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 	enum scsi_host_status hs = DID_OK;
41 	enum exec_status stat = SAS_SAM_STAT_GOOD;
42 
43 	if (ts->resp == SAS_TASK_UNDELIVERED) {
44 		/* transport error */
45 		hs = DID_NO_CONNECT;
46 	} else { /* ts->resp == SAS_TASK_COMPLETE */
47 		/* task delivered, what happened afterwards? */
48 		switch (ts->stat) {
49 		case SAS_DEV_NO_RESPONSE:
50 		case SAS_INTERRUPTED:
51 		case SAS_PHY_DOWN:
52 		case SAS_NAK_R_ERR:
53 		case SAS_OPEN_TO:
54 			hs = DID_NO_CONNECT;
55 			break;
56 		case SAS_DATA_UNDERRUN:
57 			scsi_set_resid(sc, ts->residual);
58 			if (scsi_bufflen(sc) - scsi_get_resid(sc) < sc->underflow)
59 				hs = DID_ERROR;
60 			break;
61 		case SAS_DATA_OVERRUN:
62 			hs = DID_ERROR;
63 			break;
64 		case SAS_QUEUE_FULL:
65 			hs = DID_SOFT_ERROR; /* retry */
66 			break;
67 		case SAS_DEVICE_UNKNOWN:
68 			hs = DID_BAD_TARGET;
69 			break;
70 		case SAS_SG_ERR:
71 			hs = DID_PARITY;
72 			break;
73 		case SAS_OPEN_REJECT:
74 			if (ts->open_rej_reason == SAS_OREJ_RSVD_RETRY)
75 				hs = DID_SOFT_ERROR; /* retry */
76 			else
77 				hs = DID_ERROR;
78 			break;
79 		case SAS_PROTO_RESPONSE:
80 			pr_notice("LLDD:%s sent SAS_PROTO_RESP for an SSP task; please report this\n",
81 				  task->dev->port->ha->sas_ha_name);
82 			break;
83 		case SAS_ABORTED_TASK:
84 			hs = DID_ABORT;
85 			break;
86 		case SAS_SAM_STAT_CHECK_CONDITION:
87 			memcpy(sc->sense_buffer, ts->buf,
88 			       min(SCSI_SENSE_BUFFERSIZE, ts->buf_valid_size));
89 			stat = SAS_SAM_STAT_CHECK_CONDITION;
90 			break;
91 		default:
92 			stat = ts->stat;
93 			break;
94 		}
95 	}
96 
97 	sc->result = (hs << 16) | stat;
98 	ASSIGN_SAS_TASK(sc, NULL);
99 	sas_free_task(task);
100 }
101 
102 static void sas_scsi_task_done(struct sas_task *task)
103 {
104 	struct scsi_cmnd *sc = task->uldd_task;
105 	struct domain_device *dev = task->dev;
106 	struct sas_ha_struct *ha = dev->port->ha;
107 	unsigned long flags;
108 
109 	spin_lock_irqsave(&dev->done_lock, flags);
110 	if (test_bit(SAS_HA_FROZEN, &ha->state))
111 		task = NULL;
112 	else
113 		ASSIGN_SAS_TASK(sc, NULL);
114 	spin_unlock_irqrestore(&dev->done_lock, flags);
115 
116 	if (unlikely(!task)) {
117 		/* task will be completed by the error handler */
118 		pr_debug("task done but aborted\n");
119 		return;
120 	}
121 
122 	if (unlikely(!sc)) {
123 		pr_debug("task_done called with non existing SCSI cmnd!\n");
124 		sas_free_task(task);
125 		return;
126 	}
127 
128 	sas_end_task(sc, task);
129 	scsi_done(sc);
130 }
131 
132 static struct sas_task *sas_create_task(struct scsi_cmnd *cmd,
133 					       struct domain_device *dev,
134 					       gfp_t gfp_flags)
135 {
136 	struct sas_task *task = sas_alloc_task(gfp_flags);
137 	struct scsi_lun lun;
138 
139 	if (!task)
140 		return NULL;
141 
142 	task->uldd_task = cmd;
143 	ASSIGN_SAS_TASK(cmd, task);
144 
145 	task->dev = dev;
146 	task->task_proto = task->dev->tproto; /* BUG_ON(!SSP) */
147 
148 	task->ssp_task.retry_count = 1;
149 	int_to_scsilun(cmd->device->lun, &lun);
150 	memcpy(task->ssp_task.LUN, &lun.scsi_lun, 8);
151 	task->ssp_task.task_attr = TASK_ATTR_SIMPLE;
152 	task->ssp_task.cmd = cmd;
153 
154 	task->scatter = scsi_sglist(cmd);
155 	task->num_scatter = scsi_sg_count(cmd);
156 	task->total_xfer_len = scsi_bufflen(cmd);
157 	task->data_dir = cmd->sc_data_direction;
158 
159 	task->task_done = sas_scsi_task_done;
160 
161 	return task;
162 }
163 
164 int sas_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
165 {
166 	struct sas_internal *i = to_sas_internal(host->transportt);
167 	struct domain_device *dev = cmd_to_domain_dev(cmd);
168 	struct sas_task *task;
169 	int res = 0;
170 
171 	/* If the device fell off, no sense in issuing commands */
172 	if (test_bit(SAS_DEV_GONE, &dev->state)) {
173 		cmd->result = DID_BAD_TARGET << 16;
174 		goto out_done;
175 	}
176 
177 	if (dev_is_sata(dev)) {
178 		spin_lock_irq(dev->sata_dev.ap->lock);
179 		res = ata_sas_queuecmd(cmd, dev->sata_dev.ap);
180 		spin_unlock_irq(dev->sata_dev.ap->lock);
181 		return res;
182 	}
183 
184 	task = sas_create_task(cmd, dev, GFP_ATOMIC);
185 	if (!task)
186 		return SCSI_MLQUEUE_HOST_BUSY;
187 
188 	res = i->dft->lldd_execute_task(task, GFP_ATOMIC);
189 	if (res)
190 		goto out_free_task;
191 	return 0;
192 
193 out_free_task:
194 	pr_debug("lldd_execute_task returned: %d\n", res);
195 	ASSIGN_SAS_TASK(cmd, NULL);
196 	sas_free_task(task);
197 	if (res == -SAS_QUEUE_FULL)
198 		cmd->result = DID_SOFT_ERROR << 16; /* retry */
199 	else
200 		cmd->result = DID_ERROR << 16;
201 out_done:
202 	scsi_done(cmd);
203 	return 0;
204 }
205 EXPORT_SYMBOL_GPL(sas_queuecommand);
206 
207 static void sas_eh_finish_cmd(struct scsi_cmnd *cmd)
208 {
209 	struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(cmd->device->host);
210 	struct domain_device *dev = cmd_to_domain_dev(cmd);
211 	struct sas_task *task = TO_SAS_TASK(cmd);
212 
213 	/* At this point, we only get called following an actual abort
214 	 * of the task, so we should be guaranteed not to be racing with
215 	 * any completions from the LLD.  Task is freed after this.
216 	 */
217 	sas_end_task(cmd, task);
218 
219 	if (dev_is_sata(dev)) {
220 		/* defer commands to libata so that libata EH can
221 		 * handle ata qcs correctly
222 		 */
223 		list_move_tail(&cmd->eh_entry, &sas_ha->eh_ata_q);
224 		return;
225 	}
226 
227 	/* now finish the command and move it on to the error
228 	 * handler done list, this also takes it off the
229 	 * error handler pending list.
230 	 */
231 	scsi_eh_finish_cmd(cmd, &sas_ha->eh_done_q);
232 }
233 
234 static void sas_scsi_clear_queue_lu(struct list_head *error_q, struct scsi_cmnd *my_cmd)
235 {
236 	struct scsi_cmnd *cmd, *n;
237 
238 	list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
239 		if (cmd->device->sdev_target == my_cmd->device->sdev_target &&
240 		    cmd->device->lun == my_cmd->device->lun)
241 			sas_eh_finish_cmd(cmd);
242 	}
243 }
244 
245 static void sas_scsi_clear_queue_I_T(struct list_head *error_q,
246 				     struct domain_device *dev)
247 {
248 	struct scsi_cmnd *cmd, *n;
249 
250 	list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
251 		struct domain_device *x = cmd_to_domain_dev(cmd);
252 
253 		if (x == dev)
254 			sas_eh_finish_cmd(cmd);
255 	}
256 }
257 
258 static void sas_scsi_clear_queue_port(struct list_head *error_q,
259 				      struct asd_sas_port *port)
260 {
261 	struct scsi_cmnd *cmd, *n;
262 
263 	list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
264 		struct domain_device *dev = cmd_to_domain_dev(cmd);
265 		struct asd_sas_port *x = dev->port;
266 
267 		if (x == port)
268 			sas_eh_finish_cmd(cmd);
269 	}
270 }
271 
272 enum task_disposition {
273 	TASK_IS_DONE,
274 	TASK_IS_ABORTED,
275 	TASK_IS_AT_LU,
276 	TASK_IS_NOT_AT_LU,
277 	TASK_ABORT_FAILED,
278 };
279 
280 static enum task_disposition sas_scsi_find_task(struct sas_task *task)
281 {
282 	unsigned long flags;
283 	int i, res;
284 	struct sas_internal *si =
285 		to_sas_internal(task->dev->port->ha->core.shost->transportt);
286 
287 	for (i = 0; i < 5; i++) {
288 		pr_notice("%s: aborting task 0x%p\n", __func__, task);
289 		res = si->dft->lldd_abort_task(task);
290 
291 		spin_lock_irqsave(&task->task_state_lock, flags);
292 		if (task->task_state_flags & SAS_TASK_STATE_DONE) {
293 			spin_unlock_irqrestore(&task->task_state_lock, flags);
294 			pr_debug("%s: task 0x%p is done\n", __func__, task);
295 			return TASK_IS_DONE;
296 		}
297 		spin_unlock_irqrestore(&task->task_state_lock, flags);
298 
299 		if (res == TMF_RESP_FUNC_COMPLETE) {
300 			pr_notice("%s: task 0x%p is aborted\n",
301 				  __func__, task);
302 			return TASK_IS_ABORTED;
303 		} else if (si->dft->lldd_query_task) {
304 			pr_notice("%s: querying task 0x%p\n", __func__, task);
305 			res = si->dft->lldd_query_task(task);
306 			switch (res) {
307 			case TMF_RESP_FUNC_SUCC:
308 				pr_notice("%s: task 0x%p at LU\n", __func__,
309 					  task);
310 				return TASK_IS_AT_LU;
311 			case TMF_RESP_FUNC_COMPLETE:
312 				pr_notice("%s: task 0x%p not at LU\n",
313 					  __func__, task);
314 				return TASK_IS_NOT_AT_LU;
315 			case TMF_RESP_FUNC_FAILED:
316 				pr_notice("%s: task 0x%p failed to abort\n",
317 					  __func__, task);
318 				return TASK_ABORT_FAILED;
319 			}
320 
321 		}
322 	}
323 	return res;
324 }
325 
326 static int sas_recover_lu(struct domain_device *dev, struct scsi_cmnd *cmd)
327 {
328 	int res = TMF_RESP_FUNC_FAILED;
329 	struct scsi_lun lun;
330 	struct sas_internal *i =
331 		to_sas_internal(dev->port->ha->core.shost->transportt);
332 
333 	int_to_scsilun(cmd->device->lun, &lun);
334 
335 	pr_notice("eh: device %016llx LUN 0x%llx has the task\n",
336 		  SAS_ADDR(dev->sas_addr),
337 		  cmd->device->lun);
338 
339 	if (i->dft->lldd_abort_task_set)
340 		res = i->dft->lldd_abort_task_set(dev, lun.scsi_lun);
341 
342 	if (res == TMF_RESP_FUNC_FAILED) {
343 		if (i->dft->lldd_clear_task_set)
344 			res = i->dft->lldd_clear_task_set(dev, lun.scsi_lun);
345 	}
346 
347 	if (res == TMF_RESP_FUNC_FAILED) {
348 		if (i->dft->lldd_lu_reset)
349 			res = i->dft->lldd_lu_reset(dev, lun.scsi_lun);
350 	}
351 
352 	return res;
353 }
354 
355 static int sas_recover_I_T(struct domain_device *dev)
356 {
357 	int res = TMF_RESP_FUNC_FAILED;
358 	struct sas_internal *i =
359 		to_sas_internal(dev->port->ha->core.shost->transportt);
360 
361 	pr_notice("I_T nexus reset for dev %016llx\n",
362 		  SAS_ADDR(dev->sas_addr));
363 
364 	if (i->dft->lldd_I_T_nexus_reset)
365 		res = i->dft->lldd_I_T_nexus_reset(dev);
366 
367 	return res;
368 }
369 
370 /* take a reference on the last known good phy for this device */
371 struct sas_phy *sas_get_local_phy(struct domain_device *dev)
372 {
373 	struct sas_ha_struct *ha = dev->port->ha;
374 	struct sas_phy *phy;
375 	unsigned long flags;
376 
377 	/* a published domain device always has a valid phy, it may be
378 	 * stale, but it is never NULL
379 	 */
380 	BUG_ON(!dev->phy);
381 
382 	spin_lock_irqsave(&ha->phy_port_lock, flags);
383 	phy = dev->phy;
384 	get_device(&phy->dev);
385 	spin_unlock_irqrestore(&ha->phy_port_lock, flags);
386 
387 	return phy;
388 }
389 EXPORT_SYMBOL_GPL(sas_get_local_phy);
390 
391 static void sas_wait_eh(struct domain_device *dev)
392 {
393 	struct sas_ha_struct *ha = dev->port->ha;
394 	DEFINE_WAIT(wait);
395 
396 	if (dev_is_sata(dev)) {
397 		ata_port_wait_eh(dev->sata_dev.ap);
398 		return;
399 	}
400  retry:
401 	spin_lock_irq(&ha->lock);
402 
403 	while (test_bit(SAS_DEV_EH_PENDING, &dev->state)) {
404 		prepare_to_wait(&ha->eh_wait_q, &wait, TASK_UNINTERRUPTIBLE);
405 		spin_unlock_irq(&ha->lock);
406 		schedule();
407 		spin_lock_irq(&ha->lock);
408 	}
409 	finish_wait(&ha->eh_wait_q, &wait);
410 
411 	spin_unlock_irq(&ha->lock);
412 
413 	/* make sure SCSI EH is complete */
414 	if (scsi_host_in_recovery(ha->core.shost)) {
415 		msleep(10);
416 		goto retry;
417 	}
418 }
419 
420 static int sas_queue_reset(struct domain_device *dev, int reset_type,
421 			   u64 lun, int wait)
422 {
423 	struct sas_ha_struct *ha = dev->port->ha;
424 	int scheduled = 0, tries = 100;
425 
426 	/* ata: promote lun reset to bus reset */
427 	if (dev_is_sata(dev)) {
428 		sas_ata_schedule_reset(dev);
429 		if (wait)
430 			sas_ata_wait_eh(dev);
431 		return SUCCESS;
432 	}
433 
434 	while (!scheduled && tries--) {
435 		spin_lock_irq(&ha->lock);
436 		if (!test_bit(SAS_DEV_EH_PENDING, &dev->state) &&
437 		    !test_bit(reset_type, &dev->state)) {
438 			scheduled = 1;
439 			ha->eh_active++;
440 			list_add_tail(&dev->ssp_dev.eh_list_node, &ha->eh_dev_q);
441 			set_bit(SAS_DEV_EH_PENDING, &dev->state);
442 			set_bit(reset_type, &dev->state);
443 			int_to_scsilun(lun, &dev->ssp_dev.reset_lun);
444 			scsi_schedule_eh(ha->core.shost);
445 		}
446 		spin_unlock_irq(&ha->lock);
447 
448 		if (wait)
449 			sas_wait_eh(dev);
450 
451 		if (scheduled)
452 			return SUCCESS;
453 	}
454 
455 	pr_warn("%s reset of %s failed\n",
456 		reset_type == SAS_DEV_LU_RESET ? "LUN" : "Bus",
457 		dev_name(&dev->rphy->dev));
458 
459 	return FAILED;
460 }
461 
462 int sas_eh_abort_handler(struct scsi_cmnd *cmd)
463 {
464 	int res = TMF_RESP_FUNC_FAILED;
465 	struct sas_task *task = TO_SAS_TASK(cmd);
466 	struct Scsi_Host *host = cmd->device->host;
467 	struct domain_device *dev = cmd_to_domain_dev(cmd);
468 	struct sas_internal *i = to_sas_internal(host->transportt);
469 	unsigned long flags;
470 
471 	if (!i->dft->lldd_abort_task)
472 		return FAILED;
473 
474 	spin_lock_irqsave(host->host_lock, flags);
475 	/* We cannot do async aborts for SATA devices */
476 	if (dev_is_sata(dev) && !host->host_eh_scheduled) {
477 		spin_unlock_irqrestore(host->host_lock, flags);
478 		return FAILED;
479 	}
480 	spin_unlock_irqrestore(host->host_lock, flags);
481 
482 	if (task)
483 		res = i->dft->lldd_abort_task(task);
484 	else
485 		pr_notice("no task to abort\n");
486 	if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE)
487 		return SUCCESS;
488 
489 	return FAILED;
490 }
491 EXPORT_SYMBOL_GPL(sas_eh_abort_handler);
492 
493 /* Attempt to send a LUN reset message to a device */
494 int sas_eh_device_reset_handler(struct scsi_cmnd *cmd)
495 {
496 	int res;
497 	struct scsi_lun lun;
498 	struct Scsi_Host *host = cmd->device->host;
499 	struct domain_device *dev = cmd_to_domain_dev(cmd);
500 	struct sas_internal *i = to_sas_internal(host->transportt);
501 
502 	if (current != host->ehandler)
503 		return sas_queue_reset(dev, SAS_DEV_LU_RESET, cmd->device->lun, 0);
504 
505 	int_to_scsilun(cmd->device->lun, &lun);
506 
507 	if (!i->dft->lldd_lu_reset)
508 		return FAILED;
509 
510 	res = i->dft->lldd_lu_reset(dev, lun.scsi_lun);
511 	if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE)
512 		return SUCCESS;
513 
514 	return FAILED;
515 }
516 EXPORT_SYMBOL_GPL(sas_eh_device_reset_handler);
517 
518 int sas_eh_target_reset_handler(struct scsi_cmnd *cmd)
519 {
520 	int res;
521 	struct Scsi_Host *host = cmd->device->host;
522 	struct domain_device *dev = cmd_to_domain_dev(cmd);
523 	struct sas_internal *i = to_sas_internal(host->transportt);
524 
525 	if (current != host->ehandler)
526 		return sas_queue_reset(dev, SAS_DEV_RESET, 0, 0);
527 
528 	if (!i->dft->lldd_I_T_nexus_reset)
529 		return FAILED;
530 
531 	res = i->dft->lldd_I_T_nexus_reset(dev);
532 	if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE ||
533 	    res == -ENODEV)
534 		return SUCCESS;
535 
536 	return FAILED;
537 }
538 EXPORT_SYMBOL_GPL(sas_eh_target_reset_handler);
539 
540 /* Try to reset a device */
541 static int try_to_reset_cmd_device(struct scsi_cmnd *cmd)
542 {
543 	int res;
544 	struct Scsi_Host *shost = cmd->device->host;
545 
546 	if (!shost->hostt->eh_device_reset_handler)
547 		goto try_target_reset;
548 
549 	res = shost->hostt->eh_device_reset_handler(cmd);
550 	if (res == SUCCESS)
551 		return res;
552 
553 try_target_reset:
554 	if (shost->hostt->eh_target_reset_handler)
555 		return shost->hostt->eh_target_reset_handler(cmd);
556 
557 	return FAILED;
558 }
559 
560 static void sas_eh_handle_sas_errors(struct Scsi_Host *shost, struct list_head *work_q)
561 {
562 	struct scsi_cmnd *cmd, *n;
563 	enum task_disposition res = TASK_IS_DONE;
564 	int tmf_resp, need_reset;
565 	struct sas_internal *i = to_sas_internal(shost->transportt);
566 	unsigned long flags;
567 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
568 	LIST_HEAD(done);
569 
570 	/* clean out any commands that won the completion vs eh race */
571 	list_for_each_entry_safe(cmd, n, work_q, eh_entry) {
572 		struct domain_device *dev = cmd_to_domain_dev(cmd);
573 		struct sas_task *task;
574 
575 		spin_lock_irqsave(&dev->done_lock, flags);
576 		/* by this point the lldd has either observed
577 		 * SAS_HA_FROZEN and is leaving the task alone, or has
578 		 * won the race with eh and decided to complete it
579 		 */
580 		task = TO_SAS_TASK(cmd);
581 		spin_unlock_irqrestore(&dev->done_lock, flags);
582 
583 		if (!task)
584 			list_move_tail(&cmd->eh_entry, &done);
585 	}
586 
587  Again:
588 	list_for_each_entry_safe(cmd, n, work_q, eh_entry) {
589 		struct sas_task *task = TO_SAS_TASK(cmd);
590 
591 		list_del_init(&cmd->eh_entry);
592 
593 		spin_lock_irqsave(&task->task_state_lock, flags);
594 		need_reset = task->task_state_flags & SAS_TASK_NEED_DEV_RESET;
595 		spin_unlock_irqrestore(&task->task_state_lock, flags);
596 
597 		if (need_reset) {
598 			pr_notice("%s: task 0x%p requests reset\n",
599 				  __func__, task);
600 			goto reset;
601 		}
602 
603 		pr_debug("trying to find task 0x%p\n", task);
604 		res = sas_scsi_find_task(task);
605 
606 		switch (res) {
607 		case TASK_IS_DONE:
608 			pr_notice("%s: task 0x%p is done\n", __func__,
609 				    task);
610 			sas_eh_finish_cmd(cmd);
611 			continue;
612 		case TASK_IS_ABORTED:
613 			pr_notice("%s: task 0x%p is aborted\n",
614 				  __func__, task);
615 			sas_eh_finish_cmd(cmd);
616 			continue;
617 		case TASK_IS_AT_LU:
618 			pr_info("task 0x%p is at LU: lu recover\n", task);
619  reset:
620 			tmf_resp = sas_recover_lu(task->dev, cmd);
621 			if (tmf_resp == TMF_RESP_FUNC_COMPLETE) {
622 				pr_notice("dev %016llx LU 0x%llx is recovered\n",
623 					  SAS_ADDR(task->dev),
624 					  cmd->device->lun);
625 				sas_eh_finish_cmd(cmd);
626 				sas_scsi_clear_queue_lu(work_q, cmd);
627 				goto Again;
628 			}
629 			fallthrough;
630 		case TASK_IS_NOT_AT_LU:
631 		case TASK_ABORT_FAILED:
632 			pr_notice("task 0x%p is not at LU: I_T recover\n",
633 				  task);
634 			tmf_resp = sas_recover_I_T(task->dev);
635 			if (tmf_resp == TMF_RESP_FUNC_COMPLETE ||
636 			    tmf_resp == -ENODEV) {
637 				struct domain_device *dev = task->dev;
638 				pr_notice("I_T %016llx recovered\n",
639 					  SAS_ADDR(task->dev->sas_addr));
640 				sas_eh_finish_cmd(cmd);
641 				sas_scsi_clear_queue_I_T(work_q, dev);
642 				goto Again;
643 			}
644 			/* Hammer time :-) */
645 			try_to_reset_cmd_device(cmd);
646 			if (i->dft->lldd_clear_nexus_port) {
647 				struct asd_sas_port *port = task->dev->port;
648 				pr_debug("clearing nexus for port:%d\n",
649 					  port->id);
650 				res = i->dft->lldd_clear_nexus_port(port);
651 				if (res == TMF_RESP_FUNC_COMPLETE) {
652 					pr_notice("clear nexus port:%d succeeded\n",
653 						  port->id);
654 					sas_eh_finish_cmd(cmd);
655 					sas_scsi_clear_queue_port(work_q,
656 								  port);
657 					goto Again;
658 				}
659 			}
660 			if (i->dft->lldd_clear_nexus_ha) {
661 				pr_debug("clear nexus ha\n");
662 				res = i->dft->lldd_clear_nexus_ha(ha);
663 				if (res == TMF_RESP_FUNC_COMPLETE) {
664 					pr_notice("clear nexus ha succeeded\n");
665 					sas_eh_finish_cmd(cmd);
666 					goto clear_q;
667 				}
668 			}
669 			/* If we are here -- this means that no amount
670 			 * of effort could recover from errors.  Quite
671 			 * possibly the HA just disappeared.
672 			 */
673 			pr_err("error from device %016llx, LUN 0x%llx couldn't be recovered in any way\n",
674 			       SAS_ADDR(task->dev->sas_addr),
675 			       cmd->device->lun);
676 
677 			sas_eh_finish_cmd(cmd);
678 			goto clear_q;
679 		}
680 	}
681  out:
682 	list_splice_tail(&done, work_q);
683 	list_splice_tail_init(&ha->eh_ata_q, work_q);
684 	return;
685 
686  clear_q:
687 	pr_debug("--- Exit %s -- clear_q\n", __func__);
688 	list_for_each_entry_safe(cmd, n, work_q, eh_entry)
689 		sas_eh_finish_cmd(cmd);
690 	goto out;
691 }
692 
693 static void sas_eh_handle_resets(struct Scsi_Host *shost)
694 {
695 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
696 	struct sas_internal *i = to_sas_internal(shost->transportt);
697 
698 	/* handle directed resets to sas devices */
699 	spin_lock_irq(&ha->lock);
700 	while (!list_empty(&ha->eh_dev_q)) {
701 		struct domain_device *dev;
702 		struct ssp_device *ssp;
703 
704 		ssp = list_entry(ha->eh_dev_q.next, typeof(*ssp), eh_list_node);
705 		list_del_init(&ssp->eh_list_node);
706 		dev = container_of(ssp, typeof(*dev), ssp_dev);
707 		kref_get(&dev->kref);
708 		WARN_ONCE(dev_is_sata(dev), "ssp reset to ata device?\n");
709 
710 		spin_unlock_irq(&ha->lock);
711 
712 		if (test_and_clear_bit(SAS_DEV_LU_RESET, &dev->state))
713 			i->dft->lldd_lu_reset(dev, ssp->reset_lun.scsi_lun);
714 
715 		if (test_and_clear_bit(SAS_DEV_RESET, &dev->state))
716 			i->dft->lldd_I_T_nexus_reset(dev);
717 
718 		sas_put_device(dev);
719 		spin_lock_irq(&ha->lock);
720 		clear_bit(SAS_DEV_EH_PENDING, &dev->state);
721 		ha->eh_active--;
722 	}
723 	spin_unlock_irq(&ha->lock);
724 }
725 
726 
727 void sas_scsi_recover_host(struct Scsi_Host *shost)
728 {
729 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
730 	LIST_HEAD(eh_work_q);
731 	int tries = 0;
732 	bool retry;
733 
734 retry:
735 	tries++;
736 	retry = true;
737 	spin_lock_irq(shost->host_lock);
738 	list_splice_init(&shost->eh_cmd_q, &eh_work_q);
739 	spin_unlock_irq(shost->host_lock);
740 
741 	pr_notice("Enter %s busy: %d failed: %d\n",
742 		  __func__, scsi_host_busy(shost), shost->host_failed);
743 	/*
744 	 * Deal with commands that still have SAS tasks (i.e. they didn't
745 	 * complete via the normal sas_task completion mechanism),
746 	 * SAS_HA_FROZEN gives eh dominion over all sas_task completion.
747 	 */
748 	set_bit(SAS_HA_FROZEN, &ha->state);
749 	sas_eh_handle_sas_errors(shost, &eh_work_q);
750 	clear_bit(SAS_HA_FROZEN, &ha->state);
751 	if (list_empty(&eh_work_q))
752 		goto out;
753 
754 	/*
755 	 * Now deal with SCSI commands that completed ok but have a an error
756 	 * code (and hopefully sense data) attached.  This is roughly what
757 	 * scsi_unjam_host does, but we skip scsi_eh_abort_cmds because any
758 	 * command we see here has no sas_task and is thus unknown to the HA.
759 	 */
760 	sas_ata_eh(shost, &eh_work_q, &ha->eh_done_q);
761 	if (!scsi_eh_get_sense(&eh_work_q, &ha->eh_done_q))
762 		scsi_eh_ready_devs(shost, &eh_work_q, &ha->eh_done_q);
763 
764 out:
765 	sas_eh_handle_resets(shost);
766 
767 	/* now link into libata eh --- if we have any ata devices */
768 	sas_ata_strategy_handler(shost);
769 
770 	scsi_eh_flush_done_q(&ha->eh_done_q);
771 
772 	/* check if any new eh work was scheduled during the last run */
773 	spin_lock_irq(&ha->lock);
774 	if (ha->eh_active == 0) {
775 		shost->host_eh_scheduled = 0;
776 		retry = false;
777 	}
778 	spin_unlock_irq(&ha->lock);
779 
780 	if (retry)
781 		goto retry;
782 
783 	pr_notice("--- Exit %s: busy: %d failed: %d tries: %d\n",
784 		  __func__, scsi_host_busy(shost),
785 		  shost->host_failed, tries);
786 }
787 
788 int sas_ioctl(struct scsi_device *sdev, unsigned int cmd, void __user *arg)
789 {
790 	struct domain_device *dev = sdev_to_domain_dev(sdev);
791 
792 	if (dev_is_sata(dev))
793 		return ata_sas_scsi_ioctl(dev->sata_dev.ap, sdev, cmd, arg);
794 
795 	return -EINVAL;
796 }
797 EXPORT_SYMBOL_GPL(sas_ioctl);
798 
799 struct domain_device *sas_find_dev_by_rphy(struct sas_rphy *rphy)
800 {
801 	struct Scsi_Host *shost = dev_to_shost(rphy->dev.parent);
802 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
803 	struct domain_device *found_dev = NULL;
804 	int i;
805 	unsigned long flags;
806 
807 	spin_lock_irqsave(&ha->phy_port_lock, flags);
808 	for (i = 0; i < ha->num_phys; i++) {
809 		struct asd_sas_port *port = ha->sas_port[i];
810 		struct domain_device *dev;
811 
812 		spin_lock(&port->dev_list_lock);
813 		list_for_each_entry(dev, &port->dev_list, dev_list_node) {
814 			if (rphy == dev->rphy) {
815 				found_dev = dev;
816 				spin_unlock(&port->dev_list_lock);
817 				goto found;
818 			}
819 		}
820 		spin_unlock(&port->dev_list_lock);
821 	}
822  found:
823 	spin_unlock_irqrestore(&ha->phy_port_lock, flags);
824 
825 	return found_dev;
826 }
827 
828 int sas_target_alloc(struct scsi_target *starget)
829 {
830 	struct sas_rphy *rphy = dev_to_rphy(starget->dev.parent);
831 	struct domain_device *found_dev = sas_find_dev_by_rphy(rphy);
832 
833 	if (!found_dev)
834 		return -ENODEV;
835 
836 	kref_get(&found_dev->kref);
837 	starget->hostdata = found_dev;
838 	return 0;
839 }
840 EXPORT_SYMBOL_GPL(sas_target_alloc);
841 
842 #define SAS_DEF_QD 256
843 
844 int sas_slave_configure(struct scsi_device *scsi_dev)
845 {
846 	struct domain_device *dev = sdev_to_domain_dev(scsi_dev);
847 
848 	BUG_ON(dev->rphy->identify.device_type != SAS_END_DEVICE);
849 
850 	if (dev_is_sata(dev)) {
851 		ata_sas_slave_configure(scsi_dev, dev->sata_dev.ap);
852 		return 0;
853 	}
854 
855 	sas_read_port_mode_page(scsi_dev);
856 
857 	if (scsi_dev->tagged_supported) {
858 		scsi_change_queue_depth(scsi_dev, SAS_DEF_QD);
859 	} else {
860 		pr_notice("device %016llx, LUN 0x%llx doesn't support TCQ\n",
861 			  SAS_ADDR(dev->sas_addr), scsi_dev->lun);
862 		scsi_change_queue_depth(scsi_dev, 1);
863 	}
864 
865 	scsi_dev->allow_restart = 1;
866 
867 	return 0;
868 }
869 EXPORT_SYMBOL_GPL(sas_slave_configure);
870 
871 int sas_change_queue_depth(struct scsi_device *sdev, int depth)
872 {
873 	struct domain_device *dev = sdev_to_domain_dev(sdev);
874 
875 	if (dev_is_sata(dev))
876 		return __ata_change_queue_depth(dev->sata_dev.ap, sdev, depth);
877 
878 	if (!sdev->tagged_supported)
879 		depth = 1;
880 	return scsi_change_queue_depth(sdev, depth);
881 }
882 EXPORT_SYMBOL_GPL(sas_change_queue_depth);
883 
884 int sas_bios_param(struct scsi_device *scsi_dev,
885 			  struct block_device *bdev,
886 			  sector_t capacity, int *hsc)
887 {
888 	hsc[0] = 255;
889 	hsc[1] = 63;
890 	sector_div(capacity, 255*63);
891 	hsc[2] = capacity;
892 
893 	return 0;
894 }
895 EXPORT_SYMBOL_GPL(sas_bios_param);
896 
897 /*
898  * Tell an upper layer that it needs to initiate an abort for a given task.
899  * This should only ever be called by an LLDD.
900  */
901 void sas_task_abort(struct sas_task *task)
902 {
903 	struct scsi_cmnd *sc = task->uldd_task;
904 
905 	/* Escape for libsas internal commands */
906 	if (!sc) {
907 		struct sas_task_slow *slow = task->slow_task;
908 
909 		if (!slow)
910 			return;
911 		if (!del_timer(&slow->timer))
912 			return;
913 		slow->timer.function(&slow->timer);
914 		return;
915 	}
916 
917 	if (dev_is_sata(task->dev))
918 		sas_ata_task_abort(task);
919 	else
920 		blk_abort_request(scsi_cmd_to_rq(sc));
921 }
922 EXPORT_SYMBOL_GPL(sas_task_abort);
923 
924 int sas_slave_alloc(struct scsi_device *sdev)
925 {
926 	if (dev_is_sata(sdev_to_domain_dev(sdev)) && sdev->lun)
927 		return -ENXIO;
928 
929 	return 0;
930 }
931 EXPORT_SYMBOL_GPL(sas_slave_alloc);
932 
933 void sas_target_destroy(struct scsi_target *starget)
934 {
935 	struct domain_device *found_dev = starget->hostdata;
936 
937 	if (!found_dev)
938 		return;
939 
940 	starget->hostdata = NULL;
941 	sas_put_device(found_dev);
942 }
943 EXPORT_SYMBOL_GPL(sas_target_destroy);
944 
945 #define SAS_STRING_ADDR_SIZE	16
946 
947 int sas_request_addr(struct Scsi_Host *shost, u8 *addr)
948 {
949 	int res;
950 	const struct firmware *fw;
951 
952 	res = request_firmware(&fw, "sas_addr", &shost->shost_gendev);
953 	if (res)
954 		return res;
955 
956 	if (fw->size < SAS_STRING_ADDR_SIZE) {
957 		res = -ENODEV;
958 		goto out;
959 	}
960 
961 	res = hex2bin(addr, fw->data, strnlen(fw->data, SAS_ADDR_SIZE * 2) / 2);
962 	if (res)
963 		goto out;
964 
965 out:
966 	release_firmware(fw);
967 	return res;
968 }
969 EXPORT_SYMBOL_GPL(sas_request_addr);
970 
971