xref: /netbsd-src/sys/dev/scsipi/st.c (revision 95b39c65ca575fb40c6bb7083e0eb7ec28eabef1)
1 /*	$NetBSD: st.c,v 1.227 2015/08/24 23:13:15 pooka 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 1.227 2015/08/24 23:13:15 pooka Exp $");
54 
55 #ifdef _KERNEL_OPT
56 #include "opt_scsi.h"
57 #endif
58 
59 #include <sys/param.h>
60 #include <sys/systm.h>
61 #include <sys/fcntl.h>
62 #include <sys/errno.h>
63 #include <sys/ioctl.h>
64 #include <sys/malloc.h>
65 #include <sys/buf.h>
66 #include <sys/bufq.h>
67 #include <sys/proc.h>
68 #include <sys/mtio.h>
69 #include <sys/device.h>
70 #include <sys/conf.h>
71 #include <sys/kernel.h>
72 #include <sys/vnode.h>
73 #include <sys/iostat.h>
74 #include <sys/sysctl.h>
75 
76 #include <dev/scsipi/scsi_spc.h>
77 #include <dev/scsipi/scsipi_all.h>
78 #include <dev/scsipi/scsi_all.h>
79 #include <dev/scsipi/scsi_tape.h>
80 #include <dev/scsipi/scsipiconf.h>
81 #include <dev/scsipi/scsipi_base.h>
82 #include <dev/scsipi/stvar.h>
83 
84 /* Defines for device specific stuff */
85 #define DEF_FIXED_BSIZE  512
86 
87 #define STMODE(z)	( minor(z)       & 0x03)
88 #define STDSTY(z)	((minor(z) >> 2) & 0x03)
89 #define STUNIT(z)	((minor(z) >> 4)       )
90 #define STNMINOR	16
91 
92 #define NORMAL_MODE	0
93 #define NOREW_MODE	1
94 #define EJECT_MODE	2
95 #define CTRL_MODE	3
96 
97 #ifndef		ST_MOUNT_DELAY
98 #define		ST_MOUNT_DELAY		0
99 #endif
100 
101 static dev_type_open(stopen);
102 static dev_type_close(stclose);
103 static dev_type_read(stread);
104 static dev_type_write(stwrite);
105 static dev_type_ioctl(stioctl);
106 static dev_type_strategy(ststrategy);
107 static dev_type_dump(stdump);
108 
109 const struct bdevsw st_bdevsw = {
110 	.d_open = stopen,
111 	.d_close = stclose,
112 	.d_strategy = ststrategy,
113 	.d_ioctl = stioctl,
114 	.d_dump = stdump,
115 	.d_psize = nosize,
116 	.d_discard = nodiscard,
117 	.d_flag = D_TAPE
118 };
119 
120 const struct cdevsw st_cdevsw = {
121 	.d_open = stopen,
122 	.d_close = stclose,
123 	.d_read = stread,
124 	.d_write = stwrite,
125 	.d_ioctl = stioctl,
126 	.d_stop = nostop,
127 	.d_tty = notty,
128 	.d_poll = nopoll,
129 	.d_mmap = nommap,
130 	.d_kqfilter = nokqfilter,
131 	.d_discard = nodiscard,
132 	.d_flag = D_TAPE
133 };
134 
135 /*
136  * Define various devices that we know mis-behave in some way,
137  * and note how they are bad, so we can correct for them
138  */
139 
140 static const struct st_quirk_inquiry_pattern st_quirk_patterns[] = {
141 	{{T_SEQUENTIAL, T_REMOV,
142 	 "        ", "                ", "    "}, {0, 0, {
143 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
144 		{ST_Q_FORCE_BLKSIZE, 512, QIC_24},	/* minor 4-7 */
145 		{ST_Q_FORCE_BLKSIZE, 0, HALFINCH_1600},	/* minor 8-11 */
146 		{ST_Q_FORCE_BLKSIZE, 0, HALFINCH_6250}	/* minor 12-15 */
147 	}}},
148 	{{T_SEQUENTIAL, T_REMOV,
149 	 "TANDBERG", " TDC 3600       ", ""},     {0, 12, {
150 		{0, 0, 0},				/* minor 0-3 */
151 		{ST_Q_FORCE_BLKSIZE, 0, QIC_525},	/* minor 4-7 */
152 		{0, 0, QIC_150},			/* minor 8-11 */
153 		{0, 0, QIC_120}				/* minor 12-15 */
154 	}}},
155  	{{T_SEQUENTIAL, T_REMOV,
156  	 "TANDBERG", " TDC 3800       ", ""},     {0, 0, {
157 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
158 		{0, 0, QIC_525},			/* minor 4-7 */
159 		{0, 0, QIC_150},			/* minor 8-11 */
160 		{0, 0, QIC_120}				/* minor 12-15 */
161 	}}},
162 	{{T_SEQUENTIAL, T_REMOV,
163 	  "TANDBERG", " SLR5 4/8GB     ", ""},     {0, 0, {
164 		{ST_Q_FORCE_BLKSIZE, 1024, 0},		/* minor 0-3 */
165 		{0, 0, 0},				/* minor 4-7 */
166 		{0, 0, 0},				/* minor 8-11 */
167 		{0, 0, 0}				/* minor 12-15 */
168 	}}},
169 	/*
170 	 * lacking a manual for the 4200, it's not clear what the
171 	 * specific density codes should be- the device is a 2.5GB
172 	 * capable QIC drive, those density codes aren't readily
173 	 * availabel. The 'default' will just have to do.
174 	 */
175  	{{T_SEQUENTIAL, T_REMOV,
176  	 "TANDBERG", " TDC 4200       ", ""},     {0, 0, {
177 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
178 		{0, 0, QIC_525},			/* minor 4-7 */
179 		{0, 0, QIC_150},			/* minor 8-11 */
180 		{0, 0, QIC_120}				/* minor 12-15 */
181 	}}},
182 	/*
183 	 * At least -005 and -007 need this.  I'll assume they all do unless I
184 	 * hear otherwise.  - mycroft, 31MAR1994
185 	 */
186 	{{T_SEQUENTIAL, T_REMOV,
187 	 "ARCHIVE ", "VIPER 2525 25462", ""},     {0, 0, {
188 		{ST_Q_SENSE_HELP, 0, 0},		/* minor 0-3 */
189 		{ST_Q_SENSE_HELP, 0, QIC_525},		/* minor 4-7 */
190 		{0, 0, QIC_150},			/* minor 8-11 */
191 		{0, 0, QIC_120}				/* minor 12-15 */
192 	}}},
193 	/*
194 	 * One user reports that this works for his tape drive.  It probably
195 	 * needs more work.  - mycroft, 09APR1994
196 	 */
197 	{{T_SEQUENTIAL, T_REMOV,
198 	 "SANKYO  ", "CP525           ", ""},    {0, 0, {
199 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
200 		{ST_Q_FORCE_BLKSIZE, 512, QIC_525},	/* minor 4-7 */
201 		{0, 0, QIC_150},			/* minor 8-11 */
202 		{0, 0, QIC_120}				/* minor 12-15 */
203 	}}},
204 	{{T_SEQUENTIAL, T_REMOV,
205 	 "ANRITSU ", "DMT780          ", ""},     {0, 0, {
206 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
207 		{ST_Q_FORCE_BLKSIZE, 512, QIC_525},	/* minor 4-7 */
208 		{0, 0, QIC_150},			/* minor 8-11 */
209 		{0, 0, QIC_120}				/* minor 12-15 */
210 	}}},
211 	{{T_SEQUENTIAL, T_REMOV,
212 	 "ARCHIVE ", "VIPER 150  21247", ""},     {ST_Q_ERASE_NOIMM, 12, {
213 		{ST_Q_SENSE_HELP, 0, 0},		/* minor 0-3 */
214 		{0, 0, QIC_150},			/* minor 4-7 */
215 		{0, 0, QIC_120},			/* minor 8-11 */
216 		{0, 0, QIC_24}				/* minor 12-15 */
217 	}}},
218 	{{T_SEQUENTIAL, T_REMOV,
219 	 "ARCHIVE ", "VIPER 150  21531", ""},     {ST_Q_ERASE_NOIMM, 12, {
220 		{ST_Q_SENSE_HELP, 0, 0},		/* minor 0-3 */
221 		{0, 0, QIC_150},			/* minor 4-7 */
222 		{0, 0, QIC_120},			/* minor 8-11 */
223 		{0, 0, QIC_24}				/* minor 12-15 */
224 	}}},
225 	{{T_SEQUENTIAL, T_REMOV,
226 	 "WANGTEK ", "5099ES SCSI", ""},          {0, 0, {
227 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
228 		{0, 0, QIC_11},				/* minor 4-7 */
229 		{0, 0, QIC_24},				/* minor 8-11 */
230 		{0, 0, QIC_24}				/* minor 12-15 */
231 	}}},
232 	{{T_SEQUENTIAL, T_REMOV,
233 	 "WANGTEK ", "5150ES SCSI", ""},          {0, 0, {
234 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
235 		{0, 0, QIC_24},				/* minor 4-7 */
236 		{0, 0, QIC_120},			/* minor 8-11 */
237 		{0, 0, QIC_150}				/* minor 12-15 */
238 	}}},
239 	{{T_SEQUENTIAL, T_REMOV,
240 	 "WANGTEK ", "5525ES SCSI REV7", ""},     {0, 0, {
241 		{0, 0, 0},				/* minor 0-3 */
242 		{ST_Q_BLKSIZE, 0, QIC_525},		/* minor 4-7 */
243 		{0, 0, QIC_150},			/* minor 8-11 */
244 		{0, 0, QIC_120}				/* minor 12-15 */
245 	}}},
246 	{{T_SEQUENTIAL, T_REMOV,
247 	 "WangDAT ", "Model 1300      ", ""},     {0, 0, {
248 		{0, 0, 0},				/* minor 0-3 */
249 		{ST_Q_FORCE_BLKSIZE, 512, DDS},		/* minor 4-7 */
250 		{ST_Q_FORCE_BLKSIZE, 1024, DDS},	/* minor 8-11 */
251 		{ST_Q_FORCE_BLKSIZE, 0, DDS}		/* minor 12-15 */
252 	}}},
253 	{{T_SEQUENTIAL, T_REMOV,
254 	 "EXABYTE ", "EXB-8200        ", "263H"}, {0, 5, {
255 		{0, 0, 0},				/* minor 0-3 */
256 		{0, 0, 0},				/* minor 4-7 */
257 		{0, 0, 0},				/* minor 8-11 */
258 		{0, 0, 0}				/* minor 12-15 */
259 	}}},
260 	{{T_SEQUENTIAL, T_REMOV,
261 	 "STK",      "9490",             ""},
262 				{ST_Q_FORCE_BLKSIZE, 0, {
263 		{0, 0, 0},				/* minor 0-3 */
264 		{0, 0, 0},				/* minor 4-7 */
265 		{0, 0, 0},				/* minor 8-11 */
266 		{0, 0, 0}				/* minor 12-15 */
267 	}}},
268 	{{T_SEQUENTIAL, T_REMOV,
269 	 "STK",      "SD-3",             ""},
270 				{ST_Q_FORCE_BLKSIZE, 0, {
271 		{0, 0, 0},				/* minor 0-3 */
272 		{0, 0, 0},				/* minor 4-7 */
273 		{0, 0, 0},				/* minor 8-11 */
274 		{0, 0, 0}				/* minor 12-15 */
275 	}}},
276 	{{T_SEQUENTIAL, T_REMOV,
277 	 "IBM",      "03590",            ""},     {ST_Q_IGNORE_LOADS, 0, {
278 		{0, 0, 0},				/* minor 0-3 */
279 		{0, 0, 0},				/* minor 4-7 */
280 		{0, 0, 0},				/* minor 8-11 */
281 		{0, 0, 0}				/* minor 12-15 */
282 	}}},
283 	{{T_SEQUENTIAL, T_REMOV,
284 	 "HP      ", "T4000s          ", ""},     {ST_Q_UNIMODAL, 0, {
285 		{0, 0, QIC_3095},			/* minor 0-3 */
286 		{0, 0, QIC_3095},			/* minor 4-7 */
287 		{0, 0, QIC_3095},			/* minor 8-11 */
288 		{0, 0, QIC_3095},			/* minor 12-15 */
289 	}}},
290 #if 0
291 	{{T_SEQUENTIAL, T_REMOV,
292 	 "EXABYTE ", "EXB-8200        ", ""},     {0, 12, {
293 		{0, 0, 0},				/* minor 0-3 */
294 		{0, 0, 0},				/* minor 4-7 */
295 		{0, 0, 0},				/* minor 8-11 */
296 		{0, 0, 0}				/* minor 12-15 */
297 	}}},
298 #endif
299 	{{T_SEQUENTIAL, T_REMOV,
300 	 "TEAC    ", "MT-2ST/N50      ", ""},     {ST_Q_IGNORE_LOADS, 0, {
301 		{0, 0, 0},			        /* minor 0-3 */
302 		{0, 0, 0},			        /* minor 4-7 */
303 		{0, 0, 0},			        /* minor 8-11 */
304 		{0, 0, 0}			        /* minor 12-15 */
305 	}}},
306 	{{T_SEQUENTIAL, T_REMOV,
307 	 "OnStream", "ADR50 Drive", ""},	  {ST_Q_UNIMODAL, 0, {
308 		{ST_Q_FORCE_BLKSIZE, 512, 0},	        /* minor 0-3 */
309 		{ST_Q_FORCE_BLKSIZE, 512, 0},	        /* minor 4-7 */
310 		{ST_Q_FORCE_BLKSIZE, 512, 0},	        /* minor 8-11 */
311 		{ST_Q_FORCE_BLKSIZE, 512, 0},	        /* minor 12-15 */
312 	}}},
313 	{{T_SEQUENTIAL, T_REMOV,
314 	 "OnStream DI-30",      "",   "1.0"},  {ST_Q_NOFILEMARKS, 0, {
315 		{0, 0, 0},                              /* minor 0-3 */
316 		{0, 0, 0},                              /* minor 4-7 */
317 		{0, 0, 0},                              /* minor 8-11 */
318 		{0, 0, 0}                               /* minor 12-15 */
319 	}}},
320 	{{T_SEQUENTIAL, T_REMOV,
321 	 "NCR H621", "0-STD-03-46F880 ", ""},     {ST_Q_NOPREVENT, 0, {
322 		{0, 0, 0},			       /* minor 0-3 */
323 		{0, 0, 0},			       /* minor 4-7 */
324 		{0, 0, 0},			       /* minor 8-11 */
325 		{0, 0, 0}			       /* minor 12-15 */
326 	}}},
327 	{{T_SEQUENTIAL, T_REMOV,
328 	 "Seagate STT3401A", "hp0atxa", ""},	{0, 0, {
329 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
330 		{ST_Q_FORCE_BLKSIZE, 1024, 0},		/* minor 4-7 */
331 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 8-11 */
332 		{ST_Q_FORCE_BLKSIZE, 512, 0}		/* minor 12-15 */
333 	}}},
334 };
335 
336 #define NOEJECT 0
337 #define EJECT 1
338 
339 static void	st_identify_drive(struct st_softc *,
340 		    struct scsipi_inquiry_pattern *);
341 static void	st_loadquirks(struct st_softc *);
342 static int	st_mount_tape(dev_t, int);
343 static void	st_unmount(struct st_softc *, boolean);
344 static int	st_decide_mode(struct st_softc *, boolean);
345 static void	ststart(struct scsipi_periph *);
346 static void	strestart(void *);
347 static void	stdone(struct scsipi_xfer *, int);
348 static int	st_read(struct st_softc *, char *, int, int);
349 static int	st_space(struct st_softc *, int, u_int, int);
350 static int	st_write_filemarks(struct st_softc *, int, int);
351 static int	st_check_eod(struct st_softc *, boolean, int *, int);
352 static int	st_load(struct st_softc *, u_int, int);
353 static int	st_rewind(struct st_softc *, u_int, int);
354 static int	st_interpret_sense(struct scsipi_xfer *);
355 static int	st_touch_tape(struct st_softc *);
356 static int	st_erase(struct st_softc *, int full, int flags);
357 static int	st_rdpos(struct st_softc *, int, uint32_t *);
358 static int	st_setpos(struct st_softc *, int, uint32_t *);
359 
360 static const struct scsipi_periphsw st_switch = {
361 	st_interpret_sense,
362 	ststart,
363 	NULL,
364 	stdone
365 };
366 
367 #if defined(ST_ENABLE_EARLYWARN)
368 #define	ST_INIT_FLAGS	ST_EARLYWARN
369 #else
370 #define	ST_INIT_FLAGS	0
371 #endif
372 
373 /*
374  * The routine called by the low level scsi routine when it discovers
375  * A device suitable for this driver
376  */
377 void
378 stattach(device_t parent, device_t self, void *aux)
379 {
380 	struct st_softc *st = device_private(self);
381 	struct scsipibus_attach_args *sa = aux;
382 	struct scsipi_periph *periph = sa->sa_periph;
383 
384 	SC_DEBUG(periph, SCSIPI_DB2, ("stattach: "));
385 	st->sc_dev = self;
386 
387 	/* Store information needed to contact our base driver */
388 	st->sc_periph = periph;
389 	periph->periph_dev = st->sc_dev;
390 	periph->periph_switch = &st_switch;
391 
392 	/* Set initial flags  */
393 	st->flags = ST_INIT_FLAGS;
394 
395 	/* Set up the buf queue for this device */
396 	bufq_alloc(&st->buf_queue, "fcfs", 0);
397 	callout_init(&st->sc_callout, 0);
398 
399 	/*
400 	 * Check if the drive is a known criminal and take
401 	 * Any steps needed to bring it into line
402 	 */
403 	st_identify_drive(st, &sa->sa_inqbuf);
404 	printf("\n");
405 	/* Use the subdriver to request information regarding the drive.  */
406 	printf("%s : %s", device_xname(st->sc_dev), st->quirkdata
407 	    ? "quirks apply, " : "");
408 	if (scsipi_test_unit_ready(periph,
409 	    XS_CTL_DISCOVERY | XS_CTL_SILENT | XS_CTL_IGNORE_MEDIA_CHANGE) ||
410 	    st->ops(st, ST_OPS_MODESENSE,
411 	    XS_CTL_DISCOVERY | XS_CTL_SILENT | XS_CTL_IGNORE_MEDIA_CHANGE))
412 		printf("drive empty\n");
413 	else {
414 		printf("density code %d, ", st->media_density);
415 		if (st->media_blksize > 0)
416 			printf("%d-byte", st->media_blksize);
417 		else
418 			printf("variable");
419 		printf(" blocks, write-%s\n",
420 		    (st->flags & ST_READONLY) ? "protected" : "enabled");
421 	}
422 
423 	st->stats = iostat_alloc(IOSTAT_TAPE, parent,
424 	    device_xname(st->sc_dev));
425 
426 	rnd_attach_source(&st->rnd_source, device_xname(st->sc_dev),
427 	    RND_TYPE_TAPE, RND_FLAG_DEFAULT);
428 }
429 
430 int
431 stdetach(device_t self, int flags)
432 {
433 	struct st_softc *st = device_private(self);
434 	int s, bmaj, cmaj, mn;
435 
436 	/* locate the major number */
437 	bmaj = bdevsw_lookup_major(&st_bdevsw);
438 	cmaj = cdevsw_lookup_major(&st_cdevsw);
439 
440 	/* kill any pending restart */
441 	callout_stop(&st->sc_callout);
442 
443 	s = splbio();
444 
445 	/* Kill off any queued buffers. */
446 	bufq_drain(st->buf_queue);
447 
448 	bufq_free(st->buf_queue);
449 
450 	/* Kill off any pending commands. */
451 	scsipi_kill_pending(st->sc_periph);
452 
453 	splx(s);
454 
455 	/* Nuke the vnodes for any open instances */
456 	mn = STUNIT(device_unit(self));
457 	vdevgone(bmaj, mn, mn+STNMINOR-1, VBLK);
458 	vdevgone(cmaj, mn, mn+STNMINOR-1, VCHR);
459 
460 	iostat_free(st->stats);
461 
462 	/* Unhook the entropy source. */
463 	rnd_detach_source(&st->rnd_source);
464 
465 	return 0;
466 }
467 
468 /*
469  * Use the inquiry routine in 'scsi_base' to get drive info so we can
470  * Further tailor our behaviour.
471  */
472 static void
473 st_identify_drive(struct st_softc *st, struct scsipi_inquiry_pattern *inqbuf)
474 {
475 	const struct st_quirk_inquiry_pattern *finger;
476 	int priority;
477 
478 	finger = scsipi_inqmatch(inqbuf,
479 	    st_quirk_patterns,
480 	    sizeof(st_quirk_patterns) / sizeof(st_quirk_patterns[0]),
481 	    sizeof(st_quirk_patterns[0]), &priority);
482 	if (priority != 0) {
483 		st->quirkdata = &finger->quirkdata;
484 		st->drive_quirks = finger->quirkdata.quirks;
485 		st->quirks = finger->quirkdata.quirks;	/* start value */
486 		st->page_0_size = finger->quirkdata.page_0_size;
487 		KASSERT(st->page_0_size <= MAX_PAGE_0_SIZE);
488 		st_loadquirks(st);
489 	}
490 }
491 
492 /*
493  * initialise the subdevices to the default (QUIRK) state.
494  * this will remove any setting made by the system operator or previous
495  * operations.
496  */
497 static void
498 st_loadquirks(struct st_softc *st)
499 {
500 	const struct	modes *mode;
501 	struct	modes *mode2;
502 	int i;
503 
504 	mode = st->quirkdata->modes;
505 	mode2 = st->modes;
506 	for (i = 0; i < 4; i++) {
507 		memset(mode2, 0, sizeof(struct modes));
508 		st->modeflags[i] &= ~(BLKSIZE_SET_BY_QUIRK |
509 		    DENSITY_SET_BY_QUIRK | BLKSIZE_SET_BY_USER |
510 		    DENSITY_SET_BY_USER);
511 		if ((mode->quirks | st->drive_quirks) & ST_Q_FORCE_BLKSIZE) {
512 			mode2->blksize = mode->blksize;
513 			st->modeflags[i] |= BLKSIZE_SET_BY_QUIRK;
514 		}
515 		if (mode->density) {
516 			mode2->density = mode->density;
517 			st->modeflags[i] |= DENSITY_SET_BY_QUIRK;
518 		}
519 		mode2->quirks |= mode->quirks;
520 		mode++;
521 		mode2++;
522 	}
523 }
524 
525 /* open the device. */
526 static int
527 stopen(dev_t dev, int flags, int mode, struct lwp *l)
528 {
529 	u_int stmode, dsty;
530 	int error, sflags, unit, tries, ntries;
531 	struct st_softc *st;
532 	struct scsipi_periph *periph;
533 	struct scsipi_adapter *adapt;
534 
535 	unit = STUNIT(dev);
536 	st = device_lookup_private(&st_cd, unit);
537 	if (st == NULL)
538 		return ENXIO;
539 
540 	stmode = STMODE(dev);
541 	dsty = STDSTY(dev);
542 
543 	periph = st->sc_periph;
544 	adapt = periph->periph_channel->chan_adapter;
545 
546 	SC_DEBUG(periph, SCSIPI_DB1,
547 	    ("open: dev=0x%"PRIx64" (unit %d (of %d))\n", dev, unit,
548 	    st_cd.cd_ndevs));
549 
550 	/* Only allow one at a time */
551 	if (periph->periph_flags & PERIPH_OPEN) {
552 		aprint_error_dev(st->sc_dev, "already open\n");
553 		return EBUSY;
554 	}
555 
556 	if ((error = scsipi_adapter_addref(adapt)) != 0)
557 		return error;
558 
559 	/* clear any latched errors. */
560 	st->mt_resid = 0;
561 	st->mt_erreg = 0;
562 	st->asc = 0;
563 	st->ascq = 0;
564 
565 	/*
566 	 * Catch any unit attention errors. Be silent about this
567 	 * unless we're already mounted. We ignore media change
568 	 * if we're in control mode or not mounted yet.
569 	 */
570 	if ((st->flags & ST_MOUNTED) == 0 || stmode == CTRL_MODE) {
571 #ifdef SCSIDEBUG
572 		sflags = XS_CTL_IGNORE_MEDIA_CHANGE;
573 #else
574 		sflags = XS_CTL_SILENT|XS_CTL_IGNORE_MEDIA_CHANGE;
575 #endif
576 	} else
577 		sflags = 0;
578 
579 	/*
580 	 * If we're already mounted or we aren't configured for
581 	 * a mount delay, only try a test unit ready once. Otherwise,
582 	 * try up to ST_MOUNT_DELAY times with a rest interval of
583 	 * one second between each try.
584 	 */
585 	if ((st->flags & ST_MOUNTED) || ST_MOUNT_DELAY == 0)
586 		ntries = 1;
587 	else
588 		ntries = ST_MOUNT_DELAY;
589 
590 	for (error = tries = 0; tries < ntries; tries++) {
591 		int slpintr, oflags;
592 
593 		/*
594 		 * If we had no error, or we're opening the control mode
595 		 * device, we jump out right away.
596 		 */
597 		error = scsipi_test_unit_ready(periph, sflags);
598 		if (error == 0 || stmode == CTRL_MODE)
599 			break;
600 
601 		/*
602 		 * We had an error.
603 		 *
604 		 * If we're already mounted or we aren't configured for
605 		 * a mount delay, or the error isn't a NOT READY error,
606 		 * skip to the error exit now.
607 		 */
608 		if ((st->flags & ST_MOUNTED) || ST_MOUNT_DELAY == 0 ||
609 		    (st->mt_key != SKEY_NOT_READY)) {
610 			goto bad;
611 		}
612 
613 		/* clear any latched errors. */
614 		st->mt_resid = 0;
615 		st->mt_erreg = 0;
616 		st->asc = 0;
617 		st->ascq = 0;
618 
619 		/*
620 		 * Fake that we have the device open so
621 		 * we block other apps from getting in.
622 		 */
623 		oflags = periph->periph_flags;
624 		periph->periph_flags |= PERIPH_OPEN;
625 
626 		slpintr = kpause("stload", true, hz, NULL);
627 
628 		periph->periph_flags = oflags;	/* restore flags */
629 		if (slpintr != 0 && slpintr != EWOULDBLOCK) {
630 			goto bad;
631 		}
632 	}
633 
634 
635 	/*
636 	 * If the mode is 3 (e.g. minor = 3,7,11,15) then the device has
637 	 * been opened to set defaults and perform other, usually non-I/O
638 	 * related, operations. In this case, do a quick check to see
639 	 * whether the unit actually had a tape loaded (this will be known
640 	 * as to whether or not we got a NOT READY for the above
641 	 * unit attention). If a tape is there, go do a mount sequence.
642 	 */
643 	if (stmode == CTRL_MODE && st->mt_key == SKEY_NOT_READY) {
644 		periph->periph_flags |= PERIPH_OPEN;
645 		return 0;
646 	}
647 
648 	/*
649 	 * If we get this far and had an error set, that means we failed
650 	 * to pass the 'test unit ready' test for the non-controlmode device,
651 	 * so we bounce the open.
652 	 */
653 	if (error)
654 		return error;
655 
656 	/* Else, we're now committed to saying we're open. */
657 	periph->periph_flags |= PERIPH_OPEN; /* unit attn are now errors */
658 
659 	/*
660 	 * If it's a different mode, or if the media has been
661 	 * invalidated, unmount the tape from the previous
662 	 * session but continue with open processing
663 	 */
664 	if (st->last_dsty != dsty ||
665 	    (periph->periph_flags & PERIPH_MEDIA_LOADED) == 0)
666 		st_unmount(st, NOEJECT);
667 
668 	/*
669 	 * If we are not mounted, then we should start a new
670 	 * mount session.
671 	 */
672 	if (!(st->flags & ST_MOUNTED)) {
673 		if ((error = st_mount_tape(dev, flags)) != 0)
674 			goto bad;
675 		st->last_dsty = dsty;
676 	}
677 	if (!(st->quirks & ST_Q_NOPREVENT)) {
678 		scsipi_prevent(periph, SPAMR_PREVENT_DT,
679 		    XS_CTL_IGNORE_ILLEGAL_REQUEST | XS_CTL_IGNORE_NOT_READY);
680 	}
681 
682 	SC_DEBUG(periph, SCSIPI_DB2, ("open complete\n"));
683 	return 0;
684 
685 bad:
686 	st_unmount(st, NOEJECT);
687 	scsipi_adapter_delref(adapt);
688 	periph->periph_flags &= ~PERIPH_OPEN;
689 	return error;
690 }
691 
692 static int
693 stclose(dev_t dev, int flags, int mode, struct lwp *l)
694 {
695 	int stxx, error = 0;
696 	struct st_softc *st = device_lookup_private(&st_cd, STUNIT(dev));
697 	struct scsipi_periph *periph = st->sc_periph;
698 	struct scsipi_adapter *adapt = periph->periph_channel->chan_adapter;
699 
700 	SC_DEBUG(st->sc_periph, SCSIPI_DB1, ("closing\n"));
701 
702 	/*
703 	 * Make sure that a tape opened in write-only mode will have
704 	 * file marks written on it when closed, even if not written to.
705 	 *
706 	 * This is for SUN compatibility. Actually, the Sun way of
707 	 * things is to:
708 	 *
709 	 *	only write filemarks if there are fmks to be written and
710 	 *   		- open for write (possibly read/write)
711 	 *		- the last operation was a write
712 	 * 	or:
713 	 *		- opened for wronly
714 	 *		- no data was written (including filemarks)
715 	 */
716 
717 	stxx = st->flags & (ST_WRITTEN | ST_FM_WRITTEN);
718 	if (((flags & FWRITE) && stxx == ST_WRITTEN) ||
719 	    ((flags & O_ACCMODE) == FWRITE && stxx == 0)) {
720 		int nm;
721 		error = st_check_eod(st, FALSE, &nm, 0);
722 	}
723 
724 	/* Allow robots to eject tape if needed.  */
725 	scsipi_prevent(periph, SPAMR_ALLOW,
726 	    XS_CTL_IGNORE_ILLEGAL_REQUEST | XS_CTL_IGNORE_NOT_READY);
727 
728 	switch (STMODE(dev)) {
729 	case NORMAL_MODE:
730 		st_unmount(st, NOEJECT);
731 		break;
732 	case NOREW_MODE:
733 	case CTRL_MODE:
734 		/*
735 		 * Leave mounted unless media seems to have been removed.
736 		 *
737 		 * Otherwise, if we're to terminate a tape with more than one
738 		 * filemark [ and because we're not rewinding here ], backspace
739 		 * one filemark so that later appends will see an unbroken
740 		 * sequence of:
741 		 *
742 		 *	file - FMK - file - FMK ... file - FMK FMK (EOM)
743 		 */
744 		if ((periph->periph_flags & PERIPH_MEDIA_LOADED) == 0) {
745 			st_unmount(st, NOEJECT);
746 		} else if (error == 0) {
747 			/*
748 			 * ST_WRITTEN was preserved from above.
749 			 *
750 			 * All we need to know here is:
751 			 *
752 			 *	Were we writing this tape and was the last
753 			 *	operation a write?
754 			 *
755 			 *	Are there supposed to be 2FM at EOD?
756 			 *
757 			 * If both statements are true, then we backspace
758 			 * one filemark.
759 			 */
760 			stxx |= (st->flags & ST_2FM_AT_EOD);
761 			if ((flags & FWRITE) != 0 &&
762 			    (stxx == (ST_2FM_AT_EOD|ST_WRITTEN))) {
763 				error = st_space(st, -1, SP_FILEMARKS, 0);
764 			}
765 		}
766 		break;
767 	case EJECT_MODE:
768 		st_unmount(st, EJECT);
769 		break;
770 	}
771 
772 	scsipi_wait_drain(periph);
773 
774 	scsipi_adapter_delref(adapt);
775 	periph->periph_flags &= ~PERIPH_OPEN;
776 
777 	return error;
778 }
779 
780 /*
781  * Start a new mount session.
782  * Copy in all the default parameters from the selected device mode.
783  * and try guess any that seem to be defaulted.
784  */
785 static int
786 st_mount_tape(dev_t dev, int flags)
787 {
788 	int unit;
789 	u_int dsty;
790 	struct st_softc *st;
791 	struct scsipi_periph *periph;
792 	int error = 0;
793 
794 	unit = STUNIT(dev);
795 	dsty = STDSTY(dev);
796 	st = device_lookup_private(&st_cd, unit);
797 	periph = st->sc_periph;
798 
799 	if (st->flags & ST_MOUNTED)
800 		return 0;
801 
802 	SC_DEBUG(periph, SCSIPI_DB1, ("mounting\n "));
803 	st->flags |= ST_NEW_MOUNT;
804 	st->quirks = st->drive_quirks | st->modes[dsty].quirks;
805 	/*
806 	 * If the media is new, then make sure we give it a chance to
807 	 * to do a 'load' instruction.  (We assume it is new.)
808 	 */
809 	if ((error = st_load(st, LD_LOAD, XS_CTL_SILENT)) != 0)
810 		return error;
811 	/*
812 	 * Throw another dummy instruction to catch
813 	 * 'Unit attention' errors. Many drives give
814 	 * these after doing a Load instruction (with
815 	 * the MEDIUM MAY HAVE CHANGED asc/ascq).
816 	 */
817 	scsipi_test_unit_ready(periph, XS_CTL_SILENT);	/* XXX */
818 
819 	/*
820 	 * Some devices can't tell you much until they have been
821 	 * asked to look at the media. This quirk does this.
822 	 */
823 	if (st->quirks & ST_Q_SENSE_HELP)
824 		if ((error = st_touch_tape(st)) != 0)
825 			return error;
826 	/*
827 	 * Load the physical device parameters
828 	 * loads: blkmin, blkmax
829 	 */
830 	if ((error = st->ops(st, ST_OPS_RBL, 0)) != 0)
831 		return error;
832 	/*
833 	 * Load the media dependent parameters
834 	 * includes: media_blksize,media_density,numblks
835 	 * As we have a tape in, it should be reflected here.
836 	 * If not you may need the "quirk" above.
837 	 */
838 	if ((error = st->ops(st, ST_OPS_MODESENSE, 0)) != 0)
839 		return error;
840 	/*
841 	 * If we have gained a permanent density from somewhere,
842 	 * then use it in preference to the one supplied by
843 	 * default by the driver.
844 	 */
845 	if (st->modeflags[dsty] & (DENSITY_SET_BY_QUIRK | DENSITY_SET_BY_USER))
846 		st->density = st->modes[dsty].density;
847 	else
848 		st->density = st->media_density;
849 	/*
850 	 * If we have gained a permanent blocksize
851 	 * then use it in preference to the one supplied by
852 	 * default by the driver.
853 	 */
854 	st->flags &= ~ST_FIXEDBLOCKS;
855 	if (st->modeflags[dsty] &
856 	    (BLKSIZE_SET_BY_QUIRK | BLKSIZE_SET_BY_USER)) {
857 		st->blksize = st->modes[dsty].blksize;
858 		if (st->blksize)
859 			st->flags |= ST_FIXEDBLOCKS;
860 	} else {
861 		if ((error = st_decide_mode(st, FALSE)) != 0)
862 			return error;
863 	}
864 	if ((error = st->ops(st, ST_OPS_MODESELECT, 0)) != 0) {
865 		/* ATAPI will return ENODEV for this, and this may be OK */
866 		if (error != ENODEV) {
867 			aprint_error_dev(st->sc_dev,
868 			    "cannot set selected mode\n");
869 			return error;
870 		}
871 	}
872 	st->flags &= ~ST_NEW_MOUNT;
873 	st->flags |= ST_MOUNTED;
874 	periph->periph_flags |= PERIPH_MEDIA_LOADED;	/* move earlier? */
875 	st->blkno = st->fileno = (daddr_t) 0;
876 	return 0;
877 }
878 
879 /*
880  * End the present mount session.
881  * Rewind, and optionally eject the tape.
882  * Reset various flags to indicate that all new
883  * operations require another mount operation
884  */
885 static void
886 st_unmount(struct st_softc *st, boolean eject)
887 {
888 	struct scsipi_periph *periph = st->sc_periph;
889 	int nmarks;
890 
891 	if ((st->flags & ST_MOUNTED) == 0)
892 		return;
893 	SC_DEBUG(periph, SCSIPI_DB1, ("unmounting\n"));
894 	st_check_eod(st, FALSE, &nmarks, XS_CTL_IGNORE_NOT_READY);
895 	st_rewind(st, 0, XS_CTL_IGNORE_NOT_READY);
896 
897 	/*
898 	 * Section 9.3.3 of the SCSI specs states that a device shall return
899 	 * the density value specified in the last succesfull MODE SELECT
900 	 * after an unload operation, in case it is not able to
901 	 * automatically determine the density of the new medium.
902 	 *
903 	 * So we instruct the device to use the default density, which will
904 	 * prevent the use of stale density values (in particular,
905 	 * in st_touch_tape().
906 	 */
907 	st->density = 0;
908 	if (st->ops(st, ST_OPS_MODESELECT, 0) != 0) {
909 		aprint_error_dev(st->sc_dev,
910 		    "WARNING: cannot revert to default density\n");
911 	}
912 
913 	if (eject) {
914 		if (!(st->quirks & ST_Q_NOPREVENT)) {
915 			scsipi_prevent(periph, SPAMR_ALLOW,
916 			    XS_CTL_IGNORE_ILLEGAL_REQUEST |
917 			    XS_CTL_IGNORE_NOT_READY);
918 		}
919 		st_load(st, LD_UNLOAD, XS_CTL_IGNORE_NOT_READY);
920 		st->blkno = st->fileno = (daddr_t) -1;
921 	} else {
922 		st->blkno = st->fileno = (daddr_t) 0;
923 	}
924 	st->flags &= ~(ST_MOUNTED | ST_NEW_MOUNT);
925 	periph->periph_flags &= ~PERIPH_MEDIA_LOADED;
926 }
927 
928 /*
929  * Given all we know about the device, media, mode, 'quirks' and
930  * initial operation, make a decision as to how we should be set
931  * to run (regarding blocking and EOD marks)
932  */
933 int
934 st_decide_mode(struct st_softc *st, boolean first_read)
935 {
936 
937 	SC_DEBUG(st->sc_periph, SCSIPI_DB2, ("starting block mode decision\n"));
938 
939 	/*
940 	 * If the drive can only handle fixed-length blocks and only at
941 	 * one size, perhaps we should just do that.
942 	 */
943 	if (st->blkmin && (st->blkmin == st->blkmax)) {
944 		st->flags |= ST_FIXEDBLOCKS;
945 		st->blksize = st->blkmin;
946 		SC_DEBUG(st->sc_periph, SCSIPI_DB3,
947 		    ("blkmin == blkmax of %d\n", st->blkmin));
948 		goto done;
949 	}
950 	/*
951 	 * If the tape density mandates (or even suggests) use of fixed
952 	 * or variable-length blocks, comply.
953 	 */
954 	switch (st->density) {
955 	case HALFINCH_800:
956 	case HALFINCH_1600:
957 	case HALFINCH_6250:
958 	case DDS:
959 		st->flags &= ~ST_FIXEDBLOCKS;
960 		st->blksize = 0;
961 		SC_DEBUG(st->sc_periph, SCSIPI_DB3,
962 		    ("density specified variable\n"));
963 		goto done;
964 	case QIC_11:
965 	case QIC_24:
966 	case QIC_120:
967 	case QIC_150:
968 	case QIC_525:
969 	case QIC_1320:
970 	case QIC_3095:
971 	case QIC_3220:
972 		st->flags |= ST_FIXEDBLOCKS;
973 		if (st->media_blksize > 0)
974 			st->blksize = st->media_blksize;
975 		else
976 			st->blksize = DEF_FIXED_BSIZE;
977 		SC_DEBUG(st->sc_periph, SCSIPI_DB3,
978 		    ("density specified fixed\n"));
979 		goto done;
980 	}
981 	/*
982 	 * If we're about to read the tape, perhaps we should choose
983 	 * fixed or variable-length blocks and block size according to
984 	 * what the drive found on the tape.
985 	 */
986 	if (first_read &&
987 	    (!(st->quirks & ST_Q_BLKSIZE) || (st->media_blksize == 0) ||
988 	    (st->media_blksize == DEF_FIXED_BSIZE) ||
989 	    (st->media_blksize == 1024))) {
990 		if (st->media_blksize > 0)
991 			st->flags |= ST_FIXEDBLOCKS;
992 		else
993 			st->flags &= ~ST_FIXEDBLOCKS;
994 		st->blksize = st->media_blksize;
995 		SC_DEBUG(st->sc_periph, SCSIPI_DB3,
996 		    ("Used media_blksize of %d\n", st->media_blksize));
997 		goto done;
998 	}
999 	/*
1000 	 * We're getting no hints from any direction.  Choose variable-
1001 	 * length blocks arbitrarily.
1002 	 */
1003 	st->flags &= ~ST_FIXEDBLOCKS;
1004 	st->blksize = 0;
1005 	SC_DEBUG(st->sc_periph, SCSIPI_DB3,
1006 	    ("Give up and default to variable mode\n"));
1007 
1008 done:
1009 	/*
1010 	 * Decide whether or not to write two file marks to signify end-
1011 	 * of-data.  Make the decision as a function of density.  If
1012 	 * the decision is not to use a second file mark, the SCSI BLANK
1013 	 * CHECK condition code will be recognized as end-of-data when
1014 	 * first read.
1015 	 * (I think this should be a by-product of fixed/variable..julian)
1016 	 */
1017 	switch (st->density) {
1018 /*      case 8 mm:   What is the SCSI density code for 8 mm, anyway? */
1019 	case QIC_11:
1020 	case QIC_24:
1021 	case QIC_120:
1022 	case QIC_150:
1023 	case QIC_525:
1024 	case QIC_1320:
1025 	case QIC_3095:
1026 	case QIC_3220:
1027 		st->flags &= ~ST_2FM_AT_EOD;
1028 		break;
1029 	default:
1030 		st->flags |= ST_2FM_AT_EOD;
1031 	}
1032 	return 0;
1033 }
1034 
1035 /*
1036  * Actually translate the requested transfer into
1037  * one the physical driver can understand
1038  * The transfer is described by a buf and will include
1039  * only one physical transfer.
1040  */
1041 static void
1042 ststrategy(struct buf *bp)
1043 {
1044 	struct st_softc *st = device_lookup_private(&st_cd, STUNIT(bp->b_dev));
1045 	int s;
1046 
1047 	SC_DEBUG(st->sc_periph, SCSIPI_DB1,
1048 	    ("ststrategy %d bytes @ blk %" PRId64 "\n", bp->b_bcount,
1049 	        bp->b_blkno));
1050 	/* If it's a null transfer, return immediately */
1051 	if (bp->b_bcount == 0)
1052 		goto abort;
1053 
1054 	/* If offset is negative, error */
1055 	if (bp->b_blkno < 0) {
1056 		bp->b_error = EINVAL;
1057 		goto abort;
1058 	}
1059 
1060 	/* Odd sized request on fixed drives are verboten */
1061 	if (st->flags & ST_FIXEDBLOCKS) {
1062 		if (bp->b_bcount % st->blksize) {
1063 			aprint_error_dev(st->sc_dev, "bad request, must be multiple of %d\n",
1064 			    st->blksize);
1065 			bp->b_error = EIO;
1066 			goto abort;
1067 		}
1068 	}
1069 	/* as are out-of-range requests on variable drives. */
1070 	else if (bp->b_bcount < st->blkmin ||
1071 	    (st->blkmax && bp->b_bcount > st->blkmax)) {
1072 		aprint_error_dev(st->sc_dev, "bad request, must be between %d and %d\n",
1073 		    st->blkmin, st->blkmax);
1074 		bp->b_error = EIO;
1075 		goto abort;
1076 	}
1077 	s = splbio();
1078 
1079 	/*
1080 	 * Place it in the queue of activities for this tape
1081 	 * at the end (a bit silly because we only have on user..
1082 	 * (but it could fork()))
1083 	 */
1084 	bufq_put(st->buf_queue, bp);
1085 
1086 	/*
1087 	 * Tell the device to get going on the transfer if it's
1088 	 * not doing anything, otherwise just wait for completion
1089 	 * (All a bit silly if we're only allowing 1 open but..)
1090 	 */
1091 	ststart(st->sc_periph);
1092 
1093 	splx(s);
1094 	return;
1095 abort:
1096 	/*
1097 	 * Reset the residue because we didn't do anything,
1098 	 * and send the buffer back as done.
1099 	 */
1100 	bp->b_resid = bp->b_bcount;
1101 	biodone(bp);
1102 	return;
1103 }
1104 
1105 /*
1106  * ststart looks to see if there is a buf waiting for the device
1107  * and that the device is not already busy. If both are true,
1108  * It dequeues the buf and creates a scsi command to perform the
1109  * transfer required. The transfer request will call scsipi_done
1110  * on completion, which will in turn call this routine again
1111  * so that the next queued transfer is performed.
1112  * The bufs are queued by the strategy routine (ststrategy)
1113  *
1114  * This routine is also called after other non-queued requests
1115  * have been made of the scsi driver, to ensure that the queue
1116  * continues to be drained.
1117  * ststart() is called at splbio
1118  */
1119 static void
1120 ststart(struct scsipi_periph *periph)
1121 {
1122 	struct st_softc *st = device_private(periph->periph_dev);
1123 	struct buf *bp;
1124 	struct scsi_rw_tape cmd;
1125 	struct scsipi_xfer *xs;
1126 	int flags, error __diagused;
1127 
1128 	SC_DEBUG(periph, SCSIPI_DB2, ("ststart "));
1129 	/* See if there is a buf to do and we are not already  doing one */
1130 	while (periph->periph_active < periph->periph_openings) {
1131 		/* if a special awaits, let it proceed first */
1132 		if (periph->periph_flags & PERIPH_WAITING) {
1133 			periph->periph_flags &= ~PERIPH_WAITING;
1134 			wakeup((void *)periph);
1135 			return;
1136 		}
1137 
1138 		/*
1139 		 * If the device has been unmounted by the user
1140 		 * then throw away all requests until done.
1141 		 */
1142 		if (__predict_false((st->flags & ST_MOUNTED) == 0 ||
1143 		    (periph->periph_flags & PERIPH_MEDIA_LOADED) == 0)) {
1144 			if ((bp = bufq_get(st->buf_queue)) != NULL) {
1145 				/* make sure that one implies the other.. */
1146 				periph->periph_flags &= ~PERIPH_MEDIA_LOADED;
1147 				bp->b_error = EIO;
1148 				bp->b_resid = bp->b_bcount;
1149 				biodone(bp);
1150 				continue;
1151 			} else
1152 				return;
1153 		}
1154 
1155 		if ((bp = bufq_peek(st->buf_queue)) == NULL)
1156 			return;
1157 
1158 		iostat_busy(st->stats);
1159 
1160 		/*
1161 		 * only FIXEDBLOCK devices have pending I/O or space operations.
1162 		 */
1163 		if (st->flags & ST_FIXEDBLOCKS) {
1164 			/*
1165 			 * If we are at a filemark but have not reported it yet
1166 			 * then we should report it now
1167 			 */
1168 			if (st->flags & ST_AT_FILEMARK) {
1169 				if ((bp->b_flags & B_READ) == B_WRITE) {
1170 					/*
1171 					 * Handling of ST_AT_FILEMARK in
1172 					 * st_space will fill in the right file
1173 					 * mark count.
1174 					 * Back up over filemark
1175 					 */
1176 					if (st_space(st, 0, SP_FILEMARKS, 0)) {
1177 						bufq_get(st->buf_queue);
1178 						bp->b_error = EIO;
1179 						bp->b_resid = bp->b_bcount;
1180 						biodone(bp);
1181 						continue;
1182 					}
1183 				} else {
1184 					bufq_get(st->buf_queue);
1185 					bp->b_resid = bp->b_bcount;
1186 					bp->b_error = 0;
1187 					st->flags &= ~ST_AT_FILEMARK;
1188 					biodone(bp);
1189 					continue;	/* seek more work */
1190 				}
1191 			}
1192 		}
1193 		/*
1194 		 * If we are at EOM but have not reported it
1195 		 * yet then we should report it now.
1196 		 */
1197 		if (st->flags & (ST_EOM_PENDING|ST_EIO_PENDING)) {
1198 			bufq_get(st->buf_queue);
1199 			bp->b_resid = bp->b_bcount;
1200 			if (st->flags & ST_EIO_PENDING)
1201 				bp->b_error = EIO;
1202 			st->flags &= ~(ST_EOM_PENDING|ST_EIO_PENDING);
1203 			biodone(bp);
1204 			continue;	/* seek more work */
1205 		}
1206 
1207 		/* Fill out the scsi command */
1208 		memset(&cmd, 0, sizeof(cmd));
1209 		flags = XS_CTL_NOSLEEP | XS_CTL_ASYNC;
1210 		if ((bp->b_flags & B_READ) == B_WRITE) {
1211 			cmd.opcode = WRITE;
1212 			st->flags &= ~ST_FM_WRITTEN;
1213 			flags |= XS_CTL_DATA_OUT;
1214 		} else {
1215 			cmd.opcode = READ;
1216 			flags |= XS_CTL_DATA_IN;
1217 		}
1218 
1219 		/*
1220 		 * Handle "fixed-block-mode" tape drives by using the
1221 		 * block count instead of the length.
1222 		 */
1223 		if (st->flags & ST_FIXEDBLOCKS) {
1224 			cmd.byte2 |= SRW_FIXED;
1225 			_lto3b(bp->b_bcount / st->blksize, cmd.len);
1226 		} else
1227 			_lto3b(bp->b_bcount, cmd.len);
1228 
1229 		/* Clear 'position updated' indicator */
1230 		st->flags &= ~ST_POSUPDATED;
1231 
1232 		/* go ask the adapter to do all this for us */
1233 		xs = scsipi_make_xs(periph,
1234 		    (struct scsipi_generic *)&cmd, sizeof(cmd),
1235 		    (u_char *)bp->b_data, bp->b_bcount,
1236 		    0, ST_IO_TIME, bp, flags);
1237 		if (__predict_false(xs == NULL)) {
1238 			/*
1239 			 * out of memory. Keep this buffer in the queue, and
1240 			 * retry later.
1241 			 */
1242 			callout_reset(&st->sc_callout, hz / 2, strestart,
1243 			    periph);
1244 			return;
1245 		}
1246 		/*
1247 		 * need to dequeue the buffer before queuing the command,
1248 		 * because cdstart may be called recursively from the
1249 		 * HBA driver
1250 		 */
1251 #ifdef DIAGNOSTIC
1252 		if (bufq_get(st->buf_queue) != bp)
1253 			panic("ststart(): dequeued wrong buf");
1254 #else
1255 		bufq_get(st->buf_queue);
1256 #endif
1257 		error = scsipi_execute_xs(xs);
1258 		/* with a scsipi_xfer preallocated, scsipi_command can't fail */
1259 		KASSERT(error == 0);
1260 	} /* go back and see if we can cram more work in.. */
1261 }
1262 
1263 static void
1264 strestart(void *v)
1265 {
1266 	int s = splbio();
1267 	ststart((struct scsipi_periph *)v);
1268 	splx(s);
1269 }
1270 
1271 static void
1272 stdone(struct scsipi_xfer *xs, int error)
1273 {
1274 	struct st_softc *st = device_private(xs->xs_periph->periph_dev);
1275 	struct buf *bp = xs->bp;
1276 
1277 	if (bp) {
1278 		bp->b_error = error;
1279 		bp->b_resid = xs->resid;
1280 		/*
1281 		 * buggy device ? A SDLT320 can report an info
1282 		 * field of 0x3de8000 on a Media Error/Write Error
1283 		 * for this CBD: 0x0a 00 00 80 00 00
1284 		 */
1285 		if (bp->b_resid > bp->b_bcount || bp->b_resid < 0)
1286 			bp->b_resid = bp->b_bcount;
1287 
1288 		if ((bp->b_flags & B_READ) == B_WRITE)
1289 			st->flags |= ST_WRITTEN;
1290 		else
1291 			st->flags &= ~ST_WRITTEN;
1292 
1293 		iostat_unbusy(st->stats, bp->b_bcount,
1294 			     ((bp->b_flags & B_READ) == B_READ));
1295 
1296 		rnd_add_uint32(&st->rnd_source, bp->b_blkno);
1297 
1298 		if ((st->flags & ST_POSUPDATED) == 0) {
1299 			if (error) {
1300 				st->fileno = st->blkno = -1;
1301 			} else if (st->blkno != -1) {
1302 				if (st->flags & ST_FIXEDBLOCKS)
1303 					st->blkno +=
1304 					    (bp->b_bcount / st->blksize);
1305 				else
1306 					st->blkno++;
1307 			}
1308 		}
1309 		biodone(bp);
1310 	}
1311 }
1312 
1313 static int
1314 stread(dev_t dev, struct uio *uio, int iomode)
1315 {
1316 	struct st_softc *st = device_lookup_private(&st_cd, STUNIT(dev));
1317 
1318 	return physio(ststrategy, NULL, dev, B_READ,
1319 	    st->sc_periph->periph_channel->chan_adapter->adapt_minphys, uio);
1320 }
1321 
1322 static int
1323 stwrite(dev_t dev, struct uio *uio, int iomode)
1324 {
1325 	struct st_softc *st = device_lookup_private(&st_cd, STUNIT(dev));
1326 
1327 	return physio(ststrategy, NULL, dev, B_WRITE,
1328 	    st->sc_periph->periph_channel->chan_adapter->adapt_minphys, uio);
1329 }
1330 
1331 /*
1332  * Perform special action on behalf of the user;
1333  * knows about the internals of this device
1334  */
1335 static int
1336 stioctl(dev_t dev, u_long cmd, void *arg, int flag, struct lwp *l)
1337 {
1338 	int error = 0;
1339 	int unit;
1340 	int number, nmarks, dsty;
1341 	int flags;
1342 	struct st_softc *st;
1343 	int hold_blksize;
1344 	uint8_t hold_density;
1345 	struct mtop *mt = (struct mtop *) arg;
1346 
1347 	/* Find the device that the user is talking about */
1348 	flags = 0;		/* give error messages, act on errors etc. */
1349 	unit = STUNIT(dev);
1350 	dsty = STDSTY(dev);
1351 	st = device_lookup_private(&st_cd, unit);
1352 	hold_blksize = st->blksize;
1353 	hold_density = st->density;
1354 
1355 	switch ((u_int)cmd) {
1356 	case MTIOCGET: {
1357 		struct mtget *g = (struct mtget *) arg;
1358 		/*
1359 		 * (to get the current state of READONLY)
1360 		 */
1361 		error = st->ops(st, ST_OPS_MODESENSE, XS_CTL_SILENT);
1362 		if (error) {
1363 			/*
1364 			 * Ignore the error if in control mode;
1365 			 * this is mandated by st(4).
1366 			 */
1367 			if (STMODE(dev) != CTRL_MODE)
1368 				break;
1369 			error = 0;
1370 		}
1371 		SC_DEBUG(st->sc_periph, SCSIPI_DB1, ("[ioctl: get status]\n"));
1372 		memset(g, 0, sizeof(struct mtget));
1373 		g->mt_type = MT_ISAR;	/* Ultrix compat *//*? */
1374 		g->mt_blksiz = st->blksize;
1375 		g->mt_density = st->density;
1376 		g->mt_mblksiz[0] = st->modes[0].blksize;
1377 		g->mt_mblksiz[1] = st->modes[1].blksize;
1378 		g->mt_mblksiz[2] = st->modes[2].blksize;
1379 		g->mt_mblksiz[3] = st->modes[3].blksize;
1380 		g->mt_mdensity[0] = st->modes[0].density;
1381 		g->mt_mdensity[1] = st->modes[1].density;
1382 		g->mt_mdensity[2] = st->modes[2].density;
1383 		g->mt_mdensity[3] = st->modes[3].density;
1384 		g->mt_fileno = st->fileno;
1385 		g->mt_blkno = st->blkno;
1386 		if (st->flags & ST_READONLY)
1387 			g->mt_dsreg |= MT_DS_RDONLY;
1388 		if (st->flags & ST_MOUNTED)
1389 			g->mt_dsreg |= MT_DS_MOUNTED;
1390 		g->mt_resid = st->mt_resid;
1391 		g->mt_erreg = st->mt_erreg;
1392 		/*
1393 		 * clear latched errors.
1394 		 */
1395 		st->mt_resid = 0;
1396 		st->mt_erreg = 0;
1397 		st->asc = 0;
1398 		st->ascq = 0;
1399 		break;
1400 	}
1401 	case MTIOCTOP: {
1402 		SC_DEBUG(st->sc_periph, SCSIPI_DB1,
1403 		    ("[ioctl: op=0x%x count=0x%x]\n", mt->mt_op,
1404 			mt->mt_count));
1405 
1406 		/* compat: in U*x it is a short */
1407 		number = mt->mt_count;
1408 		switch ((short) (mt->mt_op)) {
1409 		case MTWEOF:	/* write an end-of-file record */
1410 			error = st_write_filemarks(st, number, flags);
1411 			break;
1412 		case MTBSF:	/* backward space file */
1413 			number = -number;
1414 		case MTFSF:	/* forward space file */
1415 			error = st_check_eod(st, FALSE, &nmarks, flags);
1416 			if (!error)
1417 				error = st_space(st, number - nmarks,
1418 				    SP_FILEMARKS, flags);
1419 			break;
1420 		case MTBSR:	/* backward space record */
1421 			number = -number;
1422 		case MTFSR:	/* forward space record */
1423 			error = st_check_eod(st, true, &nmarks, flags);
1424 			if (!error)
1425 				error = st_space(st, number, SP_BLKS, flags);
1426 			break;
1427 		case MTREW:	/* rewind */
1428 			error = st_rewind(st, 0, flags);
1429 			break;
1430 		case MTOFFL:	/* rewind and put the drive offline */
1431 			st_unmount(st, EJECT);
1432 			break;
1433 		case MTNOP:	/* no operation, sets status only */
1434 			break;
1435 		case MTRETEN:	/* retension the tape */
1436 			error = st_load(st, LD_RETENSION, flags);
1437 			if (!error)
1438 				error = st_load(st, LD_LOAD, flags);
1439 			break;
1440 		case MTEOM:	/* forward space to end of media */
1441 			error = st_check_eod(st, FALSE, &nmarks, flags);
1442 			if (!error)
1443 				error = st_space(st, 1, SP_EOM, flags);
1444 			break;
1445 		case MTCACHE:	/* enable controller cache */
1446 			st->flags &= ~ST_DONTBUFFER;
1447 			goto try_new_value;
1448 		case MTNOCACHE:	/* disable controller cache */
1449 			st->flags |= ST_DONTBUFFER;
1450 			goto try_new_value;
1451 		case MTERASE:	/* erase volume */
1452 			error = st_erase(st, number, flags);
1453 			break;
1454 		case MTSETBSIZ:	/* Set block size for device */
1455 #ifdef	NOTYET
1456 			if (!(st->flags & ST_NEW_MOUNT)) {
1457 				uprintf("re-mount tape before changing "
1458 				    "blocksize");
1459 				error = EINVAL;
1460 				break;
1461 			}
1462 #endif
1463 			if (number == 0)
1464 				st->flags &= ~ST_FIXEDBLOCKS;
1465 			else {
1466 				if ((st->blkmin || st->blkmax) &&
1467 				    (number < st->blkmin ||
1468 				    number > st->blkmax)) {
1469 					error = EINVAL;
1470 					break;
1471 				}
1472 				st->flags |= ST_FIXEDBLOCKS;
1473 			}
1474 			st->blksize = number;
1475 			st->flags |= ST_BLOCK_SET;	/*XXX */
1476 			goto try_new_value;
1477 		case MTSETDNSTY:	/* Set density for device and mode */
1478 			/*
1479 			 * Any number >= 0 and <= 0xff is legal. Numbers
1480 			 * above 0x80 are 'vendor unique'.
1481 			 */
1482 			if (number < 0 || number > 255) {
1483 				error = EINVAL;
1484 				break;
1485 			} else
1486 				st->density = number;
1487 			goto try_new_value;
1488 		case MTCMPRESS:
1489 			error = st->ops(st, (number == 0) ?
1490 			    ST_OPS_CMPRSS_OFF : ST_OPS_CMPRSS_ON,
1491 			    XS_CTL_SILENT);
1492 			break;
1493 		case MTEWARN:
1494 			if (number)
1495 				st->flags |= ST_EARLYWARN;
1496 			else
1497 				st->flags &= ~ST_EARLYWARN;
1498 			break;
1499 
1500 		default:
1501 			error = EINVAL;
1502 		}
1503 		break;
1504 	}
1505 	case MTIOCIEOT:
1506 	case MTIOCEEOT:
1507 		break;
1508 	case MTIOCRDSPOS:
1509 		error = st_rdpos(st, 0, (uint32_t *)arg);
1510 		break;
1511 	case MTIOCRDHPOS:
1512 		error = st_rdpos(st, 1, (uint32_t *)arg);
1513 		break;
1514 	case MTIOCSLOCATE:
1515 		error = st_setpos(st, 0, (uint32_t *)arg);
1516 		break;
1517 	case MTIOCHLOCATE:
1518 		error = st_setpos(st, 1, (uint32_t *)arg);
1519 		break;
1520 	default:
1521 		error = scsipi_do_ioctl(st->sc_periph, dev, cmd, arg, flag, l);
1522 		break;
1523 	}
1524 	return error;
1525 
1526 try_new_value:
1527 	/*
1528 	 * Check that the mode being asked for is aggreeable to the
1529 	 * drive. If not, put it back the way it was.
1530 	 *
1531 	 * If in control mode, we can make (persistent) mode changes
1532 	 * even if no medium is loaded (see st(4)).
1533 	 */
1534 	if ((STMODE(dev) != CTRL_MODE || (st->flags & ST_MOUNTED) != 0) &&
1535 	    (error = st->ops(st, ST_OPS_MODESELECT, 0)) != 0) {
1536 		/* put it back as it was */
1537 		aprint_error_dev(st->sc_dev, "cannot set selected mode\n");
1538 		st->density = hold_density;
1539 		st->blksize = hold_blksize;
1540 		if (st->blksize)
1541 			st->flags |= ST_FIXEDBLOCKS;
1542 		else
1543 			st->flags &= ~ST_FIXEDBLOCKS;
1544 		return error;
1545 	}
1546 	/*
1547 	 * As the drive liked it, if we are setting a new default,
1548 	 * set it into the structures as such.
1549 	 *
1550 	 * The means for deciding this are not finalised yet- but
1551 	 * if the device was opened in Control Mode, the values
1552 	 * are persistent now across mounts.
1553 	 */
1554 	if (STMODE(dev) == CTRL_MODE) {
1555 		switch ((short) (mt->mt_op)) {
1556 		case MTSETBSIZ:
1557 			st->modes[dsty].blksize = st->blksize;
1558 			st->modeflags[dsty] |= BLKSIZE_SET_BY_USER;
1559 			break;
1560 		case MTSETDNSTY:
1561 			st->modes[dsty].density = st->density;
1562 			st->modeflags[dsty] |= DENSITY_SET_BY_USER;
1563 			break;
1564 		}
1565 	}
1566 	return 0;
1567 }
1568 
1569 /* Do a synchronous read. */
1570 static int
1571 st_read(struct st_softc *st, char *bf, int size, int flags)
1572 {
1573 	struct scsi_rw_tape cmd;
1574 
1575 	/* If it's a null transfer, return immediatly */
1576 	if (size == 0)
1577 		return 0;
1578 	memset(&cmd, 0, sizeof(cmd));
1579 	cmd.opcode = READ;
1580 	if (st->flags & ST_FIXEDBLOCKS) {
1581 		cmd.byte2 |= SRW_FIXED;
1582 		_lto3b(size / (st->blksize ? st->blksize : DEF_FIXED_BSIZE),
1583 		    cmd.len);
1584 	} else
1585 		_lto3b(size, cmd.len);
1586 	return scsipi_command(st->sc_periph,
1587 	    (void *)&cmd, sizeof(cmd), (void *)bf, size, 0, ST_IO_TIME, NULL,
1588 	    flags | XS_CTL_DATA_IN);
1589 }
1590 
1591 /* issue an erase command */
1592 static int
1593 st_erase(struct st_softc *st, int full, int flags)
1594 {
1595 	int tmo;
1596 	struct scsi_erase cmd;
1597 
1598 	/*
1599 	 * Full erase means set LONG bit in erase command, which asks
1600 	 * the drive to erase the entire unit.  Without this bit, we're
1601 	 * asking the drive to write an erase gap.
1602 	 */
1603 	memset(&cmd, 0, sizeof(cmd));
1604 	cmd.opcode = ERASE;
1605 	if (full) {
1606 		cmd.byte2 = SE_LONG;
1607 		tmo = ST_SPC_TIME;
1608 	} else
1609 		tmo = ST_IO_TIME;
1610 
1611 	/*
1612 	 * XXX We always do this asynchronously, for now, unless the device
1613 	 * has the ST_Q_ERASE_NOIMM quirk.  How long should we wait if we
1614 	 * want to (eventually) to it synchronously?
1615 	 */
1616 	if ((st->quirks & ST_Q_ERASE_NOIMM) == 0)
1617 		cmd.byte2 |= SE_IMMED;
1618 
1619 	return scsipi_command(st->sc_periph, (void *)&cmd, sizeof(cmd), 0, 0,
1620 	    ST_RETRIES, tmo, NULL, flags);
1621 }
1622 
1623 /* skip N blocks/filemarks/seq filemarks/eom */
1624 static int
1625 st_space(struct st_softc *st, int number, u_int what, int flags)
1626 {
1627 	struct scsi_space cmd;
1628 	int error;
1629 
1630 	switch (what) {
1631 	case SP_BLKS:
1632 		if (st->flags & ST_PER_ACTION) {
1633 			if (number > 0) {
1634 				st->flags &= ~ST_PER_ACTION;
1635 				return EIO;
1636 			} else if (number < 0) {
1637 				if (st->flags & ST_AT_FILEMARK) {
1638 					/*
1639 					 * Handling of ST_AT_FILEMARK
1640 					 * in st_space will fill in the
1641 					 * right file mark count.
1642 					 */
1643 					error = st_space(st, 0, SP_FILEMARKS,
1644 					    flags);
1645 					if (error)
1646 						return error;
1647 				}
1648 				if (st->flags & ST_BLANK_READ) {
1649 					st->flags &= ~ST_BLANK_READ;
1650 					return EIO;
1651 				}
1652 				st->flags &= ~(ST_EIO_PENDING|ST_EOM_PENDING);
1653 			}
1654 		}
1655 		break;
1656 	case SP_FILEMARKS:
1657 		if (st->flags & ST_EIO_PENDING) {
1658 			if (number > 0) {
1659 				/* pretend we just discovered the error */
1660 				st->flags &= ~ST_EIO_PENDING;
1661 				return EIO;
1662 			} else if (number < 0) {
1663 				/* back away from the error */
1664 				st->flags &= ~ST_EIO_PENDING;
1665 			}
1666 		}
1667 		if (st->flags & ST_AT_FILEMARK) {
1668 			st->flags &= ~ST_AT_FILEMARK;
1669 			number--;
1670 		}
1671 		if ((st->flags & ST_BLANK_READ) && (number < 0)) {
1672 			/* back away from unwritten tape */
1673 			st->flags &= ~ST_BLANK_READ;
1674 			number++;	/* XXX dubious */
1675 		}
1676 		break;
1677 	case SP_EOM:
1678 		if (st->flags & ST_EOM_PENDING) {
1679 			/* we're already there */
1680 			st->flags &= ~ST_EOM_PENDING;
1681 			return 0;
1682 		}
1683 		if (st->flags & ST_EIO_PENDING) {
1684 			/* pretend we just discovered the error */
1685 			st->flags &= ~ST_EIO_PENDING;
1686 			return EIO;
1687 		}
1688 		if (st->flags & ST_AT_FILEMARK)
1689 			st->flags &= ~ST_AT_FILEMARK;
1690 		break;
1691 	}
1692 	if (number == 0)
1693 		return 0;
1694 
1695 	memset(&cmd, 0, sizeof(cmd));
1696 	cmd.opcode = SPACE;
1697 	cmd.byte2 = what;
1698 	_lto3b(number, cmd.number);
1699 
1700 	st->flags &= ~ST_POSUPDATED;
1701 	st->last_ctl_resid = 0;
1702 	error = scsipi_command(st->sc_periph, (void *)&cmd, sizeof(cmd), 0, 0,
1703 	    0, ST_SPC_TIME, NULL, flags);
1704 
1705 	if (error == 0 && (st->flags & ST_POSUPDATED) == 0) {
1706 		number = number - st->last_ctl_resid;
1707 		if (what == SP_BLKS) {
1708 			if (st->blkno != -1)
1709 				st->blkno += number;
1710 		} else if (what == SP_FILEMARKS) {
1711 			if (st->fileno != -1) {
1712 				st->fileno += number;
1713 				if (number > 0)
1714 					st->blkno = 0;
1715 				else if (number < 0)
1716 					st->blkno = -1;
1717 			}
1718 		} else if (what == SP_EOM) {
1719 			/* This loses us relative position. */
1720 			st->fileno = st->blkno = -1;
1721 		}
1722 	}
1723 	return error;
1724 }
1725 
1726 /*
1727  * write N filemarks
1728  */
1729 static int
1730 st_write_filemarks(struct st_softc *st, int number, int flags)
1731 {
1732 	int error;
1733 	struct scsi_write_filemarks cmd;
1734 
1735 	/*
1736 	 * It's hard to write a negative number of file marks.
1737 	 * Don't try.
1738 	 */
1739 	if (number < 0)
1740 		return EINVAL;
1741 	switch (number) {
1742 	case 0:		/* really a command to sync the drive's buffers */
1743 		break;
1744 	case 1:
1745 		if (st->flags & ST_FM_WRITTEN)	/* already have one down */
1746 			st->flags &= ~ST_WRITTEN;
1747 		else
1748 			st->flags |= ST_FM_WRITTEN;
1749 		st->flags &= ~ST_PER_ACTION;
1750 		break;
1751 	default:
1752 		st->flags &= ~(ST_PER_ACTION | ST_WRITTEN);
1753 	}
1754 
1755 	memset(&cmd, 0, sizeof(cmd));
1756 	cmd.opcode = WRITE_FILEMARKS;
1757 	if (SCSIPI_BUSTYPE_TYPE(scsipi_periph_bustype(st->sc_periph)) ==
1758 	    SCSIPI_BUSTYPE_ATAPI)
1759 		cmd.byte2 = SR_IMMED;
1760 	/*
1761 	 * The ATAPI Onstream DI-30 doesn't support writing filemarks, but
1762 	 * WRITE_FILEMARKS is still used to flush the buffer
1763 	 */
1764 	if ((st->quirks & ST_Q_NOFILEMARKS) == 0)
1765 		_lto3b(number, cmd.number);
1766 
1767 	/* XXX WE NEED TO BE ABLE TO GET A RESIDIUAL XXX */
1768 	error = scsipi_command(st->sc_periph, (void *)&cmd, sizeof(cmd), 0, 0,
1769 	    0, ST_IO_TIME * 4, NULL, flags);
1770 	if (error == 0 && st->fileno != -1)
1771 		st->fileno += number;
1772 	return error;
1773 }
1774 
1775 /*
1776  * Make sure the right number of file marks is on tape if the
1777  * tape has been written.  If the position argument is true,
1778  * leave the tape positioned where it was originally.
1779  *
1780  * nmarks returns the number of marks to skip (or, if position
1781  * true, which were skipped) to get back original position.
1782  */
1783 static int
1784 st_check_eod(struct st_softc *st, boolean position, int *nmarks, int flags)
1785 {
1786 	int error;
1787 
1788 	switch (st->flags & (ST_WRITTEN | ST_FM_WRITTEN | ST_2FM_AT_EOD)) {
1789 	default:
1790 		*nmarks = 0;
1791 		return 0;
1792 	case ST_WRITTEN:
1793 	case ST_WRITTEN | ST_FM_WRITTEN | ST_2FM_AT_EOD:
1794 		*nmarks = 1;
1795 		break;
1796 	case ST_WRITTEN | ST_2FM_AT_EOD:
1797 		*nmarks = 2;
1798 	}
1799 	error = st_write_filemarks(st, *nmarks, flags);
1800 	if (position && !error)
1801 		error = st_space(st, -*nmarks, SP_FILEMARKS, flags);
1802 	return error;
1803 }
1804 
1805 /* load/unload/retension */
1806 static int
1807 st_load(struct st_softc *st, u_int type, int flags)
1808 {
1809 	int error;
1810 	struct scsi_load cmd;
1811 
1812 	if (type != LD_LOAD) {
1813 		int nmarks;
1814 
1815 		error = st_check_eod(st, FALSE, &nmarks, flags);
1816 		if (error) {
1817 			aprint_error_dev(st->sc_dev,
1818 			    "failed to write closing filemarks at "
1819 			    "unload, errno=%d\n", error);
1820 			return error;
1821 		}
1822 	}
1823 	if (st->quirks & ST_Q_IGNORE_LOADS) {
1824 		if (type == LD_LOAD)
1825 			/*
1826 			 * If we ignore loads, at least we should try a rewind.
1827 			 */
1828 			return st_rewind(st, 0, flags);
1829 		/* otherwise, we should do what's asked of us */
1830 	}
1831 
1832 	memset(&cmd, 0, sizeof(cmd));
1833 	cmd.opcode = LOAD;
1834 	if (SCSIPI_BUSTYPE_TYPE(scsipi_periph_bustype(st->sc_periph)) ==
1835 	    SCSIPI_BUSTYPE_ATAPI)
1836 		cmd.byte2 = SR_IMMED;
1837 	cmd.how = type;
1838 
1839 	error = scsipi_command(st->sc_periph, (void *)&cmd, sizeof(cmd), 0, 0,
1840 	    ST_RETRIES, ST_SPC_TIME, NULL, flags);
1841 	if (error) {
1842 		aprint_error_dev(st->sc_dev, "error %d in st_load (op %d)\n",
1843 		    error, type);
1844 	}
1845 	return error;
1846 }
1847 
1848 /* Rewind the device */
1849 static int
1850 st_rewind(struct st_softc *st, u_int immediate, int flags)
1851 {
1852 	struct scsi_rewind cmd;
1853 	int error;
1854 	int nmarks;
1855 	int timeout;
1856 
1857 	error = st_check_eod(st, FALSE, &nmarks, flags);
1858 	if (error) {
1859 		aprint_error_dev(st->sc_dev,
1860 		    "failed to write closing filemarks at "
1861 		    "rewind, errno=%d\n", error);
1862 		return error;
1863 	}
1864 	st->flags &= ~ST_PER_ACTION;
1865 
1866 	/* If requestor asked for immediate response, set a short timeout */
1867 	timeout = immediate ? ST_CTL_TIME : ST_SPC_TIME;
1868 
1869 	/* ATAPI tapes always need immediate to be set */
1870 	if (scsipi_periph_bustype(st->sc_periph) == SCSIPI_BUSTYPE_ATAPI)
1871 		immediate = SR_IMMED;
1872 
1873 	memset(&cmd, 0, sizeof(cmd));
1874 	cmd.opcode = REWIND;
1875 	cmd.byte2 = immediate;
1876 
1877 	error = scsipi_command(st->sc_periph, (void *)&cmd, sizeof(cmd), 0, 0,
1878 	    ST_RETRIES, timeout, NULL, flags);
1879 	if (error) {
1880 		aprint_error_dev(st->sc_dev, "error %d trying to rewind\n",
1881 		    error);
1882 		/* lost position */
1883 		st->fileno = st->blkno = -1;
1884 	} else
1885 		st->fileno = st->blkno = 0;
1886 	return error;
1887 }
1888 
1889 static int
1890 st_rdpos(struct st_softc *st, int hard, uint32_t *blkptr)
1891 {
1892 	int error;
1893 	uint8_t posdata[20];
1894 	struct scsi_tape_read_position cmd;
1895 
1896 	/*
1897 	 * We try and flush any buffered writes here if we were writing
1898 	 * and we're trying to get hardware block position. It eats
1899 	 * up performance substantially, but I'm wary of drive firmware.
1900 	 *
1901 	 * I think that *logical* block position is probably okay-
1902 	 * but hardware block position might have to wait for data
1903 	 * to hit media to be valid. Caveat Emptor.
1904 	 */
1905 
1906 	if (hard && (st->flags & ST_WRITTEN)) {
1907 		/* First flush any pending writes... */
1908 		error = st_write_filemarks(st, 0, XS_CTL_SILENT);
1909 		/*
1910 		 * The latter case is for 'write protected' tapes
1911 		 * which are too stupid to recognize a zero count
1912 		 * for writing filemarks as a no-op.
1913 		 */
1914 		if (error != 0 && error != EACCES && error != EROFS)
1915 			return error;
1916 	}
1917 
1918 	memset(&cmd, 0, sizeof(cmd));
1919 	memset(&posdata, 0, sizeof(posdata));
1920 	cmd.opcode = READ_POSITION;
1921 	if (hard)
1922 		cmd.byte1 = 1;
1923 
1924 	error = scsipi_command(st->sc_periph, (void *)&cmd, sizeof(cmd),
1925 	    (void *)&posdata, sizeof(posdata), ST_RETRIES, ST_CTL_TIME, NULL,
1926 	    XS_CTL_SILENT | XS_CTL_DATA_IN);
1927 
1928 	if (error == 0) {
1929 #if	0
1930 		printf("posdata:");
1931 		for (hard = 0; hard < sizeof(posdata); hard++)
1932 			printf("%02x ", posdata[hard] & 0xff);
1933 		printf("\n");
1934 #endif
1935 		if (posdata[0] & 0x4)	/* Block Position Unknown */
1936 			error = EINVAL;
1937 		else
1938 			*blkptr = _4btol(&posdata[4]);
1939 	}
1940 	return error;
1941 }
1942 
1943 static int
1944 st_setpos(struct st_softc *st, int hard, uint32_t *blkptr)
1945 {
1946 	int error;
1947 	struct scsi_tape_locate cmd;
1948 
1949 	/*
1950 	 * We used to try and flush any buffered writes here.
1951 	 * Now we push this onto user applications to either
1952 	 * flush the pending writes themselves (via a zero count
1953 	 * WRITE FILEMARKS command) or they can trust their tape
1954 	 * drive to do this correctly for them.
1955 	 *
1956 	 * There are very ugly performance limitations otherwise.
1957 	 */
1958 
1959 	memset(&cmd, 0, sizeof(cmd));
1960 	cmd.opcode = LOCATE;
1961 	if (hard)
1962 		cmd.byte2 = 1 << 2;
1963 	_lto4b(*blkptr, cmd.blkaddr);
1964 	error = scsipi_command(st->sc_periph, (void *)&cmd, sizeof(cmd), 0, 0,
1965 	    ST_RETRIES, ST_SPC_TIME, NULL, 0);
1966 	/*
1967 	 * Note file && block number position now unknown (if
1968 	 * these things ever start being maintained in this driver)
1969 	 */
1970 	st->fileno = st->blkno = -1;
1971 	return error;
1972 }
1973 
1974 
1975 /*
1976  * Look at the returned sense and act on the error and determine
1977  * the unix error number to pass back..., 0 (== report no error),
1978  * -1 = retry the operation, -2 continue error processing.
1979  */
1980 static int
1981 st_interpret_sense(struct scsipi_xfer *xs)
1982 {
1983 	struct scsipi_periph *periph = xs->xs_periph;
1984 	struct scsi_sense_data *sense = &xs->sense.scsi_sense;
1985 	struct buf *bp = xs->bp;
1986 	struct st_softc *st = device_private(periph->periph_dev);
1987 	int retval = EJUSTRETURN;
1988 	int doprint = ((xs->xs_control & XS_CTL_SILENT) == 0);
1989 	uint8_t key;
1990 	int32_t info;
1991 
1992 	/*
1993 	 * If it isn't a extended or extended/deferred error, let
1994 	 * the generic code handle it.
1995 	 */
1996 	if (SSD_RCODE(sense->response_code) != SSD_RCODE_CURRENT &&
1997 	    SSD_RCODE(sense->response_code) != SSD_RCODE_DEFERRED)
1998 		return retval;
1999 
2000 	if (sense->response_code & SSD_RCODE_VALID)
2001 		info = _4btol(sense->info);
2002 	else
2003 		info = (st->flags & ST_FIXEDBLOCKS) ?
2004 		    xs->datalen / st->blksize : xs->datalen;
2005 	key = SSD_SENSE_KEY(sense->flags);
2006 	st->mt_erreg = key;
2007 	st->asc = sense->asc;
2008 	st->ascq = sense->ascq;
2009 	st->mt_resid = (short) info;
2010 
2011 	if (key == SKEY_NOT_READY && st->asc == 0x4 && st->ascq == 0x1) {
2012 		/* Not Ready, Logical Unit Is in Process Of Becoming Ready */
2013 		if (!callout_pending(&periph->periph_callout))
2014 			scsipi_periph_freeze(periph, 1);
2015 		callout_reset(&periph->periph_callout,
2016 		    hz, scsipi_periph_timed_thaw, periph);
2017 		return ERESTART;
2018 	}
2019 
2020 	/* If the device is not open yet, let generic handle */
2021 	if ((periph->periph_flags & PERIPH_OPEN) == 0)
2022 		return retval;
2023 
2024 	xs->resid = info;
2025 	if (st->flags & ST_FIXEDBLOCKS) {
2026 		if (bp) {
2027 			xs->resid *= st->blksize;
2028 			st->last_io_resid = xs->resid;
2029 		} else
2030 			st->last_ctl_resid = xs->resid;
2031 		if (key == SKEY_VOLUME_OVERFLOW) {
2032 			st->flags |= ST_EIO_PENDING;
2033 			if (bp)
2034 				bp->b_resid = xs->resid;
2035 		} else if (sense->flags & SSD_EOM) {
2036 			if ((st->flags & ST_EARLYWARN) == 0)
2037 				st->flags |= ST_EIO_PENDING;
2038 			st->flags |= ST_EOM_PENDING;
2039 			if (bp) {
2040 #if 0
2041 				bp->b_resid = xs->resid;
2042 #else
2043 				/*
2044 				 * Grotesque as it seems, the few times
2045 				 * I've actually seen a non-zero resid,
2046 				 * the tape drive actually lied and had
2047 				 * written all the data!
2048 				 */
2049 				bp->b_resid = 0;
2050 #endif
2051 			}
2052 		}
2053 		if (sense->flags & SSD_FILEMARK) {
2054 			st->flags |= ST_AT_FILEMARK;
2055 			if (bp)
2056 				bp->b_resid = xs->resid;
2057 			if (st->fileno != (daddr_t) -1) {
2058 				st->fileno++;
2059 				st->blkno = 0;
2060 				st->flags |= ST_POSUPDATED;
2061 			}
2062 		}
2063 		if (sense->flags & SSD_ILI) {
2064 			st->flags |= ST_EIO_PENDING;
2065 			if (bp)
2066 				bp->b_resid = xs->resid;
2067 			if (sense->response_code & SSD_RCODE_VALID &&
2068 			    (xs->xs_control & XS_CTL_SILENT) == 0)
2069 				aprint_error_dev(st->sc_dev,
2070 				    "block wrong size, %d blocks residual\n",
2071 				    info);
2072 
2073 			/*
2074 			 * This quirk code helps the drive read
2075 			 * the first tape block, regardless of
2076 			 * format.  That is required for these
2077 			 * drives to return proper MODE SENSE
2078 			 * information.
2079 			 */
2080 			if ((st->quirks & ST_Q_SENSE_HELP) &&
2081 			    (periph->periph_flags & PERIPH_MEDIA_LOADED) == 0)
2082 				st->blksize -= 512;
2083 			else if ((st->flags & ST_POSUPDATED) == 0) {
2084 				if (st->blkno != (daddr_t) -1) {
2085 					st->blkno +=
2086 					    (xs->datalen / st->blksize);
2087 					st->flags |= ST_POSUPDATED;
2088 				}
2089 			}
2090 		}
2091 		/*
2092 		 * If data wanted and no data was transferred, do it immediately
2093 		 */
2094 		if (xs->datalen && xs->resid >= xs->datalen) {
2095 			if (st->flags & ST_EIO_PENDING)
2096 				return EIO;
2097 			if (st->flags & ST_AT_FILEMARK) {
2098 				if (bp)
2099 					bp->b_resid = xs->resid;
2100 				return 0;
2101 			}
2102 		}
2103 	} else {		/* must be variable mode */
2104 		if (bp)
2105 			st->last_io_resid = xs->resid;
2106 		else
2107 			st->last_ctl_resid = xs->resid;
2108 		if (sense->flags & SSD_EOM) {
2109 			/*
2110 			 * The current semantics of this
2111 			 * driver requires EOM detection
2112 			 * to return EIO unless early
2113 			 * warning detection is enabled
2114 			 * for variable mode (this is always
2115 			 * on for fixed block mode).
2116 			 */
2117 			if (st->flags & ST_EARLYWARN) {
2118 				st->flags |= ST_EOM_PENDING;
2119 				retval = 0;
2120 			} else {
2121 				retval = EIO;
2122 				/*
2123 				 * If we return an error we can't claim to
2124 				 * have transfered all data.
2125 				 */
2126 				if (xs->resid == 0)
2127 					xs->resid = xs->datalen;
2128 			}
2129 
2130 			/*
2131 			 * If it's an unadorned EOM detection,
2132 			 * suppress printing an error.
2133 			 */
2134 			if (key == SKEY_NO_SENSE) {
2135 				doprint = 0;
2136 			}
2137 		} else if (sense->flags & SSD_FILEMARK) {
2138 			retval = 0;
2139 			if (st->fileno != (daddr_t) -1) {
2140 				st->fileno++;
2141 				st->blkno = 0;
2142 				st->flags |= ST_POSUPDATED;
2143 			}
2144 		} else if (sense->flags & SSD_ILI) {
2145 			if (info < 0) {
2146 				/*
2147 				 * The tape record was bigger than the read
2148 				 * we issued.
2149 				 */
2150 				if ((xs->xs_control & XS_CTL_SILENT) == 0) {
2151 					aprint_error_dev(st->sc_dev,
2152 					    "%d-byte tape record too big"
2153 					    " for %d-byte user buffer\n",
2154 					    xs->datalen - info, xs->datalen);
2155 				}
2156 				retval = EIO;
2157 			} else {
2158 				retval = 0;
2159 				if (st->blkno != (daddr_t) -1) {
2160 					st->blkno++;
2161 					st->flags |= ST_POSUPDATED;
2162 				}
2163 			}
2164 		}
2165 		if (bp)
2166 			bp->b_resid = xs->resid;
2167 	}
2168 
2169 #ifndef SCSIPI_DEBUG
2170 	if (retval == 0 && key == SKEY_NO_SENSE)
2171 		doprint = 0;
2172 #endif
2173 	if (key == SKEY_BLANK_CHECK) {
2174 		/*
2175 		 * This quirk code helps the drive read the
2176 		 * first tape block, regardless of format.  That
2177 		 * is required for these drives to return proper
2178 		 * MODE SENSE information.
2179 		 */
2180 		if ((st->quirks & ST_Q_SENSE_HELP) &&
2181 		    (periph->periph_flags & PERIPH_MEDIA_LOADED) == 0) {
2182 			/* still starting */
2183 			st->blksize -= 512;
2184 		} else if (!(st->flags & (ST_2FM_AT_EOD | ST_BLANK_READ))) {
2185 			st->flags |= ST_BLANK_READ;
2186 			xs->resid = xs->datalen;
2187 			if (bp) {
2188 				bp->b_resid = xs->resid;
2189 				/* return an EOF */
2190 			}
2191 			retval = 0;
2192 			/* lost position */
2193 			st->fileno = st->blkno = -1;
2194 		}
2195 	}
2196 
2197 	/*
2198 	 * If generic sense processing will continue, we should not
2199 	 * print sense info here.
2200 	 */
2201 	if (retval == EJUSTRETURN)
2202 		doprint = 0;
2203 
2204 	if (doprint) {
2205 		/* Print verbose sense info if possible */
2206 		if (scsipi_print_sense(xs, 0) != 0)
2207 			return retval;
2208 
2209 		/* Print less-verbose sense info */
2210 		scsipi_printaddr(periph);
2211 		printf("Sense Key 0x%02x", key);
2212 		if ((sense->response_code & SSD_RCODE_VALID) != 0) {
2213 			switch (key) {
2214 			case SKEY_NOT_READY:
2215 			case SKEY_ILLEGAL_REQUEST:
2216 			case SKEY_UNIT_ATTENTION:
2217 			case SKEY_DATA_PROTECT:
2218 				break;
2219 			case SKEY_VOLUME_OVERFLOW:
2220 			case SKEY_BLANK_CHECK:
2221 				printf(", requested size: %d (decimal)", info);
2222 				break;
2223 			case SKEY_ABORTED_COMMAND:
2224 				if (xs->xs_retries)
2225 					printf(", retrying");
2226 				printf(", cmd 0x%x, info 0x%x",
2227 				    xs->cmd->opcode, info);
2228 				break;
2229 			default:
2230 				printf(", info = %d (decimal)", info);
2231 			}
2232 		}
2233 		if (sense->extra_len != 0) {
2234 			int n;
2235 			printf(", data =");
2236 			for (n = 0; n < sense->extra_len; n++)
2237 				printf(" %02x", sense->csi[n]);
2238 		}
2239 		printf("\n");
2240 	}
2241 	return retval;
2242 }
2243 
2244 /*
2245  * The quirk here is that the drive returns some value to st_mode_sense
2246  * incorrectly until the tape has actually passed by the head.
2247  *
2248  * The method is to set the drive to large fixed-block state (user-specified
2249  * density and 1024-byte blocks), then read and rewind to get it to sense the
2250  * tape.  If that doesn't work, try 512-byte fixed blocks.  If that doesn't
2251  * work, as a last resort, try variable- length blocks.  The result will be
2252  * the ability to do an accurate st_mode_sense.
2253  *
2254  * We know we can do a rewind because we just did a load, which implies rewind.
2255  * Rewind seems preferable to space backward if we have a virgin tape.
2256  *
2257  * The rest of the code for this quirk is in ILI processing and BLANK CHECK
2258  * error processing, both part of st_interpret_sense.
2259  */
2260 static int
2261 st_touch_tape(struct st_softc *st)
2262 {
2263 	char *bf;
2264 	int readsize;
2265 	int error;
2266 
2267 	bf = malloc(1024, M_TEMP, M_NOWAIT);
2268 	if (bf == NULL)
2269 		return ENOMEM;
2270 
2271 	if ((error = st->ops(st, ST_OPS_MODESENSE, 0)) != 0)
2272 		goto bad;
2273 
2274 	/*
2275 	 * If the block size is already known from the
2276 	 * sense data, use it. Else start probing at 1024.
2277 	 */
2278 	if (st->media_blksize > 0)
2279 		st->blksize = st->media_blksize;
2280 	else
2281 		st->blksize = 1024;
2282 
2283 	do {
2284 		switch (st->blksize) {
2285 		case 512:
2286 		case 1024:
2287 			readsize = st->blksize;
2288 			st->flags |= ST_FIXEDBLOCKS;
2289 			break;
2290 		default:
2291 			readsize = 1;
2292 			st->flags &= ~ST_FIXEDBLOCKS;
2293 		}
2294 		if ((error = st->ops(st, ST_OPS_MODESELECT, XS_CTL_SILENT))
2295 		    != 0) {
2296 			/*
2297 			 * The device did not agree with the proposed
2298 			 * block size. If we exhausted our options,
2299 			 * return failure, else try another.
2300 			 */
2301 			if (readsize == 1)
2302 				goto bad;
2303 			st->blksize -= 512;
2304 			continue;
2305 		}
2306 		st_read(st, bf, readsize, XS_CTL_SILENT);	/* XXX */
2307 		if ((error = st_rewind(st, 0, 0)) != 0) {
2308 bad:			free(bf, M_TEMP);
2309 			return error;
2310 		}
2311 	} while (readsize != 1 && readsize > st->blksize);
2312 
2313 	free(bf, M_TEMP);
2314 	return 0;
2315 }
2316 
2317 static int
2318 stdump(dev_t dev, daddr_t blkno, void *va, size_t size)
2319 {
2320 	/* Not implemented. */
2321 	return ENXIO;
2322 }
2323 
2324 /*
2325  * Send a filled out parameter structure to the drive to
2326  * set it into the desire modes etc.
2327  */
2328 int
2329 st_mode_select(struct st_softc *st, int flags)
2330 {
2331 	u_int select_len;
2332 	struct select {
2333 		struct scsi_mode_parameter_header_6 header;
2334 		struct scsi_general_block_descriptor blk_desc;
2335 		u_char sense_data[MAX_PAGE_0_SIZE];
2336 	} select;
2337 	struct scsipi_periph *periph = st->sc_periph;
2338 
2339 	select_len = sizeof(select.header) + sizeof(select.blk_desc) +
2340 		     st->page_0_size;
2341 
2342 	/*
2343 	 * This quirk deals with drives that have only one valid mode
2344 	 * and think this gives them license to reject all mode selects,
2345 	 * even if the selected mode is the one that is supported.
2346 	 */
2347 	if (st->quirks & ST_Q_UNIMODAL) {
2348 		SC_DEBUG(periph, SCSIPI_DB3,
2349 		    ("not setting density 0x%x blksize 0x%x\n",
2350 		    st->density, st->blksize));
2351 		return 0;
2352 	}
2353 
2354 	/* Set up for a mode select */
2355 	memset(&select, 0, sizeof(select));
2356 	select.header.blk_desc_len = sizeof(struct
2357 	    scsi_general_block_descriptor);
2358 	select.header.dev_spec &= ~SMH_DSP_BUFF_MODE;
2359 	select.blk_desc.density = st->density;
2360 	if (st->flags & ST_DONTBUFFER)
2361 		select.header.dev_spec |= SMH_DSP_BUFF_MODE_OFF;
2362 	else
2363 		select.header.dev_spec |= SMH_DSP_BUFF_MODE_ON;
2364 	if (st->flags & ST_FIXEDBLOCKS)
2365 		_lto3b(st->blksize, select.blk_desc.blklen);
2366 	if (st->page_0_size)
2367 		memcpy(select.sense_data, st->sense_data, st->page_0_size);
2368 
2369 	/* do the command */
2370 	return scsipi_mode_select(periph, 0, &select.header, select_len,
2371 				  flags, ST_RETRIES, ST_CTL_TIME);
2372 }
2373