xref: /freebsd/sys/cam/cam_periph.c (revision 45dc13f1ea17f98ac7b92768814d579ac48bfd04)
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 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/types.h>
36 #include <sys/malloc.h>
37 #include <sys/kernel.h>
38 #include <sys/bio.h>
39 #include <sys/lock.h>
40 #include <sys/mutex.h>
41 #include <sys/buf.h>
42 #include <sys/proc.h>
43 #include <sys/devicestat.h>
44 #include <sys/bus.h>
45 #include <sys/sbuf.h>
46 #include <vm/vm.h>
47 #include <vm/vm_extern.h>
48 
49 #include <cam/cam.h>
50 #include <cam/cam_ccb.h>
51 #include <cam/cam_queue.h>
52 #include <cam/cam_xpt_periph.h>
53 #include <cam/cam_periph.h>
54 #include <cam/cam_debug.h>
55 #include <cam/cam_sim.h>
56 
57 #include <cam/scsi/scsi_all.h>
58 #include <cam/scsi/scsi_message.h>
59 #include <cam/scsi/scsi_pass.h>
60 
61 static	u_int		camperiphnextunit(struct periph_driver *p_drv,
62 					  u_int newunit, int wired,
63 					  path_id_t pathid, target_id_t target,
64 					  lun_id_t lun);
65 static	u_int		camperiphunit(struct periph_driver *p_drv,
66 				      path_id_t pathid, target_id_t target,
67 				      lun_id_t lun);
68 static	void		camperiphdone(struct cam_periph *periph,
69 					union ccb *done_ccb);
70 static  void		camperiphfree(struct cam_periph *periph);
71 static int		camperiphscsistatuserror(union ccb *ccb,
72 					        union ccb **orig_ccb,
73 						 cam_flags camflags,
74 						 u_int32_t sense_flags,
75 						 int *openings,
76 						 u_int32_t *relsim_flags,
77 						 u_int32_t *timeout,
78 						 u_int32_t  *action,
79 						 const char **action_string);
80 static	int		camperiphscsisenseerror(union ccb *ccb,
81 					        union ccb **orig_ccb,
82 					        cam_flags camflags,
83 					        u_int32_t sense_flags,
84 					        int *openings,
85 					        u_int32_t *relsim_flags,
86 					        u_int32_t *timeout,
87 					        u_int32_t *action,
88 					        const char **action_string);
89 
90 static int nperiph_drivers;
91 static int initialized = 0;
92 struct periph_driver **periph_drivers;
93 
94 static MALLOC_DEFINE(M_CAMPERIPH, "CAM periph", "CAM peripheral buffers");
95 
96 static int periph_selto_delay = 1000;
97 TUNABLE_INT("kern.cam.periph_selto_delay", &periph_selto_delay);
98 static int periph_noresrc_delay = 500;
99 TUNABLE_INT("kern.cam.periph_noresrc_delay", &periph_noresrc_delay);
100 static int periph_busy_delay = 500;
101 TUNABLE_INT("kern.cam.periph_busy_delay", &periph_busy_delay);
102 
103 
104 void
105 periphdriver_register(void *data)
106 {
107 	struct periph_driver *drv = (struct periph_driver *)data;
108 	struct periph_driver **newdrivers, **old;
109 	int ndrivers;
110 
111 again:
112 	ndrivers = nperiph_drivers + 2;
113 	newdrivers = malloc(sizeof(*newdrivers) * ndrivers, M_CAMPERIPH,
114 			    M_WAITOK);
115 	xpt_lock_buses();
116 	if (ndrivers != nperiph_drivers + 2) {
117 		/*
118 		 * Lost race against itself; go around.
119 		 */
120 		xpt_unlock_buses();
121 		free(newdrivers, M_CAMPERIPH);
122 		goto again;
123 	}
124 	if (periph_drivers)
125 		bcopy(periph_drivers, newdrivers,
126 		      sizeof(*newdrivers) * nperiph_drivers);
127 	newdrivers[nperiph_drivers] = drv;
128 	newdrivers[nperiph_drivers + 1] = NULL;
129 	old = periph_drivers;
130 	periph_drivers = newdrivers;
131 	nperiph_drivers++;
132 	xpt_unlock_buses();
133 	if (old)
134 		free(old, M_CAMPERIPH);
135 	/* If driver marked as early or it is late now, initialize it. */
136 	if (((drv->flags & CAM_PERIPH_DRV_EARLY) != 0 && initialized > 0) ||
137 	    initialized > 1)
138 		(*drv->init)();
139 }
140 
141 void
142 periphdriver_init(int level)
143 {
144 	int	i, early;
145 
146 	initialized = max(initialized, level);
147 	for (i = 0; periph_drivers[i] != NULL; i++) {
148 		early = (periph_drivers[i]->flags & CAM_PERIPH_DRV_EARLY) ? 1 : 2;
149 		if (early == initialized)
150 			(*periph_drivers[i]->init)();
151 	}
152 }
153 
154 cam_status
155 cam_periph_alloc(periph_ctor_t *periph_ctor,
156 		 periph_oninv_t *periph_oninvalidate,
157 		 periph_dtor_t *periph_dtor, periph_start_t *periph_start,
158 		 char *name, cam_periph_type type, struct cam_path *path,
159 		 ac_callback_t *ac_callback, ac_code code, void *arg)
160 {
161 	struct		periph_driver **p_drv;
162 	struct		cam_sim *sim;
163 	struct		cam_periph *periph;
164 	struct		cam_periph *cur_periph;
165 	path_id_t	path_id;
166 	target_id_t	target_id;
167 	lun_id_t	lun_id;
168 	cam_status	status;
169 	u_int		init_level;
170 
171 	init_level = 0;
172 	/*
173 	 * Handle Hot-Plug scenarios.  If there is already a peripheral
174 	 * of our type assigned to this path, we are likely waiting for
175 	 * final close on an old, invalidated, peripheral.  If this is
176 	 * the case, queue up a deferred call to the peripheral's async
177 	 * handler.  If it looks like a mistaken re-allocation, complain.
178 	 */
179 	if ((periph = cam_periph_find(path, name)) != NULL) {
180 
181 		if ((periph->flags & CAM_PERIPH_INVALID) != 0
182 		 && (periph->flags & CAM_PERIPH_NEW_DEV_FOUND) == 0) {
183 			periph->flags |= CAM_PERIPH_NEW_DEV_FOUND;
184 			periph->deferred_callback = ac_callback;
185 			periph->deferred_ac = code;
186 			return (CAM_REQ_INPROG);
187 		} else {
188 			printf("cam_periph_alloc: attempt to re-allocate "
189 			       "valid device %s%d rejected flags %#x "
190 			       "refcount %d\n", periph->periph_name,
191 			       periph->unit_number, periph->flags,
192 			       periph->refcount);
193 		}
194 		return (CAM_REQ_INVALID);
195 	}
196 
197 	periph = (struct cam_periph *)malloc(sizeof(*periph), M_CAMPERIPH,
198 					     M_NOWAIT|M_ZERO);
199 
200 	if (periph == NULL)
201 		return (CAM_RESRC_UNAVAIL);
202 
203 	init_level++;
204 
205 
206 	sim = xpt_path_sim(path);
207 	path_id = xpt_path_path_id(path);
208 	target_id = xpt_path_target_id(path);
209 	lun_id = xpt_path_lun_id(path);
210 	periph->periph_start = periph_start;
211 	periph->periph_dtor = periph_dtor;
212 	periph->periph_oninval = periph_oninvalidate;
213 	periph->type = type;
214 	periph->periph_name = name;
215 	periph->scheduled_priority = CAM_PRIORITY_NONE;
216 	periph->immediate_priority = CAM_PRIORITY_NONE;
217 	periph->refcount = 1;		/* Dropped by invalidation. */
218 	periph->sim = sim;
219 	SLIST_INIT(&periph->ccb_list);
220 	status = xpt_create_path(&path, periph, path_id, target_id, lun_id);
221 	if (status != CAM_REQ_CMP)
222 		goto failure;
223 	periph->path = path;
224 
225 	xpt_lock_buses();
226 	for (p_drv = periph_drivers; *p_drv != NULL; p_drv++) {
227 		if (strcmp((*p_drv)->driver_name, name) == 0)
228 			break;
229 	}
230 	if (*p_drv == NULL) {
231 		printf("cam_periph_alloc: invalid periph name '%s'\n", name);
232 		xpt_unlock_buses();
233 		xpt_free_path(periph->path);
234 		free(periph, M_CAMPERIPH);
235 		return (CAM_REQ_INVALID);
236 	}
237 	periph->unit_number = camperiphunit(*p_drv, path_id, target_id, lun_id);
238 	cur_periph = TAILQ_FIRST(&(*p_drv)->units);
239 	while (cur_periph != NULL
240 	    && cur_periph->unit_number < periph->unit_number)
241 		cur_periph = TAILQ_NEXT(cur_periph, unit_links);
242 	if (cur_periph != NULL) {
243 		KASSERT(cur_periph->unit_number != periph->unit_number, ("duplicate units on periph list"));
244 		TAILQ_INSERT_BEFORE(cur_periph, periph, unit_links);
245 	} else {
246 		TAILQ_INSERT_TAIL(&(*p_drv)->units, periph, unit_links);
247 		(*p_drv)->generation++;
248 	}
249 	xpt_unlock_buses();
250 
251 	init_level++;
252 
253 	status = xpt_add_periph(periph);
254 	if (status != CAM_REQ_CMP)
255 		goto failure;
256 
257 	init_level++;
258 	CAM_DEBUG(periph->path, CAM_DEBUG_INFO, ("Periph created\n"));
259 
260 	status = periph_ctor(periph, arg);
261 
262 	if (status == CAM_REQ_CMP)
263 		init_level++;
264 
265 failure:
266 	switch (init_level) {
267 	case 4:
268 		/* Initialized successfully */
269 		break;
270 	case 3:
271 		CAM_DEBUG(periph->path, CAM_DEBUG_INFO, ("Periph destroyed\n"));
272 		xpt_remove_periph(periph);
273 		/* FALLTHROUGH */
274 	case 2:
275 		xpt_lock_buses();
276 		TAILQ_REMOVE(&(*p_drv)->units, periph, unit_links);
277 		xpt_unlock_buses();
278 		xpt_free_path(periph->path);
279 		/* FALLTHROUGH */
280 	case 1:
281 		free(periph, M_CAMPERIPH);
282 		/* FALLTHROUGH */
283 	case 0:
284 		/* No cleanup to perform. */
285 		break;
286 	default:
287 		panic("%s: Unknown init level", __func__);
288 	}
289 	return(status);
290 }
291 
292 /*
293  * Find a peripheral structure with the specified path, target, lun,
294  * and (optionally) type.  If the name is NULL, this function will return
295  * the first peripheral driver that matches the specified path.
296  */
297 struct cam_periph *
298 cam_periph_find(struct cam_path *path, char *name)
299 {
300 	struct periph_driver **p_drv;
301 	struct cam_periph *periph;
302 
303 	xpt_lock_buses();
304 	for (p_drv = periph_drivers; *p_drv != NULL; p_drv++) {
305 
306 		if (name != NULL && (strcmp((*p_drv)->driver_name, name) != 0))
307 			continue;
308 
309 		TAILQ_FOREACH(periph, &(*p_drv)->units, unit_links) {
310 			if (xpt_path_comp(periph->path, path) == 0) {
311 				xpt_unlock_buses();
312 				cam_periph_assert(periph, MA_OWNED);
313 				return(periph);
314 			}
315 		}
316 		if (name != NULL) {
317 			xpt_unlock_buses();
318 			return(NULL);
319 		}
320 	}
321 	xpt_unlock_buses();
322 	return(NULL);
323 }
324 
325 /*
326  * Find peripheral driver instances attached to the specified path.
327  */
328 int
329 cam_periph_list(struct cam_path *path, struct sbuf *sb)
330 {
331 	struct sbuf local_sb;
332 	struct periph_driver **p_drv;
333 	struct cam_periph *periph;
334 	int count;
335 	int sbuf_alloc_len;
336 
337 	sbuf_alloc_len = 16;
338 retry:
339 	sbuf_new(&local_sb, NULL, sbuf_alloc_len, SBUF_FIXEDLEN);
340 	count = 0;
341 	xpt_lock_buses();
342 	for (p_drv = periph_drivers; *p_drv != NULL; p_drv++) {
343 
344 		TAILQ_FOREACH(periph, &(*p_drv)->units, unit_links) {
345 			if (xpt_path_comp(periph->path, path) != 0)
346 				continue;
347 
348 			if (sbuf_len(&local_sb) != 0)
349 				sbuf_cat(&local_sb, ",");
350 
351 			sbuf_printf(&local_sb, "%s%d", periph->periph_name,
352 				    periph->unit_number);
353 
354 			if (sbuf_error(&local_sb) == ENOMEM) {
355 				sbuf_alloc_len *= 2;
356 				xpt_unlock_buses();
357 				sbuf_delete(&local_sb);
358 				goto retry;
359 			}
360 			count++;
361 		}
362 	}
363 	xpt_unlock_buses();
364 	sbuf_finish(&local_sb);
365 	sbuf_cpy(sb, sbuf_data(&local_sb));
366 	sbuf_delete(&local_sb);
367 	return (count);
368 }
369 
370 cam_status
371 cam_periph_acquire(struct cam_periph *periph)
372 {
373 	cam_status status;
374 
375 	status = CAM_REQ_CMP_ERR;
376 	if (periph == NULL)
377 		return (status);
378 
379 	xpt_lock_buses();
380 	if ((periph->flags & CAM_PERIPH_INVALID) == 0) {
381 		periph->refcount++;
382 		status = CAM_REQ_CMP;
383 	}
384 	xpt_unlock_buses();
385 
386 	return (status);
387 }
388 
389 void
390 cam_periph_doacquire(struct cam_periph *periph)
391 {
392 
393 	xpt_lock_buses();
394 	KASSERT(periph->refcount >= 1,
395 	    ("cam_periph_doacquire() with refcount == %d", periph->refcount));
396 	periph->refcount++;
397 	xpt_unlock_buses();
398 }
399 
400 void
401 cam_periph_release_locked_buses(struct cam_periph *periph)
402 {
403 
404 	cam_periph_assert(periph, MA_OWNED);
405 	KASSERT(periph->refcount >= 1, ("periph->refcount >= 1"));
406 	if (--periph->refcount == 0)
407 		camperiphfree(periph);
408 }
409 
410 void
411 cam_periph_release_locked(struct cam_periph *periph)
412 {
413 
414 	if (periph == NULL)
415 		return;
416 
417 	xpt_lock_buses();
418 	cam_periph_release_locked_buses(periph);
419 	xpt_unlock_buses();
420 }
421 
422 void
423 cam_periph_release(struct cam_periph *periph)
424 {
425 	struct mtx *mtx;
426 
427 	if (periph == NULL)
428 		return;
429 
430 	cam_periph_assert(periph, MA_NOTOWNED);
431 	mtx = cam_periph_mtx(periph);
432 	mtx_lock(mtx);
433 	cam_periph_release_locked(periph);
434 	mtx_unlock(mtx);
435 }
436 
437 int
438 cam_periph_hold(struct cam_periph *periph, int priority)
439 {
440 	int error;
441 
442 	/*
443 	 * Increment the reference count on the peripheral
444 	 * while we wait for our lock attempt to succeed
445 	 * to ensure the peripheral doesn't disappear out
446 	 * from user us while we sleep.
447 	 */
448 
449 	if (cam_periph_acquire(periph) != CAM_REQ_CMP)
450 		return (ENXIO);
451 
452 	cam_periph_assert(periph, MA_OWNED);
453 	while ((periph->flags & CAM_PERIPH_LOCKED) != 0) {
454 		periph->flags |= CAM_PERIPH_LOCK_WANTED;
455 		if ((error = cam_periph_sleep(periph, periph, priority,
456 		    "caplck", 0)) != 0) {
457 			cam_periph_release_locked(periph);
458 			return (error);
459 		}
460 		if (periph->flags & CAM_PERIPH_INVALID) {
461 			cam_periph_release_locked(periph);
462 			return (ENXIO);
463 		}
464 	}
465 
466 	periph->flags |= CAM_PERIPH_LOCKED;
467 	return (0);
468 }
469 
470 void
471 cam_periph_unhold(struct cam_periph *periph)
472 {
473 
474 	cam_periph_assert(periph, MA_OWNED);
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_locked(periph);
483 }
484 
485 /*
486  * Look for the next unit number that is not currently in use for this
487  * peripheral type starting at "newunit".  Also exclude unit numbers that
488  * are reserved by for future "hardwiring" unless we already know that this
489  * is a potential wired device.  Only assume that the device is "wired" the
490  * first time through the loop since after that we'll be looking at unit
491  * numbers that did not match a wiring entry.
492  */
493 static u_int
494 camperiphnextunit(struct periph_driver *p_drv, u_int newunit, int wired,
495 		  path_id_t pathid, target_id_t target, lun_id_t lun)
496 {
497 	struct	cam_periph *periph;
498 	char	*periph_name;
499 	int	i, val, dunit, r;
500 	const char *dname, *strval;
501 
502 	periph_name = p_drv->driver_name;
503 	for (;;newunit++) {
504 
505 		for (periph = TAILQ_FIRST(&p_drv->units);
506 		     periph != NULL && periph->unit_number != newunit;
507 		     periph = TAILQ_NEXT(periph, unit_links))
508 			;
509 
510 		if (periph != NULL && periph->unit_number == newunit) {
511 			if (wired != 0) {
512 				xpt_print(periph->path, "Duplicate Wired "
513 				    "Device entry!\n");
514 				xpt_print(periph->path, "Second device (%s "
515 				    "device at scbus%d target %d lun %d) will "
516 				    "not be wired\n", periph_name, pathid,
517 				    target, lun);
518 				wired = 0;
519 			}
520 			continue;
521 		}
522 		if (wired)
523 			break;
524 
525 		/*
526 		 * Don't match entries like "da 4" as a wired down
527 		 * device, but do match entries like "da 4 target 5"
528 		 * or even "da 4 scbus 1".
529 		 */
530 		i = 0;
531 		dname = periph_name;
532 		for (;;) {
533 			r = resource_find_dev(&i, dname, &dunit, NULL, NULL);
534 			if (r != 0)
535 				break;
536 			/* if no "target" and no specific scbus, skip */
537 			if (resource_int_value(dname, dunit, "target", &val) &&
538 			    (resource_string_value(dname, dunit, "at",&strval)||
539 			     strcmp(strval, "scbus") == 0))
540 				continue;
541 			if (newunit == dunit)
542 				break;
543 		}
544 		if (r != 0)
545 			break;
546 	}
547 	return (newunit);
548 }
549 
550 static u_int
551 camperiphunit(struct periph_driver *p_drv, path_id_t pathid,
552 	      target_id_t target, lun_id_t lun)
553 {
554 	u_int	unit;
555 	int	wired, i, val, dunit;
556 	const char *dname, *strval;
557 	char	pathbuf[32], *periph_name;
558 
559 	periph_name = p_drv->driver_name;
560 	snprintf(pathbuf, sizeof(pathbuf), "scbus%d", pathid);
561 	unit = 0;
562 	i = 0;
563 	dname = periph_name;
564 	for (wired = 0; resource_find_dev(&i, dname, &dunit, NULL, NULL) == 0;
565 	     wired = 0) {
566 		if (resource_string_value(dname, dunit, "at", &strval) == 0) {
567 			if (strcmp(strval, pathbuf) != 0)
568 				continue;
569 			wired++;
570 		}
571 		if (resource_int_value(dname, dunit, "target", &val) == 0) {
572 			if (val != target)
573 				continue;
574 			wired++;
575 		}
576 		if (resource_int_value(dname, dunit, "lun", &val) == 0) {
577 			if (val != lun)
578 				continue;
579 			wired++;
580 		}
581 		if (wired != 0) {
582 			unit = dunit;
583 			break;
584 		}
585 	}
586 
587 	/*
588 	 * Either start from 0 looking for the next unit or from
589 	 * the unit number given in the resource config.  This way,
590 	 * if we have wildcard matches, we don't return the same
591 	 * unit number twice.
592 	 */
593 	unit = camperiphnextunit(p_drv, unit, wired, pathid, target, lun);
594 
595 	return (unit);
596 }
597 
598 void
599 cam_periph_invalidate(struct cam_periph *periph)
600 {
601 
602 	cam_periph_assert(periph, MA_OWNED);
603 	/*
604 	 * We only call this routine the first time a peripheral is
605 	 * invalidated.
606 	 */
607 	if ((periph->flags & CAM_PERIPH_INVALID) != 0)
608 		return;
609 
610 	CAM_DEBUG(periph->path, CAM_DEBUG_INFO, ("Periph invalidated\n"));
611 	if ((periph->flags & CAM_PERIPH_ANNOUNCED) && !rebooting)
612 		xpt_denounce_periph(periph);
613 	periph->flags |= CAM_PERIPH_INVALID;
614 	periph->flags &= ~CAM_PERIPH_NEW_DEV_FOUND;
615 	if (periph->periph_oninval != NULL)
616 		periph->periph_oninval(periph);
617 	cam_periph_release_locked(periph);
618 }
619 
620 static void
621 camperiphfree(struct cam_periph *periph)
622 {
623 	struct periph_driver **p_drv;
624 
625 	cam_periph_assert(periph, MA_OWNED);
626 	KASSERT(periph->periph_allocating == 0, ("%s%d: freed while allocating",
627 	    periph->periph_name, periph->unit_number));
628 	for (p_drv = periph_drivers; *p_drv != NULL; p_drv++) {
629 		if (strcmp((*p_drv)->driver_name, periph->periph_name) == 0)
630 			break;
631 	}
632 	if (*p_drv == NULL) {
633 		printf("camperiphfree: attempt to free non-existant periph\n");
634 		return;
635 	}
636 
637 	/*
638 	 * We need to set this flag before dropping the topology lock, to
639 	 * let anyone who is traversing the list that this peripheral is
640 	 * about to be freed, and there will be no more reference count
641 	 * checks.
642 	 */
643 	periph->flags |= CAM_PERIPH_FREE;
644 
645 	/*
646 	 * The peripheral destructor semantics dictate calling with only the
647 	 * SIM mutex held.  Since it might sleep, it should not be called
648 	 * with the topology lock held.
649 	 */
650 	xpt_unlock_buses();
651 
652 	/*
653 	 * We need to call the peripheral destructor prior to removing the
654 	 * peripheral from the list.  Otherwise, we risk running into a
655 	 * scenario where the peripheral unit number may get reused
656 	 * (because it has been removed from the list), but some resources
657 	 * used by the peripheral are still hanging around.  In particular,
658 	 * the devfs nodes used by some peripherals like the pass(4) driver
659 	 * aren't fully cleaned up until the destructor is run.  If the
660 	 * unit number is reused before the devfs instance is fully gone,
661 	 * devfs will panic.
662 	 */
663 	if (periph->periph_dtor != NULL)
664 		periph->periph_dtor(periph);
665 
666 	/*
667 	 * The peripheral list is protected by the topology lock.
668 	 */
669 	xpt_lock_buses();
670 
671 	TAILQ_REMOVE(&(*p_drv)->units, periph, unit_links);
672 	(*p_drv)->generation++;
673 
674 	xpt_remove_periph(periph);
675 
676 	xpt_unlock_buses();
677 	if ((periph->flags & CAM_PERIPH_ANNOUNCED) && !rebooting)
678 		xpt_print(periph->path, "Periph destroyed\n");
679 	else
680 		CAM_DEBUG(periph->path, CAM_DEBUG_INFO, ("Periph destroyed\n"));
681 
682 	if (periph->flags & CAM_PERIPH_NEW_DEV_FOUND) {
683 		union ccb ccb;
684 		void *arg;
685 
686 		switch (periph->deferred_ac) {
687 		case AC_FOUND_DEVICE:
688 			ccb.ccb_h.func_code = XPT_GDEV_TYPE;
689 			xpt_setup_ccb(&ccb.ccb_h, periph->path, CAM_PRIORITY_NORMAL);
690 			xpt_action(&ccb);
691 			arg = &ccb;
692 			break;
693 		case AC_PATH_REGISTERED:
694 			ccb.ccb_h.func_code = XPT_PATH_INQ;
695 			xpt_setup_ccb(&ccb.ccb_h, periph->path, CAM_PRIORITY_NORMAL);
696 			xpt_action(&ccb);
697 			arg = &ccb;
698 			break;
699 		default:
700 			arg = NULL;
701 			break;
702 		}
703 		periph->deferred_callback(NULL, periph->deferred_ac,
704 					  periph->path, arg);
705 	}
706 	xpt_free_path(periph->path);
707 	free(periph, M_CAMPERIPH);
708 	xpt_lock_buses();
709 }
710 
711 /*
712  * Map user virtual pointers into kernel virtual address space, so we can
713  * access the memory.  This is now a generic function that centralizes most
714  * of the sanity checks on the data flags, if any.
715  * This also only works for up to MAXPHYS memory.  Since we use
716  * buffers to map stuff in and out, we're limited to the buffer size.
717  */
718 int
719 cam_periph_mapmem(union ccb *ccb, struct cam_periph_map_info *mapinfo,
720     u_int maxmap)
721 {
722 	int numbufs, i, j;
723 	int flags[CAM_PERIPH_MAXMAPS];
724 	u_int8_t **data_ptrs[CAM_PERIPH_MAXMAPS];
725 	u_int32_t lengths[CAM_PERIPH_MAXMAPS];
726 	u_int32_t dirs[CAM_PERIPH_MAXMAPS];
727 
728 	if (maxmap == 0)
729 		maxmap = DFLTPHYS;	/* traditional default */
730 	else if (maxmap > MAXPHYS)
731 		maxmap = MAXPHYS;	/* for safety */
732 	switch(ccb->ccb_h.func_code) {
733 	case XPT_DEV_MATCH:
734 		if (ccb->cdm.match_buf_len == 0) {
735 			printf("cam_periph_mapmem: invalid match buffer "
736 			       "length 0\n");
737 			return(EINVAL);
738 		}
739 		if (ccb->cdm.pattern_buf_len > 0) {
740 			data_ptrs[0] = (u_int8_t **)&ccb->cdm.patterns;
741 			lengths[0] = ccb->cdm.pattern_buf_len;
742 			dirs[0] = CAM_DIR_OUT;
743 			data_ptrs[1] = (u_int8_t **)&ccb->cdm.matches;
744 			lengths[1] = ccb->cdm.match_buf_len;
745 			dirs[1] = CAM_DIR_IN;
746 			numbufs = 2;
747 		} else {
748 			data_ptrs[0] = (u_int8_t **)&ccb->cdm.matches;
749 			lengths[0] = ccb->cdm.match_buf_len;
750 			dirs[0] = CAM_DIR_IN;
751 			numbufs = 1;
752 		}
753 		/*
754 		 * This request will not go to the hardware, no reason
755 		 * to be so strict. vmapbuf() is able to map up to MAXPHYS.
756 		 */
757 		maxmap = MAXPHYS;
758 		break;
759 	case XPT_SCSI_IO:
760 	case XPT_CONT_TARGET_IO:
761 		if ((ccb->ccb_h.flags & CAM_DIR_MASK) == CAM_DIR_NONE)
762 			return(0);
763 		if ((ccb->ccb_h.flags & CAM_DATA_MASK) != CAM_DATA_VADDR)
764 			return (EINVAL);
765 		data_ptrs[0] = &ccb->csio.data_ptr;
766 		lengths[0] = ccb->csio.dxfer_len;
767 		dirs[0] = ccb->ccb_h.flags & CAM_DIR_MASK;
768 		numbufs = 1;
769 		break;
770 	case XPT_ATA_IO:
771 		if ((ccb->ccb_h.flags & CAM_DIR_MASK) == CAM_DIR_NONE)
772 			return(0);
773 		if ((ccb->ccb_h.flags & CAM_DATA_MASK) != CAM_DATA_VADDR)
774 			return (EINVAL);
775 		data_ptrs[0] = &ccb->ataio.data_ptr;
776 		lengths[0] = ccb->ataio.dxfer_len;
777 		dirs[0] = ccb->ccb_h.flags & CAM_DIR_MASK;
778 		numbufs = 1;
779 		break;
780 	case XPT_SMP_IO:
781 		data_ptrs[0] = &ccb->smpio.smp_request;
782 		lengths[0] = ccb->smpio.smp_request_len;
783 		dirs[0] = CAM_DIR_OUT;
784 		data_ptrs[1] = &ccb->smpio.smp_response;
785 		lengths[1] = ccb->smpio.smp_response_len;
786 		dirs[1] = CAM_DIR_IN;
787 		numbufs = 2;
788 		break;
789 	case XPT_DEV_ADVINFO:
790 		if (ccb->cdai.bufsiz == 0)
791 			return (0);
792 
793 		data_ptrs[0] = (uint8_t **)&ccb->cdai.buf;
794 		lengths[0] = ccb->cdai.bufsiz;
795 		dirs[0] = CAM_DIR_IN;
796 		numbufs = 1;
797 
798 		/*
799 		 * This request will not go to the hardware, no reason
800 		 * to be so strict. vmapbuf() is able to map up to MAXPHYS.
801 		 */
802 		maxmap = MAXPHYS;
803 		break;
804 	default:
805 		return(EINVAL);
806 		break; /* NOTREACHED */
807 	}
808 
809 	/*
810 	 * Check the transfer length and permissions first, so we don't
811 	 * have to unmap any previously mapped buffers.
812 	 */
813 	for (i = 0; i < numbufs; i++) {
814 
815 		flags[i] = 0;
816 
817 		/*
818 		 * The userland data pointer passed in may not be page
819 		 * aligned.  vmapbuf() truncates the address to a page
820 		 * boundary, so if the address isn't page aligned, we'll
821 		 * need enough space for the given transfer length, plus
822 		 * whatever extra space is necessary to make it to the page
823 		 * boundary.
824 		 */
825 		if ((lengths[i] +
826 		    (((vm_offset_t)(*data_ptrs[i])) & PAGE_MASK)) > maxmap){
827 			printf("cam_periph_mapmem: attempt to map %lu bytes, "
828 			       "which is greater than %lu\n",
829 			       (long)(lengths[i] +
830 			       (((vm_offset_t)(*data_ptrs[i])) & PAGE_MASK)),
831 			       (u_long)maxmap);
832 			return(E2BIG);
833 		}
834 
835 		if (dirs[i] & CAM_DIR_OUT) {
836 			flags[i] = BIO_WRITE;
837 		}
838 
839 		if (dirs[i] & CAM_DIR_IN) {
840 			flags[i] = BIO_READ;
841 		}
842 
843 	}
844 
845 	/*
846 	 * This keeps the the kernel stack of current thread from getting
847 	 * swapped.  In low-memory situations where the kernel stack might
848 	 * otherwise get swapped out, this holds it and allows the thread
849 	 * to make progress and release the kernel mapped pages sooner.
850 	 *
851 	 * XXX KDM should I use P_NOSWAP instead?
852 	 */
853 	PHOLD(curproc);
854 
855 	for (i = 0; i < numbufs; i++) {
856 		/*
857 		 * Get the buffer.
858 		 */
859 		mapinfo->bp[i] = getpbuf(NULL);
860 
861 		/* put our pointer in the data slot */
862 		mapinfo->bp[i]->b_data = *data_ptrs[i];
863 
864 		/* save the user's data address */
865 		mapinfo->bp[i]->b_caller1 = *data_ptrs[i];
866 
867 		/* set the transfer length, we know it's < MAXPHYS */
868 		mapinfo->bp[i]->b_bufsize = lengths[i];
869 
870 		/* set the direction */
871 		mapinfo->bp[i]->b_iocmd = flags[i];
872 
873 		/*
874 		 * Map the buffer into kernel memory.
875 		 *
876 		 * Note that useracc() alone is not a  sufficient test.
877 		 * vmapbuf() can still fail due to a smaller file mapped
878 		 * into a larger area of VM, or if userland races against
879 		 * vmapbuf() after the useracc() check.
880 		 */
881 		if (vmapbuf(mapinfo->bp[i], 1) < 0) {
882 			for (j = 0; j < i; ++j) {
883 				*data_ptrs[j] = mapinfo->bp[j]->b_caller1;
884 				vunmapbuf(mapinfo->bp[j]);
885 				relpbuf(mapinfo->bp[j], NULL);
886 			}
887 			relpbuf(mapinfo->bp[i], NULL);
888 			PRELE(curproc);
889 			return(EACCES);
890 		}
891 
892 		/* set our pointer to the new mapped area */
893 		*data_ptrs[i] = mapinfo->bp[i]->b_data;
894 
895 		mapinfo->num_bufs_used++;
896 	}
897 
898 	/*
899 	 * Now that we've gotten this far, change ownership to the kernel
900 	 * of the buffers so that we don't run afoul of returning to user
901 	 * space with locks (on the buffer) held.
902 	 */
903 	for (i = 0; i < numbufs; i++) {
904 		BUF_KERNPROC(mapinfo->bp[i]);
905 	}
906 
907 
908 	return(0);
909 }
910 
911 /*
912  * Unmap memory segments mapped into kernel virtual address space by
913  * cam_periph_mapmem().
914  */
915 void
916 cam_periph_unmapmem(union ccb *ccb, struct cam_periph_map_info *mapinfo)
917 {
918 	int numbufs, i;
919 	u_int8_t **data_ptrs[CAM_PERIPH_MAXMAPS];
920 
921 	if (mapinfo->num_bufs_used <= 0) {
922 		/* nothing to free and the process wasn't held. */
923 		return;
924 	}
925 
926 	switch (ccb->ccb_h.func_code) {
927 	case XPT_DEV_MATCH:
928 		numbufs = min(mapinfo->num_bufs_used, 2);
929 
930 		if (numbufs == 1) {
931 			data_ptrs[0] = (u_int8_t **)&ccb->cdm.matches;
932 		} else {
933 			data_ptrs[0] = (u_int8_t **)&ccb->cdm.patterns;
934 			data_ptrs[1] = (u_int8_t **)&ccb->cdm.matches;
935 		}
936 		break;
937 	case XPT_SCSI_IO:
938 	case XPT_CONT_TARGET_IO:
939 		data_ptrs[0] = &ccb->csio.data_ptr;
940 		numbufs = min(mapinfo->num_bufs_used, 1);
941 		break;
942 	case XPT_ATA_IO:
943 		data_ptrs[0] = &ccb->ataio.data_ptr;
944 		numbufs = min(mapinfo->num_bufs_used, 1);
945 		break;
946 	case XPT_SMP_IO:
947 		numbufs = min(mapinfo->num_bufs_used, 2);
948 		data_ptrs[0] = &ccb->smpio.smp_request;
949 		data_ptrs[1] = &ccb->smpio.smp_response;
950 		break;
951 	case XPT_DEV_ADVINFO:
952 		numbufs = min(mapinfo->num_bufs_used, 1);
953 		data_ptrs[0] = (uint8_t **)&ccb->cdai.buf;
954 		break;
955 	default:
956 		/* allow ourselves to be swapped once again */
957 		PRELE(curproc);
958 		return;
959 		break; /* NOTREACHED */
960 	}
961 
962 	for (i = 0; i < numbufs; i++) {
963 		/* Set the user's pointer back to the original value */
964 		*data_ptrs[i] = mapinfo->bp[i]->b_caller1;
965 
966 		/* unmap the buffer */
967 		vunmapbuf(mapinfo->bp[i]);
968 
969 		/* release the buffer */
970 		relpbuf(mapinfo->bp[i], NULL);
971 	}
972 
973 	/* allow ourselves to be swapped once again */
974 	PRELE(curproc);
975 }
976 
977 void
978 cam_periph_ccbwait(union ccb *ccb)
979 {
980 
981 	if ((ccb->ccb_h.pinfo.index != CAM_UNQUEUED_INDEX)
982 	 || ((ccb->ccb_h.status & CAM_STATUS_MASK) == CAM_REQ_INPROG))
983 		xpt_path_sleep(ccb->ccb_h.path, &ccb->ccb_h.cbfcnp, PRIBIO,
984 		    "cbwait", 0);
985 }
986 
987 int
988 cam_periph_ioctl(struct cam_periph *periph, u_long cmd, caddr_t addr,
989 		 int (*error_routine)(union ccb *ccb,
990 				      cam_flags camflags,
991 				      u_int32_t sense_flags))
992 {
993 	union ccb 	     *ccb;
994 	int 		     error;
995 	int		     found;
996 
997 	error = found = 0;
998 
999 	switch(cmd){
1000 	case CAMGETPASSTHRU:
1001 		ccb = cam_periph_getccb(periph, CAM_PRIORITY_NORMAL);
1002 		xpt_setup_ccb(&ccb->ccb_h,
1003 			      ccb->ccb_h.path,
1004 			      CAM_PRIORITY_NORMAL);
1005 		ccb->ccb_h.func_code = XPT_GDEVLIST;
1006 
1007 		/*
1008 		 * Basically, the point of this is that we go through
1009 		 * getting the list of devices, until we find a passthrough
1010 		 * device.  In the current version of the CAM code, the
1011 		 * only way to determine what type of device we're dealing
1012 		 * with is by its name.
1013 		 */
1014 		while (found == 0) {
1015 			ccb->cgdl.index = 0;
1016 			ccb->cgdl.status = CAM_GDEVLIST_MORE_DEVS;
1017 			while (ccb->cgdl.status == CAM_GDEVLIST_MORE_DEVS) {
1018 
1019 				/* we want the next device in the list */
1020 				xpt_action(ccb);
1021 				if (strncmp(ccb->cgdl.periph_name,
1022 				    "pass", 4) == 0){
1023 					found = 1;
1024 					break;
1025 				}
1026 			}
1027 			if ((ccb->cgdl.status == CAM_GDEVLIST_LAST_DEVICE) &&
1028 			    (found == 0)) {
1029 				ccb->cgdl.periph_name[0] = '\0';
1030 				ccb->cgdl.unit_number = 0;
1031 				break;
1032 			}
1033 		}
1034 
1035 		/* copy the result back out */
1036 		bcopy(ccb, addr, sizeof(union ccb));
1037 
1038 		/* and release the ccb */
1039 		xpt_release_ccb(ccb);
1040 
1041 		break;
1042 	default:
1043 		error = ENOTTY;
1044 		break;
1045 	}
1046 	return(error);
1047 }
1048 
1049 static void
1050 cam_periph_done(struct cam_periph *periph, union ccb *done_ccb)
1051 {
1052 
1053 	/* Caller will release the CCB */
1054 	wakeup(&done_ccb->ccb_h.cbfcnp);
1055 }
1056 
1057 int
1058 cam_periph_runccb(union ccb *ccb,
1059 		  int (*error_routine)(union ccb *ccb,
1060 				       cam_flags camflags,
1061 				       u_int32_t sense_flags),
1062 		  cam_flags camflags, u_int32_t sense_flags,
1063 		  struct devstat *ds)
1064 {
1065 	struct bintime *starttime;
1066 	struct bintime ltime;
1067 	int error;
1068 
1069 	starttime = NULL;
1070 	xpt_path_assert(ccb->ccb_h.path, MA_OWNED);
1071 
1072 	/*
1073 	 * If the user has supplied a stats structure, and if we understand
1074 	 * this particular type of ccb, record the transaction start.
1075 	 */
1076 	if ((ds != NULL) && (ccb->ccb_h.func_code == XPT_SCSI_IO ||
1077 	    ccb->ccb_h.func_code == XPT_ATA_IO)) {
1078 		starttime = &ltime;
1079 		binuptime(starttime);
1080 		devstat_start_transaction(ds, starttime);
1081 	}
1082 
1083 	ccb->ccb_h.cbfcnp = cam_periph_done;
1084 	xpt_action(ccb);
1085 
1086 	do {
1087 		cam_periph_ccbwait(ccb);
1088 		if ((ccb->ccb_h.status & CAM_STATUS_MASK) == CAM_REQ_CMP)
1089 			error = 0;
1090 		else if (error_routine != NULL)
1091 			error = (*error_routine)(ccb, camflags, sense_flags);
1092 		else
1093 			error = 0;
1094 
1095 	} while (error == ERESTART);
1096 
1097 	if ((ccb->ccb_h.status & CAM_DEV_QFRZN) != 0) {
1098 		cam_release_devq(ccb->ccb_h.path,
1099 				 /* relsim_flags */0,
1100 				 /* openings */0,
1101 				 /* timeout */0,
1102 				 /* getcount_only */ FALSE);
1103 		ccb->ccb_h.status &= ~CAM_DEV_QFRZN;
1104 	}
1105 
1106 	if (ds != NULL) {
1107 		if (ccb->ccb_h.func_code == XPT_SCSI_IO) {
1108 			devstat_end_transaction(ds,
1109 					ccb->csio.dxfer_len - ccb->csio.resid,
1110 					ccb->csio.tag_action & 0x3,
1111 					((ccb->ccb_h.flags & CAM_DIR_MASK) ==
1112 					CAM_DIR_NONE) ?  DEVSTAT_NO_DATA :
1113 					(ccb->ccb_h.flags & CAM_DIR_OUT) ?
1114 					DEVSTAT_WRITE :
1115 					DEVSTAT_READ, NULL, starttime);
1116 		} else if (ccb->ccb_h.func_code == XPT_ATA_IO) {
1117 			devstat_end_transaction(ds,
1118 					ccb->ataio.dxfer_len - ccb->ataio.resid,
1119 					ccb->ataio.tag_action & 0x3,
1120 					((ccb->ccb_h.flags & CAM_DIR_MASK) ==
1121 					CAM_DIR_NONE) ?  DEVSTAT_NO_DATA :
1122 					(ccb->ccb_h.flags & CAM_DIR_OUT) ?
1123 					DEVSTAT_WRITE :
1124 					DEVSTAT_READ, NULL, starttime);
1125 		}
1126 	}
1127 
1128 	return(error);
1129 }
1130 
1131 void
1132 cam_freeze_devq(struct cam_path *path)
1133 {
1134 	struct ccb_hdr ccb_h;
1135 
1136 	CAM_DEBUG(path, CAM_DEBUG_TRACE, ("cam_freeze_devq\n"));
1137 	xpt_setup_ccb(&ccb_h, path, /*priority*/1);
1138 	ccb_h.func_code = XPT_NOOP;
1139 	ccb_h.flags = CAM_DEV_QFREEZE;
1140 	xpt_action((union ccb *)&ccb_h);
1141 }
1142 
1143 u_int32_t
1144 cam_release_devq(struct cam_path *path, u_int32_t relsim_flags,
1145 		 u_int32_t openings, u_int32_t arg,
1146 		 int getcount_only)
1147 {
1148 	struct ccb_relsim crs;
1149 
1150 	CAM_DEBUG(path, CAM_DEBUG_TRACE, ("cam_release_devq(%u, %u, %u, %d)\n",
1151 	    relsim_flags, openings, arg, getcount_only));
1152 	xpt_setup_ccb(&crs.ccb_h, path, CAM_PRIORITY_NORMAL);
1153 	crs.ccb_h.func_code = XPT_REL_SIMQ;
1154 	crs.ccb_h.flags = getcount_only ? CAM_DEV_QFREEZE : 0;
1155 	crs.release_flags = relsim_flags;
1156 	crs.openings = openings;
1157 	crs.release_timeout = arg;
1158 	xpt_action((union ccb *)&crs);
1159 	return (crs.qfrozen_cnt);
1160 }
1161 
1162 #define saved_ccb_ptr ppriv_ptr0
1163 static void
1164 camperiphdone(struct cam_periph *periph, union ccb *done_ccb)
1165 {
1166 	union ccb      *saved_ccb;
1167 	cam_status	status;
1168 	struct scsi_start_stop_unit *scsi_cmd;
1169 	int    error_code, sense_key, asc, ascq;
1170 
1171 	scsi_cmd = (struct scsi_start_stop_unit *)
1172 	    &done_ccb->csio.cdb_io.cdb_bytes;
1173 	status = done_ccb->ccb_h.status;
1174 
1175 	if ((status & CAM_STATUS_MASK) != CAM_REQ_CMP) {
1176 		if (scsi_extract_sense_ccb(done_ccb,
1177 		    &error_code, &sense_key, &asc, &ascq)) {
1178 			/*
1179 			 * If the error is "invalid field in CDB",
1180 			 * and the load/eject flag is set, turn the
1181 			 * flag off and try again.  This is just in
1182 			 * case the drive in question barfs on the
1183 			 * load eject flag.  The CAM code should set
1184 			 * the load/eject flag by default for
1185 			 * removable media.
1186 			 */
1187 			if ((scsi_cmd->opcode == START_STOP_UNIT) &&
1188 			    ((scsi_cmd->how & SSS_LOEJ) != 0) &&
1189 			     (asc == 0x24) && (ascq == 0x00)) {
1190 				scsi_cmd->how &= ~SSS_LOEJ;
1191 				if (status & CAM_DEV_QFRZN) {
1192 					cam_release_devq(done_ccb->ccb_h.path,
1193 					    0, 0, 0, 0);
1194 					done_ccb->ccb_h.status &=
1195 					    ~CAM_DEV_QFRZN;
1196 				}
1197 				xpt_action(done_ccb);
1198 				goto out;
1199 			}
1200 		}
1201 		if (cam_periph_error(done_ccb,
1202 		    0, SF_RETRY_UA | SF_NO_PRINT, NULL) == ERESTART)
1203 			goto out;
1204 		if (done_ccb->ccb_h.status & CAM_DEV_QFRZN) {
1205 			cam_release_devq(done_ccb->ccb_h.path, 0, 0, 0, 0);
1206 			done_ccb->ccb_h.status &= ~CAM_DEV_QFRZN;
1207 		}
1208 	} else {
1209 		/*
1210 		 * If we have successfully taken a device from the not
1211 		 * ready to ready state, re-scan the device and re-get
1212 		 * the inquiry information.  Many devices (mostly disks)
1213 		 * don't properly report their inquiry information unless
1214 		 * they are spun up.
1215 		 */
1216 		if (scsi_cmd->opcode == START_STOP_UNIT)
1217 			xpt_async(AC_INQ_CHANGED, done_ccb->ccb_h.path, NULL);
1218 	}
1219 
1220 	/*
1221 	 * Perform the final retry with the original CCB so that final
1222 	 * error processing is performed by the owner of the CCB.
1223 	 */
1224 	saved_ccb = (union ccb *)done_ccb->ccb_h.saved_ccb_ptr;
1225 	bcopy(saved_ccb, done_ccb, sizeof(*done_ccb));
1226 	xpt_free_ccb(saved_ccb);
1227 	if (done_ccb->ccb_h.cbfcnp != camperiphdone)
1228 		periph->flags &= ~CAM_PERIPH_RECOVERY_INPROG;
1229 	xpt_action(done_ccb);
1230 
1231 out:
1232 	/* Drop freeze taken due to CAM_DEV_QFREEZE flag set. */
1233 	cam_release_devq(done_ccb->ccb_h.path, 0, 0, 0, 0);
1234 }
1235 
1236 /*
1237  * Generic Async Event handler.  Peripheral drivers usually
1238  * filter out the events that require personal attention,
1239  * and leave the rest to this function.
1240  */
1241 void
1242 cam_periph_async(struct cam_periph *periph, u_int32_t code,
1243 		 struct cam_path *path, void *arg)
1244 {
1245 	switch (code) {
1246 	case AC_LOST_DEVICE:
1247 		cam_periph_invalidate(periph);
1248 		break;
1249 	default:
1250 		break;
1251 	}
1252 }
1253 
1254 void
1255 cam_periph_bus_settle(struct cam_periph *periph, u_int bus_settle)
1256 {
1257 	struct ccb_getdevstats cgds;
1258 
1259 	xpt_setup_ccb(&cgds.ccb_h, periph->path, CAM_PRIORITY_NORMAL);
1260 	cgds.ccb_h.func_code = XPT_GDEV_STATS;
1261 	xpt_action((union ccb *)&cgds);
1262 	cam_periph_freeze_after_event(periph, &cgds.last_reset, bus_settle);
1263 }
1264 
1265 void
1266 cam_periph_freeze_after_event(struct cam_periph *periph,
1267 			      struct timeval* event_time, u_int duration_ms)
1268 {
1269 	struct timeval delta;
1270 	struct timeval duration_tv;
1271 
1272 	if (!timevalisset(event_time))
1273 		return;
1274 
1275 	microtime(&delta);
1276 	timevalsub(&delta, event_time);
1277 	duration_tv.tv_sec = duration_ms / 1000;
1278 	duration_tv.tv_usec = (duration_ms % 1000) * 1000;
1279 	if (timevalcmp(&delta, &duration_tv, <)) {
1280 		timevalsub(&duration_tv, &delta);
1281 
1282 		duration_ms = duration_tv.tv_sec * 1000;
1283 		duration_ms += duration_tv.tv_usec / 1000;
1284 		cam_freeze_devq(periph->path);
1285 		cam_release_devq(periph->path,
1286 				RELSIM_RELEASE_AFTER_TIMEOUT,
1287 				/*reduction*/0,
1288 				/*timeout*/duration_ms,
1289 				/*getcount_only*/0);
1290 	}
1291 
1292 }
1293 
1294 static int
1295 camperiphscsistatuserror(union ccb *ccb, union ccb **orig_ccb,
1296     cam_flags camflags, u_int32_t sense_flags,
1297     int *openings, u_int32_t *relsim_flags,
1298     u_int32_t *timeout, u_int32_t *action, const char **action_string)
1299 {
1300 	int error;
1301 
1302 	switch (ccb->csio.scsi_status) {
1303 	case SCSI_STATUS_OK:
1304 	case SCSI_STATUS_COND_MET:
1305 	case SCSI_STATUS_INTERMED:
1306 	case SCSI_STATUS_INTERMED_COND_MET:
1307 		error = 0;
1308 		break;
1309 	case SCSI_STATUS_CMD_TERMINATED:
1310 	case SCSI_STATUS_CHECK_COND:
1311 		error = camperiphscsisenseerror(ccb, orig_ccb,
1312 					        camflags,
1313 					        sense_flags,
1314 					        openings,
1315 					        relsim_flags,
1316 					        timeout,
1317 					        action,
1318 					        action_string);
1319 		break;
1320 	case SCSI_STATUS_QUEUE_FULL:
1321 	{
1322 		/* no decrement */
1323 		struct ccb_getdevstats cgds;
1324 
1325 		/*
1326 		 * First off, find out what the current
1327 		 * transaction counts are.
1328 		 */
1329 		xpt_setup_ccb(&cgds.ccb_h,
1330 			      ccb->ccb_h.path,
1331 			      CAM_PRIORITY_NORMAL);
1332 		cgds.ccb_h.func_code = XPT_GDEV_STATS;
1333 		xpt_action((union ccb *)&cgds);
1334 
1335 		/*
1336 		 * If we were the only transaction active, treat
1337 		 * the QUEUE FULL as if it were a BUSY condition.
1338 		 */
1339 		if (cgds.dev_active != 0) {
1340 			int total_openings;
1341 
1342 			/*
1343 		 	 * Reduce the number of openings to
1344 			 * be 1 less than the amount it took
1345 			 * to get a queue full bounded by the
1346 			 * minimum allowed tag count for this
1347 			 * device.
1348 		 	 */
1349 			total_openings = cgds.dev_active + cgds.dev_openings;
1350 			*openings = cgds.dev_active;
1351 			if (*openings < cgds.mintags)
1352 				*openings = cgds.mintags;
1353 			if (*openings < total_openings)
1354 				*relsim_flags = RELSIM_ADJUST_OPENINGS;
1355 			else {
1356 				/*
1357 				 * Some devices report queue full for
1358 				 * temporary resource shortages.  For
1359 				 * this reason, we allow a minimum
1360 				 * tag count to be entered via a
1361 				 * quirk entry to prevent the queue
1362 				 * count on these devices from falling
1363 				 * to a pessimisticly low value.  We
1364 				 * still wait for the next successful
1365 				 * completion, however, before queueing
1366 				 * more transactions to the device.
1367 				 */
1368 				*relsim_flags = RELSIM_RELEASE_AFTER_CMDCMPLT;
1369 			}
1370 			*timeout = 0;
1371 			error = ERESTART;
1372 			*action &= ~SSQ_PRINT_SENSE;
1373 			break;
1374 		}
1375 		/* FALLTHROUGH */
1376 	}
1377 	case SCSI_STATUS_BUSY:
1378 		/*
1379 		 * Restart the queue after either another
1380 		 * command completes or a 1 second timeout.
1381 		 */
1382 		if ((sense_flags & SF_RETRY_BUSY) != 0 ||
1383 		    (ccb->ccb_h.retry_count--) > 0) {
1384 			error = ERESTART;
1385 			*relsim_flags = RELSIM_RELEASE_AFTER_TIMEOUT
1386 				      | RELSIM_RELEASE_AFTER_CMDCMPLT;
1387 			*timeout = 1000;
1388 		} else {
1389 			error = EIO;
1390 		}
1391 		break;
1392 	case SCSI_STATUS_RESERV_CONFLICT:
1393 	default:
1394 		error = EIO;
1395 		break;
1396 	}
1397 	return (error);
1398 }
1399 
1400 static int
1401 camperiphscsisenseerror(union ccb *ccb, union ccb **orig,
1402     cam_flags camflags, u_int32_t sense_flags,
1403     int *openings, u_int32_t *relsim_flags,
1404     u_int32_t *timeout, u_int32_t *action, const char **action_string)
1405 {
1406 	struct cam_periph *periph;
1407 	union ccb *orig_ccb = ccb;
1408 	int error, recoveryccb;
1409 
1410 	periph = xpt_path_periph(ccb->ccb_h.path);
1411 	recoveryccb = (ccb->ccb_h.cbfcnp == camperiphdone);
1412 	if ((periph->flags & CAM_PERIPH_RECOVERY_INPROG) && !recoveryccb) {
1413 		/*
1414 		 * If error recovery is already in progress, don't attempt
1415 		 * to process this error, but requeue it unconditionally
1416 		 * and attempt to process it once error recovery has
1417 		 * completed.  This failed command is probably related to
1418 		 * the error that caused the currently active error recovery
1419 		 * action so our  current recovery efforts should also
1420 		 * address this command.  Be aware that the error recovery
1421 		 * code assumes that only one recovery action is in progress
1422 		 * on a particular peripheral instance at any given time
1423 		 * (e.g. only one saved CCB for error recovery) so it is
1424 		 * imperitive that we don't violate this assumption.
1425 		 */
1426 		error = ERESTART;
1427 		*action &= ~SSQ_PRINT_SENSE;
1428 	} else {
1429 		scsi_sense_action err_action;
1430 		struct ccb_getdev cgd;
1431 
1432 		/*
1433 		 * Grab the inquiry data for this device.
1434 		 */
1435 		xpt_setup_ccb(&cgd.ccb_h, ccb->ccb_h.path, CAM_PRIORITY_NORMAL);
1436 		cgd.ccb_h.func_code = XPT_GDEV_TYPE;
1437 		xpt_action((union ccb *)&cgd);
1438 
1439 		err_action = scsi_error_action(&ccb->csio, &cgd.inq_data,
1440 		    sense_flags);
1441 		error = err_action & SS_ERRMASK;
1442 
1443 		/*
1444 		 * Do not autostart sequential access devices
1445 		 * to avoid unexpected tape loading.
1446 		 */
1447 		if ((err_action & SS_MASK) == SS_START &&
1448 		    SID_TYPE(&cgd.inq_data) == T_SEQUENTIAL) {
1449 			*action_string = "Will not autostart a "
1450 			    "sequential access device";
1451 			goto sense_error_done;
1452 		}
1453 
1454 		/*
1455 		 * Avoid recovery recursion if recovery action is the same.
1456 		 */
1457 		if ((err_action & SS_MASK) >= SS_START && recoveryccb) {
1458 			if (((err_action & SS_MASK) == SS_START &&
1459 			     ccb->csio.cdb_io.cdb_bytes[0] == START_STOP_UNIT) ||
1460 			    ((err_action & SS_MASK) == SS_TUR &&
1461 			     (ccb->csio.cdb_io.cdb_bytes[0] == TEST_UNIT_READY))) {
1462 				err_action = SS_RETRY|SSQ_DECREMENT_COUNT|EIO;
1463 				*relsim_flags = RELSIM_RELEASE_AFTER_TIMEOUT;
1464 				*timeout = 500;
1465 			}
1466 		}
1467 
1468 		/*
1469 		 * If the recovery action will consume a retry,
1470 		 * make sure we actually have retries available.
1471 		 */
1472 		if ((err_action & SSQ_DECREMENT_COUNT) != 0) {
1473 		 	if (ccb->ccb_h.retry_count > 0 &&
1474 			    (periph->flags & CAM_PERIPH_INVALID) == 0)
1475 		 		ccb->ccb_h.retry_count--;
1476 			else {
1477 				*action_string = "Retries exhausted";
1478 				goto sense_error_done;
1479 			}
1480 		}
1481 
1482 		if ((err_action & SS_MASK) >= SS_START) {
1483 			/*
1484 			 * Do common portions of commands that
1485 			 * use recovery CCBs.
1486 			 */
1487 			orig_ccb = xpt_alloc_ccb_nowait();
1488 			if (orig_ccb == NULL) {
1489 				*action_string = "Can't allocate recovery CCB";
1490 				goto sense_error_done;
1491 			}
1492 			/*
1493 			 * Clear freeze flag for original request here, as
1494 			 * this freeze will be dropped as part of ERESTART.
1495 			 */
1496 			ccb->ccb_h.status &= ~CAM_DEV_QFRZN;
1497 			bcopy(ccb, orig_ccb, sizeof(*orig_ccb));
1498 		}
1499 
1500 		switch (err_action & SS_MASK) {
1501 		case SS_NOP:
1502 			*action_string = "No recovery action needed";
1503 			error = 0;
1504 			break;
1505 		case SS_RETRY:
1506 			*action_string = "Retrying command (per sense data)";
1507 			error = ERESTART;
1508 			break;
1509 		case SS_FAIL:
1510 			*action_string = "Unretryable error";
1511 			break;
1512 		case SS_START:
1513 		{
1514 			int le;
1515 
1516 			/*
1517 			 * Send a start unit command to the device, and
1518 			 * then retry the command.
1519 			 */
1520 			*action_string = "Attempting to start unit";
1521 			periph->flags |= CAM_PERIPH_RECOVERY_INPROG;
1522 
1523 			/*
1524 			 * Check for removable media and set
1525 			 * load/eject flag appropriately.
1526 			 */
1527 			if (SID_IS_REMOVABLE(&cgd.inq_data))
1528 				le = TRUE;
1529 			else
1530 				le = FALSE;
1531 
1532 			scsi_start_stop(&ccb->csio,
1533 					/*retries*/1,
1534 					camperiphdone,
1535 					MSG_SIMPLE_Q_TAG,
1536 					/*start*/TRUE,
1537 					/*load/eject*/le,
1538 					/*immediate*/FALSE,
1539 					SSD_FULL_SIZE,
1540 					/*timeout*/50000);
1541 			break;
1542 		}
1543 		case SS_TUR:
1544 		{
1545 			/*
1546 			 * Send a Test Unit Ready to the device.
1547 			 * If the 'many' flag is set, we send 120
1548 			 * test unit ready commands, one every half
1549 			 * second.  Otherwise, we just send one TUR.
1550 			 * We only want to do this if the retry
1551 			 * count has not been exhausted.
1552 			 */
1553 			int retries;
1554 
1555 			if ((err_action & SSQ_MANY) != 0) {
1556 				*action_string = "Polling device for readiness";
1557 				retries = 120;
1558 			} else {
1559 				*action_string = "Testing device for readiness";
1560 				retries = 1;
1561 			}
1562 			periph->flags |= CAM_PERIPH_RECOVERY_INPROG;
1563 			scsi_test_unit_ready(&ccb->csio,
1564 					     retries,
1565 					     camperiphdone,
1566 					     MSG_SIMPLE_Q_TAG,
1567 					     SSD_FULL_SIZE,
1568 					     /*timeout*/5000);
1569 
1570 			/*
1571 			 * Accomplish our 500ms delay by deferring
1572 			 * the release of our device queue appropriately.
1573 			 */
1574 			*relsim_flags = RELSIM_RELEASE_AFTER_TIMEOUT;
1575 			*timeout = 500;
1576 			break;
1577 		}
1578 		default:
1579 			panic("Unhandled error action %x", err_action);
1580 		}
1581 
1582 		if ((err_action & SS_MASK) >= SS_START) {
1583 			/*
1584 			 * Drop the priority, so that the recovery
1585 			 * CCB is the first to execute.  Freeze the queue
1586 			 * after this command is sent so that we can
1587 			 * restore the old csio and have it queued in
1588 			 * the proper order before we release normal
1589 			 * transactions to the device.
1590 			 */
1591 			ccb->ccb_h.pinfo.priority--;
1592 			ccb->ccb_h.flags |= CAM_DEV_QFREEZE;
1593 			ccb->ccb_h.saved_ccb_ptr = orig_ccb;
1594 			error = ERESTART;
1595 			*orig = orig_ccb;
1596 		}
1597 
1598 sense_error_done:
1599 		*action = err_action;
1600 	}
1601 	return (error);
1602 }
1603 
1604 /*
1605  * Generic error handler.  Peripheral drivers usually filter
1606  * out the errors that they handle in a unique mannor, then
1607  * call this function.
1608  */
1609 int
1610 cam_periph_error(union ccb *ccb, cam_flags camflags,
1611 		 u_int32_t sense_flags, union ccb *save_ccb)
1612 {
1613 	struct cam_path *newpath;
1614 	union ccb  *orig_ccb, *scan_ccb;
1615 	struct cam_periph *periph;
1616 	const char *action_string;
1617 	cam_status  status;
1618 	int	    frozen, error, openings;
1619 	u_int32_t   action, relsim_flags, timeout;
1620 
1621 	action = SSQ_PRINT_SENSE;
1622 	periph = xpt_path_periph(ccb->ccb_h.path);
1623 	action_string = NULL;
1624 	status = ccb->ccb_h.status;
1625 	frozen = (status & CAM_DEV_QFRZN) != 0;
1626 	status &= CAM_STATUS_MASK;
1627 	openings = relsim_flags = timeout = 0;
1628 	orig_ccb = ccb;
1629 
1630 	switch (status) {
1631 	case CAM_REQ_CMP:
1632 		error = 0;
1633 		action &= ~SSQ_PRINT_SENSE;
1634 		break;
1635 	case CAM_SCSI_STATUS_ERROR:
1636 		error = camperiphscsistatuserror(ccb, &orig_ccb,
1637 		    camflags, sense_flags, &openings, &relsim_flags,
1638 		    &timeout, &action, &action_string);
1639 		break;
1640 	case CAM_AUTOSENSE_FAIL:
1641 		error = EIO;	/* we have to kill the command */
1642 		break;
1643 	case CAM_UA_ABORT:
1644 	case CAM_UA_TERMIO:
1645 	case CAM_MSG_REJECT_REC:
1646 		/* XXX Don't know that these are correct */
1647 		error = EIO;
1648 		break;
1649 	case CAM_SEL_TIMEOUT:
1650 		if ((camflags & CAM_RETRY_SELTO) != 0) {
1651 			if (ccb->ccb_h.retry_count > 0 &&
1652 			    (periph->flags & CAM_PERIPH_INVALID) == 0) {
1653 				ccb->ccb_h.retry_count--;
1654 				error = ERESTART;
1655 
1656 				/*
1657 				 * Wait a bit to give the device
1658 				 * time to recover before we try again.
1659 				 */
1660 				relsim_flags = RELSIM_RELEASE_AFTER_TIMEOUT;
1661 				timeout = periph_selto_delay;
1662 				break;
1663 			}
1664 			action_string = "Retries exhausted";
1665 		}
1666 		/* FALLTHROUGH */
1667 	case CAM_DEV_NOT_THERE:
1668 		error = ENXIO;
1669 		action = SSQ_LOST;
1670 		break;
1671 	case CAM_REQ_INVALID:
1672 	case CAM_PATH_INVALID:
1673 	case CAM_NO_HBA:
1674 	case CAM_PROVIDE_FAIL:
1675 	case CAM_REQ_TOO_BIG:
1676 	case CAM_LUN_INVALID:
1677 	case CAM_TID_INVALID:
1678 	case CAM_FUNC_NOTAVAIL:
1679 		error = EINVAL;
1680 		break;
1681 	case CAM_SCSI_BUS_RESET:
1682 	case CAM_BDR_SENT:
1683 		/*
1684 		 * Commands that repeatedly timeout and cause these
1685 		 * kinds of error recovery actions, should return
1686 		 * CAM_CMD_TIMEOUT, which allows us to safely assume
1687 		 * that this command was an innocent bystander to
1688 		 * these events and should be unconditionally
1689 		 * retried.
1690 		 */
1691 	case CAM_REQUEUE_REQ:
1692 		/* Unconditional requeue if device is still there */
1693 		if (periph->flags & CAM_PERIPH_INVALID) {
1694 			action_string = "Periph was invalidated";
1695 			error = EIO;
1696 		} else if (sense_flags & SF_NO_RETRY) {
1697 			error = EIO;
1698 			action_string = "Retry was blocked";
1699 		} else {
1700 			error = ERESTART;
1701 			action &= ~SSQ_PRINT_SENSE;
1702 		}
1703 		break;
1704 	case CAM_RESRC_UNAVAIL:
1705 		/* Wait a bit for the resource shortage to abate. */
1706 		timeout = periph_noresrc_delay;
1707 		/* FALLTHROUGH */
1708 	case CAM_BUSY:
1709 		if (timeout == 0) {
1710 			/* Wait a bit for the busy condition to abate. */
1711 			timeout = periph_busy_delay;
1712 		}
1713 		relsim_flags = RELSIM_RELEASE_AFTER_TIMEOUT;
1714 		/* FALLTHROUGH */
1715 	case CAM_ATA_STATUS_ERROR:
1716 	case CAM_REQ_CMP_ERR:
1717 	case CAM_CMD_TIMEOUT:
1718 	case CAM_UNEXP_BUSFREE:
1719 	case CAM_UNCOR_PARITY:
1720 	case CAM_DATA_RUN_ERR:
1721 	default:
1722 		if (periph->flags & CAM_PERIPH_INVALID) {
1723 			error = EIO;
1724 			action_string = "Periph was invalidated";
1725 		} else if (ccb->ccb_h.retry_count == 0) {
1726 			error = EIO;
1727 			action_string = "Retries exhausted";
1728 		} else if (sense_flags & SF_NO_RETRY) {
1729 			error = EIO;
1730 			action_string = "Retry was blocked";
1731 		} else {
1732 			ccb->ccb_h.retry_count--;
1733 			error = ERESTART;
1734 		}
1735 		break;
1736 	}
1737 
1738 	if ((sense_flags & SF_PRINT_ALWAYS) ||
1739 	    CAM_DEBUGGED(ccb->ccb_h.path, CAM_DEBUG_INFO))
1740 		action |= SSQ_PRINT_SENSE;
1741 	else if (sense_flags & SF_NO_PRINT)
1742 		action &= ~SSQ_PRINT_SENSE;
1743 	if ((action & SSQ_PRINT_SENSE) != 0)
1744 		cam_error_print(orig_ccb, CAM_ESF_ALL, CAM_EPF_ALL);
1745 	if (error != 0 && (action & SSQ_PRINT_SENSE) != 0) {
1746 		if (error != ERESTART) {
1747 			if (action_string == NULL)
1748 				action_string = "Unretryable error";
1749 			xpt_print(ccb->ccb_h.path, "Error %d, %s\n",
1750 			    error, action_string);
1751 		} else if (action_string != NULL)
1752 			xpt_print(ccb->ccb_h.path, "%s\n", action_string);
1753 		else
1754 			xpt_print(ccb->ccb_h.path, "Retrying command\n");
1755 	}
1756 
1757 	if ((action & SSQ_LOST) != 0) {
1758 		lun_id_t lun_id;
1759 
1760 		/*
1761 		 * For a selection timeout, we consider all of the LUNs on
1762 		 * the target to be gone.  If the status is CAM_DEV_NOT_THERE,
1763 		 * then we only get rid of the device(s) specified by the
1764 		 * path in the original CCB.
1765 		 */
1766 		if (status == CAM_SEL_TIMEOUT)
1767 			lun_id = CAM_LUN_WILDCARD;
1768 		else
1769 			lun_id = xpt_path_lun_id(ccb->ccb_h.path);
1770 
1771 		/* Should we do more if we can't create the path?? */
1772 		if (xpt_create_path(&newpath, periph,
1773 				    xpt_path_path_id(ccb->ccb_h.path),
1774 				    xpt_path_target_id(ccb->ccb_h.path),
1775 				    lun_id) == CAM_REQ_CMP) {
1776 
1777 			/*
1778 			 * Let peripheral drivers know that this
1779 			 * device has gone away.
1780 			 */
1781 			xpt_async(AC_LOST_DEVICE, newpath, NULL);
1782 			xpt_free_path(newpath);
1783 		}
1784 	}
1785 
1786 	/* Broadcast UNIT ATTENTIONs to all periphs. */
1787 	if ((action & SSQ_UA) != 0)
1788 		xpt_async(AC_UNIT_ATTENTION, orig_ccb->ccb_h.path, orig_ccb);
1789 
1790 	/* Rescan target on "Reported LUNs data has changed" */
1791 	if ((action & SSQ_RESCAN) != 0) {
1792 		if (xpt_create_path(&newpath, NULL,
1793 				    xpt_path_path_id(ccb->ccb_h.path),
1794 				    xpt_path_target_id(ccb->ccb_h.path),
1795 				    CAM_LUN_WILDCARD) == CAM_REQ_CMP) {
1796 
1797 			scan_ccb = xpt_alloc_ccb_nowait();
1798 			if (scan_ccb != NULL) {
1799 				scan_ccb->ccb_h.path = newpath;
1800 				scan_ccb->ccb_h.func_code = XPT_SCAN_TGT;
1801 				scan_ccb->crcn.flags = 0;
1802 				xpt_rescan(scan_ccb);
1803 			} else {
1804 				xpt_print(newpath,
1805 				    "Can't allocate CCB to rescan target\n");
1806 				xpt_free_path(newpath);
1807 			}
1808 		}
1809 	}
1810 
1811 	/* Attempt a retry */
1812 	if (error == ERESTART || error == 0) {
1813 		if (frozen != 0)
1814 			ccb->ccb_h.status &= ~CAM_DEV_QFRZN;
1815 		if (error == ERESTART)
1816 			xpt_action(ccb);
1817 		if (frozen != 0)
1818 			cam_release_devq(ccb->ccb_h.path,
1819 					 relsim_flags,
1820 					 openings,
1821 					 timeout,
1822 					 /*getcount_only*/0);
1823 	}
1824 
1825 	return (error);
1826 }
1827