1 /*
2  * Serial Attached SCSI (SAS) class SCSI Host glue.
3  *
4  * Copyright (C) 2005 Adaptec, Inc.  All rights reserved.
5  * Copyright (C) 2005 Luben Tuikov <luben_tuikov@adaptec.com>
6  *
7  * This file is licensed under GPLv2.
8  *
9  * This program is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU General Public License as
11  * published by the Free Software Foundation; either version 2 of the
12  * License, or (at your option) any later version.
13  *
14  * This program is distributed in the hope that it will be useful, but
15  * WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17  * General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
22  * USA
23  *
24  */
25 
26 #include <linux/kthread.h>
27 #include <linux/firmware.h>
28 #include <linux/export.h>
29 #include <linux/ctype.h>
30 #include <linux/kernel.h>
31 
32 #include "sas_internal.h"
33 
34 #include <scsi/scsi_host.h>
35 #include <scsi/scsi_device.h>
36 #include <scsi/scsi_tcq.h>
37 #include <scsi/scsi.h>
38 #include <scsi/scsi_eh.h>
39 #include <scsi/scsi_transport.h>
40 #include <scsi/scsi_transport_sas.h>
41 #include <scsi/sas_ata.h>
42 #include "../scsi_sas_internal.h"
43 #include "../scsi_transport_api.h"
44 #include "../scsi_priv.h"
45 
46 #include <linux/err.h>
47 #include <linux/blkdev.h>
48 #include <linux/freezer.h>
49 #include <linux/gfp.h>
50 #include <linux/scatterlist.h>
51 #include <linux/libata.h>
52 
53 /* record final status and free the task */
54 static void sas_end_task(struct scsi_cmnd *sc, struct sas_task *task)
55 {
56 	struct task_status_struct *ts = &task->task_status;
57 	int hs = 0, stat = 0;
58 
59 	if (ts->resp == SAS_TASK_UNDELIVERED) {
60 		/* transport error */
61 		hs = DID_NO_CONNECT;
62 	} else { /* ts->resp == SAS_TASK_COMPLETE */
63 		/* task delivered, what happened afterwards? */
64 		switch (ts->stat) {
65 		case SAS_DEV_NO_RESPONSE:
66 		case SAS_INTERRUPTED:
67 		case SAS_PHY_DOWN:
68 		case SAS_NAK_R_ERR:
69 		case SAS_OPEN_TO:
70 			hs = DID_NO_CONNECT;
71 			break;
72 		case SAS_DATA_UNDERRUN:
73 			scsi_set_resid(sc, ts->residual);
74 			if (scsi_bufflen(sc) - scsi_get_resid(sc) < sc->underflow)
75 				hs = DID_ERROR;
76 			break;
77 		case SAS_DATA_OVERRUN:
78 			hs = DID_ERROR;
79 			break;
80 		case SAS_QUEUE_FULL:
81 			hs = DID_SOFT_ERROR; /* retry */
82 			break;
83 		case SAS_DEVICE_UNKNOWN:
84 			hs = DID_BAD_TARGET;
85 			break;
86 		case SAS_SG_ERR:
87 			hs = DID_PARITY;
88 			break;
89 		case SAS_OPEN_REJECT:
90 			if (ts->open_rej_reason == SAS_OREJ_RSVD_RETRY)
91 				hs = DID_SOFT_ERROR; /* retry */
92 			else
93 				hs = DID_ERROR;
94 			break;
95 		case SAS_PROTO_RESPONSE:
96 			SAS_DPRINTK("LLDD:%s sent SAS_PROTO_RESP for an SSP "
97 				    "task; please report this\n",
98 				    task->dev->port->ha->sas_ha_name);
99 			break;
100 		case SAS_ABORTED_TASK:
101 			hs = DID_ABORT;
102 			break;
103 		case SAM_STAT_CHECK_CONDITION:
104 			memcpy(sc->sense_buffer, ts->buf,
105 			       min(SCSI_SENSE_BUFFERSIZE, ts->buf_valid_size));
106 			stat = SAM_STAT_CHECK_CONDITION;
107 			break;
108 		default:
109 			stat = ts->stat;
110 			break;
111 		}
112 	}
113 
114 	sc->result = (hs << 16) | stat;
115 	ASSIGN_SAS_TASK(sc, NULL);
116 	sas_free_task(task);
117 }
118 
119 static void sas_scsi_task_done(struct sas_task *task)
120 {
121 	struct scsi_cmnd *sc = task->uldd_task;
122 	struct domain_device *dev = task->dev;
123 	struct sas_ha_struct *ha = dev->port->ha;
124 	unsigned long flags;
125 
126 	spin_lock_irqsave(&dev->done_lock, flags);
127 	if (test_bit(SAS_HA_FROZEN, &ha->state))
128 		task = NULL;
129 	else
130 		ASSIGN_SAS_TASK(sc, NULL);
131 	spin_unlock_irqrestore(&dev->done_lock, flags);
132 
133 	if (unlikely(!task)) {
134 		/* task will be completed by the error handler */
135 		SAS_DPRINTK("task done but aborted\n");
136 		return;
137 	}
138 
139 	if (unlikely(!sc)) {
140 		SAS_DPRINTK("task_done called with non existing SCSI cmnd!\n");
141 		sas_free_task(task);
142 		return;
143 	}
144 
145 	sas_end_task(sc, task);
146 	sc->scsi_done(sc);
147 }
148 
149 static struct sas_task *sas_create_task(struct scsi_cmnd *cmd,
150 					       struct domain_device *dev,
151 					       gfp_t gfp_flags)
152 {
153 	struct sas_task *task = sas_alloc_task(gfp_flags);
154 	struct scsi_lun lun;
155 
156 	if (!task)
157 		return NULL;
158 
159 	task->uldd_task = cmd;
160 	ASSIGN_SAS_TASK(cmd, task);
161 
162 	task->dev = dev;
163 	task->task_proto = task->dev->tproto; /* BUG_ON(!SSP) */
164 
165 	task->ssp_task.retry_count = 1;
166 	int_to_scsilun(cmd->device->lun, &lun);
167 	memcpy(task->ssp_task.LUN, &lun.scsi_lun, 8);
168 	task->ssp_task.task_attr = TASK_ATTR_SIMPLE;
169 	task->ssp_task.cmd = cmd;
170 
171 	task->scatter = scsi_sglist(cmd);
172 	task->num_scatter = scsi_sg_count(cmd);
173 	task->total_xfer_len = scsi_bufflen(cmd);
174 	task->data_dir = cmd->sc_data_direction;
175 
176 	task->task_done = sas_scsi_task_done;
177 
178 	return task;
179 }
180 
181 int sas_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
182 {
183 	struct sas_internal *i = to_sas_internal(host->transportt);
184 	struct domain_device *dev = cmd_to_domain_dev(cmd);
185 	struct sas_task *task;
186 	int res = 0;
187 
188 	/* If the device fell off, no sense in issuing commands */
189 	if (test_bit(SAS_DEV_GONE, &dev->state)) {
190 		cmd->result = DID_BAD_TARGET << 16;
191 		goto out_done;
192 	}
193 
194 	if (dev_is_sata(dev)) {
195 		spin_lock_irq(dev->sata_dev.ap->lock);
196 		res = ata_sas_queuecmd(cmd, dev->sata_dev.ap);
197 		spin_unlock_irq(dev->sata_dev.ap->lock);
198 		return res;
199 	}
200 
201 	task = sas_create_task(cmd, dev, GFP_ATOMIC);
202 	if (!task)
203 		return SCSI_MLQUEUE_HOST_BUSY;
204 
205 	res = i->dft->lldd_execute_task(task, GFP_ATOMIC);
206 	if (res)
207 		goto out_free_task;
208 	return 0;
209 
210 out_free_task:
211 	SAS_DPRINTK("lldd_execute_task returned: %d\n", res);
212 	ASSIGN_SAS_TASK(cmd, NULL);
213 	sas_free_task(task);
214 	if (res == -SAS_QUEUE_FULL)
215 		cmd->result = DID_SOFT_ERROR << 16; /* retry */
216 	else
217 		cmd->result = DID_ERROR << 16;
218 out_done:
219 	cmd->scsi_done(cmd);
220 	return 0;
221 }
222 
223 static void sas_eh_finish_cmd(struct scsi_cmnd *cmd)
224 {
225 	struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(cmd->device->host);
226 	struct domain_device *dev = cmd_to_domain_dev(cmd);
227 	struct sas_task *task = TO_SAS_TASK(cmd);
228 
229 	/* At this point, we only get called following an actual abort
230 	 * of the task, so we should be guaranteed not to be racing with
231 	 * any completions from the LLD.  Task is freed after this.
232 	 */
233 	sas_end_task(cmd, task);
234 
235 	if (dev_is_sata(dev)) {
236 		/* defer commands to libata so that libata EH can
237 		 * handle ata qcs correctly
238 		 */
239 		list_move_tail(&cmd->eh_entry, &sas_ha->eh_ata_q);
240 		return;
241 	}
242 
243 	/* now finish the command and move it on to the error
244 	 * handler done list, this also takes it off the
245 	 * error handler pending list.
246 	 */
247 	scsi_eh_finish_cmd(cmd, &sas_ha->eh_done_q);
248 }
249 
250 static void sas_scsi_clear_queue_lu(struct list_head *error_q, struct scsi_cmnd *my_cmd)
251 {
252 	struct scsi_cmnd *cmd, *n;
253 
254 	list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
255 		if (cmd->device->sdev_target == my_cmd->device->sdev_target &&
256 		    cmd->device->lun == my_cmd->device->lun)
257 			sas_eh_finish_cmd(cmd);
258 	}
259 }
260 
261 static void sas_scsi_clear_queue_I_T(struct list_head *error_q,
262 				     struct domain_device *dev)
263 {
264 	struct scsi_cmnd *cmd, *n;
265 
266 	list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
267 		struct domain_device *x = cmd_to_domain_dev(cmd);
268 
269 		if (x == dev)
270 			sas_eh_finish_cmd(cmd);
271 	}
272 }
273 
274 static void sas_scsi_clear_queue_port(struct list_head *error_q,
275 				      struct asd_sas_port *port)
276 {
277 	struct scsi_cmnd *cmd, *n;
278 
279 	list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
280 		struct domain_device *dev = cmd_to_domain_dev(cmd);
281 		struct asd_sas_port *x = dev->port;
282 
283 		if (x == port)
284 			sas_eh_finish_cmd(cmd);
285 	}
286 }
287 
288 enum task_disposition {
289 	TASK_IS_DONE,
290 	TASK_IS_ABORTED,
291 	TASK_IS_AT_LU,
292 	TASK_IS_NOT_AT_LU,
293 	TASK_ABORT_FAILED,
294 };
295 
296 static enum task_disposition sas_scsi_find_task(struct sas_task *task)
297 {
298 	unsigned long flags;
299 	int i, res;
300 	struct sas_internal *si =
301 		to_sas_internal(task->dev->port->ha->core.shost->transportt);
302 
303 	for (i = 0; i < 5; i++) {
304 		SAS_DPRINTK("%s: aborting task 0x%p\n", __func__, task);
305 		res = si->dft->lldd_abort_task(task);
306 
307 		spin_lock_irqsave(&task->task_state_lock, flags);
308 		if (task->task_state_flags & SAS_TASK_STATE_DONE) {
309 			spin_unlock_irqrestore(&task->task_state_lock, flags);
310 			SAS_DPRINTK("%s: task 0x%p is done\n", __func__,
311 				    task);
312 			return TASK_IS_DONE;
313 		}
314 		spin_unlock_irqrestore(&task->task_state_lock, flags);
315 
316 		if (res == TMF_RESP_FUNC_COMPLETE) {
317 			SAS_DPRINTK("%s: task 0x%p is aborted\n",
318 				    __func__, task);
319 			return TASK_IS_ABORTED;
320 		} else if (si->dft->lldd_query_task) {
321 			SAS_DPRINTK("%s: querying task 0x%p\n",
322 				    __func__, task);
323 			res = si->dft->lldd_query_task(task);
324 			switch (res) {
325 			case TMF_RESP_FUNC_SUCC:
326 				SAS_DPRINTK("%s: task 0x%p at LU\n",
327 					    __func__, task);
328 				return TASK_IS_AT_LU;
329 			case TMF_RESP_FUNC_COMPLETE:
330 				SAS_DPRINTK("%s: task 0x%p not at LU\n",
331 					    __func__, task);
332 				return TASK_IS_NOT_AT_LU;
333 			case TMF_RESP_FUNC_FAILED:
334                                 SAS_DPRINTK("%s: task 0x%p failed to abort\n",
335                                                 __func__, task);
336                                 return TASK_ABORT_FAILED;
337                         }
338 
339 		}
340 	}
341 	return res;
342 }
343 
344 static int sas_recover_lu(struct domain_device *dev, struct scsi_cmnd *cmd)
345 {
346 	int res = TMF_RESP_FUNC_FAILED;
347 	struct scsi_lun lun;
348 	struct sas_internal *i =
349 		to_sas_internal(dev->port->ha->core.shost->transportt);
350 
351 	int_to_scsilun(cmd->device->lun, &lun);
352 
353 	SAS_DPRINTK("eh: device %llx LUN %llx has the task\n",
354 		    SAS_ADDR(dev->sas_addr),
355 		    cmd->device->lun);
356 
357 	if (i->dft->lldd_abort_task_set)
358 		res = i->dft->lldd_abort_task_set(dev, lun.scsi_lun);
359 
360 	if (res == TMF_RESP_FUNC_FAILED) {
361 		if (i->dft->lldd_clear_task_set)
362 			res = i->dft->lldd_clear_task_set(dev, lun.scsi_lun);
363 	}
364 
365 	if (res == TMF_RESP_FUNC_FAILED) {
366 		if (i->dft->lldd_lu_reset)
367 			res = i->dft->lldd_lu_reset(dev, lun.scsi_lun);
368 	}
369 
370 	return res;
371 }
372 
373 static int sas_recover_I_T(struct domain_device *dev)
374 {
375 	int res = TMF_RESP_FUNC_FAILED;
376 	struct sas_internal *i =
377 		to_sas_internal(dev->port->ha->core.shost->transportt);
378 
379 	SAS_DPRINTK("I_T nexus reset for dev %016llx\n",
380 		    SAS_ADDR(dev->sas_addr));
381 
382 	if (i->dft->lldd_I_T_nexus_reset)
383 		res = i->dft->lldd_I_T_nexus_reset(dev);
384 
385 	return res;
386 }
387 
388 /* take a reference on the last known good phy for this device */
389 struct sas_phy *sas_get_local_phy(struct domain_device *dev)
390 {
391 	struct sas_ha_struct *ha = dev->port->ha;
392 	struct sas_phy *phy;
393 	unsigned long flags;
394 
395 	/* a published domain device always has a valid phy, it may be
396 	 * stale, but it is never NULL
397 	 */
398 	BUG_ON(!dev->phy);
399 
400 	spin_lock_irqsave(&ha->phy_port_lock, flags);
401 	phy = dev->phy;
402 	get_device(&phy->dev);
403 	spin_unlock_irqrestore(&ha->phy_port_lock, flags);
404 
405 	return phy;
406 }
407 EXPORT_SYMBOL_GPL(sas_get_local_phy);
408 
409 static void sas_wait_eh(struct domain_device *dev)
410 {
411 	struct sas_ha_struct *ha = dev->port->ha;
412 	DEFINE_WAIT(wait);
413 
414 	if (dev_is_sata(dev)) {
415 		ata_port_wait_eh(dev->sata_dev.ap);
416 		return;
417 	}
418  retry:
419 	spin_lock_irq(&ha->lock);
420 
421 	while (test_bit(SAS_DEV_EH_PENDING, &dev->state)) {
422 		prepare_to_wait(&ha->eh_wait_q, &wait, TASK_UNINTERRUPTIBLE);
423 		spin_unlock_irq(&ha->lock);
424 		schedule();
425 		spin_lock_irq(&ha->lock);
426 	}
427 	finish_wait(&ha->eh_wait_q, &wait);
428 
429 	spin_unlock_irq(&ha->lock);
430 
431 	/* make sure SCSI EH is complete */
432 	if (scsi_host_in_recovery(ha->core.shost)) {
433 		msleep(10);
434 		goto retry;
435 	}
436 }
437 EXPORT_SYMBOL(sas_wait_eh);
438 
439 static int sas_queue_reset(struct domain_device *dev, int reset_type,
440 			   u64 lun, int wait)
441 {
442 	struct sas_ha_struct *ha = dev->port->ha;
443 	int scheduled = 0, tries = 100;
444 
445 	/* ata: promote lun reset to bus reset */
446 	if (dev_is_sata(dev)) {
447 		sas_ata_schedule_reset(dev);
448 		if (wait)
449 			sas_ata_wait_eh(dev);
450 		return SUCCESS;
451 	}
452 
453 	while (!scheduled && tries--) {
454 		spin_lock_irq(&ha->lock);
455 		if (!test_bit(SAS_DEV_EH_PENDING, &dev->state) &&
456 		    !test_bit(reset_type, &dev->state)) {
457 			scheduled = 1;
458 			ha->eh_active++;
459 			list_add_tail(&dev->ssp_dev.eh_list_node, &ha->eh_dev_q);
460 			set_bit(SAS_DEV_EH_PENDING, &dev->state);
461 			set_bit(reset_type, &dev->state);
462 			int_to_scsilun(lun, &dev->ssp_dev.reset_lun);
463 			scsi_schedule_eh(ha->core.shost);
464 		}
465 		spin_unlock_irq(&ha->lock);
466 
467 		if (wait)
468 			sas_wait_eh(dev);
469 
470 		if (scheduled)
471 			return SUCCESS;
472 	}
473 
474 	SAS_DPRINTK("%s reset of %s failed\n",
475 		    reset_type == SAS_DEV_LU_RESET ? "LUN" : "Bus",
476 		    dev_name(&dev->rphy->dev));
477 
478 	return FAILED;
479 }
480 
481 int sas_eh_abort_handler(struct scsi_cmnd *cmd)
482 {
483 	int res = TMF_RESP_FUNC_FAILED;
484 	struct sas_task *task = TO_SAS_TASK(cmd);
485 	struct Scsi_Host *host = cmd->device->host;
486 	struct domain_device *dev = cmd_to_domain_dev(cmd);
487 	struct sas_internal *i = to_sas_internal(host->transportt);
488 	unsigned long flags;
489 
490 	if (!i->dft->lldd_abort_task)
491 		return FAILED;
492 
493 	spin_lock_irqsave(host->host_lock, flags);
494 	/* We cannot do async aborts for SATA devices */
495 	if (dev_is_sata(dev) && !host->host_eh_scheduled) {
496 		spin_unlock_irqrestore(host->host_lock, flags);
497 		return FAILED;
498 	}
499 	spin_unlock_irqrestore(host->host_lock, flags);
500 
501 	if (task)
502 		res = i->dft->lldd_abort_task(task);
503 	else
504 		SAS_DPRINTK("no task to abort\n");
505 	if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE)
506 		return SUCCESS;
507 
508 	return FAILED;
509 }
510 EXPORT_SYMBOL_GPL(sas_eh_abort_handler);
511 
512 /* Attempt to send a LUN reset message to a device */
513 int sas_eh_device_reset_handler(struct scsi_cmnd *cmd)
514 {
515 	int res;
516 	struct scsi_lun lun;
517 	struct Scsi_Host *host = cmd->device->host;
518 	struct domain_device *dev = cmd_to_domain_dev(cmd);
519 	struct sas_internal *i = to_sas_internal(host->transportt);
520 
521 	if (current != host->ehandler)
522 		return sas_queue_reset(dev, SAS_DEV_LU_RESET, cmd->device->lun, 0);
523 
524 	int_to_scsilun(cmd->device->lun, &lun);
525 
526 	if (!i->dft->lldd_lu_reset)
527 		return FAILED;
528 
529 	res = i->dft->lldd_lu_reset(dev, lun.scsi_lun);
530 	if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE)
531 		return SUCCESS;
532 
533 	return FAILED;
534 }
535 
536 int sas_eh_target_reset_handler(struct scsi_cmnd *cmd)
537 {
538 	int res;
539 	struct Scsi_Host *host = cmd->device->host;
540 	struct domain_device *dev = cmd_to_domain_dev(cmd);
541 	struct sas_internal *i = to_sas_internal(host->transportt);
542 
543 	if (current != host->ehandler)
544 		return sas_queue_reset(dev, SAS_DEV_RESET, 0, 0);
545 
546 	if (!i->dft->lldd_I_T_nexus_reset)
547 		return FAILED;
548 
549 	res = i->dft->lldd_I_T_nexus_reset(dev);
550 	if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE ||
551 	    res == -ENODEV)
552 		return SUCCESS;
553 
554 	return FAILED;
555 }
556 
557 /* Try to reset a device */
558 static int try_to_reset_cmd_device(struct scsi_cmnd *cmd)
559 {
560 	int res;
561 	struct Scsi_Host *shost = cmd->device->host;
562 
563 	if (!shost->hostt->eh_device_reset_handler)
564 		goto try_target_reset;
565 
566 	res = shost->hostt->eh_device_reset_handler(cmd);
567 	if (res == SUCCESS)
568 		return res;
569 
570 try_target_reset:
571 	if (shost->hostt->eh_target_reset_handler)
572 		return shost->hostt->eh_target_reset_handler(cmd);
573 
574 	return FAILED;
575 }
576 
577 static void sas_eh_handle_sas_errors(struct Scsi_Host *shost, struct list_head *work_q)
578 {
579 	struct scsi_cmnd *cmd, *n;
580 	enum task_disposition res = TASK_IS_DONE;
581 	int tmf_resp, need_reset;
582 	struct sas_internal *i = to_sas_internal(shost->transportt);
583 	unsigned long flags;
584 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
585 	LIST_HEAD(done);
586 
587 	/* clean out any commands that won the completion vs eh race */
588 	list_for_each_entry_safe(cmd, n, work_q, eh_entry) {
589 		struct domain_device *dev = cmd_to_domain_dev(cmd);
590 		struct sas_task *task;
591 
592 		spin_lock_irqsave(&dev->done_lock, flags);
593 		/* by this point the lldd has either observed
594 		 * SAS_HA_FROZEN and is leaving the task alone, or has
595 		 * won the race with eh and decided to complete it
596 		 */
597 		task = TO_SAS_TASK(cmd);
598 		spin_unlock_irqrestore(&dev->done_lock, flags);
599 
600 		if (!task)
601 			list_move_tail(&cmd->eh_entry, &done);
602 	}
603 
604  Again:
605 	list_for_each_entry_safe(cmd, n, work_q, eh_entry) {
606 		struct sas_task *task = TO_SAS_TASK(cmd);
607 
608 		list_del_init(&cmd->eh_entry);
609 
610 		spin_lock_irqsave(&task->task_state_lock, flags);
611 		need_reset = task->task_state_flags & SAS_TASK_NEED_DEV_RESET;
612 		spin_unlock_irqrestore(&task->task_state_lock, flags);
613 
614 		if (need_reset) {
615 			SAS_DPRINTK("%s: task 0x%p requests reset\n",
616 				    __func__, task);
617 			goto reset;
618 		}
619 
620 		SAS_DPRINTK("trying to find task 0x%p\n", task);
621 		res = sas_scsi_find_task(task);
622 
623 		switch (res) {
624 		case TASK_IS_DONE:
625 			SAS_DPRINTK("%s: task 0x%p is done\n", __func__,
626 				    task);
627 			sas_eh_finish_cmd(cmd);
628 			continue;
629 		case TASK_IS_ABORTED:
630 			SAS_DPRINTK("%s: task 0x%p is aborted\n",
631 				    __func__, task);
632 			sas_eh_finish_cmd(cmd);
633 			continue;
634 		case TASK_IS_AT_LU:
635 			SAS_DPRINTK("task 0x%p is at LU: lu recover\n", task);
636  reset:
637 			tmf_resp = sas_recover_lu(task->dev, cmd);
638 			if (tmf_resp == TMF_RESP_FUNC_COMPLETE) {
639 				SAS_DPRINTK("dev %016llx LU %llx is "
640 					    "recovered\n",
641 					    SAS_ADDR(task->dev),
642 					    cmd->device->lun);
643 				sas_eh_finish_cmd(cmd);
644 				sas_scsi_clear_queue_lu(work_q, cmd);
645 				goto Again;
646 			}
647 			/* fallthrough */
648 		case TASK_IS_NOT_AT_LU:
649 		case TASK_ABORT_FAILED:
650 			SAS_DPRINTK("task 0x%p is not at LU: I_T recover\n",
651 				    task);
652 			tmf_resp = sas_recover_I_T(task->dev);
653 			if (tmf_resp == TMF_RESP_FUNC_COMPLETE ||
654 			    tmf_resp == -ENODEV) {
655 				struct domain_device *dev = task->dev;
656 				SAS_DPRINTK("I_T %016llx recovered\n",
657 					    SAS_ADDR(task->dev->sas_addr));
658 				sas_eh_finish_cmd(cmd);
659 				sas_scsi_clear_queue_I_T(work_q, dev);
660 				goto Again;
661 			}
662 			/* Hammer time :-) */
663 			try_to_reset_cmd_device(cmd);
664 			if (i->dft->lldd_clear_nexus_port) {
665 				struct asd_sas_port *port = task->dev->port;
666 				SAS_DPRINTK("clearing nexus for port:%d\n",
667 					    port->id);
668 				res = i->dft->lldd_clear_nexus_port(port);
669 				if (res == TMF_RESP_FUNC_COMPLETE) {
670 					SAS_DPRINTK("clear nexus port:%d "
671 						    "succeeded\n", port->id);
672 					sas_eh_finish_cmd(cmd);
673 					sas_scsi_clear_queue_port(work_q,
674 								  port);
675 					goto Again;
676 				}
677 			}
678 			if (i->dft->lldd_clear_nexus_ha) {
679 				SAS_DPRINTK("clear nexus ha\n");
680 				res = i->dft->lldd_clear_nexus_ha(ha);
681 				if (res == TMF_RESP_FUNC_COMPLETE) {
682 					SAS_DPRINTK("clear nexus ha "
683 						    "succeeded\n");
684 					sas_eh_finish_cmd(cmd);
685 					goto clear_q;
686 				}
687 			}
688 			/* If we are here -- this means that no amount
689 			 * of effort could recover from errors.  Quite
690 			 * possibly the HA just disappeared.
691 			 */
692 			SAS_DPRINTK("error from  device %llx, LUN %llx "
693 				    "couldn't be recovered in any way\n",
694 				    SAS_ADDR(task->dev->sas_addr),
695 				    cmd->device->lun);
696 
697 			sas_eh_finish_cmd(cmd);
698 			goto clear_q;
699 		}
700 	}
701  out:
702 	list_splice_tail(&done, work_q);
703 	list_splice_tail_init(&ha->eh_ata_q, work_q);
704 	return;
705 
706  clear_q:
707 	SAS_DPRINTK("--- Exit %s -- clear_q\n", __func__);
708 	list_for_each_entry_safe(cmd, n, work_q, eh_entry)
709 		sas_eh_finish_cmd(cmd);
710 	goto out;
711 }
712 
713 static void sas_eh_handle_resets(struct Scsi_Host *shost)
714 {
715 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
716 	struct sas_internal *i = to_sas_internal(shost->transportt);
717 
718 	/* handle directed resets to sas devices */
719 	spin_lock_irq(&ha->lock);
720 	while (!list_empty(&ha->eh_dev_q)) {
721 		struct domain_device *dev;
722 		struct ssp_device *ssp;
723 
724 		ssp = list_entry(ha->eh_dev_q.next, typeof(*ssp), eh_list_node);
725 		list_del_init(&ssp->eh_list_node);
726 		dev = container_of(ssp, typeof(*dev), ssp_dev);
727 		kref_get(&dev->kref);
728 		WARN_ONCE(dev_is_sata(dev), "ssp reset to ata device?\n");
729 
730 		spin_unlock_irq(&ha->lock);
731 
732 		if (test_and_clear_bit(SAS_DEV_LU_RESET, &dev->state))
733 			i->dft->lldd_lu_reset(dev, ssp->reset_lun.scsi_lun);
734 
735 		if (test_and_clear_bit(SAS_DEV_RESET, &dev->state))
736 			i->dft->lldd_I_T_nexus_reset(dev);
737 
738 		sas_put_device(dev);
739 		spin_lock_irq(&ha->lock);
740 		clear_bit(SAS_DEV_EH_PENDING, &dev->state);
741 		ha->eh_active--;
742 	}
743 	spin_unlock_irq(&ha->lock);
744 }
745 
746 
747 void sas_scsi_recover_host(struct Scsi_Host *shost)
748 {
749 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
750 	LIST_HEAD(eh_work_q);
751 	int tries = 0;
752 	bool retry;
753 
754 retry:
755 	tries++;
756 	retry = true;
757 	spin_lock_irq(shost->host_lock);
758 	list_splice_init(&shost->eh_cmd_q, &eh_work_q);
759 	spin_unlock_irq(shost->host_lock);
760 
761 	SAS_DPRINTK("Enter %s busy: %d failed: %d\n",
762 		    __func__, scsi_host_busy(shost), shost->host_failed);
763 	/*
764 	 * Deal with commands that still have SAS tasks (i.e. they didn't
765 	 * complete via the normal sas_task completion mechanism),
766 	 * SAS_HA_FROZEN gives eh dominion over all sas_task completion.
767 	 */
768 	set_bit(SAS_HA_FROZEN, &ha->state);
769 	sas_eh_handle_sas_errors(shost, &eh_work_q);
770 	clear_bit(SAS_HA_FROZEN, &ha->state);
771 	if (list_empty(&eh_work_q))
772 		goto out;
773 
774 	/*
775 	 * Now deal with SCSI commands that completed ok but have a an error
776 	 * code (and hopefully sense data) attached.  This is roughly what
777 	 * scsi_unjam_host does, but we skip scsi_eh_abort_cmds because any
778 	 * command we see here has no sas_task and is thus unknown to the HA.
779 	 */
780 	sas_ata_eh(shost, &eh_work_q, &ha->eh_done_q);
781 	if (!scsi_eh_get_sense(&eh_work_q, &ha->eh_done_q))
782 		scsi_eh_ready_devs(shost, &eh_work_q, &ha->eh_done_q);
783 
784 out:
785 	sas_eh_handle_resets(shost);
786 
787 	/* now link into libata eh --- if we have any ata devices */
788 	sas_ata_strategy_handler(shost);
789 
790 	scsi_eh_flush_done_q(&ha->eh_done_q);
791 
792 	/* check if any new eh work was scheduled during the last run */
793 	spin_lock_irq(&ha->lock);
794 	if (ha->eh_active == 0) {
795 		shost->host_eh_scheduled = 0;
796 		retry = false;
797 	}
798 	spin_unlock_irq(&ha->lock);
799 
800 	if (retry)
801 		goto retry;
802 
803 	SAS_DPRINTK("--- Exit %s: busy: %d failed: %d tries: %d\n",
804 		    __func__, scsi_host_busy(shost),
805 		    shost->host_failed, tries);
806 }
807 
808 int sas_ioctl(struct scsi_device *sdev, int cmd, void __user *arg)
809 {
810 	struct domain_device *dev = sdev_to_domain_dev(sdev);
811 
812 	if (dev_is_sata(dev))
813 		return ata_sas_scsi_ioctl(dev->sata_dev.ap, sdev, cmd, arg);
814 
815 	return -EINVAL;
816 }
817 
818 struct domain_device *sas_find_dev_by_rphy(struct sas_rphy *rphy)
819 {
820 	struct Scsi_Host *shost = dev_to_shost(rphy->dev.parent);
821 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
822 	struct domain_device *found_dev = NULL;
823 	int i;
824 	unsigned long flags;
825 
826 	spin_lock_irqsave(&ha->phy_port_lock, flags);
827 	for (i = 0; i < ha->num_phys; i++) {
828 		struct asd_sas_port *port = ha->sas_port[i];
829 		struct domain_device *dev;
830 
831 		spin_lock(&port->dev_list_lock);
832 		list_for_each_entry(dev, &port->dev_list, dev_list_node) {
833 			if (rphy == dev->rphy) {
834 				found_dev = dev;
835 				spin_unlock(&port->dev_list_lock);
836 				goto found;
837 			}
838 		}
839 		spin_unlock(&port->dev_list_lock);
840 	}
841  found:
842 	spin_unlock_irqrestore(&ha->phy_port_lock, flags);
843 
844 	return found_dev;
845 }
846 
847 int sas_target_alloc(struct scsi_target *starget)
848 {
849 	struct sas_rphy *rphy = dev_to_rphy(starget->dev.parent);
850 	struct domain_device *found_dev = sas_find_dev_by_rphy(rphy);
851 
852 	if (!found_dev)
853 		return -ENODEV;
854 
855 	kref_get(&found_dev->kref);
856 	starget->hostdata = found_dev;
857 	return 0;
858 }
859 
860 #define SAS_DEF_QD 256
861 
862 int sas_slave_configure(struct scsi_device *scsi_dev)
863 {
864 	struct domain_device *dev = sdev_to_domain_dev(scsi_dev);
865 
866 	BUG_ON(dev->rphy->identify.device_type != SAS_END_DEVICE);
867 
868 	if (dev_is_sata(dev)) {
869 		ata_sas_slave_configure(scsi_dev, dev->sata_dev.ap);
870 		return 0;
871 	}
872 
873 	sas_read_port_mode_page(scsi_dev);
874 
875 	if (scsi_dev->tagged_supported) {
876 		scsi_change_queue_depth(scsi_dev, SAS_DEF_QD);
877 	} else {
878 		SAS_DPRINTK("device %llx, LUN %llx doesn't support "
879 			    "TCQ\n", SAS_ADDR(dev->sas_addr),
880 			    scsi_dev->lun);
881 		scsi_change_queue_depth(scsi_dev, 1);
882 	}
883 
884 	scsi_dev->allow_restart = 1;
885 
886 	return 0;
887 }
888 
889 int sas_change_queue_depth(struct scsi_device *sdev, int depth)
890 {
891 	struct domain_device *dev = sdev_to_domain_dev(sdev);
892 
893 	if (dev_is_sata(dev))
894 		return __ata_change_queue_depth(dev->sata_dev.ap, sdev, depth);
895 
896 	if (!sdev->tagged_supported)
897 		depth = 1;
898 	return scsi_change_queue_depth(sdev, depth);
899 }
900 
901 int sas_bios_param(struct scsi_device *scsi_dev,
902 			  struct block_device *bdev,
903 			  sector_t capacity, int *hsc)
904 {
905 	hsc[0] = 255;
906 	hsc[1] = 63;
907 	sector_div(capacity, 255*63);
908 	hsc[2] = capacity;
909 
910 	return 0;
911 }
912 
913 /*
914  * Tell an upper layer that it needs to initiate an abort for a given task.
915  * This should only ever be called by an LLDD.
916  */
917 void sas_task_abort(struct sas_task *task)
918 {
919 	struct scsi_cmnd *sc = task->uldd_task;
920 
921 	/* Escape for libsas internal commands */
922 	if (!sc) {
923 		struct sas_task_slow *slow = task->slow_task;
924 
925 		if (!slow)
926 			return;
927 		if (!del_timer(&slow->timer))
928 			return;
929 		slow->timer.function(&slow->timer);
930 		return;
931 	}
932 
933 	if (dev_is_sata(task->dev)) {
934 		sas_ata_task_abort(task);
935 	} else {
936 		struct request_queue *q = sc->device->request_queue;
937 		unsigned long flags;
938 
939 		spin_lock_irqsave(q->queue_lock, flags);
940 		blk_abort_request(sc->request);
941 		spin_unlock_irqrestore(q->queue_lock, flags);
942 	}
943 }
944 
945 void sas_target_destroy(struct scsi_target *starget)
946 {
947 	struct domain_device *found_dev = starget->hostdata;
948 
949 	if (!found_dev)
950 		return;
951 
952 	starget->hostdata = NULL;
953 	sas_put_device(found_dev);
954 }
955 
956 #define SAS_STRING_ADDR_SIZE	16
957 
958 int sas_request_addr(struct Scsi_Host *shost, u8 *addr)
959 {
960 	int res;
961 	const struct firmware *fw;
962 
963 	res = request_firmware(&fw, "sas_addr", &shost->shost_gendev);
964 	if (res)
965 		return res;
966 
967 	if (fw->size < SAS_STRING_ADDR_SIZE) {
968 		res = -ENODEV;
969 		goto out;
970 	}
971 
972 	res = hex2bin(addr, fw->data, strnlen(fw->data, SAS_ADDR_SIZE * 2) / 2);
973 	if (res)
974 		goto out;
975 
976 out:
977 	release_firmware(fw);
978 	return res;
979 }
980 EXPORT_SYMBOL_GPL(sas_request_addr);
981 
982 EXPORT_SYMBOL_GPL(sas_queuecommand);
983 EXPORT_SYMBOL_GPL(sas_target_alloc);
984 EXPORT_SYMBOL_GPL(sas_slave_configure);
985 EXPORT_SYMBOL_GPL(sas_change_queue_depth);
986 EXPORT_SYMBOL_GPL(sas_bios_param);
987 EXPORT_SYMBOL_GPL(sas_task_abort);
988 EXPORT_SYMBOL_GPL(sas_phy_reset);
989 EXPORT_SYMBOL_GPL(sas_eh_device_reset_handler);
990 EXPORT_SYMBOL_GPL(sas_eh_target_reset_handler);
991 EXPORT_SYMBOL_GPL(sas_target_destroy);
992 EXPORT_SYMBOL_GPL(sas_ioctl);
993