1	// SPDX-License-Identifier: GPL-2.0-or-later
2	/*
3	* libata-eh.c - libata error handling
4	*
5	* Copyright 2006 Tejun Heo <htejun@gmail.com>
6	*
7	* libata documentation is available via 'make {ps|pdf}docs',
8	* as Documentation/driver-api/libata.rst
9	*
10	* Hardware documentation available from http://www.t13.org/ and
11	* http://www.sata-io.org/
12	*/
13
14	#include <linux/kernel.h>
15	#include <linux/blkdev.h>
16	#include <linux/export.h>
17	#include <linux/pci.h>
18	#include <scsi/scsi.h>
19	#include <scsi/scsi_host.h>
20	#include <scsi/scsi_eh.h>
21	#include <scsi/scsi_device.h>
22	#include <scsi/scsi_cmnd.h>
23	#include <scsi/scsi_dbg.h>
24	#include "../scsi/scsi_transport_api.h"
25
26	#include <linux/libata.h>
27
28	#include <trace/events/libata.h>
29	#include "libata.h"
30
31	enum {
32	/* speed down verdicts */
33	ATA_EH_SPDN_NCQ_OFF = (1 << 0),
34	ATA_EH_SPDN_SPEED_DOWN = (1 << 1),
35	ATA_EH_SPDN_FALLBACK_TO_PIO = (1 << 2),
36	ATA_EH_SPDN_KEEP_ERRORS = (1 << 3),
37
38	/* error flags */
39	ATA_EFLAG_IS_IO = (1 << 0),
40	ATA_EFLAG_DUBIOUS_XFER = (1 << 1),
41	ATA_EFLAG_OLD_ER = (1 << 31),
42
43	/* error categories */
44	ATA_ECAT_NONE = 0,
45	ATA_ECAT_ATA_BUS = 1,
46	ATA_ECAT_TOUT_HSM = 2,
47	ATA_ECAT_UNK_DEV = 3,
48	ATA_ECAT_DUBIOUS_NONE = 4,
49	ATA_ECAT_DUBIOUS_ATA_BUS = 5,
50	ATA_ECAT_DUBIOUS_TOUT_HSM = 6,
51	ATA_ECAT_DUBIOUS_UNK_DEV = 7,
52	ATA_ECAT_NR = 8,
53
54	ATA_EH_CMD_DFL_TIMEOUT = 5000,
55
56	/* always put at least this amount of time between resets */
57	ATA_EH_RESET_COOL_DOWN = 5000,
58
59	/* Waiting in ->prereset can never be reliable. It's
60	* sometimes nice to wait there but it can't be depended upon;
61	* otherwise, we wouldn't be resetting. Just give it enough
62	* time for most drives to spin up.
63	*/
64	ATA_EH_PRERESET_TIMEOUT = 10000,
65	ATA_EH_FASTDRAIN_INTERVAL = 3000,
66
67	ATA_EH_UA_TRIES = 5,
68
69	/* probe speed down parameters, see ata_eh_schedule_probe() */
70	ATA_EH_PROBE_TRIAL_INTERVAL = 60000, /* 1 min */
71	ATA_EH_PROBE_TRIALS = 2,
72	};
73
74	/* The following table determines how we sequence resets. Each entry
75	* represents timeout for that try. The first try can be soft or
76	* hardreset. All others are hardreset if available. In most cases
77	* the first reset w/ 10sec timeout should succeed. Following entries
78	* are mostly for error handling, hotplug and those outlier devices that
79	* take an exceptionally long time to recover from reset.
80	*/
81	static const unsigned int ata_eh_reset_timeouts[] = {
82	10000, /* most drives spin up by 10sec */
83	10000, /* > 99% working drives spin up before 20sec */
84	35000, /* give > 30 secs of idleness for outlier devices */
85	5000, /* and sweet one last chance */
86	UINT_MAX, /* > 1 min has elapsed, give up */
87	};
88
89	static const unsigned int ata_eh_identify_timeouts[] = {
90	5000, /* covers > 99% of successes and not too boring on failures */
91	10000, /* combined time till here is enough even for media access */
92	30000, /* for true idiots */
93	UINT_MAX,
94	};
95
96	static const unsigned int ata_eh_revalidate_timeouts[] = {
97	15000, /* Some drives are slow to read log pages when waking-up */
98	15000, /* combined time till here is enough even for media access */
99	UINT_MAX,
100	};
101
102	static const unsigned int ata_eh_flush_timeouts[] = {
103	15000, /* be generous with flush */
104	15000, /* ditto */
105	30000, /* and even more generous */
106	UINT_MAX,
107	};
108
109	static const unsigned int ata_eh_other_timeouts[] = {
110	5000, /* same rationale as identify timeout */
111	10000, /* ditto */
112	/* but no merciful 30sec for other commands, it just isn't worth it */
113	UINT_MAX,
114	};
115
116	struct ata_eh_cmd_timeout_ent {
117	const u8 *commands;
118	const unsigned int *timeouts;
119	};
120
121	/* The following table determines timeouts to use for EH internal
122	* commands. Each table entry is a command class and matches the
123	* commands the entry applies to and the timeout table to use.
124	*
125	* On the retry after a command timed out, the next timeout value from
126	* the table is used. If the table doesn't contain further entries,
127	* the last value is used.
128	*
129	* ehc->cmd_timeout_idx keeps track of which timeout to use per
130	* command class, so if SET_FEATURES times out on the first try, the
131	* next try will use the second timeout value only for that class.
132	*/
133	#define CMDS(cmds...) (const u8 []){ cmds, 0 }
134	static const struct ata_eh_cmd_timeout_ent
135	ata_eh_cmd_timeout_table[ATA_EH_CMD_TIMEOUT_TABLE_SIZE] = {
136	{ .commands = CMDS(ATA_CMD_ID_ATA, ATA_CMD_ID_ATAPI),
137	.timeouts = ata_eh_identify_timeouts, },
138	{ .commands = CMDS(ATA_CMD_READ_LOG_EXT, ATA_CMD_READ_LOG_DMA_EXT),
139	.timeouts = ata_eh_revalidate_timeouts, },
140	{ .commands = CMDS(ATA_CMD_READ_NATIVE_MAX, ATA_CMD_READ_NATIVE_MAX_EXT),
141	.timeouts = ata_eh_other_timeouts, },
142	{ .commands = CMDS(ATA_CMD_SET_MAX, ATA_CMD_SET_MAX_EXT),
143	.timeouts = ata_eh_other_timeouts, },
144	{ .commands = CMDS(ATA_CMD_SET_FEATURES),
145	.timeouts = ata_eh_other_timeouts, },
146	{ .commands = CMDS(ATA_CMD_INIT_DEV_PARAMS),
147	.timeouts = ata_eh_other_timeouts, },
148	{ .commands = CMDS(ATA_CMD_FLUSH, ATA_CMD_FLUSH_EXT),
149	.timeouts = ata_eh_flush_timeouts },
150	{ .commands = CMDS(ATA_CMD_VERIFY),
151	.timeouts = ata_eh_reset_timeouts },
152	};
153	#undef CMDS
154
155	static void __ata_port_freeze(struct ata_port *ap);
156	static int ata_eh_set_lpm(struct ata_link *link, enum ata_lpm_policy policy,
157	struct ata_device **r_failed_dev);
158	#ifdef CONFIG_PM
159	static void ata_eh_handle_port_suspend(struct ata_port *ap);
160	static void ata_eh_handle_port_resume(struct ata_port *ap);
161	#else /* CONFIG_PM */
162	static void ata_eh_handle_port_suspend(struct ata_port *ap)
163	{ }
164
165	static void ata_eh_handle_port_resume(struct ata_port *ap)
166	{ }
167	#endif /* CONFIG_PM */
168
169	static __printf(2, 0) void __ata_ehi_pushv_desc(struct ata_eh_info *ehi,
170	const char *fmt, va_list args)
171	{
172	ehi->desc_len += vscnprintf(buf: ehi->desc + ehi->desc_len,
173	size: ATA_EH_DESC_LEN - ehi->desc_len,
174	fmt, args);
175	}
176
177	/**
178	* __ata_ehi_push_desc - push error description without adding separator
179	* @ehi: target EHI
180	* @fmt: printf format string
181	*
182	* Format string according to @fmt and append it to @ehi->desc.
183	*
184	* LOCKING:
185	* spin_lock_irqsave(host lock)
186	*/
187	void __ata_ehi_push_desc(struct ata_eh_info *ehi, const char *fmt, ...)
188	{
189	va_list args;
190
191	va_start(args, fmt);
192	__ata_ehi_pushv_desc(ehi, fmt, args);
193	va_end(args);
194	}
195	EXPORT_SYMBOL_GPL(__ata_ehi_push_desc);
196
197	/**
198	* ata_ehi_push_desc - push error description with separator
199	* @ehi: target EHI
200	* @fmt: printf format string
201	*
202	* Format string according to @fmt and append it to @ehi->desc.
203	* If @ehi->desc is not empty, ", " is added in-between.
204	*
205	* LOCKING:
206	* spin_lock_irqsave(host lock)
207	*/
208	void ata_ehi_push_desc(struct ata_eh_info *ehi, const char *fmt, ...)
209	{
210	va_list args;
211
212	if (ehi->desc_len)
213	__ata_ehi_push_desc(ehi, ", ");
214
215	va_start(args, fmt);
216	__ata_ehi_pushv_desc(ehi, fmt, args);
217	va_end(args);
218	}
219	EXPORT_SYMBOL_GPL(ata_ehi_push_desc);
220
221	/**
222	* ata_ehi_clear_desc - clean error description
223	* @ehi: target EHI
224	*
225	* Clear @ehi->desc.
226	*
227	* LOCKING:
228	* spin_lock_irqsave(host lock)
229	*/
230	void ata_ehi_clear_desc(struct ata_eh_info *ehi)
231	{
232	ehi->desc[0] = '\0';
233	ehi->desc_len = 0;
234	}
235	EXPORT_SYMBOL_GPL(ata_ehi_clear_desc);
236
237	/**
238	* ata_port_desc - append port description
239	* @ap: target ATA port
240	* @fmt: printf format string
241	*
242	* Format string according to @fmt and append it to port
243	* description. If port description is not empty, " " is added
244	* in-between. This function is to be used while initializing
245	* ata_host. The description is printed on host registration.
246	*
247	* LOCKING:
248	* None.
249	*/
250	void ata_port_desc(struct ata_port *ap, const char *fmt, ...)
251	{
252	va_list args;
253
254	WARN_ON(!(ap->pflags & ATA_PFLAG_INITIALIZING));
255
256	if (ap->link.eh_info.desc_len)
257	__ata_ehi_push_desc(&ap->link.eh_info, " ");
258
259	va_start(args, fmt);
260	__ata_ehi_pushv_desc(ehi: &ap->link.eh_info, fmt, args);
261	va_end(args);
262	}
263	EXPORT_SYMBOL_GPL(ata_port_desc);
264
265	#ifdef CONFIG_PCI
266	/**
267	* ata_port_pbar_desc - append PCI BAR description
268	* @ap: target ATA port
269	* @bar: target PCI BAR
270	* @offset: offset into PCI BAR
271	* @name: name of the area
272	*
273	* If @offset is negative, this function formats a string which
274	* contains the name, address, size and type of the BAR and
275	* appends it to the port description. If @offset is zero or
276	* positive, only name and offsetted address is appended.
277	*
278	* LOCKING:
279	* None.
280	*/
281	void ata_port_pbar_desc(struct ata_port *ap, int bar, ssize_t offset,
282	const char *name)
283	{
284	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
285	char *type = "";
286	unsigned long long start, len;
287
288	if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM)
289	type = "m";
290	else if (pci_resource_flags(pdev, bar) & IORESOURCE_IO)
291	type = "i";
292
293	start = (unsigned long long)pci_resource_start(pdev, bar);
294	len = (unsigned long long)pci_resource_len(pdev, bar);
295
296	if (offset < 0)
297	ata_port_desc(ap, "%s %s%llu@0x%llx", name, type, len, start);
298	else
299	ata_port_desc(ap, "%s 0x%llx", name,
300	start + (unsigned long long)offset);
301	}
302	EXPORT_SYMBOL_GPL(ata_port_pbar_desc);
303	#endif /* CONFIG_PCI */
304
305	static int ata_lookup_timeout_table(u8 cmd)
306	{
307	int i;
308
309	for (i = 0; i < ATA_EH_CMD_TIMEOUT_TABLE_SIZE; i++) {
310	const u8 *cur;
311
312	for (cur = ata_eh_cmd_timeout_table[i].commands; *cur; cur++)
313	if (*cur == cmd)
314	return i;
315	}
316
317	return -1;
318	}
319
320	/**
321	* ata_internal_cmd_timeout - determine timeout for an internal command
322	* @dev: target device
323	* @cmd: internal command to be issued
324	*
325	* Determine timeout for internal command @cmd for @dev.
326	*
327	* LOCKING:
328	* EH context.
329	*
330	* RETURNS:
331	* Determined timeout.
332	*/
333	unsigned int ata_internal_cmd_timeout(struct ata_device *dev, u8 cmd)
334	{
335	struct ata_eh_context *ehc = &dev->link->eh_context;
336	int ent = ata_lookup_timeout_table(cmd);
337	int idx;
338
339	if (ent < 0)
340	return ATA_EH_CMD_DFL_TIMEOUT;
341
342	idx = ehc->cmd_timeout_idx[dev->devno][ent];
343	return ata_eh_cmd_timeout_table[ent].timeouts[idx];
344	}
345
346	/**
347	* ata_internal_cmd_timed_out - notification for internal command timeout
348	* @dev: target device
349	* @cmd: internal command which timed out
350	*
351	* Notify EH that internal command @cmd for @dev timed out. This
352	* function should be called only for commands whose timeouts are
353	* determined using ata_internal_cmd_timeout().
354	*
355	* LOCKING:
356	* EH context.
357	*/
358	void ata_internal_cmd_timed_out(struct ata_device *dev, u8 cmd)
359	{
360	struct ata_eh_context *ehc = &dev->link->eh_context;
361	int ent = ata_lookup_timeout_table(cmd);
362	int idx;
363
364	if (ent < 0)
365	return;
366
367	idx = ehc->cmd_timeout_idx[dev->devno][ent];
368	if (ata_eh_cmd_timeout_table[ent].timeouts[idx + 1] != UINT_MAX)
369	ehc->cmd_timeout_idx[dev->devno][ent]++;
370	}
371
372	static void ata_ering_record(struct ata_ering *ering, unsigned int eflags,
373	unsigned int err_mask)
374	{
375	struct ata_ering_entry *ent;
376
377	WARN_ON(!err_mask);
378
379	ering->cursor++;
380	ering->cursor %= ATA_ERING_SIZE;
381
382	ent = &ering->ring[ering->cursor];
383	ent->eflags = eflags;
384	ent->err_mask = err_mask;
385	ent->timestamp = get_jiffies_64();
386	}
387
388	static struct ata_ering_entry *ata_ering_top(struct ata_ering *ering)
389	{
390	struct ata_ering_entry *ent = &ering->ring[ering->cursor];
391
392	if (ent->err_mask)
393	return ent;
394	return NULL;
395	}
396
397	int ata_ering_map(struct ata_ering *ering,
398	int (*map_fn)(struct ata_ering_entry *, void *),
399	void *arg)
400	{
401	int idx, rc = 0;
402	struct ata_ering_entry *ent;
403
404	idx = ering->cursor;
405	do {
406	ent = &ering->ring[idx];
407	if (!ent->err_mask)
408	break;
409	rc = map_fn(ent, arg);
410	if (rc)
411	break;
412	idx = (idx - 1 + ATA_ERING_SIZE) % ATA_ERING_SIZE;
413	} while (idx != ering->cursor);
414
415	return rc;
416	}
417
418	static int ata_ering_clear_cb(struct ata_ering_entry *ent, void *void_arg)
419	{
420	ent->eflags |= ATA_EFLAG_OLD_ER;
421	return 0;
422	}
423
424	static void ata_ering_clear(struct ata_ering *ering)
425	{
426	ata_ering_map(ering, map_fn: ata_ering_clear_cb, NULL);
427	}
428
429	static unsigned int ata_eh_dev_action(struct ata_device *dev)
430	{
431	struct ata_eh_context *ehc = &dev->link->eh_context;
432
433	return ehc->i.action | ehc->i.dev_action[dev->devno];
434	}
435
436	static void ata_eh_clear_action(struct ata_link *link, struct ata_device *dev,
437	struct ata_eh_info *ehi, unsigned int action)
438	{
439	struct ata_device *tdev;
440
441	if (!dev) {
442	ehi->action &= ~action;
443	ata_for_each_dev(tdev, link, ALL)
444	ehi->dev_action[tdev->devno] &= ~action;
445	} else {
446	/* doesn't make sense for port-wide EH actions */
447	WARN_ON(!(action & ATA_EH_PERDEV_MASK));
448
449	/* break ehi->action into ehi->dev_action */
450	if (ehi->action & action) {
451	ata_for_each_dev(tdev, link, ALL)
452	ehi->dev_action[tdev->devno] |=
453	ehi->action & action;
454	ehi->action &= ~action;
455	}
456
457	/* turn off the specified per-dev action */
458	ehi->dev_action[dev->devno] &= ~action;
459	}
460	}
461
462	/**
463	* ata_eh_acquire - acquire EH ownership
464	* @ap: ATA port to acquire EH ownership for
465	*
466	* Acquire EH ownership for @ap. This is the basic exclusion
467	* mechanism for ports sharing a host. Only one port hanging off
468	* the same host can claim the ownership of EH.
469	*
470	* LOCKING:
471	* EH context.
472	*/
473	void ata_eh_acquire(struct ata_port *ap)
474	{
475	mutex_lock(&ap->host->eh_mutex);
476	WARN_ON_ONCE(ap->host->eh_owner);
477	ap->host->eh_owner = current;
478	}
479
480	/**
481	* ata_eh_release - release EH ownership
482	* @ap: ATA port to release EH ownership for
483	*
484	* Release EH ownership for @ap if the caller. The caller must
485	* have acquired EH ownership using ata_eh_acquire() previously.
486	*
487	* LOCKING:
488	* EH context.
489	*/
490	void ata_eh_release(struct ata_port *ap)
491	{
492	WARN_ON_ONCE(ap->host->eh_owner != current);
493	ap->host->eh_owner = NULL;
494	mutex_unlock(lock: &ap->host->eh_mutex);
495	}
496
497	static void ata_eh_dev_disable(struct ata_device *dev)
498	{
499	ata_acpi_on_disable(dev);
500	ata_down_xfermask_limit(dev, sel: ATA_DNXFER_FORCE_PIO0 | ATA_DNXFER_QUIET);
501	dev->class++;
502
503	/* From now till the next successful probe, ering is used to
504	* track probe failures. Clear accumulated device error info.
505	*/
506	ata_ering_clear(ering: &dev->ering);
507	}
508
509	static void ata_eh_unload(struct ata_port *ap)
510	{
511	struct ata_link *link;
512	struct ata_device *dev;
513	unsigned long flags;
514
515	/*
516	* Unless we are restarting, transition all enabled devices to
517	* standby power mode.
518	*/
519	if (system_state != SYSTEM_RESTART) {
520	ata_for_each_link(link, ap, PMP_FIRST) {
521	ata_for_each_dev(dev, link, ENABLED)
522	ata_dev_power_set_standby(dev);
523	}
524	}
525
526	/*
527	* Restore SControl IPM and SPD for the next driver and
528	* disable attached devices.
529	*/
530	ata_for_each_link(link, ap, PMP_FIRST) {
531	sata_scr_write(link, reg: SCR_CONTROL, val: link->saved_scontrol & 0xff0);
532	ata_for_each_dev(dev, link, ENABLED)
533	ata_eh_dev_disable(dev);
534	}
535
536	/* freeze and set UNLOADED */
537	spin_lock_irqsave(ap->lock, flags);
538
539	ata_port_freeze(ap); /* won't be thawed */
540	ap->pflags &= ~ATA_PFLAG_EH_PENDING; /* clear pending from freeze */
541	ap->pflags |= ATA_PFLAG_UNLOADED;
542
543	spin_unlock_irqrestore(lock: ap->lock, flags);
544	}
545
546	/**
547	* ata_scsi_error - SCSI layer error handler callback
548	* @host: SCSI host on which error occurred
549	*
550	* Handles SCSI-layer-thrown error events.
551	*
552	* LOCKING:
553	* Inherited from SCSI layer (none, can sleep)
554	*
555	* RETURNS:
556	* Zero.
557	*/
558	void ata_scsi_error(struct Scsi_Host *host)
559	{
560	struct ata_port *ap = ata_shost_to_port(host);
561	unsigned long flags;
562	LIST_HEAD(eh_work_q);
563
564	spin_lock_irqsave(host->host_lock, flags);
565	list_splice_init(list: &host->eh_cmd_q, head: &eh_work_q);
566	spin_unlock_irqrestore(lock: host->host_lock, flags);
567
568	ata_scsi_cmd_error_handler(host, ap, eh_q: &eh_work_q);
569
570	/* If we timed raced normal completion and there is nothing to
571	recover nr_timedout == 0 why exactly are we doing error recovery ? */
572	ata_scsi_port_error_handler(host, ap);
573
574	/* finish or retry handled scmd's and clean up */
575	WARN_ON(!list_empty(&eh_work_q));
576
577	}
578
579	/**
580	* ata_scsi_cmd_error_handler - error callback for a list of commands
581	* @host: scsi host containing the port
582	* @ap: ATA port within the host
583	* @eh_work_q: list of commands to process
584	*
585	* process the given list of commands and return those finished to the
586	* ap->eh_done_q. This function is the first part of the libata error
587	* handler which processes a given list of failed commands.
588	*/
589	void ata_scsi_cmd_error_handler(struct Scsi_Host *host, struct ata_port *ap,
590	struct list_head *eh_work_q)
591	{
592	int i;
593	unsigned long flags;
594	struct scsi_cmnd *scmd, *tmp;
595	int nr_timedout = 0;
596
597	/* make sure sff pio task is not running */
598	ata_sff_flush_pio_task(ap);
599
600	/* synchronize with host lock and sort out timeouts */
601
602	/*
603	* For EH, all qcs are finished in one of three ways -
604	* normal completion, error completion, and SCSI timeout.
605	* Both completions can race against SCSI timeout. When normal
606	* completion wins, the qc never reaches EH. When error
607	* completion wins, the qc has ATA_QCFLAG_EH set.
608	*
609	* When SCSI timeout wins, things are a bit more complex.
610	* Normal or error completion can occur after the timeout but
611	* before this point. In such cases, both types of
612	* completions are honored. A scmd is determined to have
613	* timed out iff its associated qc is active and not failed.
614	*/
615	spin_lock_irqsave(ap->lock, flags);
616
617	/*
618	* This must occur under the ap->lock as we don't want
619	* a polled recovery to race the real interrupt handler
620	*
621	* The lost_interrupt handler checks for any completed but
622	* non-notified command and completes much like an IRQ handler.
623	*
624	* We then fall into the error recovery code which will treat
625	* this as if normal completion won the race
626	*/
627	if (ap->ops->lost_interrupt)
628	ap->ops->lost_interrupt(ap);
629
630	list_for_each_entry_safe(scmd, tmp, eh_work_q, eh_entry) {
631	struct ata_queued_cmd *qc;
632
633	ata_qc_for_each_raw(ap, qc, i) {
634	if (qc->flags & ATA_QCFLAG_ACTIVE &&
635	qc->scsicmd == scmd)
636	break;
637	}
638
639	if (i < ATA_MAX_QUEUE) {
640	/* the scmd has an associated qc */
641	if (!(qc->flags & ATA_QCFLAG_EH)) {
642	/* which hasn't failed yet, timeout */
643	qc->err_mask |= AC_ERR_TIMEOUT;
644	qc->flags |= ATA_QCFLAG_EH;
645	nr_timedout++;
646	}
647	} else {
648	/* Normal completion occurred after
649	* SCSI timeout but before this point.
650	* Successfully complete it.
651	*/
652	scmd->retries = scmd->allowed;
653	scsi_eh_finish_cmd(scmd, done_q: &ap->eh_done_q);
654	}
655	}
656
657	/*
658	* If we have timed out qcs. They belong to EH from
659	* this point but the state of the controller is
660	* unknown. Freeze the port to make sure the IRQ
661	* handler doesn't diddle with those qcs. This must
662	* be done atomically w.r.t. setting ATA_QCFLAG_EH.
663	*/
664	if (nr_timedout)
665	__ata_port_freeze(ap);
666
667	/* initialize eh_tries */
668	ap->eh_tries = ATA_EH_MAX_TRIES;
669
670	spin_unlock_irqrestore(lock: ap->lock, flags);
671	}
672	EXPORT_SYMBOL(ata_scsi_cmd_error_handler);
673
674	/**
675	* ata_scsi_port_error_handler - recover the port after the commands
676	* @host: SCSI host containing the port
677	* @ap: the ATA port
678	*
679	* Handle the recovery of the port @ap after all the commands
680	* have been recovered.
681	*/
682	void ata_scsi_port_error_handler(struct Scsi_Host *host, struct ata_port *ap)
683	{
684	unsigned long flags;
685	struct ata_link *link;
686
687	/* acquire EH ownership */
688	ata_eh_acquire(ap);
689	repeat:
690	/* kill fast drain timer */
691	del_timer_sync(timer: &ap->fastdrain_timer);
692
693	/* process port resume request */
694	ata_eh_handle_port_resume(ap);
695
696	/* fetch & clear EH info */
697	spin_lock_irqsave(ap->lock, flags);
698
699	ata_for_each_link(link, ap, HOST_FIRST) {
700	struct ata_eh_context *ehc = &link->eh_context;
701	struct ata_device *dev;
702
703	memset(&link->eh_context, 0, sizeof(link->eh_context));
704	link->eh_context.i = link->eh_info;
705	memset(&link->eh_info, 0, sizeof(link->eh_info));
706
707	ata_for_each_dev(dev, link, ENABLED) {
708	int devno = dev->devno;
709
710	ehc->saved_xfer_mode[devno] = dev->xfer_mode;
711	if (ata_ncq_enabled(dev))
712	ehc->saved_ncq_enabled |= 1 << devno;
713
714	/* If we are resuming, wake up the device */
715	if (ap->pflags & ATA_PFLAG_RESUMING) {
716	dev->flags |= ATA_DFLAG_RESUMING;
717	ehc->i.dev_action[devno] |= ATA_EH_SET_ACTIVE;
718	}
719	}
720	}
721
722	ap->pflags |= ATA_PFLAG_EH_IN_PROGRESS;
723	ap->pflags &= ~ATA_PFLAG_EH_PENDING;
724	ap->excl_link = NULL; /* don't maintain exclusion over EH */
725
726	spin_unlock_irqrestore(lock: ap->lock, flags);
727
728	/* invoke EH, skip if unloading or suspended */
729	if (!(ap->pflags & (ATA_PFLAG_UNLOADING | ATA_PFLAG_SUSPENDED)))
730	ap->ops->error_handler(ap);
731	else {
732	/* if unloading, commence suicide */
733	if ((ap->pflags & ATA_PFLAG_UNLOADING) &&
734	!(ap->pflags & ATA_PFLAG_UNLOADED))
735	ata_eh_unload(ap);
736	ata_eh_finish(ap);
737	}
738
739	/* process port suspend request */
740	ata_eh_handle_port_suspend(ap);
741
742	/*
743	* Exception might have happened after ->error_handler recovered the
744	* port but before this point. Repeat EH in such case.
745	*/
746	spin_lock_irqsave(ap->lock, flags);
747
748	if (ap->pflags & ATA_PFLAG_EH_PENDING) {
749	if (--ap->eh_tries) {
750	spin_unlock_irqrestore(lock: ap->lock, flags);
751	goto repeat;
752	}
753	ata_port_err(ap,
754	"EH pending after %d tries, giving up\n",
755	ATA_EH_MAX_TRIES);
756	ap->pflags &= ~ATA_PFLAG_EH_PENDING;
757	}
758
759	/* this run is complete, make sure EH info is clear */
760	ata_for_each_link(link, ap, HOST_FIRST)
761	memset(&link->eh_info, 0, sizeof(link->eh_info));
762
763	/*
764	* end eh (clear host_eh_scheduled) while holding ap->lock such that if
765	* exception occurs after this point but before EH completion, SCSI
766	* midlayer will re-initiate EH.
767	*/
768	ap->ops->end_eh(ap);
769
770	spin_unlock_irqrestore(lock: ap->lock, flags);
771	ata_eh_release(ap);
772
773	scsi_eh_flush_done_q(done_q: &ap->eh_done_q);
774
775	/* clean up */
776	spin_lock_irqsave(ap->lock, flags);
777
778	ap->pflags &= ~ATA_PFLAG_RESUMING;
779
780	if (ap->pflags & ATA_PFLAG_LOADING)
781	ap->pflags &= ~ATA_PFLAG_LOADING;
782	else if ((ap->pflags & ATA_PFLAG_SCSI_HOTPLUG) &&
783	!(ap->flags & ATA_FLAG_SAS_HOST))
784	schedule_delayed_work(dwork: &ap->hotplug_task, delay: 0);
785
786	if (ap->pflags & ATA_PFLAG_RECOVERED)
787	ata_port_info(ap, "EH complete\n");
788
789	ap->pflags &= ~(ATA_PFLAG_SCSI_HOTPLUG | ATA_PFLAG_RECOVERED);
790
791	/* tell wait_eh that we're done */
792	ap->pflags &= ~ATA_PFLAG_EH_IN_PROGRESS;
793	wake_up_all(&ap->eh_wait_q);
794
795	spin_unlock_irqrestore(lock: ap->lock, flags);
796	}
797	EXPORT_SYMBOL_GPL(ata_scsi_port_error_handler);
798
799	/**
800	* ata_port_wait_eh - Wait for the currently pending EH to complete
801	* @ap: Port to wait EH for
802	*
803	* Wait until the currently pending EH is complete.
804	*
805	* LOCKING:
806	* Kernel thread context (may sleep).
807	*/
808	void ata_port_wait_eh(struct ata_port *ap)
809	{
810	unsigned long flags;
811	DEFINE_WAIT(wait);
812
813	retry:
814	spin_lock_irqsave(ap->lock, flags);
815
816	while (ap->pflags & (ATA_PFLAG_EH_PENDING | ATA_PFLAG_EH_IN_PROGRESS)) {
817	prepare_to_wait(wq_head: &ap->eh_wait_q, wq_entry: &wait, TASK_UNINTERRUPTIBLE);
818	spin_unlock_irqrestore(lock: ap->lock, flags);
819	schedule();
820	spin_lock_irqsave(ap->lock, flags);
821	}
822	finish_wait(wq_head: &ap->eh_wait_q, wq_entry: &wait);
823
824	spin_unlock_irqrestore(lock: ap->lock, flags);
825
826	/* make sure SCSI EH is complete */
827	if (scsi_host_in_recovery(shost: ap->scsi_host)) {
828	ata_msleep(ap, msecs: 10);
829	goto retry;
830	}
831	}
832	EXPORT_SYMBOL_GPL(ata_port_wait_eh);
833
834	static unsigned int ata_eh_nr_in_flight(struct ata_port *ap)
835	{
836	struct ata_queued_cmd *qc;
837	unsigned int tag;
838	unsigned int nr = 0;
839
840	/* count only non-internal commands */
841	ata_qc_for_each(ap, qc, tag) {
842	if (qc)
843	nr++;
844	}
845
846	return nr;
847	}
848
849	void ata_eh_fastdrain_timerfn(struct timer_list *t)
850	{
851	struct ata_port *ap = from_timer(ap, t, fastdrain_timer);
852	unsigned long flags;
853	unsigned int cnt;
854
855	spin_lock_irqsave(ap->lock, flags);
856
857	cnt = ata_eh_nr_in_flight(ap);
858
859	/* are we done? */
860	if (!cnt)
861	goto out_unlock;
862
863	if (cnt == ap->fastdrain_cnt) {
864	struct ata_queued_cmd *qc;
865	unsigned int tag;
866
867	/* No progress during the last interval, tag all
868	* in-flight qcs as timed out and freeze the port.
869	*/
870	ata_qc_for_each(ap, qc, tag) {
871	if (qc)
872	qc->err_mask |= AC_ERR_TIMEOUT;
873	}
874
875	ata_port_freeze(ap);
876	} else {
877	/* some qcs have finished, give it another chance */
878	ap->fastdrain_cnt = cnt;
879	ap->fastdrain_timer.expires =
880	ata_deadline(from_jiffies: jiffies, timeout_msecs: ATA_EH_FASTDRAIN_INTERVAL);
881	add_timer(timer: &ap->fastdrain_timer);
882	}
883
884	out_unlock:
885	spin_unlock_irqrestore(lock: ap->lock, flags);
886	}
887
888	/**
889	* ata_eh_set_pending - set ATA_PFLAG_EH_PENDING and activate fast drain
890	* @ap: target ATA port
891	* @fastdrain: activate fast drain
892	*
893	* Set ATA_PFLAG_EH_PENDING and activate fast drain if @fastdrain
894	* is non-zero and EH wasn't pending before. Fast drain ensures
895	* that EH kicks in in timely manner.
896	*
897	* LOCKING:
898	* spin_lock_irqsave(host lock)
899	*/
900	static void ata_eh_set_pending(struct ata_port *ap, int fastdrain)
901	{
902	unsigned int cnt;
903
904	/* already scheduled? */
905	if (ap->pflags & ATA_PFLAG_EH_PENDING)
906	return;
907
908	ap->pflags |= ATA_PFLAG_EH_PENDING;
909
910	if (!fastdrain)
911	return;
912
913	/* do we have in-flight qcs? */
914	cnt = ata_eh_nr_in_flight(ap);
915	if (!cnt)
916	return;
917
918	/* activate fast drain */
919	ap->fastdrain_cnt = cnt;
920	ap->fastdrain_timer.expires =
921	ata_deadline(from_jiffies: jiffies, timeout_msecs: ATA_EH_FASTDRAIN_INTERVAL);
922	add_timer(timer: &ap->fastdrain_timer);
923	}
924
925	/**
926	* ata_qc_schedule_eh - schedule qc for error handling
927	* @qc: command to schedule error handling for
928	*
929	* Schedule error handling for @qc. EH will kick in as soon as
930	* other commands are drained.
931	*
932	* LOCKING:
933	* spin_lock_irqsave(host lock)
934	*/
935	void ata_qc_schedule_eh(struct ata_queued_cmd *qc)
936	{
937	struct ata_port *ap = qc->ap;
938
939	qc->flags |= ATA_QCFLAG_EH;
940	ata_eh_set_pending(ap, fastdrain: 1);
941
942	/* The following will fail if timeout has already expired.
943	* ata_scsi_error() takes care of such scmds on EH entry.
944	* Note that ATA_QCFLAG_EH is unconditionally set after
945	* this function completes.
946	*/
947	blk_abort_request(scsi_cmd_to_rq(scmd: qc->scsicmd));
948	}
949
950	/**
951	* ata_std_sched_eh - non-libsas ata_ports issue eh with this common routine
952	* @ap: ATA port to schedule EH for
953	*
954	* LOCKING: inherited from ata_port_schedule_eh
955	* spin_lock_irqsave(host lock)
956	*/
957	void ata_std_sched_eh(struct ata_port *ap)
958	{
959	if (ap->pflags & ATA_PFLAG_INITIALIZING)
960	return;
961
962	ata_eh_set_pending(ap, fastdrain: 1);
963	scsi_schedule_eh(shost: ap->scsi_host);
964
965	trace_ata_std_sched_eh(ap);
966	}
967	EXPORT_SYMBOL_GPL(ata_std_sched_eh);
968
969	/**
970	* ata_std_end_eh - non-libsas ata_ports complete eh with this common routine
971	* @ap: ATA port to end EH for
972	*
973	* In the libata object model there is a 1:1 mapping of ata_port to
974	* shost, so host fields can be directly manipulated under ap->lock, in
975	* the libsas case we need to hold a lock at the ha->level to coordinate
976	* these events.
977	*
978	* LOCKING:
979	* spin_lock_irqsave(host lock)
980	*/
981	void ata_std_end_eh(struct ata_port *ap)
982	{
983	struct Scsi_Host *host = ap->scsi_host;
984
985	host->host_eh_scheduled = 0;
986	}
987	EXPORT_SYMBOL(ata_std_end_eh);
988
989
990	/**
991	* ata_port_schedule_eh - schedule error handling without a qc
992	* @ap: ATA port to schedule EH for
993	*
994	* Schedule error handling for @ap. EH will kick in as soon as
995	* all commands are drained.
996	*
997	* LOCKING:
998	* spin_lock_irqsave(host lock)
999	*/
1000	void ata_port_schedule_eh(struct ata_port *ap)
1001	{
1002	/* see: ata_std_sched_eh, unless you know better */
1003	ap->ops->sched_eh(ap);
1004	}
1005	EXPORT_SYMBOL_GPL(ata_port_schedule_eh);
1006
1007	static int ata_do_link_abort(struct ata_port *ap, struct ata_link *link)
1008	{
1009	struct ata_queued_cmd *qc;
1010	int tag, nr_aborted = 0;
1011
1012	/* we're gonna abort all commands, no need for fast drain */
1013	ata_eh_set_pending(ap, fastdrain: 0);
1014
1015	/* include internal tag in iteration */
1016	ata_qc_for_each_with_internal(ap, qc, tag) {
1017	if (qc && (!link || qc->dev->link == link)) {
1018	qc->flags |= ATA_QCFLAG_EH;
1019	ata_qc_complete(qc);
1020	nr_aborted++;
1021	}
1022	}
1023
1024	if (!nr_aborted)
1025	ata_port_schedule_eh(ap);
1026
1027	return nr_aborted;
1028	}
1029
1030	/**
1031	* ata_link_abort - abort all qc's on the link
1032	* @link: ATA link to abort qc's for
1033	*
1034	* Abort all active qc's active on @link and schedule EH.
1035	*
1036	* LOCKING:
1037	* spin_lock_irqsave(host lock)
1038	*
1039	* RETURNS:
1040	* Number of aborted qc's.
1041	*/
1042	int ata_link_abort(struct ata_link *link)
1043	{
1044	return ata_do_link_abort(ap: link->ap, link);
1045	}
1046	EXPORT_SYMBOL_GPL(ata_link_abort);
1047
1048	/**
1049	* ata_port_abort - abort all qc's on the port
1050	* @ap: ATA port to abort qc's for
1051	*
1052	* Abort all active qc's of @ap and schedule EH.
1053	*
1054	* LOCKING:
1055	* spin_lock_irqsave(host_set lock)
1056	*
1057	* RETURNS:
1058	* Number of aborted qc's.
1059	*/
1060	int ata_port_abort(struct ata_port *ap)
1061	{
1062	return ata_do_link_abort(ap, NULL);
1063	}
1064	EXPORT_SYMBOL_GPL(ata_port_abort);
1065
1066	/**
1067	* __ata_port_freeze - freeze port
1068	* @ap: ATA port to freeze
1069	*
1070	* This function is called when HSM violation or some other
1071	* condition disrupts normal operation of the port. Frozen port
1072	* is not allowed to perform any operation until the port is
1073	* thawed, which usually follows a successful reset.
1074	*
1075	* ap->ops->freeze() callback can be used for freezing the port
1076	* hardware-wise (e.g. mask interrupt and stop DMA engine). If a
1077	* port cannot be frozen hardware-wise, the interrupt handler
1078	* must ack and clear interrupts unconditionally while the port
1079	* is frozen.
1080	*
1081	* LOCKING:
1082	* spin_lock_irqsave(host lock)
1083	*/
1084	static void __ata_port_freeze(struct ata_port *ap)
1085	{
1086	if (ap->ops->freeze)
1087	ap->ops->freeze(ap);
1088
1089	ap->pflags |= ATA_PFLAG_FROZEN;
1090
1091	trace_ata_port_freeze(ap);
1092	}
1093
1094	/**
1095	* ata_port_freeze - abort & freeze port
1096	* @ap: ATA port to freeze
1097	*
1098	* Abort and freeze @ap. The freeze operation must be called
1099	* first, because some hardware requires special operations
1100	* before the taskfile registers are accessible.
1101	*
1102	* LOCKING:
1103	* spin_lock_irqsave(host lock)
1104	*
1105	* RETURNS:
1106	* Number of aborted commands.
1107	*/
1108	int ata_port_freeze(struct ata_port *ap)
1109	{
1110	__ata_port_freeze(ap);
1111
1112	return ata_port_abort(ap);
1113	}
1114	EXPORT_SYMBOL_GPL(ata_port_freeze);
1115
1116	/**
1117	* ata_eh_freeze_port - EH helper to freeze port
1118	* @ap: ATA port to freeze
1119	*
1120	* Freeze @ap.
1121	*
1122	* LOCKING:
1123	* None.
1124	*/
1125	void ata_eh_freeze_port(struct ata_port *ap)
1126	{
1127	unsigned long flags;
1128
1129	spin_lock_irqsave(ap->lock, flags);
1130	__ata_port_freeze(ap);
1131	spin_unlock_irqrestore(lock: ap->lock, flags);
1132	}
1133	EXPORT_SYMBOL_GPL(ata_eh_freeze_port);
1134
1135	/**
1136	* ata_eh_thaw_port - EH helper to thaw port
1137	* @ap: ATA port to thaw
1138	*
1139	* Thaw frozen port @ap.
1140	*
1141	* LOCKING:
1142	* None.
1143	*/
1144	void ata_eh_thaw_port(struct ata_port *ap)
1145	{
1146	unsigned long flags;
1147
1148	spin_lock_irqsave(ap->lock, flags);
1149
1150	ap->pflags &= ~ATA_PFLAG_FROZEN;
1151
1152	if (ap->ops->thaw)
1153	ap->ops->thaw(ap);
1154
1155	spin_unlock_irqrestore(lock: ap->lock, flags);
1156
1157	trace_ata_port_thaw(ap);
1158	}
1159
1160	static void ata_eh_scsidone(struct scsi_cmnd *scmd)
1161	{
1162	/* nada */
1163	}
1164
1165	static void __ata_eh_qc_complete(struct ata_queued_cmd *qc)
1166	{
1167	struct ata_port *ap = qc->ap;
1168	struct scsi_cmnd *scmd = qc->scsicmd;
1169	unsigned long flags;
1170
1171	spin_lock_irqsave(ap->lock, flags);
1172	qc->scsidone = ata_eh_scsidone;
1173	__ata_qc_complete(qc);
1174	WARN_ON(ata_tag_valid(qc->tag));
1175	spin_unlock_irqrestore(lock: ap->lock, flags);
1176
1177	scsi_eh_finish_cmd(scmd, done_q: &ap->eh_done_q);
1178	}
1179
1180	/**
1181	* ata_eh_qc_complete - Complete an active ATA command from EH
1182	* @qc: Command to complete
1183	*
1184	* Indicate to the mid and upper layers that an ATA command has
1185	* completed. To be used from EH.
1186	*/
1187	void ata_eh_qc_complete(struct ata_queued_cmd *qc)
1188	{
1189	struct scsi_cmnd *scmd = qc->scsicmd;
1190	scmd->retries = scmd->allowed;
1191	__ata_eh_qc_complete(qc);
1192	}
1193
1194	/**
1195	* ata_eh_qc_retry - Tell midlayer to retry an ATA command after EH
1196	* @qc: Command to retry
1197	*
1198	* Indicate to the mid and upper layers that an ATA command
1199	* should be retried. To be used from EH.
1200	*
1201	* SCSI midlayer limits the number of retries to scmd->allowed.
1202	* scmd->allowed is incremented for commands which get retried
1203	* due to unrelated failures (qc->err_mask is zero).
1204	*/
1205	void ata_eh_qc_retry(struct ata_queued_cmd *qc)
1206	{
1207	struct scsi_cmnd *scmd = qc->scsicmd;
1208	if (!qc->err_mask)
1209	scmd->allowed++;
1210	__ata_eh_qc_complete(qc);
1211	}
1212
1213	/**
1214	* ata_dev_disable - disable ATA device
1215	* @dev: ATA device to disable
1216	*
1217	* Disable @dev.
1218	*
1219	* Locking:
1220	* EH context.
1221	*/
1222	void ata_dev_disable(struct ata_device *dev)
1223	{
1224	if (!ata_dev_enabled(dev))
1225	return;
1226
1227	ata_dev_warn(dev, "disable device\n");
1228
1229	ata_eh_dev_disable(dev);
1230	}
1231	EXPORT_SYMBOL_GPL(ata_dev_disable);
1232
1233	/**
1234	* ata_eh_detach_dev - detach ATA device
1235	* @dev: ATA device to detach
1236	*
1237	* Detach @dev.
1238	*
1239	* LOCKING:
1240	* None.
1241	*/
1242	void ata_eh_detach_dev(struct ata_device *dev)
1243	{
1244	struct ata_link *link = dev->link;
1245	struct ata_port *ap = link->ap;
1246	struct ata_eh_context *ehc = &link->eh_context;
1247	unsigned long flags;
1248
1249	/*
1250	* If the device is still enabled, transition it to standby power mode
1251	* (i.e. spin down HDDs) and disable it.
1252	*/
1253	if (ata_dev_enabled(dev)) {
1254	ata_dev_power_set_standby(dev);
1255	ata_eh_dev_disable(dev);
1256	}
1257
1258	spin_lock_irqsave(ap->lock, flags);
1259
1260	dev->flags &= ~ATA_DFLAG_DETACH;
1261
1262	if (ata_scsi_offline_dev(dev)) {
1263	dev->flags |= ATA_DFLAG_DETACHED;
1264	ap->pflags |= ATA_PFLAG_SCSI_HOTPLUG;
1265	}
1266
1267	/* clear per-dev EH info */
1268	ata_eh_clear_action(link, dev, ehi: &link->eh_info, action: ATA_EH_PERDEV_MASK);
1269	ata_eh_clear_action(link, dev, ehi: &link->eh_context.i, action: ATA_EH_PERDEV_MASK);
1270	ehc->saved_xfer_mode[dev->devno] = 0;
1271	ehc->saved_ncq_enabled &= ~(1 << dev->devno);
1272
1273	spin_unlock_irqrestore(lock: ap->lock, flags);
1274	}
1275
1276	/**
1277	* ata_eh_about_to_do - about to perform eh_action
1278	* @link: target ATA link
1279	* @dev: target ATA dev for per-dev action (can be NULL)
1280	* @action: action about to be performed
1281	*
1282	* Called just before performing EH actions to clear related bits
1283	* in @link->eh_info such that eh actions are not unnecessarily
1284	* repeated.
1285	*
1286	* LOCKING:
1287	* None.
1288	*/
1289	void ata_eh_about_to_do(struct ata_link *link, struct ata_device *dev,
1290	unsigned int action)
1291	{
1292	struct ata_port *ap = link->ap;
1293	struct ata_eh_info *ehi = &link->eh_info;
1294	struct ata_eh_context *ehc = &link->eh_context;
1295	unsigned long flags;
1296
1297	trace_ata_eh_about_to_do(link, devno: dev ? dev->devno : 0, eh_action: action);
1298
1299	spin_lock_irqsave(ap->lock, flags);
1300
1301	ata_eh_clear_action(link, dev, ehi, action);
1302
1303	/* About to take EH action, set RECOVERED. Ignore actions on
1304	* slave links as master will do them again.
1305	*/
1306	if (!(ehc->i.flags & ATA_EHI_QUIET) && link != ap->slave_link)
1307	ap->pflags |= ATA_PFLAG_RECOVERED;
1308
1309	spin_unlock_irqrestore(lock: ap->lock, flags);
1310	}
1311
1312	/**
1313	* ata_eh_done - EH action complete
1314	* @link: ATA link for which EH actions are complete
1315	* @dev: target ATA dev for per-dev action (can be NULL)
1316	* @action: action just completed
1317	*
1318	* Called right after performing EH actions to clear related bits
1319	* in @link->eh_context.
1320	*
1321	* LOCKING:
1322	* None.
1323	*/
1324	void ata_eh_done(struct ata_link *link, struct ata_device *dev,
1325	unsigned int action)
1326	{
1327	struct ata_eh_context *ehc = &link->eh_context;
1328
1329	trace_ata_eh_done(link, devno: dev ? dev->devno : 0, eh_action: action);
1330
1331	ata_eh_clear_action(link, dev, ehi: &ehc->i, action);
1332	}
1333
1334	/**
1335	* ata_err_string - convert err_mask to descriptive string
1336	* @err_mask: error mask to convert to string
1337	*
1338	* Convert @err_mask to descriptive string. Errors are
1339	* prioritized according to severity and only the most severe
1340	* error is reported.
1341	*
1342	* LOCKING:
1343	* None.
1344	*
1345	* RETURNS:
1346	* Descriptive string for @err_mask
1347	*/
1348	static const char *ata_err_string(unsigned int err_mask)
1349	{
1350	if (err_mask & AC_ERR_HOST_BUS)
1351	return "host bus error";
1352	if (err_mask & AC_ERR_ATA_BUS)
1353	return "ATA bus error";
1354	if (err_mask & AC_ERR_TIMEOUT)
1355	return "timeout";
1356	if (err_mask & AC_ERR_HSM)
1357	return "HSM violation";
1358	if (err_mask & AC_ERR_SYSTEM)
1359	return "internal error";
1360	if (err_mask & AC_ERR_MEDIA)
1361	return "media error";
1362	if (err_mask & AC_ERR_INVALID)
1363	return "invalid argument";
1364	if (err_mask & AC_ERR_DEV)
1365	return "device error";
1366	if (err_mask & AC_ERR_NCQ)
1367	return "NCQ error";
1368	if (err_mask & AC_ERR_NODEV_HINT)
1369	return "Polling detection error";
1370	return "unknown error";
1371	}
1372
1373	/**
1374	* atapi_eh_tur - perform ATAPI TEST_UNIT_READY
1375	* @dev: target ATAPI device
1376	* @r_sense_key: out parameter for sense_key
1377	*
1378	* Perform ATAPI TEST_UNIT_READY.
1379	*
1380	* LOCKING:
1381	* EH context (may sleep).
1382	*
1383	* RETURNS:
1384	* 0 on success, AC_ERR_* mask on failure.
1385	*/
1386	unsigned int atapi_eh_tur(struct ata_device *dev, u8 *r_sense_key)
1387	{
1388	u8 cdb[ATAPI_CDB_LEN] = { TEST_UNIT_READY, 0, 0, 0, 0, 0 };
1389	struct ata_taskfile tf;
1390	unsigned int err_mask;
1391
1392	ata_tf_init(dev, tf: &tf);
1393
1394	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
1395	tf.command = ATA_CMD_PACKET;
1396	tf.protocol = ATAPI_PROT_NODATA;
1397
1398	err_mask = ata_exec_internal(dev, tf: &tf, cdb, dma_dir: DMA_NONE, NULL, buflen: 0, timeout: 0);
1399	if (err_mask == AC_ERR_DEV)
1400	*r_sense_key = tf.error >> 4;
1401	return err_mask;
1402	}
1403
1404	/**
1405	* ata_eh_request_sense - perform REQUEST_SENSE_DATA_EXT
1406	* @qc: qc to perform REQUEST_SENSE_SENSE_DATA_EXT to
1407	*
1408	* Perform REQUEST_SENSE_DATA_EXT after the device reported CHECK
1409	* SENSE. This function is an EH helper.
1410	*
1411	* LOCKING:
1412	* Kernel thread context (may sleep).
1413	*
1414	* RETURNS:
1415	* true if sense data could be fetched, false otherwise.
1416	*/
1417	static bool ata_eh_request_sense(struct ata_queued_cmd *qc)
1418	{
1419	struct scsi_cmnd *cmd = qc->scsicmd;
1420	struct ata_device *dev = qc->dev;
1421	struct ata_taskfile tf;
1422	unsigned int err_mask;
1423
1424	if (ata_port_is_frozen(ap: qc->ap)) {
1425	ata_dev_warn(dev, "sense data available but port frozen\n");
1426	return false;
1427	}
1428
1429	if (!ata_id_sense_reporting_enabled(id: dev->id)) {
1430	ata_dev_warn(qc->dev, "sense data reporting disabled\n");
1431	return false;
1432	}
1433
1434	ata_tf_init(dev, tf: &tf);
1435	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
1436	tf.flags |= ATA_TFLAG_LBA | ATA_TFLAG_LBA48;
1437	tf.command = ATA_CMD_REQ_SENSE_DATA;
1438	tf.protocol = ATA_PROT_NODATA;
1439
1440	err_mask = ata_exec_internal(dev, tf: &tf, NULL, dma_dir: DMA_NONE, NULL, buflen: 0, timeout: 0);
1441	/* Ignore err_mask; ATA_ERR might be set */
1442	if (tf.status & ATA_SENSE) {
1443	if (ata_scsi_sense_is_valid(sk: tf.lbah, asc: tf.lbam, ascq: tf.lbal)) {
1444	/* Set sense without also setting scsicmd->result */
1445	scsi_build_sense_buffer(desc: dev->flags & ATA_DFLAG_D_SENSE,
1446	buf: cmd->sense_buffer, key: tf.lbah,
1447	asc: tf.lbam, ascq: tf.lbal);
1448	qc->flags |= ATA_QCFLAG_SENSE_VALID;
1449	return true;
1450	}
1451	} else {
1452	ata_dev_warn(dev, "request sense failed stat %02x emask %x\n",
1453	tf.status, err_mask);
1454	}
1455
1456	return false;
1457	}
1458
1459	/**
1460	* atapi_eh_request_sense - perform ATAPI REQUEST_SENSE
1461	* @dev: device to perform REQUEST_SENSE to
1462	* @sense_buf: result sense data buffer (SCSI_SENSE_BUFFERSIZE bytes long)
1463	* @dfl_sense_key: default sense key to use
1464	*
1465	* Perform ATAPI REQUEST_SENSE after the device reported CHECK
1466	* SENSE. This function is EH helper.
1467	*
1468	* LOCKING:
1469	* Kernel thread context (may sleep).
1470	*
1471	* RETURNS:
1472	* 0 on success, AC_ERR_* mask on failure
1473	*/
1474	unsigned int atapi_eh_request_sense(struct ata_device *dev,
1475	u8 *sense_buf, u8 dfl_sense_key)
1476	{
1477	u8 cdb[ATAPI_CDB_LEN] =
1478	{ REQUEST_SENSE, 0, 0, 0, SCSI_SENSE_BUFFERSIZE, 0 };
1479	struct ata_port *ap = dev->link->ap;
1480	struct ata_taskfile tf;
1481
1482	memset(sense_buf, 0, SCSI_SENSE_BUFFERSIZE);
1483
1484	/* initialize sense_buf with the error register,
1485	* for the case where they are -not- overwritten
1486	*/
1487	sense_buf[0] = 0x70;
1488	sense_buf[2] = dfl_sense_key;
1489
1490	/* some devices time out if garbage left in tf */
1491	ata_tf_init(dev, tf: &tf);
1492
1493	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
1494	tf.command = ATA_CMD_PACKET;
1495
1496	/* is it pointless to prefer PIO for "safety reasons"? */
1497	if (ap->flags & ATA_FLAG_PIO_DMA) {
1498	tf.protocol = ATAPI_PROT_DMA;
1499	tf.feature |= ATAPI_PKT_DMA;
1500	} else {
1501	tf.protocol = ATAPI_PROT_PIO;
1502	tf.lbam = SCSI_SENSE_BUFFERSIZE;
1503	tf.lbah = 0;
1504	}
1505
1506	return ata_exec_internal(dev, tf: &tf, cdb, dma_dir: DMA_FROM_DEVICE,
1507	buf: sense_buf, SCSI_SENSE_BUFFERSIZE, timeout: 0);
1508	}
1509
1510	/**
1511	* ata_eh_analyze_serror - analyze SError for a failed port
1512	* @link: ATA link to analyze SError for
1513	*
1514	* Analyze SError if available and further determine cause of
1515	* failure.
1516	*
1517	* LOCKING:
1518	* None.
1519	*/
1520	static void ata_eh_analyze_serror(struct ata_link *link)
1521	{
1522	struct ata_eh_context *ehc = &link->eh_context;
1523	u32 serror = ehc->i.serror;
1524	unsigned int err_mask = 0, action = 0;
1525	u32 hotplug_mask;
1526
1527	if (serror & (SERR_PERSISTENT | SERR_DATA)) {
1528	err_mask |= AC_ERR_ATA_BUS;
1529	action |= ATA_EH_RESET;
1530	}
1531	if (serror & SERR_PROTOCOL) {
1532	err_mask |= AC_ERR_HSM;
1533	action |= ATA_EH_RESET;
1534	}
1535	if (serror & SERR_INTERNAL) {
1536	err_mask |= AC_ERR_SYSTEM;
1537	action |= ATA_EH_RESET;
1538	}
1539
1540	/* Determine whether a hotplug event has occurred. Both
1541	* SError.N/X are considered hotplug events for enabled or
1542	* host links. For disabled PMP links, only N bit is
1543	* considered as X bit is left at 1 for link plugging.
1544	*/
1545	if (link->lpm_policy > ATA_LPM_MAX_POWER)
1546	hotplug_mask = 0; /* hotplug doesn't work w/ LPM */
1547	else if (!(link->flags & ATA_LFLAG_DISABLED) || ata_is_host_link(link))
1548	hotplug_mask = SERR_PHYRDY_CHG | SERR_DEV_XCHG;
1549	else
1550	hotplug_mask = SERR_PHYRDY_CHG;
1551
1552	if (serror & hotplug_mask)
1553	ata_ehi_hotplugged(ehi: &ehc->i);
1554
1555	ehc->i.err_mask |= err_mask;
1556	ehc->i.action |= action;
1557	}
1558
1559	/**
1560	* ata_eh_analyze_tf - analyze taskfile of a failed qc
1561	* @qc: qc to analyze
1562	*
1563	* Analyze taskfile of @qc and further determine cause of
1564	* failure. This function also requests ATAPI sense data if
1565	* available.
1566	*
1567	* LOCKING:
1568	* Kernel thread context (may sleep).
1569	*
1570	* RETURNS:
1571	* Determined recovery action
1572	*/
1573	static unsigned int ata_eh_analyze_tf(struct ata_queued_cmd *qc)
1574	{
1575	const struct ata_taskfile *tf = &qc->result_tf;
1576	unsigned int tmp, action = 0;
1577	u8 stat = tf->status, err = tf->error;
1578
1579	if ((stat & (ATA_BUSY | ATA_DRQ | ATA_DRDY)) != ATA_DRDY) {
1580	qc->err_mask |= AC_ERR_HSM;
1581	return ATA_EH_RESET;
1582	}
1583
1584	if (stat & (ATA_ERR | ATA_DF)) {
1585	qc->err_mask |= AC_ERR_DEV;
1586	/*
1587	* Sense data reporting does not work if the
1588	* device fault bit is set.
1589	*/
1590	if (stat & ATA_DF)
1591	stat &= ~ATA_SENSE;
1592	} else {
1593	return 0;
1594	}
1595
1596	switch (qc->dev->class) {
1597	case ATA_DEV_ATA:
1598	case ATA_DEV_ZAC:
1599	/*
1600	* Fetch the sense data explicitly if:
1601	* -It was a non-NCQ command that failed, or
1602	* -It was a NCQ command that failed, but the sense data
1603	* was not included in the NCQ command error log
1604	* (i.e. NCQ autosense is not supported by the device).
1605	*/
1606	if (!(qc->flags & ATA_QCFLAG_SENSE_VALID) &&
1607	(stat & ATA_SENSE) && ata_eh_request_sense(qc))
1608	set_status_byte(cmd: qc->scsicmd, status: SAM_STAT_CHECK_CONDITION);
1609	if (err & ATA_ICRC)
1610	qc->err_mask |= AC_ERR_ATA_BUS;
1611	if (err & (ATA_UNC | ATA_AMNF))
1612	qc->err_mask |= AC_ERR_MEDIA;
1613	if (err & ATA_IDNF)
1614	qc->err_mask |= AC_ERR_INVALID;
1615	break;
1616
1617	case ATA_DEV_ATAPI:
1618	if (!ata_port_is_frozen(ap: qc->ap)) {
1619	tmp = atapi_eh_request_sense(dev: qc->dev,
1620	sense_buf: qc->scsicmd->sense_buffer,
1621	dfl_sense_key: qc->result_tf.error >> 4);
1622	if (!tmp)
1623	qc->flags |= ATA_QCFLAG_SENSE_VALID;
1624	else
1625	qc->err_mask |= tmp;
1626	}
1627	}
1628
1629	if (qc->flags & ATA_QCFLAG_SENSE_VALID) {
1630	enum scsi_disposition ret = scsi_check_sense(qc->scsicmd);
1631	/*
1632	* SUCCESS here means that the sense code could be
1633	* evaluated and should be passed to the upper layers
1634	* for correct evaluation.
1635	* FAILED means the sense code could not be interpreted
1636	* and the device would need to be reset.
1637	* NEEDS_RETRY and ADD_TO_MLQUEUE means that the
1638	* command would need to be retried.
1639	*/
1640	if (ret == NEEDS_RETRY || ret == ADD_TO_MLQUEUE) {
1641	qc->flags |= ATA_QCFLAG_RETRY;
1642	qc->err_mask |= AC_ERR_OTHER;
1643	} else if (ret != SUCCESS) {
1644	qc->err_mask |= AC_ERR_HSM;
1645	}
1646	}
1647	if (qc->err_mask & (AC_ERR_HSM | AC_ERR_TIMEOUT | AC_ERR_ATA_BUS))
1648	action |= ATA_EH_RESET;
1649
1650	return action;
1651	}
1652
1653	static int ata_eh_categorize_error(unsigned int eflags, unsigned int err_mask,
1654	int *xfer_ok)
1655	{
1656	int base = 0;
1657
1658	if (!(eflags & ATA_EFLAG_DUBIOUS_XFER))
1659	*xfer_ok = 1;
1660
1661	if (!*xfer_ok)
1662	base = ATA_ECAT_DUBIOUS_NONE;
1663
1664	if (err_mask & AC_ERR_ATA_BUS)
1665	return base + ATA_ECAT_ATA_BUS;
1666
1667	if (err_mask & AC_ERR_TIMEOUT)
1668	return base + ATA_ECAT_TOUT_HSM;
1669
1670	if (eflags & ATA_EFLAG_IS_IO) {
1671	if (err_mask & AC_ERR_HSM)
1672	return base + ATA_ECAT_TOUT_HSM;
1673	if ((err_mask &
1674	(AC_ERR_DEV|AC_ERR_MEDIA|AC_ERR_INVALID)) == AC_ERR_DEV)
1675	return base + ATA_ECAT_UNK_DEV;
1676	}
1677
1678	return 0;
1679	}
1680
1681	struct speed_down_verdict_arg {
1682	u64 since;
1683	int xfer_ok;
1684	int nr_errors[ATA_ECAT_NR];
1685	};
1686
1687	static int speed_down_verdict_cb(struct ata_ering_entry *ent, void *void_arg)
1688	{
1689	struct speed_down_verdict_arg *arg = void_arg;
1690	int cat;
1691
1692	if ((ent->eflags & ATA_EFLAG_OLD_ER) || (ent->timestamp < arg->since))
1693	return -1;
1694
1695	cat = ata_eh_categorize_error(eflags: ent->eflags, err_mask: ent->err_mask,
1696	xfer_ok: &arg->xfer_ok);
1697	arg->nr_errors[cat]++;
1698
1699	return 0;
1700	}
1701
1702	/**
1703	* ata_eh_speed_down_verdict - Determine speed down verdict
1704	* @dev: Device of interest
1705	*
1706	* This function examines error ring of @dev and determines
1707	* whether NCQ needs to be turned off, transfer speed should be
1708	* stepped down, or falling back to PIO is necessary.
1709	*
1710	* ECAT_ATA_BUS : ATA_BUS error for any command
1711	*
1712	* ECAT_TOUT_HSM : TIMEOUT for any command or HSM violation for
1713	* IO commands
1714	*
1715	* ECAT_UNK_DEV : Unknown DEV error for IO commands
1716	*
1717	* ECAT_DUBIOUS_* : Identical to above three but occurred while
1718	* data transfer hasn't been verified.
1719	*
1720	* Verdicts are
1721	*
1722	* NCQ_OFF : Turn off NCQ.
1723	*
1724	* SPEED_DOWN : Speed down transfer speed but don't fall back
1725	* to PIO.
1726	*
1727	* FALLBACK_TO_PIO : Fall back to PIO.
1728	*
1729	* Even if multiple verdicts are returned, only one action is
1730	* taken per error. An action triggered by non-DUBIOUS errors
1731	* clears ering, while one triggered by DUBIOUS_* errors doesn't.
1732	* This is to expedite speed down decisions right after device is
1733	* initially configured.
1734	*
1735	* The following are speed down rules. #1 and #2 deal with
1736	* DUBIOUS errors.
1737	*
1738	* 1. If more than one DUBIOUS_ATA_BUS or DUBIOUS_TOUT_HSM errors
1739	* occurred during last 5 mins, SPEED_DOWN and FALLBACK_TO_PIO.
1740	*
1741	* 2. If more than one DUBIOUS_TOUT_HSM or DUBIOUS_UNK_DEV errors
1742	* occurred during last 5 mins, NCQ_OFF.
1743	*
1744	* 3. If more than 8 ATA_BUS, TOUT_HSM or UNK_DEV errors
1745	* occurred during last 5 mins, FALLBACK_TO_PIO
1746	*
1747	* 4. If more than 3 TOUT_HSM or UNK_DEV errors occurred
1748	* during last 10 mins, NCQ_OFF.
1749	*
1750	* 5. If more than 3 ATA_BUS or TOUT_HSM errors, or more than 6
1751	* UNK_DEV errors occurred during last 10 mins, SPEED_DOWN.
1752	*
1753	* LOCKING:
1754	* Inherited from caller.
1755	*
1756	* RETURNS:
1757	* OR of ATA_EH_SPDN_* flags.
1758	*/
1759	static unsigned int ata_eh_speed_down_verdict(struct ata_device *dev)
1760	{
1761	const u64 j5mins = 5LLU * 60 * HZ, j10mins = 10LLU * 60 * HZ;
1762	u64 j64 = get_jiffies_64();
1763	struct speed_down_verdict_arg arg;
1764	unsigned int verdict = 0;
1765
1766	/* scan past 5 mins of error history */
1767	memset(&arg, 0, sizeof(arg));
1768	arg.since = j64 - min(j64, j5mins);
1769	ata_ering_map(ering: &dev->ering, map_fn: speed_down_verdict_cb, arg: &arg);
1770
1771	if (arg.nr_errors[ATA_ECAT_DUBIOUS_ATA_BUS] +
1772	arg.nr_errors[ATA_ECAT_DUBIOUS_TOUT_HSM] > 1)
1773	verdict |= ATA_EH_SPDN_SPEED_DOWN |
1774	ATA_EH_SPDN_FALLBACK_TO_PIO | ATA_EH_SPDN_KEEP_ERRORS;
1775
1776	if (arg.nr_errors[ATA_ECAT_DUBIOUS_TOUT_HSM] +
1777	arg.nr_errors[ATA_ECAT_DUBIOUS_UNK_DEV] > 1)
1778	verdict |= ATA_EH_SPDN_NCQ_OFF | ATA_EH_SPDN_KEEP_ERRORS;
1779
1780	if (arg.nr_errors[ATA_ECAT_ATA_BUS] +
1781	arg.nr_errors[ATA_ECAT_TOUT_HSM] +
1782	arg.nr_errors[ATA_ECAT_UNK_DEV] > 6)
1783	verdict |= ATA_EH_SPDN_FALLBACK_TO_PIO;
1784
1785	/* scan past 10 mins of error history */
1786	memset(&arg, 0, sizeof(arg));
1787	arg.since = j64 - min(j64, j10mins);
1788	ata_ering_map(ering: &dev->ering, map_fn: speed_down_verdict_cb, arg: &arg);
1789
1790	if (arg.nr_errors[ATA_ECAT_TOUT_HSM] +
1791	arg.nr_errors[ATA_ECAT_UNK_DEV] > 3)
1792	verdict |= ATA_EH_SPDN_NCQ_OFF;
1793
1794	if (arg.nr_errors[ATA_ECAT_ATA_BUS] +
1795	arg.nr_errors[ATA_ECAT_TOUT_HSM] > 3 ||
1796	arg.nr_errors[ATA_ECAT_UNK_DEV] > 6)
1797	verdict |= ATA_EH_SPDN_SPEED_DOWN;
1798
1799	return verdict;
1800	}
1801
1802	/**
1803	* ata_eh_speed_down - record error and speed down if necessary
1804	* @dev: Failed device
1805	* @eflags: mask of ATA_EFLAG_* flags
1806	* @err_mask: err_mask of the error
1807	*
1808	* Record error and examine error history to determine whether
1809	* adjusting transmission speed is necessary. It also sets
1810	* transmission limits appropriately if such adjustment is
1811	* necessary.
1812	*
1813	* LOCKING:
1814	* Kernel thread context (may sleep).
1815	*
1816	* RETURNS:
1817	* Determined recovery action.
1818	*/
1819	static unsigned int ata_eh_speed_down(struct ata_device *dev,
1820	unsigned int eflags, unsigned int err_mask)
1821	{
1822	struct ata_link *link = ata_dev_phys_link(dev);
1823	int xfer_ok = 0;
1824	unsigned int verdict;
1825	unsigned int action = 0;
1826
1827	/* don't bother if Cat-0 error */
1828	if (ata_eh_categorize_error(eflags, err_mask, xfer_ok: &xfer_ok) == 0)
1829	return 0;
1830
1831	/* record error and determine whether speed down is necessary */
1832	ata_ering_record(ering: &dev->ering, eflags, err_mask);
1833	verdict = ata_eh_speed_down_verdict(dev);
1834
1835	/* turn off NCQ? */
1836	if ((verdict & ATA_EH_SPDN_NCQ_OFF) && ata_ncq_enabled(dev)) {
1837	dev->flags |= ATA_DFLAG_NCQ_OFF;
1838	ata_dev_warn(dev, "NCQ disabled due to excessive errors\n");
1839	goto done;
1840	}
1841
1842	/* speed down? */
1843	if (verdict & ATA_EH_SPDN_SPEED_DOWN) {
1844	/* speed down SATA link speed if possible */
1845	if (sata_down_spd_limit(link, spd_limit: 0) == 0) {
1846	action |= ATA_EH_RESET;
1847	goto done;
1848	}
1849
1850	/* lower transfer mode */
1851	if (dev->spdn_cnt < 2) {
1852	static const int dma_dnxfer_sel[] =
1853	{ ATA_DNXFER_DMA, ATA_DNXFER_40C };
1854	static const int pio_dnxfer_sel[] =
1855	{ ATA_DNXFER_PIO, ATA_DNXFER_FORCE_PIO0 };
1856	int sel;
1857
1858	if (dev->xfer_shift != ATA_SHIFT_PIO)
1859	sel = dma_dnxfer_sel[dev->spdn_cnt];
1860	else
1861	sel = pio_dnxfer_sel[dev->spdn_cnt];
1862
1863	dev->spdn_cnt++;
1864
1865	if (ata_down_xfermask_limit(dev, sel) == 0) {
1866	action |= ATA_EH_RESET;
1867	goto done;
1868	}
1869	}
1870	}
1871
1872	/* Fall back to PIO? Slowing down to PIO is meaningless for
1873	* SATA ATA devices. Consider it only for PATA and SATAPI.
1874	*/
1875	if ((verdict & ATA_EH_SPDN_FALLBACK_TO_PIO) && (dev->spdn_cnt >= 2) &&
1876	(link->ap->cbl != ATA_CBL_SATA || dev->class == ATA_DEV_ATAPI) &&
1877	(dev->xfer_shift != ATA_SHIFT_PIO)) {
1878	if (ata_down_xfermask_limit(dev, sel: ATA_DNXFER_FORCE_PIO) == 0) {
1879	dev->spdn_cnt = 0;
1880	action |= ATA_EH_RESET;
1881	goto done;
1882	}
1883	}
1884
1885	return 0;
1886	done:
1887	/* device has been slowed down, blow error history */
1888	if (!(verdict & ATA_EH_SPDN_KEEP_ERRORS))
1889	ata_ering_clear(ering: &dev->ering);
1890	return action;
1891	}
1892
1893	/**
1894	* ata_eh_worth_retry - analyze error and decide whether to retry
1895	* @qc: qc to possibly retry
1896	*
1897	* Look at the cause of the error and decide if a retry
1898	* might be useful or not. We don't want to retry media errors
1899	* because the drive itself has probably already taken 10-30 seconds
1900	* doing its own internal retries before reporting the failure.
1901	*/
1902	static inline int ata_eh_worth_retry(struct ata_queued_cmd *qc)
1903	{
1904	if (qc->err_mask & AC_ERR_MEDIA)
1905	return 0; /* don't retry media errors */
1906	if (qc->flags & ATA_QCFLAG_IO)
1907	return 1; /* otherwise retry anything from fs stack */
1908	if (qc->err_mask & AC_ERR_INVALID)
1909	return 0; /* don't retry these */
1910	return qc->err_mask != AC_ERR_DEV; /* retry if not dev error */
1911	}
1912
1913	/**
1914	* ata_eh_quiet - check if we need to be quiet about a command error
1915	* @qc: qc to check
1916	*
1917	* Look at the qc flags anbd its scsi command request flags to determine
1918	* if we need to be quiet about the command failure.
1919	*/
1920	static inline bool ata_eh_quiet(struct ata_queued_cmd *qc)
1921	{
1922	if (qc->scsicmd && scsi_cmd_to_rq(scmd: qc->scsicmd)->rq_flags & RQF_QUIET)
1923	qc->flags |= ATA_QCFLAG_QUIET;
1924	return qc->flags & ATA_QCFLAG_QUIET;
1925	}
1926
1927	static int ata_eh_read_sense_success_non_ncq(struct ata_link *link)
1928	{
1929	struct ata_port *ap = link->ap;
1930	struct ata_queued_cmd *qc;
1931
1932	qc = __ata_qc_from_tag(ap, tag: link->active_tag);
1933	if (!qc)
1934	return -EIO;
1935
1936	if (!(qc->flags & ATA_QCFLAG_EH) ||
1937	!(qc->flags & ATA_QCFLAG_EH_SUCCESS_CMD) ||
1938	qc->err_mask)
1939	return -EIO;
1940
1941	if (!ata_eh_request_sense(qc))
1942	return -EIO;
1943
1944	/*
1945	* If we have sense data, call scsi_check_sense() in order to set the
1946	* correct SCSI ML byte (if any). No point in checking the return value,
1947	* since the command has already completed successfully.
1948	*/
1949	scsi_check_sense(qc->scsicmd);
1950
1951	return 0;
1952	}
1953
1954	static void ata_eh_get_success_sense(struct ata_link *link)
1955	{
1956	struct ata_eh_context *ehc = &link->eh_context;
1957	struct ata_device *dev = link->device;
1958	struct ata_port *ap = link->ap;
1959	struct ata_queued_cmd *qc;
1960	int tag, ret = 0;
1961
1962	if (!(ehc->i.dev_action[dev->devno] & ATA_EH_GET_SUCCESS_SENSE))
1963	return;
1964
1965	/* if frozen, we can't do much */
1966	if (ata_port_is_frozen(ap)) {
1967	ata_dev_warn(dev,
1968	"successful sense data available but port frozen\n");
1969	goto out;
1970	}
1971
1972	/*
1973	* If the link has sactive set, then we have outstanding NCQ commands
1974	* and have to read the Successful NCQ Commands log to get the sense
1975	* data. Otherwise, we are dealing with a non-NCQ command and use
1976	* request sense ext command to retrieve the sense data.
1977	*/
1978	if (link->sactive)
1979	ret = ata_eh_read_sense_success_ncq_log(link);
1980	else
1981	ret = ata_eh_read_sense_success_non_ncq(link);
1982	if (ret)
1983	goto out;
1984
1985	ata_eh_done(link, dev, action: ATA_EH_GET_SUCCESS_SENSE);
1986	return;
1987
1988	out:
1989	/*
1990	* If we failed to get sense data for a successful command that ought to
1991	* have sense data, we cannot simply return BLK_STS_OK to user space.
1992	* This is because we can't know if the sense data that we couldn't get
1993	* was actually "DATA CURRENTLY UNAVAILABLE". Reporting such a command
1994	* as success to user space would result in a silent data corruption.
1995	* Thus, add a bogus ABORTED_COMMAND sense data to such commands, such
1996	* that SCSI will report these commands as BLK_STS_IOERR to user space.
1997	*/
1998	ata_qc_for_each_raw(ap, qc, tag) {
1999	if (!(qc->flags & ATA_QCFLAG_EH) ||
2000	!(qc->flags & ATA_QCFLAG_EH_SUCCESS_CMD) ||
2001	qc->err_mask ||
2002	ata_dev_phys_link(dev: qc->dev) != link)
2003	continue;
2004
2005	/* We managed to get sense for this success command, skip. */
2006	if (qc->flags & ATA_QCFLAG_SENSE_VALID)
2007	continue;
2008
2009	/* This success command did not have any sense data, skip. */
2010	if (!(qc->result_tf.status & ATA_SENSE))
2011	continue;
2012
2013	/* This success command had sense data, but we failed to get. */
2014	ata_scsi_set_sense(dev, cmd: qc->scsicmd, ABORTED_COMMAND, asc: 0, ascq: 0);
2015	qc->flags |= ATA_QCFLAG_SENSE_VALID;
2016	}
2017	ata_eh_done(link, dev, action: ATA_EH_GET_SUCCESS_SENSE);
2018	}
2019
2020	/**
2021	* ata_eh_link_autopsy - analyze error and determine recovery action
2022	* @link: host link to perform autopsy on
2023	*
2024	* Analyze why @link failed and determine which recovery actions
2025	* are needed. This function also sets more detailed AC_ERR_*
2026	* values and fills sense data for ATAPI CHECK SENSE.
2027	*
2028	* LOCKING:
2029	* Kernel thread context (may sleep).
2030	*/
2031	static void ata_eh_link_autopsy(struct ata_link *link)
2032	{
2033	struct ata_port *ap = link->ap;
2034	struct ata_eh_context *ehc = &link->eh_context;
2035	struct ata_queued_cmd *qc;
2036	struct ata_device *dev;
2037	unsigned int all_err_mask = 0, eflags = 0;
2038	int tag, nr_failed = 0, nr_quiet = 0;
2039	u32 serror;
2040	int rc;
2041
2042	if (ehc->i.flags & ATA_EHI_NO_AUTOPSY)
2043	return;
2044
2045	/* obtain and analyze SError */
2046	rc = sata_scr_read(link, reg: SCR_ERROR, val: &serror);
2047	if (rc == 0) {
2048	ehc->i.serror |= serror;
2049	ata_eh_analyze_serror(link);
2050	} else if (rc != -EOPNOTSUPP) {
2051	/* SError read failed, force reset and probing */
2052	ehc->i.probe_mask |= ATA_ALL_DEVICES;
2053	ehc->i.action |= ATA_EH_RESET;
2054	ehc->i.err_mask |= AC_ERR_OTHER;
2055	}
2056
2057	/* analyze NCQ failure */
2058	ata_eh_analyze_ncq_error(link);
2059
2060	/*
2061	* Check if this was a successful command that simply needs sense data.
2062	* Since the sense data is not part of the completion, we need to fetch
2063	* it using an additional command. Since this can't be done from irq
2064	* context, the sense data for successful commands are fetched by EH.
2065	*/
2066	ata_eh_get_success_sense(link);
2067
2068	/* any real error trumps AC_ERR_OTHER */
2069	if (ehc->i.err_mask & ~AC_ERR_OTHER)
2070	ehc->i.err_mask &= ~AC_ERR_OTHER;
2071
2072	all_err_mask |= ehc->i.err_mask;
2073
2074	ata_qc_for_each_raw(ap, qc, tag) {
2075	if (!(qc->flags & ATA_QCFLAG_EH) ||
2076	qc->flags & ATA_QCFLAG_RETRY ||
2077	qc->flags & ATA_QCFLAG_EH_SUCCESS_CMD ||
2078	ata_dev_phys_link(dev: qc->dev) != link)
2079	continue;
2080
2081	/* inherit upper level err_mask */
2082	qc->err_mask |= ehc->i.err_mask;
2083
2084	/* analyze TF */
2085	ehc->i.action |= ata_eh_analyze_tf(qc);
2086
2087	/* DEV errors are probably spurious in case of ATA_BUS error */
2088	if (qc->err_mask & AC_ERR_ATA_BUS)
2089	qc->err_mask &= ~(AC_ERR_DEV | AC_ERR_MEDIA |
2090	AC_ERR_INVALID);
2091
2092	/* any real error trumps unknown error */
2093	if (qc->err_mask & ~AC_ERR_OTHER)
2094	qc->err_mask &= ~AC_ERR_OTHER;
2095
2096	/*
2097	* SENSE_VALID trumps dev/unknown error and revalidation. Upper
2098	* layers will determine whether the command is worth retrying
2099	* based on the sense data and device class/type. Otherwise,
2100	* determine directly if the command is worth retrying using its
2101	* error mask and flags.
2102	*/
2103	if (qc->flags & ATA_QCFLAG_SENSE_VALID)
2104	qc->err_mask &= ~(AC_ERR_DEV | AC_ERR_OTHER);
2105	else if (ata_eh_worth_retry(qc))
2106	qc->flags |= ATA_QCFLAG_RETRY;
2107
2108	/* accumulate error info */
2109	ehc->i.dev = qc->dev;
2110	all_err_mask |= qc->err_mask;
2111	if (qc->flags & ATA_QCFLAG_IO)
2112	eflags |= ATA_EFLAG_IS_IO;
2113	trace_ata_eh_link_autopsy_qc(qc);
2114
2115	/* Count quiet errors */
2116	if (ata_eh_quiet(qc))
2117	nr_quiet++;
2118	nr_failed++;
2119	}
2120
2121	/* If all failed commands requested silence, then be quiet */
2122	if (nr_quiet == nr_failed)
2123	ehc->i.flags |= ATA_EHI_QUIET;
2124
2125	/* enforce default EH actions */
2126	if (ata_port_is_frozen(ap) ||
2127	all_err_mask & (AC_ERR_HSM | AC_ERR_TIMEOUT))
2128	ehc->i.action |= ATA_EH_RESET;
2129	else if (((eflags & ATA_EFLAG_IS_IO) && all_err_mask) ||
2130	(!(eflags & ATA_EFLAG_IS_IO) && (all_err_mask & ~AC_ERR_DEV)))
2131	ehc->i.action |= ATA_EH_REVALIDATE;
2132
2133	/* If we have offending qcs and the associated failed device,
2134	* perform per-dev EH action only on the offending device.
2135	*/
2136	if (ehc->i.dev) {
2137	ehc->i.dev_action[ehc->i.dev->devno] |=
2138	ehc->i.action & ATA_EH_PERDEV_MASK;
2139	ehc->i.action &= ~ATA_EH_PERDEV_MASK;
2140	}
2141
2142	/* propagate timeout to host link */
2143	if ((all_err_mask & AC_ERR_TIMEOUT) && !ata_is_host_link(link))
2144	ap->link.eh_context.i.err_mask |= AC_ERR_TIMEOUT;
2145
2146	/* record error and consider speeding down */
2147	dev = ehc->i.dev;
2148	if (!dev && ((ata_link_max_devices(link) == 1 &&
2149	ata_dev_enabled(dev: link->device))))
2150	dev = link->device;
2151
2152	if (dev) {
2153	if (dev->flags & ATA_DFLAG_DUBIOUS_XFER)
2154	eflags |= ATA_EFLAG_DUBIOUS_XFER;
2155	ehc->i.action |= ata_eh_speed_down(dev, eflags, err_mask: all_err_mask);
2156	trace_ata_eh_link_autopsy(dev, eh_action: ehc->i.action, eh_err_mask: all_err_mask);
2157	}
2158	}
2159
2160	/**
2161	* ata_eh_autopsy - analyze error and determine recovery action
2162	* @ap: host port to perform autopsy on
2163	*
2164	* Analyze all links of @ap and determine why they failed and
2165	* which recovery actions are needed.
2166	*
2167	* LOCKING:
2168	* Kernel thread context (may sleep).
2169	*/
2170	void ata_eh_autopsy(struct ata_port *ap)
2171	{
2172	struct ata_link *link;
2173
2174	ata_for_each_link(link, ap, EDGE)
2175	ata_eh_link_autopsy(link);
2176
2177	/* Handle the frigging slave link. Autopsy is done similarly
2178	* but actions and flags are transferred over to the master
2179	* link and handled from there.
2180	*/
2181	if (ap->slave_link) {
2182	struct ata_eh_context *mehc = &ap->link.eh_context;
2183	struct ata_eh_context *sehc = &ap->slave_link->eh_context;
2184
2185	/* transfer control flags from master to slave */
2186	sehc->i.flags |= mehc->i.flags & ATA_EHI_TO_SLAVE_MASK;
2187
2188	/* perform autopsy on the slave link */
2189	ata_eh_link_autopsy(link: ap->slave_link);
2190
2191	/* transfer actions from slave to master and clear slave */
2192	ata_eh_about_to_do(link: ap->slave_link, NULL, action: ATA_EH_ALL_ACTIONS);
2193	mehc->i.action |= sehc->i.action;
2194	mehc->i.dev_action[1] |= sehc->i.dev_action[1];
2195	mehc->i.flags |= sehc->i.flags;
2196	ata_eh_done(link: ap->slave_link, NULL, action: ATA_EH_ALL_ACTIONS);
2197	}
2198
2199	/* Autopsy of fanout ports can affect host link autopsy.
2200	* Perform host link autopsy last.
2201	*/
2202	if (sata_pmp_attached(ap))
2203	ata_eh_link_autopsy(link: &ap->link);
2204	}
2205
2206	/**
2207	* ata_get_cmd_name - get name for ATA command
2208	* @command: ATA command code to get name for
2209	*
2210	* Return a textual name of the given command or "unknown"
2211	*
2212	* LOCKING:
2213	* None
2214	*/
2215	const char *ata_get_cmd_name(u8 command)
2216	{
2217	#ifdef CONFIG_ATA_VERBOSE_ERROR
2218	static const struct
2219	{
2220	u8 command;
2221	const char *text;
2222	} cmd_descr[] = {
2223	{ ATA_CMD_DEV_RESET, "DEVICE RESET" },
2224	{ ATA_CMD_CHK_POWER, "CHECK POWER MODE" },
2225	{ ATA_CMD_STANDBY, "STANDBY" },
2226	{ ATA_CMD_IDLE, "IDLE" },
2227	{ ATA_CMD_EDD, "EXECUTE DEVICE DIAGNOSTIC" },
2228	{ ATA_CMD_DOWNLOAD_MICRO, "DOWNLOAD MICROCODE" },
2229	{ ATA_CMD_DOWNLOAD_MICRO_DMA, "DOWNLOAD MICROCODE DMA" },
2230	{ ATA_CMD_NOP, "NOP" },
2231	{ ATA_CMD_FLUSH, "FLUSH CACHE" },
2232	{ ATA_CMD_FLUSH_EXT, "FLUSH CACHE EXT" },
2233	{ ATA_CMD_ID_ATA, "IDENTIFY DEVICE" },
2234	{ ATA_CMD_ID_ATAPI, "IDENTIFY PACKET DEVICE" },
2235	{ ATA_CMD_SERVICE, "SERVICE" },
2236	{ ATA_CMD_READ, "READ DMA" },
2237	{ ATA_CMD_READ_EXT, "READ DMA EXT" },
2238	{ ATA_CMD_READ_QUEUED, "READ DMA QUEUED" },
2239	{ ATA_CMD_READ_STREAM_EXT, "READ STREAM EXT" },
2240	{ ATA_CMD_READ_STREAM_DMA_EXT, "READ STREAM DMA EXT" },
2241	{ ATA_CMD_WRITE, "WRITE DMA" },
2242	{ ATA_CMD_WRITE_EXT, "WRITE DMA EXT" },
2243	{ ATA_CMD_WRITE_QUEUED, "WRITE DMA QUEUED EXT" },
2244	{ ATA_CMD_WRITE_STREAM_EXT, "WRITE STREAM EXT" },
2245	{ ATA_CMD_WRITE_STREAM_DMA_EXT, "WRITE STREAM DMA EXT" },
2246	{ ATA_CMD_WRITE_FUA_EXT, "WRITE DMA FUA EXT" },
2247	{ ATA_CMD_WRITE_QUEUED_FUA_EXT, "WRITE DMA QUEUED FUA EXT" },
2248	{ ATA_CMD_FPDMA_READ, "READ FPDMA QUEUED" },
2249	{ ATA_CMD_FPDMA_WRITE, "WRITE FPDMA QUEUED" },
2250	{ ATA_CMD_NCQ_NON_DATA, "NCQ NON-DATA" },
2251	{ ATA_CMD_FPDMA_SEND, "SEND FPDMA QUEUED" },
2252	{ ATA_CMD_FPDMA_RECV, "RECEIVE FPDMA QUEUED" },
2253	{ ATA_CMD_PIO_READ, "READ SECTOR(S)" },
2254	{ ATA_CMD_PIO_READ_EXT, "READ SECTOR(S) EXT" },
2255	{ ATA_CMD_PIO_WRITE, "WRITE SECTOR(S)" },
2256	{ ATA_CMD_PIO_WRITE_EXT, "WRITE SECTOR(S) EXT" },
2257	{ ATA_CMD_READ_MULTI, "READ MULTIPLE" },
2258	{ ATA_CMD_READ_MULTI_EXT, "READ MULTIPLE EXT" },
2259	{ ATA_CMD_WRITE_MULTI, "WRITE MULTIPLE" },
2260	{ ATA_CMD_WRITE_MULTI_EXT, "WRITE MULTIPLE EXT" },
2261	{ ATA_CMD_WRITE_MULTI_FUA_EXT, "WRITE MULTIPLE FUA EXT" },
2262	{ ATA_CMD_SET_FEATURES, "SET FEATURES" },
2263	{ ATA_CMD_SET_MULTI, "SET MULTIPLE MODE" },
2264	{ ATA_CMD_VERIFY, "READ VERIFY SECTOR(S)" },
2265	{ ATA_CMD_VERIFY_EXT, "READ VERIFY SECTOR(S) EXT" },
2266	{ ATA_CMD_WRITE_UNCORR_EXT, "WRITE UNCORRECTABLE EXT" },
2267	{ ATA_CMD_STANDBYNOW1, "STANDBY IMMEDIATE" },
2268	{ ATA_CMD_IDLEIMMEDIATE, "IDLE IMMEDIATE" },
2269	{ ATA_CMD_SLEEP, "SLEEP" },
2270	{ ATA_CMD_INIT_DEV_PARAMS, "INITIALIZE DEVICE PARAMETERS" },
2271	{ ATA_CMD_READ_NATIVE_MAX, "READ NATIVE MAX ADDRESS" },
2272	{ ATA_CMD_READ_NATIVE_MAX_EXT, "READ NATIVE MAX ADDRESS EXT" },
2273	{ ATA_CMD_SET_MAX, "SET MAX ADDRESS" },
2274	{ ATA_CMD_SET_MAX_EXT, "SET MAX ADDRESS EXT" },
2275	{ ATA_CMD_READ_LOG_EXT, "READ LOG EXT" },
2276	{ ATA_CMD_WRITE_LOG_EXT, "WRITE LOG EXT" },
2277	{ ATA_CMD_READ_LOG_DMA_EXT, "READ LOG DMA EXT" },
2278	{ ATA_CMD_WRITE_LOG_DMA_EXT, "WRITE LOG DMA EXT" },
2279	{ ATA_CMD_TRUSTED_NONDATA, "TRUSTED NON-DATA" },
2280	{ ATA_CMD_TRUSTED_RCV, "TRUSTED RECEIVE" },
2281	{ ATA_CMD_TRUSTED_RCV_DMA, "TRUSTED RECEIVE DMA" },
2282	{ ATA_CMD_TRUSTED_SND, "TRUSTED SEND" },
2283	{ ATA_CMD_TRUSTED_SND_DMA, "TRUSTED SEND DMA" },
2284	{ ATA_CMD_PMP_READ, "READ BUFFER" },
2285	{ ATA_CMD_PMP_READ_DMA, "READ BUFFER DMA" },
2286	{ ATA_CMD_PMP_WRITE, "WRITE BUFFER" },
2287	{ ATA_CMD_PMP_WRITE_DMA, "WRITE BUFFER DMA" },
2288	{ ATA_CMD_CONF_OVERLAY, "DEVICE CONFIGURATION OVERLAY" },
2289	{ ATA_CMD_SEC_SET_PASS, "SECURITY SET PASSWORD" },
2290	{ ATA_CMD_SEC_UNLOCK, "SECURITY UNLOCK" },
2291	{ ATA_CMD_SEC_ERASE_PREP, "SECURITY ERASE PREPARE" },
2292	{ ATA_CMD_SEC_ERASE_UNIT, "SECURITY ERASE UNIT" },
2293	{ ATA_CMD_SEC_FREEZE_LOCK, "SECURITY FREEZE LOCK" },
2294	{ ATA_CMD_SEC_DISABLE_PASS, "SECURITY DISABLE PASSWORD" },
2295	{ ATA_CMD_CONFIG_STREAM, "CONFIGURE STREAM" },
2296	{ ATA_CMD_SMART, "SMART" },
2297	{ ATA_CMD_MEDIA_LOCK, "DOOR LOCK" },
2298	{ ATA_CMD_MEDIA_UNLOCK, "DOOR UNLOCK" },
2299	{ ATA_CMD_DSM, "DATA SET MANAGEMENT" },
2300	{ ATA_CMD_CHK_MED_CRD_TYP, "CHECK MEDIA CARD TYPE" },
2301	{ ATA_CMD_CFA_REQ_EXT_ERR, "CFA REQUEST EXTENDED ERROR" },
2302	{ ATA_CMD_CFA_WRITE_NE, "CFA WRITE SECTORS WITHOUT ERASE" },
2303	{ ATA_CMD_CFA_TRANS_SECT, "CFA TRANSLATE SECTOR" },
2304	{ ATA_CMD_CFA_ERASE, "CFA ERASE SECTORS" },
2305	{ ATA_CMD_CFA_WRITE_MULT_NE, "CFA WRITE MULTIPLE WITHOUT ERASE" },
2306	{ ATA_CMD_REQ_SENSE_DATA, "REQUEST SENSE DATA EXT" },
2307	{ ATA_CMD_SANITIZE_DEVICE, "SANITIZE DEVICE" },
2308	{ ATA_CMD_ZAC_MGMT_IN, "ZAC MANAGEMENT IN" },
2309	{ ATA_CMD_ZAC_MGMT_OUT, "ZAC MANAGEMENT OUT" },
2310	{ ATA_CMD_READ_LONG, "READ LONG (with retries)" },
2311	{ ATA_CMD_READ_LONG_ONCE, "READ LONG (without retries)" },
2312	{ ATA_CMD_WRITE_LONG, "WRITE LONG (with retries)" },
2313	{ ATA_CMD_WRITE_LONG_ONCE, "WRITE LONG (without retries)" },
2314	{ ATA_CMD_RESTORE, "RECALIBRATE" },
2315	{ 0, NULL } /* terminate list */
2316	};
2317
2318	unsigned int i;
2319	for (i = 0; cmd_descr[i].text; i++)
2320	if (cmd_descr[i].command == command)
2321	return cmd_descr[i].text;
2322	#endif
2323
2324	return "unknown";
2325	}
2326	EXPORT_SYMBOL_GPL(ata_get_cmd_name);
2327
2328	/**
2329	* ata_eh_link_report - report error handling to user
2330	* @link: ATA link EH is going on
2331	*
2332	* Report EH to user.
2333	*
2334	* LOCKING:
2335	* None.
2336	*/
2337	static void ata_eh_link_report(struct ata_link *link)
2338	{
2339	struct ata_port *ap = link->ap;
2340	struct ata_eh_context *ehc = &link->eh_context;
2341	struct ata_queued_cmd *qc;
2342	const char *frozen, *desc;
2343	char tries_buf[16] = "";
2344	int tag, nr_failed = 0;
2345
2346	if (ehc->i.flags & ATA_EHI_QUIET)
2347	return;
2348
2349	desc = NULL;
2350	if (ehc->i.desc[0] != '\0')
2351	desc = ehc->i.desc;
2352
2353	ata_qc_for_each_raw(ap, qc, tag) {
2354	if (!(qc->flags & ATA_QCFLAG_EH) ||
2355	ata_dev_phys_link(dev: qc->dev) != link ||
2356	((qc->flags & ATA_QCFLAG_QUIET) &&
2357	qc->err_mask == AC_ERR_DEV))
2358	continue;
2359	if (qc->flags & ATA_QCFLAG_SENSE_VALID && !qc->err_mask)
2360	continue;
2361
2362	nr_failed++;
2363	}
2364
2365	if (!nr_failed && !ehc->i.err_mask)
2366	return;
2367
2368	frozen = "";
2369	if (ata_port_is_frozen(ap))
2370	frozen = " frozen";
2371
2372	if (ap->eh_tries < ATA_EH_MAX_TRIES)
2373	snprintf(buf: tries_buf, size: sizeof(tries_buf), fmt: " t%d",
2374	ap->eh_tries);
2375
2376	if (ehc->i.dev) {
2377	ata_dev_err(ehc->i.dev, "exception Emask 0x%x "
2378	"SAct 0x%x SErr 0x%x action 0x%x%s%s\n",
2379	ehc->i.err_mask, link->sactive, ehc->i.serror,
2380	ehc->i.action, frozen, tries_buf);
2381	if (desc)
2382	ata_dev_err(ehc->i.dev, "%s\n", desc);
2383	} else {
2384	ata_link_err(link, "exception Emask 0x%x "
2385	"SAct 0x%x SErr 0x%x action 0x%x%s%s\n",
2386	ehc->i.err_mask, link->sactive, ehc->i.serror,
2387	ehc->i.action, frozen, tries_buf);
2388	if (desc)
2389	ata_link_err(link, "%s\n", desc);
2390	}
2391
2392	#ifdef CONFIG_ATA_VERBOSE_ERROR
2393	if (ehc->i.serror)
2394	ata_link_err(link,
2395	"SError: { %s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s}\n",
2396	ehc->i.serror & SERR_DATA_RECOVERED ? "RecovData " : "",
2397	ehc->i.serror & SERR_COMM_RECOVERED ? "RecovComm " : "",
2398	ehc->i.serror & SERR_DATA ? "UnrecovData " : "",
2399	ehc->i.serror & SERR_PERSISTENT ? "Persist " : "",
2400	ehc->i.serror & SERR_PROTOCOL ? "Proto " : "",
2401	ehc->i.serror & SERR_INTERNAL ? "HostInt " : "",
2402	ehc->i.serror & SERR_PHYRDY_CHG ? "PHYRdyChg " : "",
2403	ehc->i.serror & SERR_PHY_INT_ERR ? "PHYInt " : "",
2404	ehc->i.serror & SERR_COMM_WAKE ? "CommWake " : "",
2405	ehc->i.serror & SERR_10B_8B_ERR ? "10B8B " : "",
2406	ehc->i.serror & SERR_DISPARITY ? "Dispar " : "",
2407	ehc->i.serror & SERR_CRC ? "BadCRC " : "",
2408	ehc->i.serror & SERR_HANDSHAKE ? "Handshk " : "",
2409	ehc->i.serror & SERR_LINK_SEQ_ERR ? "LinkSeq " : "",
2410	ehc->i.serror & SERR_TRANS_ST_ERROR ? "TrStaTrns " : "",
2411	ehc->i.serror & SERR_UNRECOG_FIS ? "UnrecFIS " : "",
2412	ehc->i.serror & SERR_DEV_XCHG ? "DevExch " : "");
2413	#endif
2414
2415	ata_qc_for_each_raw(ap, qc, tag) {
2416	struct ata_taskfile *cmd = &qc->tf, *res = &qc->result_tf;
2417	char data_buf[20] = "";
2418	char cdb_buf[70] = "";
2419
2420	if (!(qc->flags & ATA_QCFLAG_EH) ||
2421	ata_dev_phys_link(dev: qc->dev) != link || !qc->err_mask)
2422	continue;
2423
2424	if (qc->dma_dir != DMA_NONE) {
2425	static const char *dma_str[] = {
2426	[DMA_BIDIRECTIONAL] = "bidi",
2427	[DMA_TO_DEVICE] = "out",
2428	[DMA_FROM_DEVICE] = "in",
2429	};
2430	const char *prot_str = NULL;
2431
2432	switch (qc->tf.protocol) {
2433	case ATA_PROT_UNKNOWN:
2434	prot_str = "unknown";
2435	break;
2436	case ATA_PROT_NODATA:
2437	prot_str = "nodata";
2438	break;
2439	case ATA_PROT_PIO:
2440	prot_str = "pio";
2441	break;
2442	case ATA_PROT_DMA:
2443	prot_str = "dma";
2444	break;
2445	case ATA_PROT_NCQ:
2446	prot_str = "ncq dma";
2447	break;
2448	case ATA_PROT_NCQ_NODATA:
2449	prot_str = "ncq nodata";
2450	break;
2451	case ATAPI_PROT_NODATA:
2452	prot_str = "nodata";
2453	break;
2454	case ATAPI_PROT_PIO:
2455	prot_str = "pio";
2456	break;
2457	case ATAPI_PROT_DMA:
2458	prot_str = "dma";
2459	break;
2460	}
2461	snprintf(buf: data_buf, size: sizeof(data_buf), fmt: " %s %u %s",
2462	prot_str, qc->nbytes, dma_str[qc->dma_dir]);
2463	}
2464
2465	if (ata_is_atapi(prot: qc->tf.protocol)) {
2466	const u8 *cdb = qc->cdb;
2467	size_t cdb_len = qc->dev->cdb_len;
2468
2469	if (qc->scsicmd) {
2470	cdb = qc->scsicmd->cmnd;
2471	cdb_len = qc->scsicmd->cmd_len;
2472	}
2473	__scsi_format_command(cdb_buf, sizeof(cdb_buf),
2474	cdb, cdb_len);
2475	} else
2476	ata_dev_err(qc->dev, "failed command: %s\n",
2477	ata_get_cmd_name(cmd->command));
2478
2479	ata_dev_err(qc->dev,
2480	"cmd %02x/%02x:%02x:%02x:%02x:%02x/%02x:%02x:%02x:%02x:%02x/%02x "
2481	"tag %d%s\n %s"
2482	"res %02x/%02x:%02x:%02x:%02x:%02x/%02x:%02x:%02x:%02x:%02x/%02x "
2483	"Emask 0x%x (%s)%s\n",
2484	cmd->command, cmd->feature, cmd->nsect,
2485	cmd->lbal, cmd->lbam, cmd->lbah,
2486	cmd->hob_feature, cmd->hob_nsect,
2487	cmd->hob_lbal, cmd->hob_lbam, cmd->hob_lbah,
2488	cmd->device, qc->tag, data_buf, cdb_buf,
2489	res->status, res->error, res->nsect,
2490	res->lbal, res->lbam, res->lbah,
2491	res->hob_feature, res->hob_nsect,
2492	res->hob_lbal, res->hob_lbam, res->hob_lbah,
2493	res->device, qc->err_mask, ata_err_string(qc->err_mask),
2494	qc->err_mask & AC_ERR_NCQ ? " <F>" : "");
2495
2496	#ifdef CONFIG_ATA_VERBOSE_ERROR
2497	if (res->status & (ATA_BUSY | ATA_DRDY | ATA_DF | ATA_DRQ |
2498	ATA_SENSE | ATA_ERR)) {
2499	if (res->status & ATA_BUSY)
2500	ata_dev_err(qc->dev, "status: { Busy }\n");
2501	else
2502	ata_dev_err(qc->dev, "status: { %s%s%s%s%s}\n",
2503	res->status & ATA_DRDY ? "DRDY " : "",
2504	res->status & ATA_DF ? "DF " : "",
2505	res->status & ATA_DRQ ? "DRQ " : "",
2506	res->status & ATA_SENSE ? "SENSE " : "",
2507	res->status & ATA_ERR ? "ERR " : "");
2508	}
2509
2510	if (cmd->command != ATA_CMD_PACKET &&
2511	(res->error & (ATA_ICRC | ATA_UNC | ATA_AMNF | ATA_IDNF |
2512	ATA_ABORTED)))
2513	ata_dev_err(qc->dev, "error: { %s%s%s%s%s}\n",
2514	res->error & ATA_ICRC ? "ICRC " : "",
2515	res->error & ATA_UNC ? "UNC " : "",
2516	res->error & ATA_AMNF ? "AMNF " : "",
2517	res->error & ATA_IDNF ? "IDNF " : "",
2518	res->error & ATA_ABORTED ? "ABRT " : "");
2519	#endif
2520	}
2521	}
2522
2523	/**
2524	* ata_eh_report - report error handling to user
2525	* @ap: ATA port to report EH about
2526	*
2527	* Report EH to user.
2528	*
2529	* LOCKING:
2530	* None.
2531	*/
2532	void ata_eh_report(struct ata_port *ap)
2533	{
2534	struct ata_link *link;
2535
2536	ata_for_each_link(link, ap, HOST_FIRST)
2537	ata_eh_link_report(link);
2538	}
2539
2540	static int ata_do_reset(struct ata_link *link, ata_reset_fn_t reset,
2541	unsigned int *classes, unsigned long deadline,
2542	bool clear_classes)
2543	{
2544	struct ata_device *dev;
2545
2546	if (clear_classes)
2547	ata_for_each_dev(dev, link, ALL)
2548	classes[dev->devno] = ATA_DEV_UNKNOWN;
2549
2550	return reset(link, classes, deadline);
2551	}
2552
2553	static int ata_eh_followup_srst_needed(struct ata_link *link, int rc)
2554	{
2555	if ((link->flags & ATA_LFLAG_NO_SRST) || ata_link_offline(link))
2556	return 0;
2557	if (rc == -EAGAIN)
2558	return 1;
2559	if (sata_pmp_supported(ap: link->ap) && ata_is_host_link(link))
2560	return 1;
2561	return 0;
2562	}
2563
2564	int ata_eh_reset(struct ata_link *link, int classify,
2565	ata_prereset_fn_t prereset, ata_reset_fn_t softreset,
2566	ata_reset_fn_t hardreset, ata_postreset_fn_t postreset)
2567	{
2568	struct ata_port *ap = link->ap;
2569	struct ata_link *slave = ap->slave_link;
2570	struct ata_eh_context *ehc = &link->eh_context;
2571	struct ata_eh_context *sehc = slave ? &slave->eh_context : NULL;
2572	unsigned int *classes = ehc->classes;
2573	unsigned int lflags = link->flags;
2574	int verbose = !(ehc->i.flags & ATA_EHI_QUIET);
2575	int max_tries = 0, try = 0;
2576	struct ata_link *failed_link;
2577	struct ata_device *dev;
2578	unsigned long deadline, now;
2579	ata_reset_fn_t reset;
2580	unsigned long flags;
2581	u32 sstatus;
2582	int nr_unknown, rc;
2583
2584	/*
2585	* Prepare to reset
2586	*/
2587	while (ata_eh_reset_timeouts[max_tries] != UINT_MAX)
2588	max_tries++;
2589	if (link->flags & ATA_LFLAG_RST_ONCE)
2590	max_tries = 1;
2591	if (link->flags & ATA_LFLAG_NO_HRST)
2592	hardreset = NULL;
2593	if (link->flags & ATA_LFLAG_NO_SRST)
2594	softreset = NULL;
2595
2596	/* make sure each reset attempt is at least COOL_DOWN apart */
2597	if (ehc->i.flags & ATA_EHI_DID_RESET) {
2598	now = jiffies;
2599	WARN_ON(time_after(ehc->last_reset, now));
2600	deadline = ata_deadline(from_jiffies: ehc->last_reset,
2601	timeout_msecs: ATA_EH_RESET_COOL_DOWN);
2602	if (time_before(now, deadline))
2603	schedule_timeout_uninterruptible(timeout: deadline - now);
2604	}
2605
2606	spin_lock_irqsave(ap->lock, flags);
2607	ap->pflags |= ATA_PFLAG_RESETTING;
2608	spin_unlock_irqrestore(lock: ap->lock, flags);
2609
2610	ata_eh_about_to_do(link, NULL, action: ATA_EH_RESET);
2611
2612	ata_for_each_dev(dev, link, ALL) {
2613	/* If we issue an SRST then an ATA drive (not ATAPI)
2614	* may change configuration and be in PIO0 timing. If
2615	* we do a hard reset (or are coming from power on)
2616	* this is true for ATA or ATAPI. Until we've set a
2617	* suitable controller mode we should not touch the
2618	* bus as we may be talking too fast.
2619	*/
2620	dev->pio_mode = XFER_PIO_0;
2621	dev->dma_mode = 0xff;
2622
2623	/* If the controller has a pio mode setup function
2624	* then use it to set the chipset to rights. Don't
2625	* touch the DMA setup as that will be dealt with when
2626	* configuring devices.
2627	*/
2628	if (ap->ops->set_piomode)
2629	ap->ops->set_piomode(ap, dev);
2630	}
2631
2632	/* prefer hardreset */
2633	reset = NULL;
2634	ehc->i.action &= ~ATA_EH_RESET;
2635	if (hardreset) {
2636	reset = hardreset;
2637	ehc->i.action |= ATA_EH_HARDRESET;
2638	} else if (softreset) {
2639	reset = softreset;
2640	ehc->i.action |= ATA_EH_SOFTRESET;
2641	}
2642
2643	if (prereset) {
2644	unsigned long deadline = ata_deadline(from_jiffies: jiffies,
2645	timeout_msecs: ATA_EH_PRERESET_TIMEOUT);
2646
2647	if (slave) {
2648	sehc->i.action &= ~ATA_EH_RESET;
2649	sehc->i.action |= ehc->i.action;
2650	}
2651
2652	rc = prereset(link, deadline);
2653
2654	/* If present, do prereset on slave link too. Reset
2655	* is skipped iff both master and slave links report
2656	* -ENOENT or clear ATA_EH_RESET.
2657	*/
2658	if (slave && (rc == 0 || rc == -ENOENT)) {
2659	int tmp;
2660
2661	tmp = prereset(slave, deadline);
2662	if (tmp != -ENOENT)
2663	rc = tmp;
2664
2665	ehc->i.action |= sehc->i.action;
2666	}
2667
2668	if (rc) {
2669	if (rc == -ENOENT) {
2670	ata_link_dbg(link, "port disabled--ignoring\n");
2671	ehc->i.action &= ~ATA_EH_RESET;
2672
2673	ata_for_each_dev(dev, link, ALL)
2674	classes[dev->devno] = ATA_DEV_NONE;
2675
2676	rc = 0;
2677	} else
2678	ata_link_err(link,
2679	"prereset failed (errno=%d)\n",
2680	rc);
2681	goto out;
2682	}
2683
2684	/* prereset() might have cleared ATA_EH_RESET. If so,
2685	* bang classes, thaw and return.
2686	*/
2687	if (reset && !(ehc->i.action & ATA_EH_RESET)) {
2688	ata_for_each_dev(dev, link, ALL)
2689	classes[dev->devno] = ATA_DEV_NONE;
2690	if (ata_port_is_frozen(ap) && ata_is_host_link(link))
2691	ata_eh_thaw_port(ap);
2692	rc = 0;
2693	goto out;
2694	}
2695	}
2696
2697	retry:
2698	/*
2699	* Perform reset
2700	*/
2701	if (ata_is_host_link(link))
2702	ata_eh_freeze_port(ap);
2703
2704	deadline = ata_deadline(from_jiffies: jiffies, timeout_msecs: ata_eh_reset_timeouts[try++]);
2705
2706	if (reset) {
2707	if (verbose)
2708	ata_link_info(link, "%s resetting link\n",
2709	reset == softreset ? "soft" : "hard");
2710
2711	/* mark that this EH session started with reset */
2712	ehc->last_reset = jiffies;
2713	if (reset == hardreset) {
2714	ehc->i.flags |= ATA_EHI_DID_HARDRESET;
2715	trace_ata_link_hardreset_begin(link, class: classes, deadline);
2716	} else {
2717	ehc->i.flags |= ATA_EHI_DID_SOFTRESET;
2718	trace_ata_link_softreset_begin(link, class: classes, deadline);
2719	}
2720
2721	rc = ata_do_reset(link, reset, classes, deadline, clear_classes: true);
2722	if (reset == hardreset)
2723	trace_ata_link_hardreset_end(link, class: classes, rc);
2724	else
2725	trace_ata_link_softreset_end(link, class: classes, rc);
2726	if (rc && rc != -EAGAIN) {
2727	failed_link = link;
2728	goto fail;
2729	}
2730
2731	/* hardreset slave link if existent */
2732	if (slave && reset == hardreset) {
2733	int tmp;
2734
2735	if (verbose)
2736	ata_link_info(slave, "hard resetting link\n");
2737
2738	ata_eh_about_to_do(link: slave, NULL, action: ATA_EH_RESET);
2739	trace_ata_slave_hardreset_begin(link: slave, class: classes,
2740	deadline);
2741	tmp = ata_do_reset(link: slave, reset, classes, deadline,
2742	clear_classes: false);
2743	trace_ata_slave_hardreset_end(link: slave, class: classes, rc: tmp);
2744	switch (tmp) {
2745	case -EAGAIN:
2746	rc = -EAGAIN;
2747	break;
2748	case 0:
2749	break;
2750	default:
2751	failed_link = slave;
2752	rc = tmp;
2753	goto fail;
2754	}
2755	}
2756
2757	/* perform follow-up SRST if necessary */
2758	if (reset == hardreset &&
2759	ata_eh_followup_srst_needed(link, rc)) {
2760	reset = softreset;
2761
2762	if (!reset) {
2763	ata_link_err(link,
2764	"follow-up softreset required but no softreset available\n");
2765	failed_link = link;
2766	rc = -EINVAL;
2767	goto fail;
2768	}
2769
2770	ata_eh_about_to_do(link, NULL, action: ATA_EH_RESET);
2771	trace_ata_link_softreset_begin(link, class: classes, deadline);
2772	rc = ata_do_reset(link, reset, classes, deadline, clear_classes: true);
2773	trace_ata_link_softreset_end(link, class: classes, rc);
2774	if (rc) {
2775	failed_link = link;
2776	goto fail;
2777	}
2778	}
2779	} else {
2780	if (verbose)
2781	ata_link_info(link,
2782	"no reset method available, skipping reset\n");
2783	if (!(lflags & ATA_LFLAG_ASSUME_CLASS))
2784	lflags |= ATA_LFLAG_ASSUME_ATA;
2785	}
2786
2787	/*
2788	* Post-reset processing
2789	*/
2790	ata_for_each_dev(dev, link, ALL) {
2791	/* After the reset, the device state is PIO 0 and the
2792	* controller state is undefined. Reset also wakes up
2793	* drives from sleeping mode.
2794	*/
2795	dev->pio_mode = XFER_PIO_0;
2796	dev->flags &= ~ATA_DFLAG_SLEEPING;
2797
2798	if (ata_phys_link_offline(link: ata_dev_phys_link(dev)))
2799	continue;
2800
2801	/* apply class override */
2802	if (lflags & ATA_LFLAG_ASSUME_ATA)
2803	classes[dev->devno] = ATA_DEV_ATA;
2804	else if (lflags & ATA_LFLAG_ASSUME_SEMB)
2805	classes[dev->devno] = ATA_DEV_SEMB_UNSUP;
2806	}
2807
2808	/* record current link speed */
2809	if (sata_scr_read(link, reg: SCR_STATUS, val: &sstatus) == 0)
2810	link->sata_spd = (sstatus >> 4) & 0xf;
2811	if (slave && sata_scr_read(link: slave, reg: SCR_STATUS, val: &sstatus) == 0)
2812	slave->sata_spd = (sstatus >> 4) & 0xf;
2813
2814	/* thaw the port */
2815	if (ata_is_host_link(link))
2816	ata_eh_thaw_port(ap);
2817
2818	/* postreset() should clear hardware SError. Although SError
2819	* is cleared during link resume, clearing SError here is
2820	* necessary as some PHYs raise hotplug events after SRST.
2821	* This introduces race condition where hotplug occurs between
2822	* reset and here. This race is mediated by cross checking
2823	* link onlineness and classification result later.
2824	*/
2825	if (postreset) {
2826	postreset(link, classes);
2827	trace_ata_link_postreset(link, class: classes, rc);
2828	if (slave) {
2829	postreset(slave, classes);
2830	trace_ata_slave_postreset(link: slave, class: classes, rc);
2831	}
2832	}
2833
2834	/* clear cached SError */
2835	spin_lock_irqsave(link->ap->lock, flags);
2836	link->eh_info.serror = 0;
2837	if (slave)
2838	slave->eh_info.serror = 0;
2839	spin_unlock_irqrestore(lock: link->ap->lock, flags);
2840
2841	/*
2842	* Make sure onlineness and classification result correspond.
2843	* Hotplug could have happened during reset and some
2844	* controllers fail to wait while a drive is spinning up after
2845	* being hotplugged causing misdetection. By cross checking
2846	* link on/offlineness and classification result, those
2847	* conditions can be reliably detected and retried.
2848	*/
2849	nr_unknown = 0;
2850	ata_for_each_dev(dev, link, ALL) {
2851	if (ata_phys_link_online(link: ata_dev_phys_link(dev))) {
2852	if (classes[dev->devno] == ATA_DEV_UNKNOWN) {
2853	ata_dev_dbg(dev, "link online but device misclassified\n");
2854	classes[dev->devno] = ATA_DEV_NONE;
2855	nr_unknown++;
2856	}
2857	} else if (ata_phys_link_offline(link: ata_dev_phys_link(dev))) {
2858	if (ata_class_enabled(class: classes[dev->devno]))
2859	ata_dev_dbg(dev,
2860	"link offline, clearing class %d to NONE\n",
2861	classes[dev->devno]);
2862	classes[dev->devno] = ATA_DEV_NONE;
2863	} else if (classes[dev->devno] == ATA_DEV_UNKNOWN) {
2864	ata_dev_dbg(dev,
2865	"link status unknown, clearing UNKNOWN to NONE\n");
2866	classes[dev->devno] = ATA_DEV_NONE;
2867	}
2868	}
2869
2870	if (classify && nr_unknown) {
2871	if (try < max_tries) {
2872	ata_link_warn(link,
2873	"link online but %d devices misclassified, retrying\n",
2874	nr_unknown);
2875	failed_link = link;
2876	rc = -EAGAIN;
2877	goto fail;
2878	}
2879	ata_link_warn(link,
2880	"link online but %d devices misclassified, "
2881	"device detection might fail\n", nr_unknown);
2882	}
2883
2884	/* reset successful, schedule revalidation */
2885	ata_eh_done(link, NULL, action: ATA_EH_RESET);
2886	if (slave)
2887	ata_eh_done(link: slave, NULL, action: ATA_EH_RESET);
2888	ehc->last_reset = jiffies; /* update to completion time */
2889	ehc->i.action |= ATA_EH_REVALIDATE;
2890	link->lpm_policy = ATA_LPM_UNKNOWN; /* reset LPM state */
2891
2892	rc = 0;
2893	out:
2894	/* clear hotplug flag */
2895	ehc->i.flags &= ~ATA_EHI_HOTPLUGGED;
2896	if (slave)
2897	sehc->i.flags &= ~ATA_EHI_HOTPLUGGED;
2898
2899	spin_lock_irqsave(ap->lock, flags);
2900	ap->pflags &= ~ATA_PFLAG_RESETTING;
2901	spin_unlock_irqrestore(lock: ap->lock, flags);
2902
2903	return rc;
2904
2905	fail:
2906	/* if SCR isn't accessible on a fan-out port, PMP needs to be reset */
2907	if (!ata_is_host_link(link) &&
2908	sata_scr_read(link, reg: SCR_STATUS, val: &sstatus))
2909	rc = -ERESTART;
2910
2911	if (try >= max_tries) {
2912	/*
2913	* Thaw host port even if reset failed, so that the port
2914	* can be retried on the next phy event. This risks
2915	* repeated EH runs but seems to be a better tradeoff than
2916	* shutting down a port after a botched hotplug attempt.
2917	*/
2918	if (ata_is_host_link(link))
2919	ata_eh_thaw_port(ap);
2920	ata_link_warn(link, "%s failed\n",
2921	reset == hardreset ? "hardreset" : "softreset");
2922	goto out;
2923	}
2924
2925	now = jiffies;
2926	if (time_before(now, deadline)) {
2927	unsigned long delta = deadline - now;
2928
2929	ata_link_warn(failed_link,
2930	"reset failed (errno=%d), retrying in %u secs\n",
2931	rc, DIV_ROUND_UP(jiffies_to_msecs(delta), 1000));
2932
2933	ata_eh_release(ap);
2934	while (delta)
2935	delta = schedule_timeout_uninterruptible(timeout: delta);
2936	ata_eh_acquire(ap);
2937	}
2938
2939	/*
2940	* While disks spinup behind PMP, some controllers fail sending SRST.
2941	* They need to be reset - as well as the PMP - before retrying.
2942	*/
2943	if (rc == -ERESTART) {
2944	if (ata_is_host_link(link))
2945	ata_eh_thaw_port(ap);
2946	goto out;
2947	}
2948
2949	if (try == max_tries - 1) {
2950	sata_down_spd_limit(link, spd_limit: 0);
2951	if (slave)
2952	sata_down_spd_limit(link: slave, spd_limit: 0);
2953	} else if (rc == -EPIPE)
2954	sata_down_spd_limit(link: failed_link, spd_limit: 0);
2955
2956	if (hardreset)
2957	reset = hardreset;
2958	goto retry;
2959	}
2960
2961	static inline void ata_eh_pull_park_action(struct ata_port *ap)
2962	{
2963	struct ata_link *link;
2964	struct ata_device *dev;
2965	unsigned long flags;
2966
2967	/*
2968	* This function can be thought of as an extended version of
2969	* ata_eh_about_to_do() specially crafted to accommodate the
2970	* requirements of ATA_EH_PARK handling. Since the EH thread
2971	* does not leave the do {} while () loop in ata_eh_recover as
2972	* long as the timeout for a park request to *one* device on
2973	* the port has not expired, and since we still want to pick
2974	* up park requests to other devices on the same port or
2975	* timeout updates for the same device, we have to pull
2976	* ATA_EH_PARK actions from eh_info into eh_context.i
2977	* ourselves at the beginning of each pass over the loop.
2978	*
2979	* Additionally, all write accesses to &ap->park_req_pending
2980	* through reinit_completion() (see below) or complete_all()
2981	* (see ata_scsi_park_store()) are protected by the host lock.
2982	* As a result we have that park_req_pending.done is zero on
2983	* exit from this function, i.e. when ATA_EH_PARK actions for
2984	* *all* devices on port ap have been pulled into the
2985	* respective eh_context structs. If, and only if,
2986	* park_req_pending.done is non-zero by the time we reach
2987	* wait_for_completion_timeout(), another ATA_EH_PARK action
2988	* has been scheduled for at least one of the devices on port
2989	* ap and we have to cycle over the do {} while () loop in
2990	* ata_eh_recover() again.
2991	*/
2992
2993	spin_lock_irqsave(ap->lock, flags);
2994	reinit_completion(x: &ap->park_req_pending);
2995	ata_for_each_link(link, ap, EDGE) {
2996	ata_for_each_dev(dev, link, ALL) {
2997	struct ata_eh_info *ehi = &link->eh_info;
2998
2999	link->eh_context.i.dev_action[dev->devno] |=
3000	ehi->dev_action[dev->devno] & ATA_EH_PARK;
3001	ata_eh_clear_action(link, dev, ehi, action: ATA_EH_PARK);
3002	}
3003	}
3004	spin_unlock_irqrestore(lock: ap->lock, flags);
3005	}
3006
3007	static void ata_eh_park_issue_cmd(struct ata_device *dev, int park)
3008	{
3009	struct ata_eh_context *ehc = &dev->link->eh_context;
3010	struct ata_taskfile tf;
3011	unsigned int err_mask;
3012
3013	ata_tf_init(dev, tf: &tf);
3014	if (park) {
3015	ehc->unloaded_mask |= 1 << dev->devno;
3016	tf.command = ATA_CMD_IDLEIMMEDIATE;
3017	tf.feature = 0x44;
3018	tf.lbal = 0x4c;
3019	tf.lbam = 0x4e;
3020	tf.lbah = 0x55;
3021	} else {
3022	ehc->unloaded_mask &= ~(1 << dev->devno);
3023	tf.command = ATA_CMD_CHK_POWER;
3024	}
3025
3026	tf.flags |= ATA_TFLAG_DEVICE | ATA_TFLAG_ISADDR;
3027	tf.protocol = ATA_PROT_NODATA;
3028	err_mask = ata_exec_internal(dev, tf: &tf, NULL, dma_dir: DMA_NONE, NULL, buflen: 0, timeout: 0);
3029	if (park && (err_mask || tf.lbal != 0xc4)) {
3030	ata_dev_err(dev, "head unload failed!\n");
3031	ehc->unloaded_mask &= ~(1 << dev->devno);
3032	}
3033	}
3034
3035	static int ata_eh_revalidate_and_attach(struct ata_link *link,
3036	struct ata_device **r_failed_dev)
3037	{
3038	struct ata_port *ap = link->ap;
3039	struct ata_eh_context *ehc = &link->eh_context;
3040	struct ata_device *dev;
3041	unsigned int new_mask = 0;
3042	unsigned long flags;
3043	int rc = 0;
3044
3045	/* For PATA drive side cable detection to work, IDENTIFY must
3046	* be done backwards such that PDIAG- is released by the slave
3047	* device before the master device is identified.
3048	*/
3049	ata_for_each_dev(dev, link, ALL_REVERSE) {
3050	unsigned int action = ata_eh_dev_action(dev);
3051	unsigned int readid_flags = 0;
3052
3053	if (ehc->i.flags & ATA_EHI_DID_RESET)
3054	readid_flags |= ATA_READID_POSTRESET;
3055
3056	if ((action & ATA_EH_REVALIDATE) && ata_dev_enabled(dev)) {
3057	WARN_ON(dev->class == ATA_DEV_PMP);
3058
3059	/*
3060	* The link may be in a deep sleep, wake it up.
3061	*
3062	* If the link is in deep sleep, ata_phys_link_offline()
3063	* will return true, causing the revalidation to fail,
3064	* which leads to a (potentially) needless hard reset.
3065	*
3066	* ata_eh_recover() will later restore the link policy
3067	* to ap->target_lpm_policy after revalidation is done.
3068	*/
3069	if (link->lpm_policy > ATA_LPM_MAX_POWER) {
3070	rc = ata_eh_set_lpm(link, policy: ATA_LPM_MAX_POWER,
3071	r_failed_dev);
3072	if (rc)
3073	goto err;
3074	}
3075
3076	if (ata_phys_link_offline(link: ata_dev_phys_link(dev))) {
3077	rc = -EIO;
3078	goto err;
3079	}
3080
3081	ata_eh_about_to_do(link, dev, action: ATA_EH_REVALIDATE);
3082	rc = ata_dev_revalidate(dev, new_class: ehc->classes[dev->devno],
3083	readid_flags);
3084	if (rc)
3085	goto err;
3086
3087	ata_eh_done(link, dev, action: ATA_EH_REVALIDATE);
3088
3089	/* Configuration may have changed, reconfigure
3090	* transfer mode.
3091	*/
3092	ehc->i.flags |= ATA_EHI_SETMODE;
3093
3094	/* schedule the scsi_rescan_device() here */
3095	schedule_delayed_work(dwork: &ap->scsi_rescan_task, delay: 0);
3096	} else if (dev->class == ATA_DEV_UNKNOWN &&
3097	ehc->tries[dev->devno] &&
3098	ata_class_enabled(class: ehc->classes[dev->devno])) {
3099	/* Temporarily set dev->class, it will be
3100	* permanently set once all configurations are
3101	* complete. This is necessary because new
3102	* device configuration is done in two
3103	* separate loops.
3104	*/
3105	dev->class = ehc->classes[dev->devno];
3106
3107	if (dev->class == ATA_DEV_PMP)
3108	rc = sata_pmp_attach(dev);
3109	else
3110	rc = ata_dev_read_id(dev, p_class: &dev->class,
3111	flags: readid_flags, id: dev->id);
3112
3113	/* read_id might have changed class, store and reset */
3114	ehc->classes[dev->devno] = dev->class;
3115	dev->class = ATA_DEV_UNKNOWN;
3116
3117	switch (rc) {
3118	case 0:
3119	/* clear error info accumulated during probe */
3120	ata_ering_clear(ering: &dev->ering);
3121	new_mask |= 1 << dev->devno;
3122	break;
3123	case -ENOENT:
3124	/* IDENTIFY was issued to non-existent
3125	* device. No need to reset. Just
3126	* thaw and ignore the device.
3127	*/
3128	ata_eh_thaw_port(ap);
3129	break;
3130	default:
3131	goto err;
3132	}
3133	}
3134	}
3135
3136	/* PDIAG- should have been released, ask cable type if post-reset */
3137	if ((ehc->i.flags & ATA_EHI_DID_RESET) && ata_is_host_link(link)) {
3138	if (ap->ops->cable_detect)
3139	ap->cbl = ap->ops->cable_detect(ap);
3140	ata_force_cbl(ap);
3141	}
3142
3143	/* Configure new devices forward such that user doesn't see
3144	* device detection messages backwards.
3145	*/
3146	ata_for_each_dev(dev, link, ALL) {
3147	if (!(new_mask & (1 << dev->devno)))
3148	continue;
3149
3150	dev->class = ehc->classes[dev->devno];
3151
3152	if (dev->class == ATA_DEV_PMP)
3153	continue;
3154
3155	ehc->i.flags |= ATA_EHI_PRINTINFO;
3156	rc = ata_dev_configure(dev);
3157	ehc->i.flags &= ~ATA_EHI_PRINTINFO;
3158	if (rc) {
3159	dev->class = ATA_DEV_UNKNOWN;
3160	goto err;
3161	}
3162
3163	spin_lock_irqsave(ap->lock, flags);
3164	ap->pflags |= ATA_PFLAG_SCSI_HOTPLUG;
3165	spin_unlock_irqrestore(lock: ap->lock, flags);
3166
3167	/* new device discovered, configure xfermode */
3168	ehc->i.flags |= ATA_EHI_SETMODE;
3169	}
3170
3171	return 0;
3172
3173	err:
3174	dev->flags &= ~ATA_DFLAG_RESUMING;
3175	*r_failed_dev = dev;
3176	return rc;
3177	}
3178
3179	/**
3180	* ata_set_mode - Program timings and issue SET FEATURES - XFER
3181	* @link: link on which timings will be programmed
3182	* @r_failed_dev: out parameter for failed device
3183	*
3184	* Set ATA device disk transfer mode (PIO3, UDMA6, etc.). If
3185	* ata_set_mode() fails, pointer to the failing device is
3186	* returned in @r_failed_dev.
3187	*
3188	* LOCKING:
3189	* PCI/etc. bus probe sem.
3190	*
3191	* RETURNS:
3192	* 0 on success, negative errno otherwise
3193	*/
3194	int ata_set_mode(struct ata_link *link, struct ata_device **r_failed_dev)
3195	{
3196	struct ata_port *ap = link->ap;
3197	struct ata_device *dev;
3198	int rc;
3199
3200	/* if data transfer is verified, clear DUBIOUS_XFER on ering top */
3201	ata_for_each_dev(dev, link, ENABLED) {
3202	if (!(dev->flags & ATA_DFLAG_DUBIOUS_XFER)) {
3203	struct ata_ering_entry *ent;
3204
3205	ent = ata_ering_top(ering: &dev->ering);
3206	if (ent)
3207	ent->eflags &= ~ATA_EFLAG_DUBIOUS_XFER;
3208	}
3209	}
3210
3211	/* has private set_mode? */
3212	if (ap->ops->set_mode)
3213	rc = ap->ops->set_mode(link, r_failed_dev);
3214	else
3215	rc = ata_do_set_mode(link, r_failed_dev);
3216
3217	/* if transfer mode has changed, set DUBIOUS_XFER on device */
3218	ata_for_each_dev(dev, link, ENABLED) {
3219	struct ata_eh_context *ehc = &link->eh_context;
3220	u8 saved_xfer_mode = ehc->saved_xfer_mode[dev->devno];
3221	u8 saved_ncq = !!(ehc->saved_ncq_enabled & (1 << dev->devno));
3222
3223	if (dev->xfer_mode != saved_xfer_mode ||
3224	ata_ncq_enabled(dev) != saved_ncq)
3225	dev->flags |= ATA_DFLAG_DUBIOUS_XFER;
3226	}
3227
3228	return rc;
3229	}
3230
3231	/**
3232	* atapi_eh_clear_ua - Clear ATAPI UNIT ATTENTION after reset
3233	* @dev: ATAPI device to clear UA for
3234	*
3235	* Resets and other operations can make an ATAPI device raise
3236	* UNIT ATTENTION which causes the next operation to fail. This
3237	* function clears UA.
3238	*
3239	* LOCKING:
3240	* EH context (may sleep).
3241	*
3242	* RETURNS:
3243	* 0 on success, -errno on failure.
3244	*/
3245	static int atapi_eh_clear_ua(struct ata_device *dev)
3246	{
3247	int i;
3248
3249	for (i = 0; i < ATA_EH_UA_TRIES; i++) {
3250	u8 *sense_buffer = dev->link->ap->sector_buf;
3251	u8 sense_key = 0;
3252	unsigned int err_mask;
3253
3254	err_mask = atapi_eh_tur(dev, r_sense_key: &sense_key);
3255	if (err_mask != 0 && err_mask != AC_ERR_DEV) {
3256	ata_dev_warn(dev,
3257	"TEST_UNIT_READY failed (err_mask=0x%x)\n",
3258	err_mask);
3259	return -EIO;
3260	}
3261
3262	if (!err_mask || sense_key != UNIT_ATTENTION)
3263	return 0;
3264
3265	err_mask = atapi_eh_request_sense(dev, sense_buf: sense_buffer, dfl_sense_key: sense_key);
3266	if (err_mask) {
3267	ata_dev_warn(dev, "failed to clear "
3268	"UNIT ATTENTION (err_mask=0x%x)\n", err_mask);
3269	return -EIO;
3270	}
3271	}
3272
3273	ata_dev_warn(dev, "UNIT ATTENTION persists after %d tries\n",
3274	ATA_EH_UA_TRIES);
3275
3276	return 0;
3277	}
3278
3279	/**
3280	* ata_eh_maybe_retry_flush - Retry FLUSH if necessary
3281	* @dev: ATA device which may need FLUSH retry
3282	*
3283	* If @dev failed FLUSH, it needs to be reported upper layer
3284	* immediately as it means that @dev failed to remap and already
3285	* lost at least a sector and further FLUSH retrials won't make
3286	* any difference to the lost sector. However, if FLUSH failed
3287	* for other reasons, for example transmission error, FLUSH needs
3288	* to be retried.
3289	*
3290	* This function determines whether FLUSH failure retry is
3291	* necessary and performs it if so.
3292	*
3293	* RETURNS:
3294	* 0 if EH can continue, -errno if EH needs to be repeated.
3295	*/
3296	static int ata_eh_maybe_retry_flush(struct ata_device *dev)
3297	{
3298	struct ata_link *link = dev->link;
3299	struct ata_port *ap = link->ap;
3300	struct ata_queued_cmd *qc;
3301	struct ata_taskfile tf;
3302	unsigned int err_mask;
3303	int rc = 0;
3304
3305	/* did flush fail for this device? */
3306	if (!ata_tag_valid(tag: link->active_tag))
3307	return 0;
3308
3309	qc = __ata_qc_from_tag(ap, tag: link->active_tag);
3310	if (qc->dev != dev || (qc->tf.command != ATA_CMD_FLUSH_EXT &&
3311	qc->tf.command != ATA_CMD_FLUSH))
3312	return 0;
3313
3314	/* if the device failed it, it should be reported to upper layers */
3315	if (qc->err_mask & AC_ERR_DEV)
3316	return 0;
3317
3318	/* flush failed for some other reason, give it another shot */
3319	ata_tf_init(dev, tf: &tf);
3320
3321	tf.command = qc->tf.command;
3322	tf.flags |= ATA_TFLAG_DEVICE;
3323	tf.protocol = ATA_PROT_NODATA;
3324
3325	ata_dev_warn(dev, "retrying FLUSH 0x%x Emask 0x%x\n",
3326	tf.command, qc->err_mask);
3327
3328	err_mask = ata_exec_internal(dev, tf: &tf, NULL, dma_dir: DMA_NONE, NULL, buflen: 0, timeout: 0);
3329	if (!err_mask) {
3330	/*
3331	* FLUSH is complete but there's no way to
3332	* successfully complete a failed command from EH.
3333	* Making sure retry is allowed at least once and
3334	* retrying it should do the trick - whatever was in
3335	* the cache is already on the platter and this won't
3336	* cause infinite loop.
3337	*/
3338	qc->scsicmd->allowed = max(qc->scsicmd->allowed, 1);
3339	} else {
3340	ata_dev_warn(dev, "FLUSH failed Emask 0x%x\n",
3341	err_mask);
3342	rc = -EIO;
3343
3344	/* if device failed it, report it to upper layers */
3345	if (err_mask & AC_ERR_DEV) {
3346	qc->err_mask |= AC_ERR_DEV;
3347	qc->result_tf = tf;
3348	if (!ata_port_is_frozen(ap))
3349	rc = 0;
3350	}
3351	}
3352	return rc;
3353	}
3354
3355	/**
3356	* ata_eh_set_lpm - configure SATA interface power management
3357	* @link: link to configure power management
3358	* @policy: the link power management policy
3359	* @r_failed_dev: out parameter for failed device
3360	*
3361	* Enable SATA Interface power management. This will enable
3362	* Device Interface Power Management (DIPM) for min_power and
3363	* medium_power_with_dipm policies, and then call driver specific
3364	* callbacks for enabling Host Initiated Power management.
3365	*
3366	* LOCKING:
3367	* EH context.
3368	*
3369	* RETURNS:
3370	* 0 on success, -errno on failure.
3371	*/
3372	static int ata_eh_set_lpm(struct ata_link *link, enum ata_lpm_policy policy,
3373	struct ata_device **r_failed_dev)
3374	{
3375	struct ata_port *ap = ata_is_host_link(link) ? link->ap : NULL;
3376	struct ata_eh_context *ehc = &link->eh_context;
3377	struct ata_device *dev, *link_dev = NULL, *lpm_dev = NULL;
3378	enum ata_lpm_policy old_policy = link->lpm_policy;
3379	bool no_dipm = link->ap->flags & ATA_FLAG_NO_DIPM;
3380	unsigned int hints = ATA_LPM_EMPTY | ATA_LPM_HIPM;
3381	unsigned int err_mask;
3382	int rc;
3383
3384	/* if the link or host doesn't do LPM, noop */
3385	if (!IS_ENABLED(CONFIG_SATA_HOST) ||
3386	(link->flags & ATA_LFLAG_NO_LPM) || (ap && !ap->ops->set_lpm))
3387	return 0;
3388
3389	/*
3390	* DIPM is enabled only for MIN_POWER as some devices
3391	* misbehave when the host NACKs transition to SLUMBER. Order
3392	* device and link configurations such that the host always
3393	* allows DIPM requests.
3394	*/
3395	ata_for_each_dev(dev, link, ENABLED) {
3396	bool hipm = ata_id_has_hipm(id: dev->id);
3397	bool dipm = ata_id_has_dipm(dev->id) && !no_dipm;
3398
3399	/* find the first enabled and LPM enabled devices */
3400	if (!link_dev)
3401	link_dev = dev;
3402
3403	if (!lpm_dev && (hipm || dipm))
3404	lpm_dev = dev;
3405
3406	hints &= ~ATA_LPM_EMPTY;
3407	if (!hipm)
3408	hints &= ~ATA_LPM_HIPM;
3409
3410	/* disable DIPM before changing link config */
3411	if (policy < ATA_LPM_MED_POWER_WITH_DIPM && dipm) {
3412	err_mask = ata_dev_set_feature(dev,
3413	subcmd: SETFEATURES_SATA_DISABLE, action: SATA_DIPM);
3414	if (err_mask && err_mask != AC_ERR_DEV) {
3415	ata_dev_warn(dev,
3416	"failed to disable DIPM, Emask 0x%x\n",
3417	err_mask);
3418	rc = -EIO;
3419	goto fail;
3420	}
3421	}
3422	}
3423
3424	if (ap) {
3425	rc = ap->ops->set_lpm(link, policy, hints);
3426	if (!rc && ap->slave_link)
3427	rc = ap->ops->set_lpm(ap->slave_link, policy, hints);
3428	} else
3429	rc = sata_pmp_set_lpm(link, policy, hints);
3430
3431	/*
3432	* Attribute link config failure to the first (LPM) enabled
3433	* device on the link.
3434	*/
3435	if (rc) {
3436	if (rc == -EOPNOTSUPP) {
3437	link->flags |= ATA_LFLAG_NO_LPM;
3438	return 0;
3439	}
3440	dev = lpm_dev ? lpm_dev : link_dev;
3441	goto fail;
3442	}
3443
3444	/*
3445	* Low level driver acked the transition. Issue DIPM command
3446	* with the new policy set.
3447	*/
3448	link->lpm_policy = policy;
3449	if (ap && ap->slave_link)
3450	ap->slave_link->lpm_policy = policy;
3451
3452	/* host config updated, enable DIPM if transitioning to MIN_POWER */
3453	ata_for_each_dev(dev, link, ENABLED) {
3454	if (policy >= ATA_LPM_MED_POWER_WITH_DIPM && !no_dipm &&
3455	ata_id_has_dipm(dev->id)) {
3456	err_mask = ata_dev_set_feature(dev,
3457	subcmd: SETFEATURES_SATA_ENABLE, action: SATA_DIPM);
3458	if (err_mask && err_mask != AC_ERR_DEV) {
3459	ata_dev_warn(dev,
3460	"failed to enable DIPM, Emask 0x%x\n",
3461	err_mask);
3462	rc = -EIO;
3463	goto fail;
3464	}
3465	}
3466	}
3467
3468	link->last_lpm_change = jiffies;
3469	link->flags |= ATA_LFLAG_CHANGED;
3470
3471	return 0;
3472
3473	fail:
3474	/* restore the old policy */
3475	link->lpm_policy = old_policy;
3476	if (ap && ap->slave_link)
3477	ap->slave_link->lpm_policy = old_policy;
3478
3479	/* if no device or only one more chance is left, disable LPM */
3480	if (!dev || ehc->tries[dev->devno] <= 2) {
3481	ata_link_warn(link, "disabling LPM on the link\n");
3482	link->flags |= ATA_LFLAG_NO_LPM;
3483	}
3484	if (r_failed_dev)
3485	*r_failed_dev = dev;
3486	return rc;
3487	}
3488
3489	int ata_link_nr_enabled(struct ata_link *link)
3490	{
3491	struct ata_device *dev;
3492	int cnt = 0;
3493
3494	ata_for_each_dev(dev, link, ENABLED)
3495	cnt++;
3496	return cnt;
3497	}
3498
3499	static int ata_link_nr_vacant(struct ata_link *link)
3500	{
3501	struct ata_device *dev;
3502	int cnt = 0;
3503
3504	ata_for_each_dev(dev, link, ALL)
3505	if (dev->class == ATA_DEV_UNKNOWN)
3506	cnt++;
3507	return cnt;
3508	}
3509
3510	static int ata_eh_skip_recovery(struct ata_link *link)
3511	{
3512	struct ata_port *ap = link->ap;
3513	struct ata_eh_context *ehc = &link->eh_context;
3514	struct ata_device *dev;
3515
3516	/* skip disabled links */
3517	if (link->flags & ATA_LFLAG_DISABLED)
3518	return 1;
3519
3520	/* skip if explicitly requested */
3521	if (ehc->i.flags & ATA_EHI_NO_RECOVERY)
3522	return 1;
3523
3524	/* thaw frozen port and recover failed devices */
3525	if (ata_port_is_frozen(ap) || ata_link_nr_enabled(link))
3526	return 0;
3527
3528	/* reset at least once if reset is requested */
3529	if ((ehc->i.action & ATA_EH_RESET) &&
3530	!(ehc->i.flags & ATA_EHI_DID_RESET))
3531	return 0;
3532
3533	/* skip if class codes for all vacant slots are ATA_DEV_NONE */
3534	ata_for_each_dev(dev, link, ALL) {
3535	if (dev->class == ATA_DEV_UNKNOWN &&
3536	ehc->classes[dev->devno] != ATA_DEV_NONE)
3537	return 0;
3538	}
3539
3540	return 1;
3541	}
3542
3543	static int ata_count_probe_trials_cb(struct ata_ering_entry *ent, void *void_arg)
3544	{
3545	u64 interval = msecs_to_jiffies(m: ATA_EH_PROBE_TRIAL_INTERVAL);
3546	u64 now = get_jiffies_64();
3547	int *trials = void_arg;
3548
3549	if ((ent->eflags & ATA_EFLAG_OLD_ER) ||
3550	(ent->timestamp < now - min(now, interval)))
3551	return -1;
3552
3553	(*trials)++;
3554	return 0;
3555	}
3556
3557	static int ata_eh_schedule_probe(struct ata_device *dev)
3558	{
3559	struct ata_eh_context *ehc = &dev->link->eh_context;
3560	struct ata_link *link = ata_dev_phys_link(dev);
3561	int trials = 0;
3562
3563	if (!(ehc->i.probe_mask & (1 << dev->devno)) ||
3564	(ehc->did_probe_mask & (1 << dev->devno)))
3565	return 0;
3566
3567	ata_eh_detach_dev(dev);
3568	ata_dev_init(dev);
3569	ehc->did_probe_mask |= (1 << dev->devno);
3570	ehc->i.action |= ATA_EH_RESET;
3571	ehc->saved_xfer_mode[dev->devno] = 0;
3572	ehc->saved_ncq_enabled &= ~(1 << dev->devno);
3573
3574	/* the link maybe in a deep sleep, wake it up */
3575	if (link->lpm_policy > ATA_LPM_MAX_POWER) {
3576	if (ata_is_host_link(link))
3577	link->ap->ops->set_lpm(link, ATA_LPM_MAX_POWER,
3578	ATA_LPM_EMPTY);
3579	else
3580	sata_pmp_set_lpm(link, policy: ATA_LPM_MAX_POWER,
3581	hints: ATA_LPM_EMPTY);
3582	}
3583
3584	/* Record and count probe trials on the ering. The specific
3585	* error mask used is irrelevant. Because a successful device
3586	* detection clears the ering, this count accumulates only if
3587	* there are consecutive failed probes.
3588	*
3589	* If the count is equal to or higher than ATA_EH_PROBE_TRIALS
3590	* in the last ATA_EH_PROBE_TRIAL_INTERVAL, link speed is
3591	* forced to 1.5Gbps.
3592	*
3593	* This is to work around cases where failed link speed
3594	* negotiation results in device misdetection leading to
3595	* infinite DEVXCHG or PHRDY CHG events.
3596	*/
3597	ata_ering_record(ering: &dev->ering, eflags: 0, err_mask: AC_ERR_OTHER);
3598	ata_ering_map(ering: &dev->ering, map_fn: ata_count_probe_trials_cb, arg: &trials);
3599
3600	if (trials > ATA_EH_PROBE_TRIALS)
3601	sata_down_spd_limit(link, spd_limit: 1);
3602
3603	return 1;
3604	}
3605
3606	static int ata_eh_handle_dev_fail(struct ata_device *dev, int err)
3607	{
3608	struct ata_eh_context *ehc = &dev->link->eh_context;
3609
3610	/* -EAGAIN from EH routine indicates retry without prejudice.
3611	* The requester is responsible for ensuring forward progress.
3612	*/
3613	if (err != -EAGAIN)
3614	ehc->tries[dev->devno]--;
3615
3616	switch (err) {
3617	case -ENODEV:
3618	/* device missing or wrong IDENTIFY data, schedule probing */
3619	ehc->i.probe_mask |= (1 << dev->devno);
3620	fallthrough;
3621	case -EINVAL:
3622	/* give it just one more chance */
3623	ehc->tries[dev->devno] = min(ehc->tries[dev->devno], 1);
3624	fallthrough;
3625	case -EIO:
3626	if (ehc->tries[dev->devno] == 1) {
3627	/* This is the last chance, better to slow
3628	* down than lose it.
3629	*/
3630	sata_down_spd_limit(link: ata_dev_phys_link(dev), spd_limit: 0);
3631	if (dev->pio_mode > XFER_PIO_0)
3632	ata_down_xfermask_limit(dev, sel: ATA_DNXFER_PIO);
3633	}
3634	}
3635
3636	if (ata_dev_enabled(dev) && !ehc->tries[dev->devno]) {
3637	/* disable device if it has used up all its chances */
3638	ata_dev_disable(dev);
3639
3640	/* detach if offline */
3641	if (ata_phys_link_offline(link: ata_dev_phys_link(dev)))
3642	ata_eh_detach_dev(dev);
3643
3644	/* schedule probe if necessary */
3645	if (ata_eh_schedule_probe(dev)) {
3646	ehc->tries[dev->devno] = ATA_EH_DEV_TRIES;
3647	memset(ehc->cmd_timeout_idx[dev->devno], 0,
3648	sizeof(ehc->cmd_timeout_idx[dev->devno]));
3649	}
3650
3651	return 1;
3652	} else {
3653	ehc->i.action |= ATA_EH_RESET;
3654	return 0;
3655	}
3656	}
3657
3658	/**
3659	* ata_eh_recover - recover host port after error
3660	* @ap: host port to recover
3661	* @prereset: prereset method (can be NULL)
3662	* @softreset: softreset method (can be NULL)
3663	* @hardreset: hardreset method (can be NULL)
3664	* @postreset: postreset method (can be NULL)
3665	* @r_failed_link: out parameter for failed link
3666	*
3667	* This is the alpha and omega, eum and yang, heart and soul of
3668	* libata exception handling. On entry, actions required to
3669	* recover each link and hotplug requests are recorded in the
3670	* link's eh_context. This function executes all the operations
3671	* with appropriate retrials and fallbacks to resurrect failed
3672	* devices, detach goners and greet newcomers.
3673	*
3674	* LOCKING:
3675	* Kernel thread context (may sleep).
3676	*
3677	* RETURNS:
3678	* 0 on success, -errno on failure.
3679	*/
3680	int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
3681	ata_reset_fn_t softreset, ata_reset_fn_t hardreset,
3682	ata_postreset_fn_t postreset,
3683	struct ata_link **r_failed_link)
3684	{
3685	struct ata_link *link;
3686	struct ata_device *dev;
3687	int rc, nr_fails;
3688	unsigned long flags, deadline;
3689
3690	/* prep for recovery */
3691	ata_for_each_link(link, ap, EDGE) {
3692	struct ata_eh_context *ehc = &link->eh_context;
3693
3694	/* re-enable link? */
3695	if (ehc->i.action & ATA_EH_ENABLE_LINK) {
3696	ata_eh_about_to_do(link, NULL, action: ATA_EH_ENABLE_LINK);
3697	spin_lock_irqsave(ap->lock, flags);
3698	link->flags &= ~ATA_LFLAG_DISABLED;
3699	spin_unlock_irqrestore(lock: ap->lock, flags);
3700	ata_eh_done(link, NULL, action: ATA_EH_ENABLE_LINK);
3701	}
3702
3703	ata_for_each_dev(dev, link, ALL) {
3704	if (link->flags & ATA_LFLAG_NO_RETRY)
3705	ehc->tries[dev->devno] = 1;
3706	else
3707	ehc->tries[dev->devno] = ATA_EH_DEV_TRIES;
3708
3709	/* collect port action mask recorded in dev actions */
3710	ehc->i.action |= ehc->i.dev_action[dev->devno] &
3711	~ATA_EH_PERDEV_MASK;
3712	ehc->i.dev_action[dev->devno] &= ATA_EH_PERDEV_MASK;
3713
3714	/* process hotplug request */
3715	if (dev->flags & ATA_DFLAG_DETACH)
3716	ata_eh_detach_dev(dev);
3717
3718	/* schedule probe if necessary */
3719	if (!ata_dev_enabled(dev))
3720	ata_eh_schedule_probe(dev);
3721	}
3722	}
3723
3724	retry:
3725	rc = 0;
3726
3727	/* if UNLOADING, finish immediately */
3728	if (ap->pflags & ATA_PFLAG_UNLOADING)
3729	goto out;
3730
3731	/* prep for EH */
3732	ata_for_each_link(link, ap, EDGE) {
3733	struct ata_eh_context *ehc = &link->eh_context;
3734
3735	/* skip EH if possible. */
3736	if (ata_eh_skip_recovery(link))
3737	ehc->i.action = 0;
3738
3739	ata_for_each_dev(dev, link, ALL)
3740	ehc->classes[dev->devno] = ATA_DEV_UNKNOWN;
3741	}
3742
3743	/* reset */
3744	ata_for_each_link(link, ap, EDGE) {
3745	struct ata_eh_context *ehc = &link->eh_context;
3746
3747	if (!(ehc->i.action & ATA_EH_RESET))
3748	continue;
3749
3750	rc = ata_eh_reset(link, classify: ata_link_nr_vacant(link),
3751	prereset, softreset, hardreset, postreset);
3752	if (rc) {
3753	ata_link_err(link, "reset failed, giving up\n");
3754	goto out;
3755	}
3756	}
3757
3758	do {
3759	unsigned long now;
3760
3761	/*
3762	* clears ATA_EH_PARK in eh_info and resets
3763	* ap->park_req_pending
3764	*/
3765	ata_eh_pull_park_action(ap);
3766
3767	deadline = jiffies;
3768	ata_for_each_link(link, ap, EDGE) {
3769	ata_for_each_dev(dev, link, ALL) {
3770	struct ata_eh_context *ehc = &link->eh_context;
3771	unsigned long tmp;
3772
3773	if (dev->class != ATA_DEV_ATA &&
3774	dev->class != ATA_DEV_ZAC)
3775	continue;
3776	if (!(ehc->i.dev_action[dev->devno] &
3777	ATA_EH_PARK))
3778	continue;
3779	tmp = dev->unpark_deadline;
3780	if (time_before(deadline, tmp))
3781	deadline = tmp;
3782	else if (time_before_eq(tmp, jiffies))
3783	continue;
3784	if (ehc->unloaded_mask & (1 << dev->devno))
3785	continue;
3786
3787	ata_eh_park_issue_cmd(dev, park: 1);
3788	}
3789	}
3790
3791	now = jiffies;
3792	if (time_before_eq(deadline, now))
3793	break;
3794
3795	ata_eh_release(ap);
3796	deadline = wait_for_completion_timeout(x: &ap->park_req_pending,
3797	timeout: deadline - now);
3798	ata_eh_acquire(ap);
3799	} while (deadline);
3800	ata_for_each_link(link, ap, EDGE) {
3801	ata_for_each_dev(dev, link, ALL) {
3802	if (!(link->eh_context.unloaded_mask &
3803	(1 << dev->devno)))
3804	continue;
3805
3806	ata_eh_park_issue_cmd(dev, park: 0);
3807	ata_eh_done(link, dev, action: ATA_EH_PARK);
3808	}
3809	}
3810
3811	/* the rest */
3812	nr_fails = 0;
3813	ata_for_each_link(link, ap, PMP_FIRST) {
3814	struct ata_eh_context *ehc = &link->eh_context;
3815
3816	if (sata_pmp_attached(ap) && ata_is_host_link(link))
3817	goto config_lpm;
3818
3819	/* revalidate existing devices and attach new ones */
3820	rc = ata_eh_revalidate_and_attach(link, r_failed_dev: &dev);
3821	if (rc)
3822	goto rest_fail;
3823
3824	/* if PMP got attached, return, pmp EH will take care of it */
3825	if (link->device->class == ATA_DEV_PMP) {
3826	ehc->i.action = 0;
3827	return 0;
3828	}
3829
3830	/* configure transfer mode if necessary */
3831	if (ehc->i.flags & ATA_EHI_SETMODE) {
3832	rc = ata_set_mode(link, r_failed_dev: &dev);
3833	if (rc)
3834	goto rest_fail;
3835	ehc->i.flags &= ~ATA_EHI_SETMODE;
3836	}
3837
3838	/* If reset has been issued, clear UA to avoid
3839	* disrupting the current users of the device.
3840	*/
3841	if (ehc->i.flags & ATA_EHI_DID_RESET) {
3842	ata_for_each_dev(dev, link, ALL) {
3843	if (dev->class != ATA_DEV_ATAPI)
3844	continue;
3845	rc = atapi_eh_clear_ua(dev);
3846	if (rc)
3847	goto rest_fail;
3848	if (zpodd_dev_enabled(dev))
3849	zpodd_post_poweron(dev);
3850	}
3851	}
3852
3853	/*
3854	* Make sure to transition devices to the active power mode
3855	* if needed (e.g. if we were scheduled on system resume).
3856	*/
3857	ata_for_each_dev(dev, link, ENABLED) {
3858	if (ehc->i.dev_action[dev->devno] & ATA_EH_SET_ACTIVE) {
3859	ata_dev_power_set_active(dev);
3860	ata_eh_done(link, dev, action: ATA_EH_SET_ACTIVE);
3861	}
3862	}
3863
3864	/* retry flush if necessary */
3865	ata_for_each_dev(dev, link, ALL) {
3866	if (dev->class != ATA_DEV_ATA &&
3867	dev->class != ATA_DEV_ZAC)
3868	continue;
3869	rc = ata_eh_maybe_retry_flush(dev);
3870	if (rc)
3871	goto rest_fail;
3872	}
3873
3874	config_lpm:
3875	/* configure link power saving */
3876	if (link->lpm_policy != ap->target_lpm_policy) {
3877	rc = ata_eh_set_lpm(link, policy: ap->target_lpm_policy, r_failed_dev: &dev);
3878	if (rc)
3879	goto rest_fail;
3880	}
3881
3882	/* this link is okay now */
3883	ehc->i.flags = 0;
3884	continue;
3885
3886	rest_fail:
3887	nr_fails++;
3888	if (dev)
3889	ata_eh_handle_dev_fail(dev, err: rc);
3890
3891	if (ata_port_is_frozen(ap)) {
3892	/* PMP reset requires working host port.
3893	* Can't retry if it's frozen.
3894	*/
3895	if (sata_pmp_attached(ap))
3896	goto out;
3897	break;
3898	}
3899	}
3900
3901	if (nr_fails)
3902	goto retry;
3903
3904	out:
3905	if (rc && r_failed_link)
3906	*r_failed_link = link;
3907
3908	return rc;
3909	}
3910
3911	/**
3912	* ata_eh_finish - finish up EH
3913	* @ap: host port to finish EH for
3914	*
3915	* Recovery is complete. Clean up EH states and retry or finish
3916	* failed qcs.
3917	*
3918	* LOCKING:
3919	* None.
3920	*/
3921	void ata_eh_finish(struct ata_port *ap)
3922	{
3923	struct ata_queued_cmd *qc;
3924	int tag;
3925
3926	/* retry or finish qcs */
3927	ata_qc_for_each_raw(ap, qc, tag) {
3928	if (!(qc->flags & ATA_QCFLAG_EH))
3929	continue;
3930
3931	if (qc->err_mask) {
3932	/* FIXME: Once EH migration is complete,
3933	* generate sense data in this function,
3934	* considering both err_mask and tf.
3935	*/
3936	if (qc->flags & ATA_QCFLAG_RETRY) {
3937	/*
3938	* Since qc->err_mask is set, ata_eh_qc_retry()
3939	* will not increment scmd->allowed, so upper
3940	* layer will only retry the command if it has
3941	* not already been retried too many times.
3942	*/
3943	ata_eh_qc_retry(qc);
3944	} else {
3945	ata_eh_qc_complete(qc);
3946	}
3947	} else {
3948	if (qc->flags & ATA_QCFLAG_SENSE_VALID ||
3949	qc->flags & ATA_QCFLAG_EH_SUCCESS_CMD) {
3950	ata_eh_qc_complete(qc);
3951	} else {
3952	/* feed zero TF to sense generation */
3953	memset(&qc->result_tf, 0, sizeof(qc->result_tf));
3954	/*
3955	* Since qc->err_mask is not set,
3956	* ata_eh_qc_retry() will increment
3957	* scmd->allowed, so upper layer is guaranteed
3958	* to retry the command.
3959	*/
3960	ata_eh_qc_retry(qc);
3961	}
3962	}
3963	}
3964
3965	/* make sure nr_active_links is zero after EH */
3966	WARN_ON(ap->nr_active_links);
3967	ap->nr_active_links = 0;
3968	}
3969
3970	/**
3971	* ata_do_eh - do standard error handling
3972	* @ap: host port to handle error for
3973	*
3974	* @prereset: prereset method (can be NULL)
3975	* @softreset: softreset method (can be NULL)
3976	* @hardreset: hardreset method (can be NULL)
3977	* @postreset: postreset method (can be NULL)
3978	*
3979	* Perform standard error handling sequence.
3980	*
3981	* LOCKING:
3982	* Kernel thread context (may sleep).
3983	*/
3984	void ata_do_eh(struct ata_port *ap, ata_prereset_fn_t prereset,
3985	ata_reset_fn_t softreset, ata_reset_fn_t hardreset,
3986	ata_postreset_fn_t postreset)
3987	{
3988	struct ata_device *dev;
3989	int rc;
3990
3991	ata_eh_autopsy(ap);
3992	ata_eh_report(ap);
3993
3994	rc = ata_eh_recover(ap, prereset, softreset, hardreset, postreset,
3995	NULL);
3996	if (rc) {
3997	ata_for_each_dev(dev, &ap->link, ALL)
3998	ata_dev_disable(dev);
3999	}
4000
4001	ata_eh_finish(ap);
4002	}
4003
4004	/**
4005	* ata_std_error_handler - standard error handler
4006	* @ap: host port to handle error for
4007	*
4008	* Standard error handler
4009	*
4010	* LOCKING:
4011	* Kernel thread context (may sleep).
4012	*/
4013	void ata_std_error_handler(struct ata_port *ap)
4014	{
4015	struct ata_port_operations *ops = ap->ops;
4016	ata_reset_fn_t hardreset = ops->hardreset;
4017
4018	/* ignore built-in hardreset if SCR access is not available */
4019	if (hardreset == sata_std_hardreset && !sata_scr_valid(link: &ap->link))
4020	hardreset = NULL;
4021
4022	ata_do_eh(ap, prereset: ops->prereset, softreset: ops->softreset, hardreset, postreset: ops->postreset);
4023	}
4024	EXPORT_SYMBOL_GPL(ata_std_error_handler);
4025
4026	#ifdef CONFIG_PM
4027	/**
4028	* ata_eh_handle_port_suspend - perform port suspend operation
4029	* @ap: port to suspend
4030	*
4031	* Suspend @ap.
4032	*
4033	* LOCKING:
4034	* Kernel thread context (may sleep).
4035	*/
4036	static void ata_eh_handle_port_suspend(struct ata_port *ap)
4037	{
4038	unsigned long flags;
4039	int rc = 0;
4040	struct ata_device *dev;
4041	struct ata_link *link;
4042
4043	/* are we suspending? */
4044	spin_lock_irqsave(ap->lock, flags);
4045	if (!(ap->pflags & ATA_PFLAG_PM_PENDING) ||
4046	ap->pm_mesg.event & PM_EVENT_RESUME) {
4047	spin_unlock_irqrestore(lock: ap->lock, flags);
4048	return;
4049	}
4050	spin_unlock_irqrestore(lock: ap->lock, flags);
4051
4052	WARN_ON(ap->pflags & ATA_PFLAG_SUSPENDED);
4053
4054	/* Set all devices attached to the port in standby mode */
4055	ata_for_each_link(link, ap, HOST_FIRST) {
4056	ata_for_each_dev(dev, link, ENABLED)
4057	ata_dev_power_set_standby(dev);
4058	}
4059
4060	/*
4061	* If we have a ZPODD attached, check its zero
4062	* power ready status before the port is frozen.
4063	* Only needed for runtime suspend.
4064	*/
4065	if (PMSG_IS_AUTO(ap->pm_mesg)) {
4066	ata_for_each_dev(dev, &ap->link, ENABLED) {
4067	if (zpodd_dev_enabled(dev))
4068	zpodd_on_suspend(dev);
4069	}
4070	}
4071
4072	/* suspend */
4073	ata_eh_freeze_port(ap);
4074
4075	if (ap->ops->port_suspend)
4076	rc = ap->ops->port_suspend(ap, ap->pm_mesg);
4077
4078	ata_acpi_set_state(ap, state: ap->pm_mesg);
4079
4080	/* update the flags */
4081	spin_lock_irqsave(ap->lock, flags);
4082
4083	ap->pflags &= ~ATA_PFLAG_PM_PENDING;
4084	if (rc == 0)
4085	ap->pflags |= ATA_PFLAG_SUSPENDED;
4086	else if (ata_port_is_frozen(ap))
4087	ata_port_schedule_eh(ap);
4088
4089	spin_unlock_irqrestore(lock: ap->lock, flags);
4090
4091	return;
4092	}
4093
4094	/**
4095	* ata_eh_handle_port_resume - perform port resume operation
4096	* @ap: port to resume
4097	*
4098	* Resume @ap.
4099	*
4100	* LOCKING:
4101	* Kernel thread context (may sleep).
4102	*/
4103	static void ata_eh_handle_port_resume(struct ata_port *ap)
4104	{
4105	struct ata_link *link;
4106	struct ata_device *dev;
4107	unsigned long flags;
4108
4109	/* are we resuming? */
4110	spin_lock_irqsave(ap->lock, flags);
4111	if (!(ap->pflags & ATA_PFLAG_PM_PENDING) ||
4112	!(ap->pm_mesg.event & PM_EVENT_RESUME)) {
4113	spin_unlock_irqrestore(lock: ap->lock, flags);
4114	return;
4115	}
4116	spin_unlock_irqrestore(lock: ap->lock, flags);
4117
4118	WARN_ON(!(ap->pflags & ATA_PFLAG_SUSPENDED));
4119
4120	/*
4121	* Error timestamps are in jiffies which doesn't run while
4122	* suspended and PHY events during resume isn't too uncommon.
4123	* When the two are combined, it can lead to unnecessary speed
4124	* downs if the machine is suspended and resumed repeatedly.
4125	* Clear error history.
4126	*/
4127	ata_for_each_link(link, ap, HOST_FIRST)
4128	ata_for_each_dev(dev, link, ALL)
4129	ata_ering_clear(ering: &dev->ering);
4130
4131	ata_acpi_set_state(ap, state: ap->pm_mesg);
4132
4133	if (ap->ops->port_resume)
4134	ap->ops->port_resume(ap);
4135
4136	/* tell ACPI that we're resuming */
4137	ata_acpi_on_resume(ap);
4138
4139	/* update the flags */
4140	spin_lock_irqsave(ap->lock, flags);
4141	ap->pflags &= ~(ATA_PFLAG_PM_PENDING | ATA_PFLAG_SUSPENDED);
4142	ap->pflags |= ATA_PFLAG_RESUMING;
4143	spin_unlock_irqrestore(lock: ap->lock, flags);
4144	}
4145	#endif /* CONFIG_PM */
4146