xref: /linux/drivers/scsi/libsas/sas_scsi_host.c (revision 63307d015b91e626c97bb82e88054af3d0b74643)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Serial Attached SCSI (SAS) class SCSI Host glue.
4  *
5  * Copyright (C) 2005 Adaptec, Inc.  All rights reserved.
6  * Copyright (C) 2005 Luben Tuikov <luben_tuikov@adaptec.com>
7  */
8 
9 #include <linux/kthread.h>
10 #include <linux/firmware.h>
11 #include <linux/export.h>
12 #include <linux/ctype.h>
13 #include <linux/kernel.h>
14 
15 #include "sas_internal.h"
16 
17 #include <scsi/scsi_host.h>
18 #include <scsi/scsi_device.h>
19 #include <scsi/scsi_tcq.h>
20 #include <scsi/scsi.h>
21 #include <scsi/scsi_eh.h>
22 #include <scsi/scsi_transport.h>
23 #include <scsi/scsi_transport_sas.h>
24 #include <scsi/sas_ata.h>
25 #include "../scsi_sas_internal.h"
26 #include "../scsi_transport_api.h"
27 #include "../scsi_priv.h"
28 
29 #include <linux/err.h>
30 #include <linux/blkdev.h>
31 #include <linux/freezer.h>
32 #include <linux/gfp.h>
33 #include <linux/scatterlist.h>
34 #include <linux/libata.h>
35 
36 /* record final status and free the task */
37 static void sas_end_task(struct scsi_cmnd *sc, struct sas_task *task)
38 {
39 	struct task_status_struct *ts = &task->task_status;
40 	int hs = 0, stat = 0;
41 
42 	if (ts->resp == SAS_TASK_UNDELIVERED) {
43 		/* transport error */
44 		hs = DID_NO_CONNECT;
45 	} else { /* ts->resp == SAS_TASK_COMPLETE */
46 		/* task delivered, what happened afterwards? */
47 		switch (ts->stat) {
48 		case SAS_DEV_NO_RESPONSE:
49 		case SAS_INTERRUPTED:
50 		case SAS_PHY_DOWN:
51 		case SAS_NAK_R_ERR:
52 		case SAS_OPEN_TO:
53 			hs = DID_NO_CONNECT;
54 			break;
55 		case SAS_DATA_UNDERRUN:
56 			scsi_set_resid(sc, ts->residual);
57 			if (scsi_bufflen(sc) - scsi_get_resid(sc) < sc->underflow)
58 				hs = DID_ERROR;
59 			break;
60 		case SAS_DATA_OVERRUN:
61 			hs = DID_ERROR;
62 			break;
63 		case SAS_QUEUE_FULL:
64 			hs = DID_SOFT_ERROR; /* retry */
65 			break;
66 		case SAS_DEVICE_UNKNOWN:
67 			hs = DID_BAD_TARGET;
68 			break;
69 		case SAS_SG_ERR:
70 			hs = DID_PARITY;
71 			break;
72 		case SAS_OPEN_REJECT:
73 			if (ts->open_rej_reason == SAS_OREJ_RSVD_RETRY)
74 				hs = DID_SOFT_ERROR; /* retry */
75 			else
76 				hs = DID_ERROR;
77 			break;
78 		case SAS_PROTO_RESPONSE:
79 			pr_notice("LLDD:%s sent SAS_PROTO_RESP for an SSP task; please report this\n",
80 				  task->dev->port->ha->sas_ha_name);
81 			break;
82 		case SAS_ABORTED_TASK:
83 			hs = DID_ABORT;
84 			break;
85 		case SAM_STAT_CHECK_CONDITION:
86 			memcpy(sc->sense_buffer, ts->buf,
87 			       min(SCSI_SENSE_BUFFERSIZE, ts->buf_valid_size));
88 			stat = SAM_STAT_CHECK_CONDITION;
89 			break;
90 		default:
91 			stat = ts->stat;
92 			break;
93 		}
94 	}
95 
96 	sc->result = (hs << 16) | stat;
97 	ASSIGN_SAS_TASK(sc, NULL);
98 	sas_free_task(task);
99 }
100 
101 static void sas_scsi_task_done(struct sas_task *task)
102 {
103 	struct scsi_cmnd *sc = task->uldd_task;
104 	struct domain_device *dev = task->dev;
105 	struct sas_ha_struct *ha = dev->port->ha;
106 	unsigned long flags;
107 
108 	spin_lock_irqsave(&dev->done_lock, flags);
109 	if (test_bit(SAS_HA_FROZEN, &ha->state))
110 		task = NULL;
111 	else
112 		ASSIGN_SAS_TASK(sc, NULL);
113 	spin_unlock_irqrestore(&dev->done_lock, flags);
114 
115 	if (unlikely(!task)) {
116 		/* task will be completed by the error handler */
117 		pr_debug("task done but aborted\n");
118 		return;
119 	}
120 
121 	if (unlikely(!sc)) {
122 		pr_debug("task_done called with non existing SCSI cmnd!\n");
123 		sas_free_task(task);
124 		return;
125 	}
126 
127 	sas_end_task(sc, task);
128 	sc->scsi_done(sc);
129 }
130 
131 static struct sas_task *sas_create_task(struct scsi_cmnd *cmd,
132 					       struct domain_device *dev,
133 					       gfp_t gfp_flags)
134 {
135 	struct sas_task *task = sas_alloc_task(gfp_flags);
136 	struct scsi_lun lun;
137 
138 	if (!task)
139 		return NULL;
140 
141 	task->uldd_task = cmd;
142 	ASSIGN_SAS_TASK(cmd, task);
143 
144 	task->dev = dev;
145 	task->task_proto = task->dev->tproto; /* BUG_ON(!SSP) */
146 
147 	task->ssp_task.retry_count = 1;
148 	int_to_scsilun(cmd->device->lun, &lun);
149 	memcpy(task->ssp_task.LUN, &lun.scsi_lun, 8);
150 	task->ssp_task.task_attr = TASK_ATTR_SIMPLE;
151 	task->ssp_task.cmd = cmd;
152 
153 	task->scatter = scsi_sglist(cmd);
154 	task->num_scatter = scsi_sg_count(cmd);
155 	task->total_xfer_len = scsi_bufflen(cmd);
156 	task->data_dir = cmd->sc_data_direction;
157 
158 	task->task_done = sas_scsi_task_done;
159 
160 	return task;
161 }
162 
163 int sas_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
164 {
165 	struct sas_internal *i = to_sas_internal(host->transportt);
166 	struct domain_device *dev = cmd_to_domain_dev(cmd);
167 	struct sas_task *task;
168 	int res = 0;
169 
170 	/* If the device fell off, no sense in issuing commands */
171 	if (test_bit(SAS_DEV_GONE, &dev->state)) {
172 		cmd->result = DID_BAD_TARGET << 16;
173 		goto out_done;
174 	}
175 
176 	if (dev_is_sata(dev)) {
177 		spin_lock_irq(dev->sata_dev.ap->lock);
178 		res = ata_sas_queuecmd(cmd, dev->sata_dev.ap);
179 		spin_unlock_irq(dev->sata_dev.ap->lock);
180 		return res;
181 	}
182 
183 	task = sas_create_task(cmd, dev, GFP_ATOMIC);
184 	if (!task)
185 		return SCSI_MLQUEUE_HOST_BUSY;
186 
187 	res = i->dft->lldd_execute_task(task, GFP_ATOMIC);
188 	if (res)
189 		goto out_free_task;
190 	return 0;
191 
192 out_free_task:
193 	pr_debug("lldd_execute_task returned: %d\n", res);
194 	ASSIGN_SAS_TASK(cmd, NULL);
195 	sas_free_task(task);
196 	if (res == -SAS_QUEUE_FULL)
197 		cmd->result = DID_SOFT_ERROR << 16; /* retry */
198 	else
199 		cmd->result = DID_ERROR << 16;
200 out_done:
201 	cmd->scsi_done(cmd);
202 	return 0;
203 }
204 
205 static void sas_eh_finish_cmd(struct scsi_cmnd *cmd)
206 {
207 	struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(cmd->device->host);
208 	struct domain_device *dev = cmd_to_domain_dev(cmd);
209 	struct sas_task *task = TO_SAS_TASK(cmd);
210 
211 	/* At this point, we only get called following an actual abort
212 	 * of the task, so we should be guaranteed not to be racing with
213 	 * any completions from the LLD.  Task is freed after this.
214 	 */
215 	sas_end_task(cmd, task);
216 
217 	if (dev_is_sata(dev)) {
218 		/* defer commands to libata so that libata EH can
219 		 * handle ata qcs correctly
220 		 */
221 		list_move_tail(&cmd->eh_entry, &sas_ha->eh_ata_q);
222 		return;
223 	}
224 
225 	/* now finish the command and move it on to the error
226 	 * handler done list, this also takes it off the
227 	 * error handler pending list.
228 	 */
229 	scsi_eh_finish_cmd(cmd, &sas_ha->eh_done_q);
230 }
231 
232 static void sas_scsi_clear_queue_lu(struct list_head *error_q, struct scsi_cmnd *my_cmd)
233 {
234 	struct scsi_cmnd *cmd, *n;
235 
236 	list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
237 		if (cmd->device->sdev_target == my_cmd->device->sdev_target &&
238 		    cmd->device->lun == my_cmd->device->lun)
239 			sas_eh_finish_cmd(cmd);
240 	}
241 }
242 
243 static void sas_scsi_clear_queue_I_T(struct list_head *error_q,
244 				     struct domain_device *dev)
245 {
246 	struct scsi_cmnd *cmd, *n;
247 
248 	list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
249 		struct domain_device *x = cmd_to_domain_dev(cmd);
250 
251 		if (x == dev)
252 			sas_eh_finish_cmd(cmd);
253 	}
254 }
255 
256 static void sas_scsi_clear_queue_port(struct list_head *error_q,
257 				      struct asd_sas_port *port)
258 {
259 	struct scsi_cmnd *cmd, *n;
260 
261 	list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
262 		struct domain_device *dev = cmd_to_domain_dev(cmd);
263 		struct asd_sas_port *x = dev->port;
264 
265 		if (x == port)
266 			sas_eh_finish_cmd(cmd);
267 	}
268 }
269 
270 enum task_disposition {
271 	TASK_IS_DONE,
272 	TASK_IS_ABORTED,
273 	TASK_IS_AT_LU,
274 	TASK_IS_NOT_AT_LU,
275 	TASK_ABORT_FAILED,
276 };
277 
278 static enum task_disposition sas_scsi_find_task(struct sas_task *task)
279 {
280 	unsigned long flags;
281 	int i, res;
282 	struct sas_internal *si =
283 		to_sas_internal(task->dev->port->ha->core.shost->transportt);
284 
285 	for (i = 0; i < 5; i++) {
286 		pr_notice("%s: aborting task 0x%p\n", __func__, task);
287 		res = si->dft->lldd_abort_task(task);
288 
289 		spin_lock_irqsave(&task->task_state_lock, flags);
290 		if (task->task_state_flags & SAS_TASK_STATE_DONE) {
291 			spin_unlock_irqrestore(&task->task_state_lock, flags);
292 			pr_debug("%s: task 0x%p is done\n", __func__, task);
293 			return TASK_IS_DONE;
294 		}
295 		spin_unlock_irqrestore(&task->task_state_lock, flags);
296 
297 		if (res == TMF_RESP_FUNC_COMPLETE) {
298 			pr_notice("%s: task 0x%p is aborted\n",
299 				  __func__, task);
300 			return TASK_IS_ABORTED;
301 		} else if (si->dft->lldd_query_task) {
302 			pr_notice("%s: querying task 0x%p\n", __func__, task);
303 			res = si->dft->lldd_query_task(task);
304 			switch (res) {
305 			case TMF_RESP_FUNC_SUCC:
306 				pr_notice("%s: task 0x%p at LU\n", __func__,
307 					  task);
308 				return TASK_IS_AT_LU;
309 			case TMF_RESP_FUNC_COMPLETE:
310 				pr_notice("%s: task 0x%p not at LU\n",
311 					  __func__, task);
312 				return TASK_IS_NOT_AT_LU;
313 			case TMF_RESP_FUNC_FAILED:
314 				pr_notice("%s: task 0x%p failed to abort\n",
315 					  __func__, task);
316 				return TASK_ABORT_FAILED;
317 			}
318 
319 		}
320 	}
321 	return res;
322 }
323 
324 static int sas_recover_lu(struct domain_device *dev, struct scsi_cmnd *cmd)
325 {
326 	int res = TMF_RESP_FUNC_FAILED;
327 	struct scsi_lun lun;
328 	struct sas_internal *i =
329 		to_sas_internal(dev->port->ha->core.shost->transportt);
330 
331 	int_to_scsilun(cmd->device->lun, &lun);
332 
333 	pr_notice("eh: device %llx LUN %llx has the task\n",
334 		  SAS_ADDR(dev->sas_addr),
335 		  cmd->device->lun);
336 
337 	if (i->dft->lldd_abort_task_set)
338 		res = i->dft->lldd_abort_task_set(dev, lun.scsi_lun);
339 
340 	if (res == TMF_RESP_FUNC_FAILED) {
341 		if (i->dft->lldd_clear_task_set)
342 			res = i->dft->lldd_clear_task_set(dev, lun.scsi_lun);
343 	}
344 
345 	if (res == TMF_RESP_FUNC_FAILED) {
346 		if (i->dft->lldd_lu_reset)
347 			res = i->dft->lldd_lu_reset(dev, lun.scsi_lun);
348 	}
349 
350 	return res;
351 }
352 
353 static int sas_recover_I_T(struct domain_device *dev)
354 {
355 	int res = TMF_RESP_FUNC_FAILED;
356 	struct sas_internal *i =
357 		to_sas_internal(dev->port->ha->core.shost->transportt);
358 
359 	pr_notice("I_T nexus reset for dev %016llx\n",
360 		  SAS_ADDR(dev->sas_addr));
361 
362 	if (i->dft->lldd_I_T_nexus_reset)
363 		res = i->dft->lldd_I_T_nexus_reset(dev);
364 
365 	return res;
366 }
367 
368 /* take a reference on the last known good phy for this device */
369 struct sas_phy *sas_get_local_phy(struct domain_device *dev)
370 {
371 	struct sas_ha_struct *ha = dev->port->ha;
372 	struct sas_phy *phy;
373 	unsigned long flags;
374 
375 	/* a published domain device always has a valid phy, it may be
376 	 * stale, but it is never NULL
377 	 */
378 	BUG_ON(!dev->phy);
379 
380 	spin_lock_irqsave(&ha->phy_port_lock, flags);
381 	phy = dev->phy;
382 	get_device(&phy->dev);
383 	spin_unlock_irqrestore(&ha->phy_port_lock, flags);
384 
385 	return phy;
386 }
387 EXPORT_SYMBOL_GPL(sas_get_local_phy);
388 
389 static void sas_wait_eh(struct domain_device *dev)
390 {
391 	struct sas_ha_struct *ha = dev->port->ha;
392 	DEFINE_WAIT(wait);
393 
394 	if (dev_is_sata(dev)) {
395 		ata_port_wait_eh(dev->sata_dev.ap);
396 		return;
397 	}
398  retry:
399 	spin_lock_irq(&ha->lock);
400 
401 	while (test_bit(SAS_DEV_EH_PENDING, &dev->state)) {
402 		prepare_to_wait(&ha->eh_wait_q, &wait, TASK_UNINTERRUPTIBLE);
403 		spin_unlock_irq(&ha->lock);
404 		schedule();
405 		spin_lock_irq(&ha->lock);
406 	}
407 	finish_wait(&ha->eh_wait_q, &wait);
408 
409 	spin_unlock_irq(&ha->lock);
410 
411 	/* make sure SCSI EH is complete */
412 	if (scsi_host_in_recovery(ha->core.shost)) {
413 		msleep(10);
414 		goto retry;
415 	}
416 }
417 EXPORT_SYMBOL(sas_wait_eh);
418 
419 static int sas_queue_reset(struct domain_device *dev, int reset_type,
420 			   u64 lun, int wait)
421 {
422 	struct sas_ha_struct *ha = dev->port->ha;
423 	int scheduled = 0, tries = 100;
424 
425 	/* ata: promote lun reset to bus reset */
426 	if (dev_is_sata(dev)) {
427 		sas_ata_schedule_reset(dev);
428 		if (wait)
429 			sas_ata_wait_eh(dev);
430 		return SUCCESS;
431 	}
432 
433 	while (!scheduled && tries--) {
434 		spin_lock_irq(&ha->lock);
435 		if (!test_bit(SAS_DEV_EH_PENDING, &dev->state) &&
436 		    !test_bit(reset_type, &dev->state)) {
437 			scheduled = 1;
438 			ha->eh_active++;
439 			list_add_tail(&dev->ssp_dev.eh_list_node, &ha->eh_dev_q);
440 			set_bit(SAS_DEV_EH_PENDING, &dev->state);
441 			set_bit(reset_type, &dev->state);
442 			int_to_scsilun(lun, &dev->ssp_dev.reset_lun);
443 			scsi_schedule_eh(ha->core.shost);
444 		}
445 		spin_unlock_irq(&ha->lock);
446 
447 		if (wait)
448 			sas_wait_eh(dev);
449 
450 		if (scheduled)
451 			return SUCCESS;
452 	}
453 
454 	pr_warn("%s reset of %s failed\n",
455 		reset_type == SAS_DEV_LU_RESET ? "LUN" : "Bus",
456 		dev_name(&dev->rphy->dev));
457 
458 	return FAILED;
459 }
460 
461 int sas_eh_abort_handler(struct scsi_cmnd *cmd)
462 {
463 	int res = TMF_RESP_FUNC_FAILED;
464 	struct sas_task *task = TO_SAS_TASK(cmd);
465 	struct Scsi_Host *host = cmd->device->host;
466 	struct domain_device *dev = cmd_to_domain_dev(cmd);
467 	struct sas_internal *i = to_sas_internal(host->transportt);
468 	unsigned long flags;
469 
470 	if (!i->dft->lldd_abort_task)
471 		return FAILED;
472 
473 	spin_lock_irqsave(host->host_lock, flags);
474 	/* We cannot do async aborts for SATA devices */
475 	if (dev_is_sata(dev) && !host->host_eh_scheduled) {
476 		spin_unlock_irqrestore(host->host_lock, flags);
477 		return FAILED;
478 	}
479 	spin_unlock_irqrestore(host->host_lock, flags);
480 
481 	if (task)
482 		res = i->dft->lldd_abort_task(task);
483 	else
484 		pr_notice("no task to abort\n");
485 	if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE)
486 		return SUCCESS;
487 
488 	return FAILED;
489 }
490 EXPORT_SYMBOL_GPL(sas_eh_abort_handler);
491 
492 /* Attempt to send a LUN reset message to a device */
493 int sas_eh_device_reset_handler(struct scsi_cmnd *cmd)
494 {
495 	int res;
496 	struct scsi_lun lun;
497 	struct Scsi_Host *host = cmd->device->host;
498 	struct domain_device *dev = cmd_to_domain_dev(cmd);
499 	struct sas_internal *i = to_sas_internal(host->transportt);
500 
501 	if (current != host->ehandler)
502 		return sas_queue_reset(dev, SAS_DEV_LU_RESET, cmd->device->lun, 0);
503 
504 	int_to_scsilun(cmd->device->lun, &lun);
505 
506 	if (!i->dft->lldd_lu_reset)
507 		return FAILED;
508 
509 	res = i->dft->lldd_lu_reset(dev, lun.scsi_lun);
510 	if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE)
511 		return SUCCESS;
512 
513 	return FAILED;
514 }
515 
516 int sas_eh_target_reset_handler(struct scsi_cmnd *cmd)
517 {
518 	int res;
519 	struct Scsi_Host *host = cmd->device->host;
520 	struct domain_device *dev = cmd_to_domain_dev(cmd);
521 	struct sas_internal *i = to_sas_internal(host->transportt);
522 
523 	if (current != host->ehandler)
524 		return sas_queue_reset(dev, SAS_DEV_RESET, 0, 0);
525 
526 	if (!i->dft->lldd_I_T_nexus_reset)
527 		return FAILED;
528 
529 	res = i->dft->lldd_I_T_nexus_reset(dev);
530 	if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE ||
531 	    res == -ENODEV)
532 		return SUCCESS;
533 
534 	return FAILED;
535 }
536 
537 /* Try to reset a device */
538 static int try_to_reset_cmd_device(struct scsi_cmnd *cmd)
539 {
540 	int res;
541 	struct Scsi_Host *shost = cmd->device->host;
542 
543 	if (!shost->hostt->eh_device_reset_handler)
544 		goto try_target_reset;
545 
546 	res = shost->hostt->eh_device_reset_handler(cmd);
547 	if (res == SUCCESS)
548 		return res;
549 
550 try_target_reset:
551 	if (shost->hostt->eh_target_reset_handler)
552 		return shost->hostt->eh_target_reset_handler(cmd);
553 
554 	return FAILED;
555 }
556 
557 static void sas_eh_handle_sas_errors(struct Scsi_Host *shost, struct list_head *work_q)
558 {
559 	struct scsi_cmnd *cmd, *n;
560 	enum task_disposition res = TASK_IS_DONE;
561 	int tmf_resp, need_reset;
562 	struct sas_internal *i = to_sas_internal(shost->transportt);
563 	unsigned long flags;
564 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
565 	LIST_HEAD(done);
566 
567 	/* clean out any commands that won the completion vs eh race */
568 	list_for_each_entry_safe(cmd, n, work_q, eh_entry) {
569 		struct domain_device *dev = cmd_to_domain_dev(cmd);
570 		struct sas_task *task;
571 
572 		spin_lock_irqsave(&dev->done_lock, flags);
573 		/* by this point the lldd has either observed
574 		 * SAS_HA_FROZEN and is leaving the task alone, or has
575 		 * won the race with eh and decided to complete it
576 		 */
577 		task = TO_SAS_TASK(cmd);
578 		spin_unlock_irqrestore(&dev->done_lock, flags);
579 
580 		if (!task)
581 			list_move_tail(&cmd->eh_entry, &done);
582 	}
583 
584  Again:
585 	list_for_each_entry_safe(cmd, n, work_q, eh_entry) {
586 		struct sas_task *task = TO_SAS_TASK(cmd);
587 
588 		list_del_init(&cmd->eh_entry);
589 
590 		spin_lock_irqsave(&task->task_state_lock, flags);
591 		need_reset = task->task_state_flags & SAS_TASK_NEED_DEV_RESET;
592 		spin_unlock_irqrestore(&task->task_state_lock, flags);
593 
594 		if (need_reset) {
595 			pr_notice("%s: task 0x%p requests reset\n",
596 				  __func__, task);
597 			goto reset;
598 		}
599 
600 		pr_debug("trying to find task 0x%p\n", task);
601 		res = sas_scsi_find_task(task);
602 
603 		switch (res) {
604 		case TASK_IS_DONE:
605 			pr_notice("%s: task 0x%p is done\n", __func__,
606 				    task);
607 			sas_eh_finish_cmd(cmd);
608 			continue;
609 		case TASK_IS_ABORTED:
610 			pr_notice("%s: task 0x%p is aborted\n",
611 				  __func__, task);
612 			sas_eh_finish_cmd(cmd);
613 			continue;
614 		case TASK_IS_AT_LU:
615 			pr_info("task 0x%p is at LU: lu recover\n", task);
616  reset:
617 			tmf_resp = sas_recover_lu(task->dev, cmd);
618 			if (tmf_resp == TMF_RESP_FUNC_COMPLETE) {
619 				pr_notice("dev %016llx LU %llx is recovered\n",
620 					  SAS_ADDR(task->dev),
621 					  cmd->device->lun);
622 				sas_eh_finish_cmd(cmd);
623 				sas_scsi_clear_queue_lu(work_q, cmd);
624 				goto Again;
625 			}
626 			/* fallthrough */
627 		case TASK_IS_NOT_AT_LU:
628 		case TASK_ABORT_FAILED:
629 			pr_notice("task 0x%p is not at LU: I_T recover\n",
630 				  task);
631 			tmf_resp = sas_recover_I_T(task->dev);
632 			if (tmf_resp == TMF_RESP_FUNC_COMPLETE ||
633 			    tmf_resp == -ENODEV) {
634 				struct domain_device *dev = task->dev;
635 				pr_notice("I_T %016llx recovered\n",
636 					  SAS_ADDR(task->dev->sas_addr));
637 				sas_eh_finish_cmd(cmd);
638 				sas_scsi_clear_queue_I_T(work_q, dev);
639 				goto Again;
640 			}
641 			/* Hammer time :-) */
642 			try_to_reset_cmd_device(cmd);
643 			if (i->dft->lldd_clear_nexus_port) {
644 				struct asd_sas_port *port = task->dev->port;
645 				pr_debug("clearing nexus for port:%d\n",
646 					  port->id);
647 				res = i->dft->lldd_clear_nexus_port(port);
648 				if (res == TMF_RESP_FUNC_COMPLETE) {
649 					pr_notice("clear nexus port:%d succeeded\n",
650 						  port->id);
651 					sas_eh_finish_cmd(cmd);
652 					sas_scsi_clear_queue_port(work_q,
653 								  port);
654 					goto Again;
655 				}
656 			}
657 			if (i->dft->lldd_clear_nexus_ha) {
658 				pr_debug("clear nexus ha\n");
659 				res = i->dft->lldd_clear_nexus_ha(ha);
660 				if (res == TMF_RESP_FUNC_COMPLETE) {
661 					pr_notice("clear nexus ha succeeded\n");
662 					sas_eh_finish_cmd(cmd);
663 					goto clear_q;
664 				}
665 			}
666 			/* If we are here -- this means that no amount
667 			 * of effort could recover from errors.  Quite
668 			 * possibly the HA just disappeared.
669 			 */
670 			pr_err("error from  device %llx, LUN %llx couldn't be recovered in any way\n",
671 			       SAS_ADDR(task->dev->sas_addr),
672 			       cmd->device->lun);
673 
674 			sas_eh_finish_cmd(cmd);
675 			goto clear_q;
676 		}
677 	}
678  out:
679 	list_splice_tail(&done, work_q);
680 	list_splice_tail_init(&ha->eh_ata_q, work_q);
681 	return;
682 
683  clear_q:
684 	pr_debug("--- Exit %s -- clear_q\n", __func__);
685 	list_for_each_entry_safe(cmd, n, work_q, eh_entry)
686 		sas_eh_finish_cmd(cmd);
687 	goto out;
688 }
689 
690 static void sas_eh_handle_resets(struct Scsi_Host *shost)
691 {
692 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
693 	struct sas_internal *i = to_sas_internal(shost->transportt);
694 
695 	/* handle directed resets to sas devices */
696 	spin_lock_irq(&ha->lock);
697 	while (!list_empty(&ha->eh_dev_q)) {
698 		struct domain_device *dev;
699 		struct ssp_device *ssp;
700 
701 		ssp = list_entry(ha->eh_dev_q.next, typeof(*ssp), eh_list_node);
702 		list_del_init(&ssp->eh_list_node);
703 		dev = container_of(ssp, typeof(*dev), ssp_dev);
704 		kref_get(&dev->kref);
705 		WARN_ONCE(dev_is_sata(dev), "ssp reset to ata device?\n");
706 
707 		spin_unlock_irq(&ha->lock);
708 
709 		if (test_and_clear_bit(SAS_DEV_LU_RESET, &dev->state))
710 			i->dft->lldd_lu_reset(dev, ssp->reset_lun.scsi_lun);
711 
712 		if (test_and_clear_bit(SAS_DEV_RESET, &dev->state))
713 			i->dft->lldd_I_T_nexus_reset(dev);
714 
715 		sas_put_device(dev);
716 		spin_lock_irq(&ha->lock);
717 		clear_bit(SAS_DEV_EH_PENDING, &dev->state);
718 		ha->eh_active--;
719 	}
720 	spin_unlock_irq(&ha->lock);
721 }
722 
723 
724 void sas_scsi_recover_host(struct Scsi_Host *shost)
725 {
726 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
727 	LIST_HEAD(eh_work_q);
728 	int tries = 0;
729 	bool retry;
730 
731 retry:
732 	tries++;
733 	retry = true;
734 	spin_lock_irq(shost->host_lock);
735 	list_splice_init(&shost->eh_cmd_q, &eh_work_q);
736 	spin_unlock_irq(shost->host_lock);
737 
738 	pr_notice("Enter %s busy: %d failed: %d\n",
739 		  __func__, scsi_host_busy(shost), shost->host_failed);
740 	/*
741 	 * Deal with commands that still have SAS tasks (i.e. they didn't
742 	 * complete via the normal sas_task completion mechanism),
743 	 * SAS_HA_FROZEN gives eh dominion over all sas_task completion.
744 	 */
745 	set_bit(SAS_HA_FROZEN, &ha->state);
746 	sas_eh_handle_sas_errors(shost, &eh_work_q);
747 	clear_bit(SAS_HA_FROZEN, &ha->state);
748 	if (list_empty(&eh_work_q))
749 		goto out;
750 
751 	/*
752 	 * Now deal with SCSI commands that completed ok but have a an error
753 	 * code (and hopefully sense data) attached.  This is roughly what
754 	 * scsi_unjam_host does, but we skip scsi_eh_abort_cmds because any
755 	 * command we see here has no sas_task and is thus unknown to the HA.
756 	 */
757 	sas_ata_eh(shost, &eh_work_q, &ha->eh_done_q);
758 	if (!scsi_eh_get_sense(&eh_work_q, &ha->eh_done_q))
759 		scsi_eh_ready_devs(shost, &eh_work_q, &ha->eh_done_q);
760 
761 out:
762 	sas_eh_handle_resets(shost);
763 
764 	/* now link into libata eh --- if we have any ata devices */
765 	sas_ata_strategy_handler(shost);
766 
767 	scsi_eh_flush_done_q(&ha->eh_done_q);
768 
769 	/* check if any new eh work was scheduled during the last run */
770 	spin_lock_irq(&ha->lock);
771 	if (ha->eh_active == 0) {
772 		shost->host_eh_scheduled = 0;
773 		retry = false;
774 	}
775 	spin_unlock_irq(&ha->lock);
776 
777 	if (retry)
778 		goto retry;
779 
780 	pr_notice("--- Exit %s: busy: %d failed: %d tries: %d\n",
781 		  __func__, scsi_host_busy(shost),
782 		  shost->host_failed, tries);
783 }
784 
785 int sas_ioctl(struct scsi_device *sdev, unsigned int cmd, void __user *arg)
786 {
787 	struct domain_device *dev = sdev_to_domain_dev(sdev);
788 
789 	if (dev_is_sata(dev))
790 		return ata_sas_scsi_ioctl(dev->sata_dev.ap, sdev, cmd, arg);
791 
792 	return -EINVAL;
793 }
794 
795 struct domain_device *sas_find_dev_by_rphy(struct sas_rphy *rphy)
796 {
797 	struct Scsi_Host *shost = dev_to_shost(rphy->dev.parent);
798 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
799 	struct domain_device *found_dev = NULL;
800 	int i;
801 	unsigned long flags;
802 
803 	spin_lock_irqsave(&ha->phy_port_lock, flags);
804 	for (i = 0; i < ha->num_phys; i++) {
805 		struct asd_sas_port *port = ha->sas_port[i];
806 		struct domain_device *dev;
807 
808 		spin_lock(&port->dev_list_lock);
809 		list_for_each_entry(dev, &port->dev_list, dev_list_node) {
810 			if (rphy == dev->rphy) {
811 				found_dev = dev;
812 				spin_unlock(&port->dev_list_lock);
813 				goto found;
814 			}
815 		}
816 		spin_unlock(&port->dev_list_lock);
817 	}
818  found:
819 	spin_unlock_irqrestore(&ha->phy_port_lock, flags);
820 
821 	return found_dev;
822 }
823 
824 int sas_target_alloc(struct scsi_target *starget)
825 {
826 	struct sas_rphy *rphy = dev_to_rphy(starget->dev.parent);
827 	struct domain_device *found_dev = sas_find_dev_by_rphy(rphy);
828 
829 	if (!found_dev)
830 		return -ENODEV;
831 
832 	kref_get(&found_dev->kref);
833 	starget->hostdata = found_dev;
834 	return 0;
835 }
836 
837 #define SAS_DEF_QD 256
838 
839 int sas_slave_configure(struct scsi_device *scsi_dev)
840 {
841 	struct domain_device *dev = sdev_to_domain_dev(scsi_dev);
842 
843 	BUG_ON(dev->rphy->identify.device_type != SAS_END_DEVICE);
844 
845 	if (dev_is_sata(dev)) {
846 		ata_sas_slave_configure(scsi_dev, dev->sata_dev.ap);
847 		return 0;
848 	}
849 
850 	sas_read_port_mode_page(scsi_dev);
851 
852 	if (scsi_dev->tagged_supported) {
853 		scsi_change_queue_depth(scsi_dev, SAS_DEF_QD);
854 	} else {
855 		pr_notice("device %llx, LUN %llx doesn't support TCQ\n",
856 			  SAS_ADDR(dev->sas_addr), scsi_dev->lun);
857 		scsi_change_queue_depth(scsi_dev, 1);
858 	}
859 
860 	scsi_dev->allow_restart = 1;
861 
862 	return 0;
863 }
864 
865 int sas_change_queue_depth(struct scsi_device *sdev, int depth)
866 {
867 	struct domain_device *dev = sdev_to_domain_dev(sdev);
868 
869 	if (dev_is_sata(dev))
870 		return __ata_change_queue_depth(dev->sata_dev.ap, sdev, depth);
871 
872 	if (!sdev->tagged_supported)
873 		depth = 1;
874 	return scsi_change_queue_depth(sdev, depth);
875 }
876 
877 int sas_bios_param(struct scsi_device *scsi_dev,
878 			  struct block_device *bdev,
879 			  sector_t capacity, int *hsc)
880 {
881 	hsc[0] = 255;
882 	hsc[1] = 63;
883 	sector_div(capacity, 255*63);
884 	hsc[2] = capacity;
885 
886 	return 0;
887 }
888 
889 /*
890  * Tell an upper layer that it needs to initiate an abort for a given task.
891  * This should only ever be called by an LLDD.
892  */
893 void sas_task_abort(struct sas_task *task)
894 {
895 	struct scsi_cmnd *sc = task->uldd_task;
896 
897 	/* Escape for libsas internal commands */
898 	if (!sc) {
899 		struct sas_task_slow *slow = task->slow_task;
900 
901 		if (!slow)
902 			return;
903 		if (!del_timer(&slow->timer))
904 			return;
905 		slow->timer.function(&slow->timer);
906 		return;
907 	}
908 
909 	if (dev_is_sata(task->dev))
910 		sas_ata_task_abort(task);
911 	else
912 		blk_abort_request(sc->request);
913 }
914 
915 void sas_target_destroy(struct scsi_target *starget)
916 {
917 	struct domain_device *found_dev = starget->hostdata;
918 
919 	if (!found_dev)
920 		return;
921 
922 	starget->hostdata = NULL;
923 	sas_put_device(found_dev);
924 }
925 
926 #define SAS_STRING_ADDR_SIZE	16
927 
928 int sas_request_addr(struct Scsi_Host *shost, u8 *addr)
929 {
930 	int res;
931 	const struct firmware *fw;
932 
933 	res = request_firmware(&fw, "sas_addr", &shost->shost_gendev);
934 	if (res)
935 		return res;
936 
937 	if (fw->size < SAS_STRING_ADDR_SIZE) {
938 		res = -ENODEV;
939 		goto out;
940 	}
941 
942 	res = hex2bin(addr, fw->data, strnlen(fw->data, SAS_ADDR_SIZE * 2) / 2);
943 	if (res)
944 		goto out;
945 
946 out:
947 	release_firmware(fw);
948 	return res;
949 }
950 EXPORT_SYMBOL_GPL(sas_request_addr);
951 
952 EXPORT_SYMBOL_GPL(sas_queuecommand);
953 EXPORT_SYMBOL_GPL(sas_target_alloc);
954 EXPORT_SYMBOL_GPL(sas_slave_configure);
955 EXPORT_SYMBOL_GPL(sas_change_queue_depth);
956 EXPORT_SYMBOL_GPL(sas_bios_param);
957 EXPORT_SYMBOL_GPL(sas_task_abort);
958 EXPORT_SYMBOL_GPL(sas_phy_reset);
959 EXPORT_SYMBOL_GPL(sas_eh_device_reset_handler);
960 EXPORT_SYMBOL_GPL(sas_eh_target_reset_handler);
961 EXPORT_SYMBOL_GPL(sas_target_destroy);
962 EXPORT_SYMBOL_GPL(sas_ioctl);
963