xref: /linux/drivers/ata/libata-eh.c (revision 3eeebf17f31c583f83e081b17b3076477cb96886)
1 /*
2  *  libata-eh.c - libata error handling
3  *
4  *  Maintained by:  Jeff Garzik <jgarzik@pobox.com>
5  *    		    Please ALWAYS copy linux-ide@vger.kernel.org
6  *		    on emails.
7  *
8  *  Copyright 2006 Tejun Heo <htejun@gmail.com>
9  *
10  *
11  *  This program is free software; you can redistribute it and/or
12  *  modify it under the terms of the GNU General Public License as
13  *  published by the Free Software Foundation; either version 2, or
14  *  (at your option) any later version.
15  *
16  *  This program is distributed in the hope that it will be useful,
17  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
18  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
19  *  General Public License for more details.
20  *
21  *  You should have received a copy of the GNU General Public License
22  *  along with this program; see the file COPYING.  If not, write to
23  *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
24  *  USA.
25  *
26  *
27  *  libata documentation is available via 'make {ps|pdf}docs',
28  *  as Documentation/DocBook/libata.*
29  *
30  *  Hardware documentation available from http://www.t13.org/ and
31  *  http://www.sata-io.org/
32  *
33  */
34 
35 #include <linux/kernel.h>
36 #include <linux/blkdev.h>
37 #include <linux/pci.h>
38 #include <scsi/scsi.h>
39 #include <scsi/scsi_host.h>
40 #include <scsi/scsi_eh.h>
41 #include <scsi/scsi_device.h>
42 #include <scsi/scsi_cmnd.h>
43 #include "../scsi/scsi_transport_api.h"
44 
45 #include <linux/libata.h>
46 
47 #include "libata.h"
48 
49 enum {
50 	/* speed down verdicts */
51 	ATA_EH_SPDN_NCQ_OFF		= (1 << 0),
52 	ATA_EH_SPDN_SPEED_DOWN		= (1 << 1),
53 	ATA_EH_SPDN_FALLBACK_TO_PIO	= (1 << 2),
54 	ATA_EH_SPDN_KEEP_ERRORS		= (1 << 3),
55 
56 	/* error flags */
57 	ATA_EFLAG_IS_IO			= (1 << 0),
58 	ATA_EFLAG_DUBIOUS_XFER		= (1 << 1),
59 
60 	/* error categories */
61 	ATA_ECAT_NONE			= 0,
62 	ATA_ECAT_ATA_BUS		= 1,
63 	ATA_ECAT_TOUT_HSM		= 2,
64 	ATA_ECAT_UNK_DEV		= 3,
65 	ATA_ECAT_DUBIOUS_NONE		= 4,
66 	ATA_ECAT_DUBIOUS_ATA_BUS	= 5,
67 	ATA_ECAT_DUBIOUS_TOUT_HSM	= 6,
68 	ATA_ECAT_DUBIOUS_UNK_DEV	= 7,
69 	ATA_ECAT_NR			= 8,
70 
71 	ATA_EH_CMD_DFL_TIMEOUT		=  5000,
72 
73 	/* always put at least this amount of time between resets */
74 	ATA_EH_RESET_COOL_DOWN		=  5000,
75 
76 	/* Waiting in ->prereset can never be reliable.  It's
77 	 * sometimes nice to wait there but it can't be depended upon;
78 	 * otherwise, we wouldn't be resetting.  Just give it enough
79 	 * time for most drives to spin up.
80 	 */
81 	ATA_EH_PRERESET_TIMEOUT		= 10000,
82 	ATA_EH_FASTDRAIN_INTERVAL	=  3000,
83 
84 	ATA_EH_UA_TRIES			= 5,
85 };
86 
87 /* The following table determines how we sequence resets.  Each entry
88  * represents timeout for that try.  The first try can be soft or
89  * hardreset.  All others are hardreset if available.  In most cases
90  * the first reset w/ 10sec timeout should succeed.  Following entries
91  * are mostly for error handling, hotplug and retarded devices.
92  */
93 static const unsigned long ata_eh_reset_timeouts[] = {
94 	10000,	/* most drives spin up by 10sec */
95 	10000,	/* > 99% working drives spin up before 20sec */
96 	35000,	/* give > 30 secs of idleness for retarded devices */
97 	 5000,	/* and sweet one last chance */
98 	ULONG_MAX, /* > 1 min has elapsed, give up */
99 };
100 
101 static const unsigned long ata_eh_identify_timeouts[] = {
102 	 5000,	/* covers > 99% of successes and not too boring on failures */
103 	10000,  /* combined time till here is enough even for media access */
104 	30000,	/* for true idiots */
105 	ULONG_MAX,
106 };
107 
108 static const unsigned long ata_eh_other_timeouts[] = {
109 	 5000,	/* same rationale as identify timeout */
110 	10000,	/* ditto */
111 	/* but no merciful 30sec for other commands, it just isn't worth it */
112 	ULONG_MAX,
113 };
114 
115 struct ata_eh_cmd_timeout_ent {
116 	const u8		*commands;
117 	const unsigned long	*timeouts;
118 };
119 
120 /* The following table determines timeouts to use for EH internal
121  * commands.  Each table entry is a command class and matches the
122  * commands the entry applies to and the timeout table to use.
123  *
124  * On the retry after a command timed out, the next timeout value from
125  * the table is used.  If the table doesn't contain further entries,
126  * the last value is used.
127  *
128  * ehc->cmd_timeout_idx keeps track of which timeout to use per
129  * command class, so if SET_FEATURES times out on the first try, the
130  * next try will use the second timeout value only for that class.
131  */
132 #define CMDS(cmds...)	(const u8 []){ cmds, 0 }
133 static const struct ata_eh_cmd_timeout_ent
134 ata_eh_cmd_timeout_table[ATA_EH_CMD_TIMEOUT_TABLE_SIZE] = {
135 	{ .commands = CMDS(ATA_CMD_ID_ATA, ATA_CMD_ID_ATAPI),
136 	  .timeouts = ata_eh_identify_timeouts, },
137 	{ .commands = CMDS(ATA_CMD_READ_NATIVE_MAX, ATA_CMD_READ_NATIVE_MAX_EXT),
138 	  .timeouts = ata_eh_other_timeouts, },
139 	{ .commands = CMDS(ATA_CMD_SET_MAX, ATA_CMD_SET_MAX_EXT),
140 	  .timeouts = ata_eh_other_timeouts, },
141 	{ .commands = CMDS(ATA_CMD_SET_FEATURES),
142 	  .timeouts = ata_eh_other_timeouts, },
143 	{ .commands = CMDS(ATA_CMD_INIT_DEV_PARAMS),
144 	  .timeouts = ata_eh_other_timeouts, },
145 };
146 #undef CMDS
147 
148 static void __ata_port_freeze(struct ata_port *ap);
149 #ifdef CONFIG_PM
150 static void ata_eh_handle_port_suspend(struct ata_port *ap);
151 static void ata_eh_handle_port_resume(struct ata_port *ap);
152 #else /* CONFIG_PM */
153 static void ata_eh_handle_port_suspend(struct ata_port *ap)
154 { }
155 
156 static void ata_eh_handle_port_resume(struct ata_port *ap)
157 { }
158 #endif /* CONFIG_PM */
159 
160 static void __ata_ehi_pushv_desc(struct ata_eh_info *ehi, const char *fmt,
161 				 va_list args)
162 {
163 	ehi->desc_len += vscnprintf(ehi->desc + ehi->desc_len,
164 				     ATA_EH_DESC_LEN - ehi->desc_len,
165 				     fmt, args);
166 }
167 
168 /**
169  *	__ata_ehi_push_desc - push error description without adding separator
170  *	@ehi: target EHI
171  *	@fmt: printf format string
172  *
173  *	Format string according to @fmt and append it to @ehi->desc.
174  *
175  *	LOCKING:
176  *	spin_lock_irqsave(host lock)
177  */
178 void __ata_ehi_push_desc(struct ata_eh_info *ehi, const char *fmt, ...)
179 {
180 	va_list args;
181 
182 	va_start(args, fmt);
183 	__ata_ehi_pushv_desc(ehi, fmt, args);
184 	va_end(args);
185 }
186 
187 /**
188  *	ata_ehi_push_desc - push error description with separator
189  *	@ehi: target EHI
190  *	@fmt: printf format string
191  *
192  *	Format string according to @fmt and append it to @ehi->desc.
193  *	If @ehi->desc is not empty, ", " is added in-between.
194  *
195  *	LOCKING:
196  *	spin_lock_irqsave(host lock)
197  */
198 void ata_ehi_push_desc(struct ata_eh_info *ehi, const char *fmt, ...)
199 {
200 	va_list args;
201 
202 	if (ehi->desc_len)
203 		__ata_ehi_push_desc(ehi, ", ");
204 
205 	va_start(args, fmt);
206 	__ata_ehi_pushv_desc(ehi, fmt, args);
207 	va_end(args);
208 }
209 
210 /**
211  *	ata_ehi_clear_desc - clean error description
212  *	@ehi: target EHI
213  *
214  *	Clear @ehi->desc.
215  *
216  *	LOCKING:
217  *	spin_lock_irqsave(host lock)
218  */
219 void ata_ehi_clear_desc(struct ata_eh_info *ehi)
220 {
221 	ehi->desc[0] = '\0';
222 	ehi->desc_len = 0;
223 }
224 
225 /**
226  *	ata_port_desc - append port description
227  *	@ap: target ATA port
228  *	@fmt: printf format string
229  *
230  *	Format string according to @fmt and append it to port
231  *	description.  If port description is not empty, " " is added
232  *	in-between.  This function is to be used while initializing
233  *	ata_host.  The description is printed on host registration.
234  *
235  *	LOCKING:
236  *	None.
237  */
238 void ata_port_desc(struct ata_port *ap, const char *fmt, ...)
239 {
240 	va_list args;
241 
242 	WARN_ON(!(ap->pflags & ATA_PFLAG_INITIALIZING));
243 
244 	if (ap->link.eh_info.desc_len)
245 		__ata_ehi_push_desc(&ap->link.eh_info, " ");
246 
247 	va_start(args, fmt);
248 	__ata_ehi_pushv_desc(&ap->link.eh_info, fmt, args);
249 	va_end(args);
250 }
251 
252 #ifdef CONFIG_PCI
253 
254 /**
255  *	ata_port_pbar_desc - append PCI BAR description
256  *	@ap: target ATA port
257  *	@bar: target PCI BAR
258  *	@offset: offset into PCI BAR
259  *	@name: name of the area
260  *
261  *	If @offset is negative, this function formats a string which
262  *	contains the name, address, size and type of the BAR and
263  *	appends it to the port description.  If @offset is zero or
264  *	positive, only name and offsetted address is appended.
265  *
266  *	LOCKING:
267  *	None.
268  */
269 void ata_port_pbar_desc(struct ata_port *ap, int bar, ssize_t offset,
270 			const char *name)
271 {
272 	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
273 	char *type = "";
274 	unsigned long long start, len;
275 
276 	if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM)
277 		type = "m";
278 	else if (pci_resource_flags(pdev, bar) & IORESOURCE_IO)
279 		type = "i";
280 
281 	start = (unsigned long long)pci_resource_start(pdev, bar);
282 	len = (unsigned long long)pci_resource_len(pdev, bar);
283 
284 	if (offset < 0)
285 		ata_port_desc(ap, "%s %s%llu@0x%llx", name, type, len, start);
286 	else
287 		ata_port_desc(ap, "%s 0x%llx", name,
288 				start + (unsigned long long)offset);
289 }
290 
291 #endif /* CONFIG_PCI */
292 
293 static int ata_lookup_timeout_table(u8 cmd)
294 {
295 	int i;
296 
297 	for (i = 0; i < ATA_EH_CMD_TIMEOUT_TABLE_SIZE; i++) {
298 		const u8 *cur;
299 
300 		for (cur = ata_eh_cmd_timeout_table[i].commands; *cur; cur++)
301 			if (*cur == cmd)
302 				return i;
303 	}
304 
305 	return -1;
306 }
307 
308 /**
309  *	ata_internal_cmd_timeout - determine timeout for an internal command
310  *	@dev: target device
311  *	@cmd: internal command to be issued
312  *
313  *	Determine timeout for internal command @cmd for @dev.
314  *
315  *	LOCKING:
316  *	EH context.
317  *
318  *	RETURNS:
319  *	Determined timeout.
320  */
321 unsigned long ata_internal_cmd_timeout(struct ata_device *dev, u8 cmd)
322 {
323 	struct ata_eh_context *ehc = &dev->link->eh_context;
324 	int ent = ata_lookup_timeout_table(cmd);
325 	int idx;
326 
327 	if (ent < 0)
328 		return ATA_EH_CMD_DFL_TIMEOUT;
329 
330 	idx = ehc->cmd_timeout_idx[dev->devno][ent];
331 	return ata_eh_cmd_timeout_table[ent].timeouts[idx];
332 }
333 
334 /**
335  *	ata_internal_cmd_timed_out - notification for internal command timeout
336  *	@dev: target device
337  *	@cmd: internal command which timed out
338  *
339  *	Notify EH that internal command @cmd for @dev timed out.  This
340  *	function should be called only for commands whose timeouts are
341  *	determined using ata_internal_cmd_timeout().
342  *
343  *	LOCKING:
344  *	EH context.
345  */
346 void ata_internal_cmd_timed_out(struct ata_device *dev, u8 cmd)
347 {
348 	struct ata_eh_context *ehc = &dev->link->eh_context;
349 	int ent = ata_lookup_timeout_table(cmd);
350 	int idx;
351 
352 	if (ent < 0)
353 		return;
354 
355 	idx = ehc->cmd_timeout_idx[dev->devno][ent];
356 	if (ata_eh_cmd_timeout_table[ent].timeouts[idx + 1] != ULONG_MAX)
357 		ehc->cmd_timeout_idx[dev->devno][ent]++;
358 }
359 
360 static void ata_ering_record(struct ata_ering *ering, unsigned int eflags,
361 			     unsigned int err_mask)
362 {
363 	struct ata_ering_entry *ent;
364 
365 	WARN_ON(!err_mask);
366 
367 	ering->cursor++;
368 	ering->cursor %= ATA_ERING_SIZE;
369 
370 	ent = &ering->ring[ering->cursor];
371 	ent->eflags = eflags;
372 	ent->err_mask = err_mask;
373 	ent->timestamp = get_jiffies_64();
374 }
375 
376 static struct ata_ering_entry *ata_ering_top(struct ata_ering *ering)
377 {
378 	struct ata_ering_entry *ent = &ering->ring[ering->cursor];
379 
380 	if (ent->err_mask)
381 		return ent;
382 	return NULL;
383 }
384 
385 static void ata_ering_clear(struct ata_ering *ering)
386 {
387 	memset(ering, 0, sizeof(*ering));
388 }
389 
390 static int ata_ering_map(struct ata_ering *ering,
391 			 int (*map_fn)(struct ata_ering_entry *, void *),
392 			 void *arg)
393 {
394 	int idx, rc = 0;
395 	struct ata_ering_entry *ent;
396 
397 	idx = ering->cursor;
398 	do {
399 		ent = &ering->ring[idx];
400 		if (!ent->err_mask)
401 			break;
402 		rc = map_fn(ent, arg);
403 		if (rc)
404 			break;
405 		idx = (idx - 1 + ATA_ERING_SIZE) % ATA_ERING_SIZE;
406 	} while (idx != ering->cursor);
407 
408 	return rc;
409 }
410 
411 static unsigned int ata_eh_dev_action(struct ata_device *dev)
412 {
413 	struct ata_eh_context *ehc = &dev->link->eh_context;
414 
415 	return ehc->i.action | ehc->i.dev_action[dev->devno];
416 }
417 
418 static void ata_eh_clear_action(struct ata_link *link, struct ata_device *dev,
419 				struct ata_eh_info *ehi, unsigned int action)
420 {
421 	struct ata_device *tdev;
422 
423 	if (!dev) {
424 		ehi->action &= ~action;
425 		ata_link_for_each_dev(tdev, link)
426 			ehi->dev_action[tdev->devno] &= ~action;
427 	} else {
428 		/* doesn't make sense for port-wide EH actions */
429 		WARN_ON(!(action & ATA_EH_PERDEV_MASK));
430 
431 		/* break ehi->action into ehi->dev_action */
432 		if (ehi->action & action) {
433 			ata_link_for_each_dev(tdev, link)
434 				ehi->dev_action[tdev->devno] |=
435 					ehi->action & action;
436 			ehi->action &= ~action;
437 		}
438 
439 		/* turn off the specified per-dev action */
440 		ehi->dev_action[dev->devno] &= ~action;
441 	}
442 }
443 
444 /**
445  *	ata_scsi_timed_out - SCSI layer time out callback
446  *	@cmd: timed out SCSI command
447  *
448  *	Handles SCSI layer timeout.  We race with normal completion of
449  *	the qc for @cmd.  If the qc is already gone, we lose and let
450  *	the scsi command finish (EH_HANDLED).  Otherwise, the qc has
451  *	timed out and EH should be invoked.  Prevent ata_qc_complete()
452  *	from finishing it by setting EH_SCHEDULED and return
453  *	EH_NOT_HANDLED.
454  *
455  *	TODO: kill this function once old EH is gone.
456  *
457  *	LOCKING:
458  *	Called from timer context
459  *
460  *	RETURNS:
461  *	EH_HANDLED or EH_NOT_HANDLED
462  */
463 enum blk_eh_timer_return ata_scsi_timed_out(struct scsi_cmnd *cmd)
464 {
465 	struct Scsi_Host *host = cmd->device->host;
466 	struct ata_port *ap = ata_shost_to_port(host);
467 	unsigned long flags;
468 	struct ata_queued_cmd *qc;
469 	enum blk_eh_timer_return ret;
470 
471 	DPRINTK("ENTER\n");
472 
473 	if (ap->ops->error_handler) {
474 		ret = BLK_EH_NOT_HANDLED;
475 		goto out;
476 	}
477 
478 	ret = BLK_EH_HANDLED;
479 	spin_lock_irqsave(ap->lock, flags);
480 	qc = ata_qc_from_tag(ap, ap->link.active_tag);
481 	if (qc) {
482 		WARN_ON(qc->scsicmd != cmd);
483 		qc->flags |= ATA_QCFLAG_EH_SCHEDULED;
484 		qc->err_mask |= AC_ERR_TIMEOUT;
485 		ret = BLK_EH_NOT_HANDLED;
486 	}
487 	spin_unlock_irqrestore(ap->lock, flags);
488 
489  out:
490 	DPRINTK("EXIT, ret=%d\n", ret);
491 	return ret;
492 }
493 
494 /**
495  *	ata_scsi_error - SCSI layer error handler callback
496  *	@host: SCSI host on which error occurred
497  *
498  *	Handles SCSI-layer-thrown error events.
499  *
500  *	LOCKING:
501  *	Inherited from SCSI layer (none, can sleep)
502  *
503  *	RETURNS:
504  *	Zero.
505  */
506 void ata_scsi_error(struct Scsi_Host *host)
507 {
508 	struct ata_port *ap = ata_shost_to_port(host);
509 	int i;
510 	unsigned long flags;
511 
512 	DPRINTK("ENTER\n");
513 
514 	/* synchronize with port task */
515 	ata_port_flush_task(ap);
516 
517 	/* synchronize with host lock and sort out timeouts */
518 
519 	/* For new EH, all qcs are finished in one of three ways -
520 	 * normal completion, error completion, and SCSI timeout.
521 	 * Both cmpletions can race against SCSI timeout.  When normal
522 	 * completion wins, the qc never reaches EH.  When error
523 	 * completion wins, the qc has ATA_QCFLAG_FAILED set.
524 	 *
525 	 * When SCSI timeout wins, things are a bit more complex.
526 	 * Normal or error completion can occur after the timeout but
527 	 * before this point.  In such cases, both types of
528 	 * completions are honored.  A scmd is determined to have
529 	 * timed out iff its associated qc is active and not failed.
530 	 */
531 	if (ap->ops->error_handler) {
532 		struct scsi_cmnd *scmd, *tmp;
533 		int nr_timedout = 0;
534 
535 		spin_lock_irqsave(ap->lock, flags);
536 
537 		list_for_each_entry_safe(scmd, tmp, &host->eh_cmd_q, eh_entry) {
538 			struct ata_queued_cmd *qc;
539 
540 			for (i = 0; i < ATA_MAX_QUEUE; i++) {
541 				qc = __ata_qc_from_tag(ap, i);
542 				if (qc->flags & ATA_QCFLAG_ACTIVE &&
543 				    qc->scsicmd == scmd)
544 					break;
545 			}
546 
547 			if (i < ATA_MAX_QUEUE) {
548 				/* the scmd has an associated qc */
549 				if (!(qc->flags & ATA_QCFLAG_FAILED)) {
550 					/* which hasn't failed yet, timeout */
551 					qc->err_mask |= AC_ERR_TIMEOUT;
552 					qc->flags |= ATA_QCFLAG_FAILED;
553 					nr_timedout++;
554 				}
555 			} else {
556 				/* Normal completion occurred after
557 				 * SCSI timeout but before this point.
558 				 * Successfully complete it.
559 				 */
560 				scmd->retries = scmd->allowed;
561 				scsi_eh_finish_cmd(scmd, &ap->eh_done_q);
562 			}
563 		}
564 
565 		/* If we have timed out qcs.  They belong to EH from
566 		 * this point but the state of the controller is
567 		 * unknown.  Freeze the port to make sure the IRQ
568 		 * handler doesn't diddle with those qcs.  This must
569 		 * be done atomically w.r.t. setting QCFLAG_FAILED.
570 		 */
571 		if (nr_timedout)
572 			__ata_port_freeze(ap);
573 
574 		spin_unlock_irqrestore(ap->lock, flags);
575 
576 		/* initialize eh_tries */
577 		ap->eh_tries = ATA_EH_MAX_TRIES;
578 	} else
579 		spin_unlock_wait(ap->lock);
580 
581  repeat:
582 	/* invoke error handler */
583 	if (ap->ops->error_handler) {
584 		struct ata_link *link;
585 
586 		/* kill fast drain timer */
587 		del_timer_sync(&ap->fastdrain_timer);
588 
589 		/* process port resume request */
590 		ata_eh_handle_port_resume(ap);
591 
592 		/* fetch & clear EH info */
593 		spin_lock_irqsave(ap->lock, flags);
594 
595 		__ata_port_for_each_link(link, ap) {
596 			struct ata_eh_context *ehc = &link->eh_context;
597 			struct ata_device *dev;
598 
599 			memset(&link->eh_context, 0, sizeof(link->eh_context));
600 			link->eh_context.i = link->eh_info;
601 			memset(&link->eh_info, 0, sizeof(link->eh_info));
602 
603 			ata_link_for_each_dev(dev, link) {
604 				int devno = dev->devno;
605 
606 				ehc->saved_xfer_mode[devno] = dev->xfer_mode;
607 				if (ata_ncq_enabled(dev))
608 					ehc->saved_ncq_enabled |= 1 << devno;
609 			}
610 
611 			/* set last reset timestamp to some time in the past */
612 			ehc->last_reset = jiffies - 60 * HZ;
613 		}
614 
615 		ap->pflags |= ATA_PFLAG_EH_IN_PROGRESS;
616 		ap->pflags &= ~ATA_PFLAG_EH_PENDING;
617 		ap->excl_link = NULL;	/* don't maintain exclusion over EH */
618 
619 		spin_unlock_irqrestore(ap->lock, flags);
620 
621 		/* invoke EH, skip if unloading or suspended */
622 		if (!(ap->pflags & (ATA_PFLAG_UNLOADING | ATA_PFLAG_SUSPENDED)))
623 			ap->ops->error_handler(ap);
624 		else
625 			ata_eh_finish(ap);
626 
627 		/* process port suspend request */
628 		ata_eh_handle_port_suspend(ap);
629 
630 		/* Exception might have happend after ->error_handler
631 		 * recovered the port but before this point.  Repeat
632 		 * EH in such case.
633 		 */
634 		spin_lock_irqsave(ap->lock, flags);
635 
636 		if (ap->pflags & ATA_PFLAG_EH_PENDING) {
637 			if (--ap->eh_tries) {
638 				spin_unlock_irqrestore(ap->lock, flags);
639 				goto repeat;
640 			}
641 			ata_port_printk(ap, KERN_ERR, "EH pending after %d "
642 					"tries, giving up\n", ATA_EH_MAX_TRIES);
643 			ap->pflags &= ~ATA_PFLAG_EH_PENDING;
644 		}
645 
646 		/* this run is complete, make sure EH info is clear */
647 		__ata_port_for_each_link(link, ap)
648 			memset(&link->eh_info, 0, sizeof(link->eh_info));
649 
650 		/* Clear host_eh_scheduled while holding ap->lock such
651 		 * that if exception occurs after this point but
652 		 * before EH completion, SCSI midlayer will
653 		 * re-initiate EH.
654 		 */
655 		host->host_eh_scheduled = 0;
656 
657 		spin_unlock_irqrestore(ap->lock, flags);
658 	} else {
659 		WARN_ON(ata_qc_from_tag(ap, ap->link.active_tag) == NULL);
660 		ap->ops->eng_timeout(ap);
661 	}
662 
663 	/* finish or retry handled scmd's and clean up */
664 	WARN_ON(host->host_failed || !list_empty(&host->eh_cmd_q));
665 
666 	scsi_eh_flush_done_q(&ap->eh_done_q);
667 
668 	/* clean up */
669 	spin_lock_irqsave(ap->lock, flags);
670 
671 	if (ap->pflags & ATA_PFLAG_LOADING)
672 		ap->pflags &= ~ATA_PFLAG_LOADING;
673 	else if (ap->pflags & ATA_PFLAG_SCSI_HOTPLUG)
674 		queue_delayed_work(ata_aux_wq, &ap->hotplug_task, 0);
675 
676 	if (ap->pflags & ATA_PFLAG_RECOVERED)
677 		ata_port_printk(ap, KERN_INFO, "EH complete\n");
678 
679 	ap->pflags &= ~(ATA_PFLAG_SCSI_HOTPLUG | ATA_PFLAG_RECOVERED);
680 
681 	/* tell wait_eh that we're done */
682 	ap->pflags &= ~ATA_PFLAG_EH_IN_PROGRESS;
683 	wake_up_all(&ap->eh_wait_q);
684 
685 	spin_unlock_irqrestore(ap->lock, flags);
686 
687 	DPRINTK("EXIT\n");
688 }
689 
690 /**
691  *	ata_port_wait_eh - Wait for the currently pending EH to complete
692  *	@ap: Port to wait EH for
693  *
694  *	Wait until the currently pending EH is complete.
695  *
696  *	LOCKING:
697  *	Kernel thread context (may sleep).
698  */
699 void ata_port_wait_eh(struct ata_port *ap)
700 {
701 	unsigned long flags;
702 	DEFINE_WAIT(wait);
703 
704  retry:
705 	spin_lock_irqsave(ap->lock, flags);
706 
707 	while (ap->pflags & (ATA_PFLAG_EH_PENDING | ATA_PFLAG_EH_IN_PROGRESS)) {
708 		prepare_to_wait(&ap->eh_wait_q, &wait, TASK_UNINTERRUPTIBLE);
709 		spin_unlock_irqrestore(ap->lock, flags);
710 		schedule();
711 		spin_lock_irqsave(ap->lock, flags);
712 	}
713 	finish_wait(&ap->eh_wait_q, &wait);
714 
715 	spin_unlock_irqrestore(ap->lock, flags);
716 
717 	/* make sure SCSI EH is complete */
718 	if (scsi_host_in_recovery(ap->scsi_host)) {
719 		msleep(10);
720 		goto retry;
721 	}
722 }
723 
724 static int ata_eh_nr_in_flight(struct ata_port *ap)
725 {
726 	unsigned int tag;
727 	int nr = 0;
728 
729 	/* count only non-internal commands */
730 	for (tag = 0; tag < ATA_MAX_QUEUE - 1; tag++)
731 		if (ata_qc_from_tag(ap, tag))
732 			nr++;
733 
734 	return nr;
735 }
736 
737 void ata_eh_fastdrain_timerfn(unsigned long arg)
738 {
739 	struct ata_port *ap = (void *)arg;
740 	unsigned long flags;
741 	int cnt;
742 
743 	spin_lock_irqsave(ap->lock, flags);
744 
745 	cnt = ata_eh_nr_in_flight(ap);
746 
747 	/* are we done? */
748 	if (!cnt)
749 		goto out_unlock;
750 
751 	if (cnt == ap->fastdrain_cnt) {
752 		unsigned int tag;
753 
754 		/* No progress during the last interval, tag all
755 		 * in-flight qcs as timed out and freeze the port.
756 		 */
757 		for (tag = 0; tag < ATA_MAX_QUEUE - 1; tag++) {
758 			struct ata_queued_cmd *qc = ata_qc_from_tag(ap, tag);
759 			if (qc)
760 				qc->err_mask |= AC_ERR_TIMEOUT;
761 		}
762 
763 		ata_port_freeze(ap);
764 	} else {
765 		/* some qcs have finished, give it another chance */
766 		ap->fastdrain_cnt = cnt;
767 		ap->fastdrain_timer.expires =
768 			ata_deadline(jiffies, ATA_EH_FASTDRAIN_INTERVAL);
769 		add_timer(&ap->fastdrain_timer);
770 	}
771 
772  out_unlock:
773 	spin_unlock_irqrestore(ap->lock, flags);
774 }
775 
776 /**
777  *	ata_eh_set_pending - set ATA_PFLAG_EH_PENDING and activate fast drain
778  *	@ap: target ATA port
779  *	@fastdrain: activate fast drain
780  *
781  *	Set ATA_PFLAG_EH_PENDING and activate fast drain if @fastdrain
782  *	is non-zero and EH wasn't pending before.  Fast drain ensures
783  *	that EH kicks in in timely manner.
784  *
785  *	LOCKING:
786  *	spin_lock_irqsave(host lock)
787  */
788 static void ata_eh_set_pending(struct ata_port *ap, int fastdrain)
789 {
790 	int cnt;
791 
792 	/* already scheduled? */
793 	if (ap->pflags & ATA_PFLAG_EH_PENDING)
794 		return;
795 
796 	ap->pflags |= ATA_PFLAG_EH_PENDING;
797 
798 	if (!fastdrain)
799 		return;
800 
801 	/* do we have in-flight qcs? */
802 	cnt = ata_eh_nr_in_flight(ap);
803 	if (!cnt)
804 		return;
805 
806 	/* activate fast drain */
807 	ap->fastdrain_cnt = cnt;
808 	ap->fastdrain_timer.expires =
809 		ata_deadline(jiffies, ATA_EH_FASTDRAIN_INTERVAL);
810 	add_timer(&ap->fastdrain_timer);
811 }
812 
813 /**
814  *	ata_qc_schedule_eh - schedule qc for error handling
815  *	@qc: command to schedule error handling for
816  *
817  *	Schedule error handling for @qc.  EH will kick in as soon as
818  *	other commands are drained.
819  *
820  *	LOCKING:
821  *	spin_lock_irqsave(host lock)
822  */
823 void ata_qc_schedule_eh(struct ata_queued_cmd *qc)
824 {
825 	struct ata_port *ap = qc->ap;
826 
827 	WARN_ON(!ap->ops->error_handler);
828 
829 	qc->flags |= ATA_QCFLAG_FAILED;
830 	ata_eh_set_pending(ap, 1);
831 
832 	/* The following will fail if timeout has already expired.
833 	 * ata_scsi_error() takes care of such scmds on EH entry.
834 	 * Note that ATA_QCFLAG_FAILED is unconditionally set after
835 	 * this function completes.
836 	 */
837 	blk_abort_request(qc->scsicmd->request);
838 }
839 
840 /**
841  *	ata_port_schedule_eh - schedule error handling without a qc
842  *	@ap: ATA port to schedule EH for
843  *
844  *	Schedule error handling for @ap.  EH will kick in as soon as
845  *	all commands are drained.
846  *
847  *	LOCKING:
848  *	spin_lock_irqsave(host lock)
849  */
850 void ata_port_schedule_eh(struct ata_port *ap)
851 {
852 	WARN_ON(!ap->ops->error_handler);
853 
854 	if (ap->pflags & ATA_PFLAG_INITIALIZING)
855 		return;
856 
857 	ata_eh_set_pending(ap, 1);
858 	scsi_schedule_eh(ap->scsi_host);
859 
860 	DPRINTK("port EH scheduled\n");
861 }
862 
863 static int ata_do_link_abort(struct ata_port *ap, struct ata_link *link)
864 {
865 	int tag, nr_aborted = 0;
866 
867 	WARN_ON(!ap->ops->error_handler);
868 
869 	/* we're gonna abort all commands, no need for fast drain */
870 	ata_eh_set_pending(ap, 0);
871 
872 	for (tag = 0; tag < ATA_MAX_QUEUE; tag++) {
873 		struct ata_queued_cmd *qc = ata_qc_from_tag(ap, tag);
874 
875 		if (qc && (!link || qc->dev->link == link)) {
876 			qc->flags |= ATA_QCFLAG_FAILED;
877 			ata_qc_complete(qc);
878 			nr_aborted++;
879 		}
880 	}
881 
882 	if (!nr_aborted)
883 		ata_port_schedule_eh(ap);
884 
885 	return nr_aborted;
886 }
887 
888 /**
889  *	ata_link_abort - abort all qc's on the link
890  *	@link: ATA link to abort qc's for
891  *
892  *	Abort all active qc's active on @link and schedule EH.
893  *
894  *	LOCKING:
895  *	spin_lock_irqsave(host lock)
896  *
897  *	RETURNS:
898  *	Number of aborted qc's.
899  */
900 int ata_link_abort(struct ata_link *link)
901 {
902 	return ata_do_link_abort(link->ap, link);
903 }
904 
905 /**
906  *	ata_port_abort - abort all qc's on the port
907  *	@ap: ATA port to abort qc's for
908  *
909  *	Abort all active qc's of @ap and schedule EH.
910  *
911  *	LOCKING:
912  *	spin_lock_irqsave(host_set lock)
913  *
914  *	RETURNS:
915  *	Number of aborted qc's.
916  */
917 int ata_port_abort(struct ata_port *ap)
918 {
919 	return ata_do_link_abort(ap, NULL);
920 }
921 
922 /**
923  *	__ata_port_freeze - freeze port
924  *	@ap: ATA port to freeze
925  *
926  *	This function is called when HSM violation or some other
927  *	condition disrupts normal operation of the port.  Frozen port
928  *	is not allowed to perform any operation until the port is
929  *	thawed, which usually follows a successful reset.
930  *
931  *	ap->ops->freeze() callback can be used for freezing the port
932  *	hardware-wise (e.g. mask interrupt and stop DMA engine).  If a
933  *	port cannot be frozen hardware-wise, the interrupt handler
934  *	must ack and clear interrupts unconditionally while the port
935  *	is frozen.
936  *
937  *	LOCKING:
938  *	spin_lock_irqsave(host lock)
939  */
940 static void __ata_port_freeze(struct ata_port *ap)
941 {
942 	WARN_ON(!ap->ops->error_handler);
943 
944 	if (ap->ops->freeze)
945 		ap->ops->freeze(ap);
946 
947 	ap->pflags |= ATA_PFLAG_FROZEN;
948 
949 	DPRINTK("ata%u port frozen\n", ap->print_id);
950 }
951 
952 /**
953  *	ata_port_freeze - abort & freeze port
954  *	@ap: ATA port to freeze
955  *
956  *	Abort and freeze @ap.
957  *
958  *	LOCKING:
959  *	spin_lock_irqsave(host lock)
960  *
961  *	RETURNS:
962  *	Number of aborted commands.
963  */
964 int ata_port_freeze(struct ata_port *ap)
965 {
966 	int nr_aborted;
967 
968 	WARN_ON(!ap->ops->error_handler);
969 
970 	nr_aborted = ata_port_abort(ap);
971 	__ata_port_freeze(ap);
972 
973 	return nr_aborted;
974 }
975 
976 /**
977  *	sata_async_notification - SATA async notification handler
978  *	@ap: ATA port where async notification is received
979  *
980  *	Handler to be called when async notification via SDB FIS is
981  *	received.  This function schedules EH if necessary.
982  *
983  *	LOCKING:
984  *	spin_lock_irqsave(host lock)
985  *
986  *	RETURNS:
987  *	1 if EH is scheduled, 0 otherwise.
988  */
989 int sata_async_notification(struct ata_port *ap)
990 {
991 	u32 sntf;
992 	int rc;
993 
994 	if (!(ap->flags & ATA_FLAG_AN))
995 		return 0;
996 
997 	rc = sata_scr_read(&ap->link, SCR_NOTIFICATION, &sntf);
998 	if (rc == 0)
999 		sata_scr_write(&ap->link, SCR_NOTIFICATION, sntf);
1000 
1001 	if (!sata_pmp_attached(ap) || rc) {
1002 		/* PMP is not attached or SNTF is not available */
1003 		if (!sata_pmp_attached(ap)) {
1004 			/* PMP is not attached.  Check whether ATAPI
1005 			 * AN is configured.  If so, notify media
1006 			 * change.
1007 			 */
1008 			struct ata_device *dev = ap->link.device;
1009 
1010 			if ((dev->class == ATA_DEV_ATAPI) &&
1011 			    (dev->flags & ATA_DFLAG_AN))
1012 				ata_scsi_media_change_notify(dev);
1013 			return 0;
1014 		} else {
1015 			/* PMP is attached but SNTF is not available.
1016 			 * ATAPI async media change notification is
1017 			 * not used.  The PMP must be reporting PHY
1018 			 * status change, schedule EH.
1019 			 */
1020 			ata_port_schedule_eh(ap);
1021 			return 1;
1022 		}
1023 	} else {
1024 		/* PMP is attached and SNTF is available */
1025 		struct ata_link *link;
1026 
1027 		/* check and notify ATAPI AN */
1028 		ata_port_for_each_link(link, ap) {
1029 			if (!(sntf & (1 << link->pmp)))
1030 				continue;
1031 
1032 			if ((link->device->class == ATA_DEV_ATAPI) &&
1033 			    (link->device->flags & ATA_DFLAG_AN))
1034 				ata_scsi_media_change_notify(link->device);
1035 		}
1036 
1037 		/* If PMP is reporting that PHY status of some
1038 		 * downstream ports has changed, schedule EH.
1039 		 */
1040 		if (sntf & (1 << SATA_PMP_CTRL_PORT)) {
1041 			ata_port_schedule_eh(ap);
1042 			return 1;
1043 		}
1044 
1045 		return 0;
1046 	}
1047 }
1048 
1049 /**
1050  *	ata_eh_freeze_port - EH helper to freeze port
1051  *	@ap: ATA port to freeze
1052  *
1053  *	Freeze @ap.
1054  *
1055  *	LOCKING:
1056  *	None.
1057  */
1058 void ata_eh_freeze_port(struct ata_port *ap)
1059 {
1060 	unsigned long flags;
1061 
1062 	if (!ap->ops->error_handler)
1063 		return;
1064 
1065 	spin_lock_irqsave(ap->lock, flags);
1066 	__ata_port_freeze(ap);
1067 	spin_unlock_irqrestore(ap->lock, flags);
1068 }
1069 
1070 /**
1071  *	ata_port_thaw_port - EH helper to thaw port
1072  *	@ap: ATA port to thaw
1073  *
1074  *	Thaw frozen port @ap.
1075  *
1076  *	LOCKING:
1077  *	None.
1078  */
1079 void ata_eh_thaw_port(struct ata_port *ap)
1080 {
1081 	unsigned long flags;
1082 
1083 	if (!ap->ops->error_handler)
1084 		return;
1085 
1086 	spin_lock_irqsave(ap->lock, flags);
1087 
1088 	ap->pflags &= ~ATA_PFLAG_FROZEN;
1089 
1090 	if (ap->ops->thaw)
1091 		ap->ops->thaw(ap);
1092 
1093 	spin_unlock_irqrestore(ap->lock, flags);
1094 
1095 	DPRINTK("ata%u port thawed\n", ap->print_id);
1096 }
1097 
1098 static void ata_eh_scsidone(struct scsi_cmnd *scmd)
1099 {
1100 	/* nada */
1101 }
1102 
1103 static void __ata_eh_qc_complete(struct ata_queued_cmd *qc)
1104 {
1105 	struct ata_port *ap = qc->ap;
1106 	struct scsi_cmnd *scmd = qc->scsicmd;
1107 	unsigned long flags;
1108 
1109 	spin_lock_irqsave(ap->lock, flags);
1110 	qc->scsidone = ata_eh_scsidone;
1111 	__ata_qc_complete(qc);
1112 	WARN_ON(ata_tag_valid(qc->tag));
1113 	spin_unlock_irqrestore(ap->lock, flags);
1114 
1115 	scsi_eh_finish_cmd(scmd, &ap->eh_done_q);
1116 }
1117 
1118 /**
1119  *	ata_eh_qc_complete - Complete an active ATA command from EH
1120  *	@qc: Command to complete
1121  *
1122  *	Indicate to the mid and upper layers that an ATA command has
1123  *	completed.  To be used from EH.
1124  */
1125 void ata_eh_qc_complete(struct ata_queued_cmd *qc)
1126 {
1127 	struct scsi_cmnd *scmd = qc->scsicmd;
1128 	scmd->retries = scmd->allowed;
1129 	__ata_eh_qc_complete(qc);
1130 }
1131 
1132 /**
1133  *	ata_eh_qc_retry - Tell midlayer to retry an ATA command after EH
1134  *	@qc: Command to retry
1135  *
1136  *	Indicate to the mid and upper layers that an ATA command
1137  *	should be retried.  To be used from EH.
1138  *
1139  *	SCSI midlayer limits the number of retries to scmd->allowed.
1140  *	scmd->retries is decremented for commands which get retried
1141  *	due to unrelated failures (qc->err_mask is zero).
1142  */
1143 void ata_eh_qc_retry(struct ata_queued_cmd *qc)
1144 {
1145 	struct scsi_cmnd *scmd = qc->scsicmd;
1146 	if (!qc->err_mask && scmd->retries)
1147 		scmd->retries--;
1148 	__ata_eh_qc_complete(qc);
1149 }
1150 
1151 /**
1152  *	ata_eh_detach_dev - detach ATA device
1153  *	@dev: ATA device to detach
1154  *
1155  *	Detach @dev.
1156  *
1157  *	LOCKING:
1158  *	None.
1159  */
1160 void ata_eh_detach_dev(struct ata_device *dev)
1161 {
1162 	struct ata_link *link = dev->link;
1163 	struct ata_port *ap = link->ap;
1164 	unsigned long flags;
1165 
1166 	ata_dev_disable(dev);
1167 
1168 	spin_lock_irqsave(ap->lock, flags);
1169 
1170 	dev->flags &= ~ATA_DFLAG_DETACH;
1171 
1172 	if (ata_scsi_offline_dev(dev)) {
1173 		dev->flags |= ATA_DFLAG_DETACHED;
1174 		ap->pflags |= ATA_PFLAG_SCSI_HOTPLUG;
1175 	}
1176 
1177 	/* clear per-dev EH actions */
1178 	ata_eh_clear_action(link, dev, &link->eh_info, ATA_EH_PERDEV_MASK);
1179 	ata_eh_clear_action(link, dev, &link->eh_context.i, ATA_EH_PERDEV_MASK);
1180 
1181 	spin_unlock_irqrestore(ap->lock, flags);
1182 }
1183 
1184 /**
1185  *	ata_eh_about_to_do - about to perform eh_action
1186  *	@link: target ATA link
1187  *	@dev: target ATA dev for per-dev action (can be NULL)
1188  *	@action: action about to be performed
1189  *
1190  *	Called just before performing EH actions to clear related bits
1191  *	in @link->eh_info such that eh actions are not unnecessarily
1192  *	repeated.
1193  *
1194  *	LOCKING:
1195  *	None.
1196  */
1197 void ata_eh_about_to_do(struct ata_link *link, struct ata_device *dev,
1198 			unsigned int action)
1199 {
1200 	struct ata_port *ap = link->ap;
1201 	struct ata_eh_info *ehi = &link->eh_info;
1202 	struct ata_eh_context *ehc = &link->eh_context;
1203 	unsigned long flags;
1204 
1205 	spin_lock_irqsave(ap->lock, flags);
1206 
1207 	ata_eh_clear_action(link, dev, ehi, action);
1208 
1209 	/* About to take EH action, set RECOVERED.  Ignore actions on
1210 	 * slave links as master will do them again.
1211 	 */
1212 	if (!(ehc->i.flags & ATA_EHI_QUIET) && link != ap->slave_link)
1213 		ap->pflags |= ATA_PFLAG_RECOVERED;
1214 
1215 	spin_unlock_irqrestore(ap->lock, flags);
1216 }
1217 
1218 /**
1219  *	ata_eh_done - EH action complete
1220 *	@ap: target ATA port
1221  *	@dev: target ATA dev for per-dev action (can be NULL)
1222  *	@action: action just completed
1223  *
1224  *	Called right after performing EH actions to clear related bits
1225  *	in @link->eh_context.
1226  *
1227  *	LOCKING:
1228  *	None.
1229  */
1230 void ata_eh_done(struct ata_link *link, struct ata_device *dev,
1231 		 unsigned int action)
1232 {
1233 	struct ata_eh_context *ehc = &link->eh_context;
1234 
1235 	ata_eh_clear_action(link, dev, &ehc->i, action);
1236 }
1237 
1238 /**
1239  *	ata_err_string - convert err_mask to descriptive string
1240  *	@err_mask: error mask to convert to string
1241  *
1242  *	Convert @err_mask to descriptive string.  Errors are
1243  *	prioritized according to severity and only the most severe
1244  *	error is reported.
1245  *
1246  *	LOCKING:
1247  *	None.
1248  *
1249  *	RETURNS:
1250  *	Descriptive string for @err_mask
1251  */
1252 static const char *ata_err_string(unsigned int err_mask)
1253 {
1254 	if (err_mask & AC_ERR_HOST_BUS)
1255 		return "host bus error";
1256 	if (err_mask & AC_ERR_ATA_BUS)
1257 		return "ATA bus error";
1258 	if (err_mask & AC_ERR_TIMEOUT)
1259 		return "timeout";
1260 	if (err_mask & AC_ERR_HSM)
1261 		return "HSM violation";
1262 	if (err_mask & AC_ERR_SYSTEM)
1263 		return "internal error";
1264 	if (err_mask & AC_ERR_MEDIA)
1265 		return "media error";
1266 	if (err_mask & AC_ERR_INVALID)
1267 		return "invalid argument";
1268 	if (err_mask & AC_ERR_DEV)
1269 		return "device error";
1270 	return "unknown error";
1271 }
1272 
1273 /**
1274  *	ata_read_log_page - read a specific log page
1275  *	@dev: target device
1276  *	@page: page to read
1277  *	@buf: buffer to store read page
1278  *	@sectors: number of sectors to read
1279  *
1280  *	Read log page using READ_LOG_EXT command.
1281  *
1282  *	LOCKING:
1283  *	Kernel thread context (may sleep).
1284  *
1285  *	RETURNS:
1286  *	0 on success, AC_ERR_* mask otherwise.
1287  */
1288 static unsigned int ata_read_log_page(struct ata_device *dev,
1289 				      u8 page, void *buf, unsigned int sectors)
1290 {
1291 	struct ata_taskfile tf;
1292 	unsigned int err_mask;
1293 
1294 	DPRINTK("read log page - page %d\n", page);
1295 
1296 	ata_tf_init(dev, &tf);
1297 	tf.command = ATA_CMD_READ_LOG_EXT;
1298 	tf.lbal = page;
1299 	tf.nsect = sectors;
1300 	tf.hob_nsect = sectors >> 8;
1301 	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_LBA48 | ATA_TFLAG_DEVICE;
1302 	tf.protocol = ATA_PROT_PIO;
1303 
1304 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_FROM_DEVICE,
1305 				     buf, sectors * ATA_SECT_SIZE, 0);
1306 
1307 	DPRINTK("EXIT, err_mask=%x\n", err_mask);
1308 	return err_mask;
1309 }
1310 
1311 /**
1312  *	ata_eh_read_log_10h - Read log page 10h for NCQ error details
1313  *	@dev: Device to read log page 10h from
1314  *	@tag: Resulting tag of the failed command
1315  *	@tf: Resulting taskfile registers of the failed command
1316  *
1317  *	Read log page 10h to obtain NCQ error details and clear error
1318  *	condition.
1319  *
1320  *	LOCKING:
1321  *	Kernel thread context (may sleep).
1322  *
1323  *	RETURNS:
1324  *	0 on success, -errno otherwise.
1325  */
1326 static int ata_eh_read_log_10h(struct ata_device *dev,
1327 			       int *tag, struct ata_taskfile *tf)
1328 {
1329 	u8 *buf = dev->link->ap->sector_buf;
1330 	unsigned int err_mask;
1331 	u8 csum;
1332 	int i;
1333 
1334 	err_mask = ata_read_log_page(dev, ATA_LOG_SATA_NCQ, buf, 1);
1335 	if (err_mask)
1336 		return -EIO;
1337 
1338 	csum = 0;
1339 	for (i = 0; i < ATA_SECT_SIZE; i++)
1340 		csum += buf[i];
1341 	if (csum)
1342 		ata_dev_printk(dev, KERN_WARNING,
1343 			       "invalid checksum 0x%x on log page 10h\n", csum);
1344 
1345 	if (buf[0] & 0x80)
1346 		return -ENOENT;
1347 
1348 	*tag = buf[0] & 0x1f;
1349 
1350 	tf->command = buf[2];
1351 	tf->feature = buf[3];
1352 	tf->lbal = buf[4];
1353 	tf->lbam = buf[5];
1354 	tf->lbah = buf[6];
1355 	tf->device = buf[7];
1356 	tf->hob_lbal = buf[8];
1357 	tf->hob_lbam = buf[9];
1358 	tf->hob_lbah = buf[10];
1359 	tf->nsect = buf[12];
1360 	tf->hob_nsect = buf[13];
1361 
1362 	return 0;
1363 }
1364 
1365 /**
1366  *	atapi_eh_tur - perform ATAPI TEST_UNIT_READY
1367  *	@dev: target ATAPI device
1368  *	@r_sense_key: out parameter for sense_key
1369  *
1370  *	Perform ATAPI TEST_UNIT_READY.
1371  *
1372  *	LOCKING:
1373  *	EH context (may sleep).
1374  *
1375  *	RETURNS:
1376  *	0 on success, AC_ERR_* mask on failure.
1377  */
1378 static unsigned int atapi_eh_tur(struct ata_device *dev, u8 *r_sense_key)
1379 {
1380 	u8 cdb[ATAPI_CDB_LEN] = { TEST_UNIT_READY, 0, 0, 0, 0, 0 };
1381 	struct ata_taskfile tf;
1382 	unsigned int err_mask;
1383 
1384 	ata_tf_init(dev, &tf);
1385 
1386 	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
1387 	tf.command = ATA_CMD_PACKET;
1388 	tf.protocol = ATAPI_PROT_NODATA;
1389 
1390 	err_mask = ata_exec_internal(dev, &tf, cdb, DMA_NONE, NULL, 0, 0);
1391 	if (err_mask == AC_ERR_DEV)
1392 		*r_sense_key = tf.feature >> 4;
1393 	return err_mask;
1394 }
1395 
1396 /**
1397  *	atapi_eh_request_sense - perform ATAPI REQUEST_SENSE
1398  *	@dev: device to perform REQUEST_SENSE to
1399  *	@sense_buf: result sense data buffer (SCSI_SENSE_BUFFERSIZE bytes long)
1400  *	@dfl_sense_key: default sense key to use
1401  *
1402  *	Perform ATAPI REQUEST_SENSE after the device reported CHECK
1403  *	SENSE.  This function is EH helper.
1404  *
1405  *	LOCKING:
1406  *	Kernel thread context (may sleep).
1407  *
1408  *	RETURNS:
1409  *	0 on success, AC_ERR_* mask on failure
1410  */
1411 static unsigned int atapi_eh_request_sense(struct ata_device *dev,
1412 					   u8 *sense_buf, u8 dfl_sense_key)
1413 {
1414 	u8 cdb[ATAPI_CDB_LEN] =
1415 		{ REQUEST_SENSE, 0, 0, 0, SCSI_SENSE_BUFFERSIZE, 0 };
1416 	struct ata_port *ap = dev->link->ap;
1417 	struct ata_taskfile tf;
1418 
1419 	DPRINTK("ATAPI request sense\n");
1420 
1421 	/* FIXME: is this needed? */
1422 	memset(sense_buf, 0, SCSI_SENSE_BUFFERSIZE);
1423 
1424 	/* initialize sense_buf with the error register,
1425 	 * for the case where they are -not- overwritten
1426 	 */
1427 	sense_buf[0] = 0x70;
1428 	sense_buf[2] = dfl_sense_key;
1429 
1430 	/* some devices time out if garbage left in tf */
1431 	ata_tf_init(dev, &tf);
1432 
1433 	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
1434 	tf.command = ATA_CMD_PACKET;
1435 
1436 	/* is it pointless to prefer PIO for "safety reasons"? */
1437 	if (ap->flags & ATA_FLAG_PIO_DMA) {
1438 		tf.protocol = ATAPI_PROT_DMA;
1439 		tf.feature |= ATAPI_PKT_DMA;
1440 	} else {
1441 		tf.protocol = ATAPI_PROT_PIO;
1442 		tf.lbam = SCSI_SENSE_BUFFERSIZE;
1443 		tf.lbah = 0;
1444 	}
1445 
1446 	return ata_exec_internal(dev, &tf, cdb, DMA_FROM_DEVICE,
1447 				 sense_buf, SCSI_SENSE_BUFFERSIZE, 0);
1448 }
1449 
1450 /**
1451  *	ata_eh_analyze_serror - analyze SError for a failed port
1452  *	@link: ATA link to analyze SError for
1453  *
1454  *	Analyze SError if available and further determine cause of
1455  *	failure.
1456  *
1457  *	LOCKING:
1458  *	None.
1459  */
1460 static void ata_eh_analyze_serror(struct ata_link *link)
1461 {
1462 	struct ata_eh_context *ehc = &link->eh_context;
1463 	u32 serror = ehc->i.serror;
1464 	unsigned int err_mask = 0, action = 0;
1465 	u32 hotplug_mask;
1466 
1467 	if (serror & (SERR_PERSISTENT | SERR_DATA)) {
1468 		err_mask |= AC_ERR_ATA_BUS;
1469 		action |= ATA_EH_RESET;
1470 	}
1471 	if (serror & SERR_PROTOCOL) {
1472 		err_mask |= AC_ERR_HSM;
1473 		action |= ATA_EH_RESET;
1474 	}
1475 	if (serror & SERR_INTERNAL) {
1476 		err_mask |= AC_ERR_SYSTEM;
1477 		action |= ATA_EH_RESET;
1478 	}
1479 
1480 	/* Determine whether a hotplug event has occurred.  Both
1481 	 * SError.N/X are considered hotplug events for enabled or
1482 	 * host links.  For disabled PMP links, only N bit is
1483 	 * considered as X bit is left at 1 for link plugging.
1484 	 */
1485 	hotplug_mask = 0;
1486 
1487 	if (!(link->flags & ATA_LFLAG_DISABLED) || ata_is_host_link(link))
1488 		hotplug_mask = SERR_PHYRDY_CHG | SERR_DEV_XCHG;
1489 	else
1490 		hotplug_mask = SERR_PHYRDY_CHG;
1491 
1492 	if (serror & hotplug_mask)
1493 		ata_ehi_hotplugged(&ehc->i);
1494 
1495 	ehc->i.err_mask |= err_mask;
1496 	ehc->i.action |= action;
1497 }
1498 
1499 /**
1500  *	ata_eh_analyze_ncq_error - analyze NCQ error
1501  *	@link: ATA link to analyze NCQ error for
1502  *
1503  *	Read log page 10h, determine the offending qc and acquire
1504  *	error status TF.  For NCQ device errors, all LLDDs have to do
1505  *	is setting AC_ERR_DEV in ehi->err_mask.  This function takes
1506  *	care of the rest.
1507  *
1508  *	LOCKING:
1509  *	Kernel thread context (may sleep).
1510  */
1511 void ata_eh_analyze_ncq_error(struct ata_link *link)
1512 {
1513 	struct ata_port *ap = link->ap;
1514 	struct ata_eh_context *ehc = &link->eh_context;
1515 	struct ata_device *dev = link->device;
1516 	struct ata_queued_cmd *qc;
1517 	struct ata_taskfile tf;
1518 	int tag, rc;
1519 
1520 	/* if frozen, we can't do much */
1521 	if (ap->pflags & ATA_PFLAG_FROZEN)
1522 		return;
1523 
1524 	/* is it NCQ device error? */
1525 	if (!link->sactive || !(ehc->i.err_mask & AC_ERR_DEV))
1526 		return;
1527 
1528 	/* has LLDD analyzed already? */
1529 	for (tag = 0; tag < ATA_MAX_QUEUE; tag++) {
1530 		qc = __ata_qc_from_tag(ap, tag);
1531 
1532 		if (!(qc->flags & ATA_QCFLAG_FAILED))
1533 			continue;
1534 
1535 		if (qc->err_mask)
1536 			return;
1537 	}
1538 
1539 	/* okay, this error is ours */
1540 	rc = ata_eh_read_log_10h(dev, &tag, &tf);
1541 	if (rc) {
1542 		ata_link_printk(link, KERN_ERR, "failed to read log page 10h "
1543 				"(errno=%d)\n", rc);
1544 		return;
1545 	}
1546 
1547 	if (!(link->sactive & (1 << tag))) {
1548 		ata_link_printk(link, KERN_ERR, "log page 10h reported "
1549 				"inactive tag %d\n", tag);
1550 		return;
1551 	}
1552 
1553 	/* we've got the perpetrator, condemn it */
1554 	qc = __ata_qc_from_tag(ap, tag);
1555 	memcpy(&qc->result_tf, &tf, sizeof(tf));
1556 	qc->result_tf.flags = ATA_TFLAG_ISADDR | ATA_TFLAG_LBA | ATA_TFLAG_LBA48;
1557 	qc->err_mask |= AC_ERR_DEV | AC_ERR_NCQ;
1558 	ehc->i.err_mask &= ~AC_ERR_DEV;
1559 }
1560 
1561 /**
1562  *	ata_eh_analyze_tf - analyze taskfile of a failed qc
1563  *	@qc: qc to analyze
1564  *	@tf: Taskfile registers to analyze
1565  *
1566  *	Analyze taskfile of @qc and further determine cause of
1567  *	failure.  This function also requests ATAPI sense data if
1568  *	avaliable.
1569  *
1570  *	LOCKING:
1571  *	Kernel thread context (may sleep).
1572  *
1573  *	RETURNS:
1574  *	Determined recovery action
1575  */
1576 static unsigned int ata_eh_analyze_tf(struct ata_queued_cmd *qc,
1577 				      const struct ata_taskfile *tf)
1578 {
1579 	unsigned int tmp, action = 0;
1580 	u8 stat = tf->command, err = tf->feature;
1581 
1582 	if ((stat & (ATA_BUSY | ATA_DRQ | ATA_DRDY)) != ATA_DRDY) {
1583 		qc->err_mask |= AC_ERR_HSM;
1584 		return ATA_EH_RESET;
1585 	}
1586 
1587 	if (stat & (ATA_ERR | ATA_DF))
1588 		qc->err_mask |= AC_ERR_DEV;
1589 	else
1590 		return 0;
1591 
1592 	switch (qc->dev->class) {
1593 	case ATA_DEV_ATA:
1594 		if (err & ATA_ICRC)
1595 			qc->err_mask |= AC_ERR_ATA_BUS;
1596 		if (err & ATA_UNC)
1597 			qc->err_mask |= AC_ERR_MEDIA;
1598 		if (err & ATA_IDNF)
1599 			qc->err_mask |= AC_ERR_INVALID;
1600 		break;
1601 
1602 	case ATA_DEV_ATAPI:
1603 		if (!(qc->ap->pflags & ATA_PFLAG_FROZEN)) {
1604 			tmp = atapi_eh_request_sense(qc->dev,
1605 						qc->scsicmd->sense_buffer,
1606 						qc->result_tf.feature >> 4);
1607 			if (!tmp) {
1608 				/* ATA_QCFLAG_SENSE_VALID is used to
1609 				 * tell atapi_qc_complete() that sense
1610 				 * data is already valid.
1611 				 *
1612 				 * TODO: interpret sense data and set
1613 				 * appropriate err_mask.
1614 				 */
1615 				qc->flags |= ATA_QCFLAG_SENSE_VALID;
1616 			} else
1617 				qc->err_mask |= tmp;
1618 		}
1619 	}
1620 
1621 	if (qc->err_mask & (AC_ERR_HSM | AC_ERR_TIMEOUT | AC_ERR_ATA_BUS))
1622 		action |= ATA_EH_RESET;
1623 
1624 	return action;
1625 }
1626 
1627 static int ata_eh_categorize_error(unsigned int eflags, unsigned int err_mask,
1628 				   int *xfer_ok)
1629 {
1630 	int base = 0;
1631 
1632 	if (!(eflags & ATA_EFLAG_DUBIOUS_XFER))
1633 		*xfer_ok = 1;
1634 
1635 	if (!*xfer_ok)
1636 		base = ATA_ECAT_DUBIOUS_NONE;
1637 
1638 	if (err_mask & AC_ERR_ATA_BUS)
1639 		return base + ATA_ECAT_ATA_BUS;
1640 
1641 	if (err_mask & AC_ERR_TIMEOUT)
1642 		return base + ATA_ECAT_TOUT_HSM;
1643 
1644 	if (eflags & ATA_EFLAG_IS_IO) {
1645 		if (err_mask & AC_ERR_HSM)
1646 			return base + ATA_ECAT_TOUT_HSM;
1647 		if ((err_mask &
1648 		     (AC_ERR_DEV|AC_ERR_MEDIA|AC_ERR_INVALID)) == AC_ERR_DEV)
1649 			return base + ATA_ECAT_UNK_DEV;
1650 	}
1651 
1652 	return 0;
1653 }
1654 
1655 struct speed_down_verdict_arg {
1656 	u64 since;
1657 	int xfer_ok;
1658 	int nr_errors[ATA_ECAT_NR];
1659 };
1660 
1661 static int speed_down_verdict_cb(struct ata_ering_entry *ent, void *void_arg)
1662 {
1663 	struct speed_down_verdict_arg *arg = void_arg;
1664 	int cat;
1665 
1666 	if (ent->timestamp < arg->since)
1667 		return -1;
1668 
1669 	cat = ata_eh_categorize_error(ent->eflags, ent->err_mask,
1670 				      &arg->xfer_ok);
1671 	arg->nr_errors[cat]++;
1672 
1673 	return 0;
1674 }
1675 
1676 /**
1677  *	ata_eh_speed_down_verdict - Determine speed down verdict
1678  *	@dev: Device of interest
1679  *
1680  *	This function examines error ring of @dev and determines
1681  *	whether NCQ needs to be turned off, transfer speed should be
1682  *	stepped down, or falling back to PIO is necessary.
1683  *
1684  *	ECAT_ATA_BUS	: ATA_BUS error for any command
1685  *
1686  *	ECAT_TOUT_HSM	: TIMEOUT for any command or HSM violation for
1687  *			  IO commands
1688  *
1689  *	ECAT_UNK_DEV	: Unknown DEV error for IO commands
1690  *
1691  *	ECAT_DUBIOUS_*	: Identical to above three but occurred while
1692  *			  data transfer hasn't been verified.
1693  *
1694  *	Verdicts are
1695  *
1696  *	NCQ_OFF		: Turn off NCQ.
1697  *
1698  *	SPEED_DOWN	: Speed down transfer speed but don't fall back
1699  *			  to PIO.
1700  *
1701  *	FALLBACK_TO_PIO	: Fall back to PIO.
1702  *
1703  *	Even if multiple verdicts are returned, only one action is
1704  *	taken per error.  An action triggered by non-DUBIOUS errors
1705  *	clears ering, while one triggered by DUBIOUS_* errors doesn't.
1706  *	This is to expedite speed down decisions right after device is
1707  *	initially configured.
1708  *
1709  *	The followings are speed down rules.  #1 and #2 deal with
1710  *	DUBIOUS errors.
1711  *
1712  *	1. If more than one DUBIOUS_ATA_BUS or DUBIOUS_TOUT_HSM errors
1713  *	   occurred during last 5 mins, SPEED_DOWN and FALLBACK_TO_PIO.
1714  *
1715  *	2. If more than one DUBIOUS_TOUT_HSM or DUBIOUS_UNK_DEV errors
1716  *	   occurred during last 5 mins, NCQ_OFF.
1717  *
1718  *	3. If more than 8 ATA_BUS, TOUT_HSM or UNK_DEV errors
1719  *	   ocurred during last 5 mins, FALLBACK_TO_PIO
1720  *
1721  *	4. If more than 3 TOUT_HSM or UNK_DEV errors occurred
1722  *	   during last 10 mins, NCQ_OFF.
1723  *
1724  *	5. If more than 3 ATA_BUS or TOUT_HSM errors, or more than 6
1725  *	   UNK_DEV errors occurred during last 10 mins, SPEED_DOWN.
1726  *
1727  *	LOCKING:
1728  *	Inherited from caller.
1729  *
1730  *	RETURNS:
1731  *	OR of ATA_EH_SPDN_* flags.
1732  */
1733 static unsigned int ata_eh_speed_down_verdict(struct ata_device *dev)
1734 {
1735 	const u64 j5mins = 5LLU * 60 * HZ, j10mins = 10LLU * 60 * HZ;
1736 	u64 j64 = get_jiffies_64();
1737 	struct speed_down_verdict_arg arg;
1738 	unsigned int verdict = 0;
1739 
1740 	/* scan past 5 mins of error history */
1741 	memset(&arg, 0, sizeof(arg));
1742 	arg.since = j64 - min(j64, j5mins);
1743 	ata_ering_map(&dev->ering, speed_down_verdict_cb, &arg);
1744 
1745 	if (arg.nr_errors[ATA_ECAT_DUBIOUS_ATA_BUS] +
1746 	    arg.nr_errors[ATA_ECAT_DUBIOUS_TOUT_HSM] > 1)
1747 		verdict |= ATA_EH_SPDN_SPEED_DOWN |
1748 			ATA_EH_SPDN_FALLBACK_TO_PIO | ATA_EH_SPDN_KEEP_ERRORS;
1749 
1750 	if (arg.nr_errors[ATA_ECAT_DUBIOUS_TOUT_HSM] +
1751 	    arg.nr_errors[ATA_ECAT_DUBIOUS_UNK_DEV] > 1)
1752 		verdict |= ATA_EH_SPDN_NCQ_OFF | ATA_EH_SPDN_KEEP_ERRORS;
1753 
1754 	if (arg.nr_errors[ATA_ECAT_ATA_BUS] +
1755 	    arg.nr_errors[ATA_ECAT_TOUT_HSM] +
1756 	    arg.nr_errors[ATA_ECAT_UNK_DEV] > 6)
1757 		verdict |= ATA_EH_SPDN_FALLBACK_TO_PIO;
1758 
1759 	/* scan past 10 mins of error history */
1760 	memset(&arg, 0, sizeof(arg));
1761 	arg.since = j64 - min(j64, j10mins);
1762 	ata_ering_map(&dev->ering, speed_down_verdict_cb, &arg);
1763 
1764 	if (arg.nr_errors[ATA_ECAT_TOUT_HSM] +
1765 	    arg.nr_errors[ATA_ECAT_UNK_DEV] > 3)
1766 		verdict |= ATA_EH_SPDN_NCQ_OFF;
1767 
1768 	if (arg.nr_errors[ATA_ECAT_ATA_BUS] +
1769 	    arg.nr_errors[ATA_ECAT_TOUT_HSM] > 3 ||
1770 	    arg.nr_errors[ATA_ECAT_UNK_DEV] > 6)
1771 		verdict |= ATA_EH_SPDN_SPEED_DOWN;
1772 
1773 	return verdict;
1774 }
1775 
1776 /**
1777  *	ata_eh_speed_down - record error and speed down if necessary
1778  *	@dev: Failed device
1779  *	@eflags: mask of ATA_EFLAG_* flags
1780  *	@err_mask: err_mask of the error
1781  *
1782  *	Record error and examine error history to determine whether
1783  *	adjusting transmission speed is necessary.  It also sets
1784  *	transmission limits appropriately if such adjustment is
1785  *	necessary.
1786  *
1787  *	LOCKING:
1788  *	Kernel thread context (may sleep).
1789  *
1790  *	RETURNS:
1791  *	Determined recovery action.
1792  */
1793 static unsigned int ata_eh_speed_down(struct ata_device *dev,
1794 				unsigned int eflags, unsigned int err_mask)
1795 {
1796 	struct ata_link *link = ata_dev_phys_link(dev);
1797 	int xfer_ok = 0;
1798 	unsigned int verdict;
1799 	unsigned int action = 0;
1800 
1801 	/* don't bother if Cat-0 error */
1802 	if (ata_eh_categorize_error(eflags, err_mask, &xfer_ok) == 0)
1803 		return 0;
1804 
1805 	/* record error and determine whether speed down is necessary */
1806 	ata_ering_record(&dev->ering, eflags, err_mask);
1807 	verdict = ata_eh_speed_down_verdict(dev);
1808 
1809 	/* turn off NCQ? */
1810 	if ((verdict & ATA_EH_SPDN_NCQ_OFF) &&
1811 	    (dev->flags & (ATA_DFLAG_PIO | ATA_DFLAG_NCQ |
1812 			   ATA_DFLAG_NCQ_OFF)) == ATA_DFLAG_NCQ) {
1813 		dev->flags |= ATA_DFLAG_NCQ_OFF;
1814 		ata_dev_printk(dev, KERN_WARNING,
1815 			       "NCQ disabled due to excessive errors\n");
1816 		goto done;
1817 	}
1818 
1819 	/* speed down? */
1820 	if (verdict & ATA_EH_SPDN_SPEED_DOWN) {
1821 		/* speed down SATA link speed if possible */
1822 		if (sata_down_spd_limit(link) == 0) {
1823 			action |= ATA_EH_RESET;
1824 			goto done;
1825 		}
1826 
1827 		/* lower transfer mode */
1828 		if (dev->spdn_cnt < 2) {
1829 			static const int dma_dnxfer_sel[] =
1830 				{ ATA_DNXFER_DMA, ATA_DNXFER_40C };
1831 			static const int pio_dnxfer_sel[] =
1832 				{ ATA_DNXFER_PIO, ATA_DNXFER_FORCE_PIO0 };
1833 			int sel;
1834 
1835 			if (dev->xfer_shift != ATA_SHIFT_PIO)
1836 				sel = dma_dnxfer_sel[dev->spdn_cnt];
1837 			else
1838 				sel = pio_dnxfer_sel[dev->spdn_cnt];
1839 
1840 			dev->spdn_cnt++;
1841 
1842 			if (ata_down_xfermask_limit(dev, sel) == 0) {
1843 				action |= ATA_EH_RESET;
1844 				goto done;
1845 			}
1846 		}
1847 	}
1848 
1849 	/* Fall back to PIO?  Slowing down to PIO is meaningless for
1850 	 * SATA ATA devices.  Consider it only for PATA and SATAPI.
1851 	 */
1852 	if ((verdict & ATA_EH_SPDN_FALLBACK_TO_PIO) && (dev->spdn_cnt >= 2) &&
1853 	    (link->ap->cbl != ATA_CBL_SATA || dev->class == ATA_DEV_ATAPI) &&
1854 	    (dev->xfer_shift != ATA_SHIFT_PIO)) {
1855 		if (ata_down_xfermask_limit(dev, ATA_DNXFER_FORCE_PIO) == 0) {
1856 			dev->spdn_cnt = 0;
1857 			action |= ATA_EH_RESET;
1858 			goto done;
1859 		}
1860 	}
1861 
1862 	return 0;
1863  done:
1864 	/* device has been slowed down, blow error history */
1865 	if (!(verdict & ATA_EH_SPDN_KEEP_ERRORS))
1866 		ata_ering_clear(&dev->ering);
1867 	return action;
1868 }
1869 
1870 /**
1871  *	ata_eh_link_autopsy - analyze error and determine recovery action
1872  *	@link: host link to perform autopsy on
1873  *
1874  *	Analyze why @link failed and determine which recovery actions
1875  *	are needed.  This function also sets more detailed AC_ERR_*
1876  *	values and fills sense data for ATAPI CHECK SENSE.
1877  *
1878  *	LOCKING:
1879  *	Kernel thread context (may sleep).
1880  */
1881 static void ata_eh_link_autopsy(struct ata_link *link)
1882 {
1883 	struct ata_port *ap = link->ap;
1884 	struct ata_eh_context *ehc = &link->eh_context;
1885 	struct ata_device *dev;
1886 	unsigned int all_err_mask = 0, eflags = 0;
1887 	int tag;
1888 	u32 serror;
1889 	int rc;
1890 
1891 	DPRINTK("ENTER\n");
1892 
1893 	if (ehc->i.flags & ATA_EHI_NO_AUTOPSY)
1894 		return;
1895 
1896 	/* obtain and analyze SError */
1897 	rc = sata_scr_read(link, SCR_ERROR, &serror);
1898 	if (rc == 0) {
1899 		ehc->i.serror |= serror;
1900 		ata_eh_analyze_serror(link);
1901 	} else if (rc != -EOPNOTSUPP) {
1902 		/* SError read failed, force reset and probing */
1903 		ehc->i.probe_mask |= ATA_ALL_DEVICES;
1904 		ehc->i.action |= ATA_EH_RESET;
1905 		ehc->i.err_mask |= AC_ERR_OTHER;
1906 	}
1907 
1908 	/* analyze NCQ failure */
1909 	ata_eh_analyze_ncq_error(link);
1910 
1911 	/* any real error trumps AC_ERR_OTHER */
1912 	if (ehc->i.err_mask & ~AC_ERR_OTHER)
1913 		ehc->i.err_mask &= ~AC_ERR_OTHER;
1914 
1915 	all_err_mask |= ehc->i.err_mask;
1916 
1917 	for (tag = 0; tag < ATA_MAX_QUEUE; tag++) {
1918 		struct ata_queued_cmd *qc = __ata_qc_from_tag(ap, tag);
1919 
1920 		if (!(qc->flags & ATA_QCFLAG_FAILED) ||
1921 		    ata_dev_phys_link(qc->dev) != link)
1922 			continue;
1923 
1924 		/* inherit upper level err_mask */
1925 		qc->err_mask |= ehc->i.err_mask;
1926 
1927 		/* analyze TF */
1928 		ehc->i.action |= ata_eh_analyze_tf(qc, &qc->result_tf);
1929 
1930 		/* DEV errors are probably spurious in case of ATA_BUS error */
1931 		if (qc->err_mask & AC_ERR_ATA_BUS)
1932 			qc->err_mask &= ~(AC_ERR_DEV | AC_ERR_MEDIA |
1933 					  AC_ERR_INVALID);
1934 
1935 		/* any real error trumps unknown error */
1936 		if (qc->err_mask & ~AC_ERR_OTHER)
1937 			qc->err_mask &= ~AC_ERR_OTHER;
1938 
1939 		/* SENSE_VALID trumps dev/unknown error and revalidation */
1940 		if (qc->flags & ATA_QCFLAG_SENSE_VALID)
1941 			qc->err_mask &= ~(AC_ERR_DEV | AC_ERR_OTHER);
1942 
1943 		/* determine whether the command is worth retrying */
1944 		if (!(qc->err_mask & AC_ERR_INVALID) &&
1945 		    ((qc->flags & ATA_QCFLAG_IO) || qc->err_mask != AC_ERR_DEV))
1946 			qc->flags |= ATA_QCFLAG_RETRY;
1947 
1948 		/* accumulate error info */
1949 		ehc->i.dev = qc->dev;
1950 		all_err_mask |= qc->err_mask;
1951 		if (qc->flags & ATA_QCFLAG_IO)
1952 			eflags |= ATA_EFLAG_IS_IO;
1953 	}
1954 
1955 	/* enforce default EH actions */
1956 	if (ap->pflags & ATA_PFLAG_FROZEN ||
1957 	    all_err_mask & (AC_ERR_HSM | AC_ERR_TIMEOUT))
1958 		ehc->i.action |= ATA_EH_RESET;
1959 	else if (((eflags & ATA_EFLAG_IS_IO) && all_err_mask) ||
1960 		 (!(eflags & ATA_EFLAG_IS_IO) && (all_err_mask & ~AC_ERR_DEV)))
1961 		ehc->i.action |= ATA_EH_REVALIDATE;
1962 
1963 	/* If we have offending qcs and the associated failed device,
1964 	 * perform per-dev EH action only on the offending device.
1965 	 */
1966 	if (ehc->i.dev) {
1967 		ehc->i.dev_action[ehc->i.dev->devno] |=
1968 			ehc->i.action & ATA_EH_PERDEV_MASK;
1969 		ehc->i.action &= ~ATA_EH_PERDEV_MASK;
1970 	}
1971 
1972 	/* propagate timeout to host link */
1973 	if ((all_err_mask & AC_ERR_TIMEOUT) && !ata_is_host_link(link))
1974 		ap->link.eh_context.i.err_mask |= AC_ERR_TIMEOUT;
1975 
1976 	/* record error and consider speeding down */
1977 	dev = ehc->i.dev;
1978 	if (!dev && ((ata_link_max_devices(link) == 1 &&
1979 		      ata_dev_enabled(link->device))))
1980 	    dev = link->device;
1981 
1982 	if (dev) {
1983 		if (dev->flags & ATA_DFLAG_DUBIOUS_XFER)
1984 			eflags |= ATA_EFLAG_DUBIOUS_XFER;
1985 		ehc->i.action |= ata_eh_speed_down(dev, eflags, all_err_mask);
1986 	}
1987 
1988 	DPRINTK("EXIT\n");
1989 }
1990 
1991 /**
1992  *	ata_eh_autopsy - analyze error and determine recovery action
1993  *	@ap: host port to perform autopsy on
1994  *
1995  *	Analyze all links of @ap and determine why they failed and
1996  *	which recovery actions are needed.
1997  *
1998  *	LOCKING:
1999  *	Kernel thread context (may sleep).
2000  */
2001 void ata_eh_autopsy(struct ata_port *ap)
2002 {
2003 	struct ata_link *link;
2004 
2005 	ata_port_for_each_link(link, ap)
2006 		ata_eh_link_autopsy(link);
2007 
2008 	/* Handle the frigging slave link.  Autopsy is done similarly
2009 	 * but actions and flags are transferred over to the master
2010 	 * link and handled from there.
2011 	 */
2012 	if (ap->slave_link) {
2013 		struct ata_eh_context *mehc = &ap->link.eh_context;
2014 		struct ata_eh_context *sehc = &ap->slave_link->eh_context;
2015 
2016 		/* transfer control flags from master to slave */
2017 		sehc->i.flags |= mehc->i.flags & ATA_EHI_TO_SLAVE_MASK;
2018 
2019 		/* perform autopsy on the slave link */
2020 		ata_eh_link_autopsy(ap->slave_link);
2021 
2022 		/* transfer actions from slave to master and clear slave */
2023 		ata_eh_about_to_do(ap->slave_link, NULL, ATA_EH_ALL_ACTIONS);
2024 		mehc->i.action		|= sehc->i.action;
2025 		mehc->i.dev_action[1]	|= sehc->i.dev_action[1];
2026 		mehc->i.flags		|= sehc->i.flags;
2027 		ata_eh_done(ap->slave_link, NULL, ATA_EH_ALL_ACTIONS);
2028 	}
2029 
2030 	/* Autopsy of fanout ports can affect host link autopsy.
2031 	 * Perform host link autopsy last.
2032 	 */
2033 	if (sata_pmp_attached(ap))
2034 		ata_eh_link_autopsy(&ap->link);
2035 }
2036 
2037 /**
2038  *	ata_eh_link_report - report error handling to user
2039  *	@link: ATA link EH is going on
2040  *
2041  *	Report EH to user.
2042  *
2043  *	LOCKING:
2044  *	None.
2045  */
2046 static void ata_eh_link_report(struct ata_link *link)
2047 {
2048 	struct ata_port *ap = link->ap;
2049 	struct ata_eh_context *ehc = &link->eh_context;
2050 	const char *frozen, *desc;
2051 	char tries_buf[6];
2052 	int tag, nr_failed = 0;
2053 
2054 	if (ehc->i.flags & ATA_EHI_QUIET)
2055 		return;
2056 
2057 	desc = NULL;
2058 	if (ehc->i.desc[0] != '\0')
2059 		desc = ehc->i.desc;
2060 
2061 	for (tag = 0; tag < ATA_MAX_QUEUE; tag++) {
2062 		struct ata_queued_cmd *qc = __ata_qc_from_tag(ap, tag);
2063 
2064 		if (!(qc->flags & ATA_QCFLAG_FAILED) ||
2065 		    ata_dev_phys_link(qc->dev) != link ||
2066 		    ((qc->flags & ATA_QCFLAG_QUIET) &&
2067 		     qc->err_mask == AC_ERR_DEV))
2068 			continue;
2069 		if (qc->flags & ATA_QCFLAG_SENSE_VALID && !qc->err_mask)
2070 			continue;
2071 
2072 		nr_failed++;
2073 	}
2074 
2075 	if (!nr_failed && !ehc->i.err_mask)
2076 		return;
2077 
2078 	frozen = "";
2079 	if (ap->pflags & ATA_PFLAG_FROZEN)
2080 		frozen = " frozen";
2081 
2082 	memset(tries_buf, 0, sizeof(tries_buf));
2083 	if (ap->eh_tries < ATA_EH_MAX_TRIES)
2084 		snprintf(tries_buf, sizeof(tries_buf) - 1, " t%d",
2085 			 ap->eh_tries);
2086 
2087 	if (ehc->i.dev) {
2088 		ata_dev_printk(ehc->i.dev, KERN_ERR, "exception Emask 0x%x "
2089 			       "SAct 0x%x SErr 0x%x action 0x%x%s%s\n",
2090 			       ehc->i.err_mask, link->sactive, ehc->i.serror,
2091 			       ehc->i.action, frozen, tries_buf);
2092 		if (desc)
2093 			ata_dev_printk(ehc->i.dev, KERN_ERR, "%s\n", desc);
2094 	} else {
2095 		ata_link_printk(link, KERN_ERR, "exception Emask 0x%x "
2096 				"SAct 0x%x SErr 0x%x action 0x%x%s%s\n",
2097 				ehc->i.err_mask, link->sactive, ehc->i.serror,
2098 				ehc->i.action, frozen, tries_buf);
2099 		if (desc)
2100 			ata_link_printk(link, KERN_ERR, "%s\n", desc);
2101 	}
2102 
2103 	if (ehc->i.serror)
2104 		ata_link_printk(link, KERN_ERR,
2105 		  "SError: { %s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s}\n",
2106 		  ehc->i.serror & SERR_DATA_RECOVERED ? "RecovData " : "",
2107 		  ehc->i.serror & SERR_COMM_RECOVERED ? "RecovComm " : "",
2108 		  ehc->i.serror & SERR_DATA ? "UnrecovData " : "",
2109 		  ehc->i.serror & SERR_PERSISTENT ? "Persist " : "",
2110 		  ehc->i.serror & SERR_PROTOCOL ? "Proto " : "",
2111 		  ehc->i.serror & SERR_INTERNAL ? "HostInt " : "",
2112 		  ehc->i.serror & SERR_PHYRDY_CHG ? "PHYRdyChg " : "",
2113 		  ehc->i.serror & SERR_PHY_INT_ERR ? "PHYInt " : "",
2114 		  ehc->i.serror & SERR_COMM_WAKE ? "CommWake " : "",
2115 		  ehc->i.serror & SERR_10B_8B_ERR ? "10B8B " : "",
2116 		  ehc->i.serror & SERR_DISPARITY ? "Dispar " : "",
2117 		  ehc->i.serror & SERR_CRC ? "BadCRC " : "",
2118 		  ehc->i.serror & SERR_HANDSHAKE ? "Handshk " : "",
2119 		  ehc->i.serror & SERR_LINK_SEQ_ERR ? "LinkSeq " : "",
2120 		  ehc->i.serror & SERR_TRANS_ST_ERROR ? "TrStaTrns " : "",
2121 		  ehc->i.serror & SERR_UNRECOG_FIS ? "UnrecFIS " : "",
2122 		  ehc->i.serror & SERR_DEV_XCHG ? "DevExch " : "");
2123 
2124 	for (tag = 0; tag < ATA_MAX_QUEUE; tag++) {
2125 		struct ata_queued_cmd *qc = __ata_qc_from_tag(ap, tag);
2126 		struct ata_taskfile *cmd = &qc->tf, *res = &qc->result_tf;
2127 		const u8 *cdb = qc->cdb;
2128 		char data_buf[20] = "";
2129 		char cdb_buf[70] = "";
2130 
2131 		if (!(qc->flags & ATA_QCFLAG_FAILED) ||
2132 		    ata_dev_phys_link(qc->dev) != link || !qc->err_mask)
2133 			continue;
2134 
2135 		if (qc->dma_dir != DMA_NONE) {
2136 			static const char *dma_str[] = {
2137 				[DMA_BIDIRECTIONAL]	= "bidi",
2138 				[DMA_TO_DEVICE]		= "out",
2139 				[DMA_FROM_DEVICE]	= "in",
2140 			};
2141 			static const char *prot_str[] = {
2142 				[ATA_PROT_PIO]		= "pio",
2143 				[ATA_PROT_DMA]		= "dma",
2144 				[ATA_PROT_NCQ]		= "ncq",
2145 				[ATAPI_PROT_PIO]	= "pio",
2146 				[ATAPI_PROT_DMA]	= "dma",
2147 			};
2148 
2149 			snprintf(data_buf, sizeof(data_buf), " %s %u %s",
2150 				 prot_str[qc->tf.protocol], qc->nbytes,
2151 				 dma_str[qc->dma_dir]);
2152 		}
2153 
2154 		if (ata_is_atapi(qc->tf.protocol))
2155 			snprintf(cdb_buf, sizeof(cdb_buf),
2156 				 "cdb %02x %02x %02x %02x %02x %02x %02x %02x  "
2157 				 "%02x %02x %02x %02x %02x %02x %02x %02x\n         ",
2158 				 cdb[0], cdb[1], cdb[2], cdb[3],
2159 				 cdb[4], cdb[5], cdb[6], cdb[7],
2160 				 cdb[8], cdb[9], cdb[10], cdb[11],
2161 				 cdb[12], cdb[13], cdb[14], cdb[15]);
2162 
2163 		ata_dev_printk(qc->dev, KERN_ERR,
2164 			"cmd %02x/%02x:%02x:%02x:%02x:%02x/%02x:%02x:%02x:%02x:%02x/%02x "
2165 			"tag %d%s\n         %s"
2166 			"res %02x/%02x:%02x:%02x:%02x:%02x/%02x:%02x:%02x:%02x:%02x/%02x "
2167 			"Emask 0x%x (%s)%s\n",
2168 			cmd->command, cmd->feature, cmd->nsect,
2169 			cmd->lbal, cmd->lbam, cmd->lbah,
2170 			cmd->hob_feature, cmd->hob_nsect,
2171 			cmd->hob_lbal, cmd->hob_lbam, cmd->hob_lbah,
2172 			cmd->device, qc->tag, data_buf, cdb_buf,
2173 			res->command, res->feature, res->nsect,
2174 			res->lbal, res->lbam, res->lbah,
2175 			res->hob_feature, res->hob_nsect,
2176 			res->hob_lbal, res->hob_lbam, res->hob_lbah,
2177 			res->device, qc->err_mask, ata_err_string(qc->err_mask),
2178 			qc->err_mask & AC_ERR_NCQ ? " <F>" : "");
2179 
2180 		if (res->command & (ATA_BUSY | ATA_DRDY | ATA_DF | ATA_DRQ |
2181 				    ATA_ERR)) {
2182 			if (res->command & ATA_BUSY)
2183 				ata_dev_printk(qc->dev, KERN_ERR,
2184 				  "status: { Busy }\n");
2185 			else
2186 				ata_dev_printk(qc->dev, KERN_ERR,
2187 				  "status: { %s%s%s%s}\n",
2188 				  res->command & ATA_DRDY ? "DRDY " : "",
2189 				  res->command & ATA_DF ? "DF " : "",
2190 				  res->command & ATA_DRQ ? "DRQ " : "",
2191 				  res->command & ATA_ERR ? "ERR " : "");
2192 		}
2193 
2194 		if (cmd->command != ATA_CMD_PACKET &&
2195 		    (res->feature & (ATA_ICRC | ATA_UNC | ATA_IDNF |
2196 				     ATA_ABORTED)))
2197 			ata_dev_printk(qc->dev, KERN_ERR,
2198 			  "error: { %s%s%s%s}\n",
2199 			  res->feature & ATA_ICRC ? "ICRC " : "",
2200 			  res->feature & ATA_UNC ? "UNC " : "",
2201 			  res->feature & ATA_IDNF ? "IDNF " : "",
2202 			  res->feature & ATA_ABORTED ? "ABRT " : "");
2203 	}
2204 }
2205 
2206 /**
2207  *	ata_eh_report - report error handling to user
2208  *	@ap: ATA port to report EH about
2209  *
2210  *	Report EH to user.
2211  *
2212  *	LOCKING:
2213  *	None.
2214  */
2215 void ata_eh_report(struct ata_port *ap)
2216 {
2217 	struct ata_link *link;
2218 
2219 	__ata_port_for_each_link(link, ap)
2220 		ata_eh_link_report(link);
2221 }
2222 
2223 static int ata_do_reset(struct ata_link *link, ata_reset_fn_t reset,
2224 			unsigned int *classes, unsigned long deadline,
2225 			bool clear_classes)
2226 {
2227 	struct ata_device *dev;
2228 
2229 	if (clear_classes)
2230 		ata_link_for_each_dev(dev, link)
2231 			classes[dev->devno] = ATA_DEV_UNKNOWN;
2232 
2233 	return reset(link, classes, deadline);
2234 }
2235 
2236 static int ata_eh_followup_srst_needed(struct ata_link *link,
2237 				       int rc, const unsigned int *classes)
2238 {
2239 	if ((link->flags & ATA_LFLAG_NO_SRST) || ata_link_offline(link))
2240 		return 0;
2241 	if (rc == -EAGAIN)
2242 		return 1;
2243 	if (sata_pmp_supported(link->ap) && ata_is_host_link(link))
2244 		return 1;
2245 	return 0;
2246 }
2247 
2248 int ata_eh_reset(struct ata_link *link, int classify,
2249 		 ata_prereset_fn_t prereset, ata_reset_fn_t softreset,
2250 		 ata_reset_fn_t hardreset, ata_postreset_fn_t postreset)
2251 {
2252 	struct ata_port *ap = link->ap;
2253 	struct ata_link *slave = ap->slave_link;
2254 	struct ata_eh_context *ehc = &link->eh_context;
2255 	struct ata_eh_context *sehc = &slave->eh_context;
2256 	unsigned int *classes = ehc->classes;
2257 	unsigned int lflags = link->flags;
2258 	int verbose = !(ehc->i.flags & ATA_EHI_QUIET);
2259 	int max_tries = 0, try = 0;
2260 	struct ata_link *failed_link;
2261 	struct ata_device *dev;
2262 	unsigned long deadline, now;
2263 	ata_reset_fn_t reset;
2264 	unsigned long flags;
2265 	u32 sstatus;
2266 	int nr_unknown, rc;
2267 
2268 	/*
2269 	 * Prepare to reset
2270 	 */
2271 	while (ata_eh_reset_timeouts[max_tries] != ULONG_MAX)
2272 		max_tries++;
2273 	if (link->flags & ATA_LFLAG_NO_HRST)
2274 		hardreset = NULL;
2275 	if (link->flags & ATA_LFLAG_NO_SRST)
2276 		softreset = NULL;
2277 
2278 	now = jiffies;
2279 	deadline = ata_deadline(ehc->last_reset, ATA_EH_RESET_COOL_DOWN);
2280 	if (time_before(now, deadline))
2281 		schedule_timeout_uninterruptible(deadline - now);
2282 
2283 	spin_lock_irqsave(ap->lock, flags);
2284 	ap->pflags |= ATA_PFLAG_RESETTING;
2285 	spin_unlock_irqrestore(ap->lock, flags);
2286 
2287 	ata_eh_about_to_do(link, NULL, ATA_EH_RESET);
2288 	ehc->last_reset = jiffies;
2289 
2290 	ata_link_for_each_dev(dev, link) {
2291 		/* If we issue an SRST then an ATA drive (not ATAPI)
2292 		 * may change configuration and be in PIO0 timing. If
2293 		 * we do a hard reset (or are coming from power on)
2294 		 * this is true for ATA or ATAPI. Until we've set a
2295 		 * suitable controller mode we should not touch the
2296 		 * bus as we may be talking too fast.
2297 		 */
2298 		dev->pio_mode = XFER_PIO_0;
2299 
2300 		/* If the controller has a pio mode setup function
2301 		 * then use it to set the chipset to rights. Don't
2302 		 * touch the DMA setup as that will be dealt with when
2303 		 * configuring devices.
2304 		 */
2305 		if (ap->ops->set_piomode)
2306 			ap->ops->set_piomode(ap, dev);
2307 	}
2308 
2309 	/* prefer hardreset */
2310 	reset = NULL;
2311 	ehc->i.action &= ~ATA_EH_RESET;
2312 	if (hardreset) {
2313 		reset = hardreset;
2314 		ehc->i.action |= ATA_EH_HARDRESET;
2315 	} else if (softreset) {
2316 		reset = softreset;
2317 		ehc->i.action |= ATA_EH_SOFTRESET;
2318 	}
2319 
2320 	if (prereset) {
2321 		unsigned long deadline = ata_deadline(jiffies,
2322 						      ATA_EH_PRERESET_TIMEOUT);
2323 
2324 		if (slave) {
2325 			sehc->i.action &= ~ATA_EH_RESET;
2326 			sehc->i.action |= ehc->i.action;
2327 		}
2328 
2329 		rc = prereset(link, deadline);
2330 
2331 		/* If present, do prereset on slave link too.  Reset
2332 		 * is skipped iff both master and slave links report
2333 		 * -ENOENT or clear ATA_EH_RESET.
2334 		 */
2335 		if (slave && (rc == 0 || rc == -ENOENT)) {
2336 			int tmp;
2337 
2338 			tmp = prereset(slave, deadline);
2339 			if (tmp != -ENOENT)
2340 				rc = tmp;
2341 
2342 			ehc->i.action |= sehc->i.action;
2343 		}
2344 
2345 		if (rc) {
2346 			if (rc == -ENOENT) {
2347 				ata_link_printk(link, KERN_DEBUG,
2348 						"port disabled. ignoring.\n");
2349 				ehc->i.action &= ~ATA_EH_RESET;
2350 
2351 				ata_link_for_each_dev(dev, link)
2352 					classes[dev->devno] = ATA_DEV_NONE;
2353 
2354 				rc = 0;
2355 			} else
2356 				ata_link_printk(link, KERN_ERR,
2357 					"prereset failed (errno=%d)\n", rc);
2358 			goto out;
2359 		}
2360 
2361 		/* prereset() might have cleared ATA_EH_RESET.  If so,
2362 		 * bang classes and return.
2363 		 */
2364 		if (reset && !(ehc->i.action & ATA_EH_RESET)) {
2365 			ata_link_for_each_dev(dev, link)
2366 				classes[dev->devno] = ATA_DEV_NONE;
2367 			rc = 0;
2368 			goto out;
2369 		}
2370 	}
2371 
2372  retry:
2373 	/*
2374 	 * Perform reset
2375 	 */
2376 	ehc->last_reset = jiffies;
2377 	if (ata_is_host_link(link))
2378 		ata_eh_freeze_port(ap);
2379 
2380 	deadline = ata_deadline(jiffies, ata_eh_reset_timeouts[try++]);
2381 
2382 	if (reset) {
2383 		if (verbose)
2384 			ata_link_printk(link, KERN_INFO, "%s resetting link\n",
2385 					reset == softreset ? "soft" : "hard");
2386 
2387 		/* mark that this EH session started with reset */
2388 		if (reset == hardreset)
2389 			ehc->i.flags |= ATA_EHI_DID_HARDRESET;
2390 		else
2391 			ehc->i.flags |= ATA_EHI_DID_SOFTRESET;
2392 
2393 		rc = ata_do_reset(link, reset, classes, deadline, true);
2394 		if (rc && rc != -EAGAIN) {
2395 			failed_link = link;
2396 			goto fail;
2397 		}
2398 
2399 		/* hardreset slave link if existent */
2400 		if (slave && reset == hardreset) {
2401 			int tmp;
2402 
2403 			if (verbose)
2404 				ata_link_printk(slave, KERN_INFO,
2405 						"hard resetting link\n");
2406 
2407 			ata_eh_about_to_do(slave, NULL, ATA_EH_RESET);
2408 			tmp = ata_do_reset(slave, reset, classes, deadline,
2409 					   false);
2410 			switch (tmp) {
2411 			case -EAGAIN:
2412 				rc = -EAGAIN;
2413 			case 0:
2414 				break;
2415 			default:
2416 				failed_link = slave;
2417 				rc = tmp;
2418 				goto fail;
2419 			}
2420 		}
2421 
2422 		/* perform follow-up SRST if necessary */
2423 		if (reset == hardreset &&
2424 		    ata_eh_followup_srst_needed(link, rc, classes)) {
2425 			reset = softreset;
2426 
2427 			if (!reset) {
2428 				ata_link_printk(link, KERN_ERR,
2429 						"follow-up softreset required "
2430 						"but no softreset avaliable\n");
2431 				failed_link = link;
2432 				rc = -EINVAL;
2433 				goto fail;
2434 			}
2435 
2436 			ata_eh_about_to_do(link, NULL, ATA_EH_RESET);
2437 			rc = ata_do_reset(link, reset, classes, deadline, true);
2438 		}
2439 	} else {
2440 		if (verbose)
2441 			ata_link_printk(link, KERN_INFO, "no reset method "
2442 					"available, skipping reset\n");
2443 		if (!(lflags & ATA_LFLAG_ASSUME_CLASS))
2444 			lflags |= ATA_LFLAG_ASSUME_ATA;
2445 	}
2446 
2447 	/*
2448 	 * Post-reset processing
2449 	 */
2450 	ata_link_for_each_dev(dev, link) {
2451 		/* After the reset, the device state is PIO 0 and the
2452 		 * controller state is undefined.  Reset also wakes up
2453 		 * drives from sleeping mode.
2454 		 */
2455 		dev->pio_mode = XFER_PIO_0;
2456 		dev->flags &= ~ATA_DFLAG_SLEEPING;
2457 
2458 		if (!ata_phys_link_offline(ata_dev_phys_link(dev))) {
2459 			/* apply class override */
2460 			if (lflags & ATA_LFLAG_ASSUME_ATA)
2461 				classes[dev->devno] = ATA_DEV_ATA;
2462 			else if (lflags & ATA_LFLAG_ASSUME_SEMB)
2463 				classes[dev->devno] = ATA_DEV_SEMB_UNSUP;
2464 		} else
2465 			classes[dev->devno] = ATA_DEV_NONE;
2466 	}
2467 
2468 	/* record current link speed */
2469 	if (sata_scr_read(link, SCR_STATUS, &sstatus) == 0)
2470 		link->sata_spd = (sstatus >> 4) & 0xf;
2471 	if (slave && sata_scr_read(slave, SCR_STATUS, &sstatus) == 0)
2472 		slave->sata_spd = (sstatus >> 4) & 0xf;
2473 
2474 	/* thaw the port */
2475 	if (ata_is_host_link(link))
2476 		ata_eh_thaw_port(ap);
2477 
2478 	/* postreset() should clear hardware SError.  Although SError
2479 	 * is cleared during link resume, clearing SError here is
2480 	 * necessary as some PHYs raise hotplug events after SRST.
2481 	 * This introduces race condition where hotplug occurs between
2482 	 * reset and here.  This race is mediated by cross checking
2483 	 * link onlineness and classification result later.
2484 	 */
2485 	if (postreset) {
2486 		postreset(link, classes);
2487 		if (slave)
2488 			postreset(slave, classes);
2489 	}
2490 
2491 	/* clear cached SError */
2492 	spin_lock_irqsave(link->ap->lock, flags);
2493 	link->eh_info.serror = 0;
2494 	if (slave)
2495 		slave->eh_info.serror = 0;
2496 	spin_unlock_irqrestore(link->ap->lock, flags);
2497 
2498 	/* Make sure onlineness and classification result correspond.
2499 	 * Hotplug could have happened during reset and some
2500 	 * controllers fail to wait while a drive is spinning up after
2501 	 * being hotplugged causing misdetection.  By cross checking
2502 	 * link onlineness and classification result, those conditions
2503 	 * can be reliably detected and retried.
2504 	 */
2505 	nr_unknown = 0;
2506 	ata_link_for_each_dev(dev, link) {
2507 		/* convert all ATA_DEV_UNKNOWN to ATA_DEV_NONE */
2508 		if (classes[dev->devno] == ATA_DEV_UNKNOWN) {
2509 			classes[dev->devno] = ATA_DEV_NONE;
2510 			if (ata_phys_link_online(ata_dev_phys_link(dev)))
2511 				nr_unknown++;
2512 		}
2513 	}
2514 
2515 	if (classify && nr_unknown) {
2516 		if (try < max_tries) {
2517 			ata_link_printk(link, KERN_WARNING, "link online but "
2518 				       "device misclassified, retrying\n");
2519 			failed_link = link;
2520 			rc = -EAGAIN;
2521 			goto fail;
2522 		}
2523 		ata_link_printk(link, KERN_WARNING,
2524 			       "link online but device misclassified, "
2525 			       "device detection might fail\n");
2526 	}
2527 
2528 	/* reset successful, schedule revalidation */
2529 	ata_eh_done(link, NULL, ATA_EH_RESET);
2530 	if (slave)
2531 		ata_eh_done(slave, NULL, ATA_EH_RESET);
2532 	ehc->last_reset = jiffies;
2533 	ehc->i.action |= ATA_EH_REVALIDATE;
2534 
2535 	rc = 0;
2536  out:
2537 	/* clear hotplug flag */
2538 	ehc->i.flags &= ~ATA_EHI_HOTPLUGGED;
2539 	if (slave)
2540 		sehc->i.flags &= ~ATA_EHI_HOTPLUGGED;
2541 
2542 	spin_lock_irqsave(ap->lock, flags);
2543 	ap->pflags &= ~ATA_PFLAG_RESETTING;
2544 	spin_unlock_irqrestore(ap->lock, flags);
2545 
2546 	return rc;
2547 
2548  fail:
2549 	/* if SCR isn't accessible on a fan-out port, PMP needs to be reset */
2550 	if (!ata_is_host_link(link) &&
2551 	    sata_scr_read(link, SCR_STATUS, &sstatus))
2552 		rc = -ERESTART;
2553 
2554 	if (rc == -ERESTART || try >= max_tries)
2555 		goto out;
2556 
2557 	now = jiffies;
2558 	if (time_before(now, deadline)) {
2559 		unsigned long delta = deadline - now;
2560 
2561 		ata_link_printk(failed_link, KERN_WARNING,
2562 			"reset failed (errno=%d), retrying in %u secs\n",
2563 			rc, DIV_ROUND_UP(jiffies_to_msecs(delta), 1000));
2564 
2565 		while (delta)
2566 			delta = schedule_timeout_uninterruptible(delta);
2567 	}
2568 
2569 	if (try == max_tries - 1) {
2570 		sata_down_spd_limit(link);
2571 		if (slave)
2572 			sata_down_spd_limit(slave);
2573 	} else if (rc == -EPIPE)
2574 		sata_down_spd_limit(failed_link);
2575 
2576 	if (hardreset)
2577 		reset = hardreset;
2578 	goto retry;
2579 }
2580 
2581 static inline void ata_eh_pull_park_action(struct ata_port *ap)
2582 {
2583 	struct ata_link *link;
2584 	struct ata_device *dev;
2585 	unsigned long flags;
2586 
2587 	/*
2588 	 * This function can be thought of as an extended version of
2589 	 * ata_eh_about_to_do() specially crafted to accommodate the
2590 	 * requirements of ATA_EH_PARK handling. Since the EH thread
2591 	 * does not leave the do {} while () loop in ata_eh_recover as
2592 	 * long as the timeout for a park request to *one* device on
2593 	 * the port has not expired, and since we still want to pick
2594 	 * up park requests to other devices on the same port or
2595 	 * timeout updates for the same device, we have to pull
2596 	 * ATA_EH_PARK actions from eh_info into eh_context.i
2597 	 * ourselves at the beginning of each pass over the loop.
2598 	 *
2599 	 * Additionally, all write accesses to &ap->park_req_pending
2600 	 * through INIT_COMPLETION() (see below) or complete_all()
2601 	 * (see ata_scsi_park_store()) are protected by the host lock.
2602 	 * As a result we have that park_req_pending.done is zero on
2603 	 * exit from this function, i.e. when ATA_EH_PARK actions for
2604 	 * *all* devices on port ap have been pulled into the
2605 	 * respective eh_context structs. If, and only if,
2606 	 * park_req_pending.done is non-zero by the time we reach
2607 	 * wait_for_completion_timeout(), another ATA_EH_PARK action
2608 	 * has been scheduled for at least one of the devices on port
2609 	 * ap and we have to cycle over the do {} while () loop in
2610 	 * ata_eh_recover() again.
2611 	 */
2612 
2613 	spin_lock_irqsave(ap->lock, flags);
2614 	INIT_COMPLETION(ap->park_req_pending);
2615 	ata_port_for_each_link(link, ap) {
2616 		ata_link_for_each_dev(dev, link) {
2617 			struct ata_eh_info *ehi = &link->eh_info;
2618 
2619 			link->eh_context.i.dev_action[dev->devno] |=
2620 				ehi->dev_action[dev->devno] & ATA_EH_PARK;
2621 			ata_eh_clear_action(link, dev, ehi, ATA_EH_PARK);
2622 		}
2623 	}
2624 	spin_unlock_irqrestore(ap->lock, flags);
2625 }
2626 
2627 static void ata_eh_park_issue_cmd(struct ata_device *dev, int park)
2628 {
2629 	struct ata_eh_context *ehc = &dev->link->eh_context;
2630 	struct ata_taskfile tf;
2631 	unsigned int err_mask;
2632 
2633 	ata_tf_init(dev, &tf);
2634 	if (park) {
2635 		ehc->unloaded_mask |= 1 << dev->devno;
2636 		tf.command = ATA_CMD_IDLEIMMEDIATE;
2637 		tf.feature = 0x44;
2638 		tf.lbal = 0x4c;
2639 		tf.lbam = 0x4e;
2640 		tf.lbah = 0x55;
2641 	} else {
2642 		ehc->unloaded_mask &= ~(1 << dev->devno);
2643 		tf.command = ATA_CMD_CHK_POWER;
2644 	}
2645 
2646 	tf.flags |= ATA_TFLAG_DEVICE | ATA_TFLAG_ISADDR;
2647 	tf.protocol |= ATA_PROT_NODATA;
2648 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
2649 	if (park && (err_mask || tf.lbal != 0xc4)) {
2650 		ata_dev_printk(dev, KERN_ERR, "head unload failed!\n");
2651 		ehc->unloaded_mask &= ~(1 << dev->devno);
2652 	}
2653 }
2654 
2655 static int ata_eh_revalidate_and_attach(struct ata_link *link,
2656 					struct ata_device **r_failed_dev)
2657 {
2658 	struct ata_port *ap = link->ap;
2659 	struct ata_eh_context *ehc = &link->eh_context;
2660 	struct ata_device *dev;
2661 	unsigned int new_mask = 0;
2662 	unsigned long flags;
2663 	int rc = 0;
2664 
2665 	DPRINTK("ENTER\n");
2666 
2667 	/* For PATA drive side cable detection to work, IDENTIFY must
2668 	 * be done backwards such that PDIAG- is released by the slave
2669 	 * device before the master device is identified.
2670 	 */
2671 	ata_link_for_each_dev_reverse(dev, link) {
2672 		unsigned int action = ata_eh_dev_action(dev);
2673 		unsigned int readid_flags = 0;
2674 
2675 		if (ehc->i.flags & ATA_EHI_DID_RESET)
2676 			readid_flags |= ATA_READID_POSTRESET;
2677 
2678 		if ((action & ATA_EH_REVALIDATE) && ata_dev_enabled(dev)) {
2679 			WARN_ON(dev->class == ATA_DEV_PMP);
2680 
2681 			if (ata_phys_link_offline(ata_dev_phys_link(dev))) {
2682 				rc = -EIO;
2683 				goto err;
2684 			}
2685 
2686 			ata_eh_about_to_do(link, dev, ATA_EH_REVALIDATE);
2687 			rc = ata_dev_revalidate(dev, ehc->classes[dev->devno],
2688 						readid_flags);
2689 			if (rc)
2690 				goto err;
2691 
2692 			ata_eh_done(link, dev, ATA_EH_REVALIDATE);
2693 
2694 			/* Configuration may have changed, reconfigure
2695 			 * transfer mode.
2696 			 */
2697 			ehc->i.flags |= ATA_EHI_SETMODE;
2698 
2699 			/* schedule the scsi_rescan_device() here */
2700 			queue_work(ata_aux_wq, &(ap->scsi_rescan_task));
2701 		} else if (dev->class == ATA_DEV_UNKNOWN &&
2702 			   ehc->tries[dev->devno] &&
2703 			   ata_class_enabled(ehc->classes[dev->devno])) {
2704 			dev->class = ehc->classes[dev->devno];
2705 
2706 			if (dev->class == ATA_DEV_PMP)
2707 				rc = sata_pmp_attach(dev);
2708 			else
2709 				rc = ata_dev_read_id(dev, &dev->class,
2710 						     readid_flags, dev->id);
2711 			switch (rc) {
2712 			case 0:
2713 				new_mask |= 1 << dev->devno;
2714 				break;
2715 			case -ENOENT:
2716 				/* IDENTIFY was issued to non-existent
2717 				 * device.  No need to reset.  Just
2718 				 * thaw and kill the device.
2719 				 */
2720 				ata_eh_thaw_port(ap);
2721 				dev->class = ATA_DEV_UNKNOWN;
2722 				break;
2723 			default:
2724 				dev->class = ATA_DEV_UNKNOWN;
2725 				goto err;
2726 			}
2727 		}
2728 	}
2729 
2730 	/* PDIAG- should have been released, ask cable type if post-reset */
2731 	if ((ehc->i.flags & ATA_EHI_DID_RESET) && ata_is_host_link(link)) {
2732 		if (ap->ops->cable_detect)
2733 			ap->cbl = ap->ops->cable_detect(ap);
2734 		ata_force_cbl(ap);
2735 	}
2736 
2737 	/* Configure new devices forward such that user doesn't see
2738 	 * device detection messages backwards.
2739 	 */
2740 	ata_link_for_each_dev(dev, link) {
2741 		if (!(new_mask & (1 << dev->devno)) ||
2742 		    dev->class == ATA_DEV_PMP)
2743 			continue;
2744 
2745 		ehc->i.flags |= ATA_EHI_PRINTINFO;
2746 		rc = ata_dev_configure(dev);
2747 		ehc->i.flags &= ~ATA_EHI_PRINTINFO;
2748 		if (rc)
2749 			goto err;
2750 
2751 		spin_lock_irqsave(ap->lock, flags);
2752 		ap->pflags |= ATA_PFLAG_SCSI_HOTPLUG;
2753 		spin_unlock_irqrestore(ap->lock, flags);
2754 
2755 		/* new device discovered, configure xfermode */
2756 		ehc->i.flags |= ATA_EHI_SETMODE;
2757 	}
2758 
2759 	return 0;
2760 
2761  err:
2762 	*r_failed_dev = dev;
2763 	DPRINTK("EXIT rc=%d\n", rc);
2764 	return rc;
2765 }
2766 
2767 /**
2768  *	ata_set_mode - Program timings and issue SET FEATURES - XFER
2769  *	@link: link on which timings will be programmed
2770  *	@r_failed_dev: out paramter for failed device
2771  *
2772  *	Set ATA device disk transfer mode (PIO3, UDMA6, etc.).  If
2773  *	ata_set_mode() fails, pointer to the failing device is
2774  *	returned in @r_failed_dev.
2775  *
2776  *	LOCKING:
2777  *	PCI/etc. bus probe sem.
2778  *
2779  *	RETURNS:
2780  *	0 on success, negative errno otherwise
2781  */
2782 int ata_set_mode(struct ata_link *link, struct ata_device **r_failed_dev)
2783 {
2784 	struct ata_port *ap = link->ap;
2785 	struct ata_device *dev;
2786 	int rc;
2787 
2788 	/* if data transfer is verified, clear DUBIOUS_XFER on ering top */
2789 	ata_link_for_each_dev(dev, link) {
2790 		if (!(dev->flags & ATA_DFLAG_DUBIOUS_XFER)) {
2791 			struct ata_ering_entry *ent;
2792 
2793 			ent = ata_ering_top(&dev->ering);
2794 			if (ent)
2795 				ent->eflags &= ~ATA_EFLAG_DUBIOUS_XFER;
2796 		}
2797 	}
2798 
2799 	/* has private set_mode? */
2800 	if (ap->ops->set_mode)
2801 		rc = ap->ops->set_mode(link, r_failed_dev);
2802 	else
2803 		rc = ata_do_set_mode(link, r_failed_dev);
2804 
2805 	/* if transfer mode has changed, set DUBIOUS_XFER on device */
2806 	ata_link_for_each_dev(dev, link) {
2807 		struct ata_eh_context *ehc = &link->eh_context;
2808 		u8 saved_xfer_mode = ehc->saved_xfer_mode[dev->devno];
2809 		u8 saved_ncq = !!(ehc->saved_ncq_enabled & (1 << dev->devno));
2810 
2811 		if (dev->xfer_mode != saved_xfer_mode ||
2812 		    ata_ncq_enabled(dev) != saved_ncq)
2813 			dev->flags |= ATA_DFLAG_DUBIOUS_XFER;
2814 	}
2815 
2816 	return rc;
2817 }
2818 
2819 /**
2820  *	atapi_eh_clear_ua - Clear ATAPI UNIT ATTENTION after reset
2821  *	@dev: ATAPI device to clear UA for
2822  *
2823  *	Resets and other operations can make an ATAPI device raise
2824  *	UNIT ATTENTION which causes the next operation to fail.  This
2825  *	function clears UA.
2826  *
2827  *	LOCKING:
2828  *	EH context (may sleep).
2829  *
2830  *	RETURNS:
2831  *	0 on success, -errno on failure.
2832  */
2833 static int atapi_eh_clear_ua(struct ata_device *dev)
2834 {
2835 	int i;
2836 
2837 	for (i = 0; i < ATA_EH_UA_TRIES; i++) {
2838 		u8 sense_buffer[SCSI_SENSE_BUFFERSIZE];
2839 		u8 sense_key = 0;
2840 		unsigned int err_mask;
2841 
2842 		err_mask = atapi_eh_tur(dev, &sense_key);
2843 		if (err_mask != 0 && err_mask != AC_ERR_DEV) {
2844 			ata_dev_printk(dev, KERN_WARNING, "TEST_UNIT_READY "
2845 				"failed (err_mask=0x%x)\n", err_mask);
2846 			return -EIO;
2847 		}
2848 
2849 		if (!err_mask || sense_key != UNIT_ATTENTION)
2850 			return 0;
2851 
2852 		err_mask = atapi_eh_request_sense(dev, sense_buffer, sense_key);
2853 		if (err_mask) {
2854 			ata_dev_printk(dev, KERN_WARNING, "failed to clear "
2855 				"UNIT ATTENTION (err_mask=0x%x)\n", err_mask);
2856 			return -EIO;
2857 		}
2858 	}
2859 
2860 	ata_dev_printk(dev, KERN_WARNING,
2861 		"UNIT ATTENTION persists after %d tries\n", ATA_EH_UA_TRIES);
2862 
2863 	return 0;
2864 }
2865 
2866 static int ata_link_nr_enabled(struct ata_link *link)
2867 {
2868 	struct ata_device *dev;
2869 	int cnt = 0;
2870 
2871 	ata_link_for_each_dev(dev, link)
2872 		if (ata_dev_enabled(dev))
2873 			cnt++;
2874 	return cnt;
2875 }
2876 
2877 static int ata_link_nr_vacant(struct ata_link *link)
2878 {
2879 	struct ata_device *dev;
2880 	int cnt = 0;
2881 
2882 	ata_link_for_each_dev(dev, link)
2883 		if (dev->class == ATA_DEV_UNKNOWN)
2884 			cnt++;
2885 	return cnt;
2886 }
2887 
2888 static int ata_eh_skip_recovery(struct ata_link *link)
2889 {
2890 	struct ata_port *ap = link->ap;
2891 	struct ata_eh_context *ehc = &link->eh_context;
2892 	struct ata_device *dev;
2893 
2894 	/* skip disabled links */
2895 	if (link->flags & ATA_LFLAG_DISABLED)
2896 		return 1;
2897 
2898 	/* thaw frozen port and recover failed devices */
2899 	if ((ap->pflags & ATA_PFLAG_FROZEN) || ata_link_nr_enabled(link))
2900 		return 0;
2901 
2902 	/* reset at least once if reset is requested */
2903 	if ((ehc->i.action & ATA_EH_RESET) &&
2904 	    !(ehc->i.flags & ATA_EHI_DID_RESET))
2905 		return 0;
2906 
2907 	/* skip if class codes for all vacant slots are ATA_DEV_NONE */
2908 	ata_link_for_each_dev(dev, link) {
2909 		if (dev->class == ATA_DEV_UNKNOWN &&
2910 		    ehc->classes[dev->devno] != ATA_DEV_NONE)
2911 			return 0;
2912 	}
2913 
2914 	return 1;
2915 }
2916 
2917 static int ata_eh_schedule_probe(struct ata_device *dev)
2918 {
2919 	struct ata_eh_context *ehc = &dev->link->eh_context;
2920 
2921 	if (!(ehc->i.probe_mask & (1 << dev->devno)) ||
2922 	    (ehc->did_probe_mask & (1 << dev->devno)))
2923 		return 0;
2924 
2925 	ata_eh_detach_dev(dev);
2926 	ata_dev_init(dev);
2927 	ehc->did_probe_mask |= (1 << dev->devno);
2928 	ehc->i.action |= ATA_EH_RESET;
2929 	ehc->saved_xfer_mode[dev->devno] = 0;
2930 	ehc->saved_ncq_enabled &= ~(1 << dev->devno);
2931 
2932 	return 1;
2933 }
2934 
2935 static int ata_eh_handle_dev_fail(struct ata_device *dev, int err)
2936 {
2937 	struct ata_eh_context *ehc = &dev->link->eh_context;
2938 
2939 	ehc->tries[dev->devno]--;
2940 
2941 	switch (err) {
2942 	case -ENODEV:
2943 		/* device missing or wrong IDENTIFY data, schedule probing */
2944 		ehc->i.probe_mask |= (1 << dev->devno);
2945 	case -EINVAL:
2946 		/* give it just one more chance */
2947 		ehc->tries[dev->devno] = min(ehc->tries[dev->devno], 1);
2948 	case -EIO:
2949 		if (ehc->tries[dev->devno] == 1 && dev->pio_mode > XFER_PIO_0) {
2950 			/* This is the last chance, better to slow
2951 			 * down than lose it.
2952 			 */
2953 			sata_down_spd_limit(ata_dev_phys_link(dev));
2954 			ata_down_xfermask_limit(dev, ATA_DNXFER_PIO);
2955 		}
2956 	}
2957 
2958 	if (ata_dev_enabled(dev) && !ehc->tries[dev->devno]) {
2959 		/* disable device if it has used up all its chances */
2960 		ata_dev_disable(dev);
2961 
2962 		/* detach if offline */
2963 		if (ata_phys_link_offline(ata_dev_phys_link(dev)))
2964 			ata_eh_detach_dev(dev);
2965 
2966 		/* schedule probe if necessary */
2967 		if (ata_eh_schedule_probe(dev)) {
2968 			ehc->tries[dev->devno] = ATA_EH_DEV_TRIES;
2969 			memset(ehc->cmd_timeout_idx[dev->devno], 0,
2970 			       sizeof(ehc->cmd_timeout_idx[dev->devno]));
2971 		}
2972 
2973 		return 1;
2974 	} else {
2975 		ehc->i.action |= ATA_EH_RESET;
2976 		return 0;
2977 	}
2978 }
2979 
2980 /**
2981  *	ata_eh_recover - recover host port after error
2982  *	@ap: host port to recover
2983  *	@prereset: prereset method (can be NULL)
2984  *	@softreset: softreset method (can be NULL)
2985  *	@hardreset: hardreset method (can be NULL)
2986  *	@postreset: postreset method (can be NULL)
2987  *	@r_failed_link: out parameter for failed link
2988  *
2989  *	This is the alpha and omega, eum and yang, heart and soul of
2990  *	libata exception handling.  On entry, actions required to
2991  *	recover each link and hotplug requests are recorded in the
2992  *	link's eh_context.  This function executes all the operations
2993  *	with appropriate retrials and fallbacks to resurrect failed
2994  *	devices, detach goners and greet newcomers.
2995  *
2996  *	LOCKING:
2997  *	Kernel thread context (may sleep).
2998  *
2999  *	RETURNS:
3000  *	0 on success, -errno on failure.
3001  */
3002 int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
3003 		   ata_reset_fn_t softreset, ata_reset_fn_t hardreset,
3004 		   ata_postreset_fn_t postreset,
3005 		   struct ata_link **r_failed_link)
3006 {
3007 	struct ata_link *link;
3008 	struct ata_device *dev;
3009 	int nr_failed_devs;
3010 	int rc;
3011 	unsigned long flags, deadline;
3012 
3013 	DPRINTK("ENTER\n");
3014 
3015 	/* prep for recovery */
3016 	ata_port_for_each_link(link, ap) {
3017 		struct ata_eh_context *ehc = &link->eh_context;
3018 
3019 		/* re-enable link? */
3020 		if (ehc->i.action & ATA_EH_ENABLE_LINK) {
3021 			ata_eh_about_to_do(link, NULL, ATA_EH_ENABLE_LINK);
3022 			spin_lock_irqsave(ap->lock, flags);
3023 			link->flags &= ~ATA_LFLAG_DISABLED;
3024 			spin_unlock_irqrestore(ap->lock, flags);
3025 			ata_eh_done(link, NULL, ATA_EH_ENABLE_LINK);
3026 		}
3027 
3028 		ata_link_for_each_dev(dev, link) {
3029 			if (link->flags & ATA_LFLAG_NO_RETRY)
3030 				ehc->tries[dev->devno] = 1;
3031 			else
3032 				ehc->tries[dev->devno] = ATA_EH_DEV_TRIES;
3033 
3034 			/* collect port action mask recorded in dev actions */
3035 			ehc->i.action |= ehc->i.dev_action[dev->devno] &
3036 					 ~ATA_EH_PERDEV_MASK;
3037 			ehc->i.dev_action[dev->devno] &= ATA_EH_PERDEV_MASK;
3038 
3039 			/* process hotplug request */
3040 			if (dev->flags & ATA_DFLAG_DETACH)
3041 				ata_eh_detach_dev(dev);
3042 
3043 			/* schedule probe if necessary */
3044 			if (!ata_dev_enabled(dev))
3045 				ata_eh_schedule_probe(dev);
3046 		}
3047 	}
3048 
3049  retry:
3050 	rc = 0;
3051 	nr_failed_devs = 0;
3052 
3053 	/* if UNLOADING, finish immediately */
3054 	if (ap->pflags & ATA_PFLAG_UNLOADING)
3055 		goto out;
3056 
3057 	/* prep for EH */
3058 	ata_port_for_each_link(link, ap) {
3059 		struct ata_eh_context *ehc = &link->eh_context;
3060 
3061 		/* skip EH if possible. */
3062 		if (ata_eh_skip_recovery(link))
3063 			ehc->i.action = 0;
3064 
3065 		ata_link_for_each_dev(dev, link)
3066 			ehc->classes[dev->devno] = ATA_DEV_UNKNOWN;
3067 	}
3068 
3069 	/* reset */
3070 	ata_port_for_each_link(link, ap) {
3071 		struct ata_eh_context *ehc = &link->eh_context;
3072 
3073 		if (!(ehc->i.action & ATA_EH_RESET))
3074 			continue;
3075 
3076 		rc = ata_eh_reset(link, ata_link_nr_vacant(link),
3077 				  prereset, softreset, hardreset, postreset);
3078 		if (rc) {
3079 			ata_link_printk(link, KERN_ERR,
3080 					"reset failed, giving up\n");
3081 			goto out;
3082 		}
3083 	}
3084 
3085 	do {
3086 		unsigned long now;
3087 
3088 		/*
3089 		 * clears ATA_EH_PARK in eh_info and resets
3090 		 * ap->park_req_pending
3091 		 */
3092 		ata_eh_pull_park_action(ap);
3093 
3094 		deadline = jiffies;
3095 		ata_port_for_each_link(link, ap) {
3096 			ata_link_for_each_dev(dev, link) {
3097 				struct ata_eh_context *ehc = &link->eh_context;
3098 				unsigned long tmp;
3099 
3100 				if (dev->class != ATA_DEV_ATA)
3101 					continue;
3102 				if (!(ehc->i.dev_action[dev->devno] &
3103 				      ATA_EH_PARK))
3104 					continue;
3105 				tmp = dev->unpark_deadline;
3106 				if (time_before(deadline, tmp))
3107 					deadline = tmp;
3108 				else if (time_before_eq(tmp, jiffies))
3109 					continue;
3110 				if (ehc->unloaded_mask & (1 << dev->devno))
3111 					continue;
3112 
3113 				ata_eh_park_issue_cmd(dev, 1);
3114 			}
3115 		}
3116 
3117 		now = jiffies;
3118 		if (time_before_eq(deadline, now))
3119 			break;
3120 
3121 		deadline = wait_for_completion_timeout(&ap->park_req_pending,
3122 						       deadline - now);
3123 	} while (deadline);
3124 	ata_port_for_each_link(link, ap) {
3125 		ata_link_for_each_dev(dev, link) {
3126 			if (!(link->eh_context.unloaded_mask &
3127 			      (1 << dev->devno)))
3128 				continue;
3129 
3130 			ata_eh_park_issue_cmd(dev, 0);
3131 			ata_eh_done(link, dev, ATA_EH_PARK);
3132 		}
3133 	}
3134 
3135 	/* the rest */
3136 	ata_port_for_each_link(link, ap) {
3137 		struct ata_eh_context *ehc = &link->eh_context;
3138 
3139 		/* revalidate existing devices and attach new ones */
3140 		rc = ata_eh_revalidate_and_attach(link, &dev);
3141 		if (rc)
3142 			goto dev_fail;
3143 
3144 		/* if PMP got attached, return, pmp EH will take care of it */
3145 		if (link->device->class == ATA_DEV_PMP) {
3146 			ehc->i.action = 0;
3147 			return 0;
3148 		}
3149 
3150 		/* configure transfer mode if necessary */
3151 		if (ehc->i.flags & ATA_EHI_SETMODE) {
3152 			rc = ata_set_mode(link, &dev);
3153 			if (rc)
3154 				goto dev_fail;
3155 			ehc->i.flags &= ~ATA_EHI_SETMODE;
3156 		}
3157 
3158 		/* If reset has been issued, clear UA to avoid
3159 		 * disrupting the current users of the device.
3160 		 */
3161 		if (ehc->i.flags & ATA_EHI_DID_RESET) {
3162 			ata_link_for_each_dev(dev, link) {
3163 				if (dev->class != ATA_DEV_ATAPI)
3164 					continue;
3165 				rc = atapi_eh_clear_ua(dev);
3166 				if (rc)
3167 					goto dev_fail;
3168 			}
3169 		}
3170 
3171 		/* configure link power saving */
3172 		if (ehc->i.action & ATA_EH_LPM)
3173 			ata_link_for_each_dev(dev, link)
3174 				ata_dev_enable_pm(dev, ap->pm_policy);
3175 
3176 		/* this link is okay now */
3177 		ehc->i.flags = 0;
3178 		continue;
3179 
3180 dev_fail:
3181 		nr_failed_devs++;
3182 		ata_eh_handle_dev_fail(dev, rc);
3183 
3184 		if (ap->pflags & ATA_PFLAG_FROZEN) {
3185 			/* PMP reset requires working host port.
3186 			 * Can't retry if it's frozen.
3187 			 */
3188 			if (sata_pmp_attached(ap))
3189 				goto out;
3190 			break;
3191 		}
3192 	}
3193 
3194 	if (nr_failed_devs)
3195 		goto retry;
3196 
3197  out:
3198 	if (rc && r_failed_link)
3199 		*r_failed_link = link;
3200 
3201 	DPRINTK("EXIT, rc=%d\n", rc);
3202 	return rc;
3203 }
3204 
3205 /**
3206  *	ata_eh_finish - finish up EH
3207  *	@ap: host port to finish EH for
3208  *
3209  *	Recovery is complete.  Clean up EH states and retry or finish
3210  *	failed qcs.
3211  *
3212  *	LOCKING:
3213  *	None.
3214  */
3215 void ata_eh_finish(struct ata_port *ap)
3216 {
3217 	int tag;
3218 
3219 	/* retry or finish qcs */
3220 	for (tag = 0; tag < ATA_MAX_QUEUE; tag++) {
3221 		struct ata_queued_cmd *qc = __ata_qc_from_tag(ap, tag);
3222 
3223 		if (!(qc->flags & ATA_QCFLAG_FAILED))
3224 			continue;
3225 
3226 		if (qc->err_mask) {
3227 			/* FIXME: Once EH migration is complete,
3228 			 * generate sense data in this function,
3229 			 * considering both err_mask and tf.
3230 			 */
3231 			if (qc->flags & ATA_QCFLAG_RETRY)
3232 				ata_eh_qc_retry(qc);
3233 			else
3234 				ata_eh_qc_complete(qc);
3235 		} else {
3236 			if (qc->flags & ATA_QCFLAG_SENSE_VALID) {
3237 				ata_eh_qc_complete(qc);
3238 			} else {
3239 				/* feed zero TF to sense generation */
3240 				memset(&qc->result_tf, 0, sizeof(qc->result_tf));
3241 				ata_eh_qc_retry(qc);
3242 			}
3243 		}
3244 	}
3245 
3246 	/* make sure nr_active_links is zero after EH */
3247 	WARN_ON(ap->nr_active_links);
3248 	ap->nr_active_links = 0;
3249 }
3250 
3251 /**
3252  *	ata_do_eh - do standard error handling
3253  *	@ap: host port to handle error for
3254  *
3255  *	@prereset: prereset method (can be NULL)
3256  *	@softreset: softreset method (can be NULL)
3257  *	@hardreset: hardreset method (can be NULL)
3258  *	@postreset: postreset method (can be NULL)
3259  *
3260  *	Perform standard error handling sequence.
3261  *
3262  *	LOCKING:
3263  *	Kernel thread context (may sleep).
3264  */
3265 void ata_do_eh(struct ata_port *ap, ata_prereset_fn_t prereset,
3266 	       ata_reset_fn_t softreset, ata_reset_fn_t hardreset,
3267 	       ata_postreset_fn_t postreset)
3268 {
3269 	struct ata_device *dev;
3270 	int rc;
3271 
3272 	ata_eh_autopsy(ap);
3273 	ata_eh_report(ap);
3274 
3275 	rc = ata_eh_recover(ap, prereset, softreset, hardreset, postreset,
3276 			    NULL);
3277 	if (rc) {
3278 		ata_link_for_each_dev(dev, &ap->link)
3279 			ata_dev_disable(dev);
3280 	}
3281 
3282 	ata_eh_finish(ap);
3283 }
3284 
3285 /**
3286  *	ata_std_error_handler - standard error handler
3287  *	@ap: host port to handle error for
3288  *
3289  *	Standard error handler
3290  *
3291  *	LOCKING:
3292  *	Kernel thread context (may sleep).
3293  */
3294 void ata_std_error_handler(struct ata_port *ap)
3295 {
3296 	struct ata_port_operations *ops = ap->ops;
3297 	ata_reset_fn_t hardreset = ops->hardreset;
3298 
3299 	/* ignore built-in hardreset if SCR access is not available */
3300 	if (ata_is_builtin_hardreset(hardreset) && !sata_scr_valid(&ap->link))
3301 		hardreset = NULL;
3302 
3303 	ata_do_eh(ap, ops->prereset, ops->softreset, hardreset, ops->postreset);
3304 }
3305 
3306 #ifdef CONFIG_PM
3307 /**
3308  *	ata_eh_handle_port_suspend - perform port suspend operation
3309  *	@ap: port to suspend
3310  *
3311  *	Suspend @ap.
3312  *
3313  *	LOCKING:
3314  *	Kernel thread context (may sleep).
3315  */
3316 static void ata_eh_handle_port_suspend(struct ata_port *ap)
3317 {
3318 	unsigned long flags;
3319 	int rc = 0;
3320 
3321 	/* are we suspending? */
3322 	spin_lock_irqsave(ap->lock, flags);
3323 	if (!(ap->pflags & ATA_PFLAG_PM_PENDING) ||
3324 	    ap->pm_mesg.event == PM_EVENT_ON) {
3325 		spin_unlock_irqrestore(ap->lock, flags);
3326 		return;
3327 	}
3328 	spin_unlock_irqrestore(ap->lock, flags);
3329 
3330 	WARN_ON(ap->pflags & ATA_PFLAG_SUSPENDED);
3331 
3332 	/* tell ACPI we're suspending */
3333 	rc = ata_acpi_on_suspend(ap);
3334 	if (rc)
3335 		goto out;
3336 
3337 	/* suspend */
3338 	ata_eh_freeze_port(ap);
3339 
3340 	if (ap->ops->port_suspend)
3341 		rc = ap->ops->port_suspend(ap, ap->pm_mesg);
3342 
3343 	ata_acpi_set_state(ap, PMSG_SUSPEND);
3344  out:
3345 	/* report result */
3346 	spin_lock_irqsave(ap->lock, flags);
3347 
3348 	ap->pflags &= ~ATA_PFLAG_PM_PENDING;
3349 	if (rc == 0)
3350 		ap->pflags |= ATA_PFLAG_SUSPENDED;
3351 	else if (ap->pflags & ATA_PFLAG_FROZEN)
3352 		ata_port_schedule_eh(ap);
3353 
3354 	if (ap->pm_result) {
3355 		*ap->pm_result = rc;
3356 		ap->pm_result = NULL;
3357 	}
3358 
3359 	spin_unlock_irqrestore(ap->lock, flags);
3360 
3361 	return;
3362 }
3363 
3364 /**
3365  *	ata_eh_handle_port_resume - perform port resume operation
3366  *	@ap: port to resume
3367  *
3368  *	Resume @ap.
3369  *
3370  *	LOCKING:
3371  *	Kernel thread context (may sleep).
3372  */
3373 static void ata_eh_handle_port_resume(struct ata_port *ap)
3374 {
3375 	unsigned long flags;
3376 	int rc = 0;
3377 
3378 	/* are we resuming? */
3379 	spin_lock_irqsave(ap->lock, flags);
3380 	if (!(ap->pflags & ATA_PFLAG_PM_PENDING) ||
3381 	    ap->pm_mesg.event != PM_EVENT_ON) {
3382 		spin_unlock_irqrestore(ap->lock, flags);
3383 		return;
3384 	}
3385 	spin_unlock_irqrestore(ap->lock, flags);
3386 
3387 	WARN_ON(!(ap->pflags & ATA_PFLAG_SUSPENDED));
3388 
3389 	ata_acpi_set_state(ap, PMSG_ON);
3390 
3391 	if (ap->ops->port_resume)
3392 		rc = ap->ops->port_resume(ap);
3393 
3394 	/* tell ACPI that we're resuming */
3395 	ata_acpi_on_resume(ap);
3396 
3397 	/* report result */
3398 	spin_lock_irqsave(ap->lock, flags);
3399 	ap->pflags &= ~(ATA_PFLAG_PM_PENDING | ATA_PFLAG_SUSPENDED);
3400 	if (ap->pm_result) {
3401 		*ap->pm_result = rc;
3402 		ap->pm_result = NULL;
3403 	}
3404 	spin_unlock_irqrestore(ap->lock, flags);
3405 }
3406 #endif /* CONFIG_PM */
3407