xref: /netbsd-src/sys/dev/scsipi/st.c (revision df0caa2637da0538ecdf6b878c4d08e684b43d8f)
1 /*	$NetBSD: st.c,v 1.181 2005/05/29 22:00:50 christos 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  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *        This product includes software developed by the NetBSD
21  *        Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 /*
40  * Originally written by Julian Elischer (julian@tfs.com)
41  * for TRW Financial Systems for use under the MACH(2.5) operating system.
42  *
43  * TRW Financial Systems, in accordance with their agreement with Carnegie
44  * Mellon University, makes this software available to CMU to distribute
45  * or use in any manner that they see fit as long as this message is kept with
46  * the software. For this reason TFS also grants any other persons or
47  * organisations permission to use or modify this software.
48  *
49  * TFS supplies this software to be publicly redistributed
50  * on the understanding that TFS is not responsible for the correct
51  * functioning of this software in any circumstances.
52  *
53  * Ported to run under 386BSD by Julian Elischer (julian@tfs.com) Sept 1992
54  * major changes by Julian Elischer (julian@jules.dialix.oz.au) May 1993
55  *
56  * A lot of rewhacking done by mjacob (mjacob@nas.nasa.gov).
57  */
58 
59 #include <sys/cdefs.h>
60 __KERNEL_RCSID(0, "$NetBSD: st.c,v 1.181 2005/05/29 22:00:50 christos Exp $");
61 
62 #include "opt_scsi.h"
63 
64 #include <sys/param.h>
65 #include <sys/systm.h>
66 #include <sys/fcntl.h>
67 #include <sys/errno.h>
68 #include <sys/ioctl.h>
69 #include <sys/malloc.h>
70 #include <sys/buf.h>
71 #include <sys/bufq.h>
72 #include <sys/proc.h>
73 #include <sys/user.h>
74 #include <sys/mtio.h>
75 #include <sys/device.h>
76 #include <sys/conf.h>
77 #include <sys/kernel.h>
78 #include <sys/vnode.h>
79 
80 #include <dev/scsipi/scsi_spc.h>
81 #include <dev/scsipi/scsipi_all.h>
82 #include <dev/scsipi/scsi_all.h>
83 #include <dev/scsipi/scsi_tape.h>
84 #include <dev/scsipi/scsipiconf.h>
85 #include <dev/scsipi/scsipi_base.h>
86 #include <dev/scsipi/stvar.h>
87 
88 /* Defines for device specific stuff */
89 #define DEF_FIXED_BSIZE  512
90 
91 #define STMODE(z)	( minor(z)       & 0x03)
92 #define STDSTY(z)	((minor(z) >> 2) & 0x03)
93 #define STUNIT(z)	((minor(z) >> 4)       )
94 #define STNMINOR	16
95 
96 #define NORMAL_MODE	0
97 #define NOREW_MODE	1
98 #define EJECT_MODE	2
99 #define CTRL_MODE	3
100 
101 #define	FALSE		0
102 #define	TRUE		1
103 
104 #ifndef		ST_MOUNT_DELAY
105 #define		ST_MOUNT_DELAY		0
106 #endif
107 
108 static dev_type_open(stopen);
109 static dev_type_close(stclose);
110 static dev_type_read(stread);
111 static dev_type_write(stwrite);
112 static dev_type_ioctl(stioctl);
113 static dev_type_strategy(ststrategy);
114 static dev_type_dump(stdump);
115 
116 const struct bdevsw st_bdevsw = {
117 	stopen, stclose, ststrategy, stioctl, stdump, nosize, D_TAPE
118 };
119 
120 const struct cdevsw st_cdevsw = {
121 	stopen, stclose, stread, stwrite, stioctl,
122 	nostop, notty, nopoll, nommap, nokqfilter, D_TAPE
123 };
124 
125 /*
126  * Define various devices that we know mis-behave in some way,
127  * and note how they are bad, so we can correct for them
128  */
129 
130 static const struct st_quirk_inquiry_pattern st_quirk_patterns[] = {
131 	{{T_SEQUENTIAL, T_REMOV,
132 	 "        ", "                ", "    "}, {0, 0, {
133 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
134 		{ST_Q_FORCE_BLKSIZE, 512, QIC_24},	/* minor 4-7 */
135 		{ST_Q_FORCE_BLKSIZE, 0, HALFINCH_1600},	/* minor 8-11 */
136 		{ST_Q_FORCE_BLKSIZE, 0, HALFINCH_6250}	/* minor 12-15 */
137 	}}},
138 	{{T_SEQUENTIAL, T_REMOV,
139 	 "TANDBERG", " TDC 3600       ", ""},     {0, 12, {
140 		{0, 0, 0},				/* minor 0-3 */
141 		{ST_Q_FORCE_BLKSIZE, 0, QIC_525},	/* minor 4-7 */
142 		{0, 0, QIC_150},			/* minor 8-11 */
143 		{0, 0, QIC_120}				/* minor 12-15 */
144 	}}},
145  	{{T_SEQUENTIAL, T_REMOV,
146  	 "TANDBERG", " TDC 3800       ", ""},     {0, 0, {
147 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
148 		{0, 0, QIC_525},			/* minor 4-7 */
149 		{0, 0, QIC_150},			/* minor 8-11 */
150 		{0, 0, QIC_120}				/* minor 12-15 */
151 	}}},
152 	{{T_SEQUENTIAL, T_REMOV,
153 	  "TANDBERG", " SLR5 4/8GB     ", ""},     {0, 0, {
154 		{ST_Q_FORCE_BLKSIZE, 1024, 0},		/* minor 0-3 */
155 		{0, 0, 0},				/* minor 4-7 */
156 		{0, 0, 0},				/* minor 8-11 */
157 		{0, 0, 0}				/* minor 12-15 */
158 	}}},
159 	/*
160 	 * lacking a manual for the 4200, it's not clear what the
161 	 * specific density codes should be- the device is a 2.5GB
162 	 * capable QIC drive, those density codes aren't readily
163 	 * availabel. The 'default' will just have to do.
164 	 */
165  	{{T_SEQUENTIAL, T_REMOV,
166  	 "TANDBERG", " TDC 4200       ", ""},     {0, 0, {
167 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
168 		{0, 0, QIC_525},			/* minor 4-7 */
169 		{0, 0, QIC_150},			/* minor 8-11 */
170 		{0, 0, QIC_120}				/* minor 12-15 */
171 	}}},
172 	/*
173 	 * At least -005 and -007 need this.  I'll assume they all do unless I
174 	 * hear otherwise.  - mycroft, 31MAR1994
175 	 */
176 	{{T_SEQUENTIAL, T_REMOV,
177 	 "ARCHIVE ", "VIPER 2525 25462", ""},     {0, 0, {
178 		{ST_Q_SENSE_HELP, 0, 0},		/* minor 0-3 */
179 		{ST_Q_SENSE_HELP, 0, QIC_525},		/* minor 4-7 */
180 		{0, 0, QIC_150},			/* minor 8-11 */
181 		{0, 0, QIC_120}				/* minor 12-15 */
182 	}}},
183 	/*
184 	 * One user reports that this works for his tape drive.  It probably
185 	 * needs more work.  - mycroft, 09APR1994
186 	 */
187 	{{T_SEQUENTIAL, T_REMOV,
188 	 "SANKYO  ", "CP525           ", ""},    {0, 0, {
189 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
190 		{ST_Q_FORCE_BLKSIZE, 512, QIC_525},	/* minor 4-7 */
191 		{0, 0, QIC_150},			/* minor 8-11 */
192 		{0, 0, QIC_120}				/* minor 12-15 */
193 	}}},
194 	{{T_SEQUENTIAL, T_REMOV,
195 	 "ANRITSU ", "DMT780          ", ""},     {0, 0, {
196 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
197 		{ST_Q_FORCE_BLKSIZE, 512, QIC_525},	/* minor 4-7 */
198 		{0, 0, QIC_150},			/* minor 8-11 */
199 		{0, 0, QIC_120}				/* minor 12-15 */
200 	}}},
201 	{{T_SEQUENTIAL, T_REMOV,
202 	 "ARCHIVE ", "VIPER 150  21247", ""},     {ST_Q_ERASE_NOIMM, 12, {
203 		{ST_Q_SENSE_HELP, 0, 0},		/* minor 0-3 */
204 		{0, 0, QIC_150},			/* minor 4-7 */
205 		{0, 0, QIC_120},			/* minor 8-11 */
206 		{0, 0, QIC_24}				/* minor 12-15 */
207 	}}},
208 	{{T_SEQUENTIAL, T_REMOV,
209 	 "ARCHIVE ", "VIPER 150  21531", ""},     {ST_Q_ERASE_NOIMM, 12, {
210 		{ST_Q_SENSE_HELP, 0, 0},		/* minor 0-3 */
211 		{0, 0, QIC_150},			/* minor 4-7 */
212 		{0, 0, QIC_120},			/* minor 8-11 */
213 		{0, 0, QIC_24}				/* minor 12-15 */
214 	}}},
215 	{{T_SEQUENTIAL, T_REMOV,
216 	 "WANGTEK ", "5099ES SCSI", ""},          {0, 0, {
217 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
218 		{0, 0, QIC_11},				/* minor 4-7 */
219 		{0, 0, QIC_24},				/* minor 8-11 */
220 		{0, 0, QIC_24}				/* minor 12-15 */
221 	}}},
222 	{{T_SEQUENTIAL, T_REMOV,
223 	 "WANGTEK ", "5150ES SCSI", ""},          {0, 0, {
224 		{ST_Q_FORCE_BLKSIZE, 512, 0},		/* minor 0-3 */
225 		{0, 0, QIC_24},				/* minor 4-7 */
226 		{0, 0, QIC_120},			/* minor 8-11 */
227 		{0, 0, QIC_150}				/* minor 12-15 */
228 	}}},
229 	{{T_SEQUENTIAL, T_REMOV,
230 	 "WANGTEK ", "5525ES SCSI REV7", ""},     {0, 0, {
231 		{0, 0, 0},				/* minor 0-3 */
232 		{ST_Q_BLKSIZE, 0, QIC_525},		/* minor 4-7 */
233 		{0, 0, QIC_150},			/* minor 8-11 */
234 		{0, 0, QIC_120}				/* minor 12-15 */
235 	}}},
236 	{{T_SEQUENTIAL, T_REMOV,
237 	 "WangDAT ", "Model 1300      ", ""},     {0, 0, {
238 		{0, 0, 0},				/* minor 0-3 */
239 		{ST_Q_FORCE_BLKSIZE, 512, DDS},		/* minor 4-7 */
240 		{ST_Q_FORCE_BLKSIZE, 1024, DDS},	/* minor 8-11 */
241 		{ST_Q_FORCE_BLKSIZE, 0, DDS}		/* minor 12-15 */
242 	}}},
243 	{{T_SEQUENTIAL, T_REMOV,
244 	 "EXABYTE ", "EXB-8200        ", "263H"}, {0, 5, {
245 		{0, 0, 0},				/* minor 0-3 */
246 		{0, 0, 0},				/* minor 4-7 */
247 		{0, 0, 0},				/* minor 8-11 */
248 		{0, 0, 0}				/* minor 12-15 */
249 	}}},
250 	{{T_SEQUENTIAL, T_REMOV,
251 	 "STK",      "9490",             ""},
252 				{ST_Q_FORCE_BLKSIZE, 0, {
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",      "SD-3",             ""},
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 	 "IBM",      "03590",            ""},     {ST_Q_IGNORE_LOADS, 0, {
268 		{0, 0, 0},				/* minor 0-3 */
269 		{0, 0, 0},				/* minor 4-7 */
270 		{0, 0, 0},				/* minor 8-11 */
271 		{0, 0, 0}				/* minor 12-15 */
272 	}}},
273 	{{T_SEQUENTIAL, T_REMOV,
274 	 "HP      ", "T4000s          ", ""},     {ST_Q_UNIMODAL, 0, {
275 		{0, 0, QIC_3095},			/* minor 0-3 */
276 		{0, 0, QIC_3095},			/* minor 4-7 */
277 		{0, 0, QIC_3095},			/* minor 8-11 */
278 		{0, 0, QIC_3095},			/* minor 12-15 */
279 	}}},
280 #if 0
281 	{{T_SEQUENTIAL, T_REMOV,
282 	 "EXABYTE ", "EXB-8200        ", ""},     {0, 12, {
283 		{0, 0, 0},				/* minor 0-3 */
284 		{0, 0, 0},				/* minor 4-7 */
285 		{0, 0, 0},				/* minor 8-11 */
286 		{0, 0, 0}				/* minor 12-15 */
287 	}}},
288 #endif
289 	{{T_SEQUENTIAL, T_REMOV,
290 	 "TEAC    ", "MT-2ST/N50      ", ""},     {ST_Q_IGNORE_LOADS, 0, {
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 	{{T_SEQUENTIAL, T_REMOV,
297 	 "OnStream", "ADR50 Drive", ""},	  {ST_Q_UNIMODAL, 0, {
298 		{ST_Q_FORCE_BLKSIZE, 512, 0},	        /* minor 0-3 */
299 		{ST_Q_FORCE_BLKSIZE, 512, 0},	        /* minor 4-7 */
300 		{ST_Q_FORCE_BLKSIZE, 512, 0},	        /* minor 8-11 */
301 		{ST_Q_FORCE_BLKSIZE, 512, 0},	        /* minor 12-15 */
302 	}}},
303 	{{T_SEQUENTIAL, T_REMOV,
304 	 "OnStream DI-30",      "",   "1.0"},  {ST_Q_NOFILEMARKS, 0, {
305 		{0, 0, 0},                              /* minor 0-3 */
306 		{0, 0, 0},                              /* minor 4-7 */
307 		{0, 0, 0},                              /* minor 8-11 */
308 		{0, 0, 0}                               /* minor 12-15 */
309 	}}},
310 	{{T_SEQUENTIAL, T_REMOV,
311 	 "NCR H621", "0-STD-03-46F880 ", ""},     {ST_Q_NOPREVENT, 0, {
312 		{0, 0, 0},			       /* minor 0-3 */
313 		{0, 0, 0},			       /* minor 4-7 */
314 		{0, 0, 0},			       /* minor 8-11 */
315 		{0, 0, 0}			       /* minor 12-15 */
316 	}}},
317 };
318 
319 #define NOEJECT 0
320 #define EJECT 1
321 
322 static void	st_identify_drive(struct st_softc *,
323 		    struct scsipi_inquiry_pattern *);
324 static void	st_loadquirks(struct st_softc *);
325 static int	st_mount_tape(dev_t, int);
326 static void	st_unmount(struct st_softc *, boolean);
327 static int	st_decide_mode(struct st_softc *, boolean);
328 static void	ststart(struct scsipi_periph *);
329 static void	strestart(void *);
330 static void	stdone(struct scsipi_xfer *, int);
331 static int	st_read(struct st_softc *, char *, int, int);
332 static int	st_space(struct st_softc *, int, u_int, int);
333 static int	st_write_filemarks(struct st_softc *, int, int);
334 static int	st_check_eod(struct st_softc *, boolean, int *, int);
335 static int	st_load(struct st_softc *, u_int, int);
336 static int	st_rewind(struct st_softc *, u_int, int);
337 static int	st_interpret_sense(struct scsipi_xfer *);
338 static int	st_touch_tape(struct st_softc *);
339 static int	st_erase(struct st_softc *, int full, int flags);
340 static int	st_rdpos(struct st_softc *, int, u_int32_t *);
341 static int	st_setpos(struct st_softc *, int, u_int32_t *);
342 
343 static const struct scsipi_periphsw st_switch = {
344 	st_interpret_sense,
345 	ststart,
346 	NULL,
347 	stdone
348 };
349 
350 #if	defined(ST_ENABLE_EARLYWARN)
351 #define	ST_INIT_FLAGS	ST_EARLYWARN
352 #else
353 #define	ST_INIT_FLAGS	0
354 #endif
355 
356 /*
357  * The routine called by the low level scsi routine when it discovers
358  * A device suitable for this driver
359  */
360 void
361 stattach(struct device *parent, struct st_softc *st, void *aux)
362 {
363 	struct scsipibus_attach_args *sa = aux;
364 	struct scsipi_periph *periph = sa->sa_periph;
365 
366 	SC_DEBUG(periph, SCSIPI_DB2, ("stattach: "));
367 
368 	/*
369 	 * Store information needed to contact our base driver
370 	 */
371 	st->sc_periph = periph;
372 	periph->periph_dev = &st->sc_dev;
373 	periph->periph_switch = &st_switch;
374 
375 	/*
376 	 * Set initial flags
377 	 */
378 
379 	st->flags = ST_INIT_FLAGS;
380 
381 	/*
382 	 * Set up the buf queue for this device
383 	 */
384 	bufq_alloc(&st->buf_queue, BUFQ_FCFS);
385 
386 	callout_init(&st->sc_callout);
387 
388 	/*
389 	 * Check if the drive is a known criminal and take
390 	 * Any steps needed to bring it into line
391 	 */
392 	st_identify_drive(st, &sa->sa_inqbuf);
393 	/*
394 	 * Use the subdriver to request information regarding the drive.
395 	 */
396 	printf("\n");
397 	printf("%s: %s", st->sc_dev.dv_xname, st->quirkdata ? "rogue, " : "");
398 	if (scsipi_test_unit_ready(periph,
399 	    XS_CTL_DISCOVERY | XS_CTL_SILENT | XS_CTL_IGNORE_MEDIA_CHANGE) ||
400 	    st->ops(st, ST_OPS_MODESENSE,
401 	    XS_CTL_DISCOVERY | XS_CTL_SILENT | XS_CTL_IGNORE_MEDIA_CHANGE))
402 		printf("drive empty\n");
403 	else {
404 		printf("density code %d, ", st->media_density);
405 		if (st->media_blksize > 0)
406 			printf("%d-byte", st->media_blksize);
407 		else
408 			printf("variable");
409 		printf(" blocks, write-%s\n",
410 		    (st->flags & ST_READONLY) ? "protected" : "enabled");
411 	}
412 
413 #if NRND > 0
414 	rnd_attach_source(&st->rnd_source, st->sc_dev.dv_xname,
415 			  RND_TYPE_TAPE, 0);
416 #endif
417 }
418 
419 int
420 stactivate(struct device *self, enum devact act)
421 {
422 	int rv = 0;
423 
424 	switch (act) {
425 	case DVACT_ACTIVATE:
426 		rv = EOPNOTSUPP;
427 		break;
428 
429 	case DVACT_DEACTIVATE:
430 		/*
431 		 * Nothing to do; we key off the device's DVF_ACTIVE.
432 		 */
433 		break;
434 	}
435 	return (rv);
436 }
437 
438 int
439 stdetach(struct device *self, int flags)
440 {
441 	struct st_softc *st = (struct st_softc *)self;
442 	int s, bmaj, cmaj, mn;
443 
444 	/* locate the major number */
445 	bmaj = bdevsw_lookup_major(&st_bdevsw);
446 	cmaj = cdevsw_lookup_major(&st_cdevsw);
447 
448 	/* kill any pending restart */
449 	callout_stop(&st->sc_callout);
450 
451 	s = splbio();
452 
453 	/* Kill off any queued buffers. */
454 	bufq_drain(&st->buf_queue);
455 
456 	bufq_free(&st->buf_queue);
457 
458 	/* Kill off any pending commands. */
459 	scsipi_kill_pending(st->sc_periph);
460 
461 	splx(s);
462 
463 	/* Nuke the vnodes for any open instances */
464 	mn = STUNIT(self->dv_unit);
465 	vdevgone(bmaj, mn, mn+STNMINOR-1, VBLK);
466 	vdevgone(cmaj, mn, mn+STNMINOR-1, VCHR);
467 
468 
469 #if NRND > 0
470 	/* Unhook the entropy source. */
471 	rnd_detach_source(&st->rnd_source);
472 #endif
473 
474 	return (0);
475 }
476 
477 /*
478  * Use the inquiry routine in 'scsi_base' to get drive info so we can
479  * Further tailor our behaviour.
480  */
481 static void
482 st_identify_drive(struct st_softc *st, struct scsipi_inquiry_pattern *inqbuf)
483 {
484 	const struct st_quirk_inquiry_pattern *finger;
485 	int priority;
486 
487 	finger = scsipi_inqmatch(inqbuf,
488 	    st_quirk_patterns,
489 	    sizeof(st_quirk_patterns) / sizeof(st_quirk_patterns[0]),
490 	    sizeof(st_quirk_patterns[0]), &priority);
491 	if (priority != 0) {
492 		st->quirkdata = &finger->quirkdata;
493 		st->drive_quirks = finger->quirkdata.quirks;
494 		st->quirks = finger->quirkdata.quirks;	/* start value */
495 		st->page_0_size = finger->quirkdata.page_0_size;
496 		st_loadquirks(st);
497 	}
498 }
499 
500 /*
501  * initialise the subdevices to the default (QUIRK) state.
502  * this will remove any setting made by the system operator or previous
503  * operations.
504  */
505 static void
506 st_loadquirks(struct st_softc *st)
507 {
508 	int i;
509 	const struct	modes *mode;
510 	struct	modes *mode2;
511 
512 	mode = st->quirkdata->modes;
513 	mode2 = st->modes;
514 	for (i = 0; i < 4; i++) {
515 		memset(mode2, 0, sizeof(struct modes));
516 		st->modeflags[i] &= ~(BLKSIZE_SET_BY_QUIRK |
517 		    DENSITY_SET_BY_QUIRK | BLKSIZE_SET_BY_USER |
518 		    DENSITY_SET_BY_USER);
519 		if ((mode->quirks | st->drive_quirks) & ST_Q_FORCE_BLKSIZE) {
520 			mode2->blksize = mode->blksize;
521 			st->modeflags[i] |= BLKSIZE_SET_BY_QUIRK;
522 		}
523 		if (mode->density) {
524 			mode2->density = mode->density;
525 			st->modeflags[i] |= DENSITY_SET_BY_QUIRK;
526 		}
527 		mode2->quirks |= mode->quirks;
528 		mode++;
529 		mode2++;
530 	}
531 }
532 
533 /*
534  * open the device.
535  */
536 static int
537 stopen(dev_t dev, int flags, int mode, struct proc *p)
538 {
539 	u_int stmode, dsty;
540 	int error, sflags, unit, tries, ntries;
541 	struct st_softc *st;
542 	struct scsipi_periph *periph;
543 	struct scsipi_adapter *adapt;
544 
545 	unit = STUNIT(dev);
546 	if (unit >= st_cd.cd_ndevs)
547 		return (ENXIO);
548 	st = st_cd.cd_devs[unit];
549 	if (st == NULL)
550 		return (ENXIO);
551 
552 	stmode = STMODE(dev);
553 	dsty = STDSTY(dev);
554 
555 	periph = st->sc_periph;
556 	adapt = periph->periph_channel->chan_adapter;
557 
558 	SC_DEBUG(periph, SCSIPI_DB1, ("open: dev=0x%x (unit %d (of %d))\n", dev,
559 	    unit, st_cd.cd_ndevs));
560 
561 
562 	/*
563 	 * Only allow one at a time
564 	 */
565 	if (periph->periph_flags & PERIPH_OPEN) {
566 		printf("%s: already open\n", st->sc_dev.dv_xname);
567 		return (EBUSY);
568 	}
569 
570 	if ((error = scsipi_adapter_addref(adapt)) != 0)
571 		return (error);
572 
573 	/*
574 	 * clear any latched errors.
575 	 */
576 	st->mt_resid = 0;
577 	st->mt_erreg = 0;
578 	st->asc = 0;
579 	st->ascq = 0;
580 
581 	/*
582 	 * Catch any unit attention errors. Be silent about this
583 	 * unless we're already mounted. We ignore media change
584 	 * if we're in control mode or not mounted yet.
585 	 */
586 	if ((st->flags & ST_MOUNTED) == 0 || stmode == CTRL_MODE) {
587 #ifdef SCSIDEBUG
588 		sflags = XS_CTL_IGNORE_MEDIA_CHANGE;
589 #else
590 		sflags = XS_CTL_SILENT|XS_CTL_IGNORE_MEDIA_CHANGE;
591 #endif
592 	} else
593 		sflags = 0;
594 
595 	/*
596 	 * If we're already mounted or we aren't configured for
597 	 * a mount delay, only try a test unit ready once. Otherwise,
598 	 * try up to ST_MOUNT_DELAY times with a rest interval of
599 	 * one second between each try.
600 	 */
601 
602 	if ((st->flags & ST_MOUNTED) || ST_MOUNT_DELAY == 0) {
603 		ntries = 1;
604 	} else {
605 		ntries = ST_MOUNT_DELAY;
606 	}
607 
608 	for (error = tries = 0; tries < ntries; tries++) {
609 		int slpintr, oflags;
610 
611 		/*
612 		 * If we had no error, or we're opening the control mode
613 		 * device, we jump out right away.
614 		 */
615 
616 		error = scsipi_test_unit_ready(periph, sflags);
617 		if (error == 0 || stmode == CTRL_MODE) {
618 			break;
619 		}
620 
621 		/*
622 		 * We had an error.
623 		 *
624 		 * If we're already mounted or we aren't configured for
625 		 * a mount delay, or the error isn't a NOT READY error,
626 		 * skip to the error exit now.
627 		 */
628 		if ((st->flags & ST_MOUNTED) || ST_MOUNT_DELAY == 0 ||
629 		    (st->mt_key != SKEY_NOT_READY)) {
630 			goto bad;
631 		}
632 
633 		/*
634 		 * clear any latched errors.
635 		 */
636 		st->mt_resid = 0;
637 		st->mt_erreg = 0;
638 		st->asc = 0;
639 		st->ascq = 0;
640 
641 		/*
642 		 * Fake that we have the device open so
643 		 * we block other apps from getting in.
644 		 */
645 
646 		oflags = periph->periph_flags;
647 		periph->periph_flags |= PERIPH_OPEN;
648 
649 		slpintr = tsleep(&lbolt, PUSER|PCATCH, "stload", 0);
650 
651 		periph->periph_flags = oflags;	/* restore flags */
652 		if (slpintr) {
653 			goto bad;
654 		}
655 	}
656 
657 
658 	/*
659 	 * If the mode is 3 (e.g. minor = 3,7,11,15) then the device has
660 	 * been opened to set defaults and perform other, usually non-I/O
661 	 * related, operations. In this case, do a quick check to see
662 	 * whether the unit actually had a tape loaded (this will be known
663 	 * as to whether or not we got a NOT READY for the above
664 	 * unit attention). If a tape is there, go do a mount sequence.
665 	 */
666 	if (stmode == CTRL_MODE && st->mt_key == SKEY_NOT_READY) {
667 		periph->periph_flags |= PERIPH_OPEN;
668 		return (0);
669 	}
670 
671 	/*
672 	 * If we get this far and had an error set, that means we failed
673 	 * to pass the 'test unit ready' test for the non-controlmode device,
674 	 * so we bounce the open.
675 	 */
676 
677 	if (error)
678 		return (error);
679 
680 	/*
681 	 * Else, we're now committed to saying we're open.
682 	 */
683 
684 	periph->periph_flags |= PERIPH_OPEN; /* unit attn are now errors */
685 
686 	/*
687 	 * If it's a different mode, or if the media has been
688 	 * invalidated, unmount the tape from the previous
689 	 * session but continue with open processing
690 	 */
691 	if (st->last_dsty != dsty ||
692 	    (periph->periph_flags & PERIPH_MEDIA_LOADED) == 0)
693 		st_unmount(st, NOEJECT);
694 
695 	/*
696 	 * If we are not mounted, then we should start a new
697 	 * mount session.
698 	 */
699 	if (!(st->flags & ST_MOUNTED)) {
700 		if ((error = st_mount_tape(dev, flags)) != 0)
701 			goto bad;
702 		st->last_dsty = dsty;
703 	}
704 	if (!(st->quirks & ST_Q_NOPREVENT)) {
705 		scsipi_prevent(periph, SPAMR_PREVENT_DT,
706 		    XS_CTL_IGNORE_ILLEGAL_REQUEST | XS_CTL_IGNORE_NOT_READY);
707 	}
708 
709 	SC_DEBUG(periph, SCSIPI_DB2, ("open complete\n"));
710 	return (0);
711 
712 bad:
713 	st_unmount(st, NOEJECT);
714 	scsipi_adapter_delref(adapt);
715 	periph->periph_flags &= ~PERIPH_OPEN;
716 	return (error);
717 }
718 
719 /*
720  * close the device.. only called if we are the LAST
721  * occurence of an open device
722  */
723 static int
724 stclose(dev_t dev, int flags, int mode, struct proc *p)
725 {
726 	int stxx, error = 0;
727 	struct st_softc *st = st_cd.cd_devs[STUNIT(dev)];
728 	struct scsipi_periph *periph = st->sc_periph;
729 	struct scsipi_adapter *adapt = periph->periph_channel->chan_adapter;
730 
731 	SC_DEBUG(st->sc_periph, SCSIPI_DB1, ("closing\n"));
732 
733 	/*
734 	 * Make sure that a tape opened in write-only mode will have
735 	 * file marks written on it when closed, even if not written to.
736 	 *
737 	 * This is for SUN compatibility. Actually, the Sun way of
738 	 * things is to:
739 	 *
740 	 *	only write filemarks if there are fmks to be written and
741 	 *   		- open for write (possibly read/write)
742 	 *		- the last operation was a write
743 	 * 	or:
744 	 *		- opened for wronly
745 	 *		- no data was written (including filemarks)
746 	 */
747 
748 	stxx = st->flags & (ST_WRITTEN | ST_FM_WRITTEN);
749 	if (((flags & FWRITE) && stxx == ST_WRITTEN) ||
750 	    ((flags & O_ACCMODE) == FWRITE && stxx == 0)) {
751 		int nm;
752 		error = st_check_eod(st, FALSE, &nm, 0);
753 	}
754 
755 	/*
756 	 * Allow robots to eject tape if needed.
757 	 */
758 	scsipi_prevent(periph, SPAMR_ALLOW,
759 	    XS_CTL_IGNORE_ILLEGAL_REQUEST | XS_CTL_IGNORE_NOT_READY);
760 
761 	switch (STMODE(dev)) {
762 	case NORMAL_MODE:
763 		st_unmount(st, NOEJECT);
764 		break;
765 	case NOREW_MODE:
766 	case CTRL_MODE:
767 		/*
768 		 * Leave mounted unless media seems to have been removed.
769 		 *
770 		 * Otherwise, if we're to terminate a tape with more than one
771 		 * filemark [ and because we're not rewinding here ], backspace
772 		 * one filemark so that later appends will see an unbroken
773 		 * sequence of:
774 		 *
775 		 *	file - FMK - file - FMK ... file - FMK FMK (EOM)
776 		 */
777 		if ((periph->periph_flags & PERIPH_MEDIA_LOADED) == 0) {
778 			st_unmount(st, NOEJECT);
779 		} else if (error == 0) {
780 			/*
781 			 * ST_WRITTEN was preserved from above.
782 			 *
783 			 * All we need to know here is:
784 			 *
785 			 *	Were we writing this tape and was the last
786 			 *	operation a write?
787 			 *
788 			 *	Are there supposed to be 2FM at EOD?
789 			 *
790 			 * If both statements are true, then we backspace
791 			 * one filemark.
792 			 */
793 			stxx |= (st->flags & ST_2FM_AT_EOD);
794 			if ((flags & FWRITE) != 0 &&
795 			    (stxx == (ST_2FM_AT_EOD|ST_WRITTEN))) {
796 				error = st_space(st, -1, SP_FILEMARKS, 0);
797 			}
798 		}
799 		break;
800 	case EJECT_MODE:
801 		st_unmount(st, EJECT);
802 		break;
803 	}
804 
805 	scsipi_wait_drain(periph);
806 
807 	scsipi_adapter_delref(adapt);
808 	periph->periph_flags &= ~PERIPH_OPEN;
809 
810 	return (error);
811 }
812 
813 /*
814  * Start a new mount session.
815  * Copy in all the default parameters from the selected device mode.
816  * and try guess any that seem to be defaulted.
817  */
818 static int
819 st_mount_tape(dev_t dev, int flags)
820 {
821 	int unit;
822 	u_int dsty;
823 	struct st_softc *st;
824 	struct scsipi_periph *periph;
825 	int error = 0;
826 
827 	unit = STUNIT(dev);
828 	dsty = STDSTY(dev);
829 	st = st_cd.cd_devs[unit];
830 	periph = st->sc_periph;
831 
832 	if (st->flags & ST_MOUNTED)
833 		return (0);
834 
835 	SC_DEBUG(periph, SCSIPI_DB1, ("mounting\n "));
836 	st->flags |= ST_NEW_MOUNT;
837 	st->quirks = st->drive_quirks | st->modes[dsty].quirks;
838 	/*
839 	 * If the media is new, then make sure we give it a chance to
840 	 * to do a 'load' instruction.  (We assume it is new.)
841 	 */
842 	if ((error = st_load(st, LD_LOAD, XS_CTL_SILENT)) != 0)
843 		return (error);
844 	/*
845 	 * Throw another dummy instruction to catch
846 	 * 'Unit attention' errors. Many drives give
847 	 * these after doing a Load instruction (with
848 	 * the MEDIUM MAY HAVE CHANGED asc/ascq).
849 	 */
850 	scsipi_test_unit_ready(periph, XS_CTL_SILENT);	/* XXX */
851 
852 	/*
853 	 * Some devices can't tell you much until they have been
854 	 * asked to look at the media. This quirk does this.
855 	 */
856 	if (st->quirks & ST_Q_SENSE_HELP)
857 		if ((error = st_touch_tape(st)) != 0)
858 			return (error);
859 	/*
860 	 * Load the physical device parameters
861 	 * loads: blkmin, blkmax
862 	 */
863 	if ((error = st->ops(st, ST_OPS_RBL, 0)) != 0)
864 		return (error);
865 	/*
866 	 * Load the media dependent parameters
867 	 * includes: media_blksize,media_density,numblks
868 	 * As we have a tape in, it should be reflected here.
869 	 * If not you may need the "quirk" above.
870 	 */
871 	if ((error = st->ops(st, ST_OPS_MODESENSE, 0)) != 0)
872 		return (error);
873 	/*
874 	 * If we have gained a permanent density from somewhere,
875 	 * then use it in preference to the one supplied by
876 	 * default by the driver.
877 	 */
878 	if (st->modeflags[dsty] & (DENSITY_SET_BY_QUIRK | DENSITY_SET_BY_USER))
879 		st->density = st->modes[dsty].density;
880 	else
881 		st->density = st->media_density;
882 	/*
883 	 * If we have gained a permanent blocksize
884 	 * then use it in preference to the one supplied by
885 	 * default by the driver.
886 	 */
887 	st->flags &= ~ST_FIXEDBLOCKS;
888 	if (st->modeflags[dsty] &
889 	    (BLKSIZE_SET_BY_QUIRK | BLKSIZE_SET_BY_USER)) {
890 		st->blksize = st->modes[dsty].blksize;
891 		if (st->blksize)
892 			st->flags |= ST_FIXEDBLOCKS;
893 	} else {
894 		if ((error = st_decide_mode(st, FALSE)) != 0)
895 			return (error);
896 	}
897 	if ((error = st->ops(st, ST_OPS_MODESELECT, 0)) != 0) {
898 		/* ATAPI will return ENODEV for this, and this may be OK */
899 		if (error != ENODEV) {
900 			printf("%s: cannot set selected mode\n",
901 			    st->sc_dev.dv_xname);
902 			return (error);
903 		}
904 	}
905 	st->flags &= ~ST_NEW_MOUNT;
906 	st->flags |= ST_MOUNTED;
907 	periph->periph_flags |= PERIPH_MEDIA_LOADED;	/* move earlier? */
908 	st->blkno = st->fileno = (daddr_t) 0;
909 	return (0);
910 }
911 
912 /*
913  * End the present mount session.
914  * Rewind, and optionally eject the tape.
915  * Reset various flags to indicate that all new
916  * operations require another mount operation
917  */
918 static void
919 st_unmount(struct st_softc *st, boolean eject)
920 {
921 	struct scsipi_periph *periph = st->sc_periph;
922 	int nmarks;
923 
924 	if ((st->flags & ST_MOUNTED) == 0)
925 		return;
926 	SC_DEBUG(periph, SCSIPI_DB1, ("unmounting\n"));
927 	st_check_eod(st, FALSE, &nmarks, XS_CTL_IGNORE_NOT_READY);
928 	st_rewind(st, 0, XS_CTL_IGNORE_NOT_READY);
929 
930 	/*
931 	 * Section 9.3.3 of the SCSI specs states that a device shall return
932 	 * the density value specified in the last succesfull MODE SELECT
933 	 * after an unload operation, in case it is not able to
934 	 * automatically determine the density of the new medium.
935 	 *
936 	 * So we instruct the device to use the default density, which will
937 	 * prevent the use of stale density values (in particular,
938 	 * in st_touch_tape().
939 	 */
940 	st->density = 0;
941 	if (st->ops(st, ST_OPS_MODESELECT, 0) != 0) {
942 		printf("%s: WARNING: cannot revert to default density\n",
943 			st->sc_dev.dv_xname);
944 	}
945 
946 	if (eject) {
947 		if (!(st->quirks & ST_Q_NOPREVENT)) {
948 			scsipi_prevent(periph, SPAMR_ALLOW,
949 			    XS_CTL_IGNORE_ILLEGAL_REQUEST |
950 			    XS_CTL_IGNORE_NOT_READY);
951 		}
952 		st_load(st, LD_UNLOAD, XS_CTL_IGNORE_NOT_READY);
953 		st->blkno = st->fileno = (daddr_t) -1;
954 	} else {
955 		st->blkno = st->fileno = (daddr_t) 0;
956 	}
957 	st->flags &= ~(ST_MOUNTED | ST_NEW_MOUNT);
958 	periph->periph_flags &= ~PERIPH_MEDIA_LOADED;
959 }
960 
961 /*
962  * Given all we know about the device, media, mode, 'quirks' and
963  * initial operation, make a decision as to how we should be set
964  * to run (regarding blocking and EOD marks)
965  */
966 int
967 st_decide_mode(struct st_softc *st, boolean first_read)
968 {
969 
970 	SC_DEBUG(st->sc_periph, SCSIPI_DB2, ("starting block mode decision\n"));
971 
972 	/*
973 	 * If the drive can only handle fixed-length blocks and only at
974 	 * one size, perhaps we should just do that.
975 	 */
976 	if (st->blkmin && (st->blkmin == st->blkmax)) {
977 		st->flags |= ST_FIXEDBLOCKS;
978 		st->blksize = st->blkmin;
979 		SC_DEBUG(st->sc_periph, SCSIPI_DB3,
980 		    ("blkmin == blkmax of %d\n", st->blkmin));
981 		goto done;
982 	}
983 	/*
984 	 * If the tape density mandates (or even suggests) use of fixed
985 	 * or variable-length blocks, comply.
986 	 */
987 	switch (st->density) {
988 	case HALFINCH_800:
989 	case HALFINCH_1600:
990 	case HALFINCH_6250:
991 	case DDS:
992 		st->flags &= ~ST_FIXEDBLOCKS;
993 		st->blksize = 0;
994 		SC_DEBUG(st->sc_periph, SCSIPI_DB3,
995 		    ("density specified variable\n"));
996 		goto done;
997 	case QIC_11:
998 	case QIC_24:
999 	case QIC_120:
1000 	case QIC_150:
1001 	case QIC_525:
1002 	case QIC_1320:
1003 	case QIC_3095:
1004 	case QIC_3220:
1005 		st->flags |= ST_FIXEDBLOCKS;
1006 		if (st->media_blksize > 0)
1007 			st->blksize = st->media_blksize;
1008 		else
1009 			st->blksize = DEF_FIXED_BSIZE;
1010 		SC_DEBUG(st->sc_periph, SCSIPI_DB3,
1011 		    ("density specified fixed\n"));
1012 		goto done;
1013 	}
1014 	/*
1015 	 * If we're about to read the tape, perhaps we should choose
1016 	 * fixed or variable-length blocks and block size according to
1017 	 * what the drive found on the tape.
1018 	 */
1019 	if (first_read &&
1020 	    (!(st->quirks & ST_Q_BLKSIZE) || (st->media_blksize == 0) ||
1021 	    (st->media_blksize == DEF_FIXED_BSIZE) ||
1022 	    (st->media_blksize == 1024))) {
1023 		if (st->media_blksize > 0)
1024 			st->flags |= ST_FIXEDBLOCKS;
1025 		else
1026 			st->flags &= ~ST_FIXEDBLOCKS;
1027 		st->blksize = st->media_blksize;
1028 		SC_DEBUG(st->sc_periph, SCSIPI_DB3,
1029 		    ("Used media_blksize of %d\n", st->media_blksize));
1030 		goto done;
1031 	}
1032 	/*
1033 	 * We're getting no hints from any direction.  Choose variable-
1034 	 * length blocks arbitrarily.
1035 	 */
1036 	st->flags &= ~ST_FIXEDBLOCKS;
1037 	st->blksize = 0;
1038 	SC_DEBUG(st->sc_periph, SCSIPI_DB3,
1039 	    ("Give up and default to variable mode\n"));
1040 
1041 done:
1042 	/*
1043 	 * Decide whether or not to write two file marks to signify end-
1044 	 * of-data.  Make the decision as a function of density.  If
1045 	 * the decision is not to use a second file mark, the SCSI BLANK
1046 	 * CHECK condition code will be recognized as end-of-data when
1047 	 * first read.
1048 	 * (I think this should be a by-product of fixed/variable..julian)
1049 	 */
1050 	switch (st->density) {
1051 /*      case 8 mm:   What is the SCSI density code for 8 mm, anyway? */
1052 	case QIC_11:
1053 	case QIC_24:
1054 	case QIC_120:
1055 	case QIC_150:
1056 	case QIC_525:
1057 	case QIC_1320:
1058 	case QIC_3095:
1059 	case QIC_3220:
1060 		st->flags &= ~ST_2FM_AT_EOD;
1061 		break;
1062 	default:
1063 		st->flags |= ST_2FM_AT_EOD;
1064 	}
1065 	return (0);
1066 }
1067 
1068 /*
1069  * Actually translate the requested transfer into
1070  * one the physical driver can understand
1071  * The transfer is described by a buf and will include
1072  * only one physical transfer.
1073  */
1074 static void
1075 ststrategy(struct buf *bp)
1076 {
1077 	struct st_softc *st = st_cd.cd_devs[STUNIT(bp->b_dev)];
1078 	int s;
1079 
1080 	SC_DEBUG(st->sc_periph, SCSIPI_DB1,
1081 	    ("ststrategy %d bytes @ blk %" PRId64 "\n", bp->b_bcount, bp->b_blkno));
1082 	/*
1083 	 * If it's a null transfer, return immediatly
1084 	 */
1085 	if (bp->b_bcount == 0)
1086 		goto done;
1087 
1088 	/* If offset is negative, error */
1089 	if (bp->b_blkno < 0) {
1090 		bp->b_error = EINVAL;
1091 		goto bad;
1092 	}
1093 
1094 	/*
1095 	 * Odd sized request on fixed drives are verboten
1096 	 */
1097 	if (st->flags & ST_FIXEDBLOCKS) {
1098 		if (bp->b_bcount % st->blksize) {
1099 			printf("%s: bad request, must be multiple of %d\n",
1100 			    st->sc_dev.dv_xname, st->blksize);
1101 			bp->b_error = EIO;
1102 			goto bad;
1103 		}
1104 	}
1105 	/*
1106 	 * as are out-of-range requests on variable drives.
1107 	 */
1108 	else if (bp->b_bcount < st->blkmin ||
1109 	    (st->blkmax && bp->b_bcount > st->blkmax)) {
1110 		printf("%s: bad request, must be between %d and %d\n",
1111 		    st->sc_dev.dv_xname, st->blkmin, st->blkmax);
1112 		bp->b_error = EIO;
1113 		goto bad;
1114 	}
1115 	s = splbio();
1116 
1117 	/*
1118 	 * Place it in the queue of activities for this tape
1119 	 * at the end (a bit silly because we only have on user..
1120 	 * (but it could fork()))
1121 	 */
1122 	BUFQ_PUT(&st->buf_queue, bp);
1123 
1124 	/*
1125 	 * Tell the device to get going on the transfer if it's
1126 	 * not doing anything, otherwise just wait for completion
1127 	 * (All a bit silly if we're only allowing 1 open but..)
1128 	 */
1129 	ststart(st->sc_periph);
1130 
1131 	splx(s);
1132 	return;
1133 bad:
1134 	bp->b_flags |= B_ERROR;
1135 done:
1136 	/*
1137 	 * Correctly set the buf to indicate a completed xfer
1138 	 */
1139 	bp->b_resid = bp->b_bcount;
1140 	biodone(bp);
1141 	return;
1142 }
1143 
1144 /*
1145  * ststart looks to see if there is a buf waiting for the device
1146  * and that the device is not already busy. If both are true,
1147  * It dequeues the buf and creates a scsi command to perform the
1148  * transfer required. The transfer request will call scsipi_done
1149  * on completion, which will in turn call this routine again
1150  * so that the next queued transfer is performed.
1151  * The bufs are queued by the strategy routine (ststrategy)
1152  *
1153  * This routine is also called after other non-queued requests
1154  * have been made of the scsi driver, to ensure that the queue
1155  * continues to be drained.
1156  * ststart() is called at splbio
1157  */
1158 static void
1159 ststart(struct scsipi_periph *periph)
1160 {
1161 	struct st_softc *st = (void *)periph->periph_dev;
1162 	struct buf *bp;
1163 	struct scsi_rw_tape cmd;
1164 	struct scsipi_xfer *xs;
1165 	int flags, error;
1166 
1167 	SC_DEBUG(periph, SCSIPI_DB2, ("ststart "));
1168 	/*
1169 	 * See if there is a buf to do and we are not already
1170 	 * doing one
1171 	 */
1172 	while (periph->periph_active < periph->periph_openings) {
1173 		/* if a special awaits, let it proceed first */
1174 		if (periph->periph_flags & PERIPH_WAITING) {
1175 			periph->periph_flags &= ~PERIPH_WAITING;
1176 			wakeup((caddr_t)periph);
1177 			return;
1178 		}
1179 
1180 		/*
1181 		 * If the device has been unmounted by the user
1182 		 * then throw away all requests until done.
1183 		 */
1184 		if (__predict_false((st->flags & ST_MOUNTED) == 0 ||
1185 		    (periph->periph_flags & PERIPH_MEDIA_LOADED) == 0)) {
1186 			if ((bp = BUFQ_GET(&st->buf_queue)) != NULL) {
1187 				/* make sure that one implies the other.. */
1188 				periph->periph_flags &= ~PERIPH_MEDIA_LOADED;
1189 				bp->b_flags |= B_ERROR;
1190 				bp->b_error = EIO;
1191 				bp->b_resid = bp->b_bcount;
1192 				biodone(bp);
1193 				continue;
1194 			} else {
1195 				return;
1196 			}
1197 		}
1198 
1199 		if ((bp = BUFQ_PEEK(&st->buf_queue)) == NULL)
1200 			return;
1201 
1202 		/*
1203 		 * only FIXEDBLOCK devices have pending I/O or space operations.
1204 		 */
1205 		if (st->flags & ST_FIXEDBLOCKS) {
1206 			/*
1207 			 * If we are at a filemark but have not reported it yet
1208 			 * then we should report it now
1209 			 */
1210 			if (st->flags & ST_AT_FILEMARK) {
1211 				if ((bp->b_flags & B_READ) == B_WRITE) {
1212 					/*
1213 					 * Handling of ST_AT_FILEMARK in
1214 					 * st_space will fill in the right file
1215 					 * mark count.
1216 					 * Back up over filemark
1217 					 */
1218 					if (st_space(st, 0, SP_FILEMARKS, 0)) {
1219 						BUFQ_GET(&st->buf_queue);
1220 						bp->b_flags |= B_ERROR;
1221 						bp->b_error = EIO;
1222 						biodone(bp);
1223 						continue;
1224 					}
1225 				} else {
1226 					BUFQ_GET(&st->buf_queue);
1227 					bp->b_resid = bp->b_bcount;
1228 					bp->b_error = 0;
1229 					bp->b_flags &= ~B_ERROR;
1230 					st->flags &= ~ST_AT_FILEMARK;
1231 					biodone(bp);
1232 					continue;	/* seek more work */
1233 				}
1234 			}
1235 		}
1236 		/*
1237 		 * If we are at EOM but have not reported it
1238 		 * yet then we should report it now.
1239 		 */
1240 		if (st->flags & (ST_EOM_PENDING|ST_EIO_PENDING)) {
1241 			BUFQ_GET(&st->buf_queue);
1242 			bp->b_resid = bp->b_bcount;
1243 			if (st->flags & ST_EIO_PENDING) {
1244 				bp->b_error = EIO;
1245 				bp->b_flags |= B_ERROR;
1246 			}
1247 			st->flags &= ~(ST_EOM_PENDING|ST_EIO_PENDING);
1248 			biodone(bp);
1249 			continue;	/* seek more work */
1250 		}
1251 
1252 		/*
1253 		 * Fill out the scsi command
1254 		 */
1255 		memset(&cmd, 0, sizeof(cmd));
1256 		flags = XS_CTL_NOSLEEP | XS_CTL_ASYNC;
1257 		if ((bp->b_flags & B_READ) == B_WRITE) {
1258 			cmd.opcode = WRITE;
1259 			st->flags &= ~ST_FM_WRITTEN;
1260 			flags |= XS_CTL_DATA_OUT;
1261 		} else {
1262 			cmd.opcode = READ;
1263 			flags |= XS_CTL_DATA_IN;
1264 		}
1265 
1266 		/*
1267 		 * Handle "fixed-block-mode" tape drives by using the
1268 		 * block count instead of the length.
1269 		 */
1270 		if (st->flags & ST_FIXEDBLOCKS) {
1271 			cmd.byte2 |= SRW_FIXED;
1272 			_lto3b(bp->b_bcount / st->blksize, cmd.len);
1273 		} else
1274 			_lto3b(bp->b_bcount, cmd.len);
1275 
1276 		/*
1277 		 * Clear 'position updated' indicator
1278 		 */
1279 		st->flags &= ~ST_POSUPDATED;
1280 
1281 		/*
1282 		 * go ask the adapter to do all this for us
1283 		 */
1284 		xs = scsipi_make_xs(periph,
1285 		    (struct scsipi_generic *)&cmd, sizeof(cmd),
1286 		    (u_char *)bp->b_data, bp->b_bcount,
1287 		    0, ST_IO_TIME, bp, flags);
1288 		if (__predict_false(xs == NULL)) {
1289 			/*
1290 			 * out of memory. Keep this buffer in the queue, and
1291 			 * retry later.
1292 			 */
1293 			callout_reset(&st->sc_callout, hz / 2, strestart,
1294 			    periph);
1295 			return;
1296 		}
1297 		/*
1298 		 * need to dequeue the buffer before queuing the command,
1299 		 * because cdstart may be called recursively from the
1300 		 * HBA driver
1301 		 */
1302 #ifdef DIAGNOSTIC
1303 		if (BUFQ_GET(&st->buf_queue) != bp)
1304 			panic("ststart(): dequeued wrong buf");
1305 #else
1306 		BUFQ_GET(&st->buf_queue);
1307 #endif
1308 		error = scsipi_execute_xs(xs);
1309 		/* with a scsipi_xfer preallocated, scsipi_command can't fail */
1310 		KASSERT(error == 0);
1311 	} /* go back and see if we can cram more work in.. */
1312 }
1313 
1314 static void
1315 strestart(void *v)
1316 {
1317 	int s = splbio();
1318 	ststart((struct scsipi_periph *)v);
1319 	splx(s);
1320 }
1321 
1322 
1323 static void
1324 stdone(struct scsipi_xfer *xs, int error)
1325 {
1326 	struct st_softc *st = (void *)xs->xs_periph->periph_dev;
1327 	struct buf *bp = xs->bp;
1328 
1329 	if (bp) {
1330 		bp->b_error = error;
1331 		bp->b_resid = xs->resid;
1332 		if (error)
1333 			bp->b_flags |= B_ERROR;
1334 
1335 		if ((bp->b_flags & B_READ) == B_WRITE)
1336 			st->flags |= ST_WRITTEN;
1337 		else
1338 			st->flags &= ~ST_WRITTEN;
1339 #if NRND > 0
1340 		rnd_add_uint32(&st->rnd_source, bp->b_blkno);
1341 #endif
1342 
1343 		if ((st->flags & ST_POSUPDATED) == 0) {
1344 			if (error) {
1345 				st->fileno = st->blkno = -1;
1346 			} else if (st->blkno != -1) {
1347 				if (st->flags & ST_FIXEDBLOCKS)
1348 					st->blkno +=
1349 					    (bp->b_bcount / st->blksize);
1350 				else
1351 					st->blkno++;
1352 			}
1353 		}
1354 
1355 		biodone(bp);
1356 	}
1357 }
1358 
1359 static int
1360 stread(dev_t dev, struct uio *uio, int iomode)
1361 {
1362 	struct st_softc *st = st_cd.cd_devs[STUNIT(dev)];
1363 
1364 	return (physio(ststrategy, NULL, dev, B_READ,
1365 	    st->sc_periph->periph_channel->chan_adapter->adapt_minphys, uio));
1366 }
1367 
1368 static int
1369 stwrite(dev_t dev, struct uio *uio, int iomode)
1370 {
1371 	struct st_softc *st = st_cd.cd_devs[STUNIT(dev)];
1372 
1373 	return (physio(ststrategy, NULL, dev, B_WRITE,
1374 	    st->sc_periph->periph_channel->chan_adapter->adapt_minphys, uio));
1375 }
1376 
1377 /*
1378  * Perform special action on behalf of the user;
1379  * knows about the internals of this device
1380  */
1381 static int
1382 stioctl(dev_t dev, u_long cmd, caddr_t arg, int flag, struct proc *p)
1383 {
1384 	int error = 0;
1385 	int unit;
1386 	int number, nmarks, dsty;
1387 	int flags;
1388 	struct st_softc *st;
1389 	int hold_blksize;
1390 	u_int8_t hold_density;
1391 	struct mtop *mt = (struct mtop *) arg;
1392 
1393 	/*
1394 	 * Find the device that the user is talking about
1395 	 */
1396 	flags = 0;		/* give error messages, act on errors etc. */
1397 	unit = STUNIT(dev);
1398 	dsty = STDSTY(dev);
1399 	st = st_cd.cd_devs[unit];
1400 	hold_blksize = st->blksize;
1401 	hold_density = st->density;
1402 
1403 	switch ((u_int) cmd) {
1404 
1405 	case MTIOCGET: {
1406 		struct mtget *g = (struct mtget *) arg;
1407 		/*
1408 		 * (to get the current state of READONLY)
1409 		 */
1410 		error = st->ops(st, ST_OPS_MODESENSE, XS_CTL_SILENT);
1411 		if (error) {
1412 			/*
1413 			 * Ignore the error if in control mode;
1414 			 * this is mandated by st(4).
1415 			 */
1416 			if (STMODE(dev) != CTRL_MODE)
1417 				break;
1418 			error = 0;
1419 		}
1420 		SC_DEBUG(st->sc_periph, SCSIPI_DB1, ("[ioctl: get status]\n"));
1421 		memset(g, 0, sizeof(struct mtget));
1422 		g->mt_type = 0x7;	/* Ultrix compat *//*? */
1423 		g->mt_blksiz = st->blksize;
1424 		g->mt_density = st->density;
1425 		g->mt_mblksiz[0] = st->modes[0].blksize;
1426 		g->mt_mblksiz[1] = st->modes[1].blksize;
1427 		g->mt_mblksiz[2] = st->modes[2].blksize;
1428 		g->mt_mblksiz[3] = st->modes[3].blksize;
1429 		g->mt_mdensity[0] = st->modes[0].density;
1430 		g->mt_mdensity[1] = st->modes[1].density;
1431 		g->mt_mdensity[2] = st->modes[2].density;
1432 		g->mt_mdensity[3] = st->modes[3].density;
1433 		g->mt_fileno = st->fileno;
1434 		g->mt_blkno = st->blkno;
1435 		if (st->flags & ST_READONLY)
1436 			g->mt_dsreg |= MT_DS_RDONLY;
1437 		if (st->flags & ST_MOUNTED)
1438 			g->mt_dsreg |= MT_DS_MOUNTED;
1439 		g->mt_resid = st->mt_resid;
1440 		g->mt_erreg = st->mt_erreg;
1441 		/*
1442 		 * clear latched errors.
1443 		 */
1444 		st->mt_resid = 0;
1445 		st->mt_erreg = 0;
1446 		st->asc = 0;
1447 		st->ascq = 0;
1448 		break;
1449 	}
1450 	case MTIOCTOP: {
1451 
1452 		SC_DEBUG(st->sc_periph, SCSIPI_DB1,
1453 		    ("[ioctl: op=0x%x count=0x%x]\n", mt->mt_op,
1454 			mt->mt_count));
1455 
1456 		/* compat: in U*x it is a short */
1457 		number = mt->mt_count;
1458 		switch ((short) (mt->mt_op)) {
1459 		case MTWEOF:	/* write an end-of-file record */
1460 			error = st_write_filemarks(st, number, flags);
1461 			break;
1462 		case MTBSF:	/* backward space file */
1463 			number = -number;
1464 		case MTFSF:	/* forward space file */
1465 			error = st_check_eod(st, FALSE, &nmarks, flags);
1466 			if (!error)
1467 				error = st_space(st, number - nmarks,
1468 				    SP_FILEMARKS, flags);
1469 			break;
1470 		case MTBSR:	/* backward space record */
1471 			number = -number;
1472 		case MTFSR:	/* forward space record */
1473 			error = st_check_eod(st, TRUE, &nmarks, flags);
1474 			if (!error)
1475 				error = st_space(st, number, SP_BLKS, flags);
1476 			break;
1477 		case MTREW:	/* rewind */
1478 			error = st_rewind(st, 0, flags);
1479 			break;
1480 		case MTOFFL:	/* rewind and put the drive offline */
1481 			st_unmount(st, EJECT);
1482 			break;
1483 		case MTNOP:	/* no operation, sets status only */
1484 			break;
1485 		case MTRETEN:	/* retension the tape */
1486 			error = st_load(st, LD_RETENSION, flags);
1487 			if (!error)
1488 				error = st_load(st, LD_LOAD, flags);
1489 			break;
1490 		case MTEOM:	/* forward space to end of media */
1491 			error = st_check_eod(st, FALSE, &nmarks, flags);
1492 			if (!error)
1493 				error = st_space(st, 1, SP_EOM, flags);
1494 			break;
1495 		case MTCACHE:	/* enable controller cache */
1496 			st->flags &= ~ST_DONTBUFFER;
1497 			goto try_new_value;
1498 		case MTNOCACHE:	/* disable controller cache */
1499 			st->flags |= ST_DONTBUFFER;
1500 			goto try_new_value;
1501 		case MTERASE:	/* erase volume */
1502 			error = st_erase(st, number, flags);
1503 			break;
1504 		case MTSETBSIZ:	/* Set block size for device */
1505 #ifdef	NOTYET
1506 			if (!(st->flags & ST_NEW_MOUNT)) {
1507 				uprintf("re-mount tape before changing blocksize");
1508 				error = EINVAL;
1509 				break;
1510 			}
1511 #endif
1512 			if (number == 0)
1513 				st->flags &= ~ST_FIXEDBLOCKS;
1514 			else {
1515 				if ((st->blkmin || st->blkmax) &&
1516 				    (number < st->blkmin ||
1517 				    number > st->blkmax)) {
1518 					error = EINVAL;
1519 					break;
1520 				}
1521 				st->flags |= ST_FIXEDBLOCKS;
1522 			}
1523 			st->blksize = number;
1524 			st->flags |= ST_BLOCK_SET;	/*XXX */
1525 			goto try_new_value;
1526 
1527 		case MTSETDNSTY:	/* Set density for device and mode */
1528 			/*
1529 			 * Any number >= 0 and <= 0xff is legal. Numbers
1530 			 * above 0x80 are 'vendor unique'.
1531 			 */
1532 			if (number < 0 || number > 255) {
1533 				error = EINVAL;
1534 				break;
1535 			} else
1536 				st->density = number;
1537 			goto try_new_value;
1538 
1539 		case MTCMPRESS:
1540 			error = st->ops(st, (number == 0) ?
1541 			    ST_OPS_CMPRSS_OFF : ST_OPS_CMPRSS_ON,
1542 			    XS_CTL_SILENT);
1543 			break;
1544 
1545 		case MTEWARN:
1546 			if (number)
1547 				st->flags |= ST_EARLYWARN;
1548 			else
1549 				st->flags &= ~ST_EARLYWARN;
1550 			break;
1551 
1552 		default:
1553 			error = EINVAL;
1554 		}
1555 		break;
1556 	}
1557 	case MTIOCIEOT:
1558 	case MTIOCEEOT:
1559 		break;
1560 
1561 	case MTIOCRDSPOS:
1562 		error = st_rdpos(st, 0, (u_int32_t *) arg);
1563 		break;
1564 
1565 	case MTIOCRDHPOS:
1566 		error = st_rdpos(st, 1, (u_int32_t *) arg);
1567 		break;
1568 
1569 	case MTIOCSLOCATE:
1570 		error = st_setpos(st, 0, (u_int32_t *) arg);
1571 		break;
1572 
1573 	case MTIOCHLOCATE:
1574 		error = st_setpos(st, 1, (u_int32_t *) arg);
1575 		break;
1576 
1577 
1578 	default:
1579 		error = scsipi_do_ioctl(st->sc_periph, dev, cmd, arg,
1580 					flag, p);
1581 		break;
1582 	}
1583 	return (error);
1584 /*-----------------------------*/
1585 try_new_value:
1586 	/*
1587 	 * Check that the mode being asked for is aggreeable to the
1588 	 * drive. If not, put it back the way it was.
1589 	 *
1590 	 * If in control mode, we can make (persistent) mode changes
1591 	 * even if no medium is loaded (see st(4)).
1592 	 */
1593 	if ((STMODE(dev) != CTRL_MODE || (st->flags & ST_MOUNTED) != 0) &&
1594 	    (error = st->ops(st, ST_OPS_MODESELECT, 0)) != 0) {
1595 		/* put it back as it was */
1596 		printf("%s: cannot set selected mode\n", st->sc_dev.dv_xname);
1597 		st->density = hold_density;
1598 		st->blksize = hold_blksize;
1599 		if (st->blksize)
1600 			st->flags |= ST_FIXEDBLOCKS;
1601 		else
1602 			st->flags &= ~ST_FIXEDBLOCKS;
1603 		return (error);
1604 	}
1605 	/*
1606 	 * As the drive liked it, if we are setting a new default,
1607 	 * set it into the structures as such.
1608 	 *
1609 	 * The means for deciding this are not finalised yet- but
1610 	 * if the device was opened in Control Mode, the values
1611 	 * are persistent now across mounts.
1612 	 */
1613 	if (STMODE(dev) == CTRL_MODE) {
1614 		switch ((short) (mt->mt_op)) {
1615 		case MTSETBSIZ:
1616 			st->modes[dsty].blksize = st->blksize;
1617 			st->modeflags[dsty] |= BLKSIZE_SET_BY_USER;
1618 			break;
1619 		case MTSETDNSTY:
1620 			st->modes[dsty].density = st->density;
1621 			st->modeflags[dsty] |= DENSITY_SET_BY_USER;
1622 			break;
1623 		}
1624 	}
1625 	return (0);
1626 }
1627 
1628 /*
1629  * Do a synchronous read.
1630  */
1631 static int
1632 st_read(struct st_softc *st, char *bf, int size, int flags)
1633 {
1634 	struct scsi_rw_tape cmd;
1635 
1636 	/*
1637 	 * If it's a null transfer, return immediatly
1638 	 */
1639 	if (size == 0)
1640 		return (0);
1641 	memset(&cmd, 0, sizeof(cmd));
1642 	cmd.opcode = READ;
1643 	if (st->flags & ST_FIXEDBLOCKS) {
1644 		cmd.byte2 |= SRW_FIXED;
1645 		_lto3b(size / (st->blksize ? st->blksize : DEF_FIXED_BSIZE),
1646 		    cmd.len);
1647 	} else
1648 		_lto3b(size, cmd.len);
1649 	return (scsipi_command(st->sc_periph,
1650 	    (void *)&cmd, sizeof(cmd), (void *)bf, size, 0, ST_IO_TIME, NULL,
1651 	    flags | XS_CTL_DATA_IN));
1652 }
1653 
1654 /*
1655  * issue an erase command
1656  */
1657 static int
1658 st_erase(struct st_softc *st, int full, int flags)
1659 {
1660 	int tmo;
1661 	struct scsi_erase cmd;
1662 
1663 	/*
1664 	 * Full erase means set LONG bit in erase command, which asks
1665 	 * the drive to erase the entire unit.  Without this bit, we're
1666 	 * asking the drive to write an erase gap.
1667 	 */
1668 	memset(&cmd, 0, sizeof(cmd));
1669 	cmd.opcode = ERASE;
1670 	if (full) {
1671 		cmd.byte2 = SE_LONG;
1672 		tmo = ST_SPC_TIME;
1673 	} else {
1674 		tmo = ST_IO_TIME;
1675 	}
1676 
1677 	/*
1678 	 * XXX We always do this asynchronously, for now, unless the device
1679 	 * has the ST_Q_ERASE_NOIMM quirk.  How long should we wait if we
1680 	 * want to (eventually) to it synchronously?
1681 	 */
1682 	if ((st->quirks & ST_Q_ERASE_NOIMM) == 0)
1683 		cmd.byte2 |= SE_IMMED;
1684 
1685 	return (scsipi_command(st->sc_periph, (void *)&cmd, sizeof(cmd), 0, 0,
1686 	    ST_RETRIES, tmo, NULL, flags));
1687 }
1688 
1689 /*
1690  * skip N blocks/filemarks/seq filemarks/eom
1691  */
1692 static int
1693 st_space(struct st_softc *st, int number, u_int what, int flags)
1694 {
1695 	struct scsi_space cmd;
1696 	int error;
1697 
1698 	switch (what) {
1699 	case SP_BLKS:
1700 		if (st->flags & ST_PER_ACTION) {
1701 			if (number > 0) {
1702 				st->flags &= ~ST_PER_ACTION;
1703 				return (EIO);
1704 			} else if (number < 0) {
1705 				if (st->flags & ST_AT_FILEMARK) {
1706 					/*
1707 					 * Handling of ST_AT_FILEMARK
1708 					 * in st_space will fill in the
1709 					 * right file mark count.
1710 					 */
1711 					error = st_space(st, 0, SP_FILEMARKS,
1712 					    flags);
1713 					if (error)
1714 						return (error);
1715 				}
1716 				if (st->flags & ST_BLANK_READ) {
1717 					st->flags &= ~ST_BLANK_READ;
1718 					return (EIO);
1719 				}
1720 				st->flags &= ~(ST_EIO_PENDING|ST_EOM_PENDING);
1721 			}
1722 		}
1723 		break;
1724 	case SP_FILEMARKS:
1725 		if (st->flags & ST_EIO_PENDING) {
1726 			if (number > 0) {
1727 				/* pretend we just discovered the error */
1728 				st->flags &= ~ST_EIO_PENDING;
1729 				return (EIO);
1730 			} else if (number < 0) {
1731 				/* back away from the error */
1732 				st->flags &= ~ST_EIO_PENDING;
1733 			}
1734 		}
1735 		if (st->flags & ST_AT_FILEMARK) {
1736 			st->flags &= ~ST_AT_FILEMARK;
1737 			number--;
1738 		}
1739 		if ((st->flags & ST_BLANK_READ) && (number < 0)) {
1740 			/* back away from unwritten tape */
1741 			st->flags &= ~ST_BLANK_READ;
1742 			number++;	/* XXX dubious */
1743 		}
1744 		break;
1745 	case SP_EOM:
1746 		if (st->flags & ST_EOM_PENDING) {
1747 			/* we're already there */
1748 			st->flags &= ~ST_EOM_PENDING;
1749 			return (0);
1750 		}
1751 		if (st->flags & ST_EIO_PENDING) {
1752 			/* pretend we just discovered the error */
1753 			st->flags &= ~ST_EIO_PENDING;
1754 			return (EIO);
1755 		}
1756 		if (st->flags & ST_AT_FILEMARK)
1757 			st->flags &= ~ST_AT_FILEMARK;
1758 		break;
1759 	}
1760 	if (number == 0)
1761 		return (0);
1762 
1763 	memset(&cmd, 0, sizeof(cmd));
1764 	cmd.opcode = SPACE;
1765 	cmd.byte2 = what;
1766 	_lto3b(number, cmd.number);
1767 
1768 	st->flags &= ~ST_POSUPDATED;
1769 	st->last_ctl_resid = 0;
1770 	error = scsipi_command(st->sc_periph, (void *)&cmd, sizeof(cmd), 0, 0,
1771 	    0, ST_SPC_TIME, NULL, flags);
1772 
1773 	if (error == 0 && (st->flags & ST_POSUPDATED) == 0) {
1774 		number = number - st->last_ctl_resid;
1775 		if (what == SP_BLKS) {
1776 			if (st->blkno != -1) {
1777 				st->blkno += number;
1778 			}
1779 		} else if (what == SP_FILEMARKS) {
1780 			if (st->fileno != -1) {
1781 				st->fileno += number;
1782 				if (number > 0) {
1783 					st->blkno = 0;
1784 				} else if (number < 0) {
1785 					st->blkno = -1;
1786 				}
1787 			}
1788 		} else if (what == SP_EOM) {
1789 			/*
1790 			 * This loses us relative position.
1791 			 */
1792 			st->fileno = st->blkno = -1;
1793 		}
1794 	}
1795 	return (error);
1796 }
1797 
1798 /*
1799  * write N filemarks
1800  */
1801 static int
1802 st_write_filemarks(struct st_softc *st, int number, int flags)
1803 {
1804 	int error;
1805 	struct scsi_write_filemarks cmd;
1806 
1807 	/*
1808 	 * It's hard to write a negative number of file marks.
1809 	 * Don't try.
1810 	 */
1811 	if (number < 0)
1812 		return (EINVAL);
1813 	switch (number) {
1814 	case 0:		/* really a command to sync the drive's buffers */
1815 		break;
1816 	case 1:
1817 		if (st->flags & ST_FM_WRITTEN)	/* already have one down */
1818 			st->flags &= ~ST_WRITTEN;
1819 		else
1820 			st->flags |= ST_FM_WRITTEN;
1821 		st->flags &= ~ST_PER_ACTION;
1822 		break;
1823 	default:
1824 		st->flags &= ~(ST_PER_ACTION | ST_WRITTEN);
1825 	}
1826 
1827 	memset(&cmd, 0, sizeof(cmd));
1828 	cmd.opcode = WRITE_FILEMARKS;
1829 	if (scsipi_periph_bustype(st->sc_periph) == SCSIPI_BUSTYPE_ATAPI)
1830 		cmd.byte2 = SR_IMMED;
1831 	/*
1832 	 * The ATAPI Onstream DI-30 doesn't support writing filemarks, but
1833 	 * WRITE_FILEMARKS is still used to flush the buffer
1834 	 */
1835 	if ((st->quirks & ST_Q_NOFILEMARKS) == 0)
1836 		_lto3b(number, cmd.number);
1837 
1838 	/* XXX WE NEED TO BE ABLE TO GET A RESIDIUAL XXX */
1839 	error = scsipi_command(st->sc_periph, (void *)&cmd, sizeof(cmd), 0, 0,
1840 	    0, ST_IO_TIME * 4, NULL, flags);
1841 	if (error == 0 && st->fileno != -1) {
1842 		st->fileno += number;
1843 	}
1844 	return (error);
1845 }
1846 
1847 /*
1848  * Make sure the right number of file marks is on tape if the
1849  * tape has been written.  If the position argument is true,
1850  * leave the tape positioned where it was originally.
1851  *
1852  * nmarks returns the number of marks to skip (or, if position
1853  * true, which were skipped) to get back original position.
1854  */
1855 static int
1856 st_check_eod(struct st_softc *st, boolean position, int *nmarks, int flags)
1857 {
1858 	int error;
1859 
1860 	switch (st->flags & (ST_WRITTEN | ST_FM_WRITTEN | ST_2FM_AT_EOD)) {
1861 	default:
1862 		*nmarks = 0;
1863 		return (0);
1864 	case ST_WRITTEN:
1865 	case ST_WRITTEN | ST_FM_WRITTEN | ST_2FM_AT_EOD:
1866 		*nmarks = 1;
1867 		break;
1868 	case ST_WRITTEN | ST_2FM_AT_EOD:
1869 		*nmarks = 2;
1870 	}
1871 	error = st_write_filemarks(st, *nmarks, flags);
1872 	if (position && !error)
1873 		error = st_space(st, -*nmarks, SP_FILEMARKS, flags);
1874 	return (error);
1875 }
1876 
1877 /*
1878  * load/unload/retension
1879  */
1880 static int
1881 st_load(struct st_softc *st, u_int type, int flags)
1882 {
1883 	int error;
1884 	struct scsi_load cmd;
1885 
1886 	if (type != LD_LOAD) {
1887 		int nmarks;
1888 
1889 		error = st_check_eod(st, FALSE, &nmarks, flags);
1890 		if (error) {
1891 			printf("%s: failed to write closing filemarks at "
1892 			    "unload, errno=%d\n", st->sc_dev.dv_xname, error);
1893 			return (error);
1894 		}
1895 	}
1896 	if (st->quirks & ST_Q_IGNORE_LOADS) {
1897 		if (type == LD_LOAD) {
1898 			/*
1899 			 * If we ignore loads, at least we should try a rewind.
1900 			 */
1901 			return st_rewind(st, 0, flags);
1902 		}
1903 		/* otherwise, we should do what's asked of us */
1904 	}
1905 
1906 	memset(&cmd, 0, sizeof(cmd));
1907 	cmd.opcode = LOAD;
1908 	if (scsipi_periph_bustype(st->sc_periph) == SCSIPI_BUSTYPE_ATAPI)
1909 		cmd.byte2 = SR_IMMED;
1910 	cmd.how = type;
1911 
1912 	error = scsipi_command(st->sc_periph, (void *)&cmd, sizeof(cmd), 0, 0,
1913 	    ST_RETRIES, ST_SPC_TIME, NULL, flags);
1914 	if (error) {
1915 		printf("%s: error %d in st_load (op %d)\n",
1916 		    st->sc_dev.dv_xname, error, type);
1917 	}
1918 	return (error);
1919 }
1920 
1921 /*
1922  *  Rewind the device
1923  */
1924 static int
1925 st_rewind(struct st_softc *st, u_int immediate, int flags)
1926 {
1927 	struct scsi_rewind cmd;
1928 	int error;
1929 	int nmarks;
1930 
1931 	error = st_check_eod(st, FALSE, &nmarks, flags);
1932 	if (error) {
1933 		printf("%s: failed to write closing filemarks at "
1934 		    "rewind, errno=%d\n", st->sc_dev.dv_xname, error);
1935 		return (error);
1936 	}
1937 	st->flags &= ~ST_PER_ACTION;
1938 
1939 	/*
1940 	 * ATAPI tapes always need immediate to be set
1941 	 */
1942 	if (scsipi_periph_bustype(st->sc_periph) == SCSIPI_BUSTYPE_ATAPI)
1943 		immediate = SR_IMMED;
1944 
1945 	memset(&cmd, 0, sizeof(cmd));
1946 	cmd.opcode = REWIND;
1947 	cmd.byte2 = immediate;
1948 
1949 	error = scsipi_command(st->sc_periph, (void *)&cmd, sizeof(cmd), 0, 0,
1950 	    ST_RETRIES, immediate ? ST_CTL_TIME: ST_SPC_TIME, NULL, flags);
1951 	if (error) {
1952 		printf("%s: error %d trying to rewind\n",
1953 		    st->sc_dev.dv_xname, error);
1954 		/* lost position */
1955 		st->fileno = st->blkno = -1;
1956 	} else {
1957 		st->fileno = st->blkno = 0;
1958 	}
1959 	return (error);
1960 }
1961 
1962 static int
1963 st_rdpos(struct st_softc *st, int hard, u_int32_t *blkptr)
1964 {
1965 	int error;
1966 	u_int8_t posdata[20];
1967 	struct scsi_tape_read_position cmd;
1968 
1969 	/*
1970 	 * We try and flush any buffered writes here if we were writing
1971 	 * and we're trying to get hardware block position. It eats
1972 	 * up performance substantially, but I'm wary of drive firmware.
1973 	 *
1974 	 * I think that *logical* block position is probably okay-
1975 	 * but hardware block position might have to wait for data
1976 	 * to hit media to be valid. Caveat Emptor.
1977 	 */
1978 
1979 	if (hard && (st->flags & ST_WRITTEN)) {
1980 		/*
1981 		 * First flush any pending writes...
1982 		 */
1983 		error = st_write_filemarks(st, 0, XS_CTL_SILENT);
1984 		/*
1985 		 * The latter case is for 'write protected' tapes
1986 		 * which are too stupid to recognize a zero count
1987 		 * for writing filemarks as a no-op.
1988 		 */
1989 		if (error != 0 && error != EACCES && error != EROFS)
1990 			return (error);
1991 	}
1992 
1993 	memset(&cmd, 0, sizeof(cmd));
1994 	memset(&posdata, 0, sizeof(posdata));
1995 	cmd.opcode = READ_POSITION;
1996 	if (hard)
1997 		cmd.byte1 = 1;
1998 
1999 	error = scsipi_command(st->sc_periph, (void *)&cmd, sizeof(cmd),
2000 	    (void *)&posdata, sizeof(posdata), ST_RETRIES, ST_CTL_TIME, NULL,
2001 	    XS_CTL_SILENT | XS_CTL_DATA_IN | XS_CTL_DATA_ONSTACK);
2002 
2003 	if (error == 0) {
2004 #if	0
2005 		printf("posdata:");
2006 		for (hard = 0; hard < sizeof(posdata); hard++)
2007 			printf("%02x ", posdata[hard] & 0xff);
2008 		printf("\n");
2009 #endif
2010 		if (posdata[0] & 0x4)	/* Block Position Unknown */
2011 			error = EINVAL;
2012 		else
2013 			*blkptr = _4btol(&posdata[4]);
2014 	}
2015 	return (error);
2016 }
2017 
2018 static int
2019 st_setpos(struct st_softc *st, int hard, u_int32_t *blkptr)
2020 {
2021 	int error;
2022 	struct scsi_tape_locate cmd;
2023 
2024 	/*
2025 	 * We used to try and flush any buffered writes here.
2026 	 * Now we push this onto user applications to either
2027 	 * flush the pending writes themselves (via a zero count
2028 	 * WRITE FILEMARKS command) or they can trust their tape
2029 	 * drive to do this correctly for them.
2030 	 *
2031 	 * There are very ugly performance limitations otherwise.
2032 	 */
2033 
2034 	memset(&cmd, 0, sizeof(cmd));
2035 	cmd.opcode = LOCATE;
2036 	if (hard)
2037 		cmd.byte2 = 1 << 2;
2038 	_lto4b(*blkptr, cmd.blkaddr);
2039 	error = scsipi_command(st->sc_periph, (void *)&cmd, sizeof(cmd), 0, 0,
2040 	    ST_RETRIES, ST_SPC_TIME, NULL, 0);
2041 	/*
2042 	 * Note file && block number position now unknown (if
2043 	 * these things ever start being maintained in this driver)
2044 	 */
2045 	st->fileno = st->blkno = -1;
2046 	return (error);
2047 }
2048 
2049 
2050 /*
2051  * Look at the returned sense and act on the error and determine
2052  * the unix error number to pass back..., 0 (== report no error),
2053  * -1 = retry the operation, -2 continue error processing.
2054  */
2055 static int
2056 st_interpret_sense(struct scsipi_xfer *xs)
2057 {
2058 	struct scsipi_periph *periph = xs->xs_periph;
2059 	struct scsi_sense_data *sense = &xs->sense.scsi_sense;
2060 	struct buf *bp = xs->bp;
2061 	struct st_softc *st = (void *)periph->periph_dev;
2062 	int retval = EJUSTRETURN;
2063 	int doprint = ((xs->xs_control & XS_CTL_SILENT) == 0);
2064 	u_int8_t key;
2065 	int32_t info;
2066 
2067 	/*
2068 	 * If it isn't a extended or extended/deferred error, let
2069 	 * the generic code handle it.
2070 	 */
2071 	if (SSD_RCODE(sense->response_code) != SSD_RCODE_CURRENT &&
2072 	    SSD_RCODE(sense->response_code) != SSD_RCODE_DEFERRED)
2073 		return (retval);
2074 
2075 	if (sense->response_code & SSD_RCODE_VALID)
2076 		info = _4btol(sense->info);
2077 	else
2078 		info = (st->flags & ST_FIXEDBLOCKS) ?
2079 		    xs->datalen / st->blksize : xs->datalen;
2080 	key = SSD_SENSE_KEY(sense->flags);
2081 	st->mt_erreg = key;
2082 	st->asc = sense->asc;
2083 	st->ascq = sense->ascq;
2084 	st->mt_resid = (short) info;
2085 
2086 	if (key == SKEY_NOT_READY && st->asc == 0x4 && st->ascq == 0x1) {
2087 		/* Not Ready, Logical Unit Is in Process Of Becoming Ready */
2088 		if (!callout_pending(&periph->periph_callout))
2089 			scsipi_periph_freeze(periph, 1);
2090 		callout_reset(&periph->periph_callout,
2091 		    hz, scsipi_periph_timed_thaw, periph);
2092 		return (ERESTART);
2093 	}
2094 
2095 	/*
2096 	 * If the device is not open yet, let generic handle
2097 	 */
2098 	if ((periph->periph_flags & PERIPH_OPEN) == 0) {
2099 		return (retval);
2100 	}
2101 
2102 	xs->resid = info;
2103 	if (st->flags & ST_FIXEDBLOCKS) {
2104 		if (bp) {
2105 			xs->resid *= st->blksize;
2106 			st->last_io_resid = xs->resid;
2107 		} else {
2108 			st->last_ctl_resid = xs->resid;
2109 		}
2110 		if (key == SKEY_VOLUME_OVERFLOW) {
2111 			st->flags |= ST_EIO_PENDING;
2112 			if (bp)
2113 				bp->b_resid = xs->resid;
2114 		} else if (sense->flags & SSD_EOM) {
2115 			if ((st->flags & ST_EARLYWARN) == 0)
2116 				st->flags |= ST_EIO_PENDING;
2117 			st->flags |= ST_EOM_PENDING;
2118 			if (bp) {
2119 #if 0
2120 				bp->b_resid = xs->resid;
2121 #else
2122 				/*
2123 				 * Grotesque as it seems, the few times
2124 				 * I've actually seen a non-zero resid,
2125 				 * the tape drive actually lied and had
2126 				 * written all the data!
2127 				 */
2128 				bp->b_resid = 0;
2129 #endif
2130 			}
2131 		}
2132 		if (sense->flags & SSD_FILEMARK) {
2133 			st->flags |= ST_AT_FILEMARK;
2134 			if (bp)
2135 				bp->b_resid = xs->resid;
2136 			if (st->fileno != (daddr_t) -1) {
2137 				st->fileno++;
2138 				st->blkno = 0;
2139 				st->flags |= ST_POSUPDATED;
2140 			}
2141 		}
2142 		if (sense->flags & SSD_ILI) {
2143 			st->flags |= ST_EIO_PENDING;
2144 			if (bp)
2145 				bp->b_resid = xs->resid;
2146 			if (sense->response_code & SSD_RCODE_VALID &&
2147 			    (xs->xs_control & XS_CTL_SILENT) == 0)
2148 				printf("%s: block wrong size, %d blocks "
2149 				    "residual\n", st->sc_dev.dv_xname, info);
2150 
2151 			/*
2152 			 * This quirk code helps the drive read
2153 			 * the first tape block, regardless of
2154 			 * format.  That is required for these
2155 			 * drives to return proper MODE SENSE
2156 			 * information.
2157 			 */
2158 			if ((st->quirks & ST_Q_SENSE_HELP) &&
2159 			    (periph->periph_flags & PERIPH_MEDIA_LOADED) == 0)
2160 				st->blksize -= 512;
2161 			else if ((st->flags & ST_POSUPDATED) == 0) {
2162 				if (st->blkno != (daddr_t) -1) {
2163 					st->blkno +=
2164 					    (xs->datalen / st->blksize);
2165 					st->flags |= ST_POSUPDATED;
2166 				}
2167 			}
2168 		}
2169 		/*
2170 		 * If data wanted and no data was transferred, do it immediately
2171 		 */
2172 		if (xs->datalen && xs->resid >= xs->datalen) {
2173 			if (st->flags & ST_EIO_PENDING)
2174 				return (EIO);
2175 			if (st->flags & ST_AT_FILEMARK) {
2176 				if (bp)
2177 					bp->b_resid = xs->resid;
2178 				return (0);
2179 			}
2180 		}
2181 	} else {		/* must be variable mode */
2182 		if (bp) {
2183 			st->last_io_resid = xs->resid;
2184 		} else {
2185 			st->last_ctl_resid = xs->resid;
2186 		}
2187 		if (sense->flags & SSD_EOM) {
2188 			/*
2189 			 * The current semantics of this
2190 			 * driver requires EOM detection
2191 			 * to return EIO unless early
2192 			 * warning detection is enabled
2193 			 * for variable mode (this is always
2194 			 * on for fixed block mode).
2195 			 */
2196 			if (st->flags & ST_EARLYWARN) {
2197 				st->flags |= ST_EOM_PENDING;
2198 				retval = 0;
2199 			} else {
2200 				retval = EIO;
2201 			}
2202 
2203 			/*
2204 			 * If it's an unadorned EOM detection,
2205 			 * suppress printing an error.
2206 			 */
2207 			if (key == SKEY_NO_SENSE) {
2208 				doprint = 0;
2209 			}
2210 		} else if (sense->flags & SSD_FILEMARK) {
2211 			retval = 0;
2212 			if (st->fileno != (daddr_t) -1) {
2213 				st->fileno++;
2214 				st->blkno = 0;
2215 				st->flags |= ST_POSUPDATED;
2216 			}
2217 		} else if (sense->flags & SSD_ILI) {
2218 			if (info < 0) {
2219 				/*
2220 				 * The tape record was bigger than the read
2221 				 * we issued.
2222 				 */
2223 				if ((xs->xs_control & XS_CTL_SILENT) == 0) {
2224 					printf("%s: %d-byte tape record too big"
2225 					    " for %d-byte user buffer\n",
2226 					    st->sc_dev.dv_xname,
2227 					    xs->datalen - info, xs->datalen);
2228 				}
2229 				retval = EIO;
2230 			} else {
2231 				retval = 0;
2232 				if (st->blkno != (daddr_t) -1) {
2233 					st->blkno++;
2234 					st->flags |= ST_POSUPDATED;
2235 				}
2236 			}
2237 		}
2238 		if (bp)
2239 			bp->b_resid = info;
2240 	}
2241 
2242 #ifndef SCSIPI_DEBUG
2243 	if (retval == 0 && key == SKEY_NO_SENSE)
2244 		doprint = 0;
2245 #endif
2246 	if (key == SKEY_BLANK_CHECK) {
2247 		/*
2248 		 * This quirk code helps the drive read the
2249 		 * first tape block, regardless of format.  That
2250 		 * is required for these drives to return proper
2251 		 * MODE SENSE information.
2252 		 */
2253 		if ((st->quirks & ST_Q_SENSE_HELP) &&
2254 		    (periph->periph_flags & PERIPH_MEDIA_LOADED) == 0) {
2255 			/* still starting */
2256 			st->blksize -= 512;
2257 		} else if (!(st->flags & (ST_2FM_AT_EOD | ST_BLANK_READ))) {
2258 			st->flags |= ST_BLANK_READ;
2259 			xs->resid = xs->datalen;
2260 			if (bp) {
2261 				bp->b_resid = xs->resid;
2262 				/* return an EOF */
2263 			}
2264 			retval = 0;
2265 			/* lost position */
2266 			st->fileno = st->blkno = -1;
2267 		}
2268 	}
2269 
2270 	/*
2271 	 * If generic sense processing will continue, we should not
2272 	 * print sense info here.
2273 	 */
2274 	if (retval == EJUSTRETURN)
2275 		doprint = 0;
2276 
2277 	if (doprint) {
2278 #ifdef	SCSIVERBOSE
2279 		scsipi_print_sense(xs, 0);
2280 #else
2281 		scsipi_printaddr(periph);
2282 		printf("Sense Key 0x%02x", key);
2283 		if ((sense->response_code & SSD_RCODE_VALID) != 0) {
2284 			switch (key) {
2285 			case SKEY_NOT_READY:
2286 			case SKEY_ILLEGAL_REQUEST:
2287 			case SKEY_UNIT_ATTENTION:
2288 			case SKEY_DATA_PROTECT:
2289 				break;
2290 			case SKEY_VOLUME_OVERFLOW:
2291 			case SKEY_BLANK_CHECK:
2292 				printf(", requested size: %d (decimal)", info);
2293 				break;
2294 			case SKEY_ABORTED_COMMAND:
2295 				if (xs->xs_retries)
2296 					printf(", retrying");
2297 				printf(", cmd 0x%x, info 0x%x",
2298 				    xs->cmd->opcode, info);
2299 				break;
2300 			default:
2301 				printf(", info = %d (decimal)", info);
2302 			}
2303 		}
2304 		if (sense->extra_len != 0) {
2305 			int n;
2306 			printf(", data =");
2307 			for (n = 0; n < sense->extra_len; n++)
2308 				printf(" %02x", sense->csi[n]);
2309 		}
2310 		printf("\n");
2311 #endif
2312 	}
2313 	return (retval);
2314 }
2315 
2316 /*
2317  * The quirk here is that the drive returns some value to st_mode_sense
2318  * incorrectly until the tape has actually passed by the head.
2319  *
2320  * The method is to set the drive to large fixed-block state (user-specified
2321  * density and 1024-byte blocks), then read and rewind to get it to sense the
2322  * tape.  If that doesn't work, try 512-byte fixed blocks.  If that doesn't
2323  * work, as a last resort, try variable- length blocks.  The result will be
2324  * the ability to do an accurate st_mode_sense.
2325  *
2326  * We know we can do a rewind because we just did a load, which implies rewind.
2327  * Rewind seems preferable to space backward if we have a virgin tape.
2328  *
2329  * The rest of the code for this quirk is in ILI processing and BLANK CHECK
2330  * error processing, both part of st_interpret_sense.
2331  */
2332 static int
2333 st_touch_tape(struct st_softc *st)
2334 {
2335 	char *bf;
2336 	int readsize;
2337 	int error;
2338 
2339 	bf = malloc(1024, M_TEMP, M_NOWAIT);
2340 	if (bf == NULL)
2341 		return (ENOMEM);
2342 
2343 	if ((error = st->ops(st, ST_OPS_MODESENSE, 0)) != 0)
2344 		goto bad;
2345 
2346 	/*
2347 	 * If the block size is already known from the
2348 	 * sense data, use it. Else start probing at 1024.
2349 	 */
2350 	if (st->media_blksize > 0)
2351 		st->blksize = st->media_blksize;
2352 	else
2353 		st->blksize = 1024;
2354 
2355 	do {
2356 		switch (st->blksize) {
2357 		case 512:
2358 		case 1024:
2359 			readsize = st->blksize;
2360 			st->flags |= ST_FIXEDBLOCKS;
2361 			break;
2362 		default:
2363 			readsize = 1;
2364 			st->flags &= ~ST_FIXEDBLOCKS;
2365 		}
2366 		if ((error = st->ops(st, ST_OPS_MODESELECT, XS_CTL_SILENT))
2367 		    != 0) {
2368 			/*
2369 			 * The device did not agree with the proposed
2370 			 * block size. If we exhausted our options,
2371 			 * return failure, else try another.
2372 			 */
2373 			if (readsize == 1)
2374 				goto bad;
2375 			st->blksize -= 512;
2376 			continue;
2377 		}
2378 		st_read(st, bf, readsize, XS_CTL_SILENT);	/* XXX */
2379 		if ((error = st_rewind(st, 0, 0)) != 0) {
2380 bad:			free(bf, M_TEMP);
2381 			return (error);
2382 		}
2383 	} while (readsize != 1 && readsize > st->blksize);
2384 
2385 	free(bf, M_TEMP);
2386 	return (0);
2387 }
2388 
2389 static int
2390 stdump(dev_t dev, daddr_t blkno, caddr_t va, size_t size)
2391 {
2392 
2393 	/* Not implemented. */
2394 	return (ENXIO);
2395 }
2396