xref: /netbsd-src/sys/dev/scsipi/st.c (revision e4d7c2e329d54c97e0c0bd3016bbe74f550c3d5e)
1 /*	$NetBSD: st.c,v 1.120 2000/02/21 05:11:09 mjacob 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 "opt_scsi.h"
60 #include "rnd.h"
61 
62 #include <sys/types.h>
63 #include <sys/param.h>
64 #include <sys/systm.h>
65 #include <sys/fcntl.h>
66 #include <sys/errno.h>
67 #include <sys/ioctl.h>
68 #include <sys/malloc.h>
69 #include <sys/buf.h>
70 #include <sys/proc.h>
71 #include <sys/user.h>
72 #include <sys/mtio.h>
73 #include <sys/device.h>
74 #include <sys/conf.h>
75 #include <sys/kernel.h>
76 #if NRND > 0
77 #include <sys/rnd.h>
78 #endif
79 
80 #include <dev/scsipi/scsipi_all.h>
81 #include <dev/scsipi/scsi_all.h>
82 #include <dev/scsipi/scsi_tape.h>
83 #include <dev/scsipi/scsiconf.h>
84 
85 /* Defines for device specific stuff */
86 #define DEF_FIXED_BSIZE  512
87 #define	ST_RETRIES	4	/* only on non IO commands */
88 
89 #define STMODE(z)	( minor(z)       & 0x03)
90 #define STDSTY(z)	((minor(z) >> 2) & 0x03)
91 #define STUNIT(z)	((minor(z) >> 4)       )
92 
93 #define NORMAL_MODE	0
94 #define NOREW_MODE	1
95 #define EJECT_MODE	2
96 #define CTRL_MODE	3
97 
98 #define	FALSE		0
99 #define	TRUE		1
100 
101 #define	ST_IO_TIME	(3 * 60 * 1000)		/* 3 minutes */
102 #define	ST_CTL_TIME	(30 * 1000)		/* 30 seconds */
103 #define	ST_SPC_TIME	(4 * 60 * 60 * 1000)	/* 4 hours */
104 
105 #ifndef	ST_MOUNT_DELAY
106 #define	ST_MOUNT_DELAY		0
107 #endif
108 
109 /*
110  * Define various devices that we know mis-behave in some way,
111  * and note how they are bad, so we can correct for them
112  */
113 struct modes {
114 	u_int quirks;			/* same definitions as in quirkdata */
115 	int blksize;
116 	u_int8_t density;
117 };
118 
119 struct quirkdata {
120 	u_int quirks;
121 #define	ST_Q_FORCE_BLKSIZE	0x0001
122 #define	ST_Q_SENSE_HELP		0x0002	/* must do READ for good MODE SENSE */
123 #define	ST_Q_IGNORE_LOADS	0x0004
124 #define	ST_Q_BLKSIZE		0x0008	/* variable-block media_blksize > 0 */
125 #define	ST_Q_UNIMODAL		0x0010	/* unimode drive rejects mode select */
126 	u_int page_0_size;
127 #define	MAX_PAGE_0_SIZE	64
128 	struct modes modes[4];
129 };
130 
131 struct st_quirk_inquiry_pattern {
132 	struct scsipi_inquiry_pattern pattern;
133 	struct quirkdata quirkdata;
134 };
135 
136 struct st_quirk_inquiry_pattern st_quirk_patterns[] = {
137 	{{T_SEQUENTIAL, T_REMOV,
138 	 "        ", "                ", "    "}, {0, 0, {
139 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
140 		{ST_Q_FORCE_BLKSIZE, 512, QIC_24},	/* minor 4-7 */
141 		{ST_Q_FORCE_BLKSIZE, 0, HALFINCH_1600},	/* minor 8-11 */
142 		{ST_Q_FORCE_BLKSIZE, 0, HALFINCH_6250}	/* minor 12-15 */
143 	}}},
144 	{{T_SEQUENTIAL, T_REMOV,
145 	 "TANDBERG", " TDC 3600       ", ""},     {0, 12, {
146 		{0, 0, 0},				/* minor 0-3 */
147 		{ST_Q_FORCE_BLKSIZE, 0, QIC_525},	/* minor 4-7 */
148 		{0, 0, QIC_150},			/* minor 8-11 */
149 		{0, 0, QIC_120}				/* minor 12-15 */
150 	}}},
151  	{{T_SEQUENTIAL, T_REMOV,
152  	 "TANDBERG", " TDC 3800       ", ""},     {0, 0, {
153 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
154 		{0, 0, QIC_525},			/* minor 4-7 */
155 		{0, 0, QIC_150},			/* minor 8-11 */
156 		{0, 0, QIC_120}				/* minor 12-15 */
157 	}}},
158 	/*
159 	 * lacking a manual for the 4200, it's not clear what the
160 	 * specific density codes should be- the device is a 2.5GB
161 	 * capable QIC drive, those density codes aren't readily
162 	 * availabel. The 'default' will just have to do.
163 	 */
164  	{{T_SEQUENTIAL, T_REMOV,
165  	 "TANDBERG", " TDC 4200       ", ""},     {0, 0, {
166 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
167 		{0, 0, QIC_525},			/* minor 4-7 */
168 		{0, 0, QIC_150},			/* minor 8-11 */
169 		{0, 0, QIC_120}				/* minor 12-15 */
170 	}}},
171 	/*
172 	 * At least -005 and -007 need this.  I'll assume they all do unless I
173 	 * hear otherwise.  - mycroft, 31MAR1994
174 	 */
175 	{{T_SEQUENTIAL, T_REMOV,
176 	 "ARCHIVE ", "VIPER 2525 25462", ""},     {0, 0, {
177 		{ST_Q_SENSE_HELP, 0, 0},		/* minor 0-3 */
178 		{ST_Q_SENSE_HELP, 0, QIC_525},		/* minor 4-7 */
179 		{0, 0, QIC_150},			/* minor 8-11 */
180 		{0, 0, QIC_120}				/* minor 12-15 */
181 	}}},
182 	/*
183 	 * One user reports that this works for his tape drive.  It probably
184 	 * needs more work.  - mycroft, 09APR1994
185 	 */
186 	{{T_SEQUENTIAL, T_REMOV,
187 	 "SANKYO  ", "CP525           ", ""},    {0, 0, {
188 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
189 		{ST_Q_FORCE_BLKSIZE, 512, QIC_525},	/* minor 4-7 */
190 		{0, 0, QIC_150},			/* minor 8-11 */
191 		{0, 0, QIC_120}				/* minor 12-15 */
192 	}}},
193 	{{T_SEQUENTIAL, T_REMOV,
194 	 "ANRITSU ", "DMT780          ", ""},     {0, 0, {
195 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
196 		{ST_Q_FORCE_BLKSIZE, 512, QIC_525},	/* minor 4-7 */
197 		{0, 0, QIC_150},			/* minor 8-11 */
198 		{0, 0, QIC_120}				/* minor 12-15 */
199 	}}},
200 	{{T_SEQUENTIAL, T_REMOV,
201 	 "ARCHIVE ", "VIPER 150  21247", ""},     {0, 12, {
202 		{ST_Q_SENSE_HELP, 0, 0},		/* minor 0-3 */
203 		{0, 0, QIC_150},			/* minor 4-7 */
204 		{0, 0, QIC_120},			/* minor 8-11 */
205 		{0, 0, QIC_24}				/* minor 12-15 */
206 	}}},
207 	{{T_SEQUENTIAL, T_REMOV,
208 	 "ARCHIVE ", "VIPER 150  21531", ""},     {0, 12, {
209 		{ST_Q_SENSE_HELP, 0, 0},		/* minor 0-3 */
210 		{0, 0, QIC_150},			/* minor 4-7 */
211 		{0, 0, QIC_120},			/* minor 8-11 */
212 		{0, 0, QIC_24}				/* minor 12-15 */
213 	}}},
214 	{{T_SEQUENTIAL, T_REMOV,
215 	 "WANGTEK ", "5099ES SCSI", ""},          {0, 0, {
216 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
217 		{0, 0, QIC_11},				/* minor 4-7 */
218 		{0, 0, QIC_24},				/* minor 8-11 */
219 		{0, 0, QIC_24}				/* minor 12-15 */
220 	}}},
221 	{{T_SEQUENTIAL, T_REMOV,
222 	 "WANGTEK ", "5150ES SCSI", ""},          {0, 0, {
223 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
224 		{0, 0, QIC_24},				/* minor 4-7 */
225 		{0, 0, QIC_120},			/* minor 8-11 */
226 		{0, 0, QIC_150}				/* minor 12-15 */
227 	}}},
228 	{{T_SEQUENTIAL, T_REMOV,
229 	 "WANGTEK ", "5525ES SCSI REV7", ""},     {0, 0, {
230 		{0, 0, 0},				/* minor 0-3 */
231 		{ST_Q_BLKSIZE, 0, QIC_525},		/* minor 4-7 */
232 		{0, 0, QIC_150},			/* minor 8-11 */
233 		{0, 0, QIC_120}				/* minor 12-15 */
234 	}}},
235 	{{T_SEQUENTIAL, T_REMOV,
236 	 "WangDAT ", "Model 1300      ", ""},     {0, 0, {
237 		{0, 0, 0},				/* minor 0-3 */
238 		{ST_Q_FORCE_BLKSIZE, 512, DDS},		/* minor 4-7 */
239 		{ST_Q_FORCE_BLKSIZE, 1024, DDS},	/* minor 8-11 */
240 		{ST_Q_FORCE_BLKSIZE, 0, DDS}		/* minor 12-15 */
241 	}}},
242 	{{T_SEQUENTIAL, T_REMOV,
243 	 "EXABYTE ", "EXB-8200        ", "263H"}, {0, 5, {
244 		{0, 0, 0},				/* minor 0-3 */
245 		{0, 0, 0},				/* minor 4-7 */
246 		{0, 0, 0},				/* minor 8-11 */
247 		{0, 0, 0}				/* minor 12-15 */
248 	}}},
249 	{{T_SEQUENTIAL, T_REMOV,
250 	 "STK",      "9490",             ""},
251 				{ST_Q_FORCE_BLKSIZE, 0, {
252 		{0, 0, 0},				/* minor 0-3 */
253 		{0, 0, 0},				/* minor 4-7 */
254 		{0, 0, 0},				/* minor 8-11 */
255 		{0, 0, 0}				/* minor 12-15 */
256 	}}},
257 	{{T_SEQUENTIAL, T_REMOV,
258 	 "STK",      "SD-3",             ""},
259 				{ST_Q_FORCE_BLKSIZE, 0, {
260 		{0, 0, 0},				/* minor 0-3 */
261 		{0, 0, 0},				/* minor 4-7 */
262 		{0, 0, 0},				/* minor 8-11 */
263 		{0, 0, 0}				/* minor 12-15 */
264 	}}},
265 	{{T_SEQUENTIAL, T_REMOV,
266 	 "IBM",      "03590",            ""},     {ST_Q_IGNORE_LOADS, 0, {
267 		{0, 0, 0},				/* minor 0-3 */
268 		{0, 0, 0},				/* minor 4-7 */
269 		{0, 0, 0},				/* minor 8-11 */
270 		{0, 0, 0}				/* minor 12-15 */
271 	}}},
272 	{{T_SEQUENTIAL, T_REMOV,
273 	 "HP      ", "T4000s          ", ""},     {ST_Q_UNIMODAL, 0, {
274 		{0, 0, QIC_3095},			/* minor 0-3 */
275 		{0, 0, QIC_3095},			/* minor 4-7 */
276 		{0, 0, QIC_3095},			/* minor 8-11 */
277 		{0, 0, QIC_3095},			/* minor 12-15 */
278 	}}},
279 #if 0
280 	{{T_SEQUENTIAL, T_REMOV,
281 	 "EXABYTE ", "EXB-8200        ", ""},     {0, 12, {
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 #endif
288 	{{T_SEQUENTIAL, T_REMOV,
289 	 "TEAC    ", "MT-2ST/N50      ", ""},     {ST_Q_IGNORE_LOADS, 0, {
290 		{0, 0, 0},				/* minor 0-3 */
291 		{0, 0, 0},				/* minor 4-7 */
292 		{0, 0, 0},				/* minor 8-11 */
293 		{0, 0, 0}				/* minor 12-15 */
294 	}}},
295 };
296 
297 #define NOEJECT 0
298 #define EJECT 1
299 
300 struct st_softc {
301 	struct device sc_dev;
302 /*--------------------present operating parameters, flags etc.---------------*/
303 	int flags;		/* see below                         */
304 	u_int quirks;		/* quirks for the open mode          */
305 	int blksize;		/* blksize we are using              */
306 	u_int8_t density;	/* present density                   */
307 	u_int page_0_size;	/* size of page 0 data		     */
308 	u_int last_dsty;	/* last density opened               */
309 	short mt_resid;		/* last (short) resid                */
310 	short mt_erreg;		/* last error (sense key) seen       */
311 #define	mt_key	mt_erreg
312 	u_int8_t asc;		/* last asc code seen                */
313 	u_int8_t ascq;		/* last asc code seen                */
314 /*--------------------device/scsi parameters---------------------------------*/
315 	struct scsipi_link *sc_link;	/* our link to the adpter etc.       */
316 /*--------------------parameters reported by the device ---------------------*/
317 	int blkmin;		/* min blk size                       */
318 	int blkmax;		/* max blk size                       */
319 	struct quirkdata *quirkdata;	/* if we have a rogue entry          */
320 /*--------------------parameters reported by the device for this media-------*/
321 	u_long numblks;		/* nominal blocks capacity            */
322 	int media_blksize;	/* 0 if not ST_FIXEDBLOCKS            */
323 	u_int8_t media_density;	/* this is what it said when asked    */
324 /*--------------------quirks for the whole drive-----------------------------*/
325 	u_int drive_quirks;	/* quirks of this drive               */
326 /*--------------------How we should set up when opening each minor device----*/
327 	struct modes modes[4];	/* plus more for each mode            */
328 	u_int8_t  modeflags[4];	/* flags for the modes                */
329 #define DENSITY_SET_BY_USER	0x01
330 #define DENSITY_SET_BY_QUIRK	0x02
331 #define BLKSIZE_SET_BY_USER	0x04
332 #define BLKSIZE_SET_BY_QUIRK	0x08
333 /*--------------------storage for sense data returned by the drive-----------*/
334 	u_char sense_data[MAX_PAGE_0_SIZE];	/*
335 						 * additional sense data needed
336 						 * for mode sense/select.
337 						 */
338 	struct buf_queue buf_queue;	/* the queue of pending IO */
339 					/* operations */
340 #if NRND > 0
341 	rndsource_element_t	rnd_source;
342 #endif
343 };
344 
345 
346 int	stmatch __P((struct device *, struct cfdata *, void *));
347 void	stattach __P((struct device *, struct device *, void *));
348 void	st_identify_drive __P((struct st_softc *,
349 	    struct scsipi_inquiry_pattern *));
350 void	st_loadquirks __P((struct st_softc *));
351 int	st_mount_tape __P((dev_t, int));
352 void	st_unmount __P((struct st_softc *, boolean));
353 int	st_decide_mode __P((struct st_softc *, boolean));
354 void	ststart __P((void *));
355 void	stdone __P((struct scsipi_xfer *));
356 int	st_read __P((struct st_softc *, char *, int, int));
357 int	st_read_block_limits __P((struct st_softc *, int));
358 int	st_mode_sense __P((struct st_softc *, int));
359 int	st_mode_select __P((struct st_softc *, int));
360 int	st_cmprss __P((struct st_softc *, int));
361 int	st_space __P((struct st_softc *, int, u_int, int));
362 int	st_write_filemarks __P((struct st_softc *, int, int));
363 int	st_check_eod __P((struct st_softc *, boolean, int *, int));
364 int	st_load __P((struct st_softc *, u_int, int));
365 int	st_rewind __P((struct st_softc *, u_int, int));
366 int	st_interpret_sense __P((struct scsipi_xfer *));
367 int	st_touch_tape __P((struct st_softc *));
368 int	st_erase __P((struct st_softc *, int full, int flags));
369 int	st_rdpos __P((struct st_softc *, int, u_int32_t *));
370 int	st_setpos __P((struct st_softc *, int, u_int32_t *));
371 
372 struct cfattach st_ca = {
373 	sizeof(struct st_softc), stmatch, stattach
374 };
375 
376 extern struct cfdriver st_cd;
377 
378 struct scsipi_device st_switch = {
379 	st_interpret_sense,
380 	ststart,
381 	NULL,
382 	stdone
383 };
384 
385 #define	ST_INFO_VALID	0x0001
386 #define	ST_BLOCK_SET	0x0002	/* block size, mode set by ioctl      */
387 #define	ST_WRITTEN	0x0004	/* data has been written, EOD needed */
388 #define	ST_FIXEDBLOCKS	0x0008
389 #define	ST_AT_FILEMARK	0x0010
390 #define	ST_EIO_PENDING	0x0020	/* error reporting deferred until next op */
391 #define	ST_NEW_MOUNT	0x0040	/* still need to decide mode             */
392 #define	ST_READONLY	0x0080	/* st_mode_sense says write protected */
393 #define	ST_FM_WRITTEN	0x0100	/*
394 				 * EOF file mark written  -- used with
395 				 * ~ST_WRITTEN to indicate that multiple file
396 				 * marks have been written
397 				 */
398 #define	ST_BLANK_READ	0x0200	/* BLANK CHECK encountered already */
399 #define	ST_2FM_AT_EOD	0x0400	/* write 2 file marks at EOD */
400 #define	ST_MOUNTED	0x0800	/* Device is presently mounted */
401 #define	ST_DONTBUFFER	0x1000	/* Disable buffering/caching */
402 #define	ST_EARLYWARN	0x2000	/* Do (deferred) EOM for variable mode */
403 #define	ST_EOM_PENDING	0x4000	/* EOM reporting deferred until next op */
404 
405 #define	ST_PER_ACTION	(ST_AT_FILEMARK | ST_EIO_PENDING | ST_EOM_PENDING | \
406 			 ST_BLANK_READ)
407 #define	ST_PER_MOUNT	(ST_INFO_VALID | ST_BLOCK_SET | ST_WRITTEN |	\
408 			 ST_FIXEDBLOCKS | ST_READONLY | ST_FM_WRITTEN |	\
409 			 ST_2FM_AT_EOD | ST_PER_ACTION)
410 
411 #if	defined(ST_ENABLE_EARLYWARN)
412 #define	ST_INIT_FLAGS	ST_EARLYWARN
413 #else
414 #define	ST_INIT_FLAGS	0
415 #endif
416 
417 struct scsipi_inquiry_pattern st_patterns[] = {
418 	{T_SEQUENTIAL, T_REMOV,
419 	 "",         "",                 ""},
420 };
421 
422 int
423 stmatch(parent, match, aux)
424 	struct device *parent;
425 	struct cfdata *match;
426 	void *aux;
427 {
428 	struct scsipibus_attach_args *sa = aux;
429 	int priority;
430 
431 	(void)scsipi_inqmatch(&sa->sa_inqbuf,
432 	    (caddr_t)st_patterns, sizeof(st_patterns)/sizeof(st_patterns[0]),
433 	    sizeof(st_patterns[0]), &priority);
434 	return (priority);
435 }
436 
437 /*
438  * The routine called by the low level scsi routine when it discovers
439  * A device suitable for this driver
440  */
441 void
442 stattach(parent, self, aux)
443 	struct device *parent, *self;
444 	void *aux;
445 {
446 	struct st_softc *st = (void *)self;
447 	struct scsipibus_attach_args *sa = aux;
448 	struct scsipi_link *sc_link = sa->sa_sc_link;
449 
450 	SC_DEBUG(sc_link, SDEV_DB2, ("stattach: "));
451 
452 	/*
453 	 * Store information needed to contact our base driver
454 	 */
455 	st->sc_link = sc_link;
456 	sc_link->device = &st_switch;
457 	sc_link->device_softc = st;
458 	sc_link->openings = 1;
459 
460 	/*
461 	 * Set initial flags
462 	 */
463 
464 	st->flags = ST_INIT_FLAGS;
465 
466 	/*
467 	 * Check if the drive is a known criminal and take
468 	 * Any steps needed to bring it into line
469 	 */
470 	st_identify_drive(st, &sa->sa_inqbuf);
471 	/*
472 	 * Use the subdriver to request information regarding
473 	 * the drive. We cannot use interrupts yet, so the
474 	 * request must specify this.
475 	 */
476 	printf("\n");
477 	printf("%s: %s", st->sc_dev.dv_xname, st->quirkdata ? "rogue, " : "");
478 	if (scsipi_test_unit_ready(sc_link,
479 	    XS_CTL_DISCOVERY | XS_CTL_SILENT | XS_CTL_IGNORE_MEDIA_CHANGE) ||
480 	    st_mode_sense(st,
481 	    XS_CTL_DISCOVERY | XS_CTL_SILENT | XS_CTL_IGNORE_MEDIA_CHANGE))
482 		printf("drive empty\n");
483 	else {
484 		printf("density code 0x%x, ", st->media_density);
485 		if (st->media_blksize > 0)
486 			printf("%d-byte", st->media_blksize);
487 		else
488 			printf("variable");
489 		printf(" blocks, write-%s\n",
490 		    (st->flags & ST_READONLY) ? "protected" : "enabled");
491 	}
492 
493 	/*
494 	 * Set up the buf queue for this device
495 	 */
496 	BUFQ_INIT(&st->buf_queue);
497 
498 #if NRND > 0
499 	rnd_attach_source(&st->rnd_source, st->sc_dev.dv_xname,
500 			  RND_TYPE_TAPE, 0);
501 #endif
502 }
503 
504 /*
505  * Use the inquiry routine in 'scsi_base' to get drive info so we can
506  * Further tailor our behaviour.
507  */
508 void
509 st_identify_drive(st, inqbuf)
510 	struct st_softc *st;
511 	struct scsipi_inquiry_pattern *inqbuf;
512 {
513 	struct st_quirk_inquiry_pattern *finger;
514 	int priority;
515 
516 	finger = (struct st_quirk_inquiry_pattern *)scsipi_inqmatch(inqbuf,
517 	    (caddr_t)st_quirk_patterns,
518 	    sizeof(st_quirk_patterns) / sizeof(st_quirk_patterns[0]),
519 	    sizeof(st_quirk_patterns[0]), &priority);
520 	if (priority != 0) {
521 		st->quirkdata = &finger->quirkdata;
522 		st->drive_quirks = finger->quirkdata.quirks;
523 		st->quirks = finger->quirkdata.quirks;	/* start value */
524 		st->page_0_size = finger->quirkdata.page_0_size;
525 		st_loadquirks(st);
526 	}
527 }
528 
529 /*
530  * initialise the subdevices to the default (QUIRK) state.
531  * this will remove any setting made by the system operator or previous
532  * operations.
533  */
534 void
535 st_loadquirks(st)
536 	struct st_softc *st;
537 {
538 	int i;
539 	struct	modes *mode;
540 	struct	modes *mode2;
541 
542 	mode = st->quirkdata->modes;
543 	mode2 = st->modes;
544 	for (i = 0; i < 4; i++) {
545 		bzero(mode2, sizeof(struct modes));
546 		st->modeflags[i] &= ~(BLKSIZE_SET_BY_QUIRK |
547 		    DENSITY_SET_BY_QUIRK | BLKSIZE_SET_BY_USER |
548 		    DENSITY_SET_BY_USER);
549 		if ((mode->quirks | st->drive_quirks) & ST_Q_FORCE_BLKSIZE) {
550 			mode2->blksize = mode->blksize;
551 			st->modeflags[i] |= BLKSIZE_SET_BY_QUIRK;
552 		}
553 		if (mode->density) {
554 			mode2->density = mode->density;
555 			st->modeflags[i] |= DENSITY_SET_BY_QUIRK;
556 		}
557 		mode++;
558 		mode2++;
559 	}
560 }
561 
562 /*
563  * open the device.
564  */
565 int
566 stopen(dev, flags, mode, p)
567 	dev_t dev;
568 	int flags;
569 	int mode;
570 	struct proc *p;
571 {
572 	u_int stmode, dsty;
573 	int error, sflags, unit, tries, ntries;
574 	struct st_softc *st;
575 	struct scsipi_link *sc_link;
576 
577 	unit = STUNIT(dev);
578 	if (unit >= st_cd.cd_ndevs)
579 		return (ENXIO);
580 	st = st_cd.cd_devs[unit];
581 	if (st == NULL)
582 		return (ENXIO);
583 
584 	stmode = STMODE(dev);
585 	dsty = STDSTY(dev);
586 	sc_link = st->sc_link;
587 
588 	SC_DEBUG(sc_link, SDEV_DB1, ("open: dev=0x%x (unit %d (of %d))\n", dev,
589 	    unit, st_cd.cd_ndevs));
590 
591 
592 	/*
593 	 * Only allow one at a time
594 	 */
595 	if (sc_link->flags & SDEV_OPEN) {
596 		printf("%s: already open\n", st->sc_dev.dv_xname);
597 		return (EBUSY);
598 	}
599 
600 	if ((error = scsipi_adapter_addref(sc_link)) != 0)
601 		return (error);
602 
603 	/*
604 	 * clear any latched errors.
605 	 */
606 	st->mt_resid = 0;
607 	st->mt_erreg = 0;
608 	st->asc = 0;
609 	st->ascq = 0;
610 
611 	/*
612 	 * Catch any unit attention errors. Be silent about this
613 	 * unless we're already mounted. We ignore media change
614 	 * if we're in control mode or not mounted yet.
615 	 */
616 	if ((st->flags & ST_MOUNTED) == 0 || stmode == CTRL_MODE) {
617 #ifdef	SCSIDEBUG
618 		sflags = XS_CTL_IGNORE_MEDIA_CHANGE;
619 #else
620 		sflags = XS_CTL_SILENT|XS_CTL_IGNORE_MEDIA_CHANGE;
621 #endif
622 	} else
623 		sflags = 0;
624 
625 	/*
626 	 * If we're already mounted or we aren't configured for
627 	 * a mount delay, only try a test unit ready once. Otherwise,
628 	 * try up to ST_MOUNT_DELAY times with a rest interval of
629 	 * one second between each try.
630 	 */
631 
632 	if ((st->flags & ST_MOUNTED) || ST_MOUNT_DELAY == 0) {
633 		ntries = 1;
634 	} else {
635 		ntries = ST_MOUNT_DELAY;
636 	}
637 
638 	for (error = tries = 0; tries < ntries; tries++) {
639 		int slpintr, oflags;
640 
641 		/*
642 		 * If we had no error, or we're opening the control mode
643 		 * device, we jump out right away.
644 		 */
645 
646 		error = scsipi_test_unit_ready(sc_link, sflags);
647 		if (error == 0 || stmode == CTRL_MODE) {
648 			break;
649 		}
650 
651 		/*
652 		 * We had an error.
653 		 *
654 		 * If we're already mounted or we aren't configured for
655 		 * a mount delay, or the error isn't a NOT READY error,
656 		 * skip to the error exit now.
657 		 */
658 		if ((st->flags & ST_MOUNTED) || ST_MOUNT_DELAY == 0 ||
659 		    (st->mt_key != SKEY_NOT_READY)) {
660 			goto bad;
661 		}
662 
663 		/*
664 		 * clear any latched errors.
665 		 */
666 		st->mt_resid = 0;
667 		st->mt_erreg = 0;
668 		st->asc = 0;
669 		st->ascq = 0;
670 
671 		/*
672 		 * Fake that we have the device open so
673 		 * we block other apps from getting in.
674 		 */
675 
676 		oflags = sc_link->flags;
677 		sc_link->flags |= SDEV_OPEN;
678 
679 		slpintr = tsleep(&lbolt, PUSER|PCATCH, "stload", 0);
680 
681 		sc_link->flags = oflags;	/* restore flags */
682 
683 		if (slpintr) {
684 			goto bad;
685 		}
686 	}
687 
688 
689 	/*
690 	 * If the mode is 3 (e.g. minor = 3,7,11,15) then the device has
691 	 * been opened to set defaults and perform other, usually non-I/O
692 	 * related, operations. In this case, do a quick check to see
693 	 * whether the unit actually had a tape loaded (this will be known
694 	 * as to whether or not we got a NOT READY for the above
695 	 * unit attention). If a tape is there, go do a mount sequence.
696 	 */
697 	if (stmode == CTRL_MODE && st->mt_key == SKEY_NOT_READY) {
698 		sc_link->flags |= SDEV_OPEN;
699 		return (0);
700 	}
701 
702 	/*
703 	 * If we get this far and had an error set, that means we failed
704 	 * to pass the 'test unit ready' test for the non-controlmode device,
705 	 * so we bounce the open.
706 	 */
707 
708 	if (error)
709 		return (error);
710 
711 	/*
712 	 * Else, we're now committed to saying we're open.
713 	 */
714 
715 	sc_link->flags |= SDEV_OPEN;	/* unit attn are now errors */
716 
717 	/*
718 	 * If it's a different mode, or if the media has been
719 	 * invalidated, unmount the tape from the previous
720 	 * session but continue with open processing
721 	 */
722 	if (st->last_dsty != dsty || !(sc_link->flags & SDEV_MEDIA_LOADED))
723 		st_unmount(st, NOEJECT);
724 
725 	/*
726 	 * If we are not mounted, then we should start a new
727 	 * mount session.
728 	 */
729 	if (!(st->flags & ST_MOUNTED)) {
730 		st_mount_tape(dev, flags);
731 		st->last_dsty = dsty;
732 	}
733 
734 	SC_DEBUG(sc_link, SDEV_DB2, ("open complete\n"));
735 	return (0);
736 
737 bad:
738 	st_unmount(st, NOEJECT);
739 	scsipi_adapter_delref(sc_link);
740 	sc_link->flags &= ~SDEV_OPEN;
741 	return (error);
742 }
743 
744 /*
745  * close the device.. only called if we are the LAST
746  * occurence of an open device
747  */
748 int
749 stclose(dev, flags, mode, p)
750 	dev_t dev;
751 	int flags;
752 	int mode;
753 	struct proc *p;
754 {
755 	int stxx, error = 0;
756 	struct st_softc *st = st_cd.cd_devs[STUNIT(dev)];
757 
758 	SC_DEBUG(st->sc_link, SDEV_DB1, ("closing\n"));
759 
760 	/*
761 	 * Make sure that a tape opened in write-only mode will have
762 	 * file marks written on it when closed, even if not written to.
763 	 *
764 	 * This is for SUN compatibility. Actually, the Sun way of
765 	 * things is to:
766 	 *
767 	 *	only write filemarks if there are fmks to be written and
768 	 *   		- open for write (possibly read/write)
769 	 *		- the last operation was a write
770 	 * 	or:
771 	 *		- opened for wronly
772 	 *		- no data was written (including filemarks)
773 	 */
774 
775 	stxx = st->flags & (ST_WRITTEN | ST_FM_WRITTEN);
776 	if (((flags & FWRITE) && stxx == ST_WRITTEN) ||
777 	    ((flags & O_ACCMODE) == FWRITE && stxx == 0)) {
778 		int nm;
779 		error = st_check_eod(st, FALSE, &nm, 0);
780 	}
781 
782 	switch (STMODE(dev)) {
783 	case NORMAL_MODE:
784 		st_unmount(st, NOEJECT);
785 		break;
786 	case NOREW_MODE:
787 	case CTRL_MODE:
788 		/*
789 		 * Leave mounted unless media seems to have been removed.
790 		 *
791 		 * Otherwise, if we're to terminate a tape with more than one
792 		 * filemark [ and because we're not rewinding here ], backspace
793 		 * one filemark so that later appends will see an unbroken
794 		 * sequence of:
795 		 *
796 		 *	file - FMK - file - FMK ... file - FMK FMK (EOM)
797 		 */
798 		if (!(st->sc_link->flags & SDEV_MEDIA_LOADED)) {
799 			st_unmount(st, NOEJECT);
800 		} else if (error == 0) {
801 			/*
802 			 * ST_WRITTEN was preserved from above.
803 			 *
804 			 * All we need to know here is:
805 			 *
806 			 *	Were we writing this tape and was the last
807 			 *	operation a write?
808 			 *
809 			 *	Are there supposed to be 2FM at EOD?
810 			 *
811 			 * If both statements are true, then we backspace
812 			 * one filemark.
813 			 */
814 			stxx |= (st->flags & ST_2FM_AT_EOD);
815 			if ((flags & FWRITE) != 0 &&
816 			    (stxx == (ST_2FM_AT_EOD|ST_WRITTEN))) {
817 				error = st_space(st, -1, SP_FILEMARKS, 0);
818 			}
819 		}
820 		break;
821 	case EJECT_MODE:
822 		st_unmount(st, EJECT);
823 		break;
824 	}
825 
826 	scsipi_wait_drain(st->sc_link);
827 
828 	scsipi_adapter_delref(st->sc_link);
829 	st->sc_link->flags &= ~SDEV_OPEN;
830 
831 	return (error);
832 }
833 
834 /*
835  * Start a new mount session.
836  * Copy in all the default parameters from the selected device mode.
837  * and try guess any that seem to be defaulted.
838  */
839 int
840 st_mount_tape(dev, flags)
841 	dev_t dev;
842 	int flags;
843 {
844 	int unit;
845 	u_int dsty;
846 	struct st_softc *st;
847 	struct scsipi_link *sc_link;
848 	int error = 0;
849 
850 	unit = STUNIT(dev);
851 	dsty = STDSTY(dev);
852 	st = st_cd.cd_devs[unit];
853 	sc_link = st->sc_link;
854 
855 	if (st->flags & ST_MOUNTED)
856 		return (0);
857 
858 	SC_DEBUG(sc_link, SDEV_DB1, ("mounting\n "));
859 	st->flags |= ST_NEW_MOUNT;
860 	st->quirks = st->drive_quirks | st->modes[dsty].quirks;
861 	/*
862 	 * If the media is new, then make sure we give it a chance to
863 	 * to do a 'load' instruction.  (We assume it is new.)
864 	 */
865 	if ((error = st_load(st, LD_LOAD, XS_CTL_SILENT)) != 0)
866 		return (error);
867 	/*
868 	 * Throw another dummy instruction to catch
869 	 * 'Unit attention' errors. Many drives give
870 	 * these after doing a Load instruction (with
871 	 * the MEDIUM MAY HAVE CHANGED asc/ascq).
872 	 */
873 	scsipi_test_unit_ready(sc_link, XS_CTL_SILENT);	/* XXX */
874 
875 	/*
876 	 * Some devices can't tell you much until they have been
877 	 * asked to look at the media. This quirk does this.
878 	 */
879 	if (st->quirks & ST_Q_SENSE_HELP)
880 		if ((error = st_touch_tape(st)) != 0)
881 			return (error);
882 	/*
883 	 * Load the physical device parameters
884 	 * loads: blkmin, blkmax
885 	 */
886 	if ((error = st_read_block_limits(st, 0)) != 0)
887 		return (error);
888 	/*
889 	 * Load the media dependent parameters
890 	 * includes: media_blksize,media_density,numblks
891 	 * As we have a tape in, it should be reflected here.
892 	 * If not you may need the "quirk" above.
893 	 */
894 	if ((error = st_mode_sense(st, 0)) != 0)
895 		return (error);
896 	/*
897 	 * If we have gained a permanent density from somewhere,
898 	 * then use it in preference to the one supplied by
899 	 * default by the driver.
900 	 */
901 	if (st->modeflags[dsty] & (DENSITY_SET_BY_QUIRK | DENSITY_SET_BY_USER))
902 		st->density = st->modes[dsty].density;
903 	else
904 		st->density = st->media_density;
905 	/*
906 	 * If we have gained a permanent blocksize
907 	 * then use it in preference to the one supplied by
908 	 * default by the driver.
909 	 */
910 	st->flags &= ~ST_FIXEDBLOCKS;
911 	if (st->modeflags[dsty] &
912 	    (BLKSIZE_SET_BY_QUIRK | BLKSIZE_SET_BY_USER)) {
913 		st->blksize = st->modes[dsty].blksize;
914 		if (st->blksize)
915 			st->flags |= ST_FIXEDBLOCKS;
916 	} else {
917 		if ((error = st_decide_mode(st, FALSE)) != 0)
918 			return (error);
919 	}
920 	if ((error = st_mode_select(st, 0)) != 0) {
921 		printf("%s: cannot set selected mode\n", st->sc_dev.dv_xname);
922 		return (error);
923 	}
924 	scsipi_prevent(sc_link, PR_PREVENT,
925 	    XS_CTL_IGNORE_ILLEGAL_REQUEST | XS_CTL_IGNORE_NOT_READY);
926 	st->flags &= ~ST_NEW_MOUNT;
927 	st->flags |= ST_MOUNTED;
928 	sc_link->flags |= SDEV_MEDIA_LOADED;	/* move earlier? */
929 
930 	return (0);
931 }
932 
933 /*
934  * End the present mount session.
935  * Rewind, and optionally eject the tape.
936  * Reset various flags to indicate that all new
937  * operations require another mount operation
938  */
939 void
940 st_unmount(st, eject)
941 	struct st_softc *st;
942 	boolean eject;
943 {
944 	struct scsipi_link *sc_link = st->sc_link;
945 	int nmarks;
946 
947 	if (!(st->flags & ST_MOUNTED))
948 		return;
949 	SC_DEBUG(sc_link, SDEV_DB1, ("unmounting\n"));
950 	st_check_eod(st, FALSE, &nmarks, XS_CTL_IGNORE_NOT_READY);
951 	st_rewind(st, 0, XS_CTL_IGNORE_NOT_READY);
952 	scsipi_prevent(sc_link, PR_ALLOW,
953 	    XS_CTL_IGNORE_ILLEGAL_REQUEST | XS_CTL_IGNORE_NOT_READY);
954 	if (eject)
955 		st_load(st, LD_UNLOAD, XS_CTL_IGNORE_NOT_READY);
956 	st->flags &= ~(ST_MOUNTED | ST_NEW_MOUNT);
957 	sc_link->flags &= ~SDEV_MEDIA_LOADED;
958 }
959 
960 /*
961  * Given all we know about the device, media, mode, 'quirks' and
962  * initial operation, make a decision as to how we should be set
963  * to run (regarding blocking and EOD marks)
964  */
965 int
966 st_decide_mode(st, first_read)
967 	struct st_softc *st;
968 	boolean	first_read;
969 {
970 #ifdef SCSIDEBUG
971 	struct scsipi_link *sc_link = st->sc_link;
972 #endif
973 
974 	SC_DEBUG(sc_link, SDEV_DB2, ("starting block mode decision\n"));
975 
976 	/*
977 	 * If the drive can only handle fixed-length blocks and only at
978 	 * one size, perhaps we should just do that.
979 	 */
980 	if (st->blkmin && (st->blkmin == st->blkmax)) {
981 		st->flags |= ST_FIXEDBLOCKS;
982 		st->blksize = st->blkmin;
983 		SC_DEBUG(sc_link, SDEV_DB3,
984 		    ("blkmin == blkmax of %d\n", st->blkmin));
985 		goto done;
986 	}
987 	/*
988 	 * If the tape density mandates (or even suggests) use of fixed
989 	 * or variable-length blocks, comply.
990 	 */
991 	switch (st->density) {
992 	case HALFINCH_800:
993 	case HALFINCH_1600:
994 	case HALFINCH_6250:
995 	case DDS:
996 		st->flags &= ~ST_FIXEDBLOCKS;
997 		st->blksize = 0;
998 		SC_DEBUG(sc_link, SDEV_DB3, ("density specified variable\n"));
999 		goto done;
1000 	case QIC_11:
1001 	case QIC_24:
1002 	case QIC_120:
1003 	case QIC_150:
1004 	case QIC_525:
1005 	case QIC_1320:
1006 	case QIC_3095:
1007 	case QIC_3220:
1008 		st->flags |= ST_FIXEDBLOCKS;
1009 		if (st->media_blksize > 0)
1010 			st->blksize = st->media_blksize;
1011 		else
1012 			st->blksize = DEF_FIXED_BSIZE;
1013 		SC_DEBUG(sc_link, SDEV_DB3, ("density specified fixed\n"));
1014 		goto done;
1015 	}
1016 	/*
1017 	 * If we're about to read the tape, perhaps we should choose
1018 	 * fixed or variable-length blocks and block size according to
1019 	 * what the drive found on the tape.
1020 	 */
1021 	if (first_read &&
1022 	    (!(st->quirks & ST_Q_BLKSIZE) || (st->media_blksize == 0) ||
1023 	    (st->media_blksize == DEF_FIXED_BSIZE) ||
1024 	    (st->media_blksize == 1024))) {
1025 		if (st->media_blksize > 0)
1026 			st->flags |= ST_FIXEDBLOCKS;
1027 		else
1028 			st->flags &= ~ST_FIXEDBLOCKS;
1029 		st->blksize = st->media_blksize;
1030 		SC_DEBUG(sc_link, SDEV_DB3,
1031 		    ("Used media_blksize of %d\n", st->media_blksize));
1032 		goto done;
1033 	}
1034 	/*
1035 	 * We're getting no hints from any direction.  Choose variable-
1036 	 * length blocks arbitrarily.
1037 	 */
1038 	st->flags &= ~ST_FIXEDBLOCKS;
1039 	st->blksize = 0;
1040 	SC_DEBUG(sc_link, SDEV_DB3,
1041 	    ("Give up and default to variable mode\n"));
1042 
1043 done:
1044 	/*
1045 	 * Decide whether or not to write two file marks to signify end-
1046 	 * of-data.  Make the decision as a function of density.  If
1047 	 * the decision is not to use a second file mark, the SCSI BLANK
1048 	 * CHECK condition code will be recognized as end-of-data when
1049 	 * first read.
1050 	 * (I think this should be a by-product of fixed/variable..julian)
1051 	 */
1052 	switch (st->density) {
1053 /*      case 8 mm:   What is the SCSI density code for 8 mm, anyway? */
1054 	case QIC_11:
1055 	case QIC_24:
1056 	case QIC_120:
1057 	case QIC_150:
1058 	case QIC_525:
1059 	case QIC_1320:
1060 	case QIC_3095:
1061 	case QIC_3220:
1062 		st->flags &= ~ST_2FM_AT_EOD;
1063 		break;
1064 	default:
1065 		st->flags |= ST_2FM_AT_EOD;
1066 	}
1067 	return (0);
1068 }
1069 
1070 /*
1071  * Actually translate the requested transfer into
1072  * one the physical driver can understand
1073  * The transfer is described by a buf and will include
1074  * only one physical transfer.
1075  */
1076 void
1077 ststrategy(bp)
1078 	struct buf *bp;
1079 {
1080 	struct st_softc *st = st_cd.cd_devs[STUNIT(bp->b_dev)];
1081 	int s;
1082 
1083 	SC_DEBUG(st->sc_link, SDEV_DB1,
1084 	    ("ststrategy %ld bytes @ blk %d\n", bp->b_bcount, bp->b_blkno));
1085 	/*
1086 	 * If it's a null transfer, return immediatly
1087 	 */
1088 	if (bp->b_bcount == 0)
1089 		goto done;
1090 
1091 	/* If offset is negative, error */
1092 	if (bp->b_blkno < 0) {
1093 		bp->b_error = EINVAL;
1094 		goto bad;
1095 	}
1096 
1097 	/*
1098 	 * Odd sized request on fixed drives are verboten
1099 	 */
1100 	if (st->flags & ST_FIXEDBLOCKS) {
1101 		if (bp->b_bcount % st->blksize) {
1102 			printf("%s: bad request, must be multiple of %d\n",
1103 			    st->sc_dev.dv_xname, st->blksize);
1104 			bp->b_error = EIO;
1105 			goto bad;
1106 		}
1107 	}
1108 	/*
1109 	 * as are out-of-range requests on variable drives.
1110 	 */
1111 	else if (bp->b_bcount < st->blkmin ||
1112 	    (st->blkmax && bp->b_bcount > st->blkmax)) {
1113 		printf("%s: bad request, must be between %d and %d\n",
1114 		    st->sc_dev.dv_xname, st->blkmin, st->blkmax);
1115 		bp->b_error = EIO;
1116 		goto bad;
1117 	}
1118 	s = splbio();
1119 
1120 	/*
1121 	 * Place it in the queue of activities for this tape
1122 	 * at the end (a bit silly because we only have on user..
1123 	 * (but it could fork()))
1124 	 */
1125 	BUFQ_INSERT_TAIL(&st->buf_queue, bp);
1126 
1127 	/*
1128 	 * Tell the device to get going on the transfer if it's
1129 	 * not doing anything, otherwise just wait for completion
1130 	 * (All a bit silly if we're only allowing 1 open but..)
1131 	 */
1132 	ststart(st);
1133 
1134 	splx(s);
1135 	return;
1136 bad:
1137 	bp->b_flags |= B_ERROR;
1138 done:
1139 	/*
1140 	 * Correctly set the buf to indicate a completed xfer
1141 	 */
1142 	bp->b_resid = bp->b_bcount;
1143 	biodone(bp);
1144 	return;
1145 }
1146 
1147 /*
1148  * ststart looks to see if there is a buf waiting for the device
1149  * and that the device is not already busy. If both are true,
1150  * It dequeues the buf and creates a scsi command to perform the
1151  * transfer required. The transfer request will call scsipi_done
1152  * on completion, which will in turn call this routine again
1153  * so that the next queued transfer is performed.
1154  * The bufs are queued by the strategy routine (ststrategy)
1155  *
1156  * This routine is also called after other non-queued requests
1157  * have been made of the scsi driver, to ensure that the queue
1158  * continues to be drained.
1159  * ststart() is called at splbio
1160  */
1161 void
1162 ststart(v)
1163 	void *v;
1164 {
1165 	struct st_softc *st = v;
1166 	struct scsipi_link *sc_link = st->sc_link;
1167 	register struct buf *bp;
1168 	struct scsi_rw_tape cmd;
1169 	int flags, error;
1170 
1171 	SC_DEBUG(sc_link, SDEV_DB2, ("ststart "));
1172 	/*
1173 	 * See if there is a buf to do and we are not already
1174 	 * doing one
1175 	 */
1176 	while (sc_link->active < sc_link->openings) {
1177 		/* if a special awaits, let it proceed first */
1178 		if (sc_link->flags & SDEV_WAITING) {
1179 			sc_link->flags &= ~SDEV_WAITING;
1180 			wakeup((caddr_t)sc_link);
1181 			return;
1182 		}
1183 
1184 		if ((bp = BUFQ_FIRST(&st->buf_queue)) == NULL)
1185 			return;
1186 		BUFQ_REMOVE(&st->buf_queue, bp);
1187 
1188 		/*
1189 		 * If the device has been unmounted by the user
1190 		 * then throw away all requests until done.
1191 		 */
1192 		if (!(st->flags & ST_MOUNTED) ||
1193 		    !(sc_link->flags & SDEV_MEDIA_LOADED)) {
1194 			/* make sure that one implies the other.. */
1195 			sc_link->flags &= ~SDEV_MEDIA_LOADED;
1196 			bp->b_flags |= B_ERROR;
1197 			bp->b_error = EIO;
1198 			bp->b_resid = bp->b_bcount;
1199 			biodone(bp);
1200 			continue;
1201 		}
1202 		/*
1203 		 * only FIXEDBLOCK devices have pending I/O or space operations.
1204 		 */
1205 		if (st->flags & ST_FIXEDBLOCKS) {
1206 			/*
1207 			 * If we are at a filemark but have not reported it yet
1208 			 * then we should report it now
1209 			 */
1210 			if (st->flags & ST_AT_FILEMARK) {
1211 				if ((bp->b_flags & B_READ) == B_WRITE) {
1212 					/*
1213 					 * Handling of ST_AT_FILEMARK in
1214 					 * st_space will fill in the right file
1215 					 * mark count.
1216 					 * Back up over filemark
1217 					 */
1218 					if (st_space(st, 0, SP_FILEMARKS, 0)) {
1219 						bp->b_flags |= B_ERROR;
1220 						bp->b_error = EIO;
1221 						biodone(bp);
1222 						continue;
1223 					}
1224 				} else {
1225 					bp->b_resid = bp->b_bcount;
1226 					bp->b_error = 0;
1227 					bp->b_flags &= ~B_ERROR;
1228 					st->flags &= ~ST_AT_FILEMARK;
1229 					biodone(bp);
1230 					continue;	/* seek more work */
1231 				}
1232 			}
1233 		}
1234 		/*
1235 		 * If we are at EOM but have not reported it
1236 		 * yet then we should report it now.
1237 		 */
1238 		if (st->flags & (ST_EOM_PENDING|ST_EIO_PENDING)) {
1239 			bp->b_resid = bp->b_bcount;
1240 			if (st->flags & ST_EIO_PENDING) {
1241 				bp->b_error = EIO;
1242 				bp->b_flags |= B_ERROR;
1243 			}
1244 			st->flags &= ~(ST_EOM_PENDING|ST_EIO_PENDING);
1245 			biodone(bp);
1246 			continue;	/* seek more work */
1247 		}
1248 
1249 		/*
1250 		 *  Fill out the scsi command
1251 		 */
1252 		bzero(&cmd, sizeof(cmd));
1253 		if ((bp->b_flags & B_READ) == B_WRITE) {
1254 			cmd.opcode = WRITE;
1255 			st->flags &= ~ST_FM_WRITTEN;
1256 			flags = XS_CTL_DATA_OUT;
1257 		} else {
1258 			cmd.opcode = READ;
1259 			flags = XS_CTL_DATA_IN;
1260 		}
1261 
1262 		/*
1263 		 * Handle "fixed-block-mode" tape drives by using the
1264 		 * block count instead of the length.
1265 		 */
1266 		if (st->flags & ST_FIXEDBLOCKS) {
1267 			cmd.byte2 |= SRW_FIXED;
1268 			_lto3b(bp->b_bcount / st->blksize, cmd.len);
1269 		} else
1270 			_lto3b(bp->b_bcount, cmd.len);
1271 
1272 		/*
1273 		 * go ask the adapter to do all this for us
1274 		 * XXX Really need NOSLEEP?
1275 		 */
1276 		error = scsipi_command(sc_link,
1277 		    (struct scsipi_generic *)&cmd, sizeof(cmd),
1278 		    (u_char *)bp->b_data, bp->b_bcount,
1279 		    0, ST_IO_TIME, bp, flags | XS_CTL_NOSLEEP | XS_CTL_ASYNC);
1280 		if (error) {
1281 			printf("%s: not queued, error %d\n",
1282 			    st->sc_dev.dv_xname, error);
1283 		}
1284 	} /* go back and see if we can cram more work in.. */
1285 }
1286 
1287 void
1288 stdone(xs)
1289 	struct scsipi_xfer *xs;
1290 {
1291 
1292 	if (xs->bp != NULL) {
1293 		struct st_softc *st = xs->sc_link->device_softc;
1294 		if ((xs->bp->b_flags & B_READ) == B_WRITE) {
1295 			st->flags |= ST_WRITTEN;
1296 		} else {
1297 			st->flags &= ~ST_WRITTEN;
1298 		}
1299 #if NRND > 0
1300 		rnd_add_uint32(&st->rnd_source, xs->bp->b_blkno);
1301 #endif
1302 	}
1303 }
1304 
1305 int
1306 stread(dev, uio, iomode)
1307 	dev_t dev;
1308 	struct uio *uio;
1309 	int iomode;
1310 {
1311 	struct st_softc *st = st_cd.cd_devs[STUNIT(dev)];
1312 
1313 	return (physio(ststrategy, NULL, dev, B_READ,
1314 	    st->sc_link->adapter->scsipi_minphys, uio));
1315 }
1316 
1317 int
1318 stwrite(dev, uio, iomode)
1319 	dev_t dev;
1320 	struct uio *uio;
1321 	int iomode;
1322 {
1323 	struct st_softc *st = st_cd.cd_devs[STUNIT(dev)];
1324 
1325 	return (physio(ststrategy, NULL, dev, B_WRITE,
1326 	    st->sc_link->adapter->scsipi_minphys, uio));
1327 }
1328 
1329 /*
1330  * Perform special action on behalf of the user;
1331  * knows about the internals of this device
1332  */
1333 int
1334 stioctl(dev, cmd, arg, flag, p)
1335 	dev_t dev;
1336 	u_long cmd;
1337 	caddr_t arg;
1338 	int flag;
1339 	struct proc *p;
1340 {
1341 	int error = 0;
1342 	int unit;
1343 	int number, nmarks, dsty;
1344 	int flags;
1345 	struct st_softc *st;
1346 	int hold_blksize;
1347 	u_int8_t hold_density;
1348 	struct mtop *mt = (struct mtop *) arg;
1349 
1350 	/*
1351 	 * Find the device that the user is talking about
1352 	 */
1353 	flags = 0;		/* give error messages, act on errors etc. */
1354 	unit = STUNIT(dev);
1355 	dsty = STDSTY(dev);
1356 	st = st_cd.cd_devs[unit];
1357 	hold_blksize = st->blksize;
1358 	hold_density = st->density;
1359 
1360 	switch ((u_int) cmd) {
1361 
1362 	case MTIOCGET: {
1363 		struct mtget *g = (struct mtget *) arg;
1364 		/*
1365 		 * (to get the current state of READONLY)
1366 		 */
1367 		error = st_mode_sense(st, XS_CTL_SILENT);
1368 		if (error)
1369 			break;
1370 		SC_DEBUG(st->sc_link, SDEV_DB1, ("[ioctl: get status]\n"));
1371 		bzero(g, sizeof(struct mtget));
1372 		g->mt_type = 0x7;	/* Ultrix compat *//*? */
1373 		g->mt_blksiz = st->blksize;
1374 		g->mt_density = st->density;
1375 		g->mt_mblksiz[0] = st->modes[0].blksize;
1376 		g->mt_mblksiz[1] = st->modes[1].blksize;
1377 		g->mt_mblksiz[2] = st->modes[2].blksize;
1378 		g->mt_mblksiz[3] = st->modes[3].blksize;
1379 		g->mt_mdensity[0] = st->modes[0].density;
1380 		g->mt_mdensity[1] = st->modes[1].density;
1381 		g->mt_mdensity[2] = st->modes[2].density;
1382 		g->mt_mdensity[3] = st->modes[3].density;
1383 		if (st->flags & ST_READONLY)
1384 			g->mt_dsreg |= MT_DS_RDONLY;
1385 		if (st->flags & ST_MOUNTED)
1386 			g->mt_dsreg |= MT_DS_MOUNTED;
1387 		g->mt_resid = st->mt_resid;
1388 		g->mt_erreg = st->mt_erreg;
1389 		/*
1390 		 * clear latched errors.
1391 		 */
1392 		st->mt_resid = 0;
1393 		st->mt_erreg = 0;
1394 		st->asc = 0;
1395 		st->ascq = 0;
1396 		break;
1397 	}
1398 	case MTIOCTOP: {
1399 
1400 		SC_DEBUG(st->sc_link, SDEV_DB1,
1401 		    ("[ioctl: op=0x%x count=0x%x]\n", mt->mt_op,
1402 			mt->mt_count));
1403 
1404 		/* compat: in U*x it is a short */
1405 		number = mt->mt_count;
1406 		switch ((short) (mt->mt_op)) {
1407 		case MTWEOF:	/* write an end-of-file record */
1408 			error = st_write_filemarks(st, number, flags);
1409 			break;
1410 		case MTBSF:	/* backward space file */
1411 			number = -number;
1412 		case MTFSF:	/* forward space file */
1413 			error = st_check_eod(st, FALSE, &nmarks, flags);
1414 			if (!error)
1415 				error = st_space(st, number - nmarks,
1416 				    SP_FILEMARKS, flags);
1417 			break;
1418 		case MTBSR:	/* backward space record */
1419 			number = -number;
1420 		case MTFSR:	/* forward space record */
1421 			error = st_check_eod(st, TRUE, &nmarks, flags);
1422 			if (!error)
1423 				error = st_space(st, number, SP_BLKS, flags);
1424 			break;
1425 		case MTREW:	/* rewind */
1426 			error = st_rewind(st, 0, flags);
1427 			break;
1428 		case MTOFFL:	/* rewind and put the drive offline */
1429 			st_unmount(st, EJECT);
1430 			break;
1431 		case MTNOP:	/* no operation, sets status only */
1432 			break;
1433 		case MTRETEN:	/* retension the tape */
1434 			error = st_load(st, LD_RETENSION, flags);
1435 			if (!error)
1436 				error = st_load(st, LD_LOAD, flags);
1437 			break;
1438 		case MTEOM:	/* forward space to end of media */
1439 			error = st_check_eod(st, FALSE, &nmarks, flags);
1440 			if (!error)
1441 				error = st_space(st, 1, SP_EOM, flags);
1442 			break;
1443 		case MTCACHE:	/* enable controller cache */
1444 			st->flags &= ~ST_DONTBUFFER;
1445 			goto try_new_value;
1446 		case MTNOCACHE:	/* disable controller cache */
1447 			st->flags |= ST_DONTBUFFER;
1448 			goto try_new_value;
1449 		case MTERASE:	/* erase volume */
1450 			error = st_erase(st, number, flags);
1451 			break;
1452 		case MTSETBSIZ:	/* Set block size for device */
1453 #ifdef	NOTYET
1454 			if (!(st->flags & ST_NEW_MOUNT)) {
1455 				uprintf("re-mount tape before changing blocksize");
1456 				error = EINVAL;
1457 				break;
1458 			}
1459 #endif
1460 			if (number == 0)
1461 				st->flags &= ~ST_FIXEDBLOCKS;
1462 			else {
1463 				if ((st->blkmin || st->blkmax) &&
1464 				    (number < st->blkmin ||
1465 				    number > st->blkmax)) {
1466 					error = EINVAL;
1467 					break;
1468 				}
1469 				st->flags |= ST_FIXEDBLOCKS;
1470 			}
1471 			st->blksize = number;
1472 			st->flags |= ST_BLOCK_SET;	/*XXX */
1473 			goto try_new_value;
1474 
1475 		case MTSETDNSTY:	/* Set density for device and mode */
1476 			/*
1477 			 * Any number >= 0 and <= 0xff is legal. Numbers
1478 			 * above 0x80 are 'vendor unique'.
1479 			 */
1480 			if (number < 0 || number > 255) {
1481 				error = EINVAL;
1482 				break;
1483 			} else
1484 				st->density = number;
1485 			goto try_new_value;
1486 
1487 		case MTCMPRESS:
1488 			error = st_cmprss(st, number);
1489 			break;
1490 
1491 		case MTEWARN:
1492 			if (number)
1493 				st->flags |= ST_EARLYWARN;
1494 			else
1495 				st->flags &= ~ST_EARLYWARN;
1496 			break;
1497 
1498 		default:
1499 			error = EINVAL;
1500 		}
1501 		break;
1502 	}
1503 	case MTIOCIEOT:
1504 	case MTIOCEEOT:
1505 		break;
1506 
1507 	case MTIOCRDSPOS:
1508 		error = st_rdpos(st, 0, (u_int32_t *) arg);
1509 		break;
1510 
1511 	case MTIOCRDHPOS:
1512 		error = st_rdpos(st, 1, (u_int32_t *) arg);
1513 		break;
1514 
1515 	case MTIOCSLOCATE:
1516 		error = st_setpos(st, 0, (u_int32_t *) arg);
1517 		break;
1518 
1519 	case MTIOCHLOCATE:
1520 		error = st_setpos(st, 1, (u_int32_t *) arg);
1521 		break;
1522 
1523 
1524 	default:
1525 		error = scsipi_do_ioctl(st->sc_link, dev, cmd, arg,
1526 					flag, p);
1527 		break;
1528 	}
1529 	return (error);
1530 /*-----------------------------*/
1531 try_new_value:
1532 	/*
1533 	 * Check that the mode being asked for is aggreeable to the
1534 	 * drive. If not, put it back the way it was.
1535 	 */
1536 	if ((error = st_mode_select(st, 0)) != 0) {/* put it back as it was */
1537 		printf("%s: cannot set selected mode\n", st->sc_dev.dv_xname);
1538 		st->density = hold_density;
1539 		st->blksize = hold_blksize;
1540 		if (st->blksize)
1541 			st->flags |= ST_FIXEDBLOCKS;
1542 		else
1543 			st->flags &= ~ST_FIXEDBLOCKS;
1544 		return (error);
1545 	}
1546 	/*
1547 	 * As the drive liked it, if we are setting a new default,
1548 	 * set it into the structures as such.
1549 	 *
1550 	 * The means for deciding this are not finalised yet- but
1551 	 * if the device was opened in Control Mode, the values
1552 	 * are persistent now across mounts.
1553 	 */
1554 	if (STMODE(dev) == CTRL_MODE) {
1555 		switch ((short) (mt->mt_op)) {
1556 		case MTSETBSIZ:
1557 			st->modes[dsty].blksize = st->blksize;
1558 			st->modeflags[dsty] |= BLKSIZE_SET_BY_USER;
1559 			break;
1560 		case MTSETDNSTY:
1561 			st->modes[dsty].density = st->density;
1562 			st->modeflags[dsty] |= DENSITY_SET_BY_USER;
1563 			break;
1564 		}
1565 	}
1566 	return (0);
1567 }
1568 
1569 /*
1570  * Do a synchronous read.
1571  */
1572 int
1573 st_read(st, buf, size, flags)
1574 	struct st_softc *st;
1575 	int size;
1576 	int flags;
1577 	char *buf;
1578 {
1579 	struct scsi_rw_tape cmd;
1580 
1581 	/*
1582 	 * If it's a null transfer, return immediatly
1583 	 */
1584 	if (size == 0)
1585 		return (0);
1586 	bzero(&cmd, sizeof(cmd));
1587 	cmd.opcode = READ;
1588 	if (st->flags & ST_FIXEDBLOCKS) {
1589 		cmd.byte2 |= SRW_FIXED;
1590 		_lto3b(size / (st->blksize ? st->blksize : DEF_FIXED_BSIZE),
1591 		    cmd.len);
1592 	} else
1593 		_lto3b(size, cmd.len);
1594 	return (scsipi_command(st->sc_link,
1595 	    (struct scsipi_generic *)&cmd, sizeof(cmd),
1596 	    (u_char *)buf, size, 0, ST_IO_TIME, NULL, flags | XS_CTL_DATA_IN));
1597 }
1598 
1599 /*
1600  * Ask the drive what it's min and max blk sizes are.
1601  */
1602 int
1603 st_read_block_limits(st, flags)
1604 	struct st_softc *st;
1605 	int flags;
1606 {
1607 	struct scsi_block_limits cmd;
1608 	struct scsi_block_limits_data block_limits;
1609 	struct scsipi_link *sc_link = st->sc_link;
1610 	int error;
1611 
1612 	/*
1613 	 * First check if we have it all loaded
1614 	 */
1615 	if ((sc_link->flags & SDEV_MEDIA_LOADED))
1616 		return (0);
1617 
1618 	/*
1619 	 * do a 'Read Block Limits'
1620 	 */
1621 	bzero(&cmd, sizeof(cmd));
1622 	cmd.opcode = READ_BLOCK_LIMITS;
1623 
1624 	/*
1625 	 * do the command, update the global values
1626 	 */
1627 	error = scsipi_command(sc_link, (struct scsipi_generic *)&cmd,
1628 	    sizeof(cmd), (u_char *)&block_limits, sizeof(block_limits),
1629 	    ST_RETRIES, ST_CTL_TIME, NULL, flags | XS_CTL_DATA_IN);
1630 	if (error)
1631 		return (error);
1632 
1633 	st->blkmin = _2btol(block_limits.min_length);
1634 	st->blkmax = _3btol(block_limits.max_length);
1635 
1636 	SC_DEBUG(sc_link, SDEV_DB3,
1637 	    ("(%d <= blksize <= %d)\n", st->blkmin, st->blkmax));
1638 	return (0);
1639 }
1640 
1641 /*
1642  * Get the scsi driver to send a full inquiry to the
1643  * device and use the results to fill out the global
1644  * parameter structure.
1645  *
1646  * called from:
1647  * attach
1648  * open
1649  * ioctl (to reset original blksize)
1650  */
1651 int
1652 st_mode_sense(st, flags)
1653 	struct st_softc *st;
1654 	int flags;
1655 {
1656 	u_int scsipi_sense_len;
1657 	int error;
1658 	struct scsi_mode_sense cmd;
1659 	struct scsipi_sense {
1660 		struct scsi_mode_header header;
1661 		struct scsi_blk_desc blk_desc;
1662 		u_char sense_data[MAX_PAGE_0_SIZE];
1663 	} scsipi_sense;
1664 	struct scsipi_link *sc_link = st->sc_link;
1665 
1666 	scsipi_sense_len = 12 + st->page_0_size;
1667 
1668 	/*
1669 	 * Set up a mode sense
1670 	 */
1671 	bzero(&cmd, sizeof(cmd));
1672 	cmd.opcode = SCSI_MODE_SENSE;
1673 	cmd.length = scsipi_sense_len;
1674 
1675 	/*
1676 	 * do the command, but we don't need the results
1677 	 * just print them for our interest's sake, if asked,
1678 	 * or if we need it as a template for the mode select
1679 	 * store it away.
1680 	 */
1681 	error = scsipi_command(sc_link, (struct scsipi_generic *)&cmd,
1682 	    sizeof(cmd), (u_char *)&scsipi_sense, scsipi_sense_len,
1683 	    ST_RETRIES, ST_CTL_TIME, NULL, flags | XS_CTL_DATA_IN);
1684 	if (error)
1685 		return (error);
1686 
1687 	st->numblks = _3btol(scsipi_sense.blk_desc.nblocks);
1688 	st->media_blksize = _3btol(scsipi_sense.blk_desc.blklen);
1689 	st->media_density = scsipi_sense.blk_desc.density;
1690 	if (scsipi_sense.header.dev_spec & SMH_DSP_WRITE_PROT)
1691 		st->flags |= ST_READONLY;
1692 	else
1693 		st->flags &= ~ST_READONLY;
1694 	SC_DEBUG(sc_link, SDEV_DB3,
1695 	    ("density code 0x%x, %d-byte blocks, write-%s, ",
1696 	    st->media_density, st->media_blksize,
1697 	    st->flags & ST_READONLY ? "protected" : "enabled"));
1698 	SC_DEBUG(sc_link, SDEV_DB3,
1699 	    ("%sbuffered\n",
1700 	    scsipi_sense.header.dev_spec & SMH_DSP_BUFF_MODE ? "" : "un"));
1701 	if (st->page_0_size)
1702 		bcopy(scsipi_sense.sense_data, st->sense_data,
1703 		    st->page_0_size);
1704 	sc_link->flags |= SDEV_MEDIA_LOADED;
1705 	return (0);
1706 }
1707 
1708 /*
1709  * Send a filled out parameter structure to the drive to
1710  * set it into the desire modes etc.
1711  */
1712 int
1713 st_mode_select(st, flags)
1714 	struct st_softc *st;
1715 	int flags;
1716 {
1717 	u_int scsi_select_len;
1718 	struct scsi_mode_select cmd;
1719 	struct scsi_select {
1720 		struct scsi_mode_header header;
1721 		struct scsi_blk_desc blk_desc;
1722 		u_char sense_data[MAX_PAGE_0_SIZE];
1723 	} scsi_select;
1724 	struct scsipi_link *sc_link = st->sc_link;
1725 
1726 	scsi_select_len = 12 + st->page_0_size;
1727 
1728 	/*
1729 	 * This quirk deals with drives that have only one valid mode
1730 	 * and think this gives them license to reject all mode selects,
1731 	 * even if the selected mode is the one that is supported.
1732 	 */
1733 	if (st->quirks & ST_Q_UNIMODAL) {
1734 		SC_DEBUG(sc_link, SDEV_DB3,
1735 		    ("not setting density 0x%x blksize 0x%x\n",
1736 		    st->density, st->blksize));
1737 		return (0);
1738 	}
1739 
1740 	/*
1741 	 * Set up for a mode select
1742 	 */
1743 	bzero(&cmd, sizeof(cmd));
1744 	cmd.opcode = SCSI_MODE_SELECT;
1745 	cmd.length = scsi_select_len;
1746 
1747 	bzero(&scsi_select, scsi_select_len);
1748 	scsi_select.header.blk_desc_len = sizeof(struct scsi_blk_desc);
1749 	scsi_select.header.dev_spec &= ~SMH_DSP_BUFF_MODE;
1750 	scsi_select.blk_desc.density = st->density;
1751 	if (st->flags & ST_DONTBUFFER)
1752 		scsi_select.header.dev_spec |= SMH_DSP_BUFF_MODE_OFF;
1753 	else
1754 		scsi_select.header.dev_spec |= SMH_DSP_BUFF_MODE_ON;
1755 	if (st->flags & ST_FIXEDBLOCKS)
1756 		_lto3b(st->blksize, scsi_select.blk_desc.blklen);
1757 	if (st->page_0_size)
1758 		bcopy(st->sense_data, scsi_select.sense_data, st->page_0_size);
1759 
1760 	/*
1761 	 * do the command
1762 	 */
1763 	return (scsipi_command(sc_link, (struct scsipi_generic *)&cmd,
1764 	    sizeof(cmd), (u_char *)&scsi_select, scsi_select_len,
1765 	    ST_RETRIES, ST_CTL_TIME, NULL, flags | XS_CTL_DATA_OUT));
1766 }
1767 
1768 int
1769 st_cmprss(st, onoff)
1770 	struct st_softc *st;
1771 	int onoff;
1772 {
1773 	u_int scsi_dlen;
1774 	struct scsi_mode_select mcmd;
1775 	struct scsi_mode_sense scmd;
1776 	struct scsi_select {
1777 		struct scsi_mode_header header;
1778 		struct scsi_blk_desc blk_desc;
1779 		u_char pdata[max(sizeof(struct scsi_tape_dev_conf_page),
1780 		    sizeof(struct scsi_tape_dev_compression_page))];
1781 	} scsi_pdata;
1782 	struct scsi_tape_dev_conf_page *ptr;
1783 	struct scsi_tape_dev_compression_page *cptr;
1784 	struct scsipi_link *sc_link = st->sc_link;
1785 	int error, ison, flags;
1786 
1787 	scsi_dlen = sizeof(scsi_pdata);
1788 	bzero(&scsi_pdata, scsi_dlen);
1789 
1790 	/*
1791 	 * Set up for a mode sense.
1792 	 * Do DATA COMPRESSION page first.
1793 	 */
1794 	bzero(&scmd, sizeof(scmd));
1795 	scmd.opcode = SCSI_MODE_SENSE;
1796 	scmd.page = SMS_PAGE_CTRL_CURRENT | 0xf;
1797 	scmd.length = scsi_dlen;
1798 
1799 	flags = XS_CTL_SILENT;
1800 
1801 	/*
1802 	 * Do the MODE SENSE command...
1803 	 */
1804 again:
1805 	bzero(&scsi_pdata, scsi_dlen);
1806 	error = scsipi_command(sc_link,
1807 	    (struct scsipi_generic *)&scmd, sizeof(scmd),
1808 	    (u_char *)&scsi_pdata, scsi_dlen,
1809 	    ST_RETRIES, ST_CTL_TIME, NULL, flags | XS_CTL_DATA_IN);
1810 
1811 	if (error) {
1812 		if (scmd.byte2 != SMS_DBD) {
1813 			scmd.byte2 = SMS_DBD;
1814 			goto again;
1815 		}
1816 		/*
1817 		 * Try a different page?
1818 		 */
1819 		if (scmd.page == (SMS_PAGE_CTRL_CURRENT | 0xf)) {
1820 			scmd.page = SMS_PAGE_CTRL_CURRENT | 0x10;
1821 			scmd.byte2 = 0;
1822 			goto again;
1823 		}
1824 		return (error);
1825 	}
1826 
1827 	if (scsi_pdata.header.blk_desc_len)
1828 		ptr = (struct scsi_tape_dev_conf_page *) scsi_pdata.pdata;
1829 	else
1830 		ptr = (struct scsi_tape_dev_conf_page *) &scsi_pdata.blk_desc;
1831 
1832 	if ((scmd.page & SMS_PAGE_CODE) == 0xf) {
1833 		cptr = (struct scsi_tape_dev_compression_page *) ptr;
1834 		ison = (cptr->dce_dcc & DCP_DCE) != 0;
1835 		if (onoff)
1836 			cptr->dce_dcc |= DCP_DCE;
1837 		else
1838 			cptr->dce_dcc &= ~DCP_DCE;
1839 		cptr->pagecode &= ~0x80;
1840 	} else {
1841 		ison =  (ptr->sel_comp_alg != 0);
1842 		if (onoff)
1843 			ptr->sel_comp_alg = 1;
1844 		else
1845 			ptr->sel_comp_alg = 0;
1846 		ptr->pagecode &= ~0x80;
1847 		ptr->byte2 = 0;
1848 		ptr->active_partition = 0;
1849 		ptr->wb_full_ratio = 0;
1850 		ptr->rb_empty_ratio = 0;
1851 		ptr->byte8 &= ~0x30;
1852 		ptr->gap_size = 0;
1853 		ptr->byte10 &= ~0xe7;
1854 		ptr->ew_bufsize[0] = 0;
1855 		ptr->ew_bufsize[1] = 0;
1856 		ptr->ew_bufsize[2] = 0;
1857 		ptr->reserved = 0;
1858 	}
1859 	onoff = onoff ? 1 : 0;
1860 	/*
1861 	 * There might be a virtue in actually doing the MODE SELECTS,
1862 	 * but let's not clog the bus over it.
1863 	 */
1864 	if (onoff == ison)
1865 		return (0);
1866 
1867 	/*
1868 	 * Set up for a mode select
1869 	 */
1870 
1871 	scsi_pdata.header.data_length = 0;
1872 	scsi_pdata.header.medium_type = 0;
1873 	if ((st->flags & ST_DONTBUFFER) == 0)
1874 		scsi_pdata.header.dev_spec = SMH_DSP_BUFF_MODE_ON;
1875 	else
1876 		scsi_pdata.header.dev_spec = 0;
1877 
1878 	bzero(&mcmd, sizeof(mcmd));
1879 	mcmd.opcode = SCSI_MODE_SELECT;
1880 	mcmd.byte2 = SMS_PF;
1881 	mcmd.length = scsi_dlen;
1882 	if (scsi_pdata.header.blk_desc_len) {
1883 		scsi_pdata.blk_desc.density = 0;
1884 		scsi_pdata.blk_desc.nblocks[0] = 0;
1885 		scsi_pdata.blk_desc.nblocks[1] = 0;
1886 		scsi_pdata.blk_desc.nblocks[2] = 0;
1887 	}
1888 
1889 	/*
1890 	 * Do the command
1891 	 */
1892 	error = scsipi_command(sc_link,
1893 	    (struct scsipi_generic *)&mcmd, sizeof(mcmd),
1894 	    (u_char *)&scsi_pdata, scsi_dlen,
1895 	    ST_RETRIES, ST_CTL_TIME, NULL, flags | XS_CTL_DATA_OUT);
1896 
1897 	if (error && (scmd.page & SMS_PAGE_CODE) == 0xf) {
1898 		/*
1899 		 * Try DEVICE CONFIGURATION page.
1900 		 */
1901 		scmd.page = SMS_PAGE_CTRL_CURRENT | 0x10;
1902 		goto again;
1903 	}
1904 	return (error);
1905 }
1906 /*
1907  * issue an erase command
1908  */
1909 int
1910 st_erase(st, full, flags)
1911 	struct st_softc *st;
1912 	int full, flags;
1913 {
1914 	int tmo;
1915 	struct scsi_erase cmd;
1916 
1917 	/*
1918 	 * Full erase means set LONG bit in erase command, which asks
1919 	 * the drive to erase the entire unit.  Without this bit, we're
1920 	 * asking the drive to write an erase gap.
1921 	 */
1922 	bzero(&cmd, sizeof(cmd));
1923 	cmd.opcode = ERASE;
1924 	if (full) {
1925 		cmd.byte2 = SE_IMMED|SE_LONG;
1926 		tmo = ST_SPC_TIME;
1927 	} else {
1928 		tmo = ST_IO_TIME;
1929 		cmd.byte2 = SE_IMMED;
1930 	}
1931 
1932 	/*
1933 	 * XXX We always do this asynchronously, for now.  How long should
1934 	 * we wait if we want to (eventually) to it synchronously?
1935 	 */
1936 	return (scsipi_command(st->sc_link,
1937 	    (struct scsipi_generic *)&cmd, sizeof(cmd),
1938 	    0, 0, ST_RETRIES, tmo, NULL, flags));
1939 }
1940 
1941 /*
1942  * skip N blocks/filemarks/seq filemarks/eom
1943  */
1944 int
1945 st_space(st, number, what, flags)
1946 	struct st_softc *st;
1947 	u_int what;
1948 	int flags;
1949 	int number;
1950 {
1951 	struct scsi_space cmd;
1952 	int error;
1953 
1954 	switch (what) {
1955 	case SP_BLKS:
1956 		if (st->flags & ST_PER_ACTION) {
1957 			if (number > 0) {
1958 				st->flags &= ~ST_PER_ACTION;
1959 				return (EIO);
1960 			} else if (number < 0) {
1961 				if (st->flags & ST_AT_FILEMARK) {
1962 					/*
1963 					 * Handling of ST_AT_FILEMARK
1964 					 * in st_space will fill in the
1965 					 * right file mark count.
1966 					 */
1967 					error = st_space(st, 0, SP_FILEMARKS,
1968 					    flags);
1969 					if (error)
1970 						return (error);
1971 				}
1972 				if (st->flags & ST_BLANK_READ) {
1973 					st->flags &= ~ST_BLANK_READ;
1974 					return (EIO);
1975 				}
1976 				st->flags &= ~(ST_EIO_PENDING|ST_EOM_PENDING);
1977 			}
1978 		}
1979 		break;
1980 	case SP_FILEMARKS:
1981 		if (st->flags & ST_EIO_PENDING) {
1982 			if (number > 0) {
1983 				/* pretend we just discovered the error */
1984 				st->flags &= ~ST_EIO_PENDING;
1985 				return (EIO);
1986 			} else if (number < 0) {
1987 				/* back away from the error */
1988 				st->flags &= ~ST_EIO_PENDING;
1989 			}
1990 		}
1991 		if (st->flags & ST_AT_FILEMARK) {
1992 			st->flags &= ~ST_AT_FILEMARK;
1993 			number--;
1994 		}
1995 		if ((st->flags & ST_BLANK_READ) && (number < 0)) {
1996 			/* back away from unwritten tape */
1997 			st->flags &= ~ST_BLANK_READ;
1998 			number++;	/* XXX dubious */
1999 		}
2000 		break;
2001 	case SP_EOM:
2002 		if (st->flags & ST_EOM_PENDING) {
2003 			/* we're already there */
2004 			st->flags &= ~ST_EOM_PENDING;
2005 			return (0);
2006 		}
2007 		if (st->flags & ST_EIO_PENDING) {
2008 			/* pretend we just discovered the error */
2009 			st->flags &= ~ST_EIO_PENDING;
2010 			return (EIO);
2011 		}
2012 		if (st->flags & ST_AT_FILEMARK)
2013 			st->flags &= ~ST_AT_FILEMARK;
2014 		break;
2015 	}
2016 	if (number == 0)
2017 		return (0);
2018 
2019 	bzero(&cmd, sizeof(cmd));
2020 	cmd.opcode = SPACE;
2021 	cmd.byte2 = what;
2022 	_lto3b(number, cmd.number);
2023 
2024 	return (scsipi_command(st->sc_link,
2025 	    (struct scsipi_generic *)&cmd, sizeof(cmd),
2026 	    0, 0, 0, ST_SPC_TIME, NULL, flags));
2027 }
2028 
2029 /*
2030  * write N filemarks
2031  */
2032 int
2033 st_write_filemarks(st, number, flags)
2034 	struct st_softc *st;
2035 	int flags;
2036 	int number;
2037 {
2038 	struct scsi_write_filemarks cmd;
2039 
2040 	/*
2041 	 * It's hard to write a negative number of file marks.
2042 	 * Don't try.
2043 	 */
2044 	if (number < 0)
2045 		return (EINVAL);
2046 	switch (number) {
2047 	case 0:		/* really a command to sync the drive's buffers */
2048 		break;
2049 	case 1:
2050 		if (st->flags & ST_FM_WRITTEN)	/* already have one down */
2051 			st->flags &= ~ST_WRITTEN;
2052 		else
2053 			st->flags |= ST_FM_WRITTEN;
2054 		st->flags &= ~ST_PER_ACTION;
2055 		break;
2056 	default:
2057 		st->flags &= ~(ST_PER_ACTION | ST_WRITTEN);
2058 	}
2059 
2060 	bzero(&cmd, sizeof(cmd));
2061 	cmd.opcode = WRITE_FILEMARKS;
2062 	_lto3b(number, cmd.number);
2063 
2064 	return (scsipi_command(st->sc_link,
2065 	    (struct scsipi_generic *)&cmd, sizeof(cmd),
2066 	    0, 0, 0, ST_IO_TIME * 4, NULL, flags));
2067 }
2068 
2069 /*
2070  * Make sure the right number of file marks is on tape if the
2071  * tape has been written.  If the position argument is true,
2072  * leave the tape positioned where it was originally.
2073  *
2074  * nmarks returns the number of marks to skip (or, if position
2075  * true, which were skipped) to get back original position.
2076  */
2077 int
2078 st_check_eod(st, position, nmarks, flags)
2079 	struct st_softc *st;
2080 	boolean position;
2081 	int *nmarks;
2082 	int flags;
2083 {
2084 	int error;
2085 
2086 	switch (st->flags & (ST_WRITTEN | ST_FM_WRITTEN | ST_2FM_AT_EOD)) {
2087 	default:
2088 		*nmarks = 0;
2089 		return (0);
2090 	case ST_WRITTEN:
2091 	case ST_WRITTEN | ST_FM_WRITTEN | ST_2FM_AT_EOD:
2092 		*nmarks = 1;
2093 		break;
2094 	case ST_WRITTEN | ST_2FM_AT_EOD:
2095 		*nmarks = 2;
2096 	}
2097 	error = st_write_filemarks(st, *nmarks, flags);
2098 	if (position && !error)
2099 		error = st_space(st, -*nmarks, SP_FILEMARKS, flags);
2100 	return (error);
2101 }
2102 
2103 /*
2104  * load/unload/retension
2105  */
2106 int
2107 st_load(st, type, flags)
2108 	struct st_softc *st;
2109 	u_int type;
2110 	int flags;
2111 {
2112 	int error;
2113 	struct scsi_load cmd;
2114 
2115 	if (type != LD_LOAD) {
2116 		int nmarks;
2117 
2118 		error = st_check_eod(st, FALSE, &nmarks, flags);
2119 		if (error) {
2120 			printf("%s: failed to write closing filemarks at "
2121 			    "unload, errno=%d\n", st->sc_dev.dv_xname, error);
2122 			return (error);
2123 		}
2124 	}
2125 	if (st->quirks & ST_Q_IGNORE_LOADS) {
2126 		if (type == LD_LOAD) {
2127 			/*
2128 			 * If we ignore loads, at least we should try a rewind.
2129 			 */
2130 			return st_rewind(st, 0, flags);
2131 		}
2132 		/* otherwise, we should do what's asked of us */
2133 	}
2134 
2135 	bzero(&cmd, sizeof(cmd));
2136 	cmd.opcode = LOAD;
2137 	cmd.how = type;
2138 
2139 	error = scsipi_command(st->sc_link,
2140 	    (struct scsipi_generic *)&cmd, sizeof(cmd),
2141 	    0, 0, ST_RETRIES, ST_SPC_TIME, NULL, flags);
2142 	if (error) {
2143 		printf("%s: error %d in st_load (op %d)\n",
2144 		    st->sc_dev.dv_xname, error, type);
2145 	}
2146 	return (error);
2147 }
2148 
2149 /*
2150  *  Rewind the device
2151  */
2152 int
2153 st_rewind(st, immediate, flags)
2154 	struct st_softc *st;
2155 	u_int immediate;
2156 	int flags;
2157 {
2158 	struct scsi_rewind cmd;
2159 	int error;
2160 	int nmarks;
2161 
2162 	error = st_check_eod(st, FALSE, &nmarks, flags);
2163 	if (error) {
2164 		printf("%s: failed to write closing filemarks at "
2165 		    "rewind, errno=%d\n", st->sc_dev.dv_xname, error);
2166 		return (error);
2167 	}
2168 	st->flags &= ~ST_PER_ACTION;
2169 
2170 	bzero(&cmd, sizeof(cmd));
2171 	cmd.opcode = REWIND;
2172 	cmd.byte2 = immediate;
2173 
2174 	error = scsipi_command(st->sc_link,
2175 	    (struct scsipi_generic *)&cmd, sizeof(cmd), 0, 0, ST_RETRIES,
2176 	    immediate ? ST_CTL_TIME: ST_SPC_TIME, NULL, flags);
2177 	if (error) {
2178 		printf("%s: error %d trying to rewind\n",
2179 		    st->sc_dev.dv_xname, error);
2180 	}
2181 	return (error);
2182 }
2183 
2184 int
2185 st_rdpos(st, hard, blkptr)
2186 	struct st_softc *st;
2187 	int hard;
2188 	u_int32_t *blkptr;
2189 {
2190 	int error;
2191 	u_int8_t posdata[20];
2192 	struct scsi_tape_read_position cmd;
2193 
2194 	/*
2195 	 * First flush any pending writes...
2196 	 */
2197 	error = st_write_filemarks(st, 0, XS_CTL_SILENT);
2198 
2199 	/*
2200 	 * The latter case is for 'write protected' tapes
2201 	 * which are too stupid to recognize a zero count
2202 	 * for writing filemarks as a no-op.
2203 	 */
2204 	if (error != 0 && error != EACCES && error != EROFS)
2205 		return (error);
2206 
2207 	bzero(&cmd, sizeof(cmd));
2208 	bzero(&posdata, sizeof(posdata));
2209 	cmd.opcode = READ_POSITION;
2210 	if (hard)
2211 		cmd.byte1 = 1;
2212 
2213 	error = scsipi_command(st->sc_link,
2214 	    (struct scsipi_generic *)&cmd, sizeof(cmd), (u_char *)&posdata,
2215 	    sizeof(posdata), ST_RETRIES, ST_CTL_TIME, NULL,
2216 	    XS_CTL_SILENT | XS_CTL_DATA_IN);
2217 
2218 	if (error == 0) {
2219 #if	0
2220 		printf("posdata:");
2221 		for (hard = 0; hard < sizeof(posdata); hard++)
2222 			printf("%02x ", posdata[hard] & 0xff);
2223 		printf("\n");
2224 #endif
2225 		if (posdata[0] & 0x4)	/* Block Position Unknown */
2226 			error = EINVAL;
2227 		else
2228 			*blkptr = _4btol(&posdata[4]);
2229 	}
2230 	return (error);
2231 }
2232 
2233 int
2234 st_setpos(st, hard, blkptr)
2235 	struct st_softc *st;
2236 	int hard;
2237 	u_int32_t *blkptr;
2238 {
2239 	int error;
2240 	struct scsi_tape_locate cmd;
2241 
2242 	/*
2243 	 * First flush any pending writes. Strictly speaking,
2244 	 * we're not supposed to have to worry about this,
2245 	 * but let's be untrusting.
2246 	 */
2247 	error = st_write_filemarks(st, 0, XS_CTL_SILENT);
2248 
2249 	/*
2250 	 * The latter case is for 'write protected' tapes
2251 	 * which are too stupid to recognize a zero count
2252 	 * for writing filemarks as a no-op.
2253 	 */
2254 	if (error != 0 && error != EACCES && error != EROFS)
2255 		return (error);
2256 
2257 	bzero(&cmd, sizeof(cmd));
2258 	cmd.opcode = LOCATE;
2259 	if (hard)
2260 		cmd.byte2 = 1 << 2;
2261 	_lto4b(*blkptr, cmd.blkaddr);
2262 	error = scsipi_command(st->sc_link,
2263 		(struct scsipi_generic *)&cmd, sizeof(cmd),
2264 		NULL, 0, ST_RETRIES, ST_SPC_TIME, NULL, 0);
2265 	/*
2266 	 * XXX: Note file && block number position now unknown (if
2267 	 * XXX: these things ever start being maintained in this driver)
2268 	 */
2269 	return (error);
2270 }
2271 
2272 
2273 /*
2274  * Look at the returned sense and act on the error and determine
2275  * the unix error number to pass back..., 0 (== report no error),
2276  * -1 = retry the operation, -2 continue error processing.
2277  */
2278 int
2279 st_interpret_sense(xs)
2280 	struct scsipi_xfer *xs;
2281 {
2282 	struct scsipi_link *sc_link = xs->sc_link;
2283 	struct scsipi_sense_data *sense = &xs->sense.scsi_sense;
2284 	struct buf *bp = xs->bp;
2285 	struct st_softc *st = sc_link->device_softc;
2286 	int retval = SCSIRET_CONTINUE;
2287 	int doprint = ((xs->xs_control & XS_CTL_SILENT) == 0);
2288 	u_int8_t key;
2289 	int32_t info;
2290 
2291 	/*
2292 	 * If it isn't a extended or extended/deferred error, let
2293 	 * the generic code handle it.
2294 	 */
2295 	if ((sense->error_code & SSD_ERRCODE) != 0x70 &&
2296 	    (sense->error_code & SSD_ERRCODE) != 0x71) {	/* DEFFERRED */
2297 		return (retval);
2298 	}
2299 
2300 	if (sense->error_code & SSD_ERRCODE_VALID)
2301 		info = _4btol(sense->info);
2302 	else
2303 		info = xs->datalen;	/* bad choice if fixed blocks */
2304 	key = sense->flags & SSD_KEY;
2305 	st->mt_erreg = key;
2306 	st->asc = sense->add_sense_code;
2307 	st->ascq = sense->add_sense_code_qual;
2308 	st->mt_resid = (short) info;
2309 
2310 	/*
2311 	 * If the device is not open yet, let generic handle
2312 	 */
2313 	if ((sc_link->flags & SDEV_OPEN) == 0) {
2314 		return (retval);
2315 	}
2316 
2317 
2318 	if (st->flags & ST_FIXEDBLOCKS) {
2319 		xs->resid = info * st->blksize;
2320 		if (sense->flags & SSD_EOM) {
2321 			if ((st->flags & ST_EARLYWARN) == 0)
2322 				st->flags |= ST_EIO_PENDING;
2323 			st->flags |= ST_EOM_PENDING;
2324 			if (bp)
2325 				bp->b_resid = xs->resid;
2326 		}
2327 		if (sense->flags & SSD_FILEMARK) {
2328 			st->flags |= ST_AT_FILEMARK;
2329 			if (bp)
2330 				bp->b_resid = xs->resid;
2331 		}
2332 		if (sense->flags & SSD_ILI) {
2333 			st->flags |= ST_EIO_PENDING;
2334 			if (bp)
2335 				bp->b_resid = xs->resid;
2336 			if (sense->error_code & SSD_ERRCODE_VALID &&
2337 			    (xs->xs_control & XS_CTL_SILENT) == 0)
2338 				printf("%s: block wrong size, %d blocks "
2339 				    "residual\n", st->sc_dev.dv_xname, info);
2340 
2341 			/*
2342 			 * This quirk code helps the drive read
2343 			 * the first tape block, regardless of
2344 			 * format.  That is required for these
2345 			 * drives to return proper MODE SENSE
2346 			 * information.
2347 			 */
2348 			if ((st->quirks & ST_Q_SENSE_HELP) &&
2349 			    !(sc_link->flags & SDEV_MEDIA_LOADED))
2350 				st->blksize -= 512;
2351 		}
2352 		/*
2353 		 * If data wanted and no data was tranfered, do it immediatly
2354 		 */
2355 		if (xs->datalen && xs->resid >= xs->datalen) {
2356 			if (st->flags & ST_EIO_PENDING)
2357 				return (EIO);
2358 			if (st->flags & ST_AT_FILEMARK) {
2359 				if (bp)
2360 					bp->b_resid = xs->resid;
2361 				return (SCSIRET_NOERROR);
2362 			}
2363 		}
2364 	} else {		/* must be variable mode */
2365 		if (sense->flags & SSD_EOM) {
2366 			/*
2367 			 * The current semantics of this
2368 			 * driver requires EOM detection
2369 			 * to return EIO unless early
2370 			 * warning detection is enabled
2371 			 * for variable mode (this is always
2372 			 * on for fixed block mode).
2373 			 */
2374 			if (st->flags & ST_EARLYWARN) {
2375 				st->flags |= ST_EOM_PENDING;
2376 				retval = SCSIRET_NOERROR;
2377 			} else {
2378 				retval = EIO;
2379 			}
2380 
2381 			/*
2382 			 * If it's an unadorned EOM detection,
2383 			 * suppress printing an error.
2384 			 */
2385 			if (key == SKEY_NO_SENSE) {
2386 				doprint = 0;
2387 			}
2388 		} else if (sense->flags & SSD_FILEMARK) {
2389 			retval = SCSIRET_NOERROR;
2390 		} else if (sense->flags & SSD_ILI) {
2391 			if (info < 0) {
2392 				/*
2393 				 * The tape record was bigger than the read
2394 				 * we issued.
2395 				 */
2396 				if ((xs->xs_control & XS_CTL_SILENT) == 0) {
2397 					printf("%s: %d-byte tape record too big"
2398 					    " for %d-byte user buffer\n",
2399 					    st->sc_dev.dv_xname,
2400 					    xs->datalen - info, xs->datalen);
2401 				}
2402 				retval = EIO;
2403 			} else {
2404 				retval = SCSIRET_NOERROR;
2405 			}
2406 		}
2407 		xs->resid = info;
2408 		if (bp)
2409 			bp->b_resid = info;
2410 	}
2411 
2412 #ifndef	SCSIDEBUG
2413 	if (retval == SCSIRET_NOERROR && key == SKEY_NO_SENSE) {
2414 		doprint = 0;
2415 	}
2416 #endif
2417 	if (key == SKEY_BLANK_CHECK) {
2418 		/*
2419 		 * This quirk code helps the drive read the
2420 		 * first tape block, regardless of format.  That
2421 		 * is required for these drives to return proper
2422 		 * MODE SENSE information.
2423 		 */
2424 		if ((st->quirks & ST_Q_SENSE_HELP) &&
2425 		    !(sc_link->flags & SDEV_MEDIA_LOADED)) {
2426 			/* still starting */
2427 			st->blksize -= 512;
2428 		} else if (!(st->flags & (ST_2FM_AT_EOD | ST_BLANK_READ))) {
2429 			st->flags |= ST_BLANK_READ;
2430 			xs->resid = xs->datalen;
2431 			if (bp) {
2432 				bp->b_resid = xs->resid;
2433 				/* return an EOF */
2434 			}
2435 			retval = SCSIRET_NOERROR;
2436 		}
2437 	}
2438 #ifdef	SCSIVERBOSE
2439 	if (doprint) {
2440 		scsipi_print_sense(xs, 0);
2441 	}
2442 #else
2443 	if (doprint) {
2444 		xs->sc_link->sc_print_addr(xs->sc_link);
2445 		printf("Sense Key 0x%02x", key);
2446 		if ((sense->error_code & SSD_ERRCODE_VALID) != 0) {
2447 			switch (key) {
2448 			case SKEY_NOT_READY:
2449 			case SKEY_ILLEGAL_REQUEST:
2450 			case SKEY_UNIT_ATTENTION:
2451 			case SKEY_WRITE_PROTECT:
2452 				break;
2453 			case SKEY_BLANK_CHECK:
2454 				printf(", requested size: %d (decimal)", info);
2455 				break;
2456 			case SKEY_ABORTED_COMMAND:
2457 				if (xs->retries)
2458 					printf(", retrying");
2459 				printf(", cmd 0x%x, info 0x%x",
2460 				    xs->cmd->opcode, info);
2461 				break;
2462 			default:
2463 				printf(", info = %d (decimal)", info);
2464 			}
2465 		}
2466 		if (sense->extra_len != 0) {
2467 			int n;
2468 			printf(", data =");
2469 			for (n = 0; n < sense->extra_len; n++)
2470 				printf(" %02x", sense->cmd_spec_info[n]);
2471 		}
2472 		printf("\n");
2473 	}
2474 #endif
2475 	return (retval);
2476 }
2477 
2478 /*
2479  * The quirk here is that the drive returns some value to st_mode_sense
2480  * incorrectly until the tape has actually passed by the head.
2481  *
2482  * The method is to set the drive to large fixed-block state (user-specified
2483  * density and 1024-byte blocks), then read and rewind to get it to sense the
2484  * tape.  If that doesn't work, try 512-byte fixed blocks.  If that doesn't
2485  * work, as a last resort, try variable- length blocks.  The result will be
2486  * the ability to do an accurate st_mode_sense.
2487  *
2488  * We know we can do a rewind because we just did a load, which implies rewind.
2489  * Rewind seems preferable to space backward if we have a virgin tape.
2490  *
2491  * The rest of the code for this quirk is in ILI processing and BLANK CHECK
2492  * error processing, both part of st_interpret_sense.
2493  */
2494 int
2495 st_touch_tape(st)
2496 	struct st_softc *st;
2497 {
2498 	char *buf;
2499 	int readsize;
2500 	int error;
2501 
2502 	buf = malloc(1024, M_TEMP, M_NOWAIT);
2503 	if (buf == NULL)
2504 		return (ENOMEM);
2505 
2506 	if ((error = st_mode_sense(st, 0)) != 0)
2507 		goto bad;
2508 	st->blksize = 1024;
2509 	do {
2510 		switch (st->blksize) {
2511 		case 512:
2512 		case 1024:
2513 			readsize = st->blksize;
2514 			st->flags |= ST_FIXEDBLOCKS;
2515 			break;
2516 		default:
2517 			readsize = 1;
2518 			st->flags &= ~ST_FIXEDBLOCKS;
2519 		}
2520 		if ((error = st_mode_select(st, 0)) != 0)
2521 			goto bad;
2522 		st_read(st, buf, readsize, XS_CTL_SILENT);	/* XXX */
2523 		if ((error = st_rewind(st, 0, 0)) != 0) {
2524 bad:			free(buf, M_TEMP);
2525 			return (error);
2526 		}
2527 	} while (readsize != 1 && readsize > st->blksize);
2528 
2529 	free(buf, M_TEMP);
2530 	return (0);
2531 }
2532 
2533 int
2534 stdump(dev, blkno, va, size)
2535 	dev_t dev;
2536 	daddr_t blkno;
2537 	caddr_t va;
2538 	size_t size;
2539 {
2540 
2541 	/* Not implemented. */
2542 	return (ENXIO);
2543 }
2544