xref: /linux/drivers/ata/libata-sata.c (revision 41e0d49104dbff888ef6446ea46842fde66c0a76)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  SATA specific part of ATA helper library
4  *
5  *  Copyright 2003-2004 Red Hat, Inc.  All rights reserved.
6  *  Copyright 2003-2004 Jeff Garzik
7  *  Copyright 2006 Tejun Heo <htejun@gmail.com>
8  */
9 
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <scsi/scsi_cmnd.h>
13 #include <scsi/scsi_device.h>
14 #include <linux/libata.h>
15 
16 #include "libata.h"
17 #include "libata-transport.h"
18 
19 /* debounce timing parameters in msecs { interval, duration, timeout } */
20 const unsigned long sata_deb_timing_normal[]		= {   5,  100, 2000 };
21 EXPORT_SYMBOL_GPL(sata_deb_timing_normal);
22 const unsigned long sata_deb_timing_hotplug[]		= {  25,  500, 2000 };
23 EXPORT_SYMBOL_GPL(sata_deb_timing_hotplug);
24 const unsigned long sata_deb_timing_long[]		= { 100, 2000, 5000 };
25 EXPORT_SYMBOL_GPL(sata_deb_timing_long);
26 
27 /**
28  *	sata_scr_valid - test whether SCRs are accessible
29  *	@link: ATA link to test SCR accessibility for
30  *
31  *	Test whether SCRs are accessible for @link.
32  *
33  *	LOCKING:
34  *	None.
35  *
36  *	RETURNS:
37  *	1 if SCRs are accessible, 0 otherwise.
38  */
39 int sata_scr_valid(struct ata_link *link)
40 {
41 	struct ata_port *ap = link->ap;
42 
43 	return (ap->flags & ATA_FLAG_SATA) && ap->ops->scr_read;
44 }
45 EXPORT_SYMBOL_GPL(sata_scr_valid);
46 
47 /**
48  *	sata_scr_read - read SCR register of the specified port
49  *	@link: ATA link to read SCR for
50  *	@reg: SCR to read
51  *	@val: Place to store read value
52  *
53  *	Read SCR register @reg of @link into *@val.  This function is
54  *	guaranteed to succeed if @link is ap->link, the cable type of
55  *	the port is SATA and the port implements ->scr_read.
56  *
57  *	LOCKING:
58  *	None if @link is ap->link.  Kernel thread context otherwise.
59  *
60  *	RETURNS:
61  *	0 on success, negative errno on failure.
62  */
63 int sata_scr_read(struct ata_link *link, int reg, u32 *val)
64 {
65 	if (ata_is_host_link(link)) {
66 		if (sata_scr_valid(link))
67 			return link->ap->ops->scr_read(link, reg, val);
68 		return -EOPNOTSUPP;
69 	}
70 
71 	return sata_pmp_scr_read(link, reg, val);
72 }
73 EXPORT_SYMBOL_GPL(sata_scr_read);
74 
75 /**
76  *	sata_scr_write - write SCR register of the specified port
77  *	@link: ATA link to write SCR for
78  *	@reg: SCR to write
79  *	@val: value to write
80  *
81  *	Write @val to SCR register @reg of @link.  This function is
82  *	guaranteed to succeed if @link is ap->link, the cable type of
83  *	the port is SATA and the port implements ->scr_read.
84  *
85  *	LOCKING:
86  *	None if @link is ap->link.  Kernel thread context otherwise.
87  *
88  *	RETURNS:
89  *	0 on success, negative errno on failure.
90  */
91 int sata_scr_write(struct ata_link *link, int reg, u32 val)
92 {
93 	if (ata_is_host_link(link)) {
94 		if (sata_scr_valid(link))
95 			return link->ap->ops->scr_write(link, reg, val);
96 		return -EOPNOTSUPP;
97 	}
98 
99 	return sata_pmp_scr_write(link, reg, val);
100 }
101 EXPORT_SYMBOL_GPL(sata_scr_write);
102 
103 /**
104  *	sata_scr_write_flush - write SCR register of the specified port and flush
105  *	@link: ATA link to write SCR for
106  *	@reg: SCR to write
107  *	@val: value to write
108  *
109  *	This function is identical to sata_scr_write() except that this
110  *	function performs flush after writing to the register.
111  *
112  *	LOCKING:
113  *	None if @link is ap->link.  Kernel thread context otherwise.
114  *
115  *	RETURNS:
116  *	0 on success, negative errno on failure.
117  */
118 int sata_scr_write_flush(struct ata_link *link, int reg, u32 val)
119 {
120 	if (ata_is_host_link(link)) {
121 		int rc;
122 
123 		if (sata_scr_valid(link)) {
124 			rc = link->ap->ops->scr_write(link, reg, val);
125 			if (rc == 0)
126 				rc = link->ap->ops->scr_read(link, reg, &val);
127 			return rc;
128 		}
129 		return -EOPNOTSUPP;
130 	}
131 
132 	return sata_pmp_scr_write(link, reg, val);
133 }
134 EXPORT_SYMBOL_GPL(sata_scr_write_flush);
135 
136 /**
137  *	ata_tf_to_fis - Convert ATA taskfile to SATA FIS structure
138  *	@tf: Taskfile to convert
139  *	@pmp: Port multiplier port
140  *	@is_cmd: This FIS is for command
141  *	@fis: Buffer into which data will output
142  *
143  *	Converts a standard ATA taskfile to a Serial ATA
144  *	FIS structure (Register - Host to Device).
145  *
146  *	LOCKING:
147  *	Inherited from caller.
148  */
149 void ata_tf_to_fis(const struct ata_taskfile *tf, u8 pmp, int is_cmd, u8 *fis)
150 {
151 	fis[0] = 0x27;			/* Register - Host to Device FIS */
152 	fis[1] = pmp & 0xf;		/* Port multiplier number*/
153 	if (is_cmd)
154 		fis[1] |= (1 << 7);	/* bit 7 indicates Command FIS */
155 
156 	fis[2] = tf->command;
157 	fis[3] = tf->feature;
158 
159 	fis[4] = tf->lbal;
160 	fis[5] = tf->lbam;
161 	fis[6] = tf->lbah;
162 	fis[7] = tf->device;
163 
164 	fis[8] = tf->hob_lbal;
165 	fis[9] = tf->hob_lbam;
166 	fis[10] = tf->hob_lbah;
167 	fis[11] = tf->hob_feature;
168 
169 	fis[12] = tf->nsect;
170 	fis[13] = tf->hob_nsect;
171 	fis[14] = 0;
172 	fis[15] = tf->ctl;
173 
174 	fis[16] = tf->auxiliary & 0xff;
175 	fis[17] = (tf->auxiliary >> 8) & 0xff;
176 	fis[18] = (tf->auxiliary >> 16) & 0xff;
177 	fis[19] = (tf->auxiliary >> 24) & 0xff;
178 }
179 EXPORT_SYMBOL_GPL(ata_tf_to_fis);
180 
181 /**
182  *	ata_tf_from_fis - Convert SATA FIS to ATA taskfile
183  *	@fis: Buffer from which data will be input
184  *	@tf: Taskfile to output
185  *
186  *	Converts a serial ATA FIS structure to a standard ATA taskfile.
187  *
188  *	LOCKING:
189  *	Inherited from caller.
190  */
191 
192 void ata_tf_from_fis(const u8 *fis, struct ata_taskfile *tf)
193 {
194 	tf->status	= fis[2];
195 	tf->error	= fis[3];
196 
197 	tf->lbal	= fis[4];
198 	tf->lbam	= fis[5];
199 	tf->lbah	= fis[6];
200 	tf->device	= fis[7];
201 
202 	tf->hob_lbal	= fis[8];
203 	tf->hob_lbam	= fis[9];
204 	tf->hob_lbah	= fis[10];
205 
206 	tf->nsect	= fis[12];
207 	tf->hob_nsect	= fis[13];
208 }
209 EXPORT_SYMBOL_GPL(ata_tf_from_fis);
210 
211 /**
212  *	sata_link_debounce - debounce SATA phy status
213  *	@link: ATA link to debounce SATA phy status for
214  *	@params: timing parameters { interval, duration, timeout } in msec
215  *	@deadline: deadline jiffies for the operation
216  *
217  *	Make sure SStatus of @link reaches stable state, determined by
218  *	holding the same value where DET is not 1 for @duration polled
219  *	every @interval, before @timeout.  Timeout constraints the
220  *	beginning of the stable state.  Because DET gets stuck at 1 on
221  *	some controllers after hot unplugging, this functions waits
222  *	until timeout then returns 0 if DET is stable at 1.
223  *
224  *	@timeout is further limited by @deadline.  The sooner of the
225  *	two is used.
226  *
227  *	LOCKING:
228  *	Kernel thread context (may sleep)
229  *
230  *	RETURNS:
231  *	0 on success, -errno on failure.
232  */
233 int sata_link_debounce(struct ata_link *link, const unsigned long *params,
234 		       unsigned long deadline)
235 {
236 	unsigned long interval = params[0];
237 	unsigned long duration = params[1];
238 	unsigned long last_jiffies, t;
239 	u32 last, cur;
240 	int rc;
241 
242 	t = ata_deadline(jiffies, params[2]);
243 	if (time_before(t, deadline))
244 		deadline = t;
245 
246 	if ((rc = sata_scr_read(link, SCR_STATUS, &cur)))
247 		return rc;
248 	cur &= 0xf;
249 
250 	last = cur;
251 	last_jiffies = jiffies;
252 
253 	while (1) {
254 		ata_msleep(link->ap, interval);
255 		if ((rc = sata_scr_read(link, SCR_STATUS, &cur)))
256 			return rc;
257 		cur &= 0xf;
258 
259 		/* DET stable? */
260 		if (cur == last) {
261 			if (cur == 1 && time_before(jiffies, deadline))
262 				continue;
263 			if (time_after(jiffies,
264 				       ata_deadline(last_jiffies, duration)))
265 				return 0;
266 			continue;
267 		}
268 
269 		/* unstable, start over */
270 		last = cur;
271 		last_jiffies = jiffies;
272 
273 		/* Check deadline.  If debouncing failed, return
274 		 * -EPIPE to tell upper layer to lower link speed.
275 		 */
276 		if (time_after(jiffies, deadline))
277 			return -EPIPE;
278 	}
279 }
280 EXPORT_SYMBOL_GPL(sata_link_debounce);
281 
282 /**
283  *	sata_link_resume - resume SATA link
284  *	@link: ATA link to resume SATA
285  *	@params: timing parameters { interval, duration, timeout } in msec
286  *	@deadline: deadline jiffies for the operation
287  *
288  *	Resume SATA phy @link and debounce it.
289  *
290  *	LOCKING:
291  *	Kernel thread context (may sleep)
292  *
293  *	RETURNS:
294  *	0 on success, -errno on failure.
295  */
296 int sata_link_resume(struct ata_link *link, const unsigned long *params,
297 		     unsigned long deadline)
298 {
299 	int tries = ATA_LINK_RESUME_TRIES;
300 	u32 scontrol, serror;
301 	int rc;
302 
303 	if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
304 		return rc;
305 
306 	/*
307 	 * Writes to SControl sometimes get ignored under certain
308 	 * controllers (ata_piix SIDPR).  Make sure DET actually is
309 	 * cleared.
310 	 */
311 	do {
312 		scontrol = (scontrol & 0x0f0) | 0x300;
313 		if ((rc = sata_scr_write(link, SCR_CONTROL, scontrol)))
314 			return rc;
315 		/*
316 		 * Some PHYs react badly if SStatus is pounded
317 		 * immediately after resuming.  Delay 200ms before
318 		 * debouncing.
319 		 */
320 		if (!(link->flags & ATA_LFLAG_NO_DEBOUNCE_DELAY))
321 			ata_msleep(link->ap, 200);
322 
323 		/* is SControl restored correctly? */
324 		if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
325 			return rc;
326 	} while ((scontrol & 0xf0f) != 0x300 && --tries);
327 
328 	if ((scontrol & 0xf0f) != 0x300) {
329 		ata_link_warn(link, "failed to resume link (SControl %X)\n",
330 			     scontrol);
331 		return 0;
332 	}
333 
334 	if (tries < ATA_LINK_RESUME_TRIES)
335 		ata_link_warn(link, "link resume succeeded after %d retries\n",
336 			      ATA_LINK_RESUME_TRIES - tries);
337 
338 	if ((rc = sata_link_debounce(link, params, deadline)))
339 		return rc;
340 
341 	/* clear SError, some PHYs require this even for SRST to work */
342 	if (!(rc = sata_scr_read(link, SCR_ERROR, &serror)))
343 		rc = sata_scr_write(link, SCR_ERROR, serror);
344 
345 	return rc != -EINVAL ? rc : 0;
346 }
347 EXPORT_SYMBOL_GPL(sata_link_resume);
348 
349 /**
350  *	sata_link_scr_lpm - manipulate SControl IPM and SPM fields
351  *	@link: ATA link to manipulate SControl for
352  *	@policy: LPM policy to configure
353  *	@spm_wakeup: initiate LPM transition to active state
354  *
355  *	Manipulate the IPM field of the SControl register of @link
356  *	according to @policy.  If @policy is ATA_LPM_MAX_POWER and
357  *	@spm_wakeup is %true, the SPM field is manipulated to wake up
358  *	the link.  This function also clears PHYRDY_CHG before
359  *	returning.
360  *
361  *	LOCKING:
362  *	EH context.
363  *
364  *	RETURNS:
365  *	0 on success, -errno otherwise.
366  */
367 int sata_link_scr_lpm(struct ata_link *link, enum ata_lpm_policy policy,
368 		      bool spm_wakeup)
369 {
370 	struct ata_eh_context *ehc = &link->eh_context;
371 	bool woken_up = false;
372 	u32 scontrol;
373 	int rc;
374 
375 	rc = sata_scr_read(link, SCR_CONTROL, &scontrol);
376 	if (rc)
377 		return rc;
378 
379 	switch (policy) {
380 	case ATA_LPM_MAX_POWER:
381 		/* disable all LPM transitions */
382 		scontrol |= (0x7 << 8);
383 		/* initiate transition to active state */
384 		if (spm_wakeup) {
385 			scontrol |= (0x4 << 12);
386 			woken_up = true;
387 		}
388 		break;
389 	case ATA_LPM_MED_POWER:
390 		/* allow LPM to PARTIAL */
391 		scontrol &= ~(0x1 << 8);
392 		scontrol |= (0x6 << 8);
393 		break;
394 	case ATA_LPM_MED_POWER_WITH_DIPM:
395 	case ATA_LPM_MIN_POWER_WITH_PARTIAL:
396 	case ATA_LPM_MIN_POWER:
397 		if (ata_link_nr_enabled(link) > 0)
398 			/* no restrictions on LPM transitions */
399 			scontrol &= ~(0x7 << 8);
400 		else {
401 			/* empty port, power off */
402 			scontrol &= ~0xf;
403 			scontrol |= (0x1 << 2);
404 		}
405 		break;
406 	default:
407 		WARN_ON(1);
408 	}
409 
410 	rc = sata_scr_write(link, SCR_CONTROL, scontrol);
411 	if (rc)
412 		return rc;
413 
414 	/* give the link time to transit out of LPM state */
415 	if (woken_up)
416 		msleep(10);
417 
418 	/* clear PHYRDY_CHG from SError */
419 	ehc->i.serror &= ~SERR_PHYRDY_CHG;
420 	return sata_scr_write(link, SCR_ERROR, SERR_PHYRDY_CHG);
421 }
422 EXPORT_SYMBOL_GPL(sata_link_scr_lpm);
423 
424 static int __sata_set_spd_needed(struct ata_link *link, u32 *scontrol)
425 {
426 	struct ata_link *host_link = &link->ap->link;
427 	u32 limit, target, spd;
428 
429 	limit = link->sata_spd_limit;
430 
431 	/* Don't configure downstream link faster than upstream link.
432 	 * It doesn't speed up anything and some PMPs choke on such
433 	 * configuration.
434 	 */
435 	if (!ata_is_host_link(link) && host_link->sata_spd)
436 		limit &= (1 << host_link->sata_spd) - 1;
437 
438 	if (limit == UINT_MAX)
439 		target = 0;
440 	else
441 		target = fls(limit);
442 
443 	spd = (*scontrol >> 4) & 0xf;
444 	*scontrol = (*scontrol & ~0xf0) | ((target & 0xf) << 4);
445 
446 	return spd != target;
447 }
448 
449 /**
450  *	sata_set_spd_needed - is SATA spd configuration needed
451  *	@link: Link in question
452  *
453  *	Test whether the spd limit in SControl matches
454  *	@link->sata_spd_limit.  This function is used to determine
455  *	whether hardreset is necessary to apply SATA spd
456  *	configuration.
457  *
458  *	LOCKING:
459  *	Inherited from caller.
460  *
461  *	RETURNS:
462  *	1 if SATA spd configuration is needed, 0 otherwise.
463  */
464 static int sata_set_spd_needed(struct ata_link *link)
465 {
466 	u32 scontrol;
467 
468 	if (sata_scr_read(link, SCR_CONTROL, &scontrol))
469 		return 1;
470 
471 	return __sata_set_spd_needed(link, &scontrol);
472 }
473 
474 /**
475  *	sata_set_spd - set SATA spd according to spd limit
476  *	@link: Link to set SATA spd for
477  *
478  *	Set SATA spd of @link according to sata_spd_limit.
479  *
480  *	LOCKING:
481  *	Inherited from caller.
482  *
483  *	RETURNS:
484  *	0 if spd doesn't need to be changed, 1 if spd has been
485  *	changed.  Negative errno if SCR registers are inaccessible.
486  */
487 int sata_set_spd(struct ata_link *link)
488 {
489 	u32 scontrol;
490 	int rc;
491 
492 	if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
493 		return rc;
494 
495 	if (!__sata_set_spd_needed(link, &scontrol))
496 		return 0;
497 
498 	if ((rc = sata_scr_write(link, SCR_CONTROL, scontrol)))
499 		return rc;
500 
501 	return 1;
502 }
503 EXPORT_SYMBOL_GPL(sata_set_spd);
504 
505 /**
506  *	sata_link_hardreset - reset link via SATA phy reset
507  *	@link: link to reset
508  *	@timing: timing parameters { interval, duration, timeout } in msec
509  *	@deadline: deadline jiffies for the operation
510  *	@online: optional out parameter indicating link onlineness
511  *	@check_ready: optional callback to check link readiness
512  *
513  *	SATA phy-reset @link using DET bits of SControl register.
514  *	After hardreset, link readiness is waited upon using
515  *	ata_wait_ready() if @check_ready is specified.  LLDs are
516  *	allowed to not specify @check_ready and wait itself after this
517  *	function returns.  Device classification is LLD's
518  *	responsibility.
519  *
520  *	*@online is set to one iff reset succeeded and @link is online
521  *	after reset.
522  *
523  *	LOCKING:
524  *	Kernel thread context (may sleep)
525  *
526  *	RETURNS:
527  *	0 on success, -errno otherwise.
528  */
529 int sata_link_hardreset(struct ata_link *link, const unsigned long *timing,
530 			unsigned long deadline,
531 			bool *online, int (*check_ready)(struct ata_link *))
532 {
533 	u32 scontrol;
534 	int rc;
535 
536 	if (online)
537 		*online = false;
538 
539 	if (sata_set_spd_needed(link)) {
540 		/* SATA spec says nothing about how to reconfigure
541 		 * spd.  To be on the safe side, turn off phy during
542 		 * reconfiguration.  This works for at least ICH7 AHCI
543 		 * and Sil3124.
544 		 */
545 		if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
546 			goto out;
547 
548 		scontrol = (scontrol & 0x0f0) | 0x304;
549 
550 		if ((rc = sata_scr_write(link, SCR_CONTROL, scontrol)))
551 			goto out;
552 
553 		sata_set_spd(link);
554 	}
555 
556 	/* issue phy wake/reset */
557 	if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
558 		goto out;
559 
560 	scontrol = (scontrol & 0x0f0) | 0x301;
561 
562 	if ((rc = sata_scr_write_flush(link, SCR_CONTROL, scontrol)))
563 		goto out;
564 
565 	/* Couldn't find anything in SATA I/II specs, but AHCI-1.1
566 	 * 10.4.2 says at least 1 ms.
567 	 */
568 	ata_msleep(link->ap, 1);
569 
570 	/* bring link back */
571 	rc = sata_link_resume(link, timing, deadline);
572 	if (rc)
573 		goto out;
574 	/* if link is offline nothing more to do */
575 	if (ata_phys_link_offline(link))
576 		goto out;
577 
578 	/* Link is online.  From this point, -ENODEV too is an error. */
579 	if (online)
580 		*online = true;
581 
582 	if (sata_pmp_supported(link->ap) && ata_is_host_link(link)) {
583 		/* If PMP is supported, we have to do follow-up SRST.
584 		 * Some PMPs don't send D2H Reg FIS after hardreset if
585 		 * the first port is empty.  Wait only for
586 		 * ATA_TMOUT_PMP_SRST_WAIT.
587 		 */
588 		if (check_ready) {
589 			unsigned long pmp_deadline;
590 
591 			pmp_deadline = ata_deadline(jiffies,
592 						    ATA_TMOUT_PMP_SRST_WAIT);
593 			if (time_after(pmp_deadline, deadline))
594 				pmp_deadline = deadline;
595 			ata_wait_ready(link, pmp_deadline, check_ready);
596 		}
597 		rc = -EAGAIN;
598 		goto out;
599 	}
600 
601 	rc = 0;
602 	if (check_ready)
603 		rc = ata_wait_ready(link, deadline, check_ready);
604  out:
605 	if (rc && rc != -EAGAIN) {
606 		/* online is set iff link is online && reset succeeded */
607 		if (online)
608 			*online = false;
609 		ata_link_err(link, "COMRESET failed (errno=%d)\n", rc);
610 	}
611 	return rc;
612 }
613 EXPORT_SYMBOL_GPL(sata_link_hardreset);
614 
615 /**
616  *	ata_qc_complete_multiple - Complete multiple qcs successfully
617  *	@ap: port in question
618  *	@qc_active: new qc_active mask
619  *
620  *	Complete in-flight commands.  This functions is meant to be
621  *	called from low-level driver's interrupt routine to complete
622  *	requests normally.  ap->qc_active and @qc_active is compared
623  *	and commands are completed accordingly.
624  *
625  *	Always use this function when completing multiple NCQ commands
626  *	from IRQ handlers instead of calling ata_qc_complete()
627  *	multiple times to keep IRQ expect status properly in sync.
628  *
629  *	LOCKING:
630  *	spin_lock_irqsave(host lock)
631  *
632  *	RETURNS:
633  *	Number of completed commands on success, -errno otherwise.
634  */
635 int ata_qc_complete_multiple(struct ata_port *ap, u64 qc_active)
636 {
637 	u64 done_mask, ap_qc_active = ap->qc_active;
638 	int nr_done = 0;
639 
640 	/*
641 	 * If the internal tag is set on ap->qc_active, then we care about
642 	 * bit0 on the passed in qc_active mask. Move that bit up to match
643 	 * the internal tag.
644 	 */
645 	if (ap_qc_active & (1ULL << ATA_TAG_INTERNAL)) {
646 		qc_active |= (qc_active & 0x01) << ATA_TAG_INTERNAL;
647 		qc_active ^= qc_active & 0x01;
648 	}
649 
650 	done_mask = ap_qc_active ^ qc_active;
651 
652 	if (unlikely(done_mask & qc_active)) {
653 		ata_port_err(ap, "illegal qc_active transition (%08llx->%08llx)\n",
654 			     ap->qc_active, qc_active);
655 		return -EINVAL;
656 	}
657 
658 	while (done_mask) {
659 		struct ata_queued_cmd *qc;
660 		unsigned int tag = __ffs64(done_mask);
661 
662 		qc = ata_qc_from_tag(ap, tag);
663 		if (qc) {
664 			ata_qc_complete(qc);
665 			nr_done++;
666 		}
667 		done_mask &= ~(1ULL << tag);
668 	}
669 
670 	return nr_done;
671 }
672 EXPORT_SYMBOL_GPL(ata_qc_complete_multiple);
673 
674 /**
675  *	ata_slave_link_init - initialize slave link
676  *	@ap: port to initialize slave link for
677  *
678  *	Create and initialize slave link for @ap.  This enables slave
679  *	link handling on the port.
680  *
681  *	In libata, a port contains links and a link contains devices.
682  *	There is single host link but if a PMP is attached to it,
683  *	there can be multiple fan-out links.  On SATA, there's usually
684  *	a single device connected to a link but PATA and SATA
685  *	controllers emulating TF based interface can have two - master
686  *	and slave.
687  *
688  *	However, there are a few controllers which don't fit into this
689  *	abstraction too well - SATA controllers which emulate TF
690  *	interface with both master and slave devices but also have
691  *	separate SCR register sets for each device.  These controllers
692  *	need separate links for physical link handling
693  *	(e.g. onlineness, link speed) but should be treated like a
694  *	traditional M/S controller for everything else (e.g. command
695  *	issue, softreset).
696  *
697  *	slave_link is libata's way of handling this class of
698  *	controllers without impacting core layer too much.  For
699  *	anything other than physical link handling, the default host
700  *	link is used for both master and slave.  For physical link
701  *	handling, separate @ap->slave_link is used.  All dirty details
702  *	are implemented inside libata core layer.  From LLD's POV, the
703  *	only difference is that prereset, hardreset and postreset are
704  *	called once more for the slave link, so the reset sequence
705  *	looks like the following.
706  *
707  *	prereset(M) -> prereset(S) -> hardreset(M) -> hardreset(S) ->
708  *	softreset(M) -> postreset(M) -> postreset(S)
709  *
710  *	Note that softreset is called only for the master.  Softreset
711  *	resets both M/S by definition, so SRST on master should handle
712  *	both (the standard method will work just fine).
713  *
714  *	LOCKING:
715  *	Should be called before host is registered.
716  *
717  *	RETURNS:
718  *	0 on success, -errno on failure.
719  */
720 int ata_slave_link_init(struct ata_port *ap)
721 {
722 	struct ata_link *link;
723 
724 	WARN_ON(ap->slave_link);
725 	WARN_ON(ap->flags & ATA_FLAG_PMP);
726 
727 	link = kzalloc(sizeof(*link), GFP_KERNEL);
728 	if (!link)
729 		return -ENOMEM;
730 
731 	ata_link_init(ap, link, 1);
732 	ap->slave_link = link;
733 	return 0;
734 }
735 EXPORT_SYMBOL_GPL(ata_slave_link_init);
736 
737 /**
738  *	sata_lpm_ignore_phy_events - test if PHY event should be ignored
739  *	@link: Link receiving the event
740  *
741  *	Test whether the received PHY event has to be ignored or not.
742  *
743  *	LOCKING:
744  *	None:
745  *
746  *	RETURNS:
747  *	True if the event has to be ignored.
748  */
749 bool sata_lpm_ignore_phy_events(struct ata_link *link)
750 {
751 	unsigned long lpm_timeout = link->last_lpm_change +
752 				    msecs_to_jiffies(ATA_TMOUT_SPURIOUS_PHY);
753 
754 	/* if LPM is enabled, PHYRDY doesn't mean anything */
755 	if (link->lpm_policy > ATA_LPM_MAX_POWER)
756 		return true;
757 
758 	/* ignore the first PHY event after the LPM policy changed
759 	 * as it is might be spurious
760 	 */
761 	if ((link->flags & ATA_LFLAG_CHANGED) &&
762 	    time_before(jiffies, lpm_timeout))
763 		return true;
764 
765 	return false;
766 }
767 EXPORT_SYMBOL_GPL(sata_lpm_ignore_phy_events);
768 
769 static const char *ata_lpm_policy_names[] = {
770 	[ATA_LPM_UNKNOWN]		= "max_performance",
771 	[ATA_LPM_MAX_POWER]		= "max_performance",
772 	[ATA_LPM_MED_POWER]		= "medium_power",
773 	[ATA_LPM_MED_POWER_WITH_DIPM]	= "med_power_with_dipm",
774 	[ATA_LPM_MIN_POWER_WITH_PARTIAL] = "min_power_with_partial",
775 	[ATA_LPM_MIN_POWER]		= "min_power",
776 };
777 
778 static ssize_t ata_scsi_lpm_store(struct device *device,
779 				  struct device_attribute *attr,
780 				  const char *buf, size_t count)
781 {
782 	struct Scsi_Host *shost = class_to_shost(device);
783 	struct ata_port *ap = ata_shost_to_port(shost);
784 	struct ata_link *link;
785 	struct ata_device *dev;
786 	enum ata_lpm_policy policy;
787 	unsigned long flags;
788 
789 	/* UNKNOWN is internal state, iterate from MAX_POWER */
790 	for (policy = ATA_LPM_MAX_POWER;
791 	     policy < ARRAY_SIZE(ata_lpm_policy_names); policy++) {
792 		const char *name = ata_lpm_policy_names[policy];
793 
794 		if (strncmp(name, buf, strlen(name)) == 0)
795 			break;
796 	}
797 	if (policy == ARRAY_SIZE(ata_lpm_policy_names))
798 		return -EINVAL;
799 
800 	spin_lock_irqsave(ap->lock, flags);
801 
802 	ata_for_each_link(link, ap, EDGE) {
803 		ata_for_each_dev(dev, &ap->link, ENABLED) {
804 			if (dev->horkage & ATA_HORKAGE_NOLPM) {
805 				count = -EOPNOTSUPP;
806 				goto out_unlock;
807 			}
808 		}
809 	}
810 
811 	ap->target_lpm_policy = policy;
812 	ata_port_schedule_eh(ap);
813 out_unlock:
814 	spin_unlock_irqrestore(ap->lock, flags);
815 	return count;
816 }
817 
818 static ssize_t ata_scsi_lpm_show(struct device *dev,
819 				 struct device_attribute *attr, char *buf)
820 {
821 	struct Scsi_Host *shost = class_to_shost(dev);
822 	struct ata_port *ap = ata_shost_to_port(shost);
823 
824 	if (ap->target_lpm_policy >= ARRAY_SIZE(ata_lpm_policy_names))
825 		return -EINVAL;
826 
827 	return sysfs_emit(buf, "%s\n",
828 			ata_lpm_policy_names[ap->target_lpm_policy]);
829 }
830 DEVICE_ATTR(link_power_management_policy, S_IRUGO | S_IWUSR,
831 	    ata_scsi_lpm_show, ata_scsi_lpm_store);
832 EXPORT_SYMBOL_GPL(dev_attr_link_power_management_policy);
833 
834 static ssize_t ata_ncq_prio_supported_show(struct device *device,
835 					   struct device_attribute *attr,
836 					   char *buf)
837 {
838 	struct scsi_device *sdev = to_scsi_device(device);
839 	struct ata_port *ap = ata_shost_to_port(sdev->host);
840 	struct ata_device *dev;
841 	bool ncq_prio_supported;
842 	int rc = 0;
843 
844 	spin_lock_irq(ap->lock);
845 	dev = ata_scsi_find_dev(ap, sdev);
846 	if (!dev)
847 		rc = -ENODEV;
848 	else
849 		ncq_prio_supported = dev->flags & ATA_DFLAG_NCQ_PRIO;
850 	spin_unlock_irq(ap->lock);
851 
852 	return rc ? rc : sysfs_emit(buf, "%u\n", ncq_prio_supported);
853 }
854 
855 DEVICE_ATTR(ncq_prio_supported, S_IRUGO, ata_ncq_prio_supported_show, NULL);
856 EXPORT_SYMBOL_GPL(dev_attr_ncq_prio_supported);
857 
858 static ssize_t ata_ncq_prio_enable_show(struct device *device,
859 					struct device_attribute *attr,
860 					char *buf)
861 {
862 	struct scsi_device *sdev = to_scsi_device(device);
863 	struct ata_port *ap = ata_shost_to_port(sdev->host);
864 	struct ata_device *dev;
865 	bool ncq_prio_enable;
866 	int rc = 0;
867 
868 	spin_lock_irq(ap->lock);
869 	dev = ata_scsi_find_dev(ap, sdev);
870 	if (!dev)
871 		rc = -ENODEV;
872 	else
873 		ncq_prio_enable = dev->flags & ATA_DFLAG_NCQ_PRIO_ENABLED;
874 	spin_unlock_irq(ap->lock);
875 
876 	return rc ? rc : sysfs_emit(buf, "%u\n", ncq_prio_enable);
877 }
878 
879 static ssize_t ata_ncq_prio_enable_store(struct device *device,
880 					 struct device_attribute *attr,
881 					 const char *buf, size_t len)
882 {
883 	struct scsi_device *sdev = to_scsi_device(device);
884 	struct ata_port *ap;
885 	struct ata_device *dev;
886 	long int input;
887 	int rc = 0;
888 
889 	rc = kstrtol(buf, 10, &input);
890 	if (rc)
891 		return rc;
892 	if ((input < 0) || (input > 1))
893 		return -EINVAL;
894 
895 	ap = ata_shost_to_port(sdev->host);
896 	dev = ata_scsi_find_dev(ap, sdev);
897 	if (unlikely(!dev))
898 		return  -ENODEV;
899 
900 	spin_lock_irq(ap->lock);
901 
902 	if (!(dev->flags & ATA_DFLAG_NCQ_PRIO)) {
903 		rc = -EINVAL;
904 		goto unlock;
905 	}
906 
907 	if (input)
908 		dev->flags |= ATA_DFLAG_NCQ_PRIO_ENABLED;
909 	else
910 		dev->flags &= ~ATA_DFLAG_NCQ_PRIO_ENABLED;
911 
912 unlock:
913 	spin_unlock_irq(ap->lock);
914 
915 	return rc ? rc : len;
916 }
917 
918 DEVICE_ATTR(ncq_prio_enable, S_IRUGO | S_IWUSR,
919 	    ata_ncq_prio_enable_show, ata_ncq_prio_enable_store);
920 EXPORT_SYMBOL_GPL(dev_attr_ncq_prio_enable);
921 
922 static struct attribute *ata_ncq_sdev_attrs[] = {
923 	&dev_attr_unload_heads.attr,
924 	&dev_attr_ncq_prio_enable.attr,
925 	&dev_attr_ncq_prio_supported.attr,
926 	NULL
927 };
928 
929 static const struct attribute_group ata_ncq_sdev_attr_group = {
930 	.attrs = ata_ncq_sdev_attrs
931 };
932 
933 const struct attribute_group *ata_ncq_sdev_groups[] = {
934 	&ata_ncq_sdev_attr_group,
935 	NULL
936 };
937 EXPORT_SYMBOL_GPL(ata_ncq_sdev_groups);
938 
939 static ssize_t
940 ata_scsi_em_message_store(struct device *dev, struct device_attribute *attr,
941 			  const char *buf, size_t count)
942 {
943 	struct Scsi_Host *shost = class_to_shost(dev);
944 	struct ata_port *ap = ata_shost_to_port(shost);
945 	if (ap->ops->em_store && (ap->flags & ATA_FLAG_EM))
946 		return ap->ops->em_store(ap, buf, count);
947 	return -EINVAL;
948 }
949 
950 static ssize_t
951 ata_scsi_em_message_show(struct device *dev, struct device_attribute *attr,
952 			 char *buf)
953 {
954 	struct Scsi_Host *shost = class_to_shost(dev);
955 	struct ata_port *ap = ata_shost_to_port(shost);
956 
957 	if (ap->ops->em_show && (ap->flags & ATA_FLAG_EM))
958 		return ap->ops->em_show(ap, buf);
959 	return -EINVAL;
960 }
961 DEVICE_ATTR(em_message, S_IRUGO | S_IWUSR,
962 		ata_scsi_em_message_show, ata_scsi_em_message_store);
963 EXPORT_SYMBOL_GPL(dev_attr_em_message);
964 
965 static ssize_t
966 ata_scsi_em_message_type_show(struct device *dev, struct device_attribute *attr,
967 			      char *buf)
968 {
969 	struct Scsi_Host *shost = class_to_shost(dev);
970 	struct ata_port *ap = ata_shost_to_port(shost);
971 
972 	return sysfs_emit(buf, "%d\n", ap->em_message_type);
973 }
974 DEVICE_ATTR(em_message_type, S_IRUGO,
975 		  ata_scsi_em_message_type_show, NULL);
976 EXPORT_SYMBOL_GPL(dev_attr_em_message_type);
977 
978 static ssize_t
979 ata_scsi_activity_show(struct device *dev, struct device_attribute *attr,
980 		char *buf)
981 {
982 	struct scsi_device *sdev = to_scsi_device(dev);
983 	struct ata_port *ap = ata_shost_to_port(sdev->host);
984 	struct ata_device *atadev = ata_scsi_find_dev(ap, sdev);
985 
986 	if (atadev && ap->ops->sw_activity_show &&
987 	    (ap->flags & ATA_FLAG_SW_ACTIVITY))
988 		return ap->ops->sw_activity_show(atadev, buf);
989 	return -EINVAL;
990 }
991 
992 static ssize_t
993 ata_scsi_activity_store(struct device *dev, struct device_attribute *attr,
994 	const char *buf, size_t count)
995 {
996 	struct scsi_device *sdev = to_scsi_device(dev);
997 	struct ata_port *ap = ata_shost_to_port(sdev->host);
998 	struct ata_device *atadev = ata_scsi_find_dev(ap, sdev);
999 	enum sw_activity val;
1000 	int rc;
1001 
1002 	if (atadev && ap->ops->sw_activity_store &&
1003 	    (ap->flags & ATA_FLAG_SW_ACTIVITY)) {
1004 		val = simple_strtoul(buf, NULL, 0);
1005 		switch (val) {
1006 		case OFF: case BLINK_ON: case BLINK_OFF:
1007 			rc = ap->ops->sw_activity_store(atadev, val);
1008 			if (!rc)
1009 				return count;
1010 			else
1011 				return rc;
1012 		}
1013 	}
1014 	return -EINVAL;
1015 }
1016 DEVICE_ATTR(sw_activity, S_IWUSR | S_IRUGO, ata_scsi_activity_show,
1017 			ata_scsi_activity_store);
1018 EXPORT_SYMBOL_GPL(dev_attr_sw_activity);
1019 
1020 /**
1021  *	ata_change_queue_depth - Set a device maximum queue depth
1022  *	@ap: ATA port of the target device
1023  *	@dev: target ATA device
1024  *	@sdev: SCSI device to configure queue depth for
1025  *	@queue_depth: new queue depth
1026  *
1027  *	Helper to set a device maximum queue depth, usable with both libsas
1028  *	and libata.
1029  *
1030  */
1031 int ata_change_queue_depth(struct ata_port *ap, struct ata_device *dev,
1032 			   struct scsi_device *sdev, int queue_depth)
1033 {
1034 	unsigned long flags;
1035 
1036 	if (!dev || !ata_dev_enabled(dev))
1037 		return sdev->queue_depth;
1038 
1039 	if (queue_depth < 1 || queue_depth == sdev->queue_depth)
1040 		return sdev->queue_depth;
1041 
1042 	/* NCQ enabled? */
1043 	spin_lock_irqsave(ap->lock, flags);
1044 	dev->flags &= ~ATA_DFLAG_NCQ_OFF;
1045 	if (queue_depth == 1 || !ata_ncq_enabled(dev)) {
1046 		dev->flags |= ATA_DFLAG_NCQ_OFF;
1047 		queue_depth = 1;
1048 	}
1049 	spin_unlock_irqrestore(ap->lock, flags);
1050 
1051 	/* limit and apply queue depth */
1052 	queue_depth = min(queue_depth, sdev->host->can_queue);
1053 	queue_depth = min(queue_depth, ata_id_queue_depth(dev->id));
1054 	queue_depth = min(queue_depth, ATA_MAX_QUEUE);
1055 
1056 	if (sdev->queue_depth == queue_depth)
1057 		return -EINVAL;
1058 
1059 	return scsi_change_queue_depth(sdev, queue_depth);
1060 }
1061 EXPORT_SYMBOL_GPL(ata_change_queue_depth);
1062 
1063 /**
1064  *	ata_scsi_change_queue_depth - SCSI callback for queue depth config
1065  *	@sdev: SCSI device to configure queue depth for
1066  *	@queue_depth: new queue depth
1067  *
1068  *	This is libata standard hostt->change_queue_depth callback.
1069  *	SCSI will call into this callback when user tries to set queue
1070  *	depth via sysfs.
1071  *
1072  *	LOCKING:
1073  *	SCSI layer (we don't care)
1074  *
1075  *	RETURNS:
1076  *	Newly configured queue depth.
1077  */
1078 int ata_scsi_change_queue_depth(struct scsi_device *sdev, int queue_depth)
1079 {
1080 	struct ata_port *ap = ata_shost_to_port(sdev->host);
1081 
1082 	return ata_change_queue_depth(ap, ata_scsi_find_dev(ap, sdev),
1083 				      sdev, queue_depth);
1084 }
1085 EXPORT_SYMBOL_GPL(ata_scsi_change_queue_depth);
1086 
1087 /**
1088  *	ata_sas_port_alloc - Allocate port for a SAS attached SATA device
1089  *	@host: ATA host container for all SAS ports
1090  *	@port_info: Information from low-level host driver
1091  *	@shost: SCSI host that the scsi device is attached to
1092  *
1093  *	LOCKING:
1094  *	PCI/etc. bus probe sem.
1095  *
1096  *	RETURNS:
1097  *	ata_port pointer on success / NULL on failure.
1098  */
1099 
1100 struct ata_port *ata_sas_port_alloc(struct ata_host *host,
1101 				    struct ata_port_info *port_info,
1102 				    struct Scsi_Host *shost)
1103 {
1104 	struct ata_port *ap;
1105 
1106 	ap = ata_port_alloc(host);
1107 	if (!ap)
1108 		return NULL;
1109 
1110 	ap->port_no = 0;
1111 	ap->lock = &host->lock;
1112 	ap->pio_mask = port_info->pio_mask;
1113 	ap->mwdma_mask = port_info->mwdma_mask;
1114 	ap->udma_mask = port_info->udma_mask;
1115 	ap->flags |= port_info->flags;
1116 	ap->ops = port_info->port_ops;
1117 	ap->cbl = ATA_CBL_SATA;
1118 
1119 	return ap;
1120 }
1121 EXPORT_SYMBOL_GPL(ata_sas_port_alloc);
1122 
1123 /**
1124  *	ata_sas_port_start - Set port up for dma.
1125  *	@ap: Port to initialize
1126  *
1127  *	Called just after data structures for each port are
1128  *	initialized.
1129  *
1130  *	May be used as the port_start() entry in ata_port_operations.
1131  *
1132  *	LOCKING:
1133  *	Inherited from caller.
1134  */
1135 int ata_sas_port_start(struct ata_port *ap)
1136 {
1137 	/*
1138 	 * the port is marked as frozen at allocation time, but if we don't
1139 	 * have new eh, we won't thaw it
1140 	 */
1141 	if (!ap->ops->error_handler)
1142 		ap->pflags &= ~ATA_PFLAG_FROZEN;
1143 	return 0;
1144 }
1145 EXPORT_SYMBOL_GPL(ata_sas_port_start);
1146 
1147 /**
1148  *	ata_sas_port_stop - Undo ata_sas_port_start()
1149  *	@ap: Port to shut down
1150  *
1151  *	May be used as the port_stop() entry in ata_port_operations.
1152  *
1153  *	LOCKING:
1154  *	Inherited from caller.
1155  */
1156 
1157 void ata_sas_port_stop(struct ata_port *ap)
1158 {
1159 }
1160 EXPORT_SYMBOL_GPL(ata_sas_port_stop);
1161 
1162 /**
1163  * ata_sas_async_probe - simply schedule probing and return
1164  * @ap: Port to probe
1165  *
1166  * For batch scheduling of probe for sas attached ata devices, assumes
1167  * the port has already been through ata_sas_port_init()
1168  */
1169 void ata_sas_async_probe(struct ata_port *ap)
1170 {
1171 	__ata_port_probe(ap);
1172 }
1173 EXPORT_SYMBOL_GPL(ata_sas_async_probe);
1174 
1175 int ata_sas_sync_probe(struct ata_port *ap)
1176 {
1177 	return ata_port_probe(ap);
1178 }
1179 EXPORT_SYMBOL_GPL(ata_sas_sync_probe);
1180 
1181 
1182 /**
1183  *	ata_sas_port_init - Initialize a SATA device
1184  *	@ap: SATA port to initialize
1185  *
1186  *	LOCKING:
1187  *	PCI/etc. bus probe sem.
1188  *
1189  *	RETURNS:
1190  *	Zero on success, non-zero on error.
1191  */
1192 
1193 int ata_sas_port_init(struct ata_port *ap)
1194 {
1195 	int rc = ap->ops->port_start(ap);
1196 
1197 	if (rc)
1198 		return rc;
1199 	ap->print_id = atomic_inc_return(&ata_print_id);
1200 	return 0;
1201 }
1202 EXPORT_SYMBOL_GPL(ata_sas_port_init);
1203 
1204 int ata_sas_tport_add(struct device *parent, struct ata_port *ap)
1205 {
1206 	return ata_tport_add(parent, ap);
1207 }
1208 EXPORT_SYMBOL_GPL(ata_sas_tport_add);
1209 
1210 void ata_sas_tport_delete(struct ata_port *ap)
1211 {
1212 	ata_tport_delete(ap);
1213 }
1214 EXPORT_SYMBOL_GPL(ata_sas_tport_delete);
1215 
1216 /**
1217  *	ata_sas_port_destroy - Destroy a SATA port allocated by ata_sas_port_alloc
1218  *	@ap: SATA port to destroy
1219  *
1220  */
1221 
1222 void ata_sas_port_destroy(struct ata_port *ap)
1223 {
1224 	if (ap->ops->port_stop)
1225 		ap->ops->port_stop(ap);
1226 	kfree(ap);
1227 }
1228 EXPORT_SYMBOL_GPL(ata_sas_port_destroy);
1229 
1230 /**
1231  *	ata_sas_slave_configure - Default slave_config routine for libata devices
1232  *	@sdev: SCSI device to configure
1233  *	@ap: ATA port to which SCSI device is attached
1234  *
1235  *	RETURNS:
1236  *	Zero.
1237  */
1238 
1239 int ata_sas_slave_configure(struct scsi_device *sdev, struct ata_port *ap)
1240 {
1241 	ata_scsi_sdev_config(sdev);
1242 	ata_scsi_dev_config(sdev, ap->link.device);
1243 	return 0;
1244 }
1245 EXPORT_SYMBOL_GPL(ata_sas_slave_configure);
1246 
1247 /**
1248  *	ata_sas_queuecmd - Issue SCSI cdb to libata-managed device
1249  *	@cmd: SCSI command to be sent
1250  *	@ap:	ATA port to which the command is being sent
1251  *
1252  *	RETURNS:
1253  *	Return value from __ata_scsi_queuecmd() if @cmd can be queued,
1254  *	0 otherwise.
1255  */
1256 
1257 int ata_sas_queuecmd(struct scsi_cmnd *cmd, struct ata_port *ap)
1258 {
1259 	int rc = 0;
1260 
1261 	if (likely(ata_dev_enabled(ap->link.device)))
1262 		rc = __ata_scsi_queuecmd(cmd, ap->link.device);
1263 	else {
1264 		cmd->result = (DID_BAD_TARGET << 16);
1265 		scsi_done(cmd);
1266 	}
1267 	return rc;
1268 }
1269 EXPORT_SYMBOL_GPL(ata_sas_queuecmd);
1270 
1271 /**
1272  *	sata_async_notification - SATA async notification handler
1273  *	@ap: ATA port where async notification is received
1274  *
1275  *	Handler to be called when async notification via SDB FIS is
1276  *	received.  This function schedules EH if necessary.
1277  *
1278  *	LOCKING:
1279  *	spin_lock_irqsave(host lock)
1280  *
1281  *	RETURNS:
1282  *	1 if EH is scheduled, 0 otherwise.
1283  */
1284 int sata_async_notification(struct ata_port *ap)
1285 {
1286 	u32 sntf;
1287 	int rc;
1288 
1289 	if (!(ap->flags & ATA_FLAG_AN))
1290 		return 0;
1291 
1292 	rc = sata_scr_read(&ap->link, SCR_NOTIFICATION, &sntf);
1293 	if (rc == 0)
1294 		sata_scr_write(&ap->link, SCR_NOTIFICATION, sntf);
1295 
1296 	if (!sata_pmp_attached(ap) || rc) {
1297 		/* PMP is not attached or SNTF is not available */
1298 		if (!sata_pmp_attached(ap)) {
1299 			/* PMP is not attached.  Check whether ATAPI
1300 			 * AN is configured.  If so, notify media
1301 			 * change.
1302 			 */
1303 			struct ata_device *dev = ap->link.device;
1304 
1305 			if ((dev->class == ATA_DEV_ATAPI) &&
1306 			    (dev->flags & ATA_DFLAG_AN))
1307 				ata_scsi_media_change_notify(dev);
1308 			return 0;
1309 		} else {
1310 			/* PMP is attached but SNTF is not available.
1311 			 * ATAPI async media change notification is
1312 			 * not used.  The PMP must be reporting PHY
1313 			 * status change, schedule EH.
1314 			 */
1315 			ata_port_schedule_eh(ap);
1316 			return 1;
1317 		}
1318 	} else {
1319 		/* PMP is attached and SNTF is available */
1320 		struct ata_link *link;
1321 
1322 		/* check and notify ATAPI AN */
1323 		ata_for_each_link(link, ap, EDGE) {
1324 			if (!(sntf & (1 << link->pmp)))
1325 				continue;
1326 
1327 			if ((link->device->class == ATA_DEV_ATAPI) &&
1328 			    (link->device->flags & ATA_DFLAG_AN))
1329 				ata_scsi_media_change_notify(link->device);
1330 		}
1331 
1332 		/* If PMP is reporting that PHY status of some
1333 		 * downstream ports has changed, schedule EH.
1334 		 */
1335 		if (sntf & (1 << SATA_PMP_CTRL_PORT)) {
1336 			ata_port_schedule_eh(ap);
1337 			return 1;
1338 		}
1339 
1340 		return 0;
1341 	}
1342 }
1343 EXPORT_SYMBOL_GPL(sata_async_notification);
1344 
1345 /**
1346  *	ata_eh_read_log_10h - Read log page 10h for NCQ error details
1347  *	@dev: Device to read log page 10h from
1348  *	@tag: Resulting tag of the failed command
1349  *	@tf: Resulting taskfile registers of the failed command
1350  *
1351  *	Read log page 10h to obtain NCQ error details and clear error
1352  *	condition.
1353  *
1354  *	LOCKING:
1355  *	Kernel thread context (may sleep).
1356  *
1357  *	RETURNS:
1358  *	0 on success, -errno otherwise.
1359  */
1360 static int ata_eh_read_log_10h(struct ata_device *dev,
1361 			       int *tag, struct ata_taskfile *tf)
1362 {
1363 	u8 *buf = dev->link->ap->sector_buf;
1364 	unsigned int err_mask;
1365 	u8 csum;
1366 	int i;
1367 
1368 	err_mask = ata_read_log_page(dev, ATA_LOG_SATA_NCQ, 0, buf, 1);
1369 	if (err_mask)
1370 		return -EIO;
1371 
1372 	csum = 0;
1373 	for (i = 0; i < ATA_SECT_SIZE; i++)
1374 		csum += buf[i];
1375 	if (csum)
1376 		ata_dev_warn(dev, "invalid checksum 0x%x on log page 10h\n",
1377 			     csum);
1378 
1379 	if (buf[0] & 0x80)
1380 		return -ENOENT;
1381 
1382 	*tag = buf[0] & 0x1f;
1383 
1384 	tf->status = buf[2];
1385 	tf->error = buf[3];
1386 	tf->lbal = buf[4];
1387 	tf->lbam = buf[5];
1388 	tf->lbah = buf[6];
1389 	tf->device = buf[7];
1390 	tf->hob_lbal = buf[8];
1391 	tf->hob_lbam = buf[9];
1392 	tf->hob_lbah = buf[10];
1393 	tf->nsect = buf[12];
1394 	tf->hob_nsect = buf[13];
1395 	if (ata_id_has_ncq_autosense(dev->id) && (tf->status & ATA_SENSE))
1396 		tf->auxiliary = buf[14] << 16 | buf[15] << 8 | buf[16];
1397 
1398 	return 0;
1399 }
1400 
1401 /**
1402  *	ata_eh_analyze_ncq_error - analyze NCQ error
1403  *	@link: ATA link to analyze NCQ error for
1404  *
1405  *	Read log page 10h, determine the offending qc and acquire
1406  *	error status TF.  For NCQ device errors, all LLDDs have to do
1407  *	is setting AC_ERR_DEV in ehi->err_mask.  This function takes
1408  *	care of the rest.
1409  *
1410  *	LOCKING:
1411  *	Kernel thread context (may sleep).
1412  */
1413 void ata_eh_analyze_ncq_error(struct ata_link *link)
1414 {
1415 	struct ata_port *ap = link->ap;
1416 	struct ata_eh_context *ehc = &link->eh_context;
1417 	struct ata_device *dev = link->device;
1418 	struct ata_queued_cmd *qc;
1419 	struct ata_taskfile tf;
1420 	int tag, rc;
1421 
1422 	/* if frozen, we can't do much */
1423 	if (ata_port_is_frozen(ap))
1424 		return;
1425 
1426 	/* is it NCQ device error? */
1427 	if (!link->sactive || !(ehc->i.err_mask & AC_ERR_DEV))
1428 		return;
1429 
1430 	/* has LLDD analyzed already? */
1431 	ata_qc_for_each_raw(ap, qc, tag) {
1432 		if (!(qc->flags & ATA_QCFLAG_FAILED))
1433 			continue;
1434 
1435 		if (qc->err_mask)
1436 			return;
1437 	}
1438 
1439 	/* okay, this error is ours */
1440 	memset(&tf, 0, sizeof(tf));
1441 	rc = ata_eh_read_log_10h(dev, &tag, &tf);
1442 	if (rc) {
1443 		ata_link_err(link, "failed to read log page 10h (errno=%d)\n",
1444 			     rc);
1445 		return;
1446 	}
1447 
1448 	if (!(link->sactive & (1 << tag))) {
1449 		ata_link_err(link, "log page 10h reported inactive tag %d\n",
1450 			     tag);
1451 		return;
1452 	}
1453 
1454 	/* we've got the perpetrator, condemn it */
1455 	qc = __ata_qc_from_tag(ap, tag);
1456 	memcpy(&qc->result_tf, &tf, sizeof(tf));
1457 	qc->result_tf.flags = ATA_TFLAG_ISADDR | ATA_TFLAG_LBA | ATA_TFLAG_LBA48;
1458 	qc->err_mask |= AC_ERR_DEV | AC_ERR_NCQ;
1459 
1460 	/*
1461 	 * If the device supports NCQ autosense, ata_eh_read_log_10h() will have
1462 	 * stored the sense data in qc->result_tf.auxiliary.
1463 	 */
1464 	if (qc->result_tf.auxiliary) {
1465 		char sense_key, asc, ascq;
1466 
1467 		sense_key = (qc->result_tf.auxiliary >> 16) & 0xff;
1468 		asc = (qc->result_tf.auxiliary >> 8) & 0xff;
1469 		ascq = qc->result_tf.auxiliary & 0xff;
1470 		if (ata_scsi_sense_is_valid(sense_key, asc, ascq)) {
1471 			ata_scsi_set_sense(dev, qc->scsicmd, sense_key, asc,
1472 					   ascq);
1473 			ata_scsi_set_sense_information(dev, qc->scsicmd,
1474 						       &qc->result_tf);
1475 			qc->flags |= ATA_QCFLAG_SENSE_VALID;
1476 		}
1477 	}
1478 
1479 	ata_qc_for_each_raw(ap, qc, tag) {
1480 		if (!(qc->flags & ATA_QCFLAG_FAILED) ||
1481 		    ata_dev_phys_link(qc->dev) != link)
1482 			continue;
1483 
1484 		/* Skip the single QC which caused the NCQ error. */
1485 		if (qc->err_mask)
1486 			continue;
1487 
1488 		/*
1489 		 * For SATA, the STATUS and ERROR fields are shared for all NCQ
1490 		 * commands that were completed with the same SDB FIS.
1491 		 * Therefore, we have to clear the ATA_ERR bit for all QCs
1492 		 * except the one that caused the NCQ error.
1493 		 */
1494 		qc->result_tf.status &= ~ATA_ERR;
1495 		qc->result_tf.error = 0;
1496 
1497 		/*
1498 		 * If we get a NCQ error, that means that a single command was
1499 		 * aborted. All other failed commands for our link should be
1500 		 * retried and has no business of going though further scrutiny
1501 		 * by ata_eh_link_autopsy().
1502 		 */
1503 		qc->flags |= ATA_QCFLAG_RETRY;
1504 	}
1505 
1506 	ehc->i.err_mask &= ~AC_ERR_DEV;
1507 }
1508 EXPORT_SYMBOL_GPL(ata_eh_analyze_ncq_error);
1509