xref: /freebsd/sys/cam/cam_periph.c (revision 77a0943ded95b9e6438f7db70c4a28e4d93946d4)
1 /*
2  * Common functions for CAM "type" (peripheral) drivers.
3  *
4  * Copyright (c) 1997, 1998 Justin T. Gibbs.
5  * Copyright (c) 1997, 1998, 1999, 2000 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  * $FreeBSD$
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/bio.h>
38 #include <sys/buf.h>
39 #include <sys/proc.h>
40 #include <sys/devicestat.h>
41 #include <sys/bus.h>
42 #include <vm/vm.h>
43 #include <vm/vm_extern.h>
44 
45 #include <cam/cam.h>
46 #include <cam/cam_ccb.h>
47 #include <cam/cam_xpt_periph.h>
48 #include <cam/cam_periph.h>
49 #include <cam/cam_debug.h>
50 
51 #include <cam/scsi/scsi_all.h>
52 #include <cam/scsi/scsi_message.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 					  path_id_t pathid, target_id_t target,
58 					  lun_id_t lun);
59 static	u_int		camperiphunit(struct periph_driver *p_drv,
60 				      path_id_t pathid, target_id_t target,
61 				      lun_id_t lun);
62 static	void		camperiphdone(struct cam_periph *periph,
63 					union ccb *done_ccb);
64 static  void		camperiphfree(struct cam_periph *periph);
65 
66 cam_status
67 cam_periph_alloc(periph_ctor_t *periph_ctor,
68 		 periph_oninv_t *periph_oninvalidate,
69 		 periph_dtor_t *periph_dtor, periph_start_t *periph_start,
70 		 char *name, cam_periph_type type, struct cam_path *path,
71 		 ac_callback_t *ac_callback, ac_code code, void *arg)
72 {
73 	struct		periph_driver **p_drv;
74 	struct		cam_periph *periph;
75 	struct		cam_periph *cur_periph;
76 	path_id_t	path_id;
77 	target_id_t	target_id;
78 	lun_id_t	lun_id;
79 	cam_status	status;
80 	u_int		init_level;
81 	int s;
82 
83 	init_level = 0;
84 	/*
85 	 * Handle Hot-Plug scenarios.  If there is already a peripheral
86 	 * of our type assigned to this path, we are likely waiting for
87 	 * final close on an old, invalidated, peripheral.  If this is
88 	 * the case, queue up a deferred call to the peripheral's async
89 	 * handler.  If it looks like a mistaken re-alloation, complain.
90 	 */
91 	if ((periph = cam_periph_find(path, name)) != NULL) {
92 
93 		if ((periph->flags & CAM_PERIPH_INVALID) != 0
94 		 && (periph->flags & CAM_PERIPH_NEW_DEV_FOUND) == 0) {
95 			periph->flags |= CAM_PERIPH_NEW_DEV_FOUND;
96 			periph->deferred_callback = ac_callback;
97 			periph->deferred_ac = code;
98 			return (CAM_REQ_INPROG);
99 		} else {
100 			printf("cam_periph_alloc: attempt to re-allocate "
101 			       "valid device %s%d rejected\n",
102 			       periph->periph_name, periph->unit_number);
103 		}
104 		return (CAM_REQ_INVALID);
105 	}
106 
107 	periph = (struct cam_periph *)malloc(sizeof(*periph), M_DEVBUF,
108 					     M_NOWAIT);
109 
110 	if (periph == NULL)
111 		return (CAM_RESRC_UNAVAIL);
112 
113 	init_level++;
114 
115 	for (p_drv = (struct periph_driver **)periphdriver_set.ls_items;
116 	     *p_drv != NULL; p_drv++) {
117 		if (strcmp((*p_drv)->driver_name, name) == 0)
118 			break;
119 	}
120 
121 	path_id = xpt_path_path_id(path);
122 	target_id = xpt_path_target_id(path);
123 	lun_id = xpt_path_lun_id(path);
124 	bzero(periph, sizeof(*periph));
125 	cam_init_pinfo(&periph->pinfo);
126 	periph->periph_start = periph_start;
127 	periph->periph_dtor = periph_dtor;
128 	periph->periph_oninval = periph_oninvalidate;
129 	periph->type = type;
130 	periph->periph_name = name;
131 	periph->unit_number = camperiphunit(*p_drv, path_id, target_id, lun_id);
132 	periph->immediate_priority = CAM_PRIORITY_NONE;
133 	periph->refcount = 0;
134 	SLIST_INIT(&periph->ccb_list);
135 	status = xpt_create_path(&path, periph, path_id, target_id, lun_id);
136 	if (status != CAM_REQ_CMP)
137 		goto failure;
138 
139 	periph->path = path;
140 	init_level++;
141 
142 	status = xpt_add_periph(periph);
143 
144 	if (status != CAM_REQ_CMP)
145 		goto failure;
146 
147 	s = splsoftcam();
148 	cur_periph = TAILQ_FIRST(&(*p_drv)->units);
149 	while (cur_periph != NULL
150 	    && cur_periph->unit_number < periph->unit_number)
151 		cur_periph = TAILQ_NEXT(cur_periph, unit_links);
152 
153 	if (cur_periph != NULL)
154 		TAILQ_INSERT_BEFORE(cur_periph, periph, unit_links);
155 	else {
156 		TAILQ_INSERT_TAIL(&(*p_drv)->units, periph, unit_links);
157 		(*p_drv)->generation++;
158 	}
159 
160 	splx(s);
161 
162 	init_level++;
163 
164 	status = periph_ctor(periph, arg);
165 
166 	if (status == CAM_REQ_CMP)
167 		init_level++;
168 
169 failure:
170 	switch (init_level) {
171 	case 4:
172 		/* Initialized successfully */
173 		break;
174 	case 3:
175 		s = splsoftcam();
176 		TAILQ_REMOVE(&(*p_drv)->units, periph, unit_links);
177 		splx(s);
178 		xpt_remove_periph(periph);
179 	case 2:
180 		xpt_free_path(periph->path);
181 	case 1:
182 		free(periph, M_DEVBUF);
183 	case 0:
184 		/* No cleanup to perform. */
185 		break;
186 	default:
187 		panic("cam_periph_alloc: Unkown init level");
188 	}
189 	return(status);
190 }
191 
192 /*
193  * Find a peripheral structure with the specified path, target, lun,
194  * and (optionally) type.  If the name is NULL, this function will return
195  * the first peripheral driver that matches the specified path.
196  */
197 struct cam_periph *
198 cam_periph_find(struct cam_path *path, char *name)
199 {
200 	struct periph_driver **p_drv;
201 	struct cam_periph *periph;
202 	int s;
203 
204 	for (p_drv = (struct periph_driver **)periphdriver_set.ls_items;
205 	     *p_drv != NULL; p_drv++) {
206 
207 		if (name != NULL && (strcmp((*p_drv)->driver_name, name) != 0))
208 			continue;
209 
210 		s = splsoftcam();
211 		for (periph = TAILQ_FIRST(&(*p_drv)->units); periph != NULL;
212 		     periph = TAILQ_NEXT(periph, unit_links)) {
213 			if (xpt_path_comp(periph->path, path) == 0) {
214 				splx(s);
215 				return(periph);
216 			}
217 		}
218 		splx(s);
219 		if (name != NULL)
220 			return(NULL);
221 	}
222 	return(NULL);
223 }
224 
225 cam_status
226 cam_periph_acquire(struct cam_periph *periph)
227 {
228 	int s;
229 
230 	if (periph == NULL)
231 		return(CAM_REQ_CMP_ERR);
232 
233 	s = splsoftcam();
234 	periph->refcount++;
235 	splx(s);
236 
237 	return(CAM_REQ_CMP);
238 }
239 
240 void
241 cam_periph_release(struct cam_periph *periph)
242 {
243 	int s;
244 
245 	if (periph == NULL)
246 		return;
247 
248 	s = splsoftcam();
249 	if ((--periph->refcount == 0)
250 	 && (periph->flags & CAM_PERIPH_INVALID)) {
251 		camperiphfree(periph);
252 	}
253 	splx(s);
254 
255 }
256 
257 /*
258  * Look for the next unit number that is not currently in use for this
259  * peripheral type starting at "newunit".  Also exclude unit numbers that
260  * are reserved by for future "hardwiring" unless we already know that this
261  * is a potential wired device.  Only assume that the device is "wired" the
262  * first time through the loop since after that we'll be looking at unit
263  * numbers that did not match a wiring entry.
264  */
265 static u_int
266 camperiphnextunit(struct periph_driver *p_drv, u_int newunit, int wired,
267 		  path_id_t pathid, target_id_t target, lun_id_t lun)
268 {
269 	struct	cam_periph *periph;
270 	char	*periph_name, *strval;
271 	int	s;
272 	int	i, val, dunit;
273 	const char *dname;
274 
275 	s = splsoftcam();
276 	periph_name = p_drv->driver_name;
277 	for (;;newunit++) {
278 
279 		for (periph = TAILQ_FIRST(&p_drv->units);
280 		     periph != NULL && periph->unit_number != newunit;
281 		     periph = TAILQ_NEXT(periph, unit_links))
282 			;
283 
284 		if (periph != NULL && periph->unit_number == newunit) {
285 			if (wired != 0) {
286 				xpt_print_path(periph->path);
287 				printf("Duplicate Wired Device entry!\n");
288 				xpt_print_path(periph->path);
289 				printf("Second device (%s device at scbus%d "
290 				       "target %d lun %d) will not be wired\n",
291 				       periph_name, pathid, target, lun);
292 				wired = 0;
293 			}
294 			continue;
295 		}
296 		if (wired)
297 			break;
298 
299 		/*
300 		 * Don't match entries like "da 4" as a wired down
301 		 * device, but do match entries like "da 4 target 5"
302 		 * or even "da 4 scbus 1".
303 		 */
304 		i = -1;
305 		while ((i = resource_locate(i, periph_name)) != -1) {
306 			dname = resource_query_name(i);
307 			dunit = resource_query_unit(i);
308 			/* if no "target" and no specific scbus, skip */
309 			if (resource_int_value(dname, dunit, "target", &val) &&
310 			    (resource_string_value(dname, dunit, "at",&strval)||
311 			     strcmp(strval, "scbus") == 0))
312 				continue;
313 			if (newunit == dunit)
314 				break;
315 		}
316 		if (i == -1)
317 			break;
318 	}
319 	splx(s);
320 	return (newunit);
321 }
322 
323 static u_int
324 camperiphunit(struct periph_driver *p_drv, path_id_t pathid,
325 	      target_id_t target, lun_id_t lun)
326 {
327 	u_int	unit;
328 	int	hit, i, val, dunit;
329 	const char *dname;
330 	char	pathbuf[32], *strval, *periph_name;
331 
332 	unit = 0;
333 	hit = 0;
334 
335 	periph_name = p_drv->driver_name;
336 	snprintf(pathbuf, sizeof(pathbuf), "scbus%d", pathid);
337 	i = -1;
338 	while ((i = resource_locate(i, periph_name)) != -1) {
339 		dname = resource_query_name(i);
340 		dunit = resource_query_unit(i);
341 		if (resource_string_value(dname, dunit, "at", &strval) == 0) {
342 			if (strcmp(strval, pathbuf) != 0)
343 				continue;
344 			hit++;
345 		}
346 		if (resource_int_value(dname, dunit, "target", &val) == 0) {
347 			if (val != target)
348 				continue;
349 			hit++;
350 		}
351 		if (resource_int_value(dname, dunit, "lun", &val) == 0) {
352 			if (val != lun)
353 				continue;
354 			hit++;
355 		}
356 		if (hit != 0) {
357 			unit = dunit;
358 			break;
359 		}
360 	}
361 
362 	/*
363 	 * Either start from 0 looking for the next unit or from
364 	 * the unit number given in the resource config.  This way,
365 	 * if we have wildcard matches, we don't return the same
366 	 * unit number twice.
367 	 */
368 	unit = camperiphnextunit(p_drv, unit, /*wired*/hit, pathid,
369 				 target, lun);
370 
371 	return (unit);
372 }
373 
374 void
375 cam_periph_invalidate(struct cam_periph *periph)
376 {
377 	int s;
378 
379 	s = splsoftcam();
380 	/*
381 	 * We only call this routine the first time a peripheral is
382 	 * invalidated.  The oninvalidate() routine is always called at
383 	 * splsoftcam().
384 	 */
385 	if (((periph->flags & CAM_PERIPH_INVALID) == 0)
386 	 && (periph->periph_oninval != NULL))
387 		periph->periph_oninval(periph);
388 
389 	periph->flags |= CAM_PERIPH_INVALID;
390 	periph->flags &= ~CAM_PERIPH_NEW_DEV_FOUND;
391 
392 	if (periph->refcount == 0)
393 		camperiphfree(periph);
394 	else if (periph->refcount < 0)
395 		printf("cam_invalidate_periph: refcount < 0!!\n");
396 	splx(s);
397 }
398 
399 static void
400 camperiphfree(struct cam_periph *periph)
401 {
402 	int s;
403 	struct periph_driver **p_drv;
404 
405 	for (p_drv = (struct periph_driver **)periphdriver_set.ls_items;
406 	     *p_drv != NULL; p_drv++) {
407 		if (strcmp((*p_drv)->driver_name, periph->periph_name) == 0)
408 			break;
409 	}
410 
411 	if (periph->periph_dtor != NULL)
412 		periph->periph_dtor(periph);
413 
414 	s = splsoftcam();
415 	TAILQ_REMOVE(&(*p_drv)->units, periph, unit_links);
416 	(*p_drv)->generation++;
417 	splx(s);
418 
419 	xpt_remove_periph(periph);
420 
421 	if (periph->flags & CAM_PERIPH_NEW_DEV_FOUND) {
422 		union ccb ccb;
423 		void *arg;
424 
425 		switch (periph->deferred_ac) {
426 		case AC_FOUND_DEVICE:
427 			ccb.ccb_h.func_code = XPT_GDEV_TYPE;
428 			xpt_setup_ccb(&ccb.ccb_h, periph->path, /*priority*/ 1);
429 			xpt_action(&ccb);
430 			arg = &ccb;
431 			break;
432 		case AC_PATH_REGISTERED:
433 			ccb.ccb_h.func_code = XPT_PATH_INQ;
434 			xpt_setup_ccb(&ccb.ccb_h, periph->path, /*priority*/ 1);
435 			xpt_action(&ccb);
436 			arg = &ccb;
437 			break;
438 		default:
439 			arg = NULL;
440 			break;
441 		}
442 		periph->deferred_callback(NULL, periph->deferred_ac,
443 					  periph->path, arg);
444 	}
445 	xpt_free_path(periph->path);
446 	free(periph, M_DEVBUF);
447 }
448 
449 /*
450  * Wait interruptibly for an exclusive lock.
451  */
452 int
453 cam_periph_lock(struct cam_periph *periph, int priority)
454 {
455 	int error;
456 
457 	while ((periph->flags & CAM_PERIPH_LOCKED) != 0) {
458 		periph->flags |= CAM_PERIPH_LOCK_WANTED;
459 		if ((error = tsleep(periph, priority, "caplck", 0)) != 0)
460 			return error;
461 	}
462 
463 	if (cam_periph_acquire(periph) != CAM_REQ_CMP)
464 		return(ENXIO);
465 
466 	periph->flags |= CAM_PERIPH_LOCKED;
467 	return 0;
468 }
469 
470 /*
471  * Unlock and wake up any waiters.
472  */
473 void
474 cam_periph_unlock(struct cam_periph *periph)
475 {
476 	periph->flags &= ~CAM_PERIPH_LOCKED;
477 	if ((periph->flags & CAM_PERIPH_LOCK_WANTED) != 0) {
478 		periph->flags &= ~CAM_PERIPH_LOCK_WANTED;
479 		wakeup(periph);
480 	}
481 
482 	cam_periph_release(periph);
483 }
484 
485 /*
486  * Map user virtual pointers into kernel virtual address space, so we can
487  * access the memory.  This won't work on physical pointers, for now it's
488  * up to the caller to check for that.  (XXX KDM -- should we do that here
489  * instead?)  This also only works for up to MAXPHYS memory.  Since we use
490  * buffers to map stuff in and out, we're limited to the buffer size.
491  */
492 int
493 cam_periph_mapmem(union ccb *ccb, struct cam_periph_map_info *mapinfo)
494 {
495 	int numbufs, i;
496 	int flags[CAM_PERIPH_MAXMAPS];
497 	u_int8_t **data_ptrs[CAM_PERIPH_MAXMAPS];
498 	u_int32_t lengths[CAM_PERIPH_MAXMAPS];
499 	u_int32_t dirs[CAM_PERIPH_MAXMAPS];
500 
501 	switch(ccb->ccb_h.func_code) {
502 	case XPT_DEV_MATCH:
503 		if (ccb->cdm.match_buf_len == 0) {
504 			printf("cam_periph_mapmem: invalid match buffer "
505 			       "length 0\n");
506 			return(EINVAL);
507 		}
508 		if (ccb->cdm.pattern_buf_len > 0) {
509 			data_ptrs[0] = (u_int8_t **)&ccb->cdm.patterns;
510 			lengths[0] = ccb->cdm.pattern_buf_len;
511 			dirs[0] = CAM_DIR_OUT;
512 			data_ptrs[1] = (u_int8_t **)&ccb->cdm.matches;
513 			lengths[1] = ccb->cdm.match_buf_len;
514 			dirs[1] = CAM_DIR_IN;
515 			numbufs = 2;
516 		} else {
517 			data_ptrs[0] = (u_int8_t **)&ccb->cdm.matches;
518 			lengths[0] = ccb->cdm.match_buf_len;
519 			dirs[0] = CAM_DIR_IN;
520 			numbufs = 1;
521 		}
522 		break;
523 	case XPT_SCSI_IO:
524 	case XPT_CONT_TARGET_IO:
525 		if ((ccb->ccb_h.flags & CAM_DIR_MASK) == CAM_DIR_NONE)
526 			return(0);
527 
528 		data_ptrs[0] = &ccb->csio.data_ptr;
529 		lengths[0] = ccb->csio.dxfer_len;
530 		dirs[0] = ccb->ccb_h.flags & CAM_DIR_MASK;
531 		numbufs = 1;
532 		break;
533 	default:
534 		return(EINVAL);
535 		break; /* NOTREACHED */
536 	}
537 
538 	/*
539 	 * Check the transfer length and permissions first, so we don't
540 	 * have to unmap any previously mapped buffers.
541 	 */
542 	for (i = 0; i < numbufs; i++) {
543 
544 		flags[i] = 0;
545 
546 		/*
547 		 * The userland data pointer passed in may not be page
548 		 * aligned.  vmapbuf() truncates the address to a page
549 		 * boundary, so if the address isn't page aligned, we'll
550 		 * need enough space for the given transfer length, plus
551 		 * whatever extra space is necessary to make it to the page
552 		 * boundary.
553 		 */
554 		if ((lengths[i] +
555 		    (((vm_offset_t)(*data_ptrs[i])) & PAGE_MASK)) > DFLTPHYS){
556 			printf("cam_periph_mapmem: attempt to map %lu bytes, "
557 			       "which is greater than DFLTPHYS(%d)\n",
558 			       (long)(lengths[i] +
559 			       (((vm_offset_t)(*data_ptrs[i])) & PAGE_MASK)),
560 			       DFLTPHYS);
561 			return(E2BIG);
562 		}
563 
564 		if (dirs[i] & CAM_DIR_OUT) {
565 			flags[i] = BIO_WRITE;
566 			if (!useracc(*data_ptrs[i], lengths[i],
567 				     VM_PROT_READ)) {
568 				printf("cam_periph_mapmem: error, "
569 					"address %p, length %lu isn't "
570 					"user accessible for READ\n",
571 					(void *)*data_ptrs[i],
572 					(u_long)lengths[i]);
573 				return(EACCES);
574 			}
575 		}
576 
577 		if (dirs[i] & CAM_DIR_IN) {
578 			flags[i] = BIO_READ;
579 			if (!useracc(*data_ptrs[i], lengths[i],
580 				     VM_PROT_WRITE)) {
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 = B_PHYS;
616 
617 		/* set the direction */
618 		mapinfo->bp[i]->b_iocmd = flags[i];
619 
620 		/* map the buffer into kernel memory */
621 		vmapbuf(mapinfo->bp[i]);
622 
623 		/* set our pointer to the new mapped area */
624 		*data_ptrs[i] = mapinfo->bp[i]->b_data;
625 
626 		mapinfo->num_bufs_used++;
627 	}
628 
629 	return(0);
630 }
631 
632 /*
633  * Unmap memory segments mapped into kernel virtual address space by
634  * cam_periph_mapmem().
635  */
636 void
637 cam_periph_unmapmem(union ccb *ccb, struct cam_periph_map_info *mapinfo)
638 {
639 	int numbufs, i;
640 	u_int8_t **data_ptrs[CAM_PERIPH_MAXMAPS];
641 
642 	if (mapinfo->num_bufs_used <= 0) {
643 		/* allow ourselves to be swapped once again */
644 		PRELE(curproc);
645 		return;
646 	}
647 
648 	switch (ccb->ccb_h.func_code) {
649 	case XPT_DEV_MATCH:
650 		numbufs = min(mapinfo->num_bufs_used, 2);
651 
652 		if (numbufs == 1) {
653 			data_ptrs[0] = (u_int8_t **)&ccb->cdm.matches;
654 		} else {
655 			data_ptrs[0] = (u_int8_t **)&ccb->cdm.patterns;
656 			data_ptrs[1] = (u_int8_t **)&ccb->cdm.matches;
657 		}
658 		break;
659 	case XPT_SCSI_IO:
660 	case XPT_CONT_TARGET_IO:
661 		data_ptrs[0] = &ccb->csio.data_ptr;
662 		numbufs = min(mapinfo->num_bufs_used, 1);
663 		break;
664 	default:
665 		/* allow ourselves to be swapped once again */
666 		PRELE(curproc);
667 		return;
668 		break; /* NOTREACHED */
669 	}
670 
671 	for (i = 0; i < numbufs; i++) {
672 		/* Set the user's pointer back to the original value */
673 		*data_ptrs[i] = mapinfo->bp[i]->b_saveaddr;
674 
675 		/* unmap the buffer */
676 		vunmapbuf(mapinfo->bp[i]);
677 
678 		/* clear the flags we set above */
679 		mapinfo->bp[i]->b_flags &= ~B_PHYS;
680 
681 		/* release the buffer */
682 		relpbuf(mapinfo->bp[i], NULL);
683 	}
684 
685 	/* allow ourselves to be swapped once again */
686 	PRELE(curproc);
687 }
688 
689 union ccb *
690 cam_periph_getccb(struct cam_periph *periph, u_int32_t priority)
691 {
692 	struct ccb_hdr *ccb_h;
693 	int s;
694 
695 	CAM_DEBUG(periph->path, CAM_DEBUG_TRACE, ("entering cdgetccb\n"));
696 
697 	s = splsoftcam();
698 
699 	while (periph->ccb_list.slh_first == NULL) {
700 		if (periph->immediate_priority > priority)
701 			periph->immediate_priority = priority;
702 		xpt_schedule(periph, priority);
703 		if ((periph->ccb_list.slh_first != NULL)
704 		 && (periph->ccb_list.slh_first->pinfo.priority == priority))
705 			break;
706 		tsleep(&periph->ccb_list, PRIBIO, "cgticb", 0);
707 	}
708 
709 	ccb_h = periph->ccb_list.slh_first;
710 	SLIST_REMOVE_HEAD(&periph->ccb_list, periph_links.sle);
711 	splx(s);
712 	return ((union ccb *)ccb_h);
713 }
714 
715 void
716 cam_periph_ccbwait(union ccb *ccb)
717 {
718 	int s;
719 
720 	s = splsoftcam();
721 	if ((ccb->ccb_h.pinfo.index != CAM_UNQUEUED_INDEX)
722 	 || ((ccb->ccb_h.status & CAM_STATUS_MASK) == CAM_REQ_INPROG))
723 		tsleep(&ccb->ccb_h.cbfcnp, PRIBIO, "cbwait", 0);
724 
725 	splx(s);
726 }
727 
728 int
729 cam_periph_ioctl(struct cam_periph *periph, int cmd, caddr_t addr,
730 		 int (*error_routine)(union ccb *ccb,
731 				      cam_flags camflags,
732 				      u_int32_t sense_flags))
733 {
734 	union ccb 	     *ccb;
735 	int 		     error;
736 	int		     found;
737 
738 	error = found = 0;
739 
740 	switch(cmd){
741 	case CAMGETPASSTHRU:
742 		ccb = cam_periph_getccb(periph, /* priority */ 1);
743 		xpt_setup_ccb(&ccb->ccb_h,
744 			      ccb->ccb_h.path,
745 			      /*priority*/1);
746 		ccb->ccb_h.func_code = XPT_GDEVLIST;
747 
748 		/*
749 		 * Basically, the point of this is that we go through
750 		 * getting the list of devices, until we find a passthrough
751 		 * device.  In the current version of the CAM code, the
752 		 * only way to determine what type of device we're dealing
753 		 * with is by its name.
754 		 */
755 		while (found == 0) {
756 			ccb->cgdl.index = 0;
757 			ccb->cgdl.status = CAM_GDEVLIST_MORE_DEVS;
758 			while (ccb->cgdl.status == CAM_GDEVLIST_MORE_DEVS) {
759 
760 				/* we want the next device in the list */
761 				xpt_action(ccb);
762 				if (strncmp(ccb->cgdl.periph_name,
763 				    "pass", 4) == 0){
764 					found = 1;
765 					break;
766 				}
767 			}
768 			if ((ccb->cgdl.status == CAM_GDEVLIST_LAST_DEVICE) &&
769 			    (found == 0)) {
770 				ccb->cgdl.periph_name[0] = '\0';
771 				ccb->cgdl.unit_number = 0;
772 				break;
773 			}
774 		}
775 
776 		/* copy the result back out */
777 		bcopy(ccb, addr, sizeof(union ccb));
778 
779 		/* and release the ccb */
780 		xpt_release_ccb(ccb);
781 
782 		break;
783 	default:
784 		error = ENOTTY;
785 		break;
786 	}
787 	return(error);
788 }
789 
790 int
791 cam_periph_runccb(union ccb *ccb,
792 		  int (*error_routine)(union ccb *ccb,
793 				       cam_flags camflags,
794 				       u_int32_t sense_flags),
795 		  cam_flags camflags, u_int32_t sense_flags,
796 		  struct devstat *ds)
797 {
798 	int error;
799 
800 	error = 0;
801 
802 	/*
803 	 * If the user has supplied a stats structure, and if we understand
804 	 * this particular type of ccb, record the transaction start.
805 	 */
806 	if ((ds != NULL) && (ccb->ccb_h.func_code == XPT_SCSI_IO))
807 		devstat_start_transaction(ds);
808 
809 	xpt_action(ccb);
810 
811 	do {
812 		cam_periph_ccbwait(ccb);
813 		if ((ccb->ccb_h.status & CAM_STATUS_MASK) == CAM_REQ_CMP)
814 			error = 0;
815 		else if (error_routine != NULL)
816 			error = (*error_routine)(ccb, camflags, sense_flags);
817 		else
818 			error = 0;
819 
820 	} while (error == ERESTART);
821 
822 	if ((ccb->ccb_h.status & CAM_DEV_QFRZN) != 0)
823 		cam_release_devq(ccb->ccb_h.path,
824 				 /* relsim_flags */0,
825 				 /* openings */0,
826 				 /* timeout */0,
827 				 /* getcount_only */ FALSE);
828 
829 	if ((ds != NULL) && (ccb->ccb_h.func_code == XPT_SCSI_IO))
830 		devstat_end_transaction(ds,
831 					ccb->csio.dxfer_len,
832 					ccb->csio.tag_action & 0xf,
833 					((ccb->ccb_h.flags & CAM_DIR_MASK) ==
834 					CAM_DIR_NONE) ?  DEVSTAT_NO_DATA :
835 					(ccb->ccb_h.flags & CAM_DIR_OUT) ?
836 					DEVSTAT_WRITE :
837 					DEVSTAT_READ);
838 
839 	return(error);
840 }
841 
842 void
843 cam_freeze_devq(struct cam_path *path)
844 {
845 	struct ccb_hdr ccb_h;
846 
847 	xpt_setup_ccb(&ccb_h, path, /*priority*/1);
848 	ccb_h.func_code = XPT_NOOP;
849 	ccb_h.flags = CAM_DEV_QFREEZE;
850 	xpt_action((union ccb *)&ccb_h);
851 }
852 
853 u_int32_t
854 cam_release_devq(struct cam_path *path, u_int32_t relsim_flags,
855 		 u_int32_t openings, u_int32_t timeout,
856 		 int getcount_only)
857 {
858 	struct ccb_relsim crs;
859 
860 	xpt_setup_ccb(&crs.ccb_h, path,
861 		      /*priority*/1);
862 	crs.ccb_h.func_code = XPT_REL_SIMQ;
863 	crs.ccb_h.flags = getcount_only ? CAM_DEV_QFREEZE : 0;
864 	crs.release_flags = relsim_flags;
865 	crs.openings = openings;
866 	crs.release_timeout = timeout;
867 	xpt_action((union ccb *)&crs);
868 	return (crs.qfrozen_cnt);
869 }
870 
871 #define saved_ccb_ptr ppriv_ptr0
872 static void
873 camperiphdone(struct cam_periph *periph, union ccb *done_ccb)
874 {
875 	cam_status	status;
876 	int		frozen;
877 	int		sense;
878 	struct scsi_start_stop_unit *scsi_cmd;
879 	u_int32_t	relsim_flags, timeout;
880 	u_int32_t	qfrozen_cnt;
881 
882 	status = done_ccb->ccb_h.status;
883 	frozen = (status & CAM_DEV_QFRZN) != 0;
884 	sense  = (status & CAM_AUTOSNS_VALID) != 0;
885 	status &= CAM_STATUS_MASK;
886 
887 	timeout = 0;
888 	relsim_flags = 0;
889 
890 	/*
891 	 * Unfreeze the queue once if it is already frozen..
892 	 */
893 	if (frozen != 0) {
894 		qfrozen_cnt = cam_release_devq(done_ccb->ccb_h.path,
895 					      /*relsim_flags*/0,
896 					      /*openings*/0,
897 					      /*timeout*/0,
898 					      /*getcount_only*/0);
899 	}
900 
901 	switch (status) {
902 
903 	case CAM_REQ_CMP:
904 
905 		/*
906 		 * If we have successfully taken a device from the not
907 		 * ready to ready state, re-scan the device and re-get the
908 		 * inquiry information.  Many devices (mostly disks) don't
909 		 * properly report their inquiry information unless they
910 		 * are spun up.
911 		 */
912 		if (done_ccb->ccb_h.func_code == XPT_SCSI_IO) {
913 			scsi_cmd = (struct scsi_start_stop_unit *)
914 					&done_ccb->csio.cdb_io.cdb_bytes;
915 
916 		 	if (scsi_cmd->opcode == START_STOP_UNIT)
917 				xpt_async(AC_INQ_CHANGED,
918 					  done_ccb->ccb_h.path, NULL);
919 		}
920 		bcopy(done_ccb->ccb_h.saved_ccb_ptr, done_ccb,
921 		      sizeof(union ccb));
922 
923 		periph->flags &= ~CAM_PERIPH_RECOVERY_INPROG;
924 
925 		xpt_action(done_ccb);
926 
927 		break;
928 	case CAM_SCSI_STATUS_ERROR:
929 		scsi_cmd = (struct scsi_start_stop_unit *)
930 				&done_ccb->csio.cdb_io.cdb_bytes;
931 		if (sense != 0) {
932 			struct scsi_sense_data *sense;
933 			int    error_code, sense_key, asc, ascq;
934 
935 			sense = &done_ccb->csio.sense_data;
936 			scsi_extract_sense(sense, &error_code,
937 					   &sense_key, &asc, &ascq);
938 
939 			/*
940 	 		 * If the error is "invalid field in CDB",
941 			 * and the load/eject flag is set, turn the
942 			 * flag off and try again.  This is just in
943 			 * case the drive in question barfs on the
944 			 * load eject flag.  The CAM code should set
945 			 * the load/eject flag by default for
946 			 * removable media.
947 			 */
948 
949 			/* XXX KDM
950 			 * Should we check to see what the specific
951 			 * scsi status is??  Or does it not matter
952 			 * since we already know that there was an
953 			 * error, and we know what the specific
954 			 * error code was, and we know what the
955 			 * opcode is..
956 			 */
957 			if ((scsi_cmd->opcode == START_STOP_UNIT) &&
958 			    ((scsi_cmd->how & SSS_LOEJ) != 0) &&
959 			     (asc == 0x24) && (ascq == 0x00) &&
960 			     (done_ccb->ccb_h.retry_count > 0)) {
961 
962 				scsi_cmd->how &= ~SSS_LOEJ;
963 
964 				xpt_action(done_ccb);
965 
966 			} else if (done_ccb->ccb_h.retry_count > 0) {
967 				/*
968 				 * In this case, the error recovery
969 				 * command failed, but we've got
970 				 * some retries left on it.  Give
971 				 * it another try.
972 				 */
973 
974 				/* set the timeout to .5 sec */
975 				relsim_flags =
976 					RELSIM_RELEASE_AFTER_TIMEOUT;
977 				timeout = 500;
978 
979 				xpt_action(done_ccb);
980 
981 				break;
982 
983 			} else {
984 				/*
985 				 * Copy the original CCB back and
986 				 * send it back to the caller.
987 				 */
988 				bcopy(done_ccb->ccb_h.saved_ccb_ptr,
989 				      done_ccb, sizeof(union ccb));
990 
991 				periph->flags &= ~CAM_PERIPH_RECOVERY_INPROG;
992 
993 				xpt_action(done_ccb);
994 			}
995 		} else {
996 			/*
997 			 * Eh??  The command failed, but we don't
998 			 * have any sense.  What's up with that?
999 			 * Fire the CCB again to return it to the
1000 			 * caller.
1001 			 */
1002 			bcopy(done_ccb->ccb_h.saved_ccb_ptr,
1003 			      done_ccb, sizeof(union ccb));
1004 
1005 			periph->flags &= ~CAM_PERIPH_RECOVERY_INPROG;
1006 
1007 			xpt_action(done_ccb);
1008 
1009 		}
1010 		break;
1011 	default:
1012 		bcopy(done_ccb->ccb_h.saved_ccb_ptr, done_ccb,
1013 		      sizeof(union ccb));
1014 
1015 		periph->flags &= ~CAM_PERIPH_RECOVERY_INPROG;
1016 
1017 		xpt_action(done_ccb);
1018 
1019 		break;
1020 	}
1021 
1022 	/* decrement the retry count */
1023 	if (done_ccb->ccb_h.retry_count > 0)
1024 		done_ccb->ccb_h.retry_count--;
1025 
1026 	qfrozen_cnt = cam_release_devq(done_ccb->ccb_h.path,
1027 				      /*relsim_flags*/relsim_flags,
1028 				      /*openings*/0,
1029 				      /*timeout*/timeout,
1030 				      /*getcount_only*/0);
1031 }
1032 
1033 /*
1034  * Generic Async Event handler.  Peripheral drivers usually
1035  * filter out the events that require personal attention,
1036  * and leave the rest to this function.
1037  */
1038 void
1039 cam_periph_async(struct cam_periph *periph, u_int32_t code,
1040 		 struct cam_path *path, void *arg)
1041 {
1042 	switch (code) {
1043 	case AC_LOST_DEVICE:
1044 		cam_periph_invalidate(periph);
1045 		break;
1046 	case AC_SENT_BDR:
1047 	case AC_BUS_RESET:
1048 	{
1049 		cam_periph_bus_settle(periph, SCSI_DELAY);
1050 		break;
1051 	}
1052 	default:
1053 		break;
1054 	}
1055 }
1056 
1057 void
1058 cam_periph_bus_settle(struct cam_periph *periph, u_int bus_settle)
1059 {
1060 	struct ccb_getdevstats cgds;
1061 
1062 	xpt_setup_ccb(&cgds.ccb_h, periph->path, /*priority*/1);
1063 	cgds.ccb_h.func_code = XPT_GDEV_STATS;
1064 	xpt_action((union ccb *)&cgds);
1065 	cam_periph_freeze_after_event(periph, &cgds.last_reset, bus_settle);
1066 }
1067 
1068 void
1069 cam_periph_freeze_after_event(struct cam_periph *periph,
1070 			      struct timeval* event_time, u_int duration_ms)
1071 {
1072 	struct timeval delta;
1073 	struct timeval duration_tv;
1074 	int s;
1075 
1076 	s = splclock();
1077 	microtime(&delta);
1078 	splx(s);
1079 	timevalsub(&delta, event_time);
1080 	duration_tv.tv_sec = duration_ms / 1000;
1081 	duration_tv.tv_usec = (duration_ms % 1000) * 1000;
1082 	if (timevalcmp(&delta, &duration_tv, <)) {
1083 		timevalsub(&duration_tv, &delta);
1084 
1085 		duration_ms = duration_tv.tv_sec * 1000;
1086 		duration_ms += duration_tv.tv_usec / 1000;
1087 		cam_freeze_devq(periph->path);
1088 		cam_release_devq(periph->path,
1089 				RELSIM_RELEASE_AFTER_TIMEOUT,
1090 				/*reduction*/0,
1091 				/*timeout*/duration_ms,
1092 				/*getcount_only*/0);
1093 	}
1094 
1095 }
1096 
1097 /*
1098  * Generic error handler.  Peripheral drivers usually filter
1099  * out the errors that they handle in a unique mannor, then
1100  * call this function.
1101  */
1102 int
1103 cam_periph_error(union ccb *ccb, cam_flags camflags,
1104 		 u_int32_t sense_flags, union ccb *save_ccb)
1105 {
1106 	cam_status status;
1107 	int	   frozen;
1108 	int	   sense;
1109 	int	   error;
1110 	int        openings;
1111 	int	   retry;
1112 	u_int32_t  relsim_flags;
1113 	u_int32_t  timeout;
1114 
1115 	status = ccb->ccb_h.status;
1116 	frozen = (status & CAM_DEV_QFRZN) != 0;
1117 	sense  = (status & CAM_AUTOSNS_VALID) != 0;
1118 	status &= CAM_STATUS_MASK;
1119 	relsim_flags = 0;
1120 
1121 	switch (status) {
1122 	case CAM_REQ_CMP:
1123 		/* decrement the number of retries */
1124 		retry = ccb->ccb_h.retry_count > 0;
1125 		if (retry)
1126 			ccb->ccb_h.retry_count--;
1127 		error = 0;
1128 		break;
1129 	case CAM_AUTOSENSE_FAIL:
1130 	case CAM_SCSI_STATUS_ERROR:
1131 
1132 		switch (ccb->csio.scsi_status) {
1133 		case SCSI_STATUS_OK:
1134 		case SCSI_STATUS_COND_MET:
1135 		case SCSI_STATUS_INTERMED:
1136 		case SCSI_STATUS_INTERMED_COND_MET:
1137 			error = 0;
1138 			break;
1139 		case SCSI_STATUS_CMD_TERMINATED:
1140 		case SCSI_STATUS_CHECK_COND:
1141 			if (sense != 0) {
1142 				struct scsi_sense_data *sense;
1143 				int    error_code, sense_key, asc, ascq;
1144 				struct cam_periph *periph;
1145 				scsi_sense_action err_action;
1146 				struct ccb_getdev cgd;
1147 
1148 				sense = &ccb->csio.sense_data;
1149 				scsi_extract_sense(sense, &error_code,
1150 						   &sense_key, &asc, &ascq);
1151 				periph = xpt_path_periph(ccb->ccb_h.path);
1152 
1153 				/*
1154 				 * Grab the inquiry data for this device.
1155 				 */
1156 				xpt_setup_ccb(&cgd.ccb_h, ccb->ccb_h.path,
1157 					      /*priority*/ 1);
1158 				cgd.ccb_h.func_code = XPT_GDEV_TYPE;
1159 				xpt_action((union ccb *)&cgd);
1160 
1161 				err_action = scsi_error_action(asc, ascq,
1162 							       &cgd.inq_data);
1163 
1164 				/*
1165 				 * Send a Test Unit Ready to the device.
1166 				 * If the 'many' flag is set, we send 120
1167 				 * test unit ready commands, one every half
1168 				 * second.  Otherwise, we just send one TUR.
1169 				 * We only want to do this if the retry
1170 				 * count has not been exhausted.
1171 				 */
1172 				if (((err_action & SS_MASK) == SS_TUR)
1173 				 && save_ccb != NULL
1174 				 && ccb->ccb_h.retry_count > 0) {
1175 
1176 					/*
1177 					 * Since error recovery is already
1178 					 * in progress, don't attempt to
1179 					 * process this error.  It is probably
1180 					 * related to the error that caused
1181 					 * the currently active error recovery
1182 					 * action.  Also, we only have
1183 					 * space for one saved CCB, so if we
1184 					 * had two concurrent error recovery
1185 					 * actions, we would end up
1186 					 * over-writing one error recovery
1187 					 * CCB with another one.
1188 					 */
1189 					if (periph->flags &
1190 					    CAM_PERIPH_RECOVERY_INPROG) {
1191 						error = ERESTART;
1192 						break;
1193 					}
1194 
1195 					periph->flags |=
1196 						CAM_PERIPH_RECOVERY_INPROG;
1197 
1198 					/* decrement the number of retries */
1199 					if ((err_action &
1200 					     SSQ_DECREMENT_COUNT) != 0) {
1201 						retry = 1;
1202 						ccb->ccb_h.retry_count--;
1203 					}
1204 
1205 					bcopy(ccb, save_ccb, sizeof(*save_ccb));
1206 
1207 					/*
1208 					 * We retry this one every half
1209 					 * second for a minute.  If the
1210 					 * device hasn't become ready in a
1211 					 * minute's time, it's unlikely to
1212 					 * ever become ready.  If the table
1213 					 * doesn't specify SSQ_MANY, we can
1214 					 * only try this once.  Oh well.
1215 					 */
1216 					if ((err_action & SSQ_MANY) != 0)
1217 						scsi_test_unit_ready(&ccb->csio,
1218 							       /*retries*/120,
1219 							       camperiphdone,
1220 						 	       MSG_SIMPLE_Q_TAG,
1221 							       SSD_FULL_SIZE,
1222 							       /*timeout*/5000);
1223 					else
1224 						scsi_test_unit_ready(&ccb->csio,
1225 							       /*retries*/1,
1226 							       camperiphdone,
1227 						 	       MSG_SIMPLE_Q_TAG,
1228 							       SSD_FULL_SIZE,
1229 							       /*timeout*/5000);
1230 
1231 					/* release the queue after .5 sec.  */
1232 					relsim_flags =
1233 						RELSIM_RELEASE_AFTER_TIMEOUT;
1234 					timeout = 500;
1235 					/*
1236 					 * Drop the priority to 0 so that
1237 					 * we are the first to execute.  Also
1238 					 * freeze the queue after this command
1239 					 * is sent so that we can restore the
1240 					 * old csio and have it queued in the
1241 					 * proper order before we let normal
1242 					 * transactions go to the drive.
1243 					 */
1244 					ccb->ccb_h.pinfo.priority = 0;
1245 					ccb->ccb_h.flags |= CAM_DEV_QFREEZE;
1246 
1247 					/*
1248 					 * Save a pointer to the original
1249 					 * CCB in the new CCB.
1250 					 */
1251 					ccb->ccb_h.saved_ccb_ptr = save_ccb;
1252 
1253 					error = ERESTART;
1254 				}
1255 				/*
1256 				 * Send a start unit command to the device,
1257 				 * and then retry the command.  We only
1258 				 * want to do this if the retry count has
1259 				 * not been exhausted.  If the user
1260 				 * specified 0 retries, then we follow
1261 				 * their request and do not retry.
1262 				 */
1263 				else if (((err_action & SS_MASK) == SS_START)
1264 				      && save_ccb != NULL
1265 				      && ccb->ccb_h.retry_count > 0) {
1266 					int le;
1267 
1268 					/*
1269 					 * Only one error recovery action
1270 					 * at a time.  See above.
1271 					 */
1272 					if (periph->flags &
1273 					    CAM_PERIPH_RECOVERY_INPROG) {
1274 						error = ERESTART;
1275 						break;
1276 					}
1277 
1278 					periph->flags |=
1279 						CAM_PERIPH_RECOVERY_INPROG;
1280 
1281 					/* decrement the number of retries */
1282 					retry = 1;
1283 					ccb->ccb_h.retry_count--;
1284 
1285 					/*
1286 					 * Check for removable media and
1287 					 * set load/eject flag
1288 					 * appropriately.
1289 					 */
1290 					if (SID_IS_REMOVABLE(&cgd.inq_data))
1291 						le = TRUE;
1292 					else
1293 						le = FALSE;
1294 
1295 					/*
1296 					 * Attempt to start the drive up.
1297 					 *
1298 					 * Save the current ccb so it can
1299 					 * be restored and retried once the
1300 					 * drive is started up.
1301 					 */
1302 					bcopy(ccb, save_ccb, sizeof(*save_ccb));
1303 
1304 					scsi_start_stop(&ccb->csio,
1305 							/*retries*/1,
1306 							camperiphdone,
1307 							MSG_SIMPLE_Q_TAG,
1308 							/*start*/TRUE,
1309 							/*load/eject*/le,
1310 							/*immediate*/FALSE,
1311 							SSD_FULL_SIZE,
1312 							/*timeout*/50000);
1313 					/*
1314 					 * Drop the priority to 0 so that
1315 					 * we are the first to execute.  Also
1316 					 * freeze the queue after this command
1317 					 * is sent so that we can restore the
1318 					 * old csio and have it queued in the
1319 					 * proper order before we let normal
1320 					 * transactions go to the drive.
1321 					 */
1322 					ccb->ccb_h.pinfo.priority = 0;
1323 					ccb->ccb_h.flags |= CAM_DEV_QFREEZE;
1324 
1325 					/*
1326 					 * Save a pointer to the original
1327 					 * CCB in the new CCB.
1328 					 */
1329 					ccb->ccb_h.saved_ccb_ptr = save_ccb;
1330 
1331 					error = ERESTART;
1332 				} else if ((sense_flags & SF_RETRY_UA) != 0) {
1333 					/*
1334 					 * XXX KDM this is a *horrible*
1335 					 * hack.
1336 					 */
1337 					error = scsi_interpret_sense(ccb,
1338 								  sense_flags,
1339 								  &relsim_flags,
1340 								  &openings,
1341 								  &timeout,
1342 								  err_action);
1343 				}
1344 
1345 				/*
1346 				 * Theoretically, this code should send a
1347 				 * test unit ready to the given device, and
1348 				 * if it returns and error, send a start
1349 				 * unit command.  Since we don't yet have
1350 				 * the capability to do two-command error
1351 				 * recovery, just send a start unit.
1352 				 * XXX KDM fix this!
1353 				 */
1354 				else if (((err_action & SS_MASK) == SS_TURSTART)
1355 				      && save_ccb != NULL
1356 				      && ccb->ccb_h.retry_count > 0) {
1357 					int le;
1358 
1359 					/*
1360 					 * Only one error recovery action
1361 					 * at a time.  See above.
1362 					 */
1363 					if (periph->flags &
1364 					    CAM_PERIPH_RECOVERY_INPROG) {
1365 						error = ERESTART;
1366 						break;
1367 					}
1368 
1369 					periph->flags |=
1370 						CAM_PERIPH_RECOVERY_INPROG;
1371 
1372 					/* decrement the number of retries */
1373 					retry = 1;
1374 					ccb->ccb_h.retry_count--;
1375 
1376 					/*
1377 					 * Check for removable media and
1378 					 * set load/eject flag
1379 					 * appropriately.
1380 					 */
1381 					if (SID_IS_REMOVABLE(&cgd.inq_data))
1382 						le = TRUE;
1383 					else
1384 						le = FALSE;
1385 
1386 					/*
1387 					 * Attempt to start the drive up.
1388 					 *
1389 					 * Save the current ccb so it can
1390 					 * be restored and retried once the
1391 					 * drive is started up.
1392 					 */
1393 					bcopy(ccb, save_ccb, sizeof(*save_ccb));
1394 
1395 					scsi_start_stop(&ccb->csio,
1396 							/*retries*/1,
1397 							camperiphdone,
1398 							MSG_SIMPLE_Q_TAG,
1399 							/*start*/TRUE,
1400 							/*load/eject*/le,
1401 							/*immediate*/FALSE,
1402 							SSD_FULL_SIZE,
1403 							/*timeout*/50000);
1404 
1405 					/* release the queue after .5 sec.  */
1406 					relsim_flags =
1407 						RELSIM_RELEASE_AFTER_TIMEOUT;
1408 					timeout = 500;
1409 					/*
1410 					 * Drop the priority to 0 so that
1411 					 * we are the first to execute.  Also
1412 					 * freeze the queue after this command
1413 					 * is sent so that we can restore the
1414 					 * old csio and have it queued in the
1415 					 * proper order before we let normal
1416 					 * transactions go to the drive.
1417 					 */
1418 					ccb->ccb_h.pinfo.priority = 0;
1419 					ccb->ccb_h.flags |= CAM_DEV_QFREEZE;
1420 
1421 					/*
1422 					 * Save a pointer to the original
1423 					 * CCB in the new CCB.
1424 					 */
1425 					ccb->ccb_h.saved_ccb_ptr = save_ccb;
1426 
1427 					error = ERESTART;
1428 				} else {
1429 					error = scsi_interpret_sense(ccb,
1430 								  sense_flags,
1431 								  &relsim_flags,
1432 								  &openings,
1433 								  &timeout,
1434 								  err_action);
1435 				}
1436 			} else if (ccb->csio.scsi_status ==
1437 				   SCSI_STATUS_CHECK_COND
1438 				&& status != CAM_AUTOSENSE_FAIL) {
1439 				/* no point in decrementing the retry count */
1440 				panic("cam_periph_error: scsi status of "
1441 				      "CHECK COND returned but no sense "
1442 				      "information is availible.  "
1443 				      "Controller should have returned "
1444 				      "CAM_AUTOSENSE_FAILED");
1445 				/* NOTREACHED */
1446 				error = EIO;
1447 			} else if (ccb->ccb_h.retry_count == 0) {
1448 				/*
1449 				 * XXX KDM shouldn't there be a better
1450 				 * argument to return??
1451 				 */
1452 				error = EIO;
1453 			} else {
1454 				/* decrement the number of retries */
1455 				retry = ccb->ccb_h.retry_count > 0;
1456 				if (retry)
1457 					ccb->ccb_h.retry_count--;
1458 				/*
1459 				 * If it was aborted with no
1460 				 * clue as to the reason, just
1461 				 * retry it again.
1462 				 */
1463 				error = ERESTART;
1464 			}
1465 			break;
1466 		case SCSI_STATUS_QUEUE_FULL:
1467 		{
1468 			/* no decrement */
1469 			struct ccb_getdevstats cgds;
1470 
1471 			/*
1472 			 * First off, find out what the current
1473 			 * transaction counts are.
1474 			 */
1475 			xpt_setup_ccb(&cgds.ccb_h,
1476 				      ccb->ccb_h.path,
1477 				      /*priority*/1);
1478 			cgds.ccb_h.func_code = XPT_GDEV_STATS;
1479 			xpt_action((union ccb *)&cgds);
1480 
1481 			/*
1482 			 * If we were the only transaction active, treat
1483 			 * the QUEUE FULL as if it were a BUSY condition.
1484 			 */
1485 			if (cgds.dev_active != 0) {
1486 				int total_openings;
1487 
1488 				/*
1489 			 	 * Reduce the number of openings to
1490 				 * be 1 less than the amount it took
1491 				 * to get a queue full bounded by the
1492 				 * minimum allowed tag count for this
1493 				 * device.
1494 			 	 */
1495 				total_openings =
1496 				    cgds.dev_active+cgds.dev_openings;
1497 				openings = cgds.dev_active;
1498 				if (openings < cgds.mintags)
1499 					openings = cgds.mintags;
1500 				if (openings < total_openings)
1501 					relsim_flags = RELSIM_ADJUST_OPENINGS;
1502 				else {
1503 					/*
1504 					 * Some devices report queue full for
1505 					 * temporary resource shortages.  For
1506 					 * this reason, we allow a minimum
1507 					 * tag count to be entered via a
1508 					 * quirk entry to prevent the queue
1509 					 * count on these devices from falling
1510 					 * to a pessimisticly low value.  We
1511 					 * still wait for the next successful
1512 					 * completion, however, before queueing
1513 					 * more transactions to the device.
1514 					 */
1515 					relsim_flags =
1516 					    RELSIM_RELEASE_AFTER_CMDCMPLT;
1517 				}
1518 				timeout = 0;
1519 				error = ERESTART;
1520 				break;
1521 			}
1522 			/* FALLTHROUGH */
1523 		}
1524 		case SCSI_STATUS_BUSY:
1525 			/*
1526 			 * Restart the queue after either another
1527 			 * command completes or a 1 second timeout.
1528 			 * If we have any retries left, that is.
1529 			 */
1530 			retry = ccb->ccb_h.retry_count > 0;
1531 			if (retry) {
1532 				ccb->ccb_h.retry_count--;
1533 				error = ERESTART;
1534 				relsim_flags = RELSIM_RELEASE_AFTER_TIMEOUT
1535 					     | RELSIM_RELEASE_AFTER_CMDCMPLT;
1536 				timeout = 1000;
1537 			} else {
1538 				error = EIO;
1539 			}
1540 			break;
1541 		case SCSI_STATUS_RESERV_CONFLICT:
1542 			error = EIO;
1543 			break;
1544 		default:
1545 			error = EIO;
1546 			break;
1547 		}
1548 		break;
1549 	case CAM_REQ_CMP_ERR:
1550 	case CAM_CMD_TIMEOUT:
1551 	case CAM_UNEXP_BUSFREE:
1552 	case CAM_UNCOR_PARITY:
1553 	case CAM_DATA_RUN_ERR:
1554 		/* decrement the number of retries */
1555 		retry = ccb->ccb_h.retry_count > 0;
1556 		if (retry) {
1557 			ccb->ccb_h.retry_count--;
1558 			error = ERESTART;
1559 		} else {
1560 			error = EIO;
1561 		}
1562 		break;
1563 	case CAM_UA_ABORT:
1564 	case CAM_UA_TERMIO:
1565 	case CAM_MSG_REJECT_REC:
1566 		/* XXX Don't know that these are correct */
1567 		error = EIO;
1568 		break;
1569 	case CAM_SEL_TIMEOUT:
1570 	{
1571 		/*
1572 		 * XXX
1573 		 * A single selection timeout should not be enough
1574 		 * to invalidate a device.  We should retry for multiple
1575 		 * seconds assuming this isn't a probe.  We'll probably
1576 		 * need a special flag for that.
1577 		 */
1578 #if 0
1579 		struct cam_path *newpath;
1580 
1581 		/* Should we do more if we can't create the path?? */
1582 		if (xpt_create_path(&newpath, xpt_path_periph(ccb->ccb_h.path),
1583 				    xpt_path_path_id(ccb->ccb_h.path),
1584 				    xpt_path_target_id(ccb->ccb_h.path),
1585 				    CAM_LUN_WILDCARD) != CAM_REQ_CMP)
1586 			break;
1587 		/*
1588 		 * Let peripheral drivers know that this device has gone
1589 		 * away.
1590 		 */
1591 		xpt_async(AC_LOST_DEVICE, newpath, NULL);
1592 		xpt_free_path(newpath);
1593 #endif
1594 		if ((sense_flags & SF_RETRY_SELTO) != 0) {
1595 			retry = ccb->ccb_h.retry_count > 0;
1596 			if (retry) {
1597 				ccb->ccb_h.retry_count--;
1598 				error = ERESTART;
1599 				/*
1600 				 * Wait half a second to give the device
1601 				 * time to recover before we try again.
1602 				 */
1603 				relsim_flags = RELSIM_RELEASE_AFTER_TIMEOUT;
1604 				timeout = 500;
1605 			} else {
1606 				error = ENXIO;
1607 			}
1608 		} else {
1609 			error = ENXIO;
1610 		}
1611 		break;
1612 	}
1613 	case CAM_REQ_INVALID:
1614 	case CAM_PATH_INVALID:
1615 	case CAM_DEV_NOT_THERE:
1616 	case CAM_NO_HBA:
1617 	case CAM_PROVIDE_FAIL:
1618 	case CAM_REQ_TOO_BIG:
1619 		error = EINVAL;
1620 		break;
1621 	case CAM_SCSI_BUS_RESET:
1622 	case CAM_BDR_SENT:
1623 	case CAM_REQUEUE_REQ:
1624 		/* Unconditional requeue, dammit */
1625 		error = ERESTART;
1626 		break;
1627 	case CAM_RESRC_UNAVAIL:
1628 	case CAM_BUSY:
1629 		/* timeout??? */
1630 	default:
1631 		/* decrement the number of retries */
1632 		retry = ccb->ccb_h.retry_count > 0;
1633 		if (retry) {
1634 			ccb->ccb_h.retry_count--;
1635 			error = ERESTART;
1636 		} else {
1637 			/* Check the sense codes */
1638 			error = EIO;
1639 		}
1640 		break;
1641 	}
1642 
1643 	/* Attempt a retry */
1644 	if (error == ERESTART || error == 0) {
1645 		if (frozen != 0)
1646 			ccb->ccb_h.status &= ~CAM_DEV_QFRZN;
1647 
1648 		if (error == ERESTART)
1649 			xpt_action(ccb);
1650 
1651 		if (frozen != 0) {
1652 			cam_release_devq(ccb->ccb_h.path,
1653 					 relsim_flags,
1654 					 openings,
1655 					 timeout,
1656 					 /*getcount_only*/0);
1657 		}
1658 	}
1659 
1660 
1661 	return (error);
1662 }
1663