xref: /freebsd/sys/cam/scsi/scsi_targ_bh.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
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 	xpt_setup_ccb(&immed_ccb.ccb_h, periph->path, CAM_PRIORITY_NORMAL);
245 	immed_ccb.ccb_h.func_code = XPT_EN_LUN;
246 
247 	/* Don't need support for any vendor specific commands */
248 	immed_ccb.cel.grp6_len = 0;
249 	immed_ccb.cel.grp7_len = 0;
250 	immed_ccb.cel.enable = 1;
251 	xpt_action(&immed_ccb);
252 	status = immed_ccb.ccb_h.status;
253 	if (status != CAM_REQ_CMP) {
254 		xpt_print(periph->path,
255 		    "targbhenlun - Enable Lun Rejected with status 0x%x\n",
256 		    status);
257 		return (status);
258 	}
259 
260 	softc->flags |= TARGBH_FLAG_LUN_ENABLED;
261 
262 	/*
263 	 * Build up a buffer of accept target I/O
264 	 * operations for incoming selections.
265 	 */
266 	for (i = 0; i < MAX_ACCEPT; i++) {
267 		struct ccb_accept_tio *atio;
268 
269 		atio = (struct ccb_accept_tio*)malloc(sizeof(*atio), M_SCSIBH,
270 						      M_NOWAIT);
271 		if (atio == NULL) {
272 			status = CAM_RESRC_UNAVAIL;
273 			break;
274 		}
275 
276 		atio->ccb_h.ccb_descr = targbhallocdescr();
277 
278 		if (atio->ccb_h.ccb_descr == NULL) {
279 			free(atio, M_SCSIBH);
280 			status = CAM_RESRC_UNAVAIL;
281 			break;
282 		}
283 
284 		xpt_setup_ccb(&atio->ccb_h, periph->path, CAM_PRIORITY_NORMAL);
285 		atio->ccb_h.func_code = XPT_ACCEPT_TARGET_IO;
286 		atio->ccb_h.cbfcnp = targbhdone;
287 		((struct targbh_cmd_desc*)atio->ccb_h.ccb_descr)->atio_link =
288 		    softc->accept_tio_list;
289 		softc->accept_tio_list = atio;
290 		xpt_action((union ccb *)atio);
291 		status = atio->ccb_h.status;
292 		if (status != CAM_REQ_INPROG)
293 			break;
294 	}
295 
296 	if (i == 0) {
297 		xpt_print(periph->path,
298 		    "targbhenlun - Could not allocate accept tio CCBs: status "
299 		    "= 0x%x\n", status);
300 		targbhdislun(periph);
301 		return (CAM_REQ_CMP_ERR);
302 	}
303 
304 	/*
305 	 * Build up a buffer of immediate notify CCBs
306 	 * so the SIM can tell us of asynchronous target mode events.
307 	 */
308 	for (i = 0; i < MAX_ACCEPT; i++) {
309 		struct ccb_immediate_notify *inot;
310 
311 		inot = (struct ccb_immediate_notify*)malloc(sizeof(*inot),
312 			    M_SCSIBH, M_NOWAIT);
313 
314 		if (inot == NULL) {
315 			status = CAM_RESRC_UNAVAIL;
316 			break;
317 		}
318 
319 		xpt_setup_ccb(&inot->ccb_h, periph->path, CAM_PRIORITY_NORMAL);
320 		inot->ccb_h.func_code = XPT_IMMEDIATE_NOTIFY;
321 		inot->ccb_h.cbfcnp = targbhdone;
322 		SLIST_INSERT_HEAD(&softc->immed_notify_slist, &inot->ccb_h,
323 				  periph_links.sle);
324 		xpt_action((union ccb *)inot);
325 		status = inot->ccb_h.status;
326 		if (status != CAM_REQ_INPROG)
327 			break;
328 	}
329 
330 	if (i == 0) {
331 		xpt_print(periph->path,
332 		    "targbhenlun - Could not allocate immediate notify "
333 		    "CCBs: status = 0x%x\n", status);
334 		targbhdislun(periph);
335 		return (CAM_REQ_CMP_ERR);
336 	}
337 
338 	return (CAM_REQ_CMP);
339 }
340 
341 static cam_status
342 targbhdislun(struct cam_periph *periph)
343 {
344 	union ccb ccb;
345 	struct targbh_softc *softc;
346 	struct ccb_accept_tio* atio;
347 	struct ccb_hdr *ccb_h;
348 
349 	softc = (struct targbh_softc *)periph->softc;
350 	if ((softc->flags & TARGBH_FLAG_LUN_ENABLED) == 0)
351 		return CAM_REQ_CMP;
352 
353 	/* XXX Block for Continue I/O completion */
354 
355 	/* Kill off all ACCECPT and IMMEDIATE CCBs */
356 	while ((atio = softc->accept_tio_list) != NULL) {
357 
358 		softc->accept_tio_list =
359 		    ((struct targbh_cmd_desc*)atio->ccb_h.ccb_descr)->atio_link;
360 		xpt_setup_ccb(&ccb.cab.ccb_h, periph->path, CAM_PRIORITY_NORMAL);
361 		ccb.cab.ccb_h.func_code = XPT_ABORT;
362 		ccb.cab.abort_ccb = (union ccb *)atio;
363 		xpt_action(&ccb);
364 	}
365 
366 	while ((ccb_h = SLIST_FIRST(&softc->immed_notify_slist)) != NULL) {
367 		SLIST_REMOVE_HEAD(&softc->immed_notify_slist, periph_links.sle);
368 		xpt_setup_ccb(&ccb.cab.ccb_h, periph->path, CAM_PRIORITY_NORMAL);
369 		ccb.cab.ccb_h.func_code = XPT_ABORT;
370 		ccb.cab.abort_ccb = (union ccb *)ccb_h;
371 		xpt_action(&ccb);
372 	}
373 
374 	/*
375 	 * Dissable this lun.
376 	 */
377 	xpt_setup_ccb(&ccb.cel.ccb_h, periph->path, CAM_PRIORITY_NORMAL);
378 	ccb.cel.ccb_h.func_code = XPT_EN_LUN;
379 	ccb.cel.enable = 0;
380 	xpt_action(&ccb);
381 
382 	if (ccb.cel.ccb_h.status != CAM_REQ_CMP)
383 		printf("targbhdislun - Disabling lun on controller failed "
384 		       "with status 0x%x\n", ccb.cel.ccb_h.status);
385 	else
386 		softc->flags &= ~TARGBH_FLAG_LUN_ENABLED;
387 	return (ccb.cel.ccb_h.status);
388 }
389 
390 static cam_status
391 targbhctor(struct cam_periph *periph, void *arg)
392 {
393 	struct targbh_softc *softc;
394 
395 	/* Allocate our per-instance private storage */
396 	softc = (struct targbh_softc *)malloc(sizeof(*softc),
397 					      M_SCSIBH, M_NOWAIT);
398 	if (softc == NULL) {
399 		printf("targctor: unable to malloc softc\n");
400 		return (CAM_REQ_CMP_ERR);
401 	}
402 
403 	bzero(softc, sizeof(*softc));
404 	TAILQ_INIT(&softc->pending_queue);
405 	TAILQ_INIT(&softc->work_queue);
406 	softc->accept_tio_list = NULL;
407 	SLIST_INIT(&softc->immed_notify_slist);
408 	softc->state = TARGBH_STATE_NORMAL;
409 	periph->softc = softc;
410 	softc->init_level++;
411 
412 	if (targbhenlun(periph) != CAM_REQ_CMP)
413 		cam_periph_invalidate(periph);
414 	return (CAM_REQ_CMP);
415 }
416 
417 static void
418 targbhdtor(struct cam_periph *periph)
419 {
420 	struct targbh_softc *softc;
421 
422 	softc = (struct targbh_softc *)periph->softc;
423 
424 	softc->state = TARGBH_STATE_TEARDOWN;
425 
426 	targbhdislun(periph);
427 
428 	switch (softc->init_level) {
429 	case 0:
430 		panic("targdtor - impossible init level");
431 	case 1:
432 		/* FALLTHROUGH */
433 	default:
434 		/* XXX Wait for callback of targbhdislun() */
435 		cam_periph_sleep(periph, softc, PRIBIO, "targbh", hz/2);
436 		free(softc, M_SCSIBH);
437 		break;
438 	}
439 }
440 
441 static void
442 targbhstart(struct cam_periph *periph, union ccb *start_ccb)
443 {
444 	struct targbh_softc *softc;
445 	struct ccb_hdr *ccbh;
446 	struct ccb_accept_tio *atio;
447 	struct targbh_cmd_desc *desc;
448 	struct ccb_scsiio *csio;
449 	ccb_flags flags;
450 
451 	softc = (struct targbh_softc *)periph->softc;
452 
453 	ccbh = TAILQ_FIRST(&softc->work_queue);
454 	if (ccbh == NULL) {
455 		xpt_release_ccb(start_ccb);
456 	} else {
457 		TAILQ_REMOVE(&softc->work_queue, ccbh, periph_links.tqe);
458 		TAILQ_INSERT_HEAD(&softc->pending_queue, ccbh,
459 				  periph_links.tqe);
460 		atio = (struct ccb_accept_tio*)ccbh;
461 		desc = (struct targbh_cmd_desc *)atio->ccb_h.ccb_descr;
462 
463 		/* Is this a tagged request? */
464 		flags = atio->ccb_h.flags &
465 		    (CAM_DIS_DISCONNECT|CAM_TAG_ACTION_VALID|CAM_DIR_MASK);
466 
467 		csio = &start_ccb->csio;
468 		/*
469 		 * If we are done with the transaction, tell the
470 		 * controller to send status and perform a CMD_CMPLT.
471 		 * If we have associated sense data, see if we can
472 		 * send that too.
473 		 */
474 		if (desc->data_resid == desc->data_increment) {
475 			flags |= CAM_SEND_STATUS;
476 			if (atio->sense_len) {
477 				csio->sense_len = atio->sense_len;
478 				csio->sense_data = atio->sense_data;
479 				flags |= CAM_SEND_SENSE;
480 			}
481 		}
482 
483 		cam_fill_ctio(csio,
484 			      /*retries*/2,
485 			      targbhdone,
486 			      flags,
487 			      (flags & CAM_TAG_ACTION_VALID)?
488 				MSG_SIMPLE_Q_TAG : 0,
489 			      atio->tag_id,
490 			      atio->init_id,
491 			      desc->status,
492 			      /*data_ptr*/desc->data_increment == 0
493 					  ? NULL : desc->data,
494 			      /*dxfer_len*/desc->data_increment,
495 			      /*timeout*/desc->timeout);
496 
497 		/* Override our wildcard attachment */
498 		start_ccb->ccb_h.target_id = atio->ccb_h.target_id;
499 		start_ccb->ccb_h.target_lun = atio->ccb_h.target_lun;
500 
501 		start_ccb->ccb_h.ccb_type = TARGBH_CCB_WORKQ;
502 		start_ccb->ccb_h.ccb_atio = atio;
503 		CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE,
504 			  ("Sending a CTIO\n"));
505 		xpt_action(start_ccb);
506 		/*
507 		 * If the queue was frozen waiting for the response
508 		 * to this ATIO (for instance disconnection was disallowed),
509 		 * then release it now that our response has been queued.
510 		 */
511 		if ((atio->ccb_h.status & CAM_DEV_QFRZN) != 0) {
512 			cam_release_devq(periph->path,
513 					 /*relsim_flags*/0,
514 					 /*reduction*/0,
515 					 /*timeout*/0,
516 					 /*getcount_only*/0);
517 			atio->ccb_h.status &= ~CAM_DEV_QFRZN;
518 		}
519 		ccbh = TAILQ_FIRST(&softc->work_queue);
520 	}
521 	if (ccbh != NULL)
522 		xpt_schedule(periph, CAM_PRIORITY_NORMAL);
523 }
524 
525 static void
526 targbhdone(struct cam_periph *periph, union ccb *done_ccb)
527 {
528 	struct targbh_softc *softc;
529 
530 	softc = (struct targbh_softc *)periph->softc;
531 
532 	switch (done_ccb->ccb_h.func_code) {
533 	case XPT_ACCEPT_TARGET_IO:
534 	{
535 		struct ccb_accept_tio *atio;
536 		struct targbh_cmd_desc *descr;
537 		u_int8_t *cdb;
538 		int priority;
539 
540 		atio = &done_ccb->atio;
541 		descr = (struct targbh_cmd_desc*)atio->ccb_h.ccb_descr;
542 		cdb = atio->cdb_io.cdb_bytes;
543 		if (softc->state == TARGBH_STATE_TEARDOWN
544 		 || atio->ccb_h.status == CAM_REQ_ABORTED) {
545 			targbhfreedescr(descr);
546 			xpt_free_ccb(done_ccb);
547 			return;
548 		}
549 
550 		/*
551 		 * Determine the type of incoming command and
552 		 * setup our buffer for a response.
553 		 */
554 		switch (cdb[0]) {
555 		case INQUIRY:
556 		{
557 			struct scsi_inquiry *inq;
558 
559 			inq = (struct scsi_inquiry *)cdb;
560 			CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE,
561 				  ("Saw an inquiry!\n"));
562 			/*
563 			 * Validate the command.  We don't
564 			 * support any VPD pages, so complain
565 			 * if EVPD is set.
566 			 */
567 			if ((inq->byte2 & SI_EVPD) != 0
568 			 || inq->page_code != 0) {
569 				atio->ccb_h.flags &= ~CAM_DIR_MASK;
570 				atio->ccb_h.flags |= CAM_DIR_NONE;
571 				/*
572 				 * This needs to have other than a
573 				 * no_lun_sense_data response.
574 				 */
575 				bcopy(&no_lun_sense_data, &atio->sense_data,
576 				      min(sizeof(no_lun_sense_data),
577 					  sizeof(atio->sense_data)));
578 				atio->sense_len = sizeof(no_lun_sense_data);
579 				descr->data_resid = 0;
580 				descr->data_increment = 0;
581 				descr->status = SCSI_STATUS_CHECK_COND;
582 				break;
583 			}
584 			/*
585 			 * Direction is always relative
586 			 * to the initator.
587 			 */
588 			atio->ccb_h.flags &= ~CAM_DIR_MASK;
589 			atio->ccb_h.flags |= CAM_DIR_IN;
590 			descr->data = &no_lun_inq_data;
591 			descr->data_resid = MIN(sizeof(no_lun_inq_data),
592 						scsi_2btoul(inq->length));
593 			descr->data_increment = descr->data_resid;
594 			descr->timeout = 5 * 1000;
595 			descr->status = SCSI_STATUS_OK;
596 			break;
597 		}
598 		case REQUEST_SENSE:
599 		{
600 			struct scsi_request_sense *rsense;
601 
602 			rsense = (struct scsi_request_sense *)cdb;
603 			/* Refer to static sense data */
604 			atio->ccb_h.flags &= ~CAM_DIR_MASK;
605 			atio->ccb_h.flags |= CAM_DIR_IN;
606 			descr->data = &no_lun_sense_data;
607 			descr->data_resid = request_sense_size;
608 			descr->data_resid = MIN(descr->data_resid,
609 						SCSI_CDB6_LEN(rsense->length));
610 			descr->data_increment = descr->data_resid;
611 			descr->timeout = 5 * 1000;
612 			descr->status = SCSI_STATUS_OK;
613 			break;
614 		}
615 		default:
616 			/* Constant CA, tell initiator */
617 			/* Direction is always relative to the initator */
618 			atio->ccb_h.flags &= ~CAM_DIR_MASK;
619 			atio->ccb_h.flags |= CAM_DIR_NONE;
620 			bcopy(&no_lun_sense_data, &atio->sense_data,
621 			      min(sizeof(no_lun_sense_data),
622 				  sizeof(atio->sense_data)));
623 			atio->sense_len = sizeof (no_lun_sense_data);
624 			descr->data_resid = 0;
625 			descr->data_increment = 0;
626 			descr->timeout = 5 * 1000;
627 			descr->status = SCSI_STATUS_CHECK_COND;
628 			break;
629 		}
630 
631 		/* Queue us up to receive a Continue Target I/O ccb. */
632 		if ((atio->ccb_h.flags & CAM_DIS_DISCONNECT) != 0) {
633 			TAILQ_INSERT_HEAD(&softc->work_queue, &atio->ccb_h,
634 					  periph_links.tqe);
635 			priority = 0;
636 		} else {
637 			TAILQ_INSERT_TAIL(&softc->work_queue, &atio->ccb_h,
638 					  periph_links.tqe);
639 			priority = CAM_PRIORITY_NORMAL;
640 		}
641 		xpt_schedule(periph, priority);
642 		break;
643 	}
644 	case XPT_CONT_TARGET_IO:
645 	{
646 		struct ccb_accept_tio *atio;
647 		struct targbh_cmd_desc *desc;
648 
649 		CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE,
650 			  ("Received completed CTIO\n"));
651 		atio = (struct ccb_accept_tio*)done_ccb->ccb_h.ccb_atio;
652 		desc = (struct targbh_cmd_desc *)atio->ccb_h.ccb_descr;
653 
654 		TAILQ_REMOVE(&softc->pending_queue, &atio->ccb_h,
655 			     periph_links.tqe);
656 
657 		/*
658 		 * We could check for CAM_SENT_SENSE bein set here,
659 		 * but since we're not maintaining any CA/UA state,
660 		 * there's no point.
661 		 */
662 		atio->sense_len = 0;
663 		done_ccb->ccb_h.flags &= ~CAM_SEND_SENSE;
664 		done_ccb->ccb_h.status &= ~CAM_SENT_SENSE;
665 
666 		/*
667 		 * Any errors will not change the data we return,
668 		 * so make sure the queue is not left frozen.
669 		 * XXX - At some point there may be errors that
670 		 *       leave us in a connected state with the
671 		 *       initiator...
672 		 */
673 		if ((done_ccb->ccb_h.status & CAM_DEV_QFRZN) != 0) {
674 			printf("Releasing Queue\n");
675 			cam_release_devq(done_ccb->ccb_h.path,
676 					 /*relsim_flags*/0,
677 					 /*reduction*/0,
678 					 /*timeout*/0,
679 					 /*getcount_only*/0);
680 			done_ccb->ccb_h.status &= ~CAM_DEV_QFRZN;
681 		}
682 		desc->data_resid -= desc->data_increment;
683 		xpt_release_ccb(done_ccb);
684 		if (softc->state != TARGBH_STATE_TEARDOWN) {
685 			/*
686 			 * Send the original accept TIO back to the
687 			 * controller to handle more work.
688 			 */
689 			CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE,
690 				  ("Returning ATIO to target\n"));
691 			/* Restore wildcards */
692 			atio->ccb_h.target_id = CAM_TARGET_WILDCARD;
693 			atio->ccb_h.target_lun = CAM_LUN_WILDCARD;
694 			xpt_action((union ccb *)atio);
695 			break;
696 		} else {
697 			targbhfreedescr(desc);
698 			free(atio, M_SCSIBH);
699 		}
700 		break;
701 	}
702 	case XPT_IMMEDIATE_NOTIFY:
703 	{
704 		int frozen;
705 
706 		frozen = (done_ccb->ccb_h.status & CAM_DEV_QFRZN) != 0;
707 		if (softc->state == TARGBH_STATE_TEARDOWN
708 		 || done_ccb->ccb_h.status == CAM_REQ_ABORTED) {
709 			printf("Freed an immediate notify\n");
710 			xpt_free_ccb(done_ccb);
711 		} else {
712 			/* Requeue for another immediate event */
713 			xpt_action(done_ccb);
714 		}
715 		if (frozen != 0)
716 			cam_release_devq(periph->path,
717 					 /*relsim_flags*/0,
718 					 /*opening reduction*/0,
719 					 /*timeout*/0,
720 					 /*getcount_only*/0);
721 		break;
722 	}
723 	default:
724 		panic("targbhdone: Unexpected ccb opcode");
725 		break;
726 	}
727 }
728 
729 #ifdef NOTYET
730 static int
731 targbherror(union ccb *ccb, u_int32_t cam_flags, u_int32_t sense_flags)
732 {
733 	return 0;
734 }
735 #endif
736 
737 static struct targbh_cmd_desc*
738 targbhallocdescr(void)
739 {
740 	struct targbh_cmd_desc* descr;
741 
742 	/* Allocate the targbh_descr structure */
743 	descr = (struct targbh_cmd_desc *)malloc(sizeof(*descr),
744 					       M_SCSIBH, M_NOWAIT);
745 	if (descr == NULL)
746 		return (NULL);
747 
748 	bzero(descr, sizeof(*descr));
749 
750 	/* Allocate buffer backing store */
751 	descr->backing_store = malloc(MAX_BUF_SIZE, M_SCSIBH, M_NOWAIT);
752 	if (descr->backing_store == NULL) {
753 		free(descr, M_SCSIBH);
754 		return (NULL);
755 	}
756 	descr->max_size = MAX_BUF_SIZE;
757 	return (descr);
758 }
759 
760 static void
761 targbhfreedescr(struct targbh_cmd_desc *descr)
762 {
763 	free(descr->backing_store, M_SCSIBH);
764 	free(descr, M_SCSIBH);
765 }
766