xref: /netbsd-src/sys/dev/scsipi/st.c (revision aad9773e38ed2370a628a6416e098f9008fc10a7)
1 /*	$NetBSD: st.c,v 1.226 2014/08/10 16:44:36 tls 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 1.226 2014/08/10 16:44:36 tls 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 	.d_open = stopen,
109 	.d_close = stclose,
110 	.d_strategy = ststrategy,
111 	.d_ioctl = stioctl,
112 	.d_dump = stdump,
113 	.d_psize = nosize,
114 	.d_discard = nodiscard,
115 	.d_flag = D_TAPE
116 };
117 
118 const struct cdevsw st_cdevsw = {
119 	.d_open = stopen,
120 	.d_close = stclose,
121 	.d_read = stread,
122 	.d_write = stwrite,
123 	.d_ioctl = stioctl,
124 	.d_stop = nostop,
125 	.d_tty = notty,
126 	.d_poll = nopoll,
127 	.d_mmap = nommap,
128 	.d_kqfilter = nokqfilter,
129 	.d_discard = nodiscard,
130 	.d_flag = D_TAPE
131 };
132 
133 /*
134  * Define various devices that we know mis-behave in some way,
135  * and note how they are bad, so we can correct for them
136  */
137 
138 static const struct st_quirk_inquiry_pattern st_quirk_patterns[] = {
139 	{{T_SEQUENTIAL, T_REMOV,
140 	 "        ", "                ", "    "}, {0, 0, {
141 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
142 		{ST_Q_FORCE_BLKSIZE, 512, QIC_24},	/* minor 4-7 */
143 		{ST_Q_FORCE_BLKSIZE, 0, HALFINCH_1600},	/* minor 8-11 */
144 		{ST_Q_FORCE_BLKSIZE, 0, HALFINCH_6250}	/* minor 12-15 */
145 	}}},
146 	{{T_SEQUENTIAL, T_REMOV,
147 	 "TANDBERG", " TDC 3600       ", ""},     {0, 12, {
148 		{0, 0, 0},				/* minor 0-3 */
149 		{ST_Q_FORCE_BLKSIZE, 0, QIC_525},	/* minor 4-7 */
150 		{0, 0, QIC_150},			/* minor 8-11 */
151 		{0, 0, QIC_120}				/* minor 12-15 */
152 	}}},
153  	{{T_SEQUENTIAL, T_REMOV,
154  	 "TANDBERG", " TDC 3800       ", ""},     {0, 0, {
155 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
156 		{0, 0, QIC_525},			/* minor 4-7 */
157 		{0, 0, QIC_150},			/* minor 8-11 */
158 		{0, 0, QIC_120}				/* minor 12-15 */
159 	}}},
160 	{{T_SEQUENTIAL, T_REMOV,
161 	  "TANDBERG", " SLR5 4/8GB     ", ""},     {0, 0, {
162 		{ST_Q_FORCE_BLKSIZE, 1024, 0},		/* minor 0-3 */
163 		{0, 0, 0},				/* minor 4-7 */
164 		{0, 0, 0},				/* minor 8-11 */
165 		{0, 0, 0}				/* minor 12-15 */
166 	}}},
167 	/*
168 	 * lacking a manual for the 4200, it's not clear what the
169 	 * specific density codes should be- the device is a 2.5GB
170 	 * capable QIC drive, those density codes aren't readily
171 	 * availabel. The 'default' will just have to do.
172 	 */
173  	{{T_SEQUENTIAL, T_REMOV,
174  	 "TANDBERG", " TDC 4200       ", ""},     {0, 0, {
175 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
176 		{0, 0, QIC_525},			/* minor 4-7 */
177 		{0, 0, QIC_150},			/* minor 8-11 */
178 		{0, 0, QIC_120}				/* minor 12-15 */
179 	}}},
180 	/*
181 	 * At least -005 and -007 need this.  I'll assume they all do unless I
182 	 * hear otherwise.  - mycroft, 31MAR1994
183 	 */
184 	{{T_SEQUENTIAL, T_REMOV,
185 	 "ARCHIVE ", "VIPER 2525 25462", ""},     {0, 0, {
186 		{ST_Q_SENSE_HELP, 0, 0},		/* minor 0-3 */
187 		{ST_Q_SENSE_HELP, 0, QIC_525},		/* minor 4-7 */
188 		{0, 0, QIC_150},			/* minor 8-11 */
189 		{0, 0, QIC_120}				/* minor 12-15 */
190 	}}},
191 	/*
192 	 * One user reports that this works for his tape drive.  It probably
193 	 * needs more work.  - mycroft, 09APR1994
194 	 */
195 	{{T_SEQUENTIAL, T_REMOV,
196 	 "SANKYO  ", "CP525           ", ""},    {0, 0, {
197 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
198 		{ST_Q_FORCE_BLKSIZE, 512, QIC_525},	/* minor 4-7 */
199 		{0, 0, QIC_150},			/* minor 8-11 */
200 		{0, 0, QIC_120}				/* minor 12-15 */
201 	}}},
202 	{{T_SEQUENTIAL, T_REMOV,
203 	 "ANRITSU ", "DMT780          ", ""},     {0, 0, {
204 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
205 		{ST_Q_FORCE_BLKSIZE, 512, QIC_525},	/* minor 4-7 */
206 		{0, 0, QIC_150},			/* minor 8-11 */
207 		{0, 0, QIC_120}				/* minor 12-15 */
208 	}}},
209 	{{T_SEQUENTIAL, T_REMOV,
210 	 "ARCHIVE ", "VIPER 150  21247", ""},     {ST_Q_ERASE_NOIMM, 12, {
211 		{ST_Q_SENSE_HELP, 0, 0},		/* minor 0-3 */
212 		{0, 0, QIC_150},			/* minor 4-7 */
213 		{0, 0, QIC_120},			/* minor 8-11 */
214 		{0, 0, QIC_24}				/* minor 12-15 */
215 	}}},
216 	{{T_SEQUENTIAL, T_REMOV,
217 	 "ARCHIVE ", "VIPER 150  21531", ""},     {ST_Q_ERASE_NOIMM, 12, {
218 		{ST_Q_SENSE_HELP, 0, 0},		/* minor 0-3 */
219 		{0, 0, QIC_150},			/* minor 4-7 */
220 		{0, 0, QIC_120},			/* minor 8-11 */
221 		{0, 0, QIC_24}				/* minor 12-15 */
222 	}}},
223 	{{T_SEQUENTIAL, T_REMOV,
224 	 "WANGTEK ", "5099ES SCSI", ""},          {0, 0, {
225 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
226 		{0, 0, QIC_11},				/* minor 4-7 */
227 		{0, 0, QIC_24},				/* minor 8-11 */
228 		{0, 0, QIC_24}				/* minor 12-15 */
229 	}}},
230 	{{T_SEQUENTIAL, T_REMOV,
231 	 "WANGTEK ", "5150ES SCSI", ""},          {0, 0, {
232 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
233 		{0, 0, QIC_24},				/* minor 4-7 */
234 		{0, 0, QIC_120},			/* minor 8-11 */
235 		{0, 0, QIC_150}				/* minor 12-15 */
236 	}}},
237 	{{T_SEQUENTIAL, T_REMOV,
238 	 "WANGTEK ", "5525ES SCSI REV7", ""},     {0, 0, {
239 		{0, 0, 0},				/* minor 0-3 */
240 		{ST_Q_BLKSIZE, 0, QIC_525},		/* minor 4-7 */
241 		{0, 0, QIC_150},			/* minor 8-11 */
242 		{0, 0, QIC_120}				/* minor 12-15 */
243 	}}},
244 	{{T_SEQUENTIAL, T_REMOV,
245 	 "WangDAT ", "Model 1300      ", ""},     {0, 0, {
246 		{0, 0, 0},				/* minor 0-3 */
247 		{ST_Q_FORCE_BLKSIZE, 512, DDS},		/* minor 4-7 */
248 		{ST_Q_FORCE_BLKSIZE, 1024, DDS},	/* minor 8-11 */
249 		{ST_Q_FORCE_BLKSIZE, 0, DDS}		/* minor 12-15 */
250 	}}},
251 	{{T_SEQUENTIAL, T_REMOV,
252 	 "EXABYTE ", "EXB-8200        ", "263H"}, {0, 5, {
253 		{0, 0, 0},				/* minor 0-3 */
254 		{0, 0, 0},				/* minor 4-7 */
255 		{0, 0, 0},				/* minor 8-11 */
256 		{0, 0, 0}				/* minor 12-15 */
257 	}}},
258 	{{T_SEQUENTIAL, T_REMOV,
259 	 "STK",      "9490",             ""},
260 				{ST_Q_FORCE_BLKSIZE, 0, {
261 		{0, 0, 0},				/* minor 0-3 */
262 		{0, 0, 0},				/* minor 4-7 */
263 		{0, 0, 0},				/* minor 8-11 */
264 		{0, 0, 0}				/* minor 12-15 */
265 	}}},
266 	{{T_SEQUENTIAL, T_REMOV,
267 	 "STK",      "SD-3",             ""},
268 				{ST_Q_FORCE_BLKSIZE, 0, {
269 		{0, 0, 0},				/* minor 0-3 */
270 		{0, 0, 0},				/* minor 4-7 */
271 		{0, 0, 0},				/* minor 8-11 */
272 		{0, 0, 0}				/* minor 12-15 */
273 	}}},
274 	{{T_SEQUENTIAL, T_REMOV,
275 	 "IBM",      "03590",            ""},     {ST_Q_IGNORE_LOADS, 0, {
276 		{0, 0, 0},				/* minor 0-3 */
277 		{0, 0, 0},				/* minor 4-7 */
278 		{0, 0, 0},				/* minor 8-11 */
279 		{0, 0, 0}				/* minor 12-15 */
280 	}}},
281 	{{T_SEQUENTIAL, T_REMOV,
282 	 "HP      ", "T4000s          ", ""},     {ST_Q_UNIMODAL, 0, {
283 		{0, 0, QIC_3095},			/* minor 0-3 */
284 		{0, 0, QIC_3095},			/* minor 4-7 */
285 		{0, 0, QIC_3095},			/* minor 8-11 */
286 		{0, 0, QIC_3095},			/* minor 12-15 */
287 	}}},
288 #if 0
289 	{{T_SEQUENTIAL, T_REMOV,
290 	 "EXABYTE ", "EXB-8200        ", ""},     {0, 12, {
291 		{0, 0, 0},				/* minor 0-3 */
292 		{0, 0, 0},				/* minor 4-7 */
293 		{0, 0, 0},				/* minor 8-11 */
294 		{0, 0, 0}				/* minor 12-15 */
295 	}}},
296 #endif
297 	{{T_SEQUENTIAL, T_REMOV,
298 	 "TEAC    ", "MT-2ST/N50      ", ""},     {ST_Q_IGNORE_LOADS, 0, {
299 		{0, 0, 0},			        /* minor 0-3 */
300 		{0, 0, 0},			        /* minor 4-7 */
301 		{0, 0, 0},			        /* minor 8-11 */
302 		{0, 0, 0}			        /* minor 12-15 */
303 	}}},
304 	{{T_SEQUENTIAL, T_REMOV,
305 	 "OnStream", "ADR50 Drive", ""},	  {ST_Q_UNIMODAL, 0, {
306 		{ST_Q_FORCE_BLKSIZE, 512, 0},	        /* minor 0-3 */
307 		{ST_Q_FORCE_BLKSIZE, 512, 0},	        /* minor 4-7 */
308 		{ST_Q_FORCE_BLKSIZE, 512, 0},	        /* minor 8-11 */
309 		{ST_Q_FORCE_BLKSIZE, 512, 0},	        /* minor 12-15 */
310 	}}},
311 	{{T_SEQUENTIAL, T_REMOV,
312 	 "OnStream DI-30",      "",   "1.0"},  {ST_Q_NOFILEMARKS, 0, {
313 		{0, 0, 0},                              /* minor 0-3 */
314 		{0, 0, 0},                              /* minor 4-7 */
315 		{0, 0, 0},                              /* minor 8-11 */
316 		{0, 0, 0}                               /* minor 12-15 */
317 	}}},
318 	{{T_SEQUENTIAL, T_REMOV,
319 	 "NCR H621", "0-STD-03-46F880 ", ""},     {ST_Q_NOPREVENT, 0, {
320 		{0, 0, 0},			       /* minor 0-3 */
321 		{0, 0, 0},			       /* minor 4-7 */
322 		{0, 0, 0},			       /* minor 8-11 */
323 		{0, 0, 0}			       /* minor 12-15 */
324 	}}},
325 	{{T_SEQUENTIAL, T_REMOV,
326 	 "Seagate STT3401A", "hp0atxa", ""},	{0, 0, {
327 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
328 		{ST_Q_FORCE_BLKSIZE, 1024, 0},		/* minor 4-7 */
329 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 8-11 */
330 		{ST_Q_FORCE_BLKSIZE, 512, 0}		/* minor 12-15 */
331 	}}},
332 };
333 
334 #define NOEJECT 0
335 #define EJECT 1
336 
337 static void	st_identify_drive(struct st_softc *,
338 		    struct scsipi_inquiry_pattern *);
339 static void	st_loadquirks(struct st_softc *);
340 static int	st_mount_tape(dev_t, int);
341 static void	st_unmount(struct st_softc *, boolean);
342 static int	st_decide_mode(struct st_softc *, boolean);
343 static void	ststart(struct scsipi_periph *);
344 static void	strestart(void *);
345 static void	stdone(struct scsipi_xfer *, int);
346 static int	st_read(struct st_softc *, char *, int, int);
347 static int	st_space(struct st_softc *, int, u_int, int);
348 static int	st_write_filemarks(struct st_softc *, int, int);
349 static int	st_check_eod(struct st_softc *, boolean, int *, int);
350 static int	st_load(struct st_softc *, u_int, int);
351 static int	st_rewind(struct st_softc *, u_int, int);
352 static int	st_interpret_sense(struct scsipi_xfer *);
353 static int	st_touch_tape(struct st_softc *);
354 static int	st_erase(struct st_softc *, int full, int flags);
355 static int	st_rdpos(struct st_softc *, int, uint32_t *);
356 static int	st_setpos(struct st_softc *, int, uint32_t *);
357 
358 static const struct scsipi_periphsw st_switch = {
359 	st_interpret_sense,
360 	ststart,
361 	NULL,
362 	stdone
363 };
364 
365 #if defined(ST_ENABLE_EARLYWARN)
366 #define	ST_INIT_FLAGS	ST_EARLYWARN
367 #else
368 #define	ST_INIT_FLAGS	0
369 #endif
370 
371 /*
372  * The routine called by the low level scsi routine when it discovers
373  * A device suitable for this driver
374  */
375 void
376 stattach(device_t parent, device_t self, void *aux)
377 {
378 	struct st_softc *st = device_private(self);
379 	struct scsipibus_attach_args *sa = aux;
380 	struct scsipi_periph *periph = sa->sa_periph;
381 
382 	SC_DEBUG(periph, SCSIPI_DB2, ("stattach: "));
383 	st->sc_dev = self;
384 
385 	/* Store information needed to contact our base driver */
386 	st->sc_periph = periph;
387 	periph->periph_dev = st->sc_dev;
388 	periph->periph_switch = &st_switch;
389 
390 	/* Set initial flags  */
391 	st->flags = ST_INIT_FLAGS;
392 
393 	/* Set up the buf queue for this device */
394 	bufq_alloc(&st->buf_queue, "fcfs", 0);
395 	callout_init(&st->sc_callout, 0);
396 
397 	/*
398 	 * Check if the drive is a known criminal and take
399 	 * Any steps needed to bring it into line
400 	 */
401 	st_identify_drive(st, &sa->sa_inqbuf);
402 	printf("\n");
403 	/* Use the subdriver to request information regarding the drive.  */
404 	printf("%s : %s", device_xname(st->sc_dev), st->quirkdata
405 	    ? "quirks apply, " : "");
406 	if (scsipi_test_unit_ready(periph,
407 	    XS_CTL_DISCOVERY | XS_CTL_SILENT | XS_CTL_IGNORE_MEDIA_CHANGE) ||
408 	    st->ops(st, ST_OPS_MODESENSE,
409 	    XS_CTL_DISCOVERY | XS_CTL_SILENT | XS_CTL_IGNORE_MEDIA_CHANGE))
410 		printf("drive empty\n");
411 	else {
412 		printf("density code %d, ", st->media_density);
413 		if (st->media_blksize > 0)
414 			printf("%d-byte", st->media_blksize);
415 		else
416 			printf("variable");
417 		printf(" blocks, write-%s\n",
418 		    (st->flags & ST_READONLY) ? "protected" : "enabled");
419 	}
420 
421 	st->stats = iostat_alloc(IOSTAT_TAPE, parent,
422 	    device_xname(st->sc_dev));
423 
424 	rnd_attach_source(&st->rnd_source, device_xname(st->sc_dev),
425 	    RND_TYPE_TAPE, RND_FLAG_DEFAULT);
426 }
427 
428 int
429 stdetach(device_t self, int flags)
430 {
431 	struct st_softc *st = device_private(self);
432 	int s, bmaj, cmaj, mn;
433 
434 	/* locate the major number */
435 	bmaj = bdevsw_lookup_major(&st_bdevsw);
436 	cmaj = cdevsw_lookup_major(&st_cdevsw);
437 
438 	/* kill any pending restart */
439 	callout_stop(&st->sc_callout);
440 
441 	s = splbio();
442 
443 	/* Kill off any queued buffers. */
444 	bufq_drain(st->buf_queue);
445 
446 	bufq_free(st->buf_queue);
447 
448 	/* Kill off any pending commands. */
449 	scsipi_kill_pending(st->sc_periph);
450 
451 	splx(s);
452 
453 	/* Nuke the vnodes for any open instances */
454 	mn = STUNIT(device_unit(self));
455 	vdevgone(bmaj, mn, mn+STNMINOR-1, VBLK);
456 	vdevgone(cmaj, mn, mn+STNMINOR-1, VCHR);
457 
458 	iostat_free(st->stats);
459 
460 	/* Unhook the entropy source. */
461 	rnd_detach_source(&st->rnd_source);
462 
463 	return 0;
464 }
465 
466 /*
467  * Use the inquiry routine in 'scsi_base' to get drive info so we can
468  * Further tailor our behaviour.
469  */
470 static void
471 st_identify_drive(struct st_softc *st, struct scsipi_inquiry_pattern *inqbuf)
472 {
473 	const struct st_quirk_inquiry_pattern *finger;
474 	int priority;
475 
476 	finger = scsipi_inqmatch(inqbuf,
477 	    st_quirk_patterns,
478 	    sizeof(st_quirk_patterns) / sizeof(st_quirk_patterns[0]),
479 	    sizeof(st_quirk_patterns[0]), &priority);
480 	if (priority != 0) {
481 		st->quirkdata = &finger->quirkdata;
482 		st->drive_quirks = finger->quirkdata.quirks;
483 		st->quirks = finger->quirkdata.quirks;	/* start value */
484 		st->page_0_size = finger->quirkdata.page_0_size;
485 		KASSERT(st->page_0_size <= MAX_PAGE_0_SIZE);
486 		st_loadquirks(st);
487 	}
488 }
489 
490 /*
491  * initialise the subdevices to the default (QUIRK) state.
492  * this will remove any setting made by the system operator or previous
493  * operations.
494  */
495 static void
496 st_loadquirks(struct st_softc *st)
497 {
498 	const struct	modes *mode;
499 	struct	modes *mode2;
500 	int i;
501 
502 	mode = st->quirkdata->modes;
503 	mode2 = st->modes;
504 	for (i = 0; i < 4; i++) {
505 		memset(mode2, 0, sizeof(struct modes));
506 		st->modeflags[i] &= ~(BLKSIZE_SET_BY_QUIRK |
507 		    DENSITY_SET_BY_QUIRK | BLKSIZE_SET_BY_USER |
508 		    DENSITY_SET_BY_USER);
509 		if ((mode->quirks | st->drive_quirks) & ST_Q_FORCE_BLKSIZE) {
510 			mode2->blksize = mode->blksize;
511 			st->modeflags[i] |= BLKSIZE_SET_BY_QUIRK;
512 		}
513 		if (mode->density) {
514 			mode2->density = mode->density;
515 			st->modeflags[i] |= DENSITY_SET_BY_QUIRK;
516 		}
517 		mode2->quirks |= mode->quirks;
518 		mode++;
519 		mode2++;
520 	}
521 }
522 
523 /* open the device. */
524 static int
525 stopen(dev_t dev, int flags, int mode, struct lwp *l)
526 {
527 	u_int stmode, dsty;
528 	int error, sflags, unit, tries, ntries;
529 	struct st_softc *st;
530 	struct scsipi_periph *periph;
531 	struct scsipi_adapter *adapt;
532 
533 	unit = STUNIT(dev);
534 	st = device_lookup_private(&st_cd, unit);
535 	if (st == NULL)
536 		return ENXIO;
537 
538 	stmode = STMODE(dev);
539 	dsty = STDSTY(dev);
540 
541 	periph = st->sc_periph;
542 	adapt = periph->periph_channel->chan_adapter;
543 
544 	SC_DEBUG(periph, SCSIPI_DB1,
545 	    ("open: dev=0x%"PRIx64" (unit %d (of %d))\n", dev, unit,
546 	    st_cd.cd_ndevs));
547 
548 	/* Only allow one at a time */
549 	if (periph->periph_flags & PERIPH_OPEN) {
550 		aprint_error_dev(st->sc_dev, "already open\n");
551 		return EBUSY;
552 	}
553 
554 	if ((error = scsipi_adapter_addref(adapt)) != 0)
555 		return error;
556 
557 	/* clear any latched errors. */
558 	st->mt_resid = 0;
559 	st->mt_erreg = 0;
560 	st->asc = 0;
561 	st->ascq = 0;
562 
563 	/*
564 	 * Catch any unit attention errors. Be silent about this
565 	 * unless we're already mounted. We ignore media change
566 	 * if we're in control mode or not mounted yet.
567 	 */
568 	if ((st->flags & ST_MOUNTED) == 0 || stmode == CTRL_MODE) {
569 #ifdef SCSIDEBUG
570 		sflags = XS_CTL_IGNORE_MEDIA_CHANGE;
571 #else
572 		sflags = XS_CTL_SILENT|XS_CTL_IGNORE_MEDIA_CHANGE;
573 #endif
574 	} else
575 		sflags = 0;
576 
577 	/*
578 	 * If we're already mounted or we aren't configured for
579 	 * a mount delay, only try a test unit ready once. Otherwise,
580 	 * try up to ST_MOUNT_DELAY times with a rest interval of
581 	 * one second between each try.
582 	 */
583 	if ((st->flags & ST_MOUNTED) || ST_MOUNT_DELAY == 0)
584 		ntries = 1;
585 	else
586 		ntries = ST_MOUNT_DELAY;
587 
588 	for (error = tries = 0; tries < ntries; tries++) {
589 		int slpintr, oflags;
590 
591 		/*
592 		 * If we had no error, or we're opening the control mode
593 		 * device, we jump out right away.
594 		 */
595 		error = scsipi_test_unit_ready(periph, sflags);
596 		if (error == 0 || stmode == CTRL_MODE)
597 			break;
598 
599 		/*
600 		 * We had an error.
601 		 *
602 		 * If we're already mounted or we aren't configured for
603 		 * a mount delay, or the error isn't a NOT READY error,
604 		 * skip to the error exit now.
605 		 */
606 		if ((st->flags & ST_MOUNTED) || ST_MOUNT_DELAY == 0 ||
607 		    (st->mt_key != SKEY_NOT_READY)) {
608 			goto bad;
609 		}
610 
611 		/* clear any latched errors. */
612 		st->mt_resid = 0;
613 		st->mt_erreg = 0;
614 		st->asc = 0;
615 		st->ascq = 0;
616 
617 		/*
618 		 * Fake that we have the device open so
619 		 * we block other apps from getting in.
620 		 */
621 		oflags = periph->periph_flags;
622 		periph->periph_flags |= PERIPH_OPEN;
623 
624 		slpintr = kpause("stload", true, hz, NULL);
625 
626 		periph->periph_flags = oflags;	/* restore flags */
627 		if (slpintr != 0 && slpintr != EWOULDBLOCK) {
628 			goto bad;
629 		}
630 	}
631 
632 
633 	/*
634 	 * If the mode is 3 (e.g. minor = 3,7,11,15) then the device has
635 	 * been opened to set defaults and perform other, usually non-I/O
636 	 * related, operations. In this case, do a quick check to see
637 	 * whether the unit actually had a tape loaded (this will be known
638 	 * as to whether or not we got a NOT READY for the above
639 	 * unit attention). If a tape is there, go do a mount sequence.
640 	 */
641 	if (stmode == CTRL_MODE && st->mt_key == SKEY_NOT_READY) {
642 		periph->periph_flags |= PERIPH_OPEN;
643 		return 0;
644 	}
645 
646 	/*
647 	 * If we get this far and had an error set, that means we failed
648 	 * to pass the 'test unit ready' test for the non-controlmode device,
649 	 * so we bounce the open.
650 	 */
651 	if (error)
652 		return error;
653 
654 	/* Else, we're now committed to saying we're open. */
655 	periph->periph_flags |= PERIPH_OPEN; /* unit attn are now errors */
656 
657 	/*
658 	 * If it's a different mode, or if the media has been
659 	 * invalidated, unmount the tape from the previous
660 	 * session but continue with open processing
661 	 */
662 	if (st->last_dsty != dsty ||
663 	    (periph->periph_flags & PERIPH_MEDIA_LOADED) == 0)
664 		st_unmount(st, NOEJECT);
665 
666 	/*
667 	 * If we are not mounted, then we should start a new
668 	 * mount session.
669 	 */
670 	if (!(st->flags & ST_MOUNTED)) {
671 		if ((error = st_mount_tape(dev, flags)) != 0)
672 			goto bad;
673 		st->last_dsty = dsty;
674 	}
675 	if (!(st->quirks & ST_Q_NOPREVENT)) {
676 		scsipi_prevent(periph, SPAMR_PREVENT_DT,
677 		    XS_CTL_IGNORE_ILLEGAL_REQUEST | XS_CTL_IGNORE_NOT_READY);
678 	}
679 
680 	SC_DEBUG(periph, SCSIPI_DB2, ("open complete\n"));
681 	return 0;
682 
683 bad:
684 	st_unmount(st, NOEJECT);
685 	scsipi_adapter_delref(adapt);
686 	periph->periph_flags &= ~PERIPH_OPEN;
687 	return error;
688 }
689 
690 static int
691 stclose(dev_t dev, int flags, int mode, struct lwp *l)
692 {
693 	int stxx, error = 0;
694 	struct st_softc *st = device_lookup_private(&st_cd, STUNIT(dev));
695 	struct scsipi_periph *periph = st->sc_periph;
696 	struct scsipi_adapter *adapt = periph->periph_channel->chan_adapter;
697 
698 	SC_DEBUG(st->sc_periph, SCSIPI_DB1, ("closing\n"));
699 
700 	/*
701 	 * Make sure that a tape opened in write-only mode will have
702 	 * file marks written on it when closed, even if not written to.
703 	 *
704 	 * This is for SUN compatibility. Actually, the Sun way of
705 	 * things is to:
706 	 *
707 	 *	only write filemarks if there are fmks to be written and
708 	 *   		- open for write (possibly read/write)
709 	 *		- the last operation was a write
710 	 * 	or:
711 	 *		- opened for wronly
712 	 *		- no data was written (including filemarks)
713 	 */
714 
715 	stxx = st->flags & (ST_WRITTEN | ST_FM_WRITTEN);
716 	if (((flags & FWRITE) && stxx == ST_WRITTEN) ||
717 	    ((flags & O_ACCMODE) == FWRITE && stxx == 0)) {
718 		int nm;
719 		error = st_check_eod(st, FALSE, &nm, 0);
720 	}
721 
722 	/* Allow robots to eject tape if needed.  */
723 	scsipi_prevent(periph, SPAMR_ALLOW,
724 	    XS_CTL_IGNORE_ILLEGAL_REQUEST | XS_CTL_IGNORE_NOT_READY);
725 
726 	switch (STMODE(dev)) {
727 	case NORMAL_MODE:
728 		st_unmount(st, NOEJECT);
729 		break;
730 	case NOREW_MODE:
731 	case CTRL_MODE:
732 		/*
733 		 * Leave mounted unless media seems to have been removed.
734 		 *
735 		 * Otherwise, if we're to terminate a tape with more than one
736 		 * filemark [ and because we're not rewinding here ], backspace
737 		 * one filemark so that later appends will see an unbroken
738 		 * sequence of:
739 		 *
740 		 *	file - FMK - file - FMK ... file - FMK FMK (EOM)
741 		 */
742 		if ((periph->periph_flags & PERIPH_MEDIA_LOADED) == 0) {
743 			st_unmount(st, NOEJECT);
744 		} else if (error == 0) {
745 			/*
746 			 * ST_WRITTEN was preserved from above.
747 			 *
748 			 * All we need to know here is:
749 			 *
750 			 *	Were we writing this tape and was the last
751 			 *	operation a write?
752 			 *
753 			 *	Are there supposed to be 2FM at EOD?
754 			 *
755 			 * If both statements are true, then we backspace
756 			 * one filemark.
757 			 */
758 			stxx |= (st->flags & ST_2FM_AT_EOD);
759 			if ((flags & FWRITE) != 0 &&
760 			    (stxx == (ST_2FM_AT_EOD|ST_WRITTEN))) {
761 				error = st_space(st, -1, SP_FILEMARKS, 0);
762 			}
763 		}
764 		break;
765 	case EJECT_MODE:
766 		st_unmount(st, EJECT);
767 		break;
768 	}
769 
770 	scsipi_wait_drain(periph);
771 
772 	scsipi_adapter_delref(adapt);
773 	periph->periph_flags &= ~PERIPH_OPEN;
774 
775 	return error;
776 }
777 
778 /*
779  * Start a new mount session.
780  * Copy in all the default parameters from the selected device mode.
781  * and try guess any that seem to be defaulted.
782  */
783 static int
784 st_mount_tape(dev_t dev, int flags)
785 {
786 	int unit;
787 	u_int dsty;
788 	struct st_softc *st;
789 	struct scsipi_periph *periph;
790 	int error = 0;
791 
792 	unit = STUNIT(dev);
793 	dsty = STDSTY(dev);
794 	st = device_lookup_private(&st_cd, unit);
795 	periph = st->sc_periph;
796 
797 	if (st->flags & ST_MOUNTED)
798 		return 0;
799 
800 	SC_DEBUG(periph, SCSIPI_DB1, ("mounting\n "));
801 	st->flags |= ST_NEW_MOUNT;
802 	st->quirks = st->drive_quirks | st->modes[dsty].quirks;
803 	/*
804 	 * If the media is new, then make sure we give it a chance to
805 	 * to do a 'load' instruction.  (We assume it is new.)
806 	 */
807 	if ((error = st_load(st, LD_LOAD, XS_CTL_SILENT)) != 0)
808 		return error;
809 	/*
810 	 * Throw another dummy instruction to catch
811 	 * 'Unit attention' errors. Many drives give
812 	 * these after doing a Load instruction (with
813 	 * the MEDIUM MAY HAVE CHANGED asc/ascq).
814 	 */
815 	scsipi_test_unit_ready(periph, XS_CTL_SILENT);	/* XXX */
816 
817 	/*
818 	 * Some devices can't tell you much until they have been
819 	 * asked to look at the media. This quirk does this.
820 	 */
821 	if (st->quirks & ST_Q_SENSE_HELP)
822 		if ((error = st_touch_tape(st)) != 0)
823 			return error;
824 	/*
825 	 * Load the physical device parameters
826 	 * loads: blkmin, blkmax
827 	 */
828 	if ((error = st->ops(st, ST_OPS_RBL, 0)) != 0)
829 		return error;
830 	/*
831 	 * Load the media dependent parameters
832 	 * includes: media_blksize,media_density,numblks
833 	 * As we have a tape in, it should be reflected here.
834 	 * If not you may need the "quirk" above.
835 	 */
836 	if ((error = st->ops(st, ST_OPS_MODESENSE, 0)) != 0)
837 		return error;
838 	/*
839 	 * If we have gained a permanent density from somewhere,
840 	 * then use it in preference to the one supplied by
841 	 * default by the driver.
842 	 */
843 	if (st->modeflags[dsty] & (DENSITY_SET_BY_QUIRK | DENSITY_SET_BY_USER))
844 		st->density = st->modes[dsty].density;
845 	else
846 		st->density = st->media_density;
847 	/*
848 	 * If we have gained a permanent blocksize
849 	 * then use it in preference to the one supplied by
850 	 * default by the driver.
851 	 */
852 	st->flags &= ~ST_FIXEDBLOCKS;
853 	if (st->modeflags[dsty] &
854 	    (BLKSIZE_SET_BY_QUIRK | BLKSIZE_SET_BY_USER)) {
855 		st->blksize = st->modes[dsty].blksize;
856 		if (st->blksize)
857 			st->flags |= ST_FIXEDBLOCKS;
858 	} else {
859 		if ((error = st_decide_mode(st, FALSE)) != 0)
860 			return error;
861 	}
862 	if ((error = st->ops(st, ST_OPS_MODESELECT, 0)) != 0) {
863 		/* ATAPI will return ENODEV for this, and this may be OK */
864 		if (error != ENODEV) {
865 			aprint_error_dev(st->sc_dev,
866 			    "cannot set selected mode\n");
867 			return error;
868 		}
869 	}
870 	st->flags &= ~ST_NEW_MOUNT;
871 	st->flags |= ST_MOUNTED;
872 	periph->periph_flags |= PERIPH_MEDIA_LOADED;	/* move earlier? */
873 	st->blkno = st->fileno = (daddr_t) 0;
874 	return 0;
875 }
876 
877 /*
878  * End the present mount session.
879  * Rewind, and optionally eject the tape.
880  * Reset various flags to indicate that all new
881  * operations require another mount operation
882  */
883 static void
884 st_unmount(struct st_softc *st, boolean eject)
885 {
886 	struct scsipi_periph *periph = st->sc_periph;
887 	int nmarks;
888 
889 	if ((st->flags & ST_MOUNTED) == 0)
890 		return;
891 	SC_DEBUG(periph, SCSIPI_DB1, ("unmounting\n"));
892 	st_check_eod(st, FALSE, &nmarks, XS_CTL_IGNORE_NOT_READY);
893 	st_rewind(st, 0, XS_CTL_IGNORE_NOT_READY);
894 
895 	/*
896 	 * Section 9.3.3 of the SCSI specs states that a device shall return
897 	 * the density value specified in the last succesfull MODE SELECT
898 	 * after an unload operation, in case it is not able to
899 	 * automatically determine the density of the new medium.
900 	 *
901 	 * So we instruct the device to use the default density, which will
902 	 * prevent the use of stale density values (in particular,
903 	 * in st_touch_tape().
904 	 */
905 	st->density = 0;
906 	if (st->ops(st, ST_OPS_MODESELECT, 0) != 0) {
907 		aprint_error_dev(st->sc_dev,
908 		    "WARNING: cannot revert to default density\n");
909 	}
910 
911 	if (eject) {
912 		if (!(st->quirks & ST_Q_NOPREVENT)) {
913 			scsipi_prevent(periph, SPAMR_ALLOW,
914 			    XS_CTL_IGNORE_ILLEGAL_REQUEST |
915 			    XS_CTL_IGNORE_NOT_READY);
916 		}
917 		st_load(st, LD_UNLOAD, XS_CTL_IGNORE_NOT_READY);
918 		st->blkno = st->fileno = (daddr_t) -1;
919 	} else {
920 		st->blkno = st->fileno = (daddr_t) 0;
921 	}
922 	st->flags &= ~(ST_MOUNTED | ST_NEW_MOUNT);
923 	periph->periph_flags &= ~PERIPH_MEDIA_LOADED;
924 }
925 
926 /*
927  * Given all we know about the device, media, mode, 'quirks' and
928  * initial operation, make a decision as to how we should be set
929  * to run (regarding blocking and EOD marks)
930  */
931 int
932 st_decide_mode(struct st_softc *st, boolean first_read)
933 {
934 
935 	SC_DEBUG(st->sc_periph, SCSIPI_DB2, ("starting block mode decision\n"));
936 
937 	/*
938 	 * If the drive can only handle fixed-length blocks and only at
939 	 * one size, perhaps we should just do that.
940 	 */
941 	if (st->blkmin && (st->blkmin == st->blkmax)) {
942 		st->flags |= ST_FIXEDBLOCKS;
943 		st->blksize = st->blkmin;
944 		SC_DEBUG(st->sc_periph, SCSIPI_DB3,
945 		    ("blkmin == blkmax of %d\n", st->blkmin));
946 		goto done;
947 	}
948 	/*
949 	 * If the tape density mandates (or even suggests) use of fixed
950 	 * or variable-length blocks, comply.
951 	 */
952 	switch (st->density) {
953 	case HALFINCH_800:
954 	case HALFINCH_1600:
955 	case HALFINCH_6250:
956 	case DDS:
957 		st->flags &= ~ST_FIXEDBLOCKS;
958 		st->blksize = 0;
959 		SC_DEBUG(st->sc_periph, SCSIPI_DB3,
960 		    ("density specified variable\n"));
961 		goto done;
962 	case QIC_11:
963 	case QIC_24:
964 	case QIC_120:
965 	case QIC_150:
966 	case QIC_525:
967 	case QIC_1320:
968 	case QIC_3095:
969 	case QIC_3220:
970 		st->flags |= ST_FIXEDBLOCKS;
971 		if (st->media_blksize > 0)
972 			st->blksize = st->media_blksize;
973 		else
974 			st->blksize = DEF_FIXED_BSIZE;
975 		SC_DEBUG(st->sc_periph, SCSIPI_DB3,
976 		    ("density specified fixed\n"));
977 		goto done;
978 	}
979 	/*
980 	 * If we're about to read the tape, perhaps we should choose
981 	 * fixed or variable-length blocks and block size according to
982 	 * what the drive found on the tape.
983 	 */
984 	if (first_read &&
985 	    (!(st->quirks & ST_Q_BLKSIZE) || (st->media_blksize == 0) ||
986 	    (st->media_blksize == DEF_FIXED_BSIZE) ||
987 	    (st->media_blksize == 1024))) {
988 		if (st->media_blksize > 0)
989 			st->flags |= ST_FIXEDBLOCKS;
990 		else
991 			st->flags &= ~ST_FIXEDBLOCKS;
992 		st->blksize = st->media_blksize;
993 		SC_DEBUG(st->sc_periph, SCSIPI_DB3,
994 		    ("Used media_blksize of %d\n", st->media_blksize));
995 		goto done;
996 	}
997 	/*
998 	 * We're getting no hints from any direction.  Choose variable-
999 	 * length blocks arbitrarily.
1000 	 */
1001 	st->flags &= ~ST_FIXEDBLOCKS;
1002 	st->blksize = 0;
1003 	SC_DEBUG(st->sc_periph, SCSIPI_DB3,
1004 	    ("Give up and default to variable mode\n"));
1005 
1006 done:
1007 	/*
1008 	 * Decide whether or not to write two file marks to signify end-
1009 	 * of-data.  Make the decision as a function of density.  If
1010 	 * the decision is not to use a second file mark, the SCSI BLANK
1011 	 * CHECK condition code will be recognized as end-of-data when
1012 	 * first read.
1013 	 * (I think this should be a by-product of fixed/variable..julian)
1014 	 */
1015 	switch (st->density) {
1016 /*      case 8 mm:   What is the SCSI density code for 8 mm, anyway? */
1017 	case QIC_11:
1018 	case QIC_24:
1019 	case QIC_120:
1020 	case QIC_150:
1021 	case QIC_525:
1022 	case QIC_1320:
1023 	case QIC_3095:
1024 	case QIC_3220:
1025 		st->flags &= ~ST_2FM_AT_EOD;
1026 		break;
1027 	default:
1028 		st->flags |= ST_2FM_AT_EOD;
1029 	}
1030 	return 0;
1031 }
1032 
1033 /*
1034  * Actually translate the requested transfer into
1035  * one the physical driver can understand
1036  * The transfer is described by a buf and will include
1037  * only one physical transfer.
1038  */
1039 static void
1040 ststrategy(struct buf *bp)
1041 {
1042 	struct st_softc *st = device_lookup_private(&st_cd, STUNIT(bp->b_dev));
1043 	int s;
1044 
1045 	SC_DEBUG(st->sc_periph, SCSIPI_DB1,
1046 	    ("ststrategy %d bytes @ blk %" PRId64 "\n", bp->b_bcount,
1047 	        bp->b_blkno));
1048 	/* If it's a null transfer, return immediately */
1049 	if (bp->b_bcount == 0)
1050 		goto abort;
1051 
1052 	/* If offset is negative, error */
1053 	if (bp->b_blkno < 0) {
1054 		bp->b_error = EINVAL;
1055 		goto abort;
1056 	}
1057 
1058 	/* Odd sized request on fixed drives are verboten */
1059 	if (st->flags & ST_FIXEDBLOCKS) {
1060 		if (bp->b_bcount % st->blksize) {
1061 			aprint_error_dev(st->sc_dev, "bad request, must be multiple of %d\n",
1062 			    st->blksize);
1063 			bp->b_error = EIO;
1064 			goto abort;
1065 		}
1066 	}
1067 	/* as are out-of-range requests on variable drives. */
1068 	else if (bp->b_bcount < st->blkmin ||
1069 	    (st->blkmax && bp->b_bcount > st->blkmax)) {
1070 		aprint_error_dev(st->sc_dev, "bad request, must be between %d and %d\n",
1071 		    st->blkmin, st->blkmax);
1072 		bp->b_error = EIO;
1073 		goto abort;
1074 	}
1075 	s = splbio();
1076 
1077 	/*
1078 	 * Place it in the queue of activities for this tape
1079 	 * at the end (a bit silly because we only have on user..
1080 	 * (but it could fork()))
1081 	 */
1082 	bufq_put(st->buf_queue, bp);
1083 
1084 	/*
1085 	 * Tell the device to get going on the transfer if it's
1086 	 * not doing anything, otherwise just wait for completion
1087 	 * (All a bit silly if we're only allowing 1 open but..)
1088 	 */
1089 	ststart(st->sc_periph);
1090 
1091 	splx(s);
1092 	return;
1093 abort:
1094 	/*
1095 	 * Reset the residue because we didn't do anything,
1096 	 * and send the buffer back as done.
1097 	 */
1098 	bp->b_resid = bp->b_bcount;
1099 	biodone(bp);
1100 	return;
1101 }
1102 
1103 /*
1104  * ststart looks to see if there is a buf waiting for the device
1105  * and that the device is not already busy. If both are true,
1106  * It dequeues the buf and creates a scsi command to perform the
1107  * transfer required. The transfer request will call scsipi_done
1108  * on completion, which will in turn call this routine again
1109  * so that the next queued transfer is performed.
1110  * The bufs are queued by the strategy routine (ststrategy)
1111  *
1112  * This routine is also called after other non-queued requests
1113  * have been made of the scsi driver, to ensure that the queue
1114  * continues to be drained.
1115  * ststart() is called at splbio
1116  */
1117 static void
1118 ststart(struct scsipi_periph *periph)
1119 {
1120 	struct st_softc *st = device_private(periph->periph_dev);
1121 	struct buf *bp;
1122 	struct scsi_rw_tape cmd;
1123 	struct scsipi_xfer *xs;
1124 	int flags, error __diagused;
1125 
1126 	SC_DEBUG(periph, SCSIPI_DB2, ("ststart "));
1127 	/* See if there is a buf to do and we are not already  doing one */
1128 	while (periph->periph_active < periph->periph_openings) {
1129 		/* if a special awaits, let it proceed first */
1130 		if (periph->periph_flags & PERIPH_WAITING) {
1131 			periph->periph_flags &= ~PERIPH_WAITING;
1132 			wakeup((void *)periph);
1133 			return;
1134 		}
1135 
1136 		/*
1137 		 * If the device has been unmounted by the user
1138 		 * then throw away all requests until done.
1139 		 */
1140 		if (__predict_false((st->flags & ST_MOUNTED) == 0 ||
1141 		    (periph->periph_flags & PERIPH_MEDIA_LOADED) == 0)) {
1142 			if ((bp = bufq_get(st->buf_queue)) != NULL) {
1143 				/* make sure that one implies the other.. */
1144 				periph->periph_flags &= ~PERIPH_MEDIA_LOADED;
1145 				bp->b_error = EIO;
1146 				bp->b_resid = bp->b_bcount;
1147 				biodone(bp);
1148 				continue;
1149 			} else
1150 				return;
1151 		}
1152 
1153 		if ((bp = bufq_peek(st->buf_queue)) == NULL)
1154 			return;
1155 
1156 		iostat_busy(st->stats);
1157 
1158 		/*
1159 		 * only FIXEDBLOCK devices have pending I/O or space operations.
1160 		 */
1161 		if (st->flags & ST_FIXEDBLOCKS) {
1162 			/*
1163 			 * If we are at a filemark but have not reported it yet
1164 			 * then we should report it now
1165 			 */
1166 			if (st->flags & ST_AT_FILEMARK) {
1167 				if ((bp->b_flags & B_READ) == B_WRITE) {
1168 					/*
1169 					 * Handling of ST_AT_FILEMARK in
1170 					 * st_space will fill in the right file
1171 					 * mark count.
1172 					 * Back up over filemark
1173 					 */
1174 					if (st_space(st, 0, SP_FILEMARKS, 0)) {
1175 						bufq_get(st->buf_queue);
1176 						bp->b_error = EIO;
1177 						bp->b_resid = bp->b_bcount;
1178 						biodone(bp);
1179 						continue;
1180 					}
1181 				} else {
1182 					bufq_get(st->buf_queue);
1183 					bp->b_resid = bp->b_bcount;
1184 					bp->b_error = 0;
1185 					st->flags &= ~ST_AT_FILEMARK;
1186 					biodone(bp);
1187 					continue;	/* seek more work */
1188 				}
1189 			}
1190 		}
1191 		/*
1192 		 * If we are at EOM but have not reported it
1193 		 * yet then we should report it now.
1194 		 */
1195 		if (st->flags & (ST_EOM_PENDING|ST_EIO_PENDING)) {
1196 			bufq_get(st->buf_queue);
1197 			bp->b_resid = bp->b_bcount;
1198 			if (st->flags & ST_EIO_PENDING)
1199 				bp->b_error = EIO;
1200 			st->flags &= ~(ST_EOM_PENDING|ST_EIO_PENDING);
1201 			biodone(bp);
1202 			continue;	/* seek more work */
1203 		}
1204 
1205 		/* Fill out the scsi command */
1206 		memset(&cmd, 0, sizeof(cmd));
1207 		flags = XS_CTL_NOSLEEP | XS_CTL_ASYNC;
1208 		if ((bp->b_flags & B_READ) == B_WRITE) {
1209 			cmd.opcode = WRITE;
1210 			st->flags &= ~ST_FM_WRITTEN;
1211 			flags |= XS_CTL_DATA_OUT;
1212 		} else {
1213 			cmd.opcode = READ;
1214 			flags |= XS_CTL_DATA_IN;
1215 		}
1216 
1217 		/*
1218 		 * Handle "fixed-block-mode" tape drives by using the
1219 		 * block count instead of the length.
1220 		 */
1221 		if (st->flags & ST_FIXEDBLOCKS) {
1222 			cmd.byte2 |= SRW_FIXED;
1223 			_lto3b(bp->b_bcount / st->blksize, cmd.len);
1224 		} else
1225 			_lto3b(bp->b_bcount, cmd.len);
1226 
1227 		/* Clear 'position updated' indicator */
1228 		st->flags &= ~ST_POSUPDATED;
1229 
1230 		/* go ask the adapter to do all this for us */
1231 		xs = scsipi_make_xs(periph,
1232 		    (struct scsipi_generic *)&cmd, sizeof(cmd),
1233 		    (u_char *)bp->b_data, bp->b_bcount,
1234 		    0, ST_IO_TIME, bp, flags);
1235 		if (__predict_false(xs == NULL)) {
1236 			/*
1237 			 * out of memory. Keep this buffer in the queue, and
1238 			 * retry later.
1239 			 */
1240 			callout_reset(&st->sc_callout, hz / 2, strestart,
1241 			    periph);
1242 			return;
1243 		}
1244 		/*
1245 		 * need to dequeue the buffer before queuing the command,
1246 		 * because cdstart may be called recursively from the
1247 		 * HBA driver
1248 		 */
1249 #ifdef DIAGNOSTIC
1250 		if (bufq_get(st->buf_queue) != bp)
1251 			panic("ststart(): dequeued wrong buf");
1252 #else
1253 		bufq_get(st->buf_queue);
1254 #endif
1255 		error = scsipi_execute_xs(xs);
1256 		/* with a scsipi_xfer preallocated, scsipi_command can't fail */
1257 		KASSERT(error == 0);
1258 	} /* go back and see if we can cram more work in.. */
1259 }
1260 
1261 static void
1262 strestart(void *v)
1263 {
1264 	int s = splbio();
1265 	ststart((struct scsipi_periph *)v);
1266 	splx(s);
1267 }
1268 
1269 static void
1270 stdone(struct scsipi_xfer *xs, int error)
1271 {
1272 	struct st_softc *st = device_private(xs->xs_periph->periph_dev);
1273 	struct buf *bp = xs->bp;
1274 
1275 	if (bp) {
1276 		bp->b_error = error;
1277 		bp->b_resid = xs->resid;
1278 		/*
1279 		 * buggy device ? A SDLT320 can report an info
1280 		 * field of 0x3de8000 on a Media Error/Write Error
1281 		 * for this CBD: 0x0a 00 00 80 00 00
1282 		 */
1283 		if (bp->b_resid > bp->b_bcount || bp->b_resid < 0)
1284 			bp->b_resid = bp->b_bcount;
1285 
1286 		if ((bp->b_flags & B_READ) == B_WRITE)
1287 			st->flags |= ST_WRITTEN;
1288 		else
1289 			st->flags &= ~ST_WRITTEN;
1290 
1291 		iostat_unbusy(st->stats, bp->b_bcount,
1292 			     ((bp->b_flags & B_READ) == B_READ));
1293 
1294 		rnd_add_uint32(&st->rnd_source, bp->b_blkno);
1295 
1296 		if ((st->flags & ST_POSUPDATED) == 0) {
1297 			if (error) {
1298 				st->fileno = st->blkno = -1;
1299 			} else if (st->blkno != -1) {
1300 				if (st->flags & ST_FIXEDBLOCKS)
1301 					st->blkno +=
1302 					    (bp->b_bcount / st->blksize);
1303 				else
1304 					st->blkno++;
1305 			}
1306 		}
1307 		biodone(bp);
1308 	}
1309 }
1310 
1311 static int
1312 stread(dev_t dev, struct uio *uio, int iomode)
1313 {
1314 	struct st_softc *st = device_lookup_private(&st_cd, STUNIT(dev));
1315 
1316 	return physio(ststrategy, NULL, dev, B_READ,
1317 	    st->sc_periph->periph_channel->chan_adapter->adapt_minphys, uio);
1318 }
1319 
1320 static int
1321 stwrite(dev_t dev, struct uio *uio, int iomode)
1322 {
1323 	struct st_softc *st = device_lookup_private(&st_cd, STUNIT(dev));
1324 
1325 	return physio(ststrategy, NULL, dev, B_WRITE,
1326 	    st->sc_periph->periph_channel->chan_adapter->adapt_minphys, uio);
1327 }
1328 
1329 /*
1330  * Perform special action on behalf of the user;
1331  * knows about the internals of this device
1332  */
1333 static int
1334 stioctl(dev_t dev, u_long cmd, void *arg, int flag, struct lwp *l)
1335 {
1336 	int error = 0;
1337 	int unit;
1338 	int number, nmarks, dsty;
1339 	int flags;
1340 	struct st_softc *st;
1341 	int hold_blksize;
1342 	uint8_t hold_density;
1343 	struct mtop *mt = (struct mtop *) arg;
1344 
1345 	/* Find the device that the user is talking about */
1346 	flags = 0;		/* give error messages, act on errors etc. */
1347 	unit = STUNIT(dev);
1348 	dsty = STDSTY(dev);
1349 	st = device_lookup_private(&st_cd, unit);
1350 	hold_blksize = st->blksize;
1351 	hold_density = st->density;
1352 
1353 	switch ((u_int)cmd) {
1354 	case MTIOCGET: {
1355 		struct mtget *g = (struct mtget *) arg;
1356 		/*
1357 		 * (to get the current state of READONLY)
1358 		 */
1359 		error = st->ops(st, ST_OPS_MODESENSE, XS_CTL_SILENT);
1360 		if (error) {
1361 			/*
1362 			 * Ignore the error if in control mode;
1363 			 * this is mandated by st(4).
1364 			 */
1365 			if (STMODE(dev) != CTRL_MODE)
1366 				break;
1367 			error = 0;
1368 		}
1369 		SC_DEBUG(st->sc_periph, SCSIPI_DB1, ("[ioctl: get status]\n"));
1370 		memset(g, 0, sizeof(struct mtget));
1371 		g->mt_type = MT_ISAR;	/* Ultrix compat *//*? */
1372 		g->mt_blksiz = st->blksize;
1373 		g->mt_density = st->density;
1374 		g->mt_mblksiz[0] = st->modes[0].blksize;
1375 		g->mt_mblksiz[1] = st->modes[1].blksize;
1376 		g->mt_mblksiz[2] = st->modes[2].blksize;
1377 		g->mt_mblksiz[3] = st->modes[3].blksize;
1378 		g->mt_mdensity[0] = st->modes[0].density;
1379 		g->mt_mdensity[1] = st->modes[1].density;
1380 		g->mt_mdensity[2] = st->modes[2].density;
1381 		g->mt_mdensity[3] = st->modes[3].density;
1382 		g->mt_fileno = st->fileno;
1383 		g->mt_blkno = st->blkno;
1384 		if (st->flags & ST_READONLY)
1385 			g->mt_dsreg |= MT_DS_RDONLY;
1386 		if (st->flags & ST_MOUNTED)
1387 			g->mt_dsreg |= MT_DS_MOUNTED;
1388 		g->mt_resid = st->mt_resid;
1389 		g->mt_erreg = st->mt_erreg;
1390 		/*
1391 		 * clear latched errors.
1392 		 */
1393 		st->mt_resid = 0;
1394 		st->mt_erreg = 0;
1395 		st->asc = 0;
1396 		st->ascq = 0;
1397 		break;
1398 	}
1399 	case MTIOCTOP: {
1400 		SC_DEBUG(st->sc_periph, SCSIPI_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 "
1456 				    "blocksize");
1457 				error = EINVAL;
1458 				break;
1459 			}
1460 #endif
1461 			if (number == 0)
1462 				st->flags &= ~ST_FIXEDBLOCKS;
1463 			else {
1464 				if ((st->blkmin || st->blkmax) &&
1465 				    (number < st->blkmin ||
1466 				    number > st->blkmax)) {
1467 					error = EINVAL;
1468 					break;
1469 				}
1470 				st->flags |= ST_FIXEDBLOCKS;
1471 			}
1472 			st->blksize = number;
1473 			st->flags |= ST_BLOCK_SET;	/*XXX */
1474 			goto try_new_value;
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 		case MTCMPRESS:
1487 			error = st->ops(st, (number == 0) ?
1488 			    ST_OPS_CMPRSS_OFF : ST_OPS_CMPRSS_ON,
1489 			    XS_CTL_SILENT);
1490 			break;
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 	case MTIOCRDSPOS:
1507 		error = st_rdpos(st, 0, (uint32_t *)arg);
1508 		break;
1509 	case MTIOCRDHPOS:
1510 		error = st_rdpos(st, 1, (uint32_t *)arg);
1511 		break;
1512 	case MTIOCSLOCATE:
1513 		error = st_setpos(st, 0, (uint32_t *)arg);
1514 		break;
1515 	case MTIOCHLOCATE:
1516 		error = st_setpos(st, 1, (uint32_t *)arg);
1517 		break;
1518 	default:
1519 		error = scsipi_do_ioctl(st->sc_periph, dev, cmd, arg, flag, l);
1520 		break;
1521 	}
1522 	return error;
1523 
1524 try_new_value:
1525 	/*
1526 	 * Check that the mode being asked for is aggreeable to the
1527 	 * drive. If not, put it back the way it was.
1528 	 *
1529 	 * If in control mode, we can make (persistent) mode changes
1530 	 * even if no medium is loaded (see st(4)).
1531 	 */
1532 	if ((STMODE(dev) != CTRL_MODE || (st->flags & ST_MOUNTED) != 0) &&
1533 	    (error = st->ops(st, ST_OPS_MODESELECT, 0)) != 0) {
1534 		/* put it back as it was */
1535 		aprint_error_dev(st->sc_dev, "cannot set selected mode\n");
1536 		st->density = hold_density;
1537 		st->blksize = hold_blksize;
1538 		if (st->blksize)
1539 			st->flags |= ST_FIXEDBLOCKS;
1540 		else
1541 			st->flags &= ~ST_FIXEDBLOCKS;
1542 		return error;
1543 	}
1544 	/*
1545 	 * As the drive liked it, if we are setting a new default,
1546 	 * set it into the structures as such.
1547 	 *
1548 	 * The means for deciding this are not finalised yet- but
1549 	 * if the device was opened in Control Mode, the values
1550 	 * are persistent now across mounts.
1551 	 */
1552 	if (STMODE(dev) == CTRL_MODE) {
1553 		switch ((short) (mt->mt_op)) {
1554 		case MTSETBSIZ:
1555 			st->modes[dsty].blksize = st->blksize;
1556 			st->modeflags[dsty] |= BLKSIZE_SET_BY_USER;
1557 			break;
1558 		case MTSETDNSTY:
1559 			st->modes[dsty].density = st->density;
1560 			st->modeflags[dsty] |= DENSITY_SET_BY_USER;
1561 			break;
1562 		}
1563 	}
1564 	return 0;
1565 }
1566 
1567 /* Do a synchronous read. */
1568 static int
1569 st_read(struct st_softc *st, char *bf, int size, int flags)
1570 {
1571 	struct scsi_rw_tape cmd;
1572 
1573 	/* If it's a null transfer, return immediatly */
1574 	if (size == 0)
1575 		return 0;
1576 	memset(&cmd, 0, sizeof(cmd));
1577 	cmd.opcode = READ;
1578 	if (st->flags & ST_FIXEDBLOCKS) {
1579 		cmd.byte2 |= SRW_FIXED;
1580 		_lto3b(size / (st->blksize ? st->blksize : DEF_FIXED_BSIZE),
1581 		    cmd.len);
1582 	} else
1583 		_lto3b(size, cmd.len);
1584 	return scsipi_command(st->sc_periph,
1585 	    (void *)&cmd, sizeof(cmd), (void *)bf, size, 0, ST_IO_TIME, NULL,
1586 	    flags | XS_CTL_DATA_IN);
1587 }
1588 
1589 /* issue an erase command */
1590 static int
1591 st_erase(struct st_softc *st, int full, int flags)
1592 {
1593 	int tmo;
1594 	struct scsi_erase cmd;
1595 
1596 	/*
1597 	 * Full erase means set LONG bit in erase command, which asks
1598 	 * the drive to erase the entire unit.  Without this bit, we're
1599 	 * asking the drive to write an erase gap.
1600 	 */
1601 	memset(&cmd, 0, sizeof(cmd));
1602 	cmd.opcode = ERASE;
1603 	if (full) {
1604 		cmd.byte2 = SE_LONG;
1605 		tmo = ST_SPC_TIME;
1606 	} else
1607 		tmo = ST_IO_TIME;
1608 
1609 	/*
1610 	 * XXX We always do this asynchronously, for now, unless the device
1611 	 * has the ST_Q_ERASE_NOIMM quirk.  How long should we wait if we
1612 	 * want to (eventually) to it synchronously?
1613 	 */
1614 	if ((st->quirks & ST_Q_ERASE_NOIMM) == 0)
1615 		cmd.byte2 |= SE_IMMED;
1616 
1617 	return scsipi_command(st->sc_periph, (void *)&cmd, sizeof(cmd), 0, 0,
1618 	    ST_RETRIES, tmo, NULL, flags);
1619 }
1620 
1621 /* skip N blocks/filemarks/seq filemarks/eom */
1622 static int
1623 st_space(struct st_softc *st, int number, u_int what, int flags)
1624 {
1625 	struct scsi_space cmd;
1626 	int error;
1627 
1628 	switch (what) {
1629 	case SP_BLKS:
1630 		if (st->flags & ST_PER_ACTION) {
1631 			if (number > 0) {
1632 				st->flags &= ~ST_PER_ACTION;
1633 				return EIO;
1634 			} else if (number < 0) {
1635 				if (st->flags & ST_AT_FILEMARK) {
1636 					/*
1637 					 * Handling of ST_AT_FILEMARK
1638 					 * in st_space will fill in the
1639 					 * right file mark count.
1640 					 */
1641 					error = st_space(st, 0, SP_FILEMARKS,
1642 					    flags);
1643 					if (error)
1644 						return error;
1645 				}
1646 				if (st->flags & ST_BLANK_READ) {
1647 					st->flags &= ~ST_BLANK_READ;
1648 					return EIO;
1649 				}
1650 				st->flags &= ~(ST_EIO_PENDING|ST_EOM_PENDING);
1651 			}
1652 		}
1653 		break;
1654 	case SP_FILEMARKS:
1655 		if (st->flags & ST_EIO_PENDING) {
1656 			if (number > 0) {
1657 				/* pretend we just discovered the error */
1658 				st->flags &= ~ST_EIO_PENDING;
1659 				return EIO;
1660 			} else if (number < 0) {
1661 				/* back away from the error */
1662 				st->flags &= ~ST_EIO_PENDING;
1663 			}
1664 		}
1665 		if (st->flags & ST_AT_FILEMARK) {
1666 			st->flags &= ~ST_AT_FILEMARK;
1667 			number--;
1668 		}
1669 		if ((st->flags & ST_BLANK_READ) && (number < 0)) {
1670 			/* back away from unwritten tape */
1671 			st->flags &= ~ST_BLANK_READ;
1672 			number++;	/* XXX dubious */
1673 		}
1674 		break;
1675 	case SP_EOM:
1676 		if (st->flags & ST_EOM_PENDING) {
1677 			/* we're already there */
1678 			st->flags &= ~ST_EOM_PENDING;
1679 			return 0;
1680 		}
1681 		if (st->flags & ST_EIO_PENDING) {
1682 			/* pretend we just discovered the error */
1683 			st->flags &= ~ST_EIO_PENDING;
1684 			return EIO;
1685 		}
1686 		if (st->flags & ST_AT_FILEMARK)
1687 			st->flags &= ~ST_AT_FILEMARK;
1688 		break;
1689 	}
1690 	if (number == 0)
1691 		return 0;
1692 
1693 	memset(&cmd, 0, sizeof(cmd));
1694 	cmd.opcode = SPACE;
1695 	cmd.byte2 = what;
1696 	_lto3b(number, cmd.number);
1697 
1698 	st->flags &= ~ST_POSUPDATED;
1699 	st->last_ctl_resid = 0;
1700 	error = scsipi_command(st->sc_periph, (void *)&cmd, sizeof(cmd), 0, 0,
1701 	    0, ST_SPC_TIME, NULL, flags);
1702 
1703 	if (error == 0 && (st->flags & ST_POSUPDATED) == 0) {
1704 		number = number - st->last_ctl_resid;
1705 		if (what == SP_BLKS) {
1706 			if (st->blkno != -1)
1707 				st->blkno += number;
1708 		} else if (what == SP_FILEMARKS) {
1709 			if (st->fileno != -1) {
1710 				st->fileno += number;
1711 				if (number > 0)
1712 					st->blkno = 0;
1713 				else if (number < 0)
1714 					st->blkno = -1;
1715 			}
1716 		} else if (what == SP_EOM) {
1717 			/* This loses us relative position. */
1718 			st->fileno = st->blkno = -1;
1719 		}
1720 	}
1721 	return error;
1722 }
1723 
1724 /*
1725  * write N filemarks
1726  */
1727 static int
1728 st_write_filemarks(struct st_softc *st, int number, int flags)
1729 {
1730 	int error;
1731 	struct scsi_write_filemarks cmd;
1732 
1733 	/*
1734 	 * It's hard to write a negative number of file marks.
1735 	 * Don't try.
1736 	 */
1737 	if (number < 0)
1738 		return EINVAL;
1739 	switch (number) {
1740 	case 0:		/* really a command to sync the drive's buffers */
1741 		break;
1742 	case 1:
1743 		if (st->flags & ST_FM_WRITTEN)	/* already have one down */
1744 			st->flags &= ~ST_WRITTEN;
1745 		else
1746 			st->flags |= ST_FM_WRITTEN;
1747 		st->flags &= ~ST_PER_ACTION;
1748 		break;
1749 	default:
1750 		st->flags &= ~(ST_PER_ACTION | ST_WRITTEN);
1751 	}
1752 
1753 	memset(&cmd, 0, sizeof(cmd));
1754 	cmd.opcode = WRITE_FILEMARKS;
1755 	if (SCSIPI_BUSTYPE_TYPE(scsipi_periph_bustype(st->sc_periph)) ==
1756 	    SCSIPI_BUSTYPE_ATAPI)
1757 		cmd.byte2 = SR_IMMED;
1758 	/*
1759 	 * The ATAPI Onstream DI-30 doesn't support writing filemarks, but
1760 	 * WRITE_FILEMARKS is still used to flush the buffer
1761 	 */
1762 	if ((st->quirks & ST_Q_NOFILEMARKS) == 0)
1763 		_lto3b(number, cmd.number);
1764 
1765 	/* XXX WE NEED TO BE ABLE TO GET A RESIDIUAL XXX */
1766 	error = scsipi_command(st->sc_periph, (void *)&cmd, sizeof(cmd), 0, 0,
1767 	    0, ST_IO_TIME * 4, NULL, flags);
1768 	if (error == 0 && st->fileno != -1)
1769 		st->fileno += number;
1770 	return error;
1771 }
1772 
1773 /*
1774  * Make sure the right number of file marks is on tape if the
1775  * tape has been written.  If the position argument is true,
1776  * leave the tape positioned where it was originally.
1777  *
1778  * nmarks returns the number of marks to skip (or, if position
1779  * true, which were skipped) to get back original position.
1780  */
1781 static int
1782 st_check_eod(struct st_softc *st, boolean position, int *nmarks, int flags)
1783 {
1784 	int error;
1785 
1786 	switch (st->flags & (ST_WRITTEN | ST_FM_WRITTEN | ST_2FM_AT_EOD)) {
1787 	default:
1788 		*nmarks = 0;
1789 		return 0;
1790 	case ST_WRITTEN:
1791 	case ST_WRITTEN | ST_FM_WRITTEN | ST_2FM_AT_EOD:
1792 		*nmarks = 1;
1793 		break;
1794 	case ST_WRITTEN | ST_2FM_AT_EOD:
1795 		*nmarks = 2;
1796 	}
1797 	error = st_write_filemarks(st, *nmarks, flags);
1798 	if (position && !error)
1799 		error = st_space(st, -*nmarks, SP_FILEMARKS, flags);
1800 	return error;
1801 }
1802 
1803 /* load/unload/retension */
1804 static int
1805 st_load(struct st_softc *st, u_int type, int flags)
1806 {
1807 	int error;
1808 	struct scsi_load cmd;
1809 
1810 	if (type != LD_LOAD) {
1811 		int nmarks;
1812 
1813 		error = st_check_eod(st, FALSE, &nmarks, flags);
1814 		if (error) {
1815 			aprint_error_dev(st->sc_dev,
1816 			    "failed to write closing filemarks at "
1817 			    "unload, errno=%d\n", error);
1818 			return error;
1819 		}
1820 	}
1821 	if (st->quirks & ST_Q_IGNORE_LOADS) {
1822 		if (type == LD_LOAD)
1823 			/*
1824 			 * If we ignore loads, at least we should try a rewind.
1825 			 */
1826 			return st_rewind(st, 0, flags);
1827 		/* otherwise, we should do what's asked of us */
1828 	}
1829 
1830 	memset(&cmd, 0, sizeof(cmd));
1831 	cmd.opcode = LOAD;
1832 	if (SCSIPI_BUSTYPE_TYPE(scsipi_periph_bustype(st->sc_periph)) ==
1833 	    SCSIPI_BUSTYPE_ATAPI)
1834 		cmd.byte2 = SR_IMMED;
1835 	cmd.how = type;
1836 
1837 	error = scsipi_command(st->sc_periph, (void *)&cmd, sizeof(cmd), 0, 0,
1838 	    ST_RETRIES, ST_SPC_TIME, NULL, flags);
1839 	if (error) {
1840 		aprint_error_dev(st->sc_dev, "error %d in st_load (op %d)\n",
1841 		    error, type);
1842 	}
1843 	return error;
1844 }
1845 
1846 /* Rewind the device */
1847 static int
1848 st_rewind(struct st_softc *st, u_int immediate, int flags)
1849 {
1850 	struct scsi_rewind cmd;
1851 	int error;
1852 	int nmarks;
1853 	int timeout;
1854 
1855 	error = st_check_eod(st, FALSE, &nmarks, flags);
1856 	if (error) {
1857 		aprint_error_dev(st->sc_dev,
1858 		    "failed to write closing filemarks at "
1859 		    "rewind, errno=%d\n", error);
1860 		return error;
1861 	}
1862 	st->flags &= ~ST_PER_ACTION;
1863 
1864 	/* If requestor asked for immediate response, set a short timeout */
1865 	timeout = immediate ? ST_CTL_TIME : ST_SPC_TIME;
1866 
1867 	/* ATAPI tapes always need immediate to be set */
1868 	if (scsipi_periph_bustype(st->sc_periph) == SCSIPI_BUSTYPE_ATAPI)
1869 		immediate = SR_IMMED;
1870 
1871 	memset(&cmd, 0, sizeof(cmd));
1872 	cmd.opcode = REWIND;
1873 	cmd.byte2 = immediate;
1874 
1875 	error = scsipi_command(st->sc_periph, (void *)&cmd, sizeof(cmd), 0, 0,
1876 	    ST_RETRIES, timeout, NULL, flags);
1877 	if (error) {
1878 		aprint_error_dev(st->sc_dev, "error %d trying to rewind\n",
1879 		    error);
1880 		/* lost position */
1881 		st->fileno = st->blkno = -1;
1882 	} else
1883 		st->fileno = st->blkno = 0;
1884 	return error;
1885 }
1886 
1887 static int
1888 st_rdpos(struct st_softc *st, int hard, uint32_t *blkptr)
1889 {
1890 	int error;
1891 	uint8_t posdata[20];
1892 	struct scsi_tape_read_position cmd;
1893 
1894 	/*
1895 	 * We try and flush any buffered writes here if we were writing
1896 	 * and we're trying to get hardware block position. It eats
1897 	 * up performance substantially, but I'm wary of drive firmware.
1898 	 *
1899 	 * I think that *logical* block position is probably okay-
1900 	 * but hardware block position might have to wait for data
1901 	 * to hit media to be valid. Caveat Emptor.
1902 	 */
1903 
1904 	if (hard && (st->flags & ST_WRITTEN)) {
1905 		/* First flush any pending writes... */
1906 		error = st_write_filemarks(st, 0, XS_CTL_SILENT);
1907 		/*
1908 		 * The latter case is for 'write protected' tapes
1909 		 * which are too stupid to recognize a zero count
1910 		 * for writing filemarks as a no-op.
1911 		 */
1912 		if (error != 0 && error != EACCES && error != EROFS)
1913 			return error;
1914 	}
1915 
1916 	memset(&cmd, 0, sizeof(cmd));
1917 	memset(&posdata, 0, sizeof(posdata));
1918 	cmd.opcode = READ_POSITION;
1919 	if (hard)
1920 		cmd.byte1 = 1;
1921 
1922 	error = scsipi_command(st->sc_periph, (void *)&cmd, sizeof(cmd),
1923 	    (void *)&posdata, sizeof(posdata), ST_RETRIES, ST_CTL_TIME, NULL,
1924 	    XS_CTL_SILENT | XS_CTL_DATA_IN);
1925 
1926 	if (error == 0) {
1927 #if	0
1928 		printf("posdata:");
1929 		for (hard = 0; hard < sizeof(posdata); hard++)
1930 			printf("%02x ", posdata[hard] & 0xff);
1931 		printf("\n");
1932 #endif
1933 		if (posdata[0] & 0x4)	/* Block Position Unknown */
1934 			error = EINVAL;
1935 		else
1936 			*blkptr = _4btol(&posdata[4]);
1937 	}
1938 	return error;
1939 }
1940 
1941 static int
1942 st_setpos(struct st_softc *st, int hard, uint32_t *blkptr)
1943 {
1944 	int error;
1945 	struct scsi_tape_locate cmd;
1946 
1947 	/*
1948 	 * We used to try and flush any buffered writes here.
1949 	 * Now we push this onto user applications to either
1950 	 * flush the pending writes themselves (via a zero count
1951 	 * WRITE FILEMARKS command) or they can trust their tape
1952 	 * drive to do this correctly for them.
1953 	 *
1954 	 * There are very ugly performance limitations otherwise.
1955 	 */
1956 
1957 	memset(&cmd, 0, sizeof(cmd));
1958 	cmd.opcode = LOCATE;
1959 	if (hard)
1960 		cmd.byte2 = 1 << 2;
1961 	_lto4b(*blkptr, cmd.blkaddr);
1962 	error = scsipi_command(st->sc_periph, (void *)&cmd, sizeof(cmd), 0, 0,
1963 	    ST_RETRIES, ST_SPC_TIME, NULL, 0);
1964 	/*
1965 	 * Note file && block number position now unknown (if
1966 	 * these things ever start being maintained in this driver)
1967 	 */
1968 	st->fileno = st->blkno = -1;
1969 	return error;
1970 }
1971 
1972 
1973 /*
1974  * Look at the returned sense and act on the error and determine
1975  * the unix error number to pass back..., 0 (== report no error),
1976  * -1 = retry the operation, -2 continue error processing.
1977  */
1978 static int
1979 st_interpret_sense(struct scsipi_xfer *xs)
1980 {
1981 	struct scsipi_periph *periph = xs->xs_periph;
1982 	struct scsi_sense_data *sense = &xs->sense.scsi_sense;
1983 	struct buf *bp = xs->bp;
1984 	struct st_softc *st = device_private(periph->periph_dev);
1985 	int retval = EJUSTRETURN;
1986 	int doprint = ((xs->xs_control & XS_CTL_SILENT) == 0);
1987 	uint8_t key;
1988 	int32_t info;
1989 
1990 	/*
1991 	 * If it isn't a extended or extended/deferred error, let
1992 	 * the generic code handle it.
1993 	 */
1994 	if (SSD_RCODE(sense->response_code) != SSD_RCODE_CURRENT &&
1995 	    SSD_RCODE(sense->response_code) != SSD_RCODE_DEFERRED)
1996 		return retval;
1997 
1998 	if (sense->response_code & SSD_RCODE_VALID)
1999 		info = _4btol(sense->info);
2000 	else
2001 		info = (st->flags & ST_FIXEDBLOCKS) ?
2002 		    xs->datalen / st->blksize : xs->datalen;
2003 	key = SSD_SENSE_KEY(sense->flags);
2004 	st->mt_erreg = key;
2005 	st->asc = sense->asc;
2006 	st->ascq = sense->ascq;
2007 	st->mt_resid = (short) info;
2008 
2009 	if (key == SKEY_NOT_READY && st->asc == 0x4 && st->ascq == 0x1) {
2010 		/* Not Ready, Logical Unit Is in Process Of Becoming Ready */
2011 		if (!callout_pending(&periph->periph_callout))
2012 			scsipi_periph_freeze(periph, 1);
2013 		callout_reset(&periph->periph_callout,
2014 		    hz, scsipi_periph_timed_thaw, periph);
2015 		return ERESTART;
2016 	}
2017 
2018 	/* If the device is not open yet, let generic handle */
2019 	if ((periph->periph_flags & PERIPH_OPEN) == 0)
2020 		return retval;
2021 
2022 	xs->resid = info;
2023 	if (st->flags & ST_FIXEDBLOCKS) {
2024 		if (bp) {
2025 			xs->resid *= st->blksize;
2026 			st->last_io_resid = xs->resid;
2027 		} else
2028 			st->last_ctl_resid = xs->resid;
2029 		if (key == SKEY_VOLUME_OVERFLOW) {
2030 			st->flags |= ST_EIO_PENDING;
2031 			if (bp)
2032 				bp->b_resid = xs->resid;
2033 		} else if (sense->flags & SSD_EOM) {
2034 			if ((st->flags & ST_EARLYWARN) == 0)
2035 				st->flags |= ST_EIO_PENDING;
2036 			st->flags |= ST_EOM_PENDING;
2037 			if (bp) {
2038 #if 0
2039 				bp->b_resid = xs->resid;
2040 #else
2041 				/*
2042 				 * Grotesque as it seems, the few times
2043 				 * I've actually seen a non-zero resid,
2044 				 * the tape drive actually lied and had
2045 				 * written all the data!
2046 				 */
2047 				bp->b_resid = 0;
2048 #endif
2049 			}
2050 		}
2051 		if (sense->flags & SSD_FILEMARK) {
2052 			st->flags |= ST_AT_FILEMARK;
2053 			if (bp)
2054 				bp->b_resid = xs->resid;
2055 			if (st->fileno != (daddr_t) -1) {
2056 				st->fileno++;
2057 				st->blkno = 0;
2058 				st->flags |= ST_POSUPDATED;
2059 			}
2060 		}
2061 		if (sense->flags & SSD_ILI) {
2062 			st->flags |= ST_EIO_PENDING;
2063 			if (bp)
2064 				bp->b_resid = xs->resid;
2065 			if (sense->response_code & SSD_RCODE_VALID &&
2066 			    (xs->xs_control & XS_CTL_SILENT) == 0)
2067 				aprint_error_dev(st->sc_dev,
2068 				    "block wrong size, %d blocks residual\n",
2069 				    info);
2070 
2071 			/*
2072 			 * This quirk code helps the drive read
2073 			 * the first tape block, regardless of
2074 			 * format.  That is required for these
2075 			 * drives to return proper MODE SENSE
2076 			 * information.
2077 			 */
2078 			if ((st->quirks & ST_Q_SENSE_HELP) &&
2079 			    (periph->periph_flags & PERIPH_MEDIA_LOADED) == 0)
2080 				st->blksize -= 512;
2081 			else if ((st->flags & ST_POSUPDATED) == 0) {
2082 				if (st->blkno != (daddr_t) -1) {
2083 					st->blkno +=
2084 					    (xs->datalen / st->blksize);
2085 					st->flags |= ST_POSUPDATED;
2086 				}
2087 			}
2088 		}
2089 		/*
2090 		 * If data wanted and no data was transferred, do it immediately
2091 		 */
2092 		if (xs->datalen && xs->resid >= xs->datalen) {
2093 			if (st->flags & ST_EIO_PENDING)
2094 				return EIO;
2095 			if (st->flags & ST_AT_FILEMARK) {
2096 				if (bp)
2097 					bp->b_resid = xs->resid;
2098 				return 0;
2099 			}
2100 		}
2101 	} else {		/* must be variable mode */
2102 		if (bp)
2103 			st->last_io_resid = xs->resid;
2104 		else
2105 			st->last_ctl_resid = xs->resid;
2106 		if (sense->flags & SSD_EOM) {
2107 			/*
2108 			 * The current semantics of this
2109 			 * driver requires EOM detection
2110 			 * to return EIO unless early
2111 			 * warning detection is enabled
2112 			 * for variable mode (this is always
2113 			 * on for fixed block mode).
2114 			 */
2115 			if (st->flags & ST_EARLYWARN) {
2116 				st->flags |= ST_EOM_PENDING;
2117 				retval = 0;
2118 			} else {
2119 				retval = EIO;
2120 				/*
2121 				 * If we return an error we can't claim to
2122 				 * have transfered all data.
2123 				 */
2124 				if (xs->resid == 0)
2125 					xs->resid = xs->datalen;
2126 			}
2127 
2128 			/*
2129 			 * If it's an unadorned EOM detection,
2130 			 * suppress printing an error.
2131 			 */
2132 			if (key == SKEY_NO_SENSE) {
2133 				doprint = 0;
2134 			}
2135 		} else if (sense->flags & SSD_FILEMARK) {
2136 			retval = 0;
2137 			if (st->fileno != (daddr_t) -1) {
2138 				st->fileno++;
2139 				st->blkno = 0;
2140 				st->flags |= ST_POSUPDATED;
2141 			}
2142 		} else if (sense->flags & SSD_ILI) {
2143 			if (info < 0) {
2144 				/*
2145 				 * The tape record was bigger than the read
2146 				 * we issued.
2147 				 */
2148 				if ((xs->xs_control & XS_CTL_SILENT) == 0) {
2149 					aprint_error_dev(st->sc_dev,
2150 					    "%d-byte tape record too big"
2151 					    " for %d-byte user buffer\n",
2152 					    xs->datalen - info, xs->datalen);
2153 				}
2154 				retval = EIO;
2155 			} else {
2156 				retval = 0;
2157 				if (st->blkno != (daddr_t) -1) {
2158 					st->blkno++;
2159 					st->flags |= ST_POSUPDATED;
2160 				}
2161 			}
2162 		}
2163 		if (bp)
2164 			bp->b_resid = xs->resid;
2165 	}
2166 
2167 #ifndef SCSIPI_DEBUG
2168 	if (retval == 0 && key == SKEY_NO_SENSE)
2169 		doprint = 0;
2170 #endif
2171 	if (key == SKEY_BLANK_CHECK) {
2172 		/*
2173 		 * This quirk code helps the drive read the
2174 		 * first tape block, regardless of format.  That
2175 		 * is required for these drives to return proper
2176 		 * MODE SENSE information.
2177 		 */
2178 		if ((st->quirks & ST_Q_SENSE_HELP) &&
2179 		    (periph->periph_flags & PERIPH_MEDIA_LOADED) == 0) {
2180 			/* still starting */
2181 			st->blksize -= 512;
2182 		} else if (!(st->flags & (ST_2FM_AT_EOD | ST_BLANK_READ))) {
2183 			st->flags |= ST_BLANK_READ;
2184 			xs->resid = xs->datalen;
2185 			if (bp) {
2186 				bp->b_resid = xs->resid;
2187 				/* return an EOF */
2188 			}
2189 			retval = 0;
2190 			/* lost position */
2191 			st->fileno = st->blkno = -1;
2192 		}
2193 	}
2194 
2195 	/*
2196 	 * If generic sense processing will continue, we should not
2197 	 * print sense info here.
2198 	 */
2199 	if (retval == EJUSTRETURN)
2200 		doprint = 0;
2201 
2202 	if (doprint) {
2203 		/* Print verbose sense info if possible */
2204 		if (scsipi_print_sense(xs, 0) != 0)
2205 			return retval;
2206 
2207 		/* Print less-verbose sense info */
2208 		scsipi_printaddr(periph);
2209 		printf("Sense Key 0x%02x", key);
2210 		if ((sense->response_code & SSD_RCODE_VALID) != 0) {
2211 			switch (key) {
2212 			case SKEY_NOT_READY:
2213 			case SKEY_ILLEGAL_REQUEST:
2214 			case SKEY_UNIT_ATTENTION:
2215 			case SKEY_DATA_PROTECT:
2216 				break;
2217 			case SKEY_VOLUME_OVERFLOW:
2218 			case SKEY_BLANK_CHECK:
2219 				printf(", requested size: %d (decimal)", info);
2220 				break;
2221 			case SKEY_ABORTED_COMMAND:
2222 				if (xs->xs_retries)
2223 					printf(", retrying");
2224 				printf(", cmd 0x%x, info 0x%x",
2225 				    xs->cmd->opcode, info);
2226 				break;
2227 			default:
2228 				printf(", info = %d (decimal)", info);
2229 			}
2230 		}
2231 		if (sense->extra_len != 0) {
2232 			int n;
2233 			printf(", data =");
2234 			for (n = 0; n < sense->extra_len; n++)
2235 				printf(" %02x", sense->csi[n]);
2236 		}
2237 		printf("\n");
2238 	}
2239 	return retval;
2240 }
2241 
2242 /*
2243  * The quirk here is that the drive returns some value to st_mode_sense
2244  * incorrectly until the tape has actually passed by the head.
2245  *
2246  * The method is to set the drive to large fixed-block state (user-specified
2247  * density and 1024-byte blocks), then read and rewind to get it to sense the
2248  * tape.  If that doesn't work, try 512-byte fixed blocks.  If that doesn't
2249  * work, as a last resort, try variable- length blocks.  The result will be
2250  * the ability to do an accurate st_mode_sense.
2251  *
2252  * We know we can do a rewind because we just did a load, which implies rewind.
2253  * Rewind seems preferable to space backward if we have a virgin tape.
2254  *
2255  * The rest of the code for this quirk is in ILI processing and BLANK CHECK
2256  * error processing, both part of st_interpret_sense.
2257  */
2258 static int
2259 st_touch_tape(struct st_softc *st)
2260 {
2261 	char *bf;
2262 	int readsize;
2263 	int error;
2264 
2265 	bf = malloc(1024, M_TEMP, M_NOWAIT);
2266 	if (bf == NULL)
2267 		return ENOMEM;
2268 
2269 	if ((error = st->ops(st, ST_OPS_MODESENSE, 0)) != 0)
2270 		goto bad;
2271 
2272 	/*
2273 	 * If the block size is already known from the
2274 	 * sense data, use it. Else start probing at 1024.
2275 	 */
2276 	if (st->media_blksize > 0)
2277 		st->blksize = st->media_blksize;
2278 	else
2279 		st->blksize = 1024;
2280 
2281 	do {
2282 		switch (st->blksize) {
2283 		case 512:
2284 		case 1024:
2285 			readsize = st->blksize;
2286 			st->flags |= ST_FIXEDBLOCKS;
2287 			break;
2288 		default:
2289 			readsize = 1;
2290 			st->flags &= ~ST_FIXEDBLOCKS;
2291 		}
2292 		if ((error = st->ops(st, ST_OPS_MODESELECT, XS_CTL_SILENT))
2293 		    != 0) {
2294 			/*
2295 			 * The device did not agree with the proposed
2296 			 * block size. If we exhausted our options,
2297 			 * return failure, else try another.
2298 			 */
2299 			if (readsize == 1)
2300 				goto bad;
2301 			st->blksize -= 512;
2302 			continue;
2303 		}
2304 		st_read(st, bf, readsize, XS_CTL_SILENT);	/* XXX */
2305 		if ((error = st_rewind(st, 0, 0)) != 0) {
2306 bad:			free(bf, M_TEMP);
2307 			return error;
2308 		}
2309 	} while (readsize != 1 && readsize > st->blksize);
2310 
2311 	free(bf, M_TEMP);
2312 	return 0;
2313 }
2314 
2315 static int
2316 stdump(dev_t dev, daddr_t blkno, void *va, size_t size)
2317 {
2318 	/* Not implemented. */
2319 	return ENXIO;
2320 }
2321 
2322 /*
2323  * Send a filled out parameter structure to the drive to
2324  * set it into the desire modes etc.
2325  */
2326 int
2327 st_mode_select(struct st_softc *st, int flags)
2328 {
2329 	u_int select_len;
2330 	struct select {
2331 		struct scsi_mode_parameter_header_6 header;
2332 		struct scsi_general_block_descriptor blk_desc;
2333 		u_char sense_data[MAX_PAGE_0_SIZE];
2334 	} select;
2335 	struct scsipi_periph *periph = st->sc_periph;
2336 
2337 	select_len = sizeof(select.header) + sizeof(select.blk_desc) +
2338 		     st->page_0_size;
2339 
2340 	/*
2341 	 * This quirk deals with drives that have only one valid mode
2342 	 * and think this gives them license to reject all mode selects,
2343 	 * even if the selected mode is the one that is supported.
2344 	 */
2345 	if (st->quirks & ST_Q_UNIMODAL) {
2346 		SC_DEBUG(periph, SCSIPI_DB3,
2347 		    ("not setting density 0x%x blksize 0x%x\n",
2348 		    st->density, st->blksize));
2349 		return 0;
2350 	}
2351 
2352 	/* Set up for a mode select */
2353 	memset(&select, 0, sizeof(select));
2354 	select.header.blk_desc_len = sizeof(struct
2355 	    scsi_general_block_descriptor);
2356 	select.header.dev_spec &= ~SMH_DSP_BUFF_MODE;
2357 	select.blk_desc.density = st->density;
2358 	if (st->flags & ST_DONTBUFFER)
2359 		select.header.dev_spec |= SMH_DSP_BUFF_MODE_OFF;
2360 	else
2361 		select.header.dev_spec |= SMH_DSP_BUFF_MODE_ON;
2362 	if (st->flags & ST_FIXEDBLOCKS)
2363 		_lto3b(st->blksize, select.blk_desc.blklen);
2364 	if (st->page_0_size)
2365 		memcpy(select.sense_data, st->sense_data, st->page_0_size);
2366 
2367 	/* do the command */
2368 	return scsipi_mode_select(periph, 0, &select.header, select_len,
2369 				  flags, ST_RETRIES, ST_CTL_TIME);
2370 }
2371