xref: /freebsd/sys/cam/scsi/scsi_targ_bh.c (revision 3fc9e2c36555140de248a0b4def91bbfa44d7c2c)
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 static 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_fixed 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_fixed, fru)
122                    - offsetof(struct scsi_sense_data_fixed, 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_fixed, 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, CAM_PRIORITY_NORMAL);
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, CAM_PRIORITY_NORMAL);
284 		atio->ccb_h.func_code = XPT_ACCEPT_TARGET_IO;
285 		atio->ccb_h.cbfcnp = targbhdone;
286 		((struct targbh_cmd_desc*)atio->ccb_h.ccb_descr)->atio_link =
287 		    softc->accept_tio_list;
288 		softc->accept_tio_list = atio;
289 		xpt_action((union ccb *)atio);
290 		status = atio->ccb_h.status;
291 		if (status != CAM_REQ_INPROG)
292 			break;
293 	}
294 
295 	if (i == 0) {
296 		xpt_print(periph->path,
297 		    "targbhenlun - Could not allocate accept tio CCBs: status "
298 		    "= 0x%x\n", status);
299 		targbhdislun(periph);
300 		return (CAM_REQ_CMP_ERR);
301 	}
302 
303 	/*
304 	 * Build up a buffer of immediate notify CCBs
305 	 * so the SIM can tell us of asynchronous target mode events.
306 	 */
307 	for (i = 0; i < MAX_ACCEPT; i++) {
308 		struct ccb_immediate_notify *inot;
309 
310 		inot = (struct ccb_immediate_notify*)malloc(sizeof(*inot),
311 			    M_SCSIBH, M_NOWAIT);
312 
313 		if (inot == NULL) {
314 			status = CAM_RESRC_UNAVAIL;
315 			break;
316 		}
317 
318 		xpt_setup_ccb(&inot->ccb_h, periph->path, CAM_PRIORITY_NORMAL);
319 		inot->ccb_h.func_code = XPT_IMMEDIATE_NOTIFY;
320 		inot->ccb_h.cbfcnp = targbhdone;
321 		SLIST_INSERT_HEAD(&softc->immed_notify_slist, &inot->ccb_h,
322 				  periph_links.sle);
323 		xpt_action((union ccb *)inot);
324 		status = inot->ccb_h.status;
325 		if (status != CAM_REQ_INPROG)
326 			break;
327 	}
328 
329 	if (i == 0) {
330 		xpt_print(periph->path,
331 		    "targbhenlun - Could not allocate immediate notify "
332 		    "CCBs: status = 0x%x\n", status);
333 		targbhdislun(periph);
334 		return (CAM_REQ_CMP_ERR);
335 	}
336 
337 	return (CAM_REQ_CMP);
338 }
339 
340 static cam_status
341 targbhdislun(struct cam_periph *periph)
342 {
343 	union ccb ccb;
344 	struct targbh_softc *softc;
345 	struct ccb_accept_tio* atio;
346 	struct ccb_hdr *ccb_h;
347 
348 	softc = (struct targbh_softc *)periph->softc;
349 	if ((softc->flags & TARGBH_FLAG_LUN_ENABLED) == 0)
350 		return CAM_REQ_CMP;
351 
352 	/* XXX Block for Continue I/O completion */
353 
354 	/* Kill off all ACCECPT and IMMEDIATE CCBs */
355 	while ((atio = softc->accept_tio_list) != NULL) {
356 
357 		softc->accept_tio_list =
358 		    ((struct targbh_cmd_desc*)atio->ccb_h.ccb_descr)->atio_link;
359 		xpt_setup_ccb(&ccb.cab.ccb_h, periph->path, CAM_PRIORITY_NORMAL);
360 		ccb.cab.ccb_h.func_code = XPT_ABORT;
361 		ccb.cab.abort_ccb = (union ccb *)atio;
362 		xpt_action(&ccb);
363 	}
364 
365 	while ((ccb_h = SLIST_FIRST(&softc->immed_notify_slist)) != NULL) {
366 		SLIST_REMOVE_HEAD(&softc->immed_notify_slist, periph_links.sle);
367 		xpt_setup_ccb(&ccb.cab.ccb_h, periph->path, CAM_PRIORITY_NORMAL);
368 		ccb.cab.ccb_h.func_code = XPT_ABORT;
369 		ccb.cab.abort_ccb = (union ccb *)ccb_h;
370 		xpt_action(&ccb);
371 	}
372 
373 	/*
374 	 * Dissable this lun.
375 	 */
376 	xpt_setup_ccb(&ccb.cel.ccb_h, periph->path, CAM_PRIORITY_NORMAL);
377 	ccb.cel.ccb_h.func_code = XPT_EN_LUN;
378 	ccb.cel.enable = 0;
379 	xpt_action(&ccb);
380 
381 	if (ccb.cel.ccb_h.status != CAM_REQ_CMP)
382 		printf("targbhdislun - Disabling lun on controller failed "
383 		       "with status 0x%x\n", ccb.cel.ccb_h.status);
384 	else
385 		softc->flags &= ~TARGBH_FLAG_LUN_ENABLED;
386 	return (ccb.cel.ccb_h.status);
387 }
388 
389 static cam_status
390 targbhctor(struct cam_periph *periph, void *arg)
391 {
392 	struct targbh_softc *softc;
393 
394 	/* Allocate our per-instance private storage */
395 	softc = (struct targbh_softc *)malloc(sizeof(*softc),
396 					      M_SCSIBH, M_NOWAIT);
397 	if (softc == NULL) {
398 		printf("targctor: unable to malloc softc\n");
399 		return (CAM_REQ_CMP_ERR);
400 	}
401 
402 	bzero(softc, sizeof(*softc));
403 	TAILQ_INIT(&softc->pending_queue);
404 	TAILQ_INIT(&softc->work_queue);
405 	softc->accept_tio_list = NULL;
406 	SLIST_INIT(&softc->immed_notify_slist);
407 	softc->state = TARGBH_STATE_NORMAL;
408 	periph->softc = softc;
409 	softc->init_level++;
410 
411 	if (targbhenlun(periph) != CAM_REQ_CMP)
412 		cam_periph_invalidate(periph);
413 	return (CAM_REQ_CMP);
414 }
415 
416 static void
417 targbhdtor(struct cam_periph *periph)
418 {
419 	struct targbh_softc *softc;
420 
421 	softc = (struct targbh_softc *)periph->softc;
422 
423 	softc->state = TARGBH_STATE_TEARDOWN;
424 
425 	targbhdislun(periph);
426 
427 	switch (softc->init_level) {
428 	case 0:
429 		panic("targdtor - impossible init level");
430 	case 1:
431 		/* FALLTHROUGH */
432 	default:
433 		/* XXX Wait for callback of targbhdislun() */
434 		msleep(softc, periph->sim->mtx, PRIBIO, "targbh", hz/2);
435 		free(softc, M_SCSIBH);
436 		break;
437 	}
438 }
439 
440 static void
441 targbhstart(struct cam_periph *periph, union ccb *start_ccb)
442 {
443 	struct targbh_softc *softc;
444 	struct ccb_hdr *ccbh;
445 	struct ccb_accept_tio *atio;
446 	struct targbh_cmd_desc *desc;
447 	struct ccb_scsiio *csio;
448 	ccb_flags flags;
449 
450 	softc = (struct targbh_softc *)periph->softc;
451 
452 	ccbh = TAILQ_FIRST(&softc->work_queue);
453 	if (periph->immediate_priority <= periph->pinfo.priority) {
454 		start_ccb->ccb_h.ccb_type = TARGBH_CCB_WAITING;
455 		SLIST_INSERT_HEAD(&periph->ccb_list, &start_ccb->ccb_h,
456 				  periph_links.sle);
457 		periph->immediate_priority = CAM_PRIORITY_NONE;
458 		wakeup(&periph->ccb_list);
459 	} else if (ccbh == NULL) {
460 		xpt_release_ccb(start_ccb);
461 	} else {
462 		TAILQ_REMOVE(&softc->work_queue, ccbh, periph_links.tqe);
463 		TAILQ_INSERT_HEAD(&softc->pending_queue, ccbh,
464 				  periph_links.tqe);
465 		atio = (struct ccb_accept_tio*)ccbh;
466 		desc = (struct targbh_cmd_desc *)atio->ccb_h.ccb_descr;
467 
468 		/* Is this a tagged request? */
469 		flags = atio->ccb_h.flags &
470 		    (CAM_DIS_DISCONNECT|CAM_TAG_ACTION_VALID|CAM_DIR_MASK);
471 
472 		csio = &start_ccb->csio;
473 		/*
474 		 * If we are done with the transaction, tell the
475 		 * controller to send status and perform a CMD_CMPLT.
476 		 * If we have associated sense data, see if we can
477 		 * send that too.
478 		 */
479 		if (desc->data_resid == desc->data_increment) {
480 			flags |= CAM_SEND_STATUS;
481 			if (atio->sense_len) {
482 				csio->sense_len = atio->sense_len;
483 				csio->sense_data = atio->sense_data;
484 				flags |= CAM_SEND_SENSE;
485 			}
486 
487 		}
488 
489 		cam_fill_ctio(csio,
490 			      /*retries*/2,
491 			      targbhdone,
492 			      flags,
493 			      (flags & CAM_TAG_ACTION_VALID)?
494 				MSG_SIMPLE_Q_TAG : 0,
495 			      atio->tag_id,
496 			      atio->init_id,
497 			      desc->status,
498 			      /*data_ptr*/desc->data_increment == 0
499 					  ? NULL : desc->data,
500 			      /*dxfer_len*/desc->data_increment,
501 			      /*timeout*/desc->timeout);
502 
503 		/* Override our wildcard attachment */
504 		start_ccb->ccb_h.target_id = atio->ccb_h.target_id;
505 		start_ccb->ccb_h.target_lun = atio->ccb_h.target_lun;
506 
507 		start_ccb->ccb_h.ccb_type = TARGBH_CCB_WORKQ;
508 		start_ccb->ccb_h.ccb_atio = atio;
509 		CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE,
510 			  ("Sending a CTIO\n"));
511 		xpt_action(start_ccb);
512 		/*
513 		 * If the queue was frozen waiting for the response
514 		 * to this ATIO (for instance disconnection was disallowed),
515 		 * then release it now that our response has been queued.
516 		 */
517 		if ((atio->ccb_h.status & CAM_DEV_QFRZN) != 0) {
518 			cam_release_devq(periph->path,
519 					 /*relsim_flags*/0,
520 					 /*reduction*/0,
521 					 /*timeout*/0,
522 					 /*getcount_only*/0);
523 			atio->ccb_h.status &= ~CAM_DEV_QFRZN;
524 		}
525 		ccbh = TAILQ_FIRST(&softc->work_queue);
526 	}
527 	if (ccbh != NULL)
528 		xpt_schedule(periph, CAM_PRIORITY_NORMAL);
529 }
530 
531 static void
532 targbhdone(struct cam_periph *periph, union ccb *done_ccb)
533 {
534 	struct targbh_softc *softc;
535 
536 	softc = (struct targbh_softc *)periph->softc;
537 
538 	if (done_ccb->ccb_h.ccb_type == TARGBH_CCB_WAITING) {
539 		/* Caller will release the CCB */
540 		wakeup(&done_ccb->ccb_h.cbfcnp);
541 		return;
542 	}
543 
544 	switch (done_ccb->ccb_h.func_code) {
545 	case XPT_ACCEPT_TARGET_IO:
546 	{
547 		struct ccb_accept_tio *atio;
548 		struct targbh_cmd_desc *descr;
549 		u_int8_t *cdb;
550 		int priority;
551 
552 		atio = &done_ccb->atio;
553 		descr = (struct targbh_cmd_desc*)atio->ccb_h.ccb_descr;
554 		cdb = atio->cdb_io.cdb_bytes;
555 		if (softc->state == TARGBH_STATE_TEARDOWN
556 		 || atio->ccb_h.status == CAM_REQ_ABORTED) {
557 			targbhfreedescr(descr);
558 			xpt_free_ccb(done_ccb);
559 			return;
560 		}
561 
562 		/*
563 		 * Determine the type of incoming command and
564 		 * setup our buffer for a response.
565 		 */
566 		switch (cdb[0]) {
567 		case INQUIRY:
568 		{
569 			struct scsi_inquiry *inq;
570 
571 			inq = (struct scsi_inquiry *)cdb;
572 			CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE,
573 				  ("Saw an inquiry!\n"));
574 			/*
575 			 * Validate the command.  We don't
576 			 * support any VPD pages, so complain
577 			 * if EVPD is set.
578 			 */
579 			if ((inq->byte2 & SI_EVPD) != 0
580 			 || inq->page_code != 0) {
581 				atio->ccb_h.flags &= ~CAM_DIR_MASK;
582 				atio->ccb_h.flags |= CAM_DIR_NONE;
583 				/*
584 				 * This needs to have other than a
585 				 * no_lun_sense_data response.
586 				 */
587 				bcopy(&no_lun_sense_data, &atio->sense_data,
588 				      min(sizeof(no_lun_sense_data),
589 					  sizeof(atio->sense_data)));
590 				atio->sense_len = sizeof(no_lun_sense_data);
591 				descr->data_resid = 0;
592 				descr->data_increment = 0;
593 				descr->status = SCSI_STATUS_CHECK_COND;
594 				break;
595 			}
596 			/*
597 			 * Direction is always relative
598 			 * to the initator.
599 			 */
600 			atio->ccb_h.flags &= ~CAM_DIR_MASK;
601 			atio->ccb_h.flags |= CAM_DIR_IN;
602 			descr->data = &no_lun_inq_data;
603 			descr->data_resid = MIN(sizeof(no_lun_inq_data),
604 						scsi_2btoul(inq->length));
605 			descr->data_increment = descr->data_resid;
606 			descr->timeout = 5 * 1000;
607 			descr->status = SCSI_STATUS_OK;
608 			break;
609 		}
610 		case REQUEST_SENSE:
611 		{
612 			struct scsi_request_sense *rsense;
613 
614 			rsense = (struct scsi_request_sense *)cdb;
615 			/* Refer to static sense data */
616 			atio->ccb_h.flags &= ~CAM_DIR_MASK;
617 			atio->ccb_h.flags |= CAM_DIR_IN;
618 			descr->data = &no_lun_sense_data;
619 			descr->data_resid = request_sense_size;
620 			descr->data_resid = MIN(descr->data_resid,
621 						SCSI_CDB6_LEN(rsense->length));
622 			descr->data_increment = descr->data_resid;
623 			descr->timeout = 5 * 1000;
624 			descr->status = SCSI_STATUS_OK;
625 			break;
626 		}
627 		default:
628 			/* Constant CA, tell initiator */
629 			/* Direction is always relative to the initator */
630 			atio->ccb_h.flags &= ~CAM_DIR_MASK;
631 			atio->ccb_h.flags |= CAM_DIR_NONE;
632 			bcopy(&no_lun_sense_data, &atio->sense_data,
633 			      min(sizeof(no_lun_sense_data),
634 				  sizeof(atio->sense_data)));
635 			atio->sense_len = sizeof (no_lun_sense_data);
636 			descr->data_resid = 0;
637 			descr->data_increment = 0;
638 			descr->timeout = 5 * 1000;
639 			descr->status = SCSI_STATUS_CHECK_COND;
640 			break;
641 		}
642 
643 		/* Queue us up to receive a Continue Target I/O ccb. */
644 		if ((atio->ccb_h.flags & CAM_DIS_DISCONNECT) != 0) {
645 			TAILQ_INSERT_HEAD(&softc->work_queue, &atio->ccb_h,
646 					  periph_links.tqe);
647 			priority = 0;
648 		} else {
649 			TAILQ_INSERT_TAIL(&softc->work_queue, &atio->ccb_h,
650 					  periph_links.tqe);
651 			priority = CAM_PRIORITY_NORMAL;
652 		}
653 		xpt_schedule(periph, priority);
654 		break;
655 	}
656 	case XPT_CONT_TARGET_IO:
657 	{
658 		struct ccb_accept_tio *atio;
659 		struct targbh_cmd_desc *desc;
660 
661 		CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE,
662 			  ("Received completed CTIO\n"));
663 		atio = (struct ccb_accept_tio*)done_ccb->ccb_h.ccb_atio;
664 		desc = (struct targbh_cmd_desc *)atio->ccb_h.ccb_descr;
665 
666 		TAILQ_REMOVE(&softc->pending_queue, &atio->ccb_h,
667 			     periph_links.tqe);
668 
669 		/*
670 		 * We could check for CAM_SENT_SENSE bein set here,
671 		 * but since we're not maintaining any CA/UA state,
672 		 * there's no point.
673 		 */
674 		atio->sense_len = 0;
675 		done_ccb->ccb_h.flags &= ~CAM_SEND_SENSE;
676 		done_ccb->ccb_h.status &= ~CAM_SENT_SENSE;
677 
678 		/*
679 		 * Any errors will not change the data we return,
680 		 * so make sure the queue is not left frozen.
681 		 * XXX - At some point there may be errors that
682 		 *       leave us in a connected state with the
683 		 *       initiator...
684 		 */
685 		if ((done_ccb->ccb_h.status & CAM_DEV_QFRZN) != 0) {
686 			printf("Releasing Queue\n");
687 			cam_release_devq(done_ccb->ccb_h.path,
688 					 /*relsim_flags*/0,
689 					 /*reduction*/0,
690 					 /*timeout*/0,
691 					 /*getcount_only*/0);
692 			done_ccb->ccb_h.status &= ~CAM_DEV_QFRZN;
693 		}
694 		desc->data_resid -= desc->data_increment;
695 		xpt_release_ccb(done_ccb);
696 		if (softc->state != TARGBH_STATE_TEARDOWN) {
697 
698 			/*
699 			 * Send the original accept TIO back to the
700 			 * controller to handle more work.
701 			 */
702 			CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE,
703 				  ("Returning ATIO to target\n"));
704 			/* Restore wildcards */
705 			atio->ccb_h.target_id = CAM_TARGET_WILDCARD;
706 			atio->ccb_h.target_lun = CAM_LUN_WILDCARD;
707 			xpt_action((union ccb *)atio);
708 			break;
709 		} else {
710 			targbhfreedescr(desc);
711 			free(atio, M_SCSIBH);
712 		}
713 		break;
714 	}
715 	case XPT_IMMEDIATE_NOTIFY:
716 	{
717 		int frozen;
718 
719 		frozen = (done_ccb->ccb_h.status & CAM_DEV_QFRZN) != 0;
720 		if (softc->state == TARGBH_STATE_TEARDOWN
721 		 || done_ccb->ccb_h.status == CAM_REQ_ABORTED) {
722 			printf("Freed an immediate notify\n");
723 			xpt_free_ccb(done_ccb);
724 		} else {
725 			/* Requeue for another immediate event */
726 			xpt_action(done_ccb);
727 		}
728 		if (frozen != 0)
729 			cam_release_devq(periph->path,
730 					 /*relsim_flags*/0,
731 					 /*opening reduction*/0,
732 					 /*timeout*/0,
733 					 /*getcount_only*/0);
734 		break;
735 	}
736 	default:
737 		panic("targbhdone: Unexpected ccb opcode");
738 		break;
739 	}
740 }
741 
742 #ifdef NOTYET
743 static int
744 targbherror(union ccb *ccb, u_int32_t cam_flags, u_int32_t sense_flags)
745 {
746 	return 0;
747 }
748 #endif
749 
750 static struct targbh_cmd_desc*
751 targbhallocdescr()
752 {
753 	struct targbh_cmd_desc* descr;
754 
755 	/* Allocate the targbh_descr structure */
756 	descr = (struct targbh_cmd_desc *)malloc(sizeof(*descr),
757 					       M_SCSIBH, M_NOWAIT);
758 	if (descr == NULL)
759 		return (NULL);
760 
761 	bzero(descr, sizeof(*descr));
762 
763 	/* Allocate buffer backing store */
764 	descr->backing_store = malloc(MAX_BUF_SIZE, M_SCSIBH, M_NOWAIT);
765 	if (descr->backing_store == NULL) {
766 		free(descr, M_SCSIBH);
767 		return (NULL);
768 	}
769 	descr->max_size = MAX_BUF_SIZE;
770 	return (descr);
771 }
772 
773 static void
774 targbhfreedescr(struct targbh_cmd_desc *descr)
775 {
776 	free(descr->backing_store, M_SCSIBH);
777 	free(descr, M_SCSIBH);
778 }
779