xref: /freebsd/sys/cam/scsi/scsi_target.c (revision 3fc9e2c36555140de248a0b4def91bbfa44d7c2c)
1 /*-
2  * Generic SCSI Target Kernel Mode Driver
3  *
4  * Copyright (c) 2002 Nate Lawson.
5  * Copyright (c) 1998, 1999, 2001, 2002 Justin T. Gibbs.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions, and the following disclaimer,
13  *    without modification, immediately at the beginning of the file.
14  * 2. The name of the author may not be used to endorse or promote products
15  *    derived from this software without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
21  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/kernel.h>
37 #include <sys/conf.h>
38 #include <sys/malloc.h>
39 #include <sys/poll.h>
40 #include <sys/vnode.h>
41 #include <sys/lock.h>
42 #include <sys/mutex.h>
43 #include <sys/devicestat.h>
44 #include <sys/proc.h>
45 /* Includes to support callout */
46 #include <sys/types.h>
47 #include <sys/systm.h>
48 
49 #include <cam/cam.h>
50 #include <cam/cam_ccb.h>
51 #include <cam/cam_periph.h>
52 #include <cam/cam_xpt_periph.h>
53 #include <cam/cam_sim.h>
54 #include <cam/scsi/scsi_targetio.h>
55 
56 
57 /* Transaction information attached to each CCB sent by the user */
58 struct targ_cmd_descr {
59 	struct cam_periph_map_info  mapinfo;
60 	TAILQ_ENTRY(targ_cmd_descr) tqe;
61 	union ccb *user_ccb;
62 	int	   priority;
63 	int	   func_code;
64 };
65 
66 /* Offset into the private CCB area for storing our descriptor */
67 #define targ_descr	periph_priv.entries[1].ptr
68 
69 TAILQ_HEAD(descr_queue, targ_cmd_descr);
70 
71 typedef enum {
72 	TARG_STATE_RESV		= 0x00, /* Invalid state */
73 	TARG_STATE_OPENED	= 0x01, /* Device opened, softc initialized */
74 	TARG_STATE_LUN_ENABLED	= 0x02  /* Device enabled for a path */
75 } targ_state;
76 
77 /* Per-instance device software context */
78 struct targ_softc {
79 	/* CCBs (CTIOs, ATIOs, INOTs) pending on the controller */
80 	struct ccb_queue	 pending_ccb_queue;
81 
82 	/* Command descriptors awaiting CTIO resources from the XPT */
83 	struct descr_queue	 work_queue;
84 
85 	/* Command descriptors that have been aborted back to the user. */
86 	struct descr_queue	 abort_queue;
87 
88 	/*
89 	 * Queue of CCBs that have been copied out to userland, but our
90 	 * userland daemon has not yet seen.
91 	 */
92 	struct ccb_queue	 user_ccb_queue;
93 
94 	struct cam_periph	*periph;
95 	struct cam_path		*path;
96 	targ_state		 state;
97 	struct selinfo		 read_select;
98 	struct devstat		 device_stats;
99 };
100 
101 static d_open_t		targopen;
102 static d_read_t		targread;
103 static d_write_t	targwrite;
104 static d_ioctl_t	targioctl;
105 static d_poll_t		targpoll;
106 static d_kqfilter_t	targkqfilter;
107 static void		targreadfiltdetach(struct knote *kn);
108 static int		targreadfilt(struct knote *kn, long hint);
109 static struct filterops targread_filtops = {
110 	.f_isfd = 1,
111 	.f_detach = targreadfiltdetach,
112 	.f_event = targreadfilt,
113 };
114 
115 static struct cdevsw targ_cdevsw = {
116 	.d_version =	D_VERSION,
117 	.d_flags =	D_NEEDGIANT,
118 	.d_open =	targopen,
119 	.d_read =	targread,
120 	.d_write =	targwrite,
121 	.d_ioctl =	targioctl,
122 	.d_poll =	targpoll,
123 	.d_name =	"targ",
124 	.d_kqfilter =	targkqfilter
125 };
126 
127 static cam_status	targendislun(struct cam_path *path, int enable,
128 				     int grp6_len, int grp7_len);
129 static cam_status	targenable(struct targ_softc *softc,
130 				   struct cam_path *path,
131 				   int grp6_len, int grp7_len);
132 static cam_status	targdisable(struct targ_softc *softc);
133 static periph_ctor_t    targctor;
134 static periph_dtor_t    targdtor;
135 static periph_start_t   targstart;
136 static int		targusermerge(struct targ_softc *softc,
137 				      struct targ_cmd_descr *descr,
138 				      union ccb *ccb);
139 static int		targsendccb(struct targ_softc *softc, union ccb *ccb,
140 				    struct targ_cmd_descr *descr);
141 static void		targdone(struct cam_periph *periph,
142 				 union  ccb *done_ccb);
143 static int		targreturnccb(struct targ_softc *softc,
144 				      union  ccb *ccb);
145 static union ccb *	targgetccb(struct targ_softc *softc, xpt_opcode type,
146 				   int priority);
147 static void		targfreeccb(struct targ_softc *softc, union ccb *ccb);
148 static struct targ_cmd_descr *
149 			targgetdescr(struct targ_softc *softc);
150 static periph_init_t	targinit;
151 static void		targasync(void *callback_arg, u_int32_t code,
152 				  struct cam_path *path, void *arg);
153 static void		abort_all_pending(struct targ_softc *softc);
154 static void		notify_user(struct targ_softc *softc);
155 static int		targcamstatus(cam_status status);
156 static size_t		targccblen(xpt_opcode func_code);
157 
158 static struct periph_driver targdriver =
159 {
160 	targinit, "targ",
161 	TAILQ_HEAD_INITIALIZER(targdriver.units), /* generation */ 0
162 };
163 PERIPHDRIVER_DECLARE(targ, targdriver);
164 
165 static MALLOC_DEFINE(M_TARG, "TARG", "TARG data");
166 
167 /* Disable LUN if enabled and teardown softc */
168 static void
169 targcdevdtor(void *data)
170 {
171 	struct targ_softc *softc;
172 	struct cam_periph *periph;
173 
174 	softc = data;
175 	if (softc->periph == NULL) {
176 		printf("%s: destroying non-enabled target\n", __func__);
177 		free(softc, M_TARG);
178 		return;
179 	}
180 
181 	/*
182 	 * Acquire a hold on the periph so that it doesn't go away before
183 	 * we are ready at the end of the function.
184 	 */
185 	periph = softc->periph;
186 	cam_periph_acquire(periph);
187 	cam_periph_lock(periph);
188 	(void)targdisable(softc);
189 	if (softc->periph != NULL) {
190 		cam_periph_invalidate(softc->periph);
191 		softc->periph = NULL;
192 	}
193 	cam_periph_unlock(periph);
194 	cam_periph_release(periph);
195 	free(softc, M_TARG);
196 }
197 
198 /*
199  * Create softc and initialize it.  There is no locking here because a
200  * periph doesn't get created until an ioctl is issued to do so, and
201  * that can't happen until this method returns.
202  */
203 static int
204 targopen(struct cdev *dev, int flags, int fmt, struct thread *td)
205 {
206 	struct targ_softc *softc;
207 
208 	/* Allocate its softc, initialize it */
209 	softc = malloc(sizeof(*softc), M_TARG,
210 	       M_WAITOK | M_ZERO);
211 	softc->state = TARG_STATE_OPENED;
212 	softc->periph = NULL;
213 	softc->path = NULL;
214 
215 	TAILQ_INIT(&softc->pending_ccb_queue);
216 	TAILQ_INIT(&softc->work_queue);
217 	TAILQ_INIT(&softc->abort_queue);
218 	TAILQ_INIT(&softc->user_ccb_queue);
219 	knlist_init_mtx(&softc->read_select.si_note, NULL);
220 
221 	devfs_set_cdevpriv(softc, targcdevdtor);
222 	return (0);
223 }
224 
225 /* Enable/disable LUNs, set debugging level */
226 static int
227 targioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flag, struct thread *td)
228 {
229 	struct targ_softc *softc;
230 	cam_status	   status;
231 
232 	devfs_get_cdevpriv((void **)&softc);
233 
234 	switch (cmd) {
235 	case TARGIOCENABLE:
236 	{
237 		struct ioc_enable_lun	*new_lun;
238 		struct cam_path		*path;
239 		struct cam_sim		*sim;
240 
241 		new_lun = (struct ioc_enable_lun *)addr;
242 		status = xpt_create_path_unlocked(&path, /*periph*/NULL,
243 						  new_lun->path_id,
244 						  new_lun->target_id,
245 						  new_lun->lun_id);
246 		if (status != CAM_REQ_CMP) {
247 			printf("Couldn't create path, status %#x\n", status);
248 			break;
249 		}
250 		sim = xpt_path_sim(path);
251 		mtx_lock(sim->mtx);
252 		status = targenable(softc, path, new_lun->grp6_len,
253 				    new_lun->grp7_len);
254 		xpt_free_path(path);
255 		mtx_unlock(sim->mtx);
256 		break;
257 	}
258 	case TARGIOCDISABLE:
259 		if (softc->periph == NULL) {
260 			status = CAM_DEV_NOT_THERE;
261 			break;
262 		}
263 		cam_periph_lock(softc->periph);
264 		status = targdisable(softc);
265 		cam_periph_unlock(softc->periph);
266 		break;
267 	case TARGIOCDEBUG:
268 	{
269 		struct ccb_debug cdbg;
270 
271 		/* If no periph available, disallow debugging changes */
272 		if ((softc->state & TARG_STATE_LUN_ENABLED) == 0) {
273 			status = CAM_DEV_NOT_THERE;
274 			break;
275 		}
276 		bzero(&cdbg, sizeof cdbg);
277 		if (*((int *)addr) != 0)
278 			cdbg.flags = CAM_DEBUG_PERIPH;
279 		else
280 			cdbg.flags = CAM_DEBUG_NONE;
281 		cam_periph_lock(softc->periph);
282 		xpt_setup_ccb(&cdbg.ccb_h, softc->path, CAM_PRIORITY_NORMAL);
283 		cdbg.ccb_h.func_code = XPT_DEBUG;
284 		cdbg.ccb_h.cbfcnp = targdone;
285 
286 		xpt_action((union ccb *)&cdbg);
287 		cam_periph_unlock(softc->periph);
288 		status = cdbg.ccb_h.status & CAM_STATUS_MASK;
289 		break;
290 	}
291 	default:
292 		status = CAM_PROVIDE_FAIL;
293 		break;
294 	}
295 
296 	return (targcamstatus(status));
297 }
298 
299 /* Writes are always ready, reads wait for user_ccb_queue or abort_queue */
300 static int
301 targpoll(struct cdev *dev, int poll_events, struct thread *td)
302 {
303 	struct targ_softc *softc;
304 	int	revents;
305 
306 	devfs_get_cdevpriv((void **)&softc);
307 
308 	/* Poll for write() is always ok. */
309 	revents = poll_events & (POLLOUT | POLLWRNORM);
310 	if ((poll_events & (POLLIN | POLLRDNORM)) != 0) {
311 		/* Poll for read() depends on user and abort queues. */
312 		cam_periph_lock(softc->periph);
313 		if (!TAILQ_EMPTY(&softc->user_ccb_queue) ||
314 		    !TAILQ_EMPTY(&softc->abort_queue)) {
315 			revents |= poll_events & (POLLIN | POLLRDNORM);
316 		}
317 		cam_periph_unlock(softc->periph);
318 		/* Only sleep if the user didn't poll for write. */
319 		if (revents == 0)
320 			selrecord(td, &softc->read_select);
321 	}
322 
323 	return (revents);
324 }
325 
326 static int
327 targkqfilter(struct cdev *dev, struct knote *kn)
328 {
329 	struct  targ_softc *softc;
330 
331 	devfs_get_cdevpriv((void **)&softc);
332 	kn->kn_hook = (caddr_t)softc;
333 	kn->kn_fop = &targread_filtops;
334 	knlist_add(&softc->read_select.si_note, kn, 0);
335 	return (0);
336 }
337 
338 static void
339 targreadfiltdetach(struct knote *kn)
340 {
341 	struct  targ_softc *softc;
342 
343 	softc = (struct targ_softc *)kn->kn_hook;
344 	knlist_remove(&softc->read_select.si_note, kn, 0);
345 }
346 
347 /* Notify the user's kqueue when the user queue or abort queue gets a CCB */
348 static int
349 targreadfilt(struct knote *kn, long hint)
350 {
351 	struct targ_softc *softc;
352 	int	retval;
353 
354 	softc = (struct targ_softc *)kn->kn_hook;
355 	cam_periph_lock(softc->periph);
356 	retval = !TAILQ_EMPTY(&softc->user_ccb_queue) ||
357 		 !TAILQ_EMPTY(&softc->abort_queue);
358 	cam_periph_unlock(softc->periph);
359 	return (retval);
360 }
361 
362 /* Send the HBA the enable/disable message */
363 static cam_status
364 targendislun(struct cam_path *path, int enable, int grp6_len, int grp7_len)
365 {
366 	struct ccb_en_lun en_ccb;
367 	cam_status	  status;
368 
369 	/* Tell the lun to begin answering selects */
370 	xpt_setup_ccb(&en_ccb.ccb_h, path, CAM_PRIORITY_NORMAL);
371 	en_ccb.ccb_h.func_code = XPT_EN_LUN;
372 	/* Don't need support for any vendor specific commands */
373 	en_ccb.grp6_len = grp6_len;
374 	en_ccb.grp7_len = grp7_len;
375 	en_ccb.enable = enable ? 1 : 0;
376 	xpt_action((union ccb *)&en_ccb);
377 	status = en_ccb.ccb_h.status & CAM_STATUS_MASK;
378 	if (status != CAM_REQ_CMP) {
379 		xpt_print(path, "%sable lun CCB rejected, status %#x\n",
380 		    enable ? "en" : "dis", status);
381 	}
382 	return (status);
383 }
384 
385 /* Enable target mode on a LUN, given its path */
386 static cam_status
387 targenable(struct targ_softc *softc, struct cam_path *path, int grp6_len,
388 	   int grp7_len)
389 {
390 	struct cam_periph *periph;
391 	struct ccb_pathinq cpi;
392 	cam_status	   status;
393 
394 	if ((softc->state & TARG_STATE_LUN_ENABLED) != 0)
395 		return (CAM_LUN_ALRDY_ENA);
396 
397 	/* Make sure SIM supports target mode */
398 	xpt_setup_ccb(&cpi.ccb_h, path, CAM_PRIORITY_NORMAL);
399 	cpi.ccb_h.func_code = XPT_PATH_INQ;
400 	xpt_action((union ccb *)&cpi);
401 	status = cpi.ccb_h.status & CAM_STATUS_MASK;
402 	if (status != CAM_REQ_CMP) {
403 		printf("pathinq failed, status %#x\n", status);
404 		goto enable_fail;
405 	}
406 	if ((cpi.target_sprt & PIT_PROCESSOR) == 0) {
407 		printf("controller does not support target mode\n");
408 		status = CAM_FUNC_NOTAVAIL;
409 		goto enable_fail;
410 	}
411 
412 	/* Destroy any periph on our path if it is disabled */
413 	periph = cam_periph_find(path, "targ");
414 	if (periph != NULL) {
415 		struct targ_softc *del_softc;
416 
417 		del_softc = (struct targ_softc *)periph->softc;
418 		if ((del_softc->state & TARG_STATE_LUN_ENABLED) == 0) {
419 			cam_periph_invalidate(del_softc->periph);
420 			del_softc->periph = NULL;
421 		} else {
422 			printf("Requested path still in use by targ%d\n",
423 			       periph->unit_number);
424 			status = CAM_LUN_ALRDY_ENA;
425 			goto enable_fail;
426 		}
427 	}
428 
429 	/* Create a periph instance attached to this path */
430 	status = cam_periph_alloc(targctor, NULL, targdtor, targstart,
431 			"targ", CAM_PERIPH_BIO, path, targasync, 0, softc);
432 	if (status != CAM_REQ_CMP) {
433 		printf("cam_periph_alloc failed, status %#x\n", status);
434 		goto enable_fail;
435 	}
436 
437 	/* Ensure that the periph now exists. */
438 	if (cam_periph_find(path, "targ") == NULL) {
439 		panic("targenable: succeeded but no periph?");
440 		/* NOTREACHED */
441 	}
442 
443 	/* Send the enable lun message */
444 	status = targendislun(path, /*enable*/1, grp6_len, grp7_len);
445 	if (status != CAM_REQ_CMP) {
446 		printf("enable lun failed, status %#x\n", status);
447 		goto enable_fail;
448 	}
449 	softc->state |= TARG_STATE_LUN_ENABLED;
450 
451 enable_fail:
452 	return (status);
453 }
454 
455 /* Disable this softc's target instance if enabled */
456 static cam_status
457 targdisable(struct targ_softc *softc)
458 {
459 	cam_status status;
460 
461 	if ((softc->state & TARG_STATE_LUN_ENABLED) == 0)
462 		return (CAM_REQ_CMP);
463 
464 	CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("targdisable\n"));
465 
466 	/* Abort any ccbs pending on the controller */
467 	abort_all_pending(softc);
468 
469 	/* Disable this lun */
470 	status = targendislun(softc->path, /*enable*/0,
471 			      /*grp6_len*/0, /*grp7_len*/0);
472 	if (status == CAM_REQ_CMP)
473 		softc->state &= ~TARG_STATE_LUN_ENABLED;
474 	else
475 		printf("Disable lun failed, status %#x\n", status);
476 
477 	return (status);
478 }
479 
480 /* Initialize a periph (called from cam_periph_alloc) */
481 static cam_status
482 targctor(struct cam_periph *periph, void *arg)
483 {
484 	struct targ_softc *softc;
485 
486 	/* Store pointer to softc for periph-driven routines */
487 	softc = (struct targ_softc *)arg;
488 	periph->softc = softc;
489 	softc->periph = periph;
490 	softc->path = periph->path;
491 	return (CAM_REQ_CMP);
492 }
493 
494 static void
495 targdtor(struct cam_periph *periph)
496 {
497 	struct targ_softc     *softc;
498 	struct ccb_hdr	      *ccb_h;
499 	struct targ_cmd_descr *descr;
500 
501 	softc = (struct targ_softc *)periph->softc;
502 
503 	/*
504 	 * targdisable() aborts CCBs back to the user and leaves them
505 	 * on user_ccb_queue and abort_queue in case the user is still
506 	 * interested in them.  We free them now.
507 	 */
508 	while ((ccb_h = TAILQ_FIRST(&softc->user_ccb_queue)) != NULL) {
509 		TAILQ_REMOVE(&softc->user_ccb_queue, ccb_h, periph_links.tqe);
510 		targfreeccb(softc, (union ccb *)ccb_h);
511 	}
512 	while ((descr = TAILQ_FIRST(&softc->abort_queue)) != NULL) {
513 		TAILQ_REMOVE(&softc->abort_queue, descr, tqe);
514 		free(descr, M_TARG);
515 	}
516 
517 	softc->periph = NULL;
518 	softc->path = NULL;
519 	periph->softc = NULL;
520 }
521 
522 /* Receive CCBs from user mode proc and send them to the HBA */
523 static int
524 targwrite(struct cdev *dev, struct uio *uio, int ioflag)
525 {
526 	union ccb *user_ccb;
527 	struct targ_softc *softc;
528 	struct targ_cmd_descr *descr;
529 	int write_len, error;
530 	int func_code, priority;
531 
532 	devfs_get_cdevpriv((void **)&softc);
533 	write_len = error = 0;
534 	CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
535 		  ("write - uio_resid %zd\n", uio->uio_resid));
536 	while (uio->uio_resid >= sizeof(user_ccb) && error == 0) {
537 		union ccb *ccb;
538 
539 		error = uiomove((caddr_t)&user_ccb, sizeof(user_ccb), uio);
540 		if (error != 0) {
541 			CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
542 				  ("write - uiomove failed (%d)\n", error));
543 			break;
544 		}
545 		priority = fuword32(&user_ccb->ccb_h.pinfo.priority);
546 		if (priority == CAM_PRIORITY_NONE) {
547 			error = EINVAL;
548 			break;
549 		}
550 		func_code = fuword32(&user_ccb->ccb_h.func_code);
551 		switch (func_code) {
552 		case XPT_ACCEPT_TARGET_IO:
553 		case XPT_IMMED_NOTIFY:
554 		case XPT_IMMEDIATE_NOTIFY:
555 			cam_periph_lock(softc->periph);
556 			ccb = targgetccb(softc, func_code, priority);
557 			descr = (struct targ_cmd_descr *)ccb->ccb_h.targ_descr;
558 			descr->user_ccb = user_ccb;
559 			descr->func_code = func_code;
560 			CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
561 				  ("Sent ATIO/INOT (%p)\n", user_ccb));
562 			xpt_action(ccb);
563 			TAILQ_INSERT_TAIL(&softc->pending_ccb_queue,
564 					  &ccb->ccb_h,
565 					  periph_links.tqe);
566 			cam_periph_unlock(softc->periph);
567 			break;
568 		default:
569 			cam_periph_lock(softc->periph);
570 			if ((func_code & XPT_FC_QUEUED) != 0) {
571 				CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
572 					  ("Sending queued ccb %#x (%p)\n",
573 					  func_code, user_ccb));
574 				descr = targgetdescr(softc);
575 				descr->user_ccb = user_ccb;
576 				descr->priority = priority;
577 				descr->func_code = func_code;
578 				TAILQ_INSERT_TAIL(&softc->work_queue,
579 						  descr, tqe);
580 				xpt_schedule(softc->periph, priority);
581 			} else {
582 				CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
583 					  ("Sending inline ccb %#x (%p)\n",
584 					  func_code, user_ccb));
585 				ccb = targgetccb(softc, func_code, priority);
586 				descr = (struct targ_cmd_descr *)
587 					 ccb->ccb_h.targ_descr;
588 				descr->user_ccb = user_ccb;
589 				descr->priority = priority;
590 				descr->func_code = func_code;
591 				if (targusermerge(softc, descr, ccb) != EFAULT)
592 					targsendccb(softc, ccb, descr);
593 				targreturnccb(softc, ccb);
594 			}
595 			cam_periph_unlock(softc->periph);
596 			break;
597 		}
598 		write_len += sizeof(user_ccb);
599 	}
600 
601 	/*
602 	 * If we've successfully taken in some amount of
603 	 * data, return success for that data first.  If
604 	 * an error is persistent, it will be reported
605 	 * on the next write.
606 	 */
607 	if (error != 0 && write_len == 0)
608 		return (error);
609 	if (write_len == 0 && uio->uio_resid != 0)
610 		return (ENOSPC);
611 	return (0);
612 }
613 
614 /* Process requests (descrs) via the periph-supplied CCBs */
615 static void
616 targstart(struct cam_periph *periph, union ccb *start_ccb)
617 {
618 	struct targ_softc *softc;
619 	struct targ_cmd_descr *descr, *next_descr;
620 	int error;
621 
622 	softc = (struct targ_softc *)periph->softc;
623 	CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("targstart %p\n", start_ccb));
624 
625 	descr = TAILQ_FIRST(&softc->work_queue);
626 	if (descr == NULL) {
627 		xpt_release_ccb(start_ccb);
628 	} else {
629 		TAILQ_REMOVE(&softc->work_queue, descr, tqe);
630 		next_descr = TAILQ_FIRST(&softc->work_queue);
631 
632 		/* Initiate a transaction using the descr and supplied CCB */
633 		error = targusermerge(softc, descr, start_ccb);
634 		if (error == 0)
635 			error = targsendccb(softc, start_ccb, descr);
636 		if (error != 0) {
637 			xpt_print(periph->path,
638 			    "targsendccb failed, err %d\n", error);
639 			xpt_release_ccb(start_ccb);
640 			suword(&descr->user_ccb->ccb_h.status,
641 			       CAM_REQ_CMP_ERR);
642 			TAILQ_INSERT_TAIL(&softc->abort_queue, descr, tqe);
643 			notify_user(softc);
644 		}
645 
646 		/* If we have more work to do, stay scheduled */
647 		if (next_descr != NULL)
648 			xpt_schedule(periph, next_descr->priority);
649 	}
650 }
651 
652 static int
653 targusermerge(struct targ_softc *softc, struct targ_cmd_descr *descr,
654 	      union ccb *ccb)
655 {
656 	struct ccb_hdr *u_ccbh, *k_ccbh;
657 	size_t ccb_len;
658 	int error;
659 
660 	u_ccbh = &descr->user_ccb->ccb_h;
661 	k_ccbh = &ccb->ccb_h;
662 
663 	/*
664 	 * There are some fields in the CCB header that need to be
665 	 * preserved, the rest we get from the user ccb. (See xpt_merge_ccb)
666 	 */
667 	xpt_setup_ccb(k_ccbh, softc->path, descr->priority);
668 	k_ccbh->retry_count = fuword32(&u_ccbh->retry_count);
669 	k_ccbh->func_code = descr->func_code;
670 	k_ccbh->flags = fuword32(&u_ccbh->flags);
671 	k_ccbh->timeout = fuword32(&u_ccbh->timeout);
672 	ccb_len = targccblen(k_ccbh->func_code) - sizeof(struct ccb_hdr);
673 	error = copyin(u_ccbh + 1, k_ccbh + 1, ccb_len);
674 	if (error != 0) {
675 		k_ccbh->status = CAM_REQ_CMP_ERR;
676 		return (error);
677 	}
678 
679 	/* Translate usermode abort_ccb pointer to its kernel counterpart */
680 	if (k_ccbh->func_code == XPT_ABORT) {
681 		struct ccb_abort *cab;
682 		struct ccb_hdr *ccb_h;
683 
684 		cab = (struct ccb_abort *)ccb;
685 		TAILQ_FOREACH(ccb_h, &softc->pending_ccb_queue,
686 		    periph_links.tqe) {
687 			struct targ_cmd_descr *ab_descr;
688 
689 			ab_descr = (struct targ_cmd_descr *)ccb_h->targ_descr;
690 			if (ab_descr->user_ccb == cab->abort_ccb) {
691 				CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
692 					  ("Changing abort for %p to %p\n",
693 					  cab->abort_ccb, ccb_h));
694 				cab->abort_ccb = (union ccb *)ccb_h;
695 				break;
696 			}
697 		}
698 		/* CCB not found, set appropriate status */
699 		if (ccb_h == NULL) {
700 			k_ccbh->status = CAM_PATH_INVALID;
701 			error = ESRCH;
702 		}
703 	}
704 
705 	return (error);
706 }
707 
708 /* Build and send a kernel CCB formed from descr->user_ccb */
709 static int
710 targsendccb(struct targ_softc *softc, union ccb *ccb,
711 	    struct targ_cmd_descr *descr)
712 {
713 	struct cam_periph_map_info *mapinfo;
714 	struct ccb_hdr *ccb_h;
715 	int error;
716 
717 	ccb_h = &ccb->ccb_h;
718 	mapinfo = &descr->mapinfo;
719 	mapinfo->num_bufs_used = 0;
720 
721 	/*
722 	 * There's no way for the user to have a completion
723 	 * function, so we put our own completion function in here.
724 	 * We also stash in a reference to our descriptor so targreturnccb()
725 	 * can find our mapping info.
726 	 */
727 	ccb_h->cbfcnp = targdone;
728 	ccb_h->targ_descr = descr;
729 
730 	if ((ccb_h->func_code == XPT_CONT_TARGET_IO) ||
731 	    (ccb_h->func_code == XPT_DEV_MATCH)) {
732 
733 		error = cam_periph_mapmem(ccb, mapinfo);
734 
735 		/*
736 		 * cam_periph_mapmem returned an error, we can't continue.
737 		 * Return the error to the user.
738 		 */
739 		if (error) {
740 			ccb_h->status = CAM_REQ_CMP_ERR;
741 			mapinfo->num_bufs_used = 0;
742 			return (error);
743 		}
744 	}
745 
746 	/*
747 	 * Once queued on the pending CCB list, this CCB will be protected
748 	 * by our error recovery handler.
749 	 */
750 	CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("sendccb %p\n", ccb));
751 	if (XPT_FC_IS_QUEUED(ccb)) {
752 		TAILQ_INSERT_TAIL(&softc->pending_ccb_queue, ccb_h,
753 				  periph_links.tqe);
754 	}
755 	xpt_action(ccb);
756 
757 	return (0);
758 }
759 
760 /* Completion routine for CCBs (called at splsoftcam) */
761 static void
762 targdone(struct cam_periph *periph, union ccb *done_ccb)
763 {
764 	struct targ_softc *softc;
765 	cam_status status;
766 
767 	CAM_DEBUG(periph->path, CAM_DEBUG_PERIPH, ("targdone %p\n", done_ccb));
768 	softc = (struct targ_softc *)periph->softc;
769 	TAILQ_REMOVE(&softc->pending_ccb_queue, &done_ccb->ccb_h,
770 		     periph_links.tqe);
771 	status = done_ccb->ccb_h.status & CAM_STATUS_MASK;
772 
773 	/* If we're no longer enabled, throw away CCB */
774 	if ((softc->state & TARG_STATE_LUN_ENABLED) == 0) {
775 		targfreeccb(softc, done_ccb);
776 		return;
777 	}
778 	/* abort_all_pending() waits for pending queue to be empty */
779 	if (TAILQ_EMPTY(&softc->pending_ccb_queue))
780 		wakeup(&softc->pending_ccb_queue);
781 
782 	switch (done_ccb->ccb_h.func_code) {
783 	/* All FC_*_QUEUED CCBs go back to userland */
784 	case XPT_IMMED_NOTIFY:
785 	case XPT_IMMEDIATE_NOTIFY:
786 	case XPT_ACCEPT_TARGET_IO:
787 	case XPT_CONT_TARGET_IO:
788 		TAILQ_INSERT_TAIL(&softc->user_ccb_queue, &done_ccb->ccb_h,
789 				  periph_links.tqe);
790  		cam_periph_unlock(softc->periph);
791 		notify_user(softc);
792  		cam_periph_lock(softc->periph);
793 		break;
794 	default:
795 		panic("targdone: impossible xpt opcode %#x",
796 		      done_ccb->ccb_h.func_code);
797 		/* NOTREACHED */
798 	}
799 }
800 
801 /* Return CCBs to the user from the user queue and abort queue */
802 static int
803 targread(struct cdev *dev, struct uio *uio, int ioflag)
804 {
805 	struct descr_queue	*abort_queue;
806 	struct targ_cmd_descr	*user_descr;
807 	struct targ_softc	*softc;
808 	struct ccb_queue  *user_queue;
809 	struct ccb_hdr	  *ccb_h;
810 	union  ccb	  *user_ccb;
811 	int		   read_len, error;
812 
813 	error = 0;
814 	read_len = 0;
815 	devfs_get_cdevpriv((void **)&softc);
816 	user_queue = &softc->user_ccb_queue;
817 	abort_queue = &softc->abort_queue;
818 	CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("targread\n"));
819 
820 	/* If no data is available, wait or return immediately */
821 	cam_periph_lock(softc->periph);
822 	ccb_h = TAILQ_FIRST(user_queue);
823 	user_descr = TAILQ_FIRST(abort_queue);
824 	while (ccb_h == NULL && user_descr == NULL) {
825 		if ((ioflag & IO_NDELAY) == 0) {
826 			error = msleep(user_queue, softc->periph->sim->mtx,
827 			    PRIBIO | PCATCH, "targrd", 0);
828 			ccb_h = TAILQ_FIRST(user_queue);
829 			user_descr = TAILQ_FIRST(abort_queue);
830 			if (error != 0) {
831 				if (error == ERESTART) {
832 					continue;
833 				} else {
834 					goto read_fail;
835 				}
836 			}
837 		} else {
838 			cam_periph_unlock(softc->periph);
839 			return (EAGAIN);
840 		}
841 	}
842 
843 	/* Data is available so fill the user's buffer */
844 	while (ccb_h != NULL) {
845 		struct targ_cmd_descr *descr;
846 
847 		if (uio->uio_resid < sizeof(user_ccb))
848 			break;
849 		TAILQ_REMOVE(user_queue, ccb_h, periph_links.tqe);
850 		descr = (struct targ_cmd_descr *)ccb_h->targ_descr;
851 		user_ccb = descr->user_ccb;
852 		CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
853 			  ("targread ccb %p (%p)\n", ccb_h, user_ccb));
854 		error = targreturnccb(softc, (union ccb *)ccb_h);
855 		if (error != 0)
856 			goto read_fail;
857 		cam_periph_unlock(softc->periph);
858 		error = uiomove((caddr_t)&user_ccb, sizeof(user_ccb), uio);
859 		cam_periph_lock(softc->periph);
860 		if (error != 0)
861 			goto read_fail;
862 		read_len += sizeof(user_ccb);
863 
864 		ccb_h = TAILQ_FIRST(user_queue);
865 	}
866 
867 	/* Flush out any aborted descriptors */
868 	while (user_descr != NULL) {
869 		if (uio->uio_resid < sizeof(user_ccb))
870 			break;
871 		TAILQ_REMOVE(abort_queue, user_descr, tqe);
872 		user_ccb = user_descr->user_ccb;
873 		CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
874 			  ("targread aborted descr %p (%p)\n",
875 			  user_descr, user_ccb));
876 		suword(&user_ccb->ccb_h.status, CAM_REQ_ABORTED);
877 		cam_periph_unlock(softc->periph);
878 		error = uiomove((caddr_t)&user_ccb, sizeof(user_ccb), uio);
879 		cam_periph_lock(softc->periph);
880 		if (error != 0)
881 			goto read_fail;
882 		read_len += sizeof(user_ccb);
883 
884 		user_descr = TAILQ_FIRST(abort_queue);
885 	}
886 
887 	/*
888 	 * If we've successfully read some amount of data, don't report an
889 	 * error.  If the error is persistent, it will be reported on the
890 	 * next read().
891 	 */
892 	if (read_len == 0 && uio->uio_resid != 0)
893 		error = ENOSPC;
894 
895 read_fail:
896 	cam_periph_unlock(softc->periph);
897 	return (error);
898 }
899 
900 /* Copy completed ccb back to the user */
901 static int
902 targreturnccb(struct targ_softc *softc, union ccb *ccb)
903 {
904 	struct targ_cmd_descr *descr;
905 	struct ccb_hdr *u_ccbh;
906 	size_t ccb_len;
907 	int error;
908 
909 	CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("targreturnccb %p\n", ccb));
910 	descr = (struct targ_cmd_descr *)ccb->ccb_h.targ_descr;
911 	u_ccbh = &descr->user_ccb->ccb_h;
912 
913 	/* Copy out the central portion of the ccb_hdr */
914 	copyout(&ccb->ccb_h.retry_count, &u_ccbh->retry_count,
915 		offsetof(struct ccb_hdr, periph_priv) -
916 		offsetof(struct ccb_hdr, retry_count));
917 
918 	/* Copy out the rest of the ccb (after the ccb_hdr) */
919 	ccb_len = targccblen(ccb->ccb_h.func_code) - sizeof(struct ccb_hdr);
920 	if (descr->mapinfo.num_bufs_used != 0)
921 		cam_periph_unmapmem(ccb, &descr->mapinfo);
922 	error = copyout(&ccb->ccb_h + 1, u_ccbh + 1, ccb_len);
923 	if (error != 0) {
924 		xpt_print(softc->path,
925 		    "targreturnccb - CCB copyout failed (%d)\n", error);
926 	}
927 	/* Free CCB or send back to devq. */
928 	targfreeccb(softc, ccb);
929 
930 	return (error);
931 }
932 
933 static union ccb *
934 targgetccb(struct targ_softc *softc, xpt_opcode type, int priority)
935 {
936 	union ccb *ccb;
937 	int ccb_len;
938 
939 	ccb_len = targccblen(type);
940 	ccb = malloc(ccb_len, M_TARG, M_NOWAIT);
941 	CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("getccb %p\n", ccb));
942 	if (ccb == NULL) {
943 		return (ccb);
944 	}
945 	xpt_setup_ccb(&ccb->ccb_h, softc->path, priority);
946 	ccb->ccb_h.func_code = type;
947 	ccb->ccb_h.cbfcnp = targdone;
948 	ccb->ccb_h.targ_descr = targgetdescr(softc);
949 	if (ccb->ccb_h.targ_descr == NULL) {
950 		free (ccb, M_TARG);
951 		ccb = NULL;
952 	}
953 	return (ccb);
954 }
955 
956 static void
957 targfreeccb(struct targ_softc *softc, union ccb *ccb)
958 {
959 	CAM_DEBUG_PRINT(CAM_DEBUG_PERIPH, ("targfreeccb descr %p and\n",
960 			ccb->ccb_h.targ_descr));
961 	free(ccb->ccb_h.targ_descr, M_TARG);
962 
963 	switch (ccb->ccb_h.func_code) {
964 	case XPT_ACCEPT_TARGET_IO:
965 	case XPT_IMMED_NOTIFY:
966 	case XPT_IMMEDIATE_NOTIFY:
967 		CAM_DEBUG_PRINT(CAM_DEBUG_PERIPH, ("freeing ccb %p\n", ccb));
968 		free(ccb, M_TARG);
969 		break;
970 	default:
971 		/* Send back CCB if we got it from the periph */
972 		if (XPT_FC_IS_QUEUED(ccb)) {
973 			CAM_DEBUG_PRINT(CAM_DEBUG_PERIPH,
974 					("returning queued ccb %p\n", ccb));
975 			xpt_release_ccb(ccb);
976 		} else {
977 			CAM_DEBUG_PRINT(CAM_DEBUG_PERIPH,
978 					("freeing ccb %p\n", ccb));
979 			free(ccb, M_TARG);
980 		}
981 		break;
982 	}
983 }
984 
985 static struct targ_cmd_descr *
986 targgetdescr(struct targ_softc *softc)
987 {
988 	struct targ_cmd_descr *descr;
989 
990 	descr = malloc(sizeof(*descr), M_TARG,
991 	       M_NOWAIT);
992 	if (descr) {
993 		descr->mapinfo.num_bufs_used = 0;
994 	}
995 	return (descr);
996 }
997 
998 static void
999 targinit(void)
1000 {
1001 	struct cdev *dev;
1002 
1003 	/* Add symbolic link to targ0 for compatibility. */
1004 	dev = make_dev(&targ_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "targ");
1005 	make_dev_alias(dev, "targ0");
1006 }
1007 
1008 static void
1009 targasync(void *callback_arg, u_int32_t code, struct cam_path *path, void *arg)
1010 {
1011 	/* All events are handled in usermode by INOTs */
1012 	panic("targasync() called, should be an INOT instead");
1013 }
1014 
1015 /* Cancel all pending requests and CCBs awaiting work. */
1016 static void
1017 abort_all_pending(struct targ_softc *softc)
1018 {
1019 	struct targ_cmd_descr   *descr;
1020 	struct ccb_abort	 cab;
1021 	struct ccb_hdr		*ccb_h;
1022 	struct cam_sim		*sim;
1023 
1024 	CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("abort_all_pending\n"));
1025 
1026 	/* First abort the descriptors awaiting resources */
1027 	while ((descr = TAILQ_FIRST(&softc->work_queue)) != NULL) {
1028 		CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
1029 			  ("Aborting descr from workq %p\n", descr));
1030 		TAILQ_REMOVE(&softc->work_queue, descr, tqe);
1031 		TAILQ_INSERT_TAIL(&softc->abort_queue, descr, tqe);
1032 	}
1033 
1034 	/*
1035 	 * Then abort all pending CCBs.
1036 	 * targdone() will return the aborted CCB via user_ccb_queue
1037 	 */
1038 	xpt_setup_ccb(&cab.ccb_h, softc->path, CAM_PRIORITY_NORMAL);
1039 	cab.ccb_h.func_code = XPT_ABORT;
1040 	cab.ccb_h.status = CAM_REQ_CMP_ERR;
1041 	TAILQ_FOREACH(ccb_h, &softc->pending_ccb_queue, periph_links.tqe) {
1042 		CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
1043 			  ("Aborting pending CCB %p\n", ccb_h));
1044 		cab.abort_ccb = (union ccb *)ccb_h;
1045 		xpt_action((union ccb *)&cab);
1046 		if (cab.ccb_h.status != CAM_REQ_CMP) {
1047 			xpt_print(cab.ccb_h.path,
1048 			    "Unable to abort CCB, status %#x\n",
1049 			    cab.ccb_h.status);
1050 		}
1051 	}
1052 
1053 	/* If we aborted at least one pending CCB ok, wait for it. */
1054 	if (cab.ccb_h.status == CAM_REQ_CMP) {
1055 		sim = xpt_path_sim(softc->path);
1056 		msleep(&softc->pending_ccb_queue, sim->mtx,
1057 		       PRIBIO | PCATCH, "tgabrt", 0);
1058 	}
1059 
1060 	/* If we aborted anything from the work queue, wakeup user. */
1061 	if (!TAILQ_EMPTY(&softc->user_ccb_queue)
1062 	 || !TAILQ_EMPTY(&softc->abort_queue)) {
1063 		cam_periph_unlock(softc->periph);
1064 		notify_user(softc);
1065 		cam_periph_lock(softc->periph);
1066 	}
1067 }
1068 
1069 /* Notify the user that data is ready */
1070 static void
1071 notify_user(struct targ_softc *softc)
1072 {
1073 	/*
1074 	 * Notify users sleeping via poll(), kqueue(), and
1075 	 * blocking read().
1076 	 */
1077 	selwakeuppri(&softc->read_select, PRIBIO);
1078 	KNOTE_UNLOCKED(&softc->read_select.si_note, 0);
1079 	wakeup(&softc->user_ccb_queue);
1080 }
1081 
1082 /* Convert CAM status to errno values */
1083 static int
1084 targcamstatus(cam_status status)
1085 {
1086 	switch (status & CAM_STATUS_MASK) {
1087 	case CAM_REQ_CMP:	/* CCB request completed without error */
1088 		return (0);
1089 	case CAM_REQ_INPROG:	/* CCB request is in progress */
1090 		return (EINPROGRESS);
1091 	case CAM_REQ_CMP_ERR:	/* CCB request completed with an error */
1092 		return (EIO);
1093 	case CAM_PROVIDE_FAIL:	/* Unable to provide requested capability */
1094 		return (ENOTTY);
1095 	case CAM_FUNC_NOTAVAIL:	/* The requested function is not available */
1096 		return (ENOTSUP);
1097 	case CAM_LUN_ALRDY_ENA:	/* LUN is already enabled for target mode */
1098 		return (EADDRINUSE);
1099 	case CAM_PATH_INVALID:	/* Supplied Path ID is invalid */
1100 	case CAM_DEV_NOT_THERE:	/* SCSI Device Not Installed/there */
1101 		return (ENOENT);
1102 	case CAM_REQ_ABORTED:	/* CCB request aborted by the host */
1103 		return (ECANCELED);
1104 	case CAM_CMD_TIMEOUT:	/* Command timeout */
1105 		return (ETIMEDOUT);
1106 	case CAM_REQUEUE_REQ:	/* Requeue to preserve transaction ordering */
1107 		return (EAGAIN);
1108 	case CAM_REQ_INVALID:	/* CCB request was invalid */
1109 		return (EINVAL);
1110 	case CAM_RESRC_UNAVAIL:	/* Resource Unavailable */
1111 		return (ENOMEM);
1112 	case CAM_BUSY:		/* CAM subsystem is busy */
1113 	case CAM_UA_ABORT:	/* Unable to abort CCB request */
1114 		return (EBUSY);
1115 	default:
1116 		return (ENXIO);
1117 	}
1118 }
1119 
1120 static size_t
1121 targccblen(xpt_opcode func_code)
1122 {
1123 	int len;
1124 
1125 	/* Codes we expect to see as a target */
1126 	switch (func_code) {
1127 	case XPT_CONT_TARGET_IO:
1128 	case XPT_SCSI_IO:
1129 		len = sizeof(struct ccb_scsiio);
1130 		break;
1131 	case XPT_ACCEPT_TARGET_IO:
1132 		len = sizeof(struct ccb_accept_tio);
1133 		break;
1134 	case XPT_IMMED_NOTIFY:
1135 		len = sizeof(struct ccb_immed_notify);
1136 		break;
1137 	case XPT_IMMEDIATE_NOTIFY:
1138 		len = sizeof(struct ccb_immediate_notify);
1139 		break;
1140 	case XPT_REL_SIMQ:
1141 		len = sizeof(struct ccb_relsim);
1142 		break;
1143 	case XPT_PATH_INQ:
1144 		len = sizeof(struct ccb_pathinq);
1145 		break;
1146 	case XPT_DEBUG:
1147 		len = sizeof(struct ccb_debug);
1148 		break;
1149 	case XPT_ABORT:
1150 		len = sizeof(struct ccb_abort);
1151 		break;
1152 	case XPT_EN_LUN:
1153 		len = sizeof(struct ccb_en_lun);
1154 		break;
1155 	default:
1156 		len = sizeof(union ccb);
1157 		break;
1158 	}
1159 
1160 	return (len);
1161 }
1162