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