xref: /freebsd/sys/cam/scsi/scsi_target.c (revision 031beb4e239bfce798af17f5fe8dba8bcaf13d99)
1 /*-
2  * Generic SCSI Target Kernel Mode Driver
3  *
4  * SPDX-License-Identifier: BSD-2-Clause
5  *
6  * Copyright (c) 2002 Nate Lawson.
7  * Copyright (c) 1998, 1999, 2001, 2002 Justin T. Gibbs.
8  * All rights reserved.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions, and the following disclaimer,
15  *    without modification, immediately at the beginning of the file.
16  * 2. The name of the author may not be used to endorse or promote products
17  *    derived from this software without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
23  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/kernel.h>
36 #include <sys/conf.h>
37 #include <sys/malloc.h>
38 #include <sys/poll.h>
39 #include <sys/vnode.h>
40 #include <sys/lock.h>
41 #include <sys/mutex.h>
42 #include <sys/devicestat.h>
43 #include <sys/proc.h>
44 /* Includes to support callout */
45 #include <sys/types.h>
46 #include <sys/systm.h>
47 
48 #include <cam/cam.h>
49 #include <cam/cam_ccb.h>
50 #include <cam/cam_periph.h>
51 #include <cam/cam_xpt_periph.h>
52 #include <cam/cam_sim.h>
53 #include <cam/scsi/scsi_targetio.h>
54 
55 /* Transaction information attached to each CCB sent by the user */
56 struct targ_cmd_descr {
57 	struct cam_periph_map_info  mapinfo;
58 	TAILQ_ENTRY(targ_cmd_descr) tqe;
59 	union ccb *user_ccb;
60 	int	   priority;
61 	int	   func_code;
62 };
63 
64 /* Offset into the private CCB area for storing our descriptor */
65 #define targ_descr	periph_priv.entries[1].ptr
66 
67 TAILQ_HEAD(descr_queue, targ_cmd_descr);
68 
69 typedef enum {
70 	TARG_STATE_RESV		= 0x00, /* Invalid state */
71 	TARG_STATE_OPENED	= 0x01, /* Device opened, softc initialized */
72 	TARG_STATE_LUN_ENABLED	= 0x02  /* Device enabled for a path */
73 } targ_state;
74 
75 /* Per-instance device software context */
76 struct targ_softc {
77 	/* CCBs (CTIOs, ATIOs, INOTs) pending on the controller */
78 	struct ccb_queue	 pending_ccb_queue;
79 
80 	/* Command descriptors awaiting CTIO resources from the XPT */
81 	struct descr_queue	 work_queue;
82 
83 	/* Command descriptors that have been aborted back to the user. */
84 	struct descr_queue	 abort_queue;
85 
86 	/*
87 	 * Queue of CCBs that have been copied out to userland, but our
88 	 * userland daemon has not yet seen.
89 	 */
90 	struct ccb_queue	 user_ccb_queue;
91 
92 	struct cam_periph	*periph;
93 	struct cam_path		*path;
94 	targ_state		 state;
95 	u_int			 maxio;
96 	struct selinfo		 read_select;
97 	struct devstat		 device_stats;
98 };
99 
100 static d_open_t		targopen;
101 static d_read_t		targread;
102 static d_write_t	targwrite;
103 static d_ioctl_t	targioctl;
104 static d_poll_t		targpoll;
105 static d_kqfilter_t	targkqfilter;
106 static void		targreadfiltdetach(struct knote *kn);
107 static int		targreadfilt(struct knote *kn, long hint);
108 static struct filterops targread_filtops = {
109 	.f_isfd = 1,
110 	.f_detach = targreadfiltdetach,
111 	.f_event = targreadfilt,
112 };
113 
114 static struct cdevsw targ_cdevsw = {
115 	.d_version =	D_VERSION,
116 	.d_open =	targopen,
117 	.d_read =	targread,
118 	.d_write =	targwrite,
119 	.d_ioctl =	targioctl,
120 	.d_poll =	targpoll,
121 	.d_name =	"targ",
122 	.d_kqfilter =	targkqfilter
123 };
124 
125 static cam_status	targendislun(struct cam_path *path, int enable,
126 				     int grp6_len, int grp7_len);
127 static cam_status	targenable(struct targ_softc *softc,
128 				   struct cam_path *path,
129 				   int grp6_len, int grp7_len);
130 static cam_status	targdisable(struct targ_softc *softc);
131 static periph_ctor_t    targctor;
132 static periph_dtor_t    targdtor;
133 static periph_start_t   targstart;
134 static int		targusermerge(struct targ_softc *softc,
135 				      struct targ_cmd_descr *descr,
136 				      union ccb *ccb);
137 static int		targsendccb(struct targ_softc *softc, union ccb *ccb,
138 				    struct targ_cmd_descr *descr);
139 static void		targdone(struct cam_periph *periph,
140 				 union  ccb *done_ccb);
141 static int		targreturnccb(struct targ_softc *softc,
142 				      union  ccb *ccb);
143 static union ccb *	targgetccb(struct targ_softc *softc, xpt_opcode type,
144 				   int priority);
145 static void		targfreeccb(struct targ_softc *softc, union ccb *ccb);
146 static struct targ_cmd_descr *
147 			targgetdescr(struct targ_softc *softc);
148 static periph_init_t	targinit;
149 static void		targasync(void *callback_arg, uint32_t code,
150 				  struct cam_path *path, void *arg);
151 static void		abort_all_pending(struct targ_softc *softc);
152 static void		notify_user(struct targ_softc *softc);
153 static int		targcamstatus(cam_status status);
154 static size_t		targccblen(xpt_opcode func_code);
155 
156 static struct periph_driver targdriver =
157 {
158 	targinit, "targ",
159 	TAILQ_HEAD_INITIALIZER(targdriver.units), /* generation */ 0
160 };
161 PERIPHDRIVER_DECLARE(targ, targdriver);
162 
163 static MALLOC_DEFINE(M_TARG, "TARG", "TARG data");
164 
165 /* Disable LUN if enabled and teardown softc */
166 static void
167 targcdevdtor(void *data)
168 {
169 	struct targ_softc *softc;
170 	struct cam_periph *periph;
171 
172 	softc = data;
173 	if (softc->periph == NULL) {
174 		printf("%s: destroying non-enabled target\n", __func__);
175 		free(softc, M_TARG);
176 		return;
177 	}
178 
179 	/*
180 	 * Acquire a hold on the periph so that it doesn't go away before
181 	 * we are ready at the end of the function.
182 	 */
183 	periph = softc->periph;
184 	cam_periph_acquire(periph);
185 	cam_periph_lock(periph);
186 	(void)targdisable(softc);
187 	if (softc->periph != NULL) {
188 		cam_periph_invalidate(softc->periph);
189 		softc->periph = NULL;
190 	}
191 	cam_periph_unlock(periph);
192 	cam_periph_release(periph);
193 	free(softc, M_TARG);
194 }
195 
196 /*
197  * Create softc and initialize it.  There is no locking here because a
198  * periph doesn't get created until an ioctl is issued to do so, and
199  * that can't happen until this method returns.
200  */
201 static int
202 targopen(struct cdev *dev, int flags, int fmt, struct thread *td)
203 {
204 	struct targ_softc *softc;
205 
206 	/* Allocate its softc, initialize it */
207 	softc = malloc(sizeof(*softc), M_TARG,
208 	       M_WAITOK | M_ZERO);
209 	softc->state = TARG_STATE_OPENED;
210 	softc->periph = NULL;
211 	softc->path = NULL;
212 
213 	TAILQ_INIT(&softc->pending_ccb_queue);
214 	TAILQ_INIT(&softc->work_queue);
215 	TAILQ_INIT(&softc->abort_queue);
216 	TAILQ_INIT(&softc->user_ccb_queue);
217 	knlist_init_mtx(&softc->read_select.si_note, NULL);
218 
219 	devfs_set_cdevpriv(softc, targcdevdtor);
220 	return (0);
221 }
222 
223 /* Enable/disable LUNs, set debugging level */
224 static int
225 targioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flag, struct thread *td)
226 {
227 	struct targ_softc *softc;
228 	cam_status	   status;
229 
230 	devfs_get_cdevpriv((void **)&softc);
231 
232 	switch (cmd) {
233 	case TARGIOCENABLE:
234 	{
235 		struct ioc_enable_lun	*new_lun;
236 		struct cam_path		*path;
237 
238 		new_lun = (struct ioc_enable_lun *)addr;
239 		status = xpt_create_path(&path, /*periph*/NULL,
240 					  new_lun->path_id,
241 					  new_lun->target_id,
242 					  new_lun->lun_id);
243 		if (status != CAM_REQ_CMP) {
244 			printf("Couldn't create path, status %#x\n", status);
245 			break;
246 		}
247 		xpt_path_lock(path);
248 		status = targenable(softc, path, new_lun->grp6_len,
249 				    new_lun->grp7_len);
250 		xpt_path_unlock(path);
251 		xpt_free_path(path);
252 		break;
253 	}
254 	case TARGIOCDISABLE:
255 		if (softc->periph == NULL) {
256 			status = CAM_DEV_NOT_THERE;
257 			break;
258 		}
259 		cam_periph_lock(softc->periph);
260 		status = targdisable(softc);
261 		cam_periph_unlock(softc->periph);
262 		break;
263 	case TARGIOCDEBUG:
264 	{
265 		struct ccb_debug cdbg;
266 
267 		/* If no periph available, disallow debugging changes */
268 		if ((softc->state & TARG_STATE_LUN_ENABLED) == 0) {
269 			status = CAM_DEV_NOT_THERE;
270 			break;
271 		}
272 		bzero(&cdbg, sizeof cdbg);
273 		if (*((int *)addr) != 0)
274 			cdbg.flags = CAM_DEBUG_PERIPH;
275 		else
276 			cdbg.flags = CAM_DEBUG_NONE;
277 		xpt_setup_ccb(&cdbg.ccb_h, softc->path, CAM_PRIORITY_NORMAL);
278 		cdbg.ccb_h.func_code = XPT_DEBUG;
279 		cdbg.ccb_h.cbfcnp = targdone;
280 		xpt_action((union ccb *)&cdbg);
281 		status = cdbg.ccb_h.status & CAM_STATUS_MASK;
282 		break;
283 	}
284 	default:
285 		status = CAM_PROVIDE_FAIL;
286 		break;
287 	}
288 
289 	return (targcamstatus(status));
290 }
291 
292 /* Writes are always ready, reads wait for user_ccb_queue or abort_queue */
293 static int
294 targpoll(struct cdev *dev, int poll_events, struct thread *td)
295 {
296 	struct targ_softc *softc;
297 	int	revents;
298 
299 	devfs_get_cdevpriv((void **)&softc);
300 
301 	/* Poll for write() is always ok. */
302 	revents = poll_events & (POLLOUT | POLLWRNORM);
303 	if ((poll_events & (POLLIN | POLLRDNORM)) != 0) {
304 		/* Poll for read() depends on user and abort queues. */
305 		cam_periph_lock(softc->periph);
306 		if (!TAILQ_EMPTY(&softc->user_ccb_queue) ||
307 		    !TAILQ_EMPTY(&softc->abort_queue)) {
308 			revents |= poll_events & (POLLIN | POLLRDNORM);
309 		}
310 		cam_periph_unlock(softc->periph);
311 		/* Only sleep if the user didn't poll for write. */
312 		if (revents == 0)
313 			selrecord(td, &softc->read_select);
314 	}
315 
316 	return (revents);
317 }
318 
319 static int
320 targkqfilter(struct cdev *dev, struct knote *kn)
321 {
322 	struct  targ_softc *softc;
323 
324 	devfs_get_cdevpriv((void **)&softc);
325 	kn->kn_hook = (caddr_t)softc;
326 	kn->kn_fop = &targread_filtops;
327 	knlist_add(&softc->read_select.si_note, kn, 0);
328 	return (0);
329 }
330 
331 static void
332 targreadfiltdetach(struct knote *kn)
333 {
334 	struct  targ_softc *softc;
335 
336 	softc = (struct targ_softc *)kn->kn_hook;
337 	knlist_remove(&softc->read_select.si_note, kn, 0);
338 }
339 
340 /* Notify the user's kqueue when the user queue or abort queue gets a CCB */
341 static int
342 targreadfilt(struct knote *kn, long hint)
343 {
344 	struct targ_softc *softc;
345 	int	retval;
346 
347 	softc = (struct targ_softc *)kn->kn_hook;
348 	cam_periph_lock(softc->periph);
349 	retval = !TAILQ_EMPTY(&softc->user_ccb_queue) ||
350 		 !TAILQ_EMPTY(&softc->abort_queue);
351 	cam_periph_unlock(softc->periph);
352 	return (retval);
353 }
354 
355 /* Send the HBA the enable/disable message */
356 static cam_status
357 targendislun(struct cam_path *path, int enable, int grp6_len, int grp7_len)
358 {
359 	struct ccb_en_lun en_ccb;
360 	cam_status	  status;
361 
362 	/* Tell the lun to begin answering selects */
363 	memset(&en_ccb, 0, sizeof(en_ccb));
364 	xpt_setup_ccb(&en_ccb.ccb_h, path, CAM_PRIORITY_NORMAL);
365 	en_ccb.ccb_h.func_code = XPT_EN_LUN;
366 	/* Don't need support for any vendor specific commands */
367 	en_ccb.grp6_len = grp6_len;
368 	en_ccb.grp7_len = grp7_len;
369 	en_ccb.enable = enable ? 1 : 0;
370 	xpt_action((union ccb *)&en_ccb);
371 	status = en_ccb.ccb_h.status & CAM_STATUS_MASK;
372 	if (status != CAM_REQ_CMP) {
373 		xpt_print(path, "%sable lun CCB rejected, status %#x\n",
374 		    enable ? "en" : "dis", status);
375 	}
376 	return (status);
377 }
378 
379 /* Enable target mode on a LUN, given its path */
380 static cam_status
381 targenable(struct targ_softc *softc, struct cam_path *path, int grp6_len,
382 	   int grp7_len)
383 {
384 	struct cam_periph *periph;
385 	struct ccb_pathinq cpi;
386 	cam_status	   status;
387 
388 	if ((softc->state & TARG_STATE_LUN_ENABLED) != 0)
389 		return (CAM_LUN_ALRDY_ENA);
390 
391 	/* Make sure SIM supports target mode */
392 	xpt_path_inq(&cpi, path);
393 	status = cpi.ccb_h.status & CAM_STATUS_MASK;
394 	if (status != CAM_REQ_CMP) {
395 		printf("pathinq failed, status %#x\n", status);
396 		goto enable_fail;
397 	}
398 	if ((cpi.target_sprt & PIT_PROCESSOR) == 0) {
399 		printf("controller does not support target mode\n");
400 		status = CAM_FUNC_NOTAVAIL;
401 		goto enable_fail;
402 	}
403 	if (cpi.maxio == 0)
404 		softc->maxio = DFLTPHYS;	/* traditional default */
405 	else if (cpi.maxio > maxphys)
406 		softc->maxio = maxphys;		/* for safety */
407 	else
408 		softc->maxio = cpi.maxio;	/* real value */
409 
410 	/* Destroy any periph on our path if it is disabled */
411 	periph = cam_periph_find(path, "targ");
412 	if (periph != NULL) {
413 		struct targ_softc *del_softc;
414 
415 		del_softc = (struct targ_softc *)periph->softc;
416 		if ((del_softc->state & TARG_STATE_LUN_ENABLED) == 0) {
417 			cam_periph_invalidate(del_softc->periph);
418 			del_softc->periph = NULL;
419 		} else {
420 			printf("Requested path still in use by targ%d\n",
421 			       periph->unit_number);
422 			status = CAM_LUN_ALRDY_ENA;
423 			goto enable_fail;
424 		}
425 	}
426 
427 	/* Create a periph instance attached to this path */
428 	status = cam_periph_alloc(targctor, NULL, targdtor, targstart,
429 			"targ", CAM_PERIPH_BIO, path, targasync, 0, softc);
430 	if (status != CAM_REQ_CMP) {
431 		printf("cam_periph_alloc failed, status %#x\n", status);
432 		goto enable_fail;
433 	}
434 
435 	/* Ensure that the periph now exists. */
436 	if (cam_periph_find(path, "targ") == NULL) {
437 		panic("targenable: succeeded but no periph?");
438 		/* NOTREACHED */
439 	}
440 
441 	/* Send the enable lun message */
442 	status = targendislun(path, /*enable*/1, grp6_len, grp7_len);
443 	if (status != CAM_REQ_CMP) {
444 		printf("enable lun failed, status %#x\n", status);
445 		goto enable_fail;
446 	}
447 	softc->state |= TARG_STATE_LUN_ENABLED;
448 
449 enable_fail:
450 	return (status);
451 }
452 
453 /* Disable this softc's target instance if enabled */
454 static cam_status
455 targdisable(struct targ_softc *softc)
456 {
457 	cam_status status;
458 
459 	if ((softc->state & TARG_STATE_LUN_ENABLED) == 0)
460 		return (CAM_REQ_CMP);
461 
462 	CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("targdisable\n"));
463 
464 	/* Abort any ccbs pending on the controller */
465 	abort_all_pending(softc);
466 
467 	/* Disable this lun */
468 	status = targendislun(softc->path, /*enable*/0,
469 			      /*grp6_len*/0, /*grp7_len*/0);
470 	if (status == CAM_REQ_CMP)
471 		softc->state &= ~TARG_STATE_LUN_ENABLED;
472 	else
473 		printf("Disable lun failed, status %#x\n", status);
474 
475 	return (status);
476 }
477 
478 /* Initialize a periph (called from cam_periph_alloc) */
479 static cam_status
480 targctor(struct cam_periph *periph, void *arg)
481 {
482 	struct targ_softc *softc;
483 
484 	/* Store pointer to softc for periph-driven routines */
485 	softc = (struct targ_softc *)arg;
486 	periph->softc = softc;
487 	softc->periph = periph;
488 	softc->path = periph->path;
489 	return (CAM_REQ_CMP);
490 }
491 
492 static void
493 targdtor(struct cam_periph *periph)
494 {
495 	struct targ_softc     *softc;
496 	struct ccb_hdr	      *ccb_h;
497 	struct targ_cmd_descr *descr;
498 
499 	softc = (struct targ_softc *)periph->softc;
500 
501 	/*
502 	 * targdisable() aborts CCBs back to the user and leaves them
503 	 * on user_ccb_queue and abort_queue in case the user is still
504 	 * interested in them.  We free them now.
505 	 */
506 	while ((ccb_h = TAILQ_FIRST(&softc->user_ccb_queue)) != NULL) {
507 		TAILQ_REMOVE(&softc->user_ccb_queue, ccb_h, periph_links.tqe);
508 		targfreeccb(softc, (union ccb *)ccb_h);
509 	}
510 	while ((descr = TAILQ_FIRST(&softc->abort_queue)) != NULL) {
511 		TAILQ_REMOVE(&softc->abort_queue, descr, tqe);
512 		free(descr, M_TARG);
513 	}
514 
515 	softc->periph = NULL;
516 	softc->path = NULL;
517 	periph->softc = NULL;
518 }
519 
520 /* Receive CCBs from user mode proc and send them to the HBA */
521 static int
522 targwrite(struct cdev *dev, struct uio *uio, int ioflag)
523 {
524 	union ccb *user_ccb;
525 	struct targ_softc *softc;
526 	struct targ_cmd_descr *descr;
527 	int write_len, error;
528 	int func_code, priority;
529 
530 	devfs_get_cdevpriv((void **)&softc);
531 	write_len = error = 0;
532 	CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
533 		  ("write - uio_resid %zd\n", uio->uio_resid));
534 	while (uio->uio_resid >= sizeof(user_ccb) && error == 0) {
535 		union ccb *ccb;
536 
537 		error = uiomove((caddr_t)&user_ccb, sizeof(user_ccb), uio);
538 		if (error != 0) {
539 			CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
540 				  ("write - uiomove failed (%d)\n", error));
541 			break;
542 		}
543 		priority = fuword32(&user_ccb->ccb_h.pinfo.priority);
544 		if (priority == CAM_PRIORITY_NONE) {
545 			error = EINVAL;
546 			break;
547 		}
548 		func_code = fuword32(&user_ccb->ccb_h.func_code);
549 		switch (func_code) {
550 		case XPT_ACCEPT_TARGET_IO:
551 		case XPT_IMMED_NOTIFY:
552 		case XPT_IMMEDIATE_NOTIFY:
553 			cam_periph_lock(softc->periph);
554 			ccb = targgetccb(softc, func_code, priority);
555 			descr = (struct targ_cmd_descr *)ccb->ccb_h.targ_descr;
556 			descr->user_ccb = user_ccb;
557 			descr->func_code = func_code;
558 			CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
559 				  ("Sent ATIO/INOT (%p)\n", user_ccb));
560 			xpt_action(ccb);
561 			TAILQ_INSERT_TAIL(&softc->pending_ccb_queue,
562 					  &ccb->ccb_h,
563 					  periph_links.tqe);
564 			cam_periph_unlock(softc->periph);
565 			break;
566 		default:
567 			cam_periph_lock(softc->periph);
568 			if ((func_code & XPT_FC_QUEUED) != 0) {
569 				CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
570 					  ("Sending queued ccb %#x (%p)\n",
571 					  func_code, user_ccb));
572 				descr = targgetdescr(softc);
573 				descr->user_ccb = user_ccb;
574 				descr->priority = priority;
575 				descr->func_code = func_code;
576 				TAILQ_INSERT_TAIL(&softc->work_queue,
577 						  descr, tqe);
578 				xpt_schedule(softc->periph, priority);
579 			} else {
580 				CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
581 					  ("Sending inline ccb %#x (%p)\n",
582 					  func_code, user_ccb));
583 				ccb = targgetccb(softc, func_code, priority);
584 				descr = (struct targ_cmd_descr *)
585 					 ccb->ccb_h.targ_descr;
586 				descr->user_ccb = user_ccb;
587 				descr->priority = priority;
588 				descr->func_code = func_code;
589 				if (targusermerge(softc, descr, ccb) != EFAULT)
590 					targsendccb(softc, ccb, descr);
591 				targreturnccb(softc, ccb);
592 			}
593 			cam_periph_unlock(softc->periph);
594 			break;
595 		}
596 		write_len += sizeof(user_ccb);
597 	}
598 
599 	/*
600 	 * If we've successfully taken in some amount of
601 	 * data, return success for that data first.  If
602 	 * an error is persistent, it will be reported
603 	 * on the next write.
604 	 */
605 	if (error != 0 && write_len == 0)
606 		return (error);
607 	if (write_len == 0 && uio->uio_resid != 0)
608 		return (ENOSPC);
609 	return (0);
610 }
611 
612 /* Process requests (descrs) via the periph-supplied CCBs */
613 static void
614 targstart(struct cam_periph *periph, union ccb *start_ccb)
615 {
616 	struct targ_softc *softc;
617 	struct targ_cmd_descr *descr, *next_descr;
618 	int error;
619 
620 	softc = (struct targ_softc *)periph->softc;
621 	CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("targstart %p\n", start_ccb));
622 
623 	descr = TAILQ_FIRST(&softc->work_queue);
624 	if (descr == NULL) {
625 		xpt_release_ccb(start_ccb);
626 	} else {
627 		TAILQ_REMOVE(&softc->work_queue, descr, tqe);
628 		next_descr = TAILQ_FIRST(&softc->work_queue);
629 
630 		/* Initiate a transaction using the descr and supplied CCB */
631 		error = targusermerge(softc, descr, start_ccb);
632 		if (error == 0)
633 			error = targsendccb(softc, start_ccb, descr);
634 		if (error != 0) {
635 			xpt_print(periph->path,
636 			    "targsendccb failed, err %d\n", error);
637 			xpt_release_ccb(start_ccb);
638 			suword(&descr->user_ccb->ccb_h.status,
639 			       CAM_REQ_CMP_ERR);
640 			TAILQ_INSERT_TAIL(&softc->abort_queue, descr, tqe);
641 			notify_user(softc);
642 		}
643 
644 		/* If we have more work to do, stay scheduled */
645 		if (next_descr != NULL)
646 			xpt_schedule(periph, next_descr->priority);
647 	}
648 }
649 
650 static int
651 targusermerge(struct targ_softc *softc, struct targ_cmd_descr *descr,
652 	      union ccb *ccb)
653 {
654 	struct ccb_hdr *u_ccbh, *k_ccbh;
655 	size_t ccb_len;
656 	int error;
657 
658 	u_ccbh = &descr->user_ccb->ccb_h;
659 	k_ccbh = &ccb->ccb_h;
660 
661 	/*
662 	 * There are some fields in the CCB header that need to be
663 	 * preserved, the rest we get from the user ccb. (See xpt_merge_ccb)
664 	 */
665 	xpt_setup_ccb(k_ccbh, softc->path, descr->priority);
666 	k_ccbh->retry_count = fuword32(&u_ccbh->retry_count);
667 	k_ccbh->func_code = descr->func_code;
668 	k_ccbh->flags = fuword32(&u_ccbh->flags);
669 	k_ccbh->timeout = fuword32(&u_ccbh->timeout);
670 	ccb_len = targccblen(k_ccbh->func_code) - sizeof(struct ccb_hdr);
671 	error = copyin(u_ccbh + 1, k_ccbh + 1, ccb_len);
672 	if (error != 0) {
673 		k_ccbh->status = CAM_REQ_CMP_ERR;
674 		return (error);
675 	}
676 
677 	/* Translate usermode abort_ccb pointer to its kernel counterpart */
678 	if (k_ccbh->func_code == XPT_ABORT) {
679 		struct ccb_abort *cab;
680 		struct ccb_hdr *ccb_h;
681 
682 		cab = (struct ccb_abort *)ccb;
683 		TAILQ_FOREACH(ccb_h, &softc->pending_ccb_queue,
684 		    periph_links.tqe) {
685 			struct targ_cmd_descr *ab_descr;
686 
687 			ab_descr = (struct targ_cmd_descr *)ccb_h->targ_descr;
688 			if (ab_descr->user_ccb == cab->abort_ccb) {
689 				CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
690 					  ("Changing abort for %p to %p\n",
691 					  cab->abort_ccb, ccb_h));
692 				cab->abort_ccb = (union ccb *)ccb_h;
693 				break;
694 			}
695 		}
696 		/* CCB not found, set appropriate status */
697 		if (ccb_h == NULL) {
698 			k_ccbh->status = CAM_PATH_INVALID;
699 			error = ESRCH;
700 		}
701 	}
702 
703 	return (error);
704 }
705 
706 /* Build and send a kernel CCB formed from descr->user_ccb */
707 static int
708 targsendccb(struct targ_softc *softc, union ccb *ccb,
709 	    struct targ_cmd_descr *descr)
710 {
711 	struct cam_periph_map_info *mapinfo;
712 	struct ccb_hdr *ccb_h;
713 	int error;
714 
715 	ccb_h = &ccb->ccb_h;
716 	mapinfo = &descr->mapinfo;
717 	mapinfo->num_bufs_used = 0;
718 
719 	/*
720 	 * There's no way for the user to have a completion
721 	 * function, so we put our own completion function in here.
722 	 * We also stash in a reference to our descriptor so targreturnccb()
723 	 * can find our mapping info.
724 	 */
725 	ccb_h->cbfcnp = targdone;
726 	ccb_h->targ_descr = descr;
727 
728 	if ((ccb_h->func_code == XPT_CONT_TARGET_IO) ||
729 	    (ccb_h->func_code == XPT_DEV_MATCH)) {
730 		error = cam_periph_mapmem(ccb, mapinfo, softc->maxio);
731 
732 		/*
733 		 * cam_periph_mapmem returned an error, we can't continue.
734 		 * Return the error to the user.
735 		 */
736 		if (error) {
737 			ccb_h->status = CAM_REQ_CMP_ERR;
738 			mapinfo->num_bufs_used = 0;
739 			return (error);
740 		}
741 	}
742 
743 	/*
744 	 * Once queued on the pending CCB list, this CCB will be protected
745 	 * by our error recovery handler.
746 	 */
747 	CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("sendccb %p\n", ccb));
748 	if (XPT_FC_IS_QUEUED(ccb)) {
749 		TAILQ_INSERT_TAIL(&softc->pending_ccb_queue, ccb_h,
750 				  periph_links.tqe);
751 	}
752 	xpt_action(ccb);
753 
754 	return (0);
755 }
756 
757 /* Completion routine for CCBs (called at splsoftcam) */
758 static void
759 targdone(struct cam_periph *periph, union ccb *done_ccb)
760 {
761 	struct targ_softc *softc;
762 
763 	CAM_DEBUG(periph->path, CAM_DEBUG_PERIPH, ("targdone %p\n", done_ccb));
764 	softc = (struct targ_softc *)periph->softc;
765 	TAILQ_REMOVE(&softc->pending_ccb_queue, &done_ccb->ccb_h,
766 		     periph_links.tqe);
767 
768 	/* If we're no longer enabled, throw away CCB */
769 	if ((softc->state & TARG_STATE_LUN_ENABLED) == 0) {
770 		targfreeccb(softc, done_ccb);
771 		return;
772 	}
773 	/* abort_all_pending() waits for pending queue to be empty */
774 	if (TAILQ_EMPTY(&softc->pending_ccb_queue))
775 		wakeup(&softc->pending_ccb_queue);
776 
777 	switch (done_ccb->ccb_h.func_code) {
778 	/* All FC_*_QUEUED CCBs go back to userland */
779 	case XPT_IMMED_NOTIFY:
780 	case XPT_IMMEDIATE_NOTIFY:
781 	case XPT_ACCEPT_TARGET_IO:
782 	case XPT_CONT_TARGET_IO:
783 		TAILQ_INSERT_TAIL(&softc->user_ccb_queue, &done_ccb->ccb_h,
784 				  periph_links.tqe);
785  		cam_periph_unlock(softc->periph);
786 		notify_user(softc);
787  		cam_periph_lock(softc->periph);
788 		break;
789 	default:
790 		panic("targdone: impossible xpt opcode %#x",
791 		      done_ccb->ccb_h.func_code);
792 		/* NOTREACHED */
793 	}
794 }
795 
796 /* Return CCBs to the user from the user queue and abort queue */
797 static int
798 targread(struct cdev *dev, struct uio *uio, int ioflag)
799 {
800 	struct descr_queue	*abort_queue;
801 	struct targ_cmd_descr	*user_descr;
802 	struct targ_softc	*softc;
803 	struct ccb_queue  *user_queue;
804 	struct ccb_hdr	  *ccb_h;
805 	union  ccb	  *user_ccb;
806 	int		   read_len, error;
807 
808 	error = 0;
809 	read_len = 0;
810 	devfs_get_cdevpriv((void **)&softc);
811 	user_queue = &softc->user_ccb_queue;
812 	abort_queue = &softc->abort_queue;
813 	CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("targread\n"));
814 
815 	/* If no data is available, wait or return immediately */
816 	cam_periph_lock(softc->periph);
817 	ccb_h = TAILQ_FIRST(user_queue);
818 	user_descr = TAILQ_FIRST(abort_queue);
819 	while (ccb_h == NULL && user_descr == NULL) {
820 		if ((ioflag & IO_NDELAY) == 0) {
821 			error = cam_periph_sleep(softc->periph, user_queue,
822 			    PRIBIO | PCATCH, "targrd", 0);
823 			ccb_h = TAILQ_FIRST(user_queue);
824 			user_descr = TAILQ_FIRST(abort_queue);
825 			if (error != 0) {
826 				if (error == ERESTART) {
827 					continue;
828 				} else {
829 					goto read_fail;
830 				}
831 			}
832 		} else {
833 			cam_periph_unlock(softc->periph);
834 			return (EAGAIN);
835 		}
836 	}
837 
838 	/* Data is available so fill the user's buffer */
839 	while (ccb_h != NULL) {
840 		struct targ_cmd_descr *descr;
841 
842 		if (uio->uio_resid < sizeof(user_ccb))
843 			break;
844 		TAILQ_REMOVE(user_queue, ccb_h, periph_links.tqe);
845 		descr = (struct targ_cmd_descr *)ccb_h->targ_descr;
846 		user_ccb = descr->user_ccb;
847 		CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
848 			  ("targread ccb %p (%p)\n", ccb_h, user_ccb));
849 		error = targreturnccb(softc, (union ccb *)ccb_h);
850 		if (error != 0)
851 			goto read_fail;
852 		cam_periph_unlock(softc->periph);
853 		error = uiomove((caddr_t)&user_ccb, sizeof(user_ccb), uio);
854 		cam_periph_lock(softc->periph);
855 		if (error != 0)
856 			goto read_fail;
857 		read_len += sizeof(user_ccb);
858 
859 		ccb_h = TAILQ_FIRST(user_queue);
860 	}
861 
862 	/* Flush out any aborted descriptors */
863 	while (user_descr != NULL) {
864 		if (uio->uio_resid < sizeof(user_ccb))
865 			break;
866 		TAILQ_REMOVE(abort_queue, user_descr, tqe);
867 		user_ccb = user_descr->user_ccb;
868 		CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
869 			  ("targread aborted descr %p (%p)\n",
870 			  user_descr, user_ccb));
871 		suword(&user_ccb->ccb_h.status, CAM_REQ_ABORTED);
872 		cam_periph_unlock(softc->periph);
873 		error = uiomove((caddr_t)&user_ccb, sizeof(user_ccb), uio);
874 		cam_periph_lock(softc->periph);
875 		if (error != 0)
876 			goto read_fail;
877 		read_len += sizeof(user_ccb);
878 
879 		user_descr = TAILQ_FIRST(abort_queue);
880 	}
881 
882 	/*
883 	 * If we've successfully read some amount of data, don't report an
884 	 * error.  If the error is persistent, it will be reported on the
885 	 * next read().
886 	 */
887 	if (read_len == 0 && uio->uio_resid != 0)
888 		error = ENOSPC;
889 
890 read_fail:
891 	cam_periph_unlock(softc->periph);
892 	return (error);
893 }
894 
895 /* Copy completed ccb back to the user */
896 static int
897 targreturnccb(struct targ_softc *softc, union ccb *ccb)
898 {
899 	struct targ_cmd_descr *descr;
900 	struct ccb_hdr *u_ccbh;
901 	size_t ccb_len;
902 	int error;
903 
904 	CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("targreturnccb %p\n", ccb));
905 	descr = (struct targ_cmd_descr *)ccb->ccb_h.targ_descr;
906 	u_ccbh = &descr->user_ccb->ccb_h;
907 
908 	/* Copy out the central portion of the ccb_hdr */
909 	copyout(&ccb->ccb_h.retry_count, &u_ccbh->retry_count,
910 		offsetof(struct ccb_hdr, periph_priv) -
911 		offsetof(struct ccb_hdr, retry_count));
912 
913 	/* Copy out the rest of the ccb (after the ccb_hdr) */
914 	ccb_len = targccblen(ccb->ccb_h.func_code) - sizeof(struct ccb_hdr);
915 	if (descr->mapinfo.num_bufs_used != 0)
916 		cam_periph_unmapmem(ccb, &descr->mapinfo);
917 	error = copyout(&ccb->ccb_h + 1, u_ccbh + 1, ccb_len);
918 	if (error != 0) {
919 		xpt_print(softc->path,
920 		    "targreturnccb - CCB copyout failed (%d)\n", error);
921 	}
922 	/* Free CCB or send back to devq. */
923 	targfreeccb(softc, ccb);
924 
925 	return (error);
926 }
927 
928 static union ccb *
929 targgetccb(struct targ_softc *softc, xpt_opcode type, int priority)
930 {
931 	union ccb *ccb;
932 	int ccb_len;
933 
934 	ccb_len = targccblen(type);
935 	ccb = malloc(ccb_len, M_TARG, M_NOWAIT | M_ZERO);
936 	CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("getccb %p\n", ccb));
937 	if (ccb == NULL) {
938 		return (ccb);
939 	}
940 	xpt_setup_ccb(&ccb->ccb_h, softc->path, priority);
941 	ccb->ccb_h.func_code = type;
942 	ccb->ccb_h.cbfcnp = targdone;
943 	ccb->ccb_h.targ_descr = targgetdescr(softc);
944 	if (ccb->ccb_h.targ_descr == NULL) {
945 		free (ccb, M_TARG);
946 		ccb = NULL;
947 	}
948 	return (ccb);
949 }
950 
951 static void
952 targfreeccb(struct targ_softc *softc, union ccb *ccb)
953 {
954 	CAM_DEBUG_PRINT(CAM_DEBUG_PERIPH, ("targfreeccb descr %p and\n",
955 			ccb->ccb_h.targ_descr));
956 	free(ccb->ccb_h.targ_descr, M_TARG);
957 
958 	switch (ccb->ccb_h.func_code) {
959 	case XPT_ACCEPT_TARGET_IO:
960 	case XPT_IMMED_NOTIFY:
961 	case XPT_IMMEDIATE_NOTIFY:
962 		CAM_DEBUG_PRINT(CAM_DEBUG_PERIPH, ("freeing ccb %p\n", ccb));
963 		free(ccb, M_TARG);
964 		break;
965 	default:
966 		/* Send back CCB if we got it from the periph */
967 		if (XPT_FC_IS_QUEUED(ccb)) {
968 			CAM_DEBUG_PRINT(CAM_DEBUG_PERIPH,
969 					("returning queued ccb %p\n", ccb));
970 			xpt_release_ccb(ccb);
971 		} else {
972 			CAM_DEBUG_PRINT(CAM_DEBUG_PERIPH,
973 					("freeing ccb %p\n", ccb));
974 			free(ccb, M_TARG);
975 		}
976 		break;
977 	}
978 }
979 
980 static struct targ_cmd_descr *
981 targgetdescr(struct targ_softc *softc)
982 {
983 	struct targ_cmd_descr *descr;
984 
985 	descr = malloc(sizeof(*descr), M_TARG,
986 	       M_NOWAIT);
987 	if (descr) {
988 		descr->mapinfo.num_bufs_used = 0;
989 	}
990 	return (descr);
991 }
992 
993 static void
994 targinit(void)
995 {
996 	struct cdev *dev;
997 
998 	/* Add symbolic link to targ0 for compatibility. */
999 	dev = make_dev(&targ_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "targ");
1000 	make_dev_alias(dev, "targ0");
1001 }
1002 
1003 static void
1004 targasync(void *callback_arg, uint32_t code, struct cam_path *path, void *arg)
1005 {
1006 	/* All events are handled in usermode by INOTs */
1007 	panic("targasync() called, should be an INOT instead");
1008 }
1009 
1010 /* Cancel all pending requests and CCBs awaiting work. */
1011 static void
1012 abort_all_pending(struct targ_softc *softc)
1013 {
1014 	struct targ_cmd_descr   *descr;
1015 	struct ccb_abort	 cab;
1016 	struct ccb_hdr		*ccb_h;
1017 
1018 	CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("abort_all_pending\n"));
1019 
1020 	/* First abort the descriptors awaiting resources */
1021 	while ((descr = TAILQ_FIRST(&softc->work_queue)) != NULL) {
1022 		CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
1023 			  ("Aborting descr from workq %p\n", descr));
1024 		TAILQ_REMOVE(&softc->work_queue, descr, tqe);
1025 		TAILQ_INSERT_TAIL(&softc->abort_queue, descr, tqe);
1026 	}
1027 
1028 	/*
1029 	 * Then abort all pending CCBs.
1030 	 * targdone() will return the aborted CCB via user_ccb_queue
1031 	 */
1032 	memset(&cab, 0, sizeof(cab));
1033 	xpt_setup_ccb(&cab.ccb_h, softc->path, CAM_PRIORITY_NORMAL);
1034 	cab.ccb_h.func_code = XPT_ABORT;
1035 	cab.ccb_h.status = CAM_REQ_CMP_ERR;
1036 	TAILQ_FOREACH(ccb_h, &softc->pending_ccb_queue, periph_links.tqe) {
1037 		CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
1038 			  ("Aborting pending CCB %p\n", ccb_h));
1039 		cab.abort_ccb = (union ccb *)ccb_h;
1040 		xpt_action((union ccb *)&cab);
1041 		if (cab.ccb_h.status != CAM_REQ_CMP) {
1042 			xpt_print(cab.ccb_h.path,
1043 			    "Unable to abort CCB, status %#x\n",
1044 			    cab.ccb_h.status);
1045 		}
1046 	}
1047 
1048 	/* If we aborted at least one pending CCB ok, wait for it. */
1049 	if (cab.ccb_h.status == CAM_REQ_CMP) {
1050 		cam_periph_sleep(softc->periph, &softc->pending_ccb_queue,
1051 		       PRIBIO | PCATCH, "tgabrt", 0);
1052 	}
1053 
1054 	/* If we aborted anything from the work queue, wakeup user. */
1055 	if (!TAILQ_EMPTY(&softc->user_ccb_queue)
1056 	 || !TAILQ_EMPTY(&softc->abort_queue)) {
1057 		cam_periph_unlock(softc->periph);
1058 		notify_user(softc);
1059 		cam_periph_lock(softc->periph);
1060 	}
1061 }
1062 
1063 /* Notify the user that data is ready */
1064 static void
1065 notify_user(struct targ_softc *softc)
1066 {
1067 	/*
1068 	 * Notify users sleeping via poll(), kqueue(), and
1069 	 * blocking read().
1070 	 */
1071 	selwakeuppri(&softc->read_select, PRIBIO);
1072 	KNOTE_UNLOCKED(&softc->read_select.si_note, 0);
1073 	wakeup(&softc->user_ccb_queue);
1074 }
1075 
1076 /* Convert CAM status to errno values */
1077 static int
1078 targcamstatus(cam_status status)
1079 {
1080 	switch (status & CAM_STATUS_MASK) {
1081 	case CAM_REQ_CMP:	/* CCB request completed without error */
1082 		return (0);
1083 	case CAM_REQ_INPROG:	/* CCB request is in progress */
1084 		return (EINPROGRESS);
1085 	case CAM_REQ_CMP_ERR:	/* CCB request completed with an error */
1086 		return (EIO);
1087 	case CAM_PROVIDE_FAIL:	/* Unable to provide requested capability */
1088 		return (ENOTTY);
1089 	case CAM_FUNC_NOTAVAIL:	/* The requested function is not available */
1090 		return (ENOTSUP);
1091 	case CAM_LUN_ALRDY_ENA:	/* LUN is already enabled for target mode */
1092 		return (EADDRINUSE);
1093 	case CAM_PATH_INVALID:	/* Supplied Path ID is invalid */
1094 	case CAM_DEV_NOT_THERE:	/* SCSI Device Not Installed/there */
1095 		return (ENOENT);
1096 	case CAM_REQ_ABORTED:	/* CCB request aborted by the host */
1097 		return (ECANCELED);
1098 	case CAM_CMD_TIMEOUT:	/* Command timeout */
1099 		return (ETIMEDOUT);
1100 	case CAM_REQUEUE_REQ:	/* Requeue to preserve transaction ordering */
1101 		return (EAGAIN);
1102 	case CAM_REQ_INVALID:	/* CCB request was invalid */
1103 		return (EINVAL);
1104 	case CAM_RESRC_UNAVAIL:	/* Resource Unavailable */
1105 		return (ENOMEM);
1106 	case CAM_BUSY:		/* CAM subsystem is busy */
1107 	case CAM_UA_ABORT:	/* Unable to abort CCB request */
1108 		return (EBUSY);
1109 	default:
1110 		return (ENXIO);
1111 	}
1112 }
1113 
1114 static size_t
1115 targccblen(xpt_opcode func_code)
1116 {
1117 	int len;
1118 
1119 	/* Codes we expect to see as a target */
1120 	switch (func_code) {
1121 	case XPT_CONT_TARGET_IO:
1122 	case XPT_SCSI_IO:
1123 		len = sizeof(struct ccb_scsiio);
1124 		break;
1125 	case XPT_ACCEPT_TARGET_IO:
1126 		len = sizeof(struct ccb_accept_tio);
1127 		break;
1128 	case XPT_IMMED_NOTIFY:
1129 		len = sizeof(struct ccb_immed_notify);
1130 		break;
1131 	case XPT_IMMEDIATE_NOTIFY:
1132 		len = sizeof(struct ccb_immediate_notify);
1133 		break;
1134 	case XPT_REL_SIMQ:
1135 		len = sizeof(struct ccb_relsim);
1136 		break;
1137 	case XPT_PATH_INQ:
1138 		len = sizeof(struct ccb_pathinq);
1139 		break;
1140 	case XPT_DEBUG:
1141 		len = sizeof(struct ccb_debug);
1142 		break;
1143 	case XPT_ABORT:
1144 		len = sizeof(struct ccb_abort);
1145 		break;
1146 	case XPT_EN_LUN:
1147 		len = sizeof(struct ccb_en_lun);
1148 		break;
1149 	default:
1150 		len = sizeof(union ccb);
1151 		break;
1152 	}
1153 
1154 	return (len);
1155 }
1156