xref: /openbmc/linux/drivers/ata/libata-pmp.c (revision b6dcefde)
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_RW_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_RW_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 << 3))
225 		return "1.2";
226 	if (rev & (1 << 2))
227 		return "1.1";
228 	if (rev & (1 << 1))
229 		return "1.0";
230 	return "<unknown>";
231 }
232 
233 static int sata_pmp_configure(struct ata_device *dev, int print_info)
234 {
235 	struct ata_port *ap = dev->link->ap;
236 	u32 *gscr = dev->gscr;
237 	unsigned int err_mask = 0;
238 	const char *reason;
239 	int nr_ports, rc;
240 
241 	nr_ports = sata_pmp_gscr_ports(gscr);
242 
243 	if (nr_ports <= 0 || nr_ports > SATA_PMP_MAX_PORTS) {
244 		rc = -EINVAL;
245 		reason = "invalid nr_ports";
246 		goto fail;
247 	}
248 
249 	if ((ap->flags & ATA_FLAG_AN) &&
250 	    (gscr[SATA_PMP_GSCR_FEAT] & SATA_PMP_FEAT_NOTIFY))
251 		dev->flags |= ATA_DFLAG_AN;
252 
253 	/* monitor SERR_PHYRDY_CHG on fan-out ports */
254 	err_mask = sata_pmp_write(dev->link, SATA_PMP_GSCR_ERROR_EN,
255 				  SERR_PHYRDY_CHG);
256 	if (err_mask) {
257 		rc = -EIO;
258 		reason = "failed to write GSCR_ERROR_EN";
259 		goto fail;
260 	}
261 
262 	if (print_info) {
263 		ata_dev_printk(dev, KERN_INFO, "Port Multiplier %s, "
264 			       "0x%04x:0x%04x r%d, %d ports, feat 0x%x/0x%x\n",
265 			       sata_pmp_spec_rev_str(gscr),
266 			       sata_pmp_gscr_vendor(gscr),
267 			       sata_pmp_gscr_devid(gscr),
268 			       sata_pmp_gscr_rev(gscr),
269 			       nr_ports, gscr[SATA_PMP_GSCR_FEAT_EN],
270 			       gscr[SATA_PMP_GSCR_FEAT]);
271 
272 		if (!(dev->flags & ATA_DFLAG_AN))
273 			ata_dev_printk(dev, KERN_INFO,
274 				"Asynchronous notification not supported, "
275 				"hotplug won't\n         work on fan-out "
276 				"ports. Use warm-plug instead.\n");
277 	}
278 
279 	return 0;
280 
281  fail:
282 	ata_dev_printk(dev, KERN_ERR,
283 		       "failed to configure Port Multiplier (%s, Emask=0x%x)\n",
284 		       reason, err_mask);
285 	return rc;
286 }
287 
288 static int sata_pmp_init_links(struct ata_port *ap, int nr_ports)
289 {
290 	struct ata_link *pmp_link = ap->pmp_link;
291 	int i;
292 
293 	if (!pmp_link) {
294 		pmp_link = kzalloc(sizeof(pmp_link[0]) * SATA_PMP_MAX_PORTS,
295 				   GFP_NOIO);
296 		if (!pmp_link)
297 			return -ENOMEM;
298 
299 		for (i = 0; i < SATA_PMP_MAX_PORTS; i++)
300 			ata_link_init(ap, &pmp_link[i], i);
301 
302 		ap->pmp_link = pmp_link;
303 	}
304 
305 	for (i = 0; i < nr_ports; i++) {
306 		struct ata_link *link = &pmp_link[i];
307 		struct ata_eh_context *ehc = &link->eh_context;
308 
309 		link->flags = 0;
310 		ehc->i.probe_mask |= ATA_ALL_DEVICES;
311 		ehc->i.action |= ATA_EH_RESET;
312 	}
313 
314 	return 0;
315 }
316 
317 static void sata_pmp_quirks(struct ata_port *ap)
318 {
319 	u32 *gscr = ap->link.device->gscr;
320 	u16 vendor = sata_pmp_gscr_vendor(gscr);
321 	u16 devid = sata_pmp_gscr_devid(gscr);
322 	struct ata_link *link;
323 
324 	if (vendor == 0x1095 && devid == 0x3726) {
325 		/* sil3726 quirks */
326 		ata_for_each_link(link, ap, EDGE) {
327 			/* Class code report is unreliable and SRST
328 			 * times out under certain configurations.
329 			 */
330 			if (link->pmp < 5)
331 				link->flags |= ATA_LFLAG_NO_SRST |
332 					       ATA_LFLAG_ASSUME_ATA;
333 
334 			/* port 5 is for SEMB device and it doesn't like SRST */
335 			if (link->pmp == 5)
336 				link->flags |= ATA_LFLAG_NO_SRST |
337 					       ATA_LFLAG_ASSUME_SEMB;
338 		}
339 	} else if (vendor == 0x1095 && devid == 0x4723) {
340 		/* sil4723 quirks */
341 		ata_for_each_link(link, ap, EDGE) {
342 			/* class code report is unreliable */
343 			if (link->pmp < 2)
344 				link->flags |= ATA_LFLAG_ASSUME_ATA;
345 
346 			/* the config device at port 2 locks up on SRST */
347 			if (link->pmp == 2)
348 				link->flags |= ATA_LFLAG_NO_SRST |
349 					       ATA_LFLAG_ASSUME_ATA;
350 		}
351 	} else if (vendor == 0x1095 && devid == 0x4726) {
352 		/* sil4726 quirks */
353 		ata_for_each_link(link, ap, EDGE) {
354 			/* Class code report is unreliable and SRST
355 			 * times out under certain configurations.
356 			 * Config device can be at port 0 or 5 and
357 			 * locks up on SRST.
358 			 */
359 			if (link->pmp <= 5)
360 				link->flags |= ATA_LFLAG_NO_SRST |
361 					       ATA_LFLAG_ASSUME_ATA;
362 
363 			/* Port 6 is for SEMB device which doesn't
364 			 * like SRST either.
365 			 */
366 			if (link->pmp == 6)
367 				link->flags |= ATA_LFLAG_NO_SRST |
368 					       ATA_LFLAG_ASSUME_SEMB;
369 		}
370 	} else if (vendor == 0x1095 && (devid == 0x5723 || devid == 0x5733 ||
371 					devid == 0x5734 || devid == 0x5744)) {
372 		/* sil5723/5744 quirks */
373 
374 		/* sil5723/5744 has either two or three downstream
375 		 * ports depending on operation mode.  The last port
376 		 * is empty if any actual IO device is available or
377 		 * occupied by a pseudo configuration device
378 		 * otherwise.  Don't try hard to recover it.
379 		 */
380 		ap->pmp_link[ap->nr_pmp_links - 1].flags |= ATA_LFLAG_NO_RETRY;
381 	}
382 }
383 
384 /**
385  *	sata_pmp_attach - attach a SATA PMP device
386  *	@dev: SATA PMP device to attach
387  *
388  *	Configure and attach SATA PMP device @dev.  This function is
389  *	also responsible for allocating and initializing PMP links.
390  *
391  *	LOCKING:
392  *	Kernel thread context (may sleep).
393  *
394  *	RETURNS:
395  *	0 on success, -errno on failure.
396  */
397 int sata_pmp_attach(struct ata_device *dev)
398 {
399 	struct ata_link *link = dev->link;
400 	struct ata_port *ap = link->ap;
401 	unsigned long flags;
402 	struct ata_link *tlink;
403 	int rc;
404 
405 	/* is it hanging off the right place? */
406 	if (!sata_pmp_supported(ap)) {
407 		ata_dev_printk(dev, KERN_ERR,
408 			       "host does not support Port Multiplier\n");
409 		return -EINVAL;
410 	}
411 
412 	if (!ata_is_host_link(link)) {
413 		ata_dev_printk(dev, KERN_ERR,
414 			       "Port Multipliers cannot be nested\n");
415 		return -EINVAL;
416 	}
417 
418 	if (dev->devno) {
419 		ata_dev_printk(dev, KERN_ERR,
420 			       "Port Multiplier must be the first device\n");
421 		return -EINVAL;
422 	}
423 
424 	WARN_ON(link->pmp != 0);
425 	link->pmp = SATA_PMP_CTRL_PORT;
426 
427 	/* read GSCR block */
428 	rc = sata_pmp_read_gscr(dev, dev->gscr);
429 	if (rc)
430 		goto fail;
431 
432 	/* config PMP */
433 	rc = sata_pmp_configure(dev, 1);
434 	if (rc)
435 		goto fail;
436 
437 	rc = sata_pmp_init_links(ap, sata_pmp_gscr_ports(dev->gscr));
438 	if (rc) {
439 		ata_dev_printk(dev, KERN_INFO,
440 			       "failed to initialize PMP links\n");
441 		goto fail;
442 	}
443 
444 	/* attach it */
445 	spin_lock_irqsave(ap->lock, flags);
446 	WARN_ON(ap->nr_pmp_links);
447 	ap->nr_pmp_links = sata_pmp_gscr_ports(dev->gscr);
448 	spin_unlock_irqrestore(ap->lock, flags);
449 
450 	sata_pmp_quirks(ap);
451 
452 	if (ap->ops->pmp_attach)
453 		ap->ops->pmp_attach(ap);
454 
455 	ata_for_each_link(tlink, ap, EDGE)
456 		sata_link_init_spd(tlink);
457 
458 	ata_acpi_associate_sata_port(ap);
459 
460 	return 0;
461 
462  fail:
463 	link->pmp = 0;
464 	return rc;
465 }
466 
467 /**
468  *	sata_pmp_detach - detach a SATA PMP device
469  *	@dev: SATA PMP device to detach
470  *
471  *	Detach SATA PMP device @dev.  This function is also
472  *	responsible for deconfiguring PMP links.
473  *
474  *	LOCKING:
475  *	Kernel thread context (may sleep).
476  */
477 static void sata_pmp_detach(struct ata_device *dev)
478 {
479 	struct ata_link *link = dev->link;
480 	struct ata_port *ap = link->ap;
481 	struct ata_link *tlink;
482 	unsigned long flags;
483 
484 	ata_dev_printk(dev, KERN_INFO, "Port Multiplier detaching\n");
485 
486 	WARN_ON(!ata_is_host_link(link) || dev->devno ||
487 		link->pmp != SATA_PMP_CTRL_PORT);
488 
489 	if (ap->ops->pmp_detach)
490 		ap->ops->pmp_detach(ap);
491 
492 	ata_for_each_link(tlink, ap, EDGE)
493 		ata_eh_detach_dev(tlink->device);
494 
495 	spin_lock_irqsave(ap->lock, flags);
496 	ap->nr_pmp_links = 0;
497 	link->pmp = 0;
498 	spin_unlock_irqrestore(ap->lock, flags);
499 
500 	ata_acpi_associate_sata_port(ap);
501 }
502 
503 /**
504  *	sata_pmp_same_pmp - does new GSCR matches the configured PMP?
505  *	@dev: PMP device to compare against
506  *	@new_gscr: GSCR block of the new device
507  *
508  *	Compare @new_gscr against @dev and determine whether @dev is
509  *	the PMP described by @new_gscr.
510  *
511  *	LOCKING:
512  *	None.
513  *
514  *	RETURNS:
515  *	1 if @dev matches @new_gscr, 0 otherwise.
516  */
517 static int sata_pmp_same_pmp(struct ata_device *dev, const u32 *new_gscr)
518 {
519 	const u32 *old_gscr = dev->gscr;
520 	u16 old_vendor, new_vendor, old_devid, new_devid;
521 	int old_nr_ports, new_nr_ports;
522 
523 	old_vendor = sata_pmp_gscr_vendor(old_gscr);
524 	new_vendor = sata_pmp_gscr_vendor(new_gscr);
525 	old_devid = sata_pmp_gscr_devid(old_gscr);
526 	new_devid = sata_pmp_gscr_devid(new_gscr);
527 	old_nr_ports = sata_pmp_gscr_ports(old_gscr);
528 	new_nr_ports = sata_pmp_gscr_ports(new_gscr);
529 
530 	if (old_vendor != new_vendor) {
531 		ata_dev_printk(dev, KERN_INFO, "Port Multiplier "
532 			       "vendor mismatch '0x%x' != '0x%x'\n",
533 			       old_vendor, new_vendor);
534 		return 0;
535 	}
536 
537 	if (old_devid != new_devid) {
538 		ata_dev_printk(dev, KERN_INFO, "Port Multiplier "
539 			       "device ID mismatch '0x%x' != '0x%x'\n",
540 			       old_devid, new_devid);
541 		return 0;
542 	}
543 
544 	if (old_nr_ports != new_nr_ports) {
545 		ata_dev_printk(dev, KERN_INFO, "Port Multiplier "
546 			       "nr_ports mismatch '0x%x' != '0x%x'\n",
547 			       old_nr_ports, new_nr_ports);
548 		return 0;
549 	}
550 
551 	return 1;
552 }
553 
554 /**
555  *	sata_pmp_revalidate - revalidate SATA PMP
556  *	@dev: PMP device to revalidate
557  *	@new_class: new class code
558  *
559  *	Re-read GSCR block and make sure @dev is still attached to the
560  *	port and properly configured.
561  *
562  *	LOCKING:
563  *	Kernel thread context (may sleep).
564  *
565  *	RETURNS:
566  *	0 on success, -errno otherwise.
567  */
568 static int sata_pmp_revalidate(struct ata_device *dev, unsigned int new_class)
569 {
570 	struct ata_link *link = dev->link;
571 	struct ata_port *ap = link->ap;
572 	u32 *gscr = (void *)ap->sector_buf;
573 	int rc;
574 
575 	DPRINTK("ENTER\n");
576 
577 	ata_eh_about_to_do(link, NULL, ATA_EH_REVALIDATE);
578 
579 	if (!ata_dev_enabled(dev)) {
580 		rc = -ENODEV;
581 		goto fail;
582 	}
583 
584 	/* wrong class? */
585 	if (ata_class_enabled(new_class) && new_class != ATA_DEV_PMP) {
586 		rc = -ENODEV;
587 		goto fail;
588 	}
589 
590 	/* read GSCR */
591 	rc = sata_pmp_read_gscr(dev, gscr);
592 	if (rc)
593 		goto fail;
594 
595 	/* is the pmp still there? */
596 	if (!sata_pmp_same_pmp(dev, gscr)) {
597 		rc = -ENODEV;
598 		goto fail;
599 	}
600 
601 	memcpy(dev->gscr, gscr, sizeof(gscr[0]) * SATA_PMP_GSCR_DWORDS);
602 
603 	rc = sata_pmp_configure(dev, 0);
604 	if (rc)
605 		goto fail;
606 
607 	ata_eh_done(link, NULL, ATA_EH_REVALIDATE);
608 
609 	DPRINTK("EXIT, rc=0\n");
610 	return 0;
611 
612  fail:
613 	ata_dev_printk(dev, KERN_ERR,
614 		       "PMP revalidation failed (errno=%d)\n", rc);
615 	DPRINTK("EXIT, rc=%d\n", rc);
616 	return rc;
617 }
618 
619 /**
620  *	sata_pmp_revalidate_quick - revalidate SATA PMP quickly
621  *	@dev: PMP device to revalidate
622  *
623  *	Make sure the attached PMP is accessible.
624  *
625  *	LOCKING:
626  *	Kernel thread context (may sleep).
627  *
628  *	RETURNS:
629  *	0 on success, -errno otherwise.
630  */
631 static int sata_pmp_revalidate_quick(struct ata_device *dev)
632 {
633 	unsigned int err_mask;
634 	u32 prod_id;
635 
636 	err_mask = sata_pmp_read(dev->link, SATA_PMP_GSCR_PROD_ID, &prod_id);
637 	if (err_mask) {
638 		ata_dev_printk(dev, KERN_ERR, "failed to read PMP product ID "
639 			       "(Emask=0x%x)\n", err_mask);
640 		return -EIO;
641 	}
642 
643 	if (prod_id != dev->gscr[SATA_PMP_GSCR_PROD_ID]) {
644 		ata_dev_printk(dev, KERN_ERR, "PMP product ID mismatch\n");
645 		/* something weird is going on, request full PMP recovery */
646 		return -EIO;
647 	}
648 
649 	return 0;
650 }
651 
652 /**
653  *	sata_pmp_eh_recover_pmp - recover PMP
654  *	@ap: ATA port PMP is attached to
655  *	@prereset: prereset method (can be NULL)
656  *	@softreset: softreset method
657  *	@hardreset: hardreset method
658  *	@postreset: postreset method (can be NULL)
659  *
660  *	Recover PMP attached to @ap.  Recovery procedure is somewhat
661  *	similar to that of ata_eh_recover() except that reset should
662  *	always be performed in hard->soft sequence and recovery
663  *	failure results in PMP detachment.
664  *
665  *	LOCKING:
666  *	Kernel thread context (may sleep).
667  *
668  *	RETURNS:
669  *	0 on success, -errno on failure.
670  */
671 static int sata_pmp_eh_recover_pmp(struct ata_port *ap,
672 		ata_prereset_fn_t prereset, ata_reset_fn_t softreset,
673 		ata_reset_fn_t hardreset, ata_postreset_fn_t postreset)
674 {
675 	struct ata_link *link = &ap->link;
676 	struct ata_eh_context *ehc = &link->eh_context;
677 	struct ata_device *dev = link->device;
678 	int tries = ATA_EH_PMP_TRIES;
679 	int detach = 0, rc = 0;
680 	int reval_failed = 0;
681 
682 	DPRINTK("ENTER\n");
683 
684 	if (dev->flags & ATA_DFLAG_DETACH) {
685 		detach = 1;
686 		goto fail;
687 	}
688 
689  retry:
690 	ehc->classes[0] = ATA_DEV_UNKNOWN;
691 
692 	if (ehc->i.action & ATA_EH_RESET) {
693 		struct ata_link *tlink;
694 
695 		/* reset */
696 		rc = ata_eh_reset(link, 0, prereset, softreset, hardreset,
697 				  postreset);
698 		if (rc) {
699 			ata_link_printk(link, KERN_ERR,
700 					"failed to reset PMP, giving up\n");
701 			goto fail;
702 		}
703 
704 		/* PMP is reset, SErrors cannot be trusted, scan all */
705 		ata_for_each_link(tlink, ap, EDGE) {
706 			struct ata_eh_context *ehc = &tlink->eh_context;
707 
708 			ehc->i.probe_mask |= ATA_ALL_DEVICES;
709 			ehc->i.action |= ATA_EH_RESET;
710 		}
711 	}
712 
713 	/* If revalidation is requested, revalidate and reconfigure;
714 	 * otherwise, do quick revalidation.
715 	 */
716 	if (ehc->i.action & ATA_EH_REVALIDATE)
717 		rc = sata_pmp_revalidate(dev, ehc->classes[0]);
718 	else
719 		rc = sata_pmp_revalidate_quick(dev);
720 
721 	if (rc) {
722 		tries--;
723 
724 		if (rc == -ENODEV) {
725 			ehc->i.probe_mask |= ATA_ALL_DEVICES;
726 			detach = 1;
727 			/* give it just two more chances */
728 			tries = min(tries, 2);
729 		}
730 
731 		if (tries) {
732 			/* consecutive revalidation failures? speed down */
733 			if (reval_failed)
734 				sata_down_spd_limit(link, 0);
735 			else
736 				reval_failed = 1;
737 
738 			ehc->i.action |= ATA_EH_RESET;
739 			goto retry;
740 		} else {
741 			ata_dev_printk(dev, KERN_ERR, "failed to recover PMP "
742 				       "after %d tries, giving up\n",
743 				       ATA_EH_PMP_TRIES);
744 			goto fail;
745 		}
746 	}
747 
748 	/* okay, PMP resurrected */
749 	ehc->i.flags = 0;
750 
751 	DPRINTK("EXIT, rc=0\n");
752 	return 0;
753 
754  fail:
755 	sata_pmp_detach(dev);
756 	if (detach)
757 		ata_eh_detach_dev(dev);
758 	else
759 		ata_dev_disable(dev);
760 
761 	DPRINTK("EXIT, rc=%d\n", rc);
762 	return rc;
763 }
764 
765 static int sata_pmp_eh_handle_disabled_links(struct ata_port *ap)
766 {
767 	struct ata_link *link;
768 	unsigned long flags;
769 	int rc;
770 
771 	spin_lock_irqsave(ap->lock, flags);
772 
773 	ata_for_each_link(link, ap, EDGE) {
774 		if (!(link->flags & ATA_LFLAG_DISABLED))
775 			continue;
776 
777 		spin_unlock_irqrestore(ap->lock, flags);
778 
779 		/* Some PMPs require hardreset sequence to get
780 		 * SError.N working.
781 		 */
782 		sata_link_hardreset(link, sata_deb_timing_normal,
783 				ata_deadline(jiffies, ATA_TMOUT_INTERNAL_QUICK),
784 				NULL, NULL);
785 
786 		/* unconditionally clear SError.N */
787 		rc = sata_scr_write(link, SCR_ERROR, SERR_PHYRDY_CHG);
788 		if (rc) {
789 			ata_link_printk(link, KERN_ERR, "failed to clear "
790 					"SError.N (errno=%d)\n", rc);
791 			return rc;
792 		}
793 
794 		spin_lock_irqsave(ap->lock, flags);
795 	}
796 
797 	spin_unlock_irqrestore(ap->lock, flags);
798 
799 	return 0;
800 }
801 
802 static int sata_pmp_handle_link_fail(struct ata_link *link, int *link_tries)
803 {
804 	struct ata_port *ap = link->ap;
805 	unsigned long flags;
806 
807 	if (link_tries[link->pmp] && --link_tries[link->pmp])
808 		return 1;
809 
810 	/* disable this link */
811 	if (!(link->flags & ATA_LFLAG_DISABLED)) {
812 		ata_link_printk(link, KERN_WARNING,
813 			"failed to recover link after %d tries, disabling\n",
814 			ATA_EH_PMP_LINK_TRIES);
815 
816 		spin_lock_irqsave(ap->lock, flags);
817 		link->flags |= ATA_LFLAG_DISABLED;
818 		spin_unlock_irqrestore(ap->lock, flags);
819 	}
820 
821 	ata_dev_disable(link->device);
822 	link->eh_context.i.action = 0;
823 
824 	return 0;
825 }
826 
827 /**
828  *	sata_pmp_eh_recover - recover PMP-enabled port
829  *	@ap: ATA port to recover
830  *
831  *	Drive EH recovery operation for PMP enabled port @ap.  This
832  *	function recovers host and PMP ports with proper retrials and
833  *	fallbacks.  Actual recovery operations are performed using
834  *	ata_eh_recover() and sata_pmp_eh_recover_pmp().
835  *
836  *	LOCKING:
837  *	Kernel thread context (may sleep).
838  *
839  *	RETURNS:
840  *	0 on success, -errno on failure.
841  */
842 static int sata_pmp_eh_recover(struct ata_port *ap)
843 {
844 	struct ata_port_operations *ops = ap->ops;
845 	int pmp_tries, link_tries[SATA_PMP_MAX_PORTS];
846 	struct ata_link *pmp_link = &ap->link;
847 	struct ata_device *pmp_dev = pmp_link->device;
848 	struct ata_eh_context *pmp_ehc = &pmp_link->eh_context;
849 	u32 *gscr = pmp_dev->gscr;
850 	struct ata_link *link;
851 	struct ata_device *dev;
852 	unsigned int err_mask;
853 	u32 gscr_error, sntf;
854 	int cnt, rc;
855 
856 	pmp_tries = ATA_EH_PMP_TRIES;
857 	ata_for_each_link(link, ap, EDGE)
858 		link_tries[link->pmp] = ATA_EH_PMP_LINK_TRIES;
859 
860  retry:
861 	/* PMP attached? */
862 	if (!sata_pmp_attached(ap)) {
863 		rc = ata_eh_recover(ap, ops->prereset, ops->softreset,
864 				    ops->hardreset, ops->postreset, NULL);
865 		if (rc) {
866 			ata_for_each_dev(dev, &ap->link, ALL)
867 				ata_dev_disable(dev);
868 			return rc;
869 		}
870 
871 		if (pmp_dev->class != ATA_DEV_PMP)
872 			return 0;
873 
874 		/* new PMP online */
875 		ata_for_each_link(link, ap, EDGE)
876 			link_tries[link->pmp] = ATA_EH_PMP_LINK_TRIES;
877 
878 		/* fall through */
879 	}
880 
881 	/* recover pmp */
882 	rc = sata_pmp_eh_recover_pmp(ap, ops->prereset, ops->softreset,
883 				     ops->hardreset, ops->postreset);
884 	if (rc)
885 		goto pmp_fail;
886 
887 	/* PHY event notification can disturb reset and other recovery
888 	 * operations.  Turn it off.
889 	 */
890 	if (gscr[SATA_PMP_GSCR_FEAT_EN] & SATA_PMP_FEAT_NOTIFY) {
891 		gscr[SATA_PMP_GSCR_FEAT_EN] &= ~SATA_PMP_FEAT_NOTIFY;
892 
893 		err_mask = sata_pmp_write(pmp_link, SATA_PMP_GSCR_FEAT_EN,
894 					  gscr[SATA_PMP_GSCR_FEAT_EN]);
895 		if (err_mask) {
896 			ata_link_printk(pmp_link, KERN_WARNING,
897 				"failed to disable NOTIFY (err_mask=0x%x)\n",
898 				err_mask);
899 			goto pmp_fail;
900 		}
901 	}
902 
903 	/* handle disabled links */
904 	rc = sata_pmp_eh_handle_disabled_links(ap);
905 	if (rc)
906 		goto pmp_fail;
907 
908 	/* recover links */
909 	rc = ata_eh_recover(ap, ops->pmp_prereset, ops->pmp_softreset,
910 			    ops->pmp_hardreset, ops->pmp_postreset, &link);
911 	if (rc)
912 		goto link_fail;
913 
914 	/* Connection status might have changed while resetting other
915 	 * links, check SATA_PMP_GSCR_ERROR before returning.
916 	 */
917 
918 	/* clear SNotification */
919 	rc = sata_scr_read(&ap->link, SCR_NOTIFICATION, &sntf);
920 	if (rc == 0)
921 		sata_scr_write(&ap->link, SCR_NOTIFICATION, sntf);
922 
923 	/* enable notification */
924 	if (pmp_dev->flags & ATA_DFLAG_AN) {
925 		gscr[SATA_PMP_GSCR_FEAT_EN] |= SATA_PMP_FEAT_NOTIFY;
926 
927 		err_mask = sata_pmp_write(pmp_link, SATA_PMP_GSCR_FEAT_EN,
928 					  gscr[SATA_PMP_GSCR_FEAT_EN]);
929 		if (err_mask) {
930 			ata_dev_printk(pmp_dev, KERN_ERR, "failed to write "
931 				       "PMP_FEAT_EN (Emask=0x%x)\n", err_mask);
932 			rc = -EIO;
933 			goto pmp_fail;
934 		}
935 	}
936 
937 	/* check GSCR_ERROR */
938 	err_mask = sata_pmp_read(pmp_link, SATA_PMP_GSCR_ERROR, &gscr_error);
939 	if (err_mask) {
940 		ata_dev_printk(pmp_dev, KERN_ERR, "failed to read "
941 			       "PMP_GSCR_ERROR (Emask=0x%x)\n", err_mask);
942 		rc = -EIO;
943 		goto pmp_fail;
944 	}
945 
946 	cnt = 0;
947 	ata_for_each_link(link, ap, EDGE) {
948 		if (!(gscr_error & (1 << link->pmp)))
949 			continue;
950 
951 		if (sata_pmp_handle_link_fail(link, link_tries)) {
952 			ata_ehi_hotplugged(&link->eh_context.i);
953 			cnt++;
954 		} else {
955 			ata_link_printk(link, KERN_WARNING,
956 				"PHY status changed but maxed out on retries, "
957 				"giving up\n");
958 			ata_link_printk(link, KERN_WARNING,
959 				"Manully issue scan to resume this link\n");
960 		}
961 	}
962 
963 	if (cnt) {
964 		ata_port_printk(ap, KERN_INFO, "PMP SError.N set for some "
965 				"ports, repeating recovery\n");
966 		goto retry;
967 	}
968 
969 	return 0;
970 
971  link_fail:
972 	if (sata_pmp_handle_link_fail(link, link_tries)) {
973 		pmp_ehc->i.action |= ATA_EH_RESET;
974 		goto retry;
975 	}
976 
977 	/* fall through */
978  pmp_fail:
979 	/* Control always ends up here after detaching PMP.  Shut up
980 	 * and return if we're unloading.
981 	 */
982 	if (ap->pflags & ATA_PFLAG_UNLOADING)
983 		return rc;
984 
985 	if (!sata_pmp_attached(ap))
986 		goto retry;
987 
988 	if (--pmp_tries) {
989 		pmp_ehc->i.action |= ATA_EH_RESET;
990 		goto retry;
991 	}
992 
993 	ata_port_printk(ap, KERN_ERR,
994 			"failed to recover PMP after %d tries, giving up\n",
995 			ATA_EH_PMP_TRIES);
996 	sata_pmp_detach(pmp_dev);
997 	ata_dev_disable(pmp_dev);
998 
999 	return rc;
1000 }
1001 
1002 /**
1003  *	sata_pmp_error_handler - do standard error handling for PMP-enabled host
1004  *	@ap: host port to handle error for
1005  *
1006  *	Perform standard error handling sequence for PMP-enabled host
1007  *	@ap.
1008  *
1009  *	LOCKING:
1010  *	Kernel thread context (may sleep).
1011  */
1012 void sata_pmp_error_handler(struct ata_port *ap)
1013 {
1014 	ata_eh_autopsy(ap);
1015 	ata_eh_report(ap);
1016 	sata_pmp_eh_recover(ap);
1017 	ata_eh_finish(ap);
1018 }
1019 
1020 EXPORT_SYMBOL_GPL(sata_pmp_port_ops);
1021 EXPORT_SYMBOL_GPL(sata_pmp_qc_defer_cmd_switch);
1022 EXPORT_SYMBOL_GPL(sata_pmp_error_handler);
1023