xref: /netbsd-src/sys/dev/scsipi/st.c (revision 0dd5877adce57db949b16ae963e5a6831cccdfb6)
1 /*	$NetBSD: st.c,v 1.149 2002/01/12 20:30:11 bouyer Exp $ */
2 
3 /*-
4  * Copyright (c) 1998 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Charles M. Hannum.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *        This product includes software developed by the NetBSD
21  *        Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 /*
40  * Originally written by Julian Elischer (julian@tfs.com)
41  * for TRW Financial Systems for use under the MACH(2.5) operating system.
42  *
43  * TRW Financial Systems, in accordance with their agreement with Carnegie
44  * Mellon University, makes this software available to CMU to distribute
45  * or use in any manner that they see fit as long as this message is kept with
46  * the software. For this reason TFS also grants any other persons or
47  * organisations permission to use or modify this software.
48  *
49  * TFS supplies this software to be publicly redistributed
50  * on the understanding that TFS is not responsible for the correct
51  * functioning of this software in any circumstances.
52  *
53  * Ported to run under 386BSD by Julian Elischer (julian@tfs.com) Sept 1992
54  * major changes by Julian Elischer (julian@jules.dialix.oz.au) May 1993
55  *
56  * A lot of rewhacking done by mjacob (mjacob@nas.nasa.gov).
57  */
58 
59 #include <sys/cdefs.h>
60 __KERNEL_RCSID(0, "$NetBSD: st.c,v 1.149 2002/01/12 20:30:11 bouyer Exp $");
61 
62 #include "opt_scsi.h"
63 
64 #include <sys/param.h>
65 #include <sys/systm.h>
66 #include <sys/fcntl.h>
67 #include <sys/errno.h>
68 #include <sys/ioctl.h>
69 #include <sys/malloc.h>
70 #include <sys/buf.h>
71 #include <sys/proc.h>
72 #include <sys/user.h>
73 #include <sys/mtio.h>
74 #include <sys/device.h>
75 #include <sys/conf.h>
76 #include <sys/kernel.h>
77 #include <sys/vnode.h>
78 
79 #include <dev/scsipi/scsi_all.h>
80 #include <dev/scsipi/scsi_tape.h>
81 #include <dev/scsipi/stvar.h>
82 
83 /* Defines for device specific stuff */
84 #define DEF_FIXED_BSIZE  512
85 
86 #define STMODE(z)	( minor(z)       & 0x03)
87 #define STDSTY(z)	((minor(z) >> 2) & 0x03)
88 #define STUNIT(z)	((minor(z) >> 4)       )
89 #define STNMINOR	16
90 
91 #define NORMAL_MODE	0
92 #define NOREW_MODE	1
93 #define EJECT_MODE	2
94 #define CTRL_MODE	3
95 
96 #define	FALSE		0
97 #define	TRUE		1
98 
99 #ifndef		ST_MOUNT_DELAY
100 #define		ST_MOUNT_DELAY		0
101 #endif
102 
103 /*
104  * Define various devices that we know mis-behave in some way,
105  * and note how they are bad, so we can correct for them
106  */
107 
108 const struct st_quirk_inquiry_pattern st_quirk_patterns[] = {
109 	{{T_SEQUENTIAL, T_REMOV,
110 	 "        ", "                ", "    "}, {0, 0, {
111 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
112 		{ST_Q_FORCE_BLKSIZE, 512, QIC_24},	/* minor 4-7 */
113 		{ST_Q_FORCE_BLKSIZE, 0, HALFINCH_1600},	/* minor 8-11 */
114 		{ST_Q_FORCE_BLKSIZE, 0, HALFINCH_6250}	/* minor 12-15 */
115 	}}},
116 	{{T_SEQUENTIAL, T_REMOV,
117 	 "TANDBERG", " TDC 3600       ", ""},     {0, 12, {
118 		{0, 0, 0},				/* minor 0-3 */
119 		{ST_Q_FORCE_BLKSIZE, 0, QIC_525},	/* minor 4-7 */
120 		{0, 0, QIC_150},			/* minor 8-11 */
121 		{0, 0, QIC_120}				/* minor 12-15 */
122 	}}},
123  	{{T_SEQUENTIAL, T_REMOV,
124  	 "TANDBERG", " TDC 3800       ", ""},     {0, 0, {
125 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
126 		{0, 0, QIC_525},			/* minor 4-7 */
127 		{0, 0, QIC_150},			/* minor 8-11 */
128 		{0, 0, QIC_120}				/* minor 12-15 */
129 	}}},
130 	/*
131 	 * lacking a manual for the 4200, it's not clear what the
132 	 * specific density codes should be- the device is a 2.5GB
133 	 * capable QIC drive, those density codes aren't readily
134 	 * availabel. The 'default' will just have to do.
135 	 */
136  	{{T_SEQUENTIAL, T_REMOV,
137  	 "TANDBERG", " TDC 4200       ", ""},     {0, 0, {
138 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
139 		{0, 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 	 * At least -005 and -007 need this.  I'll assume they all do unless I
145 	 * hear otherwise.  - mycroft, 31MAR1994
146 	 */
147 	{{T_SEQUENTIAL, T_REMOV,
148 	 "ARCHIVE ", "VIPER 2525 25462", ""},     {0, 0, {
149 		{ST_Q_SENSE_HELP, 0, 0},		/* minor 0-3 */
150 		{ST_Q_SENSE_HELP, 0, QIC_525},		/* minor 4-7 */
151 		{0, 0, QIC_150},			/* minor 8-11 */
152 		{0, 0, QIC_120}				/* minor 12-15 */
153 	}}},
154 	/*
155 	 * One user reports that this works for his tape drive.  It probably
156 	 * needs more work.  - mycroft, 09APR1994
157 	 */
158 	{{T_SEQUENTIAL, T_REMOV,
159 	 "SANKYO  ", "CP525           ", ""},    {0, 0, {
160 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
161 		{ST_Q_FORCE_BLKSIZE, 512, QIC_525},	/* minor 4-7 */
162 		{0, 0, QIC_150},			/* minor 8-11 */
163 		{0, 0, QIC_120}				/* minor 12-15 */
164 	}}},
165 	{{T_SEQUENTIAL, T_REMOV,
166 	 "ANRITSU ", "DMT780          ", ""},     {0, 0, {
167 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
168 		{ST_Q_FORCE_BLKSIZE, 512, QIC_525},	/* minor 4-7 */
169 		{0, 0, QIC_150},			/* minor 8-11 */
170 		{0, 0, QIC_120}				/* minor 12-15 */
171 	}}},
172 	{{T_SEQUENTIAL, T_REMOV,
173 	 "ARCHIVE ", "VIPER 150  21247", ""},     {ST_Q_ERASE_NOIMM, 12, {
174 		{ST_Q_SENSE_HELP, 0, 0},		/* minor 0-3 */
175 		{0, 0, QIC_150},			/* minor 4-7 */
176 		{0, 0, QIC_120},			/* minor 8-11 */
177 		{0, 0, QIC_24}				/* minor 12-15 */
178 	}}},
179 	{{T_SEQUENTIAL, T_REMOV,
180 	 "ARCHIVE ", "VIPER 150  21531", ""},     {ST_Q_ERASE_NOIMM, 12, {
181 		{ST_Q_SENSE_HELP, 0, 0},		/* minor 0-3 */
182 		{0, 0, QIC_150},			/* minor 4-7 */
183 		{0, 0, QIC_120},			/* minor 8-11 */
184 		{0, 0, QIC_24}				/* minor 12-15 */
185 	}}},
186 	{{T_SEQUENTIAL, T_REMOV,
187 	 "WANGTEK ", "5099ES SCSI", ""},          {0, 0, {
188 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
189 		{0, 0, QIC_11},				/* minor 4-7 */
190 		{0, 0, QIC_24},				/* minor 8-11 */
191 		{0, 0, QIC_24}				/* minor 12-15 */
192 	}}},
193 	{{T_SEQUENTIAL, T_REMOV,
194 	 "WANGTEK ", "5150ES SCSI", ""},          {0, 0, {
195 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
196 		{0, 0, QIC_24},				/* minor 4-7 */
197 		{0, 0, QIC_120},			/* minor 8-11 */
198 		{0, 0, QIC_150}				/* minor 12-15 */
199 	}}},
200 	{{T_SEQUENTIAL, T_REMOV,
201 	 "WANGTEK ", "5525ES SCSI REV7", ""},     {0, 0, {
202 		{0, 0, 0},				/* minor 0-3 */
203 		{ST_Q_BLKSIZE, 0, QIC_525},		/* minor 4-7 */
204 		{0, 0, QIC_150},			/* minor 8-11 */
205 		{0, 0, QIC_120}				/* minor 12-15 */
206 	}}},
207 	{{T_SEQUENTIAL, T_REMOV,
208 	 "WangDAT ", "Model 1300      ", ""},     {0, 0, {
209 		{0, 0, 0},				/* minor 0-3 */
210 		{ST_Q_FORCE_BLKSIZE, 512, DDS},		/* minor 4-7 */
211 		{ST_Q_FORCE_BLKSIZE, 1024, DDS},	/* minor 8-11 */
212 		{ST_Q_FORCE_BLKSIZE, 0, DDS}		/* minor 12-15 */
213 	}}},
214 	{{T_SEQUENTIAL, T_REMOV,
215 	 "EXABYTE ", "EXB-8200        ", "263H"}, {0, 5, {
216 		{0, 0, 0},				/* minor 0-3 */
217 		{0, 0, 0},				/* minor 4-7 */
218 		{0, 0, 0},				/* minor 8-11 */
219 		{0, 0, 0}				/* minor 12-15 */
220 	}}},
221 	{{T_SEQUENTIAL, T_REMOV,
222 	 "STK",      "9490",             ""},
223 				{ST_Q_FORCE_BLKSIZE, 0, {
224 		{0, 0, 0},				/* minor 0-3 */
225 		{0, 0, 0},				/* minor 4-7 */
226 		{0, 0, 0},				/* minor 8-11 */
227 		{0, 0, 0}				/* minor 12-15 */
228 	}}},
229 	{{T_SEQUENTIAL, T_REMOV,
230 	 "STK",      "SD-3",             ""},
231 				{ST_Q_FORCE_BLKSIZE, 0, {
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 	 "IBM",      "03590",            ""},     {ST_Q_IGNORE_LOADS, 0, {
239 		{0, 0, 0},				/* minor 0-3 */
240 		{0, 0, 0},				/* minor 4-7 */
241 		{0, 0, 0},				/* minor 8-11 */
242 		{0, 0, 0}				/* minor 12-15 */
243 	}}},
244 	{{T_SEQUENTIAL, T_REMOV,
245 	 "HP      ", "T4000s          ", ""},     {ST_Q_UNIMODAL, 0, {
246 		{0, 0, QIC_3095},			/* minor 0-3 */
247 		{0, 0, QIC_3095},			/* minor 4-7 */
248 		{0, 0, QIC_3095},			/* minor 8-11 */
249 		{0, 0, QIC_3095},			/* minor 12-15 */
250 	}}},
251 #if 0
252 	{{T_SEQUENTIAL, T_REMOV,
253 	 "EXABYTE ", "EXB-8200        ", ""},     {0, 12, {
254 		{0, 0, 0},				/* minor 0-3 */
255 		{0, 0, 0},				/* minor 4-7 */
256 		{0, 0, 0},				/* minor 8-11 */
257 		{0, 0, 0}				/* minor 12-15 */
258 	}}},
259 #endif
260 	{{T_SEQUENTIAL, T_REMOV,
261 	 "TEAC    ", "MT-2ST/N50      ", ""},     {ST_Q_IGNORE_LOADS, 0, {
262 		{0, 0, 0},			        /* minor 0-3 */
263 		{0, 0, 0},			        /* minor 4-7 */
264 		{0, 0, 0},			        /* minor 8-11 */
265 		{0, 0, 0}			        /* minor 12-15 */
266 	}}},
267 	{{T_SEQUENTIAL, T_REMOV,
268 	 "OnStream", "ADR50 Drive", ""},	  {ST_Q_UNIMODAL, 0, {
269 		{ST_Q_FORCE_BLKSIZE, 512, 0},	        /* minor 0-3 */
270 		{ST_Q_FORCE_BLKSIZE, 512, 0},	        /* minor 4-7 */
271 		{ST_Q_FORCE_BLKSIZE, 512, 0},	        /* minor 8-11 */
272 		{ST_Q_FORCE_BLKSIZE, 512, 0},	        /* minor 12-15 */
273 	}}},
274 	{{T_SEQUENTIAL, T_REMOV,
275 	 "OnStream DI-30",      "",   "1.0"},  {ST_Q_NOFILEMARKS, 0, {
276 		{0, 0, 0},                              /* minor 0-3 */
277 		{0, 0, 0},                              /* minor 4-7 */
278 		{0, 0, 0},                              /* minor 8-11 */
279 		{0, 0, 0}                               /* minor 12-15 */
280 	}}},
281 	{{T_SEQUENTIAL, T_REMOV,
282 	 "NCR H621", "0-STD-03-46F880 ", ""},     {ST_Q_NOPREVENT, 0, {
283 		{0, 0, 0},			       /* minor 0-3 */
284 		{0, 0, 0},			       /* minor 4-7 */
285 		{0, 0, 0},			       /* minor 8-11 */
286 		{0, 0, 0}			       /* minor 12-15 */
287 	}}},
288 };
289 
290 #define NOEJECT 0
291 #define EJECT 1
292 
293 void	st_identify_drive __P((struct st_softc *,
294 	    struct scsipi_inquiry_pattern *));
295 void	st_loadquirks __P((struct st_softc *));
296 int	st_mount_tape __P((dev_t, int));
297 void	st_unmount __P((struct st_softc *, boolean));
298 int	st_decide_mode __P((struct st_softc *, boolean));
299 void	ststart __P((struct scsipi_periph *));
300 void	stdone __P((struct scsipi_xfer *));
301 int	st_read __P((struct st_softc *, char *, int, int));
302 int	st_space __P((struct st_softc *, int, u_int, int));
303 int	st_write_filemarks __P((struct st_softc *, int, int));
304 int	st_check_eod __P((struct st_softc *, boolean, int *, int));
305 int	st_load __P((struct st_softc *, u_int, int));
306 int	st_rewind __P((struct st_softc *, u_int, int));
307 int	st_interpret_sense __P((struct scsipi_xfer *));
308 int	st_touch_tape __P((struct st_softc *));
309 int	st_erase __P((struct st_softc *, int full, int flags));
310 int	st_rdpos __P((struct st_softc *, int, u_int32_t *));
311 int	st_setpos __P((struct st_softc *, int, u_int32_t *));
312 
313 const struct scsipi_periphsw st_switch = {
314 	st_interpret_sense,
315 	ststart,
316 	NULL,
317 	stdone
318 };
319 
320 #if	defined(ST_ENABLE_EARLYWARN)
321 #define	ST_INIT_FLAGS	ST_EARLYWARN
322 #else
323 #define	ST_INIT_FLAGS	0
324 #endif
325 
326 /*
327  * The routine called by the low level scsi routine when it discovers
328  * A device suitable for this driver
329  */
330 void
331 stattach(parent, st, aux)
332 	struct device *parent;
333 	struct st_softc *st;
334 	void *aux;
335 {
336 	struct scsipibus_attach_args *sa = aux;
337 	struct scsipi_periph *periph = sa->sa_periph;
338 
339 	SC_DEBUG(periph, SCSIPI_DB2, ("stattach: "));
340 
341 	/*
342 	 * Store information needed to contact our base driver
343 	 */
344 	st->sc_periph = periph;
345 	periph->periph_dev = &st->sc_dev;
346 	periph->periph_switch = &st_switch;
347 
348 	/*
349 	 * Set initial flags
350 	 */
351 
352 	st->flags = ST_INIT_FLAGS;
353 
354 	/*
355 	 * Check if the drive is a known criminal and take
356 	 * Any steps needed to bring it into line
357 	 */
358 	st_identify_drive(st, &sa->sa_inqbuf);
359 	/*
360 	 * Use the subdriver to request information regarding the drive.
361 	 */
362 	printf("\n");
363 	printf("%s: %s", st->sc_dev.dv_xname, st->quirkdata ? "rogue, " : "");
364 	if (scsipi_test_unit_ready(periph,
365 	    XS_CTL_DISCOVERY | XS_CTL_SILENT | XS_CTL_IGNORE_MEDIA_CHANGE) ||
366 	    st->ops(st, ST_OPS_MODESENSE,
367 	    XS_CTL_DISCOVERY | XS_CTL_SILENT | XS_CTL_IGNORE_MEDIA_CHANGE))
368 		printf("drive empty\n");
369 	else {
370 		printf("density code %d, ", st->media_density);
371 		if (st->media_blksize > 0)
372 			printf("%d-byte", st->media_blksize);
373 		else
374 			printf("variable");
375 		printf(" blocks, write-%s\n",
376 		    (st->flags & ST_READONLY) ? "protected" : "enabled");
377 	}
378 
379 	/*
380 	 * Set up the buf queue for this device
381 	 */
382 	BUFQ_INIT(&st->buf_queue);
383 
384 #if NRND > 0
385 	rnd_attach_source(&st->rnd_source, st->sc_dev.dv_xname,
386 			  RND_TYPE_TAPE, 0);
387 #endif
388 }
389 
390 int
391 stactivate(self, act)
392 	struct device *self;
393 	enum devact act;
394 {
395 	int rv = 0;
396 
397 	switch (act) {
398 	case DVACT_ACTIVATE:
399 		rv = EOPNOTSUPP;
400 		break;
401 
402 	case DVACT_DEACTIVATE:
403 		/*
404 		 * Nothing to do; we key off the device's DVF_ACTIVE.
405 		 */
406 		break;
407 	}
408 	return (rv);
409 }
410 
411 int
412 stdetach(self, flags)
413 	struct device *self;
414 	int flags;
415 {
416 	struct st_softc *st = (struct st_softc *)self;
417 	struct buf *bp;
418 	int s, bmaj, cmaj, mn;
419 
420 	/* locate the major number */
421 	for (bmaj = 0; bmaj <= nblkdev; bmaj++)
422 		if (bdevsw[bmaj].d_open == stopen)
423 			break;
424 	for (cmaj = 0; cmaj <= nchrdev; cmaj++)
425 		if (cdevsw[cmaj].d_open == stopen)
426 			break;
427 
428 	s = splbio();
429 
430 	/* Kill off any queued buffers. */
431 	while ((bp = BUFQ_FIRST(&st->buf_queue)) != NULL) {
432 		BUFQ_REMOVE(&st->buf_queue, bp);
433 		bp->b_error = EIO;
434 		bp->b_flags |= B_ERROR;
435 		bp->b_resid = bp->b_bcount;
436 		biodone(bp);
437 	}
438 
439 	/* Kill off any pending commands. */
440 	scsipi_kill_pending(st->sc_periph);
441 
442 	splx(s);
443 
444 	/* Nuke the vnodes for any open instances */
445 	mn = STUNIT(self->dv_unit);
446 	vdevgone(bmaj, mn, mn+STNMINOR-1, VBLK);
447 	vdevgone(cmaj, mn, mn+STNMINOR-1, VCHR);
448 
449 
450 #if NRND > 0
451 	/* Unhook the entropy source. */
452 	rnd_detach_source(&st->rnd_source);
453 #endif
454 
455 	return (0);
456 }
457 
458 /*
459  * Use the inquiry routine in 'scsi_base' to get drive info so we can
460  * Further tailor our behaviour.
461  */
462 void
463 st_identify_drive(st, inqbuf)
464 	struct st_softc *st;
465 	struct scsipi_inquiry_pattern *inqbuf;
466 {
467 	struct st_quirk_inquiry_pattern *finger;
468 	int priority;
469 
470 	finger = (struct st_quirk_inquiry_pattern *)scsipi_inqmatch(inqbuf,
471 	    (caddr_t)st_quirk_patterns,
472 	    sizeof(st_quirk_patterns) / sizeof(st_quirk_patterns[0]),
473 	    sizeof(st_quirk_patterns[0]), &priority);
474 	if (priority != 0) {
475 		st->quirkdata = &finger->quirkdata;
476 		st->drive_quirks = finger->quirkdata.quirks;
477 		st->quirks = finger->quirkdata.quirks;	/* start value */
478 		st->page_0_size = finger->quirkdata.page_0_size;
479 		st_loadquirks(st);
480 	}
481 }
482 
483 /*
484  * initialise the subdevices to the default (QUIRK) state.
485  * this will remove any setting made by the system operator or previous
486  * operations.
487  */
488 void
489 st_loadquirks(st)
490 	struct st_softc *st;
491 {
492 	int i;
493 	struct	modes *mode;
494 	struct	modes *mode2;
495 
496 	mode = st->quirkdata->modes;
497 	mode2 = st->modes;
498 	for (i = 0; i < 4; i++) {
499 		memset(mode2, 0, sizeof(struct modes));
500 		st->modeflags[i] &= ~(BLKSIZE_SET_BY_QUIRK |
501 		    DENSITY_SET_BY_QUIRK | BLKSIZE_SET_BY_USER |
502 		    DENSITY_SET_BY_USER);
503 		if ((mode->quirks | st->drive_quirks) & ST_Q_FORCE_BLKSIZE) {
504 			mode2->blksize = mode->blksize;
505 			st->modeflags[i] |= BLKSIZE_SET_BY_QUIRK;
506 		}
507 		if (mode->density) {
508 			mode2->density = mode->density;
509 			st->modeflags[i] |= DENSITY_SET_BY_QUIRK;
510 		}
511 		mode2->quirks |= mode->quirks;
512 		mode++;
513 		mode2++;
514 	}
515 }
516 
517 /*
518  * open the device.
519  */
520 int
521 stopen(dev, flags, mode, p)
522 	dev_t dev;
523 	int flags;
524 	int mode;
525 	struct proc *p;
526 {
527 	u_int stmode, dsty;
528 	int error, sflags, unit, tries, ntries;
529 	struct st_softc *st;
530 	struct scsipi_periph *periph;
531 	struct scsipi_adapter *adapt;
532 
533 	unit = STUNIT(dev);
534 	if (unit >= st_cd.cd_ndevs)
535 		return (ENXIO);
536 	st = st_cd.cd_devs[unit];
537 	if (st == NULL)
538 		return (ENXIO);
539 
540 	stmode = STMODE(dev);
541 	dsty = STDSTY(dev);
542 
543 	periph = st->sc_periph;
544 	adapt = periph->periph_channel->chan_adapter;
545 
546 	SC_DEBUG(periph, SCSIPI_DB1, ("open: dev=0x%x (unit %d (of %d))\n", dev,
547 	    unit, st_cd.cd_ndevs));
548 
549 
550 	/*
551 	 * Only allow one at a time
552 	 */
553 	if (periph->periph_flags & PERIPH_OPEN) {
554 		printf("%s: already open\n", st->sc_dev.dv_xname);
555 		return (EBUSY);
556 	}
557 
558 	if ((error = scsipi_adapter_addref(adapt)) != 0)
559 		return (error);
560 
561 	/*
562 	 * clear any latched errors.
563 	 */
564 	st->mt_resid = 0;
565 	st->mt_erreg = 0;
566 	st->asc = 0;
567 	st->ascq = 0;
568 
569 	/*
570 	 * Catch any unit attention errors. Be silent about this
571 	 * unless we're already mounted. We ignore media change
572 	 * if we're in control mode or not mounted yet.
573 	 */
574 	if ((st->flags & ST_MOUNTED) == 0 || stmode == CTRL_MODE) {
575 #ifdef SCSIDEBUG
576 		sflags = XS_CTL_IGNORE_MEDIA_CHANGE;
577 #else
578 		sflags = XS_CTL_SILENT|XS_CTL_IGNORE_MEDIA_CHANGE;
579 #endif
580 	} else
581 		sflags = 0;
582 
583 	/*
584 	 * If we're already mounted or we aren't configured for
585 	 * a mount delay, only try a test unit ready once. Otherwise,
586 	 * try up to ST_MOUNT_DELAY times with a rest interval of
587 	 * one second between each try.
588 	 */
589 
590 	if ((st->flags & ST_MOUNTED) || ST_MOUNT_DELAY == 0) {
591 		ntries = 1;
592 	} else {
593 		ntries = ST_MOUNT_DELAY;
594 	}
595 
596 	for (error = tries = 0; tries < ntries; tries++) {
597 		int slpintr, oflags;
598 
599 		/*
600 		 * If we had no error, or we're opening the control mode
601 		 * device, we jump out right away.
602 		 */
603 
604 		error = scsipi_test_unit_ready(periph, sflags);
605 		if (error == 0 || stmode == CTRL_MODE) {
606 			break;
607 		}
608 
609 		/*
610 		 * We had an error.
611 		 *
612 		 * If we're already mounted or we aren't configured for
613 		 * a mount delay, or the error isn't a NOT READY error,
614 		 * skip to the error exit now.
615 		 */
616 		if ((st->flags & ST_MOUNTED) || ST_MOUNT_DELAY == 0 ||
617 		    (st->mt_key != SKEY_NOT_READY)) {
618 			goto bad;
619 		}
620 
621 		/*
622 		 * clear any latched errors.
623 		 */
624 		st->mt_resid = 0;
625 		st->mt_erreg = 0;
626 		st->asc = 0;
627 		st->ascq = 0;
628 
629 		/*
630 		 * Fake that we have the device open so
631 		 * we block other apps from getting in.
632 		 */
633 
634 		oflags = periph->periph_flags;
635 		periph->periph_flags |= PERIPH_OPEN;
636 
637 		slpintr = tsleep(&lbolt, PUSER|PCATCH, "stload", 0);
638 
639 		periph->periph_flags = oflags;	/* restore flags */
640 		if (slpintr) {
641 			goto bad;
642 		}
643 	}
644 
645 
646 	/*
647 	 * If the mode is 3 (e.g. minor = 3,7,11,15) then the device has
648 	 * been opened to set defaults and perform other, usually non-I/O
649 	 * related, operations. In this case, do a quick check to see
650 	 * whether the unit actually had a tape loaded (this will be known
651 	 * as to whether or not we got a NOT READY for the above
652 	 * unit attention). If a tape is there, go do a mount sequence.
653 	 */
654 	if (stmode == CTRL_MODE && st->mt_key == SKEY_NOT_READY) {
655 		periph->periph_flags |= PERIPH_OPEN;
656 		return (0);
657 	}
658 
659 	/*
660 	 * If we get this far and had an error set, that means we failed
661 	 * to pass the 'test unit ready' test for the non-controlmode device,
662 	 * so we bounce the open.
663 	 */
664 
665 	if (error)
666 		return (error);
667 
668 	/*
669 	 * Else, we're now committed to saying we're open.
670 	 */
671 
672 	periph->periph_flags |= PERIPH_OPEN; /* unit attn are now errors */
673 
674 	/*
675 	 * If it's a different mode, or if the media has been
676 	 * invalidated, unmount the tape from the previous
677 	 * session but continue with open processing
678 	 */
679 	if (st->last_dsty != dsty ||
680 	    (periph->periph_flags & PERIPH_MEDIA_LOADED) == 0)
681 		st_unmount(st, NOEJECT);
682 
683 	/*
684 	 * If we are not mounted, then we should start a new
685 	 * mount session.
686 	 */
687 	if (!(st->flags & ST_MOUNTED)) {
688 		if ((error = st_mount_tape(dev, flags)) != 0)
689 			goto bad;
690 		st->last_dsty = dsty;
691 	}
692 
693 	SC_DEBUG(periph, SCSIPI_DB2, ("open complete\n"));
694 	return (0);
695 
696 bad:
697 	st_unmount(st, NOEJECT);
698 	scsipi_adapter_delref(adapt);
699 	periph->periph_flags &= ~PERIPH_OPEN;
700 	return (error);
701 }
702 
703 /*
704  * close the device.. only called if we are the LAST
705  * occurence of an open device
706  */
707 int
708 stclose(dev, flags, mode, p)
709 	dev_t dev;
710 	int flags;
711 	int mode;
712 	struct proc *p;
713 {
714 	int stxx, error = 0;
715 	struct st_softc *st = st_cd.cd_devs[STUNIT(dev)];
716 	struct scsipi_periph *periph = st->sc_periph;
717 	struct scsipi_adapter *adapt = periph->periph_channel->chan_adapter;
718 
719 	SC_DEBUG(st->sc_periph, SCSIPI_DB1, ("closing\n"));
720 
721 	/*
722 	 * Make sure that a tape opened in write-only mode will have
723 	 * file marks written on it when closed, even if not written to.
724 	 *
725 	 * This is for SUN compatibility. Actually, the Sun way of
726 	 * things is to:
727 	 *
728 	 *	only write filemarks if there are fmks to be written and
729 	 *   		- open for write (possibly read/write)
730 	 *		- the last operation was a write
731 	 * 	or:
732 	 *		- opened for wronly
733 	 *		- no data was written (including filemarks)
734 	 */
735 
736 	stxx = st->flags & (ST_WRITTEN | ST_FM_WRITTEN);
737 	if (((flags & FWRITE) && stxx == ST_WRITTEN) ||
738 	    ((flags & O_ACCMODE) == FWRITE && stxx == 0)) {
739 		int nm;
740 		error = st_check_eod(st, FALSE, &nm, 0);
741 	}
742 
743 	switch (STMODE(dev)) {
744 	case NORMAL_MODE:
745 		st_unmount(st, NOEJECT);
746 		break;
747 	case NOREW_MODE:
748 	case CTRL_MODE:
749 		/*
750 		 * Leave mounted unless media seems to have been removed.
751 		 *
752 		 * Otherwise, if we're to terminate a tape with more than one
753 		 * filemark [ and because we're not rewinding here ], backspace
754 		 * one filemark so that later appends will see an unbroken
755 		 * sequence of:
756 		 *
757 		 *	file - FMK - file - FMK ... file - FMK FMK (EOM)
758 		 */
759 		if ((periph->periph_flags & PERIPH_MEDIA_LOADED) == 0) {
760 			st_unmount(st, NOEJECT);
761 		} else if (error == 0) {
762 			/*
763 			 * ST_WRITTEN was preserved from above.
764 			 *
765 			 * All we need to know here is:
766 			 *
767 			 *	Were we writing this tape and was the last
768 			 *	operation a write?
769 			 *
770 			 *	Are there supposed to be 2FM at EOD?
771 			 *
772 			 * If both statements are true, then we backspace
773 			 * one filemark.
774 			 */
775 			stxx |= (st->flags & ST_2FM_AT_EOD);
776 			if ((flags & FWRITE) != 0 &&
777 			    (stxx == (ST_2FM_AT_EOD|ST_WRITTEN))) {
778 				error = st_space(st, -1, SP_FILEMARKS, 0);
779 			}
780 		}
781 		break;
782 	case EJECT_MODE:
783 		st_unmount(st, EJECT);
784 		break;
785 	}
786 
787 	scsipi_wait_drain(periph);
788 
789 	scsipi_adapter_delref(adapt);
790 	periph->periph_flags &= ~PERIPH_OPEN;
791 
792 	return (error);
793 }
794 
795 /*
796  * Start a new mount session.
797  * Copy in all the default parameters from the selected device mode.
798  * and try guess any that seem to be defaulted.
799  */
800 int
801 st_mount_tape(dev, flags)
802 	dev_t dev;
803 	int flags;
804 {
805 	int unit;
806 	u_int dsty;
807 	struct st_softc *st;
808 	struct scsipi_periph *periph;
809 	int error = 0;
810 
811 	unit = STUNIT(dev);
812 	dsty = STDSTY(dev);
813 	st = st_cd.cd_devs[unit];
814 	periph = st->sc_periph;
815 
816 	if (st->flags & ST_MOUNTED)
817 		return (0);
818 
819 	SC_DEBUG(periph, SCSIPI_DB1, ("mounting\n "));
820 	st->flags |= ST_NEW_MOUNT;
821 	st->quirks = st->drive_quirks | st->modes[dsty].quirks;
822 	/*
823 	 * If the media is new, then make sure we give it a chance to
824 	 * to do a 'load' instruction.  (We assume it is new.)
825 	 */
826 	if ((error = st_load(st, LD_LOAD, XS_CTL_SILENT)) != 0)
827 		return (error);
828 	/*
829 	 * Throw another dummy instruction to catch
830 	 * 'Unit attention' errors. Many drives give
831 	 * these after doing a Load instruction (with
832 	 * the MEDIUM MAY HAVE CHANGED asc/ascq).
833 	 */
834 	scsipi_test_unit_ready(periph, XS_CTL_SILENT);	/* XXX */
835 
836 	/*
837 	 * Some devices can't tell you much until they have been
838 	 * asked to look at the media. This quirk does this.
839 	 */
840 	if (st->quirks & ST_Q_SENSE_HELP)
841 		if ((error = st_touch_tape(st)) != 0)
842 			return (error);
843 	/*
844 	 * Load the physical device parameters
845 	 * loads: blkmin, blkmax
846 	 */
847 	if ((error = st->ops(st, ST_OPS_RBL, 0)) != 0)
848 		return (error);
849 	/*
850 	 * Load the media dependent parameters
851 	 * includes: media_blksize,media_density,numblks
852 	 * As we have a tape in, it should be reflected here.
853 	 * If not you may need the "quirk" above.
854 	 */
855 	if ((error = st->ops(st, ST_OPS_MODESENSE, 0)) != 0)
856 		return (error);
857 	/*
858 	 * If we have gained a permanent density from somewhere,
859 	 * then use it in preference to the one supplied by
860 	 * default by the driver.
861 	 */
862 	if (st->modeflags[dsty] & (DENSITY_SET_BY_QUIRK | DENSITY_SET_BY_USER))
863 		st->density = st->modes[dsty].density;
864 	else
865 		st->density = st->media_density;
866 	/*
867 	 * If we have gained a permanent blocksize
868 	 * then use it in preference to the one supplied by
869 	 * default by the driver.
870 	 */
871 	st->flags &= ~ST_FIXEDBLOCKS;
872 	if (st->modeflags[dsty] &
873 	    (BLKSIZE_SET_BY_QUIRK | BLKSIZE_SET_BY_USER)) {
874 		st->blksize = st->modes[dsty].blksize;
875 		if (st->blksize)
876 			st->flags |= ST_FIXEDBLOCKS;
877 	} else {
878 		if ((error = st_decide_mode(st, FALSE)) != 0)
879 			return (error);
880 	}
881 	if ((error = st->ops(st, ST_OPS_MODESELECT, 0)) != 0) {
882 		/* ATAPI will return ENODEV for this, and this may be OK */
883 		if (error != ENODEV) {
884 			printf("%s: cannot set selected mode\n",
885 			    st->sc_dev.dv_xname);
886 			return (error);
887 		}
888 	}
889 	if (!(st->quirks & ST_Q_NOPREVENT)) {
890 		scsipi_prevent(periph, PR_PREVENT,
891 		    XS_CTL_IGNORE_ILLEGAL_REQUEST | XS_CTL_IGNORE_NOT_READY);
892 	}
893 	st->flags &= ~ST_NEW_MOUNT;
894 	st->flags |= ST_MOUNTED;
895 	periph->periph_flags |= PERIPH_MEDIA_LOADED;	/* move earlier? */
896 
897 	return (0);
898 }
899 
900 /*
901  * End the present mount session.
902  * Rewind, and optionally eject the tape.
903  * Reset various flags to indicate that all new
904  * operations require another mount operation
905  */
906 void
907 st_unmount(st, eject)
908 	struct st_softc *st;
909 	boolean eject;
910 {
911 	struct scsipi_periph *periph = st->sc_periph;
912 	int nmarks;
913 
914 	if ((st->flags & ST_MOUNTED) == 0)
915 		return;
916 	SC_DEBUG(periph, SCSIPI_DB1, ("unmounting\n"));
917 	st_check_eod(st, FALSE, &nmarks, XS_CTL_IGNORE_NOT_READY);
918 	st_rewind(st, 0, XS_CTL_IGNORE_NOT_READY);
919 
920 	/*
921 	 * Section 9.3.3 of the SCSI specs states that a device shall return
922 	 * the density value specified in the last succesfull MODE SELECT
923 	 * after an unload operation, in case it is not able to
924 	 * automatically determine the density of the new medium.
925 	 *
926 	 * So we instruct the device to use the default density, which will
927 	 * prevent the use of stale density values (in particular,
928 	 * in st_touch_tape().
929 	 */
930 	st->density = 0;
931 	if (st->ops(st, ST_OPS_MODESELECT, 0) != 0) {
932 		printf("%s: WARNING: cannot revert to default density\n",
933 			st->sc_dev.dv_xname);
934 	}
935 
936 	scsipi_prevent(periph, PR_ALLOW,
937 	    XS_CTL_IGNORE_ILLEGAL_REQUEST | XS_CTL_IGNORE_NOT_READY);
938 	if (eject)
939 		st_load(st, LD_UNLOAD, XS_CTL_IGNORE_NOT_READY);
940 	st->flags &= ~(ST_MOUNTED | ST_NEW_MOUNT);
941 	periph->periph_flags &= ~PERIPH_MEDIA_LOADED;
942 }
943 
944 /*
945  * Given all we know about the device, media, mode, 'quirks' and
946  * initial operation, make a decision as to how we should be set
947  * to run (regarding blocking and EOD marks)
948  */
949 int
950 st_decide_mode(st, first_read)
951 	struct st_softc *st;
952 	boolean	first_read;
953 {
954 
955 	SC_DEBUG(st->sc_periph, SCSIPI_DB2, ("starting block mode decision\n"));
956 
957 	/*
958 	 * If the drive can only handle fixed-length blocks and only at
959 	 * one size, perhaps we should just do that.
960 	 */
961 	if (st->blkmin && (st->blkmin == st->blkmax)) {
962 		st->flags |= ST_FIXEDBLOCKS;
963 		st->blksize = st->blkmin;
964 		SC_DEBUG(st->sc_periph, SCSIPI_DB3,
965 		    ("blkmin == blkmax of %d\n", st->blkmin));
966 		goto done;
967 	}
968 	/*
969 	 * If the tape density mandates (or even suggests) use of fixed
970 	 * or variable-length blocks, comply.
971 	 */
972 	switch (st->density) {
973 	case HALFINCH_800:
974 	case HALFINCH_1600:
975 	case HALFINCH_6250:
976 	case DDS:
977 		st->flags &= ~ST_FIXEDBLOCKS;
978 		st->blksize = 0;
979 		SC_DEBUG(st->sc_periph, SCSIPI_DB3,
980 		    ("density specified variable\n"));
981 		goto done;
982 	case QIC_11:
983 	case QIC_24:
984 	case QIC_120:
985 	case QIC_150:
986 	case QIC_525:
987 	case QIC_1320:
988 	case QIC_3095:
989 	case QIC_3220:
990 		st->flags |= ST_FIXEDBLOCKS;
991 		if (st->media_blksize > 0)
992 			st->blksize = st->media_blksize;
993 		else
994 			st->blksize = DEF_FIXED_BSIZE;
995 		SC_DEBUG(st->sc_periph, SCSIPI_DB3,
996 		    ("density specified fixed\n"));
997 		goto done;
998 	}
999 	/*
1000 	 * If we're about to read the tape, perhaps we should choose
1001 	 * fixed or variable-length blocks and block size according to
1002 	 * what the drive found on the tape.
1003 	 */
1004 	if (first_read &&
1005 	    (!(st->quirks & ST_Q_BLKSIZE) || (st->media_blksize == 0) ||
1006 	    (st->media_blksize == DEF_FIXED_BSIZE) ||
1007 	    (st->media_blksize == 1024))) {
1008 		if (st->media_blksize > 0)
1009 			st->flags |= ST_FIXEDBLOCKS;
1010 		else
1011 			st->flags &= ~ST_FIXEDBLOCKS;
1012 		st->blksize = st->media_blksize;
1013 		SC_DEBUG(st->sc_periph, SCSIPI_DB3,
1014 		    ("Used media_blksize of %d\n", st->media_blksize));
1015 		goto done;
1016 	}
1017 	/*
1018 	 * We're getting no hints from any direction.  Choose variable-
1019 	 * length blocks arbitrarily.
1020 	 */
1021 	st->flags &= ~ST_FIXEDBLOCKS;
1022 	st->blksize = 0;
1023 	SC_DEBUG(st->sc_periph, SCSIPI_DB3,
1024 	    ("Give up and default to variable mode\n"));
1025 
1026 done:
1027 	/*
1028 	 * Decide whether or not to write two file marks to signify end-
1029 	 * of-data.  Make the decision as a function of density.  If
1030 	 * the decision is not to use a second file mark, the SCSI BLANK
1031 	 * CHECK condition code will be recognized as end-of-data when
1032 	 * first read.
1033 	 * (I think this should be a by-product of fixed/variable..julian)
1034 	 */
1035 	switch (st->density) {
1036 /*      case 8 mm:   What is the SCSI density code for 8 mm, anyway? */
1037 	case QIC_11:
1038 	case QIC_24:
1039 	case QIC_120:
1040 	case QIC_150:
1041 	case QIC_525:
1042 	case QIC_1320:
1043 	case QIC_3095:
1044 	case QIC_3220:
1045 		st->flags &= ~ST_2FM_AT_EOD;
1046 		break;
1047 	default:
1048 		st->flags |= ST_2FM_AT_EOD;
1049 	}
1050 	return (0);
1051 }
1052 
1053 /*
1054  * Actually translate the requested transfer into
1055  * one the physical driver can understand
1056  * The transfer is described by a buf and will include
1057  * only one physical transfer.
1058  */
1059 void
1060 ststrategy(bp)
1061 	struct buf *bp;
1062 {
1063 	struct st_softc *st = st_cd.cd_devs[STUNIT(bp->b_dev)];
1064 	int s;
1065 
1066 	SC_DEBUG(st->sc_periph, SCSIPI_DB1,
1067 	    ("ststrategy %ld bytes @ blk %d\n", bp->b_bcount, bp->b_blkno));
1068 	/*
1069 	 * If it's a null transfer, return immediatly
1070 	 */
1071 	if (bp->b_bcount == 0)
1072 		goto done;
1073 
1074 	/* If offset is negative, error */
1075 	if (bp->b_blkno < 0) {
1076 		bp->b_error = EINVAL;
1077 		goto bad;
1078 	}
1079 
1080 	/*
1081 	 * Odd sized request on fixed drives are verboten
1082 	 */
1083 	if (st->flags & ST_FIXEDBLOCKS) {
1084 		if (bp->b_bcount % st->blksize) {
1085 			printf("%s: bad request, must be multiple of %d\n",
1086 			    st->sc_dev.dv_xname, st->blksize);
1087 			bp->b_error = EIO;
1088 			goto bad;
1089 		}
1090 	}
1091 	/*
1092 	 * as are out-of-range requests on variable drives.
1093 	 */
1094 	else if (bp->b_bcount < st->blkmin ||
1095 	    (st->blkmax && bp->b_bcount > st->blkmax)) {
1096 		printf("%s: bad request, must be between %d and %d\n",
1097 		    st->sc_dev.dv_xname, st->blkmin, st->blkmax);
1098 		bp->b_error = EIO;
1099 		goto bad;
1100 	}
1101 	s = splbio();
1102 
1103 	/*
1104 	 * Place it in the queue of activities for this tape
1105 	 * at the end (a bit silly because we only have on user..
1106 	 * (but it could fork()))
1107 	 */
1108 	BUFQ_INSERT_TAIL(&st->buf_queue, bp);
1109 
1110 	/*
1111 	 * Tell the device to get going on the transfer if it's
1112 	 * not doing anything, otherwise just wait for completion
1113 	 * (All a bit silly if we're only allowing 1 open but..)
1114 	 */
1115 	ststart(st->sc_periph);
1116 
1117 	splx(s);
1118 	return;
1119 bad:
1120 	bp->b_flags |= B_ERROR;
1121 done:
1122 	/*
1123 	 * Correctly set the buf to indicate a completed xfer
1124 	 */
1125 	bp->b_resid = bp->b_bcount;
1126 	biodone(bp);
1127 	return;
1128 }
1129 
1130 /*
1131  * ststart looks to see if there is a buf waiting for the device
1132  * and that the device is not already busy. If both are true,
1133  * It dequeues the buf and creates a scsi command to perform the
1134  * transfer required. The transfer request will call scsipi_done
1135  * on completion, which will in turn call this routine again
1136  * so that the next queued transfer is performed.
1137  * The bufs are queued by the strategy routine (ststrategy)
1138  *
1139  * This routine is also called after other non-queued requests
1140  * have been made of the scsi driver, to ensure that the queue
1141  * continues to be drained.
1142  * ststart() is called at splbio
1143  */
1144 void
1145 ststart(periph)
1146 	struct scsipi_periph *periph;
1147 {
1148 	struct st_softc *st = (void *)periph->periph_dev;
1149 	struct buf *bp;
1150 	struct scsi_rw_tape cmd;
1151 	int flags, error;
1152 
1153 	SC_DEBUG(periph, SCSIPI_DB2, ("ststart "));
1154 	/*
1155 	 * See if there is a buf to do and we are not already
1156 	 * doing one
1157 	 */
1158 	while (periph->periph_active < periph->periph_openings) {
1159 		/* if a special awaits, let it proceed first */
1160 		if (periph->periph_flags & PERIPH_WAITING) {
1161 			periph->periph_flags &= ~PERIPH_WAITING;
1162 			wakeup((caddr_t)periph);
1163 			return;
1164 		}
1165 
1166 		if ((bp = BUFQ_FIRST(&st->buf_queue)) == NULL)
1167 			return;
1168 		BUFQ_REMOVE(&st->buf_queue, bp);
1169 
1170 		/*
1171 		 * If the device has been unmounted by the user
1172 		 * then throw away all requests until done.
1173 		 */
1174 		if ((st->flags & ST_MOUNTED) == 0 ||
1175 		    (periph->periph_flags & PERIPH_MEDIA_LOADED) == 0) {
1176 			/* make sure that one implies the other.. */
1177 			periph->periph_flags &= ~PERIPH_MEDIA_LOADED;
1178 			bp->b_flags |= B_ERROR;
1179 			bp->b_error = EIO;
1180 			bp->b_resid = bp->b_bcount;
1181 			biodone(bp);
1182 			continue;
1183 		}
1184 		/*
1185 		 * only FIXEDBLOCK devices have pending I/O or space operations.
1186 		 */
1187 		if (st->flags & ST_FIXEDBLOCKS) {
1188 			/*
1189 			 * If we are at a filemark but have not reported it yet
1190 			 * then we should report it now
1191 			 */
1192 			if (st->flags & ST_AT_FILEMARK) {
1193 				if ((bp->b_flags & B_READ) == B_WRITE) {
1194 					/*
1195 					 * Handling of ST_AT_FILEMARK in
1196 					 * st_space will fill in the right file
1197 					 * mark count.
1198 					 * Back up over filemark
1199 					 */
1200 					if (st_space(st, 0, SP_FILEMARKS, 0)) {
1201 						bp->b_flags |= B_ERROR;
1202 						bp->b_error = EIO;
1203 						biodone(bp);
1204 						continue;
1205 					}
1206 				} else {
1207 					bp->b_resid = bp->b_bcount;
1208 					bp->b_error = 0;
1209 					bp->b_flags &= ~B_ERROR;
1210 					st->flags &= ~ST_AT_FILEMARK;
1211 					biodone(bp);
1212 					continue;	/* seek more work */
1213 				}
1214 			}
1215 		}
1216 		/*
1217 		 * If we are at EOM but have not reported it
1218 		 * yet then we should report it now.
1219 		 */
1220 		if (st->flags & (ST_EOM_PENDING|ST_EIO_PENDING)) {
1221 			bp->b_resid = bp->b_bcount;
1222 			if (st->flags & ST_EIO_PENDING) {
1223 				bp->b_error = EIO;
1224 				bp->b_flags |= B_ERROR;
1225 			}
1226 			st->flags &= ~(ST_EOM_PENDING|ST_EIO_PENDING);
1227 			biodone(bp);
1228 			continue;	/* seek more work */
1229 		}
1230 
1231 		/*
1232 		 * Fill out the scsi command
1233 		 */
1234 		memset(&cmd, 0, sizeof(cmd));
1235 		flags = XS_CTL_NOSLEEP | XS_CTL_ASYNC;
1236 		if ((bp->b_flags & B_READ) == B_WRITE) {
1237 			cmd.opcode = WRITE;
1238 			st->flags &= ~ST_FM_WRITTEN;
1239 			flags |= XS_CTL_DATA_OUT;
1240 		} else {
1241 			cmd.opcode = READ;
1242 			flags |= XS_CTL_DATA_IN;
1243 		}
1244 
1245 		/*
1246 		 * Handle "fixed-block-mode" tape drives by using the
1247 		 * block count instead of the length.
1248 		 */
1249 		if (st->flags & ST_FIXEDBLOCKS) {
1250 			cmd.byte2 |= SRW_FIXED;
1251 			_lto3b(bp->b_bcount / st->blksize, cmd.len);
1252 		} else
1253 			_lto3b(bp->b_bcount, cmd.len);
1254 
1255 		/*
1256 		 * go ask the adapter to do all this for us
1257 		 */
1258 		error = scsipi_command(periph,
1259 		    (struct scsipi_generic *)&cmd, sizeof(cmd),
1260 		    (u_char *)bp->b_data, bp->b_bcount,
1261 		    0, ST_IO_TIME, bp, flags);
1262 		if (error) {
1263 			printf("%s: not queued, error %d\n",
1264 			    st->sc_dev.dv_xname, error);
1265 		}
1266 	} /* go back and see if we can cram more work in.. */
1267 }
1268 
1269 void
1270 stdone(xs)
1271 	struct scsipi_xfer *xs;
1272 {
1273 	struct st_softc *st = (void *)xs->xs_periph->periph_dev;
1274 
1275 	if (xs->bp != NULL) {
1276 		if ((xs->bp->b_flags & B_READ) == B_WRITE) {
1277 			st->flags |= ST_WRITTEN;
1278 		} else {
1279 			st->flags &= ~ST_WRITTEN;
1280 		}
1281 #if NRND > 0
1282 		rnd_add_uint32(&st->rnd_source, xs->bp->b_blkno);
1283 #endif
1284 	}
1285 }
1286 
1287 int
1288 stread(dev, uio, iomode)
1289 	dev_t dev;
1290 	struct uio *uio;
1291 	int iomode;
1292 {
1293 	struct st_softc *st = st_cd.cd_devs[STUNIT(dev)];
1294 
1295 	return (physio(ststrategy, NULL, dev, B_READ,
1296 	    st->sc_periph->periph_channel->chan_adapter->adapt_minphys, uio));
1297 }
1298 
1299 int
1300 stwrite(dev, uio, iomode)
1301 	dev_t dev;
1302 	struct uio *uio;
1303 	int iomode;
1304 {
1305 	struct st_softc *st = st_cd.cd_devs[STUNIT(dev)];
1306 
1307 	return (physio(ststrategy, NULL, dev, B_WRITE,
1308 	    st->sc_periph->periph_channel->chan_adapter->adapt_minphys, uio));
1309 }
1310 
1311 /*
1312  * Perform special action on behalf of the user;
1313  * knows about the internals of this device
1314  */
1315 int
1316 stioctl(dev, cmd, arg, flag, p)
1317 	dev_t dev;
1318 	u_long cmd;
1319 	caddr_t arg;
1320 	int flag;
1321 	struct proc *p;
1322 {
1323 	int error = 0;
1324 	int unit;
1325 	int number, nmarks, dsty;
1326 	int flags;
1327 	struct st_softc *st;
1328 	int hold_blksize;
1329 	u_int8_t hold_density;
1330 	struct mtop *mt = (struct mtop *) arg;
1331 
1332 	/*
1333 	 * Find the device that the user is talking about
1334 	 */
1335 	flags = 0;		/* give error messages, act on errors etc. */
1336 	unit = STUNIT(dev);
1337 	dsty = STDSTY(dev);
1338 	st = st_cd.cd_devs[unit];
1339 	hold_blksize = st->blksize;
1340 	hold_density = st->density;
1341 
1342 	switch ((u_int) cmd) {
1343 
1344 	case MTIOCGET: {
1345 		struct mtget *g = (struct mtget *) arg;
1346 		/*
1347 		 * (to get the current state of READONLY)
1348 		 */
1349 		error = st->ops(st, ST_OPS_MODESENSE, XS_CTL_SILENT);
1350 		if (error) {
1351 			/*
1352 			 * Ignore the error if in control mode;
1353 			 * this is mandated by st(4).
1354 			 */
1355 			if (STMODE(dev) != CTRL_MODE)
1356 				break;
1357 			error = 0;
1358 		}
1359 		SC_DEBUG(st->sc_periph, SCSIPI_DB1, ("[ioctl: get status]\n"));
1360 		memset(g, 0, sizeof(struct mtget));
1361 		g->mt_type = 0x7;	/* Ultrix compat *//*? */
1362 		g->mt_blksiz = st->blksize;
1363 		g->mt_density = st->density;
1364 		g->mt_mblksiz[0] = st->modes[0].blksize;
1365 		g->mt_mblksiz[1] = st->modes[1].blksize;
1366 		g->mt_mblksiz[2] = st->modes[2].blksize;
1367 		g->mt_mblksiz[3] = st->modes[3].blksize;
1368 		g->mt_mdensity[0] = st->modes[0].density;
1369 		g->mt_mdensity[1] = st->modes[1].density;
1370 		g->mt_mdensity[2] = st->modes[2].density;
1371 		g->mt_mdensity[3] = st->modes[3].density;
1372 		if (st->flags & ST_READONLY)
1373 			g->mt_dsreg |= MT_DS_RDONLY;
1374 		if (st->flags & ST_MOUNTED)
1375 			g->mt_dsreg |= MT_DS_MOUNTED;
1376 		g->mt_resid = st->mt_resid;
1377 		g->mt_erreg = st->mt_erreg;
1378 		/*
1379 		 * clear latched errors.
1380 		 */
1381 		st->mt_resid = 0;
1382 		st->mt_erreg = 0;
1383 		st->asc = 0;
1384 		st->ascq = 0;
1385 		break;
1386 	}
1387 	case MTIOCTOP: {
1388 
1389 		SC_DEBUG(st->sc_periph, SCSIPI_DB1,
1390 		    ("[ioctl: op=0x%x count=0x%x]\n", mt->mt_op,
1391 			mt->mt_count));
1392 
1393 		/* compat: in U*x it is a short */
1394 		number = mt->mt_count;
1395 		switch ((short) (mt->mt_op)) {
1396 		case MTWEOF:	/* write an end-of-file record */
1397 			error = st_write_filemarks(st, number, flags);
1398 			break;
1399 		case MTBSF:	/* backward space file */
1400 			number = -number;
1401 		case MTFSF:	/* forward space file */
1402 			error = st_check_eod(st, FALSE, &nmarks, flags);
1403 			if (!error)
1404 				error = st_space(st, number - nmarks,
1405 				    SP_FILEMARKS, flags);
1406 			break;
1407 		case MTBSR:	/* backward space record */
1408 			number = -number;
1409 		case MTFSR:	/* forward space record */
1410 			error = st_check_eod(st, TRUE, &nmarks, flags);
1411 			if (!error)
1412 				error = st_space(st, number, SP_BLKS, flags);
1413 			break;
1414 		case MTREW:	/* rewind */
1415 			error = st_rewind(st, 0, flags);
1416 			break;
1417 		case MTOFFL:	/* rewind and put the drive offline */
1418 			st_unmount(st, EJECT);
1419 			break;
1420 		case MTNOP:	/* no operation, sets status only */
1421 			break;
1422 		case MTRETEN:	/* retension the tape */
1423 			error = st_load(st, LD_RETENSION, flags);
1424 			if (!error)
1425 				error = st_load(st, LD_LOAD, flags);
1426 			break;
1427 		case MTEOM:	/* forward space to end of media */
1428 			error = st_check_eod(st, FALSE, &nmarks, flags);
1429 			if (!error)
1430 				error = st_space(st, 1, SP_EOM, flags);
1431 			break;
1432 		case MTCACHE:	/* enable controller cache */
1433 			st->flags &= ~ST_DONTBUFFER;
1434 			goto try_new_value;
1435 		case MTNOCACHE:	/* disable controller cache */
1436 			st->flags |= ST_DONTBUFFER;
1437 			goto try_new_value;
1438 		case MTERASE:	/* erase volume */
1439 			error = st_erase(st, number, flags);
1440 			break;
1441 		case MTSETBSIZ:	/* Set block size for device */
1442 #ifdef	NOTYET
1443 			if (!(st->flags & ST_NEW_MOUNT)) {
1444 				uprintf("re-mount tape before changing blocksize");
1445 				error = EINVAL;
1446 				break;
1447 			}
1448 #endif
1449 			if (number == 0)
1450 				st->flags &= ~ST_FIXEDBLOCKS;
1451 			else {
1452 				if ((st->blkmin || st->blkmax) &&
1453 				    (number < st->blkmin ||
1454 				    number > st->blkmax)) {
1455 					error = EINVAL;
1456 					break;
1457 				}
1458 				st->flags |= ST_FIXEDBLOCKS;
1459 			}
1460 			st->blksize = number;
1461 			st->flags |= ST_BLOCK_SET;	/*XXX */
1462 			goto try_new_value;
1463 
1464 		case MTSETDNSTY:	/* Set density for device and mode */
1465 			/*
1466 			 * Any number >= 0 and <= 0xff is legal. Numbers
1467 			 * above 0x80 are 'vendor unique'.
1468 			 */
1469 			if (number < 0 || number > 255) {
1470 				error = EINVAL;
1471 				break;
1472 			} else
1473 				st->density = number;
1474 			goto try_new_value;
1475 
1476 		case MTCMPRESS:
1477 			error = st->ops(st, (number == 0) ?
1478 			    ST_OPS_CMPRSS_OFF : ST_OPS_CMPRSS_ON,
1479 			    XS_CTL_SILENT);
1480 			break;
1481 
1482 		case MTEWARN:
1483 			if (number)
1484 				st->flags |= ST_EARLYWARN;
1485 			else
1486 				st->flags &= ~ST_EARLYWARN;
1487 			break;
1488 
1489 		default:
1490 			error = EINVAL;
1491 		}
1492 		break;
1493 	}
1494 	case MTIOCIEOT:
1495 	case MTIOCEEOT:
1496 		break;
1497 
1498 	case MTIOCRDSPOS:
1499 		error = st_rdpos(st, 0, (u_int32_t *) arg);
1500 		break;
1501 
1502 	case MTIOCRDHPOS:
1503 		error = st_rdpos(st, 1, (u_int32_t *) arg);
1504 		break;
1505 
1506 	case MTIOCSLOCATE:
1507 		error = st_setpos(st, 0, (u_int32_t *) arg);
1508 		break;
1509 
1510 	case MTIOCHLOCATE:
1511 		error = st_setpos(st, 1, (u_int32_t *) arg);
1512 		break;
1513 
1514 
1515 	default:
1516 		error = scsipi_do_ioctl(st->sc_periph, dev, cmd, arg,
1517 					flag, p);
1518 		break;
1519 	}
1520 	return (error);
1521 /*-----------------------------*/
1522 try_new_value:
1523 	/*
1524 	 * Check that the mode being asked for is aggreeable to the
1525 	 * drive. If not, put it back the way it was.
1526 	 *
1527 	 * If in control mode, we can make (persistent) mode changes
1528 	 * even if no medium is loaded (see st(4)).
1529 	 */
1530 	if ((STMODE(dev) != CTRL_MODE || (st->flags & ST_MOUNTED) != 0) &&
1531 	    (error = st->ops(st, ST_OPS_MODESELECT, 0)) != 0) {
1532 		/* put it back as it was */
1533 		printf("%s: cannot set selected mode\n", st->sc_dev.dv_xname);
1534 		st->density = hold_density;
1535 		st->blksize = hold_blksize;
1536 		if (st->blksize)
1537 			st->flags |= ST_FIXEDBLOCKS;
1538 		else
1539 			st->flags &= ~ST_FIXEDBLOCKS;
1540 		return (error);
1541 	}
1542 	/*
1543 	 * As the drive liked it, if we are setting a new default,
1544 	 * set it into the structures as such.
1545 	 *
1546 	 * The means for deciding this are not finalised yet- but
1547 	 * if the device was opened in Control Mode, the values
1548 	 * are persistent now across mounts.
1549 	 */
1550 	if (STMODE(dev) == CTRL_MODE) {
1551 		switch ((short) (mt->mt_op)) {
1552 		case MTSETBSIZ:
1553 			st->modes[dsty].blksize = st->blksize;
1554 			st->modeflags[dsty] |= BLKSIZE_SET_BY_USER;
1555 			break;
1556 		case MTSETDNSTY:
1557 			st->modes[dsty].density = st->density;
1558 			st->modeflags[dsty] |= DENSITY_SET_BY_USER;
1559 			break;
1560 		}
1561 	}
1562 	return (0);
1563 }
1564 
1565 /*
1566  * Do a synchronous read.
1567  */
1568 int
1569 st_read(st, buf, size, flags)
1570 	struct st_softc *st;
1571 	int size;
1572 	int flags;
1573 	char *buf;
1574 {
1575 	struct scsi_rw_tape cmd;
1576 
1577 	/*
1578 	 * If it's a null transfer, return immediatly
1579 	 */
1580 	if (size == 0)
1581 		return (0);
1582 	memset(&cmd, 0, sizeof(cmd));
1583 	cmd.opcode = READ;
1584 	if (st->flags & ST_FIXEDBLOCKS) {
1585 		cmd.byte2 |= SRW_FIXED;
1586 		_lto3b(size / (st->blksize ? st->blksize : DEF_FIXED_BSIZE),
1587 		    cmd.len);
1588 	} else
1589 		_lto3b(size, cmd.len);
1590 	return (scsipi_command(st->sc_periph,
1591 	    (struct scsipi_generic *)&cmd, sizeof(cmd),
1592 	    (u_char *)buf, size, 0, ST_IO_TIME, NULL, flags | XS_CTL_DATA_IN));
1593 }
1594 
1595 /*
1596  * issue an erase command
1597  */
1598 int
1599 st_erase(st, full, flags)
1600 	struct st_softc *st;
1601 	int full, flags;
1602 {
1603 	int tmo;
1604 	struct scsi_erase cmd;
1605 
1606 	/*
1607 	 * Full erase means set LONG bit in erase command, which asks
1608 	 * the drive to erase the entire unit.  Without this bit, we're
1609 	 * asking the drive to write an erase gap.
1610 	 */
1611 	memset(&cmd, 0, sizeof(cmd));
1612 	cmd.opcode = ERASE;
1613 	if (full) {
1614 		cmd.byte2 = SE_LONG;
1615 		tmo = ST_SPC_TIME;
1616 	} else {
1617 		tmo = ST_IO_TIME;
1618 	}
1619 
1620 	/*
1621 	 * XXX We always do this asynchronously, for now, unless the device
1622 	 * has the ST_Q_ERASE_NOIMM quirk.  How long should we wait if we
1623 	 * want to (eventually) to it synchronously?
1624 	 */
1625 	if ((st->quirks & ST_Q_ERASE_NOIMM) == 0)
1626 		cmd.byte2 |= SE_IMMED;
1627 
1628 	return (scsipi_command(st->sc_periph,
1629 	    (struct scsipi_generic *)&cmd, sizeof(cmd),
1630 	    0, 0, ST_RETRIES, tmo, NULL, flags));
1631 }
1632 
1633 /*
1634  * skip N blocks/filemarks/seq filemarks/eom
1635  */
1636 int
1637 st_space(st, number, what, flags)
1638 	struct st_softc *st;
1639 	u_int what;
1640 	int flags;
1641 	int number;
1642 {
1643 	struct scsi_space cmd;
1644 	int error;
1645 
1646 	switch (what) {
1647 	case SP_BLKS:
1648 		if (st->flags & ST_PER_ACTION) {
1649 			if (number > 0) {
1650 				st->flags &= ~ST_PER_ACTION;
1651 				return (EIO);
1652 			} else if (number < 0) {
1653 				if (st->flags & ST_AT_FILEMARK) {
1654 					/*
1655 					 * Handling of ST_AT_FILEMARK
1656 					 * in st_space will fill in the
1657 					 * right file mark count.
1658 					 */
1659 					error = st_space(st, 0, SP_FILEMARKS,
1660 					    flags);
1661 					if (error)
1662 						return (error);
1663 				}
1664 				if (st->flags & ST_BLANK_READ) {
1665 					st->flags &= ~ST_BLANK_READ;
1666 					return (EIO);
1667 				}
1668 				st->flags &= ~(ST_EIO_PENDING|ST_EOM_PENDING);
1669 			}
1670 		}
1671 		break;
1672 	case SP_FILEMARKS:
1673 		if (st->flags & ST_EIO_PENDING) {
1674 			if (number > 0) {
1675 				/* pretend we just discovered the error */
1676 				st->flags &= ~ST_EIO_PENDING;
1677 				return (EIO);
1678 			} else if (number < 0) {
1679 				/* back away from the error */
1680 				st->flags &= ~ST_EIO_PENDING;
1681 			}
1682 		}
1683 		if (st->flags & ST_AT_FILEMARK) {
1684 			st->flags &= ~ST_AT_FILEMARK;
1685 			number--;
1686 		}
1687 		if ((st->flags & ST_BLANK_READ) && (number < 0)) {
1688 			/* back away from unwritten tape */
1689 			st->flags &= ~ST_BLANK_READ;
1690 			number++;	/* XXX dubious */
1691 		}
1692 		break;
1693 	case SP_EOM:
1694 		if (st->flags & ST_EOM_PENDING) {
1695 			/* we're already there */
1696 			st->flags &= ~ST_EOM_PENDING;
1697 			return (0);
1698 		}
1699 		if (st->flags & ST_EIO_PENDING) {
1700 			/* pretend we just discovered the error */
1701 			st->flags &= ~ST_EIO_PENDING;
1702 			return (EIO);
1703 		}
1704 		if (st->flags & ST_AT_FILEMARK)
1705 			st->flags &= ~ST_AT_FILEMARK;
1706 		break;
1707 	}
1708 	if (number == 0)
1709 		return (0);
1710 
1711 	memset(&cmd, 0, sizeof(cmd));
1712 	cmd.opcode = SPACE;
1713 	cmd.byte2 = what;
1714 	_lto3b(number, cmd.number);
1715 
1716 	return (scsipi_command(st->sc_periph,
1717 	    (struct scsipi_generic *)&cmd, sizeof(cmd),
1718 	    0, 0, 0, ST_SPC_TIME, NULL, flags));
1719 }
1720 
1721 /*
1722  * write N filemarks
1723  */
1724 int
1725 st_write_filemarks(st, number, flags)
1726 	struct st_softc *st;
1727 	int flags;
1728 	int number;
1729 {
1730 	struct scsi_write_filemarks cmd;
1731 
1732 	/*
1733 	 * It's hard to write a negative number of file marks.
1734 	 * Don't try.
1735 	 */
1736 	if (number < 0)
1737 		return (EINVAL);
1738 	switch (number) {
1739 	case 0:		/* really a command to sync the drive's buffers */
1740 		break;
1741 	case 1:
1742 		if (st->flags & ST_FM_WRITTEN)	/* already have one down */
1743 			st->flags &= ~ST_WRITTEN;
1744 		else
1745 			st->flags |= ST_FM_WRITTEN;
1746 		st->flags &= ~ST_PER_ACTION;
1747 		break;
1748 	default:
1749 		st->flags &= ~(ST_PER_ACTION | ST_WRITTEN);
1750 	}
1751 
1752 	memset(&cmd, 0, sizeof(cmd));
1753 	cmd.opcode = WRITE_FILEMARKS;
1754 	if (scsipi_periph_bustype(st->sc_periph) == SCSIPI_BUSTYPE_ATAPI)
1755 		cmd.byte2 = SR_IMMED;
1756 	/*
1757 	 * The ATAPI Onstream DI-30 doesn't support writing filemarks, but
1758 	 * WRITE_FILEMARKS is still used to flush the buffer
1759 	 */
1760 	if ((st->quirks & ST_Q_NOFILEMARKS) == 0)
1761 		_lto3b(number, cmd.number);
1762 
1763 	return (scsipi_command(st->sc_periph,
1764 	    (struct scsipi_generic *)&cmd, sizeof(cmd),
1765 	    0, 0, 0, ST_IO_TIME * 4, NULL, flags));
1766 }
1767 
1768 /*
1769  * Make sure the right number of file marks is on tape if the
1770  * tape has been written.  If the position argument is true,
1771  * leave the tape positioned where it was originally.
1772  *
1773  * nmarks returns the number of marks to skip (or, if position
1774  * true, which were skipped) to get back original position.
1775  */
1776 int
1777 st_check_eod(st, position, nmarks, flags)
1778 	struct st_softc *st;
1779 	boolean position;
1780 	int *nmarks;
1781 	int flags;
1782 {
1783 	int error;
1784 
1785 	switch (st->flags & (ST_WRITTEN | ST_FM_WRITTEN | ST_2FM_AT_EOD)) {
1786 	default:
1787 		*nmarks = 0;
1788 		return (0);
1789 	case ST_WRITTEN:
1790 	case ST_WRITTEN | ST_FM_WRITTEN | ST_2FM_AT_EOD:
1791 		*nmarks = 1;
1792 		break;
1793 	case ST_WRITTEN | ST_2FM_AT_EOD:
1794 		*nmarks = 2;
1795 	}
1796 	error = st_write_filemarks(st, *nmarks, flags);
1797 	if (position && !error)
1798 		error = st_space(st, -*nmarks, SP_FILEMARKS, flags);
1799 	return (error);
1800 }
1801 
1802 /*
1803  * load/unload/retension
1804  */
1805 int
1806 st_load(st, type, flags)
1807 	struct st_softc *st;
1808 	u_int type;
1809 	int flags;
1810 {
1811 	int error;
1812 	struct scsi_load cmd;
1813 
1814 	if (type != LD_LOAD) {
1815 		int nmarks;
1816 
1817 		error = st_check_eod(st, FALSE, &nmarks, flags);
1818 		if (error) {
1819 			printf("%s: failed to write closing filemarks at "
1820 			    "unload, errno=%d\n", st->sc_dev.dv_xname, error);
1821 			return (error);
1822 		}
1823 	}
1824 	if (st->quirks & ST_Q_IGNORE_LOADS) {
1825 		if (type == LD_LOAD) {
1826 			/*
1827 			 * If we ignore loads, at least we should try a rewind.
1828 			 */
1829 			return st_rewind(st, 0, flags);
1830 		}
1831 		/* otherwise, we should do what's asked of us */
1832 	}
1833 
1834 	memset(&cmd, 0, sizeof(cmd));
1835 	cmd.opcode = LOAD;
1836 	if (scsipi_periph_bustype(st->sc_periph) == SCSIPI_BUSTYPE_ATAPI)
1837 		cmd.byte2 = SR_IMMED;
1838 	cmd.how = type;
1839 
1840 	error = scsipi_command(st->sc_periph,
1841 	    (struct scsipi_generic *)&cmd, sizeof(cmd),
1842 	    0, 0, ST_RETRIES, ST_SPC_TIME, NULL, flags);
1843 	if (error) {
1844 		printf("%s: error %d in st_load (op %d)\n",
1845 		    st->sc_dev.dv_xname, error, type);
1846 	}
1847 	return (error);
1848 }
1849 
1850 /*
1851  *  Rewind the device
1852  */
1853 int
1854 st_rewind(st, immediate, flags)
1855 	struct st_softc *st;
1856 	u_int immediate;
1857 	int flags;
1858 {
1859 	struct scsi_rewind cmd;
1860 	int error;
1861 	int nmarks;
1862 
1863 	error = st_check_eod(st, FALSE, &nmarks, flags);
1864 	if (error) {
1865 		printf("%s: failed to write closing filemarks at "
1866 		    "rewind, errno=%d\n", st->sc_dev.dv_xname, error);
1867 		return (error);
1868 	}
1869 	st->flags &= ~ST_PER_ACTION;
1870 
1871 	/*
1872 	 * ATAPI tapes always need immediate to be set
1873 	 */
1874 	if (scsipi_periph_bustype(st->sc_periph) == SCSIPI_BUSTYPE_ATAPI)
1875 		immediate = SR_IMMED;
1876 
1877 	memset(&cmd, 0, sizeof(cmd));
1878 	cmd.opcode = REWIND;
1879 	cmd.byte2 = immediate;
1880 
1881 	error = scsipi_command(st->sc_periph,
1882 	    (struct scsipi_generic *)&cmd, sizeof(cmd), 0, 0, ST_RETRIES,
1883 	    immediate ? ST_CTL_TIME: ST_SPC_TIME, NULL, flags);
1884 	if (error) {
1885 		printf("%s: error %d trying to rewind\n",
1886 		    st->sc_dev.dv_xname, error);
1887 	}
1888 	return (error);
1889 }
1890 
1891 int
1892 st_rdpos(st, hard, blkptr)
1893 	struct st_softc *st;
1894 	int hard;
1895 	u_int32_t *blkptr;
1896 {
1897 	int error;
1898 	u_int8_t posdata[20];
1899 	struct scsi_tape_read_position cmd;
1900 
1901 	/*
1902 	 * First flush any pending writes...
1903 	 */
1904 	error = st_write_filemarks(st, 0, XS_CTL_SILENT);
1905 
1906 	/*
1907 	 * The latter case is for 'write protected' tapes
1908 	 * which are too stupid to recognize a zero count
1909 	 * for writing filemarks as a no-op.
1910 	 */
1911 	if (error != 0 && error != EACCES && error != EROFS)
1912 		return (error);
1913 
1914 	memset(&cmd, 0, sizeof(cmd));
1915 	memset(&posdata, 0, sizeof(posdata));
1916 	cmd.opcode = READ_POSITION;
1917 	if (hard)
1918 		cmd.byte1 = 1;
1919 
1920 	error = scsipi_command(st->sc_periph,
1921 	    (struct scsipi_generic *)&cmd, sizeof(cmd), (u_char *)&posdata,
1922 	    sizeof(posdata), ST_RETRIES, ST_CTL_TIME, NULL,
1923 	    XS_CTL_SILENT | XS_CTL_DATA_IN | XS_CTL_DATA_ONSTACK);
1924 
1925 	if (error == 0) {
1926 #if	0
1927 		printf("posdata:");
1928 		for (hard = 0; hard < sizeof(posdata); hard++)
1929 			printf("%02x ", posdata[hard] & 0xff);
1930 		printf("\n");
1931 #endif
1932 		if (posdata[0] & 0x4)	/* Block Position Unknown */
1933 			error = EINVAL;
1934 		else
1935 			*blkptr = _4btol(&posdata[4]);
1936 	}
1937 	return (error);
1938 }
1939 
1940 int
1941 st_setpos(st, hard, blkptr)
1942 	struct st_softc *st;
1943 	int hard;
1944 	u_int32_t *blkptr;
1945 {
1946 	int error;
1947 	struct scsi_tape_locate cmd;
1948 
1949 	/*
1950 	 * First flush any pending writes. Strictly speaking,
1951 	 * we're not supposed to have to worry about this,
1952 	 * but let's be untrusting.
1953 	 */
1954 	error = st_write_filemarks(st, 0, XS_CTL_SILENT);
1955 
1956 	/*
1957 	 * The latter case is for 'write protected' tapes
1958 	 * which are too stupid to recognize a zero count
1959 	 * for writing filemarks as a no-op.
1960 	 */
1961 	if (error != 0 && error != EACCES && error != EROFS)
1962 		return (error);
1963 
1964 	memset(&cmd, 0, sizeof(cmd));
1965 	cmd.opcode = LOCATE;
1966 	if (hard)
1967 		cmd.byte2 = 1 << 2;
1968 	_lto4b(*blkptr, cmd.blkaddr);
1969 	error = scsipi_command(st->sc_periph,
1970 		(struct scsipi_generic *)&cmd, sizeof(cmd),
1971 		NULL, 0, ST_RETRIES, ST_SPC_TIME, NULL, 0);
1972 	/*
1973 	 * XXX: Note file && block number position now unknown (if
1974 	 * XXX: these things ever start being maintained in this driver)
1975 	 */
1976 	return (error);
1977 }
1978 
1979 
1980 /*
1981  * Look at the returned sense and act on the error and determine
1982  * the unix error number to pass back..., 0 (== report no error),
1983  * -1 = retry the operation, -2 continue error processing.
1984  */
1985 int
1986 st_interpret_sense(xs)
1987 	struct scsipi_xfer *xs;
1988 {
1989 	struct scsipi_periph *periph = xs->xs_periph;
1990 	struct scsipi_sense_data *sense = &xs->sense.scsi_sense;
1991 	struct buf *bp = xs->bp;
1992 	struct st_softc *st = (void *)periph->periph_dev;
1993 	int retval = EJUSTRETURN;
1994 	int doprint = ((xs->xs_control & XS_CTL_SILENT) == 0);
1995 	u_int8_t key;
1996 	int32_t info;
1997 
1998 	/*
1999 	 * If it isn't a extended or extended/deferred error, let
2000 	 * the generic code handle it.
2001 	 */
2002 	if ((sense->error_code & SSD_ERRCODE) != 0x70 &&
2003 	    (sense->error_code & SSD_ERRCODE) != 0x71) {	/* DEFFERRED */
2004 		return (retval);
2005 	}
2006 
2007 	if (sense->error_code & SSD_ERRCODE_VALID)
2008 		info = _4btol(sense->info);
2009 	else
2010 		info = (st->flags & ST_FIXEDBLOCKS) ?
2011 		    xs->datalen / st->blksize : xs->datalen;
2012 	key = sense->flags & SSD_KEY;
2013 	st->mt_erreg = key;
2014 	st->asc = sense->add_sense_code;
2015 	st->ascq = sense->add_sense_code_qual;
2016 	st->mt_resid = (short) info;
2017 
2018 	if (key == SKEY_NOT_READY && st->asc == 0x4 && st->ascq == 0x1) {
2019 		/* Not Ready, Logical Unit Is in Process Of Becoming Ready */
2020 		scsipi_periph_freeze(periph, 1);
2021 		callout_reset(&periph->periph_callout,
2022 		    hz, scsipi_periph_timed_thaw, periph);
2023 		return (ERESTART);
2024 	}
2025 
2026 	/*
2027 	 * If the device is not open yet, let generic handle
2028 	 */
2029 	if ((periph->periph_flags & PERIPH_OPEN) == 0) {
2030 		return (retval);
2031 	}
2032 
2033 
2034 	if (st->flags & ST_FIXEDBLOCKS) {
2035 		xs->resid = info * st->blksize;
2036 		if (sense->flags & SSD_EOM) {
2037 			if ((st->flags & ST_EARLYWARN) == 0)
2038 				st->flags |= ST_EIO_PENDING;
2039 			st->flags |= ST_EOM_PENDING;
2040 			if (bp)
2041 				bp->b_resid = xs->resid;
2042 		}
2043 		if (sense->flags & SSD_FILEMARK) {
2044 			st->flags |= ST_AT_FILEMARK;
2045 			if (bp)
2046 				bp->b_resid = xs->resid;
2047 		}
2048 		if (sense->flags & SSD_ILI) {
2049 			st->flags |= ST_EIO_PENDING;
2050 			if (bp)
2051 				bp->b_resid = xs->resid;
2052 			if (sense->error_code & SSD_ERRCODE_VALID &&
2053 			    (xs->xs_control & XS_CTL_SILENT) == 0)
2054 				printf("%s: block wrong size, %d blocks "
2055 				    "residual\n", st->sc_dev.dv_xname, info);
2056 
2057 			/*
2058 			 * This quirk code helps the drive read
2059 			 * the first tape block, regardless of
2060 			 * format.  That is required for these
2061 			 * drives to return proper MODE SENSE
2062 			 * information.
2063 			 */
2064 			if ((st->quirks & ST_Q_SENSE_HELP) &&
2065 			    (periph->periph_flags & PERIPH_MEDIA_LOADED) == 0)
2066 				st->blksize -= 512;
2067 		}
2068 		/*
2069 		 * If data wanted and no data was transferred, do it immediately
2070 		 */
2071 		if (xs->datalen && xs->resid >= xs->datalen) {
2072 			if (st->flags & ST_EIO_PENDING)
2073 				return (EIO);
2074 			if (st->flags & ST_AT_FILEMARK) {
2075 				if (bp)
2076 					bp->b_resid = xs->resid;
2077 				return (0);
2078 			}
2079 		}
2080 	} else {		/* must be variable mode */
2081 		if (sense->flags & SSD_EOM) {
2082 			/*
2083 			 * The current semantics of this
2084 			 * driver requires EOM detection
2085 			 * to return EIO unless early
2086 			 * warning detection is enabled
2087 			 * for variable mode (this is always
2088 			 * on for fixed block mode).
2089 			 */
2090 			if (st->flags & ST_EARLYWARN) {
2091 				st->flags |= ST_EOM_PENDING;
2092 				retval = 0;
2093 			} else {
2094 				retval = EIO;
2095 			}
2096 
2097 			/*
2098 			 * If it's an unadorned EOM detection,
2099 			 * suppress printing an error.
2100 			 */
2101 			if (key == SKEY_NO_SENSE) {
2102 				doprint = 0;
2103 			}
2104 		} else if (sense->flags & SSD_FILEMARK) {
2105 			retval = 0;
2106 		} else if (sense->flags & SSD_ILI) {
2107 			if (info < 0) {
2108 				/*
2109 				 * The tape record was bigger than the read
2110 				 * we issued.
2111 				 */
2112 				if ((xs->xs_control & XS_CTL_SILENT) == 0) {
2113 					printf("%s: %d-byte tape record too big"
2114 					    " for %d-byte user buffer\n",
2115 					    st->sc_dev.dv_xname,
2116 					    xs->datalen - info, xs->datalen);
2117 				}
2118 				retval = EIO;
2119 			} else {
2120 				retval = 0;
2121 			}
2122 		}
2123 		xs->resid = info;
2124 		if (bp)
2125 			bp->b_resid = info;
2126 	}
2127 
2128 #ifndef SCSIPI_DEBUG
2129 	if (retval == 0 && key == SKEY_NO_SENSE)
2130 		doprint = 0;
2131 #endif
2132 	if (key == SKEY_BLANK_CHECK) {
2133 		/*
2134 		 * This quirk code helps the drive read the
2135 		 * first tape block, regardless of format.  That
2136 		 * is required for these drives to return proper
2137 		 * MODE SENSE information.
2138 		 */
2139 		if ((st->quirks & ST_Q_SENSE_HELP) &&
2140 		    (periph->periph_flags & PERIPH_MEDIA_LOADED) == 0) {
2141 			/* still starting */
2142 			st->blksize -= 512;
2143 		} else if (!(st->flags & (ST_2FM_AT_EOD | ST_BLANK_READ))) {
2144 			st->flags |= ST_BLANK_READ;
2145 			xs->resid = xs->datalen;
2146 			if (bp) {
2147 				bp->b_resid = xs->resid;
2148 				/* return an EOF */
2149 			}
2150 			retval = 0;
2151 		}
2152 	}
2153 
2154 	/*
2155 	 * If generic sense processing will continue, we should not
2156 	 * print sense info here.
2157 	 */
2158 	if (retval == EJUSTRETURN)
2159 		doprint = 0;
2160 
2161 	if (doprint) {
2162 #ifdef	SCSIVERBOSE
2163 		scsipi_print_sense(xs, 0);
2164 #else
2165 		scsipi_printaddr(periph);
2166 		printf("Sense Key 0x%02x", key);
2167 		if ((sense->error_code & SSD_ERRCODE_VALID) != 0) {
2168 			switch (key) {
2169 			case SKEY_NOT_READY:
2170 			case SKEY_ILLEGAL_REQUEST:
2171 			case SKEY_UNIT_ATTENTION:
2172 			case SKEY_WRITE_PROTECT:
2173 				break;
2174 			case SKEY_BLANK_CHECK:
2175 				printf(", requested size: %d (decimal)", info);
2176 				break;
2177 			case SKEY_ABORTED_COMMAND:
2178 				if (xs->xs_retries)
2179 					printf(", retrying");
2180 				printf(", cmd 0x%x, info 0x%x",
2181 				    xs->cmd->opcode, info);
2182 				break;
2183 			default:
2184 				printf(", info = %d (decimal)", info);
2185 			}
2186 		}
2187 		if (sense->extra_len != 0) {
2188 			int n;
2189 			printf(", data =");
2190 			for (n = 0; n < sense->extra_len; n++)
2191 				printf(" %02x", sense->cmd_spec_info[n]);
2192 		}
2193 		printf("\n");
2194 #endif
2195 	}
2196 	return (retval);
2197 }
2198 
2199 /*
2200  * The quirk here is that the drive returns some value to st_mode_sense
2201  * incorrectly until the tape has actually passed by the head.
2202  *
2203  * The method is to set the drive to large fixed-block state (user-specified
2204  * density and 1024-byte blocks), then read and rewind to get it to sense the
2205  * tape.  If that doesn't work, try 512-byte fixed blocks.  If that doesn't
2206  * work, as a last resort, try variable- length blocks.  The result will be
2207  * the ability to do an accurate st_mode_sense.
2208  *
2209  * We know we can do a rewind because we just did a load, which implies rewind.
2210  * Rewind seems preferable to space backward if we have a virgin tape.
2211  *
2212  * The rest of the code for this quirk is in ILI processing and BLANK CHECK
2213  * error processing, both part of st_interpret_sense.
2214  */
2215 int
2216 st_touch_tape(st)
2217 	struct st_softc *st;
2218 {
2219 	char *buf;
2220 	int readsize;
2221 	int error;
2222 
2223 	buf = malloc(1024, M_TEMP, M_NOWAIT);
2224 	if (buf == NULL)
2225 		return (ENOMEM);
2226 
2227 	if ((error = st->ops(st, ST_OPS_MODESENSE, 0)) != 0)
2228 		goto bad;
2229 
2230 	/*
2231 	 * If the block size is already known from the
2232 	 * sense data, use it. Else start probing at 1024.
2233 	 */
2234 	if (st->media_blksize > 0)
2235 		st->blksize = st->media_blksize;
2236 	else
2237 		st->blksize = 1024;
2238 
2239 	do {
2240 		switch (st->blksize) {
2241 		case 512:
2242 		case 1024:
2243 			readsize = st->blksize;
2244 			st->flags |= ST_FIXEDBLOCKS;
2245 			break;
2246 		default:
2247 			readsize = 1;
2248 			st->flags &= ~ST_FIXEDBLOCKS;
2249 		}
2250 		if ((error = st->ops(st, ST_OPS_MODESELECT, XS_CTL_SILENT))
2251 		    != 0) {
2252 			/*
2253 			 * The device did not agree with the proposed
2254 			 * block size. If we exhausted our options,
2255 			 * return failure, else try another.
2256 			 */
2257 			if (readsize == 1)
2258 				goto bad;
2259 			st->blksize -= 512;
2260 			continue;
2261 		}
2262 		st_read(st, buf, readsize, XS_CTL_SILENT);	/* XXX */
2263 		if ((error = st_rewind(st, 0, 0)) != 0) {
2264 bad:			free(buf, M_TEMP);
2265 			return (error);
2266 		}
2267 	} while (readsize != 1 && readsize > st->blksize);
2268 
2269 	free(buf, M_TEMP);
2270 	return (0);
2271 }
2272 
2273 int
2274 stdump(dev, blkno, va, size)
2275 	dev_t dev;
2276 	daddr_t blkno;
2277 	caddr_t va;
2278 	size_t size;
2279 {
2280 
2281 	/* Not implemented. */
2282 	return (ENXIO);
2283 }
2284