xref: /openbsd-src/sys/scsi/ch.c (revision 99fd087599a8791921855f21bd7e36130f39aadc)
1 /*	$OpenBSD: ch.c,v 1.64 2019/12/06 16:57:24 krw 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/scsiconf.h>
54 
55 #define CHRETRIES	2
56 #define CHUNIT(x)	(minor((x)))
57 
58 struct ch_softc {
59 	struct device		 sc_dev;	/* generic device info */
60 	struct scsi_link	*sc_link;	/* link in the SCSI bus */
61 
62 	int			 sc_picker;	/* current picker */
63 
64 	/*
65 	 * The following information is obtained from the
66 	 * element address assignment page.
67 	 */
68 	int			 sc_firsts[4];	/* firsts, indexed by CHET_* */
69 	int			 sc_counts[4];	/* counts, indexed by CHET_* */
70 
71 	/*
72 	 * The following mask defines the legal combinations
73 	 * of elements for the MOVE MEDIUM command.
74 	 */
75 	u_int8_t		 sc_movemask[4];
76 
77 	/*
78 	 * As above, but for EXCHANGE MEDIUM.
79 	 */
80 	u_int8_t		 sc_exchangemask[4];
81 
82 	int			 flags;		/* misc. info */
83 
84 	/*
85 	 * Quirks; see below.
86 	 */
87 	int			 sc_settledelay; /* delay for settle */
88 
89 };
90 
91 /* sc_flags */
92 #define CHF_ROTATE	0x01		/* picker can rotate */
93 
94 /* Autoconfiguration glue */
95 int	chmatch(struct device *, void *, void *);
96 void	chattach(struct device *, struct device *, void *);
97 
98 struct cfattach ch_ca = {
99 	sizeof(struct ch_softc), chmatch, chattach
100 };
101 
102 struct cfdriver ch_cd = {
103 	NULL, "ch", DV_DULL
104 };
105 
106 const struct scsi_inquiry_pattern ch_patterns[] = {
107 	{T_CHANGER, T_REMOV,
108 	 "",		"",		""},
109 };
110 
111 int	ch_move(struct ch_softc *, struct changer_move *);
112 int	ch_exchange(struct ch_softc *, struct changer_exchange *);
113 int	ch_position(struct ch_softc *, struct changer_position *);
114 int	ch_usergetelemstatus(struct ch_softc *,
115 	    struct changer_element_status_request *);
116 int	ch_getelemstatus(struct ch_softc *, int, int, caddr_t, size_t, int);
117 int	ch_get_params(struct ch_softc *, int);
118 int	ch_interpret_sense(struct scsi_xfer *xs);
119 void	ch_get_quirks(struct ch_softc *, struct scsi_inquiry_data *);
120 
121 /*
122  * SCSI changer quirks.
123  */
124 struct chquirk {
125 	struct	scsi_inquiry_pattern cq_match; /* device id pattern */
126 	int	cq_settledelay;	/* settle delay, in seconds */
127 };
128 
129 struct chquirk chquirks[] = {
130 	{{T_CHANGER, T_REMOV,
131 	  "SPECTRA",	"9000",		"0200"},
132 	 75},
133 };
134 
135 int
136 chmatch(struct device *parent, void *match, void *aux)
137 {
138 	struct scsi_attach_args		*sa = aux;
139 	int				 priority;
140 
141 	(void)scsi_inqmatch(sa->sa_inqbuf,
142 	    ch_patterns, nitems(ch_patterns),
143 	    sizeof(ch_patterns[0]), &priority);
144 
145 	return priority;
146 }
147 
148 void
149 chattach(struct device *parent, struct device *self, void *aux)
150 {
151 	struct ch_softc			*sc = (struct ch_softc *)self;
152 	struct scsi_attach_args		*sa = aux;
153 	struct scsi_link		*link = sa->sa_sc_link;
154 
155 	/* Glue into the SCSI bus */
156 	sc->sc_link = link;
157 	link->interpret_sense = ch_interpret_sense;
158 	link->device_softc = sc;
159 	link->openings = 1;
160 
161 	printf("\n");
162 
163 	/*
164 	 * Store our our device's quirks.
165 	 */
166 	ch_get_quirks(sc, sa->sa_inqbuf);
167 
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 an element status descriptor to a user-mode
514  * changer_element_status structure.
515  */
516 static void
517 copy_element_status(int flags,	struct read_element_status_descriptor *desc,
518     struct changer_element_status *ces)
519 {
520 	ces->ces_flags = desc->flags1;
521 
522 	if (ISSET(flags, READ_ELEMENT_STATUS_PVOLTAG))
523 		copy_voltag(&ces->ces_pvoltag, &desc->pvoltag);
524 	if (ISSET(flags, READ_ELEMENT_STATUS_AVOLTAG))
525 		copy_voltag(&ces->ces_avoltag, &desc->avoltag);
526 }
527 
528 /*
529  * Perform a READ ELEMENT STATUS on behalf of the user, and return to
530  * the user only the data the user is interested in (i.e. an array of
531  * changer_element_status structures)
532  */
533 int
534 ch_usergetelemstatus(struct ch_softc *sc,
535     struct changer_element_status_request *cesr)
536 {
537 	struct changer_element_status		*user_data = NULL;
538 	struct read_element_status_header	*st_hdr;
539 	struct read_element_status_page_header	*pg_hdr;
540 	caddr_t					 desc;
541 	caddr_t					 data = NULL;
542 	size_t					 size, desclen, udsize;
543 	int					 avail, chet, i, want_voltags;
544 	int					 error = 0;
545 
546 	chet = cesr->cesr_type;
547 	want_voltags = (cesr->cesr_flags & CESR_VOLTAGS) ? 1 : 0;
548 
549 	/*
550 	 * If there are no elements of the requested type in the changer,
551 	 * the request is invalid.
552 	 */
553 	if (sc->sc_counts[chet] == 0)
554 		return EINVAL;
555 
556 	/*
557 	 * Request one descriptor for the given element type.  This
558 	 * is used to determine the size of the descriptor so that
559 	 * we can allocate enough storage for all of them.  We assume
560 	 * that the first one can fit into 1k.
561 	 */
562 	size = 1024;
563 	data = dma_alloc(size, PR_WAITOK);
564 	error = ch_getelemstatus(sc, sc->sc_firsts[chet], 1, data, size,
565 	    want_voltags);
566 	if (error)
567 		goto done;
568 
569 	st_hdr = (struct read_element_status_header *)data;
570 	pg_hdr = (struct read_element_status_page_header *) (st_hdr + 1);
571 	desclen = _2btol(pg_hdr->edl);
572 
573 	dma_free(data, size);
574 
575 	/*
576 	 * Reallocate storage for descriptors and get them from the
577 	 * device.
578 	 */
579 	size = sizeof(struct read_element_status_header) +
580 	    sizeof(struct read_element_status_page_header) +
581 	    (desclen * sc->sc_counts[chet]);
582 	data = dma_alloc(size, PR_WAITOK);
583 	error = ch_getelemstatus(sc, sc->sc_firsts[chet],
584 	    sc->sc_counts[chet], data, size, want_voltags);
585 	if (error)
586 		goto done;
587 
588 	/*
589 	 * Fill in the user status array.
590 	 */
591 	st_hdr = (struct read_element_status_header *)data;
592 	pg_hdr = (struct read_element_status_page_header *) (st_hdr + 1);
593 
594 	avail = _2btol(st_hdr->count);
595 	if (avail != sc->sc_counts[chet]) {
596 		error = EINVAL;
597 		goto done;
598 	}
599 
600 	user_data = mallocarray(avail, sizeof(struct changer_element_status),
601 	    M_DEVBUF, M_WAITOK | M_ZERO);
602 	udsize = avail * sizeof(struct changer_element_status);
603 
604 	desc = (caddr_t)(pg_hdr + 1);
605 	for (i = 0; i < avail; ++i) {
606 		struct changer_element_status *ces = &(user_data[i]);
607 		copy_element_status(pg_hdr->flags,
608 		    (struct read_element_status_descriptor *)desc, ces);
609 		desc += desclen;
610 	}
611 
612 	/* Copy array out to userspace. */
613 	error = copyout(user_data, cesr->cesr_data, udsize);
614 
615 done:
616 	if (data != NULL)
617 		dma_free(data, size);
618 	if (user_data != NULL)
619 		free(user_data, M_DEVBUF, udsize);
620 	return error;
621 }
622 
623 int
624 ch_getelemstatus(struct ch_softc *sc, int first, int count, caddr_t data,
625     size_t datalen, int voltag)
626 {
627 	struct scsi_read_element_status		*cmd;
628 	struct scsi_xfer			*xs;
629 	int					 error;
630 
631 	/*
632 	 * Build SCSI command.
633 	 */
634 	xs = scsi_xs_get(sc->sc_link, SCSI_DATA_IN);
635 	if (xs == NULL)
636 		return ENOMEM;
637 	xs->cmdlen = sizeof(*cmd);
638 	xs->data = data;
639 	xs->datalen = datalen;
640 	xs->retries = CHRETRIES;
641 	xs->timeout = 100000;
642 
643 	cmd = (struct scsi_read_element_status *)xs->cmd;
644 	cmd->opcode = READ_ELEMENT_STATUS;
645 	_lto2b(first, cmd->sea);
646 	_lto2b(count, cmd->count);
647 	_lto3b(datalen, cmd->len);
648 	if (voltag)
649 		SET(cmd->byte2, READ_ELEMENT_STATUS_VOLTAG);
650 
651 	error = scsi_xs_sync(xs);
652 	scsi_xs_put(xs);
653 
654 	return error;
655 }
656 
657 /*
658  * Ask the device about itself and fill in the parameters in our
659  * softc.
660  */
661 int
662 ch_get_params(struct ch_softc *sc, int flags)
663 {
664 	union scsi_mode_sense_buf			*data;
665 	struct page_element_address_assignment		*ea;
666 	struct page_device_capabilities			*cap;
667 	u_int8_t					*moves, *exchanges;
668 	int						 big, error, from;
669 
670 	data = dma_alloc(sizeof(*data), PR_NOWAIT);
671 	if (data == NULL)
672 		return ENOMEM;
673 
674 	/*
675 	 * Grab info from the element address assignment page (0x1d).
676 	 */
677 	error = scsi_do_mode_sense(sc->sc_link, EA_PAGE, data,
678 	    (void **)&ea, sizeof(*ea), flags, &big);
679 	if (error == 0 && ea == NULL)
680 		error = EIO;
681 	if (error != 0) {
682 #ifdef CHANGER_DEBUG
683 		printf("%s: could not sense element address page\n",
684 		    sc->sc_dev.dv_xname);
685 #endif /* CHANGER_DEBUG */
686 		dma_free(data, sizeof(*data));
687 		return error;
688 	}
689 
690 	sc->sc_firsts[CHET_MT] = _2btol(ea->mtea);
691 	sc->sc_counts[CHET_MT] = _2btol(ea->nmte);
692 	sc->sc_firsts[CHET_ST] = _2btol(ea->fsea);
693 	sc->sc_counts[CHET_ST] = _2btol(ea->nse);
694 	sc->sc_firsts[CHET_IE] = _2btol(ea->fieea);
695 	sc->sc_counts[CHET_IE] = _2btol(ea->niee);
696 	sc->sc_firsts[CHET_DT] = _2btol(ea->fdtea);
697 	sc->sc_counts[CHET_DT] = _2btol(ea->ndte);
698 
699 	/* XXX Ask for transport geometry page. */
700 
701 	/*
702 	 * Grab info from the capabilities page (0x1f).
703 	 */
704 	error = scsi_do_mode_sense(sc->sc_link, CAP_PAGE, data,
705 	    (void **)&cap, sizeof(*cap), flags, &big);
706 	if (error == 0 && cap == NULL)
707 		error = EIO;
708 	if (error != 0) {
709 #ifdef CHANGER_DEBUG
710 		printf("%s: could not sense capabilities page\n",
711 		    sc->sc_dev.dv_xname);
712 #endif /* CHANGER_DEBUG */
713 		dma_free(data, sizeof(*data));
714 		return error;
715 	}
716 
717 	bzero(sc->sc_movemask, sizeof(sc->sc_movemask));
718 	bzero(sc->sc_exchangemask, sizeof(sc->sc_exchangemask));
719 	moves = &cap->move_from_mt;
720 	exchanges = &cap->exchange_with_mt;
721 	for (from = CHET_MT; from <= CHET_DT; ++from) {
722 		sc->sc_movemask[from] = moves[from];
723 		sc->sc_exchangemask[from] = exchanges[from];
724 	}
725 
726 	SET(sc->sc_link->flags, SDEV_MEDIA_LOADED);
727 	dma_free(data, sizeof(*data));
728 	return 0;
729 }
730 
731 void
732 ch_get_quirks(struct ch_softc *sc, struct scsi_inquiry_data *inqbuf)
733 {
734 	const struct chquirk		*match;
735 	int				 priority;
736 
737 	sc->sc_settledelay = 0;
738 
739 	match = (const struct chquirk *)scsi_inqmatch(inqbuf,
740 	    (caddr_t)chquirks,
741 	    sizeof(chquirks) / sizeof(chquirks[0]),
742 	    sizeof(chquirks[0]), &priority);
743 	if (priority != 0) {
744 		sc->sc_settledelay = match->cq_settledelay;
745 	}
746 }
747 
748 /*
749  * Look at the returned sense and act on the error and detirmine
750  * The unix error number to pass back... (0 = report no error)
751  *                            (-1 = continue processing)
752  */
753 int
754 ch_interpret_sense(struct scsi_xfer *xs)
755 {
756 	struct scsi_sense_data		*sense = &xs->sense;
757 	struct scsi_link		*link = xs->sc_link;
758 	u_int8_t			 serr, skey;
759 
760 	serr = sense->error_code & SSD_ERRCODE;
761 	skey = sense->flags & SSD_KEY;
762 
763 	if (!ISSET(link->flags, SDEV_OPEN) ||
764 	    (serr != SSD_ERRCODE_CURRENT && serr != SSD_ERRCODE_DEFERRED))
765 		return scsi_interpret_sense(xs);
766 
767 	switch (skey) {
768 
769 	/*
770 	 * We do custom processing in ch for the unit becoming ready
771 	 * case.  in this case we do not allow xs->retries to be
772 	 * decremented only on the "Unit Becoming Ready" case. This is
773 	 * because tape changers report "Unit Becoming Ready" when they
774 	 * rescan their state (i.e. when the door got opened) and can
775 	 * take a long time for large units. Rather than having a
776 	 * massive timeout for all operations (which would cause other
777 	 * problems) we allow changers to wait (but be interruptable
778 	 * with Ctrl-C) forever as long as they are reporting that they
779 	 * are becoming ready.  all other cases are handled as per the
780 	 * default.
781 	 */
782 	case SKEY_NOT_READY:
783 		if (ISSET(xs->flags, SCSI_IGNORE_NOT_READY))
784 			return 0;
785 		switch (ASC_ASCQ(sense)) {
786 		case SENSE_NOT_READY_BECOMING_READY:
787 			SC_DEBUG(link, SDEV_DB1, ("not ready: busy (%#x)\n",
788 			    sense->add_sense_code_qual));
789 			/* don't count this as a retry */
790 			xs->retries++;
791 			return scsi_delay(xs, 1);
792 		default:
793 			return scsi_interpret_sense(xs);
794 		}
795 	default:
796 		return scsi_interpret_sense(xs);
797 	}
798 }
799