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 	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 	scsi_done(cmd);
202 	return 0;
203 }
204 EXPORT_SYMBOL_GPL(sas_queuecommand);
205 
206 static void sas_eh_finish_cmd(struct scsi_cmnd *cmd)
207 {
208 	struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(cmd->device->host);
209 	struct domain_device *dev = cmd_to_domain_dev(cmd);
210 	struct sas_task *task = TO_SAS_TASK(cmd);
211 
212 	/* At this point, we only get called following an actual abort
213 	 * of the task, so we should be guaranteed not to be racing with
214 	 * any completions from the LLD.  Task is freed after this.
215 	 */
216 	sas_end_task(cmd, task);
217 
218 	if (dev_is_sata(dev)) {
219 		/* defer commands to libata so that libata EH can
220 		 * handle ata qcs correctly
221 		 */
222 		list_move_tail(&cmd->eh_entry, &sas_ha->eh_ata_q);
223 		return;
224 	}
225 
226 	/* now finish the command and move it on to the error
227 	 * handler done list, this also takes it off the
228 	 * error handler pending list.
229 	 */
230 	scsi_eh_finish_cmd(cmd, &sas_ha->eh_done_q);
231 }
232 
233 static void sas_scsi_clear_queue_lu(struct list_head *error_q, struct scsi_cmnd *my_cmd)
234 {
235 	struct scsi_cmnd *cmd, *n;
236 
237 	list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
238 		if (cmd->device->sdev_target == my_cmd->device->sdev_target &&
239 		    cmd->device->lun == my_cmd->device->lun)
240 			sas_eh_finish_cmd(cmd);
241 	}
242 }
243 
244 static void sas_scsi_clear_queue_I_T(struct list_head *error_q,
245 				     struct domain_device *dev)
246 {
247 	struct scsi_cmnd *cmd, *n;
248 
249 	list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
250 		struct domain_device *x = cmd_to_domain_dev(cmd);
251 
252 		if (x == dev)
253 			sas_eh_finish_cmd(cmd);
254 	}
255 }
256 
257 static void sas_scsi_clear_queue_port(struct list_head *error_q,
258 				      struct asd_sas_port *port)
259 {
260 	struct scsi_cmnd *cmd, *n;
261 
262 	list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
263 		struct domain_device *dev = cmd_to_domain_dev(cmd);
264 		struct asd_sas_port *x = dev->port;
265 
266 		if (x == port)
267 			sas_eh_finish_cmd(cmd);
268 	}
269 }
270 
271 enum task_disposition {
272 	TASK_IS_DONE,
273 	TASK_IS_ABORTED,
274 	TASK_IS_AT_LU,
275 	TASK_IS_NOT_AT_LU,
276 	TASK_ABORT_FAILED,
277 };
278 
279 static enum task_disposition sas_scsi_find_task(struct sas_task *task)
280 {
281 	unsigned long flags;
282 	int i, res;
283 	struct sas_internal *si =
284 		to_sas_internal(task->dev->port->ha->core.shost->transportt);
285 
286 	for (i = 0; i < 5; i++) {
287 		pr_notice("%s: aborting task 0x%p\n", __func__, task);
288 		res = si->dft->lldd_abort_task(task);
289 
290 		spin_lock_irqsave(&task->task_state_lock, flags);
291 		if (task->task_state_flags & SAS_TASK_STATE_DONE) {
292 			spin_unlock_irqrestore(&task->task_state_lock, flags);
293 			pr_debug("%s: task 0x%p is done\n", __func__, task);
294 			return TASK_IS_DONE;
295 		}
296 		spin_unlock_irqrestore(&task->task_state_lock, flags);
297 
298 		if (res == TMF_RESP_FUNC_COMPLETE) {
299 			pr_notice("%s: task 0x%p is aborted\n",
300 				  __func__, task);
301 			return TASK_IS_ABORTED;
302 		} else if (si->dft->lldd_query_task) {
303 			pr_notice("%s: querying task 0x%p\n", __func__, task);
304 			res = si->dft->lldd_query_task(task);
305 			switch (res) {
306 			case TMF_RESP_FUNC_SUCC:
307 				pr_notice("%s: task 0x%p at LU\n", __func__,
308 					  task);
309 				return TASK_IS_AT_LU;
310 			case TMF_RESP_FUNC_COMPLETE:
311 				pr_notice("%s: task 0x%p not at LU\n",
312 					  __func__, task);
313 				return TASK_IS_NOT_AT_LU;
314 			case TMF_RESP_FUNC_FAILED:
315 				pr_notice("%s: task 0x%p failed to abort\n",
316 					  __func__, task);
317 				return TASK_ABORT_FAILED;
318 			}
319 
320 		}
321 	}
322 	return res;
323 }
324 
325 static int sas_recover_lu(struct domain_device *dev, struct scsi_cmnd *cmd)
326 {
327 	int res = TMF_RESP_FUNC_FAILED;
328 	struct scsi_lun lun;
329 	struct sas_internal *i =
330 		to_sas_internal(dev->port->ha->core.shost->transportt);
331 
332 	int_to_scsilun(cmd->device->lun, &lun);
333 
334 	pr_notice("eh: device %016llx LUN 0x%llx has the task\n",
335 		  SAS_ADDR(dev->sas_addr),
336 		  cmd->device->lun);
337 
338 	if (i->dft->lldd_abort_task_set)
339 		res = i->dft->lldd_abort_task_set(dev, lun.scsi_lun);
340 
341 	if (res == TMF_RESP_FUNC_FAILED) {
342 		if (i->dft->lldd_clear_task_set)
343 			res = i->dft->lldd_clear_task_set(dev, lun.scsi_lun);
344 	}
345 
346 	if (res == TMF_RESP_FUNC_FAILED) {
347 		if (i->dft->lldd_lu_reset)
348 			res = i->dft->lldd_lu_reset(dev, lun.scsi_lun);
349 	}
350 
351 	return res;
352 }
353 
354 static int sas_recover_I_T(struct domain_device *dev)
355 {
356 	int res = TMF_RESP_FUNC_FAILED;
357 	struct sas_internal *i =
358 		to_sas_internal(dev->port->ha->core.shost->transportt);
359 
360 	pr_notice("I_T nexus reset for dev %016llx\n",
361 		  SAS_ADDR(dev->sas_addr));
362 
363 	if (i->dft->lldd_I_T_nexus_reset)
364 		res = i->dft->lldd_I_T_nexus_reset(dev);
365 
366 	return res;
367 }
368 
369 /* take a reference on the last known good phy for this device */
370 struct sas_phy *sas_get_local_phy(struct domain_device *dev)
371 {
372 	struct sas_ha_struct *ha = dev->port->ha;
373 	struct sas_phy *phy;
374 	unsigned long flags;
375 
376 	/* a published domain device always has a valid phy, it may be
377 	 * stale, but it is never NULL
378 	 */
379 	BUG_ON(!dev->phy);
380 
381 	spin_lock_irqsave(&ha->phy_port_lock, flags);
382 	phy = dev->phy;
383 	get_device(&phy->dev);
384 	spin_unlock_irqrestore(&ha->phy_port_lock, flags);
385 
386 	return phy;
387 }
388 EXPORT_SYMBOL_GPL(sas_get_local_phy);
389 
390 static void sas_wait_eh(struct domain_device *dev)
391 {
392 	struct sas_ha_struct *ha = dev->port->ha;
393 	DEFINE_WAIT(wait);
394 
395 	if (dev_is_sata(dev)) {
396 		ata_port_wait_eh(dev->sata_dev.ap);
397 		return;
398 	}
399  retry:
400 	spin_lock_irq(&ha->lock);
401 
402 	while (test_bit(SAS_DEV_EH_PENDING, &dev->state)) {
403 		prepare_to_wait(&ha->eh_wait_q, &wait, TASK_UNINTERRUPTIBLE);
404 		spin_unlock_irq(&ha->lock);
405 		schedule();
406 		spin_lock_irq(&ha->lock);
407 	}
408 	finish_wait(&ha->eh_wait_q, &wait);
409 
410 	spin_unlock_irq(&ha->lock);
411 
412 	/* make sure SCSI EH is complete */
413 	if (scsi_host_in_recovery(ha->core.shost)) {
414 		msleep(10);
415 		goto retry;
416 	}
417 }
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 EXPORT_SYMBOL_GPL(sas_eh_device_reset_handler);
516 
517 int sas_eh_target_reset_handler(struct scsi_cmnd *cmd)
518 {
519 	int res;
520 	struct Scsi_Host *host = cmd->device->host;
521 	struct domain_device *dev = cmd_to_domain_dev(cmd);
522 	struct sas_internal *i = to_sas_internal(host->transportt);
523 
524 	if (current != host->ehandler)
525 		return sas_queue_reset(dev, SAS_DEV_RESET, 0, 0);
526 
527 	if (!i->dft->lldd_I_T_nexus_reset)
528 		return FAILED;
529 
530 	res = i->dft->lldd_I_T_nexus_reset(dev);
531 	if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE ||
532 	    res == -ENODEV)
533 		return SUCCESS;
534 
535 	return FAILED;
536 }
537 EXPORT_SYMBOL_GPL(sas_eh_target_reset_handler);
538 
539 /* Try to reset a device */
540 static int try_to_reset_cmd_device(struct scsi_cmnd *cmd)
541 {
542 	int res;
543 	struct Scsi_Host *shost = cmd->device->host;
544 
545 	if (!shost->hostt->eh_device_reset_handler)
546 		goto try_target_reset;
547 
548 	res = shost->hostt->eh_device_reset_handler(cmd);
549 	if (res == SUCCESS)
550 		return res;
551 
552 try_target_reset:
553 	if (shost->hostt->eh_target_reset_handler)
554 		return shost->hostt->eh_target_reset_handler(cmd);
555 
556 	return FAILED;
557 }
558 
559 static void sas_eh_handle_sas_errors(struct Scsi_Host *shost, struct list_head *work_q)
560 {
561 	struct scsi_cmnd *cmd, *n;
562 	enum task_disposition res = TASK_IS_DONE;
563 	int tmf_resp, need_reset;
564 	struct sas_internal *i = to_sas_internal(shost->transportt);
565 	unsigned long flags;
566 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
567 	LIST_HEAD(done);
568 
569 	/* clean out any commands that won the completion vs eh race */
570 	list_for_each_entry_safe(cmd, n, work_q, eh_entry) {
571 		struct domain_device *dev = cmd_to_domain_dev(cmd);
572 		struct sas_task *task;
573 
574 		spin_lock_irqsave(&dev->done_lock, flags);
575 		/* by this point the lldd has either observed
576 		 * SAS_HA_FROZEN and is leaving the task alone, or has
577 		 * won the race with eh and decided to complete it
578 		 */
579 		task = TO_SAS_TASK(cmd);
580 		spin_unlock_irqrestore(&dev->done_lock, flags);
581 
582 		if (!task)
583 			list_move_tail(&cmd->eh_entry, &done);
584 	}
585 
586  Again:
587 	list_for_each_entry_safe(cmd, n, work_q, eh_entry) {
588 		struct sas_task *task = TO_SAS_TASK(cmd);
589 
590 		list_del_init(&cmd->eh_entry);
591 
592 		spin_lock_irqsave(&task->task_state_lock, flags);
593 		need_reset = task->task_state_flags & SAS_TASK_NEED_DEV_RESET;
594 		spin_unlock_irqrestore(&task->task_state_lock, flags);
595 
596 		if (need_reset) {
597 			pr_notice("%s: task 0x%p requests reset\n",
598 				  __func__, task);
599 			goto reset;
600 		}
601 
602 		pr_debug("trying to find task 0x%p\n", task);
603 		res = sas_scsi_find_task(task);
604 
605 		switch (res) {
606 		case TASK_IS_DONE:
607 			pr_notice("%s: task 0x%p is done\n", __func__,
608 				    task);
609 			sas_eh_finish_cmd(cmd);
610 			continue;
611 		case TASK_IS_ABORTED:
612 			pr_notice("%s: task 0x%p is aborted\n",
613 				  __func__, task);
614 			sas_eh_finish_cmd(cmd);
615 			continue;
616 		case TASK_IS_AT_LU:
617 			pr_info("task 0x%p is at LU: lu recover\n", task);
618  reset:
619 			tmf_resp = sas_recover_lu(task->dev, cmd);
620 			if (tmf_resp == TMF_RESP_FUNC_COMPLETE) {
621 				pr_notice("dev %016llx LU 0x%llx is recovered\n",
622 					  SAS_ADDR(task->dev),
623 					  cmd->device->lun);
624 				sas_eh_finish_cmd(cmd);
625 				sas_scsi_clear_queue_lu(work_q, cmd);
626 				goto Again;
627 			}
628 			fallthrough;
629 		case TASK_IS_NOT_AT_LU:
630 		case TASK_ABORT_FAILED:
631 			pr_notice("task 0x%p is not at LU: I_T recover\n",
632 				  task);
633 			tmf_resp = sas_recover_I_T(task->dev);
634 			if (tmf_resp == TMF_RESP_FUNC_COMPLETE ||
635 			    tmf_resp == -ENODEV) {
636 				struct domain_device *dev = task->dev;
637 				pr_notice("I_T %016llx recovered\n",
638 					  SAS_ADDR(task->dev->sas_addr));
639 				sas_eh_finish_cmd(cmd);
640 				sas_scsi_clear_queue_I_T(work_q, dev);
641 				goto Again;
642 			}
643 			/* Hammer time :-) */
644 			try_to_reset_cmd_device(cmd);
645 			if (i->dft->lldd_clear_nexus_port) {
646 				struct asd_sas_port *port = task->dev->port;
647 				pr_debug("clearing nexus for port:%d\n",
648 					  port->id);
649 				res = i->dft->lldd_clear_nexus_port(port);
650 				if (res == TMF_RESP_FUNC_COMPLETE) {
651 					pr_notice("clear nexus port:%d succeeded\n",
652 						  port->id);
653 					sas_eh_finish_cmd(cmd);
654 					sas_scsi_clear_queue_port(work_q,
655 								  port);
656 					goto Again;
657 				}
658 			}
659 			if (i->dft->lldd_clear_nexus_ha) {
660 				pr_debug("clear nexus ha\n");
661 				res = i->dft->lldd_clear_nexus_ha(ha);
662 				if (res == TMF_RESP_FUNC_COMPLETE) {
663 					pr_notice("clear nexus ha succeeded\n");
664 					sas_eh_finish_cmd(cmd);
665 					goto clear_q;
666 				}
667 			}
668 			/* If we are here -- this means that no amount
669 			 * of effort could recover from errors.  Quite
670 			 * possibly the HA just disappeared.
671 			 */
672 			pr_err("error from device %016llx, LUN 0x%llx couldn't be recovered in any way\n",
673 			       SAS_ADDR(task->dev->sas_addr),
674 			       cmd->device->lun);
675 
676 			sas_eh_finish_cmd(cmd);
677 			goto clear_q;
678 		}
679 	}
680  out:
681 	list_splice_tail(&done, work_q);
682 	list_splice_tail_init(&ha->eh_ata_q, work_q);
683 	return;
684 
685  clear_q:
686 	pr_debug("--- Exit %s -- clear_q\n", __func__);
687 	list_for_each_entry_safe(cmd, n, work_q, eh_entry)
688 		sas_eh_finish_cmd(cmd);
689 	goto out;
690 }
691 
692 static void sas_eh_handle_resets(struct Scsi_Host *shost)
693 {
694 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
695 	struct sas_internal *i = to_sas_internal(shost->transportt);
696 
697 	/* handle directed resets to sas devices */
698 	spin_lock_irq(&ha->lock);
699 	while (!list_empty(&ha->eh_dev_q)) {
700 		struct domain_device *dev;
701 		struct ssp_device *ssp;
702 
703 		ssp = list_entry(ha->eh_dev_q.next, typeof(*ssp), eh_list_node);
704 		list_del_init(&ssp->eh_list_node);
705 		dev = container_of(ssp, typeof(*dev), ssp_dev);
706 		kref_get(&dev->kref);
707 		WARN_ONCE(dev_is_sata(dev), "ssp reset to ata device?\n");
708 
709 		spin_unlock_irq(&ha->lock);
710 
711 		if (test_and_clear_bit(SAS_DEV_LU_RESET, &dev->state))
712 			i->dft->lldd_lu_reset(dev, ssp->reset_lun.scsi_lun);
713 
714 		if (test_and_clear_bit(SAS_DEV_RESET, &dev->state))
715 			i->dft->lldd_I_T_nexus_reset(dev);
716 
717 		sas_put_device(dev);
718 		spin_lock_irq(&ha->lock);
719 		clear_bit(SAS_DEV_EH_PENDING, &dev->state);
720 		ha->eh_active--;
721 	}
722 	spin_unlock_irq(&ha->lock);
723 }
724 
725 
726 void sas_scsi_recover_host(struct Scsi_Host *shost)
727 {
728 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
729 	LIST_HEAD(eh_work_q);
730 	int tries = 0;
731 	bool retry;
732 
733 retry:
734 	tries++;
735 	retry = true;
736 	spin_lock_irq(shost->host_lock);
737 	list_splice_init(&shost->eh_cmd_q, &eh_work_q);
738 	spin_unlock_irq(shost->host_lock);
739 
740 	pr_notice("Enter %s busy: %d failed: %d\n",
741 		  __func__, scsi_host_busy(shost), shost->host_failed);
742 	/*
743 	 * Deal with commands that still have SAS tasks (i.e. they didn't
744 	 * complete via the normal sas_task completion mechanism),
745 	 * SAS_HA_FROZEN gives eh dominion over all sas_task completion.
746 	 */
747 	set_bit(SAS_HA_FROZEN, &ha->state);
748 	sas_eh_handle_sas_errors(shost, &eh_work_q);
749 	clear_bit(SAS_HA_FROZEN, &ha->state);
750 	if (list_empty(&eh_work_q))
751 		goto out;
752 
753 	/*
754 	 * Now deal with SCSI commands that completed ok but have a an error
755 	 * code (and hopefully sense data) attached.  This is roughly what
756 	 * scsi_unjam_host does, but we skip scsi_eh_abort_cmds because any
757 	 * command we see here has no sas_task and is thus unknown to the HA.
758 	 */
759 	sas_ata_eh(shost, &eh_work_q, &ha->eh_done_q);
760 	if (!scsi_eh_get_sense(&eh_work_q, &ha->eh_done_q))
761 		scsi_eh_ready_devs(shost, &eh_work_q, &ha->eh_done_q);
762 
763 out:
764 	sas_eh_handle_resets(shost);
765 
766 	/* now link into libata eh --- if we have any ata devices */
767 	sas_ata_strategy_handler(shost);
768 
769 	scsi_eh_flush_done_q(&ha->eh_done_q);
770 
771 	/* check if any new eh work was scheduled during the last run */
772 	spin_lock_irq(&ha->lock);
773 	if (ha->eh_active == 0) {
774 		shost->host_eh_scheduled = 0;
775 		retry = false;
776 	}
777 	spin_unlock_irq(&ha->lock);
778 
779 	if (retry)
780 		goto retry;
781 
782 	pr_notice("--- Exit %s: busy: %d failed: %d tries: %d\n",
783 		  __func__, scsi_host_busy(shost),
784 		  shost->host_failed, tries);
785 }
786 
787 int sas_ioctl(struct scsi_device *sdev, unsigned int cmd, void __user *arg)
788 {
789 	struct domain_device *dev = sdev_to_domain_dev(sdev);
790 
791 	if (dev_is_sata(dev))
792 		return ata_sas_scsi_ioctl(dev->sata_dev.ap, sdev, cmd, arg);
793 
794 	return -EINVAL;
795 }
796 EXPORT_SYMBOL_GPL(sas_ioctl);
797 
798 struct domain_device *sas_find_dev_by_rphy(struct sas_rphy *rphy)
799 {
800 	struct Scsi_Host *shost = dev_to_shost(rphy->dev.parent);
801 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
802 	struct domain_device *found_dev = NULL;
803 	int i;
804 	unsigned long flags;
805 
806 	spin_lock_irqsave(&ha->phy_port_lock, flags);
807 	for (i = 0; i < ha->num_phys; i++) {
808 		struct asd_sas_port *port = ha->sas_port[i];
809 		struct domain_device *dev;
810 
811 		spin_lock(&port->dev_list_lock);
812 		list_for_each_entry(dev, &port->dev_list, dev_list_node) {
813 			if (rphy == dev->rphy) {
814 				found_dev = dev;
815 				spin_unlock(&port->dev_list_lock);
816 				goto found;
817 			}
818 		}
819 		spin_unlock(&port->dev_list_lock);
820 	}
821  found:
822 	spin_unlock_irqrestore(&ha->phy_port_lock, flags);
823 
824 	return found_dev;
825 }
826 
827 int sas_target_alloc(struct scsi_target *starget)
828 {
829 	struct sas_rphy *rphy = dev_to_rphy(starget->dev.parent);
830 	struct domain_device *found_dev = sas_find_dev_by_rphy(rphy);
831 
832 	if (!found_dev)
833 		return -ENODEV;
834 
835 	kref_get(&found_dev->kref);
836 	starget->hostdata = found_dev;
837 	return 0;
838 }
839 EXPORT_SYMBOL_GPL(sas_target_alloc);
840 
841 #define SAS_DEF_QD 256
842 
843 int sas_slave_configure(struct scsi_device *scsi_dev)
844 {
845 	struct domain_device *dev = sdev_to_domain_dev(scsi_dev);
846 
847 	BUG_ON(dev->rphy->identify.device_type != SAS_END_DEVICE);
848 
849 	if (dev_is_sata(dev)) {
850 		ata_sas_slave_configure(scsi_dev, dev->sata_dev.ap);
851 		return 0;
852 	}
853 
854 	sas_read_port_mode_page(scsi_dev);
855 
856 	if (scsi_dev->tagged_supported) {
857 		scsi_change_queue_depth(scsi_dev, SAS_DEF_QD);
858 	} else {
859 		pr_notice("device %016llx, LUN 0x%llx doesn't support TCQ\n",
860 			  SAS_ADDR(dev->sas_addr), scsi_dev->lun);
861 		scsi_change_queue_depth(scsi_dev, 1);
862 	}
863 
864 	scsi_dev->allow_restart = 1;
865 
866 	return 0;
867 }
868 EXPORT_SYMBOL_GPL(sas_slave_configure);
869 
870 int sas_change_queue_depth(struct scsi_device *sdev, int depth)
871 {
872 	struct domain_device *dev = sdev_to_domain_dev(sdev);
873 
874 	if (dev_is_sata(dev))
875 		return __ata_change_queue_depth(dev->sata_dev.ap, sdev, depth);
876 
877 	if (!sdev->tagged_supported)
878 		depth = 1;
879 	return scsi_change_queue_depth(sdev, depth);
880 }
881 EXPORT_SYMBOL_GPL(sas_change_queue_depth);
882 
883 int sas_bios_param(struct scsi_device *scsi_dev,
884 			  struct block_device *bdev,
885 			  sector_t capacity, int *hsc)
886 {
887 	hsc[0] = 255;
888 	hsc[1] = 63;
889 	sector_div(capacity, 255*63);
890 	hsc[2] = capacity;
891 
892 	return 0;
893 }
894 EXPORT_SYMBOL_GPL(sas_bios_param);
895 
896 /*
897  * Tell an upper layer that it needs to initiate an abort for a given task.
898  * This should only ever be called by an LLDD.
899  */
900 void sas_task_abort(struct sas_task *task)
901 {
902 	struct scsi_cmnd *sc = task->uldd_task;
903 
904 	/* Escape for libsas internal commands */
905 	if (!sc) {
906 		struct sas_task_slow *slow = task->slow_task;
907 
908 		if (!slow)
909 			return;
910 		if (!del_timer(&slow->timer))
911 			return;
912 		slow->timer.function(&slow->timer);
913 		return;
914 	}
915 
916 	if (dev_is_sata(task->dev))
917 		sas_ata_task_abort(task);
918 	else
919 		blk_abort_request(scsi_cmd_to_rq(sc));
920 }
921 EXPORT_SYMBOL_GPL(sas_task_abort);
922 
923 int sas_slave_alloc(struct scsi_device *sdev)
924 {
925 	if (dev_is_sata(sdev_to_domain_dev(sdev)) && sdev->lun)
926 		return -ENXIO;
927 
928 	return 0;
929 }
930 EXPORT_SYMBOL_GPL(sas_slave_alloc);
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 EXPORT_SYMBOL_GPL(sas_target_destroy);
943 
944 #define SAS_STRING_ADDR_SIZE	16
945 
946 int sas_request_addr(struct Scsi_Host *shost, u8 *addr)
947 {
948 	int res;
949 	const struct firmware *fw;
950 
951 	res = request_firmware(&fw, "sas_addr", &shost->shost_gendev);
952 	if (res)
953 		return res;
954 
955 	if (fw->size < SAS_STRING_ADDR_SIZE) {
956 		res = -ENODEV;
957 		goto out;
958 	}
959 
960 	res = hex2bin(addr, fw->data, strnlen(fw->data, SAS_ADDR_SIZE * 2) / 2);
961 	if (res)
962 		goto out;
963 
964 out:
965 	release_firmware(fw);
966 	return res;
967 }
968 EXPORT_SYMBOL_GPL(sas_request_addr);
969 
970