xref: /freebsd/sys/cam/scsi/scsi_targ_bh.c (revision 99f3b482da15db6f2ae4702d592b53dd36d4cf55)
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 
50 #include <cam/scsi/scsi_all.h>
51 #include <cam/scsi/scsi_message.h>
52 
53 MALLOC_DEFINE(M_SCSIBH, "SCSI bh", "SCSI blackhole buffers");
54 
55 typedef enum {
56 	TARGBH_STATE_NORMAL,
57 	TARGBH_STATE_EXCEPTION,
58 	TARGBH_STATE_TEARDOWN
59 } targbh_state;
60 
61 typedef enum {
62 	TARGBH_FLAG_NONE	 = 0x00,
63 	TARGBH_FLAG_LUN_ENABLED	 = 0x01
64 } targbh_flags;
65 
66 typedef enum {
67 	TARGBH_CCB_WORKQ,
68 	TARGBH_CCB_WAITING
69 } targbh_ccb_types;
70 
71 #define MAX_ACCEPT	8
72 #define MAX_IMMEDIATE	16
73 #define MAX_BUF_SIZE	256	/* Max inquiry/sense/mode page transfer */
74 
75 /* Offsets into our private CCB area for storing accept information */
76 #define ccb_type	ppriv_field0
77 #define ccb_descr	ppriv_ptr1
78 
79 /* We stick a pointer to the originating accept TIO in each continue I/O CCB */
80 #define ccb_atio	ppriv_ptr1
81 
82 TAILQ_HEAD(ccb_queue, ccb_hdr);
83 
84 struct targbh_softc {
85 	struct		ccb_queue pending_queue;
86 	struct		ccb_queue work_queue;
87 	struct		ccb_queue unknown_atio_queue;
88 	struct		devstat device_stats;
89 	targbh_state	state;
90 	targbh_flags	flags;
91 	u_int		init_level;
92 	u_int		inq_data_len;
93 	struct		ccb_accept_tio *accept_tio_list;
94 	struct		ccb_hdr_slist immed_notify_slist;
95 };
96 
97 struct targbh_cmd_desc {
98 	struct	  ccb_accept_tio* atio_link;
99 	u_int	  data_resid;	/* How much left to transfer */
100 	u_int	  data_increment;/* Amount to send before next disconnect */
101 	void*	  data;		/* The data. Can be from backing_store or not */
102 	void*	  backing_store;/* Backing store allocated for this descriptor*/
103 	u_int	  max_size;	/* Size of backing_store */
104 	u_int32_t timeout;
105 	u_int8_t  status;	/* Status to return to initiator */
106 };
107 
108 static struct scsi_inquiry_data no_lun_inq_data =
109 {
110 	T_NODEVICE | (SID_QUAL_BAD_LU << 5), 0,
111 	/* version */2, /* format version */2
112 };
113 
114 static struct scsi_sense_data no_lun_sense_data =
115 {
116 	SSD_CURRENT_ERROR|SSD_ERRCODE_VALID,
117 	0,
118 	SSD_KEY_NOT_READY,
119 	{ 0, 0, 0, 0 },
120 	/*extra_len*/offsetof(struct scsi_sense_data, fru)
121                    - offsetof(struct scsi_sense_data, extra_len),
122 	{ 0, 0, 0, 0 },
123 	/* Logical Unit Not Supported */
124 	/*ASC*/0x25, /*ASCQ*/0
125 };
126 
127 static const int request_sense_size = offsetof(struct scsi_sense_data, fru);
128 
129 static periph_init_t	targbhinit;
130 static void		targbhasync(void *callback_arg, u_int32_t code,
131 				    struct cam_path *path, void *arg);
132 static cam_status	targbhenlun(struct cam_periph *periph);
133 static cam_status	targbhdislun(struct cam_periph *periph);
134 static periph_ctor_t	targbhctor;
135 static periph_dtor_t	targbhdtor;
136 static periph_start_t	targbhstart;
137 static void		targbhdone(struct cam_periph *periph,
138 				   union ccb *done_ccb);
139 #ifdef NOTYET
140 static  int		targbherror(union ccb *ccb, u_int32_t cam_flags,
141 				    u_int32_t sense_flags);
142 #endif
143 static struct targbh_cmd_desc*	targbhallocdescr(void);
144 static void		targbhfreedescr(struct targbh_cmd_desc *buf);
145 
146 static struct periph_driver targbhdriver =
147 {
148 	targbhinit, "targbh",
149 	TAILQ_HEAD_INITIALIZER(targbhdriver.units), /* generation */ 0
150 };
151 
152 PERIPHDRIVER_DECLARE(targbh, targbhdriver);
153 
154 static void
155 targbhinit(void)
156 {
157 	cam_status status;
158 	struct cam_path *path;
159 
160 	/*
161 	 * Install a global async callback.  This callback will
162 	 * receive async callbacks like "new path registered".
163 	 */
164 	status = xpt_create_path(&path, /*periph*/NULL, CAM_XPT_PATH_ID,
165 				 CAM_TARGET_WILDCARD, CAM_LUN_WILDCARD);
166 
167 	if (status == CAM_REQ_CMP) {
168 		struct ccb_setasync csa;
169 
170 		xpt_setup_ccb(&csa.ccb_h, path, /*priority*/5);
171 		csa.ccb_h.func_code = XPT_SASYNC_CB;
172 		csa.event_enable = AC_PATH_REGISTERED | AC_PATH_DEREGISTERED;
173 		csa.callback = targbhasync;
174 		csa.callback_arg = NULL;
175 		xpt_action((union ccb *)&csa);
176 		status = csa.ccb_h.status;
177 		xpt_free_path(path);
178         }
179 
180 	if (status != CAM_REQ_CMP) {
181 		printf("targbh: Failed to attach master async callback "
182 		       "due to status 0x%x!\n", status);
183 	}
184 }
185 
186 static void
187 targbhasync(void *callback_arg, u_int32_t code,
188 	    struct cam_path *path, void *arg)
189 {
190 	struct cam_path *new_path;
191 	struct ccb_pathinq *cpi;
192 	path_id_t bus_path_id;
193 	cam_status status;
194 
195 	cpi = (struct ccb_pathinq *)arg;
196 	if (code == AC_PATH_REGISTERED)
197 		bus_path_id = cpi->ccb_h.path_id;
198 	else
199 		bus_path_id = xpt_path_path_id(path);
200 	/*
201 	 * Allocate a peripheral instance for
202 	 * this target instance.
203 	 */
204 	status = xpt_create_path(&new_path, NULL,
205 				 bus_path_id,
206 				 CAM_TARGET_WILDCARD, CAM_LUN_WILDCARD);
207 	if (status != CAM_REQ_CMP) {
208 		printf("targbhasync: Unable to create path "
209 			"due to status 0x%x\n", status);
210 		return;
211 	}
212 
213 	switch (code) {
214 	case AC_PATH_REGISTERED:
215 	{
216 		/* Only attach to controllers that support target mode */
217 		if ((cpi->target_sprt & PIT_PROCESSOR) == 0)
218 			break;
219 
220 		status = cam_periph_alloc(targbhctor, NULL, targbhdtor,
221 					  targbhstart,
222 					  "targbh", CAM_PERIPH_BIO,
223 					  new_path, targbhasync,
224 					  AC_PATH_REGISTERED,
225 					  cpi);
226 		break;
227 	}
228 	case AC_PATH_DEREGISTERED:
229 	{
230 		struct cam_periph *periph;
231 
232 		if ((periph = cam_periph_find(new_path, "targbh")) != NULL)
233 			cam_periph_invalidate(periph);
234 		break;
235 	}
236 	default:
237 		break;
238 	}
239 	xpt_free_path(new_path);
240 }
241 
242 /* Attempt to enable our lun */
243 static cam_status
244 targbhenlun(struct cam_periph *periph)
245 {
246 	union ccb immed_ccb;
247 	struct targbh_softc *softc;
248 	cam_status status;
249 	int i;
250 
251 	softc = (struct targbh_softc *)periph->softc;
252 
253 	if ((softc->flags & TARGBH_FLAG_LUN_ENABLED) != 0)
254 		return (CAM_REQ_CMP);
255 
256 	xpt_setup_ccb(&immed_ccb.ccb_h, periph->path, /*priority*/1);
257 	immed_ccb.ccb_h.func_code = XPT_EN_LUN;
258 
259 	/* Don't need support for any vendor specific commands */
260 	immed_ccb.cel.grp6_len = 0;
261 	immed_ccb.cel.grp7_len = 0;
262 	immed_ccb.cel.enable = 1;
263 	xpt_action(&immed_ccb);
264 	status = immed_ccb.ccb_h.status;
265 	if (status != CAM_REQ_CMP) {
266 		xpt_print_path(periph->path);
267 		printf("targbhenlun - Enable Lun Rejected with status 0x%x\n",
268 		       status);
269 		return (status);
270 	}
271 
272 	softc->flags |= TARGBH_FLAG_LUN_ENABLED;
273 
274 	/*
275 	 * Build up a buffer of accept target I/O
276 	 * operations for incoming selections.
277 	 */
278 	for (i = 0; i < MAX_ACCEPT; i++) {
279 		struct ccb_accept_tio *atio;
280 
281 		atio = (struct ccb_accept_tio*)malloc(sizeof(*atio), M_SCSIBH,
282 						      M_NOWAIT);
283 		if (atio == NULL) {
284 			status = CAM_RESRC_UNAVAIL;
285 			break;
286 		}
287 
288 		atio->ccb_h.ccb_descr = targbhallocdescr();
289 
290 		if (atio->ccb_h.ccb_descr == NULL) {
291 			free(atio, M_SCSIBH);
292 			status = CAM_RESRC_UNAVAIL;
293 			break;
294 		}
295 
296 		xpt_setup_ccb(&atio->ccb_h, periph->path, /*priority*/1);
297 		atio->ccb_h.func_code = XPT_ACCEPT_TARGET_IO;
298 		atio->ccb_h.cbfcnp = targbhdone;
299 		xpt_action((union ccb *)atio);
300 		status = atio->ccb_h.status;
301 		if (status != CAM_REQ_INPROG) {
302 			targbhfreedescr(atio->ccb_h.ccb_descr);
303 			free(atio, M_SCSIBH);
304 			break;
305 		}
306 		((struct targbh_cmd_desc*)atio->ccb_h.ccb_descr)->atio_link =
307 		    softc->accept_tio_list;
308 		softc->accept_tio_list = atio;
309 	}
310 
311 	if (i == 0) {
312 		xpt_print_path(periph->path);
313 		printf("targbhenlun - Could not allocate accept tio CCBs: "
314 		       "status = 0x%x\n", status);
315 		targbhdislun(periph);
316 		return (CAM_REQ_CMP_ERR);
317 	}
318 
319 	/*
320 	 * Build up a buffer of immediate notify CCBs
321 	 * so the SIM can tell us of asynchronous target mode events.
322 	 */
323 	for (i = 0; i < MAX_ACCEPT; i++) {
324 		struct ccb_immed_notify *inot;
325 
326 		inot = (struct ccb_immed_notify*)malloc(sizeof(*inot), M_SCSIBH,
327 						        M_NOWAIT);
328 
329 		if (inot == NULL) {
330 			status = CAM_RESRC_UNAVAIL;
331 			break;
332 		}
333 
334 		xpt_setup_ccb(&inot->ccb_h, periph->path, /*priority*/1);
335 		inot->ccb_h.func_code = XPT_IMMED_NOTIFY;
336 		inot->ccb_h.cbfcnp = targbhdone;
337 		xpt_action((union ccb *)inot);
338 		status = inot->ccb_h.status;
339 		if (status != CAM_REQ_INPROG) {
340 			free(inot, M_SCSIBH);
341 			break;
342 		}
343 		SLIST_INSERT_HEAD(&softc->immed_notify_slist, &inot->ccb_h,
344 				  periph_links.sle);
345 	}
346 
347 	if (i == 0) {
348 		xpt_print_path(periph->path);
349 		printf("targbhenlun - Could not allocate immediate notify "
350 		       "CCBs: status = 0x%x\n", status);
351 		targbhdislun(periph);
352 		return (CAM_REQ_CMP_ERR);
353 	}
354 
355 	return (CAM_REQ_CMP);
356 }
357 
358 static cam_status
359 targbhdislun(struct cam_periph *periph)
360 {
361 	union ccb ccb;
362 	struct targbh_softc *softc;
363 	struct ccb_accept_tio* atio;
364 	struct ccb_hdr *ccb_h;
365 
366 	softc = (struct targbh_softc *)periph->softc;
367 	if ((softc->flags & TARGBH_FLAG_LUN_ENABLED) == 0)
368 		return CAM_REQ_CMP;
369 
370 	/* XXX Block for Continue I/O completion */
371 
372 	/* Kill off all ACCECPT and IMMEDIATE CCBs */
373 	while ((atio = softc->accept_tio_list) != NULL) {
374 
375 		softc->accept_tio_list =
376 		    ((struct targbh_cmd_desc*)atio->ccb_h.ccb_descr)->atio_link;
377 		xpt_setup_ccb(&ccb.cab.ccb_h, periph->path, /*priority*/1);
378 		ccb.cab.ccb_h.func_code = XPT_ABORT;
379 		ccb.cab.abort_ccb = (union ccb *)atio;
380 		xpt_action(&ccb);
381 	}
382 
383 	while ((ccb_h = SLIST_FIRST(&softc->immed_notify_slist)) != NULL) {
384 		SLIST_REMOVE_HEAD(&softc->immed_notify_slist, periph_links.sle);
385 		xpt_setup_ccb(&ccb.cab.ccb_h, periph->path, /*priority*/1);
386 		ccb.cab.ccb_h.func_code = XPT_ABORT;
387 		ccb.cab.abort_ccb = (union ccb *)ccb_h;
388 		xpt_action(&ccb);
389 	}
390 
391 	/*
392 	 * Dissable this lun.
393 	 */
394 	xpt_setup_ccb(&ccb.cel.ccb_h, periph->path, /*priority*/1);
395 	ccb.cel.ccb_h.func_code = XPT_EN_LUN;
396 	ccb.cel.enable = 0;
397 	xpt_action(&ccb);
398 
399 	if (ccb.cel.ccb_h.status != CAM_REQ_CMP)
400 		printf("targbhdislun - Disabling lun on controller failed "
401 		       "with status 0x%x\n", ccb.cel.ccb_h.status);
402 	else
403 		softc->flags &= ~TARGBH_FLAG_LUN_ENABLED;
404 	return (ccb.cel.ccb_h.status);
405 }
406 
407 static cam_status
408 targbhctor(struct cam_periph *periph, void *arg)
409 {
410 	struct targbh_softc *softc;
411 
412 	/* Allocate our per-instance private storage */
413 	softc = (struct targbh_softc *)malloc(sizeof(*softc),
414 					      M_SCSIBH, M_NOWAIT);
415 	if (softc == NULL) {
416 		printf("targctor: unable to malloc softc\n");
417 		return (CAM_REQ_CMP_ERR);
418 	}
419 
420 	bzero(softc, sizeof(*softc));
421 	TAILQ_INIT(&softc->pending_queue);
422 	TAILQ_INIT(&softc->work_queue);
423 	softc->accept_tio_list = NULL;
424 	SLIST_INIT(&softc->immed_notify_slist);
425 	softc->state = TARGBH_STATE_NORMAL;
426 	periph->softc = softc;
427 	softc->init_level++;
428 
429 	return (targbhenlun(periph));
430 }
431 
432 static void
433 targbhdtor(struct cam_periph *periph)
434 {
435 	struct targbh_softc *softc;
436 
437 	softc = (struct targbh_softc *)periph->softc;
438 
439 	softc->state = TARGBH_STATE_TEARDOWN;
440 
441 	targbhdislun(periph);
442 
443 	switch (softc->init_level) {
444 	case 0:
445 		panic("targdtor - impossible init level");;
446 	case 1:
447 		/* FALLTHROUGH */
448 	default:
449 		/* XXX Wait for callback of targbhdislun() */
450 		tsleep(softc, PRIBIO, "targbh", hz/2);
451 		free(softc, M_SCSIBH);
452 		break;
453 	}
454 }
455 
456 static void
457 targbhstart(struct cam_periph *periph, union ccb *start_ccb)
458 {
459 	struct targbh_softc *softc;
460 	struct ccb_hdr *ccbh;
461 	struct ccb_accept_tio *atio;
462 	struct targbh_cmd_desc *desc;
463 	struct ccb_scsiio *csio;
464 	ccb_flags flags;
465 	int    s;
466 
467 	softc = (struct targbh_softc *)periph->softc;
468 
469 	s = splbio();
470 	ccbh = TAILQ_FIRST(&softc->work_queue);
471 	if (periph->immediate_priority <= periph->pinfo.priority) {
472 		start_ccb->ccb_h.ccb_type = TARGBH_CCB_WAITING;
473 		SLIST_INSERT_HEAD(&periph->ccb_list, &start_ccb->ccb_h,
474 				  periph_links.sle);
475 		periph->immediate_priority = CAM_PRIORITY_NONE;
476 		splx(s);
477 		wakeup(&periph->ccb_list);
478 	} else if (ccbh == NULL) {
479 		splx(s);
480 		xpt_release_ccb(start_ccb);
481 	} else {
482 		TAILQ_REMOVE(&softc->work_queue, ccbh, periph_links.tqe);
483 		TAILQ_INSERT_HEAD(&softc->pending_queue, ccbh,
484 				  periph_links.tqe);
485 		splx(s);
486 		atio = (struct ccb_accept_tio*)ccbh;
487 		desc = (struct targbh_cmd_desc *)atio->ccb_h.ccb_descr;
488 
489 		/* Is this a tagged request? */
490 		flags = atio->ccb_h.flags &
491 		    (CAM_DIS_DISCONNECT|CAM_TAG_ACTION_VALID|CAM_DIR_MASK);
492 
493 		csio = &start_ccb->csio;
494 		/*
495 		 * If we are done with the transaction, tell the
496 		 * controller to send status and perform a CMD_CMPLT.
497 		 * If we have associated sense data, see if we can
498 		 * send that too.
499 		 */
500 		if (desc->data_resid == desc->data_increment) {
501 			flags |= CAM_SEND_STATUS;
502 			if (atio->sense_len) {
503 				csio->sense_len = atio->sense_len;
504 				csio->sense_data = atio->sense_data;
505 				flags |= CAM_SEND_SENSE;
506 			}
507 
508 		}
509 
510 		cam_fill_ctio(csio,
511 			      /*retries*/2,
512 			      targbhdone,
513 			      flags,
514 			      (flags & CAM_TAG_ACTION_VALID)?
515 				MSG_SIMPLE_Q_TAG : 0,
516 			      atio->tag_id,
517 			      atio->init_id,
518 			      desc->status,
519 			      /*data_ptr*/desc->data_increment == 0
520 					  ? NULL : desc->data,
521 			      /*dxfer_len*/desc->data_increment,
522 			      /*timeout*/desc->timeout);
523 
524 		/* Override our wildcard attachment */
525 		start_ccb->ccb_h.target_id = atio->ccb_h.target_id;
526 		start_ccb->ccb_h.target_lun = atio->ccb_h.target_lun;
527 
528 		start_ccb->ccb_h.ccb_type = TARGBH_CCB_WORKQ;
529 		start_ccb->ccb_h.ccb_atio = atio;
530 		CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE,
531 			  ("Sending a CTIO\n"));
532 		xpt_action(start_ccb);
533 		/*
534 		 * If the queue was frozen waiting for the response
535 		 * to this ATIO (for instance disconnection was disallowed),
536 		 * then release it now that our response has been queued.
537 		 */
538 		if ((atio->ccb_h.status & CAM_DEV_QFRZN) != 0) {
539 			cam_release_devq(periph->path,
540 					 /*relsim_flags*/0,
541 					 /*reduction*/0,
542 					 /*timeout*/0,
543 					 /*getcount_only*/0);
544 			atio->ccb_h.status &= ~CAM_DEV_QFRZN;
545 		}
546 		s = splbio();
547 		ccbh = TAILQ_FIRST(&softc->work_queue);
548 		splx(s);
549 	}
550 	if (ccbh != NULL)
551 		xpt_schedule(periph, /*priority*/1);
552 }
553 
554 static void
555 targbhdone(struct cam_periph *periph, union ccb *done_ccb)
556 {
557 	struct targbh_softc *softc;
558 
559 	softc = (struct targbh_softc *)periph->softc;
560 
561 	if (done_ccb->ccb_h.ccb_type == TARGBH_CCB_WAITING) {
562 		/* Caller will release the CCB */
563 		wakeup(&done_ccb->ccb_h.cbfcnp);
564 		return;
565 	}
566 
567 	switch (done_ccb->ccb_h.func_code) {
568 	case XPT_ACCEPT_TARGET_IO:
569 	{
570 		struct ccb_accept_tio *atio;
571 		struct targbh_cmd_desc *descr;
572 		u_int8_t *cdb;
573 		int priority;
574 
575 		atio = &done_ccb->atio;
576 		descr = (struct targbh_cmd_desc*)atio->ccb_h.ccb_descr;
577 		cdb = atio->cdb_io.cdb_bytes;
578 		if (softc->state == TARGBH_STATE_TEARDOWN
579 		 || atio->ccb_h.status == CAM_REQ_ABORTED) {
580 			targbhfreedescr(descr);
581 			xpt_free_ccb(done_ccb);
582 			return;
583 		}
584 
585 		/*
586 		 * Determine the type of incoming command and
587 		 * setup our buffer for a response.
588 		 */
589 		switch (cdb[0]) {
590 		case INQUIRY:
591 		{
592 			struct scsi_inquiry *inq;
593 
594 			inq = (struct scsi_inquiry *)cdb;
595 			CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE,
596 				  ("Saw an inquiry!\n"));
597 			/*
598 			 * Validate the command.  We don't
599 			 * support any VPD pages, so complain
600 			 * if EVPD is set.
601 			 */
602 			if ((inq->byte2 & SI_EVPD) != 0
603 			 || inq->page_code != 0) {
604 				atio->ccb_h.flags &= ~CAM_DIR_MASK;
605 				atio->ccb_h.flags |= CAM_DIR_NONE;
606 				/*
607 				 * This needs to have other than a
608 				 * no_lun_sense_data response.
609 				 */
610 				atio->sense_data = no_lun_sense_data;
611 				atio->sense_len = sizeof(no_lun_sense_data);
612 				descr->data_resid = 0;
613 				descr->data_increment = 0;
614 				descr->status = SCSI_STATUS_CHECK_COND;
615 				break;
616 			}
617 			/*
618 			 * Direction is always relative
619 			 * to the initator.
620 			 */
621 			atio->ccb_h.flags &= ~CAM_DIR_MASK;
622 			atio->ccb_h.flags |= CAM_DIR_IN;
623 			descr->data = &no_lun_inq_data;
624 			descr->data_resid = MIN(sizeof(no_lun_inq_data),
625 						SCSI_CDB6_LEN(inq->length));
626 			descr->data_increment = descr->data_resid;
627 			descr->timeout = 5 * 1000;
628 			descr->status = SCSI_STATUS_OK;
629 			break;
630 		}
631 		case REQUEST_SENSE:
632 		{
633 			struct scsi_request_sense *rsense;
634 
635 			rsense = (struct scsi_request_sense *)cdb;
636 			/* Refer to static sense data */
637 			atio->ccb_h.flags &= ~CAM_DIR_MASK;
638 			atio->ccb_h.flags |= CAM_DIR_IN;
639 			descr->data = &no_lun_sense_data;
640 			descr->data_resid = request_sense_size;
641 			descr->data_resid = MIN(descr->data_resid,
642 						SCSI_CDB6_LEN(rsense->length));
643 			descr->data_increment = descr->data_resid;
644 			descr->timeout = 5 * 1000;
645 			descr->status = SCSI_STATUS_OK;
646 			break;
647 		}
648 		default:
649 			/* Constant CA, tell initiator */
650 			/* Direction is always relative to the initator */
651 			atio->ccb_h.flags &= ~CAM_DIR_MASK;
652 			atio->ccb_h.flags |= CAM_DIR_NONE;
653 			atio->sense_data = no_lun_sense_data;
654 			atio->sense_len = sizeof (no_lun_sense_data);
655 			descr->data_resid = 0;
656 			descr->data_increment = 0;
657 			descr->timeout = 5 * 1000;
658 			descr->status = SCSI_STATUS_CHECK_COND;
659 			break;
660 		}
661 
662 		/* Queue us up to receive a Continue Target I/O ccb. */
663 		if ((atio->ccb_h.flags & CAM_DIS_DISCONNECT) != 0) {
664 			TAILQ_INSERT_HEAD(&softc->work_queue, &atio->ccb_h,
665 					  periph_links.tqe);
666 			priority = 0;
667 		} else {
668 			TAILQ_INSERT_TAIL(&softc->work_queue, &atio->ccb_h,
669 					  periph_links.tqe);
670 			priority = 1;
671 		}
672 		xpt_schedule(periph, priority);
673 		break;
674 	}
675 	case XPT_CONT_TARGET_IO:
676 	{
677 		struct ccb_accept_tio *atio;
678 		struct targbh_cmd_desc *desc;
679 
680 		CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE,
681 			  ("Received completed CTIO\n"));
682 		atio = (struct ccb_accept_tio*)done_ccb->ccb_h.ccb_atio;
683 		desc = (struct targbh_cmd_desc *)atio->ccb_h.ccb_descr;
684 
685 		TAILQ_REMOVE(&softc->pending_queue, &atio->ccb_h,
686 			     periph_links.tqe);
687 
688 		/*
689 		 * We could check for CAM_SENT_SENSE bein set here,
690 		 * but since we're not maintaining any CA/UA state,
691 		 * there's no point.
692 		 */
693 		atio->sense_len = 0;
694 		done_ccb->ccb_h.flags &= ~CAM_SEND_SENSE;
695 		done_ccb->ccb_h.status &= ~CAM_SENT_SENSE;
696 
697 		/*
698 		 * Any errors will not change the data we return,
699 		 * so make sure the queue is not left frozen.
700 		 * XXX - At some point there may be errors that
701 		 *       leave us in a connected state with the
702 		 *       initiator...
703 		 */
704 		if ((done_ccb->ccb_h.status & CAM_DEV_QFRZN) != 0) {
705 			printf("Releasing Queue\n");
706 			cam_release_devq(done_ccb->ccb_h.path,
707 					 /*relsim_flags*/0,
708 					 /*reduction*/0,
709 					 /*timeout*/0,
710 					 /*getcount_only*/0);
711 			done_ccb->ccb_h.status &= ~CAM_DEV_QFRZN;
712 		}
713 		desc->data_resid -= desc->data_increment;
714 		xpt_release_ccb(done_ccb);
715 		if (softc->state != TARGBH_STATE_TEARDOWN) {
716 
717 			/*
718 			 * Send the original accept TIO back to the
719 			 * controller to handle more work.
720 			 */
721 			CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE,
722 				  ("Returning ATIO to target\n"));
723 			/* Restore wildcards */
724 			atio->ccb_h.target_id = CAM_TARGET_WILDCARD;
725 			atio->ccb_h.target_lun = CAM_LUN_WILDCARD;
726 			xpt_action((union ccb *)atio);
727 			break;
728 		} else {
729 			targbhfreedescr(desc);
730 			free(atio, M_SCSIBH);
731 		}
732 		break;
733 	}
734 	case XPT_IMMED_NOTIFY:
735 	{
736 		int frozen;
737 
738 		frozen = (done_ccb->ccb_h.status & CAM_DEV_QFRZN) != 0;
739 		if (softc->state == TARGBH_STATE_TEARDOWN
740 		 || done_ccb->ccb_h.status == CAM_REQ_ABORTED) {
741 			printf("Freed an immediate notify\n");
742 			xpt_free_ccb(done_ccb);
743 		} else {
744 			/* Requeue for another immediate event */
745 			xpt_action(done_ccb);
746 		}
747 		if (frozen != 0)
748 			cam_release_devq(periph->path,
749 					 /*relsim_flags*/0,
750 					 /*opening reduction*/0,
751 					 /*timeout*/0,
752 					 /*getcount_only*/0);
753 		break;
754 	}
755 	default:
756 		panic("targbhdone: Unexpected ccb opcode");
757 		break;
758 	}
759 }
760 
761 #ifdef NOTYET
762 static int
763 targbherror(union ccb *ccb, u_int32_t cam_flags, u_int32_t sense_flags)
764 {
765 	return 0;
766 }
767 #endif
768 
769 static struct targbh_cmd_desc*
770 targbhallocdescr()
771 {
772 	struct targbh_cmd_desc* descr;
773 
774 	/* Allocate the targbh_descr structure */
775 	descr = (struct targbh_cmd_desc *)malloc(sizeof(*descr),
776 					       M_SCSIBH, M_NOWAIT);
777 	if (descr == NULL)
778 		return (NULL);
779 
780 	bzero(descr, sizeof(*descr));
781 
782 	/* Allocate buffer backing store */
783 	descr->backing_store = malloc(MAX_BUF_SIZE, M_SCSIBH, M_NOWAIT);
784 	if (descr->backing_store == NULL) {
785 		free(descr, M_SCSIBH);
786 		return (NULL);
787 	}
788 	descr->max_size = MAX_BUF_SIZE;
789 	return (descr);
790 }
791 
792 static void
793 targbhfreedescr(struct targbh_cmd_desc *descr)
794 {
795 	free(descr->backing_store, M_SCSIBH);
796 	free(descr, M_SCSIBH);
797 }
798