xref: /freebsd/sys/cam/cam_periph.c (revision 0640d357f29fb1c0daaaffadd0416c5981413afd)
1 /*
2  * Common functions for CAM "type" (peripheral) drivers.
3  *
4  * Copyright (c) 1997, 1998 Justin T. Gibbs.
5  * Copyright (c) 1997, 1998 Kenneth D. Merry.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions, and the following disclaimer,
13  *    without modification, immediately at the beginning of the file.
14  * 2. The name of the author may not be used to endorse or promote products
15  *    derived from this software without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
21  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  *      $Id: cam_periph.c,v 1.5 1998/10/15 17:46:18 ken Exp $
30  */
31 
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/types.h>
35 #include <sys/malloc.h>
36 #include <sys/kernel.h>
37 #include <sys/buf.h>
38 #include <sys/proc.h>
39 #include <sys/devicestat.h>
40 #include <vm/vm.h>
41 #include <vm/vm_extern.h>
42 
43 #include <cam/cam.h>
44 #include <cam/cam_conf.h>
45 #include <cam/cam_ccb.h>
46 #include <cam/cam_xpt_periph.h>
47 #include <cam/cam_periph.h>
48 #include <cam/cam_debug.h>
49 
50 #include <cam/scsi/scsi_all.h>
51 #include <cam/scsi/scsi_message.h>
52 #include <cam/scsi/scsi_da.h>
53 #include <cam/scsi/scsi_pass.h>
54 
55 static	u_int		camperiphnextunit(struct periph_driver *p_drv,
56 					  u_int newunit, int wired);
57 static	u_int		camperiphunit(struct periph_driver *p_drv,
58 				      path_id_t path_id_t,
59 				      target_id_t target, lun_id_t lun);
60 static	void		camperiphdone(struct cam_periph *periph,
61 					union ccb *done_ccb);
62 static  void		camperiphfree(struct cam_periph *periph);
63 
64 cam_status
65 cam_periph_alloc(periph_ctor_t *periph_ctor,
66 		 periph_oninv_t *periph_oninvalidate,
67 		 periph_dtor_t *periph_dtor, periph_start_t *periph_start,
68 		 char *name, cam_periph_type type, struct cam_path *path,
69 		 ac_callback_t *ac_callback, ac_code code, void *arg)
70 {
71 	struct		periph_driver **p_drv;
72 	struct		cam_periph *periph;
73 	struct		cam_periph *cur_periph;
74 	path_id_t	path_id;
75 	target_id_t	target_id;
76 	lun_id_t	lun_id;
77 	cam_status	status;
78 	u_int		init_level;
79 	int s;
80 
81 	init_level = 0;
82 	/*
83 	 * Handle Hot-Plug scenarios.  If there is already a peripheral
84 	 * of our type assigned to this path, we are likely waiting for
85 	 * final close on an old, invalidated, peripheral.  If this is
86 	 * the case, queue up a deferred call to the peripheral's async
87 	 * handler.  If it looks like a mistaken re-alloation, complain.
88 	 */
89 	if ((periph = cam_periph_find(path, name)) != NULL) {
90 
91 		if ((periph->flags & CAM_PERIPH_INVALID) != 0
92 		 && (periph->flags & CAM_PERIPH_NEW_DEV_FOUND) == 0) {
93 			periph->flags |= CAM_PERIPH_NEW_DEV_FOUND;
94 			periph->deferred_callback = ac_callback;
95 			periph->deferred_ac = code;
96 			return (CAM_REQ_INPROG);
97 		} else {
98 			printf("cam_periph_alloc: attempt to re-allocate "
99 			       "valid device %s%d rejected\n",
100 			       periph->periph_name, periph->unit_number);
101 		}
102 		return (CAM_REQ_INVALID);
103 	}
104 
105 	periph = (struct cam_periph *)malloc(sizeof(*periph), M_DEVBUF,
106 					     M_NOWAIT);
107 
108 	if (periph == NULL)
109 		return (CAM_RESRC_UNAVAIL);
110 
111 	init_level++;
112 
113 	for (p_drv = (struct periph_driver **)periphdriver_set.ls_items;
114 	     *p_drv != NULL; p_drv++) {
115 		if (strcmp((*p_drv)->driver_name, name) == 0)
116 			break;
117 	}
118 
119 	path_id = xpt_path_path_id(path);
120 	target_id = xpt_path_target_id(path);
121 	lun_id = xpt_path_lun_id(path);
122 	bzero(periph, sizeof(*periph));
123 	cam_init_pinfo(&periph->pinfo);
124 	periph->periph_start = periph_start;
125 	periph->periph_dtor = periph_dtor;
126 	periph->periph_oninval = periph_oninvalidate;
127 	periph->type = type;
128 	periph->periph_name = name;
129 	periph->unit_number = camperiphunit(*p_drv, path_id, target_id, lun_id);
130 	periph->immediate_priority = CAM_PRIORITY_NONE;
131 	periph->refcount = 0;
132 	SLIST_INIT(&periph->ccb_list);
133 	status = xpt_create_path(&path, periph, path_id, target_id, lun_id);
134 	if (status != CAM_REQ_CMP)
135 		goto failure;
136 
137 	periph->path = path;
138 	init_level++;
139 
140 	status = xpt_add_periph(periph);
141 
142 	if (status != CAM_REQ_CMP)
143 		goto failure;
144 
145 	s = splsoftcam();
146 	cur_periph = TAILQ_FIRST(&(*p_drv)->units);
147 	while (cur_periph != NULL
148 	    && cur_periph->unit_number < periph->unit_number)
149 		cur_periph = TAILQ_NEXT(cur_periph, unit_links);
150 
151 	if (cur_periph != NULL)
152 		TAILQ_INSERT_BEFORE(cur_periph, periph, unit_links);
153 	else {
154 		TAILQ_INSERT_TAIL(&(*p_drv)->units, periph, unit_links);
155 		(*p_drv)->generation++;
156 	}
157 
158 	splx(s);
159 
160 	init_level++;
161 
162 	status = periph_ctor(periph, arg);
163 
164 	if (status == CAM_REQ_CMP)
165 		init_level++;
166 
167 failure:
168 	switch (init_level) {
169 	case 4:
170 		/* Initialized successfully */
171 		break;
172 	case 3:
173 		s = splsoftcam();
174 		TAILQ_REMOVE(&(*p_drv)->units, periph, unit_links);
175 		splx(s);
176 		xpt_remove_periph(periph);
177 	case 2:
178 		xpt_free_path(periph->path);
179 	case 1:
180 		free(periph, M_DEVBUF);
181 	case 0:
182 		/* No cleanup to perform. */
183 		break;
184 	default:
185 		panic("cam_periph_alloc: Unkown init level");
186 	}
187 	return(status);
188 }
189 
190 /*
191  * Find a peripheral structure with the specified path, target, lun,
192  * and (optionally) type.  If the name is NULL, this function will return
193  * the first peripheral driver that matches the specified path.
194  */
195 struct cam_periph *
196 cam_periph_find(struct cam_path *path, char *name)
197 {
198 	struct periph_driver **p_drv;
199 	struct cam_periph *periph;
200 	int s;
201 
202 	for (p_drv = (struct periph_driver **)periphdriver_set.ls_items;
203 	     *p_drv != NULL; p_drv++) {
204 
205 		if (name != NULL && (strcmp((*p_drv)->driver_name, name) != 0))
206 			continue;
207 
208 		s = splsoftcam();
209 		for (periph = TAILQ_FIRST(&(*p_drv)->units); periph != NULL;
210 		     periph = TAILQ_NEXT(periph, unit_links)) {
211 			if (xpt_path_comp(periph->path, path) == 0) {
212 				splx(s);
213 				return(periph);
214 			}
215 		}
216 		splx(s);
217 		if (name != NULL)
218 			return(NULL);
219 	}
220 	return(NULL);
221 }
222 
223 cam_status
224 cam_periph_acquire(struct cam_periph *periph)
225 {
226 	int s;
227 
228 	if (periph == NULL)
229 		return(CAM_REQ_CMP_ERR);
230 
231 	s = splsoftcam();
232 	periph->refcount++;
233 	splx(s);
234 
235 	return(CAM_REQ_CMP);
236 }
237 
238 void
239 cam_periph_release(struct cam_periph *periph)
240 {
241 	int s;
242 
243 	if (periph == NULL)
244 		return;
245 
246 	s = splsoftcam();
247 	if ((--periph->refcount == 0)
248 	 && (periph->flags & CAM_PERIPH_INVALID)) {
249 		camperiphfree(periph);
250 	}
251 	splx(s);
252 
253 }
254 
255 /*
256  * Look for the next unit number that is not currently in use for this
257  * peripheral type starting at "newunit".  Also exclude unit numbers that
258  * are reserved by for future "hardwiring" unless we already know that this
259  * is a potential wired device.  Only assume that the device is "wired" the
260  * first time through the loop since after that we'll be looking at unit
261  * numbers that did not match a wiring entry.
262  */
263 static u_int
264 camperiphnextunit(struct periph_driver *p_drv, u_int newunit, int wired)
265 {
266 	struct	cam_periph *periph;
267 	struct	cam_periph_config *periph_conf;
268 	char	*periph_name;
269 	int	s;
270 
271 	s = splsoftcam();
272 	periph_name = p_drv->driver_name;
273 	for (;;newunit++) {
274 
275 		for (periph = TAILQ_FIRST(&p_drv->units);
276 		     periph != NULL && periph->unit_number != newunit;
277 		     periph = TAILQ_NEXT(periph, unit_links))
278 			;
279 
280 		if (periph != NULL && periph->unit_number == newunit) {
281 			if (wired != 0) {
282 				xpt_print_path(periph->path);
283 				printf("Duplicate Wired Device entry!\n");
284 				xpt_print_path(periph->path);
285 				printf("Second device will not be wired\n");
286 				wired = 0;
287 			}
288 			continue;
289 		}
290 
291 		for (periph_conf = cam_pinit;
292 		     wired == 0 && periph_conf->periph_name != NULL;
293 		     periph_conf++) {
294 
295 			/*
296 			 * Don't match entries like "da 4" as a wired down
297 			 * device, but do match entries like "da 4 target 5"
298 			 * or even "da 4 scbus 1".
299 			 */
300 			if (IS_SPECIFIED(periph_conf->periph_unit)
301 			 && (!strcmp(periph_name, periph_conf->periph_name))
302 			 && (IS_SPECIFIED(periph_conf->target)
303 			  || IS_SPECIFIED(periph_conf->pathid))
304 			 && (newunit == periph_conf->periph_unit))
305 				break;
306 		}
307 
308 		if (wired != 0 || periph_conf->periph_name == NULL)
309 			break;
310 	}
311 	splx(s);
312 	return (newunit);
313 }
314 
315 static u_int
316 camperiphunit(struct periph_driver *p_drv, path_id_t pathid,
317 	      target_id_t target, lun_id_t lun)
318 {
319 	struct cam_periph_config *periph_conf;
320 	u_int unit;
321 	int hit;
322 
323 	unit = 0;
324 	hit = 0;
325 
326 	for (periph_conf = cam_pinit;
327 	     periph_conf->periph_name != NULL;
328 	     periph_conf++, hit = 0) {
329 
330 		if (!strcmp(p_drv->driver_name, periph_conf->periph_name)
331 		 && IS_SPECIFIED(periph_conf->periph_unit)) {
332 
333 			if (IS_SPECIFIED(periph_conf->pathid)) {
334 
335 				if (pathid != periph_conf->pathid)
336 					continue;
337 				hit++;
338 			}
339 
340 			if (IS_SPECIFIED(periph_conf->target)) {
341 
342 				if (target != periph_conf->target)
343 					continue;
344 				hit++;
345 			}
346 
347 			if (IS_SPECIFIED(periph_conf->lun)) {
348 
349 				if (lun != periph_conf->lun)
350 					continue;
351 				hit++;
352 			}
353 
354 			if (hit != 0) {
355 				unit = periph_conf->periph_unit;
356 				break;
357 			}
358 		}
359 	}
360 
361 	/*
362 	 * Either start from 0 looking for the next unit or from
363 	 * the unit number given in the periph_conf.  This way,
364 	 * if we have wildcard matches, we don't return the same
365 	 * unit number twice.
366 	 */
367 	unit = camperiphnextunit(p_drv, unit, /*wired*/hit);
368 
369 	return (unit);
370 }
371 
372 void
373 cam_periph_invalidate(struct cam_periph *periph)
374 {
375 	int s;
376 
377 	s = splsoftcam();
378 	/*
379 	 * We only call this routine the first time a peripheral is
380 	 * invalidated.  The oninvalidate() routine is always called at
381 	 * splsoftcam().
382 	 */
383 	if (((periph->flags & CAM_PERIPH_INVALID) == 0)
384 	 && (periph->periph_oninval != NULL))
385 		periph->periph_oninval(periph);
386 
387 	periph->flags |= CAM_PERIPH_INVALID;
388 	periph->flags &= ~CAM_PERIPH_NEW_DEV_FOUND;
389 
390 	if (periph->refcount == 0)
391 		camperiphfree(periph);
392 	else if (periph->refcount < 0)
393 		printf("cam_invalidate_periph: refcount < 0!!\n");
394 	splx(s);
395 }
396 
397 static void
398 camperiphfree(struct cam_periph *periph)
399 {
400 	int s;
401 	struct periph_driver **p_drv;
402 
403 	for (p_drv = (struct periph_driver **)periphdriver_set.ls_items;
404 	     *p_drv != NULL; p_drv++) {
405 		if (strcmp((*p_drv)->driver_name, periph->periph_name) == 0)
406 			break;
407 	}
408 
409 	if (periph->periph_dtor != NULL)
410 		periph->periph_dtor(periph);
411 
412 	s = splsoftcam();
413 	TAILQ_REMOVE(&(*p_drv)->units, periph, unit_links);
414 	(*p_drv)->generation++;
415 	splx(s);
416 
417 	xpt_remove_periph(periph);
418 
419 	if (periph->flags & CAM_PERIPH_NEW_DEV_FOUND) {
420 		union ccb ccb;
421 		void *arg;
422 
423 		switch (periph->deferred_ac) {
424 		case AC_FOUND_DEVICE:
425 			ccb.ccb_h.func_code = XPT_GDEV_TYPE;
426 			xpt_setup_ccb(&ccb.ccb_h, periph->path, /*priority*/ 1);
427 			xpt_action(&ccb);
428 			arg = &ccb;
429 			break;
430 		case AC_PATH_REGISTERED:
431 			ccb.ccb_h.func_code = XPT_PATH_INQ;
432 			xpt_setup_ccb(&ccb.ccb_h, periph->path, /*priority*/ 1);
433 			xpt_action(&ccb);
434 			arg = &ccb;
435 			break;
436 		default:
437 			arg = NULL;
438 			break;
439 		}
440 		periph->deferred_callback(NULL, periph->deferred_ac,
441 					  periph->path, arg);
442 	}
443 	xpt_free_path(periph->path);
444 	free(periph, M_DEVBUF);
445 }
446 
447 /*
448  * Wait interruptibly for an exclusive lock.
449  */
450 int
451 cam_periph_lock(struct cam_periph *periph, int priority)
452 {
453 	int error;
454 
455 	while ((periph->flags & CAM_PERIPH_LOCKED) != 0) {
456 		periph->flags |= CAM_PERIPH_LOCK_WANTED;
457 		if ((error = tsleep(periph, priority, "caplck", 0)) != 0)
458 			return error;
459 	}
460 
461 	if (cam_periph_acquire(periph) != CAM_REQ_CMP)
462 		return(ENXIO);
463 
464 	periph->flags |= CAM_PERIPH_LOCKED;
465 	return 0;
466 }
467 
468 /*
469  * Unlock and wake up any waiters.
470  */
471 void
472 cam_periph_unlock(struct cam_periph *periph)
473 {
474 	periph->flags &= ~CAM_PERIPH_LOCKED;
475 	if ((periph->flags & CAM_PERIPH_LOCK_WANTED) != 0) {
476 		periph->flags &= ~CAM_PERIPH_LOCK_WANTED;
477 		wakeup(periph);
478 	}
479 
480 	cam_periph_release(periph);
481 }
482 
483 /*
484  * Map user virtual pointers into kernel virtual address space, so we can
485  * access the memory.  This won't work on physical pointers, for now it's
486  * up to the caller to check for that.  (XXX KDM -- should we do that here
487  * instead?)  This also only works for up to MAXPHYS memory.  Since we use
488  * buffers to map stuff in and out, we're limited to the buffer size.
489  */
490 int
491 cam_periph_mapmem(union ccb *ccb, struct cam_periph_map_info *mapinfo)
492 {
493 	int flags, numbufs, i;
494 	u_int8_t **data_ptrs[CAM_PERIPH_MAXMAPS];
495 	u_int32_t lengths[CAM_PERIPH_MAXMAPS];
496 	u_int32_t dirs[CAM_PERIPH_MAXMAPS];
497 
498 	switch(ccb->ccb_h.func_code) {
499 	case XPT_DEV_MATCH:
500 		if (ccb->cdm.pattern_buf_len > MAXPHYS) {
501 			printf("cam_periph_mapmem: attempt to map %u bytes, "
502 			       "which is greater than MAXPHYS(%d)\n",
503 			       ccb->cdm.pattern_buf_len, MAXPHYS);
504 			return(E2BIG);
505 		} else if (ccb->cdm.match_buf_len > MAXPHYS) {
506 			printf("cam_periph_mapmem: attempt to map %u bytes, "
507 			       "which is greater than MAXPHYS(%d)\n",
508 			       ccb->cdm.match_buf_len, MAXPHYS);
509 			return(E2BIG);
510 		}
511 		if (ccb->cdm.match_buf_len == 0) {
512 			printf("cam_periph_mapmem: invalid match buffer "
513 			       "length 0\n");
514 			return(EINVAL);
515 		}
516 		if (ccb->cdm.pattern_buf_len > 0) {
517 			data_ptrs[0] = (u_int8_t **)&ccb->cdm.patterns;
518 			lengths[0] = ccb->cdm.pattern_buf_len;
519 			dirs[0] = CAM_DIR_OUT;
520 			data_ptrs[1] = (u_int8_t **)&ccb->cdm.matches;
521 			lengths[1] = ccb->cdm.match_buf_len;
522 			dirs[1] = CAM_DIR_IN;
523 			numbufs = 2;
524 		} else {
525 			data_ptrs[0] = (u_int8_t **)&ccb->cdm.matches;
526 			lengths[0] = ccb->cdm.match_buf_len;
527 			dirs[0] = CAM_DIR_IN;
528 			numbufs = 1;
529 		}
530 		break;
531 	case XPT_SCSI_IO:
532 		if (ccb->csio.dxfer_len > MAXPHYS) {
533 			printf("cam_periph_mapmem: attempt to map %u bytes, "
534 			       "which is greater than MAXPHYS(%d)\n",
535 				ccb->csio.dxfer_len, MAXPHYS);
536 			return(E2BIG);
537 		}
538 
539 		if ((ccb->ccb_h.flags & CAM_DIR_MASK) == CAM_DIR_NONE)
540 			return(0);
541 
542 		data_ptrs[0] = &ccb->csio.data_ptr;
543 		lengths[0] = ccb->csio.dxfer_len;;
544 		dirs[0] = ccb->ccb_h.flags & CAM_DIR_MASK;
545 		numbufs = 1;
546 		break;
547 	default:
548 		return(EINVAL);
549 		break; /* NOTREACHED */
550 	}
551 
552 	/* this keeps the current process from getting swapped */
553 	/*
554 	 * XXX KDM should I use P_NOSWAP instead?
555 	 */
556 	curproc->p_flag |= P_PHYSIO;
557 
558 	for (i = 0; i < numbufs; i++) {
559 		flags = 0;
560 
561 		if (dirs[i] & CAM_DIR_IN) {
562 			flags = B_READ;
563 			if (useracc(*data_ptrs[i], lengths[i], B_READ) == 0){
564 				printf("cam_periph_mapmem: error, "
565 					"address %p, length %lu isn't "
566 					"user accessible for READ\n",
567 					(void *)*data_ptrs[i],
568 					(u_long)lengths[i]);
569 				/*
570 				 * If we've already mapped one or more
571 				 * buffers for this CCB, unmap it (them).
572 				 */
573 				if (i > 0)
574 					cam_periph_unmapmem(ccb, mapinfo);
575 				else
576 					curproc->p_flag &= ~P_PHYSIO;
577 
578 				return(EACCES);
579 			}
580 		}
581 
582 		/*
583 		 * XXX this check is really bogus, since B_WRITE currently
584 		 * is all 0's, and so it is "set" all the time.
585 		 */
586 		if (dirs[i] & CAM_DIR_OUT) {
587 			flags |= B_WRITE;
588 			if (useracc(*data_ptrs[i], lengths[i], B_WRITE) == 0){
589 				printf("cam_periph_mapmem: error, "
590 					"address %p, length %lu isn't "
591 					"user accessible for WRITE\n",
592 					(void *)*data_ptrs[i],
593 					(u_long)lengths[i]);
594 				/*
595 				 * If we've already mapped one or more
596 				 * buffers for this CCB, unmap it (them).
597 				 */
598 				if (i > 0)
599 					cam_periph_unmapmem(ccb, mapinfo);
600 				else
601 					curproc->p_flag &= ~P_PHYSIO;
602 
603 				return(EACCES);
604 			}
605 		}
606 
607 		/*
608 		 * Get the buffer.
609 		 */
610 		mapinfo->bp[i] = getpbuf();
611 
612 		/* save the buffer's data address */
613 		mapinfo->bp[i]->b_saveaddr = mapinfo->bp[i]->b_data;
614 
615 		/* put our pointer in the data slot */
616 		mapinfo->bp[i]->b_data = *data_ptrs[i];
617 
618 		/* set the transfer length, we know it's < 64K */
619 		mapinfo->bp[i]->b_bufsize = lengths[i];
620 
621 		/* set the flags */
622 		mapinfo->bp[i]->b_flags = flags | B_PHYS | B_BUSY;
623 
624 		/* map the buffer into kernel memory */
625 		vmapbuf(mapinfo->bp[i]);
626 
627 		/* set our pointer to the new mapped area */
628 		*data_ptrs[i] = mapinfo->bp[i]->b_data;
629 
630 		mapinfo->num_bufs_used++;
631 	}
632 
633 	return(0);
634 }
635 
636 /*
637  * Unmap memory segments mapped into kernel virtual address space by
638  * cam_periph_mapmem().
639  */
640 void
641 cam_periph_unmapmem(union ccb *ccb, struct cam_periph_map_info *mapinfo)
642 {
643 	int numbufs, i;
644 	u_int8_t **data_ptrs[CAM_PERIPH_MAXMAPS];
645 
646 	if (mapinfo->num_bufs_used <= 0) {
647 		/* allow ourselves to be swapped once again */
648 		curproc->p_flag &= ~P_PHYSIO;
649 		return;
650 	}
651 
652 	switch (ccb->ccb_h.func_code) {
653 	case XPT_DEV_MATCH:
654 		numbufs = min(mapinfo->num_bufs_used, 2);
655 
656 		if (numbufs == 1) {
657 			data_ptrs[0] = (u_int8_t **)&ccb->cdm.matches;
658 		} else {
659 			data_ptrs[0] = (u_int8_t **)&ccb->cdm.patterns;
660 			data_ptrs[1] = (u_int8_t **)&ccb->cdm.matches;
661 		}
662 		break;
663 	case XPT_SCSI_IO:
664 		data_ptrs[0] = &ccb->csio.data_ptr;
665 		numbufs = min(mapinfo->num_bufs_used, 1);
666 		break;
667 	default:
668 		/* allow ourselves to be swapped once again */
669 		curproc->p_flag &= ~P_PHYSIO;
670 		return;
671 		break; /* NOTREACHED */
672 	}
673 
674 	for (i = 0; i < numbufs; i++) {
675 		/* Set the user's pointer back to the original value */
676 		*data_ptrs[i] = mapinfo->bp[i]->b_saveaddr;
677 
678 		/* unmap the buffer */
679 		vunmapbuf(mapinfo->bp[i]);
680 
681 		/* clear the flags we set above */
682 		mapinfo->bp[i]->b_flags &= ~(B_PHYS|B_BUSY);
683 
684 		/* release the buffer */
685 		relpbuf(mapinfo->bp[i]);
686 	}
687 
688 	/* allow ourselves to be swapped once again */
689 	curproc->p_flag &= ~P_PHYSIO;
690 }
691 
692 union ccb *
693 cam_periph_getccb(struct cam_periph *periph, u_int32_t priority)
694 {
695 	struct ccb_hdr *ccb_h;
696 	int s;
697 
698 	CAM_DEBUG(periph->path, CAM_DEBUG_TRACE, ("entering cdgetccb\n"));
699 
700 	s = splsoftcam();
701 
702 	while (periph->ccb_list.slh_first == NULL) {
703 		if (periph->immediate_priority > priority)
704 			periph->immediate_priority = priority;
705 		xpt_schedule(periph, priority);
706 		if ((periph->ccb_list.slh_first != NULL)
707 		 && (periph->ccb_list.slh_first->pinfo.priority == priority))
708 			break;
709 		tsleep(&periph->ccb_list, PRIBIO, "cgticb", 0);
710 	}
711 
712 	ccb_h = periph->ccb_list.slh_first;
713 	SLIST_REMOVE_HEAD(&periph->ccb_list, periph_links.sle);
714 	splx(s);
715 	return ((union ccb *)ccb_h);
716 }
717 
718 void
719 cam_periph_ccbwait(union ccb *ccb)
720 {
721 	int s;
722 
723 	s = splsoftcam();
724 	if ((ccb->ccb_h.pinfo.index != CAM_UNQUEUED_INDEX)
725 	 || ((ccb->ccb_h.status & CAM_STATUS_MASK) == CAM_REQ_INPROG))
726 		tsleep(&ccb->ccb_h.cbfcnp, PRIBIO, "cbwait", 0);
727 
728 	splx(s);
729 }
730 
731 int
732 cam_periph_ioctl(struct cam_periph *periph, int cmd, caddr_t addr,
733 		 int (*error_routine)(union ccb *ccb,
734 				      cam_flags camflags,
735 				      u_int32_t sense_flags))
736 {
737 	union ccb 	     *ccb;
738 	int 		     error;
739 	int		     found;
740 
741 	error = found = 0;
742 
743 	switch(cmd){
744 	case CAMGETPASSTHRU:
745 		ccb = cam_periph_getccb(periph, /* priority */ 1);
746 		xpt_setup_ccb(&ccb->ccb_h,
747 			      ccb->ccb_h.path,
748 			      /*priority*/1);
749 		ccb->ccb_h.func_code = XPT_GDEVLIST;
750 
751 		/*
752 		 * Basically, the point of this is that we go through
753 		 * getting the list of devices, until we find a passthrough
754 		 * device.  In the current version of the CAM code, the
755 		 * only way to determine what type of device we're dealing
756 		 * with is by its name.
757 		 */
758 		while (found == 0) {
759 			ccb->cgdl.index = 0;
760 			ccb->cgdl.status = CAM_GDEVLIST_MORE_DEVS;
761 			while (ccb->cgdl.status == CAM_GDEVLIST_MORE_DEVS) {
762 
763 				/* we want the next device in the list */
764 				xpt_action(ccb);
765 				if (strncmp(ccb->cgdl.periph_name,
766 				    "pass", 4) == 0){
767 					found = 1;
768 					break;
769 				}
770 			}
771 			if ((ccb->cgdl.status == CAM_GDEVLIST_LAST_DEVICE) &&
772 			    (found == 0)) {
773 				ccb->cgdl.periph_name[0] = '\0';
774 				ccb->cgdl.unit_number = 0;
775 				break;
776 			}
777 		}
778 
779 		/* copy the result back out */
780 		bcopy(ccb, addr, sizeof(union ccb));
781 
782 		/* and release the ccb */
783 		xpt_release_ccb(ccb);
784 
785 		break;
786 	default:
787 		error = ENOTTY;
788 		break;
789 	}
790 	return(error);
791 }
792 
793 int
794 cam_periph_runccb(union ccb *ccb,
795 		  int (*error_routine)(union ccb *ccb,
796 				       cam_flags camflags,
797 				       u_int32_t sense_flags),
798 		  cam_flags camflags, u_int32_t sense_flags,
799 		  struct devstat *ds)
800 {
801 	int error;
802 
803 	error = 0;
804 
805 	/*
806 	 * If the user has supplied a stats structure, and if we understand
807 	 * this particular type of ccb, record the transaction start.
808 	 */
809 	if ((ds != NULL) && (ccb->ccb_h.func_code == XPT_SCSI_IO))
810 		devstat_start_transaction(ds);
811 
812 	xpt_action(ccb);
813 
814 	do {
815 		cam_periph_ccbwait(ccb);
816 		if ((ccb->ccb_h.status & CAM_STATUS_MASK) == CAM_REQ_CMP)
817 			error = 0;
818 		else if (error_routine != NULL)
819 			error = (*error_routine)(ccb, camflags, sense_flags);
820 		else
821 			error = 0;
822 
823 	} while (error == ERESTART);
824 
825 	if ((ccb->ccb_h.status & CAM_DEV_QFRZN) != 0)
826 		cam_release_devq(ccb->ccb_h.path,
827 				 /* relsim_flags */0,
828 				 /* openings */0,
829 				 /* timeout */0,
830 				 /* getcount_only */ FALSE);
831 
832 	if ((ds != NULL) && (ccb->ccb_h.func_code == XPT_SCSI_IO))
833 		devstat_end_transaction(ds,
834 					ccb->csio.dxfer_len,
835 					ccb->csio.tag_action & 0xf,
836 					((ccb->ccb_h.flags & CAM_DIR_MASK) ==
837 					CAM_DIR_NONE) ?  DEVSTAT_NO_DATA :
838 					(ccb->ccb_h.flags & CAM_DIR_OUT) ?
839 					DEVSTAT_WRITE :
840 					DEVSTAT_READ);
841 
842 	return(error);
843 }
844 
845 u_int32_t
846 cam_release_devq(struct cam_path *path, u_int32_t relsim_flags,
847 		 u_int32_t openings, u_int32_t timeout,
848 		 int getcount_only)
849 {
850 	struct ccb_relsim crs;
851 
852 	xpt_setup_ccb(&crs.ccb_h, path,
853 		      /*priority*/1);
854 	crs.ccb_h.func_code = XPT_REL_SIMQ;
855 	crs.ccb_h.flags = getcount_only ? CAM_DEV_QFREEZE : 0;
856 	crs.release_flags = relsim_flags;
857 	crs.openings = openings;
858 	crs.release_timeout = timeout;
859 	xpt_action((union ccb *)&crs);
860 	return (crs.qfrozen_cnt);
861 }
862 
863 #define saved_ccb_ptr ppriv_ptr0
864 static void
865 camperiphdone(struct cam_periph *periph, union ccb *done_ccb)
866 {
867 	cam_status	status;
868 	int		frozen;
869 	int		sense;
870 	struct scsi_start_stop_unit *scsi_cmd;
871 	u_int32_t	relsim_flags, timeout;
872 	u_int32_t	qfrozen_cnt;
873 
874 	status = done_ccb->ccb_h.status;
875 	frozen = (status & CAM_DEV_QFRZN) != 0;
876 	sense  = (status & CAM_AUTOSNS_VALID) != 0;
877 	status &= CAM_STATUS_MASK;
878 
879 	timeout = 0;
880 	relsim_flags = 0;
881 
882 	/*
883 	 * Unfreeze the queue once if it is already frozen..
884 	 */
885 	if (frozen != 0) {
886 		qfrozen_cnt = cam_release_devq(done_ccb->ccb_h.path,
887 					      /*relsim_flags*/0,
888 					      /*openings*/0,
889 					      /*timeout*/0,
890 					      /*getcount_only*/0);
891 	}
892 
893 	switch (status) {
894 
895 	case CAM_REQ_CMP:
896 
897 		/*
898 		 * If we have successfully taken a device from the not
899 		 * ready to ready state, re-scan the device and re-get the
900 		 * inquiry information.  Many devices (mostly disks) don't
901 		 * properly report their inquiry information unless they
902 		 * are spun up.
903 		 */
904 		if (done_ccb->ccb_h.func_code == XPT_SCSI_IO) {
905 			scsi_cmd = (struct scsi_start_stop_unit *)
906 					&done_ccb->csio.cdb_io.cdb_bytes;
907 
908 		 	if (scsi_cmd->opcode == START_STOP_UNIT)
909 				xpt_async(AC_INQ_CHANGED,
910 					  done_ccb->ccb_h.path, NULL);
911 		}
912 		bcopy(done_ccb->ccb_h.saved_ccb_ptr, done_ccb,
913 		      sizeof(union ccb));
914 
915 		periph->flags &= ~CAM_PERIPH_RECOVERY_INPROG;
916 
917 		xpt_action(done_ccb);
918 
919 		break;
920 	case CAM_SCSI_STATUS_ERROR:
921 		scsi_cmd = (struct scsi_start_stop_unit *)
922 				&done_ccb->csio.cdb_io.cdb_bytes;
923 		if (sense != 0) {
924 			struct scsi_sense_data *sense;
925 			int    error_code, sense_key, asc, ascq;
926 
927 			sense = &done_ccb->csio.sense_data;
928 			scsi_extract_sense(sense, &error_code,
929 					   &sense_key, &asc, &ascq);
930 
931 			/*
932 	 		 * If the error is "invalid field in CDB",
933 			 * and the load/eject flag is set, turn the
934 			 * flag off and try again.  This is just in
935 			 * case the drive in question barfs on the
936 			 * load eject flag.  The CAM code should set
937 			 * the load/eject flag by default for
938 			 * removable media.
939 			 */
940 
941 			/* XXX KDM
942 			 * Should we check to see what the specific
943 			 * scsi status is??  Or does it not matter
944 			 * since we already know that there was an
945 			 * error, and we know what the specific
946 			 * error code was, and we know what the
947 			 * opcode is..
948 			 */
949 			if ((scsi_cmd->opcode == START_STOP_UNIT) &&
950 			    ((scsi_cmd->how & SSS_LOEJ) != 0) &&
951 			     (asc == 0x24) && (ascq == 0x00) &&
952 			     (done_ccb->ccb_h.retry_count > 0)) {
953 
954 				scsi_cmd->how &= ~SSS_LOEJ;
955 
956 				xpt_action(done_ccb);
957 
958 			} else if (done_ccb->ccb_h.retry_count > 0) {
959 				/*
960 				 * In this case, the error recovery
961 				 * command failed, but we've got
962 				 * some retries left on it.  Give
963 				 * it another try.
964 				 */
965 
966 				/* set the timeout to .5 sec */
967 				relsim_flags =
968 					RELSIM_RELEASE_AFTER_TIMEOUT;
969 				timeout = 500;
970 
971 				xpt_action(done_ccb);
972 
973 				break;
974 
975 			} else {
976 				/*
977 				 * Copy the original CCB back and
978 				 * send it back to the caller.
979 				 */
980 				bcopy(done_ccb->ccb_h.saved_ccb_ptr,
981 				      done_ccb, sizeof(union ccb));
982 
983 				periph->flags &= ~CAM_PERIPH_RECOVERY_INPROG;
984 
985 				xpt_action(done_ccb);
986 			}
987 		} else {
988 			/*
989 			 * Eh??  The command failed, but we don't
990 			 * have any sense.  What's up with that?
991 			 * Fire the CCB again to return it to the
992 			 * caller.
993 			 */
994 			bcopy(done_ccb->ccb_h.saved_ccb_ptr,
995 			      done_ccb, sizeof(union ccb));
996 
997 			periph->flags &= ~CAM_PERIPH_RECOVERY_INPROG;
998 
999 			xpt_action(done_ccb);
1000 
1001 		}
1002 		break;
1003 	default:
1004 		bcopy(done_ccb->ccb_h.saved_ccb_ptr, done_ccb,
1005 		      sizeof(union ccb));
1006 
1007 		periph->flags &= ~CAM_PERIPH_RECOVERY_INPROG;
1008 
1009 		xpt_action(done_ccb);
1010 
1011 		break;
1012 	}
1013 
1014 	/* decrement the retry count */
1015 	if (done_ccb->ccb_h.retry_count > 0)
1016 		done_ccb->ccb_h.retry_count--;
1017 
1018 	qfrozen_cnt = cam_release_devq(done_ccb->ccb_h.path,
1019 				      /*relsim_flags*/relsim_flags,
1020 				      /*openings*/0,
1021 				      /*timeout*/timeout,
1022 				      /*getcount_only*/0);
1023 }
1024 
1025 /*
1026  * Generic error handler.  Peripheral drivers usually filter
1027  * out the errors that they handle in a unique mannor, then
1028  * call this function.
1029  */
1030 int
1031 cam_periph_error(union ccb *ccb, cam_flags camflags,
1032 		 u_int32_t sense_flags, union ccb *save_ccb)
1033 {
1034 	cam_status status;
1035 	int	   frozen;
1036 	int	   sense;
1037 	int	   error;
1038 	int        openings;
1039 	int	   retry;
1040 	u_int32_t  relsim_flags;
1041 	u_int32_t  timeout;
1042 
1043 	status = ccb->ccb_h.status;
1044 	frozen = (status & CAM_DEV_QFRZN) != 0;
1045 	sense  = (status & CAM_AUTOSNS_VALID) != 0;
1046 	status &= CAM_STATUS_MASK;
1047 	relsim_flags = 0;
1048 
1049 
1050 	switch (status) {
1051 	case CAM_REQ_CMP:
1052 		/* decrement the number of retries */
1053 		retry = ccb->ccb_h.retry_count > 0;
1054 		if (retry)
1055 			ccb->ccb_h.retry_count--;
1056 		error = 0;
1057 		break;
1058 	case CAM_SCSI_STATUS_ERROR:
1059 
1060 		switch (ccb->csio.scsi_status) {
1061 		case SCSI_STATUS_OK:
1062 		case SCSI_STATUS_COND_MET:
1063 		case SCSI_STATUS_INTERMED:
1064 		case SCSI_STATUS_INTERMED_COND_MET:
1065 			error = 0;
1066 			break;
1067 		case SCSI_STATUS_CMD_TERMINATED:
1068 		case SCSI_STATUS_CHECK_COND:
1069 			if (sense != 0) {
1070 				struct scsi_sense_data *sense;
1071 				int    error_code, sense_key, asc, ascq;
1072 				struct cam_periph *periph;
1073 				scsi_sense_action err_action;
1074 				struct ccb_getdev cgd;
1075 
1076 				sense = &ccb->csio.sense_data;
1077 				scsi_extract_sense(sense, &error_code,
1078 						   &sense_key, &asc, &ascq);
1079 				periph = xpt_path_periph(ccb->ccb_h.path);
1080 
1081 				/*
1082 				 * Grab the inquiry data for this device.
1083 				 */
1084 				xpt_setup_ccb(&cgd.ccb_h, ccb->ccb_h.path,
1085 					      /*priority*/ 1);
1086 				cgd.ccb_h.func_code = XPT_GDEV_TYPE;
1087 				xpt_action((union ccb *)&cgd);
1088 
1089 				err_action = scsi_error_action(asc, ascq,
1090 							       &cgd.inq_data);
1091 
1092 				/*
1093 				 * Send a Test Unit Ready to the device.
1094 				 * If the 'many' flag is set, we send 120
1095 				 * test unit ready commands, one every half
1096 				 * second.  Otherwise, we just send one TUR.
1097 				 * We only want to do this if the retry
1098 				 * count has not been exhausted.
1099 				 */
1100 				if (((err_action & SS_MASK) == SS_TUR)
1101 				 && save_ccb != NULL
1102 				 && ccb->ccb_h.retry_count > 0) {
1103 
1104 					/*
1105 					 * Since error recovery is already
1106 					 * in progress, don't attempt to
1107 					 * process this error.  It is probably
1108 					 * related to the error that caused
1109 					 * the currently active error recovery
1110 					 * action.  Also, we only have
1111 					 * space for one saved CCB, so if we
1112 					 * had two concurrent error recovery
1113 					 * actions, we would end up
1114 					 * over-writing one error recovery
1115 					 * CCB with another one.
1116 					 */
1117 					if (periph->flags &
1118 					    CAM_PERIPH_RECOVERY_INPROG) {
1119 						error = ERESTART;
1120 						break;
1121 					}
1122 
1123 					periph->flags |=
1124 						CAM_PERIPH_RECOVERY_INPROG;
1125 
1126 					/* decrement the number of retries */
1127 					if ((err_action &
1128 					     SSQ_DECREMENT_COUNT) != 0) {
1129 						retry = 1;
1130 						ccb->ccb_h.retry_count--;
1131 					}
1132 
1133 					bcopy(ccb, save_ccb, sizeof(*save_ccb));
1134 
1135 					/*
1136 					 * We retry this one every half
1137 					 * second for a minute.  If the
1138 					 * device hasn't become ready in a
1139 					 * minute's time, it's unlikely to
1140 					 * ever become ready.  If the table
1141 					 * doesn't specify SSQ_MANY, we can
1142 					 * only try this once.  Oh well.
1143 					 */
1144 					if ((err_action & SSQ_MANY) != 0)
1145 						scsi_test_unit_ready(&ccb->csio,
1146 							       /*retries*/120,
1147 							       camperiphdone,
1148 						 	       MSG_SIMPLE_Q_TAG,
1149 							       SSD_FULL_SIZE,
1150 							       /*timeout*/5000);
1151 					else
1152 						scsi_test_unit_ready(&ccb->csio,
1153 							       /*retries*/1,
1154 							       camperiphdone,
1155 						 	       MSG_SIMPLE_Q_TAG,
1156 							       SSD_FULL_SIZE,
1157 							       /*timeout*/5000);
1158 
1159 					/* release the queue after .5 sec.  */
1160 					relsim_flags =
1161 						RELSIM_RELEASE_AFTER_TIMEOUT;
1162 					timeout = 500;
1163 					/*
1164 					 * Drop the priority to 0 so that
1165 					 * we are the first to execute.  Also
1166 					 * freeze the queue after this command
1167 					 * is sent so that we can restore the
1168 					 * old csio and have it queued in the
1169 					 * proper order before we let normal
1170 					 * transactions go to the drive.
1171 					 */
1172 					ccb->ccb_h.pinfo.priority = 0;
1173 					ccb->ccb_h.flags |= CAM_DEV_QFREEZE;
1174 
1175 					/*
1176 					 * Save a pointer to the original
1177 					 * CCB in the new CCB.
1178 					 */
1179 					ccb->ccb_h.saved_ccb_ptr = save_ccb;
1180 
1181 					error = ERESTART;
1182 				}
1183 				/*
1184 				 * Send a start unit command to the device,
1185 				 * and then retry the command.  We only
1186 				 * want to do this if the retry count has
1187 				 * not been exhausted.  If the user
1188 				 * specified 0 retries, then we follow
1189 				 * their request and do not retry.
1190 				 */
1191 				else if (((err_action & SS_MASK) == SS_START)
1192 				      && save_ccb != NULL
1193 				      && ccb->ccb_h.retry_count > 0) {
1194 					int le;
1195 
1196 					/*
1197 					 * Only one error recovery action
1198 					 * at a time.  See above.
1199 					 */
1200 					if (periph->flags &
1201 					    CAM_PERIPH_RECOVERY_INPROG) {
1202 						error = ERESTART;
1203 						break;
1204 					}
1205 
1206 					periph->flags |=
1207 						CAM_PERIPH_RECOVERY_INPROG;
1208 
1209 					/* decrement the number of retries */
1210 					retry = 1;
1211 					ccb->ccb_h.retry_count--;
1212 
1213 					/*
1214 					 * Check for removable media and
1215 					 * set load/eject flag
1216 					 * appropriately.
1217 					 */
1218 					if (SID_IS_REMOVABLE(&cgd.inq_data))
1219 						le = TRUE;
1220 					else
1221 						le = FALSE;
1222 
1223 					/*
1224 					 * Attempt to start the drive up.
1225 					 *
1226 					 * Save the current ccb so it can
1227 					 * be restored and retried once the
1228 					 * drive is started up.
1229 					 */
1230 					bcopy(ccb, save_ccb, sizeof(*save_ccb));
1231 
1232 					scsi_start_stop(&ccb->csio,
1233 							/*retries*/1,
1234 							camperiphdone,
1235 							MSG_SIMPLE_Q_TAG,
1236 							/*start*/TRUE,
1237 							/*load/eject*/le,
1238 							/*immediate*/FALSE,
1239 							SSD_FULL_SIZE,
1240 							/*timeout*/50000);
1241 					/*
1242 					 * Drop the priority to 0 so that
1243 					 * we are the first to execute.  Also
1244 					 * freeze the queue after this command
1245 					 * is sent so that we can restore the
1246 					 * old csio and have it queued in the
1247 					 * proper order before we let normal
1248 					 * transactions go to the drive.
1249 					 */
1250 					ccb->ccb_h.pinfo.priority = 0;
1251 					ccb->ccb_h.flags |= CAM_DEV_QFREEZE;
1252 
1253 					/*
1254 					 * Save a pointer to the original
1255 					 * CCB in the new CCB.
1256 					 */
1257 					ccb->ccb_h.saved_ccb_ptr = save_ccb;
1258 
1259 					error = ERESTART;
1260 				} else if ((sense_flags & SF_RETRY_UA) != 0) {
1261 					/*
1262 					 * XXX KDM this is a *horrible*
1263 					 * hack.
1264 					 */
1265 					error = scsi_interpret_sense(ccb,
1266 								  sense_flags,
1267 								  &relsim_flags,
1268 								  &openings,
1269 								  &timeout,
1270 								  err_action);
1271 				}
1272 
1273 				/*
1274 				 * Theoretically, this code should send a
1275 				 * test unit ready to the given device, and
1276 				 * if it returns and error, send a start
1277 				 * unit command.  Since we don't yet have
1278 				 * the capability to do two-command error
1279 				 * recovery, just send a start unit.
1280 				 * XXX KDM fix this!
1281 				 */
1282 				else if (((err_action & SS_MASK) == SS_TURSTART)
1283 				      && save_ccb != NULL
1284 				      && ccb->ccb_h.retry_count > 0) {
1285 					int le;
1286 
1287 					/*
1288 					 * Only one error recovery action
1289 					 * at a time.  See above.
1290 					 */
1291 					if (periph->flags &
1292 					    CAM_PERIPH_RECOVERY_INPROG) {
1293 						error = ERESTART;
1294 						break;
1295 					}
1296 
1297 					periph->flags |=
1298 						CAM_PERIPH_RECOVERY_INPROG;
1299 
1300 					/* decrement the number of retries */
1301 					retry = 1;
1302 					ccb->ccb_h.retry_count--;
1303 
1304 					/*
1305 					 * Check for removable media and
1306 					 * set load/eject flag
1307 					 * appropriately.
1308 					 */
1309 					if (SID_IS_REMOVABLE(&cgd.inq_data))
1310 						le = TRUE;
1311 					else
1312 						le = FALSE;
1313 
1314 					/*
1315 					 * Attempt to start the drive up.
1316 					 *
1317 					 * Save the current ccb so it can
1318 					 * be restored and retried once the
1319 					 * drive is started up.
1320 					 */
1321 					bcopy(ccb, save_ccb, sizeof(*save_ccb));
1322 
1323 					scsi_start_stop(&ccb->csio,
1324 							/*retries*/1,
1325 							camperiphdone,
1326 							MSG_SIMPLE_Q_TAG,
1327 							/*start*/TRUE,
1328 							/*load/eject*/le,
1329 							/*immediate*/FALSE,
1330 							SSD_FULL_SIZE,
1331 							/*timeout*/50000);
1332 
1333 					/* release the queue after .5 sec.  */
1334 					relsim_flags =
1335 						RELSIM_RELEASE_AFTER_TIMEOUT;
1336 					timeout = 500;
1337 					/*
1338 					 * Drop the priority to 0 so that
1339 					 * we are the first to execute.  Also
1340 					 * freeze the queue after this command
1341 					 * is sent so that we can restore the
1342 					 * old csio and have it queued in the
1343 					 * proper order before we let normal
1344 					 * transactions go to the drive.
1345 					 */
1346 					ccb->ccb_h.pinfo.priority = 0;
1347 					ccb->ccb_h.flags |= CAM_DEV_QFREEZE;
1348 
1349 					/*
1350 					 * Save a pointer to the original
1351 					 * CCB in the new CCB.
1352 					 */
1353 					ccb->ccb_h.saved_ccb_ptr = save_ccb;
1354 
1355 					error = ERESTART;
1356 				} else {
1357 					error = scsi_interpret_sense(ccb,
1358 								  sense_flags,
1359 								  &relsim_flags,
1360 								  &openings,
1361 								  &timeout,
1362 								  err_action);
1363 				}
1364 			} else if (ccb->csio.scsi_status ==
1365 				   SCSI_STATUS_CHECK_COND) {
1366 				/* no point in decrementing the retry count */
1367 				panic("cam_periph_error: scsi status of "
1368 				      "CHECK COND returned but no sense "
1369 				      "information is availible.  "
1370 				      "Controller should have returned "
1371 				      "CAM_AUTOSENSE_FAILED");
1372 				/* NOTREACHED */
1373 				error = EIO;
1374 			} else if (ccb->ccb_h.retry_count > 0) {
1375 				/*
1376 				 * XXX KDM shouldn't there be a better
1377 				 * argument to return??
1378 				 */
1379 				error = EIO;
1380 			} else {
1381 				/* decrement the number of retries */
1382 				retry = ccb->ccb_h.retry_count > 0;
1383 				if (retry)
1384 					ccb->ccb_h.retry_count--;
1385 				/*
1386 				 * If it was aborted with no
1387 				 * clue as to the reason, just
1388 				 * retry it again.
1389 				 */
1390 				error = ERESTART;
1391 			}
1392 			break;
1393 		case SCSI_STATUS_QUEUE_FULL:
1394 		{
1395 			/* no decrement */
1396 			struct ccb_getdev cgd;
1397 
1398 			/*
1399 			 * First off, find out what the current
1400 			 * transaction counts are.
1401 			 */
1402 			xpt_setup_ccb(&cgd.ccb_h,
1403 				      ccb->ccb_h.path,
1404 				      /*priority*/1);
1405 			cgd.ccb_h.func_code = XPT_GDEV_TYPE;
1406 			xpt_action((union ccb *)&cgd);
1407 
1408 			/*
1409 			 * If we were the only transaction active, treat
1410 			 * the QUEUE FULL as if it were a BUSY condition.
1411 			 */
1412 			if (cgd.dev_active != 0) {
1413 				/*
1414 			 	 * Reduce the number of openings to
1415 				 * be 1 less than the amount it took
1416 				 * to get a queue full bounded by the
1417 				 * minimum allowed tag count for this
1418 				 * device.
1419 			 	 */
1420 				openings = cgd.dev_active;
1421 				if (openings < cgd.mintags)
1422 					openings = cgd.mintags;
1423 				if (openings < cgd.dev_active+cgd.dev_openings)
1424 					relsim_flags = RELSIM_ADJUST_OPENINGS;
1425 				else {
1426 					/*
1427 					 * Some devices report queue full for
1428 					 * temporary resource shortages.  For
1429 					 * this reason, we allow a minimum
1430 					 * tag count to be entered via a
1431 					 * quirk entry to prevent the queue
1432 					 * count on these devices from falling
1433 					 * to a pessimisticly low value.  We
1434 					 * still wait for the next successful
1435 					 * completion, however, before queueing
1436 					 * more transactions to the device.
1437 					 */
1438 					relsim_flags =
1439 					    RELSIM_RELEASE_AFTER_CMDCMPLT;
1440 				}
1441 				timeout = 0;
1442 				error = ERESTART;
1443 				break;
1444 			}
1445 			/* FALLTHROUGH */
1446 		}
1447 		case SCSI_STATUS_BUSY:
1448 			/*
1449 			 * Restart the queue after either another
1450 			 * command completes or a 1 second timeout.
1451 			 */
1452 			/*
1453 			 * XXX KDM ask JTG about this again, do we need to
1454 			 * be looking at the retry count here?
1455 			 */
1456 			error = ERESTART;
1457 			relsim_flags = RELSIM_RELEASE_AFTER_TIMEOUT
1458 				     | RELSIM_RELEASE_AFTER_CMDCMPLT;
1459 			timeout = 1000;
1460 			break;
1461 		case SCSI_STATUS_RESERV_CONFLICT:
1462 			error = EIO;
1463 			break;
1464 		default:
1465 			error = EIO;
1466 			break;
1467 		}
1468 		break;
1469 	case CAM_REQ_CMP_ERR:
1470 	case CAM_AUTOSENSE_FAIL:
1471 	case CAM_CMD_TIMEOUT:
1472 	case CAM_UNEXP_BUSFREE:
1473 	case CAM_UNCOR_PARITY:
1474 	case CAM_DATA_RUN_ERR:
1475 		/* decrement the number of retries */
1476 		retry = ccb->ccb_h.retry_count > 0;
1477 		if (retry) {
1478 			ccb->ccb_h.retry_count--;
1479 			error = ERESTART;
1480 		} else {
1481 			error = EIO;
1482 		}
1483 		break;
1484 	case CAM_UA_ABORT:
1485 	case CAM_UA_TERMIO:
1486 	case CAM_MSG_REJECT_REC:
1487 		/* XXX Don't know that these are correct */
1488 		error = EIO;
1489 		break;
1490 	case CAM_SEL_TIMEOUT:
1491 	{
1492 		/*
1493 		 * XXX
1494 		 * A single selection timeout should not be enough
1495 		 * to invalidate a device.  We should retry for multiple
1496 		 * seconds assuming this isn't a probe.  We'll probably
1497 		 * need a special flag for that.
1498 		 */
1499 #if 0
1500 		struct cam_path *newpath;
1501 
1502 		/* Should we do more if we can't create the path?? */
1503 		if (xpt_create_path(&newpath, xpt_path_periph(ccb->ccb_h.path),
1504 				    xpt_path_path_id(ccb->ccb_h.path),
1505 				    xpt_path_target_id(ccb->ccb_h.path),
1506 				    CAM_LUN_WILDCARD) != CAM_REQ_CMP)
1507 			break;
1508 		/*
1509 		 * Let peripheral drivers know that this device has gone
1510 		 * away.
1511 		 */
1512 		xpt_async(AC_LOST_DEVICE, newpath, NULL);
1513 		xpt_free_path(newpath);
1514 #endif
1515 		error = ENXIO;
1516 		break;
1517 	}
1518 	case CAM_REQ_INVALID:
1519 	case CAM_PATH_INVALID:
1520 	case CAM_DEV_NOT_THERE:
1521 	case CAM_NO_HBA:
1522 	case CAM_PROVIDE_FAIL:
1523 	case CAM_REQ_TOO_BIG:
1524 		error = EINVAL;
1525 		break;
1526 	case CAM_SCSI_BUS_RESET:
1527 	case CAM_BDR_SENT:
1528 	case CAM_REQUEUE_REQ:
1529 		/* Unconditional requeue, dammit */
1530 		error = ERESTART;
1531 		break;
1532 	case CAM_RESRC_UNAVAIL:
1533 	case CAM_BUSY:
1534 		/* timeout??? */
1535 	default:
1536 		/* decrement the number of retries */
1537 		retry = ccb->ccb_h.retry_count > 0;
1538 		if (retry) {
1539 			ccb->ccb_h.retry_count--;
1540 			error = ERESTART;
1541 		} else {
1542 			/* Check the sense codes */
1543 			error = EIO;
1544 		}
1545 		break;
1546 	}
1547 
1548 	/* Attempt a retry */
1549 	if (error == ERESTART || error == 0) {
1550 		if (frozen != 0)
1551 			ccb->ccb_h.status &= ~CAM_DEV_QFRZN;
1552 
1553 		if (error == ERESTART)
1554 			xpt_action(ccb);
1555 
1556 		if (frozen != 0) {
1557 			cam_release_devq(ccb->ccb_h.path,
1558 					 relsim_flags,
1559 					 openings,
1560 					 timeout,
1561 					 /*getcount_only*/0);
1562 		}
1563 	}
1564 
1565 
1566 	return (error);
1567 }
1568