xref: /netbsd-src/sys/dev/scsipi/scsipi_base.c (revision 404fbe5fb94ca1e054339640cabb2801ce52dd30)
1 /*	$NetBSD: scsipi_base.c,v 1.148 2008/05/11 05:17:23 mlelstv Exp $	*/
2 
3 /*-
4  * Copyright (c) 1998, 1999, 2000, 2002, 2003, 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; by Jason R. Thorpe of the Numerical Aerospace
9  * Simulation Facility, NASA Ames Research Center.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30  * POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 #include <sys/cdefs.h>
34 __KERNEL_RCSID(0, "$NetBSD: scsipi_base.c,v 1.148 2008/05/11 05:17:23 mlelstv Exp $");
35 
36 #include "opt_scsi.h"
37 
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/kernel.h>
41 #include <sys/buf.h>
42 #include <sys/uio.h>
43 #include <sys/malloc.h>
44 #include <sys/pool.h>
45 #include <sys/errno.h>
46 #include <sys/device.h>
47 #include <sys/proc.h>
48 #include <sys/kthread.h>
49 #include <sys/hash.h>
50 
51 #include <uvm/uvm_extern.h>
52 
53 #include <dev/scsipi/scsi_spc.h>
54 #include <dev/scsipi/scsipi_all.h>
55 #include <dev/scsipi/scsipi_disk.h>
56 #include <dev/scsipi/scsipiconf.h>
57 #include <dev/scsipi/scsipi_base.h>
58 
59 #include <dev/scsipi/scsi_all.h>
60 #include <dev/scsipi/scsi_message.h>
61 
62 static int	scsipi_complete(struct scsipi_xfer *);
63 static void	scsipi_request_sense(struct scsipi_xfer *);
64 static int	scsipi_enqueue(struct scsipi_xfer *);
65 static void	scsipi_run_queue(struct scsipi_channel *chan);
66 
67 static void	scsipi_completion_thread(void *);
68 
69 static void	scsipi_get_tag(struct scsipi_xfer *);
70 static void	scsipi_put_tag(struct scsipi_xfer *);
71 
72 static int	scsipi_get_resource(struct scsipi_channel *);
73 static void	scsipi_put_resource(struct scsipi_channel *);
74 
75 static void	scsipi_async_event_max_openings(struct scsipi_channel *,
76 		    struct scsipi_max_openings *);
77 static void	scsipi_async_event_xfer_mode(struct scsipi_channel *,
78 		    struct scsipi_xfer_mode *);
79 static void	scsipi_async_event_channel_reset(struct scsipi_channel *);
80 
81 static struct pool scsipi_xfer_pool;
82 
83 /*
84  * scsipi_init:
85  *
86  *	Called when a scsibus or atapibus is attached to the system
87  *	to initialize shared data structures.
88  */
89 void
90 scsipi_init(void)
91 {
92 	static int scsipi_init_done;
93 
94 	if (scsipi_init_done)
95 		return;
96 	scsipi_init_done = 1;
97 
98 	/* Initialize the scsipi_xfer pool. */
99 	pool_init(&scsipi_xfer_pool, sizeof(struct scsipi_xfer), 0,
100 	    0, 0, "scxspl", NULL, IPL_BIO);
101 	if (pool_prime(&scsipi_xfer_pool,
102 	    PAGE_SIZE / sizeof(struct scsipi_xfer)) == ENOMEM) {
103 		printf("WARNING: not enough memory for scsipi_xfer_pool\n");
104 	}
105 }
106 
107 /*
108  * scsipi_channel_init:
109  *
110  *	Initialize a scsipi_channel when it is attached.
111  */
112 int
113 scsipi_channel_init(struct scsipi_channel *chan)
114 {
115 	struct scsipi_adapter *adapt = chan->chan_adapter;
116 	int i;
117 
118 	/* Initialize shared data. */
119 	scsipi_init();
120 
121 	/* Initialize the queues. */
122 	TAILQ_INIT(&chan->chan_queue);
123 	TAILQ_INIT(&chan->chan_complete);
124 
125 	for (i = 0; i < SCSIPI_CHAN_PERIPH_BUCKETS; i++)
126 		LIST_INIT(&chan->chan_periphtab[i]);
127 
128 	/*
129 	 * Create the asynchronous completion thread.
130 	 */
131 	if (kthread_create(PRI_NONE, 0, NULL, scsipi_completion_thread, chan,
132 	    &chan->chan_thread, "%s", chan->chan_name)) {
133 		aprint_error_dev(adapt->adapt_dev, "unable to create completion thread for "
134 		    "channel %d\n", chan->chan_channel);
135 		panic("scsipi_channel_init");
136 	}
137 
138 	return (0);
139 }
140 
141 /*
142  * scsipi_channel_shutdown:
143  *
144  *	Shutdown a scsipi_channel.
145  */
146 void
147 scsipi_channel_shutdown(struct scsipi_channel *chan)
148 {
149 
150 	/*
151 	 * Shut down the completion thread.
152 	 */
153 	chan->chan_tflags |= SCSIPI_CHANT_SHUTDOWN;
154 	wakeup(&chan->chan_complete);
155 
156 	/*
157 	 * Now wait for the thread to exit.
158 	 */
159 	while (chan->chan_thread != NULL)
160 		(void) tsleep(&chan->chan_thread, PRIBIO, "scshut", 0);
161 }
162 
163 static uint32_t
164 scsipi_chan_periph_hash(uint64_t t, uint64_t l)
165 {
166 	uint32_t hash;
167 
168 	hash = hash32_buf(&t, sizeof(t), HASH32_BUF_INIT);
169 	hash = hash32_buf(&l, sizeof(l), hash);
170 
171 	return (hash & SCSIPI_CHAN_PERIPH_HASHMASK);
172 }
173 
174 /*
175  * scsipi_insert_periph:
176  *
177  *	Insert a periph into the channel.
178  */
179 void
180 scsipi_insert_periph(struct scsipi_channel *chan, struct scsipi_periph *periph)
181 {
182 	uint32_t hash;
183 	int s;
184 
185 	hash = scsipi_chan_periph_hash(periph->periph_target,
186 	    periph->periph_lun);
187 
188 	s = splbio();
189 	LIST_INSERT_HEAD(&chan->chan_periphtab[hash], periph, periph_hash);
190 	splx(s);
191 }
192 
193 /*
194  * scsipi_remove_periph:
195  *
196  *	Remove a periph from the channel.
197  */
198 void
199 scsipi_remove_periph(struct scsipi_channel *chan,
200     struct scsipi_periph *periph)
201 {
202 	int s;
203 
204 	s = splbio();
205 	LIST_REMOVE(periph, periph_hash);
206 	splx(s);
207 }
208 
209 /*
210  * scsipi_lookup_periph:
211  *
212  *	Lookup a periph on the specified channel.
213  */
214 struct scsipi_periph *
215 scsipi_lookup_periph(struct scsipi_channel *chan, int target, int lun)
216 {
217 	struct scsipi_periph *periph;
218 	uint32_t hash;
219 	int s;
220 
221 	if (target >= chan->chan_ntargets ||
222 	    lun >= chan->chan_nluns)
223 		return (NULL);
224 
225 	hash = scsipi_chan_periph_hash(target, lun);
226 
227 	s = splbio();
228 	LIST_FOREACH(periph, &chan->chan_periphtab[hash], periph_hash) {
229 		if (periph->periph_target == target &&
230 		    periph->periph_lun == lun)
231 			break;
232 	}
233 	splx(s);
234 
235 	return (periph);
236 }
237 
238 /*
239  * scsipi_get_resource:
240  *
241  *	Allocate a single xfer `resource' from the channel.
242  *
243  *	NOTE: Must be called at splbio().
244  */
245 static int
246 scsipi_get_resource(struct scsipi_channel *chan)
247 {
248 	struct scsipi_adapter *adapt = chan->chan_adapter;
249 
250 	if (chan->chan_flags & SCSIPI_CHAN_OPENINGS) {
251 		if (chan->chan_openings > 0) {
252 			chan->chan_openings--;
253 			return (1);
254 		}
255 		return (0);
256 	}
257 
258 	if (adapt->adapt_openings > 0) {
259 		adapt->adapt_openings--;
260 		return (1);
261 	}
262 	return (0);
263 }
264 
265 /*
266  * scsipi_grow_resources:
267  *
268  *	Attempt to grow resources for a channel.  If this succeeds,
269  *	we allocate one for our caller.
270  *
271  *	NOTE: Must be called at splbio().
272  */
273 static inline int
274 scsipi_grow_resources(struct scsipi_channel *chan)
275 {
276 
277 	if (chan->chan_flags & SCSIPI_CHAN_CANGROW) {
278 		if ((chan->chan_flags & SCSIPI_CHAN_TACTIVE) == 0) {
279 			scsipi_adapter_request(chan,
280 			    ADAPTER_REQ_GROW_RESOURCES, NULL);
281 			return (scsipi_get_resource(chan));
282 		}
283 		/*
284 		 * ask the channel thread to do it. It'll have to thaw the
285 		 * queue
286 		 */
287 		scsipi_channel_freeze(chan, 1);
288 		chan->chan_tflags |= SCSIPI_CHANT_GROWRES;
289 		wakeup(&chan->chan_complete);
290 		return (0);
291 	}
292 
293 	return (0);
294 }
295 
296 /*
297  * scsipi_put_resource:
298  *
299  *	Free a single xfer `resource' to the channel.
300  *
301  *	NOTE: Must be called at splbio().
302  */
303 static void
304 scsipi_put_resource(struct scsipi_channel *chan)
305 {
306 	struct scsipi_adapter *adapt = chan->chan_adapter;
307 
308 	if (chan->chan_flags & SCSIPI_CHAN_OPENINGS)
309 		chan->chan_openings++;
310 	else
311 		adapt->adapt_openings++;
312 }
313 
314 /*
315  * scsipi_get_tag:
316  *
317  *	Get a tag ID for the specified xfer.
318  *
319  *	NOTE: Must be called at splbio().
320  */
321 static void
322 scsipi_get_tag(struct scsipi_xfer *xs)
323 {
324 	struct scsipi_periph *periph = xs->xs_periph;
325 	int bit, tag;
326 	u_int word;
327 
328 	bit = 0;	/* XXX gcc */
329 	for (word = 0; word < PERIPH_NTAGWORDS; word++) {
330 		bit = ffs(periph->periph_freetags[word]);
331 		if (bit != 0)
332 			break;
333 	}
334 #ifdef DIAGNOSTIC
335 	if (word == PERIPH_NTAGWORDS) {
336 		scsipi_printaddr(periph);
337 		printf("no free tags\n");
338 		panic("scsipi_get_tag");
339 	}
340 #endif
341 
342 	bit -= 1;
343 	periph->periph_freetags[word] &= ~(1 << bit);
344 	tag = (word << 5) | bit;
345 
346 	/* XXX Should eventually disallow this completely. */
347 	if (tag >= periph->periph_openings) {
348 		scsipi_printaddr(periph);
349 		printf("WARNING: tag %d greater than available openings %d\n",
350 		    tag, periph->periph_openings);
351 	}
352 
353 	xs->xs_tag_id = tag;
354 }
355 
356 /*
357  * scsipi_put_tag:
358  *
359  *	Put the tag ID for the specified xfer back into the pool.
360  *
361  *	NOTE: Must be called at splbio().
362  */
363 static void
364 scsipi_put_tag(struct scsipi_xfer *xs)
365 {
366 	struct scsipi_periph *periph = xs->xs_periph;
367 	int word, bit;
368 
369 	word = xs->xs_tag_id >> 5;
370 	bit = xs->xs_tag_id & 0x1f;
371 
372 	periph->periph_freetags[word] |= (1 << bit);
373 }
374 
375 /*
376  * scsipi_get_xs:
377  *
378  *	Allocate an xfer descriptor and associate it with the
379  *	specified peripherial.  If the peripherial has no more
380  *	available command openings, we either block waiting for
381  *	one to become available, or fail.
382  */
383 struct scsipi_xfer *
384 scsipi_get_xs(struct scsipi_periph *periph, int flags)
385 {
386 	struct scsipi_xfer *xs;
387 	int s;
388 
389 	SC_DEBUG(periph, SCSIPI_DB3, ("scsipi_get_xs\n"));
390 
391 	KASSERT(!cold);
392 
393 #ifdef DIAGNOSTIC
394 	/*
395 	 * URGENT commands can never be ASYNC.
396 	 */
397 	if ((flags & (XS_CTL_URGENT|XS_CTL_ASYNC)) ==
398 	    (XS_CTL_URGENT|XS_CTL_ASYNC)) {
399 		scsipi_printaddr(periph);
400 		printf("URGENT and ASYNC\n");
401 		panic("scsipi_get_xs");
402 	}
403 #endif
404 
405 	s = splbio();
406 	/*
407 	 * Wait for a command opening to become available.  Rules:
408 	 *
409 	 *	- All xfers must wait for an available opening.
410 	 *	  Exception: URGENT xfers can proceed when
411 	 *	  active == openings, because we use the opening
412 	 *	  of the command we're recovering for.
413 	 *	- if the periph has sense pending, only URGENT & REQSENSE
414 	 *	  xfers may proceed.
415 	 *
416 	 *	- If the periph is recovering, only URGENT xfers may
417 	 *	  proceed.
418 	 *
419 	 *	- If the periph is currently executing a recovery
420 	 *	  command, URGENT commands must block, because only
421 	 *	  one recovery command can execute at a time.
422 	 */
423 	for (;;) {
424 		if (flags & XS_CTL_URGENT) {
425 			if (periph->periph_active > periph->periph_openings)
426 				goto wait_for_opening;
427 			if (periph->periph_flags & PERIPH_SENSE) {
428 				if ((flags & XS_CTL_REQSENSE) == 0)
429 					goto wait_for_opening;
430 			} else {
431 				if ((periph->periph_flags &
432 				    PERIPH_RECOVERY_ACTIVE) != 0)
433 					goto wait_for_opening;
434 				periph->periph_flags |= PERIPH_RECOVERY_ACTIVE;
435 			}
436 			break;
437 		}
438 		if (periph->periph_active >= periph->periph_openings ||
439 		    (periph->periph_flags & PERIPH_RECOVERING) != 0)
440 			goto wait_for_opening;
441 		periph->periph_active++;
442 		break;
443 
444  wait_for_opening:
445 		if (flags & XS_CTL_NOSLEEP) {
446 			splx(s);
447 			return (NULL);
448 		}
449 		SC_DEBUG(periph, SCSIPI_DB3, ("sleeping\n"));
450 		periph->periph_flags |= PERIPH_WAITING;
451 		(void) tsleep(periph, PRIBIO, "getxs", 0);
452 	}
453 	SC_DEBUG(periph, SCSIPI_DB3, ("calling pool_get\n"));
454 	xs = pool_get(&scsipi_xfer_pool,
455 	    ((flags & XS_CTL_NOSLEEP) != 0 ? PR_NOWAIT : PR_WAITOK));
456 	if (xs == NULL) {
457 		if (flags & XS_CTL_URGENT) {
458 			if ((flags & XS_CTL_REQSENSE) == 0)
459 				periph->periph_flags &= ~PERIPH_RECOVERY_ACTIVE;
460 		} else
461 			periph->periph_active--;
462 		scsipi_printaddr(periph);
463 		printf("unable to allocate %sscsipi_xfer\n",
464 		    (flags & XS_CTL_URGENT) ? "URGENT " : "");
465 	}
466 	splx(s);
467 
468 	SC_DEBUG(periph, SCSIPI_DB3, ("returning\n"));
469 
470 	if (xs != NULL) {
471 		memset(xs, 0, sizeof(*xs));
472 		callout_init(&xs->xs_callout, 0);
473 		xs->xs_periph = periph;
474 		xs->xs_control = flags;
475 		xs->xs_status = 0;
476 		s = splbio();
477 		TAILQ_INSERT_TAIL(&periph->periph_xferq, xs, device_q);
478 		splx(s);
479 	}
480 	return (xs);
481 }
482 
483 /*
484  * scsipi_put_xs:
485  *
486  *	Release an xfer descriptor, decreasing the outstanding command
487  *	count for the peripherial.  If there is a thread waiting for
488  *	an opening, wake it up.  If not, kick any queued I/O the
489  *	peripherial may have.
490  *
491  *	NOTE: Must be called at splbio().
492  */
493 void
494 scsipi_put_xs(struct scsipi_xfer *xs)
495 {
496 	struct scsipi_periph *periph = xs->xs_periph;
497 	int flags = xs->xs_control;
498 
499 	SC_DEBUG(periph, SCSIPI_DB3, ("scsipi_free_xs\n"));
500 
501 	TAILQ_REMOVE(&periph->periph_xferq, xs, device_q);
502 	pool_put(&scsipi_xfer_pool, xs);
503 
504 #ifdef DIAGNOSTIC
505 	if ((periph->periph_flags & PERIPH_RECOVERY_ACTIVE) != 0 &&
506 	    periph->periph_active == 0) {
507 		scsipi_printaddr(periph);
508 		printf("recovery without a command to recovery for\n");
509 		panic("scsipi_put_xs");
510 	}
511 #endif
512 
513 	if (flags & XS_CTL_URGENT) {
514 		if ((flags & XS_CTL_REQSENSE) == 0)
515 			periph->periph_flags &= ~PERIPH_RECOVERY_ACTIVE;
516 	} else
517 		periph->periph_active--;
518 	if (periph->periph_active == 0 &&
519 	    (periph->periph_flags & PERIPH_WAITDRAIN) != 0) {
520 		periph->periph_flags &= ~PERIPH_WAITDRAIN;
521 		wakeup(&periph->periph_active);
522 	}
523 
524 	if (periph->periph_flags & PERIPH_WAITING) {
525 		periph->periph_flags &= ~PERIPH_WAITING;
526 		wakeup(periph);
527 	} else {
528 		if (periph->periph_switch->psw_start != NULL &&
529 		    device_is_active(periph->periph_dev)) {
530 			SC_DEBUG(periph, SCSIPI_DB2,
531 			    ("calling private start()\n"));
532 			(*periph->periph_switch->psw_start)(periph);
533 		}
534 	}
535 }
536 
537 /*
538  * scsipi_channel_freeze:
539  *
540  *	Freeze a channel's xfer queue.
541  */
542 void
543 scsipi_channel_freeze(struct scsipi_channel *chan, int count)
544 {
545 	int s;
546 
547 	s = splbio();
548 	chan->chan_qfreeze += count;
549 	splx(s);
550 }
551 
552 /*
553  * scsipi_channel_thaw:
554  *
555  *	Thaw a channel's xfer queue.
556  */
557 void
558 scsipi_channel_thaw(struct scsipi_channel *chan, int count)
559 {
560 	int s;
561 
562 	s = splbio();
563 	chan->chan_qfreeze -= count;
564 	/*
565 	 * Don't let the freeze count go negative.
566 	 *
567 	 * Presumably the adapter driver could keep track of this,
568 	 * but it might just be easier to do this here so as to allow
569 	 * multiple callers, including those outside the adapter driver.
570 	 */
571 	if (chan->chan_qfreeze < 0) {
572 		chan->chan_qfreeze = 0;
573 	}
574 	splx(s);
575 	/*
576 	 * Kick the channel's queue here.  Note, we may be running in
577 	 * interrupt context (softclock or HBA's interrupt), so the adapter
578 	 * driver had better not sleep.
579 	 */
580 	if (chan->chan_qfreeze == 0)
581 		scsipi_run_queue(chan);
582 }
583 
584 /*
585  * scsipi_channel_timed_thaw:
586  *
587  *	Thaw a channel after some time has expired. This will also
588  * 	run the channel's queue if the freeze count has reached 0.
589  */
590 void
591 scsipi_channel_timed_thaw(void *arg)
592 {
593 	struct scsipi_channel *chan = arg;
594 
595 	scsipi_channel_thaw(chan, 1);
596 }
597 
598 /*
599  * scsipi_periph_freeze:
600  *
601  *	Freeze a device's xfer queue.
602  */
603 void
604 scsipi_periph_freeze(struct scsipi_periph *periph, int count)
605 {
606 	int s;
607 
608 	s = splbio();
609 	periph->periph_qfreeze += count;
610 	splx(s);
611 }
612 
613 /*
614  * scsipi_periph_thaw:
615  *
616  *	Thaw a device's xfer queue.
617  */
618 void
619 scsipi_periph_thaw(struct scsipi_periph *periph, int count)
620 {
621 	int s;
622 
623 	s = splbio();
624 	periph->periph_qfreeze -= count;
625 #ifdef DIAGNOSTIC
626 	if (periph->periph_qfreeze < 0) {
627 		static const char pc[] = "periph freeze count < 0";
628 		scsipi_printaddr(periph);
629 		printf("%s\n", pc);
630 		panic(pc);
631 	}
632 #endif
633 	if (periph->periph_qfreeze == 0 &&
634 	    (periph->periph_flags & PERIPH_WAITING) != 0)
635 		wakeup(periph);
636 	splx(s);
637 }
638 
639 /*
640  * scsipi_periph_timed_thaw:
641  *
642  *	Thaw a device after some time has expired.
643  */
644 void
645 scsipi_periph_timed_thaw(void *arg)
646 {
647 	int s;
648 	struct scsipi_periph *periph = arg;
649 
650 	callout_stop(&periph->periph_callout);
651 
652 	s = splbio();
653 	scsipi_periph_thaw(periph, 1);
654 	if ((periph->periph_channel->chan_flags & SCSIPI_CHAN_TACTIVE) == 0) {
655 		/*
656 		 * Kick the channel's queue here.  Note, we're running in
657 		 * interrupt context (softclock), so the adapter driver
658 		 * had better not sleep.
659 		 */
660 		scsipi_run_queue(periph->periph_channel);
661 	} else {
662 		/*
663 		 * Tell the completion thread to kick the channel's queue here.
664 		 */
665 		periph->periph_channel->chan_tflags |= SCSIPI_CHANT_KICK;
666 		wakeup(&periph->periph_channel->chan_complete);
667 	}
668 	splx(s);
669 }
670 
671 /*
672  * scsipi_wait_drain:
673  *
674  *	Wait for a periph's pending xfers to drain.
675  */
676 void
677 scsipi_wait_drain(struct scsipi_periph *periph)
678 {
679 	int s;
680 
681 	s = splbio();
682 	while (periph->periph_active != 0) {
683 		periph->periph_flags |= PERIPH_WAITDRAIN;
684 		(void) tsleep(&periph->periph_active, PRIBIO, "sxdrn", 0);
685 	}
686 	splx(s);
687 }
688 
689 /*
690  * scsipi_kill_pending:
691  *
692  *	Kill off all pending xfers for a periph.
693  *
694  *	NOTE: Must be called at splbio().
695  */
696 void
697 scsipi_kill_pending(struct scsipi_periph *periph)
698 {
699 
700 	(*periph->periph_channel->chan_bustype->bustype_kill_pending)(periph);
701 	scsipi_wait_drain(periph);
702 }
703 
704 /*
705  * scsipi_print_cdb:
706  * prints a command descriptor block (for debug purpose, error messages,
707  * SCSIPI_VERBOSE, ...)
708  */
709 void
710 scsipi_print_cdb(struct scsipi_generic *cmd)
711 {
712 	int i, j;
713 
714  	printf("0x%02x", cmd->opcode);
715 
716  	switch (CDB_GROUPID(cmd->opcode)) {
717  	case CDB_GROUPID_0:
718  		j = CDB_GROUP0;
719  		break;
720  	case CDB_GROUPID_1:
721  		j = CDB_GROUP1;
722  		break;
723  	case CDB_GROUPID_2:
724  		j = CDB_GROUP2;
725  		break;
726  	case CDB_GROUPID_3:
727  		j = CDB_GROUP3;
728  		break;
729  	case CDB_GROUPID_4:
730  		j = CDB_GROUP4;
731  		break;
732  	case CDB_GROUPID_5:
733  		j = CDB_GROUP5;
734  		break;
735  	case CDB_GROUPID_6:
736  		j = CDB_GROUP6;
737  		break;
738  	case CDB_GROUPID_7:
739  		j = CDB_GROUP7;
740  		break;
741  	default:
742  		j = 0;
743  	}
744  	if (j == 0)
745  		j = sizeof (cmd->bytes);
746  	for (i = 0; i < j-1; i++) /* already done the opcode */
747  		printf(" %02x", cmd->bytes[i]);
748 }
749 
750 /*
751  * scsipi_interpret_sense:
752  *
753  *	Look at the returned sense and act on the error, determining
754  *	the unix error number to pass back.  (0 = report no error)
755  *
756  *	NOTE: If we return ERESTART, we are expected to haved
757  *	thawed the device!
758  *
759  *	THIS IS THE DEFAULT ERROR HANDLER FOR SCSI DEVICES.
760  */
761 int
762 scsipi_interpret_sense(struct scsipi_xfer *xs)
763 {
764 	struct scsi_sense_data *sense;
765 	struct scsipi_periph *periph = xs->xs_periph;
766 	u_int8_t key;
767 	int error;
768 #ifndef	SCSIVERBOSE
769 	u_int32_t info;
770 	static const char *error_mes[] = {
771 		"soft error (corrected)",
772 		"not ready", "medium error",
773 		"non-media hardware failure", "illegal request",
774 		"unit attention", "readonly device",
775 		"no data found", "vendor unique",
776 		"copy aborted", "command aborted",
777 		"search returned equal", "volume overflow",
778 		"verify miscompare", "unknown error key"
779 	};
780 #endif
781 
782 	sense = &xs->sense.scsi_sense;
783 #ifdef SCSIPI_DEBUG
784 	if (periph->periph_flags & SCSIPI_DB1) {
785 		int count;
786 		scsipi_printaddr(periph);
787 		printf(" sense debug information:\n");
788 		printf("\tcode 0x%x valid %d\n",
789 			SSD_RCODE(sense->response_code),
790 			sense->response_code & SSD_RCODE_VALID ? 1 : 0);
791 		printf("\tseg 0x%x key 0x%x ili 0x%x eom 0x%x fmark 0x%x\n",
792 			sense->segment,
793 			SSD_SENSE_KEY(sense->flags),
794 			sense->flags & SSD_ILI ? 1 : 0,
795 			sense->flags & SSD_EOM ? 1 : 0,
796 			sense->flags & SSD_FILEMARK ? 1 : 0);
797 		printf("\ninfo: 0x%x 0x%x 0x%x 0x%x followed by %d "
798 			"extra bytes\n",
799 			sense->info[0],
800 			sense->info[1],
801 			sense->info[2],
802 			sense->info[3],
803 			sense->extra_len);
804 		printf("\textra: ");
805 		for (count = 0; count < SSD_ADD_BYTES_LIM(sense); count++)
806 			printf("0x%x ", sense->csi[count]);
807 		printf("\n");
808 	}
809 #endif
810 
811 	/*
812 	 * If the periph has it's own error handler, call it first.
813 	 * If it returns a legit error value, return that, otherwise
814 	 * it wants us to continue with normal error processing.
815 	 */
816 	if (periph->periph_switch->psw_error != NULL) {
817 		SC_DEBUG(periph, SCSIPI_DB2,
818 		    ("calling private err_handler()\n"));
819 		error = (*periph->periph_switch->psw_error)(xs);
820 		if (error != EJUSTRETURN)
821 			return (error);
822 	}
823 	/* otherwise use the default */
824 	switch (SSD_RCODE(sense->response_code)) {
825 
826 		/*
827 		 * Old SCSI-1 and SASI devices respond with
828 		 * codes other than 70.
829 		 */
830 	case 0x00:		/* no error (command completed OK) */
831 		return (0);
832 	case 0x04:		/* drive not ready after it was selected */
833 		if ((periph->periph_flags & PERIPH_REMOVABLE) != 0)
834 			periph->periph_flags &= ~PERIPH_MEDIA_LOADED;
835 		if ((xs->xs_control & XS_CTL_IGNORE_NOT_READY) != 0)
836 			return (0);
837 		/* XXX - display some sort of error here? */
838 		return (EIO);
839 	case 0x20:		/* invalid command */
840 		if ((xs->xs_control &
841 		     XS_CTL_IGNORE_ILLEGAL_REQUEST) != 0)
842 			return (0);
843 		return (EINVAL);
844 	case 0x25:		/* invalid LUN (Adaptec ACB-4000) */
845 		return (EACCES);
846 
847 		/*
848 		 * If it's code 70, use the extended stuff and
849 		 * interpret the key
850 		 */
851 	case 0x71:		/* delayed error */
852 		scsipi_printaddr(periph);
853 		key = SSD_SENSE_KEY(sense->flags);
854 		printf(" DEFERRED ERROR, key = 0x%x\n", key);
855 		/* FALLTHROUGH */
856 	case 0x70:
857 #ifndef	SCSIVERBOSE
858 		if ((sense->response_code & SSD_RCODE_VALID) != 0)
859 			info = _4btol(sense->info);
860 		else
861 			info = 0;
862 #endif
863 		key = SSD_SENSE_KEY(sense->flags);
864 
865 		switch (key) {
866 		case SKEY_NO_SENSE:
867 		case SKEY_RECOVERED_ERROR:
868 			if (xs->resid == xs->datalen && xs->datalen) {
869 				/*
870 				 * Why is this here?
871 				 */
872 				xs->resid = 0;	/* not short read */
873 			}
874 		case SKEY_EQUAL:
875 			error = 0;
876 			break;
877 		case SKEY_NOT_READY:
878 			if ((periph->periph_flags & PERIPH_REMOVABLE) != 0)
879 				periph->periph_flags &= ~PERIPH_MEDIA_LOADED;
880 			if ((xs->xs_control & XS_CTL_IGNORE_NOT_READY) != 0)
881 				return (0);
882 			if (sense->asc == 0x3A) {
883 				error = ENODEV; /* Medium not present */
884 				if (xs->xs_control & XS_CTL_SILENT_NODEV)
885 					return (error);
886 			} else
887 				error = EIO;
888 			if ((xs->xs_control & XS_CTL_SILENT) != 0)
889 				return (error);
890 			break;
891 		case SKEY_ILLEGAL_REQUEST:
892 			if ((xs->xs_control &
893 			     XS_CTL_IGNORE_ILLEGAL_REQUEST) != 0)
894 				return (0);
895 			/*
896 			 * Handle the case where a device reports
897 			 * Logical Unit Not Supported during discovery.
898 			 */
899 			if ((xs->xs_control & XS_CTL_DISCOVERY) != 0 &&
900 			    sense->asc == 0x25 &&
901 			    sense->ascq == 0x00)
902 				return (EINVAL);
903 			if ((xs->xs_control & XS_CTL_SILENT) != 0)
904 				return (EIO);
905 			error = EINVAL;
906 			break;
907 		case SKEY_UNIT_ATTENTION:
908 			if (sense->asc == 0x29 &&
909 			    sense->ascq == 0x00) {
910 				/* device or bus reset */
911 				return (ERESTART);
912 			}
913 			if ((periph->periph_flags & PERIPH_REMOVABLE) != 0)
914 				periph->periph_flags &= ~PERIPH_MEDIA_LOADED;
915 			if ((xs->xs_control &
916 			     XS_CTL_IGNORE_MEDIA_CHANGE) != 0 ||
917 				/* XXX Should reupload any transient state. */
918 				(periph->periph_flags &
919 				 PERIPH_REMOVABLE) == 0) {
920 				return (ERESTART);
921 			}
922 			if ((xs->xs_control & XS_CTL_SILENT) != 0)
923 				return (EIO);
924 			error = EIO;
925 			break;
926 		case SKEY_DATA_PROTECT:
927 			error = EROFS;
928 			break;
929 		case SKEY_BLANK_CHECK:
930 			error = 0;
931 			break;
932 		case SKEY_ABORTED_COMMAND:
933 			if (xs->xs_retries != 0) {
934 				xs->xs_retries--;
935 				error = ERESTART;
936 			} else
937 				error = EIO;
938 			break;
939 		case SKEY_VOLUME_OVERFLOW:
940 			error = ENOSPC;
941 			break;
942 		default:
943 			error = EIO;
944 			break;
945 		}
946 
947 #ifdef SCSIVERBOSE
948 		if (key && (xs->xs_control & XS_CTL_SILENT) == 0)
949 			scsipi_print_sense(xs, 0);
950 #else
951 		if (key) {
952 			scsipi_printaddr(periph);
953 			printf("%s", error_mes[key - 1]);
954 			if ((sense->response_code & SSD_RCODE_VALID) != 0) {
955 				switch (key) {
956 				case SKEY_NOT_READY:
957 				case SKEY_ILLEGAL_REQUEST:
958 				case SKEY_UNIT_ATTENTION:
959 				case SKEY_DATA_PROTECT:
960 					break;
961 				case SKEY_BLANK_CHECK:
962 					printf(", requested size: %d (decimal)",
963 					    info);
964 					break;
965 				case SKEY_ABORTED_COMMAND:
966 					if (xs->xs_retries)
967 						printf(", retrying");
968 					printf(", cmd 0x%x, info 0x%x",
969 					    xs->cmd->opcode, info);
970 					break;
971 				default:
972 					printf(", info = %d (decimal)", info);
973 				}
974 			}
975 			if (sense->extra_len != 0) {
976 				int n;
977 				printf(", data =");
978 				for (n = 0; n < sense->extra_len; n++)
979 					printf(" %02x",
980 					    sense->csi[n]);
981 			}
982 			printf("\n");
983 		}
984 #endif
985 		return (error);
986 
987 	/*
988 	 * Some other code, just report it
989 	 */
990 	default:
991 #if    defined(SCSIDEBUG) || defined(DEBUG)
992 	{
993 		static const char *uc = "undecodable sense error";
994 		int i;
995 		u_int8_t *cptr = (u_int8_t *) sense;
996 		scsipi_printaddr(periph);
997 		if (xs->cmd == &xs->cmdstore) {
998 			printf("%s for opcode 0x%x, data=",
999 			    uc, xs->cmdstore.opcode);
1000 		} else {
1001 			printf("%s, data=", uc);
1002 		}
1003 		for (i = 0; i < sizeof (sense); i++)
1004 			printf(" 0x%02x", *(cptr++) & 0xff);
1005 		printf("\n");
1006 	}
1007 #else
1008 		scsipi_printaddr(periph);
1009 		printf("Sense Error Code 0x%x",
1010 			SSD_RCODE(sense->response_code));
1011 		if ((sense->response_code & SSD_RCODE_VALID) != 0) {
1012 			struct scsi_sense_data_unextended *usense =
1013 			    (struct scsi_sense_data_unextended *)sense;
1014 			printf(" at block no. %d (decimal)",
1015 			    _3btol(usense->block));
1016 		}
1017 		printf("\n");
1018 #endif
1019 		return (EIO);
1020 	}
1021 }
1022 
1023 /*
1024  * scsipi_test_unit_ready:
1025  *
1026  *	Issue a `test unit ready' request.
1027  */
1028 int
1029 scsipi_test_unit_ready(struct scsipi_periph *periph, int flags)
1030 {
1031 	struct scsi_test_unit_ready cmd;
1032 	int retries;
1033 
1034 	/* some ATAPI drives don't support TEST UNIT READY. Sigh */
1035 	if (periph->periph_quirks & PQUIRK_NOTUR)
1036 		return (0);
1037 
1038 	if (flags & XS_CTL_DISCOVERY)
1039 		retries = 0;
1040 	else
1041 		retries = SCSIPIRETRIES;
1042 
1043 	memset(&cmd, 0, sizeof(cmd));
1044 	cmd.opcode = SCSI_TEST_UNIT_READY;
1045 
1046 	return (scsipi_command(periph, (void *)&cmd, sizeof(cmd), 0, 0,
1047 	    retries, 10000, NULL, flags));
1048 }
1049 
1050 /*
1051  * scsipi_inquire:
1052  *
1053  *	Ask the device about itself.
1054  */
1055 int
1056 scsipi_inquire(struct scsipi_periph *periph, struct scsipi_inquiry_data *inqbuf,
1057     int flags)
1058 {
1059 	struct scsipi_inquiry cmd;
1060 	int error;
1061 	int retries;
1062 
1063 	if (flags & XS_CTL_DISCOVERY)
1064 		retries = 0;
1065 	else
1066 		retries = SCSIPIRETRIES;
1067 
1068 	/*
1069 	 * If we request more data than the device can provide, it SHOULD just
1070 	 * return a short reponse.  However, some devices error with an
1071 	 * ILLEGAL REQUEST sense code, and yet others have even more special
1072 	 * failture modes (such as the GL641USB flash adapter, which goes loony
1073 	 * and sends corrupted CRCs).  To work around this, and to bring our
1074 	 * behavior more in line with other OSes, we do a shorter inquiry,
1075 	 * covering all the SCSI-2 information, first, and then request more
1076 	 * data iff the "additional length" field indicates there is more.
1077 	 * - mycroft, 2003/10/16
1078 	 */
1079 	memset(&cmd, 0, sizeof(cmd));
1080 	cmd.opcode = INQUIRY;
1081 	cmd.length = SCSIPI_INQUIRY_LENGTH_SCSI2;
1082 	error = scsipi_command(periph, (void *)&cmd, sizeof(cmd),
1083 	    (void *)inqbuf, SCSIPI_INQUIRY_LENGTH_SCSI2, retries,
1084 	    10000, NULL, flags | XS_CTL_DATA_IN);
1085 	if (!error &&
1086 	    inqbuf->additional_length > SCSIPI_INQUIRY_LENGTH_SCSI2 - 4) {
1087 #if 0
1088 printf("inquire: addlen=%d, retrying\n", inqbuf->additional_length);
1089 #endif
1090 		cmd.length = SCSIPI_INQUIRY_LENGTH_SCSI3;
1091 		error = scsipi_command(periph, (void *)&cmd, sizeof(cmd),
1092 		    (void *)inqbuf, SCSIPI_INQUIRY_LENGTH_SCSI3, retries,
1093 		    10000, NULL, flags | XS_CTL_DATA_IN);
1094 #if 0
1095 printf("inquire: error=%d\n", error);
1096 #endif
1097 	}
1098 
1099 #ifdef SCSI_OLD_NOINQUIRY
1100 	/*
1101 	 * Kludge for the Adaptec ACB-4000 SCSI->MFM translator.
1102 	 * This board doesn't support the INQUIRY command at all.
1103 	 */
1104 	if (error == EINVAL || error == EACCES) {
1105 		/*
1106 		 * Conjure up an INQUIRY response.
1107 		 */
1108 		inqbuf->device = (error == EINVAL ?
1109 			 SID_QUAL_LU_PRESENT :
1110 			 SID_QUAL_LU_NOTPRESENT) | T_DIRECT;
1111 		inqbuf->dev_qual2 = 0;
1112 		inqbuf->version = 0;
1113 		inqbuf->response_format = SID_FORMAT_SCSI1;
1114 		inqbuf->additional_length = SCSIPI_INQUIRY_LENGTH_SCSI2 - 4;
1115 		inqbuf->flags1 = inqbuf->flags2 = inqbuf->flags3 = 0;
1116 		memcpy(inqbuf->vendor, "ADAPTEC ACB-4000            ", 28);
1117 		error = 0;
1118 	}
1119 
1120 	/*
1121 	 * Kludge for the Emulex MT-02 SCSI->QIC translator.
1122 	 * This board gives an empty response to an INQUIRY command.
1123 	 */
1124 	else if (error == 0 &&
1125 	    inqbuf->device == (SID_QUAL_LU_PRESENT | T_DIRECT) &&
1126 	    inqbuf->dev_qual2 == 0 &&
1127 	    inqbuf->version == 0 &&
1128 	    inqbuf->response_format == SID_FORMAT_SCSI1) {
1129 		/*
1130 		 * Fill out the INQUIRY response.
1131 		 */
1132 		inqbuf->device = (SID_QUAL_LU_PRESENT | T_SEQUENTIAL);
1133 		inqbuf->dev_qual2 = SID_REMOVABLE;
1134 		inqbuf->additional_length = SCSIPI_INQUIRY_LENGTH_SCSI2 - 4;
1135 		inqbuf->flags1 = inqbuf->flags2 = inqbuf->flags3 = 0;
1136 		memcpy(inqbuf->vendor, "EMULEX  MT-02 QIC           ", 28);
1137 	}
1138 #endif /* SCSI_OLD_NOINQUIRY */
1139 
1140 	return error;
1141 }
1142 
1143 /*
1144  * scsipi_prevent:
1145  *
1146  *	Prevent or allow the user to remove the media
1147  */
1148 int
1149 scsipi_prevent(struct scsipi_periph *periph, int type, int flags)
1150 {
1151 	struct scsi_prevent_allow_medium_removal cmd;
1152 
1153 	if (periph->periph_quirks & PQUIRK_NODOORLOCK)
1154 		return 0;
1155 
1156 	memset(&cmd, 0, sizeof(cmd));
1157 	cmd.opcode = SCSI_PREVENT_ALLOW_MEDIUM_REMOVAL;
1158 	cmd.how = type;
1159 
1160 	return (scsipi_command(periph, (void *)&cmd, sizeof(cmd), 0, 0,
1161 	    SCSIPIRETRIES, 5000, NULL, flags));
1162 }
1163 
1164 /*
1165  * scsipi_start:
1166  *
1167  *	Send a START UNIT.
1168  */
1169 int
1170 scsipi_start(struct scsipi_periph *periph, int type, int flags)
1171 {
1172 	struct scsipi_start_stop cmd;
1173 
1174 	memset(&cmd, 0, sizeof(cmd));
1175 	cmd.opcode = START_STOP;
1176 	cmd.byte2 = 0x00;
1177 	cmd.how = type;
1178 
1179 	return (scsipi_command(periph, (void *)&cmd, sizeof(cmd), 0, 0,
1180 	    SCSIPIRETRIES, (type & SSS_START) ? 60000 : 10000, NULL, flags));
1181 }
1182 
1183 /*
1184  * scsipi_mode_sense, scsipi_mode_sense_big:
1185  *	get a sense page from a device
1186  */
1187 
1188 int
1189 scsipi_mode_sense(struct scsipi_periph *periph, int byte2, int page,
1190     struct scsi_mode_parameter_header_6 *data, int len, int flags, int retries,
1191     int timeout)
1192 {
1193 	struct scsi_mode_sense_6 cmd;
1194 
1195 	memset(&cmd, 0, sizeof(cmd));
1196 	cmd.opcode = SCSI_MODE_SENSE_6;
1197 	cmd.byte2 = byte2;
1198 	cmd.page = page;
1199 	cmd.length = len & 0xff;
1200 
1201 	return (scsipi_command(periph, (void *)&cmd, sizeof(cmd),
1202 	    (void *)data, len, retries, timeout, NULL, flags | XS_CTL_DATA_IN));
1203 }
1204 
1205 int
1206 scsipi_mode_sense_big(struct scsipi_periph *periph, int byte2, int page,
1207     struct scsi_mode_parameter_header_10 *data, int len, int flags, int retries,
1208     int timeout)
1209 {
1210 	struct scsi_mode_sense_10 cmd;
1211 
1212 	memset(&cmd, 0, sizeof(cmd));
1213 	cmd.opcode = SCSI_MODE_SENSE_10;
1214 	cmd.byte2 = byte2;
1215 	cmd.page = page;
1216 	_lto2b(len, cmd.length);
1217 
1218 	return (scsipi_command(periph, (void *)&cmd, sizeof(cmd),
1219 	    (void *)data, len, retries, timeout, NULL, flags | XS_CTL_DATA_IN));
1220 }
1221 
1222 int
1223 scsipi_mode_select(struct scsipi_periph *periph, int byte2,
1224     struct scsi_mode_parameter_header_6 *data, int len, int flags, int retries,
1225     int timeout)
1226 {
1227 	struct scsi_mode_select_6 cmd;
1228 
1229 	memset(&cmd, 0, sizeof(cmd));
1230 	cmd.opcode = SCSI_MODE_SELECT_6;
1231 	cmd.byte2 = byte2;
1232 	cmd.length = len & 0xff;
1233 
1234 	return (scsipi_command(periph, (void *)&cmd, sizeof(cmd),
1235 	    (void *)data, len, retries, timeout, NULL, flags | XS_CTL_DATA_OUT));
1236 }
1237 
1238 int
1239 scsipi_mode_select_big(struct scsipi_periph *periph, int byte2,
1240     struct scsi_mode_parameter_header_10 *data, int len, int flags, int retries,
1241     int timeout)
1242 {
1243 	struct scsi_mode_select_10 cmd;
1244 
1245 	memset(&cmd, 0, sizeof(cmd));
1246 	cmd.opcode = SCSI_MODE_SELECT_10;
1247 	cmd.byte2 = byte2;
1248 	_lto2b(len, cmd.length);
1249 
1250 	return (scsipi_command(periph, (void *)&cmd, sizeof(cmd),
1251 	    (void *)data, len, retries, timeout, NULL, flags | XS_CTL_DATA_OUT));
1252 }
1253 
1254 /*
1255  * scsipi_done:
1256  *
1257  *	This routine is called by an adapter's interrupt handler when
1258  *	an xfer is completed.
1259  */
1260 void
1261 scsipi_done(struct scsipi_xfer *xs)
1262 {
1263 	struct scsipi_periph *periph = xs->xs_periph;
1264 	struct scsipi_channel *chan = periph->periph_channel;
1265 	int s, freezecnt;
1266 
1267 	SC_DEBUG(periph, SCSIPI_DB2, ("scsipi_done\n"));
1268 #ifdef SCSIPI_DEBUG
1269 	if (periph->periph_dbflags & SCSIPI_DB1)
1270 		show_scsipi_cmd(xs);
1271 #endif
1272 
1273 	s = splbio();
1274 	/*
1275 	 * The resource this command was using is now free.
1276 	 */
1277 	if (xs->xs_status & XS_STS_DONE) {
1278 		/* XXX in certain circumstances, such as a device
1279 		 * being detached, a xs that has already been
1280 		 * scsipi_done()'d by the main thread will be done'd
1281 		 * again by scsibusdetach(). Putting the xs on the
1282 		 * chan_complete queue causes list corruption and
1283 		 * everyone dies. This prevents that, but perhaps
1284 		 * there should be better coordination somewhere such
1285 		 * that this won't ever happen (and can be turned into
1286 		 * a KASSERT().
1287 		 */
1288 		splx(s);
1289 		goto out;
1290 	}
1291 	scsipi_put_resource(chan);
1292 	xs->xs_periph->periph_sent--;
1293 
1294 	/*
1295 	 * If the command was tagged, free the tag.
1296 	 */
1297 	if (XS_CTL_TAGTYPE(xs) != 0)
1298 		scsipi_put_tag(xs);
1299 	else
1300 		periph->periph_flags &= ~PERIPH_UNTAG;
1301 
1302 	/* Mark the command as `done'. */
1303 	xs->xs_status |= XS_STS_DONE;
1304 
1305 #ifdef DIAGNOSTIC
1306 	if ((xs->xs_control & (XS_CTL_ASYNC|XS_CTL_POLL)) ==
1307 	    (XS_CTL_ASYNC|XS_CTL_POLL))
1308 		panic("scsipi_done: ASYNC and POLL");
1309 #endif
1310 
1311 	/*
1312 	 * If the xfer had an error of any sort, freeze the
1313 	 * periph's queue.  Freeze it again if we were requested
1314 	 * to do so in the xfer.
1315 	 */
1316 	freezecnt = 0;
1317 	if (xs->error != XS_NOERROR)
1318 		freezecnt++;
1319 	if (xs->xs_control & XS_CTL_FREEZE_PERIPH)
1320 		freezecnt++;
1321 	if (freezecnt != 0)
1322 		scsipi_periph_freeze(periph, freezecnt);
1323 
1324 	/*
1325 	 * record the xfer with a pending sense, in case a SCSI reset is
1326 	 * received before the thread is waked up.
1327 	 */
1328 	if (xs->error == XS_BUSY && xs->status == SCSI_CHECK) {
1329 		periph->periph_flags |= PERIPH_SENSE;
1330 		periph->periph_xscheck = xs;
1331 	}
1332 
1333 	/*
1334 	 * If this was an xfer that was not to complete asynchronously,
1335 	 * let the requesting thread perform error checking/handling
1336 	 * in its context.
1337 	 */
1338 	if ((xs->xs_control & XS_CTL_ASYNC) == 0) {
1339 		splx(s);
1340 		/*
1341 		 * If it's a polling job, just return, to unwind the
1342 		 * call graph.  We don't need to restart the queue,
1343 		 * because pollings jobs are treated specially, and
1344 		 * are really only used during crash dumps anyway
1345 		 * (XXX or during boot-time autconfiguration of
1346 		 * ATAPI devices).
1347 		 */
1348 		if (xs->xs_control & XS_CTL_POLL)
1349 			return;
1350 		wakeup(xs);
1351 		goto out;
1352 	}
1353 
1354 	/*
1355 	 * Catch the extremely common case of I/O completing
1356 	 * without error; no use in taking a context switch
1357 	 * if we can handle it in interrupt context.
1358 	 */
1359 	if (xs->error == XS_NOERROR) {
1360 		splx(s);
1361 		(void) scsipi_complete(xs);
1362 		goto out;
1363 	}
1364 
1365 	/*
1366 	 * There is an error on this xfer.  Put it on the channel's
1367 	 * completion queue, and wake up the completion thread.
1368 	 */
1369 	TAILQ_INSERT_TAIL(&chan->chan_complete, xs, channel_q);
1370 	splx(s);
1371 	wakeup(&chan->chan_complete);
1372 
1373  out:
1374 	/*
1375 	 * If there are more xfers on the channel's queue, attempt to
1376 	 * run them.
1377 	 */
1378 	scsipi_run_queue(chan);
1379 }
1380 
1381 /*
1382  * scsipi_complete:
1383  *
1384  *	Completion of a scsipi_xfer.  This is the guts of scsipi_done().
1385  *
1386  *	NOTE: This routine MUST be called with valid thread context
1387  *	except for the case where the following two conditions are
1388  *	true:
1389  *
1390  *		xs->error == XS_NOERROR
1391  *		XS_CTL_ASYNC is set in xs->xs_control
1392  *
1393  *	The semantics of this routine can be tricky, so here is an
1394  *	explanation:
1395  *
1396  *		0		Xfer completed successfully.
1397  *
1398  *		ERESTART	Xfer had an error, but was restarted.
1399  *
1400  *		anything else	Xfer had an error, return value is Unix
1401  *				errno.
1402  *
1403  *	If the return value is anything but ERESTART:
1404  *
1405  *		- If XS_CTL_ASYNC is set, `xs' has been freed back to
1406  *		  the pool.
1407  *		- If there is a buf associated with the xfer,
1408  *		  it has been biodone()'d.
1409  */
1410 static int
1411 scsipi_complete(struct scsipi_xfer *xs)
1412 {
1413 	struct scsipi_periph *periph = xs->xs_periph;
1414 	struct scsipi_channel *chan = periph->periph_channel;
1415 	int error, s;
1416 
1417 #ifdef DIAGNOSTIC
1418 	if ((xs->xs_control & XS_CTL_ASYNC) != 0 && xs->bp == NULL)
1419 		panic("scsipi_complete: XS_CTL_ASYNC but no buf");
1420 #endif
1421 	/*
1422 	 * If command terminated with a CHECK CONDITION, we need to issue a
1423 	 * REQUEST_SENSE command. Once the REQUEST_SENSE has been processed
1424 	 * we'll have the real status.
1425 	 * Must be processed at splbio() to avoid missing a SCSI bus reset
1426 	 * for this command.
1427 	 */
1428 	s = splbio();
1429 	if (xs->error == XS_BUSY && xs->status == SCSI_CHECK) {
1430 		/* request sense for a request sense ? */
1431 		if (xs->xs_control & XS_CTL_REQSENSE) {
1432 			scsipi_printaddr(periph);
1433 			printf("request sense for a request sense ?\n");
1434 			/* XXX maybe we should reset the device ? */
1435 			/* we've been frozen because xs->error != XS_NOERROR */
1436 			scsipi_periph_thaw(periph, 1);
1437 			splx(s);
1438 			if (xs->resid < xs->datalen) {
1439 				printf("we read %d bytes of sense anyway:\n",
1440 				    xs->datalen - xs->resid);
1441 #ifdef SCSIVERBOSE
1442 				scsipi_print_sense_data((void *)xs->data, 0);
1443 #endif
1444 			}
1445 			return EINVAL;
1446 		}
1447 		scsipi_request_sense(xs);
1448 	}
1449 	splx(s);
1450 
1451 	/*
1452 	 * If it's a user level request, bypass all usual completion
1453 	 * processing, let the user work it out..
1454 	 */
1455 	if ((xs->xs_control & XS_CTL_USERCMD) != 0) {
1456 		SC_DEBUG(periph, SCSIPI_DB3, ("calling user done()\n"));
1457 		if (xs->error != XS_NOERROR)
1458 			scsipi_periph_thaw(periph, 1);
1459 		scsipi_user_done(xs);
1460 		SC_DEBUG(periph, SCSIPI_DB3, ("returned from user done()\n "));
1461 		return 0;
1462 	}
1463 
1464 	switch (xs->error) {
1465 	case XS_NOERROR:
1466 		error = 0;
1467 		break;
1468 
1469 	case XS_SENSE:
1470 	case XS_SHORTSENSE:
1471 		error = (*chan->chan_bustype->bustype_interpret_sense)(xs);
1472 		break;
1473 
1474 	case XS_RESOURCE_SHORTAGE:
1475 		/*
1476 		 * XXX Should freeze channel's queue.
1477 		 */
1478 		scsipi_printaddr(periph);
1479 		printf("adapter resource shortage\n");
1480 		/* FALLTHROUGH */
1481 
1482 	case XS_BUSY:
1483 		if (xs->error == XS_BUSY && xs->status == SCSI_QUEUE_FULL) {
1484 			struct scsipi_max_openings mo;
1485 
1486 			/*
1487 			 * We set the openings to active - 1, assuming that
1488 			 * the command that got us here is the first one that
1489 			 * can't fit into the device's queue.  If that's not
1490 			 * the case, I guess we'll find out soon enough.
1491 			 */
1492 			mo.mo_target = periph->periph_target;
1493 			mo.mo_lun = periph->periph_lun;
1494 			if (periph->periph_active < periph->periph_openings)
1495 				mo.mo_openings = periph->periph_active - 1;
1496 			else
1497 				mo.mo_openings = periph->periph_openings - 1;
1498 #ifdef DIAGNOSTIC
1499 			if (mo.mo_openings < 0) {
1500 				scsipi_printaddr(periph);
1501 				printf("QUEUE FULL resulted in < 0 openings\n");
1502 				panic("scsipi_done");
1503 			}
1504 #endif
1505 			if (mo.mo_openings == 0) {
1506 				scsipi_printaddr(periph);
1507 				printf("QUEUE FULL resulted in 0 openings\n");
1508 				mo.mo_openings = 1;
1509 			}
1510 			scsipi_async_event(chan, ASYNC_EVENT_MAX_OPENINGS, &mo);
1511 			error = ERESTART;
1512 		} else if (xs->xs_retries != 0) {
1513 			xs->xs_retries--;
1514 			/*
1515 			 * Wait one second, and try again.
1516 			 */
1517 			if ((xs->xs_control & XS_CTL_POLL) ||
1518 			    (chan->chan_flags & SCSIPI_CHAN_TACTIVE) == 0) {
1519 				delay(1000000);
1520 			} else if (!callout_pending(&periph->periph_callout)) {
1521 				scsipi_periph_freeze(periph, 1);
1522 				callout_reset(&periph->periph_callout,
1523 				    hz, scsipi_periph_timed_thaw, periph);
1524 			}
1525 			error = ERESTART;
1526 		} else
1527 			error = EBUSY;
1528 		break;
1529 
1530 	case XS_REQUEUE:
1531 		error = ERESTART;
1532 		break;
1533 
1534 	case XS_SELTIMEOUT:
1535 	case XS_TIMEOUT:
1536 		/*
1537 		 * If the device hasn't gone away, honor retry counts.
1538 		 *
1539 		 * Note that if we're in the middle of probing it,
1540 		 * it won't be found because it isn't here yet so
1541 		 * we won't honor the retry count in that case.
1542 		 */
1543 		if (scsipi_lookup_periph(chan, periph->periph_target,
1544 		    periph->periph_lun) && xs->xs_retries != 0) {
1545 			xs->xs_retries--;
1546 			error = ERESTART;
1547 		} else
1548 			error = EIO;
1549 		break;
1550 
1551 	case XS_RESET:
1552 		if (xs->xs_control & XS_CTL_REQSENSE) {
1553 			/*
1554 			 * request sense interrupted by reset: signal it
1555 			 * with EINTR return code.
1556 			 */
1557 			error = EINTR;
1558 		} else {
1559 			if (xs->xs_retries != 0) {
1560 				xs->xs_retries--;
1561 				error = ERESTART;
1562 			} else
1563 				error = EIO;
1564 		}
1565 		break;
1566 
1567 	case XS_DRIVER_STUFFUP:
1568 		scsipi_printaddr(periph);
1569 		printf("generic HBA error\n");
1570 		error = EIO;
1571 		break;
1572 	default:
1573 		scsipi_printaddr(periph);
1574 		printf("invalid return code from adapter: %d\n", xs->error);
1575 		error = EIO;
1576 		break;
1577 	}
1578 
1579 	s = splbio();
1580 	if (error == ERESTART) {
1581 		/*
1582 		 * If we get here, the periph has been thawed and frozen
1583 		 * again if we had to issue recovery commands.  Alternatively,
1584 		 * it may have been frozen again and in a timed thaw.  In
1585 		 * any case, we thaw the periph once we re-enqueue the
1586 		 * command.  Once the periph is fully thawed, it will begin
1587 		 * operation again.
1588 		 */
1589 		xs->error = XS_NOERROR;
1590 		xs->status = SCSI_OK;
1591 		xs->xs_status &= ~XS_STS_DONE;
1592 		xs->xs_requeuecnt++;
1593 		error = scsipi_enqueue(xs);
1594 		if (error == 0) {
1595 			scsipi_periph_thaw(periph, 1);
1596 			splx(s);
1597 			return (ERESTART);
1598 		}
1599 	}
1600 
1601 	/*
1602 	 * scsipi_done() freezes the queue if not XS_NOERROR.
1603 	 * Thaw it here.
1604 	 */
1605 	if (xs->error != XS_NOERROR)
1606 		scsipi_periph_thaw(periph, 1);
1607 
1608 	if (periph->periph_switch->psw_done)
1609 		periph->periph_switch->psw_done(xs, error);
1610 
1611 	if (xs->xs_control & XS_CTL_ASYNC)
1612 		scsipi_put_xs(xs);
1613 	splx(s);
1614 
1615 	return (error);
1616 }
1617 
1618 /*
1619  * Issue a request sense for the given scsipi_xfer. Called when the xfer
1620  * returns with a CHECK_CONDITION status. Must be called in valid thread
1621  * context and at splbio().
1622  */
1623 
1624 static void
1625 scsipi_request_sense(struct scsipi_xfer *xs)
1626 {
1627 	struct scsipi_periph *periph = xs->xs_periph;
1628 	int flags, error;
1629 	struct scsi_request_sense cmd;
1630 
1631 	periph->periph_flags |= PERIPH_SENSE;
1632 
1633 	/* if command was polling, request sense will too */
1634 	flags = xs->xs_control & XS_CTL_POLL;
1635 	/* Polling commands can't sleep */
1636 	if (flags)
1637 		flags |= XS_CTL_NOSLEEP;
1638 
1639 	flags |= XS_CTL_REQSENSE | XS_CTL_URGENT | XS_CTL_DATA_IN |
1640 	    XS_CTL_THAW_PERIPH | XS_CTL_FREEZE_PERIPH;
1641 
1642 	memset(&cmd, 0, sizeof(cmd));
1643 	cmd.opcode = SCSI_REQUEST_SENSE;
1644 	cmd.length = sizeof(struct scsi_sense_data);
1645 
1646 	error = scsipi_command(periph, (void *)&cmd, sizeof(cmd),
1647 	    (void *)&xs->sense.scsi_sense, sizeof(struct scsi_sense_data),
1648 	    0, 1000, NULL, flags);
1649 	periph->periph_flags &= ~PERIPH_SENSE;
1650 	periph->periph_xscheck = NULL;
1651 	switch (error) {
1652 	case 0:
1653 		/* we have a valid sense */
1654 		xs->error = XS_SENSE;
1655 		return;
1656 	case EINTR:
1657 		/* REQUEST_SENSE interrupted by bus reset. */
1658 		xs->error = XS_RESET;
1659 		return;
1660 	case EIO:
1661 		 /* request sense coudn't be performed */
1662 		/*
1663 		 * XXX this isn't quite right but we don't have anything
1664 		 * better for now
1665 		 */
1666 		xs->error = XS_DRIVER_STUFFUP;
1667 		return;
1668 	default:
1669 		 /* Notify that request sense failed. */
1670 		xs->error = XS_DRIVER_STUFFUP;
1671 		scsipi_printaddr(periph);
1672 		printf("request sense failed with error %d\n", error);
1673 		return;
1674 	}
1675 }
1676 
1677 /*
1678  * scsipi_enqueue:
1679  *
1680  *	Enqueue an xfer on a channel.
1681  */
1682 static int
1683 scsipi_enqueue(struct scsipi_xfer *xs)
1684 {
1685 	struct scsipi_channel *chan = xs->xs_periph->periph_channel;
1686 	struct scsipi_xfer *qxs;
1687 	int s;
1688 
1689 	s = splbio();
1690 
1691 	/*
1692 	 * If the xfer is to be polled, and there are already jobs on
1693 	 * the queue, we can't proceed.
1694 	 */
1695 	if ((xs->xs_control & XS_CTL_POLL) != 0 &&
1696 	    TAILQ_FIRST(&chan->chan_queue) != NULL) {
1697 		splx(s);
1698 		xs->error = XS_DRIVER_STUFFUP;
1699 		return (EAGAIN);
1700 	}
1701 
1702 	/*
1703 	 * If we have an URGENT xfer, it's an error recovery command
1704 	 * and it should just go on the head of the channel's queue.
1705 	 */
1706 	if (xs->xs_control & XS_CTL_URGENT) {
1707 		TAILQ_INSERT_HEAD(&chan->chan_queue, xs, channel_q);
1708 		goto out;
1709 	}
1710 
1711 	/*
1712 	 * If this xfer has already been on the queue before, we
1713 	 * need to reinsert it in the correct order.  That order is:
1714 	 *
1715 	 *	Immediately before the first xfer for this periph
1716 	 *	with a requeuecnt less than xs->xs_requeuecnt.
1717 	 *
1718 	 * Failing that, at the end of the queue.  (We'll end up
1719 	 * there naturally.)
1720 	 */
1721 	if (xs->xs_requeuecnt != 0) {
1722 		for (qxs = TAILQ_FIRST(&chan->chan_queue); qxs != NULL;
1723 		     qxs = TAILQ_NEXT(qxs, channel_q)) {
1724 			if (qxs->xs_periph == xs->xs_periph &&
1725 			    qxs->xs_requeuecnt < xs->xs_requeuecnt)
1726 				break;
1727 		}
1728 		if (qxs != NULL) {
1729 			TAILQ_INSERT_AFTER(&chan->chan_queue, qxs, xs,
1730 			    channel_q);
1731 			goto out;
1732 		}
1733 	}
1734 	TAILQ_INSERT_TAIL(&chan->chan_queue, xs, channel_q);
1735  out:
1736 	if (xs->xs_control & XS_CTL_THAW_PERIPH)
1737 		scsipi_periph_thaw(xs->xs_periph, 1);
1738 	splx(s);
1739 	return (0);
1740 }
1741 
1742 /*
1743  * scsipi_run_queue:
1744  *
1745  *	Start as many xfers as possible running on the channel.
1746  */
1747 static void
1748 scsipi_run_queue(struct scsipi_channel *chan)
1749 {
1750 	struct scsipi_xfer *xs;
1751 	struct scsipi_periph *periph;
1752 	int s;
1753 
1754 	for (;;) {
1755 		s = splbio();
1756 
1757 		/*
1758 		 * If the channel is frozen, we can't do any work right
1759 		 * now.
1760 		 */
1761 		if (chan->chan_qfreeze != 0) {
1762 			splx(s);
1763 			return;
1764 		}
1765 
1766 		/*
1767 		 * Look for work to do, and make sure we can do it.
1768 		 */
1769 		for (xs = TAILQ_FIRST(&chan->chan_queue); xs != NULL;
1770 		     xs = TAILQ_NEXT(xs, channel_q)) {
1771 			periph = xs->xs_periph;
1772 
1773 			if ((periph->periph_sent >= periph->periph_openings) ||
1774 			    periph->periph_qfreeze != 0 ||
1775 			    (periph->periph_flags & PERIPH_UNTAG) != 0)
1776 				continue;
1777 
1778 			if ((periph->periph_flags &
1779 			    (PERIPH_RECOVERING | PERIPH_SENSE)) != 0 &&
1780 			    (xs->xs_control & XS_CTL_URGENT) == 0)
1781 				continue;
1782 
1783 			/*
1784 			 * We can issue this xfer!
1785 			 */
1786 			goto got_one;
1787 		}
1788 
1789 		/*
1790 		 * Can't find any work to do right now.
1791 		 */
1792 		splx(s);
1793 		return;
1794 
1795  got_one:
1796 		/*
1797 		 * Have an xfer to run.  Allocate a resource from
1798 		 * the adapter to run it.  If we can't allocate that
1799 		 * resource, we don't dequeue the xfer.
1800 		 */
1801 		if (scsipi_get_resource(chan) == 0) {
1802 			/*
1803 			 * Adapter is out of resources.  If the adapter
1804 			 * supports it, attempt to grow them.
1805 			 */
1806 			if (scsipi_grow_resources(chan) == 0) {
1807 				/*
1808 				 * Wasn't able to grow resources,
1809 				 * nothing more we can do.
1810 				 */
1811 				if (xs->xs_control & XS_CTL_POLL) {
1812 					scsipi_printaddr(xs->xs_periph);
1813 					printf("polling command but no "
1814 					    "adapter resources");
1815 					/* We'll panic shortly... */
1816 				}
1817 				splx(s);
1818 
1819 				/*
1820 				 * XXX: We should be able to note that
1821 				 * XXX: that resources are needed here!
1822 				 */
1823 				return;
1824 			}
1825 			/*
1826 			 * scsipi_grow_resources() allocated the resource
1827 			 * for us.
1828 			 */
1829 		}
1830 
1831 		/*
1832 		 * We have a resource to run this xfer, do it!
1833 		 */
1834 		TAILQ_REMOVE(&chan->chan_queue, xs, channel_q);
1835 
1836 		/*
1837 		 * If the command is to be tagged, allocate a tag ID
1838 		 * for it.
1839 		 */
1840 		if (XS_CTL_TAGTYPE(xs) != 0)
1841 			scsipi_get_tag(xs);
1842 		else
1843 			periph->periph_flags |= PERIPH_UNTAG;
1844 		periph->periph_sent++;
1845 		splx(s);
1846 
1847 		scsipi_adapter_request(chan, ADAPTER_REQ_RUN_XFER, xs);
1848 	}
1849 #ifdef DIAGNOSTIC
1850 	panic("scsipi_run_queue: impossible");
1851 #endif
1852 }
1853 
1854 /*
1855  * scsipi_execute_xs:
1856  *
1857  *	Begin execution of an xfer, waiting for it to complete, if necessary.
1858  */
1859 int
1860 scsipi_execute_xs(struct scsipi_xfer *xs)
1861 {
1862 	struct scsipi_periph *periph = xs->xs_periph;
1863 	struct scsipi_channel *chan = periph->periph_channel;
1864 	int oasync, async, poll, error, s;
1865 
1866 	KASSERT(!cold);
1867 
1868 	(chan->chan_bustype->bustype_cmd)(xs);
1869 
1870 	if (xs->xs_control & XS_CTL_DATA_ONSTACK) {
1871 #if 1
1872 		if (xs->xs_control & XS_CTL_ASYNC)
1873 			panic("scsipi_execute_xs: on stack and async");
1874 #endif
1875 		/*
1876 		 * If the I/O buffer is allocated on stack, the
1877 		 * process must NOT be swapped out, as the device will
1878 		 * be accessing the stack.
1879 		 */
1880 		uvm_lwp_hold(curlwp);
1881 	}
1882 
1883 	xs->xs_status &= ~XS_STS_DONE;
1884 	xs->error = XS_NOERROR;
1885 	xs->resid = xs->datalen;
1886 	xs->status = SCSI_OK;
1887 
1888 #ifdef SCSIPI_DEBUG
1889 	if (xs->xs_periph->periph_dbflags & SCSIPI_DB3) {
1890 		printf("scsipi_execute_xs: ");
1891 		show_scsipi_xs(xs);
1892 		printf("\n");
1893 	}
1894 #endif
1895 
1896 	/*
1897 	 * Deal with command tagging:
1898 	 *
1899 	 *	- If the device's current operating mode doesn't
1900 	 *	  include tagged queueing, clear the tag mask.
1901 	 *
1902 	 *	- If the device's current operating mode *does*
1903 	 *	  include tagged queueing, set the tag_type in
1904 	 *	  the xfer to the appropriate byte for the tag
1905 	 *	  message.
1906 	 */
1907 	if ((PERIPH_XFER_MODE(periph) & PERIPH_CAP_TQING) == 0 ||
1908 		(xs->xs_control & XS_CTL_REQSENSE)) {
1909 		xs->xs_control &= ~XS_CTL_TAGMASK;
1910 		xs->xs_tag_type = 0;
1911 	} else {
1912 		/*
1913 		 * If the request doesn't specify a tag, give Head
1914 		 * tags to URGENT operations and Ordered tags to
1915 		 * everything else.
1916 		 */
1917 		if (XS_CTL_TAGTYPE(xs) == 0) {
1918 			if (xs->xs_control & XS_CTL_URGENT)
1919 				xs->xs_control |= XS_CTL_HEAD_TAG;
1920 			else
1921 				xs->xs_control |= XS_CTL_ORDERED_TAG;
1922 		}
1923 
1924 		switch (XS_CTL_TAGTYPE(xs)) {
1925 		case XS_CTL_ORDERED_TAG:
1926 			xs->xs_tag_type = MSG_ORDERED_Q_TAG;
1927 			break;
1928 
1929 		case XS_CTL_SIMPLE_TAG:
1930 			xs->xs_tag_type = MSG_SIMPLE_Q_TAG;
1931 			break;
1932 
1933 		case XS_CTL_HEAD_TAG:
1934 			xs->xs_tag_type = MSG_HEAD_OF_Q_TAG;
1935 			break;
1936 
1937 		default:
1938 			scsipi_printaddr(periph);
1939 			printf("invalid tag mask 0x%08x\n",
1940 			    XS_CTL_TAGTYPE(xs));
1941 			panic("scsipi_execute_xs");
1942 		}
1943 	}
1944 
1945 	/* If the adaptor wants us to poll, poll. */
1946 	if (chan->chan_adapter->adapt_flags & SCSIPI_ADAPT_POLL_ONLY)
1947 		xs->xs_control |= XS_CTL_POLL;
1948 
1949 	/*
1950 	 * If we don't yet have a completion thread, or we are to poll for
1951 	 * completion, clear the ASYNC flag.
1952 	 */
1953 	oasync =  (xs->xs_control & XS_CTL_ASYNC);
1954 	if (chan->chan_thread == NULL || (xs->xs_control & XS_CTL_POLL) != 0)
1955 		xs->xs_control &= ~XS_CTL_ASYNC;
1956 
1957 	async = (xs->xs_control & XS_CTL_ASYNC);
1958 	poll = (xs->xs_control & XS_CTL_POLL);
1959 
1960 #ifdef DIAGNOSTIC
1961 	if (oasync != 0 && xs->bp == NULL)
1962 		panic("scsipi_execute_xs: XS_CTL_ASYNC but no buf");
1963 #endif
1964 
1965 	/*
1966 	 * Enqueue the transfer.  If we're not polling for completion, this
1967 	 * should ALWAYS return `no error'.
1968 	 */
1969 	error = scsipi_enqueue(xs);
1970 	if (error) {
1971 		if (poll == 0) {
1972 			scsipi_printaddr(periph);
1973 			printf("not polling, but enqueue failed with %d\n",
1974 			    error);
1975 			panic("scsipi_execute_xs");
1976 		}
1977 
1978 		scsipi_printaddr(periph);
1979 		printf("should have flushed queue?\n");
1980 		goto free_xs;
1981 	}
1982 
1983  restarted:
1984 	scsipi_run_queue(chan);
1985 
1986 	/*
1987 	 * The xfer is enqueued, and possibly running.  If it's to be
1988 	 * completed asynchronously, just return now.
1989 	 */
1990 	if (async)
1991 		return (0);
1992 
1993 	/*
1994 	 * Not an asynchronous command; wait for it to complete.
1995 	 */
1996 	s = splbio();
1997 	while ((xs->xs_status & XS_STS_DONE) == 0) {
1998 		if (poll) {
1999 			scsipi_printaddr(periph);
2000 			printf("polling command not done\n");
2001 			panic("scsipi_execute_xs");
2002 		}
2003 		(void) tsleep(xs, PRIBIO, "xscmd", 0);
2004 	}
2005 	splx(s);
2006 
2007 	/*
2008 	 * Command is complete.  scsipi_done() has awakened us to perform
2009 	 * the error handling.
2010 	 */
2011 	error = scsipi_complete(xs);
2012 	if (error == ERESTART)
2013 		goto restarted;
2014 
2015 	/*
2016 	 * If it was meant to run async and we cleared aync ourselve,
2017 	 * don't return an error here. It has already been handled
2018 	 */
2019 	if (oasync)
2020 		error = 0;
2021 	/*
2022 	 * Command completed successfully or fatal error occurred.  Fall
2023 	 * into....
2024 	 */
2025  free_xs:
2026 	if (xs->xs_control & XS_CTL_DATA_ONSTACK)
2027 		uvm_lwp_rele(curlwp);
2028 
2029 	s = splbio();
2030 	scsipi_put_xs(xs);
2031 	splx(s);
2032 
2033 	/*
2034 	 * Kick the queue, keep it running in case it stopped for some
2035 	 * reason.
2036 	 */
2037 	scsipi_run_queue(chan);
2038 
2039 	return (error);
2040 }
2041 
2042 /*
2043  * scsipi_completion_thread:
2044  *
2045  *	This is the completion thread.  We wait for errors on
2046  *	asynchronous xfers, and perform the error handling
2047  *	function, restarting the command, if necessary.
2048  */
2049 static void
2050 scsipi_completion_thread(void *arg)
2051 {
2052 	struct scsipi_channel *chan = arg;
2053 	struct scsipi_xfer *xs;
2054 	int s;
2055 
2056 	if (chan->chan_init_cb)
2057 		(*chan->chan_init_cb)(chan, chan->chan_init_cb_arg);
2058 
2059 	s = splbio();
2060 	chan->chan_flags |= SCSIPI_CHAN_TACTIVE;
2061 	splx(s);
2062 	for (;;) {
2063 		s = splbio();
2064 		xs = TAILQ_FIRST(&chan->chan_complete);
2065 		if (xs == NULL && chan->chan_tflags  == 0) {
2066 			/* nothing to do; wait */
2067 			(void) tsleep(&chan->chan_complete, PRIBIO,
2068 			    "sccomp", 0);
2069 			splx(s);
2070 			continue;
2071 		}
2072 		if (chan->chan_tflags & SCSIPI_CHANT_CALLBACK) {
2073 			/* call chan_callback from thread context */
2074 			chan->chan_tflags &= ~SCSIPI_CHANT_CALLBACK;
2075 			chan->chan_callback(chan, chan->chan_callback_arg);
2076 			splx(s);
2077 			continue;
2078 		}
2079 		if (chan->chan_tflags & SCSIPI_CHANT_GROWRES) {
2080 			/* attempt to get more openings for this channel */
2081 			chan->chan_tflags &= ~SCSIPI_CHANT_GROWRES;
2082 			scsipi_adapter_request(chan,
2083 			    ADAPTER_REQ_GROW_RESOURCES, NULL);
2084 			scsipi_channel_thaw(chan, 1);
2085 			splx(s);
2086 			if (chan->chan_tflags & SCSIPI_CHANT_GROWRES)
2087 				kpause("scsizzz", FALSE, hz/10, NULL);
2088 			continue;
2089 		}
2090 		if (chan->chan_tflags & SCSIPI_CHANT_KICK) {
2091 			/* explicitly run the queues for this channel */
2092 			chan->chan_tflags &= ~SCSIPI_CHANT_KICK;
2093 			scsipi_run_queue(chan);
2094 			splx(s);
2095 			continue;
2096 		}
2097 		if (chan->chan_tflags & SCSIPI_CHANT_SHUTDOWN) {
2098 			splx(s);
2099 			break;
2100 		}
2101 		if (xs) {
2102 			TAILQ_REMOVE(&chan->chan_complete, xs, channel_q);
2103 			splx(s);
2104 
2105 			/*
2106 			 * Have an xfer with an error; process it.
2107 			 */
2108 			(void) scsipi_complete(xs);
2109 
2110 			/*
2111 			 * Kick the queue; keep it running if it was stopped
2112 			 * for some reason.
2113 			 */
2114 			scsipi_run_queue(chan);
2115 		} else {
2116 			splx(s);
2117 		}
2118 	}
2119 
2120 	chan->chan_thread = NULL;
2121 
2122 	/* In case parent is waiting for us to exit. */
2123 	wakeup(&chan->chan_thread);
2124 
2125 	kthread_exit(0);
2126 }
2127 /*
2128  * scsipi_thread_call_callback:
2129  *
2130  * 	request to call a callback from the completion thread
2131  */
2132 int
2133 scsipi_thread_call_callback(struct scsipi_channel *chan,
2134     void (*callback)(struct scsipi_channel *, void *), void *arg)
2135 {
2136 	int s;
2137 
2138 	s = splbio();
2139 	if ((chan->chan_flags & SCSIPI_CHAN_TACTIVE) == 0) {
2140 		/* kernel thread doesn't exist yet */
2141 		splx(s);
2142 		return ESRCH;
2143 	}
2144 	if (chan->chan_tflags & SCSIPI_CHANT_CALLBACK) {
2145 		splx(s);
2146 		return EBUSY;
2147 	}
2148 	scsipi_channel_freeze(chan, 1);
2149 	chan->chan_callback = callback;
2150 	chan->chan_callback_arg = arg;
2151 	chan->chan_tflags |= SCSIPI_CHANT_CALLBACK;
2152 	wakeup(&chan->chan_complete);
2153 	splx(s);
2154 	return(0);
2155 }
2156 
2157 /*
2158  * scsipi_async_event:
2159  *
2160  *	Handle an asynchronous event from an adapter.
2161  */
2162 void
2163 scsipi_async_event(struct scsipi_channel *chan, scsipi_async_event_t event,
2164     void *arg)
2165 {
2166 	int s;
2167 
2168 	s = splbio();
2169 	switch (event) {
2170 	case ASYNC_EVENT_MAX_OPENINGS:
2171 		scsipi_async_event_max_openings(chan,
2172 		    (struct scsipi_max_openings *)arg);
2173 		break;
2174 
2175 	case ASYNC_EVENT_XFER_MODE:
2176 		scsipi_async_event_xfer_mode(chan,
2177 		    (struct scsipi_xfer_mode *)arg);
2178 		break;
2179 	case ASYNC_EVENT_RESET:
2180 		scsipi_async_event_channel_reset(chan);
2181 		break;
2182 	}
2183 	splx(s);
2184 }
2185 
2186 /*
2187  * scsipi_print_xfer_mode:
2188  *
2189  *	Print a periph's capabilities.
2190  */
2191 void
2192 scsipi_print_xfer_mode(struct scsipi_periph *periph)
2193 {
2194 	int period, freq, speed, mbs;
2195 
2196 	if ((periph->periph_flags & PERIPH_MODE_VALID) == 0)
2197 		return;
2198 
2199 	aprint_normal_dev(periph->periph_dev, "");
2200 	if (periph->periph_mode & (PERIPH_CAP_SYNC | PERIPH_CAP_DT)) {
2201 		period = scsipi_sync_factor_to_period(periph->periph_period);
2202 		aprint_normal("sync (%d.%02dns offset %d)",
2203 		    period / 100, period % 100, periph->periph_offset);
2204 	} else
2205 		aprint_normal("async");
2206 
2207 	if (periph->periph_mode & PERIPH_CAP_WIDE32)
2208 		aprint_normal(", 32-bit");
2209 	else if (periph->periph_mode & (PERIPH_CAP_WIDE16 | PERIPH_CAP_DT))
2210 		aprint_normal(", 16-bit");
2211 	else
2212 		aprint_normal(", 8-bit");
2213 
2214 	if (periph->periph_mode & (PERIPH_CAP_SYNC | PERIPH_CAP_DT)) {
2215 		freq = scsipi_sync_factor_to_freq(periph->periph_period);
2216 		speed = freq;
2217 		if (periph->periph_mode & PERIPH_CAP_WIDE32)
2218 			speed *= 4;
2219 		else if (periph->periph_mode &
2220 		    (PERIPH_CAP_WIDE16 | PERIPH_CAP_DT))
2221 			speed *= 2;
2222 		mbs = speed / 1000;
2223 		if (mbs > 0)
2224 			aprint_normal(" (%d.%03dMB/s)", mbs, speed % 1000);
2225 		else
2226 			aprint_normal(" (%dKB/s)", speed % 1000);
2227 	}
2228 
2229 	aprint_normal(" transfers");
2230 
2231 	if (periph->periph_mode & PERIPH_CAP_TQING)
2232 		aprint_normal(", tagged queueing");
2233 
2234 	aprint_normal("\n");
2235 }
2236 
2237 /*
2238  * scsipi_async_event_max_openings:
2239  *
2240  *	Update the maximum number of outstanding commands a
2241  *	device may have.
2242  */
2243 static void
2244 scsipi_async_event_max_openings(struct scsipi_channel *chan,
2245     struct scsipi_max_openings *mo)
2246 {
2247 	struct scsipi_periph *periph;
2248 	int minlun, maxlun;
2249 
2250 	if (mo->mo_lun == -1) {
2251 		/*
2252 		 * Wildcarded; apply it to all LUNs.
2253 		 */
2254 		minlun = 0;
2255 		maxlun = chan->chan_nluns - 1;
2256 	} else
2257 		minlun = maxlun = mo->mo_lun;
2258 
2259 	/* XXX This could really suck with a large LUN space. */
2260 	for (; minlun <= maxlun; minlun++) {
2261 		periph = scsipi_lookup_periph(chan, mo->mo_target, minlun);
2262 		if (periph == NULL)
2263 			continue;
2264 
2265 		if (mo->mo_openings < periph->periph_openings)
2266 			periph->periph_openings = mo->mo_openings;
2267 		else if (mo->mo_openings > periph->periph_openings &&
2268 		    (periph->periph_flags & PERIPH_GROW_OPENINGS) != 0)
2269 			periph->periph_openings = mo->mo_openings;
2270 	}
2271 }
2272 
2273 /*
2274  * scsipi_async_event_xfer_mode:
2275  *
2276  *	Update the xfer mode for all periphs sharing the
2277  *	specified I_T Nexus.
2278  */
2279 static void
2280 scsipi_async_event_xfer_mode(struct scsipi_channel *chan,
2281     struct scsipi_xfer_mode *xm)
2282 {
2283 	struct scsipi_periph *periph;
2284 	int lun, announce, mode, period, offset;
2285 
2286 	for (lun = 0; lun < chan->chan_nluns; lun++) {
2287 		periph = scsipi_lookup_periph(chan, xm->xm_target, lun);
2288 		if (periph == NULL)
2289 			continue;
2290 		announce = 0;
2291 
2292 		/*
2293 		 * Clamp the xfer mode down to this periph's capabilities.
2294 		 */
2295 		mode = xm->xm_mode & periph->periph_cap;
2296 		if (mode & PERIPH_CAP_SYNC) {
2297 			period = xm->xm_period;
2298 			offset = xm->xm_offset;
2299 		} else {
2300 			period = 0;
2301 			offset = 0;
2302 		}
2303 
2304 		/*
2305 		 * If we do not have a valid xfer mode yet, or the parameters
2306 		 * are different, announce them.
2307 		 */
2308 		if ((periph->periph_flags & PERIPH_MODE_VALID) == 0 ||
2309 		    periph->periph_mode != mode ||
2310 		    periph->periph_period != period ||
2311 		    periph->periph_offset != offset)
2312 			announce = 1;
2313 
2314 		periph->periph_mode = mode;
2315 		periph->periph_period = period;
2316 		periph->periph_offset = offset;
2317 		periph->periph_flags |= PERIPH_MODE_VALID;
2318 
2319 		if (announce)
2320 			scsipi_print_xfer_mode(periph);
2321 	}
2322 }
2323 
2324 /*
2325  * scsipi_set_xfer_mode:
2326  *
2327  *	Set the xfer mode for the specified I_T Nexus.
2328  */
2329 void
2330 scsipi_set_xfer_mode(struct scsipi_channel *chan, int target, int immed)
2331 {
2332 	struct scsipi_xfer_mode xm;
2333 	struct scsipi_periph *itperiph;
2334 	int lun, s;
2335 
2336 	/*
2337 	 * Go to the minimal xfer mode.
2338 	 */
2339 	xm.xm_target = target;
2340 	xm.xm_mode = 0;
2341 	xm.xm_period = 0;			/* ignored */
2342 	xm.xm_offset = 0;			/* ignored */
2343 
2344 	/*
2345 	 * Find the first LUN we know about on this I_T Nexus.
2346 	 */
2347 	for (itperiph = NULL, lun = 0; lun < chan->chan_nluns; lun++) {
2348 		itperiph = scsipi_lookup_periph(chan, target, lun);
2349 		if (itperiph != NULL)
2350 			break;
2351 	}
2352 	if (itperiph != NULL) {
2353 		xm.xm_mode = itperiph->periph_cap;
2354 		/*
2355 		 * Now issue the request to the adapter.
2356 		 */
2357 		s = splbio();
2358 		scsipi_adapter_request(chan, ADAPTER_REQ_SET_XFER_MODE, &xm);
2359 		splx(s);
2360 		/*
2361 		 * If we want this to happen immediately, issue a dummy
2362 		 * command, since most adapters can't really negotiate unless
2363 		 * they're executing a job.
2364 		 */
2365 		if (immed != 0) {
2366 			(void) scsipi_test_unit_ready(itperiph,
2367 			    XS_CTL_DISCOVERY | XS_CTL_IGNORE_ILLEGAL_REQUEST |
2368 			    XS_CTL_IGNORE_NOT_READY |
2369 			    XS_CTL_IGNORE_MEDIA_CHANGE);
2370 		}
2371 	}
2372 }
2373 
2374 /*
2375  * scsipi_channel_reset:
2376  *
2377  *	handle scsi bus reset
2378  * called at splbio
2379  */
2380 static void
2381 scsipi_async_event_channel_reset(struct scsipi_channel *chan)
2382 {
2383 	struct scsipi_xfer *xs, *xs_next;
2384 	struct scsipi_periph *periph;
2385 	int target, lun;
2386 
2387 	/*
2388 	 * Channel has been reset. Also mark as reset pending REQUEST_SENSE
2389 	 * commands; as the sense is not available any more.
2390 	 * can't call scsipi_done() from here, as the command has not been
2391 	 * sent to the adapter yet (this would corrupt accounting).
2392 	 */
2393 
2394 	for (xs = TAILQ_FIRST(&chan->chan_queue); xs != NULL; xs = xs_next) {
2395 		xs_next = TAILQ_NEXT(xs, channel_q);
2396 		if (xs->xs_control & XS_CTL_REQSENSE) {
2397 			TAILQ_REMOVE(&chan->chan_queue, xs, channel_q);
2398 			xs->error = XS_RESET;
2399 			if ((xs->xs_control & XS_CTL_ASYNC) != 0)
2400 				TAILQ_INSERT_TAIL(&chan->chan_complete, xs,
2401 				    channel_q);
2402 		}
2403 	}
2404 	wakeup(&chan->chan_complete);
2405 	/* Catch xs with pending sense which may not have a REQSENSE xs yet */
2406 	for (target = 0; target < chan->chan_ntargets; target++) {
2407 		if (target == chan->chan_id)
2408 			continue;
2409 		for (lun = 0; lun <  chan->chan_nluns; lun++) {
2410 			periph = scsipi_lookup_periph(chan, target, lun);
2411 			if (periph) {
2412 				xs = periph->periph_xscheck;
2413 				if (xs)
2414 					xs->error = XS_RESET;
2415 			}
2416 		}
2417 	}
2418 }
2419 
2420 /*
2421  * scsipi_target_detach:
2422  *
2423  *	detach all periph associated with a I_T
2424  * 	must be called from valid thread context
2425  */
2426 int
2427 scsipi_target_detach(struct scsipi_channel *chan, int target, int lun,
2428     int flags)
2429 {
2430 	struct scsipi_periph *periph;
2431 	int ctarget, mintarget, maxtarget;
2432 	int clun, minlun, maxlun;
2433 	int error;
2434 
2435 	if (target == -1) {
2436 		mintarget = 0;
2437 		maxtarget = chan->chan_ntargets;
2438 	} else {
2439 		if (target == chan->chan_id)
2440 			return EINVAL;
2441 		if (target < 0 || target >= chan->chan_ntargets)
2442 			return EINVAL;
2443 		mintarget = target;
2444 		maxtarget = target + 1;
2445 	}
2446 
2447 	if (lun == -1) {
2448 		minlun = 0;
2449 		maxlun = chan->chan_nluns;
2450 	} else {
2451 		if (lun < 0 || lun >= chan->chan_nluns)
2452 			return EINVAL;
2453 		minlun = lun;
2454 		maxlun = lun + 1;
2455 	}
2456 
2457 	for (ctarget = mintarget; ctarget < maxtarget; ctarget++) {
2458 		if (ctarget == chan->chan_id)
2459 			continue;
2460 
2461 		for (clun = minlun; clun < maxlun; clun++) {
2462 			periph = scsipi_lookup_periph(chan, ctarget, clun);
2463 			if (periph == NULL)
2464 				continue;
2465 			error = config_detach(periph->periph_dev, flags);
2466 			if (error)
2467 				return (error);
2468 		}
2469 	}
2470 	return(0);
2471 }
2472 
2473 /*
2474  * scsipi_adapter_addref:
2475  *
2476  *	Add a reference to the adapter pointed to by the provided
2477  *	link, enabling the adapter if necessary.
2478  */
2479 int
2480 scsipi_adapter_addref(struct scsipi_adapter *adapt)
2481 {
2482 	int s, error = 0;
2483 
2484 	s = splbio();
2485 	if (adapt->adapt_refcnt++ == 0 && adapt->adapt_enable != NULL) {
2486 		error = (*adapt->adapt_enable)(adapt->adapt_dev, 1);
2487 		if (error)
2488 			adapt->adapt_refcnt--;
2489 	}
2490 	splx(s);
2491 	return (error);
2492 }
2493 
2494 /*
2495  * scsipi_adapter_delref:
2496  *
2497  *	Delete a reference to the adapter pointed to by the provided
2498  *	link, disabling the adapter if possible.
2499  */
2500 void
2501 scsipi_adapter_delref(struct scsipi_adapter *adapt)
2502 {
2503 	int s;
2504 
2505 	s = splbio();
2506 	if (adapt->adapt_refcnt-- == 1 && adapt->adapt_enable != NULL)
2507 		(void) (*adapt->adapt_enable)(adapt->adapt_dev, 0);
2508 	splx(s);
2509 }
2510 
2511 static struct scsipi_syncparam {
2512 	int	ss_factor;
2513 	int	ss_period;	/* ns * 100 */
2514 } scsipi_syncparams[] = {
2515 	{ 0x08,		 625 },	/* FAST-160 (Ultra320) */
2516 	{ 0x09,		1250 },	/* FAST-80 (Ultra160) */
2517 	{ 0x0a,		2500 },	/* FAST-40 40MHz (Ultra2) */
2518 	{ 0x0b,		3030 },	/* FAST-40 33MHz (Ultra2) */
2519 	{ 0x0c,		5000 },	/* FAST-20 (Ultra) */
2520 };
2521 static const int scsipi_nsyncparams =
2522     sizeof(scsipi_syncparams) / sizeof(scsipi_syncparams[0]);
2523 
2524 int
2525 scsipi_sync_period_to_factor(int period /* ns * 100 */)
2526 {
2527 	int i;
2528 
2529 	for (i = 0; i < scsipi_nsyncparams; i++) {
2530 		if (period <= scsipi_syncparams[i].ss_period)
2531 			return (scsipi_syncparams[i].ss_factor);
2532 	}
2533 
2534 	return ((period / 100) / 4);
2535 }
2536 
2537 int
2538 scsipi_sync_factor_to_period(int factor)
2539 {
2540 	int i;
2541 
2542 	for (i = 0; i < scsipi_nsyncparams; i++) {
2543 		if (factor == scsipi_syncparams[i].ss_factor)
2544 			return (scsipi_syncparams[i].ss_period);
2545 	}
2546 
2547 	return ((factor * 4) * 100);
2548 }
2549 
2550 int
2551 scsipi_sync_factor_to_freq(int factor)
2552 {
2553 	int i;
2554 
2555 	for (i = 0; i < scsipi_nsyncparams; i++) {
2556 		if (factor == scsipi_syncparams[i].ss_factor)
2557 			return (100000000 / scsipi_syncparams[i].ss_period);
2558 	}
2559 
2560 	return (10000000 / ((factor * 4) * 10));
2561 }
2562 
2563 #ifdef SCSIPI_DEBUG
2564 /*
2565  * Given a scsipi_xfer, dump the request, in all it's glory
2566  */
2567 void
2568 show_scsipi_xs(struct scsipi_xfer *xs)
2569 {
2570 
2571 	printf("xs(%p): ", xs);
2572 	printf("xs_control(0x%08x)", xs->xs_control);
2573 	printf("xs_status(0x%08x)", xs->xs_status);
2574 	printf("periph(%p)", xs->xs_periph);
2575 	printf("retr(0x%x)", xs->xs_retries);
2576 	printf("timo(0x%x)", xs->timeout);
2577 	printf("cmd(%p)", xs->cmd);
2578 	printf("len(0x%x)", xs->cmdlen);
2579 	printf("data(%p)", xs->data);
2580 	printf("len(0x%x)", xs->datalen);
2581 	printf("res(0x%x)", xs->resid);
2582 	printf("err(0x%x)", xs->error);
2583 	printf("bp(%p)", xs->bp);
2584 	show_scsipi_cmd(xs);
2585 }
2586 
2587 void
2588 show_scsipi_cmd(struct scsipi_xfer *xs)
2589 {
2590 	u_char *b = (u_char *) xs->cmd;
2591 	int i = 0;
2592 
2593 	scsipi_printaddr(xs->xs_periph);
2594 	printf(" command: ");
2595 
2596 	if ((xs->xs_control & XS_CTL_RESET) == 0) {
2597 		while (i < xs->cmdlen) {
2598 			if (i)
2599 				printf(",");
2600 			printf("0x%x", b[i++]);
2601 		}
2602 		printf("-[%d bytes]\n", xs->datalen);
2603 		if (xs->datalen)
2604 			show_mem(xs->data, min(64, xs->datalen));
2605 	} else
2606 		printf("-RESET-\n");
2607 }
2608 
2609 void
2610 show_mem(u_char *address, int num)
2611 {
2612 	int x;
2613 
2614 	printf("------------------------------");
2615 	for (x = 0; x < num; x++) {
2616 		if ((x % 16) == 0)
2617 			printf("\n%03d: ", x);
2618 		printf("%02x ", *address++);
2619 	}
2620 	printf("\n------------------------------\n");
2621 }
2622 #endif /* SCSIPI_DEBUG */
2623