xref: /freebsd/sys/cam/cam_periph.c (revision 6e8394b8baa7d5d9153ab90de6824bcd19b3b4e1)
1 /*
2  * Common functions for CAM "type" (peripheral) drivers.
3  *
4  * Copyright (c) 1997, 1998 Justin T. Gibbs.
5  * Copyright (c) 1997, 1998, 1999 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 1.16 1999/05/25 17:10:04 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/linker_set.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 numbufs, i;
494 	int flags[CAM_PERIPH_MAXMAPS];
495 	u_int8_t **data_ptrs[CAM_PERIPH_MAXMAPS];
496 	u_int32_t lengths[CAM_PERIPH_MAXMAPS];
497 	u_int32_t dirs[CAM_PERIPH_MAXMAPS];
498 
499 	switch(ccb->ccb_h.func_code) {
500 	case XPT_DEV_MATCH:
501 		if (ccb->cdm.match_buf_len == 0) {
502 			printf("cam_periph_mapmem: invalid match buffer "
503 			       "length 0\n");
504 			return(EINVAL);
505 		}
506 		if (ccb->cdm.pattern_buf_len > 0) {
507 			data_ptrs[0] = (u_int8_t **)&ccb->cdm.patterns;
508 			lengths[0] = ccb->cdm.pattern_buf_len;
509 			dirs[0] = CAM_DIR_OUT;
510 			data_ptrs[1] = (u_int8_t **)&ccb->cdm.matches;
511 			lengths[1] = ccb->cdm.match_buf_len;
512 			dirs[1] = CAM_DIR_IN;
513 			numbufs = 2;
514 		} else {
515 			data_ptrs[0] = (u_int8_t **)&ccb->cdm.matches;
516 			lengths[0] = ccb->cdm.match_buf_len;
517 			dirs[0] = CAM_DIR_IN;
518 			numbufs = 1;
519 		}
520 		break;
521 	case XPT_SCSI_IO:
522 	case XPT_CONT_TARGET_IO:
523 		if ((ccb->ccb_h.flags & CAM_DIR_MASK) == CAM_DIR_NONE)
524 			return(0);
525 
526 		data_ptrs[0] = &ccb->csio.data_ptr;
527 		lengths[0] = ccb->csio.dxfer_len;
528 		dirs[0] = ccb->ccb_h.flags & CAM_DIR_MASK;
529 		numbufs = 1;
530 		break;
531 	default:
532 		return(EINVAL);
533 		break; /* NOTREACHED */
534 	}
535 
536 	/*
537 	 * Check the transfer length and permissions first, so we don't
538 	 * have to unmap any previously mapped buffers.
539 	 */
540 	for (i = 0; i < numbufs; i++) {
541 
542 		flags[i] = 0;
543 
544 		/*
545 		 * The userland data pointer passed in may not be page
546 		 * aligned.  vmapbuf() truncates the address to a page
547 		 * boundary, so if the address isn't page aligned, we'll
548 		 * need enough space for the given transfer length, plus
549 		 * whatever extra space is necessary to make it to the page
550 		 * boundary.
551 		 */
552 		if ((lengths[i] +
553 		    (((vm_offset_t)(*data_ptrs[i])) & PAGE_MASK)) > DFLTPHYS){
554 			printf("cam_periph_mapmem: attempt to map %u bytes, "
555 			       "which is greater than DFLTPHYS(%d)\n",
556 			       lengths[i] +
557 			       (((vm_offset_t)(*data_ptrs[i])) & PAGE_MASK),
558 			       DFLTPHYS);
559 			return(E2BIG);
560 		}
561 
562 		if (dirs[i] & CAM_DIR_OUT) {
563 			flags[i] = B_READ;
564 			if (useracc(*data_ptrs[i], lengths[i], B_READ) == 0){
565 				printf("cam_periph_mapmem: error, "
566 					"address %p, length %lu isn't "
567 					"user accessible for READ\n",
568 					(void *)*data_ptrs[i],
569 					(u_long)lengths[i]);
570 				return(EACCES);
571 			}
572 		}
573 
574 		/*
575 		 * XXX this check is really bogus, since B_WRITE currently
576 		 * is all 0's, and so it is "set" all the time.
577 		 */
578 		if (dirs[i] & CAM_DIR_IN) {
579 			flags[i] |= B_WRITE;
580 			if (useracc(*data_ptrs[i], lengths[i], B_WRITE) == 0){
581 				printf("cam_periph_mapmem: error, "
582 					"address %p, length %lu isn't "
583 					"user accessible for WRITE\n",
584 					(void *)*data_ptrs[i],
585 					(u_long)lengths[i]);
586 
587 				return(EACCES);
588 			}
589 		}
590 
591 	}
592 
593 	/* this keeps the current process from getting swapped */
594 	/*
595 	 * XXX KDM should I use P_NOSWAP instead?
596 	 */
597 	PHOLD(curproc);
598 
599 	for (i = 0; i < numbufs; i++) {
600 		/*
601 		 * Get the buffer.
602 		 */
603 		mapinfo->bp[i] = getpbuf(NULL);
604 
605 		/* save the buffer's data address */
606 		mapinfo->bp[i]->b_saveaddr = mapinfo->bp[i]->b_data;
607 
608 		/* put our pointer in the data slot */
609 		mapinfo->bp[i]->b_data = *data_ptrs[i];
610 
611 		/* set the transfer length, we know it's < DFLTPHYS */
612 		mapinfo->bp[i]->b_bufsize = lengths[i];
613 
614 		/* set the flags */
615 		mapinfo->bp[i]->b_flags = flags[i] | B_PHYS | B_BUSY;
616 
617 		/* map the buffer into kernel memory */
618 		vmapbuf(mapinfo->bp[i]);
619 
620 		/* set our pointer to the new mapped area */
621 		*data_ptrs[i] = mapinfo->bp[i]->b_data;
622 
623 		mapinfo->num_bufs_used++;
624 	}
625 
626 	return(0);
627 }
628 
629 /*
630  * Unmap memory segments mapped into kernel virtual address space by
631  * cam_periph_mapmem().
632  */
633 void
634 cam_periph_unmapmem(union ccb *ccb, struct cam_periph_map_info *mapinfo)
635 {
636 	int numbufs, i;
637 	u_int8_t **data_ptrs[CAM_PERIPH_MAXMAPS];
638 
639 	if (mapinfo->num_bufs_used <= 0) {
640 		/* allow ourselves to be swapped once again */
641 		PRELE(curproc);
642 		return;
643 	}
644 
645 	switch (ccb->ccb_h.func_code) {
646 	case XPT_DEV_MATCH:
647 		numbufs = min(mapinfo->num_bufs_used, 2);
648 
649 		if (numbufs == 1) {
650 			data_ptrs[0] = (u_int8_t **)&ccb->cdm.matches;
651 		} else {
652 			data_ptrs[0] = (u_int8_t **)&ccb->cdm.patterns;
653 			data_ptrs[1] = (u_int8_t **)&ccb->cdm.matches;
654 		}
655 		break;
656 	case XPT_SCSI_IO:
657 	case XPT_CONT_TARGET_IO:
658 		data_ptrs[0] = &ccb->csio.data_ptr;
659 		numbufs = min(mapinfo->num_bufs_used, 1);
660 		break;
661 	default:
662 		/* allow ourselves to be swapped once again */
663 		PRELE(curproc);
664 		return;
665 		break; /* NOTREACHED */
666 	}
667 
668 	for (i = 0; i < numbufs; i++) {
669 		/* Set the user's pointer back to the original value */
670 		*data_ptrs[i] = mapinfo->bp[i]->b_saveaddr;
671 
672 		/* unmap the buffer */
673 		vunmapbuf(mapinfo->bp[i]);
674 
675 		/* clear the flags we set above */
676 		mapinfo->bp[i]->b_flags &= ~(B_PHYS|B_BUSY);
677 
678 		/* release the buffer */
679 		relpbuf(mapinfo->bp[i], NULL);
680 	}
681 
682 	/* allow ourselves to be swapped once again */
683 	PRELE(curproc);
684 }
685 
686 union ccb *
687 cam_periph_getccb(struct cam_periph *periph, u_int32_t priority)
688 {
689 	struct ccb_hdr *ccb_h;
690 	int s;
691 
692 	CAM_DEBUG(periph->path, CAM_DEBUG_TRACE, ("entering cdgetccb\n"));
693 
694 	s = splsoftcam();
695 
696 	while (periph->ccb_list.slh_first == NULL) {
697 		if (periph->immediate_priority > priority)
698 			periph->immediate_priority = priority;
699 		xpt_schedule(periph, priority);
700 		if ((periph->ccb_list.slh_first != NULL)
701 		 && (periph->ccb_list.slh_first->pinfo.priority == priority))
702 			break;
703 		tsleep(&periph->ccb_list, PRIBIO, "cgticb", 0);
704 	}
705 
706 	ccb_h = periph->ccb_list.slh_first;
707 	SLIST_REMOVE_HEAD(&periph->ccb_list, periph_links.sle);
708 	splx(s);
709 	return ((union ccb *)ccb_h);
710 }
711 
712 void
713 cam_periph_ccbwait(union ccb *ccb)
714 {
715 	int s;
716 
717 	s = splsoftcam();
718 	if ((ccb->ccb_h.pinfo.index != CAM_UNQUEUED_INDEX)
719 	 || ((ccb->ccb_h.status & CAM_STATUS_MASK) == CAM_REQ_INPROG))
720 		tsleep(&ccb->ccb_h.cbfcnp, PRIBIO, "cbwait", 0);
721 
722 	splx(s);
723 }
724 
725 int
726 cam_periph_ioctl(struct cam_periph *periph, int cmd, caddr_t addr,
727 		 int (*error_routine)(union ccb *ccb,
728 				      cam_flags camflags,
729 				      u_int32_t sense_flags))
730 {
731 	union ccb 	     *ccb;
732 	int 		     error;
733 	int		     found;
734 
735 	error = found = 0;
736 
737 	switch(cmd){
738 	case CAMGETPASSTHRU:
739 		ccb = cam_periph_getccb(periph, /* priority */ 1);
740 		xpt_setup_ccb(&ccb->ccb_h,
741 			      ccb->ccb_h.path,
742 			      /*priority*/1);
743 		ccb->ccb_h.func_code = XPT_GDEVLIST;
744 
745 		/*
746 		 * Basically, the point of this is that we go through
747 		 * getting the list of devices, until we find a passthrough
748 		 * device.  In the current version of the CAM code, the
749 		 * only way to determine what type of device we're dealing
750 		 * with is by its name.
751 		 */
752 		while (found == 0) {
753 			ccb->cgdl.index = 0;
754 			ccb->cgdl.status = CAM_GDEVLIST_MORE_DEVS;
755 			while (ccb->cgdl.status == CAM_GDEVLIST_MORE_DEVS) {
756 
757 				/* we want the next device in the list */
758 				xpt_action(ccb);
759 				if (strncmp(ccb->cgdl.periph_name,
760 				    "pass", 4) == 0){
761 					found = 1;
762 					break;
763 				}
764 			}
765 			if ((ccb->cgdl.status == CAM_GDEVLIST_LAST_DEVICE) &&
766 			    (found == 0)) {
767 				ccb->cgdl.periph_name[0] = '\0';
768 				ccb->cgdl.unit_number = 0;
769 				break;
770 			}
771 		}
772 
773 		/* copy the result back out */
774 		bcopy(ccb, addr, sizeof(union ccb));
775 
776 		/* and release the ccb */
777 		xpt_release_ccb(ccb);
778 
779 		break;
780 	default:
781 		error = ENOTTY;
782 		break;
783 	}
784 	return(error);
785 }
786 
787 int
788 cam_periph_runccb(union ccb *ccb,
789 		  int (*error_routine)(union ccb *ccb,
790 				       cam_flags camflags,
791 				       u_int32_t sense_flags),
792 		  cam_flags camflags, u_int32_t sense_flags,
793 		  struct devstat *ds)
794 {
795 	int error;
796 
797 	error = 0;
798 
799 	/*
800 	 * If the user has supplied a stats structure, and if we understand
801 	 * this particular type of ccb, record the transaction start.
802 	 */
803 	if ((ds != NULL) && (ccb->ccb_h.func_code == XPT_SCSI_IO))
804 		devstat_start_transaction(ds);
805 
806 	xpt_action(ccb);
807 
808 	do {
809 		cam_periph_ccbwait(ccb);
810 		if ((ccb->ccb_h.status & CAM_STATUS_MASK) == CAM_REQ_CMP)
811 			error = 0;
812 		else if (error_routine != NULL)
813 			error = (*error_routine)(ccb, camflags, sense_flags);
814 		else
815 			error = 0;
816 
817 	} while (error == ERESTART);
818 
819 	if ((ccb->ccb_h.status & CAM_DEV_QFRZN) != 0)
820 		cam_release_devq(ccb->ccb_h.path,
821 				 /* relsim_flags */0,
822 				 /* openings */0,
823 				 /* timeout */0,
824 				 /* getcount_only */ FALSE);
825 
826 	if ((ds != NULL) && (ccb->ccb_h.func_code == XPT_SCSI_IO))
827 		devstat_end_transaction(ds,
828 					ccb->csio.dxfer_len,
829 					ccb->csio.tag_action & 0xf,
830 					((ccb->ccb_h.flags & CAM_DIR_MASK) ==
831 					CAM_DIR_NONE) ?  DEVSTAT_NO_DATA :
832 					(ccb->ccb_h.flags & CAM_DIR_OUT) ?
833 					DEVSTAT_WRITE :
834 					DEVSTAT_READ);
835 
836 	return(error);
837 }
838 
839 void
840 cam_freeze_devq(struct cam_path *path)
841 {
842 	struct ccb_hdr ccb_h;
843 
844 	xpt_setup_ccb(&ccb_h, path, /*priority*/1);
845 	ccb_h.func_code = XPT_NOOP;
846 	ccb_h.flags = CAM_DEV_QFREEZE;
847 	xpt_action((union ccb *)&ccb_h);
848 }
849 
850 u_int32_t
851 cam_release_devq(struct cam_path *path, u_int32_t relsim_flags,
852 		 u_int32_t openings, u_int32_t timeout,
853 		 int getcount_only)
854 {
855 	struct ccb_relsim crs;
856 
857 	xpt_setup_ccb(&crs.ccb_h, path,
858 		      /*priority*/1);
859 	crs.ccb_h.func_code = XPT_REL_SIMQ;
860 	crs.ccb_h.flags = getcount_only ? CAM_DEV_QFREEZE : 0;
861 	crs.release_flags = relsim_flags;
862 	crs.openings = openings;
863 	crs.release_timeout = timeout;
864 	xpt_action((union ccb *)&crs);
865 	return (crs.qfrozen_cnt);
866 }
867 
868 #define saved_ccb_ptr ppriv_ptr0
869 static void
870 camperiphdone(struct cam_periph *periph, union ccb *done_ccb)
871 {
872 	cam_status	status;
873 	int		frozen;
874 	int		sense;
875 	struct scsi_start_stop_unit *scsi_cmd;
876 	u_int32_t	relsim_flags, timeout;
877 	u_int32_t	qfrozen_cnt;
878 
879 	status = done_ccb->ccb_h.status;
880 	frozen = (status & CAM_DEV_QFRZN) != 0;
881 	sense  = (status & CAM_AUTOSNS_VALID) != 0;
882 	status &= CAM_STATUS_MASK;
883 
884 	timeout = 0;
885 	relsim_flags = 0;
886 
887 	/*
888 	 * Unfreeze the queue once if it is already frozen..
889 	 */
890 	if (frozen != 0) {
891 		qfrozen_cnt = cam_release_devq(done_ccb->ccb_h.path,
892 					      /*relsim_flags*/0,
893 					      /*openings*/0,
894 					      /*timeout*/0,
895 					      /*getcount_only*/0);
896 	}
897 
898 	switch (status) {
899 
900 	case CAM_REQ_CMP:
901 
902 		/*
903 		 * If we have successfully taken a device from the not
904 		 * ready to ready state, re-scan the device and re-get the
905 		 * inquiry information.  Many devices (mostly disks) don't
906 		 * properly report their inquiry information unless they
907 		 * are spun up.
908 		 */
909 		if (done_ccb->ccb_h.func_code == XPT_SCSI_IO) {
910 			scsi_cmd = (struct scsi_start_stop_unit *)
911 					&done_ccb->csio.cdb_io.cdb_bytes;
912 
913 		 	if (scsi_cmd->opcode == START_STOP_UNIT)
914 				xpt_async(AC_INQ_CHANGED,
915 					  done_ccb->ccb_h.path, NULL);
916 		}
917 		bcopy(done_ccb->ccb_h.saved_ccb_ptr, done_ccb,
918 		      sizeof(union ccb));
919 
920 		periph->flags &= ~CAM_PERIPH_RECOVERY_INPROG;
921 
922 		xpt_action(done_ccb);
923 
924 		break;
925 	case CAM_SCSI_STATUS_ERROR:
926 		scsi_cmd = (struct scsi_start_stop_unit *)
927 				&done_ccb->csio.cdb_io.cdb_bytes;
928 		if (sense != 0) {
929 			struct scsi_sense_data *sense;
930 			int    error_code, sense_key, asc, ascq;
931 
932 			sense = &done_ccb->csio.sense_data;
933 			scsi_extract_sense(sense, &error_code,
934 					   &sense_key, &asc, &ascq);
935 
936 			/*
937 	 		 * If the error is "invalid field in CDB",
938 			 * and the load/eject flag is set, turn the
939 			 * flag off and try again.  This is just in
940 			 * case the drive in question barfs on the
941 			 * load eject flag.  The CAM code should set
942 			 * the load/eject flag by default for
943 			 * removable media.
944 			 */
945 
946 			/* XXX KDM
947 			 * Should we check to see what the specific
948 			 * scsi status is??  Or does it not matter
949 			 * since we already know that there was an
950 			 * error, and we know what the specific
951 			 * error code was, and we know what the
952 			 * opcode is..
953 			 */
954 			if ((scsi_cmd->opcode == START_STOP_UNIT) &&
955 			    ((scsi_cmd->how & SSS_LOEJ) != 0) &&
956 			     (asc == 0x24) && (ascq == 0x00) &&
957 			     (done_ccb->ccb_h.retry_count > 0)) {
958 
959 				scsi_cmd->how &= ~SSS_LOEJ;
960 
961 				xpt_action(done_ccb);
962 
963 			} else if (done_ccb->ccb_h.retry_count > 0) {
964 				/*
965 				 * In this case, the error recovery
966 				 * command failed, but we've got
967 				 * some retries left on it.  Give
968 				 * it another try.
969 				 */
970 
971 				/* set the timeout to .5 sec */
972 				relsim_flags =
973 					RELSIM_RELEASE_AFTER_TIMEOUT;
974 				timeout = 500;
975 
976 				xpt_action(done_ccb);
977 
978 				break;
979 
980 			} else {
981 				/*
982 				 * Copy the original CCB back and
983 				 * send it back to the caller.
984 				 */
985 				bcopy(done_ccb->ccb_h.saved_ccb_ptr,
986 				      done_ccb, sizeof(union ccb));
987 
988 				periph->flags &= ~CAM_PERIPH_RECOVERY_INPROG;
989 
990 				xpt_action(done_ccb);
991 			}
992 		} else {
993 			/*
994 			 * Eh??  The command failed, but we don't
995 			 * have any sense.  What's up with that?
996 			 * Fire the CCB again to return it to the
997 			 * caller.
998 			 */
999 			bcopy(done_ccb->ccb_h.saved_ccb_ptr,
1000 			      done_ccb, sizeof(union ccb));
1001 
1002 			periph->flags &= ~CAM_PERIPH_RECOVERY_INPROG;
1003 
1004 			xpt_action(done_ccb);
1005 
1006 		}
1007 		break;
1008 	default:
1009 		bcopy(done_ccb->ccb_h.saved_ccb_ptr, done_ccb,
1010 		      sizeof(union ccb));
1011 
1012 		periph->flags &= ~CAM_PERIPH_RECOVERY_INPROG;
1013 
1014 		xpt_action(done_ccb);
1015 
1016 		break;
1017 	}
1018 
1019 	/* decrement the retry count */
1020 	if (done_ccb->ccb_h.retry_count > 0)
1021 		done_ccb->ccb_h.retry_count--;
1022 
1023 	qfrozen_cnt = cam_release_devq(done_ccb->ccb_h.path,
1024 				      /*relsim_flags*/relsim_flags,
1025 				      /*openings*/0,
1026 				      /*timeout*/timeout,
1027 				      /*getcount_only*/0);
1028 }
1029 
1030 /*
1031  * Generic Async Event handler.  Peripheral drivers usually
1032  * filter out the events that require personal attention,
1033  * and leave the rest to this function.
1034  */
1035 void
1036 cam_periph_async(struct cam_periph *periph, u_int32_t code,
1037 		 struct cam_path *path, void *arg)
1038 {
1039 	switch (code) {
1040 	case AC_LOST_DEVICE:
1041 		cam_periph_invalidate(periph);
1042 		break;
1043 	case AC_SENT_BDR:
1044 	case AC_BUS_RESET:
1045 	{
1046 		cam_periph_bus_settle(periph, SCSI_DELAY);
1047 		break;
1048 	}
1049 	default:
1050 		break;
1051 	}
1052 }
1053 
1054 void
1055 cam_periph_bus_settle(struct cam_periph *periph, u_int bus_settle)
1056 {
1057 	struct ccb_getdevstats cgds;
1058 
1059 	xpt_setup_ccb(&cgds.ccb_h, periph->path, /*priority*/1);
1060 	cgds.ccb_h.func_code = XPT_GDEV_STATS;
1061 	xpt_action((union ccb *)&cgds);
1062 	cam_periph_freeze_after_event(periph, &cgds.last_reset, bus_settle);
1063 }
1064 
1065 void
1066 cam_periph_freeze_after_event(struct cam_periph *periph,
1067 			      struct timeval* event_time, u_int duration_ms)
1068 {
1069 	struct timeval delta;
1070 	struct timeval duration_tv;
1071 	int s;
1072 
1073 	s = splclock();
1074 	microtime(&delta);
1075 	splx(s);
1076 	timevalsub(&delta, event_time);
1077 	duration_tv.tv_sec = duration_ms / 1000;
1078 	duration_tv.tv_usec = (duration_ms % 1000) * 1000;
1079 	if (timevalcmp(&delta, &duration_tv, <)) {
1080 		timevalsub(&duration_tv, &delta);
1081 
1082 		duration_ms = duration_tv.tv_sec * 1000;
1083 		duration_ms += duration_tv.tv_usec / 1000;
1084 		cam_freeze_devq(periph->path);
1085 		cam_release_devq(periph->path,
1086 				RELSIM_RELEASE_AFTER_TIMEOUT,
1087 				/*reduction*/0,
1088 				/*timeout*/duration_ms,
1089 				/*getcount_only*/0);
1090 	}
1091 
1092 }
1093 
1094 /*
1095  * Generic error handler.  Peripheral drivers usually filter
1096  * out the errors that they handle in a unique mannor, then
1097  * call this function.
1098  */
1099 int
1100 cam_periph_error(union ccb *ccb, cam_flags camflags,
1101 		 u_int32_t sense_flags, union ccb *save_ccb)
1102 {
1103 	cam_status status;
1104 	int	   frozen;
1105 	int	   sense;
1106 	int	   error;
1107 	int        openings;
1108 	int	   retry;
1109 	u_int32_t  relsim_flags;
1110 	u_int32_t  timeout;
1111 
1112 	status = ccb->ccb_h.status;
1113 	frozen = (status & CAM_DEV_QFRZN) != 0;
1114 	sense  = (status & CAM_AUTOSNS_VALID) != 0;
1115 	status &= CAM_STATUS_MASK;
1116 	relsim_flags = 0;
1117 
1118 	switch (status) {
1119 	case CAM_REQ_CMP:
1120 		/* decrement the number of retries */
1121 		retry = ccb->ccb_h.retry_count > 0;
1122 		if (retry)
1123 			ccb->ccb_h.retry_count--;
1124 		error = 0;
1125 		break;
1126 	case CAM_AUTOSENSE_FAIL:
1127 	case CAM_SCSI_STATUS_ERROR:
1128 
1129 		switch (ccb->csio.scsi_status) {
1130 		case SCSI_STATUS_OK:
1131 		case SCSI_STATUS_COND_MET:
1132 		case SCSI_STATUS_INTERMED:
1133 		case SCSI_STATUS_INTERMED_COND_MET:
1134 			error = 0;
1135 			break;
1136 		case SCSI_STATUS_CMD_TERMINATED:
1137 		case SCSI_STATUS_CHECK_COND:
1138 			if (sense != 0) {
1139 				struct scsi_sense_data *sense;
1140 				int    error_code, sense_key, asc, ascq;
1141 				struct cam_periph *periph;
1142 				scsi_sense_action err_action;
1143 				struct ccb_getdev cgd;
1144 
1145 				sense = &ccb->csio.sense_data;
1146 				scsi_extract_sense(sense, &error_code,
1147 						   &sense_key, &asc, &ascq);
1148 				periph = xpt_path_periph(ccb->ccb_h.path);
1149 
1150 				/*
1151 				 * Grab the inquiry data for this device.
1152 				 */
1153 				xpt_setup_ccb(&cgd.ccb_h, ccb->ccb_h.path,
1154 					      /*priority*/ 1);
1155 				cgd.ccb_h.func_code = XPT_GDEV_TYPE;
1156 				xpt_action((union ccb *)&cgd);
1157 
1158 				err_action = scsi_error_action(asc, ascq,
1159 							       &cgd.inq_data);
1160 
1161 				/*
1162 				 * Send a Test Unit Ready to the device.
1163 				 * If the 'many' flag is set, we send 120
1164 				 * test unit ready commands, one every half
1165 				 * second.  Otherwise, we just send one TUR.
1166 				 * We only want to do this if the retry
1167 				 * count has not been exhausted.
1168 				 */
1169 				if (((err_action & SS_MASK) == SS_TUR)
1170 				 && save_ccb != NULL
1171 				 && ccb->ccb_h.retry_count > 0) {
1172 
1173 					/*
1174 					 * Since error recovery is already
1175 					 * in progress, don't attempt to
1176 					 * process this error.  It is probably
1177 					 * related to the error that caused
1178 					 * the currently active error recovery
1179 					 * action.  Also, we only have
1180 					 * space for one saved CCB, so if we
1181 					 * had two concurrent error recovery
1182 					 * actions, we would end up
1183 					 * over-writing one error recovery
1184 					 * CCB with another one.
1185 					 */
1186 					if (periph->flags &
1187 					    CAM_PERIPH_RECOVERY_INPROG) {
1188 						error = ERESTART;
1189 						break;
1190 					}
1191 
1192 					periph->flags |=
1193 						CAM_PERIPH_RECOVERY_INPROG;
1194 
1195 					/* decrement the number of retries */
1196 					if ((err_action &
1197 					     SSQ_DECREMENT_COUNT) != 0) {
1198 						retry = 1;
1199 						ccb->ccb_h.retry_count--;
1200 					}
1201 
1202 					bcopy(ccb, save_ccb, sizeof(*save_ccb));
1203 
1204 					/*
1205 					 * We retry this one every half
1206 					 * second for a minute.  If the
1207 					 * device hasn't become ready in a
1208 					 * minute's time, it's unlikely to
1209 					 * ever become ready.  If the table
1210 					 * doesn't specify SSQ_MANY, we can
1211 					 * only try this once.  Oh well.
1212 					 */
1213 					if ((err_action & SSQ_MANY) != 0)
1214 						scsi_test_unit_ready(&ccb->csio,
1215 							       /*retries*/120,
1216 							       camperiphdone,
1217 						 	       MSG_SIMPLE_Q_TAG,
1218 							       SSD_FULL_SIZE,
1219 							       /*timeout*/5000);
1220 					else
1221 						scsi_test_unit_ready(&ccb->csio,
1222 							       /*retries*/1,
1223 							       camperiphdone,
1224 						 	       MSG_SIMPLE_Q_TAG,
1225 							       SSD_FULL_SIZE,
1226 							       /*timeout*/5000);
1227 
1228 					/* release the queue after .5 sec.  */
1229 					relsim_flags =
1230 						RELSIM_RELEASE_AFTER_TIMEOUT;
1231 					timeout = 500;
1232 					/*
1233 					 * Drop the priority to 0 so that
1234 					 * we are the first to execute.  Also
1235 					 * freeze the queue after this command
1236 					 * is sent so that we can restore the
1237 					 * old csio and have it queued in the
1238 					 * proper order before we let normal
1239 					 * transactions go to the drive.
1240 					 */
1241 					ccb->ccb_h.pinfo.priority = 0;
1242 					ccb->ccb_h.flags |= CAM_DEV_QFREEZE;
1243 
1244 					/*
1245 					 * Save a pointer to the original
1246 					 * CCB in the new CCB.
1247 					 */
1248 					ccb->ccb_h.saved_ccb_ptr = save_ccb;
1249 
1250 					error = ERESTART;
1251 				}
1252 				/*
1253 				 * Send a start unit command to the device,
1254 				 * and then retry the command.  We only
1255 				 * want to do this if the retry count has
1256 				 * not been exhausted.  If the user
1257 				 * specified 0 retries, then we follow
1258 				 * their request and do not retry.
1259 				 */
1260 				else if (((err_action & SS_MASK) == SS_START)
1261 				      && save_ccb != NULL
1262 				      && ccb->ccb_h.retry_count > 0) {
1263 					int le;
1264 
1265 					/*
1266 					 * Only one error recovery action
1267 					 * at a time.  See above.
1268 					 */
1269 					if (periph->flags &
1270 					    CAM_PERIPH_RECOVERY_INPROG) {
1271 						error = ERESTART;
1272 						break;
1273 					}
1274 
1275 					periph->flags |=
1276 						CAM_PERIPH_RECOVERY_INPROG;
1277 
1278 					/* decrement the number of retries */
1279 					retry = 1;
1280 					ccb->ccb_h.retry_count--;
1281 
1282 					/*
1283 					 * Check for removable media and
1284 					 * set load/eject flag
1285 					 * appropriately.
1286 					 */
1287 					if (SID_IS_REMOVABLE(&cgd.inq_data))
1288 						le = TRUE;
1289 					else
1290 						le = FALSE;
1291 
1292 					/*
1293 					 * Attempt to start the drive up.
1294 					 *
1295 					 * Save the current ccb so it can
1296 					 * be restored and retried once the
1297 					 * drive is started up.
1298 					 */
1299 					bcopy(ccb, save_ccb, sizeof(*save_ccb));
1300 
1301 					scsi_start_stop(&ccb->csio,
1302 							/*retries*/1,
1303 							camperiphdone,
1304 							MSG_SIMPLE_Q_TAG,
1305 							/*start*/TRUE,
1306 							/*load/eject*/le,
1307 							/*immediate*/FALSE,
1308 							SSD_FULL_SIZE,
1309 							/*timeout*/50000);
1310 					/*
1311 					 * Drop the priority to 0 so that
1312 					 * we are the first to execute.  Also
1313 					 * freeze the queue after this command
1314 					 * is sent so that we can restore the
1315 					 * old csio and have it queued in the
1316 					 * proper order before we let normal
1317 					 * transactions go to the drive.
1318 					 */
1319 					ccb->ccb_h.pinfo.priority = 0;
1320 					ccb->ccb_h.flags |= CAM_DEV_QFREEZE;
1321 
1322 					/*
1323 					 * Save a pointer to the original
1324 					 * CCB in the new CCB.
1325 					 */
1326 					ccb->ccb_h.saved_ccb_ptr = save_ccb;
1327 
1328 					error = ERESTART;
1329 				} else if ((sense_flags & SF_RETRY_UA) != 0) {
1330 					/*
1331 					 * XXX KDM this is a *horrible*
1332 					 * hack.
1333 					 */
1334 					error = scsi_interpret_sense(ccb,
1335 								  sense_flags,
1336 								  &relsim_flags,
1337 								  &openings,
1338 								  &timeout,
1339 								  err_action);
1340 				}
1341 
1342 				/*
1343 				 * Theoretically, this code should send a
1344 				 * test unit ready to the given device, and
1345 				 * if it returns and error, send a start
1346 				 * unit command.  Since we don't yet have
1347 				 * the capability to do two-command error
1348 				 * recovery, just send a start unit.
1349 				 * XXX KDM fix this!
1350 				 */
1351 				else if (((err_action & SS_MASK) == SS_TURSTART)
1352 				      && save_ccb != NULL
1353 				      && ccb->ccb_h.retry_count > 0) {
1354 					int le;
1355 
1356 					/*
1357 					 * Only one error recovery action
1358 					 * at a time.  See above.
1359 					 */
1360 					if (periph->flags &
1361 					    CAM_PERIPH_RECOVERY_INPROG) {
1362 						error = ERESTART;
1363 						break;
1364 					}
1365 
1366 					periph->flags |=
1367 						CAM_PERIPH_RECOVERY_INPROG;
1368 
1369 					/* decrement the number of retries */
1370 					retry = 1;
1371 					ccb->ccb_h.retry_count--;
1372 
1373 					/*
1374 					 * Check for removable media and
1375 					 * set load/eject flag
1376 					 * appropriately.
1377 					 */
1378 					if (SID_IS_REMOVABLE(&cgd.inq_data))
1379 						le = TRUE;
1380 					else
1381 						le = FALSE;
1382 
1383 					/*
1384 					 * Attempt to start the drive up.
1385 					 *
1386 					 * Save the current ccb so it can
1387 					 * be restored and retried once the
1388 					 * drive is started up.
1389 					 */
1390 					bcopy(ccb, save_ccb, sizeof(*save_ccb));
1391 
1392 					scsi_start_stop(&ccb->csio,
1393 							/*retries*/1,
1394 							camperiphdone,
1395 							MSG_SIMPLE_Q_TAG,
1396 							/*start*/TRUE,
1397 							/*load/eject*/le,
1398 							/*immediate*/FALSE,
1399 							SSD_FULL_SIZE,
1400 							/*timeout*/50000);
1401 
1402 					/* release the queue after .5 sec.  */
1403 					relsim_flags =
1404 						RELSIM_RELEASE_AFTER_TIMEOUT;
1405 					timeout = 500;
1406 					/*
1407 					 * Drop the priority to 0 so that
1408 					 * we are the first to execute.  Also
1409 					 * freeze the queue after this command
1410 					 * is sent so that we can restore the
1411 					 * old csio and have it queued in the
1412 					 * proper order before we let normal
1413 					 * transactions go to the drive.
1414 					 */
1415 					ccb->ccb_h.pinfo.priority = 0;
1416 					ccb->ccb_h.flags |= CAM_DEV_QFREEZE;
1417 
1418 					/*
1419 					 * Save a pointer to the original
1420 					 * CCB in the new CCB.
1421 					 */
1422 					ccb->ccb_h.saved_ccb_ptr = save_ccb;
1423 
1424 					error = ERESTART;
1425 				} else {
1426 					error = scsi_interpret_sense(ccb,
1427 								  sense_flags,
1428 								  &relsim_flags,
1429 								  &openings,
1430 								  &timeout,
1431 								  err_action);
1432 				}
1433 			} else if (ccb->csio.scsi_status ==
1434 				   SCSI_STATUS_CHECK_COND
1435 				&& status != CAM_AUTOSENSE_FAIL) {
1436 				/* no point in decrementing the retry count */
1437 				panic("cam_periph_error: scsi status of "
1438 				      "CHECK COND returned but no sense "
1439 				      "information is availible.  "
1440 				      "Controller should have returned "
1441 				      "CAM_AUTOSENSE_FAILED");
1442 				/* NOTREACHED */
1443 				error = EIO;
1444 			} else if (ccb->ccb_h.retry_count > 0) {
1445 				/*
1446 				 * XXX KDM shouldn't there be a better
1447 				 * argument to return??
1448 				 */
1449 				error = EIO;
1450 			} else {
1451 				/* decrement the number of retries */
1452 				retry = ccb->ccb_h.retry_count > 0;
1453 				if (retry)
1454 					ccb->ccb_h.retry_count--;
1455 				/*
1456 				 * If it was aborted with no
1457 				 * clue as to the reason, just
1458 				 * retry it again.
1459 				 */
1460 				error = ERESTART;
1461 			}
1462 			break;
1463 		case SCSI_STATUS_QUEUE_FULL:
1464 		{
1465 			/* no decrement */
1466 			struct ccb_getdevstats cgds;
1467 
1468 			/*
1469 			 * First off, find out what the current
1470 			 * transaction counts are.
1471 			 */
1472 			xpt_setup_ccb(&cgds.ccb_h,
1473 				      ccb->ccb_h.path,
1474 				      /*priority*/1);
1475 			cgds.ccb_h.func_code = XPT_GDEV_STATS;
1476 			xpt_action((union ccb *)&cgds);
1477 
1478 			/*
1479 			 * If we were the only transaction active, treat
1480 			 * the QUEUE FULL as if it were a BUSY condition.
1481 			 */
1482 			if (cgds.dev_active != 0) {
1483 				int total_openings;
1484 
1485 				/*
1486 			 	 * Reduce the number of openings to
1487 				 * be 1 less than the amount it took
1488 				 * to get a queue full bounded by the
1489 				 * minimum allowed tag count for this
1490 				 * device.
1491 			 	 */
1492 				total_openings =
1493 				    cgds.dev_active+cgds.dev_openings;
1494 				openings = cgds.dev_active;
1495 				if (openings < cgds.mintags)
1496 					openings = cgds.mintags;
1497 				if (openings < total_openings)
1498 					relsim_flags = RELSIM_ADJUST_OPENINGS;
1499 				else {
1500 					/*
1501 					 * Some devices report queue full for
1502 					 * temporary resource shortages.  For
1503 					 * this reason, we allow a minimum
1504 					 * tag count to be entered via a
1505 					 * quirk entry to prevent the queue
1506 					 * count on these devices from falling
1507 					 * to a pessimisticly low value.  We
1508 					 * still wait for the next successful
1509 					 * completion, however, before queueing
1510 					 * more transactions to the device.
1511 					 */
1512 					relsim_flags =
1513 					    RELSIM_RELEASE_AFTER_CMDCMPLT;
1514 				}
1515 				timeout = 0;
1516 				error = ERESTART;
1517 				break;
1518 			}
1519 			/* FALLTHROUGH */
1520 		}
1521 		case SCSI_STATUS_BUSY:
1522 			/*
1523 			 * Restart the queue after either another
1524 			 * command completes or a 1 second timeout.
1525 			 */
1526 			/*
1527 			 * XXX KDM ask JTG about this again, do we need to
1528 			 * be looking at the retry count here?
1529 			 */
1530 			error = ERESTART;
1531 			relsim_flags = RELSIM_RELEASE_AFTER_TIMEOUT
1532 				     | RELSIM_RELEASE_AFTER_CMDCMPLT;
1533 			timeout = 1000;
1534 			break;
1535 		case SCSI_STATUS_RESERV_CONFLICT:
1536 			error = EIO;
1537 			break;
1538 		default:
1539 			error = EIO;
1540 			break;
1541 		}
1542 		break;
1543 	case CAM_REQ_CMP_ERR:
1544 	case CAM_CMD_TIMEOUT:
1545 	case CAM_UNEXP_BUSFREE:
1546 	case CAM_UNCOR_PARITY:
1547 	case CAM_DATA_RUN_ERR:
1548 		/* decrement the number of retries */
1549 		retry = ccb->ccb_h.retry_count > 0;
1550 		if (retry) {
1551 			ccb->ccb_h.retry_count--;
1552 			error = ERESTART;
1553 		} else {
1554 			error = EIO;
1555 		}
1556 		break;
1557 	case CAM_UA_ABORT:
1558 	case CAM_UA_TERMIO:
1559 	case CAM_MSG_REJECT_REC:
1560 		/* XXX Don't know that these are correct */
1561 		error = EIO;
1562 		break;
1563 	case CAM_SEL_TIMEOUT:
1564 	{
1565 		/*
1566 		 * XXX
1567 		 * A single selection timeout should not be enough
1568 		 * to invalidate a device.  We should retry for multiple
1569 		 * seconds assuming this isn't a probe.  We'll probably
1570 		 * need a special flag for that.
1571 		 */
1572 #if 0
1573 		struct cam_path *newpath;
1574 
1575 		/* Should we do more if we can't create the path?? */
1576 		if (xpt_create_path(&newpath, xpt_path_periph(ccb->ccb_h.path),
1577 				    xpt_path_path_id(ccb->ccb_h.path),
1578 				    xpt_path_target_id(ccb->ccb_h.path),
1579 				    CAM_LUN_WILDCARD) != CAM_REQ_CMP)
1580 			break;
1581 		/*
1582 		 * Let peripheral drivers know that this device has gone
1583 		 * away.
1584 		 */
1585 		xpt_async(AC_LOST_DEVICE, newpath, NULL);
1586 		xpt_free_path(newpath);
1587 #endif
1588 		if ((sense_flags & SF_RETRY_SELTO) != 0) {
1589 			retry = ccb->ccb_h.retry_count > 0;
1590 			if (retry) {
1591 				ccb->ccb_h.retry_count--;
1592 				error = ERESTART;
1593 				/*
1594 				 * Wait half a second to give the device
1595 				 * time to recover before we try again.
1596 				 */
1597 				relsim_flags = RELSIM_RELEASE_AFTER_TIMEOUT;
1598 				timeout = 500;
1599 			} else {
1600 				error = ENXIO;
1601 			}
1602 		} else {
1603 			error = ENXIO;
1604 		}
1605 		break;
1606 	}
1607 	case CAM_REQ_INVALID:
1608 	case CAM_PATH_INVALID:
1609 	case CAM_DEV_NOT_THERE:
1610 	case CAM_NO_HBA:
1611 	case CAM_PROVIDE_FAIL:
1612 	case CAM_REQ_TOO_BIG:
1613 		error = EINVAL;
1614 		break;
1615 	case CAM_SCSI_BUS_RESET:
1616 	case CAM_BDR_SENT:
1617 	case CAM_REQUEUE_REQ:
1618 		/* Unconditional requeue, dammit */
1619 		error = ERESTART;
1620 		break;
1621 	case CAM_RESRC_UNAVAIL:
1622 	case CAM_BUSY:
1623 		/* timeout??? */
1624 	default:
1625 		/* decrement the number of retries */
1626 		retry = ccb->ccb_h.retry_count > 0;
1627 		if (retry) {
1628 			ccb->ccb_h.retry_count--;
1629 			error = ERESTART;
1630 		} else {
1631 			/* Check the sense codes */
1632 			error = EIO;
1633 		}
1634 		break;
1635 	}
1636 
1637 	/* Attempt a retry */
1638 	if (error == ERESTART || error == 0) {
1639 		if (frozen != 0)
1640 			ccb->ccb_h.status &= ~CAM_DEV_QFRZN;
1641 
1642 		if (error == ERESTART)
1643 			xpt_action(ccb);
1644 
1645 		if (frozen != 0) {
1646 			cam_release_devq(ccb->ccb_h.path,
1647 					 relsim_flags,
1648 					 openings,
1649 					 timeout,
1650 					 /*getcount_only*/0);
1651 		}
1652 	}
1653 
1654 
1655 	return (error);
1656 }
1657