xref: /freebsd/sys/cam/scsi/scsi_targ_bh.c (revision 1669d8afc64812c8d2d1d147ae1fd42ff441e1b1)
1 /*-
2  * Implementation of the Target Mode 'Black Hole device' for CAM.
3  *
4  * Copyright (c) 1999 Justin T. Gibbs.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions, and the following disclaimer,
12  *    without modification, immediately at the beginning of the file.
13  * 2. The name of the author may not be used to endorse or promote products
14  *    derived from this software without specific prior written permission.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
20  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/param.h>
33 #include <sys/queue.h>
34 #include <sys/systm.h>
35 #include <sys/kernel.h>
36 #include <sys/types.h>
37 #include <sys/bio.h>
38 #include <sys/conf.h>
39 #include <sys/devicestat.h>
40 #include <sys/malloc.h>
41 #include <sys/uio.h>
42 
43 #include <cam/cam.h>
44 #include <cam/cam_ccb.h>
45 #include <cam/cam_periph.h>
46 #include <cam/cam_queue.h>
47 #include <cam/cam_xpt_periph.h>
48 #include <cam/cam_debug.h>
49 #include <cam/cam_sim.h>
50 
51 #include <cam/scsi/scsi_all.h>
52 #include <cam/scsi/scsi_message.h>
53 
54 MALLOC_DEFINE(M_SCSIBH, "SCSI bh", "SCSI blackhole buffers");
55 
56 typedef enum {
57 	TARGBH_STATE_NORMAL,
58 	TARGBH_STATE_EXCEPTION,
59 	TARGBH_STATE_TEARDOWN
60 } targbh_state;
61 
62 typedef enum {
63 	TARGBH_FLAG_NONE	 = 0x00,
64 	TARGBH_FLAG_LUN_ENABLED	 = 0x01
65 } targbh_flags;
66 
67 typedef enum {
68 	TARGBH_CCB_WORKQ,
69 	TARGBH_CCB_WAITING
70 } targbh_ccb_types;
71 
72 #define MAX_ACCEPT	8
73 #define MAX_IMMEDIATE	16
74 #define MAX_BUF_SIZE	256	/* Max inquiry/sense/mode page transfer */
75 
76 /* Offsets into our private CCB area for storing accept information */
77 #define ccb_type	ppriv_field0
78 #define ccb_descr	ppriv_ptr1
79 
80 /* We stick a pointer to the originating accept TIO in each continue I/O CCB */
81 #define ccb_atio	ppriv_ptr1
82 
83 TAILQ_HEAD(ccb_queue, ccb_hdr);
84 
85 struct targbh_softc {
86 	struct		ccb_queue pending_queue;
87 	struct		ccb_queue work_queue;
88 	struct		ccb_queue unknown_atio_queue;
89 	struct		devstat device_stats;
90 	targbh_state	state;
91 	targbh_flags	flags;
92 	u_int		init_level;
93 	u_int		inq_data_len;
94 	struct		ccb_accept_tio *accept_tio_list;
95 	struct		ccb_hdr_slist immed_notify_slist;
96 };
97 
98 struct targbh_cmd_desc {
99 	struct	  ccb_accept_tio* atio_link;
100 	u_int	  data_resid;	/* How much left to transfer */
101 	u_int	  data_increment;/* Amount to send before next disconnect */
102 	void*	  data;		/* The data. Can be from backing_store or not */
103 	void*	  backing_store;/* Backing store allocated for this descriptor*/
104 	u_int	  max_size;	/* Size of backing_store */
105 	u_int32_t timeout;
106 	u_int8_t  status;	/* Status to return to initiator */
107 };
108 
109 static struct scsi_inquiry_data no_lun_inq_data =
110 {
111 	T_NODEVICE | (SID_QUAL_BAD_LU << 5), 0,
112 	/* version */2, /* format version */2
113 };
114 
115 static struct scsi_sense_data no_lun_sense_data =
116 {
117 	SSD_CURRENT_ERROR|SSD_ERRCODE_VALID,
118 	0,
119 	SSD_KEY_NOT_READY,
120 	{ 0, 0, 0, 0 },
121 	/*extra_len*/offsetof(struct scsi_sense_data, fru)
122                    - offsetof(struct scsi_sense_data, extra_len),
123 	{ 0, 0, 0, 0 },
124 	/* Logical Unit Not Supported */
125 	/*ASC*/0x25, /*ASCQ*/0
126 };
127 
128 static const int request_sense_size = offsetof(struct scsi_sense_data, fru);
129 
130 static periph_init_t	targbhinit;
131 static void		targbhasync(void *callback_arg, u_int32_t code,
132 				    struct cam_path *path, void *arg);
133 static cam_status	targbhenlun(struct cam_periph *periph);
134 static cam_status	targbhdislun(struct cam_periph *periph);
135 static periph_ctor_t	targbhctor;
136 static periph_dtor_t	targbhdtor;
137 static periph_start_t	targbhstart;
138 static void		targbhdone(struct cam_periph *periph,
139 				   union ccb *done_ccb);
140 #ifdef NOTYET
141 static  int		targbherror(union ccb *ccb, u_int32_t cam_flags,
142 				    u_int32_t sense_flags);
143 #endif
144 static struct targbh_cmd_desc*	targbhallocdescr(void);
145 static void		targbhfreedescr(struct targbh_cmd_desc *buf);
146 
147 static struct periph_driver targbhdriver =
148 {
149 	targbhinit, "targbh",
150 	TAILQ_HEAD_INITIALIZER(targbhdriver.units), /* generation */ 0
151 };
152 
153 PERIPHDRIVER_DECLARE(targbh, targbhdriver);
154 
155 static void
156 targbhinit(void)
157 {
158 	cam_status status;
159 
160 	/*
161 	 * Install a global async callback.  This callback will
162 	 * receive async callbacks like "new path registered".
163 	 */
164 	status = xpt_register_async(AC_PATH_REGISTERED | AC_PATH_DEREGISTERED,
165 				    targbhasync, NULL, NULL);
166 
167 	if (status != CAM_REQ_CMP) {
168 		printf("targbh: Failed to attach master async callback "
169 		       "due to status 0x%x!\n", status);
170 	}
171 }
172 
173 static void
174 targbhasync(void *callback_arg, u_int32_t code,
175 	    struct cam_path *path, void *arg)
176 {
177 	struct cam_path *new_path;
178 	struct ccb_pathinq *cpi;
179 	path_id_t bus_path_id;
180 	cam_status status;
181 
182 	cpi = (struct ccb_pathinq *)arg;
183 	if (code == AC_PATH_REGISTERED)
184 		bus_path_id = cpi->ccb_h.path_id;
185 	else
186 		bus_path_id = xpt_path_path_id(path);
187 	/*
188 	 * Allocate a peripheral instance for
189 	 * this target instance.
190 	 */
191 	status = xpt_create_path(&new_path, NULL,
192 				 bus_path_id,
193 				 CAM_TARGET_WILDCARD, CAM_LUN_WILDCARD);
194 	if (status != CAM_REQ_CMP) {
195 		printf("targbhasync: Unable to create path "
196 			"due to status 0x%x\n", status);
197 		return;
198 	}
199 
200 	switch (code) {
201 	case AC_PATH_REGISTERED:
202 	{
203 		/* Only attach to controllers that support target mode */
204 		if ((cpi->target_sprt & PIT_PROCESSOR) == 0)
205 			break;
206 
207 		status = cam_periph_alloc(targbhctor, NULL, targbhdtor,
208 					  targbhstart,
209 					  "targbh", CAM_PERIPH_BIO,
210 					  new_path, targbhasync,
211 					  AC_PATH_REGISTERED,
212 					  cpi);
213 		break;
214 	}
215 	case AC_PATH_DEREGISTERED:
216 	{
217 		struct cam_periph *periph;
218 
219 		if ((periph = cam_periph_find(new_path, "targbh")) != NULL)
220 			cam_periph_invalidate(periph);
221 		break;
222 	}
223 	default:
224 		break;
225 	}
226 	xpt_free_path(new_path);
227 }
228 
229 /* Attempt to enable our lun */
230 static cam_status
231 targbhenlun(struct cam_periph *periph)
232 {
233 	union ccb immed_ccb;
234 	struct targbh_softc *softc;
235 	cam_status status;
236 	int i;
237 
238 	softc = (struct targbh_softc *)periph->softc;
239 
240 	if ((softc->flags & TARGBH_FLAG_LUN_ENABLED) != 0)
241 		return (CAM_REQ_CMP);
242 
243 	xpt_setup_ccb(&immed_ccb.ccb_h, periph->path, /*priority*/1);
244 	immed_ccb.ccb_h.func_code = XPT_EN_LUN;
245 
246 	/* Don't need support for any vendor specific commands */
247 	immed_ccb.cel.grp6_len = 0;
248 	immed_ccb.cel.grp7_len = 0;
249 	immed_ccb.cel.enable = 1;
250 	xpt_action(&immed_ccb);
251 	status = immed_ccb.ccb_h.status;
252 	if (status != CAM_REQ_CMP) {
253 		xpt_print(periph->path,
254 		    "targbhenlun - Enable Lun Rejected with status 0x%x\n",
255 		    status);
256 		return (status);
257 	}
258 
259 	softc->flags |= TARGBH_FLAG_LUN_ENABLED;
260 
261 	/*
262 	 * Build up a buffer of accept target I/O
263 	 * operations for incoming selections.
264 	 */
265 	for (i = 0; i < MAX_ACCEPT; i++) {
266 		struct ccb_accept_tio *atio;
267 
268 		atio = (struct ccb_accept_tio*)malloc(sizeof(*atio), M_SCSIBH,
269 						      M_NOWAIT);
270 		if (atio == NULL) {
271 			status = CAM_RESRC_UNAVAIL;
272 			break;
273 		}
274 
275 		atio->ccb_h.ccb_descr = targbhallocdescr();
276 
277 		if (atio->ccb_h.ccb_descr == NULL) {
278 			free(atio, M_SCSIBH);
279 			status = CAM_RESRC_UNAVAIL;
280 			break;
281 		}
282 
283 		xpt_setup_ccb(&atio->ccb_h, periph->path, /*priority*/1);
284 		atio->ccb_h.func_code = XPT_ACCEPT_TARGET_IO;
285 		atio->ccb_h.cbfcnp = targbhdone;
286 		xpt_action((union ccb *)atio);
287 		status = atio->ccb_h.status;
288 		if (status != CAM_REQ_INPROG) {
289 			targbhfreedescr(atio->ccb_h.ccb_descr);
290 			free(atio, M_SCSIBH);
291 			break;
292 		}
293 		((struct targbh_cmd_desc*)atio->ccb_h.ccb_descr)->atio_link =
294 		    softc->accept_tio_list;
295 		softc->accept_tio_list = atio;
296 	}
297 
298 	if (i == 0) {
299 		xpt_print(periph->path,
300 		    "targbhenlun - Could not allocate accept tio CCBs: status "
301 		    "= 0x%x\n", status);
302 		targbhdislun(periph);
303 		return (CAM_REQ_CMP_ERR);
304 	}
305 
306 	/*
307 	 * Build up a buffer of immediate notify CCBs
308 	 * so the SIM can tell us of asynchronous target mode events.
309 	 */
310 	for (i = 0; i < MAX_ACCEPT; i++) {
311 		struct ccb_immed_notify *inot;
312 
313 		inot = (struct ccb_immed_notify*)malloc(sizeof(*inot), M_SCSIBH,
314 						        M_NOWAIT);
315 
316 		if (inot == NULL) {
317 			status = CAM_RESRC_UNAVAIL;
318 			break;
319 		}
320 
321 		xpt_setup_ccb(&inot->ccb_h, periph->path, /*priority*/1);
322 		inot->ccb_h.func_code = XPT_IMMED_NOTIFY;
323 		inot->ccb_h.cbfcnp = targbhdone;
324 		xpt_action((union ccb *)inot);
325 		status = inot->ccb_h.status;
326 		if (status != CAM_REQ_INPROG) {
327 			free(inot, M_SCSIBH);
328 			break;
329 		}
330 		SLIST_INSERT_HEAD(&softc->immed_notify_slist, &inot->ccb_h,
331 				  periph_links.sle);
332 	}
333 
334 	if (i == 0) {
335 		xpt_print(periph->path,
336 		    "targbhenlun - Could not allocate immediate notify "
337 		    "CCBs: status = 0x%x\n", status);
338 		targbhdislun(periph);
339 		return (CAM_REQ_CMP_ERR);
340 	}
341 
342 	return (CAM_REQ_CMP);
343 }
344 
345 static cam_status
346 targbhdislun(struct cam_periph *periph)
347 {
348 	union ccb ccb;
349 	struct targbh_softc *softc;
350 	struct ccb_accept_tio* atio;
351 	struct ccb_hdr *ccb_h;
352 
353 	softc = (struct targbh_softc *)periph->softc;
354 	if ((softc->flags & TARGBH_FLAG_LUN_ENABLED) == 0)
355 		return CAM_REQ_CMP;
356 
357 	/* XXX Block for Continue I/O completion */
358 
359 	/* Kill off all ACCECPT and IMMEDIATE CCBs */
360 	while ((atio = softc->accept_tio_list) != NULL) {
361 
362 		softc->accept_tio_list =
363 		    ((struct targbh_cmd_desc*)atio->ccb_h.ccb_descr)->atio_link;
364 		xpt_setup_ccb(&ccb.cab.ccb_h, periph->path, /*priority*/1);
365 		ccb.cab.ccb_h.func_code = XPT_ABORT;
366 		ccb.cab.abort_ccb = (union ccb *)atio;
367 		xpt_action(&ccb);
368 	}
369 
370 	while ((ccb_h = SLIST_FIRST(&softc->immed_notify_slist)) != NULL) {
371 		SLIST_REMOVE_HEAD(&softc->immed_notify_slist, periph_links.sle);
372 		xpt_setup_ccb(&ccb.cab.ccb_h, periph->path, /*priority*/1);
373 		ccb.cab.ccb_h.func_code = XPT_ABORT;
374 		ccb.cab.abort_ccb = (union ccb *)ccb_h;
375 		xpt_action(&ccb);
376 	}
377 
378 	/*
379 	 * Dissable this lun.
380 	 */
381 	xpt_setup_ccb(&ccb.cel.ccb_h, periph->path, /*priority*/1);
382 	ccb.cel.ccb_h.func_code = XPT_EN_LUN;
383 	ccb.cel.enable = 0;
384 	xpt_action(&ccb);
385 
386 	if (ccb.cel.ccb_h.status != CAM_REQ_CMP)
387 		printf("targbhdislun - Disabling lun on controller failed "
388 		       "with status 0x%x\n", ccb.cel.ccb_h.status);
389 	else
390 		softc->flags &= ~TARGBH_FLAG_LUN_ENABLED;
391 	return (ccb.cel.ccb_h.status);
392 }
393 
394 static cam_status
395 targbhctor(struct cam_periph *periph, void *arg)
396 {
397 	struct targbh_softc *softc;
398 
399 	/* Allocate our per-instance private storage */
400 	softc = (struct targbh_softc *)malloc(sizeof(*softc),
401 					      M_SCSIBH, M_NOWAIT);
402 	if (softc == NULL) {
403 		printf("targctor: unable to malloc softc\n");
404 		return (CAM_REQ_CMP_ERR);
405 	}
406 
407 	bzero(softc, sizeof(*softc));
408 	TAILQ_INIT(&softc->pending_queue);
409 	TAILQ_INIT(&softc->work_queue);
410 	softc->accept_tio_list = NULL;
411 	SLIST_INIT(&softc->immed_notify_slist);
412 	softc->state = TARGBH_STATE_NORMAL;
413 	periph->softc = softc;
414 	softc->init_level++;
415 
416 	return (targbhenlun(periph));
417 }
418 
419 static void
420 targbhdtor(struct cam_periph *periph)
421 {
422 	struct targbh_softc *softc;
423 
424 	softc = (struct targbh_softc *)periph->softc;
425 
426 	softc->state = TARGBH_STATE_TEARDOWN;
427 
428 	targbhdislun(periph);
429 
430 	switch (softc->init_level) {
431 	case 0:
432 		panic("targdtor - impossible init level");;
433 	case 1:
434 		/* FALLTHROUGH */
435 	default:
436 		/* XXX Wait for callback of targbhdislun() */
437 		msleep(softc, periph->sim->mtx, PRIBIO, "targbh", hz/2);
438 		free(softc, M_SCSIBH);
439 		break;
440 	}
441 }
442 
443 static void
444 targbhstart(struct cam_periph *periph, union ccb *start_ccb)
445 {
446 	struct targbh_softc *softc;
447 	struct ccb_hdr *ccbh;
448 	struct ccb_accept_tio *atio;
449 	struct targbh_cmd_desc *desc;
450 	struct ccb_scsiio *csio;
451 	ccb_flags flags;
452 
453 	softc = (struct targbh_softc *)periph->softc;
454 
455 	ccbh = TAILQ_FIRST(&softc->work_queue);
456 	if (periph->immediate_priority <= periph->pinfo.priority) {
457 		start_ccb->ccb_h.ccb_type = TARGBH_CCB_WAITING;
458 		SLIST_INSERT_HEAD(&periph->ccb_list, &start_ccb->ccb_h,
459 				  periph_links.sle);
460 		periph->immediate_priority = CAM_PRIORITY_NONE;
461 		wakeup(&periph->ccb_list);
462 	} else if (ccbh == NULL) {
463 		xpt_release_ccb(start_ccb);
464 	} else {
465 		TAILQ_REMOVE(&softc->work_queue, ccbh, periph_links.tqe);
466 		TAILQ_INSERT_HEAD(&softc->pending_queue, ccbh,
467 				  periph_links.tqe);
468 		atio = (struct ccb_accept_tio*)ccbh;
469 		desc = (struct targbh_cmd_desc *)atio->ccb_h.ccb_descr;
470 
471 		/* Is this a tagged request? */
472 		flags = atio->ccb_h.flags &
473 		    (CAM_DIS_DISCONNECT|CAM_TAG_ACTION_VALID|CAM_DIR_MASK);
474 
475 		csio = &start_ccb->csio;
476 		/*
477 		 * If we are done with the transaction, tell the
478 		 * controller to send status and perform a CMD_CMPLT.
479 		 * If we have associated sense data, see if we can
480 		 * send that too.
481 		 */
482 		if (desc->data_resid == desc->data_increment) {
483 			flags |= CAM_SEND_STATUS;
484 			if (atio->sense_len) {
485 				csio->sense_len = atio->sense_len;
486 				csio->sense_data = atio->sense_data;
487 				flags |= CAM_SEND_SENSE;
488 			}
489 
490 		}
491 
492 		cam_fill_ctio(csio,
493 			      /*retries*/2,
494 			      targbhdone,
495 			      flags,
496 			      (flags & CAM_TAG_ACTION_VALID)?
497 				MSG_SIMPLE_Q_TAG : 0,
498 			      atio->tag_id,
499 			      atio->init_id,
500 			      desc->status,
501 			      /*data_ptr*/desc->data_increment == 0
502 					  ? NULL : desc->data,
503 			      /*dxfer_len*/desc->data_increment,
504 			      /*timeout*/desc->timeout);
505 
506 		/* Override our wildcard attachment */
507 		start_ccb->ccb_h.target_id = atio->ccb_h.target_id;
508 		start_ccb->ccb_h.target_lun = atio->ccb_h.target_lun;
509 
510 		start_ccb->ccb_h.ccb_type = TARGBH_CCB_WORKQ;
511 		start_ccb->ccb_h.ccb_atio = atio;
512 		CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE,
513 			  ("Sending a CTIO\n"));
514 		xpt_action(start_ccb);
515 		/*
516 		 * If the queue was frozen waiting for the response
517 		 * to this ATIO (for instance disconnection was disallowed),
518 		 * then release it now that our response has been queued.
519 		 */
520 		if ((atio->ccb_h.status & CAM_DEV_QFRZN) != 0) {
521 			cam_release_devq(periph->path,
522 					 /*relsim_flags*/0,
523 					 /*reduction*/0,
524 					 /*timeout*/0,
525 					 /*getcount_only*/0);
526 			atio->ccb_h.status &= ~CAM_DEV_QFRZN;
527 		}
528 		ccbh = TAILQ_FIRST(&softc->work_queue);
529 	}
530 	if (ccbh != NULL)
531 		xpt_schedule(periph, /*priority*/1);
532 }
533 
534 static void
535 targbhdone(struct cam_periph *periph, union ccb *done_ccb)
536 {
537 	struct targbh_softc *softc;
538 
539 	softc = (struct targbh_softc *)periph->softc;
540 
541 	if (done_ccb->ccb_h.ccb_type == TARGBH_CCB_WAITING) {
542 		/* Caller will release the CCB */
543 		wakeup(&done_ccb->ccb_h.cbfcnp);
544 		return;
545 	}
546 
547 	switch (done_ccb->ccb_h.func_code) {
548 	case XPT_ACCEPT_TARGET_IO:
549 	{
550 		struct ccb_accept_tio *atio;
551 		struct targbh_cmd_desc *descr;
552 		u_int8_t *cdb;
553 		int priority;
554 
555 		atio = &done_ccb->atio;
556 		descr = (struct targbh_cmd_desc*)atio->ccb_h.ccb_descr;
557 		cdb = atio->cdb_io.cdb_bytes;
558 		if (softc->state == TARGBH_STATE_TEARDOWN
559 		 || atio->ccb_h.status == CAM_REQ_ABORTED) {
560 			targbhfreedescr(descr);
561 			xpt_free_ccb(done_ccb);
562 			return;
563 		}
564 
565 		/*
566 		 * Determine the type of incoming command and
567 		 * setup our buffer for a response.
568 		 */
569 		switch (cdb[0]) {
570 		case INQUIRY:
571 		{
572 			struct scsi_inquiry *inq;
573 
574 			inq = (struct scsi_inquiry *)cdb;
575 			CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE,
576 				  ("Saw an inquiry!\n"));
577 			/*
578 			 * Validate the command.  We don't
579 			 * support any VPD pages, so complain
580 			 * if EVPD is set.
581 			 */
582 			if ((inq->byte2 & SI_EVPD) != 0
583 			 || inq->page_code != 0) {
584 				atio->ccb_h.flags &= ~CAM_DIR_MASK;
585 				atio->ccb_h.flags |= CAM_DIR_NONE;
586 				/*
587 				 * This needs to have other than a
588 				 * no_lun_sense_data response.
589 				 */
590 				atio->sense_data = no_lun_sense_data;
591 				atio->sense_len = sizeof(no_lun_sense_data);
592 				descr->data_resid = 0;
593 				descr->data_increment = 0;
594 				descr->status = SCSI_STATUS_CHECK_COND;
595 				break;
596 			}
597 			/*
598 			 * Direction is always relative
599 			 * to the initator.
600 			 */
601 			atio->ccb_h.flags &= ~CAM_DIR_MASK;
602 			atio->ccb_h.flags |= CAM_DIR_IN;
603 			descr->data = &no_lun_inq_data;
604 			descr->data_resid = MIN(sizeof(no_lun_inq_data),
605 						SCSI_CDB6_LEN(inq->length));
606 			descr->data_increment = descr->data_resid;
607 			descr->timeout = 5 * 1000;
608 			descr->status = SCSI_STATUS_OK;
609 			break;
610 		}
611 		case REQUEST_SENSE:
612 		{
613 			struct scsi_request_sense *rsense;
614 
615 			rsense = (struct scsi_request_sense *)cdb;
616 			/* Refer to static sense data */
617 			atio->ccb_h.flags &= ~CAM_DIR_MASK;
618 			atio->ccb_h.flags |= CAM_DIR_IN;
619 			descr->data = &no_lun_sense_data;
620 			descr->data_resid = request_sense_size;
621 			descr->data_resid = MIN(descr->data_resid,
622 						SCSI_CDB6_LEN(rsense->length));
623 			descr->data_increment = descr->data_resid;
624 			descr->timeout = 5 * 1000;
625 			descr->status = SCSI_STATUS_OK;
626 			break;
627 		}
628 		default:
629 			/* Constant CA, tell initiator */
630 			/* Direction is always relative to the initator */
631 			atio->ccb_h.flags &= ~CAM_DIR_MASK;
632 			atio->ccb_h.flags |= CAM_DIR_NONE;
633 			atio->sense_data = no_lun_sense_data;
634 			atio->sense_len = sizeof (no_lun_sense_data);
635 			descr->data_resid = 0;
636 			descr->data_increment = 0;
637 			descr->timeout = 5 * 1000;
638 			descr->status = SCSI_STATUS_CHECK_COND;
639 			break;
640 		}
641 
642 		/* Queue us up to receive a Continue Target I/O ccb. */
643 		if ((atio->ccb_h.flags & CAM_DIS_DISCONNECT) != 0) {
644 			TAILQ_INSERT_HEAD(&softc->work_queue, &atio->ccb_h,
645 					  periph_links.tqe);
646 			priority = 0;
647 		} else {
648 			TAILQ_INSERT_TAIL(&softc->work_queue, &atio->ccb_h,
649 					  periph_links.tqe);
650 			priority = 1;
651 		}
652 		xpt_schedule(periph, priority);
653 		break;
654 	}
655 	case XPT_CONT_TARGET_IO:
656 	{
657 		struct ccb_accept_tio *atio;
658 		struct targbh_cmd_desc *desc;
659 
660 		CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE,
661 			  ("Received completed CTIO\n"));
662 		atio = (struct ccb_accept_tio*)done_ccb->ccb_h.ccb_atio;
663 		desc = (struct targbh_cmd_desc *)atio->ccb_h.ccb_descr;
664 
665 		TAILQ_REMOVE(&softc->pending_queue, &atio->ccb_h,
666 			     periph_links.tqe);
667 
668 		/*
669 		 * We could check for CAM_SENT_SENSE bein set here,
670 		 * but since we're not maintaining any CA/UA state,
671 		 * there's no point.
672 		 */
673 		atio->sense_len = 0;
674 		done_ccb->ccb_h.flags &= ~CAM_SEND_SENSE;
675 		done_ccb->ccb_h.status &= ~CAM_SENT_SENSE;
676 
677 		/*
678 		 * Any errors will not change the data we return,
679 		 * so make sure the queue is not left frozen.
680 		 * XXX - At some point there may be errors that
681 		 *       leave us in a connected state with the
682 		 *       initiator...
683 		 */
684 		if ((done_ccb->ccb_h.status & CAM_DEV_QFRZN) != 0) {
685 			printf("Releasing Queue\n");
686 			cam_release_devq(done_ccb->ccb_h.path,
687 					 /*relsim_flags*/0,
688 					 /*reduction*/0,
689 					 /*timeout*/0,
690 					 /*getcount_only*/0);
691 			done_ccb->ccb_h.status &= ~CAM_DEV_QFRZN;
692 		}
693 		desc->data_resid -= desc->data_increment;
694 		xpt_release_ccb(done_ccb);
695 		if (softc->state != TARGBH_STATE_TEARDOWN) {
696 
697 			/*
698 			 * Send the original accept TIO back to the
699 			 * controller to handle more work.
700 			 */
701 			CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE,
702 				  ("Returning ATIO to target\n"));
703 			/* Restore wildcards */
704 			atio->ccb_h.target_id = CAM_TARGET_WILDCARD;
705 			atio->ccb_h.target_lun = CAM_LUN_WILDCARD;
706 			xpt_action((union ccb *)atio);
707 			break;
708 		} else {
709 			targbhfreedescr(desc);
710 			free(atio, M_SCSIBH);
711 		}
712 		break;
713 	}
714 	case XPT_IMMED_NOTIFY:
715 	{
716 		int frozen;
717 
718 		frozen = (done_ccb->ccb_h.status & CAM_DEV_QFRZN) != 0;
719 		if (softc->state == TARGBH_STATE_TEARDOWN
720 		 || done_ccb->ccb_h.status == CAM_REQ_ABORTED) {
721 			printf("Freed an immediate notify\n");
722 			xpt_free_ccb(done_ccb);
723 		} else {
724 			/* Requeue for another immediate event */
725 			xpt_action(done_ccb);
726 		}
727 		if (frozen != 0)
728 			cam_release_devq(periph->path,
729 					 /*relsim_flags*/0,
730 					 /*opening reduction*/0,
731 					 /*timeout*/0,
732 					 /*getcount_only*/0);
733 		break;
734 	}
735 	default:
736 		panic("targbhdone: Unexpected ccb opcode");
737 		break;
738 	}
739 }
740 
741 #ifdef NOTYET
742 static int
743 targbherror(union ccb *ccb, u_int32_t cam_flags, u_int32_t sense_flags)
744 {
745 	return 0;
746 }
747 #endif
748 
749 static struct targbh_cmd_desc*
750 targbhallocdescr()
751 {
752 	struct targbh_cmd_desc* descr;
753 
754 	/* Allocate the targbh_descr structure */
755 	descr = (struct targbh_cmd_desc *)malloc(sizeof(*descr),
756 					       M_SCSIBH, M_NOWAIT);
757 	if (descr == NULL)
758 		return (NULL);
759 
760 	bzero(descr, sizeof(*descr));
761 
762 	/* Allocate buffer backing store */
763 	descr->backing_store = malloc(MAX_BUF_SIZE, M_SCSIBH, M_NOWAIT);
764 	if (descr->backing_store == NULL) {
765 		free(descr, M_SCSIBH);
766 		return (NULL);
767 	}
768 	descr->max_size = MAX_BUF_SIZE;
769 	return (descr);
770 }
771 
772 static void
773 targbhfreedescr(struct targbh_cmd_desc *descr)
774 {
775 	free(descr->backing_store, M_SCSIBH);
776 	free(descr, M_SCSIBH);
777 }
778