1 // SPDX-License-Identifier: GPL-2.0-only
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 %016llx LUN 0x%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 
418 static int sas_queue_reset(struct domain_device *dev, int reset_type,
419 			   u64 lun, int wait)
420 {
421 	struct sas_ha_struct *ha = dev->port->ha;
422 	int scheduled = 0, tries = 100;
423 
424 	/* ata: promote lun reset to bus reset */
425 	if (dev_is_sata(dev)) {
426 		sas_ata_schedule_reset(dev);
427 		if (wait)
428 			sas_ata_wait_eh(dev);
429 		return SUCCESS;
430 	}
431 
432 	while (!scheduled && tries--) {
433 		spin_lock_irq(&ha->lock);
434 		if (!test_bit(SAS_DEV_EH_PENDING, &dev->state) &&
435 		    !test_bit(reset_type, &dev->state)) {
436 			scheduled = 1;
437 			ha->eh_active++;
438 			list_add_tail(&dev->ssp_dev.eh_list_node, &ha->eh_dev_q);
439 			set_bit(SAS_DEV_EH_PENDING, &dev->state);
440 			set_bit(reset_type, &dev->state);
441 			int_to_scsilun(lun, &dev->ssp_dev.reset_lun);
442 			scsi_schedule_eh(ha->core.shost);
443 		}
444 		spin_unlock_irq(&ha->lock);
445 
446 		if (wait)
447 			sas_wait_eh(dev);
448 
449 		if (scheduled)
450 			return SUCCESS;
451 	}
452 
453 	pr_warn("%s reset of %s failed\n",
454 		reset_type == SAS_DEV_LU_RESET ? "LUN" : "Bus",
455 		dev_name(&dev->rphy->dev));
456 
457 	return FAILED;
458 }
459 
460 int sas_eh_abort_handler(struct scsi_cmnd *cmd)
461 {
462 	int res = TMF_RESP_FUNC_FAILED;
463 	struct sas_task *task = TO_SAS_TASK(cmd);
464 	struct Scsi_Host *host = cmd->device->host;
465 	struct domain_device *dev = cmd_to_domain_dev(cmd);
466 	struct sas_internal *i = to_sas_internal(host->transportt);
467 	unsigned long flags;
468 
469 	if (!i->dft->lldd_abort_task)
470 		return FAILED;
471 
472 	spin_lock_irqsave(host->host_lock, flags);
473 	/* We cannot do async aborts for SATA devices */
474 	if (dev_is_sata(dev) && !host->host_eh_scheduled) {
475 		spin_unlock_irqrestore(host->host_lock, flags);
476 		return FAILED;
477 	}
478 	spin_unlock_irqrestore(host->host_lock, flags);
479 
480 	if (task)
481 		res = i->dft->lldd_abort_task(task);
482 	else
483 		pr_notice("no task to abort\n");
484 	if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE)
485 		return SUCCESS;
486 
487 	return FAILED;
488 }
489 EXPORT_SYMBOL_GPL(sas_eh_abort_handler);
490 
491 /* Attempt to send a LUN reset message to a device */
492 int sas_eh_device_reset_handler(struct scsi_cmnd *cmd)
493 {
494 	int res;
495 	struct scsi_lun lun;
496 	struct Scsi_Host *host = cmd->device->host;
497 	struct domain_device *dev = cmd_to_domain_dev(cmd);
498 	struct sas_internal *i = to_sas_internal(host->transportt);
499 
500 	if (current != host->ehandler)
501 		return sas_queue_reset(dev, SAS_DEV_LU_RESET, cmd->device->lun, 0);
502 
503 	int_to_scsilun(cmd->device->lun, &lun);
504 
505 	if (!i->dft->lldd_lu_reset)
506 		return FAILED;
507 
508 	res = i->dft->lldd_lu_reset(dev, lun.scsi_lun);
509 	if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE)
510 		return SUCCESS;
511 
512 	return FAILED;
513 }
514 
515 int sas_eh_target_reset_handler(struct scsi_cmnd *cmd)
516 {
517 	int res;
518 	struct Scsi_Host *host = cmd->device->host;
519 	struct domain_device *dev = cmd_to_domain_dev(cmd);
520 	struct sas_internal *i = to_sas_internal(host->transportt);
521 
522 	if (current != host->ehandler)
523 		return sas_queue_reset(dev, SAS_DEV_RESET, 0, 0);
524 
525 	if (!i->dft->lldd_I_T_nexus_reset)
526 		return FAILED;
527 
528 	res = i->dft->lldd_I_T_nexus_reset(dev);
529 	if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE ||
530 	    res == -ENODEV)
531 		return SUCCESS;
532 
533 	return FAILED;
534 }
535 
536 /* Try to reset a device */
537 static int try_to_reset_cmd_device(struct scsi_cmnd *cmd)
538 {
539 	int res;
540 	struct Scsi_Host *shost = cmd->device->host;
541 
542 	if (!shost->hostt->eh_device_reset_handler)
543 		goto try_target_reset;
544 
545 	res = shost->hostt->eh_device_reset_handler(cmd);
546 	if (res == SUCCESS)
547 		return res;
548 
549 try_target_reset:
550 	if (shost->hostt->eh_target_reset_handler)
551 		return shost->hostt->eh_target_reset_handler(cmd);
552 
553 	return FAILED;
554 }
555 
556 static void sas_eh_handle_sas_errors(struct Scsi_Host *shost, struct list_head *work_q)
557 {
558 	struct scsi_cmnd *cmd, *n;
559 	enum task_disposition res = TASK_IS_DONE;
560 	int tmf_resp, need_reset;
561 	struct sas_internal *i = to_sas_internal(shost->transportt);
562 	unsigned long flags;
563 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
564 	LIST_HEAD(done);
565 
566 	/* clean out any commands that won the completion vs eh race */
567 	list_for_each_entry_safe(cmd, n, work_q, eh_entry) {
568 		struct domain_device *dev = cmd_to_domain_dev(cmd);
569 		struct sas_task *task;
570 
571 		spin_lock_irqsave(&dev->done_lock, flags);
572 		/* by this point the lldd has either observed
573 		 * SAS_HA_FROZEN and is leaving the task alone, or has
574 		 * won the race with eh and decided to complete it
575 		 */
576 		task = TO_SAS_TASK(cmd);
577 		spin_unlock_irqrestore(&dev->done_lock, flags);
578 
579 		if (!task)
580 			list_move_tail(&cmd->eh_entry, &done);
581 	}
582 
583  Again:
584 	list_for_each_entry_safe(cmd, n, work_q, eh_entry) {
585 		struct sas_task *task = TO_SAS_TASK(cmd);
586 
587 		list_del_init(&cmd->eh_entry);
588 
589 		spin_lock_irqsave(&task->task_state_lock, flags);
590 		need_reset = task->task_state_flags & SAS_TASK_NEED_DEV_RESET;
591 		spin_unlock_irqrestore(&task->task_state_lock, flags);
592 
593 		if (need_reset) {
594 			pr_notice("%s: task 0x%p requests reset\n",
595 				  __func__, task);
596 			goto reset;
597 		}
598 
599 		pr_debug("trying to find task 0x%p\n", task);
600 		res = sas_scsi_find_task(task);
601 
602 		switch (res) {
603 		case TASK_IS_DONE:
604 			pr_notice("%s: task 0x%p is done\n", __func__,
605 				    task);
606 			sas_eh_finish_cmd(cmd);
607 			continue;
608 		case TASK_IS_ABORTED:
609 			pr_notice("%s: task 0x%p is aborted\n",
610 				  __func__, task);
611 			sas_eh_finish_cmd(cmd);
612 			continue;
613 		case TASK_IS_AT_LU:
614 			pr_info("task 0x%p is at LU: lu recover\n", task);
615  reset:
616 			tmf_resp = sas_recover_lu(task->dev, cmd);
617 			if (tmf_resp == TMF_RESP_FUNC_COMPLETE) {
618 				pr_notice("dev %016llx LU 0x%llx is recovered\n",
619 					  SAS_ADDR(task->dev),
620 					  cmd->device->lun);
621 				sas_eh_finish_cmd(cmd);
622 				sas_scsi_clear_queue_lu(work_q, cmd);
623 				goto Again;
624 			}
625 			/* fallthrough */
626 		case TASK_IS_NOT_AT_LU:
627 		case TASK_ABORT_FAILED:
628 			pr_notice("task 0x%p is not at LU: I_T recover\n",
629 				  task);
630 			tmf_resp = sas_recover_I_T(task->dev);
631 			if (tmf_resp == TMF_RESP_FUNC_COMPLETE ||
632 			    tmf_resp == -ENODEV) {
633 				struct domain_device *dev = task->dev;
634 				pr_notice("I_T %016llx recovered\n",
635 					  SAS_ADDR(task->dev->sas_addr));
636 				sas_eh_finish_cmd(cmd);
637 				sas_scsi_clear_queue_I_T(work_q, dev);
638 				goto Again;
639 			}
640 			/* Hammer time :-) */
641 			try_to_reset_cmd_device(cmd);
642 			if (i->dft->lldd_clear_nexus_port) {
643 				struct asd_sas_port *port = task->dev->port;
644 				pr_debug("clearing nexus for port:%d\n",
645 					  port->id);
646 				res = i->dft->lldd_clear_nexus_port(port);
647 				if (res == TMF_RESP_FUNC_COMPLETE) {
648 					pr_notice("clear nexus port:%d succeeded\n",
649 						  port->id);
650 					sas_eh_finish_cmd(cmd);
651 					sas_scsi_clear_queue_port(work_q,
652 								  port);
653 					goto Again;
654 				}
655 			}
656 			if (i->dft->lldd_clear_nexus_ha) {
657 				pr_debug("clear nexus ha\n");
658 				res = i->dft->lldd_clear_nexus_ha(ha);
659 				if (res == TMF_RESP_FUNC_COMPLETE) {
660 					pr_notice("clear nexus ha succeeded\n");
661 					sas_eh_finish_cmd(cmd);
662 					goto clear_q;
663 				}
664 			}
665 			/* If we are here -- this means that no amount
666 			 * of effort could recover from errors.  Quite
667 			 * possibly the HA just disappeared.
668 			 */
669 			pr_err("error from device %016llx, LUN 0x%llx couldn't be recovered in any way\n",
670 			       SAS_ADDR(task->dev->sas_addr),
671 			       cmd->device->lun);
672 
673 			sas_eh_finish_cmd(cmd);
674 			goto clear_q;
675 		}
676 	}
677  out:
678 	list_splice_tail(&done, work_q);
679 	list_splice_tail_init(&ha->eh_ata_q, work_q);
680 	return;
681 
682  clear_q:
683 	pr_debug("--- Exit %s -- clear_q\n", __func__);
684 	list_for_each_entry_safe(cmd, n, work_q, eh_entry)
685 		sas_eh_finish_cmd(cmd);
686 	goto out;
687 }
688 
689 static void sas_eh_handle_resets(struct Scsi_Host *shost)
690 {
691 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
692 	struct sas_internal *i = to_sas_internal(shost->transportt);
693 
694 	/* handle directed resets to sas devices */
695 	spin_lock_irq(&ha->lock);
696 	while (!list_empty(&ha->eh_dev_q)) {
697 		struct domain_device *dev;
698 		struct ssp_device *ssp;
699 
700 		ssp = list_entry(ha->eh_dev_q.next, typeof(*ssp), eh_list_node);
701 		list_del_init(&ssp->eh_list_node);
702 		dev = container_of(ssp, typeof(*dev), ssp_dev);
703 		kref_get(&dev->kref);
704 		WARN_ONCE(dev_is_sata(dev), "ssp reset to ata device?\n");
705 
706 		spin_unlock_irq(&ha->lock);
707 
708 		if (test_and_clear_bit(SAS_DEV_LU_RESET, &dev->state))
709 			i->dft->lldd_lu_reset(dev, ssp->reset_lun.scsi_lun);
710 
711 		if (test_and_clear_bit(SAS_DEV_RESET, &dev->state))
712 			i->dft->lldd_I_T_nexus_reset(dev);
713 
714 		sas_put_device(dev);
715 		spin_lock_irq(&ha->lock);
716 		clear_bit(SAS_DEV_EH_PENDING, &dev->state);
717 		ha->eh_active--;
718 	}
719 	spin_unlock_irq(&ha->lock);
720 }
721 
722 
723 void sas_scsi_recover_host(struct Scsi_Host *shost)
724 {
725 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
726 	LIST_HEAD(eh_work_q);
727 	int tries = 0;
728 	bool retry;
729 
730 retry:
731 	tries++;
732 	retry = true;
733 	spin_lock_irq(shost->host_lock);
734 	list_splice_init(&shost->eh_cmd_q, &eh_work_q);
735 	spin_unlock_irq(shost->host_lock);
736 
737 	pr_notice("Enter %s busy: %d failed: %d\n",
738 		  __func__, scsi_host_busy(shost), shost->host_failed);
739 	/*
740 	 * Deal with commands that still have SAS tasks (i.e. they didn't
741 	 * complete via the normal sas_task completion mechanism),
742 	 * SAS_HA_FROZEN gives eh dominion over all sas_task completion.
743 	 */
744 	set_bit(SAS_HA_FROZEN, &ha->state);
745 	sas_eh_handle_sas_errors(shost, &eh_work_q);
746 	clear_bit(SAS_HA_FROZEN, &ha->state);
747 	if (list_empty(&eh_work_q))
748 		goto out;
749 
750 	/*
751 	 * Now deal with SCSI commands that completed ok but have a an error
752 	 * code (and hopefully sense data) attached.  This is roughly what
753 	 * scsi_unjam_host does, but we skip scsi_eh_abort_cmds because any
754 	 * command we see here has no sas_task and is thus unknown to the HA.
755 	 */
756 	sas_ata_eh(shost, &eh_work_q, &ha->eh_done_q);
757 	if (!scsi_eh_get_sense(&eh_work_q, &ha->eh_done_q))
758 		scsi_eh_ready_devs(shost, &eh_work_q, &ha->eh_done_q);
759 
760 out:
761 	sas_eh_handle_resets(shost);
762 
763 	/* now link into libata eh --- if we have any ata devices */
764 	sas_ata_strategy_handler(shost);
765 
766 	scsi_eh_flush_done_q(&ha->eh_done_q);
767 
768 	/* check if any new eh work was scheduled during the last run */
769 	spin_lock_irq(&ha->lock);
770 	if (ha->eh_active == 0) {
771 		shost->host_eh_scheduled = 0;
772 		retry = false;
773 	}
774 	spin_unlock_irq(&ha->lock);
775 
776 	if (retry)
777 		goto retry;
778 
779 	pr_notice("--- Exit %s: busy: %d failed: %d tries: %d\n",
780 		  __func__, scsi_host_busy(shost),
781 		  shost->host_failed, tries);
782 }
783 
784 int sas_ioctl(struct scsi_device *sdev, unsigned int cmd, void __user *arg)
785 {
786 	struct domain_device *dev = sdev_to_domain_dev(sdev);
787 
788 	if (dev_is_sata(dev))
789 		return ata_sas_scsi_ioctl(dev->sata_dev.ap, sdev, cmd, arg);
790 
791 	return -EINVAL;
792 }
793 
794 struct domain_device *sas_find_dev_by_rphy(struct sas_rphy *rphy)
795 {
796 	struct Scsi_Host *shost = dev_to_shost(rphy->dev.parent);
797 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
798 	struct domain_device *found_dev = NULL;
799 	int i;
800 	unsigned long flags;
801 
802 	spin_lock_irqsave(&ha->phy_port_lock, flags);
803 	for (i = 0; i < ha->num_phys; i++) {
804 		struct asd_sas_port *port = ha->sas_port[i];
805 		struct domain_device *dev;
806 
807 		spin_lock(&port->dev_list_lock);
808 		list_for_each_entry(dev, &port->dev_list, dev_list_node) {
809 			if (rphy == dev->rphy) {
810 				found_dev = dev;
811 				spin_unlock(&port->dev_list_lock);
812 				goto found;
813 			}
814 		}
815 		spin_unlock(&port->dev_list_lock);
816 	}
817  found:
818 	spin_unlock_irqrestore(&ha->phy_port_lock, flags);
819 
820 	return found_dev;
821 }
822 
823 int sas_target_alloc(struct scsi_target *starget)
824 {
825 	struct sas_rphy *rphy = dev_to_rphy(starget->dev.parent);
826 	struct domain_device *found_dev = sas_find_dev_by_rphy(rphy);
827 
828 	if (!found_dev)
829 		return -ENODEV;
830 
831 	kref_get(&found_dev->kref);
832 	starget->hostdata = found_dev;
833 	return 0;
834 }
835 
836 #define SAS_DEF_QD 256
837 
838 int sas_slave_configure(struct scsi_device *scsi_dev)
839 {
840 	struct domain_device *dev = sdev_to_domain_dev(scsi_dev);
841 
842 	BUG_ON(dev->rphy->identify.device_type != SAS_END_DEVICE);
843 
844 	if (dev_is_sata(dev)) {
845 		ata_sas_slave_configure(scsi_dev, dev->sata_dev.ap);
846 		return 0;
847 	}
848 
849 	sas_read_port_mode_page(scsi_dev);
850 
851 	if (scsi_dev->tagged_supported) {
852 		scsi_change_queue_depth(scsi_dev, SAS_DEF_QD);
853 	} else {
854 		pr_notice("device %016llx, LUN 0x%llx doesn't support TCQ\n",
855 			  SAS_ADDR(dev->sas_addr), scsi_dev->lun);
856 		scsi_change_queue_depth(scsi_dev, 1);
857 	}
858 
859 	scsi_dev->allow_restart = 1;
860 
861 	return 0;
862 }
863 
864 int sas_change_queue_depth(struct scsi_device *sdev, int depth)
865 {
866 	struct domain_device *dev = sdev_to_domain_dev(sdev);
867 
868 	if (dev_is_sata(dev))
869 		return __ata_change_queue_depth(dev->sata_dev.ap, sdev, depth);
870 
871 	if (!sdev->tagged_supported)
872 		depth = 1;
873 	return scsi_change_queue_depth(sdev, depth);
874 }
875 
876 int sas_bios_param(struct scsi_device *scsi_dev,
877 			  struct block_device *bdev,
878 			  sector_t capacity, int *hsc)
879 {
880 	hsc[0] = 255;
881 	hsc[1] = 63;
882 	sector_div(capacity, 255*63);
883 	hsc[2] = capacity;
884 
885 	return 0;
886 }
887 
888 /*
889  * Tell an upper layer that it needs to initiate an abort for a given task.
890  * This should only ever be called by an LLDD.
891  */
892 void sas_task_abort(struct sas_task *task)
893 {
894 	struct scsi_cmnd *sc = task->uldd_task;
895 
896 	/* Escape for libsas internal commands */
897 	if (!sc) {
898 		struct sas_task_slow *slow = task->slow_task;
899 
900 		if (!slow)
901 			return;
902 		if (!del_timer(&slow->timer))
903 			return;
904 		slow->timer.function(&slow->timer);
905 		return;
906 	}
907 
908 	if (dev_is_sata(task->dev))
909 		sas_ata_task_abort(task);
910 	else
911 		blk_abort_request(sc->request);
912 }
913 
914 void sas_target_destroy(struct scsi_target *starget)
915 {
916 	struct domain_device *found_dev = starget->hostdata;
917 
918 	if (!found_dev)
919 		return;
920 
921 	starget->hostdata = NULL;
922 	sas_put_device(found_dev);
923 }
924 
925 #define SAS_STRING_ADDR_SIZE	16
926 
927 int sas_request_addr(struct Scsi_Host *shost, u8 *addr)
928 {
929 	int res;
930 	const struct firmware *fw;
931 
932 	res = request_firmware(&fw, "sas_addr", &shost->shost_gendev);
933 	if (res)
934 		return res;
935 
936 	if (fw->size < SAS_STRING_ADDR_SIZE) {
937 		res = -ENODEV;
938 		goto out;
939 	}
940 
941 	res = hex2bin(addr, fw->data, strnlen(fw->data, SAS_ADDR_SIZE * 2) / 2);
942 	if (res)
943 		goto out;
944 
945 out:
946 	release_firmware(fw);
947 	return res;
948 }
949 EXPORT_SYMBOL_GPL(sas_request_addr);
950 
951 EXPORT_SYMBOL_GPL(sas_queuecommand);
952 EXPORT_SYMBOL_GPL(sas_target_alloc);
953 EXPORT_SYMBOL_GPL(sas_slave_configure);
954 EXPORT_SYMBOL_GPL(sas_change_queue_depth);
955 EXPORT_SYMBOL_GPL(sas_bios_param);
956 EXPORT_SYMBOL_GPL(sas_task_abort);
957 EXPORT_SYMBOL_GPL(sas_phy_reset);
958 EXPORT_SYMBOL_GPL(sas_eh_device_reset_handler);
959 EXPORT_SYMBOL_GPL(sas_eh_target_reset_handler);
960 EXPORT_SYMBOL_GPL(sas_target_destroy);
961 EXPORT_SYMBOL_GPL(sas_ioctl);
962