xref: /netbsd-src/sys/dev/scsipi/st.c (revision 06be8101a16cc95f40783b3cb7afd12112103a9a)
1 /*	$NetBSD: st.c,v 1.144 2001/11/13 06:56:41 lukem 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 1.144 2001/11/13 06:56:41 lukem Exp $");
61 
62 #include "opt_scsi.h"
63 
64 #include <sys/types.h>
65 #include <sys/param.h>
66 #include <sys/systm.h>
67 #include <sys/fcntl.h>
68 #include <sys/errno.h>
69 #include <sys/ioctl.h>
70 #include <sys/malloc.h>
71 #include <sys/buf.h>
72 #include <sys/proc.h>
73 #include <sys/user.h>
74 #include <sys/mtio.h>
75 #include <sys/device.h>
76 #include <sys/conf.h>
77 #include <sys/kernel.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 
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 /*
103  * Define various devices that we know mis-behave in some way,
104  * and note how they are bad, so we can correct for them
105  */
106 
107 const struct st_quirk_inquiry_pattern st_quirk_patterns[] = {
108 	{{T_SEQUENTIAL, T_REMOV,
109 	 "        ", "                ", "    "}, {0, 0, {
110 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
111 		{ST_Q_FORCE_BLKSIZE, 512, QIC_24},	/* minor 4-7 */
112 		{ST_Q_FORCE_BLKSIZE, 0, HALFINCH_1600},	/* minor 8-11 */
113 		{ST_Q_FORCE_BLKSIZE, 0, HALFINCH_6250}	/* minor 12-15 */
114 	}}},
115 	{{T_SEQUENTIAL, T_REMOV,
116 	 "TANDBERG", " TDC 3600       ", ""},     {0, 12, {
117 		{0, 0, 0},				/* minor 0-3 */
118 		{ST_Q_FORCE_BLKSIZE, 0, QIC_525},	/* minor 4-7 */
119 		{0, 0, QIC_150},			/* minor 8-11 */
120 		{0, 0, QIC_120}				/* minor 12-15 */
121 	}}},
122  	{{T_SEQUENTIAL, T_REMOV,
123  	 "TANDBERG", " TDC 3800       ", ""},     {0, 0, {
124 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
125 		{0, 0, QIC_525},			/* minor 4-7 */
126 		{0, 0, QIC_150},			/* minor 8-11 */
127 		{0, 0, QIC_120}				/* minor 12-15 */
128 	}}},
129 	/*
130 	 * lacking a manual for the 4200, it's not clear what the
131 	 * specific density codes should be- the device is a 2.5GB
132 	 * capable QIC drive, those density codes aren't readily
133 	 * availabel. The 'default' will just have to do.
134 	 */
135  	{{T_SEQUENTIAL, T_REMOV,
136  	 "TANDBERG", " TDC 4200       ", ""},     {0, 0, {
137 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
138 		{0, 0, QIC_525},			/* minor 4-7 */
139 		{0, 0, QIC_150},			/* minor 8-11 */
140 		{0, 0, QIC_120}				/* minor 12-15 */
141 	}}},
142 	/*
143 	 * At least -005 and -007 need this.  I'll assume they all do unless I
144 	 * hear otherwise.  - mycroft, 31MAR1994
145 	 */
146 	{{T_SEQUENTIAL, T_REMOV,
147 	 "ARCHIVE ", "VIPER 2525 25462", ""},     {0, 0, {
148 		{ST_Q_SENSE_HELP, 0, 0},		/* minor 0-3 */
149 		{ST_Q_SENSE_HELP, 0, QIC_525},		/* minor 4-7 */
150 		{0, 0, QIC_150},			/* minor 8-11 */
151 		{0, 0, QIC_120}				/* minor 12-15 */
152 	}}},
153 	/*
154 	 * One user reports that this works for his tape drive.  It probably
155 	 * needs more work.  - mycroft, 09APR1994
156 	 */
157 	{{T_SEQUENTIAL, T_REMOV,
158 	 "SANKYO  ", "CP525           ", ""},    {0, 0, {
159 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
160 		{ST_Q_FORCE_BLKSIZE, 512, QIC_525},	/* minor 4-7 */
161 		{0, 0, QIC_150},			/* minor 8-11 */
162 		{0, 0, QIC_120}				/* minor 12-15 */
163 	}}},
164 	{{T_SEQUENTIAL, T_REMOV,
165 	 "ANRITSU ", "DMT780          ", ""},     {0, 0, {
166 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
167 		{ST_Q_FORCE_BLKSIZE, 512, QIC_525},	/* minor 4-7 */
168 		{0, 0, QIC_150},			/* minor 8-11 */
169 		{0, 0, QIC_120}				/* minor 12-15 */
170 	}}},
171 	{{T_SEQUENTIAL, T_REMOV,
172 	 "ARCHIVE ", "VIPER 150  21247", ""},     {ST_Q_ERASE_NOIMM, 12, {
173 		{ST_Q_SENSE_HELP, 0, 0},		/* minor 0-3 */
174 		{0, 0, QIC_150},			/* minor 4-7 */
175 		{0, 0, QIC_120},			/* minor 8-11 */
176 		{0, 0, QIC_24}				/* minor 12-15 */
177 	}}},
178 	{{T_SEQUENTIAL, T_REMOV,
179 	 "ARCHIVE ", "VIPER 150  21531", ""},     {ST_Q_ERASE_NOIMM, 12, {
180 		{ST_Q_SENSE_HELP, 0, 0},		/* minor 0-3 */
181 		{0, 0, QIC_150},			/* minor 4-7 */
182 		{0, 0, QIC_120},			/* minor 8-11 */
183 		{0, 0, QIC_24}				/* minor 12-15 */
184 	}}},
185 	{{T_SEQUENTIAL, T_REMOV,
186 	 "WANGTEK ", "5099ES SCSI", ""},          {0, 0, {
187 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
188 		{0, 0, QIC_11},				/* minor 4-7 */
189 		{0, 0, QIC_24},				/* minor 8-11 */
190 		{0, 0, QIC_24}				/* minor 12-15 */
191 	}}},
192 	{{T_SEQUENTIAL, T_REMOV,
193 	 "WANGTEK ", "5150ES SCSI", ""},          {0, 0, {
194 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
195 		{0, 0, QIC_24},				/* minor 4-7 */
196 		{0, 0, QIC_120},			/* minor 8-11 */
197 		{0, 0, QIC_150}				/* minor 12-15 */
198 	}}},
199 	{{T_SEQUENTIAL, T_REMOV,
200 	 "WANGTEK ", "5525ES SCSI REV7", ""},     {0, 0, {
201 		{0, 0, 0},				/* minor 0-3 */
202 		{ST_Q_BLKSIZE, 0, QIC_525},		/* minor 4-7 */
203 		{0, 0, QIC_150},			/* minor 8-11 */
204 		{0, 0, QIC_120}				/* minor 12-15 */
205 	}}},
206 	{{T_SEQUENTIAL, T_REMOV,
207 	 "WangDAT ", "Model 1300      ", ""},     {0, 0, {
208 		{0, 0, 0},				/* minor 0-3 */
209 		{ST_Q_FORCE_BLKSIZE, 512, DDS},		/* minor 4-7 */
210 		{ST_Q_FORCE_BLKSIZE, 1024, DDS},	/* minor 8-11 */
211 		{ST_Q_FORCE_BLKSIZE, 0, DDS}		/* minor 12-15 */
212 	}}},
213 	{{T_SEQUENTIAL, T_REMOV,
214 	 "EXABYTE ", "EXB-8200        ", "263H"}, {0, 5, {
215 		{0, 0, 0},				/* minor 0-3 */
216 		{0, 0, 0},				/* minor 4-7 */
217 		{0, 0, 0},				/* minor 8-11 */
218 		{0, 0, 0}				/* minor 12-15 */
219 	}}},
220 	{{T_SEQUENTIAL, T_REMOV,
221 	 "STK",      "9490",             ""},
222 				{ST_Q_FORCE_BLKSIZE, 0, {
223 		{0, 0, 0},				/* minor 0-3 */
224 		{0, 0, 0},				/* minor 4-7 */
225 		{0, 0, 0},				/* minor 8-11 */
226 		{0, 0, 0}				/* minor 12-15 */
227 	}}},
228 	{{T_SEQUENTIAL, T_REMOV,
229 	 "STK",      "SD-3",             ""},
230 				{ST_Q_FORCE_BLKSIZE, 0, {
231 		{0, 0, 0},				/* minor 0-3 */
232 		{0, 0, 0},				/* minor 4-7 */
233 		{0, 0, 0},				/* minor 8-11 */
234 		{0, 0, 0}				/* minor 12-15 */
235 	}}},
236 	{{T_SEQUENTIAL, T_REMOV,
237 	 "IBM",      "03590",            ""},     {ST_Q_IGNORE_LOADS, 0, {
238 		{0, 0, 0},				/* minor 0-3 */
239 		{0, 0, 0},				/* minor 4-7 */
240 		{0, 0, 0},				/* minor 8-11 */
241 		{0, 0, 0}				/* minor 12-15 */
242 	}}},
243 	{{T_SEQUENTIAL, T_REMOV,
244 	 "HP      ", "T4000s          ", ""},     {ST_Q_UNIMODAL, 0, {
245 		{0, 0, QIC_3095},			/* minor 0-3 */
246 		{0, 0, QIC_3095},			/* minor 4-7 */
247 		{0, 0, QIC_3095},			/* minor 8-11 */
248 		{0, 0, QIC_3095},			/* minor 12-15 */
249 	}}},
250 #if 0
251 	{{T_SEQUENTIAL, T_REMOV,
252 	 "EXABYTE ", "EXB-8200        ", ""},     {0, 12, {
253 		{0, 0, 0},				/* minor 0-3 */
254 		{0, 0, 0},				/* minor 4-7 */
255 		{0, 0, 0},				/* minor 8-11 */
256 		{0, 0, 0}				/* minor 12-15 */
257 	}}},
258 #endif
259 	{{T_SEQUENTIAL, T_REMOV,
260 	 "TEAC    ", "MT-2ST/N50      ", ""},     {ST_Q_IGNORE_LOADS, 0, {
261 		{0, 0, 0},			        /* minor 0-3 */
262 		{0, 0, 0},			        /* minor 4-7 */
263 		{0, 0, 0},			        /* minor 8-11 */
264 		{0, 0, 0}			        /* minor 12-15 */
265 	}}},
266 	{{T_SEQUENTIAL, T_REMOV,
267 	 "OnStream", "ADR50 Drive", ""},	  {ST_Q_UNIMODAL, 0, {
268 		{ST_Q_FORCE_BLKSIZE, 512, 0},	        /* minor 0-3 */
269 		{ST_Q_FORCE_BLKSIZE, 512, 0},	        /* minor 4-7 */
270 		{ST_Q_FORCE_BLKSIZE, 512, 0},	        /* minor 8-11 */
271 		{ST_Q_FORCE_BLKSIZE, 512, 0},	        /* minor 12-15 */
272 	}}},
273 	{{T_SEQUENTIAL, T_REMOV,
274 	 "NCR H621", "0-STD-03-46F880 ", ""},     {ST_Q_NOPREVENT, 0, {
275 		{0, 0, 0},			       /* minor 0-3 */
276 		{0, 0, 0},			       /* minor 4-7 */
277 		{0, 0, 0},			       /* minor 8-11 */
278 		{0, 0, 0}			       /* minor 12-15 */
279 	}}},
280 	{{T_SEQUENTIAL, T_REMOV,
281 	 "OnStream DI-30",      "",   "1.0"},  {ST_Q_IGNORE_LOADS, 0, {
282 		{0, 0, 0},				/* minor 0-3 */
283 		{0, 0, 0},				/* minor 4-7 */
284 		{0, 0, 0},				/* minor 8-11 */
285 		{0, 0, 0}				/* minor 12-15 */
286 	}}},
287 };
288 
289 #define NOEJECT 0
290 #define EJECT 1
291 
292 void	st_identify_drive __P((struct st_softc *,
293 	    struct scsipi_inquiry_pattern *));
294 void	st_loadquirks __P((struct st_softc *));
295 int	st_mount_tape __P((dev_t, int));
296 void	st_unmount __P((struct st_softc *, boolean));
297 int	st_decide_mode __P((struct st_softc *, boolean));
298 void	ststart __P((struct scsipi_periph *));
299 void	stdone __P((struct scsipi_xfer *));
300 int	st_read __P((struct st_softc *, char *, int, int));
301 int	st_space __P((struct st_softc *, int, u_int, int));
302 int	st_write_filemarks __P((struct st_softc *, int, int));
303 int	st_check_eod __P((struct st_softc *, boolean, int *, int));
304 int	st_load __P((struct st_softc *, u_int, int));
305 int	st_rewind __P((struct st_softc *, u_int, int));
306 int	st_interpret_sense __P((struct scsipi_xfer *));
307 int	st_touch_tape __P((struct st_softc *));
308 int	st_erase __P((struct st_softc *, int full, int flags));
309 int	st_rdpos __P((struct st_softc *, int, u_int32_t *));
310 int	st_setpos __P((struct st_softc *, int, u_int32_t *));
311 
312 const struct scsipi_periphsw st_switch = {
313 	st_interpret_sense,
314 	ststart,
315 	NULL,
316 	stdone
317 };
318 
319 #if	defined(ST_ENABLE_EARLYWARN)
320 #define	ST_INIT_FLAGS	ST_EARLYWARN
321 #else
322 #define	ST_INIT_FLAGS	0
323 #endif
324 
325 /*
326  * The routine called by the low level scsi routine when it discovers
327  * A device suitable for this driver
328  */
329 void
330 stattach(parent, st, aux)
331 	struct device *parent;
332 	struct st_softc *st;
333 	void *aux;
334 {
335 	struct scsipibus_attach_args *sa = aux;
336 	struct scsipi_periph *periph = sa->sa_periph;
337 
338 	SC_DEBUG(periph, SCSIPI_DB2, ("stattach: "));
339 
340 	/*
341 	 * Store information needed to contact our base driver
342 	 */
343 	st->sc_periph = periph;
344 	periph->periph_dev = &st->sc_dev;
345 	periph->periph_switch = &st_switch;
346 
347 	/*
348 	 * Set initial flags
349 	 */
350 
351 	st->flags = ST_INIT_FLAGS;
352 
353 	/*
354 	 * Check if the drive is a known criminal and take
355 	 * Any steps needed to bring it into line
356 	 */
357 	st_identify_drive(st, &sa->sa_inqbuf);
358 	/*
359 	 * Use the subdriver to request information regarding the drive.
360 	 */
361 	printf("\n");
362 	printf("%s: %s", st->sc_dev.dv_xname, st->quirkdata ? "rogue, " : "");
363 	if (scsipi_test_unit_ready(periph,
364 	    XS_CTL_DISCOVERY | XS_CTL_SILENT | XS_CTL_IGNORE_MEDIA_CHANGE) ||
365 	    st->ops(st, ST_OPS_MODESENSE,
366 	    XS_CTL_DISCOVERY | XS_CTL_SILENT | XS_CTL_IGNORE_MEDIA_CHANGE))
367 		printf("drive empty\n");
368 	else {
369 		printf("density code %d, ", st->media_density);
370 		if (st->media_blksize > 0)
371 			printf("%d-byte", st->media_blksize);
372 		else
373 			printf("variable");
374 		printf(" blocks, write-%s\n",
375 		    (st->flags & ST_READONLY) ? "protected" : "enabled");
376 	}
377 
378 	/*
379 	 * Set up the buf queue for this device
380 	 */
381 	BUFQ_INIT(&st->buf_queue);
382 
383 #if NRND > 0
384 	rnd_attach_source(&st->rnd_source, st->sc_dev.dv_xname,
385 			  RND_TYPE_TAPE, 0);
386 #endif
387 }
388 
389 /*
390  * Use the inquiry routine in 'scsi_base' to get drive info so we can
391  * Further tailor our behaviour.
392  */
393 void
394 st_identify_drive(st, inqbuf)
395 	struct st_softc *st;
396 	struct scsipi_inquiry_pattern *inqbuf;
397 {
398 	struct st_quirk_inquiry_pattern *finger;
399 	int priority;
400 
401 	finger = (struct st_quirk_inquiry_pattern *)scsipi_inqmatch(inqbuf,
402 	    (caddr_t)st_quirk_patterns,
403 	    sizeof(st_quirk_patterns) / sizeof(st_quirk_patterns[0]),
404 	    sizeof(st_quirk_patterns[0]), &priority);
405 	if (priority != 0) {
406 		st->quirkdata = &finger->quirkdata;
407 		st->drive_quirks = finger->quirkdata.quirks;
408 		st->quirks = finger->quirkdata.quirks;	/* start value */
409 		st->page_0_size = finger->quirkdata.page_0_size;
410 		st_loadquirks(st);
411 	}
412 }
413 
414 /*
415  * initialise the subdevices to the default (QUIRK) state.
416  * this will remove any setting made by the system operator or previous
417  * operations.
418  */
419 void
420 st_loadquirks(st)
421 	struct st_softc *st;
422 {
423 	int i;
424 	struct	modes *mode;
425 	struct	modes *mode2;
426 
427 	mode = st->quirkdata->modes;
428 	mode2 = st->modes;
429 	for (i = 0; i < 4; i++) {
430 		memset(mode2, 0, sizeof(struct modes));
431 		st->modeflags[i] &= ~(BLKSIZE_SET_BY_QUIRK |
432 		    DENSITY_SET_BY_QUIRK | BLKSIZE_SET_BY_USER |
433 		    DENSITY_SET_BY_USER);
434 		if ((mode->quirks | st->drive_quirks) & ST_Q_FORCE_BLKSIZE) {
435 			mode2->blksize = mode->blksize;
436 			st->modeflags[i] |= BLKSIZE_SET_BY_QUIRK;
437 		}
438 		if (mode->density) {
439 			mode2->density = mode->density;
440 			st->modeflags[i] |= DENSITY_SET_BY_QUIRK;
441 		}
442 		mode2->quirks |= mode->quirks;
443 		mode++;
444 		mode2++;
445 	}
446 }
447 
448 /*
449  * open the device.
450  */
451 int
452 stopen(dev, flags, mode, p)
453 	dev_t dev;
454 	int flags;
455 	int mode;
456 	struct proc *p;
457 {
458 	u_int stmode, dsty;
459 	int error, sflags, unit, tries, ntries;
460 	struct st_softc *st;
461 	struct scsipi_periph *periph;
462 	struct scsipi_adapter *adapt;
463 
464 	unit = STUNIT(dev);
465 	if (unit >= st_cd.cd_ndevs)
466 		return (ENXIO);
467 	st = st_cd.cd_devs[unit];
468 	if (st == NULL)
469 		return (ENXIO);
470 
471 	stmode = STMODE(dev);
472 	dsty = STDSTY(dev);
473 
474 	periph = st->sc_periph;
475 	adapt = periph->periph_channel->chan_adapter;
476 
477 	SC_DEBUG(periph, SCSIPI_DB1, ("open: dev=0x%x (unit %d (of %d))\n", dev,
478 	    unit, st_cd.cd_ndevs));
479 
480 
481 	/*
482 	 * Only allow one at a time
483 	 */
484 	if (periph->periph_flags & PERIPH_OPEN) {
485 		printf("%s: already open\n", st->sc_dev.dv_xname);
486 		return (EBUSY);
487 	}
488 
489 	if ((error = scsipi_adapter_addref(adapt)) != 0)
490 		return (error);
491 
492 	/*
493 	 * clear any latched errors.
494 	 */
495 	st->mt_resid = 0;
496 	st->mt_erreg = 0;
497 	st->asc = 0;
498 	st->ascq = 0;
499 
500 	/*
501 	 * Catch any unit attention errors. Be silent about this
502 	 * unless we're already mounted. We ignore media change
503 	 * if we're in control mode or not mounted yet.
504 	 */
505 	if ((st->flags & ST_MOUNTED) == 0 || stmode == CTRL_MODE) {
506 #ifdef SCSIDEBUG
507 		sflags = XS_CTL_IGNORE_MEDIA_CHANGE;
508 #else
509 		sflags = XS_CTL_SILENT|XS_CTL_IGNORE_MEDIA_CHANGE;
510 #endif
511 	} else
512 		sflags = 0;
513 
514 	/*
515 	 * If we're already mounted or we aren't configured for
516 	 * a mount delay, only try a test unit ready once. Otherwise,
517 	 * try up to ST_MOUNT_DELAY times with a rest interval of
518 	 * one second between each try.
519 	 */
520 
521 	if ((st->flags & ST_MOUNTED) || ST_MOUNT_DELAY == 0) {
522 		ntries = 1;
523 	} else {
524 		ntries = ST_MOUNT_DELAY;
525 	}
526 
527 	for (error = tries = 0; tries < ntries; tries++) {
528 		int slpintr, oflags;
529 
530 		/*
531 		 * If we had no error, or we're opening the control mode
532 		 * device, we jump out right away.
533 		 */
534 
535 		error = scsipi_test_unit_ready(periph, sflags);
536 		if (error == 0 || stmode == CTRL_MODE) {
537 			break;
538 		}
539 
540 		/*
541 		 * We had an error.
542 		 *
543 		 * If we're already mounted or we aren't configured for
544 		 * a mount delay, or the error isn't a NOT READY error,
545 		 * skip to the error exit now.
546 		 */
547 		if ((st->flags & ST_MOUNTED) || ST_MOUNT_DELAY == 0 ||
548 		    (st->mt_key != SKEY_NOT_READY)) {
549 			goto bad;
550 		}
551 
552 		/*
553 		 * clear any latched errors.
554 		 */
555 		st->mt_resid = 0;
556 		st->mt_erreg = 0;
557 		st->asc = 0;
558 		st->ascq = 0;
559 
560 		/*
561 		 * Fake that we have the device open so
562 		 * we block other apps from getting in.
563 		 */
564 
565 		oflags = periph->periph_flags;
566 		periph->periph_flags |= PERIPH_OPEN;
567 
568 		slpintr = tsleep(&lbolt, PUSER|PCATCH, "stload", 0);
569 
570 		periph->periph_flags = oflags;	/* restore flags */
571 		if (slpintr) {
572 			goto bad;
573 		}
574 	}
575 
576 
577 	/*
578 	 * If the mode is 3 (e.g. minor = 3,7,11,15) then the device has
579 	 * been opened to set defaults and perform other, usually non-I/O
580 	 * related, operations. In this case, do a quick check to see
581 	 * whether the unit actually had a tape loaded (this will be known
582 	 * as to whether or not we got a NOT READY for the above
583 	 * unit attention). If a tape is there, go do a mount sequence.
584 	 */
585 	if (stmode == CTRL_MODE && st->mt_key == SKEY_NOT_READY) {
586 		periph->periph_flags |= PERIPH_OPEN;
587 		return (0);
588 	}
589 
590 	/*
591 	 * If we get this far and had an error set, that means we failed
592 	 * to pass the 'test unit ready' test for the non-controlmode device,
593 	 * so we bounce the open.
594 	 */
595 
596 	if (error)
597 		return (error);
598 
599 	/*
600 	 * Else, we're now committed to saying we're open.
601 	 */
602 
603 	periph->periph_flags |= PERIPH_OPEN; /* unit attn are now errors */
604 
605 	/*
606 	 * If it's a different mode, or if the media has been
607 	 * invalidated, unmount the tape from the previous
608 	 * session but continue with open processing
609 	 */
610 	if (st->last_dsty != dsty ||
611 	    (periph->periph_flags & PERIPH_MEDIA_LOADED) == 0)
612 		st_unmount(st, NOEJECT);
613 
614 	/*
615 	 * If we are not mounted, then we should start a new
616 	 * mount session.
617 	 */
618 	if (!(st->flags & ST_MOUNTED)) {
619 		if ((error = st_mount_tape(dev, flags)) != 0)
620 			goto bad;
621 		st->last_dsty = dsty;
622 	}
623 
624 	SC_DEBUG(periph, SCSIPI_DB2, ("open complete\n"));
625 	return (0);
626 
627 bad:
628 	st_unmount(st, NOEJECT);
629 	scsipi_adapter_delref(adapt);
630 	periph->periph_flags &= ~PERIPH_OPEN;
631 	return (error);
632 }
633 
634 /*
635  * close the device.. only called if we are the LAST
636  * occurence of an open device
637  */
638 int
639 stclose(dev, flags, mode, p)
640 	dev_t dev;
641 	int flags;
642 	int mode;
643 	struct proc *p;
644 {
645 	int stxx, error = 0;
646 	struct st_softc *st = st_cd.cd_devs[STUNIT(dev)];
647 	struct scsipi_periph *periph = st->sc_periph;
648 	struct scsipi_adapter *adapt = periph->periph_channel->chan_adapter;
649 
650 	SC_DEBUG(st->sc_periph, SCSIPI_DB1, ("closing\n"));
651 
652 	/*
653 	 * Make sure that a tape opened in write-only mode will have
654 	 * file marks written on it when closed, even if not written to.
655 	 *
656 	 * This is for SUN compatibility. Actually, the Sun way of
657 	 * things is to:
658 	 *
659 	 *	only write filemarks if there are fmks to be written and
660 	 *   		- open for write (possibly read/write)
661 	 *		- the last operation was a write
662 	 * 	or:
663 	 *		- opened for wronly
664 	 *		- no data was written (including filemarks)
665 	 */
666 
667 	stxx = st->flags & (ST_WRITTEN | ST_FM_WRITTEN);
668 	if (((flags & FWRITE) && stxx == ST_WRITTEN) ||
669 	    ((flags & O_ACCMODE) == FWRITE && stxx == 0)) {
670 		int nm;
671 		error = st_check_eod(st, FALSE, &nm, 0);
672 	}
673 
674 	switch (STMODE(dev)) {
675 	case NORMAL_MODE:
676 		st_unmount(st, NOEJECT);
677 		break;
678 	case NOREW_MODE:
679 	case CTRL_MODE:
680 		/*
681 		 * Leave mounted unless media seems to have been removed.
682 		 *
683 		 * Otherwise, if we're to terminate a tape with more than one
684 		 * filemark [ and because we're not rewinding here ], backspace
685 		 * one filemark so that later appends will see an unbroken
686 		 * sequence of:
687 		 *
688 		 *	file - FMK - file - FMK ... file - FMK FMK (EOM)
689 		 */
690 		if ((periph->periph_flags & PERIPH_MEDIA_LOADED) == 0) {
691 			st_unmount(st, NOEJECT);
692 		} else if (error == 0) {
693 			/*
694 			 * ST_WRITTEN was preserved from above.
695 			 *
696 			 * All we need to know here is:
697 			 *
698 			 *	Were we writing this tape and was the last
699 			 *	operation a write?
700 			 *
701 			 *	Are there supposed to be 2FM at EOD?
702 			 *
703 			 * If both statements are true, then we backspace
704 			 * one filemark.
705 			 */
706 			stxx |= (st->flags & ST_2FM_AT_EOD);
707 			if ((flags & FWRITE) != 0 &&
708 			    (stxx == (ST_2FM_AT_EOD|ST_WRITTEN))) {
709 				error = st_space(st, -1, SP_FILEMARKS, 0);
710 			}
711 		}
712 		break;
713 	case EJECT_MODE:
714 		st_unmount(st, EJECT);
715 		break;
716 	}
717 
718 	scsipi_wait_drain(periph);
719 
720 	scsipi_adapter_delref(adapt);
721 	periph->periph_flags &= ~PERIPH_OPEN;
722 
723 	return (error);
724 }
725 
726 /*
727  * Start a new mount session.
728  * Copy in all the default parameters from the selected device mode.
729  * and try guess any that seem to be defaulted.
730  */
731 int
732 st_mount_tape(dev, flags)
733 	dev_t dev;
734 	int flags;
735 {
736 	int unit;
737 	u_int dsty;
738 	struct st_softc *st;
739 	struct scsipi_periph *periph;
740 	int error = 0;
741 
742 	unit = STUNIT(dev);
743 	dsty = STDSTY(dev);
744 	st = st_cd.cd_devs[unit];
745 	periph = st->sc_periph;
746 
747 	if (st->flags & ST_MOUNTED)
748 		return (0);
749 
750 	SC_DEBUG(periph, SCSIPI_DB1, ("mounting\n "));
751 	st->flags |= ST_NEW_MOUNT;
752 	st->quirks = st->drive_quirks | st->modes[dsty].quirks;
753 	/*
754 	 * If the media is new, then make sure we give it a chance to
755 	 * to do a 'load' instruction.  (We assume it is new.)
756 	 */
757 	if ((error = st_load(st, LD_LOAD, XS_CTL_SILENT)) != 0)
758 		return (error);
759 	/*
760 	 * Throw another dummy instruction to catch
761 	 * 'Unit attention' errors. Many drives give
762 	 * these after doing a Load instruction (with
763 	 * the MEDIUM MAY HAVE CHANGED asc/ascq).
764 	 */
765 	scsipi_test_unit_ready(periph, XS_CTL_SILENT);	/* XXX */
766 
767 	/*
768 	 * Some devices can't tell you much until they have been
769 	 * asked to look at the media. This quirk does this.
770 	 */
771 	if (st->quirks & ST_Q_SENSE_HELP)
772 		if ((error = st_touch_tape(st)) != 0)
773 			return (error);
774 	/*
775 	 * Load the physical device parameters
776 	 * loads: blkmin, blkmax
777 	 */
778 	if ((error = st->ops(st, ST_OPS_RBL, 0)) != 0)
779 		return (error);
780 	/*
781 	 * Load the media dependent parameters
782 	 * includes: media_blksize,media_density,numblks
783 	 * As we have a tape in, it should be reflected here.
784 	 * If not you may need the "quirk" above.
785 	 */
786 	if ((error = st->ops(st, ST_OPS_MODESENSE, 0)) != 0)
787 		return (error);
788 	/*
789 	 * If we have gained a permanent density from somewhere,
790 	 * then use it in preference to the one supplied by
791 	 * default by the driver.
792 	 */
793 	if (st->modeflags[dsty] & (DENSITY_SET_BY_QUIRK | DENSITY_SET_BY_USER))
794 		st->density = st->modes[dsty].density;
795 	else
796 		st->density = st->media_density;
797 	/*
798 	 * If we have gained a permanent blocksize
799 	 * then use it in preference to the one supplied by
800 	 * default by the driver.
801 	 */
802 	st->flags &= ~ST_FIXEDBLOCKS;
803 	if (st->modeflags[dsty] &
804 	    (BLKSIZE_SET_BY_QUIRK | BLKSIZE_SET_BY_USER)) {
805 		st->blksize = st->modes[dsty].blksize;
806 		if (st->blksize)
807 			st->flags |= ST_FIXEDBLOCKS;
808 	} else {
809 		if ((error = st_decide_mode(st, FALSE)) != 0)
810 			return (error);
811 	}
812 	if ((error = st->ops(st, ST_OPS_MODESELECT, 0)) != 0) {
813 		/* ATAPI will return ENODEV for this, and this may be OK */
814 		if (error != ENODEV) {
815 			printf("%s: cannot set selected mode\n",
816 			    st->sc_dev.dv_xname);
817 			return (error);
818 		}
819 	}
820 	if (!(st->quirks & ST_Q_NOPREVENT)) {
821 		scsipi_prevent(periph, PR_PREVENT,
822 		    XS_CTL_IGNORE_ILLEGAL_REQUEST | XS_CTL_IGNORE_NOT_READY);
823 	}
824 	st->flags &= ~ST_NEW_MOUNT;
825 	st->flags |= ST_MOUNTED;
826 	periph->periph_flags |= PERIPH_MEDIA_LOADED;	/* move earlier? */
827 
828 	return (0);
829 }
830 
831 /*
832  * End the present mount session.
833  * Rewind, and optionally eject the tape.
834  * Reset various flags to indicate that all new
835  * operations require another mount operation
836  */
837 void
838 st_unmount(st, eject)
839 	struct st_softc *st;
840 	boolean eject;
841 {
842 	struct scsipi_periph *periph = st->sc_periph;
843 	int nmarks;
844 
845 	if ((st->flags & ST_MOUNTED) == 0)
846 		return;
847 	SC_DEBUG(periph, SCSIPI_DB1, ("unmounting\n"));
848 	st_check_eod(st, FALSE, &nmarks, XS_CTL_IGNORE_NOT_READY);
849 	st_rewind(st, 0, XS_CTL_IGNORE_NOT_READY);
850 
851 	/*
852 	 * Section 9.3.3 of the SCSI specs states that a device shall return
853 	 * the density value specified in the last succesfull MODE SELECT
854 	 * after an unload operation, in case it is not able to
855 	 * automatically determine the density of the new medium.
856 	 *
857 	 * So we instruct the device to use the default density, which will
858 	 * prevent the use of stale density values (in particular,
859 	 * in st_touch_tape().
860 	 */
861 	st->density = 0;
862 	if (st->ops(st, ST_OPS_MODESELECT, 0) != 0) {
863 		printf("%s: WARNING: cannot revert to default density\n",
864 			st->sc_dev.dv_xname);
865 	}
866 
867 	scsipi_prevent(periph, PR_ALLOW,
868 	    XS_CTL_IGNORE_ILLEGAL_REQUEST | XS_CTL_IGNORE_NOT_READY);
869 	if (eject)
870 		st_load(st, LD_UNLOAD, XS_CTL_IGNORE_NOT_READY);
871 	st->flags &= ~(ST_MOUNTED | ST_NEW_MOUNT);
872 	periph->periph_flags &= ~PERIPH_MEDIA_LOADED;
873 }
874 
875 /*
876  * Given all we know about the device, media, mode, 'quirks' and
877  * initial operation, make a decision as to how we should be set
878  * to run (regarding blocking and EOD marks)
879  */
880 int
881 st_decide_mode(st, first_read)
882 	struct st_softc *st;
883 	boolean	first_read;
884 {
885 
886 	SC_DEBUG(st->sc_periph, SCSIPI_DB2, ("starting block mode decision\n"));
887 
888 	/*
889 	 * If the drive can only handle fixed-length blocks and only at
890 	 * one size, perhaps we should just do that.
891 	 */
892 	if (st->blkmin && (st->blkmin == st->blkmax)) {
893 		st->flags |= ST_FIXEDBLOCKS;
894 		st->blksize = st->blkmin;
895 		SC_DEBUG(st->sc_periph, SCSIPI_DB3,
896 		    ("blkmin == blkmax of %d\n", st->blkmin));
897 		goto done;
898 	}
899 	/*
900 	 * If the tape density mandates (or even suggests) use of fixed
901 	 * or variable-length blocks, comply.
902 	 */
903 	switch (st->density) {
904 	case HALFINCH_800:
905 	case HALFINCH_1600:
906 	case HALFINCH_6250:
907 	case DDS:
908 		st->flags &= ~ST_FIXEDBLOCKS;
909 		st->blksize = 0;
910 		SC_DEBUG(st->sc_periph, SCSIPI_DB3,
911 		    ("density specified variable\n"));
912 		goto done;
913 	case QIC_11:
914 	case QIC_24:
915 	case QIC_120:
916 	case QIC_150:
917 	case QIC_525:
918 	case QIC_1320:
919 	case QIC_3095:
920 	case QIC_3220:
921 		st->flags |= ST_FIXEDBLOCKS;
922 		if (st->media_blksize > 0)
923 			st->blksize = st->media_blksize;
924 		else
925 			st->blksize = DEF_FIXED_BSIZE;
926 		SC_DEBUG(st->sc_periph, SCSIPI_DB3,
927 		    ("density specified fixed\n"));
928 		goto done;
929 	}
930 	/*
931 	 * If we're about to read the tape, perhaps we should choose
932 	 * fixed or variable-length blocks and block size according to
933 	 * what the drive found on the tape.
934 	 */
935 	if (first_read &&
936 	    (!(st->quirks & ST_Q_BLKSIZE) || (st->media_blksize == 0) ||
937 	    (st->media_blksize == DEF_FIXED_BSIZE) ||
938 	    (st->media_blksize == 1024))) {
939 		if (st->media_blksize > 0)
940 			st->flags |= ST_FIXEDBLOCKS;
941 		else
942 			st->flags &= ~ST_FIXEDBLOCKS;
943 		st->blksize = st->media_blksize;
944 		SC_DEBUG(st->sc_periph, SCSIPI_DB3,
945 		    ("Used media_blksize of %d\n", st->media_blksize));
946 		goto done;
947 	}
948 	/*
949 	 * We're getting no hints from any direction.  Choose variable-
950 	 * length blocks arbitrarily.
951 	 */
952 	st->flags &= ~ST_FIXEDBLOCKS;
953 	st->blksize = 0;
954 	SC_DEBUG(st->sc_periph, SCSIPI_DB3,
955 	    ("Give up and default to variable mode\n"));
956 
957 done:
958 	/*
959 	 * Decide whether or not to write two file marks to signify end-
960 	 * of-data.  Make the decision as a function of density.  If
961 	 * the decision is not to use a second file mark, the SCSI BLANK
962 	 * CHECK condition code will be recognized as end-of-data when
963 	 * first read.
964 	 * (I think this should be a by-product of fixed/variable..julian)
965 	 */
966 	switch (st->density) {
967 /*      case 8 mm:   What is the SCSI density code for 8 mm, anyway? */
968 	case QIC_11:
969 	case QIC_24:
970 	case QIC_120:
971 	case QIC_150:
972 	case QIC_525:
973 	case QIC_1320:
974 	case QIC_3095:
975 	case QIC_3220:
976 		st->flags &= ~ST_2FM_AT_EOD;
977 		break;
978 	default:
979 		st->flags |= ST_2FM_AT_EOD;
980 	}
981 	return (0);
982 }
983 
984 /*
985  * Actually translate the requested transfer into
986  * one the physical driver can understand
987  * The transfer is described by a buf and will include
988  * only one physical transfer.
989  */
990 void
991 ststrategy(bp)
992 	struct buf *bp;
993 {
994 	struct st_softc *st = st_cd.cd_devs[STUNIT(bp->b_dev)];
995 	int s;
996 
997 	SC_DEBUG(st->sc_periph, SCSIPI_DB1,
998 	    ("ststrategy %ld bytes @ blk %d\n", bp->b_bcount, bp->b_blkno));
999 	/*
1000 	 * If it's a null transfer, return immediatly
1001 	 */
1002 	if (bp->b_bcount == 0)
1003 		goto done;
1004 
1005 	/* If offset is negative, error */
1006 	if (bp->b_blkno < 0) {
1007 		bp->b_error = EINVAL;
1008 		goto bad;
1009 	}
1010 
1011 	/*
1012 	 * Odd sized request on fixed drives are verboten
1013 	 */
1014 	if (st->flags & ST_FIXEDBLOCKS) {
1015 		if (bp->b_bcount % st->blksize) {
1016 			printf("%s: bad request, must be multiple of %d\n",
1017 			    st->sc_dev.dv_xname, st->blksize);
1018 			bp->b_error = EIO;
1019 			goto bad;
1020 		}
1021 	}
1022 	/*
1023 	 * as are out-of-range requests on variable drives.
1024 	 */
1025 	else if (bp->b_bcount < st->blkmin ||
1026 	    (st->blkmax && bp->b_bcount > st->blkmax)) {
1027 		printf("%s: bad request, must be between %d and %d\n",
1028 		    st->sc_dev.dv_xname, st->blkmin, st->blkmax);
1029 		bp->b_error = EIO;
1030 		goto bad;
1031 	}
1032 	s = splbio();
1033 
1034 	/*
1035 	 * Place it in the queue of activities for this tape
1036 	 * at the end (a bit silly because we only have on user..
1037 	 * (but it could fork()))
1038 	 */
1039 	BUFQ_INSERT_TAIL(&st->buf_queue, bp);
1040 
1041 	/*
1042 	 * Tell the device to get going on the transfer if it's
1043 	 * not doing anything, otherwise just wait for completion
1044 	 * (All a bit silly if we're only allowing 1 open but..)
1045 	 */
1046 	ststart(st->sc_periph);
1047 
1048 	splx(s);
1049 	return;
1050 bad:
1051 	bp->b_flags |= B_ERROR;
1052 done:
1053 	/*
1054 	 * Correctly set the buf to indicate a completed xfer
1055 	 */
1056 	bp->b_resid = bp->b_bcount;
1057 	biodone(bp);
1058 	return;
1059 }
1060 
1061 /*
1062  * ststart looks to see if there is a buf waiting for the device
1063  * and that the device is not already busy. If both are true,
1064  * It dequeues the buf and creates a scsi command to perform the
1065  * transfer required. The transfer request will call scsipi_done
1066  * on completion, which will in turn call this routine again
1067  * so that the next queued transfer is performed.
1068  * The bufs are queued by the strategy routine (ststrategy)
1069  *
1070  * This routine is also called after other non-queued requests
1071  * have been made of the scsi driver, to ensure that the queue
1072  * continues to be drained.
1073  * ststart() is called at splbio
1074  */
1075 void
1076 ststart(periph)
1077 	struct scsipi_periph *periph;
1078 {
1079 	struct st_softc *st = (void *)periph->periph_dev;
1080 	struct buf *bp;
1081 	struct scsi_rw_tape cmd;
1082 	int flags, error;
1083 
1084 	SC_DEBUG(periph, SCSIPI_DB2, ("ststart "));
1085 	/*
1086 	 * See if there is a buf to do and we are not already
1087 	 * doing one
1088 	 */
1089 	while (periph->periph_active < periph->periph_openings) {
1090 		/* if a special awaits, let it proceed first */
1091 		if (periph->periph_flags & PERIPH_WAITING) {
1092 			periph->periph_flags &= ~PERIPH_WAITING;
1093 			wakeup((caddr_t)periph);
1094 			return;
1095 		}
1096 
1097 		if ((bp = BUFQ_FIRST(&st->buf_queue)) == NULL)
1098 			return;
1099 		BUFQ_REMOVE(&st->buf_queue, bp);
1100 
1101 		/*
1102 		 * If the device has been unmounted by the user
1103 		 * then throw away all requests until done.
1104 		 */
1105 		if ((st->flags & ST_MOUNTED) == 0 ||
1106 		    (periph->periph_flags & PERIPH_MEDIA_LOADED) == 0) {
1107 			/* make sure that one implies the other.. */
1108 			periph->periph_flags &= ~PERIPH_MEDIA_LOADED;
1109 			bp->b_flags |= B_ERROR;
1110 			bp->b_error = EIO;
1111 			bp->b_resid = bp->b_bcount;
1112 			biodone(bp);
1113 			continue;
1114 		}
1115 		/*
1116 		 * only FIXEDBLOCK devices have pending I/O or space operations.
1117 		 */
1118 		if (st->flags & ST_FIXEDBLOCKS) {
1119 			/*
1120 			 * If we are at a filemark but have not reported it yet
1121 			 * then we should report it now
1122 			 */
1123 			if (st->flags & ST_AT_FILEMARK) {
1124 				if ((bp->b_flags & B_READ) == B_WRITE) {
1125 					/*
1126 					 * Handling of ST_AT_FILEMARK in
1127 					 * st_space will fill in the right file
1128 					 * mark count.
1129 					 * Back up over filemark
1130 					 */
1131 					if (st_space(st, 0, SP_FILEMARKS, 0)) {
1132 						bp->b_flags |= B_ERROR;
1133 						bp->b_error = EIO;
1134 						biodone(bp);
1135 						continue;
1136 					}
1137 				} else {
1138 					bp->b_resid = bp->b_bcount;
1139 					bp->b_error = 0;
1140 					bp->b_flags &= ~B_ERROR;
1141 					st->flags &= ~ST_AT_FILEMARK;
1142 					biodone(bp);
1143 					continue;	/* seek more work */
1144 				}
1145 			}
1146 		}
1147 		/*
1148 		 * If we are at EOM but have not reported it
1149 		 * yet then we should report it now.
1150 		 */
1151 		if (st->flags & (ST_EOM_PENDING|ST_EIO_PENDING)) {
1152 			bp->b_resid = bp->b_bcount;
1153 			if (st->flags & ST_EIO_PENDING) {
1154 				bp->b_error = EIO;
1155 				bp->b_flags |= B_ERROR;
1156 			}
1157 			st->flags &= ~(ST_EOM_PENDING|ST_EIO_PENDING);
1158 			biodone(bp);
1159 			continue;	/* seek more work */
1160 		}
1161 
1162 		/*
1163 		 * Fill out the scsi command
1164 		 */
1165 		memset(&cmd, 0, sizeof(cmd));
1166 		flags = XS_CTL_NOSLEEP | XS_CTL_ASYNC;
1167 		if ((bp->b_flags & B_READ) == B_WRITE) {
1168 			cmd.opcode = WRITE;
1169 			st->flags &= ~ST_FM_WRITTEN;
1170 			flags |= XS_CTL_DATA_OUT;
1171 		} else {
1172 			cmd.opcode = READ;
1173 			flags |= XS_CTL_DATA_IN;
1174 		}
1175 
1176 		/*
1177 		 * Handle "fixed-block-mode" tape drives by using the
1178 		 * block count instead of the length.
1179 		 */
1180 		if (st->flags & ST_FIXEDBLOCKS) {
1181 			cmd.byte2 |= SRW_FIXED;
1182 			_lto3b(bp->b_bcount / st->blksize, cmd.len);
1183 		} else
1184 			_lto3b(bp->b_bcount, cmd.len);
1185 
1186 		/*
1187 		 * go ask the adapter to do all this for us
1188 		 */
1189 		error = scsipi_command(periph,
1190 		    (struct scsipi_generic *)&cmd, sizeof(cmd),
1191 		    (u_char *)bp->b_data, bp->b_bcount,
1192 		    0, ST_IO_TIME, bp, flags);
1193 		if (error) {
1194 			printf("%s: not queued, error %d\n",
1195 			    st->sc_dev.dv_xname, error);
1196 		}
1197 	} /* go back and see if we can cram more work in.. */
1198 }
1199 
1200 void
1201 stdone(xs)
1202 	struct scsipi_xfer *xs;
1203 {
1204 	struct st_softc *st = (void *)xs->xs_periph->periph_dev;
1205 
1206 	if (xs->bp != NULL) {
1207 		if ((xs->bp->b_flags & B_READ) == B_WRITE) {
1208 			st->flags |= ST_WRITTEN;
1209 		} else {
1210 			st->flags &= ~ST_WRITTEN;
1211 		}
1212 #if NRND > 0
1213 		rnd_add_uint32(&st->rnd_source, xs->bp->b_blkno);
1214 #endif
1215 	}
1216 }
1217 
1218 int
1219 stread(dev, uio, iomode)
1220 	dev_t dev;
1221 	struct uio *uio;
1222 	int iomode;
1223 {
1224 	struct st_softc *st = st_cd.cd_devs[STUNIT(dev)];
1225 
1226 	return (physio(ststrategy, NULL, dev, B_READ,
1227 	    st->sc_periph->periph_channel->chan_adapter->adapt_minphys, uio));
1228 }
1229 
1230 int
1231 stwrite(dev, uio, iomode)
1232 	dev_t dev;
1233 	struct uio *uio;
1234 	int iomode;
1235 {
1236 	struct st_softc *st = st_cd.cd_devs[STUNIT(dev)];
1237 
1238 	return (physio(ststrategy, NULL, dev, B_WRITE,
1239 	    st->sc_periph->periph_channel->chan_adapter->adapt_minphys, uio));
1240 }
1241 
1242 /*
1243  * Perform special action on behalf of the user;
1244  * knows about the internals of this device
1245  */
1246 int
1247 stioctl(dev, cmd, arg, flag, p)
1248 	dev_t dev;
1249 	u_long cmd;
1250 	caddr_t arg;
1251 	int flag;
1252 	struct proc *p;
1253 {
1254 	int error = 0;
1255 	int unit;
1256 	int number, nmarks, dsty;
1257 	int flags;
1258 	struct st_softc *st;
1259 	int hold_blksize;
1260 	u_int8_t hold_density;
1261 	struct mtop *mt = (struct mtop *) arg;
1262 
1263 	/*
1264 	 * Find the device that the user is talking about
1265 	 */
1266 	flags = 0;		/* give error messages, act on errors etc. */
1267 	unit = STUNIT(dev);
1268 	dsty = STDSTY(dev);
1269 	st = st_cd.cd_devs[unit];
1270 	hold_blksize = st->blksize;
1271 	hold_density = st->density;
1272 
1273 	switch ((u_int) cmd) {
1274 
1275 	case MTIOCGET: {
1276 		struct mtget *g = (struct mtget *) arg;
1277 		/*
1278 		 * (to get the current state of READONLY)
1279 		 */
1280 		error = st->ops(st, ST_OPS_MODESENSE, XS_CTL_SILENT);
1281 		if (error) {
1282 			/*
1283 			 * Ignore the error if in control mode;
1284 			 * this is mandated by st(4).
1285 			 */
1286 			if (STMODE(dev) != CTRL_MODE)
1287 				break;
1288 			error = 0;
1289 		}
1290 		SC_DEBUG(st->sc_periph, SCSIPI_DB1, ("[ioctl: get status]\n"));
1291 		memset(g, 0, sizeof(struct mtget));
1292 		g->mt_type = 0x7;	/* Ultrix compat *//*? */
1293 		g->mt_blksiz = st->blksize;
1294 		g->mt_density = st->density;
1295 		g->mt_mblksiz[0] = st->modes[0].blksize;
1296 		g->mt_mblksiz[1] = st->modes[1].blksize;
1297 		g->mt_mblksiz[2] = st->modes[2].blksize;
1298 		g->mt_mblksiz[3] = st->modes[3].blksize;
1299 		g->mt_mdensity[0] = st->modes[0].density;
1300 		g->mt_mdensity[1] = st->modes[1].density;
1301 		g->mt_mdensity[2] = st->modes[2].density;
1302 		g->mt_mdensity[3] = st->modes[3].density;
1303 		if (st->flags & ST_READONLY)
1304 			g->mt_dsreg |= MT_DS_RDONLY;
1305 		if (st->flags & ST_MOUNTED)
1306 			g->mt_dsreg |= MT_DS_MOUNTED;
1307 		g->mt_resid = st->mt_resid;
1308 		g->mt_erreg = st->mt_erreg;
1309 		/*
1310 		 * clear latched errors.
1311 		 */
1312 		st->mt_resid = 0;
1313 		st->mt_erreg = 0;
1314 		st->asc = 0;
1315 		st->ascq = 0;
1316 		break;
1317 	}
1318 	case MTIOCTOP: {
1319 
1320 		SC_DEBUG(st->sc_periph, SCSIPI_DB1,
1321 		    ("[ioctl: op=0x%x count=0x%x]\n", mt->mt_op,
1322 			mt->mt_count));
1323 
1324 		/* compat: in U*x it is a short */
1325 		number = mt->mt_count;
1326 		switch ((short) (mt->mt_op)) {
1327 		case MTWEOF:	/* write an end-of-file record */
1328 			error = st_write_filemarks(st, number, flags);
1329 			break;
1330 		case MTBSF:	/* backward space file */
1331 			number = -number;
1332 		case MTFSF:	/* forward space file */
1333 			error = st_check_eod(st, FALSE, &nmarks, flags);
1334 			if (!error)
1335 				error = st_space(st, number - nmarks,
1336 				    SP_FILEMARKS, flags);
1337 			break;
1338 		case MTBSR:	/* backward space record */
1339 			number = -number;
1340 		case MTFSR:	/* forward space record */
1341 			error = st_check_eod(st, TRUE, &nmarks, flags);
1342 			if (!error)
1343 				error = st_space(st, number, SP_BLKS, flags);
1344 			break;
1345 		case MTREW:	/* rewind */
1346 			error = st_rewind(st, 0, flags);
1347 			break;
1348 		case MTOFFL:	/* rewind and put the drive offline */
1349 			st_unmount(st, EJECT);
1350 			break;
1351 		case MTNOP:	/* no operation, sets status only */
1352 			break;
1353 		case MTRETEN:	/* retension the tape */
1354 			error = st_load(st, LD_RETENSION, flags);
1355 			if (!error)
1356 				error = st_load(st, LD_LOAD, flags);
1357 			break;
1358 		case MTEOM:	/* forward space to end of media */
1359 			error = st_check_eod(st, FALSE, &nmarks, flags);
1360 			if (!error)
1361 				error = st_space(st, 1, SP_EOM, flags);
1362 			break;
1363 		case MTCACHE:	/* enable controller cache */
1364 			st->flags &= ~ST_DONTBUFFER;
1365 			goto try_new_value;
1366 		case MTNOCACHE:	/* disable controller cache */
1367 			st->flags |= ST_DONTBUFFER;
1368 			goto try_new_value;
1369 		case MTERASE:	/* erase volume */
1370 			error = st_erase(st, number, flags);
1371 			break;
1372 		case MTSETBSIZ:	/* Set block size for device */
1373 #ifdef	NOTYET
1374 			if (!(st->flags & ST_NEW_MOUNT)) {
1375 				uprintf("re-mount tape before changing blocksize");
1376 				error = EINVAL;
1377 				break;
1378 			}
1379 #endif
1380 			if (number == 0)
1381 				st->flags &= ~ST_FIXEDBLOCKS;
1382 			else {
1383 				if ((st->blkmin || st->blkmax) &&
1384 				    (number < st->blkmin ||
1385 				    number > st->blkmax)) {
1386 					error = EINVAL;
1387 					break;
1388 				}
1389 				st->flags |= ST_FIXEDBLOCKS;
1390 			}
1391 			st->blksize = number;
1392 			st->flags |= ST_BLOCK_SET;	/*XXX */
1393 			goto try_new_value;
1394 
1395 		case MTSETDNSTY:	/* Set density for device and mode */
1396 			/*
1397 			 * Any number >= 0 and <= 0xff is legal. Numbers
1398 			 * above 0x80 are 'vendor unique'.
1399 			 */
1400 			if (number < 0 || number > 255) {
1401 				error = EINVAL;
1402 				break;
1403 			} else
1404 				st->density = number;
1405 			goto try_new_value;
1406 
1407 		case MTCMPRESS:
1408 			error = st->ops(st, (number == 0) ?
1409 			    ST_OPS_CMPRSS_OFF : ST_OPS_CMPRSS_ON,
1410 			    XS_CTL_SILENT);
1411 			break;
1412 
1413 		case MTEWARN:
1414 			if (number)
1415 				st->flags |= ST_EARLYWARN;
1416 			else
1417 				st->flags &= ~ST_EARLYWARN;
1418 			break;
1419 
1420 		default:
1421 			error = EINVAL;
1422 		}
1423 		break;
1424 	}
1425 	case MTIOCIEOT:
1426 	case MTIOCEEOT:
1427 		break;
1428 
1429 	case MTIOCRDSPOS:
1430 		error = st_rdpos(st, 0, (u_int32_t *) arg);
1431 		break;
1432 
1433 	case MTIOCRDHPOS:
1434 		error = st_rdpos(st, 1, (u_int32_t *) arg);
1435 		break;
1436 
1437 	case MTIOCSLOCATE:
1438 		error = st_setpos(st, 0, (u_int32_t *) arg);
1439 		break;
1440 
1441 	case MTIOCHLOCATE:
1442 		error = st_setpos(st, 1, (u_int32_t *) arg);
1443 		break;
1444 
1445 
1446 	default:
1447 		error = scsipi_do_ioctl(st->sc_periph, dev, cmd, arg,
1448 					flag, p);
1449 		break;
1450 	}
1451 	return (error);
1452 /*-----------------------------*/
1453 try_new_value:
1454 	/*
1455 	 * Check that the mode being asked for is aggreeable to the
1456 	 * drive. If not, put it back the way it was.
1457 	 *
1458 	 * If in control mode, we can make (persistent) mode changes
1459 	 * even if no medium is loaded (see st(4)).
1460 	 */
1461 	if ((STMODE(dev) != CTRL_MODE || (st->flags & ST_MOUNTED) != 0) &&
1462 	    (error = st->ops(st, ST_OPS_MODESELECT, 0)) != 0) {
1463 		/* put it back as it was */
1464 		printf("%s: cannot set selected mode\n", st->sc_dev.dv_xname);
1465 		st->density = hold_density;
1466 		st->blksize = hold_blksize;
1467 		if (st->blksize)
1468 			st->flags |= ST_FIXEDBLOCKS;
1469 		else
1470 			st->flags &= ~ST_FIXEDBLOCKS;
1471 		return (error);
1472 	}
1473 	/*
1474 	 * As the drive liked it, if we are setting a new default,
1475 	 * set it into the structures as such.
1476 	 *
1477 	 * The means for deciding this are not finalised yet- but
1478 	 * if the device was opened in Control Mode, the values
1479 	 * are persistent now across mounts.
1480 	 */
1481 	if (STMODE(dev) == CTRL_MODE) {
1482 		switch ((short) (mt->mt_op)) {
1483 		case MTSETBSIZ:
1484 			st->modes[dsty].blksize = st->blksize;
1485 			st->modeflags[dsty] |= BLKSIZE_SET_BY_USER;
1486 			break;
1487 		case MTSETDNSTY:
1488 			st->modes[dsty].density = st->density;
1489 			st->modeflags[dsty] |= DENSITY_SET_BY_USER;
1490 			break;
1491 		}
1492 	}
1493 	return (0);
1494 }
1495 
1496 /*
1497  * Do a synchronous read.
1498  */
1499 int
1500 st_read(st, buf, size, flags)
1501 	struct st_softc *st;
1502 	int size;
1503 	int flags;
1504 	char *buf;
1505 {
1506 	struct scsi_rw_tape cmd;
1507 
1508 	/*
1509 	 * If it's a null transfer, return immediatly
1510 	 */
1511 	if (size == 0)
1512 		return (0);
1513 	memset(&cmd, 0, sizeof(cmd));
1514 	cmd.opcode = READ;
1515 	if (st->flags & ST_FIXEDBLOCKS) {
1516 		cmd.byte2 |= SRW_FIXED;
1517 		_lto3b(size / (st->blksize ? st->blksize : DEF_FIXED_BSIZE),
1518 		    cmd.len);
1519 	} else
1520 		_lto3b(size, cmd.len);
1521 	return (scsipi_command(st->sc_periph,
1522 	    (struct scsipi_generic *)&cmd, sizeof(cmd),
1523 	    (u_char *)buf, size, 0, ST_IO_TIME, NULL, flags | XS_CTL_DATA_IN));
1524 }
1525 
1526 /*
1527  * issue an erase command
1528  */
1529 int
1530 st_erase(st, full, flags)
1531 	struct st_softc *st;
1532 	int full, flags;
1533 {
1534 	int tmo;
1535 	struct scsi_erase cmd;
1536 
1537 	/*
1538 	 * Full erase means set LONG bit in erase command, which asks
1539 	 * the drive to erase the entire unit.  Without this bit, we're
1540 	 * asking the drive to write an erase gap.
1541 	 */
1542 	memset(&cmd, 0, sizeof(cmd));
1543 	cmd.opcode = ERASE;
1544 	if (full) {
1545 		cmd.byte2 = SE_LONG;
1546 		tmo = ST_SPC_TIME;
1547 	} else {
1548 		tmo = ST_IO_TIME;
1549 	}
1550 
1551 	/*
1552 	 * XXX We always do this asynchronously, for now, unless the device
1553 	 * has the ST_Q_ERASE_NOIMM quirk.  How long should we wait if we
1554 	 * want to (eventually) to it synchronously?
1555 	 */
1556 	if ((st->quirks & ST_Q_ERASE_NOIMM) == 0)
1557 		cmd.byte2 |= SE_IMMED;
1558 
1559 	return (scsipi_command(st->sc_periph,
1560 	    (struct scsipi_generic *)&cmd, sizeof(cmd),
1561 	    0, 0, ST_RETRIES, tmo, NULL, flags));
1562 }
1563 
1564 /*
1565  * skip N blocks/filemarks/seq filemarks/eom
1566  */
1567 int
1568 st_space(st, number, what, flags)
1569 	struct st_softc *st;
1570 	u_int what;
1571 	int flags;
1572 	int number;
1573 {
1574 	struct scsi_space cmd;
1575 	int error;
1576 
1577 	switch (what) {
1578 	case SP_BLKS:
1579 		if (st->flags & ST_PER_ACTION) {
1580 			if (number > 0) {
1581 				st->flags &= ~ST_PER_ACTION;
1582 				return (EIO);
1583 			} else if (number < 0) {
1584 				if (st->flags & ST_AT_FILEMARK) {
1585 					/*
1586 					 * Handling of ST_AT_FILEMARK
1587 					 * in st_space will fill in the
1588 					 * right file mark count.
1589 					 */
1590 					error = st_space(st, 0, SP_FILEMARKS,
1591 					    flags);
1592 					if (error)
1593 						return (error);
1594 				}
1595 				if (st->flags & ST_BLANK_READ) {
1596 					st->flags &= ~ST_BLANK_READ;
1597 					return (EIO);
1598 				}
1599 				st->flags &= ~(ST_EIO_PENDING|ST_EOM_PENDING);
1600 			}
1601 		}
1602 		break;
1603 	case SP_FILEMARKS:
1604 		if (st->flags & ST_EIO_PENDING) {
1605 			if (number > 0) {
1606 				/* pretend we just discovered the error */
1607 				st->flags &= ~ST_EIO_PENDING;
1608 				return (EIO);
1609 			} else if (number < 0) {
1610 				/* back away from the error */
1611 				st->flags &= ~ST_EIO_PENDING;
1612 			}
1613 		}
1614 		if (st->flags & ST_AT_FILEMARK) {
1615 			st->flags &= ~ST_AT_FILEMARK;
1616 			number--;
1617 		}
1618 		if ((st->flags & ST_BLANK_READ) && (number < 0)) {
1619 			/* back away from unwritten tape */
1620 			st->flags &= ~ST_BLANK_READ;
1621 			number++;	/* XXX dubious */
1622 		}
1623 		break;
1624 	case SP_EOM:
1625 		if (st->flags & ST_EOM_PENDING) {
1626 			/* we're already there */
1627 			st->flags &= ~ST_EOM_PENDING;
1628 			return (0);
1629 		}
1630 		if (st->flags & ST_EIO_PENDING) {
1631 			/* pretend we just discovered the error */
1632 			st->flags &= ~ST_EIO_PENDING;
1633 			return (EIO);
1634 		}
1635 		if (st->flags & ST_AT_FILEMARK)
1636 			st->flags &= ~ST_AT_FILEMARK;
1637 		break;
1638 	}
1639 	if (number == 0)
1640 		return (0);
1641 
1642 	memset(&cmd, 0, sizeof(cmd));
1643 	cmd.opcode = SPACE;
1644 	cmd.byte2 = what;
1645 	_lto3b(number, cmd.number);
1646 
1647 	return (scsipi_command(st->sc_periph,
1648 	    (struct scsipi_generic *)&cmd, sizeof(cmd),
1649 	    0, 0, 0, ST_SPC_TIME, NULL, flags));
1650 }
1651 
1652 /*
1653  * write N filemarks
1654  */
1655 int
1656 st_write_filemarks(st, number, flags)
1657 	struct st_softc *st;
1658 	int flags;
1659 	int number;
1660 {
1661 	struct scsi_write_filemarks cmd;
1662 
1663 	/*
1664 	 * It's hard to write a negative number of file marks.
1665 	 * Don't try.
1666 	 */
1667 	if (number < 0)
1668 		return (EINVAL);
1669 	switch (number) {
1670 	case 0:		/* really a command to sync the drive's buffers */
1671 		break;
1672 	case 1:
1673 		if (st->flags & ST_FM_WRITTEN)	/* already have one down */
1674 			st->flags &= ~ST_WRITTEN;
1675 		else
1676 			st->flags |= ST_FM_WRITTEN;
1677 		st->flags &= ~ST_PER_ACTION;
1678 		break;
1679 	default:
1680 		st->flags &= ~(ST_PER_ACTION | ST_WRITTEN);
1681 	}
1682 
1683 	memset(&cmd, 0, sizeof(cmd));
1684 	cmd.opcode = WRITE_FILEMARKS;
1685 	_lto3b(number, cmd.number);
1686 
1687 	return (scsipi_command(st->sc_periph,
1688 	    (struct scsipi_generic *)&cmd, sizeof(cmd),
1689 	    0, 0, 0, ST_IO_TIME * 4, NULL, flags));
1690 }
1691 
1692 /*
1693  * Make sure the right number of file marks is on tape if the
1694  * tape has been written.  If the position argument is true,
1695  * leave the tape positioned where it was originally.
1696  *
1697  * nmarks returns the number of marks to skip (or, if position
1698  * true, which were skipped) to get back original position.
1699  */
1700 int
1701 st_check_eod(st, position, nmarks, flags)
1702 	struct st_softc *st;
1703 	boolean position;
1704 	int *nmarks;
1705 	int flags;
1706 {
1707 	int error;
1708 
1709 	switch (st->flags & (ST_WRITTEN | ST_FM_WRITTEN | ST_2FM_AT_EOD)) {
1710 	default:
1711 		*nmarks = 0;
1712 		return (0);
1713 	case ST_WRITTEN:
1714 	case ST_WRITTEN | ST_FM_WRITTEN | ST_2FM_AT_EOD:
1715 		*nmarks = 1;
1716 		break;
1717 	case ST_WRITTEN | ST_2FM_AT_EOD:
1718 		*nmarks = 2;
1719 	}
1720 	error = st_write_filemarks(st, *nmarks, flags);
1721 	if (position && !error)
1722 		error = st_space(st, -*nmarks, SP_FILEMARKS, flags);
1723 	return (error);
1724 }
1725 
1726 /*
1727  * load/unload/retension
1728  */
1729 int
1730 st_load(st, type, flags)
1731 	struct st_softc *st;
1732 	u_int type;
1733 	int flags;
1734 {
1735 	int error;
1736 	struct scsi_load cmd;
1737 
1738 	if (type != LD_LOAD) {
1739 		int nmarks;
1740 
1741 		error = st_check_eod(st, FALSE, &nmarks, flags);
1742 		if (error) {
1743 			printf("%s: failed to write closing filemarks at "
1744 			    "unload, errno=%d\n", st->sc_dev.dv_xname, error);
1745 			return (error);
1746 		}
1747 	}
1748 	if (st->quirks & ST_Q_IGNORE_LOADS) {
1749 		if (type == LD_LOAD) {
1750 			/*
1751 			 * If we ignore loads, at least we should try a rewind.
1752 			 */
1753 			return st_rewind(st, 0, flags);
1754 		}
1755 		/* otherwise, we should do what's asked of us */
1756 	}
1757 
1758 	memset(&cmd, 0, sizeof(cmd));
1759 	cmd.opcode = LOAD;
1760 	cmd.how = type;
1761 
1762 	error = scsipi_command(st->sc_periph,
1763 	    (struct scsipi_generic *)&cmd, sizeof(cmd),
1764 	    0, 0, ST_RETRIES, ST_SPC_TIME, NULL, flags);
1765 	if (error) {
1766 		printf("%s: error %d in st_load (op %d)\n",
1767 		    st->sc_dev.dv_xname, error, type);
1768 	}
1769 	return (error);
1770 }
1771 
1772 /*
1773  *  Rewind the device
1774  */
1775 int
1776 st_rewind(st, immediate, flags)
1777 	struct st_softc *st;
1778 	u_int immediate;
1779 	int flags;
1780 {
1781 	struct scsi_rewind cmd;
1782 	int error;
1783 	int nmarks;
1784 
1785 	error = st_check_eod(st, FALSE, &nmarks, flags);
1786 	if (error) {
1787 		printf("%s: failed to write closing filemarks at "
1788 		    "rewind, errno=%d\n", st->sc_dev.dv_xname, error);
1789 		return (error);
1790 	}
1791 	st->flags &= ~ST_PER_ACTION;
1792 
1793 	/*
1794 	 * ATAPI tapes always need foo to be set
1795 	 */
1796 	if (scsipi_periph_bustype(st->sc_periph) == SCSIPI_BUSTYPE_ATAPI)
1797 		immediate = SR_IMMED;
1798 
1799 	memset(&cmd, 0, sizeof(cmd));
1800 	cmd.opcode = REWIND;
1801 	cmd.byte2 = immediate;
1802 
1803 	error = scsipi_command(st->sc_periph,
1804 	    (struct scsipi_generic *)&cmd, sizeof(cmd), 0, 0, ST_RETRIES,
1805 	    immediate ? ST_CTL_TIME: ST_SPC_TIME, NULL, flags);
1806 	if (error) {
1807 		printf("%s: error %d trying to rewind\n",
1808 		    st->sc_dev.dv_xname, error);
1809 	}
1810 	return (error);
1811 }
1812 
1813 int
1814 st_rdpos(st, hard, blkptr)
1815 	struct st_softc *st;
1816 	int hard;
1817 	u_int32_t *blkptr;
1818 {
1819 	int error;
1820 	u_int8_t posdata[20];
1821 	struct scsi_tape_read_position cmd;
1822 
1823 	/*
1824 	 * First flush any pending writes...
1825 	 */
1826 	error = st_write_filemarks(st, 0, XS_CTL_SILENT);
1827 
1828 	/*
1829 	 * The latter case is for 'write protected' tapes
1830 	 * which are too stupid to recognize a zero count
1831 	 * for writing filemarks as a no-op.
1832 	 */
1833 	if (error != 0 && error != EACCES && error != EROFS)
1834 		return (error);
1835 
1836 	memset(&cmd, 0, sizeof(cmd));
1837 	memset(&posdata, 0, sizeof(posdata));
1838 	cmd.opcode = READ_POSITION;
1839 	if (hard)
1840 		cmd.byte1 = 1;
1841 
1842 	error = scsipi_command(st->sc_periph,
1843 	    (struct scsipi_generic *)&cmd, sizeof(cmd), (u_char *)&posdata,
1844 	    sizeof(posdata), ST_RETRIES, ST_CTL_TIME, NULL,
1845 	    XS_CTL_SILENT | XS_CTL_DATA_IN | XS_CTL_DATA_ONSTACK);
1846 
1847 	if (error == 0) {
1848 #if	0
1849 		printf("posdata:");
1850 		for (hard = 0; hard < sizeof(posdata); hard++)
1851 			printf("%02x ", posdata[hard] & 0xff);
1852 		printf("\n");
1853 #endif
1854 		if (posdata[0] & 0x4)	/* Block Position Unknown */
1855 			error = EINVAL;
1856 		else
1857 			*blkptr = _4btol(&posdata[4]);
1858 	}
1859 	return (error);
1860 }
1861 
1862 int
1863 st_setpos(st, hard, blkptr)
1864 	struct st_softc *st;
1865 	int hard;
1866 	u_int32_t *blkptr;
1867 {
1868 	int error;
1869 	struct scsi_tape_locate cmd;
1870 
1871 	/*
1872 	 * First flush any pending writes. Strictly speaking,
1873 	 * we're not supposed to have to worry about this,
1874 	 * but let's be untrusting.
1875 	 */
1876 	error = st_write_filemarks(st, 0, XS_CTL_SILENT);
1877 
1878 	/*
1879 	 * The latter case is for 'write protected' tapes
1880 	 * which are too stupid to recognize a zero count
1881 	 * for writing filemarks as a no-op.
1882 	 */
1883 	if (error != 0 && error != EACCES && error != EROFS)
1884 		return (error);
1885 
1886 	memset(&cmd, 0, sizeof(cmd));
1887 	cmd.opcode = LOCATE;
1888 	if (hard)
1889 		cmd.byte2 = 1 << 2;
1890 	_lto4b(*blkptr, cmd.blkaddr);
1891 	error = scsipi_command(st->sc_periph,
1892 		(struct scsipi_generic *)&cmd, sizeof(cmd),
1893 		NULL, 0, ST_RETRIES, ST_SPC_TIME, NULL, 0);
1894 	/*
1895 	 * XXX: Note file && block number position now unknown (if
1896 	 * XXX: these things ever start being maintained in this driver)
1897 	 */
1898 	return (error);
1899 }
1900 
1901 
1902 /*
1903  * Look at the returned sense and act on the error and determine
1904  * the unix error number to pass back..., 0 (== report no error),
1905  * -1 = retry the operation, -2 continue error processing.
1906  */
1907 int
1908 st_interpret_sense(xs)
1909 	struct scsipi_xfer *xs;
1910 {
1911 	struct scsipi_periph *periph = xs->xs_periph;
1912 	struct scsipi_sense_data *sense = &xs->sense.scsi_sense;
1913 	struct buf *bp = xs->bp;
1914 	struct st_softc *st = (void *)periph->periph_dev;
1915 	int retval = EJUSTRETURN;
1916 	int doprint = ((xs->xs_control & XS_CTL_SILENT) == 0);
1917 	u_int8_t key;
1918 	int32_t info;
1919 
1920 	/*
1921 	 * If it isn't a extended or extended/deferred error, let
1922 	 * the generic code handle it.
1923 	 */
1924 	if ((sense->error_code & SSD_ERRCODE) != 0x70 &&
1925 	    (sense->error_code & SSD_ERRCODE) != 0x71) {	/* DEFFERRED */
1926 		return (retval);
1927 	}
1928 
1929 	if (sense->error_code & SSD_ERRCODE_VALID)
1930 		info = _4btol(sense->info);
1931 	else
1932 		info = xs->datalen;	/* bad choice if fixed blocks */
1933 	key = sense->flags & SSD_KEY;
1934 	st->mt_erreg = key;
1935 	st->asc = sense->add_sense_code;
1936 	st->ascq = sense->add_sense_code_qual;
1937 	st->mt_resid = (short) info;
1938 
1939 	/*
1940 	 * If the device is not open yet, let generic handle
1941 	 */
1942 	if ((periph->periph_flags & PERIPH_OPEN) == 0) {
1943 		return (retval);
1944 	}
1945 
1946 
1947 	if (st->flags & ST_FIXEDBLOCKS) {
1948 		xs->resid = info * st->blksize;
1949 		if (sense->flags & SSD_EOM) {
1950 			if ((st->flags & ST_EARLYWARN) == 0)
1951 				st->flags |= ST_EIO_PENDING;
1952 			st->flags |= ST_EOM_PENDING;
1953 			if (bp)
1954 				bp->b_resid = xs->resid;
1955 		}
1956 		if (sense->flags & SSD_FILEMARK) {
1957 			st->flags |= ST_AT_FILEMARK;
1958 			if (bp)
1959 				bp->b_resid = xs->resid;
1960 		}
1961 		if (sense->flags & SSD_ILI) {
1962 			st->flags |= ST_EIO_PENDING;
1963 			if (bp)
1964 				bp->b_resid = xs->resid;
1965 			if (sense->error_code & SSD_ERRCODE_VALID &&
1966 			    (xs->xs_control & XS_CTL_SILENT) == 0)
1967 				printf("%s: block wrong size, %d blocks "
1968 				    "residual\n", st->sc_dev.dv_xname, info);
1969 
1970 			/*
1971 			 * This quirk code helps the drive read
1972 			 * the first tape block, regardless of
1973 			 * format.  That is required for these
1974 			 * drives to return proper MODE SENSE
1975 			 * information.
1976 			 */
1977 			if ((st->quirks & ST_Q_SENSE_HELP) &&
1978 			    (periph->periph_flags & PERIPH_MEDIA_LOADED) == 0)
1979 				st->blksize -= 512;
1980 		}
1981 		/*
1982 		 * If data wanted and no data was transferred, do it immediately
1983 		 */
1984 		if (xs->datalen && xs->resid >= xs->datalen) {
1985 			if (st->flags & ST_EIO_PENDING)
1986 				return (EIO);
1987 			if (st->flags & ST_AT_FILEMARK) {
1988 				if (bp)
1989 					bp->b_resid = xs->resid;
1990 				return (0);
1991 			}
1992 		}
1993 	} else {		/* must be variable mode */
1994 		if (sense->flags & SSD_EOM) {
1995 			/*
1996 			 * The current semantics of this
1997 			 * driver requires EOM detection
1998 			 * to return EIO unless early
1999 			 * warning detection is enabled
2000 			 * for variable mode (this is always
2001 			 * on for fixed block mode).
2002 			 */
2003 			if (st->flags & ST_EARLYWARN) {
2004 				st->flags |= ST_EOM_PENDING;
2005 				retval = 0;
2006 			} else {
2007 				retval = EIO;
2008 			}
2009 
2010 			/*
2011 			 * If it's an unadorned EOM detection,
2012 			 * suppress printing an error.
2013 			 */
2014 			if (key == SKEY_NO_SENSE) {
2015 				doprint = 0;
2016 			}
2017 		} else if (sense->flags & SSD_FILEMARK) {
2018 			retval = 0;
2019 		} else if (sense->flags & SSD_ILI) {
2020 			if (info < 0) {
2021 				/*
2022 				 * The tape record was bigger than the read
2023 				 * we issued.
2024 				 */
2025 				if ((xs->xs_control & XS_CTL_SILENT) == 0) {
2026 					printf("%s: %d-byte tape record too big"
2027 					    " for %d-byte user buffer\n",
2028 					    st->sc_dev.dv_xname,
2029 					    xs->datalen - info, xs->datalen);
2030 				}
2031 				retval = EIO;
2032 			} else {
2033 				retval = 0;
2034 			}
2035 		}
2036 		xs->resid = info;
2037 		if (bp)
2038 			bp->b_resid = info;
2039 	}
2040 
2041 #ifndef SCSIPI_DEBUG
2042 	if (retval == 0 && key == SKEY_NO_SENSE)
2043 		doprint = 0;
2044 #endif
2045 	if (key == SKEY_BLANK_CHECK) {
2046 		/*
2047 		 * This quirk code helps the drive read the
2048 		 * first tape block, regardless of format.  That
2049 		 * is required for these drives to return proper
2050 		 * MODE SENSE information.
2051 		 */
2052 		if ((st->quirks & ST_Q_SENSE_HELP) &&
2053 		    (periph->periph_flags & PERIPH_MEDIA_LOADED) == 0) {
2054 			/* still starting */
2055 			st->blksize -= 512;
2056 		} else if (!(st->flags & (ST_2FM_AT_EOD | ST_BLANK_READ))) {
2057 			st->flags |= ST_BLANK_READ;
2058 			xs->resid = xs->datalen;
2059 			if (bp) {
2060 				bp->b_resid = xs->resid;
2061 				/* return an EOF */
2062 			}
2063 			retval = 0;
2064 		}
2065 	}
2066 
2067 	/*
2068 	 * If generic sense processing will continue, we should not
2069 	 * print sense info here.
2070 	 */
2071 	if (retval == EJUSTRETURN)
2072 		doprint = 0;
2073 
2074 	if (doprint) {
2075 #ifdef	SCSIVERBOSE
2076 		scsipi_print_sense(xs, 0);
2077 #else
2078 		scsipi_printaddr(periph);
2079 		printf("Sense Key 0x%02x", key);
2080 		if ((sense->error_code & SSD_ERRCODE_VALID) != 0) {
2081 			switch (key) {
2082 			case SKEY_NOT_READY:
2083 			case SKEY_ILLEGAL_REQUEST:
2084 			case SKEY_UNIT_ATTENTION:
2085 			case SKEY_WRITE_PROTECT:
2086 				break;
2087 			case SKEY_BLANK_CHECK:
2088 				printf(", requested size: %d (decimal)", info);
2089 				break;
2090 			case SKEY_ABORTED_COMMAND:
2091 				if (xs->xs_retries)
2092 					printf(", retrying");
2093 				printf(", cmd 0x%x, info 0x%x",
2094 				    xs->cmd->opcode, info);
2095 				break;
2096 			default:
2097 				printf(", info = %d (decimal)", info);
2098 			}
2099 		}
2100 		if (sense->extra_len != 0) {
2101 			int n;
2102 			printf(", data =");
2103 			for (n = 0; n < sense->extra_len; n++)
2104 				printf(" %02x", sense->cmd_spec_info[n]);
2105 		}
2106 		printf("\n");
2107 #endif
2108 	}
2109 	return (retval);
2110 }
2111 
2112 /*
2113  * The quirk here is that the drive returns some value to st_mode_sense
2114  * incorrectly until the tape has actually passed by the head.
2115  *
2116  * The method is to set the drive to large fixed-block state (user-specified
2117  * density and 1024-byte blocks), then read and rewind to get it to sense the
2118  * tape.  If that doesn't work, try 512-byte fixed blocks.  If that doesn't
2119  * work, as a last resort, try variable- length blocks.  The result will be
2120  * the ability to do an accurate st_mode_sense.
2121  *
2122  * We know we can do a rewind because we just did a load, which implies rewind.
2123  * Rewind seems preferable to space backward if we have a virgin tape.
2124  *
2125  * The rest of the code for this quirk is in ILI processing and BLANK CHECK
2126  * error processing, both part of st_interpret_sense.
2127  */
2128 int
2129 st_touch_tape(st)
2130 	struct st_softc *st;
2131 {
2132 	char *buf;
2133 	int readsize;
2134 	int error;
2135 
2136 	buf = malloc(1024, M_TEMP, M_NOWAIT);
2137 	if (buf == NULL)
2138 		return (ENOMEM);
2139 
2140 	if ((error = st->ops(st, ST_OPS_MODESENSE, 0)) != 0)
2141 		goto bad;
2142 
2143 	/*
2144 	 * If the block size is already known from the
2145 	 * sense data, use it. Else start probing at 1024.
2146 	 */
2147 	if (st->media_blksize > 0)
2148 		st->blksize = st->media_blksize;
2149 	else
2150 		st->blksize = 1024;
2151 
2152 	do {
2153 		switch (st->blksize) {
2154 		case 512:
2155 		case 1024:
2156 			readsize = st->blksize;
2157 			st->flags |= ST_FIXEDBLOCKS;
2158 			break;
2159 		default:
2160 			readsize = 1;
2161 			st->flags &= ~ST_FIXEDBLOCKS;
2162 		}
2163 		if ((error = st->ops(st, ST_OPS_MODESELECT, XS_CTL_SILENT))
2164 		    != 0) {
2165 			/*
2166 			 * The device did not agree with the proposed
2167 			 * block size. If we exhausted our options,
2168 			 * return failure, else try another.
2169 			 */
2170 			if (readsize == 1)
2171 				goto bad;
2172 			st->blksize -= 512;
2173 			continue;
2174 		}
2175 		st_read(st, buf, readsize, XS_CTL_SILENT);	/* XXX */
2176 		if ((error = st_rewind(st, 0, 0)) != 0) {
2177 bad:			free(buf, M_TEMP);
2178 			return (error);
2179 		}
2180 	} while (readsize != 1 && readsize > st->blksize);
2181 
2182 	free(buf, M_TEMP);
2183 	return (0);
2184 }
2185 
2186 int
2187 stdump(dev, blkno, va, size)
2188 	dev_t dev;
2189 	daddr_t blkno;
2190 	caddr_t va;
2191 	size_t size;
2192 {
2193 
2194 	/* Not implemented. */
2195 	return (ENXIO);
2196 }
2197