xref: /linux/drivers/ata/libata-pmp.c (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
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, 3726 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) {
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 Sil3726 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 Sil3726 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) {
387 		/* sil3726 quirks */
388 		ata_for_each_link(link, ap, EDGE) {
389 			/* link reports offline after LPM */
390 			link->flags |= ATA_LFLAG_NO_LPM;
391 
392 			/* Class code report is unreliable. */
393 			if (link->pmp < 5)
394 				link->flags |= ATA_LFLAG_ASSUME_ATA;
395 
396 			/* port 5 is for SEMB device and it doesn't like SRST */
397 			if (link->pmp == 5)
398 				link->flags |= ATA_LFLAG_NO_SRST |
399 					       ATA_LFLAG_ASSUME_SEMB;
400 		}
401 	} else if (vendor == 0x1095 && devid == 0x4723) {
402 		/* sil4723 quirks */
403 		ata_for_each_link(link, ap, EDGE) {
404 			/* link reports offline after LPM */
405 			link->flags |= ATA_LFLAG_NO_LPM;
406 
407 			/* class code report is unreliable */
408 			if (link->pmp < 2)
409 				link->flags |= ATA_LFLAG_ASSUME_ATA;
410 
411 			/* the config device at port 2 locks up on SRST */
412 			if (link->pmp == 2)
413 				link->flags |= ATA_LFLAG_NO_SRST |
414 					       ATA_LFLAG_ASSUME_ATA;
415 		}
416 	} else if (vendor == 0x1095 && devid == 0x4726) {
417 		/* sil4726 quirks */
418 		ata_for_each_link(link, ap, EDGE) {
419 			/* link reports offline after LPM */
420 			link->flags |= ATA_LFLAG_NO_LPM;
421 
422 			/* Class code report is unreliable and SRST
423 			 * times out under certain configurations.
424 			 * Config device can be at port 0 or 5 and
425 			 * locks up on SRST.
426 			 */
427 			if (link->pmp <= 5)
428 				link->flags |= ATA_LFLAG_NO_SRST |
429 					       ATA_LFLAG_ASSUME_ATA;
430 
431 			/* Port 6 is for SEMB device which doesn't
432 			 * like SRST either.
433 			 */
434 			if (link->pmp == 6)
435 				link->flags |= ATA_LFLAG_NO_SRST |
436 					       ATA_LFLAG_ASSUME_SEMB;
437 		}
438 	} else if (vendor == 0x1095 && (devid == 0x5723 || devid == 0x5733 ||
439 					devid == 0x5734 || devid == 0x5744)) {
440 		/* sil5723/5744 quirks */
441 
442 		/* sil5723/5744 has either two or three downstream
443 		 * ports depending on operation mode.  The last port
444 		 * is empty if any actual IO device is available or
445 		 * occupied by a pseudo configuration device
446 		 * otherwise.  Don't try hard to recover it.
447 		 */
448 		ap->pmp_link[ap->nr_pmp_links - 1].flags |= ATA_LFLAG_NO_RETRY;
449 	} else if (vendor == 0x197b && devid == 0x2352) {
450 		/* chip found in Thermaltake BlackX Duet, jmicron JMB350? */
451 		ata_for_each_link(link, ap, EDGE) {
452 			/* SRST breaks detection and disks get misclassified
453 			 * LPM disabled to avoid potential problems
454 			 */
455 			link->flags |= ATA_LFLAG_NO_LPM |
456 				       ATA_LFLAG_NO_SRST |
457 				       ATA_LFLAG_ASSUME_ATA;
458 		}
459 	}
460 }
461 
462 /**
463  *	sata_pmp_attach - attach a SATA PMP device
464  *	@dev: SATA PMP device to attach
465  *
466  *	Configure and attach SATA PMP device @dev.  This function is
467  *	also responsible for allocating and initializing PMP links.
468  *
469  *	LOCKING:
470  *	Kernel thread context (may sleep).
471  *
472  *	RETURNS:
473  *	0 on success, -errno on failure.
474  */
475 int sata_pmp_attach(struct ata_device *dev)
476 {
477 	struct ata_link *link = dev->link;
478 	struct ata_port *ap = link->ap;
479 	unsigned long flags;
480 	struct ata_link *tlink;
481 	int rc;
482 
483 	/* is it hanging off the right place? */
484 	if (!sata_pmp_supported(ap)) {
485 		ata_dev_err(dev, "host does not support Port Multiplier\n");
486 		return -EINVAL;
487 	}
488 
489 	if (!ata_is_host_link(link)) {
490 		ata_dev_err(dev, "Port Multipliers cannot be nested\n");
491 		return -EINVAL;
492 	}
493 
494 	if (dev->devno) {
495 		ata_dev_err(dev, "Port Multiplier must be the first device\n");
496 		return -EINVAL;
497 	}
498 
499 	WARN_ON(link->pmp != 0);
500 	link->pmp = SATA_PMP_CTRL_PORT;
501 
502 	/* read GSCR block */
503 	rc = sata_pmp_read_gscr(dev, dev->gscr);
504 	if (rc)
505 		goto fail;
506 
507 	/* config PMP */
508 	rc = sata_pmp_configure(dev, 1);
509 	if (rc)
510 		goto fail;
511 
512 	rc = sata_pmp_init_links(ap, sata_pmp_gscr_ports(dev->gscr));
513 	if (rc) {
514 		ata_dev_info(dev, "failed to initialize PMP links\n");
515 		goto fail;
516 	}
517 
518 	/* attach it */
519 	spin_lock_irqsave(ap->lock, flags);
520 	WARN_ON(ap->nr_pmp_links);
521 	ap->nr_pmp_links = sata_pmp_gscr_ports(dev->gscr);
522 	spin_unlock_irqrestore(ap->lock, flags);
523 
524 	sata_pmp_quirks(ap);
525 
526 	if (ap->ops->pmp_attach)
527 		ap->ops->pmp_attach(ap);
528 
529 	ata_for_each_link(tlink, ap, EDGE)
530 		sata_link_init_spd(tlink);
531 
532 	return 0;
533 
534  fail:
535 	link->pmp = 0;
536 	return rc;
537 }
538 
539 /**
540  *	sata_pmp_detach - detach a SATA PMP device
541  *	@dev: SATA PMP device to detach
542  *
543  *	Detach SATA PMP device @dev.  This function is also
544  *	responsible for deconfiguring PMP links.
545  *
546  *	LOCKING:
547  *	Kernel thread context (may sleep).
548  */
549 static void sata_pmp_detach(struct ata_device *dev)
550 {
551 	struct ata_link *link = dev->link;
552 	struct ata_port *ap = link->ap;
553 	struct ata_link *tlink;
554 	unsigned long flags;
555 
556 	ata_dev_info(dev, "Port Multiplier detaching\n");
557 
558 	WARN_ON(!ata_is_host_link(link) || dev->devno ||
559 		link->pmp != SATA_PMP_CTRL_PORT);
560 
561 	if (ap->ops->pmp_detach)
562 		ap->ops->pmp_detach(ap);
563 
564 	ata_for_each_link(tlink, ap, EDGE)
565 		ata_eh_detach_dev(tlink->device);
566 
567 	spin_lock_irqsave(ap->lock, flags);
568 	ap->nr_pmp_links = 0;
569 	link->pmp = 0;
570 	spin_unlock_irqrestore(ap->lock, flags);
571 }
572 
573 /**
574  *	sata_pmp_same_pmp - does new GSCR matches the configured PMP?
575  *	@dev: PMP device to compare against
576  *	@new_gscr: GSCR block of the new device
577  *
578  *	Compare @new_gscr against @dev and determine whether @dev is
579  *	the PMP described by @new_gscr.
580  *
581  *	LOCKING:
582  *	None.
583  *
584  *	RETURNS:
585  *	1 if @dev matches @new_gscr, 0 otherwise.
586  */
587 static int sata_pmp_same_pmp(struct ata_device *dev, const u32 *new_gscr)
588 {
589 	const u32 *old_gscr = dev->gscr;
590 	u16 old_vendor, new_vendor, old_devid, new_devid;
591 	int old_nr_ports, new_nr_ports;
592 
593 	old_vendor = sata_pmp_gscr_vendor(old_gscr);
594 	new_vendor = sata_pmp_gscr_vendor(new_gscr);
595 	old_devid = sata_pmp_gscr_devid(old_gscr);
596 	new_devid = sata_pmp_gscr_devid(new_gscr);
597 	old_nr_ports = sata_pmp_gscr_ports(old_gscr);
598 	new_nr_ports = sata_pmp_gscr_ports(new_gscr);
599 
600 	if (old_vendor != new_vendor) {
601 		ata_dev_info(dev,
602 			     "Port Multiplier vendor mismatch '0x%x' != '0x%x'\n",
603 			     old_vendor, new_vendor);
604 		return 0;
605 	}
606 
607 	if (old_devid != new_devid) {
608 		ata_dev_info(dev,
609 			     "Port Multiplier device ID mismatch '0x%x' != '0x%x'\n",
610 			     old_devid, new_devid);
611 		return 0;
612 	}
613 
614 	if (old_nr_ports != new_nr_ports) {
615 		ata_dev_info(dev,
616 			     "Port Multiplier nr_ports mismatch '0x%x' != '0x%x'\n",
617 			     old_nr_ports, new_nr_ports);
618 		return 0;
619 	}
620 
621 	return 1;
622 }
623 
624 /**
625  *	sata_pmp_revalidate - revalidate SATA PMP
626  *	@dev: PMP device to revalidate
627  *	@new_class: new class code
628  *
629  *	Re-read GSCR block and make sure @dev is still attached to the
630  *	port and properly configured.
631  *
632  *	LOCKING:
633  *	Kernel thread context (may sleep).
634  *
635  *	RETURNS:
636  *	0 on success, -errno otherwise.
637  */
638 static int sata_pmp_revalidate(struct ata_device *dev, unsigned int new_class)
639 {
640 	struct ata_link *link = dev->link;
641 	struct ata_port *ap = link->ap;
642 	u32 *gscr = (void *)ap->sector_buf;
643 	int rc;
644 
645 	DPRINTK("ENTER\n");
646 
647 	ata_eh_about_to_do(link, NULL, ATA_EH_REVALIDATE);
648 
649 	if (!ata_dev_enabled(dev)) {
650 		rc = -ENODEV;
651 		goto fail;
652 	}
653 
654 	/* wrong class? */
655 	if (ata_class_enabled(new_class) && new_class != ATA_DEV_PMP) {
656 		rc = -ENODEV;
657 		goto fail;
658 	}
659 
660 	/* read GSCR */
661 	rc = sata_pmp_read_gscr(dev, gscr);
662 	if (rc)
663 		goto fail;
664 
665 	/* is the pmp still there? */
666 	if (!sata_pmp_same_pmp(dev, gscr)) {
667 		rc = -ENODEV;
668 		goto fail;
669 	}
670 
671 	memcpy(dev->gscr, gscr, sizeof(gscr[0]) * SATA_PMP_GSCR_DWORDS);
672 
673 	rc = sata_pmp_configure(dev, 0);
674 	if (rc)
675 		goto fail;
676 
677 	ata_eh_done(link, NULL, ATA_EH_REVALIDATE);
678 
679 	DPRINTK("EXIT, rc=0\n");
680 	return 0;
681 
682  fail:
683 	ata_dev_err(dev, "PMP revalidation failed (errno=%d)\n", rc);
684 	DPRINTK("EXIT, rc=%d\n", rc);
685 	return rc;
686 }
687 
688 /**
689  *	sata_pmp_revalidate_quick - revalidate SATA PMP quickly
690  *	@dev: PMP device to revalidate
691  *
692  *	Make sure the attached PMP is accessible.
693  *
694  *	LOCKING:
695  *	Kernel thread context (may sleep).
696  *
697  *	RETURNS:
698  *	0 on success, -errno otherwise.
699  */
700 static int sata_pmp_revalidate_quick(struct ata_device *dev)
701 {
702 	unsigned int err_mask;
703 	u32 prod_id;
704 
705 	err_mask = sata_pmp_read(dev->link, SATA_PMP_GSCR_PROD_ID, &prod_id);
706 	if (err_mask) {
707 		ata_dev_err(dev,
708 			    "failed to read PMP product ID (Emask=0x%x)\n",
709 			    err_mask);
710 		return -EIO;
711 	}
712 
713 	if (prod_id != dev->gscr[SATA_PMP_GSCR_PROD_ID]) {
714 		ata_dev_err(dev, "PMP product ID mismatch\n");
715 		/* something weird is going on, request full PMP recovery */
716 		return -EIO;
717 	}
718 
719 	return 0;
720 }
721 
722 /**
723  *	sata_pmp_eh_recover_pmp - recover PMP
724  *	@ap: ATA port PMP is attached to
725  *	@prereset: prereset method (can be NULL)
726  *	@softreset: softreset method
727  *	@hardreset: hardreset method
728  *	@postreset: postreset method (can be NULL)
729  *
730  *	Recover PMP attached to @ap.  Recovery procedure is somewhat
731  *	similar to that of ata_eh_recover() except that reset should
732  *	always be performed in hard->soft sequence and recovery
733  *	failure results in PMP detachment.
734  *
735  *	LOCKING:
736  *	Kernel thread context (may sleep).
737  *
738  *	RETURNS:
739  *	0 on success, -errno on failure.
740  */
741 static int sata_pmp_eh_recover_pmp(struct ata_port *ap,
742 		ata_prereset_fn_t prereset, ata_reset_fn_t softreset,
743 		ata_reset_fn_t hardreset, ata_postreset_fn_t postreset)
744 {
745 	struct ata_link *link = &ap->link;
746 	struct ata_eh_context *ehc = &link->eh_context;
747 	struct ata_device *dev = link->device;
748 	int tries = ATA_EH_PMP_TRIES;
749 	int detach = 0, rc = 0;
750 	int reval_failed = 0;
751 
752 	DPRINTK("ENTER\n");
753 
754 	if (dev->flags & ATA_DFLAG_DETACH) {
755 		detach = 1;
756 		goto fail;
757 	}
758 
759  retry:
760 	ehc->classes[0] = ATA_DEV_UNKNOWN;
761 
762 	if (ehc->i.action & ATA_EH_RESET) {
763 		struct ata_link *tlink;
764 
765 		/* reset */
766 		rc = ata_eh_reset(link, 0, prereset, softreset, hardreset,
767 				  postreset);
768 		if (rc) {
769 			ata_link_err(link, "failed to reset PMP, giving up\n");
770 			goto fail;
771 		}
772 
773 		/* PMP is reset, SErrors cannot be trusted, scan all */
774 		ata_for_each_link(tlink, ap, EDGE) {
775 			struct ata_eh_context *ehc = &tlink->eh_context;
776 
777 			ehc->i.probe_mask |= ATA_ALL_DEVICES;
778 			ehc->i.action |= ATA_EH_RESET;
779 		}
780 	}
781 
782 	/* If revalidation is requested, revalidate and reconfigure;
783 	 * otherwise, do quick revalidation.
784 	 */
785 	if (ehc->i.action & ATA_EH_REVALIDATE)
786 		rc = sata_pmp_revalidate(dev, ehc->classes[0]);
787 	else
788 		rc = sata_pmp_revalidate_quick(dev);
789 
790 	if (rc) {
791 		tries--;
792 
793 		if (rc == -ENODEV) {
794 			ehc->i.probe_mask |= ATA_ALL_DEVICES;
795 			detach = 1;
796 			/* give it just two more chances */
797 			tries = min(tries, 2);
798 		}
799 
800 		if (tries) {
801 			/* consecutive revalidation failures? speed down */
802 			if (reval_failed)
803 				sata_down_spd_limit(link, 0);
804 			else
805 				reval_failed = 1;
806 
807 			ehc->i.action |= ATA_EH_RESET;
808 			goto retry;
809 		} else {
810 			ata_dev_err(dev,
811 				    "failed to recover PMP after %d tries, giving up\n",
812 				    ATA_EH_PMP_TRIES);
813 			goto fail;
814 		}
815 	}
816 
817 	/* okay, PMP resurrected */
818 	ehc->i.flags = 0;
819 
820 	DPRINTK("EXIT, rc=0\n");
821 	return 0;
822 
823  fail:
824 	sata_pmp_detach(dev);
825 	if (detach)
826 		ata_eh_detach_dev(dev);
827 	else
828 		ata_dev_disable(dev);
829 
830 	DPRINTK("EXIT, rc=%d\n", rc);
831 	return rc;
832 }
833 
834 static int sata_pmp_eh_handle_disabled_links(struct ata_port *ap)
835 {
836 	struct ata_link *link;
837 	unsigned long flags;
838 	int rc;
839 
840 	spin_lock_irqsave(ap->lock, flags);
841 
842 	ata_for_each_link(link, ap, EDGE) {
843 		if (!(link->flags & ATA_LFLAG_DISABLED))
844 			continue;
845 
846 		spin_unlock_irqrestore(ap->lock, flags);
847 
848 		/* Some PMPs require hardreset sequence to get
849 		 * SError.N working.
850 		 */
851 		sata_link_hardreset(link, sata_deb_timing_normal,
852 				ata_deadline(jiffies, ATA_TMOUT_INTERNAL_QUICK),
853 				NULL, NULL);
854 
855 		/* unconditionally clear SError.N */
856 		rc = sata_scr_write(link, SCR_ERROR, SERR_PHYRDY_CHG);
857 		if (rc) {
858 			ata_link_err(link,
859 				     "failed to clear SError.N (errno=%d)\n",
860 				     rc);
861 			return rc;
862 		}
863 
864 		spin_lock_irqsave(ap->lock, flags);
865 	}
866 
867 	spin_unlock_irqrestore(ap->lock, flags);
868 
869 	return 0;
870 }
871 
872 static int sata_pmp_handle_link_fail(struct ata_link *link, int *link_tries)
873 {
874 	struct ata_port *ap = link->ap;
875 	unsigned long flags;
876 
877 	if (link_tries[link->pmp] && --link_tries[link->pmp])
878 		return 1;
879 
880 	/* disable this link */
881 	if (!(link->flags & ATA_LFLAG_DISABLED)) {
882 		ata_link_warn(link,
883 			"failed to recover link after %d tries, disabling\n",
884 			ATA_EH_PMP_LINK_TRIES);
885 
886 		spin_lock_irqsave(ap->lock, flags);
887 		link->flags |= ATA_LFLAG_DISABLED;
888 		spin_unlock_irqrestore(ap->lock, flags);
889 	}
890 
891 	ata_dev_disable(link->device);
892 	link->eh_context.i.action = 0;
893 
894 	return 0;
895 }
896 
897 /**
898  *	sata_pmp_eh_recover - recover PMP-enabled port
899  *	@ap: ATA port to recover
900  *
901  *	Drive EH recovery operation for PMP enabled port @ap.  This
902  *	function recovers host and PMP ports with proper retrials and
903  *	fallbacks.  Actual recovery operations are performed using
904  *	ata_eh_recover() and sata_pmp_eh_recover_pmp().
905  *
906  *	LOCKING:
907  *	Kernel thread context (may sleep).
908  *
909  *	RETURNS:
910  *	0 on success, -errno on failure.
911  */
912 static int sata_pmp_eh_recover(struct ata_port *ap)
913 {
914 	struct ata_port_operations *ops = ap->ops;
915 	int pmp_tries, link_tries[SATA_PMP_MAX_PORTS];
916 	struct ata_link *pmp_link = &ap->link;
917 	struct ata_device *pmp_dev = pmp_link->device;
918 	struct ata_eh_context *pmp_ehc = &pmp_link->eh_context;
919 	u32 *gscr = pmp_dev->gscr;
920 	struct ata_link *link;
921 	struct ata_device *dev;
922 	unsigned int err_mask;
923 	u32 gscr_error, sntf;
924 	int cnt, rc;
925 
926 	pmp_tries = ATA_EH_PMP_TRIES;
927 	ata_for_each_link(link, ap, EDGE)
928 		link_tries[link->pmp] = ATA_EH_PMP_LINK_TRIES;
929 
930  retry:
931 	/* PMP attached? */
932 	if (!sata_pmp_attached(ap)) {
933 		rc = ata_eh_recover(ap, ops->prereset, ops->softreset,
934 				    ops->hardreset, ops->postreset, NULL);
935 		if (rc) {
936 			ata_for_each_dev(dev, &ap->link, ALL)
937 				ata_dev_disable(dev);
938 			return rc;
939 		}
940 
941 		if (pmp_dev->class != ATA_DEV_PMP)
942 			return 0;
943 
944 		/* new PMP online */
945 		ata_for_each_link(link, ap, EDGE)
946 			link_tries[link->pmp] = ATA_EH_PMP_LINK_TRIES;
947 
948 		/* fall through */
949 	}
950 
951 	/* recover pmp */
952 	rc = sata_pmp_eh_recover_pmp(ap, ops->prereset, ops->softreset,
953 				     ops->hardreset, ops->postreset);
954 	if (rc)
955 		goto pmp_fail;
956 
957 	/* PHY event notification can disturb reset and other recovery
958 	 * operations.  Turn it off.
959 	 */
960 	if (gscr[SATA_PMP_GSCR_FEAT_EN] & SATA_PMP_FEAT_NOTIFY) {
961 		gscr[SATA_PMP_GSCR_FEAT_EN] &= ~SATA_PMP_FEAT_NOTIFY;
962 
963 		err_mask = sata_pmp_write(pmp_link, SATA_PMP_GSCR_FEAT_EN,
964 					  gscr[SATA_PMP_GSCR_FEAT_EN]);
965 		if (err_mask) {
966 			ata_link_warn(pmp_link,
967 				"failed to disable NOTIFY (err_mask=0x%x)\n",
968 				err_mask);
969 			goto pmp_fail;
970 		}
971 	}
972 
973 	/* handle disabled links */
974 	rc = sata_pmp_eh_handle_disabled_links(ap);
975 	if (rc)
976 		goto pmp_fail;
977 
978 	/* recover links */
979 	rc = ata_eh_recover(ap, ops->pmp_prereset, ops->pmp_softreset,
980 			    ops->pmp_hardreset, ops->pmp_postreset, &link);
981 	if (rc)
982 		goto link_fail;
983 
984 	/* clear SNotification */
985 	rc = sata_scr_read(&ap->link, SCR_NOTIFICATION, &sntf);
986 	if (rc == 0)
987 		sata_scr_write(&ap->link, SCR_NOTIFICATION, sntf);
988 
989 	/*
990 	 * If LPM is active on any fan-out port, hotplug wouldn't
991 	 * work.  Return w/ PHY event notification disabled.
992 	 */
993 	ata_for_each_link(link, ap, EDGE)
994 		if (link->lpm_policy > ATA_LPM_MAX_POWER)
995 			return 0;
996 
997 	/*
998 	 * Connection status might have changed while resetting other
999 	 * links, enable notification and check SATA_PMP_GSCR_ERROR
1000 	 * before returning.
1001 	 */
1002 
1003 	/* enable notification */
1004 	if (pmp_dev->flags & ATA_DFLAG_AN) {
1005 		gscr[SATA_PMP_GSCR_FEAT_EN] |= SATA_PMP_FEAT_NOTIFY;
1006 
1007 		err_mask = sata_pmp_write(pmp_link, SATA_PMP_GSCR_FEAT_EN,
1008 					  gscr[SATA_PMP_GSCR_FEAT_EN]);
1009 		if (err_mask) {
1010 			ata_dev_err(pmp_dev,
1011 				    "failed to write PMP_FEAT_EN (Emask=0x%x)\n",
1012 				    err_mask);
1013 			rc = -EIO;
1014 			goto pmp_fail;
1015 		}
1016 	}
1017 
1018 	/* check GSCR_ERROR */
1019 	err_mask = sata_pmp_read(pmp_link, SATA_PMP_GSCR_ERROR, &gscr_error);
1020 	if (err_mask) {
1021 		ata_dev_err(pmp_dev,
1022 			    "failed to read PMP_GSCR_ERROR (Emask=0x%x)\n",
1023 			    err_mask);
1024 		rc = -EIO;
1025 		goto pmp_fail;
1026 	}
1027 
1028 	cnt = 0;
1029 	ata_for_each_link(link, ap, EDGE) {
1030 		if (!(gscr_error & (1 << link->pmp)))
1031 			continue;
1032 
1033 		if (sata_pmp_handle_link_fail(link, link_tries)) {
1034 			ata_ehi_hotplugged(&link->eh_context.i);
1035 			cnt++;
1036 		} else {
1037 			ata_link_warn(link,
1038 				"PHY status changed but maxed out on retries, giving up\n");
1039 			ata_link_warn(link,
1040 				"Manually issue scan to resume this link\n");
1041 		}
1042 	}
1043 
1044 	if (cnt) {
1045 		ata_port_info(ap,
1046 			"PMP SError.N set for some ports, repeating recovery\n");
1047 		goto retry;
1048 	}
1049 
1050 	return 0;
1051 
1052  link_fail:
1053 	if (sata_pmp_handle_link_fail(link, link_tries)) {
1054 		pmp_ehc->i.action |= ATA_EH_RESET;
1055 		goto retry;
1056 	}
1057 
1058 	/* fall through */
1059  pmp_fail:
1060 	/* Control always ends up here after detaching PMP.  Shut up
1061 	 * and return if we're unloading.
1062 	 */
1063 	if (ap->pflags & ATA_PFLAG_UNLOADING)
1064 		return rc;
1065 
1066 	if (!sata_pmp_attached(ap))
1067 		goto retry;
1068 
1069 	if (--pmp_tries) {
1070 		pmp_ehc->i.action |= ATA_EH_RESET;
1071 		goto retry;
1072 	}
1073 
1074 	ata_port_err(ap, "failed to recover PMP after %d tries, giving up\n",
1075 		     ATA_EH_PMP_TRIES);
1076 	sata_pmp_detach(pmp_dev);
1077 	ata_dev_disable(pmp_dev);
1078 
1079 	return rc;
1080 }
1081 
1082 /**
1083  *	sata_pmp_error_handler - do standard error handling for PMP-enabled host
1084  *	@ap: host port to handle error for
1085  *
1086  *	Perform standard error handling sequence for PMP-enabled host
1087  *	@ap.
1088  *
1089  *	LOCKING:
1090  *	Kernel thread context (may sleep).
1091  */
1092 void sata_pmp_error_handler(struct ata_port *ap)
1093 {
1094 	ata_eh_autopsy(ap);
1095 	ata_eh_report(ap);
1096 	sata_pmp_eh_recover(ap);
1097 	ata_eh_finish(ap);
1098 }
1099 
1100 EXPORT_SYMBOL_GPL(sata_pmp_port_ops);
1101 EXPORT_SYMBOL_GPL(sata_pmp_qc_defer_cmd_switch);
1102 EXPORT_SYMBOL_GPL(sata_pmp_error_handler);
1103