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_ata.h>
38 #include "../scsi_sas_internal.h"
39 #include "../scsi_transport_api.h"
40 #include "../scsi_priv.h"
41 
42 #include <linux/err.h>
43 #include <linux/blkdev.h>
44 #include <linux/freezer.h>
45 #include <linux/scatterlist.h>
46 #include <linux/libata.h>
47 
48 /* ---------- SCSI Host glue ---------- */
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 			scsi_set_resid(sc, ts->residual);
80 			if (scsi_bufflen(sc) - scsi_get_resid(sc) < 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 = scsi_sglist(cmd);
165 	task->num_scatter = scsi_sg_count(cmd);
166 	task->total_xfer_len = scsi_bufflen(cmd);
167 	task->data_dir = cmd->sc_data_direction;
168 
169 	task->task_done = sas_scsi_task_done;
170 
171 	return task;
172 }
173 
174 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 		if (dev_is_sata(dev)) {
216 			unsigned long flags;
217 
218 			spin_lock_irqsave(dev->sata_dev.ap->lock, flags);
219 			res = ata_sas_queuecmd(cmd, scsi_done,
220 					       dev->sata_dev.ap);
221 			spin_unlock_irqrestore(dev->sata_dev.ap->lock, flags);
222 			goto out;
223 		}
224 
225 		res = -ENOMEM;
226 		task = sas_create_task(cmd, dev, GFP_ATOMIC);
227 		if (!task)
228 			goto out;
229 
230 		cmd->scsi_done = scsi_done;
231 		/* Queue up, Direct Mode or Task Collector Mode. */
232 		if (sas_ha->lldd_max_execute_num < 2)
233 			res = i->dft->lldd_execute_task(task, 1, GFP_ATOMIC);
234 		else
235 			res = sas_queue_up(task);
236 
237 		/* Examine */
238 		if (res) {
239 			SAS_DPRINTK("lldd_execute_task returned: %d\n", res);
240 			ASSIGN_SAS_TASK(cmd, NULL);
241 			sas_free_task(task);
242 			if (res == -SAS_QUEUE_FULL) {
243 				cmd->result = DID_SOFT_ERROR << 16; /* retry */
244 				res = 0;
245 				scsi_done(cmd);
246 			}
247 			goto out;
248 		}
249 	}
250 out:
251 	spin_lock_irq(host->host_lock);
252 	return res;
253 }
254 
255 static void sas_scsi_clear_queue_lu(struct list_head *error_q, struct scsi_cmnd *my_cmd)
256 {
257 	struct scsi_cmnd *cmd, *n;
258 
259 	list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
260 		if (cmd == my_cmd)
261 			list_del_init(&cmd->eh_entry);
262 	}
263 }
264 
265 static void sas_scsi_clear_queue_I_T(struct list_head *error_q,
266 				     struct domain_device *dev)
267 {
268 	struct scsi_cmnd *cmd, *n;
269 
270 	list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
271 		struct domain_device *x = cmd_to_domain_dev(cmd);
272 
273 		if (x == dev)
274 			list_del_init(&cmd->eh_entry);
275 	}
276 }
277 
278 static void sas_scsi_clear_queue_port(struct list_head *error_q,
279 				      struct asd_sas_port *port)
280 {
281 	struct scsi_cmnd *cmd, *n;
282 
283 	list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
284 		struct domain_device *dev = cmd_to_domain_dev(cmd);
285 		struct asd_sas_port *x = dev->port;
286 
287 		if (x == port)
288 			list_del_init(&cmd->eh_entry);
289 	}
290 }
291 
292 enum task_disposition {
293 	TASK_IS_DONE,
294 	TASK_IS_ABORTED,
295 	TASK_IS_AT_LU,
296 	TASK_IS_NOT_AT_LU,
297 	TASK_ABORT_FAILED,
298 };
299 
300 static enum task_disposition sas_scsi_find_task(struct sas_task *task)
301 {
302 	struct sas_ha_struct *ha = task->dev->port->ha;
303 	unsigned long flags;
304 	int i, res;
305 	struct sas_internal *si =
306 		to_sas_internal(task->dev->port->ha->core.shost->transportt);
307 
308 	if (ha->lldd_max_execute_num > 1) {
309 		struct scsi_core *core = &ha->core;
310 		struct sas_task *t, *n;
311 
312 		spin_lock_irqsave(&core->task_queue_lock, flags);
313 		list_for_each_entry_safe(t, n, &core->task_queue, list) {
314 			if (task == t) {
315 				list_del_init(&t->list);
316 				spin_unlock_irqrestore(&core->task_queue_lock,
317 						       flags);
318 				SAS_DPRINTK("%s: task 0x%p aborted from "
319 					    "task_queue\n",
320 					    __FUNCTION__, task);
321 				return TASK_IS_ABORTED;
322 			}
323 		}
324 		spin_unlock_irqrestore(&core->task_queue_lock, flags);
325 	}
326 
327 	for (i = 0; i < 5; i++) {
328 		SAS_DPRINTK("%s: aborting task 0x%p\n", __FUNCTION__, task);
329 		res = si->dft->lldd_abort_task(task);
330 
331 		spin_lock_irqsave(&task->task_state_lock, flags);
332 		if (task->task_state_flags & SAS_TASK_STATE_DONE) {
333 			spin_unlock_irqrestore(&task->task_state_lock, flags);
334 			SAS_DPRINTK("%s: task 0x%p is done\n", __FUNCTION__,
335 				    task);
336 			return TASK_IS_DONE;
337 		}
338 		spin_unlock_irqrestore(&task->task_state_lock, flags);
339 
340 		if (res == TMF_RESP_FUNC_COMPLETE) {
341 			SAS_DPRINTK("%s: task 0x%p is aborted\n",
342 				    __FUNCTION__, task);
343 			return TASK_IS_ABORTED;
344 		} else if (si->dft->lldd_query_task) {
345 			SAS_DPRINTK("%s: querying task 0x%p\n",
346 				    __FUNCTION__, task);
347 			res = si->dft->lldd_query_task(task);
348 			switch (res) {
349 			case TMF_RESP_FUNC_SUCC:
350 				SAS_DPRINTK("%s: task 0x%p at LU\n",
351 					    __FUNCTION__, task);
352 				return TASK_IS_AT_LU;
353 			case TMF_RESP_FUNC_COMPLETE:
354 				SAS_DPRINTK("%s: task 0x%p not at LU\n",
355 					    __FUNCTION__, task);
356 				return TASK_IS_NOT_AT_LU;
357 			case TMF_RESP_FUNC_FAILED:
358                                 SAS_DPRINTK("%s: task 0x%p failed to abort\n",
359                                                 __FUNCTION__, task);
360                                 return TASK_ABORT_FAILED;
361                         }
362 
363 		}
364 	}
365 	return res;
366 }
367 
368 static int sas_recover_lu(struct domain_device *dev, struct scsi_cmnd *cmd)
369 {
370 	int res = TMF_RESP_FUNC_FAILED;
371 	struct scsi_lun lun;
372 	struct sas_internal *i =
373 		to_sas_internal(dev->port->ha->core.shost->transportt);
374 
375 	int_to_scsilun(cmd->device->lun, &lun);
376 
377 	SAS_DPRINTK("eh: device %llx LUN %x has the task\n",
378 		    SAS_ADDR(dev->sas_addr),
379 		    cmd->device->lun);
380 
381 	if (i->dft->lldd_abort_task_set)
382 		res = i->dft->lldd_abort_task_set(dev, lun.scsi_lun);
383 
384 	if (res == TMF_RESP_FUNC_FAILED) {
385 		if (i->dft->lldd_clear_task_set)
386 			res = i->dft->lldd_clear_task_set(dev, lun.scsi_lun);
387 	}
388 
389 	if (res == TMF_RESP_FUNC_FAILED) {
390 		if (i->dft->lldd_lu_reset)
391 			res = i->dft->lldd_lu_reset(dev, lun.scsi_lun);
392 	}
393 
394 	return res;
395 }
396 
397 static int sas_recover_I_T(struct domain_device *dev)
398 {
399 	int res = TMF_RESP_FUNC_FAILED;
400 	struct sas_internal *i =
401 		to_sas_internal(dev->port->ha->core.shost->transportt);
402 
403 	SAS_DPRINTK("I_T nexus reset for dev %016llx\n",
404 		    SAS_ADDR(dev->sas_addr));
405 
406 	if (i->dft->lldd_I_T_nexus_reset)
407 		res = i->dft->lldd_I_T_nexus_reset(dev);
408 
409 	return res;
410 }
411 
412 /* Find the sas_phy that's attached to this device */
413 struct sas_phy *find_local_sas_phy(struct domain_device *dev)
414 {
415 	struct domain_device *pdev = dev->parent;
416 	struct ex_phy *exphy = NULL;
417 	int i;
418 
419 	/* Directly attached device */
420 	if (!pdev)
421 		return dev->port->phy;
422 
423 	/* Otherwise look in the expander */
424 	for (i = 0; i < pdev->ex_dev.num_phys; i++)
425 		if (!memcmp(dev->sas_addr,
426 			    pdev->ex_dev.ex_phy[i].attached_sas_addr,
427 			    SAS_ADDR_SIZE)) {
428 			exphy = &pdev->ex_dev.ex_phy[i];
429 			break;
430 		}
431 
432 	BUG_ON(!exphy);
433 	return exphy->phy;
434 }
435 
436 /* Attempt to send a LUN reset message to a device */
437 int sas_eh_device_reset_handler(struct scsi_cmnd *cmd)
438 {
439 	struct domain_device *dev = cmd_to_domain_dev(cmd);
440 	struct sas_internal *i =
441 		to_sas_internal(dev->port->ha->core.shost->transportt);
442 	struct scsi_lun lun;
443 	int res;
444 
445 	int_to_scsilun(cmd->device->lun, &lun);
446 
447 	if (!i->dft->lldd_lu_reset)
448 		return FAILED;
449 
450 	res = i->dft->lldd_lu_reset(dev, lun.scsi_lun);
451 	if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE)
452 		return SUCCESS;
453 
454 	return FAILED;
455 }
456 
457 /* Attempt to send a phy (bus) reset */
458 int sas_eh_bus_reset_handler(struct scsi_cmnd *cmd)
459 {
460 	struct domain_device *dev = cmd_to_domain_dev(cmd);
461 	struct sas_phy *phy = find_local_sas_phy(dev);
462 	int res;
463 
464 	res = sas_phy_reset(phy, 1);
465 	if (res)
466 		SAS_DPRINTK("Bus reset of %s failed 0x%x\n",
467 			    phy->dev.kobj.k_name,
468 			    res);
469 	if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE)
470 		return SUCCESS;
471 
472 	return FAILED;
473 }
474 
475 /* Try to reset a device */
476 static int try_to_reset_cmd_device(struct Scsi_Host *shost,
477 				   struct scsi_cmnd *cmd)
478 {
479 	int res;
480 
481 	if (!shost->hostt->eh_device_reset_handler)
482 		goto try_bus_reset;
483 
484 	res = shost->hostt->eh_device_reset_handler(cmd);
485 	if (res == SUCCESS)
486 		return res;
487 
488 try_bus_reset:
489 	if (shost->hostt->eh_bus_reset_handler)
490 		return shost->hostt->eh_bus_reset_handler(cmd);
491 
492 	return FAILED;
493 }
494 
495 static int sas_eh_handle_sas_errors(struct Scsi_Host *shost,
496 				    struct list_head *work_q,
497 				    struct list_head *done_q)
498 {
499 	struct scsi_cmnd *cmd, *n;
500 	enum task_disposition res = TASK_IS_DONE;
501 	int tmf_resp, need_reset;
502 	struct sas_internal *i = to_sas_internal(shost->transportt);
503 	unsigned long flags;
504 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
505 
506 Again:
507 	list_for_each_entry_safe(cmd, n, work_q, eh_entry) {
508 		struct sas_task *task = TO_SAS_TASK(cmd);
509 
510 		if (!task)
511 			continue;
512 
513 		list_del_init(&cmd->eh_entry);
514 
515 		spin_lock_irqsave(&task->task_state_lock, flags);
516 		need_reset = task->task_state_flags & SAS_TASK_NEED_DEV_RESET;
517 		spin_unlock_irqrestore(&task->task_state_lock, flags);
518 
519 		SAS_DPRINTK("trying to find task 0x%p\n", task);
520 		res = sas_scsi_find_task(task);
521 
522 		cmd->eh_eflags = 0;
523 
524 		switch (res) {
525 		case TASK_IS_DONE:
526 			SAS_DPRINTK("%s: task 0x%p is done\n", __FUNCTION__,
527 				    task);
528 			task->task_done(task);
529 			if (need_reset)
530 				try_to_reset_cmd_device(shost, cmd);
531 			continue;
532 		case TASK_IS_ABORTED:
533 			SAS_DPRINTK("%s: task 0x%p is aborted\n",
534 				    __FUNCTION__, task);
535 			task->task_done(task);
536 			if (need_reset)
537 				try_to_reset_cmd_device(shost, cmd);
538 			continue;
539 		case TASK_IS_AT_LU:
540 			SAS_DPRINTK("task 0x%p is at LU: lu recover\n", task);
541 			tmf_resp = sas_recover_lu(task->dev, cmd);
542 			if (tmf_resp == TMF_RESP_FUNC_COMPLETE) {
543 				SAS_DPRINTK("dev %016llx LU %x is "
544 					    "recovered\n",
545 					    SAS_ADDR(task->dev),
546 					    cmd->device->lun);
547 				task->task_done(task);
548 				if (need_reset)
549 					try_to_reset_cmd_device(shost, cmd);
550 				sas_scsi_clear_queue_lu(work_q, cmd);
551 				goto Again;
552 			}
553 			/* fallthrough */
554 		case TASK_IS_NOT_AT_LU:
555 		case TASK_ABORT_FAILED:
556 			SAS_DPRINTK("task 0x%p is not at LU: I_T recover\n",
557 				    task);
558 			tmf_resp = sas_recover_I_T(task->dev);
559 			if (tmf_resp == TMF_RESP_FUNC_COMPLETE) {
560 				SAS_DPRINTK("I_T %016llx recovered\n",
561 					    SAS_ADDR(task->dev->sas_addr));
562 				task->task_done(task);
563 				if (need_reset)
564 					try_to_reset_cmd_device(shost, cmd);
565 				sas_scsi_clear_queue_I_T(work_q, task->dev);
566 				goto Again;
567 			}
568 			/* Hammer time :-) */
569 			if (i->dft->lldd_clear_nexus_port) {
570 				struct asd_sas_port *port = task->dev->port;
571 				SAS_DPRINTK("clearing nexus for port:%d\n",
572 					    port->id);
573 				res = i->dft->lldd_clear_nexus_port(port);
574 				if (res == TMF_RESP_FUNC_COMPLETE) {
575 					SAS_DPRINTK("clear nexus port:%d "
576 						    "succeeded\n", port->id);
577 					task->task_done(task);
578 					if (need_reset)
579 						try_to_reset_cmd_device(shost, cmd);
580 					sas_scsi_clear_queue_port(work_q,
581 								  port);
582 					goto Again;
583 				}
584 			}
585 			if (i->dft->lldd_clear_nexus_ha) {
586 				SAS_DPRINTK("clear nexus ha\n");
587 				res = i->dft->lldd_clear_nexus_ha(ha);
588 				if (res == TMF_RESP_FUNC_COMPLETE) {
589 					SAS_DPRINTK("clear nexus ha "
590 						    "succeeded\n");
591 					task->task_done(task);
592 					if (need_reset)
593 						try_to_reset_cmd_device(shost, cmd);
594 					goto out;
595 				}
596 			}
597 			/* If we are here -- this means that no amount
598 			 * of effort could recover from errors.  Quite
599 			 * possibly the HA just disappeared.
600 			 */
601 			SAS_DPRINTK("error from  device %llx, LUN %x "
602 				    "couldn't be recovered in any way\n",
603 				    SAS_ADDR(task->dev->sas_addr),
604 				    cmd->device->lun);
605 
606 			task->task_done(task);
607 			if (need_reset)
608 				try_to_reset_cmd_device(shost, cmd);
609 			goto clear_q;
610 		}
611 	}
612 out:
613 	return list_empty(work_q);
614 clear_q:
615 	SAS_DPRINTK("--- Exit %s -- clear_q\n", __FUNCTION__);
616 	list_for_each_entry_safe(cmd, n, work_q, eh_entry) {
617 		struct sas_task *task = TO_SAS_TASK(cmd);
618 		list_del_init(&cmd->eh_entry);
619 		task->task_done(task);
620 	}
621 	return list_empty(work_q);
622 }
623 
624 void sas_scsi_recover_host(struct Scsi_Host *shost)
625 {
626 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
627 	unsigned long flags;
628 	LIST_HEAD(eh_work_q);
629 
630 	spin_lock_irqsave(shost->host_lock, flags);
631 	list_splice_init(&shost->eh_cmd_q, &eh_work_q);
632 	spin_unlock_irqrestore(shost->host_lock, flags);
633 
634 	SAS_DPRINTK("Enter %s\n", __FUNCTION__);
635 	/*
636 	 * Deal with commands that still have SAS tasks (i.e. they didn't
637 	 * complete via the normal sas_task completion mechanism)
638 	 */
639 	if (sas_eh_handle_sas_errors(shost, &eh_work_q, &ha->eh_done_q))
640 		goto out;
641 
642 	/*
643 	 * Now deal with SCSI commands that completed ok but have a an error
644 	 * code (and hopefully sense data) attached.  This is roughly what
645 	 * scsi_unjam_host does, but we skip scsi_eh_abort_cmds because any
646 	 * command we see here has no sas_task and is thus unknown to the HA.
647 	 */
648 	if (!scsi_eh_get_sense(&eh_work_q, &ha->eh_done_q))
649 		scsi_eh_ready_devs(shost, &eh_work_q, &ha->eh_done_q);
650 
651 out:
652 	scsi_eh_flush_done_q(&ha->eh_done_q);
653 	SAS_DPRINTK("--- Exit %s\n", __FUNCTION__);
654 	return;
655 }
656 
657 enum scsi_eh_timer_return sas_scsi_timed_out(struct scsi_cmnd *cmd)
658 {
659 	struct sas_task *task = TO_SAS_TASK(cmd);
660 	unsigned long flags;
661 
662 	if (!task) {
663 		cmd->timeout_per_command /= 2;
664 		SAS_DPRINTK("command 0x%p, task 0x%p, gone: %s\n",
665 			    cmd, task, (cmd->timeout_per_command ?
666 			    "EH_RESET_TIMER" : "EH_NOT_HANDLED"));
667 		if (!cmd->timeout_per_command)
668 			return EH_NOT_HANDLED;
669 		return EH_RESET_TIMER;
670 	}
671 
672 	spin_lock_irqsave(&task->task_state_lock, flags);
673 	BUG_ON(task->task_state_flags & SAS_TASK_STATE_ABORTED);
674 	if (task->task_state_flags & SAS_TASK_STATE_DONE) {
675 		spin_unlock_irqrestore(&task->task_state_lock, flags);
676 		SAS_DPRINTK("command 0x%p, task 0x%p, timed out: EH_HANDLED\n",
677 			    cmd, task);
678 		return EH_HANDLED;
679 	}
680 	if (!(task->task_state_flags & SAS_TASK_AT_INITIATOR)) {
681 		spin_unlock_irqrestore(&task->task_state_lock, flags);
682 		SAS_DPRINTK("command 0x%p, task 0x%p, not at initiator: "
683 			    "EH_RESET_TIMER\n",
684 			    cmd, task);
685 		return EH_RESET_TIMER;
686 	}
687 	task->task_state_flags |= SAS_TASK_STATE_ABORTED;
688 	spin_unlock_irqrestore(&task->task_state_lock, flags);
689 
690 	SAS_DPRINTK("command 0x%p, task 0x%p, timed out: EH_NOT_HANDLED\n",
691 		    cmd, task);
692 
693 	return EH_NOT_HANDLED;
694 }
695 
696 int sas_ioctl(struct scsi_device *sdev, int cmd, void __user *arg)
697 {
698 	struct domain_device *dev = sdev_to_domain_dev(sdev);
699 
700 	if (dev_is_sata(dev))
701 		return ata_scsi_ioctl(sdev, cmd, arg);
702 
703 	return -EINVAL;
704 }
705 
706 struct domain_device *sas_find_dev_by_rphy(struct sas_rphy *rphy)
707 {
708 	struct Scsi_Host *shost = dev_to_shost(rphy->dev.parent);
709 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
710 	struct domain_device *found_dev = NULL;
711 	int i;
712 	unsigned long flags;
713 
714 	spin_lock_irqsave(&ha->phy_port_lock, flags);
715 	for (i = 0; i < ha->num_phys; i++) {
716 		struct asd_sas_port *port = ha->sas_port[i];
717 		struct domain_device *dev;
718 
719 		spin_lock(&port->dev_list_lock);
720 		list_for_each_entry(dev, &port->dev_list, dev_list_node) {
721 			if (rphy == dev->rphy) {
722 				found_dev = dev;
723 				spin_unlock(&port->dev_list_lock);
724 				goto found;
725 			}
726 		}
727 		spin_unlock(&port->dev_list_lock);
728 	}
729  found:
730 	spin_unlock_irqrestore(&ha->phy_port_lock, flags);
731 
732 	return found_dev;
733 }
734 
735 static inline struct domain_device *sas_find_target(struct scsi_target *starget)
736 {
737 	struct sas_rphy *rphy = dev_to_rphy(starget->dev.parent);
738 
739 	return sas_find_dev_by_rphy(rphy);
740 }
741 
742 int sas_target_alloc(struct scsi_target *starget)
743 {
744 	struct domain_device *found_dev = sas_find_target(starget);
745 	int res;
746 
747 	if (!found_dev)
748 		return -ENODEV;
749 
750 	if (dev_is_sata(found_dev)) {
751 		res = sas_ata_init_host_and_port(found_dev, starget);
752 		if (res)
753 			return res;
754 	}
755 
756 	starget->hostdata = found_dev;
757 	return 0;
758 }
759 
760 #define SAS_DEF_QD 32
761 #define SAS_MAX_QD 64
762 
763 int sas_slave_configure(struct scsi_device *scsi_dev)
764 {
765 	struct domain_device *dev = sdev_to_domain_dev(scsi_dev);
766 	struct sas_ha_struct *sas_ha;
767 
768 	BUG_ON(dev->rphy->identify.device_type != SAS_END_DEVICE);
769 
770 	if (dev_is_sata(dev)) {
771 		ata_sas_slave_configure(scsi_dev, dev->sata_dev.ap);
772 		return 0;
773 	}
774 
775 	sas_ha = dev->port->ha;
776 
777 	sas_read_port_mode_page(scsi_dev);
778 
779 	if (scsi_dev->tagged_supported) {
780 		scsi_set_tag_type(scsi_dev, MSG_SIMPLE_TAG);
781 		scsi_activate_tcq(scsi_dev, SAS_DEF_QD);
782 	} else {
783 		SAS_DPRINTK("device %llx, LUN %x doesn't support "
784 			    "TCQ\n", SAS_ADDR(dev->sas_addr),
785 			    scsi_dev->lun);
786 		scsi_dev->tagged_supported = 0;
787 		scsi_set_tag_type(scsi_dev, 0);
788 		scsi_deactivate_tcq(scsi_dev, 1);
789 	}
790 
791 	scsi_dev->allow_restart = 1;
792 
793 	return 0;
794 }
795 
796 void sas_slave_destroy(struct scsi_device *scsi_dev)
797 {
798 	struct domain_device *dev = sdev_to_domain_dev(scsi_dev);
799 
800 	if (dev_is_sata(dev))
801 		ata_port_disable(dev->sata_dev.ap);
802 }
803 
804 int sas_change_queue_depth(struct scsi_device *scsi_dev, int new_depth)
805 {
806 	int res = min(new_depth, SAS_MAX_QD);
807 
808 	if (scsi_dev->tagged_supported)
809 		scsi_adjust_queue_depth(scsi_dev, scsi_get_tag_type(scsi_dev),
810 					res);
811 	else {
812 		struct domain_device *dev = sdev_to_domain_dev(scsi_dev);
813 		sas_printk("device %llx LUN %x queue depth changed to 1\n",
814 			   SAS_ADDR(dev->sas_addr),
815 			   scsi_dev->lun);
816 		scsi_adjust_queue_depth(scsi_dev, 0, 1);
817 		res = 1;
818 	}
819 
820 	return res;
821 }
822 
823 int sas_change_queue_type(struct scsi_device *scsi_dev, int qt)
824 {
825 	if (!scsi_dev->tagged_supported)
826 		return 0;
827 
828 	scsi_deactivate_tcq(scsi_dev, 1);
829 
830 	scsi_set_tag_type(scsi_dev, qt);
831 	scsi_activate_tcq(scsi_dev, scsi_dev->queue_depth);
832 
833 	return qt;
834 }
835 
836 int sas_bios_param(struct scsi_device *scsi_dev,
837 			  struct block_device *bdev,
838 			  sector_t capacity, int *hsc)
839 {
840 	hsc[0] = 255;
841 	hsc[1] = 63;
842 	sector_div(capacity, 255*63);
843 	hsc[2] = capacity;
844 
845 	return 0;
846 }
847 
848 /* ---------- Task Collector Thread implementation ---------- */
849 
850 static void sas_queue(struct sas_ha_struct *sas_ha)
851 {
852 	struct scsi_core *core = &sas_ha->core;
853 	unsigned long flags;
854 	LIST_HEAD(q);
855 	int can_queue;
856 	int res;
857 	struct sas_internal *i = to_sas_internal(core->shost->transportt);
858 
859 	spin_lock_irqsave(&core->task_queue_lock, flags);
860 	while (!kthread_should_stop() &&
861 	       !list_empty(&core->task_queue)) {
862 
863 		can_queue = sas_ha->lldd_queue_size - core->task_queue_size;
864 		if (can_queue >= 0) {
865 			can_queue = core->task_queue_size;
866 			list_splice_init(&core->task_queue, &q);
867 		} else {
868 			struct list_head *a, *n;
869 
870 			can_queue = sas_ha->lldd_queue_size;
871 			list_for_each_safe(a, n, &core->task_queue) {
872 				list_move_tail(a, &q);
873 				if (--can_queue == 0)
874 					break;
875 			}
876 			can_queue = sas_ha->lldd_queue_size;
877 		}
878 		core->task_queue_size -= can_queue;
879 		spin_unlock_irqrestore(&core->task_queue_lock, flags);
880 		{
881 			struct sas_task *task = list_entry(q.next,
882 							   struct sas_task,
883 							   list);
884 			list_del_init(&q);
885 			res = i->dft->lldd_execute_task(task, can_queue,
886 							GFP_KERNEL);
887 			if (unlikely(res))
888 				__list_add(&q, task->list.prev, &task->list);
889 		}
890 		spin_lock_irqsave(&core->task_queue_lock, flags);
891 		if (res) {
892 			list_splice_init(&q, &core->task_queue); /*at head*/
893 			core->task_queue_size += can_queue;
894 		}
895 	}
896 	spin_unlock_irqrestore(&core->task_queue_lock, flags);
897 }
898 
899 /**
900  * sas_queue_thread -- The Task Collector thread
901  * @_sas_ha: pointer to struct sas_ha
902  */
903 static int sas_queue_thread(void *_sas_ha)
904 {
905 	struct sas_ha_struct *sas_ha = _sas_ha;
906 
907 	while (1) {
908 		set_current_state(TASK_INTERRUPTIBLE);
909 		schedule();
910 		sas_queue(sas_ha);
911 		if (kthread_should_stop())
912 			break;
913 	}
914 
915 	return 0;
916 }
917 
918 int sas_init_queue(struct sas_ha_struct *sas_ha)
919 {
920 	struct scsi_core *core = &sas_ha->core;
921 
922 	spin_lock_init(&core->task_queue_lock);
923 	core->task_queue_size = 0;
924 	INIT_LIST_HEAD(&core->task_queue);
925 
926 	core->queue_thread = kthread_run(sas_queue_thread, sas_ha,
927 					 "sas_queue_%d", core->shost->host_no);
928 	if (IS_ERR(core->queue_thread))
929 		return PTR_ERR(core->queue_thread);
930 	return 0;
931 }
932 
933 void sas_shutdown_queue(struct sas_ha_struct *sas_ha)
934 {
935 	unsigned long flags;
936 	struct scsi_core *core = &sas_ha->core;
937 	struct sas_task *task, *n;
938 
939 	kthread_stop(core->queue_thread);
940 
941 	if (!list_empty(&core->task_queue))
942 		SAS_DPRINTK("HA: %llx: scsi core task queue is NOT empty!?\n",
943 			    SAS_ADDR(sas_ha->sas_addr));
944 
945 	spin_lock_irqsave(&core->task_queue_lock, flags);
946 	list_for_each_entry_safe(task, n, &core->task_queue, list) {
947 		struct scsi_cmnd *cmd = task->uldd_task;
948 
949 		list_del_init(&task->list);
950 
951 		ASSIGN_SAS_TASK(cmd, NULL);
952 		sas_free_task(task);
953 		cmd->result = DID_ABORT << 16;
954 		cmd->scsi_done(cmd);
955 	}
956 	spin_unlock_irqrestore(&core->task_queue_lock, flags);
957 }
958 
959 /*
960  * Call the LLDD task abort routine directly.  This function is intended for
961  * use by upper layers that need to tell the LLDD to abort a task.
962  */
963 int __sas_task_abort(struct sas_task *task)
964 {
965 	struct sas_internal *si =
966 		to_sas_internal(task->dev->port->ha->core.shost->transportt);
967 	unsigned long flags;
968 	int res;
969 
970 	spin_lock_irqsave(&task->task_state_lock, flags);
971 	if (task->task_state_flags & SAS_TASK_STATE_ABORTED ||
972 	    task->task_state_flags & SAS_TASK_STATE_DONE) {
973 		spin_unlock_irqrestore(&task->task_state_lock, flags);
974 		SAS_DPRINTK("%s: Task %p already finished.\n", __FUNCTION__,
975 			    task);
976 		return 0;
977 	}
978 	task->task_state_flags |= SAS_TASK_STATE_ABORTED;
979 	spin_unlock_irqrestore(&task->task_state_lock, flags);
980 
981 	if (!si->dft->lldd_abort_task)
982 		return -ENODEV;
983 
984 	res = si->dft->lldd_abort_task(task);
985 
986 	spin_lock_irqsave(&task->task_state_lock, flags);
987 	if ((task->task_state_flags & SAS_TASK_STATE_DONE) ||
988 	    (res == TMF_RESP_FUNC_COMPLETE))
989 	{
990 		spin_unlock_irqrestore(&task->task_state_lock, flags);
991 		task->task_done(task);
992 		return 0;
993 	}
994 
995 	if (!(task->task_state_flags & SAS_TASK_STATE_DONE))
996 		task->task_state_flags &= ~SAS_TASK_STATE_ABORTED;
997 	spin_unlock_irqrestore(&task->task_state_lock, flags);
998 
999 	return -EAGAIN;
1000 }
1001 
1002 /*
1003  * Tell an upper layer that it needs to initiate an abort for a given task.
1004  * This should only ever be called by an LLDD.
1005  */
1006 void sas_task_abort(struct sas_task *task)
1007 {
1008 	struct scsi_cmnd *sc = task->uldd_task;
1009 
1010 	/* Escape for libsas internal commands */
1011 	if (!sc) {
1012 		if (!del_timer(&task->timer))
1013 			return;
1014 		task->timer.function(task->timer.data);
1015 		return;
1016 	}
1017 
1018 	if (dev_is_sata(task->dev)) {
1019 		sas_ata_task_abort(task);
1020 		return;
1021 	}
1022 
1023 	scsi_req_abort_cmd(sc);
1024 	scsi_schedule_eh(sc->device->host);
1025 }
1026 
1027 int sas_slave_alloc(struct scsi_device *scsi_dev)
1028 {
1029 	struct domain_device *dev = sdev_to_domain_dev(scsi_dev);
1030 
1031 	if (dev_is_sata(dev))
1032 		return ata_sas_port_init(dev->sata_dev.ap);
1033 
1034 	return 0;
1035 }
1036 
1037 void sas_target_destroy(struct scsi_target *starget)
1038 {
1039 	struct domain_device *found_dev = sas_find_target(starget);
1040 
1041 	if (!found_dev)
1042 		return;
1043 
1044 	if (dev_is_sata(found_dev))
1045 		ata_sas_port_destroy(found_dev->sata_dev.ap);
1046 
1047 	return;
1048 }
1049 
1050 EXPORT_SYMBOL_GPL(sas_queuecommand);
1051 EXPORT_SYMBOL_GPL(sas_target_alloc);
1052 EXPORT_SYMBOL_GPL(sas_slave_configure);
1053 EXPORT_SYMBOL_GPL(sas_slave_destroy);
1054 EXPORT_SYMBOL_GPL(sas_change_queue_depth);
1055 EXPORT_SYMBOL_GPL(sas_change_queue_type);
1056 EXPORT_SYMBOL_GPL(sas_bios_param);
1057 EXPORT_SYMBOL_GPL(__sas_task_abort);
1058 EXPORT_SYMBOL_GPL(sas_task_abort);
1059 EXPORT_SYMBOL_GPL(sas_phy_reset);
1060 EXPORT_SYMBOL_GPL(sas_phy_enable);
1061 EXPORT_SYMBOL_GPL(sas_eh_device_reset_handler);
1062 EXPORT_SYMBOL_GPL(sas_eh_bus_reset_handler);
1063 EXPORT_SYMBOL_GPL(sas_slave_alloc);
1064 EXPORT_SYMBOL_GPL(sas_target_destroy);
1065 EXPORT_SYMBOL_GPL(sas_ioctl);
1066