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 #include <linux/kernel.h>
31 
32 #include "sas_internal.h"
33 
34 #include <scsi/scsi_host.h>
35 #include <scsi/scsi_device.h>
36 #include <scsi/scsi_tcq.h>
37 #include <scsi/scsi.h>
38 #include <scsi/scsi_eh.h>
39 #include <scsi/scsi_transport.h>
40 #include <scsi/scsi_transport_sas.h>
41 #include <scsi/sas_ata.h>
42 #include "../scsi_sas_internal.h"
43 #include "../scsi_transport_api.h"
44 #include "../scsi_priv.h"
45 
46 #include <linux/err.h>
47 #include <linux/blkdev.h>
48 #include <linux/freezer.h>
49 #include <linux/gfp.h>
50 #include <linux/scatterlist.h>
51 #include <linux/libata.h>
52 
53 /* record final status and free the task */
54 static void sas_end_task(struct scsi_cmnd *sc, struct sas_task *task)
55 {
56 	struct task_status_struct *ts = &task->task_status;
57 	int hs = 0, stat = 0;
58 
59 	if (ts->resp == SAS_TASK_UNDELIVERED) {
60 		/* transport error */
61 		hs = DID_NO_CONNECT;
62 	} else { /* ts->resp == SAS_TASK_COMPLETE */
63 		/* task delivered, what happened afterwards? */
64 		switch (ts->stat) {
65 		case SAS_DEV_NO_RESPONSE:
66 		case SAS_INTERRUPTED:
67 		case SAS_PHY_DOWN:
68 		case SAS_NAK_R_ERR:
69 		case SAS_OPEN_TO:
70 			hs = DID_NO_CONNECT;
71 			break;
72 		case SAS_DATA_UNDERRUN:
73 			scsi_set_resid(sc, ts->residual);
74 			if (scsi_bufflen(sc) - scsi_get_resid(sc) < sc->underflow)
75 				hs = DID_ERROR;
76 			break;
77 		case SAS_DATA_OVERRUN:
78 			hs = DID_ERROR;
79 			break;
80 		case SAS_QUEUE_FULL:
81 			hs = DID_SOFT_ERROR; /* retry */
82 			break;
83 		case SAS_DEVICE_UNKNOWN:
84 			hs = DID_BAD_TARGET;
85 			break;
86 		case SAS_SG_ERR:
87 			hs = DID_PARITY;
88 			break;
89 		case SAS_OPEN_REJECT:
90 			if (ts->open_rej_reason == SAS_OREJ_RSVD_RETRY)
91 				hs = DID_SOFT_ERROR; /* retry */
92 			else
93 				hs = DID_ERROR;
94 			break;
95 		case SAS_PROTO_RESPONSE:
96 			pr_notice("LLDD:%s sent SAS_PROTO_RESP for an SSP 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 		pr_debug("task done but aborted\n");
135 		return;
136 	}
137 
138 	if (unlikely(!sc)) {
139 		pr_debug("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 	pr_debug("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 domain_device *dev = cmd_to_domain_dev(cmd);
226 	struct sas_task *task = TO_SAS_TASK(cmd);
227 
228 	/* At this point, we only get called following an actual abort
229 	 * of the task, so we should be guaranteed not to be racing with
230 	 * any completions from the LLD.  Task is freed after this.
231 	 */
232 	sas_end_task(cmd, task);
233 
234 	if (dev_is_sata(dev)) {
235 		/* defer commands to libata so that libata EH can
236 		 * handle ata qcs correctly
237 		 */
238 		list_move_tail(&cmd->eh_entry, &sas_ha->eh_ata_q);
239 		return;
240 	}
241 
242 	/* now finish the command and move it on to the error
243 	 * handler done list, this also takes it off the
244 	 * error handler pending list.
245 	 */
246 	scsi_eh_finish_cmd(cmd, &sas_ha->eh_done_q);
247 }
248 
249 static void sas_scsi_clear_queue_lu(struct list_head *error_q, struct scsi_cmnd *my_cmd)
250 {
251 	struct scsi_cmnd *cmd, *n;
252 
253 	list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
254 		if (cmd->device->sdev_target == my_cmd->device->sdev_target &&
255 		    cmd->device->lun == my_cmd->device->lun)
256 			sas_eh_finish_cmd(cmd);
257 	}
258 }
259 
260 static void sas_scsi_clear_queue_I_T(struct list_head *error_q,
261 				     struct domain_device *dev)
262 {
263 	struct scsi_cmnd *cmd, *n;
264 
265 	list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
266 		struct domain_device *x = cmd_to_domain_dev(cmd);
267 
268 		if (x == dev)
269 			sas_eh_finish_cmd(cmd);
270 	}
271 }
272 
273 static void sas_scsi_clear_queue_port(struct list_head *error_q,
274 				      struct asd_sas_port *port)
275 {
276 	struct scsi_cmnd *cmd, *n;
277 
278 	list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
279 		struct domain_device *dev = cmd_to_domain_dev(cmd);
280 		struct asd_sas_port *x = dev->port;
281 
282 		if (x == port)
283 			sas_eh_finish_cmd(cmd);
284 	}
285 }
286 
287 enum task_disposition {
288 	TASK_IS_DONE,
289 	TASK_IS_ABORTED,
290 	TASK_IS_AT_LU,
291 	TASK_IS_NOT_AT_LU,
292 	TASK_ABORT_FAILED,
293 };
294 
295 static enum task_disposition sas_scsi_find_task(struct sas_task *task)
296 {
297 	unsigned long flags;
298 	int i, res;
299 	struct sas_internal *si =
300 		to_sas_internal(task->dev->port->ha->core.shost->transportt);
301 
302 	for (i = 0; i < 5; i++) {
303 		pr_notice("%s: aborting task 0x%p\n", __func__, task);
304 		res = si->dft->lldd_abort_task(task);
305 
306 		spin_lock_irqsave(&task->task_state_lock, flags);
307 		if (task->task_state_flags & SAS_TASK_STATE_DONE) {
308 			spin_unlock_irqrestore(&task->task_state_lock, flags);
309 			pr_debug("%s: task 0x%p is done\n", __func__, task);
310 			return TASK_IS_DONE;
311 		}
312 		spin_unlock_irqrestore(&task->task_state_lock, flags);
313 
314 		if (res == TMF_RESP_FUNC_COMPLETE) {
315 			pr_notice("%s: task 0x%p is aborted\n",
316 				  __func__, task);
317 			return TASK_IS_ABORTED;
318 		} else if (si->dft->lldd_query_task) {
319 			pr_notice("%s: querying task 0x%p\n", __func__, task);
320 			res = si->dft->lldd_query_task(task);
321 			switch (res) {
322 			case TMF_RESP_FUNC_SUCC:
323 				pr_notice("%s: task 0x%p at LU\n", __func__,
324 					  task);
325 				return TASK_IS_AT_LU;
326 			case TMF_RESP_FUNC_COMPLETE:
327 				pr_notice("%s: task 0x%p not at LU\n",
328 					  __func__, task);
329 				return TASK_IS_NOT_AT_LU;
330 			case TMF_RESP_FUNC_FAILED:
331 				pr_notice("%s: task 0x%p failed to abort\n",
332 					  __func__, task);
333 				return TASK_ABORT_FAILED;
334 			}
335 
336 		}
337 	}
338 	return res;
339 }
340 
341 static int sas_recover_lu(struct domain_device *dev, struct scsi_cmnd *cmd)
342 {
343 	int res = TMF_RESP_FUNC_FAILED;
344 	struct scsi_lun lun;
345 	struct sas_internal *i =
346 		to_sas_internal(dev->port->ha->core.shost->transportt);
347 
348 	int_to_scsilun(cmd->device->lun, &lun);
349 
350 	pr_notice("eh: device %llx LUN %llx has the task\n",
351 		  SAS_ADDR(dev->sas_addr),
352 		  cmd->device->lun);
353 
354 	if (i->dft->lldd_abort_task_set)
355 		res = i->dft->lldd_abort_task_set(dev, lun.scsi_lun);
356 
357 	if (res == TMF_RESP_FUNC_FAILED) {
358 		if (i->dft->lldd_clear_task_set)
359 			res = i->dft->lldd_clear_task_set(dev, lun.scsi_lun);
360 	}
361 
362 	if (res == TMF_RESP_FUNC_FAILED) {
363 		if (i->dft->lldd_lu_reset)
364 			res = i->dft->lldd_lu_reset(dev, lun.scsi_lun);
365 	}
366 
367 	return res;
368 }
369 
370 static int sas_recover_I_T(struct domain_device *dev)
371 {
372 	int res = TMF_RESP_FUNC_FAILED;
373 	struct sas_internal *i =
374 		to_sas_internal(dev->port->ha->core.shost->transportt);
375 
376 	pr_notice("I_T nexus reset for dev %016llx\n",
377 		  SAS_ADDR(dev->sas_addr));
378 
379 	if (i->dft->lldd_I_T_nexus_reset)
380 		res = i->dft->lldd_I_T_nexus_reset(dev);
381 
382 	return res;
383 }
384 
385 /* take a reference on the last known good phy for this device */
386 struct sas_phy *sas_get_local_phy(struct domain_device *dev)
387 {
388 	struct sas_ha_struct *ha = dev->port->ha;
389 	struct sas_phy *phy;
390 	unsigned long flags;
391 
392 	/* a published domain device always has a valid phy, it may be
393 	 * stale, but it is never NULL
394 	 */
395 	BUG_ON(!dev->phy);
396 
397 	spin_lock_irqsave(&ha->phy_port_lock, flags);
398 	phy = dev->phy;
399 	get_device(&phy->dev);
400 	spin_unlock_irqrestore(&ha->phy_port_lock, flags);
401 
402 	return phy;
403 }
404 EXPORT_SYMBOL_GPL(sas_get_local_phy);
405 
406 static void sas_wait_eh(struct domain_device *dev)
407 {
408 	struct sas_ha_struct *ha = dev->port->ha;
409 	DEFINE_WAIT(wait);
410 
411 	if (dev_is_sata(dev)) {
412 		ata_port_wait_eh(dev->sata_dev.ap);
413 		return;
414 	}
415  retry:
416 	spin_lock_irq(&ha->lock);
417 
418 	while (test_bit(SAS_DEV_EH_PENDING, &dev->state)) {
419 		prepare_to_wait(&ha->eh_wait_q, &wait, TASK_UNINTERRUPTIBLE);
420 		spin_unlock_irq(&ha->lock);
421 		schedule();
422 		spin_lock_irq(&ha->lock);
423 	}
424 	finish_wait(&ha->eh_wait_q, &wait);
425 
426 	spin_unlock_irq(&ha->lock);
427 
428 	/* make sure SCSI EH is complete */
429 	if (scsi_host_in_recovery(ha->core.shost)) {
430 		msleep(10);
431 		goto retry;
432 	}
433 }
434 EXPORT_SYMBOL(sas_wait_eh);
435 
436 static int sas_queue_reset(struct domain_device *dev, int reset_type,
437 			   u64 lun, int wait)
438 {
439 	struct sas_ha_struct *ha = dev->port->ha;
440 	int scheduled = 0, tries = 100;
441 
442 	/* ata: promote lun reset to bus reset */
443 	if (dev_is_sata(dev)) {
444 		sas_ata_schedule_reset(dev);
445 		if (wait)
446 			sas_ata_wait_eh(dev);
447 		return SUCCESS;
448 	}
449 
450 	while (!scheduled && tries--) {
451 		spin_lock_irq(&ha->lock);
452 		if (!test_bit(SAS_DEV_EH_PENDING, &dev->state) &&
453 		    !test_bit(reset_type, &dev->state)) {
454 			scheduled = 1;
455 			ha->eh_active++;
456 			list_add_tail(&dev->ssp_dev.eh_list_node, &ha->eh_dev_q);
457 			set_bit(SAS_DEV_EH_PENDING, &dev->state);
458 			set_bit(reset_type, &dev->state);
459 			int_to_scsilun(lun, &dev->ssp_dev.reset_lun);
460 			scsi_schedule_eh(ha->core.shost);
461 		}
462 		spin_unlock_irq(&ha->lock);
463 
464 		if (wait)
465 			sas_wait_eh(dev);
466 
467 		if (scheduled)
468 			return SUCCESS;
469 	}
470 
471 	pr_warn("%s reset of %s failed\n",
472 		reset_type == SAS_DEV_LU_RESET ? "LUN" : "Bus",
473 		dev_name(&dev->rphy->dev));
474 
475 	return FAILED;
476 }
477 
478 int sas_eh_abort_handler(struct scsi_cmnd *cmd)
479 {
480 	int res = TMF_RESP_FUNC_FAILED;
481 	struct sas_task *task = TO_SAS_TASK(cmd);
482 	struct Scsi_Host *host = cmd->device->host;
483 	struct domain_device *dev = cmd_to_domain_dev(cmd);
484 	struct sas_internal *i = to_sas_internal(host->transportt);
485 	unsigned long flags;
486 
487 	if (!i->dft->lldd_abort_task)
488 		return FAILED;
489 
490 	spin_lock_irqsave(host->host_lock, flags);
491 	/* We cannot do async aborts for SATA devices */
492 	if (dev_is_sata(dev) && !host->host_eh_scheduled) {
493 		spin_unlock_irqrestore(host->host_lock, flags);
494 		return FAILED;
495 	}
496 	spin_unlock_irqrestore(host->host_lock, flags);
497 
498 	if (task)
499 		res = i->dft->lldd_abort_task(task);
500 	else
501 		pr_notice("no task to abort\n");
502 	if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE)
503 		return SUCCESS;
504 
505 	return FAILED;
506 }
507 EXPORT_SYMBOL_GPL(sas_eh_abort_handler);
508 
509 /* Attempt to send a LUN reset message to a device */
510 int sas_eh_device_reset_handler(struct scsi_cmnd *cmd)
511 {
512 	int res;
513 	struct scsi_lun lun;
514 	struct Scsi_Host *host = cmd->device->host;
515 	struct domain_device *dev = cmd_to_domain_dev(cmd);
516 	struct sas_internal *i = to_sas_internal(host->transportt);
517 
518 	if (current != host->ehandler)
519 		return sas_queue_reset(dev, SAS_DEV_LU_RESET, cmd->device->lun, 0);
520 
521 	int_to_scsilun(cmd->device->lun, &lun);
522 
523 	if (!i->dft->lldd_lu_reset)
524 		return FAILED;
525 
526 	res = i->dft->lldd_lu_reset(dev, lun.scsi_lun);
527 	if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE)
528 		return SUCCESS;
529 
530 	return FAILED;
531 }
532 
533 int sas_eh_target_reset_handler(struct scsi_cmnd *cmd)
534 {
535 	int res;
536 	struct Scsi_Host *host = cmd->device->host;
537 	struct domain_device *dev = cmd_to_domain_dev(cmd);
538 	struct sas_internal *i = to_sas_internal(host->transportt);
539 
540 	if (current != host->ehandler)
541 		return sas_queue_reset(dev, SAS_DEV_RESET, 0, 0);
542 
543 	if (!i->dft->lldd_I_T_nexus_reset)
544 		return FAILED;
545 
546 	res = i->dft->lldd_I_T_nexus_reset(dev);
547 	if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE ||
548 	    res == -ENODEV)
549 		return SUCCESS;
550 
551 	return FAILED;
552 }
553 
554 /* Try to reset a device */
555 static int try_to_reset_cmd_device(struct scsi_cmnd *cmd)
556 {
557 	int res;
558 	struct Scsi_Host *shost = cmd->device->host;
559 
560 	if (!shost->hostt->eh_device_reset_handler)
561 		goto try_target_reset;
562 
563 	res = shost->hostt->eh_device_reset_handler(cmd);
564 	if (res == SUCCESS)
565 		return res;
566 
567 try_target_reset:
568 	if (shost->hostt->eh_target_reset_handler)
569 		return shost->hostt->eh_target_reset_handler(cmd);
570 
571 	return FAILED;
572 }
573 
574 static void sas_eh_handle_sas_errors(struct Scsi_Host *shost, struct list_head *work_q)
575 {
576 	struct scsi_cmnd *cmd, *n;
577 	enum task_disposition res = TASK_IS_DONE;
578 	int tmf_resp, need_reset;
579 	struct sas_internal *i = to_sas_internal(shost->transportt);
580 	unsigned long flags;
581 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
582 	LIST_HEAD(done);
583 
584 	/* clean out any commands that won the completion vs eh race */
585 	list_for_each_entry_safe(cmd, n, work_q, eh_entry) {
586 		struct domain_device *dev = cmd_to_domain_dev(cmd);
587 		struct sas_task *task;
588 
589 		spin_lock_irqsave(&dev->done_lock, flags);
590 		/* by this point the lldd has either observed
591 		 * SAS_HA_FROZEN and is leaving the task alone, or has
592 		 * won the race with eh and decided to complete it
593 		 */
594 		task = TO_SAS_TASK(cmd);
595 		spin_unlock_irqrestore(&dev->done_lock, flags);
596 
597 		if (!task)
598 			list_move_tail(&cmd->eh_entry, &done);
599 	}
600 
601  Again:
602 	list_for_each_entry_safe(cmd, n, work_q, eh_entry) {
603 		struct sas_task *task = TO_SAS_TASK(cmd);
604 
605 		list_del_init(&cmd->eh_entry);
606 
607 		spin_lock_irqsave(&task->task_state_lock, flags);
608 		need_reset = task->task_state_flags & SAS_TASK_NEED_DEV_RESET;
609 		spin_unlock_irqrestore(&task->task_state_lock, flags);
610 
611 		if (need_reset) {
612 			pr_notice("%s: task 0x%p requests reset\n",
613 				  __func__, task);
614 			goto reset;
615 		}
616 
617 		pr_debug("trying to find task 0x%p\n", task);
618 		res = sas_scsi_find_task(task);
619 
620 		switch (res) {
621 		case TASK_IS_DONE:
622 			pr_notice("%s: task 0x%p is done\n", __func__,
623 				    task);
624 			sas_eh_finish_cmd(cmd);
625 			continue;
626 		case TASK_IS_ABORTED:
627 			pr_notice("%s: task 0x%p is aborted\n",
628 				  __func__, task);
629 			sas_eh_finish_cmd(cmd);
630 			continue;
631 		case TASK_IS_AT_LU:
632 			pr_info("task 0x%p is at LU: lu recover\n", task);
633  reset:
634 			tmf_resp = sas_recover_lu(task->dev, cmd);
635 			if (tmf_resp == TMF_RESP_FUNC_COMPLETE) {
636 				pr_notice("dev %016llx LU %llx is recovered\n",
637 					  SAS_ADDR(task->dev),
638 					  cmd->device->lun);
639 				sas_eh_finish_cmd(cmd);
640 				sas_scsi_clear_queue_lu(work_q, cmd);
641 				goto Again;
642 			}
643 			/* fallthrough */
644 		case TASK_IS_NOT_AT_LU:
645 		case TASK_ABORT_FAILED:
646 			pr_notice("task 0x%p is not at LU: I_T recover\n",
647 				  task);
648 			tmf_resp = sas_recover_I_T(task->dev);
649 			if (tmf_resp == TMF_RESP_FUNC_COMPLETE ||
650 			    tmf_resp == -ENODEV) {
651 				struct domain_device *dev = task->dev;
652 				pr_notice("I_T %016llx recovered\n",
653 					  SAS_ADDR(task->dev->sas_addr));
654 				sas_eh_finish_cmd(cmd);
655 				sas_scsi_clear_queue_I_T(work_q, dev);
656 				goto Again;
657 			}
658 			/* Hammer time :-) */
659 			try_to_reset_cmd_device(cmd);
660 			if (i->dft->lldd_clear_nexus_port) {
661 				struct asd_sas_port *port = task->dev->port;
662 				pr_debug("clearing nexus for port:%d\n",
663 					  port->id);
664 				res = i->dft->lldd_clear_nexus_port(port);
665 				if (res == TMF_RESP_FUNC_COMPLETE) {
666 					pr_notice("clear nexus port:%d succeeded\n",
667 						  port->id);
668 					sas_eh_finish_cmd(cmd);
669 					sas_scsi_clear_queue_port(work_q,
670 								  port);
671 					goto Again;
672 				}
673 			}
674 			if (i->dft->lldd_clear_nexus_ha) {
675 				pr_debug("clear nexus ha\n");
676 				res = i->dft->lldd_clear_nexus_ha(ha);
677 				if (res == TMF_RESP_FUNC_COMPLETE) {
678 					pr_notice("clear nexus ha succeeded\n");
679 					sas_eh_finish_cmd(cmd);
680 					goto clear_q;
681 				}
682 			}
683 			/* If we are here -- this means that no amount
684 			 * of effort could recover from errors.  Quite
685 			 * possibly the HA just disappeared.
686 			 */
687 			pr_err("error from  device %llx, LUN %llx couldn't be recovered in any way\n",
688 			       SAS_ADDR(task->dev->sas_addr),
689 			       cmd->device->lun);
690 
691 			sas_eh_finish_cmd(cmd);
692 			goto clear_q;
693 		}
694 	}
695  out:
696 	list_splice_tail(&done, work_q);
697 	list_splice_tail_init(&ha->eh_ata_q, work_q);
698 	return;
699 
700  clear_q:
701 	pr_debug("--- Exit %s -- clear_q\n", __func__);
702 	list_for_each_entry_safe(cmd, n, work_q, eh_entry)
703 		sas_eh_finish_cmd(cmd);
704 	goto out;
705 }
706 
707 static void sas_eh_handle_resets(struct Scsi_Host *shost)
708 {
709 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
710 	struct sas_internal *i = to_sas_internal(shost->transportt);
711 
712 	/* handle directed resets to sas devices */
713 	spin_lock_irq(&ha->lock);
714 	while (!list_empty(&ha->eh_dev_q)) {
715 		struct domain_device *dev;
716 		struct ssp_device *ssp;
717 
718 		ssp = list_entry(ha->eh_dev_q.next, typeof(*ssp), eh_list_node);
719 		list_del_init(&ssp->eh_list_node);
720 		dev = container_of(ssp, typeof(*dev), ssp_dev);
721 		kref_get(&dev->kref);
722 		WARN_ONCE(dev_is_sata(dev), "ssp reset to ata device?\n");
723 
724 		spin_unlock_irq(&ha->lock);
725 
726 		if (test_and_clear_bit(SAS_DEV_LU_RESET, &dev->state))
727 			i->dft->lldd_lu_reset(dev, ssp->reset_lun.scsi_lun);
728 
729 		if (test_and_clear_bit(SAS_DEV_RESET, &dev->state))
730 			i->dft->lldd_I_T_nexus_reset(dev);
731 
732 		sas_put_device(dev);
733 		spin_lock_irq(&ha->lock);
734 		clear_bit(SAS_DEV_EH_PENDING, &dev->state);
735 		ha->eh_active--;
736 	}
737 	spin_unlock_irq(&ha->lock);
738 }
739 
740 
741 void sas_scsi_recover_host(struct Scsi_Host *shost)
742 {
743 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
744 	LIST_HEAD(eh_work_q);
745 	int tries = 0;
746 	bool retry;
747 
748 retry:
749 	tries++;
750 	retry = true;
751 	spin_lock_irq(shost->host_lock);
752 	list_splice_init(&shost->eh_cmd_q, &eh_work_q);
753 	spin_unlock_irq(shost->host_lock);
754 
755 	pr_notice("Enter %s busy: %d failed: %d\n",
756 		  __func__, scsi_host_busy(shost), shost->host_failed);
757 	/*
758 	 * Deal with commands that still have SAS tasks (i.e. they didn't
759 	 * complete via the normal sas_task completion mechanism),
760 	 * SAS_HA_FROZEN gives eh dominion over all sas_task completion.
761 	 */
762 	set_bit(SAS_HA_FROZEN, &ha->state);
763 	sas_eh_handle_sas_errors(shost, &eh_work_q);
764 	clear_bit(SAS_HA_FROZEN, &ha->state);
765 	if (list_empty(&eh_work_q))
766 		goto out;
767 
768 	/*
769 	 * Now deal with SCSI commands that completed ok but have a an error
770 	 * code (and hopefully sense data) attached.  This is roughly what
771 	 * scsi_unjam_host does, but we skip scsi_eh_abort_cmds because any
772 	 * command we see here has no sas_task and is thus unknown to the HA.
773 	 */
774 	sas_ata_eh(shost, &eh_work_q, &ha->eh_done_q);
775 	if (!scsi_eh_get_sense(&eh_work_q, &ha->eh_done_q))
776 		scsi_eh_ready_devs(shost, &eh_work_q, &ha->eh_done_q);
777 
778 out:
779 	sas_eh_handle_resets(shost);
780 
781 	/* now link into libata eh --- if we have any ata devices */
782 	sas_ata_strategy_handler(shost);
783 
784 	scsi_eh_flush_done_q(&ha->eh_done_q);
785 
786 	/* check if any new eh work was scheduled during the last run */
787 	spin_lock_irq(&ha->lock);
788 	if (ha->eh_active == 0) {
789 		shost->host_eh_scheduled = 0;
790 		retry = false;
791 	}
792 	spin_unlock_irq(&ha->lock);
793 
794 	if (retry)
795 		goto retry;
796 
797 	pr_notice("--- Exit %s: busy: %d failed: %d tries: %d\n",
798 		  __func__, scsi_host_busy(shost),
799 		  shost->host_failed, tries);
800 }
801 
802 int sas_ioctl(struct scsi_device *sdev, unsigned int cmd, void __user *arg)
803 {
804 	struct domain_device *dev = sdev_to_domain_dev(sdev);
805 
806 	if (dev_is_sata(dev))
807 		return ata_sas_scsi_ioctl(dev->sata_dev.ap, sdev, cmd, arg);
808 
809 	return -EINVAL;
810 }
811 
812 struct domain_device *sas_find_dev_by_rphy(struct sas_rphy *rphy)
813 {
814 	struct Scsi_Host *shost = dev_to_shost(rphy->dev.parent);
815 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
816 	struct domain_device *found_dev = NULL;
817 	int i;
818 	unsigned long flags;
819 
820 	spin_lock_irqsave(&ha->phy_port_lock, flags);
821 	for (i = 0; i < ha->num_phys; i++) {
822 		struct asd_sas_port *port = ha->sas_port[i];
823 		struct domain_device *dev;
824 
825 		spin_lock(&port->dev_list_lock);
826 		list_for_each_entry(dev, &port->dev_list, dev_list_node) {
827 			if (rphy == dev->rphy) {
828 				found_dev = dev;
829 				spin_unlock(&port->dev_list_lock);
830 				goto found;
831 			}
832 		}
833 		spin_unlock(&port->dev_list_lock);
834 	}
835  found:
836 	spin_unlock_irqrestore(&ha->phy_port_lock, flags);
837 
838 	return found_dev;
839 }
840 
841 int sas_target_alloc(struct scsi_target *starget)
842 {
843 	struct sas_rphy *rphy = dev_to_rphy(starget->dev.parent);
844 	struct domain_device *found_dev = sas_find_dev_by_rphy(rphy);
845 
846 	if (!found_dev)
847 		return -ENODEV;
848 
849 	kref_get(&found_dev->kref);
850 	starget->hostdata = found_dev;
851 	return 0;
852 }
853 
854 #define SAS_DEF_QD 256
855 
856 int sas_slave_configure(struct scsi_device *scsi_dev)
857 {
858 	struct domain_device *dev = sdev_to_domain_dev(scsi_dev);
859 
860 	BUG_ON(dev->rphy->identify.device_type != SAS_END_DEVICE);
861 
862 	if (dev_is_sata(dev)) {
863 		ata_sas_slave_configure(scsi_dev, dev->sata_dev.ap);
864 		return 0;
865 	}
866 
867 	sas_read_port_mode_page(scsi_dev);
868 
869 	if (scsi_dev->tagged_supported) {
870 		scsi_change_queue_depth(scsi_dev, SAS_DEF_QD);
871 	} else {
872 		pr_notice("device %llx, LUN %llx doesn't support TCQ\n",
873 			  SAS_ADDR(dev->sas_addr), scsi_dev->lun);
874 		scsi_change_queue_depth(scsi_dev, 1);
875 	}
876 
877 	scsi_dev->allow_restart = 1;
878 
879 	return 0;
880 }
881 
882 int sas_change_queue_depth(struct scsi_device *sdev, int depth)
883 {
884 	struct domain_device *dev = sdev_to_domain_dev(sdev);
885 
886 	if (dev_is_sata(dev))
887 		return __ata_change_queue_depth(dev->sata_dev.ap, sdev, depth);
888 
889 	if (!sdev->tagged_supported)
890 		depth = 1;
891 	return scsi_change_queue_depth(sdev, depth);
892 }
893 
894 int sas_bios_param(struct scsi_device *scsi_dev,
895 			  struct block_device *bdev,
896 			  sector_t capacity, int *hsc)
897 {
898 	hsc[0] = 255;
899 	hsc[1] = 63;
900 	sector_div(capacity, 255*63);
901 	hsc[2] = capacity;
902 
903 	return 0;
904 }
905 
906 /*
907  * Tell an upper layer that it needs to initiate an abort for a given task.
908  * This should only ever be called by an LLDD.
909  */
910 void sas_task_abort(struct sas_task *task)
911 {
912 	struct scsi_cmnd *sc = task->uldd_task;
913 
914 	/* Escape for libsas internal commands */
915 	if (!sc) {
916 		struct sas_task_slow *slow = task->slow_task;
917 
918 		if (!slow)
919 			return;
920 		if (!del_timer(&slow->timer))
921 			return;
922 		slow->timer.function(&slow->timer);
923 		return;
924 	}
925 
926 	if (dev_is_sata(task->dev))
927 		sas_ata_task_abort(task);
928 	else
929 		blk_abort_request(sc->request);
930 }
931 
932 void sas_target_destroy(struct scsi_target *starget)
933 {
934 	struct domain_device *found_dev = starget->hostdata;
935 
936 	if (!found_dev)
937 		return;
938 
939 	starget->hostdata = NULL;
940 	sas_put_device(found_dev);
941 }
942 
943 #define SAS_STRING_ADDR_SIZE	16
944 
945 int sas_request_addr(struct Scsi_Host *shost, u8 *addr)
946 {
947 	int res;
948 	const struct firmware *fw;
949 
950 	res = request_firmware(&fw, "sas_addr", &shost->shost_gendev);
951 	if (res)
952 		return res;
953 
954 	if (fw->size < SAS_STRING_ADDR_SIZE) {
955 		res = -ENODEV;
956 		goto out;
957 	}
958 
959 	res = hex2bin(addr, fw->data, strnlen(fw->data, SAS_ADDR_SIZE * 2) / 2);
960 	if (res)
961 		goto out;
962 
963 out:
964 	release_firmware(fw);
965 	return res;
966 }
967 EXPORT_SYMBOL_GPL(sas_request_addr);
968 
969 EXPORT_SYMBOL_GPL(sas_queuecommand);
970 EXPORT_SYMBOL_GPL(sas_target_alloc);
971 EXPORT_SYMBOL_GPL(sas_slave_configure);
972 EXPORT_SYMBOL_GPL(sas_change_queue_depth);
973 EXPORT_SYMBOL_GPL(sas_bios_param);
974 EXPORT_SYMBOL_GPL(sas_task_abort);
975 EXPORT_SYMBOL_GPL(sas_phy_reset);
976 EXPORT_SYMBOL_GPL(sas_eh_device_reset_handler);
977 EXPORT_SYMBOL_GPL(sas_eh_target_reset_handler);
978 EXPORT_SYMBOL_GPL(sas_target_destroy);
979 EXPORT_SYMBOL_GPL(sas_ioctl);
980