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 
28 #include "sas_internal.h"
29 
30 #include <scsi/scsi_host.h>
31 #include <scsi/scsi_device.h>
32 #include <scsi/scsi_tcq.h>
33 #include <scsi/scsi.h>
34 #include <scsi/scsi_eh.h>
35 #include <scsi/scsi_transport.h>
36 #include <scsi/scsi_transport_sas.h>
37 #include "../scsi_sas_internal.h"
38 #include "../scsi_transport_api.h"
39 #include "../scsi_priv.h"
40 
41 #include <linux/err.h>
42 #include <linux/blkdev.h>
43 #include <linux/scatterlist.h>
44 
45 /* ---------- SCSI Host glue ---------- */
46 
47 #define TO_SAS_TASK(_scsi_cmd)  ((void *)(_scsi_cmd)->host_scribble)
48 #define ASSIGN_SAS_TASK(_sc, _t) do { (_sc)->host_scribble = (void *) _t; } while (0)
49 
50 static void sas_scsi_task_done(struct sas_task *task)
51 {
52 	struct task_status_struct *ts = &task->task_status;
53 	struct scsi_cmnd *sc = task->uldd_task;
54 	struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(sc->device->host);
55 	unsigned ts_flags = task->task_state_flags;
56 	int hs = 0, stat = 0;
57 
58 	if (unlikely(!sc)) {
59 		SAS_DPRINTK("task_done called with non existing SCSI cmnd!\n");
60 		list_del_init(&task->list);
61 		sas_free_task(task);
62 		return;
63 	}
64 
65 	if (ts->resp == SAS_TASK_UNDELIVERED) {
66 		/* transport error */
67 		hs = DID_NO_CONNECT;
68 	} else { /* ts->resp == SAS_TASK_COMPLETE */
69 		/* task delivered, what happened afterwards? */
70 		switch (ts->stat) {
71 		case SAS_DEV_NO_RESPONSE:
72 		case SAS_INTERRUPTED:
73 		case SAS_PHY_DOWN:
74 		case SAS_NAK_R_ERR:
75 		case SAS_OPEN_TO:
76 			hs = DID_NO_CONNECT;
77 			break;
78 		case SAS_DATA_UNDERRUN:
79 			sc->resid = ts->residual;
80 			if (sc->request_bufflen - sc->resid < sc->underflow)
81 				hs = DID_ERROR;
82 			break;
83 		case SAS_DATA_OVERRUN:
84 			hs = DID_ERROR;
85 			break;
86 		case SAS_QUEUE_FULL:
87 			hs = DID_SOFT_ERROR; /* retry */
88 			break;
89 		case SAS_DEVICE_UNKNOWN:
90 			hs = DID_BAD_TARGET;
91 			break;
92 		case SAS_SG_ERR:
93 			hs = DID_PARITY;
94 			break;
95 		case SAS_OPEN_REJECT:
96 			if (ts->open_rej_reason == SAS_OREJ_RSVD_RETRY)
97 				hs = DID_SOFT_ERROR; /* retry */
98 			else
99 				hs = DID_ERROR;
100 			break;
101 		case SAS_PROTO_RESPONSE:
102 			SAS_DPRINTK("LLDD:%s sent SAS_PROTO_RESP for an SSP "
103 				    "task; please report this\n",
104 				    task->dev->port->ha->sas_ha_name);
105 			break;
106 		case SAS_ABORTED_TASK:
107 			hs = DID_ABORT;
108 			break;
109 		case SAM_CHECK_COND:
110 			memcpy(sc->sense_buffer, ts->buf,
111 			       max(SCSI_SENSE_BUFFERSIZE, ts->buf_valid_size));
112 			stat = SAM_CHECK_COND;
113 			break;
114 		default:
115 			stat = ts->stat;
116 			break;
117 		}
118 	}
119 	ASSIGN_SAS_TASK(sc, NULL);
120 	sc->result = (hs << 16) | stat;
121 	list_del_init(&task->list);
122 	sas_free_task(task);
123 	/* This is very ugly but this is how SCSI Core works. */
124 	if (ts_flags & SAS_TASK_STATE_ABORTED)
125 		scsi_eh_finish_cmd(sc, &sas_ha->eh_done_q);
126 	else
127 		sc->scsi_done(sc);
128 }
129 
130 static enum task_attribute sas_scsi_get_task_attr(struct scsi_cmnd *cmd)
131 {
132 	enum task_attribute ta = TASK_ATTR_SIMPLE;
133 	if (cmd->request && blk_rq_tagged(cmd->request)) {
134 		if (cmd->device->ordered_tags &&
135 		    (cmd->request->cmd_flags & REQ_HARDBARRIER))
136 			ta = TASK_ATTR_ORDERED;
137 	}
138 	return ta;
139 }
140 
141 static struct sas_task *sas_create_task(struct scsi_cmnd *cmd,
142 					       struct domain_device *dev,
143 					       gfp_t gfp_flags)
144 {
145 	struct sas_task *task = sas_alloc_task(gfp_flags);
146 	struct scsi_lun lun;
147 
148 	if (!task)
149 		return NULL;
150 
151 	*(u32 *)cmd->sense_buffer = 0;
152 	task->uldd_task = cmd;
153 	ASSIGN_SAS_TASK(cmd, task);
154 
155 	task->dev = dev;
156 	task->task_proto = task->dev->tproto; /* BUG_ON(!SSP) */
157 
158 	task->ssp_task.retry_count = 1;
159 	int_to_scsilun(cmd->device->lun, &lun);
160 	memcpy(task->ssp_task.LUN, &lun.scsi_lun, 8);
161 	task->ssp_task.task_attr = sas_scsi_get_task_attr(cmd);
162 	memcpy(task->ssp_task.cdb, cmd->cmnd, 16);
163 
164 	task->scatter = cmd->request_buffer;
165 	task->num_scatter = cmd->use_sg;
166 	task->total_xfer_len = cmd->request_bufflen;
167 	task->data_dir = cmd->sc_data_direction;
168 
169 	task->task_done = sas_scsi_task_done;
170 
171 	return task;
172 }
173 
174 static int sas_queue_up(struct sas_task *task)
175 {
176 	struct sas_ha_struct *sas_ha = task->dev->port->ha;
177 	struct scsi_core *core = &sas_ha->core;
178 	unsigned long flags;
179 	LIST_HEAD(list);
180 
181 	spin_lock_irqsave(&core->task_queue_lock, flags);
182 	if (sas_ha->lldd_queue_size < core->task_queue_size + 1) {
183 		spin_unlock_irqrestore(&core->task_queue_lock, flags);
184 		return -SAS_QUEUE_FULL;
185 	}
186 	list_add_tail(&task->list, &core->task_queue);
187 	core->task_queue_size += 1;
188 	spin_unlock_irqrestore(&core->task_queue_lock, flags);
189 	wake_up_process(core->queue_thread);
190 
191 	return 0;
192 }
193 
194 /**
195  * sas_queuecommand -- Enqueue a command for processing
196  * @parameters: See SCSI Core documentation
197  *
198  * Note: XXX: Remove the host unlock/lock pair when SCSI Core can
199  * call us without holding an IRQ spinlock...
200  */
201 int sas_queuecommand(struct scsi_cmnd *cmd,
202 		     void (*scsi_done)(struct scsi_cmnd *))
203 {
204 	int res = 0;
205 	struct domain_device *dev = cmd_to_domain_dev(cmd);
206 	struct Scsi_Host *host = cmd->device->host;
207 	struct sas_internal *i = to_sas_internal(host->transportt);
208 
209 	spin_unlock_irq(host->host_lock);
210 
211 	{
212 		struct sas_ha_struct *sas_ha = dev->port->ha;
213 		struct sas_task *task;
214 
215 		res = -ENOMEM;
216 		task = sas_create_task(cmd, dev, GFP_ATOMIC);
217 		if (!task)
218 			goto out;
219 
220 		cmd->scsi_done = scsi_done;
221 		/* Queue up, Direct Mode or Task Collector Mode. */
222 		if (sas_ha->lldd_max_execute_num < 2)
223 			res = i->dft->lldd_execute_task(task, 1, GFP_ATOMIC);
224 		else
225 			res = sas_queue_up(task);
226 
227 		/* Examine */
228 		if (res) {
229 			SAS_DPRINTK("lldd_execute_task returned: %d\n", res);
230 			ASSIGN_SAS_TASK(cmd, NULL);
231 			sas_free_task(task);
232 			if (res == -SAS_QUEUE_FULL) {
233 				cmd->result = DID_SOFT_ERROR << 16; /* retry */
234 				res = 0;
235 				scsi_done(cmd);
236 			}
237 			goto out;
238 		}
239 	}
240 out:
241 	spin_lock_irq(host->host_lock);
242 	return res;
243 }
244 
245 static void sas_scsi_clear_queue_lu(struct list_head *error_q, struct scsi_cmnd *my_cmd)
246 {
247 	struct scsi_cmnd *cmd, *n;
248 
249 	list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
250 		if (cmd == my_cmd)
251 			list_del_init(&cmd->eh_entry);
252 	}
253 }
254 
255 static void sas_scsi_clear_queue_I_T(struct list_head *error_q,
256 				     struct domain_device *dev)
257 {
258 	struct scsi_cmnd *cmd, *n;
259 
260 	list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
261 		struct domain_device *x = cmd_to_domain_dev(cmd);
262 
263 		if (x == dev)
264 			list_del_init(&cmd->eh_entry);
265 	}
266 }
267 
268 static void sas_scsi_clear_queue_port(struct list_head *error_q,
269 				      struct asd_sas_port *port)
270 {
271 	struct scsi_cmnd *cmd, *n;
272 
273 	list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
274 		struct domain_device *dev = cmd_to_domain_dev(cmd);
275 		struct asd_sas_port *x = dev->port;
276 
277 		if (x == port)
278 			list_del_init(&cmd->eh_entry);
279 	}
280 }
281 
282 enum task_disposition {
283 	TASK_IS_DONE,
284 	TASK_IS_ABORTED,
285 	TASK_IS_AT_LU,
286 	TASK_IS_NOT_AT_LU,
287 	TASK_ABORT_FAILED,
288 };
289 
290 static enum task_disposition sas_scsi_find_task(struct sas_task *task)
291 {
292 	struct sas_ha_struct *ha = task->dev->port->ha;
293 	unsigned long flags;
294 	int i, res;
295 	struct sas_internal *si =
296 		to_sas_internal(task->dev->port->ha->core.shost->transportt);
297 
298 	if (ha->lldd_max_execute_num > 1) {
299 		struct scsi_core *core = &ha->core;
300 		struct sas_task *t, *n;
301 
302 		spin_lock_irqsave(&core->task_queue_lock, flags);
303 		list_for_each_entry_safe(t, n, &core->task_queue, list) {
304 			if (task == t) {
305 				list_del_init(&t->list);
306 				spin_unlock_irqrestore(&core->task_queue_lock,
307 						       flags);
308 				SAS_DPRINTK("%s: task 0x%p aborted from "
309 					    "task_queue\n",
310 					    __FUNCTION__, task);
311 				return TASK_IS_ABORTED;
312 			}
313 		}
314 		spin_unlock_irqrestore(&core->task_queue_lock, flags);
315 	}
316 
317 	for (i = 0; i < 5; i++) {
318 		SAS_DPRINTK("%s: aborting task 0x%p\n", __FUNCTION__, task);
319 		res = si->dft->lldd_abort_task(task);
320 
321 		spin_lock_irqsave(&task->task_state_lock, flags);
322 		if (task->task_state_flags & SAS_TASK_STATE_DONE) {
323 			spin_unlock_irqrestore(&task->task_state_lock, flags);
324 			SAS_DPRINTK("%s: task 0x%p is done\n", __FUNCTION__,
325 				    task);
326 			return TASK_IS_DONE;
327 		}
328 		spin_unlock_irqrestore(&task->task_state_lock, flags);
329 
330 		if (res == TMF_RESP_FUNC_COMPLETE) {
331 			SAS_DPRINTK("%s: task 0x%p is aborted\n",
332 				    __FUNCTION__, task);
333 			return TASK_IS_ABORTED;
334 		} else if (si->dft->lldd_query_task) {
335 			SAS_DPRINTK("%s: querying task 0x%p\n",
336 				    __FUNCTION__, task);
337 			res = si->dft->lldd_query_task(task);
338 			switch (res) {
339 			case TMF_RESP_FUNC_SUCC:
340 				SAS_DPRINTK("%s: task 0x%p at LU\n",
341 					    __FUNCTION__, task);
342 				return TASK_IS_AT_LU;
343 			case TMF_RESP_FUNC_COMPLETE:
344 				SAS_DPRINTK("%s: task 0x%p not at LU\n",
345 					    __FUNCTION__, task);
346 				return TASK_IS_NOT_AT_LU;
347 			case TMF_RESP_FUNC_FAILED:
348                                 SAS_DPRINTK("%s: task 0x%p failed to abort\n",
349                                                 __FUNCTION__, task);
350                                 return TASK_ABORT_FAILED;
351                         }
352 
353 		}
354 	}
355 	return res;
356 }
357 
358 static int sas_recover_lu(struct domain_device *dev, struct scsi_cmnd *cmd)
359 {
360 	int res = TMF_RESP_FUNC_FAILED;
361 	struct scsi_lun lun;
362 	struct sas_internal *i =
363 		to_sas_internal(dev->port->ha->core.shost->transportt);
364 
365 	int_to_scsilun(cmd->device->lun, &lun);
366 
367 	SAS_DPRINTK("eh: device %llx LUN %x has the task\n",
368 		    SAS_ADDR(dev->sas_addr),
369 		    cmd->device->lun);
370 
371 	if (i->dft->lldd_abort_task_set)
372 		res = i->dft->lldd_abort_task_set(dev, lun.scsi_lun);
373 
374 	if (res == TMF_RESP_FUNC_FAILED) {
375 		if (i->dft->lldd_clear_task_set)
376 			res = i->dft->lldd_clear_task_set(dev, lun.scsi_lun);
377 	}
378 
379 	if (res == TMF_RESP_FUNC_FAILED) {
380 		if (i->dft->lldd_lu_reset)
381 			res = i->dft->lldd_lu_reset(dev, lun.scsi_lun);
382 	}
383 
384 	return res;
385 }
386 
387 static int sas_recover_I_T(struct domain_device *dev)
388 {
389 	int res = TMF_RESP_FUNC_FAILED;
390 	struct sas_internal *i =
391 		to_sas_internal(dev->port->ha->core.shost->transportt);
392 
393 	SAS_DPRINTK("I_T nexus reset for dev %016llx\n",
394 		    SAS_ADDR(dev->sas_addr));
395 
396 	if (i->dft->lldd_I_T_nexus_reset)
397 		res = i->dft->lldd_I_T_nexus_reset(dev);
398 
399 	return res;
400 }
401 
402 /* Find the sas_phy that's attached to this device */
403 struct sas_phy *find_local_sas_phy(struct domain_device *dev)
404 {
405 	struct domain_device *pdev = dev->parent;
406 	struct ex_phy *exphy = NULL;
407 	int i;
408 
409 	/* Directly attached device */
410 	if (!pdev)
411 		return dev->port->phy;
412 
413 	/* Otherwise look in the expander */
414 	for (i = 0; i < pdev->ex_dev.num_phys; i++)
415 		if (!memcmp(dev->sas_addr,
416 			    pdev->ex_dev.ex_phy[i].attached_sas_addr,
417 			    SAS_ADDR_SIZE)) {
418 			exphy = &pdev->ex_dev.ex_phy[i];
419 			break;
420 		}
421 
422 	BUG_ON(!exphy);
423 	return exphy->phy;
424 }
425 
426 /* Attempt to send a LUN reset message to a device */
427 int sas_eh_device_reset_handler(struct scsi_cmnd *cmd)
428 {
429 	struct domain_device *dev = cmd_to_domain_dev(cmd);
430 	struct sas_internal *i =
431 		to_sas_internal(dev->port->ha->core.shost->transportt);
432 	struct scsi_lun lun;
433 	int res;
434 
435 	int_to_scsilun(cmd->device->lun, &lun);
436 
437 	if (!i->dft->lldd_lu_reset)
438 		return FAILED;
439 
440 	res = i->dft->lldd_lu_reset(dev, lun.scsi_lun);
441 	if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE)
442 		return SUCCESS;
443 
444 	return FAILED;
445 }
446 
447 /* Attempt to send a phy (bus) reset */
448 int sas_eh_bus_reset_handler(struct scsi_cmnd *cmd)
449 {
450 	struct domain_device *dev = cmd_to_domain_dev(cmd);
451 	struct sas_phy *phy = find_local_sas_phy(dev);
452 	int res;
453 
454 	res = sas_phy_reset(phy, 1);
455 	if (res)
456 		SAS_DPRINTK("Bus reset of %s failed 0x%x\n",
457 			    phy->dev.kobj.k_name,
458 			    res);
459 	if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE)
460 		return SUCCESS;
461 
462 	return FAILED;
463 }
464 
465 /* Try to reset a device */
466 static int try_to_reset_cmd_device(struct Scsi_Host *shost,
467 				   struct scsi_cmnd *cmd)
468 {
469 	int res;
470 
471 	if (!shost->hostt->eh_device_reset_handler)
472 		goto try_bus_reset;
473 
474 	res = shost->hostt->eh_device_reset_handler(cmd);
475 	if (res == SUCCESS)
476 		return res;
477 
478 try_bus_reset:
479 	if (shost->hostt->eh_bus_reset_handler)
480 		return shost->hostt->eh_bus_reset_handler(cmd);
481 
482 	return FAILED;
483 }
484 
485 static int sas_eh_handle_sas_errors(struct Scsi_Host *shost,
486 				    struct list_head *work_q,
487 				    struct list_head *done_q)
488 {
489 	struct scsi_cmnd *cmd, *n;
490 	enum task_disposition res = TASK_IS_DONE;
491 	int tmf_resp, need_reset;
492 	struct sas_internal *i = to_sas_internal(shost->transportt);
493 	unsigned long flags;
494 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
495 
496 Again:
497 	list_for_each_entry_safe(cmd, n, work_q, eh_entry) {
498 		struct sas_task *task = TO_SAS_TASK(cmd);
499 
500 		if (!task)
501 			continue;
502 
503 		list_del_init(&cmd->eh_entry);
504 
505 		spin_lock_irqsave(&task->task_state_lock, flags);
506 		need_reset = task->task_state_flags & SAS_TASK_NEED_DEV_RESET;
507 		spin_unlock_irqrestore(&task->task_state_lock, flags);
508 
509 		SAS_DPRINTK("trying to find task 0x%p\n", task);
510 		res = sas_scsi_find_task(task);
511 
512 		cmd->eh_eflags = 0;
513 
514 		switch (res) {
515 		case TASK_IS_DONE:
516 			SAS_DPRINTK("%s: task 0x%p is done\n", __FUNCTION__,
517 				    task);
518 			task->task_done(task);
519 			if (need_reset)
520 				try_to_reset_cmd_device(shost, cmd);
521 			continue;
522 		case TASK_IS_ABORTED:
523 			SAS_DPRINTK("%s: task 0x%p is aborted\n",
524 				    __FUNCTION__, task);
525 			task->task_done(task);
526 			if (need_reset)
527 				try_to_reset_cmd_device(shost, cmd);
528 			continue;
529 		case TASK_IS_AT_LU:
530 			SAS_DPRINTK("task 0x%p is at LU: lu recover\n", task);
531 			tmf_resp = sas_recover_lu(task->dev, cmd);
532 			if (tmf_resp == TMF_RESP_FUNC_COMPLETE) {
533 				SAS_DPRINTK("dev %016llx LU %x is "
534 					    "recovered\n",
535 					    SAS_ADDR(task->dev),
536 					    cmd->device->lun);
537 				task->task_done(task);
538 				if (need_reset)
539 					try_to_reset_cmd_device(shost, cmd);
540 				sas_scsi_clear_queue_lu(work_q, cmd);
541 				goto Again;
542 			}
543 			/* fallthrough */
544 		case TASK_IS_NOT_AT_LU:
545 		case TASK_ABORT_FAILED:
546 			SAS_DPRINTK("task 0x%p is not at LU: I_T recover\n",
547 				    task);
548 			tmf_resp = sas_recover_I_T(task->dev);
549 			if (tmf_resp == TMF_RESP_FUNC_COMPLETE) {
550 				SAS_DPRINTK("I_T %016llx recovered\n",
551 					    SAS_ADDR(task->dev->sas_addr));
552 				task->task_done(task);
553 				if (need_reset)
554 					try_to_reset_cmd_device(shost, cmd);
555 				sas_scsi_clear_queue_I_T(work_q, task->dev);
556 				goto Again;
557 			}
558 			/* Hammer time :-) */
559 			if (i->dft->lldd_clear_nexus_port) {
560 				struct asd_sas_port *port = task->dev->port;
561 				SAS_DPRINTK("clearing nexus for port:%d\n",
562 					    port->id);
563 				res = i->dft->lldd_clear_nexus_port(port);
564 				if (res == TMF_RESP_FUNC_COMPLETE) {
565 					SAS_DPRINTK("clear nexus port:%d "
566 						    "succeeded\n", port->id);
567 					task->task_done(task);
568 					if (need_reset)
569 						try_to_reset_cmd_device(shost, cmd);
570 					sas_scsi_clear_queue_port(work_q,
571 								  port);
572 					goto Again;
573 				}
574 			}
575 			if (i->dft->lldd_clear_nexus_ha) {
576 				SAS_DPRINTK("clear nexus ha\n");
577 				res = i->dft->lldd_clear_nexus_ha(ha);
578 				if (res == TMF_RESP_FUNC_COMPLETE) {
579 					SAS_DPRINTK("clear nexus ha "
580 						    "succeeded\n");
581 					task->task_done(task);
582 					if (need_reset)
583 						try_to_reset_cmd_device(shost, cmd);
584 					goto out;
585 				}
586 			}
587 			/* If we are here -- this means that no amount
588 			 * of effort could recover from errors.  Quite
589 			 * possibly the HA just disappeared.
590 			 */
591 			SAS_DPRINTK("error from  device %llx, LUN %x "
592 				    "couldn't be recovered in any way\n",
593 				    SAS_ADDR(task->dev->sas_addr),
594 				    cmd->device->lun);
595 
596 			task->task_done(task);
597 			if (need_reset)
598 				try_to_reset_cmd_device(shost, cmd);
599 			goto clear_q;
600 		}
601 	}
602 out:
603 	return list_empty(work_q);
604 clear_q:
605 	SAS_DPRINTK("--- Exit %s -- clear_q\n", __FUNCTION__);
606 	list_for_each_entry_safe(cmd, n, work_q, eh_entry) {
607 		struct sas_task *task = TO_SAS_TASK(cmd);
608 		list_del_init(&cmd->eh_entry);
609 		task->task_done(task);
610 	}
611 	return list_empty(work_q);
612 }
613 
614 void sas_scsi_recover_host(struct Scsi_Host *shost)
615 {
616 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
617 	unsigned long flags;
618 	LIST_HEAD(eh_work_q);
619 
620 	spin_lock_irqsave(shost->host_lock, flags);
621 	list_splice_init(&shost->eh_cmd_q, &eh_work_q);
622 	spin_unlock_irqrestore(shost->host_lock, flags);
623 
624 	SAS_DPRINTK("Enter %s\n", __FUNCTION__);
625 	/*
626 	 * Deal with commands that still have SAS tasks (i.e. they didn't
627 	 * complete via the normal sas_task completion mechanism)
628 	 */
629 	if (sas_eh_handle_sas_errors(shost, &eh_work_q, &ha->eh_done_q))
630 		goto out;
631 
632 	/*
633 	 * Now deal with SCSI commands that completed ok but have a an error
634 	 * code (and hopefully sense data) attached.  This is roughly what
635 	 * scsi_unjam_host does, but we skip scsi_eh_abort_cmds because any
636 	 * command we see here has no sas_task and is thus unknown to the HA.
637 	 */
638 	if (!scsi_eh_get_sense(&eh_work_q, &ha->eh_done_q))
639 		scsi_eh_ready_devs(shost, &eh_work_q, &ha->eh_done_q);
640 
641 out:
642 	scsi_eh_flush_done_q(&ha->eh_done_q);
643 	SAS_DPRINTK("--- Exit %s\n", __FUNCTION__);
644 	return;
645 }
646 
647 enum scsi_eh_timer_return sas_scsi_timed_out(struct scsi_cmnd *cmd)
648 {
649 	struct sas_task *task = TO_SAS_TASK(cmd);
650 	unsigned long flags;
651 
652 	if (!task) {
653 		cmd->timeout_per_command /= 2;
654 		SAS_DPRINTK("command 0x%p, task 0x%p, gone: %s\n",
655 			    cmd, task, (cmd->timeout_per_command ?
656 			    "EH_RESET_TIMER" : "EH_NOT_HANDLED"));
657 		if (!cmd->timeout_per_command)
658 			return EH_NOT_HANDLED;
659 		return EH_RESET_TIMER;
660 	}
661 
662 	spin_lock_irqsave(&task->task_state_lock, flags);
663 	BUG_ON(task->task_state_flags & SAS_TASK_STATE_ABORTED);
664 	if (task->task_state_flags & SAS_TASK_STATE_DONE) {
665 		spin_unlock_irqrestore(&task->task_state_lock, flags);
666 		SAS_DPRINTK("command 0x%p, task 0x%p, timed out: EH_HANDLED\n",
667 			    cmd, task);
668 		return EH_HANDLED;
669 	}
670 	if (!(task->task_state_flags & SAS_TASK_AT_INITIATOR)) {
671 		spin_unlock_irqrestore(&task->task_state_lock, flags);
672 		SAS_DPRINTK("command 0x%p, task 0x%p, not at initiator: "
673 			    "EH_RESET_TIMER\n",
674 			    cmd, task);
675 		return EH_RESET_TIMER;
676 	}
677 	task->task_state_flags |= SAS_TASK_STATE_ABORTED;
678 	spin_unlock_irqrestore(&task->task_state_lock, flags);
679 
680 	SAS_DPRINTK("command 0x%p, task 0x%p, timed out: EH_NOT_HANDLED\n",
681 		    cmd, task);
682 
683 	return EH_NOT_HANDLED;
684 }
685 
686 struct domain_device *sas_find_dev_by_rphy(struct sas_rphy *rphy)
687 {
688 	struct Scsi_Host *shost = dev_to_shost(rphy->dev.parent);
689 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
690 	struct domain_device *found_dev = NULL;
691 	int i;
692 	unsigned long flags;
693 
694 	spin_lock_irqsave(&ha->phy_port_lock, flags);
695 	for (i = 0; i < ha->num_phys; i++) {
696 		struct asd_sas_port *port = ha->sas_port[i];
697 		struct domain_device *dev;
698 
699 		spin_lock(&port->dev_list_lock);
700 		list_for_each_entry(dev, &port->dev_list, dev_list_node) {
701 			if (rphy == dev->rphy) {
702 				found_dev = dev;
703 				spin_unlock(&port->dev_list_lock);
704 				goto found;
705 			}
706 		}
707 		spin_unlock(&port->dev_list_lock);
708 	}
709  found:
710 	spin_unlock_irqrestore(&ha->phy_port_lock, flags);
711 
712 	return found_dev;
713 }
714 
715 static inline struct domain_device *sas_find_target(struct scsi_target *starget)
716 {
717 	struct sas_rphy *rphy = dev_to_rphy(starget->dev.parent);
718 
719 	return sas_find_dev_by_rphy(rphy);
720 }
721 
722 int sas_target_alloc(struct scsi_target *starget)
723 {
724 	struct domain_device *found_dev = sas_find_target(starget);
725 
726 	if (!found_dev)
727 		return -ENODEV;
728 
729 	starget->hostdata = found_dev;
730 	return 0;
731 }
732 
733 #define SAS_DEF_QD 32
734 #define SAS_MAX_QD 64
735 
736 int sas_slave_configure(struct scsi_device *scsi_dev)
737 {
738 	struct domain_device *dev = sdev_to_domain_dev(scsi_dev);
739 	struct sas_ha_struct *sas_ha;
740 
741 	BUG_ON(dev->rphy->identify.device_type != SAS_END_DEVICE);
742 
743 	sas_ha = dev->port->ha;
744 
745 	sas_read_port_mode_page(scsi_dev);
746 
747 	if (scsi_dev->tagged_supported) {
748 		scsi_set_tag_type(scsi_dev, MSG_SIMPLE_TAG);
749 		scsi_activate_tcq(scsi_dev, SAS_DEF_QD);
750 	} else {
751 		SAS_DPRINTK("device %llx, LUN %x doesn't support "
752 			    "TCQ\n", SAS_ADDR(dev->sas_addr),
753 			    scsi_dev->lun);
754 		scsi_dev->tagged_supported = 0;
755 		scsi_set_tag_type(scsi_dev, 0);
756 		scsi_deactivate_tcq(scsi_dev, 1);
757 	}
758 
759 	scsi_dev->allow_restart = 1;
760 
761 	return 0;
762 }
763 
764 void sas_slave_destroy(struct scsi_device *scsi_dev)
765 {
766 }
767 
768 int sas_change_queue_depth(struct scsi_device *scsi_dev, int new_depth)
769 {
770 	int res = min(new_depth, SAS_MAX_QD);
771 
772 	if (scsi_dev->tagged_supported)
773 		scsi_adjust_queue_depth(scsi_dev, scsi_get_tag_type(scsi_dev),
774 					res);
775 	else {
776 		struct domain_device *dev = sdev_to_domain_dev(scsi_dev);
777 		sas_printk("device %llx LUN %x queue depth changed to 1\n",
778 			   SAS_ADDR(dev->sas_addr),
779 			   scsi_dev->lun);
780 		scsi_adjust_queue_depth(scsi_dev, 0, 1);
781 		res = 1;
782 	}
783 
784 	return res;
785 }
786 
787 int sas_change_queue_type(struct scsi_device *scsi_dev, int qt)
788 {
789 	if (!scsi_dev->tagged_supported)
790 		return 0;
791 
792 	scsi_deactivate_tcq(scsi_dev, 1);
793 
794 	scsi_set_tag_type(scsi_dev, qt);
795 	scsi_activate_tcq(scsi_dev, scsi_dev->queue_depth);
796 
797 	return qt;
798 }
799 
800 int sas_bios_param(struct scsi_device *scsi_dev,
801 			  struct block_device *bdev,
802 			  sector_t capacity, int *hsc)
803 {
804 	hsc[0] = 255;
805 	hsc[1] = 63;
806 	sector_div(capacity, 255*63);
807 	hsc[2] = capacity;
808 
809 	return 0;
810 }
811 
812 /* ---------- Task Collector Thread implementation ---------- */
813 
814 static void sas_queue(struct sas_ha_struct *sas_ha)
815 {
816 	struct scsi_core *core = &sas_ha->core;
817 	unsigned long flags;
818 	LIST_HEAD(q);
819 	int can_queue;
820 	int res;
821 	struct sas_internal *i = to_sas_internal(core->shost->transportt);
822 
823 	spin_lock_irqsave(&core->task_queue_lock, flags);
824 	while (!kthread_should_stop() &&
825 	       !list_empty(&core->task_queue)) {
826 
827 		can_queue = sas_ha->lldd_queue_size - core->task_queue_size;
828 		if (can_queue >= 0) {
829 			can_queue = core->task_queue_size;
830 			list_splice_init(&core->task_queue, &q);
831 		} else {
832 			struct list_head *a, *n;
833 
834 			can_queue = sas_ha->lldd_queue_size;
835 			list_for_each_safe(a, n, &core->task_queue) {
836 				list_move_tail(a, &q);
837 				if (--can_queue == 0)
838 					break;
839 			}
840 			can_queue = sas_ha->lldd_queue_size;
841 		}
842 		core->task_queue_size -= can_queue;
843 		spin_unlock_irqrestore(&core->task_queue_lock, flags);
844 		{
845 			struct sas_task *task = list_entry(q.next,
846 							   struct sas_task,
847 							   list);
848 			list_del_init(&q);
849 			res = i->dft->lldd_execute_task(task, can_queue,
850 							GFP_KERNEL);
851 			if (unlikely(res))
852 				__list_add(&q, task->list.prev, &task->list);
853 		}
854 		spin_lock_irqsave(&core->task_queue_lock, flags);
855 		if (res) {
856 			list_splice_init(&q, &core->task_queue); /*at head*/
857 			core->task_queue_size += can_queue;
858 		}
859 	}
860 	spin_unlock_irqrestore(&core->task_queue_lock, flags);
861 }
862 
863 /**
864  * sas_queue_thread -- The Task Collector thread
865  * @_sas_ha: pointer to struct sas_ha
866  */
867 static int sas_queue_thread(void *_sas_ha)
868 {
869 	struct sas_ha_struct *sas_ha = _sas_ha;
870 
871 	current->flags |= PF_NOFREEZE;
872 
873 	while (1) {
874 		set_current_state(TASK_INTERRUPTIBLE);
875 		schedule();
876 		sas_queue(sas_ha);
877 		if (kthread_should_stop())
878 			break;
879 	}
880 
881 	return 0;
882 }
883 
884 int sas_init_queue(struct sas_ha_struct *sas_ha)
885 {
886 	struct scsi_core *core = &sas_ha->core;
887 
888 	spin_lock_init(&core->task_queue_lock);
889 	core->task_queue_size = 0;
890 	INIT_LIST_HEAD(&core->task_queue);
891 
892 	core->queue_thread = kthread_run(sas_queue_thread, sas_ha,
893 					 "sas_queue_%d", core->shost->host_no);
894 	if (IS_ERR(core->queue_thread))
895 		return PTR_ERR(core->queue_thread);
896 	return 0;
897 }
898 
899 void sas_shutdown_queue(struct sas_ha_struct *sas_ha)
900 {
901 	unsigned long flags;
902 	struct scsi_core *core = &sas_ha->core;
903 	struct sas_task *task, *n;
904 
905 	kthread_stop(core->queue_thread);
906 
907 	if (!list_empty(&core->task_queue))
908 		SAS_DPRINTK("HA: %llx: scsi core task queue is NOT empty!?\n",
909 			    SAS_ADDR(sas_ha->sas_addr));
910 
911 	spin_lock_irqsave(&core->task_queue_lock, flags);
912 	list_for_each_entry_safe(task, n, &core->task_queue, list) {
913 		struct scsi_cmnd *cmd = task->uldd_task;
914 
915 		list_del_init(&task->list);
916 
917 		ASSIGN_SAS_TASK(cmd, NULL);
918 		sas_free_task(task);
919 		cmd->result = DID_ABORT << 16;
920 		cmd->scsi_done(cmd);
921 	}
922 	spin_unlock_irqrestore(&core->task_queue_lock, flags);
923 }
924 
925 /*
926  * Call the LLDD task abort routine directly.  This function is intended for
927  * use by upper layers that need to tell the LLDD to abort a task.
928  */
929 int __sas_task_abort(struct sas_task *task)
930 {
931 	struct sas_internal *si =
932 		to_sas_internal(task->dev->port->ha->core.shost->transportt);
933 	unsigned long flags;
934 	int res;
935 
936 	spin_lock_irqsave(&task->task_state_lock, flags);
937 	if (task->task_state_flags & SAS_TASK_STATE_ABORTED ||
938 	    task->task_state_flags & SAS_TASK_STATE_DONE) {
939 		spin_unlock_irqrestore(&task->task_state_lock, flags);
940 		SAS_DPRINTK("%s: Task %p already finished.\n", __FUNCTION__,
941 			    task);
942 		return 0;
943 	}
944 	task->task_state_flags |= SAS_TASK_STATE_ABORTED;
945 	spin_unlock_irqrestore(&task->task_state_lock, flags);
946 
947 	if (!si->dft->lldd_abort_task)
948 		return -ENODEV;
949 
950 	res = si->dft->lldd_abort_task(task);
951 
952 	spin_lock_irqsave(&task->task_state_lock, flags);
953 	if ((task->task_state_flags & SAS_TASK_STATE_DONE) ||
954 	    (res == TMF_RESP_FUNC_COMPLETE))
955 	{
956 		spin_unlock_irqrestore(&task->task_state_lock, flags);
957 		task->task_done(task);
958 		return 0;
959 	}
960 
961 	if (!(task->task_state_flags & SAS_TASK_STATE_DONE))
962 		task->task_state_flags &= ~SAS_TASK_STATE_ABORTED;
963 	spin_unlock_irqrestore(&task->task_state_lock, flags);
964 
965 	return -EAGAIN;
966 }
967 
968 /*
969  * Tell an upper layer that it needs to initiate an abort for a given task.
970  * This should only ever be called by an LLDD.
971  */
972 void sas_task_abort(struct sas_task *task)
973 {
974 	struct scsi_cmnd *sc = task->uldd_task;
975 
976 	/* Escape for libsas internal commands */
977 	if (!sc) {
978 		if (!del_timer(&task->timer))
979 			return;
980 		task->timer.function(task->timer.data);
981 		return;
982 	}
983 
984 	scsi_req_abort_cmd(sc);
985 	scsi_schedule_eh(sc->device->host);
986 }
987 
988 EXPORT_SYMBOL_GPL(sas_queuecommand);
989 EXPORT_SYMBOL_GPL(sas_target_alloc);
990 EXPORT_SYMBOL_GPL(sas_slave_configure);
991 EXPORT_SYMBOL_GPL(sas_slave_destroy);
992 EXPORT_SYMBOL_GPL(sas_change_queue_depth);
993 EXPORT_SYMBOL_GPL(sas_change_queue_type);
994 EXPORT_SYMBOL_GPL(sas_bios_param);
995 EXPORT_SYMBOL_GPL(__sas_task_abort);
996 EXPORT_SYMBOL_GPL(sas_task_abort);
997 EXPORT_SYMBOL_GPL(sas_phy_reset);
998 EXPORT_SYMBOL_GPL(sas_phy_enable);
999 EXPORT_SYMBOL_GPL(sas_eh_device_reset_handler);
1000 EXPORT_SYMBOL_GPL(sas_eh_bus_reset_handler);
1001