xref: /freebsd/sys/cam/scsi/scsi_targ_bh.c (revision 4b2eaea43fec8e8792be611dea204071a10b655a)
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  * $FreeBSD$
29  */
30 
31 #include <sys/param.h>
32 #include <sys/queue.h>
33 #include <sys/systm.h>
34 #include <sys/kernel.h>
35 #include <sys/types.h>
36 #include <sys/bio.h>
37 #include <sys/conf.h>
38 #include <sys/devicestat.h>
39 #include <sys/malloc.h>
40 #include <sys/uio.h>
41 
42 #include <cam/cam.h>
43 #include <cam/cam_ccb.h>
44 #include <cam/cam_periph.h>
45 #include <cam/cam_queue.h>
46 #include <cam/cam_xpt_periph.h>
47 #include <cam/cam_debug.h>
48 
49 #include <cam/scsi/scsi_all.h>
50 #include <cam/scsi/scsi_message.h>
51 
52 typedef enum {
53 	TARGBH_STATE_NORMAL,
54 	TARGBH_STATE_EXCEPTION,
55 	TARGBH_STATE_TEARDOWN
56 } targbh_state;
57 
58 typedef enum {
59 	TARGBH_FLAG_NONE	 = 0x00,
60 	TARGBH_FLAG_LUN_ENABLED	 = 0x01
61 } targbh_flags;
62 
63 typedef enum {
64 	TARGBH_CCB_WORKQ,
65 	TARGBH_CCB_WAITING
66 } targbh_ccb_types;
67 
68 #define MAX_ACCEPT	8
69 #define MAX_IMMEDIATE	16
70 #define MAX_BUF_SIZE	256	/* Max inquiry/sense/mode page transfer */
71 
72 #define MIN(a, b) ((a > b) ? b : a)
73 
74 /* Offsets into our private CCB area for storing accept information */
75 #define ccb_type	ppriv_field0
76 #define ccb_descr	ppriv_ptr1
77 
78 /* We stick a pointer to the originating accept TIO in each continue I/O CCB */
79 #define ccb_atio	ppriv_ptr1
80 
81 TAILQ_HEAD(ccb_queue, ccb_hdr);
82 
83 struct targbh_softc {
84 	struct		ccb_queue pending_queue;
85 	struct		ccb_queue work_queue;
86 	struct		ccb_queue unknown_atio_queue;
87 	struct		devstat device_stats;
88 	targbh_state	state;
89 	targbh_flags	flags;
90 	u_int		init_level;
91 	u_int		inq_data_len;
92 	struct		ccb_accept_tio *accept_tio_list;
93 	struct		ccb_hdr_slist immed_notify_slist;
94 };
95 
96 struct targbh_cmd_desc {
97 	struct	  ccb_accept_tio* atio_link;
98 	u_int	  data_resid;	/* How much left to transfer */
99 	u_int	  data_increment;/* Amount to send before next disconnect */
100 	void*	  data;		/* The data. Can be from backing_store or not */
101 	void*	  backing_store;/* Backing store allocated for this descriptor*/
102 	u_int	  max_size;	/* Size of backing_store */
103 	u_int32_t timeout;
104 	u_int8_t  status;	/* Status to return to initiator */
105 };
106 
107 static struct scsi_inquiry_data no_lun_inq_data =
108 {
109 	T_NODEVICE | (SID_QUAL_BAD_LU << 5), 0,
110 	/* version */2, /* format version */2
111 };
112 
113 static struct scsi_sense_data no_lun_sense_data =
114 {
115 	SSD_CURRENT_ERROR|SSD_ERRCODE_VALID,
116 	0,
117 	SSD_KEY_NOT_READY,
118 	{ 0, 0, 0, 0 },
119 	/*extra_len*/offsetof(struct scsi_sense_data, fru)
120                    - offsetof(struct scsi_sense_data, extra_len),
121 	{ 0, 0, 0, 0 },
122 	/* Logical Unit Not Supported */
123 	/*ASC*/0x25, /*ASCQ*/0
124 };
125 
126 static const int request_sense_size = offsetof(struct scsi_sense_data, fru);
127 
128 static periph_init_t	targbhinit;
129 static void		targbhasync(void *callback_arg, u_int32_t code,
130 				    struct cam_path *path, void *arg);
131 static cam_status	targbhenlun(struct cam_periph *periph);
132 static cam_status	targbhdislun(struct cam_periph *periph);
133 static periph_ctor_t	targbhctor;
134 static periph_dtor_t	targbhdtor;
135 static periph_start_t	targbhstart;
136 static void		targbhdone(struct cam_periph *periph,
137 				   union ccb *done_ccb);
138 #ifdef NOTYET
139 static  int		targbherror(union ccb *ccb, u_int32_t cam_flags,
140 				    u_int32_t sense_flags);
141 #endif
142 static struct targbh_cmd_desc*	targbhallocdescr(void);
143 static void		targbhfreedescr(struct targbh_cmd_desc *buf);
144 
145 static struct periph_driver targbhdriver =
146 {
147 	targbhinit, "targbh",
148 	TAILQ_HEAD_INITIALIZER(targbhdriver.units), /* generation */ 0
149 };
150 
151 PERIPHDRIVER_DECLARE(targbh, targbhdriver);
152 
153 static void
154 targbhinit(void)
155 {
156 	cam_status status;
157 	struct cam_path *path;
158 
159 	/*
160 	 * Install a global async callback.  This callback will
161 	 * receive async callbacks like "new path registered".
162 	 */
163 	status = xpt_create_path(&path, /*periph*/NULL, CAM_XPT_PATH_ID,
164 				 CAM_TARGET_WILDCARD, CAM_LUN_WILDCARD);
165 
166 	if (status == CAM_REQ_CMP) {
167 		struct ccb_setasync csa;
168 
169 		xpt_setup_ccb(&csa.ccb_h, path, /*priority*/5);
170 		csa.ccb_h.func_code = XPT_SASYNC_CB;
171 		csa.event_enable = AC_PATH_REGISTERED;
172 		csa.callback = targbhasync;
173 		csa.callback_arg = NULL;
174 		xpt_action((union ccb *)&csa);
175 		status = csa.ccb_h.status;
176 		xpt_free_path(path);
177         }
178 
179 	if (status != CAM_REQ_CMP) {
180 		printf("targbh: Failed to attach master async callback "
181 		       "due to status 0x%x!\n", status);
182 	}
183 }
184 
185 static void
186 targbhasync(void *callback_arg, u_int32_t code,
187 	    struct cam_path *path, void *arg)
188 {
189 	struct cam_periph *periph;
190 
191 	periph = (struct cam_periph *)callback_arg;
192 	switch (code) {
193 	case AC_PATH_REGISTERED:
194 	{
195 		struct ccb_pathinq *cpi;
196 		struct cam_path *new_path;
197 		cam_status status;
198 
199 		cpi = (struct ccb_pathinq *)arg;
200 
201 		/* Only attach to controllers that support target mode */
202 		if ((cpi->target_sprt & PIT_PROCESSOR) == 0)
203 			break;
204 
205 		/*
206 		 * Allocate a peripheral instance for
207 		 * this target instance.
208 		 */
209 		status = xpt_create_path(&new_path, NULL,
210 					 xpt_path_path_id(path),
211 					 CAM_TARGET_WILDCARD, CAM_LUN_WILDCARD);
212 		if (status != CAM_REQ_CMP) {
213 			printf("targbhasync: Unable to create path "
214 				"due to status 0x%x\n", status);
215 			break;
216 		}
217 		status = cam_periph_alloc(targbhctor, NULL, targbhdtor,
218 					  targbhstart,
219 					  "targbh", CAM_PERIPH_BIO,
220 					  new_path, targbhasync,
221 					  AC_PATH_REGISTERED,
222 					  cpi);
223 		xpt_free_path(new_path);
224 		break;
225 	}
226 	case AC_PATH_DEREGISTERED:
227 	{
228 		targbhdislun(periph);
229 		break;
230 	}
231 	default:
232 		break;
233 	}
234 }
235 
236 /* Attempt to enable our lun */
237 static cam_status
238 targbhenlun(struct cam_periph *periph)
239 {
240 	union ccb immed_ccb;
241 	struct targbh_softc *softc;
242 	cam_status status;
243 	int i;
244 
245 	softc = (struct targbh_softc *)periph->softc;
246 
247 	if ((softc->flags & TARGBH_FLAG_LUN_ENABLED) != 0)
248 		return (CAM_REQ_CMP);
249 
250 	xpt_setup_ccb(&immed_ccb.ccb_h, periph->path, /*priority*/1);
251 	immed_ccb.ccb_h.func_code = XPT_EN_LUN;
252 
253 	/* Don't need support for any vendor specific commands */
254 	immed_ccb.cel.grp6_len = 0;
255 	immed_ccb.cel.grp7_len = 0;
256 	immed_ccb.cel.enable = 1;
257 	xpt_action(&immed_ccb);
258 	status = immed_ccb.ccb_h.status;
259 	if (status != CAM_REQ_CMP) {
260 		xpt_print_path(periph->path);
261 		printf("targbhenlun - Enable Lun Rejected with status 0x%x\n",
262 		       status);
263 		return (status);
264 	}
265 
266 	softc->flags |= TARGBH_FLAG_LUN_ENABLED;
267 
268 	/*
269 	 * Build up a buffer of accept target I/O
270 	 * operations for incoming selections.
271 	 */
272 	for (i = 0; i < MAX_ACCEPT; i++) {
273 		struct ccb_accept_tio *atio;
274 
275 		atio = (struct ccb_accept_tio*)malloc(sizeof(*atio), M_DEVBUF,
276 						      M_NOWAIT);
277 		if (atio == NULL) {
278 			status = CAM_RESRC_UNAVAIL;
279 			break;
280 		}
281 
282 		atio->ccb_h.ccb_descr = targbhallocdescr();
283 
284 		if (atio->ccb_h.ccb_descr == NULL) {
285 			free(atio, M_DEVBUF);
286 			status = CAM_RESRC_UNAVAIL;
287 			break;
288 		}
289 
290 		xpt_setup_ccb(&atio->ccb_h, periph->path, /*priority*/1);
291 		atio->ccb_h.func_code = XPT_ACCEPT_TARGET_IO;
292 		atio->ccb_h.cbfcnp = targbhdone;
293 		xpt_action((union ccb *)atio);
294 		status = atio->ccb_h.status;
295 		if (status != CAM_REQ_INPROG) {
296 			targbhfreedescr(atio->ccb_h.ccb_descr);
297 			free(atio, M_DEVBUF);
298 			break;
299 		}
300 		((struct targbh_cmd_desc*)atio->ccb_h.ccb_descr)->atio_link =
301 		    softc->accept_tio_list;
302 		softc->accept_tio_list = atio;
303 	}
304 
305 	if (i == 0) {
306 		xpt_print_path(periph->path);
307 		printf("targbhenlun - Could not allocate accept tio CCBs: "
308 		       "status = 0x%x\n", status);
309 		targbhdislun(periph);
310 		return (CAM_REQ_CMP_ERR);
311 	}
312 
313 	/*
314 	 * Build up a buffer of immediate notify CCBs
315 	 * so the SIM can tell us of asynchronous target mode events.
316 	 */
317 	for (i = 0; i < MAX_ACCEPT; i++) {
318 		struct ccb_immed_notify *inot;
319 
320 		inot = (struct ccb_immed_notify*)malloc(sizeof(*inot), M_DEVBUF,
321 						        M_NOWAIT);
322 
323 		if (inot == NULL) {
324 			status = CAM_RESRC_UNAVAIL;
325 			break;
326 		}
327 
328 		xpt_setup_ccb(&inot->ccb_h, periph->path, /*priority*/1);
329 		inot->ccb_h.func_code = XPT_IMMED_NOTIFY;
330 		inot->ccb_h.cbfcnp = targbhdone;
331 		xpt_action((union ccb *)inot);
332 		status = inot->ccb_h.status;
333 		if (status != CAM_REQ_INPROG) {
334 			free(inot, M_DEVBUF);
335 			break;
336 		}
337 		SLIST_INSERT_HEAD(&softc->immed_notify_slist, &inot->ccb_h,
338 				  periph_links.sle);
339 	}
340 
341 	if (i == 0) {
342 		xpt_print_path(periph->path);
343 		printf("targbhenlun - Could not allocate immediate notify "
344 		       "CCBs: status = 0x%x\n", status);
345 		targbhdislun(periph);
346 		return (CAM_REQ_CMP_ERR);
347 	}
348 
349 	return (CAM_REQ_CMP);
350 }
351 
352 static cam_status
353 targbhdislun(struct cam_periph *periph)
354 {
355 	union ccb ccb;
356 	struct targbh_softc *softc;
357 	struct ccb_accept_tio* atio;
358 	struct ccb_hdr *ccb_h;
359 
360 	softc = (struct targbh_softc *)periph->softc;
361 	if ((softc->flags & TARGBH_FLAG_LUN_ENABLED) == 0)
362 		return CAM_REQ_CMP;
363 
364 	/* XXX Block for Continue I/O completion */
365 
366 	/* Kill off all ACCECPT and IMMEDIATE CCBs */
367 	while ((atio = softc->accept_tio_list) != NULL) {
368 
369 		softc->accept_tio_list =
370 		    ((struct targbh_cmd_desc*)atio->ccb_h.ccb_descr)->atio_link;
371 		xpt_setup_ccb(&ccb.cab.ccb_h, periph->path, /*priority*/1);
372 		ccb.cab.ccb_h.func_code = XPT_ABORT;
373 		ccb.cab.abort_ccb = (union ccb *)atio;
374 		xpt_action(&ccb);
375 	}
376 
377 	while ((ccb_h = SLIST_FIRST(&softc->immed_notify_slist)) != NULL) {
378 		SLIST_REMOVE_HEAD(&softc->immed_notify_slist, periph_links.sle);
379 		xpt_setup_ccb(&ccb.cab.ccb_h, periph->path, /*priority*/1);
380 		ccb.cab.ccb_h.func_code = XPT_ABORT;
381 		ccb.cab.abort_ccb = (union ccb *)ccb_h;
382 		xpt_action(&ccb);
383 	}
384 
385 	/*
386 	 * Dissable this lun.
387 	 */
388 	xpt_setup_ccb(&ccb.cel.ccb_h, periph->path, /*priority*/1);
389 	ccb.cel.ccb_h.func_code = XPT_EN_LUN;
390 	ccb.cel.enable = 0;
391 	xpt_action(&ccb);
392 
393 	if (ccb.cel.ccb_h.status != CAM_REQ_CMP)
394 		printf("targbhdislun - Disabling lun on controller failed "
395 		       "with status 0x%x\n", ccb.cel.ccb_h.status);
396 	else
397 		softc->flags &= ~TARGBH_FLAG_LUN_ENABLED;
398 	return (ccb.cel.ccb_h.status);
399 }
400 
401 static cam_status
402 targbhctor(struct cam_periph *periph, void *arg)
403 {
404 	struct ccb_pathinq *cpi;
405 	struct targbh_softc *softc;
406 
407 	cpi = (struct ccb_pathinq *)arg;
408 
409 	/* Allocate our per-instance private storage */
410 	softc = (struct targbh_softc *)malloc(sizeof(*softc),
411 					      M_DEVBUF, M_NOWAIT);
412 	if (softc == NULL) {
413 		printf("targctor: unable to malloc softc\n");
414 		return (CAM_REQ_CMP_ERR);
415 	}
416 
417 	bzero(softc, sizeof(*softc));
418 	TAILQ_INIT(&softc->pending_queue);
419 	TAILQ_INIT(&softc->work_queue);
420 	softc->accept_tio_list = NULL;
421 	SLIST_INIT(&softc->immed_notify_slist);
422 	softc->state = TARGBH_STATE_NORMAL;
423 	periph->softc = softc;
424 	softc->init_level++;
425 
426 	return (targbhenlun(periph));
427 }
428 
429 static void
430 targbhdtor(struct cam_periph *periph)
431 {
432 	struct targbh_softc *softc;
433 
434 	softc = (struct targbh_softc *)periph->softc;
435 
436 	softc->state = TARGBH_STATE_TEARDOWN;
437 
438 	targbhdislun(periph);
439 
440 	switch (softc->init_level) {
441 	default:
442 		/* FALLTHROUGH */
443 	case 1:
444 		free(softc, M_DEVBUF);
445 		break;
446 	case 0:
447 		panic("targdtor - impossible init level");;
448 	}
449 }
450 
451 static void
452 targbhstart(struct cam_periph *periph, union ccb *start_ccb)
453 {
454 	struct targbh_softc *softc;
455 	struct ccb_hdr *ccbh;
456 	struct ccb_accept_tio *atio;
457 	struct targbh_cmd_desc *desc;
458 	struct ccb_scsiio *csio;
459 	ccb_flags flags;
460 	int    s;
461 
462 	softc = (struct targbh_softc *)periph->softc;
463 
464 	s = splbio();
465 	ccbh = TAILQ_FIRST(&softc->work_queue);
466 	if (periph->immediate_priority <= periph->pinfo.priority) {
467 		start_ccb->ccb_h.ccb_type = TARGBH_CCB_WAITING;
468 		SLIST_INSERT_HEAD(&periph->ccb_list, &start_ccb->ccb_h,
469 				  periph_links.sle);
470 		periph->immediate_priority = CAM_PRIORITY_NONE;
471 		splx(s);
472 		wakeup(&periph->ccb_list);
473 	} else if (ccbh == NULL) {
474 		splx(s);
475 		xpt_release_ccb(start_ccb);
476 	} else {
477 		TAILQ_REMOVE(&softc->work_queue, ccbh, periph_links.tqe);
478 		TAILQ_INSERT_HEAD(&softc->pending_queue, ccbh,
479 				  periph_links.tqe);
480 		splx(s);
481 		atio = (struct ccb_accept_tio*)ccbh;
482 		desc = (struct targbh_cmd_desc *)atio->ccb_h.ccb_descr;
483 
484 		/* Is this a tagged request? */
485 		flags = atio->ccb_h.flags &
486 		    (CAM_DIS_DISCONNECT|CAM_TAG_ACTION_VALID|CAM_DIR_MASK);
487 
488 		csio = &start_ccb->csio;
489 		/*
490 		 * If we are done with the transaction, tell the
491 		 * controller to send status and perform a CMD_CMPLT.
492 		 * If we have associated sense data, see if we can
493 		 * send that too.
494 		 */
495 		if (desc->data_resid == desc->data_increment) {
496 			flags |= CAM_SEND_STATUS;
497 			if (atio->sense_len) {
498 				csio->sense_len = atio->sense_len;
499 				csio->sense_data = atio->sense_data;
500 				flags |= CAM_SEND_SENSE;
501 			}
502 
503 		}
504 
505 		cam_fill_ctio(csio,
506 			      /*retries*/2,
507 			      targbhdone,
508 			      flags,
509 			      (flags & CAM_TAG_ACTION_VALID)?
510 				MSG_SIMPLE_Q_TAG : 0,
511 			      atio->tag_id,
512 			      atio->init_id,
513 			      desc->status,
514 			      /*data_ptr*/desc->data_increment == 0
515 					  ? NULL : desc->data,
516 			      /*dxfer_len*/desc->data_increment,
517 			      /*timeout*/desc->timeout);
518 
519 		/* Override our wildcard attachment */
520 		start_ccb->ccb_h.target_id = atio->ccb_h.target_id;
521 		start_ccb->ccb_h.target_lun = atio->ccb_h.target_lun;
522 
523 		start_ccb->ccb_h.ccb_type = TARGBH_CCB_WORKQ;
524 		start_ccb->ccb_h.ccb_atio = atio;
525 		CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE,
526 			  ("Sending a CTIO\n"));
527 		xpt_action(start_ccb);
528 		/*
529 		 * If the queue was frozen waiting for the response
530 		 * to this ATIO (for instance disconnection was disallowed),
531 		 * then release it now that our response has been queued.
532 		 */
533 		if ((atio->ccb_h.status & CAM_DEV_QFRZN) != 0) {
534 			cam_release_devq(periph->path,
535 					 /*relsim_flags*/0,
536 					 /*reduction*/0,
537 					 /*timeout*/0,
538 					 /*getcount_only*/0);
539 			atio->ccb_h.status &= ~CAM_DEV_QFRZN;
540 		}
541 		s = splbio();
542 		ccbh = TAILQ_FIRST(&softc->work_queue);
543 		splx(s);
544 	}
545 	if (ccbh != NULL)
546 		xpt_schedule(periph, /*priority*/1);
547 }
548 
549 static void
550 targbhdone(struct cam_periph *periph, union ccb *done_ccb)
551 {
552 	struct targbh_softc *softc;
553 
554 	softc = (struct targbh_softc *)periph->softc;
555 
556 	if (done_ccb->ccb_h.ccb_type == TARGBH_CCB_WAITING) {
557 		/* Caller will release the CCB */
558 		wakeup(&done_ccb->ccb_h.cbfcnp);
559 		return;
560 	}
561 
562 	switch (done_ccb->ccb_h.func_code) {
563 	case XPT_ACCEPT_TARGET_IO:
564 	{
565 		struct ccb_accept_tio *atio;
566 		struct targbh_cmd_desc *descr;
567 		u_int8_t *cdb;
568 		int priority;
569 
570 		atio = &done_ccb->atio;
571 		descr = (struct targbh_cmd_desc*)atio->ccb_h.ccb_descr;
572 		cdb = atio->cdb_io.cdb_bytes;
573 		if (softc->state == TARGBH_STATE_TEARDOWN
574 		 || atio->ccb_h.status == CAM_REQ_ABORTED) {
575 			targbhfreedescr(descr);
576 			free(done_ccb, M_DEVBUF);
577 			return;
578 		}
579 
580 		/*
581 		 * Determine the type of incoming command and
582 		 * setup our buffer for a response.
583 		 */
584 		switch (cdb[0]) {
585 		case INQUIRY:
586 		{
587 			struct scsi_inquiry *inq;
588 
589 			inq = (struct scsi_inquiry *)cdb;
590 			CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE,
591 				  ("Saw an inquiry!\n"));
592 			/*
593 			 * Validate the command.  We don't
594 			 * support any VPD pages, so complain
595 			 * if EVPD is set.
596 			 */
597 			if ((inq->byte2 & SI_EVPD) != 0
598 			 || inq->page_code != 0) {
599 				atio->ccb_h.flags &= ~CAM_DIR_MASK;
600 				atio->ccb_h.flags |= CAM_DIR_NONE;
601 				/*
602 				 * This needs to have other than a
603 				 * no_lun_sense_data response.
604 				 */
605 				atio->sense_data = no_lun_sense_data;
606 				atio->sense_len = sizeof(no_lun_sense_data);
607 				descr->data_resid = 0;
608 				descr->data_increment = 0;
609 				descr->status = SCSI_STATUS_CHECK_COND;
610 				break;
611 			}
612 			/*
613 			 * Direction is always relative
614 			 * to the initator.
615 			 */
616 			atio->ccb_h.flags &= ~CAM_DIR_MASK;
617 			atio->ccb_h.flags |= CAM_DIR_IN;
618 			descr->data = &no_lun_inq_data;
619 			descr->data_resid = MIN(sizeof(no_lun_inq_data),
620 						SCSI_CDB6_LEN(inq->length));
621 			descr->data_increment = descr->data_resid;
622 			descr->timeout = 5 * 1000;
623 			descr->status = SCSI_STATUS_OK;
624 			break;
625 		}
626 		case REQUEST_SENSE:
627 		{
628 			struct scsi_request_sense *rsense;
629 
630 			rsense = (struct scsi_request_sense *)cdb;
631 			/* Refer to static sense data */
632 			atio->ccb_h.flags &= ~CAM_DIR_MASK;
633 			atio->ccb_h.flags |= CAM_DIR_IN;
634 			descr->data = &no_lun_sense_data;
635 			descr->data_resid = request_sense_size;
636 			descr->data_resid = MIN(descr->data_resid,
637 						SCSI_CDB6_LEN(rsense->length));
638 			descr->data_increment = descr->data_resid;
639 			descr->timeout = 5 * 1000;
640 			descr->status = SCSI_STATUS_OK;
641 			break;
642 		}
643 		default:
644 			/* Constant CA, tell initiator */
645 			/* Direction is always relative to the initator */
646 			atio->ccb_h.flags &= ~CAM_DIR_MASK;
647 			atio->ccb_h.flags |= CAM_DIR_NONE;
648 			atio->sense_data = no_lun_sense_data;
649 			atio->sense_len = sizeof (no_lun_sense_data);
650 			descr->data_resid = 0;
651 			descr->data_increment = 0;
652 			descr->timeout = 5 * 1000;
653 			descr->status = SCSI_STATUS_CHECK_COND;
654 			break;
655 		}
656 
657 		/* Queue us up to receive a Continue Target I/O ccb. */
658 		if ((atio->ccb_h.flags & CAM_DIS_DISCONNECT) != 0) {
659 			TAILQ_INSERT_HEAD(&softc->work_queue, &atio->ccb_h,
660 					  periph_links.tqe);
661 			priority = 0;
662 		} else {
663 			TAILQ_INSERT_TAIL(&softc->work_queue, &atio->ccb_h,
664 					  periph_links.tqe);
665 			priority = 1;
666 		}
667 		xpt_schedule(periph, priority);
668 		break;
669 	}
670 	case XPT_CONT_TARGET_IO:
671 	{
672 		struct ccb_accept_tio *atio;
673 		struct targbh_cmd_desc *desc;
674 
675 		CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE,
676 			  ("Received completed CTIO\n"));
677 		atio = (struct ccb_accept_tio*)done_ccb->ccb_h.ccb_atio;
678 		desc = (struct targbh_cmd_desc *)atio->ccb_h.ccb_descr;
679 
680 		TAILQ_REMOVE(&softc->pending_queue, &atio->ccb_h,
681 			     periph_links.tqe);
682 
683 		/*
684 		 * We could check for CAM_SENT_SENSE bein set here,
685 		 * but since we're not maintaining any CA/UA state,
686 		 * there's no point.
687 		 */
688 		atio->sense_len = 0;
689 		done_ccb->ccb_h.flags &= ~CAM_SEND_SENSE;
690 		done_ccb->ccb_h.status &= ~CAM_SENT_SENSE;
691 
692 		/*
693 		 * Any errors will not change the data we return,
694 		 * so make sure the queue is not left frozen.
695 		 * XXX - At some point there may be errors that
696 		 *       leave us in a connected state with the
697 		 *       initiator...
698 		 */
699 		if ((done_ccb->ccb_h.status & CAM_DEV_QFRZN) != 0) {
700 			printf("Releasing Queue\n");
701 			cam_release_devq(done_ccb->ccb_h.path,
702 					 /*relsim_flags*/0,
703 					 /*reduction*/0,
704 					 /*timeout*/0,
705 					 /*getcount_only*/0);
706 			done_ccb->ccb_h.status &= ~CAM_DEV_QFRZN;
707 		}
708 		desc->data_resid -= desc->data_increment;
709 		xpt_release_ccb(done_ccb);
710 		if (softc->state != TARGBH_STATE_TEARDOWN) {
711 
712 			/*
713 			 * Send the original accept TIO back to the
714 			 * controller to handle more work.
715 			 */
716 			CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE,
717 				  ("Returning ATIO to target\n"));
718 			/* Restore wildcards */
719 			atio->ccb_h.target_id = CAM_TARGET_WILDCARD;
720 			atio->ccb_h.target_lun = CAM_LUN_WILDCARD;
721 			xpt_action((union ccb *)atio);
722 			break;
723 		} else {
724 			targbhfreedescr(desc);
725 			free(atio, M_DEVBUF);
726 		}
727 		break;
728 	}
729 	case XPT_IMMED_NOTIFY:
730 	{
731 		int frozen;
732 
733 		frozen = (done_ccb->ccb_h.status & CAM_DEV_QFRZN) != 0;
734 		if (softc->state == TARGBH_STATE_TEARDOWN
735 		 || done_ccb->ccb_h.status == CAM_REQ_ABORTED) {
736 			printf("Freed an immediate notify\n");
737 			free(done_ccb, M_DEVBUF);
738 		} else {
739 			/* Requeue for another immediate event */
740 			xpt_action(done_ccb);
741 		}
742 		if (frozen != 0)
743 			cam_release_devq(periph->path,
744 					 /*relsim_flags*/0,
745 					 /*opening reduction*/0,
746 					 /*timeout*/0,
747 					 /*getcount_only*/0);
748 		break;
749 	}
750 	default:
751 		panic("targbhdone: Unexpected ccb opcode");
752 		break;
753 	}
754 }
755 
756 #ifdef NOTYET
757 static int
758 targbherror(union ccb *ccb, u_int32_t cam_flags, u_int32_t sense_flags)
759 {
760 	return 0;
761 }
762 #endif
763 
764 static struct targbh_cmd_desc*
765 targbhallocdescr()
766 {
767 	struct targbh_cmd_desc* descr;
768 
769 	/* Allocate the targbh_descr structure */
770 	descr = (struct targbh_cmd_desc *)malloc(sizeof(*descr),
771 					       M_DEVBUF, M_NOWAIT);
772 	if (descr == NULL)
773 		return (NULL);
774 
775 	bzero(descr, sizeof(*descr));
776 
777 	/* Allocate buffer backing store */
778 	descr->backing_store = malloc(MAX_BUF_SIZE, M_DEVBUF, M_NOWAIT);
779 	if (descr->backing_store == NULL) {
780 		free(descr, M_DEVBUF);
781 		return (NULL);
782 	}
783 	descr->max_size = MAX_BUF_SIZE;
784 	return (descr);
785 }
786 
787 static void
788 targbhfreedescr(struct targbh_cmd_desc *descr)
789 {
790 	free(descr->backing_store, M_DEVBUF);
791 	free(descr, M_DEVBUF);
792 }
793