xref: /linux/drivers/scsi/libsas/sas_scsi_host.c (revision d39d0ed196aa1685bb24771e92f78633c66ac9cb)
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 enum task_attribute sas_scsi_get_task_attr(struct scsi_cmnd *cmd)
134 {
135 	enum task_attribute ta = TASK_ATTR_SIMPLE;
136 	if (cmd->request && blk_rq_tagged(cmd->request)) {
137 		if (cmd->device->ordered_tags &&
138 		    (cmd->request->cmd_flags & REQ_HARDBARRIER))
139 			ta = TASK_ATTR_ORDERED;
140 	}
141 	return ta;
142 }
143 
144 static struct sas_task *sas_create_task(struct scsi_cmnd *cmd,
145 					       struct domain_device *dev,
146 					       gfp_t gfp_flags)
147 {
148 	struct sas_task *task = sas_alloc_task(gfp_flags);
149 	struct scsi_lun lun;
150 
151 	if (!task)
152 		return NULL;
153 
154 	task->uldd_task = cmd;
155 	ASSIGN_SAS_TASK(cmd, task);
156 
157 	task->dev = dev;
158 	task->task_proto = task->dev->tproto; /* BUG_ON(!SSP) */
159 
160 	task->ssp_task.retry_count = 1;
161 	int_to_scsilun(cmd->device->lun, &lun);
162 	memcpy(task->ssp_task.LUN, &lun.scsi_lun, 8);
163 	task->ssp_task.task_attr = sas_scsi_get_task_attr(cmd);
164 	memcpy(task->ssp_task.cdb, cmd->cmnd, 16);
165 
166 	task->scatter = scsi_sglist(cmd);
167 	task->num_scatter = scsi_sg_count(cmd);
168 	task->total_xfer_len = scsi_bufflen(cmd);
169 	task->data_dir = cmd->sc_data_direction;
170 
171 	task->task_done = sas_scsi_task_done;
172 
173 	return task;
174 }
175 
176 int sas_queue_up(struct sas_task *task)
177 {
178 	struct sas_ha_struct *sas_ha = task->dev->port->ha;
179 	struct scsi_core *core = &sas_ha->core;
180 	unsigned long flags;
181 	LIST_HEAD(list);
182 
183 	spin_lock_irqsave(&core->task_queue_lock, flags);
184 	if (sas_ha->lldd_queue_size < core->task_queue_size + 1) {
185 		spin_unlock_irqrestore(&core->task_queue_lock, flags);
186 		return -SAS_QUEUE_FULL;
187 	}
188 	list_add_tail(&task->list, &core->task_queue);
189 	core->task_queue_size += 1;
190 	spin_unlock_irqrestore(&core->task_queue_lock, flags);
191 	wake_up_process(core->queue_thread);
192 
193 	return 0;
194 }
195 
196 /**
197  * sas_queuecommand -- Enqueue a command for processing
198  * @parameters: See SCSI Core documentation
199  *
200  * Note: XXX: Remove the host unlock/lock pair when SCSI Core can
201  * call us without holding an IRQ spinlock...
202  */
203 int sas_queuecommand(struct scsi_cmnd *cmd,
204 		     void (*scsi_done)(struct scsi_cmnd *))
205 	__releases(host->host_lock)
206 	__acquires(dev->sata_dev.ap->lock)
207 	__releases(dev->sata_dev.ap->lock)
208 	__acquires(host->host_lock)
209 {
210 	int res = 0;
211 	struct domain_device *dev = cmd_to_domain_dev(cmd);
212 	struct Scsi_Host *host = cmd->device->host;
213 	struct sas_internal *i = to_sas_internal(host->transportt);
214 
215 	spin_unlock_irq(host->host_lock);
216 
217 	{
218 		struct sas_ha_struct *sas_ha = dev->port->ha;
219 		struct sas_task *task;
220 
221 		if (dev_is_sata(dev)) {
222 			unsigned long flags;
223 
224 			spin_lock_irqsave(dev->sata_dev.ap->lock, flags);
225 			res = ata_sas_queuecmd(cmd, scsi_done,
226 					       dev->sata_dev.ap);
227 			spin_unlock_irqrestore(dev->sata_dev.ap->lock, flags);
228 			goto out;
229 		}
230 
231 		res = -ENOMEM;
232 		task = sas_create_task(cmd, dev, GFP_ATOMIC);
233 		if (!task)
234 			goto out;
235 
236 		cmd->scsi_done = scsi_done;
237 		/* Queue up, Direct Mode or Task Collector Mode. */
238 		if (sas_ha->lldd_max_execute_num < 2)
239 			res = i->dft->lldd_execute_task(task, 1, GFP_ATOMIC);
240 		else
241 			res = sas_queue_up(task);
242 
243 		/* Examine */
244 		if (res) {
245 			SAS_DPRINTK("lldd_execute_task returned: %d\n", res);
246 			ASSIGN_SAS_TASK(cmd, NULL);
247 			sas_free_task(task);
248 			if (res == -SAS_QUEUE_FULL) {
249 				cmd->result = DID_SOFT_ERROR << 16; /* retry */
250 				res = 0;
251 				scsi_done(cmd);
252 			}
253 			goto out;
254 		}
255 	}
256 out:
257 	spin_lock_irq(host->host_lock);
258 	return res;
259 }
260 
261 static void sas_eh_finish_cmd(struct scsi_cmnd *cmd)
262 {
263 	struct sas_task *task = TO_SAS_TASK(cmd);
264 	struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(cmd->device->host);
265 
266 	/* remove the aborted task flag to allow the task to be
267 	 * completed now. At this point, we only get called following
268 	 * an actual abort of the task, so we should be guaranteed not
269 	 * to be racing with any completions from the LLD (hence we
270 	 * don't need the task state lock to clear the flag) */
271 	task->task_state_flags &= ~SAS_TASK_STATE_ABORTED;
272 	/* Now call task_done.  However, task will be free'd after
273 	 * this */
274 	task->task_done(task);
275 	/* now finish the command and move it on to the error
276 	 * handler done list, this also takes it off the
277 	 * error handler pending list */
278 	scsi_eh_finish_cmd(cmd, &sas_ha->eh_done_q);
279 }
280 
281 static void sas_scsi_clear_queue_lu(struct list_head *error_q, struct scsi_cmnd *my_cmd)
282 {
283 	struct scsi_cmnd *cmd, *n;
284 
285 	list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
286 		if (cmd->device->sdev_target == my_cmd->device->sdev_target &&
287 		    cmd->device->lun == my_cmd->device->lun)
288 			sas_eh_finish_cmd(cmd);
289 	}
290 }
291 
292 static void sas_scsi_clear_queue_I_T(struct list_head *error_q,
293 				     struct domain_device *dev)
294 {
295 	struct scsi_cmnd *cmd, *n;
296 
297 	list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
298 		struct domain_device *x = cmd_to_domain_dev(cmd);
299 
300 		if (x == dev)
301 			sas_eh_finish_cmd(cmd);
302 	}
303 }
304 
305 static void sas_scsi_clear_queue_port(struct list_head *error_q,
306 				      struct asd_sas_port *port)
307 {
308 	struct scsi_cmnd *cmd, *n;
309 
310 	list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
311 		struct domain_device *dev = cmd_to_domain_dev(cmd);
312 		struct asd_sas_port *x = dev->port;
313 
314 		if (x == port)
315 			sas_eh_finish_cmd(cmd);
316 	}
317 }
318 
319 enum task_disposition {
320 	TASK_IS_DONE,
321 	TASK_IS_ABORTED,
322 	TASK_IS_AT_LU,
323 	TASK_IS_NOT_AT_LU,
324 	TASK_ABORT_FAILED,
325 };
326 
327 static enum task_disposition sas_scsi_find_task(struct sas_task *task)
328 {
329 	struct sas_ha_struct *ha = task->dev->port->ha;
330 	unsigned long flags;
331 	int i, res;
332 	struct sas_internal *si =
333 		to_sas_internal(task->dev->port->ha->core.shost->transportt);
334 
335 	if (ha->lldd_max_execute_num > 1) {
336 		struct scsi_core *core = &ha->core;
337 		struct sas_task *t, *n;
338 
339 		spin_lock_irqsave(&core->task_queue_lock, flags);
340 		list_for_each_entry_safe(t, n, &core->task_queue, list) {
341 			if (task == t) {
342 				list_del_init(&t->list);
343 				spin_unlock_irqrestore(&core->task_queue_lock,
344 						       flags);
345 				SAS_DPRINTK("%s: task 0x%p aborted from "
346 					    "task_queue\n",
347 					    __func__, task);
348 				return TASK_IS_ABORTED;
349 			}
350 		}
351 		spin_unlock_irqrestore(&core->task_queue_lock, flags);
352 	}
353 
354 	for (i = 0; i < 5; i++) {
355 		SAS_DPRINTK("%s: aborting task 0x%p\n", __func__, task);
356 		res = si->dft->lldd_abort_task(task);
357 
358 		spin_lock_irqsave(&task->task_state_lock, flags);
359 		if (task->task_state_flags & SAS_TASK_STATE_DONE) {
360 			spin_unlock_irqrestore(&task->task_state_lock, flags);
361 			SAS_DPRINTK("%s: task 0x%p is done\n", __func__,
362 				    task);
363 			return TASK_IS_DONE;
364 		}
365 		spin_unlock_irqrestore(&task->task_state_lock, flags);
366 
367 		if (res == TMF_RESP_FUNC_COMPLETE) {
368 			SAS_DPRINTK("%s: task 0x%p is aborted\n",
369 				    __func__, task);
370 			return TASK_IS_ABORTED;
371 		} else if (si->dft->lldd_query_task) {
372 			SAS_DPRINTK("%s: querying task 0x%p\n",
373 				    __func__, task);
374 			res = si->dft->lldd_query_task(task);
375 			switch (res) {
376 			case TMF_RESP_FUNC_SUCC:
377 				SAS_DPRINTK("%s: task 0x%p at LU\n",
378 					    __func__, task);
379 				return TASK_IS_AT_LU;
380 			case TMF_RESP_FUNC_COMPLETE:
381 				SAS_DPRINTK("%s: task 0x%p not at LU\n",
382 					    __func__, task);
383 				return TASK_IS_NOT_AT_LU;
384 			case TMF_RESP_FUNC_FAILED:
385                                 SAS_DPRINTK("%s: task 0x%p failed to abort\n",
386                                                 __func__, task);
387                                 return TASK_ABORT_FAILED;
388                         }
389 
390 		}
391 	}
392 	return res;
393 }
394 
395 static int sas_recover_lu(struct domain_device *dev, struct scsi_cmnd *cmd)
396 {
397 	int res = TMF_RESP_FUNC_FAILED;
398 	struct scsi_lun lun;
399 	struct sas_internal *i =
400 		to_sas_internal(dev->port->ha->core.shost->transportt);
401 
402 	int_to_scsilun(cmd->device->lun, &lun);
403 
404 	SAS_DPRINTK("eh: device %llx LUN %x has the task\n",
405 		    SAS_ADDR(dev->sas_addr),
406 		    cmd->device->lun);
407 
408 	if (i->dft->lldd_abort_task_set)
409 		res = i->dft->lldd_abort_task_set(dev, lun.scsi_lun);
410 
411 	if (res == TMF_RESP_FUNC_FAILED) {
412 		if (i->dft->lldd_clear_task_set)
413 			res = i->dft->lldd_clear_task_set(dev, lun.scsi_lun);
414 	}
415 
416 	if (res == TMF_RESP_FUNC_FAILED) {
417 		if (i->dft->lldd_lu_reset)
418 			res = i->dft->lldd_lu_reset(dev, lun.scsi_lun);
419 	}
420 
421 	return res;
422 }
423 
424 static int sas_recover_I_T(struct domain_device *dev)
425 {
426 	int res = TMF_RESP_FUNC_FAILED;
427 	struct sas_internal *i =
428 		to_sas_internal(dev->port->ha->core.shost->transportt);
429 
430 	SAS_DPRINTK("I_T nexus reset for dev %016llx\n",
431 		    SAS_ADDR(dev->sas_addr));
432 
433 	if (i->dft->lldd_I_T_nexus_reset)
434 		res = i->dft->lldd_I_T_nexus_reset(dev);
435 
436 	return res;
437 }
438 
439 /* Find the sas_phy that's attached to this device */
440 struct sas_phy *sas_find_local_phy(struct domain_device *dev)
441 {
442 	struct domain_device *pdev = dev->parent;
443 	struct ex_phy *exphy = NULL;
444 	int i;
445 
446 	/* Directly attached device */
447 	if (!pdev)
448 		return dev->port->phy;
449 
450 	/* Otherwise look in the expander */
451 	for (i = 0; i < pdev->ex_dev.num_phys; i++)
452 		if (!memcmp(dev->sas_addr,
453 			    pdev->ex_dev.ex_phy[i].attached_sas_addr,
454 			    SAS_ADDR_SIZE)) {
455 			exphy = &pdev->ex_dev.ex_phy[i];
456 			break;
457 		}
458 
459 	BUG_ON(!exphy);
460 	return exphy->phy;
461 }
462 EXPORT_SYMBOL_GPL(sas_find_local_phy);
463 
464 /* Attempt to send a LUN reset message to a device */
465 int sas_eh_device_reset_handler(struct scsi_cmnd *cmd)
466 {
467 	struct domain_device *dev = cmd_to_domain_dev(cmd);
468 	struct sas_internal *i =
469 		to_sas_internal(dev->port->ha->core.shost->transportt);
470 	struct scsi_lun lun;
471 	int res;
472 
473 	int_to_scsilun(cmd->device->lun, &lun);
474 
475 	if (!i->dft->lldd_lu_reset)
476 		return FAILED;
477 
478 	res = i->dft->lldd_lu_reset(dev, lun.scsi_lun);
479 	if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE)
480 		return SUCCESS;
481 
482 	return FAILED;
483 }
484 
485 /* Attempt to send a phy (bus) reset */
486 int sas_eh_bus_reset_handler(struct scsi_cmnd *cmd)
487 {
488 	struct domain_device *dev = cmd_to_domain_dev(cmd);
489 	struct sas_phy *phy = sas_find_local_phy(dev);
490 	int res;
491 
492 	res = sas_phy_reset(phy, 1);
493 	if (res)
494 		SAS_DPRINTK("Bus reset of %s failed 0x%x\n",
495 			    kobject_name(&phy->dev.kobj),
496 			    res);
497 	if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE)
498 		return SUCCESS;
499 
500 	return FAILED;
501 }
502 
503 /* Try to reset a device */
504 static int try_to_reset_cmd_device(struct scsi_cmnd *cmd)
505 {
506 	int res;
507 	struct Scsi_Host *shost = cmd->device->host;
508 
509 	if (!shost->hostt->eh_device_reset_handler)
510 		goto try_bus_reset;
511 
512 	res = shost->hostt->eh_device_reset_handler(cmd);
513 	if (res == SUCCESS)
514 		return res;
515 
516 try_bus_reset:
517 	if (shost->hostt->eh_bus_reset_handler)
518 		return shost->hostt->eh_bus_reset_handler(cmd);
519 
520 	return FAILED;
521 }
522 
523 static int sas_eh_handle_sas_errors(struct Scsi_Host *shost,
524 				    struct list_head *work_q,
525 				    struct list_head *done_q)
526 {
527 	struct scsi_cmnd *cmd, *n;
528 	enum task_disposition res = TASK_IS_DONE;
529 	int tmf_resp, need_reset;
530 	struct sas_internal *i = to_sas_internal(shost->transportt);
531 	unsigned long flags;
532 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
533 
534 Again:
535 	list_for_each_entry_safe(cmd, n, work_q, eh_entry) {
536 		struct sas_task *task = TO_SAS_TASK(cmd);
537 
538 		if (!task)
539 			continue;
540 
541 		list_del_init(&cmd->eh_entry);
542 
543 		spin_lock_irqsave(&task->task_state_lock, flags);
544 		need_reset = task->task_state_flags & SAS_TASK_NEED_DEV_RESET;
545 		spin_unlock_irqrestore(&task->task_state_lock, flags);
546 
547 		if (need_reset) {
548 			SAS_DPRINTK("%s: task 0x%p requests reset\n",
549 				    __func__, task);
550 			goto reset;
551 		}
552 
553 		SAS_DPRINTK("trying to find task 0x%p\n", task);
554 		res = sas_scsi_find_task(task);
555 
556 		cmd->eh_eflags = 0;
557 
558 		switch (res) {
559 		case TASK_IS_DONE:
560 			SAS_DPRINTK("%s: task 0x%p is done\n", __func__,
561 				    task);
562 			sas_eh_finish_cmd(cmd);
563 			continue;
564 		case TASK_IS_ABORTED:
565 			SAS_DPRINTK("%s: task 0x%p is aborted\n",
566 				    __func__, task);
567 			sas_eh_finish_cmd(cmd);
568 			continue;
569 		case TASK_IS_AT_LU:
570 			SAS_DPRINTK("task 0x%p is at LU: lu recover\n", task);
571  reset:
572 			tmf_resp = sas_recover_lu(task->dev, cmd);
573 			if (tmf_resp == TMF_RESP_FUNC_COMPLETE) {
574 				SAS_DPRINTK("dev %016llx LU %x is "
575 					    "recovered\n",
576 					    SAS_ADDR(task->dev),
577 					    cmd->device->lun);
578 				sas_eh_finish_cmd(cmd);
579 				sas_scsi_clear_queue_lu(work_q, cmd);
580 				goto Again;
581 			}
582 			/* fallthrough */
583 		case TASK_IS_NOT_AT_LU:
584 		case TASK_ABORT_FAILED:
585 			SAS_DPRINTK("task 0x%p is not at LU: I_T recover\n",
586 				    task);
587 			tmf_resp = sas_recover_I_T(task->dev);
588 			if (tmf_resp == TMF_RESP_FUNC_COMPLETE) {
589 				struct domain_device *dev = task->dev;
590 				SAS_DPRINTK("I_T %016llx recovered\n",
591 					    SAS_ADDR(task->dev->sas_addr));
592 				sas_eh_finish_cmd(cmd);
593 				sas_scsi_clear_queue_I_T(work_q, dev);
594 				goto Again;
595 			}
596 			/* Hammer time :-) */
597 			try_to_reset_cmd_device(cmd);
598 			if (i->dft->lldd_clear_nexus_port) {
599 				struct asd_sas_port *port = task->dev->port;
600 				SAS_DPRINTK("clearing nexus for port:%d\n",
601 					    port->id);
602 				res = i->dft->lldd_clear_nexus_port(port);
603 				if (res == TMF_RESP_FUNC_COMPLETE) {
604 					SAS_DPRINTK("clear nexus port:%d "
605 						    "succeeded\n", port->id);
606 					sas_eh_finish_cmd(cmd);
607 					sas_scsi_clear_queue_port(work_q,
608 								  port);
609 					goto Again;
610 				}
611 			}
612 			if (i->dft->lldd_clear_nexus_ha) {
613 				SAS_DPRINTK("clear nexus ha\n");
614 				res = i->dft->lldd_clear_nexus_ha(ha);
615 				if (res == TMF_RESP_FUNC_COMPLETE) {
616 					SAS_DPRINTK("clear nexus ha "
617 						    "succeeded\n");
618 					sas_eh_finish_cmd(cmd);
619 					goto clear_q;
620 				}
621 			}
622 			/* If we are here -- this means that no amount
623 			 * of effort could recover from errors.  Quite
624 			 * possibly the HA just disappeared.
625 			 */
626 			SAS_DPRINTK("error from  device %llx, LUN %x "
627 				    "couldn't be recovered in any way\n",
628 				    SAS_ADDR(task->dev->sas_addr),
629 				    cmd->device->lun);
630 
631 			sas_eh_finish_cmd(cmd);
632 			goto clear_q;
633 		}
634 	}
635 	return list_empty(work_q);
636 clear_q:
637 	SAS_DPRINTK("--- Exit %s -- clear_q\n", __func__);
638 	list_for_each_entry_safe(cmd, n, work_q, eh_entry)
639 		sas_eh_finish_cmd(cmd);
640 
641 	return list_empty(work_q);
642 }
643 
644 void sas_scsi_recover_host(struct Scsi_Host *shost)
645 {
646 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
647 	unsigned long flags;
648 	LIST_HEAD(eh_work_q);
649 
650 	spin_lock_irqsave(shost->host_lock, flags);
651 	list_splice_init(&shost->eh_cmd_q, &eh_work_q);
652 	spin_unlock_irqrestore(shost->host_lock, flags);
653 
654 	SAS_DPRINTK("Enter %s\n", __func__);
655 	/*
656 	 * Deal with commands that still have SAS tasks (i.e. they didn't
657 	 * complete via the normal sas_task completion mechanism)
658 	 */
659 	if (sas_eh_handle_sas_errors(shost, &eh_work_q, &ha->eh_done_q))
660 		goto out;
661 
662 	/*
663 	 * Now deal with SCSI commands that completed ok but have a an error
664 	 * code (and hopefully sense data) attached.  This is roughly what
665 	 * scsi_unjam_host does, but we skip scsi_eh_abort_cmds because any
666 	 * command we see here has no sas_task and is thus unknown to the HA.
667 	 */
668 	if (!scsi_eh_get_sense(&eh_work_q, &ha->eh_done_q))
669 		scsi_eh_ready_devs(shost, &eh_work_q, &ha->eh_done_q);
670 
671 out:
672 	scsi_eh_flush_done_q(&ha->eh_done_q);
673 	SAS_DPRINTK("--- Exit %s\n", __func__);
674 	return;
675 }
676 
677 enum blk_eh_timer_return sas_scsi_timed_out(struct scsi_cmnd *cmd)
678 {
679 	struct sas_task *task = TO_SAS_TASK(cmd);
680 	unsigned long flags;
681 
682 	if (!task) {
683 		cmd->request->timeout /= 2;
684 		SAS_DPRINTK("command 0x%p, task 0x%p, gone: %s\n",
685 			    cmd, task, (cmd->request->timeout ?
686 			    "BLK_EH_RESET_TIMER" : "BLK_EH_NOT_HANDLED"));
687 		if (!cmd->request->timeout)
688 			return BLK_EH_NOT_HANDLED;
689 		return BLK_EH_RESET_TIMER;
690 	}
691 
692 	spin_lock_irqsave(&task->task_state_lock, flags);
693 	BUG_ON(task->task_state_flags & SAS_TASK_STATE_ABORTED);
694 	if (task->task_state_flags & SAS_TASK_STATE_DONE) {
695 		spin_unlock_irqrestore(&task->task_state_lock, flags);
696 		SAS_DPRINTK("command 0x%p, task 0x%p, timed out: "
697 			    "BLK_EH_HANDLED\n", cmd, task);
698 		return BLK_EH_HANDLED;
699 	}
700 	if (!(task->task_state_flags & SAS_TASK_AT_INITIATOR)) {
701 		spin_unlock_irqrestore(&task->task_state_lock, flags);
702 		SAS_DPRINTK("command 0x%p, task 0x%p, not at initiator: "
703 			    "BLK_EH_RESET_TIMER\n",
704 			    cmd, task);
705 		return BLK_EH_RESET_TIMER;
706 	}
707 	task->task_state_flags |= SAS_TASK_STATE_ABORTED;
708 	spin_unlock_irqrestore(&task->task_state_lock, flags);
709 
710 	SAS_DPRINTK("command 0x%p, task 0x%p, timed out: BLK_EH_NOT_HANDLED\n",
711 		    cmd, task);
712 
713 	return BLK_EH_NOT_HANDLED;
714 }
715 
716 int sas_ioctl(struct scsi_device *sdev, int cmd, void __user *arg)
717 {
718 	struct domain_device *dev = sdev_to_domain_dev(sdev);
719 
720 	if (dev_is_sata(dev))
721 		return ata_sas_scsi_ioctl(dev->sata_dev.ap, sdev, cmd, arg);
722 
723 	return -EINVAL;
724 }
725 
726 struct domain_device *sas_find_dev_by_rphy(struct sas_rphy *rphy)
727 {
728 	struct Scsi_Host *shost = dev_to_shost(rphy->dev.parent);
729 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
730 	struct domain_device *found_dev = NULL;
731 	int i;
732 	unsigned long flags;
733 
734 	spin_lock_irqsave(&ha->phy_port_lock, flags);
735 	for (i = 0; i < ha->num_phys; i++) {
736 		struct asd_sas_port *port = ha->sas_port[i];
737 		struct domain_device *dev;
738 
739 		spin_lock(&port->dev_list_lock);
740 		list_for_each_entry(dev, &port->dev_list, dev_list_node) {
741 			if (rphy == dev->rphy) {
742 				found_dev = dev;
743 				spin_unlock(&port->dev_list_lock);
744 				goto found;
745 			}
746 		}
747 		spin_unlock(&port->dev_list_lock);
748 	}
749  found:
750 	spin_unlock_irqrestore(&ha->phy_port_lock, flags);
751 
752 	return found_dev;
753 }
754 
755 static inline struct domain_device *sas_find_target(struct scsi_target *starget)
756 {
757 	struct sas_rphy *rphy = dev_to_rphy(starget->dev.parent);
758 
759 	return sas_find_dev_by_rphy(rphy);
760 }
761 
762 int sas_target_alloc(struct scsi_target *starget)
763 {
764 	struct domain_device *found_dev = sas_find_target(starget);
765 	int res;
766 
767 	if (!found_dev)
768 		return -ENODEV;
769 
770 	if (dev_is_sata(found_dev)) {
771 		res = sas_ata_init_host_and_port(found_dev, starget);
772 		if (res)
773 			return res;
774 	}
775 
776 	starget->hostdata = found_dev;
777 	return 0;
778 }
779 
780 #define SAS_DEF_QD 32
781 #define SAS_MAX_QD 64
782 
783 int sas_slave_configure(struct scsi_device *scsi_dev)
784 {
785 	struct domain_device *dev = sdev_to_domain_dev(scsi_dev);
786 	struct sas_ha_struct *sas_ha;
787 
788 	BUG_ON(dev->rphy->identify.device_type != SAS_END_DEVICE);
789 
790 	if (dev_is_sata(dev)) {
791 		ata_sas_slave_configure(scsi_dev, dev->sata_dev.ap);
792 		return 0;
793 	}
794 
795 	sas_ha = dev->port->ha;
796 
797 	sas_read_port_mode_page(scsi_dev);
798 
799 	if (scsi_dev->tagged_supported) {
800 		scsi_set_tag_type(scsi_dev, MSG_SIMPLE_TAG);
801 		scsi_activate_tcq(scsi_dev, SAS_DEF_QD);
802 	} else {
803 		SAS_DPRINTK("device %llx, LUN %x doesn't support "
804 			    "TCQ\n", SAS_ADDR(dev->sas_addr),
805 			    scsi_dev->lun);
806 		scsi_dev->tagged_supported = 0;
807 		scsi_set_tag_type(scsi_dev, 0);
808 		scsi_deactivate_tcq(scsi_dev, 1);
809 	}
810 
811 	scsi_dev->allow_restart = 1;
812 
813 	return 0;
814 }
815 
816 void sas_slave_destroy(struct scsi_device *scsi_dev)
817 {
818 	struct domain_device *dev = sdev_to_domain_dev(scsi_dev);
819 
820 	if (dev_is_sata(dev))
821 		dev->sata_dev.ap->link.device[0].class = ATA_DEV_NONE;
822 }
823 
824 int sas_change_queue_depth(struct scsi_device *scsi_dev, int new_depth,
825 			   int reason)
826 {
827 	int res = min(new_depth, SAS_MAX_QD);
828 
829 	if (reason != SCSI_QDEPTH_DEFAULT)
830 		return -EOPNOTSUPP;
831 
832 	if (scsi_dev->tagged_supported)
833 		scsi_adjust_queue_depth(scsi_dev, scsi_get_tag_type(scsi_dev),
834 					res);
835 	else {
836 		struct domain_device *dev = sdev_to_domain_dev(scsi_dev);
837 		sas_printk("device %llx LUN %x queue depth changed to 1\n",
838 			   SAS_ADDR(dev->sas_addr),
839 			   scsi_dev->lun);
840 		scsi_adjust_queue_depth(scsi_dev, 0, 1);
841 		res = 1;
842 	}
843 
844 	return res;
845 }
846 
847 int sas_change_queue_type(struct scsi_device *scsi_dev, int qt)
848 {
849 	if (!scsi_dev->tagged_supported)
850 		return 0;
851 
852 	scsi_deactivate_tcq(scsi_dev, 1);
853 
854 	scsi_set_tag_type(scsi_dev, qt);
855 	scsi_activate_tcq(scsi_dev, scsi_dev->queue_depth);
856 
857 	return qt;
858 }
859 
860 int sas_bios_param(struct scsi_device *scsi_dev,
861 			  struct block_device *bdev,
862 			  sector_t capacity, int *hsc)
863 {
864 	hsc[0] = 255;
865 	hsc[1] = 63;
866 	sector_div(capacity, 255*63);
867 	hsc[2] = capacity;
868 
869 	return 0;
870 }
871 
872 /* ---------- Task Collector Thread implementation ---------- */
873 
874 static void sas_queue(struct sas_ha_struct *sas_ha)
875 {
876 	struct scsi_core *core = &sas_ha->core;
877 	unsigned long flags;
878 	LIST_HEAD(q);
879 	int can_queue;
880 	int res;
881 	struct sas_internal *i = to_sas_internal(core->shost->transportt);
882 
883 	spin_lock_irqsave(&core->task_queue_lock, flags);
884 	while (!kthread_should_stop() &&
885 	       !list_empty(&core->task_queue)) {
886 
887 		can_queue = sas_ha->lldd_queue_size - core->task_queue_size;
888 		if (can_queue >= 0) {
889 			can_queue = core->task_queue_size;
890 			list_splice_init(&core->task_queue, &q);
891 		} else {
892 			struct list_head *a, *n;
893 
894 			can_queue = sas_ha->lldd_queue_size;
895 			list_for_each_safe(a, n, &core->task_queue) {
896 				list_move_tail(a, &q);
897 				if (--can_queue == 0)
898 					break;
899 			}
900 			can_queue = sas_ha->lldd_queue_size;
901 		}
902 		core->task_queue_size -= can_queue;
903 		spin_unlock_irqrestore(&core->task_queue_lock, flags);
904 		{
905 			struct sas_task *task = list_entry(q.next,
906 							   struct sas_task,
907 							   list);
908 			list_del_init(&q);
909 			res = i->dft->lldd_execute_task(task, can_queue,
910 							GFP_KERNEL);
911 			if (unlikely(res))
912 				__list_add(&q, task->list.prev, &task->list);
913 		}
914 		spin_lock_irqsave(&core->task_queue_lock, flags);
915 		if (res) {
916 			list_splice_init(&q, &core->task_queue); /*at head*/
917 			core->task_queue_size += can_queue;
918 		}
919 	}
920 	spin_unlock_irqrestore(&core->task_queue_lock, flags);
921 }
922 
923 /**
924  * sas_queue_thread -- The Task Collector thread
925  * @_sas_ha: pointer to struct sas_ha
926  */
927 static int sas_queue_thread(void *_sas_ha)
928 {
929 	struct sas_ha_struct *sas_ha = _sas_ha;
930 
931 	while (1) {
932 		set_current_state(TASK_INTERRUPTIBLE);
933 		schedule();
934 		sas_queue(sas_ha);
935 		if (kthread_should_stop())
936 			break;
937 	}
938 
939 	return 0;
940 }
941 
942 int sas_init_queue(struct sas_ha_struct *sas_ha)
943 {
944 	struct scsi_core *core = &sas_ha->core;
945 
946 	spin_lock_init(&core->task_queue_lock);
947 	core->task_queue_size = 0;
948 	INIT_LIST_HEAD(&core->task_queue);
949 
950 	core->queue_thread = kthread_run(sas_queue_thread, sas_ha,
951 					 "sas_queue_%d", core->shost->host_no);
952 	if (IS_ERR(core->queue_thread))
953 		return PTR_ERR(core->queue_thread);
954 	return 0;
955 }
956 
957 void sas_shutdown_queue(struct sas_ha_struct *sas_ha)
958 {
959 	unsigned long flags;
960 	struct scsi_core *core = &sas_ha->core;
961 	struct sas_task *task, *n;
962 
963 	kthread_stop(core->queue_thread);
964 
965 	if (!list_empty(&core->task_queue))
966 		SAS_DPRINTK("HA: %llx: scsi core task queue is NOT empty!?\n",
967 			    SAS_ADDR(sas_ha->sas_addr));
968 
969 	spin_lock_irqsave(&core->task_queue_lock, flags);
970 	list_for_each_entry_safe(task, n, &core->task_queue, list) {
971 		struct scsi_cmnd *cmd = task->uldd_task;
972 
973 		list_del_init(&task->list);
974 
975 		ASSIGN_SAS_TASK(cmd, NULL);
976 		sas_free_task(task);
977 		cmd->result = DID_ABORT << 16;
978 		cmd->scsi_done(cmd);
979 	}
980 	spin_unlock_irqrestore(&core->task_queue_lock, flags);
981 }
982 
983 /*
984  * Call the LLDD task abort routine directly.  This function is intended for
985  * use by upper layers that need to tell the LLDD to abort a task.
986  */
987 int __sas_task_abort(struct sas_task *task)
988 {
989 	struct sas_internal *si =
990 		to_sas_internal(task->dev->port->ha->core.shost->transportt);
991 	unsigned long flags;
992 	int res;
993 
994 	spin_lock_irqsave(&task->task_state_lock, flags);
995 	if (task->task_state_flags & SAS_TASK_STATE_ABORTED ||
996 	    task->task_state_flags & SAS_TASK_STATE_DONE) {
997 		spin_unlock_irqrestore(&task->task_state_lock, flags);
998 		SAS_DPRINTK("%s: Task %p already finished.\n", __func__,
999 			    task);
1000 		return 0;
1001 	}
1002 	task->task_state_flags |= SAS_TASK_STATE_ABORTED;
1003 	spin_unlock_irqrestore(&task->task_state_lock, flags);
1004 
1005 	if (!si->dft->lldd_abort_task)
1006 		return -ENODEV;
1007 
1008 	res = si->dft->lldd_abort_task(task);
1009 
1010 	spin_lock_irqsave(&task->task_state_lock, flags);
1011 	if ((task->task_state_flags & SAS_TASK_STATE_DONE) ||
1012 	    (res == TMF_RESP_FUNC_COMPLETE))
1013 	{
1014 		spin_unlock_irqrestore(&task->task_state_lock, flags);
1015 		task->task_done(task);
1016 		return 0;
1017 	}
1018 
1019 	if (!(task->task_state_flags & SAS_TASK_STATE_DONE))
1020 		task->task_state_flags &= ~SAS_TASK_STATE_ABORTED;
1021 	spin_unlock_irqrestore(&task->task_state_lock, flags);
1022 
1023 	return -EAGAIN;
1024 }
1025 
1026 /*
1027  * Tell an upper layer that it needs to initiate an abort for a given task.
1028  * This should only ever be called by an LLDD.
1029  */
1030 void sas_task_abort(struct sas_task *task)
1031 {
1032 	struct scsi_cmnd *sc = task->uldd_task;
1033 
1034 	/* Escape for libsas internal commands */
1035 	if (!sc) {
1036 		if (!del_timer(&task->timer))
1037 			return;
1038 		task->timer.function(task->timer.data);
1039 		return;
1040 	}
1041 
1042 	if (dev_is_sata(task->dev)) {
1043 		sas_ata_task_abort(task);
1044 	} else {
1045 		struct request_queue *q = sc->device->request_queue;
1046 		unsigned long flags;
1047 
1048 		spin_lock_irqsave(q->queue_lock, flags);
1049 		blk_abort_request(sc->request);
1050 		spin_unlock_irqrestore(q->queue_lock, flags);
1051 		scsi_schedule_eh(sc->device->host);
1052 	}
1053 }
1054 
1055 int sas_slave_alloc(struct scsi_device *scsi_dev)
1056 {
1057 	struct domain_device *dev = sdev_to_domain_dev(scsi_dev);
1058 
1059 	if (dev_is_sata(dev))
1060 		return ata_sas_port_init(dev->sata_dev.ap);
1061 
1062 	return 0;
1063 }
1064 
1065 void sas_target_destroy(struct scsi_target *starget)
1066 {
1067 	struct domain_device *found_dev = sas_find_target(starget);
1068 
1069 	if (!found_dev)
1070 		return;
1071 
1072 	if (dev_is_sata(found_dev))
1073 		ata_sas_port_destroy(found_dev->sata_dev.ap);
1074 
1075 	return;
1076 }
1077 
1078 static void sas_parse_addr(u8 *sas_addr, const char *p)
1079 {
1080 	int i;
1081 	for (i = 0; i < SAS_ADDR_SIZE; i++) {
1082 		u8 h, l;
1083 		if (!*p)
1084 			break;
1085 		h = isdigit(*p) ? *p-'0' : toupper(*p)-'A'+10;
1086 		p++;
1087 		l = isdigit(*p) ? *p-'0' : toupper(*p)-'A'+10;
1088 		p++;
1089 		sas_addr[i] = (h<<4) | l;
1090 	}
1091 }
1092 
1093 #define SAS_STRING_ADDR_SIZE	16
1094 
1095 int sas_request_addr(struct Scsi_Host *shost, u8 *addr)
1096 {
1097 	int res;
1098 	const struct firmware *fw;
1099 
1100 	res = request_firmware(&fw, "sas_addr", &shost->shost_gendev);
1101 	if (res)
1102 		return res;
1103 
1104 	if (fw->size < SAS_STRING_ADDR_SIZE) {
1105 		res = -ENODEV;
1106 		goto out;
1107 	}
1108 
1109 	sas_parse_addr(addr, fw->data);
1110 
1111 out:
1112 	release_firmware(fw);
1113 	return res;
1114 }
1115 EXPORT_SYMBOL_GPL(sas_request_addr);
1116 
1117 EXPORT_SYMBOL_GPL(sas_queuecommand);
1118 EXPORT_SYMBOL_GPL(sas_target_alloc);
1119 EXPORT_SYMBOL_GPL(sas_slave_configure);
1120 EXPORT_SYMBOL_GPL(sas_slave_destroy);
1121 EXPORT_SYMBOL_GPL(sas_change_queue_depth);
1122 EXPORT_SYMBOL_GPL(sas_change_queue_type);
1123 EXPORT_SYMBOL_GPL(sas_bios_param);
1124 EXPORT_SYMBOL_GPL(__sas_task_abort);
1125 EXPORT_SYMBOL_GPL(sas_task_abort);
1126 EXPORT_SYMBOL_GPL(sas_phy_reset);
1127 EXPORT_SYMBOL_GPL(sas_phy_enable);
1128 EXPORT_SYMBOL_GPL(sas_eh_device_reset_handler);
1129 EXPORT_SYMBOL_GPL(sas_eh_bus_reset_handler);
1130 EXPORT_SYMBOL_GPL(sas_slave_alloc);
1131 EXPORT_SYMBOL_GPL(sas_target_destroy);
1132 EXPORT_SYMBOL_GPL(sas_ioctl);
1133