xref: /openbsd/sys/scsi/ch.c (revision 4bdff4be)
1 /*	$OpenBSD: ch.c,v 1.72 2023/04/11 00:45:09 jsg Exp $	*/
2 /*	$NetBSD: ch.c,v 1.26 1997/02/21 22:06:52 thorpej Exp $	*/
3 
4 /*
5  * Copyright (c) 1996, 1997 Jason R. Thorpe <thorpej@and.com>
6  * All rights reserved.
7  *
8  * Partially based on an autochanger driver written by Stefan Grefen
9  * and on an autochanger driver written by the Systems Programming Group
10  * at the University of Utah Computer Science Department.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 3. All advertising materials mentioning features or use of this software
21  *    must display the following acknowledgements:
22  *	This product includes software developed by Jason R. Thorpe
23  *	for And Communications, http://www.and.com/
24  * 4. The name of the author may not be used to endorse or promote products
25  *    derived from this software without specific prior written permission.
26  *
27  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
28  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
29  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
30  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
31  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
32  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
33  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
34  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
35  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37  * SUCH DAMAGE.
38  */
39 
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/errno.h>
43 #include <sys/ioctl.h>
44 #include <sys/chio.h>
45 #include <sys/device.h>
46 #include <sys/malloc.h>
47 #include <sys/pool.h>
48 #include <sys/conf.h>
49 #include <sys/fcntl.h>
50 
51 #include <scsi/scsi_all.h>
52 #include <scsi/scsi_changer.h>
53 #include <scsi/scsi_debug.h>
54 #include <scsi/scsiconf.h>
55 
56 #define CHRETRIES	2
57 #define CHUNIT(x)	(minor((x)))
58 
59 struct ch_softc {
60 	struct device		 sc_dev;	/* generic device info */
61 	struct scsi_link	*sc_link;	/* link in the SCSI bus */
62 
63 	int			 sc_picker;	/* current picker */
64 
65 	/*
66 	 * The following information is obtained from the
67 	 * element address assignment page.
68 	 */
69 	int			 sc_firsts[4];	/* firsts, indexed by CHET_* */
70 	int			 sc_counts[4];	/* counts, indexed by CHET_* */
71 
72 	/*
73 	 * The following mask defines the legal combinations
74 	 * of elements for the MOVE MEDIUM command.
75 	 */
76 	u_int8_t		 sc_movemask[4];
77 
78 	/*
79 	 * As above, but for EXCHANGE MEDIUM.
80 	 */
81 	u_int8_t		 sc_exchangemask[4];
82 
83 	int			 flags;		/* misc. info */
84 
85 	/*
86 	 * Quirks; see below.
87 	 */
88 	int			 sc_settledelay; /* delay for settle */
89 
90 };
91 
92 /* sc_flags */
93 #define CHF_ROTATE	0x01		/* picker can rotate */
94 
95 /* Autoconfiguration glue */
96 int	chmatch(struct device *, void *, void *);
97 void	chattach(struct device *, struct device *, void *);
98 
99 const struct cfattach ch_ca = {
100 	sizeof(struct ch_softc), chmatch, chattach
101 };
102 
103 struct cfdriver ch_cd = {
104 	NULL, "ch", DV_DULL
105 };
106 
107 const struct scsi_inquiry_pattern ch_patterns[] = {
108 	{T_CHANGER, T_REMOV,
109 	 "",		"",		""},
110 };
111 
112 int	ch_move(struct ch_softc *, struct changer_move *);
113 int	ch_exchange(struct ch_softc *, struct changer_exchange *);
114 int	ch_position(struct ch_softc *, struct changer_position *);
115 int	ch_usergetelemstatus(struct ch_softc *,
116 	    struct changer_element_status_request *);
117 int	ch_getelemstatus(struct ch_softc *, int, int, caddr_t, size_t, int);
118 int	ch_get_params(struct ch_softc *, int);
119 int	ch_interpret_sense(struct scsi_xfer *xs);
120 void	ch_get_quirks(struct ch_softc *, struct scsi_inquiry_data *);
121 
122 /*
123  * SCSI changer quirks.
124  */
125 struct chquirk {
126 	struct	scsi_inquiry_pattern cq_match; /* device id pattern */
127 	int	cq_settledelay;	/* settle delay, in seconds */
128 };
129 
130 struct chquirk chquirks[] = {
131 	{{T_CHANGER, T_REMOV,
132 	  "SPECTRA",	"9000",		"0200"},
133 	 75},
134 };
135 
136 int
137 chmatch(struct device *parent, void *match, void *aux)
138 {
139 	struct scsi_attach_args		*sa = aux;
140 	struct scsi_inquiry_data	*inq = &sa->sa_sc_link->inqdata;
141 	int				 priority;
142 
143 	(void)scsi_inqmatch(inq, ch_patterns, nitems(ch_patterns),
144 	    sizeof(ch_patterns[0]), &priority);
145 
146 	return priority;
147 }
148 
149 void
150 chattach(struct device *parent, struct device *self, void *aux)
151 {
152 	struct ch_softc			*sc = (struct ch_softc *)self;
153 	struct scsi_attach_args		*sa = aux;
154 	struct scsi_link		*link = sa->sa_sc_link;
155 
156 	/* Glue into the SCSI bus */
157 	sc->sc_link = link;
158 	link->interpret_sense = ch_interpret_sense;
159 	link->device_softc = sc;
160 	link->openings = 1;
161 
162 	printf("\n");
163 
164 	/*
165 	 * Store our device's quirks.
166 	 */
167 	ch_get_quirks(sc, &link->inqdata);
168 }
169 
170 int
171 chopen(dev_t dev, int flags, int fmt, struct proc *p)
172 {
173 	struct ch_softc		*sc;
174 	int			 oldcounts[4];
175 	int			 i, unit, error = 0;
176 
177 	unit = CHUNIT(dev);
178 	if ((unit >= ch_cd.cd_ndevs) ||
179 	    ((sc = ch_cd.cd_devs[unit]) == NULL))
180 		return ENXIO;
181 
182 	/*
183 	 * Only allow one open at a time.
184 	 */
185 	if (ISSET(sc->sc_link->flags, SDEV_OPEN))
186 		return EBUSY;
187 
188 	SET(sc->sc_link->flags, SDEV_OPEN);
189 
190 	/*
191 	 * Absorb any unit attention errors. We must notice
192 	 * "Not ready" errors as a changer will report "In the
193 	 * process of getting ready" any time it must rescan
194 	 * itself to determine the state of the changer.
195 	 */
196 	error = scsi_test_unit_ready(sc->sc_link, TEST_READY_RETRIES,
197 	    SCSI_IGNORE_ILLEGAL_REQUEST | SCSI_IGNORE_MEDIA_CHANGE);
198 	if (error)
199 		goto bad;
200 
201 	/*
202 	 * Get information about the device. Save old information
203 	 * so we can decide whether to be verbose about new parameters.
204 	 */
205 	for (i = 0; i < 4; i++) {
206 		oldcounts[i] = sc->sc_counts[i];
207 	}
208 	error = ch_get_params(sc, scsi_autoconf);
209 	if (error)
210 		goto bad;
211 
212 	for (i = 0; i < 4; i++) {
213 		if (oldcounts[i] != sc->sc_counts[i]) {
214 			break;
215 		}
216 	}
217 	if (i < 4) {
218 #ifdef CHANGER_DEBUG
219 #define PLURAL(c)	(c) == 1 ? "" : "s"
220 		printf("%s: %d slot%s, %d drive%s, %d picker%s, %d portal%s\n",
221 		    sc->sc_dev.dv_xname,
222 		    sc->sc_counts[CHET_ST], PLURAL(sc->sc_counts[CHET_ST]),
223 		    sc->sc_counts[CHET_DT], PLURAL(sc->sc_counts[CHET_DT]),
224 		    sc->sc_counts[CHET_MT], PLURAL(sc->sc_counts[CHET_MT]),
225 		    sc->sc_counts[CHET_IE], PLURAL(sc->sc_counts[CHET_IE]));
226 #undef PLURAL
227 		printf("%s: move mask: 0x%x 0x%x 0x%x 0x%x\n",
228 		    sc->sc_dev.dv_xname,
229 		    sc->sc_movemask[CHET_MT], sc->sc_movemask[CHET_ST],
230 		    sc->sc_movemask[CHET_IE], sc->sc_movemask[CHET_DT]);
231 		printf("%s: exchange mask: 0x%x 0x%x 0x%x 0x%x\n",
232 		    sc->sc_dev.dv_xname,
233 		    sc->sc_exchangemask[CHET_MT], sc->sc_exchangemask[CHET_ST],
234 		    sc->sc_exchangemask[CHET_IE], sc->sc_exchangemask[CHET_DT]);
235 #endif /* CHANGER_DEBUG */
236 	}
237 
238 	/* Default the current picker. */
239 	sc->sc_picker = sc->sc_firsts[CHET_MT];
240 
241 	return 0;
242 
243 bad:
244 	CLR(sc->sc_link->flags, SDEV_OPEN);
245 	return error;
246 }
247 
248 int
249 chclose(dev_t dev, int flags, int fmt, struct proc *p)
250 {
251 	struct ch_softc *sc = ch_cd.cd_devs[CHUNIT(dev)];
252 
253 	CLR(sc->sc_link->flags, SDEV_OPEN);
254 	return 0;
255 }
256 
257 int
258 chioctl(dev_t dev, u_long cmd, caddr_t data, int flags, struct proc *p)
259 {
260 	struct ch_softc		*sc = ch_cd.cd_devs[CHUNIT(dev)];
261 	int			 error = 0;
262 
263 	/*
264 	 * If this command can change the device's state, we must
265 	 * have the device open for writing.
266 	 */
267 	switch (cmd) {
268 	case CHIOGPICKER:
269 	case CHIOGPARAMS:
270 	case CHIOGSTATUS:
271 		break;
272 
273 	default:
274 		if (!ISSET(flags, FWRITE))
275 			return EBADF;
276 	}
277 
278 	switch (cmd) {
279 	case CHIOMOVE:
280 		error = ch_move(sc, (struct changer_move *)data);
281 		break;
282 
283 	case CHIOEXCHANGE:
284 		error = ch_exchange(sc, (struct changer_exchange *)data);
285 		break;
286 
287 	case CHIOPOSITION:
288 		error = ch_position(sc, (struct changer_position *)data);
289 		break;
290 
291 	case CHIOGPICKER:
292 		*(int *)data = sc->sc_picker - sc->sc_firsts[CHET_MT];
293 		break;
294 
295 	case CHIOSPICKER:	{
296 		int new_picker = *(int *)data;
297 
298 		if (new_picker > (sc->sc_counts[CHET_MT] - 1))
299 			return EINVAL;
300 		sc->sc_picker = sc->sc_firsts[CHET_MT] + new_picker;
301 		break;		}
302 
303 	case CHIOGPARAMS:	{
304 		struct changer_params *cp = (struct changer_params *)data;
305 
306 		cp->cp_curpicker = sc->sc_picker - sc->sc_firsts[CHET_MT];
307 		cp->cp_npickers = sc->sc_counts[CHET_MT];
308 		cp->cp_nslots = sc->sc_counts[CHET_ST];
309 		cp->cp_nportals = sc->sc_counts[CHET_IE];
310 		cp->cp_ndrives = sc->sc_counts[CHET_DT];
311 		break;		}
312 
313 	case CHIOGSTATUS:	{
314 		struct changer_element_status_request *cesr =
315 		    (struct changer_element_status_request *)data;
316 
317 		error = ch_usergetelemstatus(sc, cesr);
318 		break;		}
319 
320 	/* Implement prevent/allow? */
321 
322 	default:
323 		error = scsi_do_ioctl(sc->sc_link, cmd, data, flags);
324 		break;
325 	}
326 
327 	return error;
328 }
329 
330 int
331 ch_move(struct ch_softc *sc, struct changer_move *cm)
332 {
333 	struct scsi_move_medium		*cmd;
334 	struct scsi_xfer		*xs;
335 	int				 error;
336 	u_int16_t			 fromelem, toelem;
337 
338 	/*
339 	 * Check arguments.
340 	 */
341 	if ((cm->cm_fromtype > CHET_DT) || (cm->cm_totype > CHET_DT))
342 		return EINVAL;
343 	if ((cm->cm_fromunit > (sc->sc_counts[cm->cm_fromtype] - 1)) ||
344 	    (cm->cm_tounit > (sc->sc_counts[cm->cm_totype] - 1)))
345 		return ENODEV;
346 
347 	/*
348 	 * Check the request against the changer's capabilities.
349 	 */
350 	if ((sc->sc_movemask[cm->cm_fromtype] & (1 << cm->cm_totype)) == 0)
351 		return EINVAL;
352 
353 	/*
354 	 * Calculate the source and destination elements.
355 	 */
356 	fromelem = sc->sc_firsts[cm->cm_fromtype] + cm->cm_fromunit;
357 	toelem = sc->sc_firsts[cm->cm_totype] + cm->cm_tounit;
358 
359 	/*
360 	 * Build the SCSI command.
361 	 */
362 	xs = scsi_xs_get(sc->sc_link, 0);
363 	if (xs == NULL)
364 		return ENOMEM;
365 	xs->cmdlen = sizeof(*cmd);
366 	xs->retries = CHRETRIES;
367 	xs->timeout = 100000;
368 
369 	cmd = (struct scsi_move_medium *)&xs->cmd;
370 	cmd->opcode = MOVE_MEDIUM;
371 	_lto2b(sc->sc_picker, cmd->tea);
372 	_lto2b(fromelem, cmd->src);
373 	_lto2b(toelem, cmd->dst);
374 	if (ISSET(cm->cm_flags, CM_INVERT))
375 		SET(cmd->flags, MOVE_MEDIUM_INVERT);
376 
377 	error = scsi_xs_sync(xs);
378 	scsi_xs_put(xs);
379 
380 	return error;
381 }
382 
383 int
384 ch_exchange(struct ch_softc *sc, struct changer_exchange *ce)
385 {
386 	struct scsi_exchange_medium	*cmd;
387 	struct scsi_xfer		*xs;
388 	int				 error;
389 	u_int16_t			 src, dst1, dst2;
390 
391 	/*
392 	 * Check arguments.
393 	 */
394 	if ((ce->ce_srctype > CHET_DT) || (ce->ce_fdsttype > CHET_DT) ||
395 	    (ce->ce_sdsttype > CHET_DT))
396 		return EINVAL;
397 	if ((ce->ce_srcunit > (sc->sc_counts[ce->ce_srctype] - 1)) ||
398 	    (ce->ce_fdstunit > (sc->sc_counts[ce->ce_fdsttype] - 1)) ||
399 	    (ce->ce_sdstunit > (sc->sc_counts[ce->ce_sdsttype] - 1)))
400 		return ENODEV;
401 
402 	/*
403 	 * Check the request against the changer's capabilities.
404 	 */
405 	if (((sc->sc_exchangemask[ce->ce_srctype] &
406 	    (1 << ce->ce_fdsttype)) == 0) ||
407 	    ((sc->sc_exchangemask[ce->ce_fdsttype] &
408 	    (1 << ce->ce_sdsttype)) == 0))
409 		return EINVAL;
410 
411 	/*
412 	 * Calculate the source and destination elements.
413 	 */
414 	src = sc->sc_firsts[ce->ce_srctype] + ce->ce_srcunit;
415 	dst1 = sc->sc_firsts[ce->ce_fdsttype] + ce->ce_fdstunit;
416 	dst2 = sc->sc_firsts[ce->ce_sdsttype] + ce->ce_sdstunit;
417 
418 	/*
419 	 * Build the SCSI command.
420 	 */
421 	xs = scsi_xs_get(sc->sc_link, 0);
422 	if (xs == NULL)
423 		return ENOMEM;
424 	xs->cmdlen = sizeof(*cmd);
425 	xs->retries = CHRETRIES;
426 	xs->timeout = 100000;
427 
428 	cmd = (struct scsi_exchange_medium *)&xs->cmd;
429 	cmd->opcode = EXCHANGE_MEDIUM;
430 	_lto2b(sc->sc_picker, cmd->tea);
431 	_lto2b(src, cmd->src);
432 	_lto2b(dst1, cmd->fdst);
433 	_lto2b(dst2, cmd->sdst);
434 	if (ISSET(ce->ce_flags, CE_INVERT1))
435 		SET(cmd->flags, EXCHANGE_MEDIUM_INV1);
436 	if (ISSET(ce->ce_flags, CE_INVERT2))
437 		SET(cmd->flags, EXCHANGE_MEDIUM_INV2);
438 
439 	error = scsi_xs_sync(xs);
440 	scsi_xs_put(xs);
441 
442 	return error;
443 }
444 
445 int
446 ch_position(struct ch_softc *sc, struct changer_position *cp)
447 {
448 	struct scsi_position_to_element		*cmd;
449 	struct scsi_xfer			*xs;
450 	int					 error;
451 	u_int16_t				 dst;
452 
453 	/*
454 	 * Check arguments.
455 	 */
456 	if (cp->cp_type > CHET_DT)
457 		return EINVAL;
458 	if (cp->cp_unit > (sc->sc_counts[cp->cp_type] - 1))
459 		return ENODEV;
460 
461 	/*
462 	 * Calculate the destination element.
463 	 */
464 	dst = sc->sc_firsts[cp->cp_type] + cp->cp_unit;
465 
466 	/*
467 	 * Build the SCSI command.
468 	 */
469 	xs = scsi_xs_get(sc->sc_link, 0);
470 	if (xs == NULL)
471 		return ENOMEM;
472 	xs->cmdlen = sizeof(*cmd);
473 	xs->retries = CHRETRIES;
474 	xs->timeout = 100000;
475 
476 	cmd = (struct scsi_position_to_element *)&xs->cmd;
477 	cmd->opcode = POSITION_TO_ELEMENT;
478 	_lto2b(sc->sc_picker, cmd->tea);
479 	_lto2b(dst, cmd->dst);
480 	if (ISSET(cp->cp_flags, CP_INVERT))
481 		SET(cmd->flags, POSITION_TO_ELEMENT_INVERT);
482 
483 	error = scsi_xs_sync(xs);
484 	scsi_xs_put(xs);
485 
486 	return error;
487 }
488 
489 /*
490  * Copy a volume tag to a volume_tag struct, converting SCSI byte order
491  * to host native byte order in the volume serial number.  The volume
492  * label as returned by the changer is transferred to user mode as
493  * nul-terminated string.  Volume labels are truncated at the first
494  * space, as suggested by SCSI-2.
495  */
496 static  void
497 copy_voltag(struct changer_voltag *uvoltag, struct volume_tag *voltag)
498 {
499 	int i;
500 
501 	for (i=0; i<CH_VOLTAG_MAXLEN; i++) {
502 		char c = voltag->vif[i];
503 		if (c && c != ' ')
504 			uvoltag->cv_volid[i] = c;
505 		else
506 			break;
507 	}
508 	uvoltag->cv_volid[i] = '\0';
509 	uvoltag->cv_serial = _2btol(voltag->vsn);
510 }
511 
512 /*
513  * Copy an element status descriptor to a user-mode
514  * changer_element_status structure.
515  */
516 static void
517 copy_element_status(struct ch_softc *sc, int flags,
518     struct read_element_status_descriptor *desc,
519     struct changer_element_status *ces)
520 {
521 	u_int16_t eaddr = _2btol(desc->eaddr);
522 	u_int16_t et;
523 
524 	for (et = CHET_MT; et <= CHET_DT; et++) {
525 		if ((sc->sc_firsts[et] <= eaddr)
526 		    && ((sc->sc_firsts[et] + sc->sc_counts[et])
527 		    > eaddr)) {
528 			ces->ces_addr = eaddr - sc->sc_firsts[et];
529 			ces->ces_type = et;
530 			break;
531 		}
532 	}
533 
534 	ces->ces_flags = desc->flags1;
535 
536 	ces->ces_sensecode = desc->sense_code;
537 	ces->ces_sensequal = desc->sense_qual;
538 
539 	if (desc->flags2 & READ_ELEMENT_STATUS_INVERT)
540 		ces->ces_flags |= READ_ELEMENT_STATUS_EXCEPT;
541 
542 	if (desc->flags2 & READ_ELEMENT_STATUS_SVALID) {
543 		eaddr = _2btol(desc->ssea);
544 
545 		/* convert source address to logical format */
546 		for (et = CHET_MT; et <= CHET_DT; et++) {
547 			if ((sc->sc_firsts[et] <= eaddr)
548 			    && ((sc->sc_firsts[et] + sc->sc_counts[et])
549 				> eaddr)) {
550 				ces->ces_source_addr =
551 					eaddr - sc->sc_firsts[et];
552 				ces->ces_source_type = et;
553 				ces->ces_flags |= READ_ELEMENT_STATUS_ACCESS;
554 				break;
555 			}
556 		}
557 
558 		if (!(ces->ces_flags & READ_ELEMENT_STATUS_ACCESS))
559 			printf("ch: warning: could not map element source "
560 			       "address %ud to a valid element type\n",
561 			       eaddr);
562 	}
563 
564 	if (ISSET(flags, READ_ELEMENT_STATUS_PVOLTAG))
565 		copy_voltag(&ces->ces_pvoltag, &desc->pvoltag);
566 	if (ISSET(flags, READ_ELEMENT_STATUS_AVOLTAG))
567 		copy_voltag(&ces->ces_avoltag, &desc->avoltag);
568 }
569 
570 /*
571  * Perform a READ ELEMENT STATUS on behalf of the user, and return to
572  * the user only the data the user is interested in (i.e. an array of
573  * changer_element_status structures)
574  */
575 int
576 ch_usergetelemstatus(struct ch_softc *sc,
577     struct changer_element_status_request *cesr)
578 {
579 	struct changer_element_status		*user_data = NULL;
580 	struct read_element_status_header	*st_hdr;
581 	struct read_element_status_page_header	*pg_hdr;
582 	caddr_t					 desc;
583 	caddr_t					 data = NULL;
584 	size_t					 size, desclen, udsize;
585 	int					 avail, chet, i, want_voltags;
586 	int					 error = 0;
587 
588 	chet = cesr->cesr_type;
589 	want_voltags = (cesr->cesr_flags & CESR_VOLTAGS) ? 1 : 0;
590 
591 	/*
592 	 * If there are no elements of the requested type in the changer,
593 	 * the request is invalid.
594 	 */
595 	if (sc->sc_counts[chet] == 0)
596 		return EINVAL;
597 
598 	/*
599 	 * Request one descriptor for the given element type.  This
600 	 * is used to determine the size of the descriptor so that
601 	 * we can allocate enough storage for all of them.  We assume
602 	 * that the first one can fit into 1k.
603 	 */
604 	size = 1024;
605 	data = dma_alloc(size, PR_WAITOK);
606 	error = ch_getelemstatus(sc, sc->sc_firsts[chet], 1, data, size,
607 	    want_voltags);
608 	if (error)
609 		goto done;
610 
611 	st_hdr = (struct read_element_status_header *)data;
612 	pg_hdr = (struct read_element_status_page_header *) (st_hdr + 1);
613 	desclen = _2btol(pg_hdr->edl);
614 
615 	dma_free(data, size);
616 
617 	/*
618 	 * Reallocate storage for descriptors and get them from the
619 	 * device.
620 	 */
621 	size = sizeof(struct read_element_status_header) +
622 	    sizeof(struct read_element_status_page_header) +
623 	    (desclen * sc->sc_counts[chet]);
624 	data = dma_alloc(size, PR_WAITOK);
625 	error = ch_getelemstatus(sc, sc->sc_firsts[chet],
626 	    sc->sc_counts[chet], data, size, want_voltags);
627 	if (error)
628 		goto done;
629 
630 	/*
631 	 * Fill in the user status array.
632 	 */
633 	st_hdr = (struct read_element_status_header *)data;
634 	pg_hdr = (struct read_element_status_page_header *) (st_hdr + 1);
635 
636 	avail = _2btol(st_hdr->count);
637 	if (avail != sc->sc_counts[chet]) {
638 		error = EINVAL;
639 		goto done;
640 	}
641 
642 	user_data = mallocarray(avail, sizeof(struct changer_element_status),
643 	    M_DEVBUF, M_WAITOK | M_ZERO);
644 	udsize = avail * sizeof(struct changer_element_status);
645 
646 	desc = (caddr_t)(pg_hdr + 1);
647 	for (i = 0; i < avail; ++i) {
648 		struct changer_element_status *ces = &(user_data[i]);
649 		copy_element_status(sc, pg_hdr->flags,
650 		    (struct read_element_status_descriptor *)desc, ces);
651 		desc += desclen;
652 	}
653 
654 	/* Copy array out to userspace. */
655 	error = copyout(user_data, cesr->cesr_data, udsize);
656 
657 done:
658 	if (data != NULL)
659 		dma_free(data, size);
660 	if (user_data != NULL)
661 		free(user_data, M_DEVBUF, udsize);
662 	return error;
663 }
664 
665 int
666 ch_getelemstatus(struct ch_softc *sc, int first, int count, caddr_t data,
667     size_t datalen, int voltag)
668 {
669 	struct scsi_read_element_status		*cmd;
670 	struct scsi_xfer			*xs;
671 	int					 error;
672 
673 	/*
674 	 * Build SCSI command.
675 	 */
676 	xs = scsi_xs_get(sc->sc_link, SCSI_DATA_IN);
677 	if (xs == NULL)
678 		return ENOMEM;
679 	xs->cmdlen = sizeof(*cmd);
680 	xs->data = data;
681 	xs->datalen = datalen;
682 	xs->retries = CHRETRIES;
683 	xs->timeout = 100000;
684 
685 	cmd = (struct scsi_read_element_status *)&xs->cmd;
686 	cmd->opcode = READ_ELEMENT_STATUS;
687 	_lto2b(first, cmd->sea);
688 	_lto2b(count, cmd->count);
689 	_lto3b(datalen, cmd->len);
690 	if (voltag)
691 		SET(cmd->byte2, READ_ELEMENT_STATUS_VOLTAG);
692 
693 	error = scsi_xs_sync(xs);
694 	scsi_xs_put(xs);
695 
696 	return error;
697 }
698 
699 /*
700  * Ask the device about itself and fill in the parameters in our
701  * softc.
702  */
703 int
704 ch_get_params(struct ch_softc *sc, int flags)
705 {
706 	union scsi_mode_sense_buf			*data;
707 	struct page_element_address_assignment		*ea;
708 	struct page_device_capabilities			*cap;
709 	u_int8_t					*moves, *exchanges;
710 	int						 big, error, from;
711 
712 	data = dma_alloc(sizeof(*data), PR_NOWAIT);
713 	if (data == NULL)
714 		return ENOMEM;
715 
716 	/*
717 	 * Grab info from the element address assignment page (0x1d).
718 	 */
719 	error = scsi_do_mode_sense(sc->sc_link, EA_PAGE, data,
720 	    (void **)&ea, sizeof(*ea), flags, &big);
721 	if (error == 0 && ea == NULL)
722 		error = EIO;
723 	if (error != 0) {
724 #ifdef CHANGER_DEBUG
725 		printf("%s: could not sense element address page\n",
726 		    sc->sc_dev.dv_xname);
727 #endif /* CHANGER_DEBUG */
728 		dma_free(data, sizeof(*data));
729 		return error;
730 	}
731 
732 	sc->sc_firsts[CHET_MT] = _2btol(ea->mtea);
733 	sc->sc_counts[CHET_MT] = _2btol(ea->nmte);
734 	sc->sc_firsts[CHET_ST] = _2btol(ea->fsea);
735 	sc->sc_counts[CHET_ST] = _2btol(ea->nse);
736 	sc->sc_firsts[CHET_IE] = _2btol(ea->fieea);
737 	sc->sc_counts[CHET_IE] = _2btol(ea->niee);
738 	sc->sc_firsts[CHET_DT] = _2btol(ea->fdtea);
739 	sc->sc_counts[CHET_DT] = _2btol(ea->ndte);
740 
741 	/* XXX Ask for transport geometry page. */
742 
743 	/*
744 	 * Grab info from the capabilities page (0x1f).
745 	 */
746 	error = scsi_do_mode_sense(sc->sc_link, CAP_PAGE, data,
747 	    (void **)&cap, sizeof(*cap), flags, &big);
748 	if (error == 0 && cap == NULL)
749 		error = EIO;
750 	if (error != 0) {
751 #ifdef CHANGER_DEBUG
752 		printf("%s: could not sense capabilities page\n",
753 		    sc->sc_dev.dv_xname);
754 #endif /* CHANGER_DEBUG */
755 		dma_free(data, sizeof(*data));
756 		return error;
757 	}
758 
759 	bzero(sc->sc_movemask, sizeof(sc->sc_movemask));
760 	bzero(sc->sc_exchangemask, sizeof(sc->sc_exchangemask));
761 	moves = &cap->move_from_mt;
762 	exchanges = &cap->exchange_with_mt;
763 	for (from = CHET_MT; from <= CHET_DT; ++from) {
764 		sc->sc_movemask[from] = moves[from];
765 		sc->sc_exchangemask[from] = exchanges[from];
766 	}
767 
768 	SET(sc->sc_link->flags, SDEV_MEDIA_LOADED);
769 	dma_free(data, sizeof(*data));
770 	return 0;
771 }
772 
773 void
774 ch_get_quirks(struct ch_softc *sc, struct scsi_inquiry_data *inqbuf)
775 {
776 	const struct chquirk		*match;
777 	int				 priority;
778 
779 	sc->sc_settledelay = 0;
780 
781 	match = (const struct chquirk *)scsi_inqmatch(inqbuf,
782 	    (caddr_t)chquirks,
783 	    sizeof(chquirks) / sizeof(chquirks[0]),
784 	    sizeof(chquirks[0]), &priority);
785 	if (priority != 0) {
786 		sc->sc_settledelay = match->cq_settledelay;
787 	}
788 }
789 
790 /*
791  * Look at the returned sense and act on the error to determine
792  * the unix error number to pass back... (0 = report no error)
793  *                            (-1 = continue processing)
794  */
795 int
796 ch_interpret_sense(struct scsi_xfer *xs)
797 {
798 	struct scsi_sense_data		*sense = &xs->sense;
799 	struct scsi_link		*link = xs->sc_link;
800 	u_int8_t			 serr, skey;
801 
802 	serr = sense->error_code & SSD_ERRCODE;
803 	skey = sense->flags & SSD_KEY;
804 
805 	if (!ISSET(link->flags, SDEV_OPEN) ||
806 	    (serr != SSD_ERRCODE_CURRENT && serr != SSD_ERRCODE_DEFERRED))
807 		return scsi_interpret_sense(xs);
808 
809 	switch (skey) {
810 
811 	/*
812 	 * We do custom processing in ch for the unit becoming ready
813 	 * case.  in this case we do not allow xs->retries to be
814 	 * decremented only on the "Unit Becoming Ready" case. This is
815 	 * because tape changers report "Unit Becoming Ready" when they
816 	 * rescan their state (i.e. when the door got opened) and can
817 	 * take a long time for large units. Rather than having a
818 	 * massive timeout for all operations (which would cause other
819 	 * problems) we allow changers to wait (but be interruptible
820 	 * with Ctrl-C) forever as long as they are reporting that they
821 	 * are becoming ready.  all other cases are handled as per the
822 	 * default.
823 	 */
824 	case SKEY_NOT_READY:
825 		if (ISSET(xs->flags, SCSI_IGNORE_NOT_READY))
826 			return 0;
827 		switch (ASC_ASCQ(sense)) {
828 		case SENSE_NOT_READY_BECOMING_READY:
829 			SC_DEBUG(link, SDEV_DB1, ("not ready: busy (%#x)\n",
830 			    sense->add_sense_code_qual));
831 			/* don't count this as a retry */
832 			xs->retries++;
833 			return scsi_delay(xs, 1);
834 		default:
835 			return scsi_interpret_sense(xs);
836 		}
837 	default:
838 		return scsi_interpret_sense(xs);
839 	}
840 }
841