xref: /openbmc/linux/drivers/ata/libata-pmp.c (revision b78412b8)
1 /*
2  * libata-pmp.c - libata port multiplier support
3  *
4  * Copyright (c) 2007  SUSE Linux Products GmbH
5  * Copyright (c) 2007  Tejun Heo <teheo@suse.de>
6  *
7  * This file is released under the GPLv2.
8  */
9 
10 #include <linux/kernel.h>
11 #include <linux/export.h>
12 #include <linux/libata.h>
13 #include <linux/slab.h>
14 #include "libata.h"
15 #include "libata-transport.h"
16 
17 const struct ata_port_operations sata_pmp_port_ops = {
18 	.inherits		= &sata_port_ops,
19 	.pmp_prereset		= ata_std_prereset,
20 	.pmp_hardreset		= sata_std_hardreset,
21 	.pmp_postreset		= ata_std_postreset,
22 	.error_handler		= sata_pmp_error_handler,
23 };
24 
25 /**
26  *	sata_pmp_read - read PMP register
27  *	@link: link to read PMP register for
28  *	@reg: register to read
29  *	@r_val: resulting value
30  *
31  *	Read PMP register.
32  *
33  *	LOCKING:
34  *	Kernel thread context (may sleep).
35  *
36  *	RETURNS:
37  *	0 on success, AC_ERR_* mask on failure.
38  */
39 static unsigned int sata_pmp_read(struct ata_link *link, int reg, u32 *r_val)
40 {
41 	struct ata_port *ap = link->ap;
42 	struct ata_device *pmp_dev = ap->link.device;
43 	struct ata_taskfile tf;
44 	unsigned int err_mask;
45 
46 	ata_tf_init(pmp_dev, &tf);
47 	tf.command = ATA_CMD_PMP_READ;
48 	tf.protocol = ATA_PROT_NODATA;
49 	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE | ATA_TFLAG_LBA48;
50 	tf.feature = reg;
51 	tf.device = link->pmp;
52 
53 	err_mask = ata_exec_internal(pmp_dev, &tf, NULL, DMA_NONE, NULL, 0,
54 				     SATA_PMP_RW_TIMEOUT);
55 	if (err_mask)
56 		return err_mask;
57 
58 	*r_val = tf.nsect | tf.lbal << 8 | tf.lbam << 16 | tf.lbah << 24;
59 	return 0;
60 }
61 
62 /**
63  *	sata_pmp_write - write PMP register
64  *	@link: link to write PMP register for
65  *	@reg: register to write
66  *	@r_val: value to write
67  *
68  *	Write PMP register.
69  *
70  *	LOCKING:
71  *	Kernel thread context (may sleep).
72  *
73  *	RETURNS:
74  *	0 on success, AC_ERR_* mask on failure.
75  */
76 static unsigned int sata_pmp_write(struct ata_link *link, int reg, u32 val)
77 {
78 	struct ata_port *ap = link->ap;
79 	struct ata_device *pmp_dev = ap->link.device;
80 	struct ata_taskfile tf;
81 
82 	ata_tf_init(pmp_dev, &tf);
83 	tf.command = ATA_CMD_PMP_WRITE;
84 	tf.protocol = ATA_PROT_NODATA;
85 	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE | ATA_TFLAG_LBA48;
86 	tf.feature = reg;
87 	tf.device = link->pmp;
88 	tf.nsect = val & 0xff;
89 	tf.lbal = (val >> 8) & 0xff;
90 	tf.lbam = (val >> 16) & 0xff;
91 	tf.lbah = (val >> 24) & 0xff;
92 
93 	return ata_exec_internal(pmp_dev, &tf, NULL, DMA_NONE, NULL, 0,
94 				 SATA_PMP_RW_TIMEOUT);
95 }
96 
97 /**
98  *	sata_pmp_qc_defer_cmd_switch - qc_defer for command switching PMP
99  *	@qc: ATA command in question
100  *
101  *	A host which has command switching PMP support cannot issue
102  *	commands to multiple links simultaneously.
103  *
104  *	LOCKING:
105  *	spin_lock_irqsave(host lock)
106  *
107  *	RETURNS:
108  *	ATA_DEFER_* if deferring is needed, 0 otherwise.
109  */
110 int sata_pmp_qc_defer_cmd_switch(struct ata_queued_cmd *qc)
111 {
112 	struct ata_link *link = qc->dev->link;
113 	struct ata_port *ap = link->ap;
114 
115 	if (ap->excl_link == NULL || ap->excl_link == link) {
116 		if (ap->nr_active_links == 0 || ata_link_active(link)) {
117 			qc->flags |= ATA_QCFLAG_CLEAR_EXCL;
118 			return ata_std_qc_defer(qc);
119 		}
120 
121 		ap->excl_link = link;
122 	}
123 
124 	return ATA_DEFER_PORT;
125 }
126 
127 /**
128  *	sata_pmp_scr_read - read PSCR
129  *	@link: ATA link to read PSCR for
130  *	@reg: PSCR to read
131  *	@r_val: resulting value
132  *
133  *	Read PSCR @reg into @r_val for @link, to be called from
134  *	ata_scr_read().
135  *
136  *	LOCKING:
137  *	Kernel thread context (may sleep).
138  *
139  *	RETURNS:
140  *	0 on success, -errno on failure.
141  */
142 int sata_pmp_scr_read(struct ata_link *link, int reg, u32 *r_val)
143 {
144 	unsigned int err_mask;
145 
146 	if (reg > SATA_PMP_PSCR_CONTROL)
147 		return -EINVAL;
148 
149 	err_mask = sata_pmp_read(link, reg, r_val);
150 	if (err_mask) {
151 		ata_link_warn(link, "failed to read SCR %d (Emask=0x%x)\n",
152 			      reg, err_mask);
153 		return -EIO;
154 	}
155 	return 0;
156 }
157 
158 /**
159  *	sata_pmp_scr_write - write PSCR
160  *	@link: ATA link to write PSCR for
161  *	@reg: PSCR to write
162  *	@val: value to be written
163  *
164  *	Write @val to PSCR @reg for @link, to be called from
165  *	ata_scr_write() and ata_scr_write_flush().
166  *
167  *	LOCKING:
168  *	Kernel thread context (may sleep).
169  *
170  *	RETURNS:
171  *	0 on success, -errno on failure.
172  */
173 int sata_pmp_scr_write(struct ata_link *link, int reg, u32 val)
174 {
175 	unsigned int err_mask;
176 
177 	if (reg > SATA_PMP_PSCR_CONTROL)
178 		return -EINVAL;
179 
180 	err_mask = sata_pmp_write(link, reg, val);
181 	if (err_mask) {
182 		ata_link_warn(link, "failed to write SCR %d (Emask=0x%x)\n",
183 			      reg, err_mask);
184 		return -EIO;
185 	}
186 	return 0;
187 }
188 
189 /**
190  *	sata_pmp_set_lpm - configure LPM for a PMP link
191  *	@link: PMP link to configure LPM for
192  *	@policy: target LPM policy
193  *	@hints: LPM hints
194  *
195  *	Configure LPM for @link.  This function will contain any PMP
196  *	specific workarounds if necessary.
197  *
198  *	LOCKING:
199  *	EH context.
200  *
201  *	RETURNS:
202  *	0 on success, -errno on failure.
203  */
204 int sata_pmp_set_lpm(struct ata_link *link, enum ata_lpm_policy policy,
205 		     unsigned hints)
206 {
207 	return sata_link_scr_lpm(link, policy, true);
208 }
209 
210 /**
211  *	sata_pmp_read_gscr - read GSCR block of SATA PMP
212  *	@dev: PMP device
213  *	@gscr: buffer to read GSCR block into
214  *
215  *	Read selected PMP GSCRs from the PMP at @dev.  This will serve
216  *	as configuration and identification info for the PMP.
217  *
218  *	LOCKING:
219  *	Kernel thread context (may sleep).
220  *
221  *	RETURNS:
222  *	0 on success, -errno on failure.
223  */
224 static int sata_pmp_read_gscr(struct ata_device *dev, u32 *gscr)
225 {
226 	static const int gscr_to_read[] = { 0, 1, 2, 32, 33, 64, 96 };
227 	int i;
228 
229 	for (i = 0; i < ARRAY_SIZE(gscr_to_read); i++) {
230 		int reg = gscr_to_read[i];
231 		unsigned int err_mask;
232 
233 		err_mask = sata_pmp_read(dev->link, reg, &gscr[reg]);
234 		if (err_mask) {
235 			ata_dev_err(dev, "failed to read PMP GSCR[%d] (Emask=0x%x)\n",
236 				    reg, err_mask);
237 			return -EIO;
238 		}
239 	}
240 
241 	return 0;
242 }
243 
244 static const char *sata_pmp_spec_rev_str(const u32 *gscr)
245 {
246 	u32 rev = gscr[SATA_PMP_GSCR_REV];
247 
248 	if (rev & (1 << 3))
249 		return "1.2";
250 	if (rev & (1 << 2))
251 		return "1.1";
252 	if (rev & (1 << 1))
253 		return "1.0";
254 	return "<unknown>";
255 }
256 
257 #define PMP_GSCR_SII_POL 129
258 
259 static int sata_pmp_configure(struct ata_device *dev, int print_info)
260 {
261 	struct ata_port *ap = dev->link->ap;
262 	u32 *gscr = dev->gscr;
263 	u16 vendor = sata_pmp_gscr_vendor(gscr);
264 	u16 devid = sata_pmp_gscr_devid(gscr);
265 	unsigned int err_mask = 0;
266 	const char *reason;
267 	int nr_ports, rc;
268 
269 	nr_ports = sata_pmp_gscr_ports(gscr);
270 
271 	if (nr_ports <= 0 || nr_ports > SATA_PMP_MAX_PORTS) {
272 		rc = -EINVAL;
273 		reason = "invalid nr_ports";
274 		goto fail;
275 	}
276 
277 	if ((ap->flags & ATA_FLAG_AN) &&
278 	    (gscr[SATA_PMP_GSCR_FEAT] & SATA_PMP_FEAT_NOTIFY))
279 		dev->flags |= ATA_DFLAG_AN;
280 
281 	/* monitor SERR_PHYRDY_CHG on fan-out ports */
282 	err_mask = sata_pmp_write(dev->link, SATA_PMP_GSCR_ERROR_EN,
283 				  SERR_PHYRDY_CHG);
284 	if (err_mask) {
285 		rc = -EIO;
286 		reason = "failed to write GSCR_ERROR_EN";
287 		goto fail;
288 	}
289 
290 	/* Disable sending Early R_OK.
291 	 * With "cached read" HDD testing and multiple ports busy on a SATA
292 	 * host controller, 3x26 PMP will very rarely drop a deferred
293 	 * R_OK that was intended for the host. Symptom will be all
294 	 * 5 drives under test will timeout, get reset, and recover.
295 	 */
296 	if (vendor == 0x1095 && (devid == 0x3726 || devid == 0x3826)) {
297 		u32 reg;
298 
299 		err_mask = sata_pmp_read(&ap->link, PMP_GSCR_SII_POL, &reg);
300 		if (err_mask) {
301 			rc = -EIO;
302 			reason = "failed to read Sil3x26 Private Register";
303 			goto fail;
304 		}
305 		reg &= ~0x1;
306 		err_mask = sata_pmp_write(&ap->link, PMP_GSCR_SII_POL, reg);
307 		if (err_mask) {
308 			rc = -EIO;
309 			reason = "failed to write Sil3x26 Private Register";
310 			goto fail;
311 		}
312 	}
313 
314 	if (print_info) {
315 		ata_dev_info(dev, "Port Multiplier %s, "
316 			     "0x%04x:0x%04x r%d, %d ports, feat 0x%x/0x%x\n",
317 			     sata_pmp_spec_rev_str(gscr), vendor, devid,
318 			     sata_pmp_gscr_rev(gscr),
319 			     nr_ports, gscr[SATA_PMP_GSCR_FEAT_EN],
320 			     gscr[SATA_PMP_GSCR_FEAT]);
321 
322 		if (!(dev->flags & ATA_DFLAG_AN))
323 			ata_dev_info(dev,
324 				"Asynchronous notification not supported, "
325 				"hotplug won't work on fan-out ports. Use warm-plug instead.\n");
326 	}
327 
328 	return 0;
329 
330  fail:
331 	ata_dev_err(dev,
332 		    "failed to configure Port Multiplier (%s, Emask=0x%x)\n",
333 		    reason, err_mask);
334 	return rc;
335 }
336 
337 static int sata_pmp_init_links (struct ata_port *ap, int nr_ports)
338 {
339 	struct ata_link *pmp_link = ap->pmp_link;
340 	int i, err;
341 
342 	if (!pmp_link) {
343 		pmp_link = kzalloc(sizeof(pmp_link[0]) * SATA_PMP_MAX_PORTS,
344 				   GFP_NOIO);
345 		if (!pmp_link)
346 			return -ENOMEM;
347 
348 		for (i = 0; i < SATA_PMP_MAX_PORTS; i++)
349 			ata_link_init(ap, &pmp_link[i], i);
350 
351 		ap->pmp_link = pmp_link;
352 
353 		for (i = 0; i < SATA_PMP_MAX_PORTS; i++) {
354 			err = ata_tlink_add(&pmp_link[i]);
355 			if (err) {
356 				goto err_tlink;
357 			}
358 		}
359 	}
360 
361 	for (i = 0; i < nr_ports; i++) {
362 		struct ata_link *link = &pmp_link[i];
363 		struct ata_eh_context *ehc = &link->eh_context;
364 
365 		link->flags = 0;
366 		ehc->i.probe_mask |= ATA_ALL_DEVICES;
367 		ehc->i.action |= ATA_EH_RESET;
368 	}
369 
370 	return 0;
371   err_tlink:
372 	while (--i >= 0)
373 		ata_tlink_delete(&pmp_link[i]);
374 	kfree(pmp_link);
375 	ap->pmp_link = NULL;
376 	return err;
377 }
378 
379 static void sata_pmp_quirks(struct ata_port *ap)
380 {
381 	u32 *gscr = ap->link.device->gscr;
382 	u16 vendor = sata_pmp_gscr_vendor(gscr);
383 	u16 devid = sata_pmp_gscr_devid(gscr);
384 	struct ata_link *link;
385 
386 	if (vendor == 0x1095 && (devid == 0x3726 || devid == 0x3826)) {
387 		/* sil3x26 quirks */
388 		ata_for_each_link(link, ap, EDGE) {
389 			/* link reports offline after LPM */
390 			link->flags |= ATA_LFLAG_NO_LPM;
391 
392 			/*
393 			 * Class code report is unreliable and SRST times
394 			 * out under certain configurations.
395 			 */
396 			if (link->pmp < 5)
397 				link->flags |= ATA_LFLAG_NO_SRST |
398 					       ATA_LFLAG_ASSUME_ATA;
399 
400 			/* port 5 is for SEMB device and it doesn't like SRST */
401 			if (link->pmp == 5)
402 				link->flags |= ATA_LFLAG_NO_SRST |
403 					       ATA_LFLAG_ASSUME_SEMB;
404 		}
405 	} else if (vendor == 0x1095 && devid == 0x4723) {
406 		/*
407 		 * sil4723 quirks
408 		 *
409 		 * Link reports offline after LPM.  Class code report is
410 		 * unreliable.  SIMG PMPs never got SRST reliable and the
411 		 * config device at port 2 locks up on SRST.
412 		 */
413 		ata_for_each_link(link, ap, EDGE)
414 			link->flags |= ATA_LFLAG_NO_LPM |
415 				       ATA_LFLAG_NO_SRST |
416 				       ATA_LFLAG_ASSUME_ATA;
417 	} else if (vendor == 0x1095 && devid == 0x4726) {
418 		/* sil4726 quirks */
419 		ata_for_each_link(link, ap, EDGE) {
420 			/* link reports offline after LPM */
421 			link->flags |= ATA_LFLAG_NO_LPM;
422 
423 			/* Class code report is unreliable and SRST
424 			 * times out under certain configurations.
425 			 * Config device can be at port 0 or 5 and
426 			 * locks up on SRST.
427 			 */
428 			if (link->pmp <= 5)
429 				link->flags |= ATA_LFLAG_NO_SRST |
430 					       ATA_LFLAG_ASSUME_ATA;
431 
432 			/* Port 6 is for SEMB device which doesn't
433 			 * like SRST either.
434 			 */
435 			if (link->pmp == 6)
436 				link->flags |= ATA_LFLAG_NO_SRST |
437 					       ATA_LFLAG_ASSUME_SEMB;
438 		}
439 	} else if (vendor == 0x1095 && (devid == 0x5723 || devid == 0x5733 ||
440 					devid == 0x5734 || devid == 0x5744)) {
441 		/* sil5723/5744 quirks */
442 
443 		/* sil5723/5744 has either two or three downstream
444 		 * ports depending on operation mode.  The last port
445 		 * is empty if any actual IO device is available or
446 		 * occupied by a pseudo configuration device
447 		 * otherwise.  Don't try hard to recover it.
448 		 */
449 		ap->pmp_link[ap->nr_pmp_links - 1].flags |= ATA_LFLAG_NO_RETRY;
450 	} else if (vendor == 0x197b && (devid == 0x2352 || devid == 0x0325)) {
451 		/*
452 		 * 0x2352: found in Thermaltake BlackX Duet, jmicron JMB350?
453 		 * 0x0325: jmicron JMB394.
454 		 */
455 		ata_for_each_link(link, ap, EDGE) {
456 			/* SRST breaks detection and disks get misclassified
457 			 * LPM disabled to avoid potential problems
458 			 */
459 			link->flags |= ATA_LFLAG_NO_LPM |
460 				       ATA_LFLAG_NO_SRST |
461 				       ATA_LFLAG_ASSUME_ATA;
462 		}
463 	} else if (vendor == 0x11ab && devid == 0x4140) {
464 		/* Marvell 4140 quirks */
465 		ata_for_each_link(link, ap, EDGE) {
466 			/* port 4 is for SEMB device and it doesn't like SRST */
467 			if (link->pmp == 4)
468 				link->flags |= ATA_LFLAG_DISABLED;
469 		}
470 	}
471 }
472 
473 /**
474  *	sata_pmp_attach - attach a SATA PMP device
475  *	@dev: SATA PMP device to attach
476  *
477  *	Configure and attach SATA PMP device @dev.  This function is
478  *	also responsible for allocating and initializing PMP links.
479  *
480  *	LOCKING:
481  *	Kernel thread context (may sleep).
482  *
483  *	RETURNS:
484  *	0 on success, -errno on failure.
485  */
486 int sata_pmp_attach(struct ata_device *dev)
487 {
488 	struct ata_link *link = dev->link;
489 	struct ata_port *ap = link->ap;
490 	unsigned long flags;
491 	struct ata_link *tlink;
492 	int rc;
493 
494 	/* is it hanging off the right place? */
495 	if (!sata_pmp_supported(ap)) {
496 		ata_dev_err(dev, "host does not support Port Multiplier\n");
497 		return -EINVAL;
498 	}
499 
500 	if (!ata_is_host_link(link)) {
501 		ata_dev_err(dev, "Port Multipliers cannot be nested\n");
502 		return -EINVAL;
503 	}
504 
505 	if (dev->devno) {
506 		ata_dev_err(dev, "Port Multiplier must be the first device\n");
507 		return -EINVAL;
508 	}
509 
510 	WARN_ON(link->pmp != 0);
511 	link->pmp = SATA_PMP_CTRL_PORT;
512 
513 	/* read GSCR block */
514 	rc = sata_pmp_read_gscr(dev, dev->gscr);
515 	if (rc)
516 		goto fail;
517 
518 	/* config PMP */
519 	rc = sata_pmp_configure(dev, 1);
520 	if (rc)
521 		goto fail;
522 
523 	rc = sata_pmp_init_links(ap, sata_pmp_gscr_ports(dev->gscr));
524 	if (rc) {
525 		ata_dev_info(dev, "failed to initialize PMP links\n");
526 		goto fail;
527 	}
528 
529 	/* attach it */
530 	spin_lock_irqsave(ap->lock, flags);
531 	WARN_ON(ap->nr_pmp_links);
532 	ap->nr_pmp_links = sata_pmp_gscr_ports(dev->gscr);
533 	spin_unlock_irqrestore(ap->lock, flags);
534 
535 	sata_pmp_quirks(ap);
536 
537 	if (ap->ops->pmp_attach)
538 		ap->ops->pmp_attach(ap);
539 
540 	ata_for_each_link(tlink, ap, EDGE)
541 		sata_link_init_spd(tlink);
542 
543 	return 0;
544 
545  fail:
546 	link->pmp = 0;
547 	return rc;
548 }
549 
550 /**
551  *	sata_pmp_detach - detach a SATA PMP device
552  *	@dev: SATA PMP device to detach
553  *
554  *	Detach SATA PMP device @dev.  This function is also
555  *	responsible for deconfiguring PMP links.
556  *
557  *	LOCKING:
558  *	Kernel thread context (may sleep).
559  */
560 static void sata_pmp_detach(struct ata_device *dev)
561 {
562 	struct ata_link *link = dev->link;
563 	struct ata_port *ap = link->ap;
564 	struct ata_link *tlink;
565 	unsigned long flags;
566 
567 	ata_dev_info(dev, "Port Multiplier detaching\n");
568 
569 	WARN_ON(!ata_is_host_link(link) || dev->devno ||
570 		link->pmp != SATA_PMP_CTRL_PORT);
571 
572 	if (ap->ops->pmp_detach)
573 		ap->ops->pmp_detach(ap);
574 
575 	ata_for_each_link(tlink, ap, EDGE)
576 		ata_eh_detach_dev(tlink->device);
577 
578 	spin_lock_irqsave(ap->lock, flags);
579 	ap->nr_pmp_links = 0;
580 	link->pmp = 0;
581 	spin_unlock_irqrestore(ap->lock, flags);
582 }
583 
584 /**
585  *	sata_pmp_same_pmp - does new GSCR matches the configured PMP?
586  *	@dev: PMP device to compare against
587  *	@new_gscr: GSCR block of the new device
588  *
589  *	Compare @new_gscr against @dev and determine whether @dev is
590  *	the PMP described by @new_gscr.
591  *
592  *	LOCKING:
593  *	None.
594  *
595  *	RETURNS:
596  *	1 if @dev matches @new_gscr, 0 otherwise.
597  */
598 static int sata_pmp_same_pmp(struct ata_device *dev, const u32 *new_gscr)
599 {
600 	const u32 *old_gscr = dev->gscr;
601 	u16 old_vendor, new_vendor, old_devid, new_devid;
602 	int old_nr_ports, new_nr_ports;
603 
604 	old_vendor = sata_pmp_gscr_vendor(old_gscr);
605 	new_vendor = sata_pmp_gscr_vendor(new_gscr);
606 	old_devid = sata_pmp_gscr_devid(old_gscr);
607 	new_devid = sata_pmp_gscr_devid(new_gscr);
608 	old_nr_ports = sata_pmp_gscr_ports(old_gscr);
609 	new_nr_ports = sata_pmp_gscr_ports(new_gscr);
610 
611 	if (old_vendor != new_vendor) {
612 		ata_dev_info(dev,
613 			     "Port Multiplier vendor mismatch '0x%x' != '0x%x'\n",
614 			     old_vendor, new_vendor);
615 		return 0;
616 	}
617 
618 	if (old_devid != new_devid) {
619 		ata_dev_info(dev,
620 			     "Port Multiplier device ID mismatch '0x%x' != '0x%x'\n",
621 			     old_devid, new_devid);
622 		return 0;
623 	}
624 
625 	if (old_nr_ports != new_nr_ports) {
626 		ata_dev_info(dev,
627 			     "Port Multiplier nr_ports mismatch '0x%x' != '0x%x'\n",
628 			     old_nr_ports, new_nr_ports);
629 		return 0;
630 	}
631 
632 	return 1;
633 }
634 
635 /**
636  *	sata_pmp_revalidate - revalidate SATA PMP
637  *	@dev: PMP device to revalidate
638  *	@new_class: new class code
639  *
640  *	Re-read GSCR block and make sure @dev is still attached to the
641  *	port and properly configured.
642  *
643  *	LOCKING:
644  *	Kernel thread context (may sleep).
645  *
646  *	RETURNS:
647  *	0 on success, -errno otherwise.
648  */
649 static int sata_pmp_revalidate(struct ata_device *dev, unsigned int new_class)
650 {
651 	struct ata_link *link = dev->link;
652 	struct ata_port *ap = link->ap;
653 	u32 *gscr = (void *)ap->sector_buf;
654 	int rc;
655 
656 	DPRINTK("ENTER\n");
657 
658 	ata_eh_about_to_do(link, NULL, ATA_EH_REVALIDATE);
659 
660 	if (!ata_dev_enabled(dev)) {
661 		rc = -ENODEV;
662 		goto fail;
663 	}
664 
665 	/* wrong class? */
666 	if (ata_class_enabled(new_class) && new_class != ATA_DEV_PMP) {
667 		rc = -ENODEV;
668 		goto fail;
669 	}
670 
671 	/* read GSCR */
672 	rc = sata_pmp_read_gscr(dev, gscr);
673 	if (rc)
674 		goto fail;
675 
676 	/* is the pmp still there? */
677 	if (!sata_pmp_same_pmp(dev, gscr)) {
678 		rc = -ENODEV;
679 		goto fail;
680 	}
681 
682 	memcpy(dev->gscr, gscr, sizeof(gscr[0]) * SATA_PMP_GSCR_DWORDS);
683 
684 	rc = sata_pmp_configure(dev, 0);
685 	if (rc)
686 		goto fail;
687 
688 	ata_eh_done(link, NULL, ATA_EH_REVALIDATE);
689 
690 	DPRINTK("EXIT, rc=0\n");
691 	return 0;
692 
693  fail:
694 	ata_dev_err(dev, "PMP revalidation failed (errno=%d)\n", rc);
695 	DPRINTK("EXIT, rc=%d\n", rc);
696 	return rc;
697 }
698 
699 /**
700  *	sata_pmp_revalidate_quick - revalidate SATA PMP quickly
701  *	@dev: PMP device to revalidate
702  *
703  *	Make sure the attached PMP is accessible.
704  *
705  *	LOCKING:
706  *	Kernel thread context (may sleep).
707  *
708  *	RETURNS:
709  *	0 on success, -errno otherwise.
710  */
711 static int sata_pmp_revalidate_quick(struct ata_device *dev)
712 {
713 	unsigned int err_mask;
714 	u32 prod_id;
715 
716 	err_mask = sata_pmp_read(dev->link, SATA_PMP_GSCR_PROD_ID, &prod_id);
717 	if (err_mask) {
718 		ata_dev_err(dev,
719 			    "failed to read PMP product ID (Emask=0x%x)\n",
720 			    err_mask);
721 		return -EIO;
722 	}
723 
724 	if (prod_id != dev->gscr[SATA_PMP_GSCR_PROD_ID]) {
725 		ata_dev_err(dev, "PMP product ID mismatch\n");
726 		/* something weird is going on, request full PMP recovery */
727 		return -EIO;
728 	}
729 
730 	return 0;
731 }
732 
733 /**
734  *	sata_pmp_eh_recover_pmp - recover PMP
735  *	@ap: ATA port PMP is attached to
736  *	@prereset: prereset method (can be NULL)
737  *	@softreset: softreset method
738  *	@hardreset: hardreset method
739  *	@postreset: postreset method (can be NULL)
740  *
741  *	Recover PMP attached to @ap.  Recovery procedure is somewhat
742  *	similar to that of ata_eh_recover() except that reset should
743  *	always be performed in hard->soft sequence and recovery
744  *	failure results in PMP detachment.
745  *
746  *	LOCKING:
747  *	Kernel thread context (may sleep).
748  *
749  *	RETURNS:
750  *	0 on success, -errno on failure.
751  */
752 static int sata_pmp_eh_recover_pmp(struct ata_port *ap,
753 		ata_prereset_fn_t prereset, ata_reset_fn_t softreset,
754 		ata_reset_fn_t hardreset, ata_postreset_fn_t postreset)
755 {
756 	struct ata_link *link = &ap->link;
757 	struct ata_eh_context *ehc = &link->eh_context;
758 	struct ata_device *dev = link->device;
759 	int tries = ATA_EH_PMP_TRIES;
760 	int detach = 0, rc = 0;
761 	int reval_failed = 0;
762 
763 	DPRINTK("ENTER\n");
764 
765 	if (dev->flags & ATA_DFLAG_DETACH) {
766 		detach = 1;
767 		goto fail;
768 	}
769 
770  retry:
771 	ehc->classes[0] = ATA_DEV_UNKNOWN;
772 
773 	if (ehc->i.action & ATA_EH_RESET) {
774 		struct ata_link *tlink;
775 
776 		/* reset */
777 		rc = ata_eh_reset(link, 0, prereset, softreset, hardreset,
778 				  postreset);
779 		if (rc) {
780 			ata_link_err(link, "failed to reset PMP, giving up\n");
781 			goto fail;
782 		}
783 
784 		/* PMP is reset, SErrors cannot be trusted, scan all */
785 		ata_for_each_link(tlink, ap, EDGE) {
786 			struct ata_eh_context *ehc = &tlink->eh_context;
787 
788 			ehc->i.probe_mask |= ATA_ALL_DEVICES;
789 			ehc->i.action |= ATA_EH_RESET;
790 		}
791 	}
792 
793 	/* If revalidation is requested, revalidate and reconfigure;
794 	 * otherwise, do quick revalidation.
795 	 */
796 	if (ehc->i.action & ATA_EH_REVALIDATE)
797 		rc = sata_pmp_revalidate(dev, ehc->classes[0]);
798 	else
799 		rc = sata_pmp_revalidate_quick(dev);
800 
801 	if (rc) {
802 		tries--;
803 
804 		if (rc == -ENODEV) {
805 			ehc->i.probe_mask |= ATA_ALL_DEVICES;
806 			detach = 1;
807 			/* give it just two more chances */
808 			tries = min(tries, 2);
809 		}
810 
811 		if (tries) {
812 			/* consecutive revalidation failures? speed down */
813 			if (reval_failed)
814 				sata_down_spd_limit(link, 0);
815 			else
816 				reval_failed = 1;
817 
818 			ehc->i.action |= ATA_EH_RESET;
819 			goto retry;
820 		} else {
821 			ata_dev_err(dev,
822 				    "failed to recover PMP after %d tries, giving up\n",
823 				    ATA_EH_PMP_TRIES);
824 			goto fail;
825 		}
826 	}
827 
828 	/* okay, PMP resurrected */
829 	ehc->i.flags = 0;
830 
831 	DPRINTK("EXIT, rc=0\n");
832 	return 0;
833 
834  fail:
835 	sata_pmp_detach(dev);
836 	if (detach)
837 		ata_eh_detach_dev(dev);
838 	else
839 		ata_dev_disable(dev);
840 
841 	DPRINTK("EXIT, rc=%d\n", rc);
842 	return rc;
843 }
844 
845 static int sata_pmp_eh_handle_disabled_links(struct ata_port *ap)
846 {
847 	struct ata_link *link;
848 	unsigned long flags;
849 	int rc;
850 
851 	spin_lock_irqsave(ap->lock, flags);
852 
853 	ata_for_each_link(link, ap, EDGE) {
854 		if (!(link->flags & ATA_LFLAG_DISABLED))
855 			continue;
856 
857 		spin_unlock_irqrestore(ap->lock, flags);
858 
859 		/* Some PMPs require hardreset sequence to get
860 		 * SError.N working.
861 		 */
862 		sata_link_hardreset(link, sata_deb_timing_normal,
863 				ata_deadline(jiffies, ATA_TMOUT_INTERNAL_QUICK),
864 				NULL, NULL);
865 
866 		/* unconditionally clear SError.N */
867 		rc = sata_scr_write(link, SCR_ERROR, SERR_PHYRDY_CHG);
868 		if (rc) {
869 			ata_link_err(link,
870 				     "failed to clear SError.N (errno=%d)\n",
871 				     rc);
872 			return rc;
873 		}
874 
875 		spin_lock_irqsave(ap->lock, flags);
876 	}
877 
878 	spin_unlock_irqrestore(ap->lock, flags);
879 
880 	return 0;
881 }
882 
883 static int sata_pmp_handle_link_fail(struct ata_link *link, int *link_tries)
884 {
885 	struct ata_port *ap = link->ap;
886 	unsigned long flags;
887 
888 	if (link_tries[link->pmp] && --link_tries[link->pmp])
889 		return 1;
890 
891 	/* disable this link */
892 	if (!(link->flags & ATA_LFLAG_DISABLED)) {
893 		ata_link_warn(link,
894 			"failed to recover link after %d tries, disabling\n",
895 			ATA_EH_PMP_LINK_TRIES);
896 
897 		spin_lock_irqsave(ap->lock, flags);
898 		link->flags |= ATA_LFLAG_DISABLED;
899 		spin_unlock_irqrestore(ap->lock, flags);
900 	}
901 
902 	ata_dev_disable(link->device);
903 	link->eh_context.i.action = 0;
904 
905 	return 0;
906 }
907 
908 /**
909  *	sata_pmp_eh_recover - recover PMP-enabled port
910  *	@ap: ATA port to recover
911  *
912  *	Drive EH recovery operation for PMP enabled port @ap.  This
913  *	function recovers host and PMP ports with proper retrials and
914  *	fallbacks.  Actual recovery operations are performed using
915  *	ata_eh_recover() and sata_pmp_eh_recover_pmp().
916  *
917  *	LOCKING:
918  *	Kernel thread context (may sleep).
919  *
920  *	RETURNS:
921  *	0 on success, -errno on failure.
922  */
923 static int sata_pmp_eh_recover(struct ata_port *ap)
924 {
925 	struct ata_port_operations *ops = ap->ops;
926 	int pmp_tries, link_tries[SATA_PMP_MAX_PORTS];
927 	struct ata_link *pmp_link = &ap->link;
928 	struct ata_device *pmp_dev = pmp_link->device;
929 	struct ata_eh_context *pmp_ehc = &pmp_link->eh_context;
930 	u32 *gscr = pmp_dev->gscr;
931 	struct ata_link *link;
932 	struct ata_device *dev;
933 	unsigned int err_mask;
934 	u32 gscr_error, sntf;
935 	int cnt, rc;
936 
937 	pmp_tries = ATA_EH_PMP_TRIES;
938 	ata_for_each_link(link, ap, EDGE)
939 		link_tries[link->pmp] = ATA_EH_PMP_LINK_TRIES;
940 
941  retry:
942 	/* PMP attached? */
943 	if (!sata_pmp_attached(ap)) {
944 		rc = ata_eh_recover(ap, ops->prereset, ops->softreset,
945 				    ops->hardreset, ops->postreset, NULL);
946 		if (rc) {
947 			ata_for_each_dev(dev, &ap->link, ALL)
948 				ata_dev_disable(dev);
949 			return rc;
950 		}
951 
952 		if (pmp_dev->class != ATA_DEV_PMP)
953 			return 0;
954 
955 		/* new PMP online */
956 		ata_for_each_link(link, ap, EDGE)
957 			link_tries[link->pmp] = ATA_EH_PMP_LINK_TRIES;
958 
959 		/* fall through */
960 	}
961 
962 	/* recover pmp */
963 	rc = sata_pmp_eh_recover_pmp(ap, ops->prereset, ops->softreset,
964 				     ops->hardreset, ops->postreset);
965 	if (rc)
966 		goto pmp_fail;
967 
968 	/* PHY event notification can disturb reset and other recovery
969 	 * operations.  Turn it off.
970 	 */
971 	if (gscr[SATA_PMP_GSCR_FEAT_EN] & SATA_PMP_FEAT_NOTIFY) {
972 		gscr[SATA_PMP_GSCR_FEAT_EN] &= ~SATA_PMP_FEAT_NOTIFY;
973 
974 		err_mask = sata_pmp_write(pmp_link, SATA_PMP_GSCR_FEAT_EN,
975 					  gscr[SATA_PMP_GSCR_FEAT_EN]);
976 		if (err_mask) {
977 			ata_link_warn(pmp_link,
978 				"failed to disable NOTIFY (err_mask=0x%x)\n",
979 				err_mask);
980 			goto pmp_fail;
981 		}
982 	}
983 
984 	/* handle disabled links */
985 	rc = sata_pmp_eh_handle_disabled_links(ap);
986 	if (rc)
987 		goto pmp_fail;
988 
989 	/* recover links */
990 	rc = ata_eh_recover(ap, ops->pmp_prereset, ops->pmp_softreset,
991 			    ops->pmp_hardreset, ops->pmp_postreset, &link);
992 	if (rc)
993 		goto link_fail;
994 
995 	/* clear SNotification */
996 	rc = sata_scr_read(&ap->link, SCR_NOTIFICATION, &sntf);
997 	if (rc == 0)
998 		sata_scr_write(&ap->link, SCR_NOTIFICATION, sntf);
999 
1000 	/*
1001 	 * If LPM is active on any fan-out port, hotplug wouldn't
1002 	 * work.  Return w/ PHY event notification disabled.
1003 	 */
1004 	ata_for_each_link(link, ap, EDGE)
1005 		if (link->lpm_policy > ATA_LPM_MAX_POWER)
1006 			return 0;
1007 
1008 	/*
1009 	 * Connection status might have changed while resetting other
1010 	 * links, enable notification and check SATA_PMP_GSCR_ERROR
1011 	 * before returning.
1012 	 */
1013 
1014 	/* enable notification */
1015 	if (pmp_dev->flags & ATA_DFLAG_AN) {
1016 		gscr[SATA_PMP_GSCR_FEAT_EN] |= SATA_PMP_FEAT_NOTIFY;
1017 
1018 		err_mask = sata_pmp_write(pmp_link, SATA_PMP_GSCR_FEAT_EN,
1019 					  gscr[SATA_PMP_GSCR_FEAT_EN]);
1020 		if (err_mask) {
1021 			ata_dev_err(pmp_dev,
1022 				    "failed to write PMP_FEAT_EN (Emask=0x%x)\n",
1023 				    err_mask);
1024 			rc = -EIO;
1025 			goto pmp_fail;
1026 		}
1027 	}
1028 
1029 	/* check GSCR_ERROR */
1030 	err_mask = sata_pmp_read(pmp_link, SATA_PMP_GSCR_ERROR, &gscr_error);
1031 	if (err_mask) {
1032 		ata_dev_err(pmp_dev,
1033 			    "failed to read PMP_GSCR_ERROR (Emask=0x%x)\n",
1034 			    err_mask);
1035 		rc = -EIO;
1036 		goto pmp_fail;
1037 	}
1038 
1039 	cnt = 0;
1040 	ata_for_each_link(link, ap, EDGE) {
1041 		if (!(gscr_error & (1 << link->pmp)))
1042 			continue;
1043 
1044 		if (sata_pmp_handle_link_fail(link, link_tries)) {
1045 			ata_ehi_hotplugged(&link->eh_context.i);
1046 			cnt++;
1047 		} else {
1048 			ata_link_warn(link,
1049 				"PHY status changed but maxed out on retries, giving up\n");
1050 			ata_link_warn(link,
1051 				"Manually issue scan to resume this link\n");
1052 		}
1053 	}
1054 
1055 	if (cnt) {
1056 		ata_port_info(ap,
1057 			"PMP SError.N set for some ports, repeating recovery\n");
1058 		goto retry;
1059 	}
1060 
1061 	return 0;
1062 
1063  link_fail:
1064 	if (sata_pmp_handle_link_fail(link, link_tries)) {
1065 		pmp_ehc->i.action |= ATA_EH_RESET;
1066 		goto retry;
1067 	}
1068 
1069 	/* fall through */
1070  pmp_fail:
1071 	/* Control always ends up here after detaching PMP.  Shut up
1072 	 * and return if we're unloading.
1073 	 */
1074 	if (ap->pflags & ATA_PFLAG_UNLOADING)
1075 		return rc;
1076 
1077 	if (!sata_pmp_attached(ap))
1078 		goto retry;
1079 
1080 	if (--pmp_tries) {
1081 		pmp_ehc->i.action |= ATA_EH_RESET;
1082 		goto retry;
1083 	}
1084 
1085 	ata_port_err(ap, "failed to recover PMP after %d tries, giving up\n",
1086 		     ATA_EH_PMP_TRIES);
1087 	sata_pmp_detach(pmp_dev);
1088 	ata_dev_disable(pmp_dev);
1089 
1090 	return rc;
1091 }
1092 
1093 /**
1094  *	sata_pmp_error_handler - do standard error handling for PMP-enabled host
1095  *	@ap: host port to handle error for
1096  *
1097  *	Perform standard error handling sequence for PMP-enabled host
1098  *	@ap.
1099  *
1100  *	LOCKING:
1101  *	Kernel thread context (may sleep).
1102  */
1103 void sata_pmp_error_handler(struct ata_port *ap)
1104 {
1105 	ata_eh_autopsy(ap);
1106 	ata_eh_report(ap);
1107 	sata_pmp_eh_recover(ap);
1108 	ata_eh_finish(ap);
1109 }
1110 
1111 EXPORT_SYMBOL_GPL(sata_pmp_port_ops);
1112 EXPORT_SYMBOL_GPL(sata_pmp_qc_defer_cmd_switch);
1113 EXPORT_SYMBOL_GPL(sata_pmp_error_handler);
1114