xref: /openbmc/linux/drivers/scsi/libsas/sas_scsi_host.c (revision df2634f43f5106947f3735a0b61a6527a4b278cd)
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/ctype.h>
29 
30 #include "sas_internal.h"
31 
32 #include <scsi/scsi_host.h>
33 #include <scsi/scsi_device.h>
34 #include <scsi/scsi_tcq.h>
35 #include <scsi/scsi.h>
36 #include <scsi/scsi_eh.h>
37 #include <scsi/scsi_transport.h>
38 #include <scsi/scsi_transport_sas.h>
39 #include <scsi/sas_ata.h>
40 #include "../scsi_sas_internal.h"
41 #include "../scsi_transport_api.h"
42 #include "../scsi_priv.h"
43 
44 #include <linux/err.h>
45 #include <linux/blkdev.h>
46 #include <linux/freezer.h>
47 #include <linux/gfp.h>
48 #include <linux/scatterlist.h>
49 #include <linux/libata.h>
50 
51 /* ---------- SCSI Host glue ---------- */
52 
53 static void sas_scsi_task_done(struct sas_task *task)
54 {
55 	struct task_status_struct *ts = &task->task_status;
56 	struct scsi_cmnd *sc = task->uldd_task;
57 	int hs = 0, stat = 0;
58 
59 	if (unlikely(task->task_state_flags & SAS_TASK_STATE_ABORTED)) {
60 		/* Aborted tasks will be completed by the error handler */
61 		SAS_DPRINTK("task done but aborted\n");
62 		return;
63 	}
64 
65 	if (unlikely(!sc)) {
66 		SAS_DPRINTK("task_done called with non existing SCSI cmnd!\n");
67 		list_del_init(&task->list);
68 		sas_free_task(task);
69 		return;
70 	}
71 
72 	if (ts->resp == SAS_TASK_UNDELIVERED) {
73 		/* transport error */
74 		hs = DID_NO_CONNECT;
75 	} else { /* ts->resp == SAS_TASK_COMPLETE */
76 		/* task delivered, what happened afterwards? */
77 		switch (ts->stat) {
78 		case SAS_DEV_NO_RESPONSE:
79 		case SAS_INTERRUPTED:
80 		case SAS_PHY_DOWN:
81 		case SAS_NAK_R_ERR:
82 		case SAS_OPEN_TO:
83 			hs = DID_NO_CONNECT;
84 			break;
85 		case SAS_DATA_UNDERRUN:
86 			scsi_set_resid(sc, ts->residual);
87 			if (scsi_bufflen(sc) - scsi_get_resid(sc) < sc->underflow)
88 				hs = DID_ERROR;
89 			break;
90 		case SAS_DATA_OVERRUN:
91 			hs = DID_ERROR;
92 			break;
93 		case SAS_QUEUE_FULL:
94 			hs = DID_SOFT_ERROR; /* retry */
95 			break;
96 		case SAS_DEVICE_UNKNOWN:
97 			hs = DID_BAD_TARGET;
98 			break;
99 		case SAS_SG_ERR:
100 			hs = DID_PARITY;
101 			break;
102 		case SAS_OPEN_REJECT:
103 			if (ts->open_rej_reason == SAS_OREJ_RSVD_RETRY)
104 				hs = DID_SOFT_ERROR; /* retry */
105 			else
106 				hs = DID_ERROR;
107 			break;
108 		case SAS_PROTO_RESPONSE:
109 			SAS_DPRINTK("LLDD:%s sent SAS_PROTO_RESP for an SSP "
110 				    "task; please report this\n",
111 				    task->dev->port->ha->sas_ha_name);
112 			break;
113 		case SAS_ABORTED_TASK:
114 			hs = DID_ABORT;
115 			break;
116 		case SAM_STAT_CHECK_CONDITION:
117 			memcpy(sc->sense_buffer, ts->buf,
118 			       min(SCSI_SENSE_BUFFERSIZE, ts->buf_valid_size));
119 			stat = SAM_STAT_CHECK_CONDITION;
120 			break;
121 		default:
122 			stat = ts->stat;
123 			break;
124 		}
125 	}
126 	ASSIGN_SAS_TASK(sc, NULL);
127 	sc->result = (hs << 16) | stat;
128 	list_del_init(&task->list);
129 	sas_free_task(task);
130 	sc->scsi_done(sc);
131 }
132 
133 static struct sas_task *sas_create_task(struct scsi_cmnd *cmd,
134 					       struct domain_device *dev,
135 					       gfp_t gfp_flags)
136 {
137 	struct sas_task *task = sas_alloc_task(gfp_flags);
138 	struct scsi_lun lun;
139 
140 	if (!task)
141 		return NULL;
142 
143 	task->uldd_task = cmd;
144 	ASSIGN_SAS_TASK(cmd, task);
145 
146 	task->dev = dev;
147 	task->task_proto = task->dev->tproto; /* BUG_ON(!SSP) */
148 
149 	task->ssp_task.retry_count = 1;
150 	int_to_scsilun(cmd->device->lun, &lun);
151 	memcpy(task->ssp_task.LUN, &lun.scsi_lun, 8);
152 	task->ssp_task.task_attr = TASK_ATTR_SIMPLE;
153 	memcpy(task->ssp_task.cdb, cmd->cmnd, 16);
154 
155 	task->scatter = scsi_sglist(cmd);
156 	task->num_scatter = scsi_sg_count(cmd);
157 	task->total_xfer_len = scsi_bufflen(cmd);
158 	task->data_dir = cmd->sc_data_direction;
159 
160 	task->task_done = sas_scsi_task_done;
161 
162 	return task;
163 }
164 
165 int sas_queue_up(struct sas_task *task)
166 {
167 	struct sas_ha_struct *sas_ha = task->dev->port->ha;
168 	struct scsi_core *core = &sas_ha->core;
169 	unsigned long flags;
170 	LIST_HEAD(list);
171 
172 	spin_lock_irqsave(&core->task_queue_lock, flags);
173 	if (sas_ha->lldd_queue_size < core->task_queue_size + 1) {
174 		spin_unlock_irqrestore(&core->task_queue_lock, flags);
175 		return -SAS_QUEUE_FULL;
176 	}
177 	list_add_tail(&task->list, &core->task_queue);
178 	core->task_queue_size += 1;
179 	spin_unlock_irqrestore(&core->task_queue_lock, flags);
180 	wake_up_process(core->queue_thread);
181 
182 	return 0;
183 }
184 
185 /**
186  * sas_queuecommand -- Enqueue a command for processing
187  * @parameters: See SCSI Core documentation
188  *
189  * Note: XXX: Remove the host unlock/lock pair when SCSI Core can
190  * call us without holding an IRQ spinlock...
191  */
192 static int sas_queuecommand_lck(struct scsi_cmnd *cmd,
193 		     void (*scsi_done)(struct scsi_cmnd *))
194 	__releases(host->host_lock)
195 	__acquires(dev->sata_dev.ap->lock)
196 	__releases(dev->sata_dev.ap->lock)
197 	__acquires(host->host_lock)
198 {
199 	int res = 0;
200 	struct domain_device *dev = cmd_to_domain_dev(cmd);
201 	struct Scsi_Host *host = cmd->device->host;
202 	struct sas_internal *i = to_sas_internal(host->transportt);
203 
204 	spin_unlock_irq(host->host_lock);
205 
206 	{
207 		struct sas_ha_struct *sas_ha = dev->port->ha;
208 		struct sas_task *task;
209 
210 		if (dev_is_sata(dev)) {
211 			unsigned long flags;
212 
213 			spin_lock_irqsave(dev->sata_dev.ap->lock, flags);
214 			res = ata_sas_queuecmd(cmd, dev->sata_dev.ap);
215 			spin_unlock_irqrestore(dev->sata_dev.ap->lock, flags);
216 			goto out;
217 		}
218 
219 		/* If the device fell off, no sense in issuing commands */
220 		if (dev->gone) {
221 			cmd->result = DID_BAD_TARGET << 16;
222 			scsi_done(cmd);
223 			goto out;
224 		}
225 
226 		res = -ENOMEM;
227 		task = sas_create_task(cmd, dev, GFP_ATOMIC);
228 		if (!task)
229 			goto out;
230 
231 		cmd->scsi_done = scsi_done;
232 		/* Queue up, Direct Mode or Task Collector Mode. */
233 		if (sas_ha->lldd_max_execute_num < 2)
234 			res = i->dft->lldd_execute_task(task, 1, GFP_ATOMIC);
235 		else
236 			res = sas_queue_up(task);
237 
238 		/* Examine */
239 		if (res) {
240 			SAS_DPRINTK("lldd_execute_task returned: %d\n", res);
241 			ASSIGN_SAS_TASK(cmd, NULL);
242 			sas_free_task(task);
243 			if (res == -SAS_QUEUE_FULL) {
244 				cmd->result = DID_SOFT_ERROR << 16; /* retry */
245 				res = 0;
246 				scsi_done(cmd);
247 			}
248 			goto out;
249 		}
250 	}
251 out:
252 	spin_lock_irq(host->host_lock);
253 	return res;
254 }
255 
256 DEF_SCSI_QCMD(sas_queuecommand)
257 
258 static void sas_eh_finish_cmd(struct scsi_cmnd *cmd)
259 {
260 	struct sas_task *task = TO_SAS_TASK(cmd);
261 	struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(cmd->device->host);
262 
263 	/* remove the aborted task flag to allow the task to be
264 	 * completed now. At this point, we only get called following
265 	 * an actual abort of the task, so we should be guaranteed not
266 	 * to be racing with any completions from the LLD (hence we
267 	 * don't need the task state lock to clear the flag) */
268 	task->task_state_flags &= ~SAS_TASK_STATE_ABORTED;
269 	/* Now call task_done.  However, task will be free'd after
270 	 * this */
271 	task->task_done(task);
272 	/* now finish the command and move it on to the error
273 	 * handler done list, this also takes it off the
274 	 * error handler pending list */
275 	scsi_eh_finish_cmd(cmd, &sas_ha->eh_done_q);
276 }
277 
278 static void sas_scsi_clear_queue_lu(struct list_head *error_q, struct scsi_cmnd *my_cmd)
279 {
280 	struct scsi_cmnd *cmd, *n;
281 
282 	list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
283 		if (cmd->device->sdev_target == my_cmd->device->sdev_target &&
284 		    cmd->device->lun == my_cmd->device->lun)
285 			sas_eh_finish_cmd(cmd);
286 	}
287 }
288 
289 static void sas_scsi_clear_queue_I_T(struct list_head *error_q,
290 				     struct domain_device *dev)
291 {
292 	struct scsi_cmnd *cmd, *n;
293 
294 	list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
295 		struct domain_device *x = cmd_to_domain_dev(cmd);
296 
297 		if (x == dev)
298 			sas_eh_finish_cmd(cmd);
299 	}
300 }
301 
302 static void sas_scsi_clear_queue_port(struct list_head *error_q,
303 				      struct asd_sas_port *port)
304 {
305 	struct scsi_cmnd *cmd, *n;
306 
307 	list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
308 		struct domain_device *dev = cmd_to_domain_dev(cmd);
309 		struct asd_sas_port *x = dev->port;
310 
311 		if (x == port)
312 			sas_eh_finish_cmd(cmd);
313 	}
314 }
315 
316 enum task_disposition {
317 	TASK_IS_DONE,
318 	TASK_IS_ABORTED,
319 	TASK_IS_AT_LU,
320 	TASK_IS_NOT_AT_LU,
321 	TASK_ABORT_FAILED,
322 };
323 
324 static enum task_disposition sas_scsi_find_task(struct sas_task *task)
325 {
326 	struct sas_ha_struct *ha = task->dev->port->ha;
327 	unsigned long flags;
328 	int i, res;
329 	struct sas_internal *si =
330 		to_sas_internal(task->dev->port->ha->core.shost->transportt);
331 
332 	if (ha->lldd_max_execute_num > 1) {
333 		struct scsi_core *core = &ha->core;
334 		struct sas_task *t, *n;
335 
336 		spin_lock_irqsave(&core->task_queue_lock, flags);
337 		list_for_each_entry_safe(t, n, &core->task_queue, list) {
338 			if (task == t) {
339 				list_del_init(&t->list);
340 				spin_unlock_irqrestore(&core->task_queue_lock,
341 						       flags);
342 				SAS_DPRINTK("%s: task 0x%p aborted from "
343 					    "task_queue\n",
344 					    __func__, task);
345 				return TASK_IS_ABORTED;
346 			}
347 		}
348 		spin_unlock_irqrestore(&core->task_queue_lock, flags);
349 	}
350 
351 	for (i = 0; i < 5; i++) {
352 		SAS_DPRINTK("%s: aborting task 0x%p\n", __func__, task);
353 		res = si->dft->lldd_abort_task(task);
354 
355 		spin_lock_irqsave(&task->task_state_lock, flags);
356 		if (task->task_state_flags & SAS_TASK_STATE_DONE) {
357 			spin_unlock_irqrestore(&task->task_state_lock, flags);
358 			SAS_DPRINTK("%s: task 0x%p is done\n", __func__,
359 				    task);
360 			return TASK_IS_DONE;
361 		}
362 		spin_unlock_irqrestore(&task->task_state_lock, flags);
363 
364 		if (res == TMF_RESP_FUNC_COMPLETE) {
365 			SAS_DPRINTK("%s: task 0x%p is aborted\n",
366 				    __func__, task);
367 			return TASK_IS_ABORTED;
368 		} else if (si->dft->lldd_query_task) {
369 			SAS_DPRINTK("%s: querying task 0x%p\n",
370 				    __func__, task);
371 			res = si->dft->lldd_query_task(task);
372 			switch (res) {
373 			case TMF_RESP_FUNC_SUCC:
374 				SAS_DPRINTK("%s: task 0x%p at LU\n",
375 					    __func__, task);
376 				return TASK_IS_AT_LU;
377 			case TMF_RESP_FUNC_COMPLETE:
378 				SAS_DPRINTK("%s: task 0x%p not at LU\n",
379 					    __func__, task);
380 				return TASK_IS_NOT_AT_LU;
381 			case TMF_RESP_FUNC_FAILED:
382                                 SAS_DPRINTK("%s: task 0x%p failed to abort\n",
383                                                 __func__, task);
384                                 return TASK_ABORT_FAILED;
385                         }
386 
387 		}
388 	}
389 	return res;
390 }
391 
392 static int sas_recover_lu(struct domain_device *dev, struct scsi_cmnd *cmd)
393 {
394 	int res = TMF_RESP_FUNC_FAILED;
395 	struct scsi_lun lun;
396 	struct sas_internal *i =
397 		to_sas_internal(dev->port->ha->core.shost->transportt);
398 
399 	int_to_scsilun(cmd->device->lun, &lun);
400 
401 	SAS_DPRINTK("eh: device %llx LUN %x has the task\n",
402 		    SAS_ADDR(dev->sas_addr),
403 		    cmd->device->lun);
404 
405 	if (i->dft->lldd_abort_task_set)
406 		res = i->dft->lldd_abort_task_set(dev, lun.scsi_lun);
407 
408 	if (res == TMF_RESP_FUNC_FAILED) {
409 		if (i->dft->lldd_clear_task_set)
410 			res = i->dft->lldd_clear_task_set(dev, lun.scsi_lun);
411 	}
412 
413 	if (res == TMF_RESP_FUNC_FAILED) {
414 		if (i->dft->lldd_lu_reset)
415 			res = i->dft->lldd_lu_reset(dev, lun.scsi_lun);
416 	}
417 
418 	return res;
419 }
420 
421 static int sas_recover_I_T(struct domain_device *dev)
422 {
423 	int res = TMF_RESP_FUNC_FAILED;
424 	struct sas_internal *i =
425 		to_sas_internal(dev->port->ha->core.shost->transportt);
426 
427 	SAS_DPRINTK("I_T nexus reset for dev %016llx\n",
428 		    SAS_ADDR(dev->sas_addr));
429 
430 	if (i->dft->lldd_I_T_nexus_reset)
431 		res = i->dft->lldd_I_T_nexus_reset(dev);
432 
433 	return res;
434 }
435 
436 /* Find the sas_phy that's attached to this device */
437 struct sas_phy *sas_find_local_phy(struct domain_device *dev)
438 {
439 	struct domain_device *pdev = dev->parent;
440 	struct ex_phy *exphy = NULL;
441 	int i;
442 
443 	/* Directly attached device */
444 	if (!pdev)
445 		return dev->port->phy;
446 
447 	/* Otherwise look in the expander */
448 	for (i = 0; i < pdev->ex_dev.num_phys; i++)
449 		if (!memcmp(dev->sas_addr,
450 			    pdev->ex_dev.ex_phy[i].attached_sas_addr,
451 			    SAS_ADDR_SIZE)) {
452 			exphy = &pdev->ex_dev.ex_phy[i];
453 			break;
454 		}
455 
456 	BUG_ON(!exphy);
457 	return exphy->phy;
458 }
459 EXPORT_SYMBOL_GPL(sas_find_local_phy);
460 
461 /* Attempt to send a LUN reset message to a device */
462 int sas_eh_device_reset_handler(struct scsi_cmnd *cmd)
463 {
464 	struct domain_device *dev = cmd_to_domain_dev(cmd);
465 	struct sas_internal *i =
466 		to_sas_internal(dev->port->ha->core.shost->transportt);
467 	struct scsi_lun lun;
468 	int res;
469 
470 	int_to_scsilun(cmd->device->lun, &lun);
471 
472 	if (!i->dft->lldd_lu_reset)
473 		return FAILED;
474 
475 	res = i->dft->lldd_lu_reset(dev, lun.scsi_lun);
476 	if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE)
477 		return SUCCESS;
478 
479 	return FAILED;
480 }
481 
482 /* Attempt to send a phy (bus) reset */
483 int sas_eh_bus_reset_handler(struct scsi_cmnd *cmd)
484 {
485 	struct domain_device *dev = cmd_to_domain_dev(cmd);
486 	struct sas_phy *phy = sas_find_local_phy(dev);
487 	int res;
488 
489 	res = sas_phy_reset(phy, 1);
490 	if (res)
491 		SAS_DPRINTK("Bus reset of %s failed 0x%x\n",
492 			    kobject_name(&phy->dev.kobj),
493 			    res);
494 	if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE)
495 		return SUCCESS;
496 
497 	return FAILED;
498 }
499 
500 /* Try to reset a device */
501 static int try_to_reset_cmd_device(struct scsi_cmnd *cmd)
502 {
503 	int res;
504 	struct Scsi_Host *shost = cmd->device->host;
505 
506 	if (!shost->hostt->eh_device_reset_handler)
507 		goto try_bus_reset;
508 
509 	res = shost->hostt->eh_device_reset_handler(cmd);
510 	if (res == SUCCESS)
511 		return res;
512 
513 try_bus_reset:
514 	if (shost->hostt->eh_bus_reset_handler)
515 		return shost->hostt->eh_bus_reset_handler(cmd);
516 
517 	return FAILED;
518 }
519 
520 static int sas_eh_handle_sas_errors(struct Scsi_Host *shost,
521 				    struct list_head *work_q,
522 				    struct list_head *done_q)
523 {
524 	struct scsi_cmnd *cmd, *n;
525 	enum task_disposition res = TASK_IS_DONE;
526 	int tmf_resp, need_reset;
527 	struct sas_internal *i = to_sas_internal(shost->transportt);
528 	unsigned long flags;
529 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
530 
531 Again:
532 	list_for_each_entry_safe(cmd, n, work_q, eh_entry) {
533 		struct sas_task *task = TO_SAS_TASK(cmd);
534 
535 		if (!task)
536 			continue;
537 
538 		list_del_init(&cmd->eh_entry);
539 
540 		spin_lock_irqsave(&task->task_state_lock, flags);
541 		need_reset = task->task_state_flags & SAS_TASK_NEED_DEV_RESET;
542 		spin_unlock_irqrestore(&task->task_state_lock, flags);
543 
544 		if (need_reset) {
545 			SAS_DPRINTK("%s: task 0x%p requests reset\n",
546 				    __func__, task);
547 			goto reset;
548 		}
549 
550 		SAS_DPRINTK("trying to find task 0x%p\n", task);
551 		res = sas_scsi_find_task(task);
552 
553 		cmd->eh_eflags = 0;
554 
555 		switch (res) {
556 		case TASK_IS_DONE:
557 			SAS_DPRINTK("%s: task 0x%p is done\n", __func__,
558 				    task);
559 			sas_eh_finish_cmd(cmd);
560 			continue;
561 		case TASK_IS_ABORTED:
562 			SAS_DPRINTK("%s: task 0x%p is aborted\n",
563 				    __func__, task);
564 			sas_eh_finish_cmd(cmd);
565 			continue;
566 		case TASK_IS_AT_LU:
567 			SAS_DPRINTK("task 0x%p is at LU: lu recover\n", task);
568  reset:
569 			tmf_resp = sas_recover_lu(task->dev, cmd);
570 			if (tmf_resp == TMF_RESP_FUNC_COMPLETE) {
571 				SAS_DPRINTK("dev %016llx LU %x is "
572 					    "recovered\n",
573 					    SAS_ADDR(task->dev),
574 					    cmd->device->lun);
575 				sas_eh_finish_cmd(cmd);
576 				sas_scsi_clear_queue_lu(work_q, cmd);
577 				goto Again;
578 			}
579 			/* fallthrough */
580 		case TASK_IS_NOT_AT_LU:
581 		case TASK_ABORT_FAILED:
582 			SAS_DPRINTK("task 0x%p is not at LU: I_T recover\n",
583 				    task);
584 			tmf_resp = sas_recover_I_T(task->dev);
585 			if (tmf_resp == TMF_RESP_FUNC_COMPLETE) {
586 				struct domain_device *dev = task->dev;
587 				SAS_DPRINTK("I_T %016llx recovered\n",
588 					    SAS_ADDR(task->dev->sas_addr));
589 				sas_eh_finish_cmd(cmd);
590 				sas_scsi_clear_queue_I_T(work_q, dev);
591 				goto Again;
592 			}
593 			/* Hammer time :-) */
594 			try_to_reset_cmd_device(cmd);
595 			if (i->dft->lldd_clear_nexus_port) {
596 				struct asd_sas_port *port = task->dev->port;
597 				SAS_DPRINTK("clearing nexus for port:%d\n",
598 					    port->id);
599 				res = i->dft->lldd_clear_nexus_port(port);
600 				if (res == TMF_RESP_FUNC_COMPLETE) {
601 					SAS_DPRINTK("clear nexus port:%d "
602 						    "succeeded\n", port->id);
603 					sas_eh_finish_cmd(cmd);
604 					sas_scsi_clear_queue_port(work_q,
605 								  port);
606 					goto Again;
607 				}
608 			}
609 			if (i->dft->lldd_clear_nexus_ha) {
610 				SAS_DPRINTK("clear nexus ha\n");
611 				res = i->dft->lldd_clear_nexus_ha(ha);
612 				if (res == TMF_RESP_FUNC_COMPLETE) {
613 					SAS_DPRINTK("clear nexus ha "
614 						    "succeeded\n");
615 					sas_eh_finish_cmd(cmd);
616 					goto clear_q;
617 				}
618 			}
619 			/* If we are here -- this means that no amount
620 			 * of effort could recover from errors.  Quite
621 			 * possibly the HA just disappeared.
622 			 */
623 			SAS_DPRINTK("error from  device %llx, LUN %x "
624 				    "couldn't be recovered in any way\n",
625 				    SAS_ADDR(task->dev->sas_addr),
626 				    cmd->device->lun);
627 
628 			sas_eh_finish_cmd(cmd);
629 			goto clear_q;
630 		}
631 	}
632 	return list_empty(work_q);
633 clear_q:
634 	SAS_DPRINTK("--- Exit %s -- clear_q\n", __func__);
635 	list_for_each_entry_safe(cmd, n, work_q, eh_entry)
636 		sas_eh_finish_cmd(cmd);
637 
638 	return list_empty(work_q);
639 }
640 
641 void sas_scsi_recover_host(struct Scsi_Host *shost)
642 {
643 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
644 	unsigned long flags;
645 	LIST_HEAD(eh_work_q);
646 
647 	spin_lock_irqsave(shost->host_lock, flags);
648 	list_splice_init(&shost->eh_cmd_q, &eh_work_q);
649 	shost->host_eh_scheduled = 0;
650 	spin_unlock_irqrestore(shost->host_lock, flags);
651 
652 	SAS_DPRINTK("Enter %s\n", __func__);
653 	/*
654 	 * Deal with commands that still have SAS tasks (i.e. they didn't
655 	 * complete via the normal sas_task completion mechanism)
656 	 */
657 	if (sas_eh_handle_sas_errors(shost, &eh_work_q, &ha->eh_done_q))
658 		goto out;
659 
660 	/*
661 	 * Now deal with SCSI commands that completed ok but have a an error
662 	 * code (and hopefully sense data) attached.  This is roughly what
663 	 * scsi_unjam_host does, but we skip scsi_eh_abort_cmds because any
664 	 * command we see here has no sas_task and is thus unknown to the HA.
665 	 */
666 	if (!scsi_eh_get_sense(&eh_work_q, &ha->eh_done_q))
667 		scsi_eh_ready_devs(shost, &eh_work_q, &ha->eh_done_q);
668 
669 out:
670 	scsi_eh_flush_done_q(&ha->eh_done_q);
671 	SAS_DPRINTK("--- Exit %s\n", __func__);
672 	return;
673 }
674 
675 enum blk_eh_timer_return sas_scsi_timed_out(struct scsi_cmnd *cmd)
676 {
677 	struct sas_task *task = TO_SAS_TASK(cmd);
678 	unsigned long flags;
679 
680 	if (!task) {
681 		cmd->request->timeout /= 2;
682 		SAS_DPRINTK("command 0x%p, task 0x%p, gone: %s\n",
683 			    cmd, task, (cmd->request->timeout ?
684 			    "BLK_EH_RESET_TIMER" : "BLK_EH_NOT_HANDLED"));
685 		if (!cmd->request->timeout)
686 			return BLK_EH_NOT_HANDLED;
687 		return BLK_EH_RESET_TIMER;
688 	}
689 
690 	spin_lock_irqsave(&task->task_state_lock, flags);
691 	BUG_ON(task->task_state_flags & SAS_TASK_STATE_ABORTED);
692 	if (task->task_state_flags & SAS_TASK_STATE_DONE) {
693 		spin_unlock_irqrestore(&task->task_state_lock, flags);
694 		SAS_DPRINTK("command 0x%p, task 0x%p, timed out: "
695 			    "BLK_EH_HANDLED\n", cmd, task);
696 		return BLK_EH_HANDLED;
697 	}
698 	if (!(task->task_state_flags & SAS_TASK_AT_INITIATOR)) {
699 		spin_unlock_irqrestore(&task->task_state_lock, flags);
700 		SAS_DPRINTK("command 0x%p, task 0x%p, not at initiator: "
701 			    "BLK_EH_RESET_TIMER\n",
702 			    cmd, task);
703 		return BLK_EH_RESET_TIMER;
704 	}
705 	task->task_state_flags |= SAS_TASK_STATE_ABORTED;
706 	spin_unlock_irqrestore(&task->task_state_lock, flags);
707 
708 	SAS_DPRINTK("command 0x%p, task 0x%p, timed out: BLK_EH_NOT_HANDLED\n",
709 		    cmd, task);
710 
711 	return BLK_EH_NOT_HANDLED;
712 }
713 
714 int sas_ioctl(struct scsi_device *sdev, int cmd, void __user *arg)
715 {
716 	struct domain_device *dev = sdev_to_domain_dev(sdev);
717 
718 	if (dev_is_sata(dev))
719 		return ata_sas_scsi_ioctl(dev->sata_dev.ap, sdev, cmd, arg);
720 
721 	return -EINVAL;
722 }
723 
724 struct domain_device *sas_find_dev_by_rphy(struct sas_rphy *rphy)
725 {
726 	struct Scsi_Host *shost = dev_to_shost(rphy->dev.parent);
727 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
728 	struct domain_device *found_dev = NULL;
729 	int i;
730 	unsigned long flags;
731 
732 	spin_lock_irqsave(&ha->phy_port_lock, flags);
733 	for (i = 0; i < ha->num_phys; i++) {
734 		struct asd_sas_port *port = ha->sas_port[i];
735 		struct domain_device *dev;
736 
737 		spin_lock(&port->dev_list_lock);
738 		list_for_each_entry(dev, &port->dev_list, dev_list_node) {
739 			if (rphy == dev->rphy) {
740 				found_dev = dev;
741 				spin_unlock(&port->dev_list_lock);
742 				goto found;
743 			}
744 		}
745 		spin_unlock(&port->dev_list_lock);
746 	}
747  found:
748 	spin_unlock_irqrestore(&ha->phy_port_lock, flags);
749 
750 	return found_dev;
751 }
752 
753 static inline struct domain_device *sas_find_target(struct scsi_target *starget)
754 {
755 	struct sas_rphy *rphy = dev_to_rphy(starget->dev.parent);
756 
757 	return sas_find_dev_by_rphy(rphy);
758 }
759 
760 int sas_target_alloc(struct scsi_target *starget)
761 {
762 	struct domain_device *found_dev = sas_find_target(starget);
763 	int res;
764 
765 	if (!found_dev)
766 		return -ENODEV;
767 
768 	if (dev_is_sata(found_dev)) {
769 		res = sas_ata_init_host_and_port(found_dev, starget);
770 		if (res)
771 			return res;
772 	}
773 
774 	starget->hostdata = found_dev;
775 	return 0;
776 }
777 
778 #define SAS_DEF_QD 32
779 #define SAS_MAX_QD 64
780 
781 int sas_slave_configure(struct scsi_device *scsi_dev)
782 {
783 	struct domain_device *dev = sdev_to_domain_dev(scsi_dev);
784 	struct sas_ha_struct *sas_ha;
785 
786 	BUG_ON(dev->rphy->identify.device_type != SAS_END_DEVICE);
787 
788 	if (dev_is_sata(dev)) {
789 		ata_sas_slave_configure(scsi_dev, dev->sata_dev.ap);
790 		return 0;
791 	}
792 
793 	sas_ha = dev->port->ha;
794 
795 	sas_read_port_mode_page(scsi_dev);
796 
797 	if (scsi_dev->tagged_supported) {
798 		scsi_set_tag_type(scsi_dev, MSG_SIMPLE_TAG);
799 		scsi_activate_tcq(scsi_dev, SAS_DEF_QD);
800 	} else {
801 		SAS_DPRINTK("device %llx, LUN %x doesn't support "
802 			    "TCQ\n", SAS_ADDR(dev->sas_addr),
803 			    scsi_dev->lun);
804 		scsi_dev->tagged_supported = 0;
805 		scsi_set_tag_type(scsi_dev, 0);
806 		scsi_deactivate_tcq(scsi_dev, 1);
807 	}
808 
809 	scsi_dev->allow_restart = 1;
810 
811 	return 0;
812 }
813 
814 void sas_slave_destroy(struct scsi_device *scsi_dev)
815 {
816 	struct domain_device *dev = sdev_to_domain_dev(scsi_dev);
817 
818 	if (dev_is_sata(dev))
819 		dev->sata_dev.ap->link.device[0].class = ATA_DEV_NONE;
820 }
821 
822 int sas_change_queue_depth(struct scsi_device *scsi_dev, int new_depth,
823 			   int reason)
824 {
825 	int res = min(new_depth, SAS_MAX_QD);
826 
827 	if (reason != SCSI_QDEPTH_DEFAULT)
828 		return -EOPNOTSUPP;
829 
830 	if (scsi_dev->tagged_supported)
831 		scsi_adjust_queue_depth(scsi_dev, scsi_get_tag_type(scsi_dev),
832 					res);
833 	else {
834 		struct domain_device *dev = sdev_to_domain_dev(scsi_dev);
835 		sas_printk("device %llx LUN %x queue depth changed to 1\n",
836 			   SAS_ADDR(dev->sas_addr),
837 			   scsi_dev->lun);
838 		scsi_adjust_queue_depth(scsi_dev, 0, 1);
839 		res = 1;
840 	}
841 
842 	return res;
843 }
844 
845 int sas_change_queue_type(struct scsi_device *scsi_dev, int qt)
846 {
847 	if (!scsi_dev->tagged_supported)
848 		return 0;
849 
850 	scsi_deactivate_tcq(scsi_dev, 1);
851 
852 	scsi_set_tag_type(scsi_dev, qt);
853 	scsi_activate_tcq(scsi_dev, scsi_dev->queue_depth);
854 
855 	return qt;
856 }
857 
858 int sas_bios_param(struct scsi_device *scsi_dev,
859 			  struct block_device *bdev,
860 			  sector_t capacity, int *hsc)
861 {
862 	hsc[0] = 255;
863 	hsc[1] = 63;
864 	sector_div(capacity, 255*63);
865 	hsc[2] = capacity;
866 
867 	return 0;
868 }
869 
870 /* ---------- Task Collector Thread implementation ---------- */
871 
872 static void sas_queue(struct sas_ha_struct *sas_ha)
873 {
874 	struct scsi_core *core = &sas_ha->core;
875 	unsigned long flags;
876 	LIST_HEAD(q);
877 	int can_queue;
878 	int res;
879 	struct sas_internal *i = to_sas_internal(core->shost->transportt);
880 
881 	spin_lock_irqsave(&core->task_queue_lock, flags);
882 	while (!kthread_should_stop() &&
883 	       !list_empty(&core->task_queue)) {
884 
885 		can_queue = sas_ha->lldd_queue_size - core->task_queue_size;
886 		if (can_queue >= 0) {
887 			can_queue = core->task_queue_size;
888 			list_splice_init(&core->task_queue, &q);
889 		} else {
890 			struct list_head *a, *n;
891 
892 			can_queue = sas_ha->lldd_queue_size;
893 			list_for_each_safe(a, n, &core->task_queue) {
894 				list_move_tail(a, &q);
895 				if (--can_queue == 0)
896 					break;
897 			}
898 			can_queue = sas_ha->lldd_queue_size;
899 		}
900 		core->task_queue_size -= can_queue;
901 		spin_unlock_irqrestore(&core->task_queue_lock, flags);
902 		{
903 			struct sas_task *task = list_entry(q.next,
904 							   struct sas_task,
905 							   list);
906 			list_del_init(&q);
907 			res = i->dft->lldd_execute_task(task, can_queue,
908 							GFP_KERNEL);
909 			if (unlikely(res))
910 				__list_add(&q, task->list.prev, &task->list);
911 		}
912 		spin_lock_irqsave(&core->task_queue_lock, flags);
913 		if (res) {
914 			list_splice_init(&q, &core->task_queue); /*at head*/
915 			core->task_queue_size += can_queue;
916 		}
917 	}
918 	spin_unlock_irqrestore(&core->task_queue_lock, flags);
919 }
920 
921 /**
922  * sas_queue_thread -- The Task Collector thread
923  * @_sas_ha: pointer to struct sas_ha
924  */
925 static int sas_queue_thread(void *_sas_ha)
926 {
927 	struct sas_ha_struct *sas_ha = _sas_ha;
928 
929 	while (1) {
930 		set_current_state(TASK_INTERRUPTIBLE);
931 		schedule();
932 		sas_queue(sas_ha);
933 		if (kthread_should_stop())
934 			break;
935 	}
936 
937 	return 0;
938 }
939 
940 int sas_init_queue(struct sas_ha_struct *sas_ha)
941 {
942 	struct scsi_core *core = &sas_ha->core;
943 
944 	spin_lock_init(&core->task_queue_lock);
945 	core->task_queue_size = 0;
946 	INIT_LIST_HEAD(&core->task_queue);
947 
948 	core->queue_thread = kthread_run(sas_queue_thread, sas_ha,
949 					 "sas_queue_%d", core->shost->host_no);
950 	if (IS_ERR(core->queue_thread))
951 		return PTR_ERR(core->queue_thread);
952 	return 0;
953 }
954 
955 void sas_shutdown_queue(struct sas_ha_struct *sas_ha)
956 {
957 	unsigned long flags;
958 	struct scsi_core *core = &sas_ha->core;
959 	struct sas_task *task, *n;
960 
961 	kthread_stop(core->queue_thread);
962 
963 	if (!list_empty(&core->task_queue))
964 		SAS_DPRINTK("HA: %llx: scsi core task queue is NOT empty!?\n",
965 			    SAS_ADDR(sas_ha->sas_addr));
966 
967 	spin_lock_irqsave(&core->task_queue_lock, flags);
968 	list_for_each_entry_safe(task, n, &core->task_queue, list) {
969 		struct scsi_cmnd *cmd = task->uldd_task;
970 
971 		list_del_init(&task->list);
972 
973 		ASSIGN_SAS_TASK(cmd, NULL);
974 		sas_free_task(task);
975 		cmd->result = DID_ABORT << 16;
976 		cmd->scsi_done(cmd);
977 	}
978 	spin_unlock_irqrestore(&core->task_queue_lock, flags);
979 }
980 
981 /*
982  * Call the LLDD task abort routine directly.  This function is intended for
983  * use by upper layers that need to tell the LLDD to abort a task.
984  */
985 int __sas_task_abort(struct sas_task *task)
986 {
987 	struct sas_internal *si =
988 		to_sas_internal(task->dev->port->ha->core.shost->transportt);
989 	unsigned long flags;
990 	int res;
991 
992 	spin_lock_irqsave(&task->task_state_lock, flags);
993 	if (task->task_state_flags & SAS_TASK_STATE_ABORTED ||
994 	    task->task_state_flags & SAS_TASK_STATE_DONE) {
995 		spin_unlock_irqrestore(&task->task_state_lock, flags);
996 		SAS_DPRINTK("%s: Task %p already finished.\n", __func__,
997 			    task);
998 		return 0;
999 	}
1000 	task->task_state_flags |= SAS_TASK_STATE_ABORTED;
1001 	spin_unlock_irqrestore(&task->task_state_lock, flags);
1002 
1003 	if (!si->dft->lldd_abort_task)
1004 		return -ENODEV;
1005 
1006 	res = si->dft->lldd_abort_task(task);
1007 
1008 	spin_lock_irqsave(&task->task_state_lock, flags);
1009 	if ((task->task_state_flags & SAS_TASK_STATE_DONE) ||
1010 	    (res == TMF_RESP_FUNC_COMPLETE))
1011 	{
1012 		spin_unlock_irqrestore(&task->task_state_lock, flags);
1013 		task->task_done(task);
1014 		return 0;
1015 	}
1016 
1017 	if (!(task->task_state_flags & SAS_TASK_STATE_DONE))
1018 		task->task_state_flags &= ~SAS_TASK_STATE_ABORTED;
1019 	spin_unlock_irqrestore(&task->task_state_lock, flags);
1020 
1021 	return -EAGAIN;
1022 }
1023 
1024 /*
1025  * Tell an upper layer that it needs to initiate an abort for a given task.
1026  * This should only ever be called by an LLDD.
1027  */
1028 void sas_task_abort(struct sas_task *task)
1029 {
1030 	struct scsi_cmnd *sc = task->uldd_task;
1031 
1032 	/* Escape for libsas internal commands */
1033 	if (!sc) {
1034 		if (!del_timer(&task->timer))
1035 			return;
1036 		task->timer.function(task->timer.data);
1037 		return;
1038 	}
1039 
1040 	if (dev_is_sata(task->dev)) {
1041 		sas_ata_task_abort(task);
1042 	} else {
1043 		struct request_queue *q = sc->device->request_queue;
1044 		unsigned long flags;
1045 
1046 		spin_lock_irqsave(q->queue_lock, flags);
1047 		blk_abort_request(sc->request);
1048 		spin_unlock_irqrestore(q->queue_lock, flags);
1049 		scsi_schedule_eh(sc->device->host);
1050 	}
1051 }
1052 
1053 int sas_slave_alloc(struct scsi_device *scsi_dev)
1054 {
1055 	struct domain_device *dev = sdev_to_domain_dev(scsi_dev);
1056 
1057 	if (dev_is_sata(dev))
1058 		return ata_sas_port_init(dev->sata_dev.ap);
1059 
1060 	return 0;
1061 }
1062 
1063 void sas_target_destroy(struct scsi_target *starget)
1064 {
1065 	struct domain_device *found_dev = sas_find_target(starget);
1066 
1067 	if (!found_dev)
1068 		return;
1069 
1070 	if (dev_is_sata(found_dev))
1071 		ata_sas_port_destroy(found_dev->sata_dev.ap);
1072 
1073 	return;
1074 }
1075 
1076 static void sas_parse_addr(u8 *sas_addr, const char *p)
1077 {
1078 	int i;
1079 	for (i = 0; i < SAS_ADDR_SIZE; i++) {
1080 		u8 h, l;
1081 		if (!*p)
1082 			break;
1083 		h = isdigit(*p) ? *p-'0' : toupper(*p)-'A'+10;
1084 		p++;
1085 		l = isdigit(*p) ? *p-'0' : toupper(*p)-'A'+10;
1086 		p++;
1087 		sas_addr[i] = (h<<4) | l;
1088 	}
1089 }
1090 
1091 #define SAS_STRING_ADDR_SIZE	16
1092 
1093 int sas_request_addr(struct Scsi_Host *shost, u8 *addr)
1094 {
1095 	int res;
1096 	const struct firmware *fw;
1097 
1098 	res = request_firmware(&fw, "sas_addr", &shost->shost_gendev);
1099 	if (res)
1100 		return res;
1101 
1102 	if (fw->size < SAS_STRING_ADDR_SIZE) {
1103 		res = -ENODEV;
1104 		goto out;
1105 	}
1106 
1107 	sas_parse_addr(addr, fw->data);
1108 
1109 out:
1110 	release_firmware(fw);
1111 	return res;
1112 }
1113 EXPORT_SYMBOL_GPL(sas_request_addr);
1114 
1115 EXPORT_SYMBOL_GPL(sas_queuecommand);
1116 EXPORT_SYMBOL_GPL(sas_target_alloc);
1117 EXPORT_SYMBOL_GPL(sas_slave_configure);
1118 EXPORT_SYMBOL_GPL(sas_slave_destroy);
1119 EXPORT_SYMBOL_GPL(sas_change_queue_depth);
1120 EXPORT_SYMBOL_GPL(sas_change_queue_type);
1121 EXPORT_SYMBOL_GPL(sas_bios_param);
1122 EXPORT_SYMBOL_GPL(__sas_task_abort);
1123 EXPORT_SYMBOL_GPL(sas_task_abort);
1124 EXPORT_SYMBOL_GPL(sas_phy_reset);
1125 EXPORT_SYMBOL_GPL(sas_phy_enable);
1126 EXPORT_SYMBOL_GPL(sas_eh_device_reset_handler);
1127 EXPORT_SYMBOL_GPL(sas_eh_bus_reset_handler);
1128 EXPORT_SYMBOL_GPL(sas_slave_alloc);
1129 EXPORT_SYMBOL_GPL(sas_target_destroy);
1130 EXPORT_SYMBOL_GPL(sas_ioctl);
1131