xref: /linux/drivers/scsi/libsas/sas_scsi_host.c (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
1 /*
2  * Serial Attached SCSI (SAS) class SCSI Host glue.
3  *
4  * Copyright (C) 2005 Adaptec, Inc.  All rights reserved.
5  * Copyright (C) 2005 Luben Tuikov <luben_tuikov@adaptec.com>
6  *
7  * This file is licensed under GPLv2.
8  *
9  * This program is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU General Public License as
11  * published by the Free Software Foundation; either version 2 of the
12  * License, or (at your option) any later version.
13  *
14  * This program is distributed in the hope that it will be useful, but
15  * WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17  * General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
22  * USA
23  *
24  */
25 
26 #include <linux/kthread.h>
27 #include <linux/firmware.h>
28 #include <linux/export.h>
29 #include <linux/ctype.h>
30 
31 #include "sas_internal.h"
32 
33 #include <scsi/scsi_host.h>
34 #include <scsi/scsi_device.h>
35 #include <scsi/scsi_tcq.h>
36 #include <scsi/scsi.h>
37 #include <scsi/scsi_eh.h>
38 #include <scsi/scsi_transport.h>
39 #include <scsi/scsi_transport_sas.h>
40 #include <scsi/sas_ata.h>
41 #include "../scsi_sas_internal.h"
42 #include "../scsi_transport_api.h"
43 #include "../scsi_priv.h"
44 
45 #include <linux/err.h>
46 #include <linux/blkdev.h>
47 #include <linux/freezer.h>
48 #include <linux/gfp.h>
49 #include <linux/scatterlist.h>
50 #include <linux/libata.h>
51 
52 /* record final status and free the task */
53 static void sas_end_task(struct scsi_cmnd *sc, struct sas_task *task)
54 {
55 	struct task_status_struct *ts = &task->task_status;
56 	int hs = 0, stat = 0;
57 
58 	if (ts->resp == SAS_TASK_UNDELIVERED) {
59 		/* transport error */
60 		hs = DID_NO_CONNECT;
61 	} else { /* ts->resp == SAS_TASK_COMPLETE */
62 		/* task delivered, what happened afterwards? */
63 		switch (ts->stat) {
64 		case SAS_DEV_NO_RESPONSE:
65 		case SAS_INTERRUPTED:
66 		case SAS_PHY_DOWN:
67 		case SAS_NAK_R_ERR:
68 		case SAS_OPEN_TO:
69 			hs = DID_NO_CONNECT;
70 			break;
71 		case SAS_DATA_UNDERRUN:
72 			scsi_set_resid(sc, ts->residual);
73 			if (scsi_bufflen(sc) - scsi_get_resid(sc) < sc->underflow)
74 				hs = DID_ERROR;
75 			break;
76 		case SAS_DATA_OVERRUN:
77 			hs = DID_ERROR;
78 			break;
79 		case SAS_QUEUE_FULL:
80 			hs = DID_SOFT_ERROR; /* retry */
81 			break;
82 		case SAS_DEVICE_UNKNOWN:
83 			hs = DID_BAD_TARGET;
84 			break;
85 		case SAS_SG_ERR:
86 			hs = DID_PARITY;
87 			break;
88 		case SAS_OPEN_REJECT:
89 			if (ts->open_rej_reason == SAS_OREJ_RSVD_RETRY)
90 				hs = DID_SOFT_ERROR; /* retry */
91 			else
92 				hs = DID_ERROR;
93 			break;
94 		case SAS_PROTO_RESPONSE:
95 			SAS_DPRINTK("LLDD:%s sent SAS_PROTO_RESP for an SSP "
96 				    "task; please report this\n",
97 				    task->dev->port->ha->sas_ha_name);
98 			break;
99 		case SAS_ABORTED_TASK:
100 			hs = DID_ABORT;
101 			break;
102 		case SAM_STAT_CHECK_CONDITION:
103 			memcpy(sc->sense_buffer, ts->buf,
104 			       min(SCSI_SENSE_BUFFERSIZE, ts->buf_valid_size));
105 			stat = SAM_STAT_CHECK_CONDITION;
106 			break;
107 		default:
108 			stat = ts->stat;
109 			break;
110 		}
111 	}
112 
113 	sc->result = (hs << 16) | stat;
114 	ASSIGN_SAS_TASK(sc, NULL);
115 	sas_free_task(task);
116 }
117 
118 static void sas_scsi_task_done(struct sas_task *task)
119 {
120 	struct scsi_cmnd *sc = task->uldd_task;
121 	struct domain_device *dev = task->dev;
122 	struct sas_ha_struct *ha = dev->port->ha;
123 	unsigned long flags;
124 
125 	spin_lock_irqsave(&dev->done_lock, flags);
126 	if (test_bit(SAS_HA_FROZEN, &ha->state))
127 		task = NULL;
128 	else
129 		ASSIGN_SAS_TASK(sc, NULL);
130 	spin_unlock_irqrestore(&dev->done_lock, flags);
131 
132 	if (unlikely(!task)) {
133 		/* task will be completed by the error handler */
134 		SAS_DPRINTK("task done but aborted\n");
135 		return;
136 	}
137 
138 	if (unlikely(!sc)) {
139 		SAS_DPRINTK("task_done called with non existing SCSI cmnd!\n");
140 		sas_free_task(task);
141 		return;
142 	}
143 
144 	sas_end_task(sc, task);
145 	sc->scsi_done(sc);
146 }
147 
148 static struct sas_task *sas_create_task(struct scsi_cmnd *cmd,
149 					       struct domain_device *dev,
150 					       gfp_t gfp_flags)
151 {
152 	struct sas_task *task = sas_alloc_task(gfp_flags);
153 	struct scsi_lun lun;
154 
155 	if (!task)
156 		return NULL;
157 
158 	task->uldd_task = cmd;
159 	ASSIGN_SAS_TASK(cmd, task);
160 
161 	task->dev = dev;
162 	task->task_proto = task->dev->tproto; /* BUG_ON(!SSP) */
163 
164 	task->ssp_task.retry_count = 1;
165 	int_to_scsilun(cmd->device->lun, &lun);
166 	memcpy(task->ssp_task.LUN, &lun.scsi_lun, 8);
167 	task->ssp_task.task_attr = TASK_ATTR_SIMPLE;
168 	task->ssp_task.cmd = cmd;
169 
170 	task->scatter = scsi_sglist(cmd);
171 	task->num_scatter = scsi_sg_count(cmd);
172 	task->total_xfer_len = scsi_bufflen(cmd);
173 	task->data_dir = cmd->sc_data_direction;
174 
175 	task->task_done = sas_scsi_task_done;
176 
177 	return task;
178 }
179 
180 int sas_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
181 {
182 	struct sas_internal *i = to_sas_internal(host->transportt);
183 	struct domain_device *dev = cmd_to_domain_dev(cmd);
184 	struct sas_task *task;
185 	int res = 0;
186 
187 	/* If the device fell off, no sense in issuing commands */
188 	if (test_bit(SAS_DEV_GONE, &dev->state)) {
189 		cmd->result = DID_BAD_TARGET << 16;
190 		goto out_done;
191 	}
192 
193 	if (dev_is_sata(dev)) {
194 		spin_lock_irq(dev->sata_dev.ap->lock);
195 		res = ata_sas_queuecmd(cmd, dev->sata_dev.ap);
196 		spin_unlock_irq(dev->sata_dev.ap->lock);
197 		return res;
198 	}
199 
200 	task = sas_create_task(cmd, dev, GFP_ATOMIC);
201 	if (!task)
202 		return SCSI_MLQUEUE_HOST_BUSY;
203 
204 	res = i->dft->lldd_execute_task(task, GFP_ATOMIC);
205 	if (res)
206 		goto out_free_task;
207 	return 0;
208 
209 out_free_task:
210 	SAS_DPRINTK("lldd_execute_task returned: %d\n", res);
211 	ASSIGN_SAS_TASK(cmd, NULL);
212 	sas_free_task(task);
213 	if (res == -SAS_QUEUE_FULL)
214 		cmd->result = DID_SOFT_ERROR << 16; /* retry */
215 	else
216 		cmd->result = DID_ERROR << 16;
217 out_done:
218 	cmd->scsi_done(cmd);
219 	return 0;
220 }
221 
222 static void sas_eh_finish_cmd(struct scsi_cmnd *cmd)
223 {
224 	struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(cmd->device->host);
225 	struct sas_task *task = TO_SAS_TASK(cmd);
226 
227 	/* At this point, we only get called following an actual abort
228 	 * of the task, so we should be guaranteed not to be racing with
229 	 * any completions from the LLD.  Task is freed after this.
230 	 */
231 	sas_end_task(cmd, task);
232 
233 	/* now finish the command and move it on to the error
234 	 * handler done list, this also takes it off the
235 	 * error handler pending list.
236 	 */
237 	scsi_eh_finish_cmd(cmd, &sas_ha->eh_done_q);
238 }
239 
240 static void sas_eh_defer_cmd(struct scsi_cmnd *cmd)
241 {
242 	struct domain_device *dev = cmd_to_domain_dev(cmd);
243 	struct sas_ha_struct *ha = dev->port->ha;
244 	struct sas_task *task = TO_SAS_TASK(cmd);
245 
246 	if (!dev_is_sata(dev)) {
247 		sas_eh_finish_cmd(cmd);
248 		return;
249 	}
250 
251 	/* report the timeout to libata */
252 	sas_end_task(cmd, task);
253 	list_move_tail(&cmd->eh_entry, &ha->eh_ata_q);
254 }
255 
256 static void sas_scsi_clear_queue_lu(struct list_head *error_q, struct scsi_cmnd *my_cmd)
257 {
258 	struct scsi_cmnd *cmd, *n;
259 
260 	list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
261 		if (cmd->device->sdev_target == my_cmd->device->sdev_target &&
262 		    cmd->device->lun == my_cmd->device->lun)
263 			sas_eh_defer_cmd(cmd);
264 	}
265 }
266 
267 static void sas_scsi_clear_queue_I_T(struct list_head *error_q,
268 				     struct domain_device *dev)
269 {
270 	struct scsi_cmnd *cmd, *n;
271 
272 	list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
273 		struct domain_device *x = cmd_to_domain_dev(cmd);
274 
275 		if (x == dev)
276 			sas_eh_finish_cmd(cmd);
277 	}
278 }
279 
280 static void sas_scsi_clear_queue_port(struct list_head *error_q,
281 				      struct asd_sas_port *port)
282 {
283 	struct scsi_cmnd *cmd, *n;
284 
285 	list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
286 		struct domain_device *dev = cmd_to_domain_dev(cmd);
287 		struct asd_sas_port *x = dev->port;
288 
289 		if (x == port)
290 			sas_eh_finish_cmd(cmd);
291 	}
292 }
293 
294 enum task_disposition {
295 	TASK_IS_DONE,
296 	TASK_IS_ABORTED,
297 	TASK_IS_AT_LU,
298 	TASK_IS_NOT_AT_LU,
299 	TASK_ABORT_FAILED,
300 };
301 
302 static enum task_disposition sas_scsi_find_task(struct sas_task *task)
303 {
304 	unsigned long flags;
305 	int i, res;
306 	struct sas_internal *si =
307 		to_sas_internal(task->dev->port->ha->core.shost->transportt);
308 
309 	for (i = 0; i < 5; i++) {
310 		SAS_DPRINTK("%s: aborting task 0x%p\n", __func__, task);
311 		res = si->dft->lldd_abort_task(task);
312 
313 		spin_lock_irqsave(&task->task_state_lock, flags);
314 		if (task->task_state_flags & SAS_TASK_STATE_DONE) {
315 			spin_unlock_irqrestore(&task->task_state_lock, flags);
316 			SAS_DPRINTK("%s: task 0x%p is done\n", __func__,
317 				    task);
318 			return TASK_IS_DONE;
319 		}
320 		spin_unlock_irqrestore(&task->task_state_lock, flags);
321 
322 		if (res == TMF_RESP_FUNC_COMPLETE) {
323 			SAS_DPRINTK("%s: task 0x%p is aborted\n",
324 				    __func__, task);
325 			return TASK_IS_ABORTED;
326 		} else if (si->dft->lldd_query_task) {
327 			SAS_DPRINTK("%s: querying task 0x%p\n",
328 				    __func__, task);
329 			res = si->dft->lldd_query_task(task);
330 			switch (res) {
331 			case TMF_RESP_FUNC_SUCC:
332 				SAS_DPRINTK("%s: task 0x%p at LU\n",
333 					    __func__, task);
334 				return TASK_IS_AT_LU;
335 			case TMF_RESP_FUNC_COMPLETE:
336 				SAS_DPRINTK("%s: task 0x%p not at LU\n",
337 					    __func__, task);
338 				return TASK_IS_NOT_AT_LU;
339 			case TMF_RESP_FUNC_FAILED:
340                                 SAS_DPRINTK("%s: task 0x%p failed to abort\n",
341                                                 __func__, task);
342                                 return TASK_ABORT_FAILED;
343                         }
344 
345 		}
346 	}
347 	return res;
348 }
349 
350 static int sas_recover_lu(struct domain_device *dev, struct scsi_cmnd *cmd)
351 {
352 	int res = TMF_RESP_FUNC_FAILED;
353 	struct scsi_lun lun;
354 	struct sas_internal *i =
355 		to_sas_internal(dev->port->ha->core.shost->transportt);
356 
357 	int_to_scsilun(cmd->device->lun, &lun);
358 
359 	SAS_DPRINTK("eh: device %llx LUN %llx has the task\n",
360 		    SAS_ADDR(dev->sas_addr),
361 		    cmd->device->lun);
362 
363 	if (i->dft->lldd_abort_task_set)
364 		res = i->dft->lldd_abort_task_set(dev, lun.scsi_lun);
365 
366 	if (res == TMF_RESP_FUNC_FAILED) {
367 		if (i->dft->lldd_clear_task_set)
368 			res = i->dft->lldd_clear_task_set(dev, lun.scsi_lun);
369 	}
370 
371 	if (res == TMF_RESP_FUNC_FAILED) {
372 		if (i->dft->lldd_lu_reset)
373 			res = i->dft->lldd_lu_reset(dev, lun.scsi_lun);
374 	}
375 
376 	return res;
377 }
378 
379 static int sas_recover_I_T(struct domain_device *dev)
380 {
381 	int res = TMF_RESP_FUNC_FAILED;
382 	struct sas_internal *i =
383 		to_sas_internal(dev->port->ha->core.shost->transportt);
384 
385 	SAS_DPRINTK("I_T nexus reset for dev %016llx\n",
386 		    SAS_ADDR(dev->sas_addr));
387 
388 	if (i->dft->lldd_I_T_nexus_reset)
389 		res = i->dft->lldd_I_T_nexus_reset(dev);
390 
391 	return res;
392 }
393 
394 /* take a reference on the last known good phy for this device */
395 struct sas_phy *sas_get_local_phy(struct domain_device *dev)
396 {
397 	struct sas_ha_struct *ha = dev->port->ha;
398 	struct sas_phy *phy;
399 	unsigned long flags;
400 
401 	/* a published domain device always has a valid phy, it may be
402 	 * stale, but it is never NULL
403 	 */
404 	BUG_ON(!dev->phy);
405 
406 	spin_lock_irqsave(&ha->phy_port_lock, flags);
407 	phy = dev->phy;
408 	get_device(&phy->dev);
409 	spin_unlock_irqrestore(&ha->phy_port_lock, flags);
410 
411 	return phy;
412 }
413 EXPORT_SYMBOL_GPL(sas_get_local_phy);
414 
415 static void sas_wait_eh(struct domain_device *dev)
416 {
417 	struct sas_ha_struct *ha = dev->port->ha;
418 	DEFINE_WAIT(wait);
419 
420 	if (dev_is_sata(dev)) {
421 		ata_port_wait_eh(dev->sata_dev.ap);
422 		return;
423 	}
424  retry:
425 	spin_lock_irq(&ha->lock);
426 
427 	while (test_bit(SAS_DEV_EH_PENDING, &dev->state)) {
428 		prepare_to_wait(&ha->eh_wait_q, &wait, TASK_UNINTERRUPTIBLE);
429 		spin_unlock_irq(&ha->lock);
430 		schedule();
431 		spin_lock_irq(&ha->lock);
432 	}
433 	finish_wait(&ha->eh_wait_q, &wait);
434 
435 	spin_unlock_irq(&ha->lock);
436 
437 	/* make sure SCSI EH is complete */
438 	if (scsi_host_in_recovery(ha->core.shost)) {
439 		msleep(10);
440 		goto retry;
441 	}
442 }
443 EXPORT_SYMBOL(sas_wait_eh);
444 
445 static int sas_queue_reset(struct domain_device *dev, int reset_type,
446 			   u64 lun, int wait)
447 {
448 	struct sas_ha_struct *ha = dev->port->ha;
449 	int scheduled = 0, tries = 100;
450 
451 	/* ata: promote lun reset to bus reset */
452 	if (dev_is_sata(dev)) {
453 		sas_ata_schedule_reset(dev);
454 		if (wait)
455 			sas_ata_wait_eh(dev);
456 		return SUCCESS;
457 	}
458 
459 	while (!scheduled && tries--) {
460 		spin_lock_irq(&ha->lock);
461 		if (!test_bit(SAS_DEV_EH_PENDING, &dev->state) &&
462 		    !test_bit(reset_type, &dev->state)) {
463 			scheduled = 1;
464 			ha->eh_active++;
465 			list_add_tail(&dev->ssp_dev.eh_list_node, &ha->eh_dev_q);
466 			set_bit(SAS_DEV_EH_PENDING, &dev->state);
467 			set_bit(reset_type, &dev->state);
468 			int_to_scsilun(lun, &dev->ssp_dev.reset_lun);
469 			scsi_schedule_eh(ha->core.shost);
470 		}
471 		spin_unlock_irq(&ha->lock);
472 
473 		if (wait)
474 			sas_wait_eh(dev);
475 
476 		if (scheduled)
477 			return SUCCESS;
478 	}
479 
480 	SAS_DPRINTK("%s reset of %s failed\n",
481 		    reset_type == SAS_DEV_LU_RESET ? "LUN" : "Bus",
482 		    dev_name(&dev->rphy->dev));
483 
484 	return FAILED;
485 }
486 
487 int sas_eh_abort_handler(struct scsi_cmnd *cmd)
488 {
489 	int res;
490 	struct sas_task *task = TO_SAS_TASK(cmd);
491 	struct Scsi_Host *host = cmd->device->host;
492 	struct sas_internal *i = to_sas_internal(host->transportt);
493 
494 	if (current != host->ehandler)
495 		return FAILED;
496 
497 	if (!i->dft->lldd_abort_task)
498 		return FAILED;
499 
500 	res = i->dft->lldd_abort_task(task);
501 	if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE)
502 		return SUCCESS;
503 
504 	return FAILED;
505 }
506 EXPORT_SYMBOL_GPL(sas_eh_abort_handler);
507 
508 /* Attempt to send a LUN reset message to a device */
509 int sas_eh_device_reset_handler(struct scsi_cmnd *cmd)
510 {
511 	int res;
512 	struct scsi_lun lun;
513 	struct Scsi_Host *host = cmd->device->host;
514 	struct domain_device *dev = cmd_to_domain_dev(cmd);
515 	struct sas_internal *i = to_sas_internal(host->transportt);
516 
517 	if (current != host->ehandler)
518 		return sas_queue_reset(dev, SAS_DEV_LU_RESET, cmd->device->lun, 0);
519 
520 	int_to_scsilun(cmd->device->lun, &lun);
521 
522 	if (!i->dft->lldd_lu_reset)
523 		return FAILED;
524 
525 	res = i->dft->lldd_lu_reset(dev, lun.scsi_lun);
526 	if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE)
527 		return SUCCESS;
528 
529 	return FAILED;
530 }
531 
532 int sas_eh_bus_reset_handler(struct scsi_cmnd *cmd)
533 {
534 	int res;
535 	struct Scsi_Host *host = cmd->device->host;
536 	struct domain_device *dev = cmd_to_domain_dev(cmd);
537 	struct sas_internal *i = to_sas_internal(host->transportt);
538 
539 	if (current != host->ehandler)
540 		return sas_queue_reset(dev, SAS_DEV_RESET, 0, 0);
541 
542 	if (!i->dft->lldd_I_T_nexus_reset)
543 		return FAILED;
544 
545 	res = i->dft->lldd_I_T_nexus_reset(dev);
546 	if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE ||
547 	    res == -ENODEV)
548 		return SUCCESS;
549 
550 	return FAILED;
551 }
552 
553 /* Try to reset a device */
554 static int try_to_reset_cmd_device(struct scsi_cmnd *cmd)
555 {
556 	int res;
557 	struct Scsi_Host *shost = cmd->device->host;
558 
559 	if (!shost->hostt->eh_device_reset_handler)
560 		goto try_bus_reset;
561 
562 	res = shost->hostt->eh_device_reset_handler(cmd);
563 	if (res == SUCCESS)
564 		return res;
565 
566 try_bus_reset:
567 	if (shost->hostt->eh_bus_reset_handler)
568 		return shost->hostt->eh_bus_reset_handler(cmd);
569 
570 	return FAILED;
571 }
572 
573 static void sas_eh_handle_sas_errors(struct Scsi_Host *shost, struct list_head *work_q)
574 {
575 	struct scsi_cmnd *cmd, *n;
576 	enum task_disposition res = TASK_IS_DONE;
577 	int tmf_resp, need_reset;
578 	struct sas_internal *i = to_sas_internal(shost->transportt);
579 	unsigned long flags;
580 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
581 	LIST_HEAD(done);
582 
583 	/* clean out any commands that won the completion vs eh race */
584 	list_for_each_entry_safe(cmd, n, work_q, eh_entry) {
585 		struct domain_device *dev = cmd_to_domain_dev(cmd);
586 		struct sas_task *task;
587 
588 		spin_lock_irqsave(&dev->done_lock, flags);
589 		/* by this point the lldd has either observed
590 		 * SAS_HA_FROZEN and is leaving the task alone, or has
591 		 * won the race with eh and decided to complete it
592 		 */
593 		task = TO_SAS_TASK(cmd);
594 		spin_unlock_irqrestore(&dev->done_lock, flags);
595 
596 		if (!task)
597 			list_move_tail(&cmd->eh_entry, &done);
598 	}
599 
600  Again:
601 	list_for_each_entry_safe(cmd, n, work_q, eh_entry) {
602 		struct sas_task *task = TO_SAS_TASK(cmd);
603 
604 		list_del_init(&cmd->eh_entry);
605 
606 		spin_lock_irqsave(&task->task_state_lock, flags);
607 		need_reset = task->task_state_flags & SAS_TASK_NEED_DEV_RESET;
608 		spin_unlock_irqrestore(&task->task_state_lock, flags);
609 
610 		if (need_reset) {
611 			SAS_DPRINTK("%s: task 0x%p requests reset\n",
612 				    __func__, task);
613 			goto reset;
614 		}
615 
616 		SAS_DPRINTK("trying to find task 0x%p\n", task);
617 		res = sas_scsi_find_task(task);
618 
619 		cmd->eh_eflags = 0;
620 
621 		switch (res) {
622 		case TASK_IS_DONE:
623 			SAS_DPRINTK("%s: task 0x%p is done\n", __func__,
624 				    task);
625 			sas_eh_defer_cmd(cmd);
626 			continue;
627 		case TASK_IS_ABORTED:
628 			SAS_DPRINTK("%s: task 0x%p is aborted\n",
629 				    __func__, task);
630 			sas_eh_defer_cmd(cmd);
631 			continue;
632 		case TASK_IS_AT_LU:
633 			SAS_DPRINTK("task 0x%p is at LU: lu recover\n", task);
634  reset:
635 			tmf_resp = sas_recover_lu(task->dev, cmd);
636 			if (tmf_resp == TMF_RESP_FUNC_COMPLETE) {
637 				SAS_DPRINTK("dev %016llx LU %llx is "
638 					    "recovered\n",
639 					    SAS_ADDR(task->dev),
640 					    cmd->device->lun);
641 				sas_eh_defer_cmd(cmd);
642 				sas_scsi_clear_queue_lu(work_q, cmd);
643 				goto Again;
644 			}
645 			/* fallthrough */
646 		case TASK_IS_NOT_AT_LU:
647 		case TASK_ABORT_FAILED:
648 			SAS_DPRINTK("task 0x%p is not at LU: I_T recover\n",
649 				    task);
650 			tmf_resp = sas_recover_I_T(task->dev);
651 			if (tmf_resp == TMF_RESP_FUNC_COMPLETE ||
652 			    tmf_resp == -ENODEV) {
653 				struct domain_device *dev = task->dev;
654 				SAS_DPRINTK("I_T %016llx recovered\n",
655 					    SAS_ADDR(task->dev->sas_addr));
656 				sas_eh_finish_cmd(cmd);
657 				sas_scsi_clear_queue_I_T(work_q, dev);
658 				goto Again;
659 			}
660 			/* Hammer time :-) */
661 			try_to_reset_cmd_device(cmd);
662 			if (i->dft->lldd_clear_nexus_port) {
663 				struct asd_sas_port *port = task->dev->port;
664 				SAS_DPRINTK("clearing nexus for port:%d\n",
665 					    port->id);
666 				res = i->dft->lldd_clear_nexus_port(port);
667 				if (res == TMF_RESP_FUNC_COMPLETE) {
668 					SAS_DPRINTK("clear nexus port:%d "
669 						    "succeeded\n", port->id);
670 					sas_eh_finish_cmd(cmd);
671 					sas_scsi_clear_queue_port(work_q,
672 								  port);
673 					goto Again;
674 				}
675 			}
676 			if (i->dft->lldd_clear_nexus_ha) {
677 				SAS_DPRINTK("clear nexus ha\n");
678 				res = i->dft->lldd_clear_nexus_ha(ha);
679 				if (res == TMF_RESP_FUNC_COMPLETE) {
680 					SAS_DPRINTK("clear nexus ha "
681 						    "succeeded\n");
682 					sas_eh_finish_cmd(cmd);
683 					goto clear_q;
684 				}
685 			}
686 			/* If we are here -- this means that no amount
687 			 * of effort could recover from errors.  Quite
688 			 * possibly the HA just disappeared.
689 			 */
690 			SAS_DPRINTK("error from  device %llx, LUN %llx "
691 				    "couldn't be recovered in any way\n",
692 				    SAS_ADDR(task->dev->sas_addr),
693 				    cmd->device->lun);
694 
695 			sas_eh_finish_cmd(cmd);
696 			goto clear_q;
697 		}
698 	}
699  out:
700 	list_splice_tail(&done, work_q);
701 	list_splice_tail_init(&ha->eh_ata_q, work_q);
702 	return;
703 
704  clear_q:
705 	SAS_DPRINTK("--- Exit %s -- clear_q\n", __func__);
706 	list_for_each_entry_safe(cmd, n, work_q, eh_entry)
707 		sas_eh_finish_cmd(cmd);
708 	goto out;
709 }
710 
711 static void sas_eh_handle_resets(struct Scsi_Host *shost)
712 {
713 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
714 	struct sas_internal *i = to_sas_internal(shost->transportt);
715 
716 	/* handle directed resets to sas devices */
717 	spin_lock_irq(&ha->lock);
718 	while (!list_empty(&ha->eh_dev_q)) {
719 		struct domain_device *dev;
720 		struct ssp_device *ssp;
721 
722 		ssp = list_entry(ha->eh_dev_q.next, typeof(*ssp), eh_list_node);
723 		list_del_init(&ssp->eh_list_node);
724 		dev = container_of(ssp, typeof(*dev), ssp_dev);
725 		kref_get(&dev->kref);
726 		WARN_ONCE(dev_is_sata(dev), "ssp reset to ata device?\n");
727 
728 		spin_unlock_irq(&ha->lock);
729 
730 		if (test_and_clear_bit(SAS_DEV_LU_RESET, &dev->state))
731 			i->dft->lldd_lu_reset(dev, ssp->reset_lun.scsi_lun);
732 
733 		if (test_and_clear_bit(SAS_DEV_RESET, &dev->state))
734 			i->dft->lldd_I_T_nexus_reset(dev);
735 
736 		sas_put_device(dev);
737 		spin_lock_irq(&ha->lock);
738 		clear_bit(SAS_DEV_EH_PENDING, &dev->state);
739 		ha->eh_active--;
740 	}
741 	spin_unlock_irq(&ha->lock);
742 }
743 
744 
745 void sas_scsi_recover_host(struct Scsi_Host *shost)
746 {
747 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
748 	LIST_HEAD(eh_work_q);
749 	int tries = 0;
750 	bool retry;
751 
752 retry:
753 	tries++;
754 	retry = true;
755 	spin_lock_irq(shost->host_lock);
756 	list_splice_init(&shost->eh_cmd_q, &eh_work_q);
757 	spin_unlock_irq(shost->host_lock);
758 
759 	SAS_DPRINTK("Enter %s busy: %d failed: %d\n",
760 		    __func__, atomic_read(&shost->host_busy), shost->host_failed);
761 	/*
762 	 * Deal with commands that still have SAS tasks (i.e. they didn't
763 	 * complete via the normal sas_task completion mechanism),
764 	 * SAS_HA_FROZEN gives eh dominion over all sas_task completion.
765 	 */
766 	set_bit(SAS_HA_FROZEN, &ha->state);
767 	sas_eh_handle_sas_errors(shost, &eh_work_q);
768 	clear_bit(SAS_HA_FROZEN, &ha->state);
769 	if (list_empty(&eh_work_q))
770 		goto out;
771 
772 	/*
773 	 * Now deal with SCSI commands that completed ok but have a an error
774 	 * code (and hopefully sense data) attached.  This is roughly what
775 	 * scsi_unjam_host does, but we skip scsi_eh_abort_cmds because any
776 	 * command we see here has no sas_task and is thus unknown to the HA.
777 	 */
778 	sas_ata_eh(shost, &eh_work_q, &ha->eh_done_q);
779 	if (!scsi_eh_get_sense(&eh_work_q, &ha->eh_done_q))
780 		scsi_eh_ready_devs(shost, &eh_work_q, &ha->eh_done_q);
781 
782 out:
783 	sas_eh_handle_resets(shost);
784 
785 	/* now link into libata eh --- if we have any ata devices */
786 	sas_ata_strategy_handler(shost);
787 
788 	scsi_eh_flush_done_q(&ha->eh_done_q);
789 
790 	/* check if any new eh work was scheduled during the last run */
791 	spin_lock_irq(&ha->lock);
792 	if (ha->eh_active == 0) {
793 		shost->host_eh_scheduled = 0;
794 		retry = false;
795 	}
796 	spin_unlock_irq(&ha->lock);
797 
798 	if (retry)
799 		goto retry;
800 
801 	SAS_DPRINTK("--- Exit %s: busy: %d failed: %d tries: %d\n",
802 		    __func__, atomic_read(&shost->host_busy),
803 		    shost->host_failed, tries);
804 }
805 
806 enum blk_eh_timer_return sas_scsi_timed_out(struct scsi_cmnd *cmd)
807 {
808 	scmd_dbg(cmd, "command %p timed out\n", cmd);
809 
810 	return BLK_EH_NOT_HANDLED;
811 }
812 
813 int sas_ioctl(struct scsi_device *sdev, int cmd, void __user *arg)
814 {
815 	struct domain_device *dev = sdev_to_domain_dev(sdev);
816 
817 	if (dev_is_sata(dev))
818 		return ata_sas_scsi_ioctl(dev->sata_dev.ap, sdev, cmd, arg);
819 
820 	return -EINVAL;
821 }
822 
823 struct domain_device *sas_find_dev_by_rphy(struct sas_rphy *rphy)
824 {
825 	struct Scsi_Host *shost = dev_to_shost(rphy->dev.parent);
826 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
827 	struct domain_device *found_dev = NULL;
828 	int i;
829 	unsigned long flags;
830 
831 	spin_lock_irqsave(&ha->phy_port_lock, flags);
832 	for (i = 0; i < ha->num_phys; i++) {
833 		struct asd_sas_port *port = ha->sas_port[i];
834 		struct domain_device *dev;
835 
836 		spin_lock(&port->dev_list_lock);
837 		list_for_each_entry(dev, &port->dev_list, dev_list_node) {
838 			if (rphy == dev->rphy) {
839 				found_dev = dev;
840 				spin_unlock(&port->dev_list_lock);
841 				goto found;
842 			}
843 		}
844 		spin_unlock(&port->dev_list_lock);
845 	}
846  found:
847 	spin_unlock_irqrestore(&ha->phy_port_lock, flags);
848 
849 	return found_dev;
850 }
851 
852 int sas_target_alloc(struct scsi_target *starget)
853 {
854 	struct sas_rphy *rphy = dev_to_rphy(starget->dev.parent);
855 	struct domain_device *found_dev = sas_find_dev_by_rphy(rphy);
856 
857 	if (!found_dev)
858 		return -ENODEV;
859 
860 	kref_get(&found_dev->kref);
861 	starget->hostdata = found_dev;
862 	return 0;
863 }
864 
865 #define SAS_DEF_QD 256
866 
867 int sas_slave_configure(struct scsi_device *scsi_dev)
868 {
869 	struct domain_device *dev = sdev_to_domain_dev(scsi_dev);
870 	struct sas_ha_struct *sas_ha;
871 
872 	BUG_ON(dev->rphy->identify.device_type != SAS_END_DEVICE);
873 
874 	if (dev_is_sata(dev)) {
875 		ata_sas_slave_configure(scsi_dev, dev->sata_dev.ap);
876 		return 0;
877 	}
878 
879 	sas_ha = dev->port->ha;
880 
881 	sas_read_port_mode_page(scsi_dev);
882 
883 	if (scsi_dev->tagged_supported) {
884 		scsi_change_queue_depth(scsi_dev, SAS_DEF_QD);
885 	} else {
886 		SAS_DPRINTK("device %llx, LUN %llx doesn't support "
887 			    "TCQ\n", SAS_ADDR(dev->sas_addr),
888 			    scsi_dev->lun);
889 		scsi_change_queue_depth(scsi_dev, 1);
890 	}
891 
892 	scsi_dev->allow_restart = 1;
893 
894 	return 0;
895 }
896 
897 int sas_change_queue_depth(struct scsi_device *sdev, int depth)
898 {
899 	struct domain_device *dev = sdev_to_domain_dev(sdev);
900 
901 	if (dev_is_sata(dev))
902 		return __ata_change_queue_depth(dev->sata_dev.ap, sdev, depth);
903 
904 	if (!sdev->tagged_supported)
905 		depth = 1;
906 	return scsi_change_queue_depth(sdev, depth);
907 }
908 
909 int sas_bios_param(struct scsi_device *scsi_dev,
910 			  struct block_device *bdev,
911 			  sector_t capacity, int *hsc)
912 {
913 	hsc[0] = 255;
914 	hsc[1] = 63;
915 	sector_div(capacity, 255*63);
916 	hsc[2] = capacity;
917 
918 	return 0;
919 }
920 
921 /*
922  * Tell an upper layer that it needs to initiate an abort for a given task.
923  * This should only ever be called by an LLDD.
924  */
925 void sas_task_abort(struct sas_task *task)
926 {
927 	struct scsi_cmnd *sc = task->uldd_task;
928 
929 	/* Escape for libsas internal commands */
930 	if (!sc) {
931 		struct sas_task_slow *slow = task->slow_task;
932 
933 		if (!slow)
934 			return;
935 		if (!del_timer(&slow->timer))
936 			return;
937 		slow->timer.function(slow->timer.data);
938 		return;
939 	}
940 
941 	if (dev_is_sata(task->dev)) {
942 		sas_ata_task_abort(task);
943 	} else {
944 		struct request_queue *q = sc->device->request_queue;
945 		unsigned long flags;
946 
947 		spin_lock_irqsave(q->queue_lock, flags);
948 		blk_abort_request(sc->request);
949 		spin_unlock_irqrestore(q->queue_lock, flags);
950 	}
951 }
952 
953 void sas_target_destroy(struct scsi_target *starget)
954 {
955 	struct domain_device *found_dev = starget->hostdata;
956 
957 	if (!found_dev)
958 		return;
959 
960 	starget->hostdata = NULL;
961 	sas_put_device(found_dev);
962 }
963 
964 static void sas_parse_addr(u8 *sas_addr, const char *p)
965 {
966 	int i;
967 	for (i = 0; i < SAS_ADDR_SIZE; i++) {
968 		u8 h, l;
969 		if (!*p)
970 			break;
971 		h = isdigit(*p) ? *p-'0' : toupper(*p)-'A'+10;
972 		p++;
973 		l = isdigit(*p) ? *p-'0' : toupper(*p)-'A'+10;
974 		p++;
975 		sas_addr[i] = (h<<4) | l;
976 	}
977 }
978 
979 #define SAS_STRING_ADDR_SIZE	16
980 
981 int sas_request_addr(struct Scsi_Host *shost, u8 *addr)
982 {
983 	int res;
984 	const struct firmware *fw;
985 
986 	res = request_firmware(&fw, "sas_addr", &shost->shost_gendev);
987 	if (res)
988 		return res;
989 
990 	if (fw->size < SAS_STRING_ADDR_SIZE) {
991 		res = -ENODEV;
992 		goto out;
993 	}
994 
995 	sas_parse_addr(addr, fw->data);
996 
997 out:
998 	release_firmware(fw);
999 	return res;
1000 }
1001 EXPORT_SYMBOL_GPL(sas_request_addr);
1002 
1003 EXPORT_SYMBOL_GPL(sas_queuecommand);
1004 EXPORT_SYMBOL_GPL(sas_target_alloc);
1005 EXPORT_SYMBOL_GPL(sas_slave_configure);
1006 EXPORT_SYMBOL_GPL(sas_change_queue_depth);
1007 EXPORT_SYMBOL_GPL(sas_bios_param);
1008 EXPORT_SYMBOL_GPL(sas_task_abort);
1009 EXPORT_SYMBOL_GPL(sas_phy_reset);
1010 EXPORT_SYMBOL_GPL(sas_eh_device_reset_handler);
1011 EXPORT_SYMBOL_GPL(sas_eh_bus_reset_handler);
1012 EXPORT_SYMBOL_GPL(sas_target_destroy);
1013 EXPORT_SYMBOL_GPL(sas_ioctl);
1014