xref: /linux/drivers/ata/libata-pmp.c (revision a67ff6a54095e27093ea501fb143fefe51a536c2)
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 and SRST
393 			 * times out under certain configurations.
394 			 */
395 			if (link->pmp < 5)
396 				link->flags |= ATA_LFLAG_NO_SRST |
397 					       ATA_LFLAG_ASSUME_ATA;
398 
399 			/* port 5 is for SEMB device and it doesn't like SRST */
400 			if (link->pmp == 5)
401 				link->flags |= ATA_LFLAG_NO_SRST |
402 					       ATA_LFLAG_ASSUME_SEMB;
403 		}
404 	} else if (vendor == 0x1095 && devid == 0x4723) {
405 		/* sil4723 quirks */
406 		ata_for_each_link(link, ap, EDGE) {
407 			/* link reports offline after LPM */
408 			link->flags |= ATA_LFLAG_NO_LPM;
409 
410 			/* class code report is unreliable */
411 			if (link->pmp < 2)
412 				link->flags |= ATA_LFLAG_ASSUME_ATA;
413 
414 			/* the config device at port 2 locks up on SRST */
415 			if (link->pmp == 2)
416 				link->flags |= ATA_LFLAG_NO_SRST |
417 					       ATA_LFLAG_ASSUME_ATA;
418 		}
419 	} else if (vendor == 0x1095 && devid == 0x4726) {
420 		/* sil4726 quirks */
421 		ata_for_each_link(link, ap, EDGE) {
422 			/* link reports offline after LPM */
423 			link->flags |= ATA_LFLAG_NO_LPM;
424 
425 			/* Class code report is unreliable and SRST
426 			 * times out under certain configurations.
427 			 * Config device can be at port 0 or 5 and
428 			 * locks up on SRST.
429 			 */
430 			if (link->pmp <= 5)
431 				link->flags |= ATA_LFLAG_NO_SRST |
432 					       ATA_LFLAG_ASSUME_ATA;
433 
434 			/* Port 6 is for SEMB device which doesn't
435 			 * like SRST either.
436 			 */
437 			if (link->pmp == 6)
438 				link->flags |= ATA_LFLAG_NO_SRST |
439 					       ATA_LFLAG_ASSUME_SEMB;
440 		}
441 	} else if (vendor == 0x1095 && (devid == 0x5723 || devid == 0x5733 ||
442 					devid == 0x5734 || devid == 0x5744)) {
443 		/* sil5723/5744 quirks */
444 
445 		/* sil5723/5744 has either two or three downstream
446 		 * ports depending on operation mode.  The last port
447 		 * is empty if any actual IO device is available or
448 		 * occupied by a pseudo configuration device
449 		 * otherwise.  Don't try hard to recover it.
450 		 */
451 		ap->pmp_link[ap->nr_pmp_links - 1].flags |= ATA_LFLAG_NO_RETRY;
452 	} else if (vendor == 0x197b && devid == 0x2352) {
453 		/* chip found in Thermaltake BlackX Duet, jmicron JMB350? */
454 		ata_for_each_link(link, ap, EDGE) {
455 			/* SRST breaks detection and disks get misclassified
456 			 * LPM disabled to avoid potential problems
457 			 */
458 			link->flags |= ATA_LFLAG_NO_LPM |
459 				       ATA_LFLAG_NO_SRST |
460 				       ATA_LFLAG_ASSUME_ATA;
461 		}
462 	}
463 }
464 
465 /**
466  *	sata_pmp_attach - attach a SATA PMP device
467  *	@dev: SATA PMP device to attach
468  *
469  *	Configure and attach SATA PMP device @dev.  This function is
470  *	also responsible for allocating and initializing PMP links.
471  *
472  *	LOCKING:
473  *	Kernel thread context (may sleep).
474  *
475  *	RETURNS:
476  *	0 on success, -errno on failure.
477  */
478 int sata_pmp_attach(struct ata_device *dev)
479 {
480 	struct ata_link *link = dev->link;
481 	struct ata_port *ap = link->ap;
482 	unsigned long flags;
483 	struct ata_link *tlink;
484 	int rc;
485 
486 	/* is it hanging off the right place? */
487 	if (!sata_pmp_supported(ap)) {
488 		ata_dev_err(dev, "host does not support Port Multiplier\n");
489 		return -EINVAL;
490 	}
491 
492 	if (!ata_is_host_link(link)) {
493 		ata_dev_err(dev, "Port Multipliers cannot be nested\n");
494 		return -EINVAL;
495 	}
496 
497 	if (dev->devno) {
498 		ata_dev_err(dev, "Port Multiplier must be the first device\n");
499 		return -EINVAL;
500 	}
501 
502 	WARN_ON(link->pmp != 0);
503 	link->pmp = SATA_PMP_CTRL_PORT;
504 
505 	/* read GSCR block */
506 	rc = sata_pmp_read_gscr(dev, dev->gscr);
507 	if (rc)
508 		goto fail;
509 
510 	/* config PMP */
511 	rc = sata_pmp_configure(dev, 1);
512 	if (rc)
513 		goto fail;
514 
515 	rc = sata_pmp_init_links(ap, sata_pmp_gscr_ports(dev->gscr));
516 	if (rc) {
517 		ata_dev_info(dev, "failed to initialize PMP links\n");
518 		goto fail;
519 	}
520 
521 	/* attach it */
522 	spin_lock_irqsave(ap->lock, flags);
523 	WARN_ON(ap->nr_pmp_links);
524 	ap->nr_pmp_links = sata_pmp_gscr_ports(dev->gscr);
525 	spin_unlock_irqrestore(ap->lock, flags);
526 
527 	sata_pmp_quirks(ap);
528 
529 	if (ap->ops->pmp_attach)
530 		ap->ops->pmp_attach(ap);
531 
532 	ata_for_each_link(tlink, ap, EDGE)
533 		sata_link_init_spd(tlink);
534 
535 	ata_acpi_associate_sata_port(ap);
536 
537 	return 0;
538 
539  fail:
540 	link->pmp = 0;
541 	return rc;
542 }
543 
544 /**
545  *	sata_pmp_detach - detach a SATA PMP device
546  *	@dev: SATA PMP device to detach
547  *
548  *	Detach SATA PMP device @dev.  This function is also
549  *	responsible for deconfiguring PMP links.
550  *
551  *	LOCKING:
552  *	Kernel thread context (may sleep).
553  */
554 static void sata_pmp_detach(struct ata_device *dev)
555 {
556 	struct ata_link *link = dev->link;
557 	struct ata_port *ap = link->ap;
558 	struct ata_link *tlink;
559 	unsigned long flags;
560 
561 	ata_dev_info(dev, "Port Multiplier detaching\n");
562 
563 	WARN_ON(!ata_is_host_link(link) || dev->devno ||
564 		link->pmp != SATA_PMP_CTRL_PORT);
565 
566 	if (ap->ops->pmp_detach)
567 		ap->ops->pmp_detach(ap);
568 
569 	ata_for_each_link(tlink, ap, EDGE)
570 		ata_eh_detach_dev(tlink->device);
571 
572 	spin_lock_irqsave(ap->lock, flags);
573 	ap->nr_pmp_links = 0;
574 	link->pmp = 0;
575 	spin_unlock_irqrestore(ap->lock, flags);
576 
577 	ata_acpi_associate_sata_port(ap);
578 }
579 
580 /**
581  *	sata_pmp_same_pmp - does new GSCR matches the configured PMP?
582  *	@dev: PMP device to compare against
583  *	@new_gscr: GSCR block of the new device
584  *
585  *	Compare @new_gscr against @dev and determine whether @dev is
586  *	the PMP described by @new_gscr.
587  *
588  *	LOCKING:
589  *	None.
590  *
591  *	RETURNS:
592  *	1 if @dev matches @new_gscr, 0 otherwise.
593  */
594 static int sata_pmp_same_pmp(struct ata_device *dev, const u32 *new_gscr)
595 {
596 	const u32 *old_gscr = dev->gscr;
597 	u16 old_vendor, new_vendor, old_devid, new_devid;
598 	int old_nr_ports, new_nr_ports;
599 
600 	old_vendor = sata_pmp_gscr_vendor(old_gscr);
601 	new_vendor = sata_pmp_gscr_vendor(new_gscr);
602 	old_devid = sata_pmp_gscr_devid(old_gscr);
603 	new_devid = sata_pmp_gscr_devid(new_gscr);
604 	old_nr_ports = sata_pmp_gscr_ports(old_gscr);
605 	new_nr_ports = sata_pmp_gscr_ports(new_gscr);
606 
607 	if (old_vendor != new_vendor) {
608 		ata_dev_info(dev,
609 			     "Port Multiplier vendor mismatch '0x%x' != '0x%x'\n",
610 			     old_vendor, new_vendor);
611 		return 0;
612 	}
613 
614 	if (old_devid != new_devid) {
615 		ata_dev_info(dev,
616 			     "Port Multiplier device ID mismatch '0x%x' != '0x%x'\n",
617 			     old_devid, new_devid);
618 		return 0;
619 	}
620 
621 	if (old_nr_ports != new_nr_ports) {
622 		ata_dev_info(dev,
623 			     "Port Multiplier nr_ports mismatch '0x%x' != '0x%x'\n",
624 			     old_nr_ports, new_nr_ports);
625 		return 0;
626 	}
627 
628 	return 1;
629 }
630 
631 /**
632  *	sata_pmp_revalidate - revalidate SATA PMP
633  *	@dev: PMP device to revalidate
634  *	@new_class: new class code
635  *
636  *	Re-read GSCR block and make sure @dev is still attached to the
637  *	port and properly configured.
638  *
639  *	LOCKING:
640  *	Kernel thread context (may sleep).
641  *
642  *	RETURNS:
643  *	0 on success, -errno otherwise.
644  */
645 static int sata_pmp_revalidate(struct ata_device *dev, unsigned int new_class)
646 {
647 	struct ata_link *link = dev->link;
648 	struct ata_port *ap = link->ap;
649 	u32 *gscr = (void *)ap->sector_buf;
650 	int rc;
651 
652 	DPRINTK("ENTER\n");
653 
654 	ata_eh_about_to_do(link, NULL, ATA_EH_REVALIDATE);
655 
656 	if (!ata_dev_enabled(dev)) {
657 		rc = -ENODEV;
658 		goto fail;
659 	}
660 
661 	/* wrong class? */
662 	if (ata_class_enabled(new_class) && new_class != ATA_DEV_PMP) {
663 		rc = -ENODEV;
664 		goto fail;
665 	}
666 
667 	/* read GSCR */
668 	rc = sata_pmp_read_gscr(dev, gscr);
669 	if (rc)
670 		goto fail;
671 
672 	/* is the pmp still there? */
673 	if (!sata_pmp_same_pmp(dev, gscr)) {
674 		rc = -ENODEV;
675 		goto fail;
676 	}
677 
678 	memcpy(dev->gscr, gscr, sizeof(gscr[0]) * SATA_PMP_GSCR_DWORDS);
679 
680 	rc = sata_pmp_configure(dev, 0);
681 	if (rc)
682 		goto fail;
683 
684 	ata_eh_done(link, NULL, ATA_EH_REVALIDATE);
685 
686 	DPRINTK("EXIT, rc=0\n");
687 	return 0;
688 
689  fail:
690 	ata_dev_err(dev, "PMP revalidation failed (errno=%d)\n", rc);
691 	DPRINTK("EXIT, rc=%d\n", rc);
692 	return rc;
693 }
694 
695 /**
696  *	sata_pmp_revalidate_quick - revalidate SATA PMP quickly
697  *	@dev: PMP device to revalidate
698  *
699  *	Make sure the attached PMP is accessible.
700  *
701  *	LOCKING:
702  *	Kernel thread context (may sleep).
703  *
704  *	RETURNS:
705  *	0 on success, -errno otherwise.
706  */
707 static int sata_pmp_revalidate_quick(struct ata_device *dev)
708 {
709 	unsigned int err_mask;
710 	u32 prod_id;
711 
712 	err_mask = sata_pmp_read(dev->link, SATA_PMP_GSCR_PROD_ID, &prod_id);
713 	if (err_mask) {
714 		ata_dev_err(dev,
715 			    "failed to read PMP product ID (Emask=0x%x)\n",
716 			    err_mask);
717 		return -EIO;
718 	}
719 
720 	if (prod_id != dev->gscr[SATA_PMP_GSCR_PROD_ID]) {
721 		ata_dev_err(dev, "PMP product ID mismatch\n");
722 		/* something weird is going on, request full PMP recovery */
723 		return -EIO;
724 	}
725 
726 	return 0;
727 }
728 
729 /**
730  *	sata_pmp_eh_recover_pmp - recover PMP
731  *	@ap: ATA port PMP is attached to
732  *	@prereset: prereset method (can be NULL)
733  *	@softreset: softreset method
734  *	@hardreset: hardreset method
735  *	@postreset: postreset method (can be NULL)
736  *
737  *	Recover PMP attached to @ap.  Recovery procedure is somewhat
738  *	similar to that of ata_eh_recover() except that reset should
739  *	always be performed in hard->soft sequence and recovery
740  *	failure results in PMP detachment.
741  *
742  *	LOCKING:
743  *	Kernel thread context (may sleep).
744  *
745  *	RETURNS:
746  *	0 on success, -errno on failure.
747  */
748 static int sata_pmp_eh_recover_pmp(struct ata_port *ap,
749 		ata_prereset_fn_t prereset, ata_reset_fn_t softreset,
750 		ata_reset_fn_t hardreset, ata_postreset_fn_t postreset)
751 {
752 	struct ata_link *link = &ap->link;
753 	struct ata_eh_context *ehc = &link->eh_context;
754 	struct ata_device *dev = link->device;
755 	int tries = ATA_EH_PMP_TRIES;
756 	int detach = 0, rc = 0;
757 	int reval_failed = 0;
758 
759 	DPRINTK("ENTER\n");
760 
761 	if (dev->flags & ATA_DFLAG_DETACH) {
762 		detach = 1;
763 		goto fail;
764 	}
765 
766  retry:
767 	ehc->classes[0] = ATA_DEV_UNKNOWN;
768 
769 	if (ehc->i.action & ATA_EH_RESET) {
770 		struct ata_link *tlink;
771 
772 		/* reset */
773 		rc = ata_eh_reset(link, 0, prereset, softreset, hardreset,
774 				  postreset);
775 		if (rc) {
776 			ata_link_err(link, "failed to reset PMP, giving up\n");
777 			goto fail;
778 		}
779 
780 		/* PMP is reset, SErrors cannot be trusted, scan all */
781 		ata_for_each_link(tlink, ap, EDGE) {
782 			struct ata_eh_context *ehc = &tlink->eh_context;
783 
784 			ehc->i.probe_mask |= ATA_ALL_DEVICES;
785 			ehc->i.action |= ATA_EH_RESET;
786 		}
787 	}
788 
789 	/* If revalidation is requested, revalidate and reconfigure;
790 	 * otherwise, do quick revalidation.
791 	 */
792 	if (ehc->i.action & ATA_EH_REVALIDATE)
793 		rc = sata_pmp_revalidate(dev, ehc->classes[0]);
794 	else
795 		rc = sata_pmp_revalidate_quick(dev);
796 
797 	if (rc) {
798 		tries--;
799 
800 		if (rc == -ENODEV) {
801 			ehc->i.probe_mask |= ATA_ALL_DEVICES;
802 			detach = 1;
803 			/* give it just two more chances */
804 			tries = min(tries, 2);
805 		}
806 
807 		if (tries) {
808 			/* consecutive revalidation failures? speed down */
809 			if (reval_failed)
810 				sata_down_spd_limit(link, 0);
811 			else
812 				reval_failed = 1;
813 
814 			ehc->i.action |= ATA_EH_RESET;
815 			goto retry;
816 		} else {
817 			ata_dev_err(dev,
818 				    "failed to recover PMP after %d tries, giving up\n",
819 				    ATA_EH_PMP_TRIES);
820 			goto fail;
821 		}
822 	}
823 
824 	/* okay, PMP resurrected */
825 	ehc->i.flags = 0;
826 
827 	DPRINTK("EXIT, rc=0\n");
828 	return 0;
829 
830  fail:
831 	sata_pmp_detach(dev);
832 	if (detach)
833 		ata_eh_detach_dev(dev);
834 	else
835 		ata_dev_disable(dev);
836 
837 	DPRINTK("EXIT, rc=%d\n", rc);
838 	return rc;
839 }
840 
841 static int sata_pmp_eh_handle_disabled_links(struct ata_port *ap)
842 {
843 	struct ata_link *link;
844 	unsigned long flags;
845 	int rc;
846 
847 	spin_lock_irqsave(ap->lock, flags);
848 
849 	ata_for_each_link(link, ap, EDGE) {
850 		if (!(link->flags & ATA_LFLAG_DISABLED))
851 			continue;
852 
853 		spin_unlock_irqrestore(ap->lock, flags);
854 
855 		/* Some PMPs require hardreset sequence to get
856 		 * SError.N working.
857 		 */
858 		sata_link_hardreset(link, sata_deb_timing_normal,
859 				ata_deadline(jiffies, ATA_TMOUT_INTERNAL_QUICK),
860 				NULL, NULL);
861 
862 		/* unconditionally clear SError.N */
863 		rc = sata_scr_write(link, SCR_ERROR, SERR_PHYRDY_CHG);
864 		if (rc) {
865 			ata_link_err(link,
866 				     "failed to clear SError.N (errno=%d)\n",
867 				     rc);
868 			return rc;
869 		}
870 
871 		spin_lock_irqsave(ap->lock, flags);
872 	}
873 
874 	spin_unlock_irqrestore(ap->lock, flags);
875 
876 	return 0;
877 }
878 
879 static int sata_pmp_handle_link_fail(struct ata_link *link, int *link_tries)
880 {
881 	struct ata_port *ap = link->ap;
882 	unsigned long flags;
883 
884 	if (link_tries[link->pmp] && --link_tries[link->pmp])
885 		return 1;
886 
887 	/* disable this link */
888 	if (!(link->flags & ATA_LFLAG_DISABLED)) {
889 		ata_link_warn(link,
890 			"failed to recover link after %d tries, disabling\n",
891 			ATA_EH_PMP_LINK_TRIES);
892 
893 		spin_lock_irqsave(ap->lock, flags);
894 		link->flags |= ATA_LFLAG_DISABLED;
895 		spin_unlock_irqrestore(ap->lock, flags);
896 	}
897 
898 	ata_dev_disable(link->device);
899 	link->eh_context.i.action = 0;
900 
901 	return 0;
902 }
903 
904 /**
905  *	sata_pmp_eh_recover - recover PMP-enabled port
906  *	@ap: ATA port to recover
907  *
908  *	Drive EH recovery operation for PMP enabled port @ap.  This
909  *	function recovers host and PMP ports with proper retrials and
910  *	fallbacks.  Actual recovery operations are performed using
911  *	ata_eh_recover() and sata_pmp_eh_recover_pmp().
912  *
913  *	LOCKING:
914  *	Kernel thread context (may sleep).
915  *
916  *	RETURNS:
917  *	0 on success, -errno on failure.
918  */
919 static int sata_pmp_eh_recover(struct ata_port *ap)
920 {
921 	struct ata_port_operations *ops = ap->ops;
922 	int pmp_tries, link_tries[SATA_PMP_MAX_PORTS];
923 	struct ata_link *pmp_link = &ap->link;
924 	struct ata_device *pmp_dev = pmp_link->device;
925 	struct ata_eh_context *pmp_ehc = &pmp_link->eh_context;
926 	u32 *gscr = pmp_dev->gscr;
927 	struct ata_link *link;
928 	struct ata_device *dev;
929 	unsigned int err_mask;
930 	u32 gscr_error, sntf;
931 	int cnt, rc;
932 
933 	pmp_tries = ATA_EH_PMP_TRIES;
934 	ata_for_each_link(link, ap, EDGE)
935 		link_tries[link->pmp] = ATA_EH_PMP_LINK_TRIES;
936 
937  retry:
938 	/* PMP attached? */
939 	if (!sata_pmp_attached(ap)) {
940 		rc = ata_eh_recover(ap, ops->prereset, ops->softreset,
941 				    ops->hardreset, ops->postreset, NULL);
942 		if (rc) {
943 			ata_for_each_dev(dev, &ap->link, ALL)
944 				ata_dev_disable(dev);
945 			return rc;
946 		}
947 
948 		if (pmp_dev->class != ATA_DEV_PMP)
949 			return 0;
950 
951 		/* new PMP online */
952 		ata_for_each_link(link, ap, EDGE)
953 			link_tries[link->pmp] = ATA_EH_PMP_LINK_TRIES;
954 
955 		/* fall through */
956 	}
957 
958 	/* recover pmp */
959 	rc = sata_pmp_eh_recover_pmp(ap, ops->prereset, ops->softreset,
960 				     ops->hardreset, ops->postreset);
961 	if (rc)
962 		goto pmp_fail;
963 
964 	/* PHY event notification can disturb reset and other recovery
965 	 * operations.  Turn it off.
966 	 */
967 	if (gscr[SATA_PMP_GSCR_FEAT_EN] & SATA_PMP_FEAT_NOTIFY) {
968 		gscr[SATA_PMP_GSCR_FEAT_EN] &= ~SATA_PMP_FEAT_NOTIFY;
969 
970 		err_mask = sata_pmp_write(pmp_link, SATA_PMP_GSCR_FEAT_EN,
971 					  gscr[SATA_PMP_GSCR_FEAT_EN]);
972 		if (err_mask) {
973 			ata_link_warn(pmp_link,
974 				"failed to disable NOTIFY (err_mask=0x%x)\n",
975 				err_mask);
976 			goto pmp_fail;
977 		}
978 	}
979 
980 	/* handle disabled links */
981 	rc = sata_pmp_eh_handle_disabled_links(ap);
982 	if (rc)
983 		goto pmp_fail;
984 
985 	/* recover links */
986 	rc = ata_eh_recover(ap, ops->pmp_prereset, ops->pmp_softreset,
987 			    ops->pmp_hardreset, ops->pmp_postreset, &link);
988 	if (rc)
989 		goto link_fail;
990 
991 	/* clear SNotification */
992 	rc = sata_scr_read(&ap->link, SCR_NOTIFICATION, &sntf);
993 	if (rc == 0)
994 		sata_scr_write(&ap->link, SCR_NOTIFICATION, sntf);
995 
996 	/*
997 	 * If LPM is active on any fan-out port, hotplug wouldn't
998 	 * work.  Return w/ PHY event notification disabled.
999 	 */
1000 	ata_for_each_link(link, ap, EDGE)
1001 		if (link->lpm_policy > ATA_LPM_MAX_POWER)
1002 			return 0;
1003 
1004 	/*
1005 	 * Connection status might have changed while resetting other
1006 	 * links, enable notification and check SATA_PMP_GSCR_ERROR
1007 	 * before returning.
1008 	 */
1009 
1010 	/* enable notification */
1011 	if (pmp_dev->flags & ATA_DFLAG_AN) {
1012 		gscr[SATA_PMP_GSCR_FEAT_EN] |= SATA_PMP_FEAT_NOTIFY;
1013 
1014 		err_mask = sata_pmp_write(pmp_link, SATA_PMP_GSCR_FEAT_EN,
1015 					  gscr[SATA_PMP_GSCR_FEAT_EN]);
1016 		if (err_mask) {
1017 			ata_dev_err(pmp_dev,
1018 				    "failed to write PMP_FEAT_EN (Emask=0x%x)\n",
1019 				    err_mask);
1020 			rc = -EIO;
1021 			goto pmp_fail;
1022 		}
1023 	}
1024 
1025 	/* check GSCR_ERROR */
1026 	err_mask = sata_pmp_read(pmp_link, SATA_PMP_GSCR_ERROR, &gscr_error);
1027 	if (err_mask) {
1028 		ata_dev_err(pmp_dev,
1029 			    "failed to read PMP_GSCR_ERROR (Emask=0x%x)\n",
1030 			    err_mask);
1031 		rc = -EIO;
1032 		goto pmp_fail;
1033 	}
1034 
1035 	cnt = 0;
1036 	ata_for_each_link(link, ap, EDGE) {
1037 		if (!(gscr_error & (1 << link->pmp)))
1038 			continue;
1039 
1040 		if (sata_pmp_handle_link_fail(link, link_tries)) {
1041 			ata_ehi_hotplugged(&link->eh_context.i);
1042 			cnt++;
1043 		} else {
1044 			ata_link_warn(link,
1045 				"PHY status changed but maxed out on retries, giving up\n");
1046 			ata_link_warn(link,
1047 				"Manually issue scan to resume this link\n");
1048 		}
1049 	}
1050 
1051 	if (cnt) {
1052 		ata_port_info(ap,
1053 			"PMP SError.N set for some ports, repeating recovery\n");
1054 		goto retry;
1055 	}
1056 
1057 	return 0;
1058 
1059  link_fail:
1060 	if (sata_pmp_handle_link_fail(link, link_tries)) {
1061 		pmp_ehc->i.action |= ATA_EH_RESET;
1062 		goto retry;
1063 	}
1064 
1065 	/* fall through */
1066  pmp_fail:
1067 	/* Control always ends up here after detaching PMP.  Shut up
1068 	 * and return if we're unloading.
1069 	 */
1070 	if (ap->pflags & ATA_PFLAG_UNLOADING)
1071 		return rc;
1072 
1073 	if (!sata_pmp_attached(ap))
1074 		goto retry;
1075 
1076 	if (--pmp_tries) {
1077 		pmp_ehc->i.action |= ATA_EH_RESET;
1078 		goto retry;
1079 	}
1080 
1081 	ata_port_err(ap, "failed to recover PMP after %d tries, giving up\n",
1082 		     ATA_EH_PMP_TRIES);
1083 	sata_pmp_detach(pmp_dev);
1084 	ata_dev_disable(pmp_dev);
1085 
1086 	return rc;
1087 }
1088 
1089 /**
1090  *	sata_pmp_error_handler - do standard error handling for PMP-enabled host
1091  *	@ap: host port to handle error for
1092  *
1093  *	Perform standard error handling sequence for PMP-enabled host
1094  *	@ap.
1095  *
1096  *	LOCKING:
1097  *	Kernel thread context (may sleep).
1098  */
1099 void sata_pmp_error_handler(struct ata_port *ap)
1100 {
1101 	ata_eh_autopsy(ap);
1102 	ata_eh_report(ap);
1103 	sata_pmp_eh_recover(ap);
1104 	ata_eh_finish(ap);
1105 }
1106 
1107 EXPORT_SYMBOL_GPL(sata_pmp_port_ops);
1108 EXPORT_SYMBOL_GPL(sata_pmp_qc_defer_cmd_switch);
1109 EXPORT_SYMBOL_GPL(sata_pmp_error_handler);
1110