xref: /openbmc/linux/drivers/ata/libata-pmp.c (revision f42b3800)
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/libata.h>
12 #include "libata.h"
13 
14 const struct ata_port_operations sata_pmp_port_ops = {
15 	.inherits		= &sata_port_ops,
16 	.pmp_prereset		= ata_std_prereset,
17 	.pmp_hardreset		= sata_std_hardreset,
18 	.pmp_postreset		= ata_std_postreset,
19 	.error_handler		= sata_pmp_error_handler,
20 };
21 
22 /**
23  *	sata_pmp_read - read PMP register
24  *	@link: link to read PMP register for
25  *	@reg: register to read
26  *	@r_val: resulting value
27  *
28  *	Read PMP register.
29  *
30  *	LOCKING:
31  *	Kernel thread context (may sleep).
32  *
33  *	RETURNS:
34  *	0 on success, AC_ERR_* mask on failure.
35  */
36 static unsigned int sata_pmp_read(struct ata_link *link, int reg, u32 *r_val)
37 {
38 	struct ata_port *ap = link->ap;
39 	struct ata_device *pmp_dev = ap->link.device;
40 	struct ata_taskfile tf;
41 	unsigned int err_mask;
42 
43 	ata_tf_init(pmp_dev, &tf);
44 	tf.command = ATA_CMD_PMP_READ;
45 	tf.protocol = ATA_PROT_NODATA;
46 	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE | ATA_TFLAG_LBA48;
47 	tf.feature = reg;
48 	tf.device = link->pmp;
49 
50 	err_mask = ata_exec_internal(pmp_dev, &tf, NULL, DMA_NONE, NULL, 0,
51 				     SATA_PMP_SCR_TIMEOUT);
52 	if (err_mask)
53 		return err_mask;
54 
55 	*r_val = tf.nsect | tf.lbal << 8 | tf.lbam << 16 | tf.lbah << 24;
56 	return 0;
57 }
58 
59 /**
60  *	sata_pmp_write - write PMP register
61  *	@link: link to write PMP register for
62  *	@reg: register to write
63  *	@r_val: value to write
64  *
65  *	Write PMP register.
66  *
67  *	LOCKING:
68  *	Kernel thread context (may sleep).
69  *
70  *	RETURNS:
71  *	0 on success, AC_ERR_* mask on failure.
72  */
73 static unsigned int sata_pmp_write(struct ata_link *link, int reg, u32 val)
74 {
75 	struct ata_port *ap = link->ap;
76 	struct ata_device *pmp_dev = ap->link.device;
77 	struct ata_taskfile tf;
78 
79 	ata_tf_init(pmp_dev, &tf);
80 	tf.command = ATA_CMD_PMP_WRITE;
81 	tf.protocol = ATA_PROT_NODATA;
82 	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE | ATA_TFLAG_LBA48;
83 	tf.feature = reg;
84 	tf.device = link->pmp;
85 	tf.nsect = val & 0xff;
86 	tf.lbal = (val >> 8) & 0xff;
87 	tf.lbam = (val >> 16) & 0xff;
88 	tf.lbah = (val >> 24) & 0xff;
89 
90 	return ata_exec_internal(pmp_dev, &tf, NULL, DMA_NONE, NULL, 0,
91 				 SATA_PMP_SCR_TIMEOUT);
92 }
93 
94 /**
95  *	sata_pmp_qc_defer_cmd_switch - qc_defer for command switching PMP
96  *	@qc: ATA command in question
97  *
98  *	A host which has command switching PMP support cannot issue
99  *	commands to multiple links simultaneously.
100  *
101  *	LOCKING:
102  *	spin_lock_irqsave(host lock)
103  *
104  *	RETURNS:
105  *	ATA_DEFER_* if deferring is needed, 0 otherwise.
106  */
107 int sata_pmp_qc_defer_cmd_switch(struct ata_queued_cmd *qc)
108 {
109 	struct ata_link *link = qc->dev->link;
110 	struct ata_port *ap = link->ap;
111 
112 	if (ap->excl_link == NULL || ap->excl_link == link) {
113 		if (ap->nr_active_links == 0 || ata_link_active(link)) {
114 			qc->flags |= ATA_QCFLAG_CLEAR_EXCL;
115 			return ata_std_qc_defer(qc);
116 		}
117 
118 		ap->excl_link = link;
119 	}
120 
121 	return ATA_DEFER_PORT;
122 }
123 
124 /**
125  *	sata_pmp_scr_read - read PSCR
126  *	@link: ATA link to read PSCR for
127  *	@reg: PSCR to read
128  *	@r_val: resulting value
129  *
130  *	Read PSCR @reg into @r_val for @link, to be called from
131  *	ata_scr_read().
132  *
133  *	LOCKING:
134  *	Kernel thread context (may sleep).
135  *
136  *	RETURNS:
137  *	0 on success, -errno on failure.
138  */
139 int sata_pmp_scr_read(struct ata_link *link, int reg, u32 *r_val)
140 {
141 	unsigned int err_mask;
142 
143 	if (reg > SATA_PMP_PSCR_CONTROL)
144 		return -EINVAL;
145 
146 	err_mask = sata_pmp_read(link, reg, r_val);
147 	if (err_mask) {
148 		ata_link_printk(link, KERN_WARNING, "failed to read SCR %d "
149 				"(Emask=0x%x)\n", reg, err_mask);
150 		return -EIO;
151 	}
152 	return 0;
153 }
154 
155 /**
156  *	sata_pmp_scr_write - write PSCR
157  *	@link: ATA link to write PSCR for
158  *	@reg: PSCR to write
159  *	@val: value to be written
160  *
161  *	Write @val to PSCR @reg for @link, to be called from
162  *	ata_scr_write() and ata_scr_write_flush().
163  *
164  *	LOCKING:
165  *	Kernel thread context (may sleep).
166  *
167  *	RETURNS:
168  *	0 on success, -errno on failure.
169  */
170 int sata_pmp_scr_write(struct ata_link *link, int reg, u32 val)
171 {
172 	unsigned int err_mask;
173 
174 	if (reg > SATA_PMP_PSCR_CONTROL)
175 		return -EINVAL;
176 
177 	err_mask = sata_pmp_write(link, reg, val);
178 	if (err_mask) {
179 		ata_link_printk(link, KERN_WARNING, "failed to write SCR %d "
180 				"(Emask=0x%x)\n", reg, err_mask);
181 		return -EIO;
182 	}
183 	return 0;
184 }
185 
186 /**
187  *	sata_pmp_read_gscr - read GSCR block of SATA PMP
188  *	@dev: PMP device
189  *	@gscr: buffer to read GSCR block into
190  *
191  *	Read selected PMP GSCRs from the PMP at @dev.  This will serve
192  *	as configuration and identification info for the PMP.
193  *
194  *	LOCKING:
195  *	Kernel thread context (may sleep).
196  *
197  *	RETURNS:
198  *	0 on success, -errno on failure.
199  */
200 static int sata_pmp_read_gscr(struct ata_device *dev, u32 *gscr)
201 {
202 	static const int gscr_to_read[] = { 0, 1, 2, 32, 33, 64, 96 };
203 	int i;
204 
205 	for (i = 0; i < ARRAY_SIZE(gscr_to_read); i++) {
206 		int reg = gscr_to_read[i];
207 		unsigned int err_mask;
208 
209 		err_mask = sata_pmp_read(dev->link, reg, &gscr[reg]);
210 		if (err_mask) {
211 			ata_dev_printk(dev, KERN_ERR, "failed to read PMP "
212 				"GSCR[%d] (Emask=0x%x)\n", reg, err_mask);
213 			return -EIO;
214 		}
215 	}
216 
217 	return 0;
218 }
219 
220 static const char *sata_pmp_spec_rev_str(const u32 *gscr)
221 {
222 	u32 rev = gscr[SATA_PMP_GSCR_REV];
223 
224 	if (rev & (1 << 2))
225 		return "1.1";
226 	if (rev & (1 << 1))
227 		return "1.0";
228 	return "<unknown>";
229 }
230 
231 static int sata_pmp_configure(struct ata_device *dev, int print_info)
232 {
233 	struct ata_port *ap = dev->link->ap;
234 	u32 *gscr = dev->gscr;
235 	unsigned int err_mask = 0;
236 	const char *reason;
237 	int nr_ports, rc;
238 
239 	nr_ports = sata_pmp_gscr_ports(gscr);
240 
241 	if (nr_ports <= 0 || nr_ports > SATA_PMP_MAX_PORTS) {
242 		rc = -EINVAL;
243 		reason = "invalid nr_ports";
244 		goto fail;
245 	}
246 
247 	if ((ap->flags & ATA_FLAG_AN) &&
248 	    (gscr[SATA_PMP_GSCR_FEAT] & SATA_PMP_FEAT_NOTIFY))
249 		dev->flags |= ATA_DFLAG_AN;
250 
251 	/* monitor SERR_PHYRDY_CHG on fan-out ports */
252 	err_mask = sata_pmp_write(dev->link, SATA_PMP_GSCR_ERROR_EN,
253 				  SERR_PHYRDY_CHG);
254 	if (err_mask) {
255 		rc = -EIO;
256 		reason = "failed to write GSCR_ERROR_EN";
257 		goto fail;
258 	}
259 
260 	/* turn off notification till fan-out ports are reset and configured */
261 	if (gscr[SATA_PMP_GSCR_FEAT_EN] & SATA_PMP_FEAT_NOTIFY) {
262 		gscr[SATA_PMP_GSCR_FEAT_EN] &= ~SATA_PMP_FEAT_NOTIFY;
263 
264 		err_mask = sata_pmp_write(dev->link, SATA_PMP_GSCR_FEAT_EN,
265 					  gscr[SATA_PMP_GSCR_FEAT_EN]);
266 		if (err_mask) {
267 			rc = -EIO;
268 			reason = "failed to write GSCR_FEAT_EN";
269 			goto fail;
270 		}
271 	}
272 
273 	if (print_info) {
274 		ata_dev_printk(dev, KERN_INFO, "Port Multiplier %s, "
275 			       "0x%04x:0x%04x r%d, %d ports, feat 0x%x/0x%x\n",
276 			       sata_pmp_spec_rev_str(gscr),
277 			       sata_pmp_gscr_vendor(gscr),
278 			       sata_pmp_gscr_devid(gscr),
279 			       sata_pmp_gscr_rev(gscr),
280 			       nr_ports, gscr[SATA_PMP_GSCR_FEAT_EN],
281 			       gscr[SATA_PMP_GSCR_FEAT]);
282 
283 		if (!(dev->flags & ATA_DFLAG_AN))
284 			ata_dev_printk(dev, KERN_INFO,
285 				"Asynchronous notification not supported, "
286 				"hotplug won't\n         work on fan-out "
287 				"ports. Use warm-plug instead.\n");
288 	}
289 
290 	return 0;
291 
292  fail:
293 	ata_dev_printk(dev, KERN_ERR,
294 		       "failed to configure Port Multiplier (%s, Emask=0x%x)\n",
295 		       reason, err_mask);
296 	return rc;
297 }
298 
299 static int sata_pmp_init_links(struct ata_port *ap, int nr_ports)
300 {
301 	struct ata_link *pmp_link = ap->pmp_link;
302 	int i;
303 
304 	if (!pmp_link) {
305 		pmp_link = kzalloc(sizeof(pmp_link[0]) * SATA_PMP_MAX_PORTS,
306 				   GFP_NOIO);
307 		if (!pmp_link)
308 			return -ENOMEM;
309 
310 		for (i = 0; i < SATA_PMP_MAX_PORTS; i++)
311 			ata_link_init(ap, &pmp_link[i], i);
312 
313 		ap->pmp_link = pmp_link;
314 	}
315 
316 	for (i = 0; i < nr_ports; i++) {
317 		struct ata_link *link = &pmp_link[i];
318 		struct ata_eh_context *ehc = &link->eh_context;
319 
320 		link->flags = 0;
321 		ehc->i.probe_mask |= ATA_ALL_DEVICES;
322 		ehc->i.action |= ATA_EH_RESET;
323 	}
324 
325 	return 0;
326 }
327 
328 static void sata_pmp_quirks(struct ata_port *ap)
329 {
330 	u32 *gscr = ap->link.device->gscr;
331 	u16 vendor = sata_pmp_gscr_vendor(gscr);
332 	u16 devid = sata_pmp_gscr_devid(gscr);
333 	struct ata_link *link;
334 
335 	if (vendor == 0x1095 && devid == 0x3726) {
336 		/* sil3726 quirks */
337 		ata_port_for_each_link(link, ap) {
338 			/* class code report is unreliable */
339 			if (link->pmp < 5)
340 				link->flags |= ATA_LFLAG_ASSUME_ATA;
341 
342 			/* port 5 is for SEMB device and it doesn't like SRST */
343 			if (link->pmp == 5)
344 				link->flags |= ATA_LFLAG_NO_SRST |
345 					       ATA_LFLAG_ASSUME_SEMB;
346 		}
347 	} else if (vendor == 0x1095 && devid == 0x4723) {
348 		/* sil4723 quirks */
349 		ata_port_for_each_link(link, ap) {
350 			/* class code report is unreliable */
351 			if (link->pmp < 2)
352 				link->flags |= ATA_LFLAG_ASSUME_ATA;
353 
354 			/* the config device at port 2 locks up on SRST */
355 			if (link->pmp == 2)
356 				link->flags |= ATA_LFLAG_NO_SRST |
357 					       ATA_LFLAG_ASSUME_ATA;
358 		}
359 	} else if (vendor == 0x1095 && devid == 0x4726) {
360 		/* sil4726 quirks */
361 		ata_port_for_each_link(link, ap) {
362 			/* Class code report is unreliable and SRST
363 			 * times out under certain configurations.
364 			 * Config device can be at port 0 or 5 and
365 			 * locks up on SRST.
366 			 */
367 			if (link->pmp <= 5)
368 				link->flags |= ATA_LFLAG_NO_SRST |
369 					       ATA_LFLAG_ASSUME_ATA;
370 
371 			/* Port 6 is for SEMB device which doesn't
372 			 * like SRST either.
373 			 */
374 			if (link->pmp == 6)
375 				link->flags |= ATA_LFLAG_NO_SRST |
376 					       ATA_LFLAG_ASSUME_SEMB;
377 		}
378 	} else if (vendor == 0x1095 && (devid == 0x5723 || devid == 0x5733 ||
379 					devid == 0x5734 || devid == 0x5744)) {
380 		/* sil5723/5744 quirks */
381 
382 		/* sil5723/5744 has either two or three downstream
383 		 * ports depending on operation mode.  The last port
384 		 * is empty if any actual IO device is available or
385 		 * occupied by a pseudo configuration device
386 		 * otherwise.  Don't try hard to recover it.
387 		 */
388 		ap->pmp_link[ap->nr_pmp_links - 1].flags |= ATA_LFLAG_NO_RETRY;
389 	}
390 }
391 
392 /**
393  *	sata_pmp_attach - attach a SATA PMP device
394  *	@dev: SATA PMP device to attach
395  *
396  *	Configure and attach SATA PMP device @dev.  This function is
397  *	also responsible for allocating and initializing PMP links.
398  *
399  *	LOCKING:
400  *	Kernel thread context (may sleep).
401  *
402  *	RETURNS:
403  *	0 on success, -errno on failure.
404  */
405 int sata_pmp_attach(struct ata_device *dev)
406 {
407 	struct ata_link *link = dev->link;
408 	struct ata_port *ap = link->ap;
409 	unsigned long flags;
410 	struct ata_link *tlink;
411 	int rc;
412 
413 	/* is it hanging off the right place? */
414 	if (!sata_pmp_supported(ap)) {
415 		ata_dev_printk(dev, KERN_ERR,
416 			       "host does not support Port Multiplier\n");
417 		return -EINVAL;
418 	}
419 
420 	if (!ata_is_host_link(link)) {
421 		ata_dev_printk(dev, KERN_ERR,
422 			       "Port Multipliers cannot be nested\n");
423 		return -EINVAL;
424 	}
425 
426 	if (dev->devno) {
427 		ata_dev_printk(dev, KERN_ERR,
428 			       "Port Multiplier must be the first device\n");
429 		return -EINVAL;
430 	}
431 
432 	WARN_ON(link->pmp != 0);
433 	link->pmp = SATA_PMP_CTRL_PORT;
434 
435 	/* read GSCR block */
436 	rc = sata_pmp_read_gscr(dev, dev->gscr);
437 	if (rc)
438 		goto fail;
439 
440 	/* config PMP */
441 	rc = sata_pmp_configure(dev, 1);
442 	if (rc)
443 		goto fail;
444 
445 	rc = sata_pmp_init_links(ap, sata_pmp_gscr_ports(dev->gscr));
446 	if (rc) {
447 		ata_dev_printk(dev, KERN_INFO,
448 			       "failed to initialize PMP links\n");
449 		goto fail;
450 	}
451 
452 	/* attach it */
453 	spin_lock_irqsave(ap->lock, flags);
454 	WARN_ON(ap->nr_pmp_links);
455 	ap->nr_pmp_links = sata_pmp_gscr_ports(dev->gscr);
456 	spin_unlock_irqrestore(ap->lock, flags);
457 
458 	sata_pmp_quirks(ap);
459 
460 	if (ap->ops->pmp_attach)
461 		ap->ops->pmp_attach(ap);
462 
463 	ata_port_for_each_link(tlink, ap)
464 		sata_link_init_spd(tlink);
465 
466 	ata_acpi_associate_sata_port(ap);
467 
468 	return 0;
469 
470  fail:
471 	link->pmp = 0;
472 	return rc;
473 }
474 
475 /**
476  *	sata_pmp_detach - detach a SATA PMP device
477  *	@dev: SATA PMP device to detach
478  *
479  *	Detach SATA PMP device @dev.  This function is also
480  *	responsible for deconfiguring PMP links.
481  *
482  *	LOCKING:
483  *	Kernel thread context (may sleep).
484  */
485 static void sata_pmp_detach(struct ata_device *dev)
486 {
487 	struct ata_link *link = dev->link;
488 	struct ata_port *ap = link->ap;
489 	struct ata_link *tlink;
490 	unsigned long flags;
491 
492 	ata_dev_printk(dev, KERN_INFO, "Port Multiplier detaching\n");
493 
494 	WARN_ON(!ata_is_host_link(link) || dev->devno ||
495 		link->pmp != SATA_PMP_CTRL_PORT);
496 
497 	if (ap->ops->pmp_detach)
498 		ap->ops->pmp_detach(ap);
499 
500 	ata_port_for_each_link(tlink, ap)
501 		ata_eh_detach_dev(tlink->device);
502 
503 	spin_lock_irqsave(ap->lock, flags);
504 	ap->nr_pmp_links = 0;
505 	link->pmp = 0;
506 	spin_unlock_irqrestore(ap->lock, flags);
507 
508 	ata_acpi_associate_sata_port(ap);
509 }
510 
511 /**
512  *	sata_pmp_same_pmp - does new GSCR matches the configured PMP?
513  *	@dev: PMP device to compare against
514  *	@new_gscr: GSCR block of the new device
515  *
516  *	Compare @new_gscr against @dev and determine whether @dev is
517  *	the PMP described by @new_gscr.
518  *
519  *	LOCKING:
520  *	None.
521  *
522  *	RETURNS:
523  *	1 if @dev matches @new_gscr, 0 otherwise.
524  */
525 static int sata_pmp_same_pmp(struct ata_device *dev, const u32 *new_gscr)
526 {
527 	const u32 *old_gscr = dev->gscr;
528 	u16 old_vendor, new_vendor, old_devid, new_devid;
529 	int old_nr_ports, new_nr_ports;
530 
531 	old_vendor = sata_pmp_gscr_vendor(old_gscr);
532 	new_vendor = sata_pmp_gscr_vendor(new_gscr);
533 	old_devid = sata_pmp_gscr_devid(old_gscr);
534 	new_devid = sata_pmp_gscr_devid(new_gscr);
535 	old_nr_ports = sata_pmp_gscr_ports(old_gscr);
536 	new_nr_ports = sata_pmp_gscr_ports(new_gscr);
537 
538 	if (old_vendor != new_vendor) {
539 		ata_dev_printk(dev, KERN_INFO, "Port Multiplier "
540 			       "vendor mismatch '0x%x' != '0x%x'\n",
541 			       old_vendor, new_vendor);
542 		return 0;
543 	}
544 
545 	if (old_devid != new_devid) {
546 		ata_dev_printk(dev, KERN_INFO, "Port Multiplier "
547 			       "device ID mismatch '0x%x' != '0x%x'\n",
548 			       old_devid, new_devid);
549 		return 0;
550 	}
551 
552 	if (old_nr_ports != new_nr_ports) {
553 		ata_dev_printk(dev, KERN_INFO, "Port Multiplier "
554 			       "nr_ports mismatch '0x%x' != '0x%x'\n",
555 			       old_nr_ports, new_nr_ports);
556 		return 0;
557 	}
558 
559 	return 1;
560 }
561 
562 /**
563  *	sata_pmp_revalidate - revalidate SATA PMP
564  *	@dev: PMP device to revalidate
565  *	@new_class: new class code
566  *
567  *	Re-read GSCR block and make sure @dev is still attached to the
568  *	port and properly configured.
569  *
570  *	LOCKING:
571  *	Kernel thread context (may sleep).
572  *
573  *	RETURNS:
574  *	0 on success, -errno otherwise.
575  */
576 static int sata_pmp_revalidate(struct ata_device *dev, unsigned int new_class)
577 {
578 	struct ata_link *link = dev->link;
579 	struct ata_port *ap = link->ap;
580 	u32 *gscr = (void *)ap->sector_buf;
581 	int rc;
582 
583 	DPRINTK("ENTER\n");
584 
585 	ata_eh_about_to_do(link, NULL, ATA_EH_REVALIDATE);
586 
587 	if (!ata_dev_enabled(dev)) {
588 		rc = -ENODEV;
589 		goto fail;
590 	}
591 
592 	/* wrong class? */
593 	if (ata_class_enabled(new_class) && new_class != ATA_DEV_PMP) {
594 		rc = -ENODEV;
595 		goto fail;
596 	}
597 
598 	/* read GSCR */
599 	rc = sata_pmp_read_gscr(dev, gscr);
600 	if (rc)
601 		goto fail;
602 
603 	/* is the pmp still there? */
604 	if (!sata_pmp_same_pmp(dev, gscr)) {
605 		rc = -ENODEV;
606 		goto fail;
607 	}
608 
609 	memcpy(dev->gscr, gscr, sizeof(gscr[0]) * SATA_PMP_GSCR_DWORDS);
610 
611 	rc = sata_pmp_configure(dev, 0);
612 	if (rc)
613 		goto fail;
614 
615 	ata_eh_done(link, NULL, ATA_EH_REVALIDATE);
616 
617 	DPRINTK("EXIT, rc=0\n");
618 	return 0;
619 
620  fail:
621 	ata_dev_printk(dev, KERN_ERR,
622 		       "PMP revalidation failed (errno=%d)\n", rc);
623 	DPRINTK("EXIT, rc=%d\n", rc);
624 	return rc;
625 }
626 
627 /**
628  *	sata_pmp_revalidate_quick - revalidate SATA PMP quickly
629  *	@dev: PMP device to revalidate
630  *
631  *	Make sure the attached PMP is accessible.
632  *
633  *	LOCKING:
634  *	Kernel thread context (may sleep).
635  *
636  *	RETURNS:
637  *	0 on success, -errno otherwise.
638  */
639 static int sata_pmp_revalidate_quick(struct ata_device *dev)
640 {
641 	unsigned int err_mask;
642 	u32 prod_id;
643 
644 	err_mask = sata_pmp_read(dev->link, SATA_PMP_GSCR_PROD_ID, &prod_id);
645 	if (err_mask) {
646 		ata_dev_printk(dev, KERN_ERR, "failed to read PMP product ID "
647 			       "(Emask=0x%x)\n", err_mask);
648 		return -EIO;
649 	}
650 
651 	if (prod_id != dev->gscr[SATA_PMP_GSCR_PROD_ID]) {
652 		ata_dev_printk(dev, KERN_ERR, "PMP product ID mismatch\n");
653 		/* something weird is going on, request full PMP recovery */
654 		return -EIO;
655 	}
656 
657 	return 0;
658 }
659 
660 /**
661  *	sata_pmp_eh_recover_pmp - recover PMP
662  *	@ap: ATA port PMP is attached to
663  *	@prereset: prereset method (can be NULL)
664  *	@softreset: softreset method
665  *	@hardreset: hardreset method
666  *	@postreset: postreset method (can be NULL)
667  *
668  *	Recover PMP attached to @ap.  Recovery procedure is somewhat
669  *	similar to that of ata_eh_recover() except that reset should
670  *	always be performed in hard->soft sequence and recovery
671  *	failure results in PMP detachment.
672  *
673  *	LOCKING:
674  *	Kernel thread context (may sleep).
675  *
676  *	RETURNS:
677  *	0 on success, -errno on failure.
678  */
679 static int sata_pmp_eh_recover_pmp(struct ata_port *ap,
680 		ata_prereset_fn_t prereset, ata_reset_fn_t softreset,
681 		ata_reset_fn_t hardreset, ata_postreset_fn_t postreset)
682 {
683 	struct ata_link *link = &ap->link;
684 	struct ata_eh_context *ehc = &link->eh_context;
685 	struct ata_device *dev = link->device;
686 	int tries = ATA_EH_PMP_TRIES;
687 	int detach = 0, rc = 0;
688 	int reval_failed = 0;
689 
690 	DPRINTK("ENTER\n");
691 
692 	if (dev->flags & ATA_DFLAG_DETACH) {
693 		detach = 1;
694 		goto fail;
695 	}
696 
697  retry:
698 	ehc->classes[0] = ATA_DEV_UNKNOWN;
699 
700 	if (ehc->i.action & ATA_EH_RESET) {
701 		struct ata_link *tlink;
702 
703 		ata_eh_freeze_port(ap);
704 
705 		/* reset */
706 		rc = ata_eh_reset(link, 0, prereset, softreset, hardreset,
707 				  postreset);
708 		if (rc) {
709 			ata_link_printk(link, KERN_ERR,
710 					"failed to reset PMP, giving up\n");
711 			goto fail;
712 		}
713 
714 		ata_eh_thaw_port(ap);
715 
716 		/* PMP is reset, SErrors cannot be trusted, scan all */
717 		ata_port_for_each_link(tlink, ap) {
718 			struct ata_eh_context *ehc = &tlink->eh_context;
719 
720 			ehc->i.probe_mask |= ATA_ALL_DEVICES;
721 			ehc->i.action |= ATA_EH_RESET;
722 		}
723 	}
724 
725 	/* If revalidation is requested, revalidate and reconfigure;
726 	 * otherwise, do quick revalidation.
727 	 */
728 	if (ehc->i.action & ATA_EH_REVALIDATE)
729 		rc = sata_pmp_revalidate(dev, ehc->classes[0]);
730 	else
731 		rc = sata_pmp_revalidate_quick(dev);
732 
733 	if (rc) {
734 		tries--;
735 
736 		if (rc == -ENODEV) {
737 			ehc->i.probe_mask |= ATA_ALL_DEVICES;
738 			detach = 1;
739 			/* give it just two more chances */
740 			tries = min(tries, 2);
741 		}
742 
743 		if (tries) {
744 			int sleep = ehc->i.flags & ATA_EHI_DID_RESET;
745 
746 			/* consecutive revalidation failures? speed down */
747 			if (reval_failed)
748 				sata_down_spd_limit(link);
749 			else
750 				reval_failed = 1;
751 
752 			ata_dev_printk(dev, KERN_WARNING,
753 				       "retrying reset%s\n",
754 				       sleep ? " in 5 secs" : "");
755 			if (sleep)
756 				ssleep(5);
757 			ehc->i.action |= ATA_EH_RESET;
758 			goto retry;
759 		} else {
760 			ata_dev_printk(dev, KERN_ERR, "failed to recover PMP "
761 				       "after %d tries, giving up\n",
762 				       ATA_EH_PMP_TRIES);
763 			goto fail;
764 		}
765 	}
766 
767 	/* okay, PMP resurrected */
768 	ehc->i.flags = 0;
769 
770 	DPRINTK("EXIT, rc=0\n");
771 	return 0;
772 
773  fail:
774 	sata_pmp_detach(dev);
775 	if (detach)
776 		ata_eh_detach_dev(dev);
777 	else
778 		ata_dev_disable(dev);
779 
780 	DPRINTK("EXIT, rc=%d\n", rc);
781 	return rc;
782 }
783 
784 static int sata_pmp_eh_handle_disabled_links(struct ata_port *ap)
785 {
786 	struct ata_link *link;
787 	unsigned long flags;
788 	int rc;
789 
790 	spin_lock_irqsave(ap->lock, flags);
791 
792 	ata_port_for_each_link(link, ap) {
793 		if (!(link->flags & ATA_LFLAG_DISABLED))
794 			continue;
795 
796 		spin_unlock_irqrestore(ap->lock, flags);
797 
798 		/* Some PMPs require hardreset sequence to get
799 		 * SError.N working.
800 		 */
801 		sata_link_hardreset(link, sata_deb_timing_normal,
802 				jiffies + ATA_TMOUT_INTERNAL_QUICK, NULL, NULL);
803 
804 		/* unconditionally clear SError.N */
805 		rc = sata_scr_write(link, SCR_ERROR, SERR_PHYRDY_CHG);
806 		if (rc) {
807 			ata_link_printk(link, KERN_ERR, "failed to clear "
808 					"SError.N (errno=%d)\n", rc);
809 			return rc;
810 		}
811 
812 		spin_lock_irqsave(ap->lock, flags);
813 	}
814 
815 	spin_unlock_irqrestore(ap->lock, flags);
816 
817 	return 0;
818 }
819 
820 static int sata_pmp_handle_link_fail(struct ata_link *link, int *link_tries)
821 {
822 	struct ata_port *ap = link->ap;
823 	unsigned long flags;
824 
825 	if (link_tries[link->pmp] && --link_tries[link->pmp])
826 		return 1;
827 
828 	/* disable this link */
829 	if (!(link->flags & ATA_LFLAG_DISABLED)) {
830 		ata_link_printk(link, KERN_WARNING,
831 			"failed to recover link after %d tries, disabling\n",
832 			ATA_EH_PMP_LINK_TRIES);
833 
834 		spin_lock_irqsave(ap->lock, flags);
835 		link->flags |= ATA_LFLAG_DISABLED;
836 		spin_unlock_irqrestore(ap->lock, flags);
837 	}
838 
839 	ata_dev_disable(link->device);
840 	link->eh_context.i.action = 0;
841 
842 	return 0;
843 }
844 
845 /**
846  *	sata_pmp_eh_recover - recover PMP-enabled port
847  *	@ap: ATA port to recover
848  *
849  *	Drive EH recovery operation for PMP enabled port @ap.  This
850  *	function recovers host and PMP ports with proper retrials and
851  *	fallbacks.  Actual recovery operations are performed using
852  *	ata_eh_recover() and sata_pmp_eh_recover_pmp().
853  *
854  *	LOCKING:
855  *	Kernel thread context (may sleep).
856  *
857  *	RETURNS:
858  *	0 on success, -errno on failure.
859  */
860 static int sata_pmp_eh_recover(struct ata_port *ap)
861 {
862 	struct ata_port_operations *ops = ap->ops;
863 	int pmp_tries, link_tries[SATA_PMP_MAX_PORTS];
864 	struct ata_link *pmp_link = &ap->link;
865 	struct ata_device *pmp_dev = pmp_link->device;
866 	struct ata_eh_context *pmp_ehc = &pmp_link->eh_context;
867 	struct ata_link *link;
868 	struct ata_device *dev;
869 	unsigned int err_mask;
870 	u32 gscr_error, sntf;
871 	int cnt, rc;
872 
873 	pmp_tries = ATA_EH_PMP_TRIES;
874 	ata_port_for_each_link(link, ap)
875 		link_tries[link->pmp] = ATA_EH_PMP_LINK_TRIES;
876 
877  retry:
878 	/* PMP attached? */
879 	if (!sata_pmp_attached(ap)) {
880 		rc = ata_eh_recover(ap, ops->prereset, ops->softreset,
881 				    ops->hardreset, ops->postreset, NULL);
882 		if (rc) {
883 			ata_link_for_each_dev(dev, &ap->link)
884 				ata_dev_disable(dev);
885 			return rc;
886 		}
887 
888 		if (pmp_dev->class != ATA_DEV_PMP)
889 			return 0;
890 
891 		/* new PMP online */
892 		ata_port_for_each_link(link, ap)
893 			link_tries[link->pmp] = ATA_EH_PMP_LINK_TRIES;
894 
895 		/* fall through */
896 	}
897 
898 	/* recover pmp */
899 	rc = sata_pmp_eh_recover_pmp(ap, ops->prereset, ops->softreset,
900 				     ops->hardreset, ops->postreset);
901 	if (rc)
902 		goto pmp_fail;
903 
904 	/* handle disabled links */
905 	rc = sata_pmp_eh_handle_disabled_links(ap);
906 	if (rc)
907 		goto pmp_fail;
908 
909 	/* recover links */
910 	rc = ata_eh_recover(ap, ops->pmp_prereset, ops->pmp_softreset,
911 			    ops->pmp_hardreset, ops->pmp_postreset, &link);
912 	if (rc)
913 		goto link_fail;
914 
915 	/* Connection status might have changed while resetting other
916 	 * links, check SATA_PMP_GSCR_ERROR before returning.
917 	 */
918 
919 	/* clear SNotification */
920 	rc = sata_scr_read(&ap->link, SCR_NOTIFICATION, &sntf);
921 	if (rc == 0)
922 		sata_scr_write(&ap->link, SCR_NOTIFICATION, sntf);
923 
924 	/* enable notification */
925 	if (pmp_dev->flags & ATA_DFLAG_AN) {
926 		pmp_dev->gscr[SATA_PMP_GSCR_FEAT_EN] |= SATA_PMP_FEAT_NOTIFY;
927 
928 		err_mask = sata_pmp_write(pmp_dev->link, SATA_PMP_GSCR_FEAT_EN,
929 					  pmp_dev->gscr[SATA_PMP_GSCR_FEAT_EN]);
930 		if (err_mask) {
931 			ata_dev_printk(pmp_dev, KERN_ERR, "failed to write "
932 				       "PMP_FEAT_EN (Emask=0x%x)\n", err_mask);
933 			rc = -EIO;
934 			goto pmp_fail;
935 		}
936 	}
937 
938 	/* check GSCR_ERROR */
939 	err_mask = sata_pmp_read(pmp_link, SATA_PMP_GSCR_ERROR, &gscr_error);
940 	if (err_mask) {
941 		ata_dev_printk(pmp_dev, KERN_ERR, "failed to read "
942 			       "PMP_GSCR_ERROR (Emask=0x%x)\n", err_mask);
943 		rc = -EIO;
944 		goto pmp_fail;
945 	}
946 
947 	cnt = 0;
948 	ata_port_for_each_link(link, ap) {
949 		if (!(gscr_error & (1 << link->pmp)))
950 			continue;
951 
952 		if (sata_pmp_handle_link_fail(link, link_tries)) {
953 			ata_ehi_hotplugged(&link->eh_context.i);
954 			cnt++;
955 		} else {
956 			ata_link_printk(link, KERN_WARNING,
957 				"PHY status changed but maxed out on retries, "
958 				"giving up\n");
959 			ata_link_printk(link, KERN_WARNING,
960 				"Manully issue scan to resume this link\n");
961 		}
962 	}
963 
964 	if (cnt) {
965 		ata_port_printk(ap, KERN_INFO, "PMP SError.N set for some "
966 				"ports, repeating recovery\n");
967 		goto retry;
968 	}
969 
970 	return 0;
971 
972  link_fail:
973 	if (sata_pmp_handle_link_fail(link, link_tries)) {
974 		pmp_ehc->i.action |= ATA_EH_RESET;
975 		goto retry;
976 	}
977 
978 	/* fall through */
979  pmp_fail:
980 	/* Control always ends up here after detaching PMP.  Shut up
981 	 * and return if we're unloading.
982 	 */
983 	if (ap->pflags & ATA_PFLAG_UNLOADING)
984 		return rc;
985 
986 	if (!sata_pmp_attached(ap))
987 		goto retry;
988 
989 	if (--pmp_tries) {
990 		ata_port_printk(ap, KERN_WARNING,
991 				"failed to recover PMP, retrying in 5 secs\n");
992 		pmp_ehc->i.action |= ATA_EH_RESET;
993 		ssleep(5);
994 		goto retry;
995 	}
996 
997 	ata_port_printk(ap, KERN_ERR,
998 			"failed to recover PMP after %d tries, giving up\n",
999 			ATA_EH_PMP_TRIES);
1000 	sata_pmp_detach(pmp_dev);
1001 	ata_dev_disable(pmp_dev);
1002 
1003 	return rc;
1004 }
1005 
1006 /**
1007  *	sata_pmp_error_handler - do standard error handling for PMP-enabled host
1008  *	@ap: host port to handle error for
1009  *
1010  *	Perform standard error handling sequence for PMP-enabled host
1011  *	@ap.
1012  *
1013  *	LOCKING:
1014  *	Kernel thread context (may sleep).
1015  */
1016 void sata_pmp_error_handler(struct ata_port *ap)
1017 {
1018 	ata_eh_autopsy(ap);
1019 	ata_eh_report(ap);
1020 	sata_pmp_eh_recover(ap);
1021 	ata_eh_finish(ap);
1022 }
1023 
1024 EXPORT_SYMBOL_GPL(sata_pmp_port_ops);
1025 EXPORT_SYMBOL_GPL(sata_pmp_qc_defer_cmd_switch);
1026 EXPORT_SYMBOL_GPL(sata_pmp_error_handler);
1027