_READ;
1717 			xs->resid = xs->datalen;
1718 			if (bp) {
1719 				bp->b_resid = xs->resid;
1720 				/* return an EOF */
1721 			}
1722 			return 0;
1723 		}
1724 	}
1725 	return -1;		/* let the default/generic handler handle it */
1726 }
1727 
1728 /*
1729  * The quirk here is that the drive returns some value to st_mode_sense
1730  * incorrectly until the tape has actually passed by the head.
1731  *
1732  * The method is to set the drive to large fixed-block state (user-specified
1733  * density and 1024-byte blocks), then read and rewind to get it to sense the
1734  * tape.  If that doesn't work, try 512-byte fixed blocks.  If that doesn't
1735  * work, as a last resort, try variable- length blocks.  The result will be
1736  * the ability to do an accurate st_mode_sense.
1737  *
1738  * We know we can do a rewind because we just did a load, which implies rewind.
1739  * Rewind seems preferable to space backward if we have a virgin tape.
1740  *
1741  * The rest of the code for this quirk is in ILI processing and BLANK CHECK
1742  * error processing, both part of st_interpret_sense.
1743  */
1744 int
1745 st_touch_tape(st)
1746 	struct st_softc *st;
1747 {
1748 	char *buf;
1749 	int readsize;
1750 	int error;
1751 
1752 	buf = malloc(1024, M_TEMP, M_NOWAIT);
1753 	if (!buf)
1754 		return ENOMEM;
1755 
1756 	if (error = st_mode_sense(st, 0))
1757 		goto bad;
1758 	st->blksize = 1024;
1759 	do {
1760 		switch (st->blksize) {
1761 		case 512:
1762 		case 1024:
1763 			readsize = st->blksize;
1764 			st->flags |= ST_FIXEDBLOCKS;
1765 			break;
1766 		default:
1767 			readsize = 1;
1768 			st->flags &= ~ST_FIXEDBLOCKS;
1769 		}
1770 		if (error = st_mode_select(st, 0))
1771 			goto bad;
1772 		st_read(st, buf, readsize, SCSI_SILENT);	/* XXX */
1773 		if (error = st_rewind(st, 0, 0)) {
1774 bad:			free(buf, M_TEMP);
1775 			return error;
1776 		}
1777 	} while (readsize != 1 && readsize > st->blksize);
1778 
1779 	free(buf, M_TEMP);
1780 	return 0;
1781 }
1782 
1783 int
1784 stdump(dev, blkno, va, size)
1785 	dev_t dev;
1786 	daddr_t blkno;
1787 	caddr_t va;
1788 	size_t size;
1789 {
1790 
1791 	/* Not implemented. */
1792 	return ENXIO;
1793 }
1794