xref: /freebsd/sys/cam/scsi/scsi_targ_bh.c (revision 2b8331622f0b212cf3bb4fc4914a501e5321d506)
1 /*-
2  * Implementation of the Target Mode 'Black Hole device' for CAM.
3  *
4  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
5  *
6  * Copyright (c) 1999 Justin T. Gibbs.
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions, and the following disclaimer,
14  *    without modification, immediately at the beginning of the file.
15  * 2. The name of the author may not be used to endorse or promote products
16  *    derived from this software without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
22  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33 
34 #include <sys/param.h>
35 #include <sys/queue.h>
36 #include <sys/systm.h>
37 #include <sys/kernel.h>
38 #include <sys/types.h>
39 #include <sys/bio.h>
40 #include <sys/conf.h>
41 #include <sys/devicestat.h>
42 #include <sys/malloc.h>
43 #include <sys/uio.h>
44 
45 #include <cam/cam.h>
46 #include <cam/cam_ccb.h>
47 #include <cam/cam_periph.h>
48 #include <cam/cam_queue.h>
49 #include <cam/cam_xpt_periph.h>
50 #include <cam/cam_debug.h>
51 #include <cam/cam_sim.h>
52 
53 #include <cam/scsi/scsi_all.h>
54 #include <cam/scsi/scsi_message.h>
55 
56 static MALLOC_DEFINE(M_SCSIBH, "SCSI bh", "SCSI blackhole buffers");
57 
58 typedef enum {
59 	TARGBH_STATE_NORMAL,
60 	TARGBH_STATE_EXCEPTION,
61 	TARGBH_STATE_TEARDOWN
62 } targbh_state;
63 
64 typedef enum {
65 	TARGBH_FLAG_NONE	 = 0x00,
66 	TARGBH_FLAG_LUN_ENABLED	 = 0x01
67 } targbh_flags;
68 
69 typedef enum {
70 	TARGBH_CCB_WORKQ
71 } targbh_ccb_types;
72 
73 #define MAX_ACCEPT	8
74 #define MAX_IMMEDIATE	16
75 #define MAX_BUF_SIZE	256	/* Max inquiry/sense/mode page transfer */
76 
77 /* Offsets into our private CCB area for storing accept information */
78 #define ccb_type	ppriv_field0
79 #define ccb_descr	ppriv_ptr1
80 
81 /* We stick a pointer to the originating accept TIO in each continue I/O CCB */
82 #define ccb_atio	ppriv_ptr1
83 
84 TAILQ_HEAD(ccb_queue, ccb_hdr);
85 
86 struct targbh_softc {
87 	struct		ccb_queue pending_queue;
88 	struct		ccb_queue work_queue;
89 	struct		ccb_queue unknown_atio_queue;
90 	struct		devstat device_stats;
91 	targbh_state	state;
92 	targbh_flags	flags;
93 	u_int		init_level;
94 	u_int		inq_data_len;
95 	struct		ccb_accept_tio *accept_tio_list;
96 	struct		ccb_hdr_slist immed_notify_slist;
97 };
98 
99 struct targbh_cmd_desc {
100 	struct	  ccb_accept_tio* atio_link;
101 	u_int	  data_resid;	/* How much left to transfer */
102 	u_int	  data_increment;/* Amount to send before next disconnect */
103 	void*	  data;		/* The data. Can be from backing_store or not */
104 	void*	  backing_store;/* Backing store allocated for this descriptor*/
105 	u_int	  max_size;	/* Size of backing_store */
106 	u_int32_t timeout;
107 	u_int8_t  status;	/* Status to return to initiator */
108 };
109 
110 static struct scsi_inquiry_data no_lun_inq_data =
111 {
112 	T_NODEVICE | (SID_QUAL_BAD_LU << 5), 0,
113 	/* version */2, /* format version */2
114 };
115 
116 static struct scsi_sense_data_fixed no_lun_sense_data =
117 {
118 	SSD_CURRENT_ERROR|SSD_ERRCODE_VALID,
119 	0,
120 	SSD_KEY_NOT_READY,
121 	{ 0, 0, 0, 0 },
122 	/*extra_len*/offsetof(struct scsi_sense_data_fixed, fru)
123                    - offsetof(struct scsi_sense_data_fixed, extra_len),
124 	{ 0, 0, 0, 0 },
125 	/* Logical Unit Not Supported */
126 	/*ASC*/0x25, /*ASCQ*/0
127 };
128 
129 static const int request_sense_size = offsetof(struct scsi_sense_data_fixed, fru);
130 
131 static periph_init_t	targbhinit;
132 static void		targbhasync(void *callback_arg, u_int32_t code,
133 				    struct cam_path *path, void *arg);
134 static cam_status	targbhenlun(struct cam_periph *periph);
135 static cam_status	targbhdislun(struct cam_periph *periph);
136 static periph_ctor_t	targbhctor;
137 static periph_dtor_t	targbhdtor;
138 static periph_start_t	targbhstart;
139 static void		targbhdone(struct cam_periph *periph,
140 				   union ccb *done_ccb);
141 #ifdef NOTYET
142 static  int		targbherror(union ccb *ccb, u_int32_t cam_flags,
143 				    u_int32_t sense_flags);
144 #endif
145 static struct targbh_cmd_desc*	targbhallocdescr(void);
146 static void		targbhfreedescr(struct targbh_cmd_desc *buf);
147 
148 static struct periph_driver targbhdriver =
149 {
150 	targbhinit, "targbh",
151 	TAILQ_HEAD_INITIALIZER(targbhdriver.units), /* generation */ 0
152 };
153 
154 PERIPHDRIVER_DECLARE(targbh, targbhdriver);
155 
156 static void
157 targbhinit(void)
158 {
159 	cam_status status;
160 
161 	/*
162 	 * Install a global async callback.  This callback will
163 	 * receive async callbacks like "new path registered".
164 	 */
165 	status = xpt_register_async(AC_PATH_REGISTERED | AC_PATH_DEREGISTERED,
166 				    targbhasync, NULL, NULL);
167 
168 	if (status != CAM_REQ_CMP) {
169 		printf("targbh: Failed to attach master async callback "
170 		       "due to status 0x%x!\n", status);
171 	}
172 }
173 
174 static void
175 targbhasync(void *callback_arg, u_int32_t code,
176 	    struct cam_path *path, void *arg)
177 {
178 	struct cam_path *new_path;
179 	struct ccb_pathinq *cpi;
180 	path_id_t bus_path_id;
181 	cam_status status;
182 
183 	cpi = (struct ccb_pathinq *)arg;
184 	if (code == AC_PATH_REGISTERED)
185 		bus_path_id = cpi->ccb_h.path_id;
186 	else
187 		bus_path_id = xpt_path_path_id(path);
188 	/*
189 	 * Allocate a peripheral instance for
190 	 * this target instance.
191 	 */
192 	status = xpt_create_path(&new_path, NULL,
193 				 bus_path_id,
194 				 CAM_TARGET_WILDCARD, CAM_LUN_WILDCARD);
195 	if (status != CAM_REQ_CMP) {
196 		printf("targbhasync: Unable to create path "
197 			"due to status 0x%x\n", status);
198 		return;
199 	}
200 
201 	switch (code) {
202 	case AC_PATH_REGISTERED:
203 	{
204 		/* Only attach to controllers that support target mode */
205 		if ((cpi->target_sprt & PIT_PROCESSOR) == 0)
206 			break;
207 
208 		status = cam_periph_alloc(targbhctor, NULL, targbhdtor,
209 					  targbhstart,
210 					  "targbh", CAM_PERIPH_BIO,
211 					  new_path, targbhasync,
212 					  AC_PATH_REGISTERED,
213 					  cpi);
214 		break;
215 	}
216 	case AC_PATH_DEREGISTERED:
217 	{
218 		struct cam_periph *periph;
219 
220 		if ((periph = cam_periph_find(new_path, "targbh")) != NULL)
221 			cam_periph_invalidate(periph);
222 		break;
223 	}
224 	default:
225 		break;
226 	}
227 	xpt_free_path(new_path);
228 }
229 
230 /* Attempt to enable our lun */
231 static cam_status
232 targbhenlun(struct cam_periph *periph)
233 {
234 	union ccb immed_ccb;
235 	struct targbh_softc *softc;
236 	cam_status status;
237 	int i;
238 
239 	softc = (struct targbh_softc *)periph->softc;
240 
241 	if ((softc->flags & TARGBH_FLAG_LUN_ENABLED) != 0)
242 		return (CAM_REQ_CMP);
243 
244 	memset(&immed_ccb, 0, sizeof(immed_ccb));
245 	xpt_setup_ccb(&immed_ccb.ccb_h, periph->path, CAM_PRIORITY_NORMAL);
246 	immed_ccb.ccb_h.func_code = XPT_EN_LUN;
247 
248 	/* Don't need support for any vendor specific commands */
249 	immed_ccb.cel.grp6_len = 0;
250 	immed_ccb.cel.grp7_len = 0;
251 	immed_ccb.cel.enable = 1;
252 	xpt_action(&immed_ccb);
253 	status = immed_ccb.ccb_h.status;
254 	if (status != CAM_REQ_CMP) {
255 		xpt_print(periph->path,
256 		    "targbhenlun - Enable Lun Rejected with status 0x%x\n",
257 		    status);
258 		return (status);
259 	}
260 
261 	softc->flags |= TARGBH_FLAG_LUN_ENABLED;
262 
263 	/*
264 	 * Build up a buffer of accept target I/O
265 	 * operations for incoming selections.
266 	 */
267 	for (i = 0; i < MAX_ACCEPT; i++) {
268 		struct ccb_accept_tio *atio;
269 
270 		atio = (struct ccb_accept_tio*)malloc(sizeof(*atio), M_SCSIBH,
271 						      M_ZERO | M_NOWAIT);
272 		if (atio == NULL) {
273 			status = CAM_RESRC_UNAVAIL;
274 			break;
275 		}
276 
277 		atio->ccb_h.ccb_descr = targbhallocdescr();
278 
279 		if (atio->ccb_h.ccb_descr == NULL) {
280 			free(atio, M_SCSIBH);
281 			status = CAM_RESRC_UNAVAIL;
282 			break;
283 		}
284 
285 		xpt_setup_ccb(&atio->ccb_h, periph->path, CAM_PRIORITY_NORMAL);
286 		atio->ccb_h.func_code = XPT_ACCEPT_TARGET_IO;
287 		atio->ccb_h.cbfcnp = targbhdone;
288 		((struct targbh_cmd_desc*)atio->ccb_h.ccb_descr)->atio_link =
289 		    softc->accept_tio_list;
290 		softc->accept_tio_list = atio;
291 		xpt_action((union ccb *)atio);
292 		status = atio->ccb_h.status;
293 		if (status != CAM_REQ_INPROG)
294 			break;
295 	}
296 
297 	if (i == 0) {
298 		xpt_print(periph->path,
299 		    "targbhenlun - Could not allocate accept tio CCBs: status "
300 		    "= 0x%x\n", status);
301 		targbhdislun(periph);
302 		return (CAM_REQ_CMP_ERR);
303 	}
304 
305 	/*
306 	 * Build up a buffer of immediate notify CCBs
307 	 * so the SIM can tell us of asynchronous target mode events.
308 	 */
309 	for (i = 0; i < MAX_ACCEPT; i++) {
310 		struct ccb_immediate_notify *inot;
311 
312 		inot = (struct ccb_immediate_notify*)malloc(sizeof(*inot),
313 			    M_SCSIBH, M_ZERO | M_NOWAIT);
314 
315 		if (inot == NULL) {
316 			status = CAM_RESRC_UNAVAIL;
317 			break;
318 		}
319 
320 		xpt_setup_ccb(&inot->ccb_h, periph->path, CAM_PRIORITY_NORMAL);
321 		inot->ccb_h.func_code = XPT_IMMEDIATE_NOTIFY;
322 		inot->ccb_h.cbfcnp = targbhdone;
323 		SLIST_INSERT_HEAD(&softc->immed_notify_slist, &inot->ccb_h,
324 				  periph_links.sle);
325 		xpt_action((union ccb *)inot);
326 		status = inot->ccb_h.status;
327 		if (status != CAM_REQ_INPROG)
328 			break;
329 	}
330 
331 	if (i == 0) {
332 		xpt_print(periph->path,
333 		    "targbhenlun - Could not allocate immediate notify "
334 		    "CCBs: status = 0x%x\n", status);
335 		targbhdislun(periph);
336 		return (CAM_REQ_CMP_ERR);
337 	}
338 
339 	return (CAM_REQ_CMP);
340 }
341 
342 static cam_status
343 targbhdislun(struct cam_periph *periph)
344 {
345 	union ccb ccb;
346 	struct targbh_softc *softc;
347 	struct ccb_accept_tio* atio;
348 	struct ccb_hdr *ccb_h;
349 
350 	softc = (struct targbh_softc *)periph->softc;
351 	if ((softc->flags & TARGBH_FLAG_LUN_ENABLED) == 0)
352 		return CAM_REQ_CMP;
353 
354 	memset(&ccb, 0, sizeof(ccb));
355 
356 	/* XXX Block for Continue I/O completion */
357 
358 	/* Kill off all ACCECPT and IMMEDIATE CCBs */
359 	while ((atio = softc->accept_tio_list) != NULL) {
360 
361 		softc->accept_tio_list =
362 		    ((struct targbh_cmd_desc*)atio->ccb_h.ccb_descr)->atio_link;
363 		xpt_setup_ccb(&ccb.cab.ccb_h, periph->path, CAM_PRIORITY_NORMAL);
364 		ccb.cab.ccb_h.func_code = XPT_ABORT;
365 		ccb.cab.abort_ccb = (union ccb *)atio;
366 		xpt_action(&ccb);
367 	}
368 
369 	while ((ccb_h = SLIST_FIRST(&softc->immed_notify_slist)) != NULL) {
370 		SLIST_REMOVE_HEAD(&softc->immed_notify_slist, periph_links.sle);
371 		xpt_setup_ccb(&ccb.cab.ccb_h, periph->path, CAM_PRIORITY_NORMAL);
372 		ccb.cab.ccb_h.func_code = XPT_ABORT;
373 		ccb.cab.abort_ccb = (union ccb *)ccb_h;
374 		xpt_action(&ccb);
375 	}
376 
377 	/*
378 	 * Dissable this lun.
379 	 */
380 	xpt_setup_ccb(&ccb.cel.ccb_h, periph->path, CAM_PRIORITY_NORMAL);
381 	ccb.cel.ccb_h.func_code = XPT_EN_LUN;
382 	ccb.cel.enable = 0;
383 	xpt_action(&ccb);
384 
385 	if (ccb.cel.ccb_h.status != CAM_REQ_CMP)
386 		printf("targbhdislun - Disabling lun on controller failed "
387 		       "with status 0x%x\n", ccb.cel.ccb_h.status);
388 	else
389 		softc->flags &= ~TARGBH_FLAG_LUN_ENABLED;
390 	return (ccb.cel.ccb_h.status);
391 }
392 
393 static cam_status
394 targbhctor(struct cam_periph *periph, void *arg)
395 {
396 	struct targbh_softc *softc;
397 
398 	/* Allocate our per-instance private storage */
399 	softc = (struct targbh_softc *)malloc(sizeof(*softc),
400 					      M_SCSIBH, M_NOWAIT);
401 	if (softc == NULL) {
402 		printf("targctor: unable to malloc softc\n");
403 		return (CAM_REQ_CMP_ERR);
404 	}
405 
406 	bzero(softc, sizeof(*softc));
407 	TAILQ_INIT(&softc->pending_queue);
408 	TAILQ_INIT(&softc->work_queue);
409 	softc->accept_tio_list = NULL;
410 	SLIST_INIT(&softc->immed_notify_slist);
411 	softc->state = TARGBH_STATE_NORMAL;
412 	periph->softc = softc;
413 	softc->init_level++;
414 
415 	if (targbhenlun(periph) != CAM_REQ_CMP)
416 		cam_periph_invalidate(periph);
417 	return (CAM_REQ_CMP);
418 }
419 
420 static void
421 targbhdtor(struct cam_periph *periph)
422 {
423 	struct targbh_softc *softc;
424 
425 	softc = (struct targbh_softc *)periph->softc;
426 
427 	softc->state = TARGBH_STATE_TEARDOWN;
428 
429 	targbhdislun(periph);
430 
431 	switch (softc->init_level) {
432 	case 0:
433 		panic("targdtor - impossible init level");
434 	case 1:
435 		/* FALLTHROUGH */
436 	default:
437 		/* XXX Wait for callback of targbhdislun() */
438 		cam_periph_sleep(periph, softc, PRIBIO, "targbh", hz/2);
439 		free(softc, M_SCSIBH);
440 		break;
441 	}
442 }
443 
444 static void
445 targbhstart(struct cam_periph *periph, union ccb *start_ccb)
446 {
447 	struct targbh_softc *softc;
448 	struct ccb_hdr *ccbh;
449 	struct ccb_accept_tio *atio;
450 	struct targbh_cmd_desc *desc;
451 	struct ccb_scsiio *csio;
452 	ccb_flags flags;
453 
454 	softc = (struct targbh_softc *)periph->softc;
455 
456 	ccbh = TAILQ_FIRST(&softc->work_queue);
457 	if (ccbh == NULL) {
458 		xpt_release_ccb(start_ccb);
459 	} else {
460 		TAILQ_REMOVE(&softc->work_queue, ccbh, periph_links.tqe);
461 		TAILQ_INSERT_HEAD(&softc->pending_queue, ccbh,
462 				  periph_links.tqe);
463 		atio = (struct ccb_accept_tio*)ccbh;
464 		desc = (struct targbh_cmd_desc *)atio->ccb_h.ccb_descr;
465 
466 		/* Is this a tagged request? */
467 		flags = atio->ccb_h.flags &
468 		    (CAM_DIS_DISCONNECT|CAM_TAG_ACTION_VALID|CAM_DIR_MASK);
469 
470 		csio = &start_ccb->csio;
471 		/*
472 		 * If we are done with the transaction, tell the
473 		 * controller to send status and perform a CMD_CMPLT.
474 		 * If we have associated sense data, see if we can
475 		 * send that too.
476 		 */
477 		if (desc->data_resid == desc->data_increment) {
478 			flags |= CAM_SEND_STATUS;
479 			if (atio->sense_len) {
480 				csio->sense_len = atio->sense_len;
481 				csio->sense_data = atio->sense_data;
482 				flags |= CAM_SEND_SENSE;
483 			}
484 		}
485 
486 		cam_fill_ctio(csio,
487 			      /*retries*/2,
488 			      targbhdone,
489 			      flags,
490 			      (flags & CAM_TAG_ACTION_VALID)?
491 				MSG_SIMPLE_Q_TAG : 0,
492 			      atio->tag_id,
493 			      atio->init_id,
494 			      desc->status,
495 			      /*data_ptr*/desc->data_increment == 0
496 					  ? NULL : desc->data,
497 			      /*dxfer_len*/desc->data_increment,
498 			      /*timeout*/desc->timeout);
499 
500 		/* Override our wildcard attachment */
501 		start_ccb->ccb_h.target_id = atio->ccb_h.target_id;
502 		start_ccb->ccb_h.target_lun = atio->ccb_h.target_lun;
503 
504 		start_ccb->ccb_h.ccb_type = TARGBH_CCB_WORKQ;
505 		start_ccb->ccb_h.ccb_atio = atio;
506 		CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE,
507 			  ("Sending a CTIO\n"));
508 		xpt_action(start_ccb);
509 		/*
510 		 * If the queue was frozen waiting for the response
511 		 * to this ATIO (for instance disconnection was disallowed),
512 		 * then release it now that our response has been queued.
513 		 */
514 		if ((atio->ccb_h.status & CAM_DEV_QFRZN) != 0) {
515 			cam_release_devq(periph->path,
516 					 /*relsim_flags*/0,
517 					 /*reduction*/0,
518 					 /*timeout*/0,
519 					 /*getcount_only*/0);
520 			atio->ccb_h.status &= ~CAM_DEV_QFRZN;
521 		}
522 		ccbh = TAILQ_FIRST(&softc->work_queue);
523 	}
524 	if (ccbh != NULL)
525 		xpt_schedule(periph, CAM_PRIORITY_NORMAL);
526 }
527 
528 static void
529 targbhdone(struct cam_periph *periph, union ccb *done_ccb)
530 {
531 	struct targbh_softc *softc;
532 
533 	softc = (struct targbh_softc *)periph->softc;
534 
535 	switch (done_ccb->ccb_h.func_code) {
536 	case XPT_ACCEPT_TARGET_IO:
537 	{
538 		struct ccb_accept_tio *atio;
539 		struct targbh_cmd_desc *descr;
540 		u_int8_t *cdb;
541 		int priority;
542 
543 		atio = &done_ccb->atio;
544 		descr = (struct targbh_cmd_desc*)atio->ccb_h.ccb_descr;
545 		cdb = atio->cdb_io.cdb_bytes;
546 		if (softc->state == TARGBH_STATE_TEARDOWN
547 		 || atio->ccb_h.status == CAM_REQ_ABORTED) {
548 			targbhfreedescr(descr);
549 			xpt_free_ccb(done_ccb);
550 			return;
551 		}
552 
553 		/*
554 		 * Determine the type of incoming command and
555 		 * setup our buffer for a response.
556 		 */
557 		switch (cdb[0]) {
558 		case INQUIRY:
559 		{
560 			struct scsi_inquiry *inq;
561 
562 			inq = (struct scsi_inquiry *)cdb;
563 			CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE,
564 				  ("Saw an inquiry!\n"));
565 			/*
566 			 * Validate the command.  We don't
567 			 * support any VPD pages, so complain
568 			 * if EVPD is set.
569 			 */
570 			if ((inq->byte2 & SI_EVPD) != 0
571 			 || inq->page_code != 0) {
572 				atio->ccb_h.flags &= ~CAM_DIR_MASK;
573 				atio->ccb_h.flags |= CAM_DIR_NONE;
574 				/*
575 				 * This needs to have other than a
576 				 * no_lun_sense_data response.
577 				 */
578 				bcopy(&no_lun_sense_data, &atio->sense_data,
579 				      min(sizeof(no_lun_sense_data),
580 					  sizeof(atio->sense_data)));
581 				atio->sense_len = sizeof(no_lun_sense_data);
582 				descr->data_resid = 0;
583 				descr->data_increment = 0;
584 				descr->status = SCSI_STATUS_CHECK_COND;
585 				break;
586 			}
587 			/*
588 			 * Direction is always relative
589 			 * to the initator.
590 			 */
591 			atio->ccb_h.flags &= ~CAM_DIR_MASK;
592 			atio->ccb_h.flags |= CAM_DIR_IN;
593 			descr->data = &no_lun_inq_data;
594 			descr->data_resid = MIN(sizeof(no_lun_inq_data),
595 						scsi_2btoul(inq->length));
596 			descr->data_increment = descr->data_resid;
597 			descr->timeout = 5 * 1000;
598 			descr->status = SCSI_STATUS_OK;
599 			break;
600 		}
601 		case REQUEST_SENSE:
602 		{
603 			struct scsi_request_sense *rsense;
604 
605 			rsense = (struct scsi_request_sense *)cdb;
606 			/* Refer to static sense data */
607 			atio->ccb_h.flags &= ~CAM_DIR_MASK;
608 			atio->ccb_h.flags |= CAM_DIR_IN;
609 			descr->data = &no_lun_sense_data;
610 			descr->data_resid = request_sense_size;
611 			descr->data_resid = MIN(descr->data_resid,
612 						SCSI_CDB6_LEN(rsense->length));
613 			descr->data_increment = descr->data_resid;
614 			descr->timeout = 5 * 1000;
615 			descr->status = SCSI_STATUS_OK;
616 			break;
617 		}
618 		default:
619 			/* Constant CA, tell initiator */
620 			/* Direction is always relative to the initator */
621 			atio->ccb_h.flags &= ~CAM_DIR_MASK;
622 			atio->ccb_h.flags |= CAM_DIR_NONE;
623 			bcopy(&no_lun_sense_data, &atio->sense_data,
624 			      min(sizeof(no_lun_sense_data),
625 				  sizeof(atio->sense_data)));
626 			atio->sense_len = sizeof (no_lun_sense_data);
627 			descr->data_resid = 0;
628 			descr->data_increment = 0;
629 			descr->timeout = 5 * 1000;
630 			descr->status = SCSI_STATUS_CHECK_COND;
631 			break;
632 		}
633 
634 		/* Queue us up to receive a Continue Target I/O ccb. */
635 		if ((atio->ccb_h.flags & CAM_DIS_DISCONNECT) != 0) {
636 			TAILQ_INSERT_HEAD(&softc->work_queue, &atio->ccb_h,
637 					  periph_links.tqe);
638 			priority = 0;
639 		} else {
640 			TAILQ_INSERT_TAIL(&softc->work_queue, &atio->ccb_h,
641 					  periph_links.tqe);
642 			priority = CAM_PRIORITY_NORMAL;
643 		}
644 		xpt_schedule(periph, priority);
645 		break;
646 	}
647 	case XPT_CONT_TARGET_IO:
648 	{
649 		struct ccb_accept_tio *atio;
650 		struct targbh_cmd_desc *desc;
651 
652 		CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE,
653 			  ("Received completed CTIO\n"));
654 		atio = (struct ccb_accept_tio*)done_ccb->ccb_h.ccb_atio;
655 		desc = (struct targbh_cmd_desc *)atio->ccb_h.ccb_descr;
656 
657 		TAILQ_REMOVE(&softc->pending_queue, &atio->ccb_h,
658 			     periph_links.tqe);
659 
660 		/*
661 		 * We could check for CAM_SENT_SENSE bein set here,
662 		 * but since we're not maintaining any CA/UA state,
663 		 * there's no point.
664 		 */
665 		atio->sense_len = 0;
666 		done_ccb->ccb_h.flags &= ~CAM_SEND_SENSE;
667 		done_ccb->ccb_h.status &= ~CAM_SENT_SENSE;
668 
669 		/*
670 		 * Any errors will not change the data we return,
671 		 * so make sure the queue is not left frozen.
672 		 * XXX - At some point there may be errors that
673 		 *       leave us in a connected state with the
674 		 *       initiator...
675 		 */
676 		if ((done_ccb->ccb_h.status & CAM_DEV_QFRZN) != 0) {
677 			printf("Releasing Queue\n");
678 			cam_release_devq(done_ccb->ccb_h.path,
679 					 /*relsim_flags*/0,
680 					 /*reduction*/0,
681 					 /*timeout*/0,
682 					 /*getcount_only*/0);
683 			done_ccb->ccb_h.status &= ~CAM_DEV_QFRZN;
684 		}
685 		desc->data_resid -= desc->data_increment;
686 		xpt_release_ccb(done_ccb);
687 		if (softc->state != TARGBH_STATE_TEARDOWN) {
688 			/*
689 			 * Send the original accept TIO back to the
690 			 * controller to handle more work.
691 			 */
692 			CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE,
693 				  ("Returning ATIO to target\n"));
694 			/* Restore wildcards */
695 			atio->ccb_h.target_id = CAM_TARGET_WILDCARD;
696 			atio->ccb_h.target_lun = CAM_LUN_WILDCARD;
697 			xpt_action((union ccb *)atio);
698 			break;
699 		} else {
700 			targbhfreedescr(desc);
701 			free(atio, M_SCSIBH);
702 		}
703 		break;
704 	}
705 	case XPT_IMMEDIATE_NOTIFY:
706 	{
707 		int frozen;
708 
709 		frozen = (done_ccb->ccb_h.status & CAM_DEV_QFRZN) != 0;
710 		if (softc->state == TARGBH_STATE_TEARDOWN
711 		 || done_ccb->ccb_h.status == CAM_REQ_ABORTED) {
712 			printf("Freed an immediate notify\n");
713 			xpt_free_ccb(done_ccb);
714 		} else {
715 			/* Requeue for another immediate event */
716 			xpt_action(done_ccb);
717 		}
718 		if (frozen != 0)
719 			cam_release_devq(periph->path,
720 					 /*relsim_flags*/0,
721 					 /*opening reduction*/0,
722 					 /*timeout*/0,
723 					 /*getcount_only*/0);
724 		break;
725 	}
726 	default:
727 		panic("targbhdone: Unexpected ccb opcode");
728 		break;
729 	}
730 }
731 
732 #ifdef NOTYET
733 static int
734 targbherror(union ccb *ccb, u_int32_t cam_flags, u_int32_t sense_flags)
735 {
736 	return 0;
737 }
738 #endif
739 
740 static struct targbh_cmd_desc*
741 targbhallocdescr(void)
742 {
743 	struct targbh_cmd_desc* descr;
744 
745 	/* Allocate the targbh_descr structure */
746 	descr = (struct targbh_cmd_desc *)malloc(sizeof(*descr),
747 					       M_SCSIBH, M_NOWAIT);
748 	if (descr == NULL)
749 		return (NULL);
750 
751 	bzero(descr, sizeof(*descr));
752 
753 	/* Allocate buffer backing store */
754 	descr->backing_store = malloc(MAX_BUF_SIZE, M_SCSIBH, M_NOWAIT);
755 	if (descr->backing_store == NULL) {
756 		free(descr, M_SCSIBH);
757 		return (NULL);
758 	}
759 	descr->max_size = MAX_BUF_SIZE;
760 	return (descr);
761 }
762 
763 static void
764 targbhfreedescr(struct targbh_cmd_desc *descr)
765 {
766 	free(descr->backing_store, M_SCSIBH);
767 	free(descr, M_SCSIBH);
768 }
769