xref: /netbsd-src/sys/dev/scsipi/st.c (revision 08c81a9c2dc8c7300e893321eb65c0925d60871c)
1 /*	$NetBSD: st.c,v 1.157 2002/09/06 13:18:43 gehenna Exp $ */
2 /*-
3  * Copyright (c) 1998 The NetBSD Foundation, Inc.
4  * All rights reserved.
5  *
6  * This code is derived from software contributed to The NetBSD Foundation
7  * by Charles M. Hannum.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. All advertising materials mentioning features or use of this software
18  *    must display the following acknowledgement:
19  *        This product includes software developed by the NetBSD
20  *        Foundation, Inc. and its contributors.
21  * 4. Neither the name of The NetBSD Foundation nor the names of its
22  *    contributors may be used to endorse or promote products derived
23  *    from this software without specific prior written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
26  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
29  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35  * POSSIBILITY OF SUCH DAMAGE.
36  */
37 
38 /*
39  * Originally written by Julian Elischer (julian@tfs.com)
40  * for TRW Financial Systems for use under the MACH(2.5) operating system.
41  *
42  * TRW Financial Systems, in accordance with their agreement with Carnegie
43  * Mellon University, makes this software available to CMU to distribute
44  * or use in any manner that they see fit as long as this message is kept with
45  * the software. For this reason TFS also grants any other persons or
46  * organisations permission to use or modify this software.
47  *
48  * TFS supplies this software to be publicly redistributed
49  * on the understanding that TFS is not responsible for the correct
50  * functioning of this software in any circumstances.
51  *
52  * Ported to run under 386BSD by Julian Elischer (julian@tfs.com) Sept 1992
53  * major changes by Julian Elischer (julian@jules.dialix.oz.au) May 1993
54  *
55  * A lot of rewhacking done by mjacob (mjacob@nas.nasa.gov).
56  */
57 
58 #include <sys/cdefs.h>
59 __KERNEL_RCSID(0, "$NetBSD: st.c,v 1.157 2002/09/06 13:18:43 gehenna Exp $");
60 
61 #include "opt_scsi.h"
62 
63 #include <sys/param.h>
64 #include <sys/systm.h>
65 #include <sys/fcntl.h>
66 #include <sys/errno.h>
67 #include <sys/ioctl.h>
68 #include <sys/malloc.h>
69 #include <sys/buf.h>
70 #include <sys/proc.h>
71 #include <sys/user.h>
72 #include <sys/mtio.h>
73 #include <sys/device.h>
74 #include <sys/conf.h>
75 #include <sys/kernel.h>
76 #include <sys/vnode.h>
77 
78 #include <dev/scsipi/scsi_all.h>
79 #include <dev/scsipi/scsi_tape.h>
80 #include <dev/scsipi/stvar.h>
81 
82 /* Defines for device specific stuff */
83 #define DEF_FIXED_BSIZE  512
84 
85 #define STMODE(z)	( minor(z)       & 0x03)
86 #define STDSTY(z)	((minor(z) >> 2) & 0x03)
87 #define STUNIT(z)	((minor(z) >> 4)       )
88 #define STNMINOR	16
89 
90 #define NORMAL_MODE	0
91 #define NOREW_MODE	1
92 #define EJECT_MODE	2
93 #define CTRL_MODE	3
94 
95 #define	FALSE		0
96 #define	TRUE		1
97 
98 #ifndef		ST_MOUNT_DELAY
99 #define		ST_MOUNT_DELAY		0
100 #endif
101 
102 dev_type_open(stopen);
103 dev_type_close(stclose);
104 dev_type_read(stread);
105 dev_type_write(stwrite);
106 dev_type_ioctl(stioctl);
107 dev_type_strategy(ststrategy);
108 dev_type_dump(stdump);
109 
110 const struct bdevsw st_bdevsw = {
111 	stopen, stclose, ststrategy, stioctl, stdump, nosize, D_TAPE
112 };
113 
114 const struct cdevsw st_cdevsw = {
115 	stopen, stclose, stread, stwrite, stioctl,
116 	nostop, notty, nopoll, nommap, D_TAPE
117 };
118 
119 /*
120  * Define various devices that we know mis-behave in some way,
121  * and note how they are bad, so we can correct for them
122  */
123 
124 const struct st_quirk_inquiry_pattern st_quirk_patterns[] = {
125 	{{T_SEQUENTIAL, T_REMOV,
126 	 "        ", "                ", "    "}, {0, 0, {
127 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
128 		{ST_Q_FORCE_BLKSIZE, 512, QIC_24},	/* minor 4-7 */
129 		{ST_Q_FORCE_BLKSIZE, 0, HALFINCH_1600},	/* minor 8-11 */
130 		{ST_Q_FORCE_BLKSIZE, 0, HALFINCH_6250}	/* minor 12-15 */
131 	}}},
132 	{{T_SEQUENTIAL, T_REMOV,
133 	 "TANDBERG", " TDC 3600       ", ""},     {0, 12, {
134 		{0, 0, 0},				/* minor 0-3 */
135 		{ST_Q_FORCE_BLKSIZE, 0, QIC_525},	/* minor 4-7 */
136 		{0, 0, QIC_150},			/* minor 8-11 */
137 		{0, 0, QIC_120}				/* minor 12-15 */
138 	}}},
139  	{{T_SEQUENTIAL, T_REMOV,
140  	 "TANDBERG", " TDC 3800       ", ""},     {0, 0, {
141 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
142 		{0, 0, QIC_525},			/* minor 4-7 */
143 		{0, 0, QIC_150},			/* minor 8-11 */
144 		{0, 0, QIC_120}				/* minor 12-15 */
145 	}}},
146 	/*
147 	 * lacking a manual for the 4200, it's not clear what the
148 	 * specific density codes should be- the device is a 2.5GB
149 	 * capable QIC drive, those density codes aren't readily
150 	 * availabel. The 'default' will just have to do.
151 	 */
152  	{{T_SEQUENTIAL, T_REMOV,
153  	 "TANDBERG", " TDC 4200       ", ""},     {0, 0, {
154 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
155 		{0, 0, QIC_525},			/* minor 4-7 */
156 		{0, 0, QIC_150},			/* minor 8-11 */
157 		{0, 0, QIC_120}				/* minor 12-15 */
158 	}}},
159 	/*
160 	 * At least -005 and -007 need this.  I'll assume they all do unless I
161 	 * hear otherwise.  - mycroft, 31MAR1994
162 	 */
163 	{{T_SEQUENTIAL, T_REMOV,
164 	 "ARCHIVE ", "VIPER 2525 25462", ""},     {0, 0, {
165 		{ST_Q_SENSE_HELP, 0, 0},		/* minor 0-3 */
166 		{ST_Q_SENSE_HELP, 0, QIC_525},		/* minor 4-7 */
167 		{0, 0, QIC_150},			/* minor 8-11 */
168 		{0, 0, QIC_120}				/* minor 12-15 */
169 	}}},
170 	/*
171 	 * One user reports that this works for his tape drive.  It probably
172 	 * needs more work.  - mycroft, 09APR1994
173 	 */
174 	{{T_SEQUENTIAL, T_REMOV,
175 	 "SANKYO  ", "CP525           ", ""},    {0, 0, {
176 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
177 		{ST_Q_FORCE_BLKSIZE, 512, QIC_525},	/* minor 4-7 */
178 		{0, 0, QIC_150},			/* minor 8-11 */
179 		{0, 0, QIC_120}				/* minor 12-15 */
180 	}}},
181 	{{T_SEQUENTIAL, T_REMOV,
182 	 "ANRITSU ", "DMT780          ", ""},     {0, 0, {
183 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
184 		{ST_Q_FORCE_BLKSIZE, 512, QIC_525},	/* minor 4-7 */
185 		{0, 0, QIC_150},			/* minor 8-11 */
186 		{0, 0, QIC_120}				/* minor 12-15 */
187 	}}},
188 	{{T_SEQUENTIAL, T_REMOV,
189 	 "ARCHIVE ", "VIPER 150  21247", ""},     {ST_Q_ERASE_NOIMM, 12, {
190 		{ST_Q_SENSE_HELP, 0, 0},		/* minor 0-3 */
191 		{0, 0, QIC_150},			/* minor 4-7 */
192 		{0, 0, QIC_120},			/* minor 8-11 */
193 		{0, 0, QIC_24}				/* minor 12-15 */
194 	}}},
195 	{{T_SEQUENTIAL, T_REMOV,
196 	 "ARCHIVE ", "VIPER 150  21531", ""},     {ST_Q_ERASE_NOIMM, 12, {
197 		{ST_Q_SENSE_HELP, 0, 0},		/* minor 0-3 */
198 		{0, 0, QIC_150},			/* minor 4-7 */
199 		{0, 0, QIC_120},			/* minor 8-11 */
200 		{0, 0, QIC_24}				/* minor 12-15 */
201 	}}},
202 	{{T_SEQUENTIAL, T_REMOV,
203 	 "WANGTEK ", "5099ES SCSI", ""},          {0, 0, {
204 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
205 		{0, 0, QIC_11},				/* minor 4-7 */
206 		{0, 0, QIC_24},				/* minor 8-11 */
207 		{0, 0, QIC_24}				/* minor 12-15 */
208 	}}},
209 	{{T_SEQUENTIAL, T_REMOV,
210 	 "WANGTEK ", "5150ES SCSI", ""},          {0, 0, {
211 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
212 		{0, 0, QIC_24},				/* minor 4-7 */
213 		{0, 0, QIC_120},			/* minor 8-11 */
214 		{0, 0, QIC_150}				/* minor 12-15 */
215 	}}},
216 	{{T_SEQUENTIAL, T_REMOV,
217 	 "WANGTEK ", "5525ES SCSI REV7", ""},     {0, 0, {
218 		{0, 0, 0},				/* minor 0-3 */
219 		{ST_Q_BLKSIZE, 0, QIC_525},		/* minor 4-7 */
220 		{0, 0, QIC_150},			/* minor 8-11 */
221 		{0, 0, QIC_120}				/* minor 12-15 */
222 	}}},
223 	{{T_SEQUENTIAL, T_REMOV,
224 	 "WangDAT ", "Model 1300      ", ""},     {0, 0, {
225 		{0, 0, 0},				/* minor 0-3 */
226 		{ST_Q_FORCE_BLKSIZE, 512, DDS},		/* minor 4-7 */
227 		{ST_Q_FORCE_BLKSIZE, 1024, DDS},	/* minor 8-11 */
228 		{ST_Q_FORCE_BLKSIZE, 0, DDS}		/* minor 12-15 */
229 	}}},
230 	{{T_SEQUENTIAL, T_REMOV,
231 	 "EXABYTE ", "EXB-8200        ", "263H"}, {0, 5, {
232 		{0, 0, 0},				/* minor 0-3 */
233 		{0, 0, 0},				/* minor 4-7 */
234 		{0, 0, 0},				/* minor 8-11 */
235 		{0, 0, 0}				/* minor 12-15 */
236 	}}},
237 	{{T_SEQUENTIAL, T_REMOV,
238 	 "STK",      "9490",             ""},
239 				{ST_Q_FORCE_BLKSIZE, 0, {
240 		{0, 0, 0},				/* minor 0-3 */
241 		{0, 0, 0},				/* minor 4-7 */
242 		{0, 0, 0},				/* minor 8-11 */
243 		{0, 0, 0}				/* minor 12-15 */
244 	}}},
245 	{{T_SEQUENTIAL, T_REMOV,
246 	 "STK",      "SD-3",             ""},
247 				{ST_Q_FORCE_BLKSIZE, 0, {
248 		{0, 0, 0},				/* minor 0-3 */
249 		{0, 0, 0},				/* minor 4-7 */
250 		{0, 0, 0},				/* minor 8-11 */
251 		{0, 0, 0}				/* minor 12-15 */
252 	}}},
253 	{{T_SEQUENTIAL, T_REMOV,
254 	 "IBM",      "03590",            ""},     {ST_Q_IGNORE_LOADS, 0, {
255 		{0, 0, 0},				/* minor 0-3 */
256 		{0, 0, 0},				/* minor 4-7 */
257 		{0, 0, 0},				/* minor 8-11 */
258 		{0, 0, 0}				/* minor 12-15 */
259 	}}},
260 	{{T_SEQUENTIAL, T_REMOV,
261 	 "HP      ", "T4000s          ", ""},     {ST_Q_UNIMODAL, 0, {
262 		{0, 0, QIC_3095},			/* minor 0-3 */
263 		{0, 0, QIC_3095},			/* minor 4-7 */
264 		{0, 0, QIC_3095},			/* minor 8-11 */
265 		{0, 0, QIC_3095},			/* minor 12-15 */
266 	}}},
267 #if 0
268 	{{T_SEQUENTIAL, T_REMOV,
269 	 "EXABYTE ", "EXB-8200        ", ""},     {0, 12, {
270 		{0, 0, 0},				/* minor 0-3 */
271 		{0, 0, 0},				/* minor 4-7 */
272 		{0, 0, 0},				/* minor 8-11 */
273 		{0, 0, 0}				/* minor 12-15 */
274 	}}},
275 #endif
276 	{{T_SEQUENTIAL, T_REMOV,
277 	 "TEAC    ", "MT-2ST/N50      ", ""},     {ST_Q_IGNORE_LOADS, 0, {
278 		{0, 0, 0},			        /* minor 0-3 */
279 		{0, 0, 0},			        /* minor 4-7 */
280 		{0, 0, 0},			        /* minor 8-11 */
281 		{0, 0, 0}			        /* minor 12-15 */
282 	}}},
283 	{{T_SEQUENTIAL, T_REMOV,
284 	 "OnStream", "ADR50 Drive", ""},	  {ST_Q_UNIMODAL, 0, {
285 		{ST_Q_FORCE_BLKSIZE, 512, 0},	        /* minor 0-3 */
286 		{ST_Q_FORCE_BLKSIZE, 512, 0},	        /* minor 4-7 */
287 		{ST_Q_FORCE_BLKSIZE, 512, 0},	        /* minor 8-11 */
288 		{ST_Q_FORCE_BLKSIZE, 512, 0},	        /* minor 12-15 */
289 	}}},
290 	{{T_SEQUENTIAL, T_REMOV,
291 	 "OnStream DI-30",      "",   "1.0"},  {ST_Q_NOFILEMARKS, 0, {
292 		{0, 0, 0},                              /* minor 0-3 */
293 		{0, 0, 0},                              /* minor 4-7 */
294 		{0, 0, 0},                              /* minor 8-11 */
295 		{0, 0, 0}                               /* minor 12-15 */
296 	}}},
297 	{{T_SEQUENTIAL, T_REMOV,
298 	 "NCR H621", "0-STD-03-46F880 ", ""},     {ST_Q_NOPREVENT, 0, {
299 		{0, 0, 0},			       /* minor 0-3 */
300 		{0, 0, 0},			       /* minor 4-7 */
301 		{0, 0, 0},			       /* minor 8-11 */
302 		{0, 0, 0}			       /* minor 12-15 */
303 	}}},
304 };
305 
306 #define NOEJECT 0
307 #define EJECT 1
308 
309 void	st_identify_drive __P((struct st_softc *,
310 	    struct scsipi_inquiry_pattern *));
311 void	st_loadquirks __P((struct st_softc *));
312 int	st_mount_tape __P((dev_t, int));
313 void	st_unmount __P((struct st_softc *, boolean));
314 int	st_decide_mode __P((struct st_softc *, boolean));
315 void	ststart __P((struct scsipi_periph *));
316 void	stdone __P((struct scsipi_xfer *));
317 int	st_read __P((struct st_softc *, char *, int, int));
318 int	st_space __P((struct st_softc *, int, u_int, int));
319 int	st_write_filemarks __P((struct st_softc *, int, int));
320 int	st_check_eod __P((struct st_softc *, boolean, int *, int));
321 int	st_load __P((struct st_softc *, u_int, int));
322 int	st_rewind __P((struct st_softc *, u_int, int));
323 int	st_interpret_sense __P((struct scsipi_xfer *));
324 int	st_touch_tape __P((struct st_softc *));
325 int	st_erase __P((struct st_softc *, int full, int flags));
326 int	st_rdpos __P((struct st_softc *, int, u_int32_t *));
327 int	st_setpos __P((struct st_softc *, int, u_int32_t *));
328 
329 const struct scsipi_periphsw st_switch = {
330 	st_interpret_sense,
331 	ststart,
332 	NULL,
333 	stdone
334 };
335 
336 #if	defined(ST_ENABLE_EARLYWARN)
337 #define	ST_INIT_FLAGS	ST_EARLYWARN
338 #else
339 #define	ST_INIT_FLAGS	0
340 #endif
341 
342 /*
343  * The routine called by the low level scsi routine when it discovers
344  * A device suitable for this driver
345  */
346 void
347 stattach(parent, st, aux)
348 	struct device *parent;
349 	struct st_softc *st;
350 	void *aux;
351 {
352 	struct scsipibus_attach_args *sa = aux;
353 	struct scsipi_periph *periph = sa->sa_periph;
354 
355 	SC_DEBUG(periph, SCSIPI_DB2, ("stattach: "));
356 
357 	/*
358 	 * Store information needed to contact our base driver
359 	 */
360 	st->sc_periph = periph;
361 	periph->periph_dev = &st->sc_dev;
362 	periph->periph_switch = &st_switch;
363 
364 	/*
365 	 * Set initial flags
366 	 */
367 
368 	st->flags = ST_INIT_FLAGS;
369 
370 	/*
371 	 * Set up the buf queue for this device
372 	 */
373 	bufq_alloc(&st->buf_queue, BUFQ_FCFS);
374 
375 	/*
376 	 * Check if the drive is a known criminal and take
377 	 * Any steps needed to bring it into line
378 	 */
379 	st_identify_drive(st, &sa->sa_inqbuf);
380 	/*
381 	 * Use the subdriver to request information regarding the drive.
382 	 */
383 	printf("\n");
384 	printf("%s: %s", st->sc_dev.dv_xname, st->quirkdata ? "rogue, " : "");
385 	if (scsipi_test_unit_ready(periph,
386 	    XS_CTL_DISCOVERY | XS_CTL_SILENT | XS_CTL_IGNORE_MEDIA_CHANGE) ||
387 	    st->ops(st, ST_OPS_MODESENSE,
388 	    XS_CTL_DISCOVERY | XS_CTL_SILENT | XS_CTL_IGNORE_MEDIA_CHANGE))
389 		printf("drive empty\n");
390 	else {
391 		printf("density code %d, ", st->media_density);
392 		if (st->media_blksize > 0)
393 			printf("%d-byte", st->media_blksize);
394 		else
395 			printf("variable");
396 		printf(" blocks, write-%s\n",
397 		    (st->flags & ST_READONLY) ? "protected" : "enabled");
398 	}
399 
400 #if NRND > 0
401 	rnd_attach_source(&st->rnd_source, st->sc_dev.dv_xname,
402 			  RND_TYPE_TAPE, 0);
403 #endif
404 }
405 
406 int
407 stactivate(self, act)
408 	struct device *self;
409 	enum devact act;
410 {
411 	int rv = 0;
412 
413 	switch (act) {
414 	case DVACT_ACTIVATE:
415 		rv = EOPNOTSUPP;
416 		break;
417 
418 	case DVACT_DEACTIVATE:
419 		/*
420 		 * Nothing to do; we key off the device's DVF_ACTIVE.
421 		 */
422 		break;
423 	}
424 	return (rv);
425 }
426 
427 int
428 stdetach(self, flags)
429 	struct device *self;
430 	int flags;
431 {
432 	struct st_softc *st = (struct st_softc *)self;
433 	struct buf *bp;
434 	int s, bmaj, cmaj, mn;
435 
436 	/* locate the major number */
437 	bmaj = bdevsw_lookup_major(&st_bdevsw);
438 	cmaj = cdevsw_lookup_major(&st_cdevsw);
439 
440 	s = splbio();
441 
442 	/* Kill off any queued buffers. */
443 	while ((bp = BUFQ_GET(&st->buf_queue)) != NULL) {
444 		bp->b_error = EIO;
445 		bp->b_flags |= B_ERROR;
446 		bp->b_resid = bp->b_bcount;
447 		biodone(bp);
448 	}
449 
450 	bufq_free(&st->buf_queue);
451 
452 	/* Kill off any pending commands. */
453 	scsipi_kill_pending(st->sc_periph);
454 
455 	splx(s);
456 
457 	/* Nuke the vnodes for any open instances */
458 	mn = STUNIT(self->dv_unit);
459 	vdevgone(bmaj, mn, mn+STNMINOR-1, VBLK);
460 	vdevgone(cmaj, mn, mn+STNMINOR-1, VCHR);
461 
462 
463 #if NRND > 0
464 	/* Unhook the entropy source. */
465 	rnd_detach_source(&st->rnd_source);
466 #endif
467 
468 	return (0);
469 }
470 
471 /*
472  * Use the inquiry routine in 'scsi_base' to get drive info so we can
473  * Further tailor our behaviour.
474  */
475 void
476 st_identify_drive(st, inqbuf)
477 	struct st_softc *st;
478 	struct scsipi_inquiry_pattern *inqbuf;
479 {
480 	struct st_quirk_inquiry_pattern *finger;
481 	int priority;
482 
483 	finger = (struct st_quirk_inquiry_pattern *)scsipi_inqmatch(inqbuf,
484 	    (caddr_t)st_quirk_patterns,
485 	    sizeof(st_quirk_patterns) / sizeof(st_quirk_patterns[0]),
486 	    sizeof(st_quirk_patterns[0]), &priority);
487 	if (priority != 0) {
488 		st->quirkdata = &finger->quirkdata;
489 		st->drive_quirks = finger->quirkdata.quirks;
490 		st->quirks = finger->quirkdata.quirks;	/* start value */
491 		st->page_0_size = finger->quirkdata.page_0_size;
492 		st_loadquirks(st);
493 	}
494 }
495 
496 /*
497  * initialise the subdevices to the default (QUIRK) state.
498  * this will remove any setting made by the system operator or previous
499  * operations.
500  */
501 void
502 st_loadquirks(st)
503 	struct st_softc *st;
504 {
505 	int i;
506 	struct	modes *mode;
507 	struct	modes *mode2;
508 
509 	mode = st->quirkdata->modes;
510 	mode2 = st->modes;
511 	for (i = 0; i < 4; i++) {
512 		memset(mode2, 0, sizeof(struct modes));
513 		st->modeflags[i] &= ~(BLKSIZE_SET_BY_QUIRK |
514 		    DENSITY_SET_BY_QUIRK | BLKSIZE_SET_BY_USER |
515 		    DENSITY_SET_BY_USER);
516 		if ((mode->quirks | st->drive_quirks) & ST_Q_FORCE_BLKSIZE) {
517 			mode2->blksize = mode->blksize;
518 			st->modeflags[i] |= BLKSIZE_SET_BY_QUIRK;
519 		}
520 		if (mode->density) {
521 			mode2->density = mode->density;
522 			st->modeflags[i] |= DENSITY_SET_BY_QUIRK;
523 		}
524 		mode2->quirks |= mode->quirks;
525 		mode++;
526 		mode2++;
527 	}
528 }
529 
530 /*
531  * open the device.
532  */
533 int
534 stopen(dev, flags, mode, p)
535 	dev_t dev;
536 	int flags;
537 	int mode;
538 	struct proc *p;
539 {
540 	u_int stmode, dsty;
541 	int error, sflags, unit, tries, ntries;
542 	struct st_softc *st;
543 	struct scsipi_periph *periph;
544 	struct scsipi_adapter *adapt;
545 
546 	unit = STUNIT(dev);
547 	if (unit >= st_cd.cd_ndevs)
548 		return (ENXIO);
549 	st = st_cd.cd_devs[unit];
550 	if (st == NULL)
551 		return (ENXIO);
552 
553 	stmode = STMODE(dev);
554 	dsty = STDSTY(dev);
555 
556 	periph = st->sc_periph;
557 	adapt = periph->periph_channel->chan_adapter;
558 
559 	SC_DEBUG(periph, SCSIPI_DB1, ("open: dev=0x%x (unit %d (of %d))\n", dev,
560 	    unit, st_cd.cd_ndevs));
561 
562 
563 	/*
564 	 * Only allow one at a time
565 	 */
566 	if (periph->periph_flags & PERIPH_OPEN) {
567 		printf("%s: already open\n", st->sc_dev.dv_xname);
568 		return (EBUSY);
569 	}
570 
571 	if ((error = scsipi_adapter_addref(adapt)) != 0)
572 		return (error);
573 
574 	/*
575 	 * clear any latched errors.
576 	 */
577 	st->mt_resid = 0;
578 	st->mt_erreg = 0;
579 	st->asc = 0;
580 	st->ascq = 0;
581 
582 	/*
583 	 * Catch any unit attention errors. Be silent about this
584 	 * unless we're already mounted. We ignore media change
585 	 * if we're in control mode or not mounted yet.
586 	 */
587 	if ((st->flags & ST_MOUNTED) == 0 || stmode == CTRL_MODE) {
588 #ifdef SCSIDEBUG
589 		sflags = XS_CTL_IGNORE_MEDIA_CHANGE;
590 #else
591 		sflags = XS_CTL_SILENT|XS_CTL_IGNORE_MEDIA_CHANGE;
592 #endif
593 	} else
594 		sflags = 0;
595 
596 	/*
597 	 * If we're already mounted or we aren't configured for
598 	 * a mount delay, only try a test unit ready once. Otherwise,
599 	 * try up to ST_MOUNT_DELAY times with a rest interval of
600 	 * one second between each try.
601 	 */
602 
603 	if ((st->flags & ST_MOUNTED) || ST_MOUNT_DELAY == 0) {
604 		ntries = 1;
605 	} else {
606 		ntries = ST_MOUNT_DELAY;
607 	}
608 
609 	for (error = tries = 0; tries < ntries; tries++) {
610 		int slpintr, oflags;
611 
612 		/*
613 		 * If we had no error, or we're opening the control mode
614 		 * device, we jump out right away.
615 		 */
616 
617 		error = scsipi_test_unit_ready(periph, sflags);
618 		if (error == 0 || stmode == CTRL_MODE) {
619 			break;
620 		}
621 
622 		/*
623 		 * We had an error.
624 		 *
625 		 * If we're already mounted or we aren't configured for
626 		 * a mount delay, or the error isn't a NOT READY error,
627 		 * skip to the error exit now.
628 		 */
629 		if ((st->flags & ST_MOUNTED) || ST_MOUNT_DELAY == 0 ||
630 		    (st->mt_key != SKEY_NOT_READY)) {
631 			goto bad;
632 		}
633 
634 		/*
635 		 * clear any latched errors.
636 		 */
637 		st->mt_resid = 0;
638 		st->mt_erreg = 0;
639 		st->asc = 0;
640 		st->ascq = 0;
641 
642 		/*
643 		 * Fake that we have the device open so
644 		 * we block other apps from getting in.
645 		 */
646 
647 		oflags = periph->periph_flags;
648 		periph->periph_flags |= PERIPH_OPEN;
649 
650 		slpintr = tsleep(&lbolt, PUSER|PCATCH, "stload", 0);
651 
652 		periph->periph_flags = oflags;	/* restore flags */
653 		if (slpintr) {
654 			goto bad;
655 		}
656 	}
657 
658 
659 	/*
660 	 * If the mode is 3 (e.g. minor = 3,7,11,15) then the device has
661 	 * been opened to set defaults and perform other, usually non-I/O
662 	 * related, operations. In this case, do a quick check to see
663 	 * whether the unit actually had a tape loaded (this will be known
664 	 * as to whether or not we got a NOT READY for the above
665 	 * unit attention). If a tape is there, go do a mount sequence.
666 	 */
667 	if (stmode == CTRL_MODE && st->mt_key == SKEY_NOT_READY) {
668 		periph->periph_flags |= PERIPH_OPEN;
669 		return (0);
670 	}
671 
672 	/*
673 	 * If we get this far and had an error set, that means we failed
674 	 * to pass the 'test unit ready' test for the non-controlmode device,
675 	 * so we bounce the open.
676 	 */
677 
678 	if (error)
679 		return (error);
680 
681 	/*
682 	 * Else, we're now committed to saying we're open.
683 	 */
684 
685 	periph->periph_flags |= PERIPH_OPEN; /* unit attn are now errors */
686 
687 	/*
688 	 * If it's a different mode, or if the media has been
689 	 * invalidated, unmount the tape from the previous
690 	 * session but continue with open processing
691 	 */
692 	if (st->last_dsty != dsty ||
693 	    (periph->periph_flags & PERIPH_MEDIA_LOADED) == 0)
694 		st_unmount(st, NOEJECT);
695 
696 	/*
697 	 * If we are not mounted, then we should start a new
698 	 * mount session.
699 	 */
700 	if (!(st->flags & ST_MOUNTED)) {
701 		if ((error = st_mount_tape(dev, flags)) != 0)
702 			goto bad;
703 		st->last_dsty = dsty;
704 	}
705 	if (!(st->quirks & ST_Q_NOPREVENT)) {
706 		scsipi_prevent(periph, PR_PREVENT,
707 		    XS_CTL_IGNORE_ILLEGAL_REQUEST | XS_CTL_IGNORE_NOT_READY);
708 	}
709 
710 	SC_DEBUG(periph, SCSIPI_DB2, ("open complete\n"));
711 	return (0);
712 
713 bad:
714 	st_unmount(st, NOEJECT);
715 	scsipi_adapter_delref(adapt);
716 	periph->periph_flags &= ~PERIPH_OPEN;
717 	return (error);
718 }
719 
720 /*
721  * close the device.. only called if we are the LAST
722  * occurence of an open device
723  */
724 int
725 stclose(dev, flags, mode, p)
726 	dev_t dev;
727 	int flags;
728 	int mode;
729 	struct proc *p;
730 {
731 	int stxx, error = 0;
732 	struct st_softc *st = st_cd.cd_devs[STUNIT(dev)];
733 	struct scsipi_periph *periph = st->sc_periph;
734 	struct scsipi_adapter *adapt = periph->periph_channel->chan_adapter;
735 
736 	SC_DEBUG(st->sc_periph, SCSIPI_DB1, ("closing\n"));
737 
738 	/*
739 	 * Make sure that a tape opened in write-only mode will have
740 	 * file marks written on it when closed, even if not written to.
741 	 *
742 	 * This is for SUN compatibility. Actually, the Sun way of
743 	 * things is to:
744 	 *
745 	 *	only write filemarks if there are fmks to be written and
746 	 *   		- open for write (possibly read/write)
747 	 *		- the last operation was a write
748 	 * 	or:
749 	 *		- opened for wronly
750 	 *		- no data was written (including filemarks)
751 	 */
752 
753 	stxx = st->flags & (ST_WRITTEN | ST_FM_WRITTEN);
754 	if (((flags & FWRITE) && stxx == ST_WRITTEN) ||
755 	    ((flags & O_ACCMODE) == FWRITE && stxx == 0)) {
756 		int nm;
757 		error = st_check_eod(st, FALSE, &nm, 0);
758 	}
759 
760 	/*
761 	 * Allow robots to eject tape if needed.
762 	 */
763 	scsipi_prevent(periph, PR_ALLOW,
764 	    XS_CTL_IGNORE_ILLEGAL_REQUEST | XS_CTL_IGNORE_NOT_READY);
765 
766 	switch (STMODE(dev)) {
767 	case NORMAL_MODE:
768 		st_unmount(st, NOEJECT);
769 		break;
770 	case NOREW_MODE:
771 	case CTRL_MODE:
772 		/*
773 		 * Leave mounted unless media seems to have been removed.
774 		 *
775 		 * Otherwise, if we're to terminate a tape with more than one
776 		 * filemark [ and because we're not rewinding here ], backspace
777 		 * one filemark so that later appends will see an unbroken
778 		 * sequence of:
779 		 *
780 		 *	file - FMK - file - FMK ... file - FMK FMK (EOM)
781 		 */
782 		if ((periph->periph_flags & PERIPH_MEDIA_LOADED) == 0) {
783 			st_unmount(st, NOEJECT);
784 		} else if (error == 0) {
785 			/*
786 			 * ST_WRITTEN was preserved from above.
787 			 *
788 			 * All we need to know here is:
789 			 *
790 			 *	Were we writing this tape and was the last
791 			 *	operation a write?
792 			 *
793 			 *	Are there supposed to be 2FM at EOD?
794 			 *
795 			 * If both statements are true, then we backspace
796 			 * one filemark.
797 			 */
798 			stxx |= (st->flags & ST_2FM_AT_EOD);
799 			if ((flags & FWRITE) != 0 &&
800 			    (stxx == (ST_2FM_AT_EOD|ST_WRITTEN))) {
801 				error = st_space(st, -1, SP_FILEMARKS, 0);
802 			}
803 		}
804 		break;
805 	case EJECT_MODE:
806 		st_unmount(st, EJECT);
807 		break;
808 	}
809 
810 	scsipi_wait_drain(periph);
811 
812 	scsipi_adapter_delref(adapt);
813 	periph->periph_flags &= ~PERIPH_OPEN;
814 
815 	return (error);
816 }
817 
818 /*
819  * Start a new mount session.
820  * Copy in all the default parameters from the selected device mode.
821  * and try guess any that seem to be defaulted.
822  */
823 int
824 st_mount_tape(dev, flags)
825 	dev_t dev;
826 	int flags;
827 {
828 	int unit;
829 	u_int dsty;
830 	struct st_softc *st;
831 	struct scsipi_periph *periph;
832 	int error = 0;
833 
834 	unit = STUNIT(dev);
835 	dsty = STDSTY(dev);
836 	st = st_cd.cd_devs[unit];
837 	periph = st->sc_periph;
838 
839 	if (st->flags & ST_MOUNTED)
840 		return (0);
841 
842 	SC_DEBUG(periph, SCSIPI_DB1, ("mounting\n "));
843 	st->flags |= ST_NEW_MOUNT;
844 	st->quirks = st->drive_quirks | st->modes[dsty].quirks;
845 	/*
846 	 * If the media is new, then make sure we give it a chance to
847 	 * to do a 'load' instruction.  (We assume it is new.)
848 	 */
849 	if ((error = st_load(st, LD_LOAD, XS_CTL_SILENT)) != 0)
850 		return (error);
851 	/*
852 	 * Throw another dummy instruction to catch
853 	 * 'Unit attention' errors. Many drives give
854 	 * these after doing a Load instruction (with
855 	 * the MEDIUM MAY HAVE CHANGED asc/ascq).
856 	 */
857 	scsipi_test_unit_ready(periph, XS_CTL_SILENT);	/* XXX */
858 
859 	/*
860 	 * Some devices can't tell you much until they have been
861 	 * asked to look at the media. This quirk does this.
862 	 */
863 	if (st->quirks & ST_Q_SENSE_HELP)
864 		if ((error = st_touch_tape(st)) != 0)
865 			return (error);
866 	/*
867 	 * Load the physical device parameters
868 	 * loads: blkmin, blkmax
869 	 */
870 	if ((error = st->ops(st, ST_OPS_RBL, 0)) != 0)
871 		return (error);
872 	/*
873 	 * Load the media dependent parameters
874 	 * includes: media_blksize,media_density,numblks
875 	 * As we have a tape in, it should be reflected here.
876 	 * If not you may need the "quirk" above.
877 	 */
878 	if ((error = st->ops(st, ST_OPS_MODESENSE, 0)) != 0)
879 		return (error);
880 	/*
881 	 * If we have gained a permanent density from somewhere,
882 	 * then use it in preference to the one supplied by
883 	 * default by the driver.
884 	 */
885 	if (st->modeflags[dsty] & (DENSITY_SET_BY_QUIRK | DENSITY_SET_BY_USER))
886 		st->density = st->modes[dsty].density;
887 	else
888 		st->density = st->media_density;
889 	/*
890 	 * If we have gained a permanent blocksize
891 	 * then use it in preference to the one supplied by
892 	 * default by the driver.
893 	 */
894 	st->flags &= ~ST_FIXEDBLOCKS;
895 	if (st->modeflags[dsty] &
896 	    (BLKSIZE_SET_BY_QUIRK | BLKSIZE_SET_BY_USER)) {
897 		st->blksize = st->modes[dsty].blksize;
898 		if (st->blksize)
899 			st->flags |= ST_FIXEDBLOCKS;
900 	} else {
901 		if ((error = st_decide_mode(st, FALSE)) != 0)
902 			return (error);
903 	}
904 	if ((error = st->ops(st, ST_OPS_MODESELECT, 0)) != 0) {
905 		/* ATAPI will return ENODEV for this, and this may be OK */
906 		if (error != ENODEV) {
907 			printf("%s: cannot set selected mode\n",
908 			    st->sc_dev.dv_xname);
909 			return (error);
910 		}
911 	}
912 	st->flags &= ~ST_NEW_MOUNT;
913 	st->flags |= ST_MOUNTED;
914 	periph->periph_flags |= PERIPH_MEDIA_LOADED;	/* move earlier? */
915 	st->blkno = st->fileno = (daddr_t) 0;
916 	return (0);
917 }
918 
919 /*
920  * End the present mount session.
921  * Rewind, and optionally eject the tape.
922  * Reset various flags to indicate that all new
923  * operations require another mount operation
924  */
925 void
926 st_unmount(st, eject)
927 	struct st_softc *st;
928 	boolean eject;
929 {
930 	struct scsipi_periph *periph = st->sc_periph;
931 	int nmarks;
932 
933 	if ((st->flags & ST_MOUNTED) == 0)
934 		return;
935 	SC_DEBUG(periph, SCSIPI_DB1, ("unmounting\n"));
936 	st_check_eod(st, FALSE, &nmarks, XS_CTL_IGNORE_NOT_READY);
937 	st_rewind(st, 0, XS_CTL_IGNORE_NOT_READY);
938 
939 	/*
940 	 * Section 9.3.3 of the SCSI specs states that a device shall return
941 	 * the density value specified in the last succesfull MODE SELECT
942 	 * after an unload operation, in case it is not able to
943 	 * automatically determine the density of the new medium.
944 	 *
945 	 * So we instruct the device to use the default density, which will
946 	 * prevent the use of stale density values (in particular,
947 	 * in st_touch_tape().
948 	 */
949 	st->density = 0;
950 	if (st->ops(st, ST_OPS_MODESELECT, 0) != 0) {
951 		printf("%s: WARNING: cannot revert to default density\n",
952 			st->sc_dev.dv_xname);
953 	}
954 
955 	if (eject) {
956 		if (!(st->quirks & ST_Q_NOPREVENT)) {
957 			scsipi_prevent(periph, PR_ALLOW,
958 			    XS_CTL_IGNORE_ILLEGAL_REQUEST |
959 			    XS_CTL_IGNORE_NOT_READY);
960 		}
961 		st_load(st, LD_UNLOAD, XS_CTL_IGNORE_NOT_READY);
962 		st->blkno = st->fileno = (daddr_t) -1;
963 	} else {
964 		st->blkno = st->fileno = (daddr_t) 0;
965 	}
966 	st->flags &= ~(ST_MOUNTED | ST_NEW_MOUNT);
967 	periph->periph_flags &= ~PERIPH_MEDIA_LOADED;
968 }
969 
970 /*
971  * Given all we know about the device, media, mode, 'quirks' and
972  * initial operation, make a decision as to how we should be set
973  * to run (regarding blocking and EOD marks)
974  */
975 int
976 st_decide_mode(st, first_read)
977 	struct st_softc *st;
978 	boolean	first_read;
979 {
980 
981 	SC_DEBUG(st->sc_periph, SCSIPI_DB2, ("starting block mode decision\n"));
982 
983 	/*
984 	 * If the drive can only handle fixed-length blocks and only at
985 	 * one size, perhaps we should just do that.
986 	 */
987 	if (st->blkmin && (st->blkmin == st->blkmax)) {
988 		st->flags |= ST_FIXEDBLOCKS;
989 		st->blksize = st->blkmin;
990 		SC_DEBUG(st->sc_periph, SCSIPI_DB3,
991 		    ("blkmin == blkmax of %d\n", st->blkmin));
992 		goto done;
993 	}
994 	/*
995 	 * If the tape density mandates (or even suggests) use of fixed
996 	 * or variable-length blocks, comply.
997 	 */
998 	switch (st->density) {
999 	case HALFINCH_800:
1000 	case HALFINCH_1600:
1001 	case HALFINCH_6250:
1002 	case DDS:
1003 		st->flags &= ~ST_FIXEDBLOCKS;
1004 		st->blksize = 0;
1005 		SC_DEBUG(st->sc_periph, SCSIPI_DB3,
1006 		    ("density specified variable\n"));
1007 		goto done;
1008 	case QIC_11:
1009 	case QIC_24:
1010 	case QIC_120:
1011 	case QIC_150:
1012 	case QIC_525:
1013 	case QIC_1320:
1014 	case QIC_3095:
1015 	case QIC_3220:
1016 		st->flags |= ST_FIXEDBLOCKS;
1017 		if (st->media_blksize > 0)
1018 			st->blksize = st->media_blksize;
1019 		else
1020 			st->blksize = DEF_FIXED_BSIZE;
1021 		SC_DEBUG(st->sc_periph, SCSIPI_DB3,
1022 		    ("density specified fixed\n"));
1023 		goto done;
1024 	}
1025 	/*
1026 	 * If we're about to read the tape, perhaps we should choose
1027 	 * fixed or variable-length blocks and block size according to
1028 	 * what the drive found on the tape.
1029 	 */
1030 	if (first_read &&
1031 	    (!(st->quirks & ST_Q_BLKSIZE) || (st->media_blksize == 0) ||
1032 	    (st->media_blksize == DEF_FIXED_BSIZE) ||
1033 	    (st->media_blksize == 1024))) {
1034 		if (st->media_blksize > 0)
1035 			st->flags |= ST_FIXEDBLOCKS;
1036 		else
1037 			st->flags &= ~ST_FIXEDBLOCKS;
1038 		st->blksize = st->media_blksize;
1039 		SC_DEBUG(st->sc_periph, SCSIPI_DB3,
1040 		    ("Used media_blksize of %d\n", st->media_blksize));
1041 		goto done;
1042 	}
1043 	/*
1044 	 * We're getting no hints from any direction.  Choose variable-
1045 	 * length blocks arbitrarily.
1046 	 */
1047 	st->flags &= ~ST_FIXEDBLOCKS;
1048 	st->blksize = 0;
1049 	SC_DEBUG(st->sc_periph, SCSIPI_DB3,
1050 	    ("Give up and default to variable mode\n"));
1051 
1052 done:
1053 	/*
1054 	 * Decide whether or not to write two file marks to signify end-
1055 	 * of-data.  Make the decision as a function of density.  If
1056 	 * the decision is not to use a second file mark, the SCSI BLANK
1057 	 * CHECK condition code will be recognized as end-of-data when
1058 	 * first read.
1059 	 * (I think this should be a by-product of fixed/variable..julian)
1060 	 */
1061 	switch (st->density) {
1062 /*      case 8 mm:   What is the SCSI density code for 8 mm, anyway? */
1063 	case QIC_11:
1064 	case QIC_24:
1065 	case QIC_120:
1066 	case QIC_150:
1067 	case QIC_525:
1068 	case QIC_1320:
1069 	case QIC_3095:
1070 	case QIC_3220:
1071 		st->flags &= ~ST_2FM_AT_EOD;
1072 		break;
1073 	default:
1074 		st->flags |= ST_2FM_AT_EOD;
1075 	}
1076 	return (0);
1077 }
1078 
1079 /*
1080  * Actually translate the requested transfer into
1081  * one the physical driver can understand
1082  * The transfer is described by a buf and will include
1083  * only one physical transfer.
1084  */
1085 void
1086 ststrategy(bp)
1087 	struct buf *bp;
1088 {
1089 	struct st_softc *st = st_cd.cd_devs[STUNIT(bp->b_dev)];
1090 	int s;
1091 
1092 	SC_DEBUG(st->sc_periph, SCSIPI_DB1,
1093 	    ("ststrategy %ld bytes @ blk %d\n", bp->b_bcount, bp->b_blkno));
1094 	/*
1095 	 * If it's a null transfer, return immediatly
1096 	 */
1097 	if (bp->b_bcount == 0)
1098 		goto done;
1099 
1100 	/* If offset is negative, error */
1101 	if (bp->b_blkno < 0) {
1102 		bp->b_error = EINVAL;
1103 		goto bad;
1104 	}
1105 
1106 	/*
1107 	 * Odd sized request on fixed drives are verboten
1108 	 */
1109 	if (st->flags & ST_FIXEDBLOCKS) {
1110 		if (bp->b_bcount % st->blksize) {
1111 			printf("%s: bad request, must be multiple of %d\n",
1112 			    st->sc_dev.dv_xname, st->blksize);
1113 			bp->b_error = EIO;
1114 			goto bad;
1115 		}
1116 	}
1117 	/*
1118 	 * as are out-of-range requests on variable drives.
1119 	 */
1120 	else if (bp->b_bcount < st->blkmin ||
1121 	    (st->blkmax && bp->b_bcount > st->blkmax)) {
1122 		printf("%s: bad request, must be between %d and %d\n",
1123 		    st->sc_dev.dv_xname, st->blkmin, st->blkmax);
1124 		bp->b_error = EIO;
1125 		goto bad;
1126 	}
1127 	s = splbio();
1128 
1129 	/*
1130 	 * Place it in the queue of activities for this tape
1131 	 * at the end (a bit silly because we only have on user..
1132 	 * (but it could fork()))
1133 	 */
1134 	BUFQ_PUT(&st->buf_queue, bp);
1135 
1136 	/*
1137 	 * Tell the device to get going on the transfer if it's
1138 	 * not doing anything, otherwise just wait for completion
1139 	 * (All a bit silly if we're only allowing 1 open but..)
1140 	 */
1141 	ststart(st->sc_periph);
1142 
1143 	splx(s);
1144 	return;
1145 bad:
1146 	bp->b_flags |= B_ERROR;
1147 done:
1148 	/*
1149 	 * Correctly set the buf to indicate a completed xfer
1150 	 */
1151 	bp->b_resid = bp->b_bcount;
1152 	biodone(bp);
1153 	return;
1154 }
1155 
1156 /*
1157  * ststart looks to see if there is a buf waiting for the device
1158  * and that the device is not already busy. If both are true,
1159  * It dequeues the buf and creates a scsi command to perform the
1160  * transfer required. The transfer request will call scsipi_done
1161  * on completion, which will in turn call this routine again
1162  * so that the next queued transfer is performed.
1163  * The bufs are queued by the strategy routine (ststrategy)
1164  *
1165  * This routine is also called after other non-queued requests
1166  * have been made of the scsi driver, to ensure that the queue
1167  * continues to be drained.
1168  * ststart() is called at splbio
1169  */
1170 void
1171 ststart(periph)
1172 	struct scsipi_periph *periph;
1173 {
1174 	struct st_softc *st = (void *)periph->periph_dev;
1175 	struct buf *bp;
1176 	struct scsi_rw_tape cmd;
1177 	int flags, error;
1178 
1179 	SC_DEBUG(periph, SCSIPI_DB2, ("ststart "));
1180 	/*
1181 	 * See if there is a buf to do and we are not already
1182 	 * doing one
1183 	 */
1184 	while (periph->periph_active < periph->periph_openings) {
1185 		/* if a special awaits, let it proceed first */
1186 		if (periph->periph_flags & PERIPH_WAITING) {
1187 			periph->periph_flags &= ~PERIPH_WAITING;
1188 			wakeup((caddr_t)periph);
1189 			return;
1190 		}
1191 
1192 		if ((bp = BUFQ_GET(&st->buf_queue)) == NULL)
1193 			return;
1194 
1195 		/*
1196 		 * If the device has been unmounted by the user
1197 		 * then throw away all requests until done.
1198 		 */
1199 		if ((st->flags & ST_MOUNTED) == 0 ||
1200 		    (periph->periph_flags & PERIPH_MEDIA_LOADED) == 0) {
1201 			/* make sure that one implies the other.. */
1202 			periph->periph_flags &= ~PERIPH_MEDIA_LOADED;
1203 			bp->b_flags |= B_ERROR;
1204 			bp->b_error = EIO;
1205 			bp->b_resid = bp->b_bcount;
1206 			biodone(bp);
1207 			continue;
1208 		}
1209 		/*
1210 		 * only FIXEDBLOCK devices have pending I/O or space operations.
1211 		 */
1212 		if (st->flags & ST_FIXEDBLOCKS) {
1213 			/*
1214 			 * If we are at a filemark but have not reported it yet
1215 			 * then we should report it now
1216 			 */
1217 			if (st->flags & ST_AT_FILEMARK) {
1218 				if ((bp->b_flags & B_READ) == B_WRITE) {
1219 					/*
1220 					 * Handling of ST_AT_FILEMARK in
1221 					 * st_space will fill in the right file
1222 					 * mark count.
1223 					 * Back up over filemark
1224 					 */
1225 					if (st_space(st, 0, SP_FILEMARKS, 0)) {
1226 						bp->b_flags |= B_ERROR;
1227 						bp->b_error = EIO;
1228 						biodone(bp);
1229 						continue;
1230 					}
1231 				} else {
1232 					bp->b_resid = bp->b_bcount;
1233 					bp->b_error = 0;
1234 					bp->b_flags &= ~B_ERROR;
1235 					st->flags &= ~ST_AT_FILEMARK;
1236 					biodone(bp);
1237 					continue;	/* seek more work */
1238 				}
1239 			}
1240 		}
1241 		/*
1242 		 * If we are at EOM but have not reported it
1243 		 * yet then we should report it now.
1244 		 */
1245 		if (st->flags & (ST_EOM_PENDING|ST_EIO_PENDING)) {
1246 			bp->b_resid = bp->b_bcount;
1247 			if (st->flags & ST_EIO_PENDING) {
1248 				bp->b_error = EIO;
1249 				bp->b_flags |= B_ERROR;
1250 			}
1251 			st->flags &= ~(ST_EOM_PENDING|ST_EIO_PENDING);
1252 			biodone(bp);
1253 			continue;	/* seek more work */
1254 		}
1255 
1256 		/*
1257 		 * Fill out the scsi command
1258 		 */
1259 		memset(&cmd, 0, sizeof(cmd));
1260 		flags = XS_CTL_NOSLEEP | XS_CTL_ASYNC;
1261 		if ((bp->b_flags & B_READ) == B_WRITE) {
1262 			cmd.opcode = WRITE;
1263 			st->flags &= ~ST_FM_WRITTEN;
1264 			flags |= XS_CTL_DATA_OUT;
1265 		} else {
1266 			cmd.opcode = READ;
1267 			flags |= XS_CTL_DATA_IN;
1268 		}
1269 
1270 		/*
1271 		 * Handle "fixed-block-mode" tape drives by using the
1272 		 * block count instead of the length.
1273 		 */
1274 		if (st->flags & ST_FIXEDBLOCKS) {
1275 			cmd.byte2 |= SRW_FIXED;
1276 			_lto3b(bp->b_bcount / st->blksize, cmd.len);
1277 		} else
1278 			_lto3b(bp->b_bcount, cmd.len);
1279 
1280 		/*
1281 		 * Clear 'position updated' indicator
1282 		 */
1283 		st->flags &= ~ST_POSUPDATED;
1284 
1285 		/*
1286 		 * go ask the adapter to do all this for us
1287 		 */
1288 		error = scsipi_command(periph,
1289 		    (struct scsipi_generic *)&cmd, sizeof(cmd),
1290 		    (u_char *)bp->b_data, bp->b_bcount,
1291 		    0, ST_IO_TIME, bp, flags);
1292 		if (error) {
1293 			printf("%s: not queued, error %d\n",
1294 			    st->sc_dev.dv_xname, error);
1295 		}
1296 	} /* go back and see if we can cram more work in.. */
1297 }
1298 
1299 void
1300 stdone(xs)
1301 	struct scsipi_xfer *xs;
1302 {
1303 	struct st_softc *st = (void *)xs->xs_periph->periph_dev;
1304 
1305 	if (xs->bp != NULL) {
1306 		if ((xs->bp->b_flags & B_READ) == B_WRITE) {
1307 			st->flags |= ST_WRITTEN;
1308 		} else {
1309 			st->flags &= ~ST_WRITTEN;
1310 		}
1311 #if NRND > 0
1312 		rnd_add_uint32(&st->rnd_source, xs->bp->b_blkno);
1313 #endif
1314 
1315 		if ((st->flags & ST_POSUPDATED) == 0) {
1316 			if (xs->bp->b_flags & B_ERROR) {
1317 				st->fileno = st->blkno = -1;
1318 			} else if (st->blkno != -1) {
1319 				if (st->flags & ST_FIXEDBLOCKS) {
1320 					st->blkno +=
1321 					    (xs->bp->b_bcount / st->blksize);
1322 				} else {
1323 					st->blkno++;
1324 				}
1325 			}
1326 		}
1327 	}
1328 }
1329 
1330 int
1331 stread(dev, uio, iomode)
1332 	dev_t dev;
1333 	struct uio *uio;
1334 	int iomode;
1335 {
1336 	struct st_softc *st = st_cd.cd_devs[STUNIT(dev)];
1337 
1338 	return (physio(ststrategy, NULL, dev, B_READ,
1339 	    st->sc_periph->periph_channel->chan_adapter->adapt_minphys, uio));
1340 }
1341 
1342 int
1343 stwrite(dev, uio, iomode)
1344 	dev_t dev;
1345 	struct uio *uio;
1346 	int iomode;
1347 {
1348 	struct st_softc *st = st_cd.cd_devs[STUNIT(dev)];
1349 
1350 	return (physio(ststrategy, NULL, dev, B_WRITE,
1351 	    st->sc_periph->periph_channel->chan_adapter->adapt_minphys, uio));
1352 }
1353 
1354 /*
1355  * Perform special action on behalf of the user;
1356  * knows about the internals of this device
1357  */
1358 int
1359 stioctl(dev, cmd, arg, flag, p)
1360 	dev_t dev;
1361 	u_long cmd;
1362 	caddr_t arg;
1363 	int flag;
1364 	struct proc *p;
1365 {
1366 	int error = 0;
1367 	int unit;
1368 	int number, nmarks, dsty;
1369 	int flags;
1370 	struct st_softc *st;
1371 	int hold_blksize;
1372 	u_int8_t hold_density;
1373 	struct mtop *mt = (struct mtop *) arg;
1374 
1375 	/*
1376 	 * Find the device that the user is talking about
1377 	 */
1378 	flags = 0;		/* give error messages, act on errors etc. */
1379 	unit = STUNIT(dev);
1380 	dsty = STDSTY(dev);
1381 	st = st_cd.cd_devs[unit];
1382 	hold_blksize = st->blksize;
1383 	hold_density = st->density;
1384 
1385 	switch ((u_int) cmd) {
1386 
1387 	case MTIOCGET: {
1388 		struct mtget *g = (struct mtget *) arg;
1389 		/*
1390 		 * (to get the current state of READONLY)
1391 		 */
1392 		error = st->ops(st, ST_OPS_MODESENSE, XS_CTL_SILENT);
1393 		if (error) {
1394 			/*
1395 			 * Ignore the error if in control mode;
1396 			 * this is mandated by st(4).
1397 			 */
1398 			if (STMODE(dev) != CTRL_MODE)
1399 				break;
1400 			error = 0;
1401 		}
1402 		SC_DEBUG(st->sc_periph, SCSIPI_DB1, ("[ioctl: get status]\n"));
1403 		memset(g, 0, sizeof(struct mtget));
1404 		g->mt_type = 0x7;	/* Ultrix compat *//*? */
1405 		g->mt_blksiz = st->blksize;
1406 		g->mt_density = st->density;
1407 		g->mt_mblksiz[0] = st->modes[0].blksize;
1408 		g->mt_mblksiz[1] = st->modes[1].blksize;
1409 		g->mt_mblksiz[2] = st->modes[2].blksize;
1410 		g->mt_mblksiz[3] = st->modes[3].blksize;
1411 		g->mt_mdensity[0] = st->modes[0].density;
1412 		g->mt_mdensity[1] = st->modes[1].density;
1413 		g->mt_mdensity[2] = st->modes[2].density;
1414 		g->mt_mdensity[3] = st->modes[3].density;
1415 		g->mt_fileno = st->fileno;
1416 		g->mt_blkno = st->blkno;
1417 		if (st->flags & ST_READONLY)
1418 			g->mt_dsreg |= MT_DS_RDONLY;
1419 		if (st->flags & ST_MOUNTED)
1420 			g->mt_dsreg |= MT_DS_MOUNTED;
1421 		g->mt_resid = st->mt_resid;
1422 		g->mt_erreg = st->mt_erreg;
1423 		/*
1424 		 * clear latched errors.
1425 		 */
1426 		st->mt_resid = 0;
1427 		st->mt_erreg = 0;
1428 		st->asc = 0;
1429 		st->ascq = 0;
1430 		break;
1431 	}
1432 	case MTIOCTOP: {
1433 
1434 		SC_DEBUG(st->sc_periph, SCSIPI_DB1,
1435 		    ("[ioctl: op=0x%x count=0x%x]\n", mt->mt_op,
1436 			mt->mt_count));
1437 
1438 		/* compat: in U*x it is a short */
1439 		number = mt->mt_count;
1440 		switch ((short) (mt->mt_op)) {
1441 		case MTWEOF:	/* write an end-of-file record */
1442 			error = st_write_filemarks(st, number, flags);
1443 			break;
1444 		case MTBSF:	/* backward space file */
1445 			number = -number;
1446 		case MTFSF:	/* forward space file */
1447 			error = st_check_eod(st, FALSE, &nmarks, flags);
1448 			if (!error)
1449 				error = st_space(st, number - nmarks,
1450 				    SP_FILEMARKS, flags);
1451 			break;
1452 		case MTBSR:	/* backward space record */
1453 			number = -number;
1454 		case MTFSR:	/* forward space record */
1455 			error = st_check_eod(st, TRUE, &nmarks, flags);
1456 			if (!error)
1457 				error = st_space(st, number, SP_BLKS, flags);
1458 			break;
1459 		case MTREW:	/* rewind */
1460 			error = st_rewind(st, 0, flags);
1461 			break;
1462 		case MTOFFL:	/* rewind and put the drive offline */
1463 			st_unmount(st, EJECT);
1464 			break;
1465 		case MTNOP:	/* no operation, sets status only */
1466 			break;
1467 		case MTRETEN:	/* retension the tape */
1468 			error = st_load(st, LD_RETENSION, flags);
1469 			if (!error)
1470 				error = st_load(st, LD_LOAD, flags);
1471 			break;
1472 		case MTEOM:	/* forward space to end of media */
1473 			error = st_check_eod(st, FALSE, &nmarks, flags);
1474 			if (!error)
1475 				error = st_space(st, 1, SP_EOM, flags);
1476 			break;
1477 		case MTCACHE:	/* enable controller cache */
1478 			st->flags &= ~ST_DONTBUFFER;
1479 			goto try_new_value;
1480 		case MTNOCACHE:	/* disable controller cache */
1481 			st->flags |= ST_DONTBUFFER;
1482 			goto try_new_value;
1483 		case MTERASE:	/* erase volume */
1484 			error = st_erase(st, number, flags);
1485 			break;
1486 		case MTSETBSIZ:	/* Set block size for device */
1487 #ifdef	NOTYET
1488 			if (!(st->flags & ST_NEW_MOUNT)) {
1489 				uprintf("re-mount tape before changing blocksize");
1490 				error = EINVAL;
1491 				break;
1492 			}
1493 #endif
1494 			if (number == 0)
1495 				st->flags &= ~ST_FIXEDBLOCKS;
1496 			else {
1497 				if ((st->blkmin || st->blkmax) &&
1498 				    (number < st->blkmin ||
1499 				    number > st->blkmax)) {
1500 					error = EINVAL;
1501 					break;
1502 				}
1503 				st->flags |= ST_FIXEDBLOCKS;
1504 			}
1505 			st->blksize = number;
1506 			st->flags |= ST_BLOCK_SET;	/*XXX */
1507 			goto try_new_value;
1508 
1509 		case MTSETDNSTY:	/* Set density for device and mode */
1510 			/*
1511 			 * Any number >= 0 and <= 0xff is legal. Numbers
1512 			 * above 0x80 are 'vendor unique'.
1513 			 */
1514 			if (number < 0 || number > 255) {
1515 				error = EINVAL;
1516 				break;
1517 			} else
1518 				st->density = number;
1519 			goto try_new_value;
1520 
1521 		case MTCMPRESS:
1522 			error = st->ops(st, (number == 0) ?
1523 			    ST_OPS_CMPRSS_OFF : ST_OPS_CMPRSS_ON,
1524 			    XS_CTL_SILENT);
1525 			break;
1526 
1527 		case MTEWARN:
1528 			if (number)
1529 				st->flags |= ST_EARLYWARN;
1530 			else
1531 				st->flags &= ~ST_EARLYWARN;
1532 			break;
1533 
1534 		default:
1535 			error = EINVAL;
1536 		}
1537 		break;
1538 	}
1539 	case MTIOCIEOT:
1540 	case MTIOCEEOT:
1541 		break;
1542 
1543 	case MTIOCRDSPOS:
1544 		error = st_rdpos(st, 0, (u_int32_t *) arg);
1545 		break;
1546 
1547 	case MTIOCRDHPOS:
1548 		error = st_rdpos(st, 1, (u_int32_t *) arg);
1549 		break;
1550 
1551 	case MTIOCSLOCATE:
1552 		error = st_setpos(st, 0, (u_int32_t *) arg);
1553 		break;
1554 
1555 	case MTIOCHLOCATE:
1556 		error = st_setpos(st, 1, (u_int32_t *) arg);
1557 		break;
1558 
1559 
1560 	default:
1561 		error = scsipi_do_ioctl(st->sc_periph, dev, cmd, arg,
1562 					flag, p);
1563 		break;
1564 	}
1565 	return (error);
1566 /*-----------------------------*/
1567 try_new_value:
1568 	/*
1569 	 * Check that the mode being asked for is aggreeable to the
1570 	 * drive. If not, put it back the way it was.
1571 	 *
1572 	 * If in control mode, we can make (persistent) mode changes
1573 	 * even if no medium is loaded (see st(4)).
1574 	 */
1575 	if ((STMODE(dev) != CTRL_MODE || (st->flags & ST_MOUNTED) != 0) &&
1576 	    (error = st->ops(st, ST_OPS_MODESELECT, 0)) != 0) {
1577 		/* put it back as it was */
1578 		printf("%s: cannot set selected mode\n", st->sc_dev.dv_xname);
1579 		st->density = hold_density;
1580 		st->blksize = hold_blksize;
1581 		if (st->blksize)
1582 			st->flags |= ST_FIXEDBLOCKS;
1583 		else
1584 			st->flags &= ~ST_FIXEDBLOCKS;
1585 		return (error);
1586 	}
1587 	/*
1588 	 * As the drive liked it, if we are setting a new default,
1589 	 * set it into the structures as such.
1590 	 *
1591 	 * The means for deciding this are not finalised yet- but
1592 	 * if the device was opened in Control Mode, the values
1593 	 * are persistent now across mounts.
1594 	 */
1595 	if (STMODE(dev) == CTRL_MODE) {
1596 		switch ((short) (mt->mt_op)) {
1597 		case MTSETBSIZ:
1598 			st->modes[dsty].blksize = st->blksize;
1599 			st->modeflags[dsty] |= BLKSIZE_SET_BY_USER;
1600 			break;
1601 		case MTSETDNSTY:
1602 			st->modes[dsty].density = st->density;
1603 			st->modeflags[dsty] |= DENSITY_SET_BY_USER;
1604 			break;
1605 		}
1606 	}
1607 	return (0);
1608 }
1609 
1610 /*
1611  * Do a synchronous read.
1612  */
1613 int
1614 st_read(st, buf, size, flags)
1615 	struct st_softc *st;
1616 	int size;
1617 	int flags;
1618 	char *buf;
1619 {
1620 	struct scsi_rw_tape cmd;
1621 
1622 	/*
1623 	 * If it's a null transfer, return immediatly
1624 	 */
1625 	if (size == 0)
1626 		return (0);
1627 	memset(&cmd, 0, sizeof(cmd));
1628 	cmd.opcode = READ;
1629 	if (st->flags & ST_FIXEDBLOCKS) {
1630 		cmd.byte2 |= SRW_FIXED;
1631 		_lto3b(size / (st->blksize ? st->blksize : DEF_FIXED_BSIZE),
1632 		    cmd.len);
1633 	} else
1634 		_lto3b(size, cmd.len);
1635 	return (scsipi_command(st->sc_periph,
1636 	    (struct scsipi_generic *)&cmd, sizeof(cmd),
1637 	    (u_char *)buf, size, 0, ST_IO_TIME, NULL, flags | XS_CTL_DATA_IN));
1638 }
1639 
1640 /*
1641  * issue an erase command
1642  */
1643 int
1644 st_erase(st, full, flags)
1645 	struct st_softc *st;
1646 	int full, flags;
1647 {
1648 	int tmo;
1649 	struct scsi_erase cmd;
1650 
1651 	/*
1652 	 * Full erase means set LONG bit in erase command, which asks
1653 	 * the drive to erase the entire unit.  Without this bit, we're
1654 	 * asking the drive to write an erase gap.
1655 	 */
1656 	memset(&cmd, 0, sizeof(cmd));
1657 	cmd.opcode = ERASE;
1658 	if (full) {
1659 		cmd.byte2 = SE_LONG;
1660 		tmo = ST_SPC_TIME;
1661 	} else {
1662 		tmo = ST_IO_TIME;
1663 	}
1664 
1665 	/*
1666 	 * XXX We always do this asynchronously, for now, unless the device
1667 	 * has the ST_Q_ERASE_NOIMM quirk.  How long should we wait if we
1668 	 * want to (eventually) to it synchronously?
1669 	 */
1670 	if ((st->quirks & ST_Q_ERASE_NOIMM) == 0)
1671 		cmd.byte2 |= SE_IMMED;
1672 
1673 	return (scsipi_command(st->sc_periph,
1674 	    (struct scsipi_generic *)&cmd, sizeof(cmd),
1675 	    0, 0, ST_RETRIES, tmo, NULL, flags));
1676 }
1677 
1678 /*
1679  * skip N blocks/filemarks/seq filemarks/eom
1680  */
1681 int
1682 st_space(st, number, what, flags)
1683 	struct st_softc *st;
1684 	u_int what;
1685 	int flags;
1686 	int number;
1687 {
1688 	struct scsi_space cmd;
1689 	int error;
1690 
1691 	switch (what) {
1692 	case SP_BLKS:
1693 		if (st->flags & ST_PER_ACTION) {
1694 			if (number > 0) {
1695 				st->flags &= ~ST_PER_ACTION;
1696 				return (EIO);
1697 			} else if (number < 0) {
1698 				if (st->flags & ST_AT_FILEMARK) {
1699 					/*
1700 					 * Handling of ST_AT_FILEMARK
1701 					 * in st_space will fill in the
1702 					 * right file mark count.
1703 					 */
1704 					error = st_space(st, 0, SP_FILEMARKS,
1705 					    flags);
1706 					if (error)
1707 						return (error);
1708 				}
1709 				if (st->flags & ST_BLANK_READ) {
1710 					st->flags &= ~ST_BLANK_READ;
1711 					return (EIO);
1712 				}
1713 				st->flags &= ~(ST_EIO_PENDING|ST_EOM_PENDING);
1714 			}
1715 		}
1716 		break;
1717 	case SP_FILEMARKS:
1718 		if (st->flags & ST_EIO_PENDING) {
1719 			if (number > 0) {
1720 				/* pretend we just discovered the error */
1721 				st->flags &= ~ST_EIO_PENDING;
1722 				return (EIO);
1723 			} else if (number < 0) {
1724 				/* back away from the error */
1725 				st->flags &= ~ST_EIO_PENDING;
1726 			}
1727 		}
1728 		if (st->flags & ST_AT_FILEMARK) {
1729 			st->flags &= ~ST_AT_FILEMARK;
1730 			number--;
1731 		}
1732 		if ((st->flags & ST_BLANK_READ) && (number < 0)) {
1733 			/* back away from unwritten tape */
1734 			st->flags &= ~ST_BLANK_READ;
1735 			number++;	/* XXX dubious */
1736 		}
1737 		break;
1738 	case SP_EOM:
1739 		if (st->flags & ST_EOM_PENDING) {
1740 			/* we're already there */
1741 			st->flags &= ~ST_EOM_PENDING;
1742 			return (0);
1743 		}
1744 		if (st->flags & ST_EIO_PENDING) {
1745 			/* pretend we just discovered the error */
1746 			st->flags &= ~ST_EIO_PENDING;
1747 			return (EIO);
1748 		}
1749 		if (st->flags & ST_AT_FILEMARK)
1750 			st->flags &= ~ST_AT_FILEMARK;
1751 		break;
1752 	}
1753 	if (number == 0)
1754 		return (0);
1755 
1756 	memset(&cmd, 0, sizeof(cmd));
1757 	cmd.opcode = SPACE;
1758 	cmd.byte2 = what;
1759 	_lto3b(number, cmd.number);
1760 
1761 	st->flags &= ~ST_POSUPDATED;
1762 	st->last_ctl_resid = 0;
1763 	error = scsipi_command(st->sc_periph,
1764 	    (struct scsipi_generic *)&cmd, sizeof(cmd),
1765 	    0, 0, 0, ST_SPC_TIME, NULL, flags);
1766 
1767 	if (error == 0 && (st->flags & ST_POSUPDATED) == 0) {
1768 		number = number - st->last_ctl_resid;
1769 		if (what == SP_BLKS) {
1770 			if (st->blkno != -1) {
1771 				st->blkno += number;
1772 			}
1773 		} else if (what == SP_FILEMARKS) {
1774 			if (st->fileno != -1) {
1775 				st->fileno += number;
1776 				if (number > 0) {
1777 					st->blkno = 0;
1778 				} else if (number < 0) {
1779 					st->blkno = -1;
1780 				}
1781 			}
1782 		} else if (what == SP_EOM) {
1783 			/*
1784 			 * This loses us relative position.
1785 			 */
1786 			st->fileno = st->blkno = -1;
1787 		}
1788 	}
1789 	return (error);
1790 }
1791 
1792 /*
1793  * write N filemarks
1794  */
1795 int
1796 st_write_filemarks(st, number, flags)
1797 	struct st_softc *st;
1798 	int flags;
1799 	int number;
1800 {
1801 	int error;
1802 	struct scsi_write_filemarks cmd;
1803 
1804 	/*
1805 	 * It's hard to write a negative number of file marks.
1806 	 * Don't try.
1807 	 */
1808 	if (number < 0)
1809 		return (EINVAL);
1810 	switch (number) {
1811 	case 0:		/* really a command to sync the drive's buffers */
1812 		break;
1813 	case 1:
1814 		if (st->flags & ST_FM_WRITTEN)	/* already have one down */
1815 			st->flags &= ~ST_WRITTEN;
1816 		else
1817 			st->flags |= ST_FM_WRITTEN;
1818 		st->flags &= ~ST_PER_ACTION;
1819 		break;
1820 	default:
1821 		st->flags &= ~(ST_PER_ACTION | ST_WRITTEN);
1822 	}
1823 
1824 	memset(&cmd, 0, sizeof(cmd));
1825 	cmd.opcode = WRITE_FILEMARKS;
1826 	if (scsipi_periph_bustype(st->sc_periph) == SCSIPI_BUSTYPE_ATAPI)
1827 		cmd.byte2 = SR_IMMED;
1828 	/*
1829 	 * The ATAPI Onstream DI-30 doesn't support writing filemarks, but
1830 	 * WRITE_FILEMARKS is still used to flush the buffer
1831 	 */
1832 	if ((st->quirks & ST_Q_NOFILEMARKS) == 0)
1833 		_lto3b(number, cmd.number);
1834 
1835 	/* XXX WE NEED TO BE ABLE TO GET A RESIDIUAL XXX */
1836 	error = scsipi_command(st->sc_periph,
1837 	    (struct scsipi_generic *)&cmd, sizeof(cmd),
1838 	    0, 0, 0, ST_IO_TIME * 4, NULL, flags);
1839 	if (error == 0 && st->fileno != -1) {
1840 		st->fileno += number;
1841 	}
1842 	return (error);
1843 }
1844 
1845 /*
1846  * Make sure the right number of file marks is on tape if the
1847  * tape has been written.  If the position argument is true,
1848  * leave the tape positioned where it was originally.
1849  *
1850  * nmarks returns the number of marks to skip (or, if position
1851  * true, which were skipped) to get back original position.
1852  */
1853 int
1854 st_check_eod(st, position, nmarks, flags)
1855 	struct st_softc *st;
1856 	boolean position;
1857 	int *nmarks;
1858 	int flags;
1859 {
1860 	int error;
1861 
1862 	switch (st->flags & (ST_WRITTEN | ST_FM_WRITTEN | ST_2FM_AT_EOD)) {
1863 	default:
1864 		*nmarks = 0;
1865 		return (0);
1866 	case ST_WRITTEN:
1867 	case ST_WRITTEN | ST_FM_WRITTEN | ST_2FM_AT_EOD:
1868 		*nmarks = 1;
1869 		break;
1870 	case ST_WRITTEN | ST_2FM_AT_EOD:
1871 		*nmarks = 2;
1872 	}
1873 	error = st_write_filemarks(st, *nmarks, flags);
1874 	if (position && !error)
1875 		error = st_space(st, -*nmarks, SP_FILEMARKS, flags);
1876 	return (error);
1877 }
1878 
1879 /*
1880  * load/unload/retension
1881  */
1882 int
1883 st_load(st, type, flags)
1884 	struct st_softc *st;
1885 	u_int type;
1886 	int flags;
1887 {
1888 	int error;
1889 	struct scsi_load cmd;
1890 
1891 	if (type != LD_LOAD) {
1892 		int nmarks;
1893 
1894 		error = st_check_eod(st, FALSE, &nmarks, flags);
1895 		if (error) {
1896 			printf("%s: failed to write closing filemarks at "
1897 			    "unload, errno=%d\n", st->sc_dev.dv_xname, error);
1898 			return (error);
1899 		}
1900 	}
1901 	if (st->quirks & ST_Q_IGNORE_LOADS) {
1902 		if (type == LD_LOAD) {
1903 			/*
1904 			 * If we ignore loads, at least we should try a rewind.
1905 			 */
1906 			return st_rewind(st, 0, flags);
1907 		}
1908 		/* otherwise, we should do what's asked of us */
1909 	}
1910 
1911 	memset(&cmd, 0, sizeof(cmd));
1912 	cmd.opcode = LOAD;
1913 	if (scsipi_periph_bustype(st->sc_periph) == SCSIPI_BUSTYPE_ATAPI)
1914 		cmd.byte2 = SR_IMMED;
1915 	cmd.how = type;
1916 
1917 	error = scsipi_command(st->sc_periph,
1918 	    (struct scsipi_generic *)&cmd, sizeof(cmd),
1919 	    0, 0, ST_RETRIES, ST_SPC_TIME, NULL, flags);
1920 	if (error) {
1921 		printf("%s: error %d in st_load (op %d)\n",
1922 		    st->sc_dev.dv_xname, error, type);
1923 	}
1924 	return (error);
1925 }
1926 
1927 /*
1928  *  Rewind the device
1929  */
1930 int
1931 st_rewind(st, immediate, flags)
1932 	struct st_softc *st;
1933 	u_int immediate;
1934 	int flags;
1935 {
1936 	struct scsi_rewind cmd;
1937 	int error;
1938 	int nmarks;
1939 
1940 	error = st_check_eod(st, FALSE, &nmarks, flags);
1941 	if (error) {
1942 		printf("%s: failed to write closing filemarks at "
1943 		    "rewind, errno=%d\n", st->sc_dev.dv_xname, error);
1944 		return (error);
1945 	}
1946 	st->flags &= ~ST_PER_ACTION;
1947 
1948 	/*
1949 	 * ATAPI tapes always need immediate to be set
1950 	 */
1951 	if (scsipi_periph_bustype(st->sc_periph) == SCSIPI_BUSTYPE_ATAPI)
1952 		immediate = SR_IMMED;
1953 
1954 	memset(&cmd, 0, sizeof(cmd));
1955 	cmd.opcode = REWIND;
1956 	cmd.byte2 = immediate;
1957 
1958 	error = scsipi_command(st->sc_periph,
1959 	    (struct scsipi_generic *)&cmd, sizeof(cmd), 0, 0, ST_RETRIES,
1960 	    immediate ? ST_CTL_TIME: ST_SPC_TIME, NULL, flags);
1961 	if (error) {
1962 		printf("%s: error %d trying to rewind\n",
1963 		    st->sc_dev.dv_xname, error);
1964 		/* lost position */
1965 		st->fileno = st->blkno = -1;
1966 	} else {
1967 		st->fileno = st->blkno = 0;
1968 	}
1969 	return (error);
1970 }
1971 
1972 int
1973 st_rdpos(st, hard, blkptr)
1974 	struct st_softc *st;
1975 	int hard;
1976 	u_int32_t *blkptr;
1977 {
1978 	int error;
1979 	u_int8_t posdata[20];
1980 	struct scsi_tape_read_position cmd;
1981 
1982 	/*
1983 	 * We try and flush any buffered writes here if we were writing
1984 	 * and we're trying to get hardware block position. It eats
1985 	 * up performance substantially, but I'm wary of drive firmware.
1986 	 *
1987 	 * I think that *logical* block position is probably okay-
1988 	 * but hardware block position might have to wait for data
1989 	 * to hit media to be valid. Caveat Emptor.
1990 	 */
1991 
1992 	if (hard && (st->flags & ST_WRITTEN)) {
1993 		/*
1994 		 * First flush any pending writes...
1995 		 */
1996 		error = st_write_filemarks(st, 0, XS_CTL_SILENT);
1997 		/*
1998 		 * The latter case is for 'write protected' tapes
1999 		 * which are too stupid to recognize a zero count
2000 		 * for writing filemarks as a no-op.
2001 		 */
2002 		if (error != 0 && error != EACCES && error != EROFS)
2003 			return (error);
2004 	}
2005 
2006 	memset(&cmd, 0, sizeof(cmd));
2007 	memset(&posdata, 0, sizeof(posdata));
2008 	cmd.opcode = READ_POSITION;
2009 	if (hard)
2010 		cmd.byte1 = 1;
2011 
2012 	error = scsipi_command(st->sc_periph,
2013 	    (struct scsipi_generic *)&cmd, sizeof(cmd), (u_char *)&posdata,
2014 	    sizeof(posdata), ST_RETRIES, ST_CTL_TIME, NULL,
2015 	    XS_CTL_SILENT | XS_CTL_DATA_IN | XS_CTL_DATA_ONSTACK);
2016 
2017 	if (error == 0) {
2018 #if	0
2019 		printf("posdata:");
2020 		for (hard = 0; hard < sizeof(posdata); hard++)
2021 			printf("%02x ", posdata[hard] & 0xff);
2022 		printf("\n");
2023 #endif
2024 		if (posdata[0] & 0x4)	/* Block Position Unknown */
2025 			error = EINVAL;
2026 		else
2027 			*blkptr = _4btol(&posdata[4]);
2028 	}
2029 	return (error);
2030 }
2031 
2032 int
2033 st_setpos(st, hard, blkptr)
2034 	struct st_softc *st;
2035 	int hard;
2036 	u_int32_t *blkptr;
2037 {
2038 	int error;
2039 	struct scsi_tape_locate cmd;
2040 
2041 	/*
2042 	 * We used to try and flush any buffered writes here.
2043 	 * Now we push this onto user applications to either
2044 	 * flush the pending writes themselves (via a zero count
2045 	 * WRITE FILEMARKS command) or they can trust their tape
2046 	 * drive to do this correctly for them.
2047 	 *
2048 	 * There are very ugly performance limitations otherwise.
2049 	 */
2050 
2051 	memset(&cmd, 0, sizeof(cmd));
2052 	cmd.opcode = LOCATE;
2053 	if (hard)
2054 		cmd.byte2 = 1 << 2;
2055 	_lto4b(*blkptr, cmd.blkaddr);
2056 	error = scsipi_command(st->sc_periph,
2057 		(struct scsipi_generic *)&cmd, sizeof(cmd),
2058 		NULL, 0, ST_RETRIES, ST_SPC_TIME, NULL, 0);
2059 	/*
2060 	 * Note file && block number position now unknown (if
2061 	 * these things ever start being maintained in this driver)
2062 	 */
2063 	st->fileno = st->blkno = -1;
2064 	return (error);
2065 }
2066 
2067 
2068 /*
2069  * Look at the returned sense and act on the error and determine
2070  * the unix error number to pass back..., 0 (== report no error),
2071  * -1 = retry the operation, -2 continue error processing.
2072  */
2073 int
2074 st_interpret_sense(xs)
2075 	struct scsipi_xfer *xs;
2076 {
2077 	struct scsipi_periph *periph = xs->xs_periph;
2078 	struct scsipi_sense_data *sense = &xs->sense.scsi_sense;
2079 	struct buf *bp = xs->bp;
2080 	struct st_softc *st = (void *)periph->periph_dev;
2081 	int retval = EJUSTRETURN;
2082 	int doprint = ((xs->xs_control & XS_CTL_SILENT) == 0);
2083 	u_int8_t key;
2084 	int32_t info;
2085 
2086 	/*
2087 	 * If it isn't a extended or extended/deferred error, let
2088 	 * the generic code handle it.
2089 	 */
2090 	if ((sense->error_code & SSD_ERRCODE) != 0x70 &&
2091 	    (sense->error_code & SSD_ERRCODE) != 0x71) {	/* DEFFERRED */
2092 		return (retval);
2093 	}
2094 
2095 	if (sense->error_code & SSD_ERRCODE_VALID)
2096 		info = _4btol(sense->info);
2097 	else
2098 		info = (st->flags & ST_FIXEDBLOCKS) ?
2099 		    xs->datalen / st->blksize : xs->datalen;
2100 	key = sense->flags & SSD_KEY;
2101 	st->mt_erreg = key;
2102 	st->asc = sense->add_sense_code;
2103 	st->ascq = sense->add_sense_code_qual;
2104 	st->mt_resid = (short) info;
2105 
2106 	if (key == SKEY_NOT_READY && st->asc == 0x4 && st->ascq == 0x1) {
2107 		/* Not Ready, Logical Unit Is in Process Of Becoming Ready */
2108 		if (!callout_active(&periph->periph_callout))
2109 			scsipi_periph_freeze(periph, 1);
2110 		callout_reset(&periph->periph_callout,
2111 		    hz, scsipi_periph_timed_thaw, periph);
2112 		return (ERESTART);
2113 	}
2114 
2115 	/*
2116 	 * If the device is not open yet, let generic handle
2117 	 */
2118 	if ((periph->periph_flags & PERIPH_OPEN) == 0) {
2119 		return (retval);
2120 	}
2121 
2122 	xs->resid = info;
2123 	if (st->flags & ST_FIXEDBLOCKS) {
2124 		if (bp) {
2125 			xs->resid *= st->blksize;
2126 			st->last_io_resid = xs->resid;
2127 		} else {
2128 			st->last_ctl_resid = xs->resid;
2129 		}
2130 		if (key == SKEY_VOLUME_OVERFLOW) {
2131 			st->flags |= ST_EIO_PENDING;
2132 			if (bp)
2133 				bp->b_resid = xs->resid;
2134 		} else if (sense->flags & SSD_EOM) {
2135 			if ((st->flags & ST_EARLYWARN) == 0)
2136 				st->flags |= ST_EIO_PENDING;
2137 			st->flags |= ST_EOM_PENDING;
2138 			if (bp) {
2139 #if 0
2140 				bp->b_resid = xs->resid;
2141 #else
2142 				/*
2143 				 * Grotesque as it seems, the few times
2144 				 * I've actually seen a non-zero resid,
2145 				 * the tape drive actually lied and had
2146 				 * written all the data!
2147 				 */
2148 				bp->b_resid = 0;
2149 #endif
2150 			}
2151 		}
2152 		if (sense->flags & SSD_FILEMARK) {
2153 			st->flags |= ST_AT_FILEMARK;
2154 			if (bp)
2155 				bp->b_resid = xs->resid;
2156 			if (st->fileno != (daddr_t) -1) {
2157 				st->fileno++;
2158 				st->blkno = 0;
2159 				st->flags |= ST_POSUPDATED;
2160 			}
2161 		}
2162 		if (sense->flags & SSD_ILI) {
2163 			st->flags |= ST_EIO_PENDING;
2164 			if (bp)
2165 				bp->b_resid = xs->resid;
2166 			if (sense->error_code & SSD_ERRCODE_VALID &&
2167 			    (xs->xs_control & XS_CTL_SILENT) == 0)
2168 				printf("%s: block wrong size, %d blocks "
2169 				    "residual\n", st->sc_dev.dv_xname, info);
2170 
2171 			/*
2172 			 * This quirk code helps the drive read
2173 			 * the first tape block, regardless of
2174 			 * format.  That is required for these
2175 			 * drives to return proper MODE SENSE
2176 			 * information.
2177 			 */
2178 			if ((st->quirks & ST_Q_SENSE_HELP) &&
2179 			    (periph->periph_flags & PERIPH_MEDIA_LOADED) == 0)
2180 				st->blksize -= 512;
2181 			else if ((st->flags & ST_POSUPDATED) == 0) {
2182 				if (st->blkno != (daddr_t) -1) {
2183 					st->blkno +=
2184 					    (xs->datalen / st->blksize);
2185 					st->flags |= ST_POSUPDATED;
2186 				}
2187 			}
2188 		}
2189 		/*
2190 		 * If data wanted and no data was transferred, do it immediately
2191 		 */
2192 		if (xs->datalen && xs->resid >= xs->datalen) {
2193 			if (st->flags & ST_EIO_PENDING)
2194 				return (EIO);
2195 			if (st->flags & ST_AT_FILEMARK) {
2196 				if (bp)
2197 					bp->b_resid = xs->resid;
2198 				return (0);
2199 			}
2200 		}
2201 	} else {		/* must be variable mode */
2202 		if (bp) {
2203 			st->last_io_resid = xs->resid;
2204 		} else {
2205 			st->last_ctl_resid = xs->resid;
2206 		}
2207 		if (sense->flags & SSD_EOM) {
2208 			/*
2209 			 * The current semantics of this
2210 			 * driver requires EOM detection
2211 			 * to return EIO unless early
2212 			 * warning detection is enabled
2213 			 * for variable mode (this is always
2214 			 * on for fixed block mode).
2215 			 */
2216 			if (st->flags & ST_EARLYWARN) {
2217 				st->flags |= ST_EOM_PENDING;
2218 				retval = 0;
2219 			} else {
2220 				retval = EIO;
2221 			}
2222 
2223 			/*
2224 			 * If it's an unadorned EOM detection,
2225 			 * suppress printing an error.
2226 			 */
2227 			if (key == SKEY_NO_SENSE) {
2228 				doprint = 0;
2229 			}
2230 		} else if (sense->flags & SSD_FILEMARK) {
2231 			retval = 0;
2232 			if (st->fileno != (daddr_t) -1) {
2233 				st->fileno++;
2234 				st->blkno = 0;
2235 				st->flags |= ST_POSUPDATED;
2236 			}
2237 		} else if (sense->flags & SSD_ILI) {
2238 			if (info < 0) {
2239 				/*
2240 				 * The tape record was bigger than the read
2241 				 * we issued.
2242 				 */
2243 				if ((xs->xs_control & XS_CTL_SILENT) == 0) {
2244 					printf("%s: %d-byte tape record too big"
2245 					    " for %d-byte user buffer\n",
2246 					    st->sc_dev.dv_xname,
2247 					    xs->datalen - info, xs->datalen);
2248 				}
2249 				retval = EIO;
2250 			} else {
2251 				retval = 0;
2252 				if (st->blkno != (daddr_t) -1) {
2253 					st->blkno++;
2254 					st->flags |= ST_POSUPDATED;
2255 				}
2256 			}
2257 		}
2258 		if (bp)
2259 			bp->b_resid = info;
2260 	}
2261 
2262 #ifndef SCSIPI_DEBUG
2263 	if (retval == 0 && key == SKEY_NO_SENSE)
2264 		doprint = 0;
2265 #endif
2266 	if (key == SKEY_BLANK_CHECK) {
2267 		/*
2268 		 * This quirk code helps the drive read the
2269 		 * first tape block, regardless of format.  That
2270 		 * is required for these drives to return proper
2271 		 * MODE SENSE information.
2272 		 */
2273 		if ((st->quirks & ST_Q_SENSE_HELP) &&
2274 		    (periph->periph_flags & PERIPH_MEDIA_LOADED) == 0) {
2275 			/* still starting */
2276 			st->blksize -= 512;
2277 		} else if (!(st->flags & (ST_2FM_AT_EOD | ST_BLANK_READ))) {
2278 			st->flags |= ST_BLANK_READ;
2279 			xs->resid = xs->datalen;
2280 			if (bp) {
2281 				bp->b_resid = xs->resid;
2282 				/* return an EOF */
2283 			}
2284 			retval = 0;
2285 			/* lost position */
2286 			st->fileno = st->blkno = -1;
2287 		}
2288 	}
2289 
2290 	/*
2291 	 * If generic sense processing will continue, we should not
2292 	 * print sense info here.
2293 	 */
2294 	if (retval == EJUSTRETURN)
2295 		doprint = 0;
2296 
2297 	if (doprint) {
2298 #ifdef	SCSIVERBOSE
2299 		scsipi_print_sense(xs, 0);
2300 #else
2301 		scsipi_printaddr(periph);
2302 		printf("Sense Key 0x%02x", key);
2303 		if ((sense->error_code & SSD_ERRCODE_VALID) != 0) {
2304 			switch (key) {
2305 			case SKEY_NOT_READY:
2306 			case SKEY_ILLEGAL_REQUEST:
2307 			case SKEY_UNIT_ATTENTION:
2308 			case SKEY_WRITE_PROTECT:
2309 				break;
2310 			case SKEY_VOLUME_OVERFLOW:
2311 			case SKEY_BLANK_CHECK:
2312 				printf(", requested size: %d (decimal)", info);
2313 				break;
2314 			case SKEY_ABORTED_COMMAND:
2315 				if (xs->xs_retries)
2316 					printf(", retrying");
2317 				printf(", cmd 0x%x, info 0x%x",
2318 				    xs->cmd->opcode, info);
2319 				break;
2320 			default:
2321 				printf(", info = %d (decimal)", info);
2322 			}
2323 		}
2324 		if (sense->extra_len != 0) {
2325 			int n;
2326 			printf(", data =");
2327 			for (n = 0; n < sense->extra_len; n++)
2328 				printf(" %02x", sense->cmd_spec_info[n]);
2329 		}
2330 		printf("\n");
2331 #endif
2332 	}
2333 	return (retval);
2334 }
2335 
2336 /*
2337  * The quirk here is that the drive returns some value to st_mode_sense
2338  * incorrectly until the tape has actually passed by the head.
2339  *
2340  * The method is to set the drive to large fixed-block state (user-specified
2341  * density and 1024-byte blocks), then read and rewind to get it to sense the
2342  * tape.  If that doesn't work, try 512-byte fixed blocks.  If that doesn't
2343  * work, as a last resort, try variable- length blocks.  The result will be
2344  * the ability to do an accurate st_mode_sense.
2345  *
2346  * We know we can do a rewind because we just did a load, which implies rewind.
2347  * Rewind seems preferable to space backward if we have a virgin tape.
2348  *
2349  * The rest of the code for this quirk is in ILI processing and BLANK CHECK
2350  * error processing, both part of st_interpret_sense.
2351  */
2352 int
2353 st_touch_tape(st)
2354 	struct st_softc *st;
2355 {
2356 	char *buf;
2357 	int readsize;
2358 	int error;
2359 
2360 	buf = malloc(1024, M_TEMP, M_NOWAIT);
2361 	if (buf == NULL)
2362 		return (ENOMEM);
2363 
2364 	if ((error = st->ops(st, ST_OPS_MODESENSE, 0)) != 0)
2365 		goto bad;
2366 
2367 	/*
2368 	 * If the block size is already known from the
2369 	 * sense data, use it. Else start probing at 1024.
2370 	 */
2371 	if (st->media_blksize > 0)
2372 		st->blksize = st->media_blksize;
2373 	else
2374 		st->blksize = 1024;
2375 
2376 	do {
2377 		switch (st->blksize) {
2378 		case 512:
2379 		case 1024:
2380 			readsize = st->blksize;
2381 			st->flags |= ST_FIXEDBLOCKS;
2382 			break;
2383 		default:
2384 			readsize = 1;
2385 			st->flags &= ~ST_FIXEDBLOCKS;
2386 		}
2387 		if ((error = st->ops(st, ST_OPS_MODESELECT, XS_CTL_SILENT))
2388 		    != 0) {
2389 			/*
2390 			 * The device did not agree with the proposed
2391 			 * block size. If we exhausted our options,
2392 			 * return failure, else try another.
2393 			 */
2394 			if (readsize == 1)
2395 				goto bad;
2396 			st->blksize -= 512;
2397 			continue;
2398 		}
2399 		st_read(st, buf, readsize, XS_CTL_SILENT);	/* XXX */
2400 		if ((error = st_rewind(st, 0, 0)) != 0) {
2401 bad:			free(buf, M_TEMP);
2402 			return (error);
2403 		}
2404 	} while (readsize != 1 && readsize > st->blksize);
2405 
2406 	free(buf, M_TEMP);
2407 	return (0);
2408 }
2409 
2410 int
2411 stdump(dev, blkno, va, size)
2412 	dev_t dev;
2413 	daddr_t blkno;
2414 	caddr_t va;
2415 	size_t size;
2416 {
2417 
2418 	/* Not implemented. */
2419 	return (ENXIO);
2420 }
2421