xref: /netbsd-src/sys/dev/scsipi/st.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /*	$NetBSD: st.c,v 1.217 2010/05/30 04:38:04 pgoyette Exp $ */
2 
3 /*-
4  * Copyright (c) 1998, 2004 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  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 /*
33  * Originally written by Julian Elischer (julian@tfs.com)
34  * for TRW Financial Systems for use under the MACH(2.5) operating system.
35  *
36  * TRW Financial Systems, in accordance with their agreement with Carnegie
37  * Mellon University, makes this software available to CMU to distribute
38  * or use in any manner that they see fit as long as this message is kept with
39  * the software. For this reason TFS also grants any other persons or
40  * organisations permission to use or modify this software.
41  *
42  * TFS supplies this software to be publicly redistributed
43  * on the understanding that TFS is not responsible for the correct
44  * functioning of this software in any circumstances.
45  *
46  * Ported to run under 386BSD by Julian Elischer (julian@tfs.com) Sept 1992
47  * major changes by Julian Elischer (julian@jules.dialix.oz.au) May 1993
48  *
49  * A lot of rewhacking done by mjacob (mjacob@nas.nasa.gov).
50  */
51 
52 #include <sys/cdefs.h>
53 __KERNEL_RCSID(0, "$NetBSD: st.c,v 1.217 2010/05/30 04:38:04 pgoyette Exp $");
54 
55 #include "opt_scsi.h"
56 
57 #include <sys/param.h>
58 #include <sys/systm.h>
59 #include <sys/fcntl.h>
60 #include <sys/errno.h>
61 #include <sys/ioctl.h>
62 #include <sys/malloc.h>
63 #include <sys/buf.h>
64 #include <sys/bufq.h>
65 #include <sys/proc.h>
66 #include <sys/mtio.h>
67 #include <sys/device.h>
68 #include <sys/conf.h>
69 #include <sys/kernel.h>
70 #include <sys/vnode.h>
71 #include <sys/iostat.h>
72 #include <sys/sysctl.h>
73 
74 #include <dev/scsipi/scsi_spc.h>
75 #include <dev/scsipi/scsipi_all.h>
76 #include <dev/scsipi/scsi_all.h>
77 #include <dev/scsipi/scsi_tape.h>
78 #include <dev/scsipi/scsipiconf.h>
79 #include <dev/scsipi/scsipi_base.h>
80 #include <dev/scsipi/stvar.h>
81 
82 /* Defines for device specific stuff */
83 #define DEF_FIXED_BSIZE  512
84 
85 #define STMODE(z)	( minor(z)       & 0x03)
86 #define STDSTY(z)	((minor(z) >> 2) & 0x03)
87 #define STUNIT(z)	((minor(z) >> 4)       )
88 #define STNMINOR	16
89 
90 #define NORMAL_MODE	0
91 #define NOREW_MODE	1
92 #define EJECT_MODE	2
93 #define CTRL_MODE	3
94 
95 #ifndef		ST_MOUNT_DELAY
96 #define		ST_MOUNT_DELAY		0
97 #endif
98 
99 static dev_type_open(stopen);
100 static dev_type_close(stclose);
101 static dev_type_read(stread);
102 static dev_type_write(stwrite);
103 static dev_type_ioctl(stioctl);
104 static dev_type_strategy(ststrategy);
105 static dev_type_dump(stdump);
106 
107 const struct bdevsw st_bdevsw = {
108 	stopen, stclose, ststrategy, stioctl, stdump, nosize, D_TAPE
109 };
110 
111 const struct cdevsw st_cdevsw = {
112 	stopen, stclose, stread, stwrite, stioctl,
113 	nostop, notty, nopoll, nommap, nokqfilter, D_TAPE
114 };
115 
116 /*
117  * Define various devices that we know mis-behave in some way,
118  * and note how they are bad, so we can correct for them
119  */
120 
121 static const struct st_quirk_inquiry_pattern st_quirk_patterns[] = {
122 	{{T_SEQUENTIAL, T_REMOV,
123 	 "        ", "                ", "    "}, {0, 0, {
124 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
125 		{ST_Q_FORCE_BLKSIZE, 512, QIC_24},	/* minor 4-7 */
126 		{ST_Q_FORCE_BLKSIZE, 0, HALFINCH_1600},	/* minor 8-11 */
127 		{ST_Q_FORCE_BLKSIZE, 0, HALFINCH_6250}	/* minor 12-15 */
128 	}}},
129 	{{T_SEQUENTIAL, T_REMOV,
130 	 "TANDBERG", " TDC 3600       ", ""},     {0, 12, {
131 		{0, 0, 0},				/* minor 0-3 */
132 		{ST_Q_FORCE_BLKSIZE, 0, QIC_525},	/* minor 4-7 */
133 		{0, 0, QIC_150},			/* minor 8-11 */
134 		{0, 0, QIC_120}				/* minor 12-15 */
135 	}}},
136  	{{T_SEQUENTIAL, T_REMOV,
137  	 "TANDBERG", " TDC 3800       ", ""},     {0, 0, {
138 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
139 		{0, 0, QIC_525},			/* minor 4-7 */
140 		{0, 0, QIC_150},			/* minor 8-11 */
141 		{0, 0, QIC_120}				/* minor 12-15 */
142 	}}},
143 	{{T_SEQUENTIAL, T_REMOV,
144 	  "TANDBERG", " SLR5 4/8GB     ", ""},     {0, 0, {
145 		{ST_Q_FORCE_BLKSIZE, 1024, 0},		/* minor 0-3 */
146 		{0, 0, 0},				/* minor 4-7 */
147 		{0, 0, 0},				/* minor 8-11 */
148 		{0, 0, 0}				/* minor 12-15 */
149 	}}},
150 	/*
151 	 * lacking a manual for the 4200, it's not clear what the
152 	 * specific density codes should be- the device is a 2.5GB
153 	 * capable QIC drive, those density codes aren't readily
154 	 * availabel. The 'default' will just have to do.
155 	 */
156  	{{T_SEQUENTIAL, T_REMOV,
157  	 "TANDBERG", " TDC 4200       ", ""},     {0, 0, {
158 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
159 		{0, 0, QIC_525},			/* minor 4-7 */
160 		{0, 0, QIC_150},			/* minor 8-11 */
161 		{0, 0, QIC_120}				/* minor 12-15 */
162 	}}},
163 	/*
164 	 * At least -005 and -007 need this.  I'll assume they all do unless I
165 	 * hear otherwise.  - mycroft, 31MAR1994
166 	 */
167 	{{T_SEQUENTIAL, T_REMOV,
168 	 "ARCHIVE ", "VIPER 2525 25462", ""},     {0, 0, {
169 		{ST_Q_SENSE_HELP, 0, 0},		/* minor 0-3 */
170 		{ST_Q_SENSE_HELP, 0, QIC_525},		/* minor 4-7 */
171 		{0, 0, QIC_150},			/* minor 8-11 */
172 		{0, 0, QIC_120}				/* minor 12-15 */
173 	}}},
174 	/*
175 	 * One user reports that this works for his tape drive.  It probably
176 	 * needs more work.  - mycroft, 09APR1994
177 	 */
178 	{{T_SEQUENTIAL, T_REMOV,
179 	 "SANKYO  ", "CP525           ", ""},    {0, 0, {
180 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
181 		{ST_Q_FORCE_BLKSIZE, 512, QIC_525},	/* minor 4-7 */
182 		{0, 0, QIC_150},			/* minor 8-11 */
183 		{0, 0, QIC_120}				/* minor 12-15 */
184 	}}},
185 	{{T_SEQUENTIAL, T_REMOV,
186 	 "ANRITSU ", "DMT780          ", ""},     {0, 0, {
187 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
188 		{ST_Q_FORCE_BLKSIZE, 512, QIC_525},	/* minor 4-7 */
189 		{0, 0, QIC_150},			/* minor 8-11 */
190 		{0, 0, QIC_120}				/* minor 12-15 */
191 	}}},
192 	{{T_SEQUENTIAL, T_REMOV,
193 	 "ARCHIVE ", "VIPER 150  21247", ""},     {ST_Q_ERASE_NOIMM, 12, {
194 		{ST_Q_SENSE_HELP, 0, 0},		/* minor 0-3 */
195 		{0, 0, QIC_150},			/* minor 4-7 */
196 		{0, 0, QIC_120},			/* minor 8-11 */
197 		{0, 0, QIC_24}				/* minor 12-15 */
198 	}}},
199 	{{T_SEQUENTIAL, T_REMOV,
200 	 "ARCHIVE ", "VIPER 150  21531", ""},     {ST_Q_ERASE_NOIMM, 12, {
201 		{ST_Q_SENSE_HELP, 0, 0},		/* minor 0-3 */
202 		{0, 0, QIC_150},			/* minor 4-7 */
203 		{0, 0, QIC_120},			/* minor 8-11 */
204 		{0, 0, QIC_24}				/* minor 12-15 */
205 	}}},
206 	{{T_SEQUENTIAL, T_REMOV,
207 	 "WANGTEK ", "5099ES SCSI", ""},          {0, 0, {
208 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
209 		{0, 0, QIC_11},				/* minor 4-7 */
210 		{0, 0, QIC_24},				/* minor 8-11 */
211 		{0, 0, QIC_24}				/* minor 12-15 */
212 	}}},
213 	{{T_SEQUENTIAL, T_REMOV,
214 	 "WANGTEK ", "5150ES SCSI", ""},          {0, 0, {
215 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
216 		{0, 0, QIC_24},				/* minor 4-7 */
217 		{0, 0, QIC_120},			/* minor 8-11 */
218 		{0, 0, QIC_150}				/* minor 12-15 */
219 	}}},
220 	{{T_SEQUENTIAL, T_REMOV,
221 	 "WANGTEK ", "5525ES SCSI REV7", ""},     {0, 0, {
222 		{0, 0, 0},				/* minor 0-3 */
223 		{ST_Q_BLKSIZE, 0, QIC_525},		/* minor 4-7 */
224 		{0, 0, QIC_150},			/* minor 8-11 */
225 		{0, 0, QIC_120}				/* minor 12-15 */
226 	}}},
227 	{{T_SEQUENTIAL, T_REMOV,
228 	 "WangDAT ", "Model 1300      ", ""},     {0, 0, {
229 		{0, 0, 0},				/* minor 0-3 */
230 		{ST_Q_FORCE_BLKSIZE, 512, DDS},		/* minor 4-7 */
231 		{ST_Q_FORCE_BLKSIZE, 1024, DDS},	/* minor 8-11 */
232 		{ST_Q_FORCE_BLKSIZE, 0, DDS}		/* minor 12-15 */
233 	}}},
234 	{{T_SEQUENTIAL, T_REMOV,
235 	 "EXABYTE ", "EXB-8200        ", "263H"}, {0, 5, {
236 		{0, 0, 0},				/* minor 0-3 */
237 		{0, 0, 0},				/* minor 4-7 */
238 		{0, 0, 0},				/* minor 8-11 */
239 		{0, 0, 0}				/* minor 12-15 */
240 	}}},
241 	{{T_SEQUENTIAL, T_REMOV,
242 	 "STK",      "9490",             ""},
243 				{ST_Q_FORCE_BLKSIZE, 0, {
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",      "SD-3",             ""},
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 	 "IBM",      "03590",            ""},     {ST_Q_IGNORE_LOADS, 0, {
259 		{0, 0, 0},				/* minor 0-3 */
260 		{0, 0, 0},				/* minor 4-7 */
261 		{0, 0, 0},				/* minor 8-11 */
262 		{0, 0, 0}				/* minor 12-15 */
263 	}}},
264 	{{T_SEQUENTIAL, T_REMOV,
265 	 "HP      ", "T4000s          ", ""},     {ST_Q_UNIMODAL, 0, {
266 		{0, 0, QIC_3095},			/* minor 0-3 */
267 		{0, 0, QIC_3095},			/* minor 4-7 */
268 		{0, 0, QIC_3095},			/* minor 8-11 */
269 		{0, 0, QIC_3095},			/* minor 12-15 */
270 	}}},
271 #if 0
272 	{{T_SEQUENTIAL, T_REMOV,
273 	 "EXABYTE ", "EXB-8200        ", ""},     {0, 12, {
274 		{0, 0, 0},				/* minor 0-3 */
275 		{0, 0, 0},				/* minor 4-7 */
276 		{0, 0, 0},				/* minor 8-11 */
277 		{0, 0, 0}				/* minor 12-15 */
278 	}}},
279 #endif
280 	{{T_SEQUENTIAL, T_REMOV,
281 	 "TEAC    ", "MT-2ST/N50      ", ""},     {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 	{{T_SEQUENTIAL, T_REMOV,
288 	 "OnStream", "ADR50 Drive", ""},	  {ST_Q_UNIMODAL, 0, {
289 		{ST_Q_FORCE_BLKSIZE, 512, 0},	        /* minor 0-3 */
290 		{ST_Q_FORCE_BLKSIZE, 512, 0},	        /* minor 4-7 */
291 		{ST_Q_FORCE_BLKSIZE, 512, 0},	        /* minor 8-11 */
292 		{ST_Q_FORCE_BLKSIZE, 512, 0},	        /* minor 12-15 */
293 	}}},
294 	{{T_SEQUENTIAL, T_REMOV,
295 	 "OnStream DI-30",      "",   "1.0"},  {ST_Q_NOFILEMARKS, 0, {
296 		{0, 0, 0},                              /* minor 0-3 */
297 		{0, 0, 0},                              /* minor 4-7 */
298 		{0, 0, 0},                              /* minor 8-11 */
299 		{0, 0, 0}                               /* minor 12-15 */
300 	}}},
301 	{{T_SEQUENTIAL, T_REMOV,
302 	 "NCR H621", "0-STD-03-46F880 ", ""},     {ST_Q_NOPREVENT, 0, {
303 		{0, 0, 0},			       /* minor 0-3 */
304 		{0, 0, 0},			       /* minor 4-7 */
305 		{0, 0, 0},			       /* minor 8-11 */
306 		{0, 0, 0}			       /* minor 12-15 */
307 	}}},
308 	{{T_SEQUENTIAL, T_REMOV,
309 	 "Seagate STT3401A", "hp0atxa", ""},	{0, 0, {
310 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
311 		{ST_Q_FORCE_BLKSIZE, 1024, 0},		/* minor 4-7 */
312 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 8-11 */
313 		{ST_Q_FORCE_BLKSIZE, 512, 0}		/* minor 12-15 */
314 	}}},
315 };
316 
317 #define NOEJECT 0
318 #define EJECT 1
319 
320 static void	st_identify_drive(struct st_softc *,
321 		    struct scsipi_inquiry_pattern *);
322 static void	st_loadquirks(struct st_softc *);
323 static int	st_mount_tape(dev_t, int);
324 static void	st_unmount(struct st_softc *, boolean);
325 static int	st_decide_mode(struct st_softc *, boolean);
326 static void	ststart(struct scsipi_periph *);
327 static void	strestart(void *);
328 static void	stdone(struct scsipi_xfer *, int);
329 static int	st_read(struct st_softc *, char *, int, int);
330 static int	st_space(struct st_softc *, int, u_int, int);
331 static int	st_write_filemarks(struct st_softc *, int, int);
332 static int	st_check_eod(struct st_softc *, boolean, int *, int);
333 static int	st_load(struct st_softc *, u_int, int);
334 static int	st_rewind(struct st_softc *, u_int, int);
335 static int	st_interpret_sense(struct scsipi_xfer *);
336 static int	st_touch_tape(struct st_softc *);
337 static int	st_erase(struct st_softc *, int full, int flags);
338 static int	st_rdpos(struct st_softc *, int, u_int32_t *);
339 static int	st_setpos(struct st_softc *, int, u_int32_t *);
340 
341 static const struct scsipi_periphsw st_switch = {
342 	st_interpret_sense,
343 	ststart,
344 	NULL,
345 	stdone
346 };
347 
348 #if	defined(ST_ENABLE_EARLYWARN)
349 #define	ST_INIT_FLAGS	ST_EARLYWARN
350 #else
351 #define	ST_INIT_FLAGS	0
352 #endif
353 
354 /*
355  * The routine called by the low level scsi routine when it discovers
356  * A device suitable for this driver
357  */
358 void
359 stattach(device_t parent, struct st_softc *st, void *aux)
360 {
361 	struct scsipibus_attach_args *sa = aux;
362 	struct scsipi_periph *periph = sa->sa_periph;
363 
364 	SC_DEBUG(periph, SCSIPI_DB2, ("stattach: "));
365 
366 	/*
367 	 * Store information needed to contact our base driver
368 	 */
369 	st->sc_periph = periph;
370 	periph->periph_dev = &st->sc_dev;
371 	periph->periph_switch = &st_switch;
372 
373 	/*
374 	 * Set initial flags
375 	 */
376 
377 	st->flags = ST_INIT_FLAGS;
378 
379 	/*
380 	 * Set up the buf queue for this device
381 	 */
382 	bufq_alloc(&st->buf_queue, "fcfs", 0);
383 
384 	callout_init(&st->sc_callout, 0);
385 
386 	/*
387 	 * Check if the drive is a known criminal and take
388 	 * Any steps needed to bring it into line
389 	 */
390 	st_identify_drive(st, &sa->sa_inqbuf);
391 	/*
392 	 * Use the subdriver to request information regarding the drive.
393 	 */
394 	printf("\n");
395 	printf("%s: %s", device_xname(&st->sc_dev), st->quirkdata ? "quirks apply, " : "");
396 	if (scsipi_test_unit_ready(periph,
397 	    XS_CTL_DISCOVERY | XS_CTL_SILENT | XS_CTL_IGNORE_MEDIA_CHANGE) ||
398 	    st->ops(st, ST_OPS_MODESENSE,
399 	    XS_CTL_DISCOVERY | XS_CTL_SILENT | XS_CTL_IGNORE_MEDIA_CHANGE))
400 		printf("drive empty\n");
401 	else {
402 		printf("density code %d, ", st->media_density);
403 		if (st->media_blksize > 0)
404 			printf("%d-byte", st->media_blksize);
405 		else
406 			printf("variable");
407 		printf(" blocks, write-%s\n",
408 		    (st->flags & ST_READONLY) ? "protected" : "enabled");
409 	}
410 
411 	st->stats = iostat_alloc(IOSTAT_TAPE, parent, device_xname(&st->sc_dev));
412 
413 #if NRND > 0
414 	rnd_attach_source(&st->rnd_source, device_xname(&st->sc_dev),
415 			  RND_TYPE_TAPE, 0);
416 #endif
417 }
418 
419 int
420 stdetach(device_t self, int flags)
421 {
422 	struct st_softc *st = device_private(self);
423 	int s, bmaj, cmaj, mn;
424 
425 	/* locate the major number */
426 	bmaj = bdevsw_lookup_major(&st_bdevsw);
427 	cmaj = cdevsw_lookup_major(&st_cdevsw);
428 
429 	/* kill any pending restart */
430 	callout_stop(&st->sc_callout);
431 
432 	s = splbio();
433 
434 	/* Kill off any queued buffers. */
435 	bufq_drain(st->buf_queue);
436 
437 	bufq_free(st->buf_queue);
438 
439 	/* Kill off any pending commands. */
440 	scsipi_kill_pending(st->sc_periph);
441 
442 	splx(s);
443 
444 	/* Nuke the vnodes for any open instances */
445 	mn = STUNIT(device_unit(self));
446 	vdevgone(bmaj, mn, mn+STNMINOR-1, VBLK);
447 	vdevgone(cmaj, mn, mn+STNMINOR-1, VCHR);
448 
449 	iostat_free(st->stats);
450 
451 #if NRND > 0
452 	/* Unhook the entropy source. */
453 	rnd_detach_source(&st->rnd_source);
454 #endif
455 
456 	return (0);
457 }
458 
459 /*
460  * Use the inquiry routine in 'scsi_base' to get drive info so we can
461  * Further tailor our behaviour.
462  */
463 static void
464 st_identify_drive(struct st_softc *st, struct scsipi_inquiry_pattern *inqbuf)
465 {
466 	const struct st_quirk_inquiry_pattern *finger;
467 	int priority;
468 
469 	finger = scsipi_inqmatch(inqbuf,
470 	    st_quirk_patterns,
471 	    sizeof(st_quirk_patterns) / sizeof(st_quirk_patterns[0]),
472 	    sizeof(st_quirk_patterns[0]), &priority);
473 	if (priority != 0) {
474 		st->quirkdata = &finger->quirkdata;
475 		st->drive_quirks = finger->quirkdata.quirks;
476 		st->quirks = finger->quirkdata.quirks;	/* start value */
477 		st->page_0_size = finger->quirkdata.page_0_size;
478 		KASSERT(st->page_0_size <= MAX_PAGE_0_SIZE);
479 		st_loadquirks(st);
480 	}
481 }
482 
483 /*
484  * initialise the subdevices to the default (QUIRK) state.
485  * this will remove any setting made by the system operator or previous
486  * operations.
487  */
488 static void
489 st_loadquirks(struct st_softc *st)
490 {
491 	int i;
492 	const struct	modes *mode;
493 	struct	modes *mode2;
494 
495 	mode = st->quirkdata->modes;
496 	mode2 = st->modes;
497 	for (i = 0; i < 4; i++) {
498 		memset(mode2, 0, sizeof(struct modes));
499 		st->modeflags[i] &= ~(BLKSIZE_SET_BY_QUIRK |
500 		    DENSITY_SET_BY_QUIRK | BLKSIZE_SET_BY_USER |
501 		    DENSITY_SET_BY_USER);
502 		if ((mode->quirks | st->drive_quirks) & ST_Q_FORCE_BLKSIZE) {
503 			mode2->blksize = mode->blksize;
504 			st->modeflags[i] |= BLKSIZE_SET_BY_QUIRK;
505 		}
506 		if (mode->density) {
507 			mode2->density = mode->density;
508 			st->modeflags[i] |= DENSITY_SET_BY_QUIRK;
509 		}
510 		mode2->quirks |= mode->quirks;
511 		mode++;
512 		mode2++;
513 	}
514 }
515 
516 /*
517  * open the device.
518  */
519 static int
520 stopen(dev_t dev, int flags, int mode, struct lwp *l)
521 {
522 	u_int stmode, dsty;
523 	int error, sflags, unit, tries, ntries;
524 	struct st_softc *st;
525 	struct scsipi_periph *periph;
526 	struct scsipi_adapter *adapt;
527 
528 	unit = STUNIT(dev);
529 	st = device_lookup_private(&st_cd, unit);
530 	if (st == NULL)
531 		return (ENXIO);
532 
533 	stmode = STMODE(dev);
534 	dsty = STDSTY(dev);
535 
536 	periph = st->sc_periph;
537 	adapt = periph->periph_channel->chan_adapter;
538 
539 	SC_DEBUG(periph, SCSIPI_DB1, ("open: dev=0x%"PRIx64" (unit %d (of %d))\n", dev,
540 	    unit, st_cd.cd_ndevs));
541 
542 
543 	/*
544 	 * Only allow one at a time
545 	 */
546 	if (periph->periph_flags & PERIPH_OPEN) {
547 		aprint_error_dev(&st->sc_dev, "already open\n");
548 		return (EBUSY);
549 	}
550 
551 	if ((error = scsipi_adapter_addref(adapt)) != 0)
552 		return (error);
553 
554 	/*
555 	 * clear any latched errors.
556 	 */
557 	st->mt_resid = 0;
558 	st->mt_erreg = 0;
559 	st->asc = 0;
560 	st->ascq = 0;
561 
562 	/*
563 	 * Catch any unit attention errors. Be silent about this
564 	 * unless we're already mounted. We ignore media change
565 	 * if we're in control mode or not mounted yet.
566 	 */
567 	if ((st->flags & ST_MOUNTED) == 0 || stmode == CTRL_MODE) {
568 #ifdef SCSIDEBUG
569 		sflags = XS_CTL_IGNORE_MEDIA_CHANGE;
570 #else
571 		sflags = XS_CTL_SILENT|XS_CTL_IGNORE_MEDIA_CHANGE;
572 #endif
573 	} else
574 		sflags = 0;
575 
576 	/*
577 	 * If we're already mounted or we aren't configured for
578 	 * a mount delay, only try a test unit ready once. Otherwise,
579 	 * try up to ST_MOUNT_DELAY times with a rest interval of
580 	 * one second between each try.
581 	 */
582 
583 	if ((st->flags & ST_MOUNTED) || ST_MOUNT_DELAY == 0) {
584 		ntries = 1;
585 	} else {
586 		ntries = ST_MOUNT_DELAY;
587 	}
588 
589 	for (error = tries = 0; tries < ntries; tries++) {
590 		int slpintr, oflags;
591 
592 		/*
593 		 * If we had no error, or we're opening the control mode
594 		 * device, we jump out right away.
595 		 */
596 
597 		error = scsipi_test_unit_ready(periph, sflags);
598 		if (error == 0 || stmode == CTRL_MODE) {
599 			break;
600 		}
601 
602 		/*
603 		 * We had an error.
604 		 *
605 		 * If we're already mounted or we aren't configured for
606 		 * a mount delay, or the error isn't a NOT READY error,
607 		 * skip to the error exit now.
608 		 */
609 		if ((st->flags & ST_MOUNTED) || ST_MOUNT_DELAY == 0 ||
610 		    (st->mt_key != SKEY_NOT_READY)) {
611 			goto bad;
612 		}
613 
614 		/*
615 		 * clear any latched errors.
616 		 */
617 		st->mt_resid = 0;
618 		st->mt_erreg = 0;
619 		st->asc = 0;
620 		st->ascq = 0;
621 
622 		/*
623 		 * Fake that we have the device open so
624 		 * we block other apps from getting in.
625 		 */
626 
627 		oflags = periph->periph_flags;
628 		periph->periph_flags |= PERIPH_OPEN;
629 
630 		slpintr = kpause("stload", true, hz, NULL);
631 
632 		periph->periph_flags = oflags;	/* restore flags */
633 		if (slpintr != 0 && slpintr != EWOULDBLOCK) {
634 			goto bad;
635 		}
636 	}
637 
638 
639 	/*
640 	 * If the mode is 3 (e.g. minor = 3,7,11,15) then the device has
641 	 * been opened to set defaults and perform other, usually non-I/O
642 	 * related, operations. In this case, do a quick check to see
643 	 * whether the unit actually had a tape loaded (this will be known
644 	 * as to whether or not we got a NOT READY for the above
645 	 * unit attention). If a tape is there, go do a mount sequence.
646 	 */
647 	if (stmode == CTRL_MODE && st->mt_key == SKEY_NOT_READY) {
648 		periph->periph_flags |= PERIPH_OPEN;
649 		return (0);
650 	}
651 
652 	/*
653 	 * If we get this far and had an error set, that means we failed
654 	 * to pass the 'test unit ready' test for the non-controlmode device,
655 	 * so we bounce the open.
656 	 */
657 
658 	if (error)
659 		return (error);
660 
661 	/*
662 	 * Else, we're now committed to saying we're open.
663 	 */
664 
665 	periph->periph_flags |= PERIPH_OPEN; /* unit attn are now errors */
666 
667 	/*
668 	 * If it's a different mode, or if the media has been
669 	 * invalidated, unmount the tape from the previous
670 	 * session but continue with open processing
671 	 */
672 	if (st->last_dsty != dsty ||
673 	    (periph->periph_flags & PERIPH_MEDIA_LOADED) == 0)
674 		st_unmount(st, NOEJECT);
675 
676 	/*
677 	 * If we are not mounted, then we should start a new
678 	 * mount session.
679 	 */
680 	if (!(st->flags & ST_MOUNTED)) {
681 		if ((error = st_mount_tape(dev, flags)) != 0)
682 			goto bad;
683 		st->last_dsty = dsty;
684 	}
685 	if (!(st->quirks & ST_Q_NOPREVENT)) {
686 		scsipi_prevent(periph, SPAMR_PREVENT_DT,
687 		    XS_CTL_IGNORE_ILLEGAL_REQUEST | XS_CTL_IGNORE_NOT_READY);
688 	}
689 
690 	SC_DEBUG(periph, SCSIPI_DB2, ("open complete\n"));
691 	return (0);
692 
693 bad:
694 	st_unmount(st, NOEJECT);
695 	scsipi_adapter_delref(adapt);
696 	periph->periph_flags &= ~PERIPH_OPEN;
697 	return (error);
698 }
699 
700 /*
701  * close the device.. only called if we are the LAST
702  * occurence of an open device
703  */
704 static int
705 stclose(dev_t dev, int flags, int mode, struct lwp *l)
706 {
707 	int stxx, error = 0;
708 	struct st_softc *st = device_lookup_private(&st_cd, STUNIT(dev));
709 	struct scsipi_periph *periph = st->sc_periph;
710 	struct scsipi_adapter *adapt = periph->periph_channel->chan_adapter;
711 
712 	SC_DEBUG(st->sc_periph, SCSIPI_DB1, ("closing\n"));
713 
714 	/*
715 	 * Make sure that a tape opened in write-only mode will have
716 	 * file marks written on it when closed, even if not written to.
717 	 *
718 	 * This is for SUN compatibility. Actually, the Sun way of
719 	 * things is to:
720 	 *
721 	 *	only write filemarks if there are fmks to be written and
722 	 *   		- open for write (possibly read/write)
723 	 *		- the last operation was a write
724 	 * 	or:
725 	 *		- opened for wronly
726 	 *		- no data was written (including filemarks)
727 	 */
728 
729 	stxx = st->flags & (ST_WRITTEN | ST_FM_WRITTEN);
730 	if (((flags & FWRITE) && stxx == ST_WRITTEN) ||
731 	    ((flags & O_ACCMODE) == FWRITE && stxx == 0)) {
732 		int nm;
733 		error = st_check_eod(st, FALSE, &nm, 0);
734 	}
735 
736 	/*
737 	 * Allow robots to eject tape if needed.
738 	 */
739 	scsipi_prevent(periph, SPAMR_ALLOW,
740 	    XS_CTL_IGNORE_ILLEGAL_REQUEST | XS_CTL_IGNORE_NOT_READY);
741 
742 	switch (STMODE(dev)) {
743 	case NORMAL_MODE:
744 		st_unmount(st, NOEJECT);
745 		break;
746 	case NOREW_MODE:
747 	case CTRL_MODE:
748 		/*
749 		 * Leave mounted unless media seems to have been removed.
750 		 *
751 		 * Otherwise, if we're to terminate a tape with more than one
752 		 * filemark [ and because we're not rewinding here ], backspace
753 		 * one filemark so that later appends will see an unbroken
754 		 * sequence of:
755 		 *
756 		 *	file - FMK - file - FMK ... file - FMK FMK (EOM)
757 		 */
758 		if ((periph->periph_flags & PERIPH_MEDIA_LOADED) == 0) {
759 			st_unmount(st, NOEJECT);
760 		} else if (error == 0) {
761 			/*
762 			 * ST_WRITTEN was preserved from above.
763 			 *
764 			 * All we need to know here is:
765 			 *
766 			 *	Were we writing this tape and was the last
767 			 *	operation a write?
768 			 *
769 			 *	Are there supposed to be 2FM at EOD?
770 			 *
771 			 * If both statements are true, then we backspace
772 			 * one filemark.
773 			 */
774 			stxx |= (st->flags & ST_2FM_AT_EOD);
775 			if ((flags & FWRITE) != 0 &&
776 			    (stxx == (ST_2FM_AT_EOD|ST_WRITTEN))) {
777 				error = st_space(st, -1, SP_FILEMARKS, 0);
778 			}
779 		}
780 		break;
781 	case EJECT_MODE:
782 		st_unmount(st, EJECT);
783 		break;
784 	}
785 
786 	scsipi_wait_drain(periph);
787 
788 	scsipi_adapter_delref(adapt);
789 	periph->periph_flags &= ~PERIPH_OPEN;
790 
791 	return (error);
792 }
793 
794 /*
795  * Start a new mount session.
796  * Copy in all the default parameters from the selected device mode.
797  * and try guess any that seem to be defaulted.
798  */
799 static int
800 st_mount_tape(dev_t dev, int flags)
801 {
802 	int unit;
803 	u_int dsty;
804 	struct st_softc *st;
805 	struct scsipi_periph *periph;
806 	int error = 0;
807 
808 	unit = STUNIT(dev);
809 	dsty = STDSTY(dev);
810 	st = device_lookup_private(&st_cd, unit);
811 	periph = st->sc_periph;
812 
813 	if (st->flags & ST_MOUNTED)
814 		return (0);
815 
816 	SC_DEBUG(periph, SCSIPI_DB1, ("mounting\n "));
817 	st->flags |= ST_NEW_MOUNT;
818 	st->quirks = st->drive_quirks | st->modes[dsty].quirks;
819 	/*
820 	 * If the media is new, then make sure we give it a chance to
821 	 * to do a 'load' instruction.  (We assume it is new.)
822 	 */
823 	if ((error = st_load(st, LD_LOAD, XS_CTL_SILENT)) != 0)
824 		return (error);
825 	/*
826 	 * Throw another dummy instruction to catch
827 	 * 'Unit attention' errors. Many drives give
828 	 * these after doing a Load instruction (with
829 	 * the MEDIUM MAY HAVE CHANGED asc/ascq).
830 	 */
831 	scsipi_test_unit_ready(periph, XS_CTL_SILENT);	/* XXX */
832 
833 	/*
834 	 * Some devices can't tell you much until they have been
835 	 * asked to look at the media. This quirk does this.
836 	 */
837 	if (st->quirks & ST_Q_SENSE_HELP)
838 		if ((error = st_touch_tape(st)) != 0)
839 			return (error);
840 	/*
841 	 * Load the physical device parameters
842 	 * loads: blkmin, blkmax
843 	 */
844 	if ((error = st->ops(st, ST_OPS_RBL, 0)) != 0)
845 		return (error);
846 	/*
847 	 * Load the media dependent parameters
848 	 * includes: media_blksize,media_density,numblks
849 	 * As we have a tape in, it should be reflected here.
850 	 * If not you may need the "quirk" above.
851 	 */
852 	if ((error = st->ops(st, ST_OPS_MODESENSE, 0)) != 0)
853 		return (error);
854 	/*
855 	 * If we have gained a permanent density from somewhere,
856 	 * then use it in preference to the one supplied by
857 	 * default by the driver.
858 	 */
859 	if (st->modeflags[dsty] & (DENSITY_SET_BY_QUIRK | DENSITY_SET_BY_USER))
860 		st->density = st->modes[dsty].density;
861 	else
862 		st->density = st->media_density;
863 	/*
864 	 * If we have gained a permanent blocksize
865 	 * then use it in preference to the one supplied by
866 	 * default by the driver.
867 	 */
868 	st->flags &= ~ST_FIXEDBLOCKS;
869 	if (st->modeflags[dsty] &
870 	    (BLKSIZE_SET_BY_QUIRK | BLKSIZE_SET_BY_USER)) {
871 		st->blksize = st->modes[dsty].blksize;
872 		if (st->blksize)
873 			st->flags |= ST_FIXEDBLOCKS;
874 	} else {
875 		if ((error = st_decide_mode(st, FALSE)) != 0)
876 			return (error);
877 	}
878 	if ((error = st->ops(st, ST_OPS_MODESELECT, 0)) != 0) {
879 		/* ATAPI will return ENODEV for this, and this may be OK */
880 		if (error != ENODEV) {
881 			aprint_error_dev(&st->sc_dev, "cannot set selected mode\n");
882 			return (error);
883 		}
884 	}
885 	st->flags &= ~ST_NEW_MOUNT;
886 	st->flags |= ST_MOUNTED;
887 	periph->periph_flags |= PERIPH_MEDIA_LOADED;	/* move earlier? */
888 	st->blkno = st->fileno = (daddr_t) 0;
889 	return (0);
890 }
891 
892 /*
893  * End the present mount session.
894  * Rewind, and optionally eject the tape.
895  * Reset various flags to indicate that all new
896  * operations require another mount operation
897  */
898 static void
899 st_unmount(struct st_softc *st, boolean eject)
900 {
901 	struct scsipi_periph *periph = st->sc_periph;
902 	int nmarks;
903 
904 	if ((st->flags & ST_MOUNTED) == 0)
905 		return;
906 	SC_DEBUG(periph, SCSIPI_DB1, ("unmounting\n"));
907 	st_check_eod(st, FALSE, &nmarks, XS_CTL_IGNORE_NOT_READY);
908 	st_rewind(st, 0, XS_CTL_IGNORE_NOT_READY);
909 
910 	/*
911 	 * Section 9.3.3 of the SCSI specs states that a device shall return
912 	 * the density value specified in the last succesfull MODE SELECT
913 	 * after an unload operation, in case it is not able to
914 	 * automatically determine the density of the new medium.
915 	 *
916 	 * So we instruct the device to use the default density, which will
917 	 * prevent the use of stale density values (in particular,
918 	 * in st_touch_tape().
919 	 */
920 	st->density = 0;
921 	if (st->ops(st, ST_OPS_MODESELECT, 0) != 0) {
922 		aprint_error_dev(&st->sc_dev, "WARNING: cannot revert to default density\n");
923 	}
924 
925 	if (eject) {
926 		if (!(st->quirks & ST_Q_NOPREVENT)) {
927 			scsipi_prevent(periph, SPAMR_ALLOW,
928 			    XS_CTL_IGNORE_ILLEGAL_REQUEST |
929 			    XS_CTL_IGNORE_NOT_READY);
930 		}
931 		st_load(st, LD_UNLOAD, XS_CTL_IGNORE_NOT_READY);
932 		st->blkno = st->fileno = (daddr_t) -1;
933 	} else {
934 		st->blkno = st->fileno = (daddr_t) 0;
935 	}
936 	st->flags &= ~(ST_MOUNTED | ST_NEW_MOUNT);
937 	periph->periph_flags &= ~PERIPH_MEDIA_LOADED;
938 }
939 
940 /*
941  * Given all we know about the device, media, mode, 'quirks' and
942  * initial operation, make a decision as to how we should be set
943  * to run (regarding blocking and EOD marks)
944  */
945 int
946 st_decide_mode(struct st_softc *st, boolean first_read)
947 {
948 
949 	SC_DEBUG(st->sc_periph, SCSIPI_DB2, ("starting block mode decision\n"));
950 
951 	/*
952 	 * If the drive can only handle fixed-length blocks and only at
953 	 * one size, perhaps we should just do that.
954 	 */
955 	if (st->blkmin && (st->blkmin == st->blkmax)) {
956 		st->flags |= ST_FIXEDBLOCKS;
957 		st->blksize = st->blkmin;
958 		SC_DEBUG(st->sc_periph, SCSIPI_DB3,
959 		    ("blkmin == blkmax of %d\n", st->blkmin));
960 		goto done;
961 	}
962 	/*
963 	 * If the tape density mandates (or even suggests) use of fixed
964 	 * or variable-length blocks, comply.
965 	 */
966 	switch (st->density) {
967 	case HALFINCH_800:
968 	case HALFINCH_1600:
969 	case HALFINCH_6250:
970 	case DDS:
971 		st->flags &= ~ST_FIXEDBLOCKS;
972 		st->blksize = 0;
973 		SC_DEBUG(st->sc_periph, SCSIPI_DB3,
974 		    ("density specified variable\n"));
975 		goto done;
976 	case QIC_11:
977 	case QIC_24:
978 	case QIC_120:
979 	case QIC_150:
980 	case QIC_525:
981 	case QIC_1320:
982 	case QIC_3095:
983 	case QIC_3220:
984 		st->flags |= ST_FIXEDBLOCKS;
985 		if (st->media_blksize > 0)
986 			st->blksize = st->media_blksize;
987 		else
988 			st->blksize = DEF_FIXED_BSIZE;
989 		SC_DEBUG(st->sc_periph, SCSIPI_DB3,
990 		    ("density specified fixed\n"));
991 		goto done;
992 	}
993 	/*
994 	 * If we're about to read the tape, perhaps we should choose
995 	 * fixed or variable-length blocks and block size according to
996 	 * what the drive found on the tape.
997 	 */
998 	if (first_read &&
999 	    (!(st->quirks & ST_Q_BLKSIZE) || (st->media_blksize == 0) ||
1000 	    (st->media_blksize == DEF_FIXED_BSIZE) ||
1001 	    (st->media_blksize == 1024))) {
1002 		if (st->media_blksize > 0)
1003 			st->flags |= ST_FIXEDBLOCKS;
1004 		else
1005 			st->flags &= ~ST_FIXEDBLOCKS;
1006 		st->blksize = st->media_blksize;
1007 		SC_DEBUG(st->sc_periph, SCSIPI_DB3,
1008 		    ("Used media_blksize of %d\n", st->media_blksize));
1009 		goto done;
1010 	}
1011 	/*
1012 	 * We're getting no hints from any direction.  Choose variable-
1013 	 * length blocks arbitrarily.
1014 	 */
1015 	st->flags &= ~ST_FIXEDBLOCKS;
1016 	st->blksize = 0;
1017 	SC_DEBUG(st->sc_periph, SCSIPI_DB3,
1018 	    ("Give up and default to variable mode\n"));
1019 
1020 done:
1021 	/*
1022 	 * Decide whether or not to write two file marks to signify end-
1023 	 * of-data.  Make the decision as a function of density.  If
1024 	 * the decision is not to use a second file mark, the SCSI BLANK
1025 	 * CHECK condition code will be recognized as end-of-data when
1026 	 * first read.
1027 	 * (I think this should be a by-product of fixed/variable..julian)
1028 	 */
1029 	switch (st->density) {
1030 /*      case 8 mm:   What is the SCSI density code for 8 mm, anyway? */
1031 	case QIC_11:
1032 	case QIC_24:
1033 	case QIC_120:
1034 	case QIC_150:
1035 	case QIC_525:
1036 	case QIC_1320:
1037 	case QIC_3095:
1038 	case QIC_3220:
1039 		st->flags &= ~ST_2FM_AT_EOD;
1040 		break;
1041 	default:
1042 		st->flags |= ST_2FM_AT_EOD;
1043 	}
1044 	return (0);
1045 }
1046 
1047 /*
1048  * Actually translate the requested transfer into
1049  * one the physical driver can understand
1050  * The transfer is described by a buf and will include
1051  * only one physical transfer.
1052  */
1053 static void
1054 ststrategy(struct buf *bp)
1055 {
1056 	struct st_softc *st = device_lookup_private(&st_cd, STUNIT(bp->b_dev));
1057 	int s;
1058 
1059 	SC_DEBUG(st->sc_periph, SCSIPI_DB1,
1060 	    ("ststrategy %d bytes @ blk %" PRId64 "\n", bp->b_bcount, bp->b_blkno));
1061 	/*
1062 	 * If it's a null transfer, return immediately
1063 	 */
1064 	if (bp->b_bcount == 0)
1065 		goto abort;
1066 
1067 	/* If offset is negative, error */
1068 	if (bp->b_blkno < 0) {
1069 		bp->b_error = EINVAL;
1070 		goto abort;
1071 	}
1072 
1073 	/*
1074 	 * Odd sized request on fixed drives are verboten
1075 	 */
1076 	if (st->flags & ST_FIXEDBLOCKS) {
1077 		if (bp->b_bcount % st->blksize) {
1078 			aprint_error_dev(&st->sc_dev, "bad request, must be multiple of %d\n",
1079 			    st->blksize);
1080 			bp->b_error = EIO;
1081 			goto abort;
1082 		}
1083 	}
1084 	/*
1085 	 * as are out-of-range requests on variable drives.
1086 	 */
1087 	else if (bp->b_bcount < st->blkmin ||
1088 	    (st->blkmax && bp->b_bcount > st->blkmax)) {
1089 		aprint_error_dev(&st->sc_dev, "bad request, must be between %d and %d\n",
1090 		    st->blkmin, st->blkmax);
1091 		bp->b_error = EIO;
1092 		goto abort;
1093 	}
1094 	s = splbio();
1095 
1096 	/*
1097 	 * Place it in the queue of activities for this tape
1098 	 * at the end (a bit silly because we only have on user..
1099 	 * (but it could fork()))
1100 	 */
1101 	bufq_put(st->buf_queue, bp);
1102 
1103 	/*
1104 	 * Tell the device to get going on the transfer if it's
1105 	 * not doing anything, otherwise just wait for completion
1106 	 * (All a bit silly if we're only allowing 1 open but..)
1107 	 */
1108 	ststart(st->sc_periph);
1109 
1110 	splx(s);
1111 	return;
1112 abort:
1113 	/*
1114 	 * Reset the residue because we didn't do anything,
1115 	 * and send the buffer back as done.
1116 	 */
1117 	bp->b_resid = bp->b_bcount;
1118 	biodone(bp);
1119 	return;
1120 }
1121 
1122 /*
1123  * ststart looks to see if there is a buf waiting for the device
1124  * and that the device is not already busy. If both are true,
1125  * It dequeues the buf and creates a scsi command to perform the
1126  * transfer required. The transfer request will call scsipi_done
1127  * on completion, which will in turn call this routine again
1128  * so that the next queued transfer is performed.
1129  * The bufs are queued by the strategy routine (ststrategy)
1130  *
1131  * This routine is also called after other non-queued requests
1132  * have been made of the scsi driver, to ensure that the queue
1133  * continues to be drained.
1134  * ststart() is called at splbio
1135  */
1136 static void
1137 ststart(struct scsipi_periph *periph)
1138 {
1139 	struct st_softc *st = (void *)periph->periph_dev;
1140 	struct buf *bp;
1141 	struct scsi_rw_tape cmd;
1142 	struct scsipi_xfer *xs;
1143 	int flags, error;
1144 
1145 	SC_DEBUG(periph, SCSIPI_DB2, ("ststart "));
1146 	/*
1147 	 * See if there is a buf to do and we are not already
1148 	 * doing one
1149 	 */
1150 	while (periph->periph_active < periph->periph_openings) {
1151 		/* if a special awaits, let it proceed first */
1152 		if (periph->periph_flags & PERIPH_WAITING) {
1153 			periph->periph_flags &= ~PERIPH_WAITING;
1154 			wakeup((void *)periph);
1155 			return;
1156 		}
1157 
1158 		/*
1159 		 * If the device has been unmounted by the user
1160 		 * then throw away all requests until done.
1161 		 */
1162 		if (__predict_false((st->flags & ST_MOUNTED) == 0 ||
1163 		    (periph->periph_flags & PERIPH_MEDIA_LOADED) == 0)) {
1164 			if ((bp = bufq_get(st->buf_queue)) != NULL) {
1165 				/* make sure that one implies the other.. */
1166 				periph->periph_flags &= ~PERIPH_MEDIA_LOADED;
1167 				bp->b_error = EIO;
1168 				bp->b_resid = bp->b_bcount;
1169 				biodone(bp);
1170 				continue;
1171 			} else {
1172 				return;
1173 			}
1174 		}
1175 
1176 		if ((bp = bufq_peek(st->buf_queue)) == NULL)
1177 			return;
1178 
1179 		iostat_busy(st->stats);
1180 
1181 		/*
1182 		 * only FIXEDBLOCK devices have pending I/O or space operations.
1183 		 */
1184 		if (st->flags & ST_FIXEDBLOCKS) {
1185 			/*
1186 			 * If we are at a filemark but have not reported it yet
1187 			 * then we should report it now
1188 			 */
1189 			if (st->flags & ST_AT_FILEMARK) {
1190 				if ((bp->b_flags & B_READ) == B_WRITE) {
1191 					/*
1192 					 * Handling of ST_AT_FILEMARK in
1193 					 * st_space will fill in the right file
1194 					 * mark count.
1195 					 * Back up over filemark
1196 					 */
1197 					if (st_space(st, 0, SP_FILEMARKS, 0)) {
1198 						bufq_get(st->buf_queue);
1199 						bp->b_error = EIO;
1200 						bp->b_resid = bp->b_bcount;
1201 						biodone(bp);
1202 						continue;
1203 					}
1204 				} else {
1205 					bufq_get(st->buf_queue);
1206 					bp->b_resid = bp->b_bcount;
1207 					bp->b_error = 0;
1208 					st->flags &= ~ST_AT_FILEMARK;
1209 					biodone(bp);
1210 					continue;	/* seek more work */
1211 				}
1212 			}
1213 		}
1214 		/*
1215 		 * If we are at EOM but have not reported it
1216 		 * yet then we should report it now.
1217 		 */
1218 		if (st->flags & (ST_EOM_PENDING|ST_EIO_PENDING)) {
1219 			bufq_get(st->buf_queue);
1220 			bp->b_resid = bp->b_bcount;
1221 			if (st->flags & ST_EIO_PENDING)
1222 				bp->b_error = EIO;
1223 			st->flags &= ~(ST_EOM_PENDING|ST_EIO_PENDING);
1224 			biodone(bp);
1225 			continue;	/* seek more work */
1226 		}
1227 
1228 		/*
1229 		 * Fill out the scsi command
1230 		 */
1231 		memset(&cmd, 0, sizeof(cmd));
1232 		flags = XS_CTL_NOSLEEP | XS_CTL_ASYNC;
1233 		if ((bp->b_flags & B_READ) == B_WRITE) {
1234 			cmd.opcode = WRITE;
1235 			st->flags &= ~ST_FM_WRITTEN;
1236 			flags |= XS_CTL_DATA_OUT;
1237 		} else {
1238 			cmd.opcode = READ;
1239 			flags |= XS_CTL_DATA_IN;
1240 		}
1241 
1242 		/*
1243 		 * Handle "fixed-block-mode" tape drives by using the
1244 		 * block count instead of the length.
1245 		 */
1246 		if (st->flags & ST_FIXEDBLOCKS) {
1247 			cmd.byte2 |= SRW_FIXED;
1248 			_lto3b(bp->b_bcount / st->blksize, cmd.len);
1249 		} else
1250 			_lto3b(bp->b_bcount, cmd.len);
1251 
1252 		/*
1253 		 * Clear 'position updated' indicator
1254 		 */
1255 		st->flags &= ~ST_POSUPDATED;
1256 
1257 		/*
1258 		 * go ask the adapter to do all this for us
1259 		 */
1260 		xs = scsipi_make_xs(periph,
1261 		    (struct scsipi_generic *)&cmd, sizeof(cmd),
1262 		    (u_char *)bp->b_data, bp->b_bcount,
1263 		    0, ST_IO_TIME, bp, flags);
1264 		if (__predict_false(xs == NULL)) {
1265 			/*
1266 			 * out of memory. Keep this buffer in the queue, and
1267 			 * retry later.
1268 			 */
1269 			callout_reset(&st->sc_callout, hz / 2, strestart,
1270 			    periph);
1271 			return;
1272 		}
1273 		/*
1274 		 * need to dequeue the buffer before queuing the command,
1275 		 * because cdstart may be called recursively from the
1276 		 * HBA driver
1277 		 */
1278 #ifdef DIAGNOSTIC
1279 		if (bufq_get(st->buf_queue) != bp)
1280 			panic("ststart(): dequeued wrong buf");
1281 #else
1282 		bufq_get(st->buf_queue);
1283 #endif
1284 		error = scsipi_execute_xs(xs);
1285 		/* with a scsipi_xfer preallocated, scsipi_command can't fail */
1286 		KASSERT(error == 0);
1287 	} /* go back and see if we can cram more work in.. */
1288 }
1289 
1290 static void
1291 strestart(void *v)
1292 {
1293 	int s = splbio();
1294 	ststart((struct scsipi_periph *)v);
1295 	splx(s);
1296 }
1297 
1298 
1299 static void
1300 stdone(struct scsipi_xfer *xs, int error)
1301 {
1302 	struct st_softc *st = (void *)xs->xs_periph->periph_dev;
1303 	struct buf *bp = xs->bp;
1304 
1305 	if (bp) {
1306 		bp->b_error = error;
1307 		bp->b_resid = xs->resid;
1308 		/*
1309 		 * buggy device ? A SDLT320 can report an info
1310 		 * field of 0x3de8000 on a Media Error/Write Error
1311 		 * for this CBD: 0x0a 00 00 80 00 00
1312 		 */
1313 		if (bp->b_resid > bp->b_bcount || bp->b_resid < 0)
1314 			bp->b_resid = bp->b_bcount;
1315 
1316 		if ((bp->b_flags & B_READ) == B_WRITE)
1317 			st->flags |= ST_WRITTEN;
1318 		else
1319 			st->flags &= ~ST_WRITTEN;
1320 
1321 		iostat_unbusy(st->stats, bp->b_bcount,
1322 			     ((bp->b_flags & B_READ) == B_READ));
1323 
1324 #if NRND > 0
1325 		rnd_add_uint32(&st->rnd_source, bp->b_blkno);
1326 #endif
1327 
1328 		if ((st->flags & ST_POSUPDATED) == 0) {
1329 			if (error) {
1330 				st->fileno = st->blkno = -1;
1331 			} else if (st->blkno != -1) {
1332 				if (st->flags & ST_FIXEDBLOCKS)
1333 					st->blkno +=
1334 					    (bp->b_bcount / st->blksize);
1335 				else
1336 					st->blkno++;
1337 			}
1338 		}
1339 
1340 		biodone(bp);
1341 	}
1342 }
1343 
1344 static int
1345 stread(dev_t dev, struct uio *uio, int iomode)
1346 {
1347 	struct st_softc *st = device_lookup_private(&st_cd, STUNIT(dev));
1348 
1349 	return (physio(ststrategy, NULL, dev, B_READ,
1350 	    st->sc_periph->periph_channel->chan_adapter->adapt_minphys, uio));
1351 }
1352 
1353 static int
1354 stwrite(dev_t dev, struct uio *uio, int iomode)
1355 {
1356 	struct st_softc *st = device_lookup_private(&st_cd, STUNIT(dev));
1357 
1358 	return (physio(ststrategy, NULL, dev, B_WRITE,
1359 	    st->sc_periph->periph_channel->chan_adapter->adapt_minphys, uio));
1360 }
1361 
1362 /*
1363  * Perform special action on behalf of the user;
1364  * knows about the internals of this device
1365  */
1366 static int
1367 stioctl(dev_t dev, u_long cmd, void *arg, int flag, struct lwp *l)
1368 {
1369 	int error = 0;
1370 	int unit;
1371 	int number, nmarks, dsty;
1372 	int flags;
1373 	struct st_softc *st;
1374 	int hold_blksize;
1375 	u_int8_t hold_density;
1376 	struct mtop *mt = (struct mtop *) arg;
1377 
1378 	/*
1379 	 * Find the device that the user is talking about
1380 	 */
1381 	flags = 0;		/* give error messages, act on errors etc. */
1382 	unit = STUNIT(dev);
1383 	dsty = STDSTY(dev);
1384 	st = device_lookup_private(&st_cd, unit);
1385 	hold_blksize = st->blksize;
1386 	hold_density = st->density;
1387 
1388 	switch ((u_int) cmd) {
1389 
1390 	case MTIOCGET: {
1391 		struct mtget *g = (struct mtget *) arg;
1392 		/*
1393 		 * (to get the current state of READONLY)
1394 		 */
1395 		error = st->ops(st, ST_OPS_MODESENSE, XS_CTL_SILENT);
1396 		if (error) {
1397 			/*
1398 			 * Ignore the error if in control mode;
1399 			 * this is mandated by st(4).
1400 			 */
1401 			if (STMODE(dev) != CTRL_MODE)
1402 				break;
1403 			error = 0;
1404 		}
1405 		SC_DEBUG(st->sc_periph, SCSIPI_DB1, ("[ioctl: get status]\n"));
1406 		memset(g, 0, sizeof(struct mtget));
1407 		g->mt_type = 0x7;	/* Ultrix compat *//*? */
1408 		g->mt_blksiz = st->blksize;
1409 		g->mt_density = st->density;
1410 		g->mt_mblksiz[0] = st->modes[0].blksize;
1411 		g->mt_mblksiz[1] = st->modes[1].blksize;
1412 		g->mt_mblksiz[2] = st->modes[2].blksize;
1413 		g->mt_mblksiz[3] = st->modes[3].blksize;
1414 		g->mt_mdensity[0] = st->modes[0].density;
1415 		g->mt_mdensity[1] = st->modes[1].density;
1416 		g->mt_mdensity[2] = st->modes[2].density;
1417 		g->mt_mdensity[3] = st->modes[3].density;
1418 		g->mt_fileno = st->fileno;
1419 		g->mt_blkno = st->blkno;
1420 		if (st->flags & ST_READONLY)
1421 			g->mt_dsreg |= MT_DS_RDONLY;
1422 		if (st->flags & ST_MOUNTED)
1423 			g->mt_dsreg |= MT_DS_MOUNTED;
1424 		g->mt_resid = st->mt_resid;
1425 		g->mt_erreg = st->mt_erreg;
1426 		/*
1427 		 * clear latched errors.
1428 		 */
1429 		st->mt_resid = 0;
1430 		st->mt_erreg = 0;
1431 		st->asc = 0;
1432 		st->ascq = 0;
1433 		break;
1434 	}
1435 	case MTIOCTOP: {
1436 
1437 		SC_DEBUG(st->sc_periph, SCSIPI_DB1,
1438 		    ("[ioctl: op=0x%x count=0x%x]\n", mt->mt_op,
1439 			mt->mt_count));
1440 
1441 		/* compat: in U*x it is a short */
1442 		number = mt->mt_count;
1443 		switch ((short) (mt->mt_op)) {
1444 		case MTWEOF:	/* write an end-of-file record */
1445 			error = st_write_filemarks(st, number, flags);
1446 			break;
1447 		case MTBSF:	/* backward space file */
1448 			number = -number;
1449 		case MTFSF:	/* forward space file */
1450 			error = st_check_eod(st, FALSE, &nmarks, flags);
1451 			if (!error)
1452 				error = st_space(st, number - nmarks,
1453 				    SP_FILEMARKS, flags);
1454 			break;
1455 		case MTBSR:	/* backward space record */
1456 			number = -number;
1457 		case MTFSR:	/* forward space record */
1458 			error = st_check_eod(st, true, &nmarks, flags);
1459 			if (!error)
1460 				error = st_space(st, number, SP_BLKS, flags);
1461 			break;
1462 		case MTREW:	/* rewind */
1463 			error = st_rewind(st, 0, flags);
1464 			break;
1465 		case MTOFFL:	/* rewind and put the drive offline */
1466 			st_unmount(st, EJECT);
1467 			break;
1468 		case MTNOP:	/* no operation, sets status only */
1469 			break;
1470 		case MTRETEN:	/* retension the tape */
1471 			error = st_load(st, LD_RETENSION, flags);
1472 			if (!error)
1473 				error = st_load(st, LD_LOAD, flags);
1474 			break;
1475 		case MTEOM:	/* forward space to end of media */
1476 			error = st_check_eod(st, FALSE, &nmarks, flags);
1477 			if (!error)
1478 				error = st_space(st, 1, SP_EOM, flags);
1479 			break;
1480 		case MTCACHE:	/* enable controller cache */
1481 			st->flags &= ~ST_DONTBUFFER;
1482 			goto try_new_value;
1483 		case MTNOCACHE:	/* disable controller cache */
1484 			st->flags |= ST_DONTBUFFER;
1485 			goto try_new_value;
1486 		case MTERASE:	/* erase volume */
1487 			error = st_erase(st, number, flags);
1488 			break;
1489 		case MTSETBSIZ:	/* Set block size for device */
1490 #ifdef	NOTYET
1491 			if (!(st->flags & ST_NEW_MOUNT)) {
1492 				uprintf("re-mount tape before changing blocksize");
1493 				error = EINVAL;
1494 				break;
1495 			}
1496 #endif
1497 			if (number == 0)
1498 				st->flags &= ~ST_FIXEDBLOCKS;
1499 			else {
1500 				if ((st->blkmin || st->blkmax) &&
1501 				    (number < st->blkmin ||
1502 				    number > st->blkmax)) {
1503 					error = EINVAL;
1504 					break;
1505 				}
1506 				st->flags |= ST_FIXEDBLOCKS;
1507 			}
1508 			st->blksize = number;
1509 			st->flags |= ST_BLOCK_SET;	/*XXX */
1510 			goto try_new_value;
1511 
1512 		case MTSETDNSTY:	/* Set density for device and mode */
1513 			/*
1514 			 * Any number >= 0 and <= 0xff is legal. Numbers
1515 			 * above 0x80 are 'vendor unique'.
1516 			 */
1517 			if (number < 0 || number > 255) {
1518 				error = EINVAL;
1519 				break;
1520 			} else
1521 				st->density = number;
1522 			goto try_new_value;
1523 
1524 		case MTCMPRESS:
1525 			error = st->ops(st, (number == 0) ?
1526 			    ST_OPS_CMPRSS_OFF : ST_OPS_CMPRSS_ON,
1527 			    XS_CTL_SILENT);
1528 			break;
1529 
1530 		case MTEWARN:
1531 			if (number)
1532 				st->flags |= ST_EARLYWARN;
1533 			else
1534 				st->flags &= ~ST_EARLYWARN;
1535 			break;
1536 
1537 		default:
1538 			error = EINVAL;
1539 		}
1540 		break;
1541 	}
1542 	case MTIOCIEOT:
1543 	case MTIOCEEOT:
1544 		break;
1545 
1546 	case MTIOCRDSPOS:
1547 		error = st_rdpos(st, 0, (u_int32_t *) arg);
1548 		break;
1549 
1550 	case MTIOCRDHPOS:
1551 		error = st_rdpos(st, 1, (u_int32_t *) arg);
1552 		break;
1553 
1554 	case MTIOCSLOCATE:
1555 		error = st_setpos(st, 0, (u_int32_t *) arg);
1556 		break;
1557 
1558 	case MTIOCHLOCATE:
1559 		error = st_setpos(st, 1, (u_int32_t *) arg);
1560 		break;
1561 
1562 
1563 	default:
1564 		error = scsipi_do_ioctl(st->sc_periph, dev, cmd, arg,
1565 					flag, l);
1566 		break;
1567 	}
1568 	return (error);
1569 /*-----------------------------*/
1570 try_new_value:
1571 	/*
1572 	 * Check that the mode being asked for is aggreeable to the
1573 	 * drive. If not, put it back the way it was.
1574 	 *
1575 	 * If in control mode, we can make (persistent) mode changes
1576 	 * even if no medium is loaded (see st(4)).
1577 	 */
1578 	if ((STMODE(dev) != CTRL_MODE || (st->flags & ST_MOUNTED) != 0) &&
1579 	    (error = st->ops(st, ST_OPS_MODESELECT, 0)) != 0) {
1580 		/* put it back as it was */
1581 		aprint_error_dev(&st->sc_dev, "cannot set selected mode\n");
1582 		st->density = hold_density;
1583 		st->blksize = hold_blksize;
1584 		if (st->blksize)
1585 			st->flags |= ST_FIXEDBLOCKS;
1586 		else
1587 			st->flags &= ~ST_FIXEDBLOCKS;
1588 		return (error);
1589 	}
1590 	/*
1591 	 * As the drive liked it, if we are setting a new default,
1592 	 * set it into the structures as such.
1593 	 *
1594 	 * The means for deciding this are not finalised yet- but
1595 	 * if the device was opened in Control Mode, the values
1596 	 * are persistent now across mounts.
1597 	 */
1598 	if (STMODE(dev) == CTRL_MODE) {
1599 		switch ((short) (mt->mt_op)) {
1600 		case MTSETBSIZ:
1601 			st->modes[dsty].blksize = st->blksize;
1602 			st->modeflags[dsty] |= BLKSIZE_SET_BY_USER;
1603 			break;
1604 		case MTSETDNSTY:
1605 			st->modes[dsty].density = st->density;
1606 			st->modeflags[dsty] |= DENSITY_SET_BY_USER;
1607 			break;
1608 		}
1609 	}
1610 	return (0);
1611 }
1612 
1613 /*
1614  * Do a synchronous read.
1615  */
1616 static int
1617 st_read(struct st_softc *st, char *bf, int size, int flags)
1618 {
1619 	struct scsi_rw_tape cmd;
1620 
1621 	/*
1622 	 * If it's a null transfer, return immediatly
1623 	 */
1624 	if (size == 0)
1625 		return (0);
1626 	memset(&cmd, 0, sizeof(cmd));
1627 	cmd.opcode = READ;
1628 	if (st->flags & ST_FIXEDBLOCKS) {
1629 		cmd.byte2 |= SRW_FIXED;
1630 		_lto3b(size / (st->blksize ? st->blksize : DEF_FIXED_BSIZE),
1631 		    cmd.len);
1632 	} else
1633 		_lto3b(size, cmd.len);
1634 	return (scsipi_command(st->sc_periph,
1635 	    (void *)&cmd, sizeof(cmd), (void *)bf, size, 0, ST_IO_TIME, NULL,
1636 	    flags | XS_CTL_DATA_IN));
1637 }
1638 
1639 /*
1640  * issue an erase command
1641  */
1642 static int
1643 st_erase(struct st_softc *st, int full, int flags)
1644 {
1645 	int tmo;
1646 	struct scsi_erase cmd;
1647 
1648 	/*
1649 	 * Full erase means set LONG bit in erase command, which asks
1650 	 * the drive to erase the entire unit.  Without this bit, we're
1651 	 * asking the drive to write an erase gap.
1652 	 */
1653 	memset(&cmd, 0, sizeof(cmd));
1654 	cmd.opcode = ERASE;
1655 	if (full) {
1656 		cmd.byte2 = SE_LONG;
1657 		tmo = ST_SPC_TIME;
1658 	} else {
1659 		tmo = ST_IO_TIME;
1660 	}
1661 
1662 	/*
1663 	 * XXX We always do this asynchronously, for now, unless the device
1664 	 * has the ST_Q_ERASE_NOIMM quirk.  How long should we wait if we
1665 	 * want to (eventually) to it synchronously?
1666 	 */
1667 	if ((st->quirks & ST_Q_ERASE_NOIMM) == 0)
1668 		cmd.byte2 |= SE_IMMED;
1669 
1670 	return (scsipi_command(st->sc_periph, (void *)&cmd, sizeof(cmd), 0, 0,
1671 	    ST_RETRIES, tmo, NULL, flags));
1672 }
1673 
1674 /*
1675  * skip N blocks/filemarks/seq filemarks/eom
1676  */
1677 static int
1678 st_space(struct st_softc *st, int number, u_int what, int flags)
1679 {
1680 	struct scsi_space cmd;
1681 	int error;
1682 
1683 	switch (what) {
1684 	case SP_BLKS:
1685 		if (st->flags & ST_PER_ACTION) {
1686 			if (number > 0) {
1687 				st->flags &= ~ST_PER_ACTION;
1688 				return (EIO);
1689 			} else if (number < 0) {
1690 				if (st->flags & ST_AT_FILEMARK) {
1691 					/*
1692 					 * Handling of ST_AT_FILEMARK
1693 					 * in st_space will fill in the
1694 					 * right file mark count.
1695 					 */
1696 					error = st_space(st, 0, SP_FILEMARKS,
1697 					    flags);
1698 					if (error)
1699 						return (error);
1700 				}
1701 				if (st->flags & ST_BLANK_READ) {
1702 					st->flags &= ~ST_BLANK_READ;
1703 					return (EIO);
1704 				}
1705 				st->flags &= ~(ST_EIO_PENDING|ST_EOM_PENDING);
1706 			}
1707 		}
1708 		break;
1709 	case SP_FILEMARKS:
1710 		if (st->flags & ST_EIO_PENDING) {
1711 			if (number > 0) {
1712 				/* pretend we just discovered the error */
1713 				st->flags &= ~ST_EIO_PENDING;
1714 				return (EIO);
1715 			} else if (number < 0) {
1716 				/* back away from the error */
1717 				st->flags &= ~ST_EIO_PENDING;
1718 			}
1719 		}
1720 		if (st->flags & ST_AT_FILEMARK) {
1721 			st->flags &= ~ST_AT_FILEMARK;
1722 			number--;
1723 		}
1724 		if ((st->flags & ST_BLANK_READ) && (number < 0)) {
1725 			/* back away from unwritten tape */
1726 			st->flags &= ~ST_BLANK_READ;
1727 			number++;	/* XXX dubious */
1728 		}
1729 		break;
1730 	case SP_EOM:
1731 		if (st->flags & ST_EOM_PENDING) {
1732 			/* we're already there */
1733 			st->flags &= ~ST_EOM_PENDING;
1734 			return (0);
1735 		}
1736 		if (st->flags & ST_EIO_PENDING) {
1737 			/* pretend we just discovered the error */
1738 			st->flags &= ~ST_EIO_PENDING;
1739 			return (EIO);
1740 		}
1741 		if (st->flags & ST_AT_FILEMARK)
1742 			st->flags &= ~ST_AT_FILEMARK;
1743 		break;
1744 	}
1745 	if (number == 0)
1746 		return (0);
1747 
1748 	memset(&cmd, 0, sizeof(cmd));
1749 	cmd.opcode = SPACE;
1750 	cmd.byte2 = what;
1751 	_lto3b(number, cmd.number);
1752 
1753 	st->flags &= ~ST_POSUPDATED;
1754 	st->last_ctl_resid = 0;
1755 	error = scsipi_command(st->sc_periph, (void *)&cmd, sizeof(cmd), 0, 0,
1756 	    0, ST_SPC_TIME, NULL, flags);
1757 
1758 	if (error == 0 && (st->flags & ST_POSUPDATED) == 0) {
1759 		number = number - st->last_ctl_resid;
1760 		if (what == SP_BLKS) {
1761 			if (st->blkno != -1) {
1762 				st->blkno += number;
1763 			}
1764 		} else if (what == SP_FILEMARKS) {
1765 			if (st->fileno != -1) {
1766 				st->fileno += number;
1767 				if (number > 0) {
1768 					st->blkno = 0;
1769 				} else if (number < 0) {
1770 					st->blkno = -1;
1771 				}
1772 			}
1773 		} else if (what == SP_EOM) {
1774 			/*
1775 			 * This loses us relative position.
1776 			 */
1777 			st->fileno = st->blkno = -1;
1778 		}
1779 	}
1780 	return (error);
1781 }
1782 
1783 /*
1784  * write N filemarks
1785  */
1786 static int
1787 st_write_filemarks(struct st_softc *st, int number, int flags)
1788 {
1789 	int error;
1790 	struct scsi_write_filemarks cmd;
1791 
1792 	/*
1793 	 * It's hard to write a negative number of file marks.
1794 	 * Don't try.
1795 	 */
1796 	if (number < 0)
1797 		return (EINVAL);
1798 	switch (number) {
1799 	case 0:		/* really a command to sync the drive's buffers */
1800 		break;
1801 	case 1:
1802 		if (st->flags & ST_FM_WRITTEN)	/* already have one down */
1803 			st->flags &= ~ST_WRITTEN;
1804 		else
1805 			st->flags |= ST_FM_WRITTEN;
1806 		st->flags &= ~ST_PER_ACTION;
1807 		break;
1808 	default:
1809 		st->flags &= ~(ST_PER_ACTION | ST_WRITTEN);
1810 	}
1811 
1812 	memset(&cmd, 0, sizeof(cmd));
1813 	cmd.opcode = WRITE_FILEMARKS;
1814 	if (scsipi_periph_bustype(st->sc_periph) == SCSIPI_BUSTYPE_ATAPI)
1815 		cmd.byte2 = SR_IMMED;
1816 	/*
1817 	 * The ATAPI Onstream DI-30 doesn't support writing filemarks, but
1818 	 * WRITE_FILEMARKS is still used to flush the buffer
1819 	 */
1820 	if ((st->quirks & ST_Q_NOFILEMARKS) == 0)
1821 		_lto3b(number, cmd.number);
1822 
1823 	/* XXX WE NEED TO BE ABLE TO GET A RESIDIUAL XXX */
1824 	error = scsipi_command(st->sc_periph, (void *)&cmd, sizeof(cmd), 0, 0,
1825 	    0, ST_IO_TIME * 4, NULL, flags);
1826 	if (error == 0 && st->fileno != -1) {
1827 		st->fileno += number;
1828 	}
1829 	return (error);
1830 }
1831 
1832 /*
1833  * Make sure the right number of file marks is on tape if the
1834  * tape has been written.  If the position argument is true,
1835  * leave the tape positioned where it was originally.
1836  *
1837  * nmarks returns the number of marks to skip (or, if position
1838  * true, which were skipped) to get back original position.
1839  */
1840 static int
1841 st_check_eod(struct st_softc *st, boolean position, int *nmarks, int flags)
1842 {
1843 	int error;
1844 
1845 	switch (st->flags & (ST_WRITTEN | ST_FM_WRITTEN | ST_2FM_AT_EOD)) {
1846 	default:
1847 		*nmarks = 0;
1848 		return (0);
1849 	case ST_WRITTEN:
1850 	case ST_WRITTEN | ST_FM_WRITTEN | ST_2FM_AT_EOD:
1851 		*nmarks = 1;
1852 		break;
1853 	case ST_WRITTEN | ST_2FM_AT_EOD:
1854 		*nmarks = 2;
1855 	}
1856 	error = st_write_filemarks(st, *nmarks, flags);
1857 	if (position && !error)
1858 		error = st_space(st, -*nmarks, SP_FILEMARKS, flags);
1859 	return (error);
1860 }
1861 
1862 /*
1863  * load/unload/retension
1864  */
1865 static int
1866 st_load(struct st_softc *st, u_int type, int flags)
1867 {
1868 	int error;
1869 	struct scsi_load cmd;
1870 
1871 	if (type != LD_LOAD) {
1872 		int nmarks;
1873 
1874 		error = st_check_eod(st, FALSE, &nmarks, flags);
1875 		if (error) {
1876 			aprint_error_dev(&st->sc_dev, "failed to write closing filemarks at "
1877 			    "unload, errno=%d\n", error);
1878 			return (error);
1879 		}
1880 	}
1881 	if (st->quirks & ST_Q_IGNORE_LOADS) {
1882 		if (type == LD_LOAD) {
1883 			/*
1884 			 * If we ignore loads, at least we should try a rewind.
1885 			 */
1886 			return st_rewind(st, 0, flags);
1887 		}
1888 		/* otherwise, we should do what's asked of us */
1889 	}
1890 
1891 	memset(&cmd, 0, sizeof(cmd));
1892 	cmd.opcode = LOAD;
1893 	if (scsipi_periph_bustype(st->sc_periph) == SCSIPI_BUSTYPE_ATAPI)
1894 		cmd.byte2 = SR_IMMED;
1895 	cmd.how = type;
1896 
1897 	error = scsipi_command(st->sc_periph, (void *)&cmd, sizeof(cmd), 0, 0,
1898 	    ST_RETRIES, ST_SPC_TIME, NULL, flags);
1899 	if (error) {
1900 		aprint_error_dev(&st->sc_dev, "error %d in st_load (op %d)\n",
1901 		    error, type);
1902 	}
1903 	return (error);
1904 }
1905 
1906 /*
1907  *  Rewind the device
1908  */
1909 static int
1910 st_rewind(struct st_softc *st, u_int immediate, int flags)
1911 {
1912 	struct scsi_rewind cmd;
1913 	int error;
1914 	int nmarks;
1915 	int timeout;
1916 
1917 	error = st_check_eod(st, FALSE, &nmarks, flags);
1918 	if (error) {
1919 		aprint_error_dev(&st->sc_dev, "failed to write closing filemarks at "
1920 		    "rewind, errno=%d\n", error);
1921 		return (error);
1922 	}
1923 	st->flags &= ~ST_PER_ACTION;
1924 
1925 	/* If requestor asked for immediate response, set a short timeout */
1926 	timeout = immediate ? ST_CTL_TIME : ST_SPC_TIME;
1927 
1928 	/*
1929 	 * ATAPI tapes always need immediate to be set
1930 	 */
1931 	if (scsipi_periph_bustype(st->sc_periph) == SCSIPI_BUSTYPE_ATAPI)
1932 		immediate = SR_IMMED;
1933 
1934 	memset(&cmd, 0, sizeof(cmd));
1935 	cmd.opcode = REWIND;
1936 	cmd.byte2 = immediate;
1937 
1938 	error = scsipi_command(st->sc_periph, (void *)&cmd, sizeof(cmd), 0, 0,
1939 	    ST_RETRIES, timeout, NULL, flags);
1940 	if (error) {
1941 		aprint_error_dev(&st->sc_dev, "error %d trying to rewind\n",
1942 		    error);
1943 		/* lost position */
1944 		st->fileno = st->blkno = -1;
1945 	} else {
1946 		st->fileno = st->blkno = 0;
1947 	}
1948 	return (error);
1949 }
1950 
1951 static int
1952 st_rdpos(struct st_softc *st, int hard, u_int32_t *blkptr)
1953 {
1954 	int error;
1955 	u_int8_t posdata[20];
1956 	struct scsi_tape_read_position cmd;
1957 
1958 	/*
1959 	 * We try and flush any buffered writes here if we were writing
1960 	 * and we're trying to get hardware block position. It eats
1961 	 * up performance substantially, but I'm wary of drive firmware.
1962 	 *
1963 	 * I think that *logical* block position is probably okay-
1964 	 * but hardware block position might have to wait for data
1965 	 * to hit media to be valid. Caveat Emptor.
1966 	 */
1967 
1968 	if (hard && (st->flags & ST_WRITTEN)) {
1969 		/*
1970 		 * First flush any pending writes...
1971 		 */
1972 		error = st_write_filemarks(st, 0, XS_CTL_SILENT);
1973 		/*
1974 		 * The latter case is for 'write protected' tapes
1975 		 * which are too stupid to recognize a zero count
1976 		 * for writing filemarks as a no-op.
1977 		 */
1978 		if (error != 0 && error != EACCES && error != EROFS)
1979 			return (error);
1980 	}
1981 
1982 	memset(&cmd, 0, sizeof(cmd));
1983 	memset(&posdata, 0, sizeof(posdata));
1984 	cmd.opcode = READ_POSITION;
1985 	if (hard)
1986 		cmd.byte1 = 1;
1987 
1988 	error = scsipi_command(st->sc_periph, (void *)&cmd, sizeof(cmd),
1989 	    (void *)&posdata, sizeof(posdata), ST_RETRIES, ST_CTL_TIME, NULL,
1990 	    XS_CTL_SILENT | XS_CTL_DATA_IN);
1991 
1992 	if (error == 0) {
1993 #if	0
1994 		printf("posdata:");
1995 		for (hard = 0; hard < sizeof(posdata); hard++)
1996 			printf("%02x ", posdata[hard] & 0xff);
1997 		printf("\n");
1998 #endif
1999 		if (posdata[0] & 0x4)	/* Block Position Unknown */
2000 			error = EINVAL;
2001 		else
2002 			*blkptr = _4btol(&posdata[4]);
2003 	}
2004 	return (error);
2005 }
2006 
2007 static int
2008 st_setpos(struct st_softc *st, int hard, u_int32_t *blkptr)
2009 {
2010 	int error;
2011 	struct scsi_tape_locate cmd;
2012 
2013 	/*
2014 	 * We used to try and flush any buffered writes here.
2015 	 * Now we push this onto user applications to either
2016 	 * flush the pending writes themselves (via a zero count
2017 	 * WRITE FILEMARKS command) or they can trust their tape
2018 	 * drive to do this correctly for them.
2019 	 *
2020 	 * There are very ugly performance limitations otherwise.
2021 	 */
2022 
2023 	memset(&cmd, 0, sizeof(cmd));
2024 	cmd.opcode = LOCATE;
2025 	if (hard)
2026 		cmd.byte2 = 1 << 2;
2027 	_lto4b(*blkptr, cmd.blkaddr);
2028 	error = scsipi_command(st->sc_periph, (void *)&cmd, sizeof(cmd), 0, 0,
2029 	    ST_RETRIES, ST_SPC_TIME, NULL, 0);
2030 	/*
2031 	 * Note file && block number position now unknown (if
2032 	 * these things ever start being maintained in this driver)
2033 	 */
2034 	st->fileno = st->blkno = -1;
2035 	return (error);
2036 }
2037 
2038 
2039 /*
2040  * Look at the returned sense and act on the error and determine
2041  * the unix error number to pass back..., 0 (== report no error),
2042  * -1 = retry the operation, -2 continue error processing.
2043  */
2044 static int
2045 st_interpret_sense(struct scsipi_xfer *xs)
2046 {
2047 	struct scsipi_periph *periph = xs->xs_periph;
2048 	struct scsi_sense_data *sense = &xs->sense.scsi_sense;
2049 	struct buf *bp = xs->bp;
2050 	struct st_softc *st = (void *)periph->periph_dev;
2051 	int retval = EJUSTRETURN;
2052 	int doprint = ((xs->xs_control & XS_CTL_SILENT) == 0);
2053 	u_int8_t key;
2054 	int32_t info;
2055 
2056 	/*
2057 	 * If it isn't a extended or extended/deferred error, let
2058 	 * the generic code handle it.
2059 	 */
2060 	if (SSD_RCODE(sense->response_code) != SSD_RCODE_CURRENT &&
2061 	    SSD_RCODE(sense->response_code) != SSD_RCODE_DEFERRED)
2062 		return (retval);
2063 
2064 	if (sense->response_code & SSD_RCODE_VALID)
2065 		info = _4btol(sense->info);
2066 	else
2067 		info = (st->flags & ST_FIXEDBLOCKS) ?
2068 		    xs->datalen / st->blksize : xs->datalen;
2069 	key = SSD_SENSE_KEY(sense->flags);
2070 	st->mt_erreg = key;
2071 	st->asc = sense->asc;
2072 	st->ascq = sense->ascq;
2073 	st->mt_resid = (short) info;
2074 
2075 	if (key == SKEY_NOT_READY && st->asc == 0x4 && st->ascq == 0x1) {
2076 		/* Not Ready, Logical Unit Is in Process Of Becoming Ready */
2077 		if (!callout_pending(&periph->periph_callout))
2078 			scsipi_periph_freeze(periph, 1);
2079 		callout_reset(&periph->periph_callout,
2080 		    hz, scsipi_periph_timed_thaw, periph);
2081 		return (ERESTART);
2082 	}
2083 
2084 	/*
2085 	 * If the device is not open yet, let generic handle
2086 	 */
2087 	if ((periph->periph_flags & PERIPH_OPEN) == 0) {
2088 		return (retval);
2089 	}
2090 
2091 	xs->resid = info;
2092 	if (st->flags & ST_FIXEDBLOCKS) {
2093 		if (bp) {
2094 			xs->resid *= st->blksize;
2095 			st->last_io_resid = xs->resid;
2096 		} else {
2097 			st->last_ctl_resid = xs->resid;
2098 		}
2099 		if (key == SKEY_VOLUME_OVERFLOW) {
2100 			st->flags |= ST_EIO_PENDING;
2101 			if (bp)
2102 				bp->b_resid = xs->resid;
2103 		} else if (sense->flags & SSD_EOM) {
2104 			if ((st->flags & ST_EARLYWARN) == 0)
2105 				st->flags |= ST_EIO_PENDING;
2106 			st->flags |= ST_EOM_PENDING;
2107 			if (bp) {
2108 #if 0
2109 				bp->b_resid = xs->resid;
2110 #else
2111 				/*
2112 				 * Grotesque as it seems, the few times
2113 				 * I've actually seen a non-zero resid,
2114 				 * the tape drive actually lied and had
2115 				 * written all the data!
2116 				 */
2117 				bp->b_resid = 0;
2118 #endif
2119 			}
2120 		}
2121 		if (sense->flags & SSD_FILEMARK) {
2122 			st->flags |= ST_AT_FILEMARK;
2123 			if (bp)
2124 				bp->b_resid = xs->resid;
2125 			if (st->fileno != (daddr_t) -1) {
2126 				st->fileno++;
2127 				st->blkno = 0;
2128 				st->flags |= ST_POSUPDATED;
2129 			}
2130 		}
2131 		if (sense->flags & SSD_ILI) {
2132 			st->flags |= ST_EIO_PENDING;
2133 			if (bp)
2134 				bp->b_resid = xs->resid;
2135 			if (sense->response_code & SSD_RCODE_VALID &&
2136 			    (xs->xs_control & XS_CTL_SILENT) == 0)
2137 				aprint_error_dev(&st->sc_dev, "block wrong size, %d blocks "
2138 				    "residual\n", info);
2139 
2140 			/*
2141 			 * This quirk code helps the drive read
2142 			 * the first tape block, regardless of
2143 			 * format.  That is required for these
2144 			 * drives to return proper MODE SENSE
2145 			 * information.
2146 			 */
2147 			if ((st->quirks & ST_Q_SENSE_HELP) &&
2148 			    (periph->periph_flags & PERIPH_MEDIA_LOADED) == 0)
2149 				st->blksize -= 512;
2150 			else if ((st->flags & ST_POSUPDATED) == 0) {
2151 				if (st->blkno != (daddr_t) -1) {
2152 					st->blkno +=
2153 					    (xs->datalen / st->blksize);
2154 					st->flags |= ST_POSUPDATED;
2155 				}
2156 			}
2157 		}
2158 		/*
2159 		 * If data wanted and no data was transferred, do it immediately
2160 		 */
2161 		if (xs->datalen && xs->resid >= xs->datalen) {
2162 			if (st->flags & ST_EIO_PENDING)
2163 				return (EIO);
2164 			if (st->flags & ST_AT_FILEMARK) {
2165 				if (bp)
2166 					bp->b_resid = xs->resid;
2167 				return (0);
2168 			}
2169 		}
2170 	} else {		/* must be variable mode */
2171 		if (bp) {
2172 			st->last_io_resid = xs->resid;
2173 		} else {
2174 			st->last_ctl_resid = xs->resid;
2175 		}
2176 		if (sense->flags & SSD_EOM) {
2177 			/*
2178 			 * The current semantics of this
2179 			 * driver requires EOM detection
2180 			 * to return EIO unless early
2181 			 * warning detection is enabled
2182 			 * for variable mode (this is always
2183 			 * on for fixed block mode).
2184 			 */
2185 			if (st->flags & ST_EARLYWARN) {
2186 				st->flags |= ST_EOM_PENDING;
2187 				retval = 0;
2188 			} else {
2189 				retval = EIO;
2190 				/*
2191 				 * If we return an error we can't claim to
2192 				 * have transfered all data.
2193 				 */
2194 				if (xs->resid == 0)
2195 					xs->resid = xs->datalen;
2196 			}
2197 
2198 			/*
2199 			 * If it's an unadorned EOM detection,
2200 			 * suppress printing an error.
2201 			 */
2202 			if (key == SKEY_NO_SENSE) {
2203 				doprint = 0;
2204 			}
2205 		} else if (sense->flags & SSD_FILEMARK) {
2206 			retval = 0;
2207 			if (st->fileno != (daddr_t) -1) {
2208 				st->fileno++;
2209 				st->blkno = 0;
2210 				st->flags |= ST_POSUPDATED;
2211 			}
2212 		} else if (sense->flags & SSD_ILI) {
2213 			if (info < 0) {
2214 				/*
2215 				 * The tape record was bigger than the read
2216 				 * we issued.
2217 				 */
2218 				if ((xs->xs_control & XS_CTL_SILENT) == 0) {
2219 					aprint_error_dev(&st->sc_dev,
2220 					    "%d-byte tape record too big"
2221 					    " for %d-byte user buffer\n",
2222 					    xs->datalen - info, xs->datalen);
2223 				}
2224 				retval = EIO;
2225 			} else {
2226 				retval = 0;
2227 				if (st->blkno != (daddr_t) -1) {
2228 					st->blkno++;
2229 					st->flags |= ST_POSUPDATED;
2230 				}
2231 			}
2232 		}
2233 		if (bp)
2234 			bp->b_resid = xs->resid;
2235 	}
2236 
2237 #ifndef SCSIPI_DEBUG
2238 	if (retval == 0 && key == SKEY_NO_SENSE)
2239 		doprint = 0;
2240 #endif
2241 	if (key == SKEY_BLANK_CHECK) {
2242 		/*
2243 		 * This quirk code helps the drive read the
2244 		 * first tape block, regardless of format.  That
2245 		 * is required for these drives to return proper
2246 		 * MODE SENSE information.
2247 		 */
2248 		if ((st->quirks & ST_Q_SENSE_HELP) &&
2249 		    (periph->periph_flags & PERIPH_MEDIA_LOADED) == 0) {
2250 			/* still starting */
2251 			st->blksize -= 512;
2252 		} else if (!(st->flags & (ST_2FM_AT_EOD | ST_BLANK_READ))) {
2253 			st->flags |= ST_BLANK_READ;
2254 			xs->resid = xs->datalen;
2255 			if (bp) {
2256 				bp->b_resid = xs->resid;
2257 				/* return an EOF */
2258 			}
2259 			retval = 0;
2260 			/* lost position */
2261 			st->fileno = st->blkno = -1;
2262 		}
2263 	}
2264 
2265 	/*
2266 	 * If generic sense processing will continue, we should not
2267 	 * print sense info here.
2268 	 */
2269 	if (retval == EJUSTRETURN)
2270 		doprint = 0;
2271 
2272 	if (doprint) {
2273 
2274 		/* Print verbose sense info if possible */
2275 		if (scsipi_print_sense(xs, 0) != 0)
2276 			return (retval);
2277 
2278 		/* Print less-verbose sense info */
2279 		scsipi_printaddr(periph);
2280 		printf("Sense Key 0x%02x", key);
2281 		if ((sense->response_code & SSD_RCODE_VALID) != 0) {
2282 			switch (key) {
2283 			case SKEY_NOT_READY:
2284 			case SKEY_ILLEGAL_REQUEST:
2285 			case SKEY_UNIT_ATTENTION:
2286 			case SKEY_DATA_PROTECT:
2287 				break;
2288 			case SKEY_VOLUME_OVERFLOW:
2289 			case SKEY_BLANK_CHECK:
2290 				printf(", requested size: %d (decimal)", info);
2291 				break;
2292 			case SKEY_ABORTED_COMMAND:
2293 				if (xs->xs_retries)
2294 					printf(", retrying");
2295 				printf(", cmd 0x%x, info 0x%x",
2296 				    xs->cmd->opcode, info);
2297 				break;
2298 			default:
2299 				printf(", info = %d (decimal)", info);
2300 			}
2301 		}
2302 		if (sense->extra_len != 0) {
2303 			int n;
2304 			printf(", data =");
2305 			for (n = 0; n < sense->extra_len; n++)
2306 				printf(" %02x", sense->csi[n]);
2307 		}
2308 		printf("\n");
2309 	}
2310 	return (retval);
2311 }
2312 
2313 /*
2314  * The quirk here is that the drive returns some value to st_mode_sense
2315  * incorrectly until the tape has actually passed by the head.
2316  *
2317  * The method is to set the drive to large fixed-block state (user-specified
2318  * density and 1024-byte blocks), then read and rewind to get it to sense the
2319  * tape.  If that doesn't work, try 512-byte fixed blocks.  If that doesn't
2320  * work, as a last resort, try variable- length blocks.  The result will be
2321  * the ability to do an accurate st_mode_sense.
2322  *
2323  * We know we can do a rewind because we just did a load, which implies rewind.
2324  * Rewind seems preferable to space backward if we have a virgin tape.
2325  *
2326  * The rest of the code for this quirk is in ILI processing and BLANK CHECK
2327  * error processing, both part of st_interpret_sense.
2328  */
2329 static int
2330 st_touch_tape(struct st_softc *st)
2331 {
2332 	char *bf;
2333 	int readsize;
2334 	int error;
2335 
2336 	bf = malloc(1024, M_TEMP, M_NOWAIT);
2337 	if (bf == NULL)
2338 		return (ENOMEM);
2339 
2340 	if ((error = st->ops(st, ST_OPS_MODESENSE, 0)) != 0)
2341 		goto bad;
2342 
2343 	/*
2344 	 * If the block size is already known from the
2345 	 * sense data, use it. Else start probing at 1024.
2346 	 */
2347 	if (st->media_blksize > 0)
2348 		st->blksize = st->media_blksize;
2349 	else
2350 		st->blksize = 1024;
2351 
2352 	do {
2353 		switch (st->blksize) {
2354 		case 512:
2355 		case 1024:
2356 			readsize = st->blksize;
2357 			st->flags |= ST_FIXEDBLOCKS;
2358 			break;
2359 		default:
2360 			readsize = 1;
2361 			st->flags &= ~ST_FIXEDBLOCKS;
2362 		}
2363 		if ((error = st->ops(st, ST_OPS_MODESELECT, XS_CTL_SILENT))
2364 		    != 0) {
2365 			/*
2366 			 * The device did not agree with the proposed
2367 			 * block size. If we exhausted our options,
2368 			 * return failure, else try another.
2369 			 */
2370 			if (readsize == 1)
2371 				goto bad;
2372 			st->blksize -= 512;
2373 			continue;
2374 		}
2375 		st_read(st, bf, readsize, XS_CTL_SILENT);	/* XXX */
2376 		if ((error = st_rewind(st, 0, 0)) != 0) {
2377 bad:			free(bf, M_TEMP);
2378 			return (error);
2379 		}
2380 	} while (readsize != 1 && readsize > st->blksize);
2381 
2382 	free(bf, M_TEMP);
2383 	return (0);
2384 }
2385 
2386 static int
2387 stdump(dev_t dev, daddr_t blkno, void *va,
2388     size_t size)
2389 {
2390 
2391 	/* Not implemented. */
2392 	return (ENXIO);
2393 }
2394 
2395 /*
2396  * Send a filled out parameter structure to the drive to
2397  * set it into the desire modes etc.
2398  */
2399 int
2400 st_mode_select(struct st_softc *st, int flags)
2401 {
2402 	u_int select_len;
2403 	struct select {
2404 		struct scsi_mode_parameter_header_6 header;
2405 		struct scsi_general_block_descriptor blk_desc;
2406 		u_char sense_data[MAX_PAGE_0_SIZE];
2407 	} select;
2408 	struct scsipi_periph *periph = st->sc_periph;
2409 
2410 	select_len = sizeof(select.header) + sizeof(select.blk_desc) +
2411 		     st->page_0_size;
2412 
2413 	/*
2414 	 * This quirk deals with drives that have only one valid mode
2415 	 * and think this gives them license to reject all mode selects,
2416 	 * even if the selected mode is the one that is supported.
2417 	 */
2418 	if (st->quirks & ST_Q_UNIMODAL) {
2419 		SC_DEBUG(periph, SCSIPI_DB3,
2420 		    ("not setting density 0x%x blksize 0x%x\n",
2421 		    st->density, st->blksize));
2422 		return (0);
2423 	}
2424 
2425 	/*
2426 	 * Set up for a mode select
2427 	 */
2428 	memset(&select, 0, sizeof(select));
2429 	select.header.blk_desc_len = sizeof(struct scsi_general_block_descriptor);
2430 	select.header.dev_spec &= ~SMH_DSP_BUFF_MODE;
2431 	select.blk_desc.density = st->density;
2432 	if (st->flags & ST_DONTBUFFER)
2433 		select.header.dev_spec |= SMH_DSP_BUFF_MODE_OFF;
2434 	else
2435 		select.header.dev_spec |= SMH_DSP_BUFF_MODE_ON;
2436 	if (st->flags & ST_FIXEDBLOCKS)
2437 		_lto3b(st->blksize, select.blk_desc.blklen);
2438 	if (st->page_0_size)
2439 		memcpy(select.sense_data, st->sense_data, st->page_0_size);
2440 
2441 	/*
2442 	 * do the command
2443 	 */
2444 	return scsipi_mode_select(periph, 0, &select.header, select_len,
2445 				  flags, ST_RETRIES, ST_CTL_TIME);
2446 }
2447