xref: /openbmc/linux/drivers/ata/libata-pmp.c (revision 732a675a)
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 << 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 	if (print_info) {
261 		ata_dev_printk(dev, KERN_INFO, "Port Multiplier %s, "
262 			       "0x%04x:0x%04x r%d, %d ports, feat 0x%x/0x%x\n",
263 			       sata_pmp_spec_rev_str(gscr),
264 			       sata_pmp_gscr_vendor(gscr),
265 			       sata_pmp_gscr_devid(gscr),
266 			       sata_pmp_gscr_rev(gscr),
267 			       nr_ports, gscr[SATA_PMP_GSCR_FEAT_EN],
268 			       gscr[SATA_PMP_GSCR_FEAT]);
269 
270 		if (!(dev->flags & ATA_DFLAG_AN))
271 			ata_dev_printk(dev, KERN_INFO,
272 				"Asynchronous notification not supported, "
273 				"hotplug won't\n         work on fan-out "
274 				"ports. Use warm-plug instead.\n");
275 	}
276 
277 	return 0;
278 
279  fail:
280 	ata_dev_printk(dev, KERN_ERR,
281 		       "failed to configure Port Multiplier (%s, Emask=0x%x)\n",
282 		       reason, err_mask);
283 	return rc;
284 }
285 
286 static int sata_pmp_init_links(struct ata_port *ap, int nr_ports)
287 {
288 	struct ata_link *pmp_link = ap->pmp_link;
289 	int i;
290 
291 	if (!pmp_link) {
292 		pmp_link = kzalloc(sizeof(pmp_link[0]) * SATA_PMP_MAX_PORTS,
293 				   GFP_NOIO);
294 		if (!pmp_link)
295 			return -ENOMEM;
296 
297 		for (i = 0; i < SATA_PMP_MAX_PORTS; i++)
298 			ata_link_init(ap, &pmp_link[i], i);
299 
300 		ap->pmp_link = pmp_link;
301 	}
302 
303 	for (i = 0; i < nr_ports; i++) {
304 		struct ata_link *link = &pmp_link[i];
305 		struct ata_eh_context *ehc = &link->eh_context;
306 
307 		link->flags = 0;
308 		ehc->i.probe_mask |= ATA_ALL_DEVICES;
309 		ehc->i.action |= ATA_EH_RESET;
310 	}
311 
312 	return 0;
313 }
314 
315 static void sata_pmp_quirks(struct ata_port *ap)
316 {
317 	u32 *gscr = ap->link.device->gscr;
318 	u16 vendor = sata_pmp_gscr_vendor(gscr);
319 	u16 devid = sata_pmp_gscr_devid(gscr);
320 	struct ata_link *link;
321 
322 	if (vendor == 0x1095 && devid == 0x3726) {
323 		/* sil3726 quirks */
324 		ata_port_for_each_link(link, ap) {
325 			/* Class code report is unreliable and SRST
326 			 * times out under certain configurations.
327 			 */
328 			if (link->pmp < 5)
329 				link->flags |= ATA_LFLAG_NO_SRST |
330 					       ATA_LFLAG_ASSUME_ATA;
331 
332 			/* port 5 is for SEMB device and it doesn't like SRST */
333 			if (link->pmp == 5)
334 				link->flags |= ATA_LFLAG_NO_SRST |
335 					       ATA_LFLAG_ASSUME_SEMB;
336 		}
337 	} else if (vendor == 0x1095 && devid == 0x4723) {
338 		/* sil4723 quirks */
339 		ata_port_for_each_link(link, ap) {
340 			/* class code report is unreliable */
341 			if (link->pmp < 2)
342 				link->flags |= ATA_LFLAG_ASSUME_ATA;
343 
344 			/* the config device at port 2 locks up on SRST */
345 			if (link->pmp == 2)
346 				link->flags |= ATA_LFLAG_NO_SRST |
347 					       ATA_LFLAG_ASSUME_ATA;
348 		}
349 	} else if (vendor == 0x1095 && devid == 0x4726) {
350 		/* sil4726 quirks */
351 		ata_port_for_each_link(link, ap) {
352 			/* Class code report is unreliable and SRST
353 			 * times out under certain configurations.
354 			 * Config device can be at port 0 or 5 and
355 			 * locks up on SRST.
356 			 */
357 			if (link->pmp <= 5)
358 				link->flags |= ATA_LFLAG_NO_SRST |
359 					       ATA_LFLAG_ASSUME_ATA;
360 
361 			/* Port 6 is for SEMB device which doesn't
362 			 * like SRST either.
363 			 */
364 			if (link->pmp == 6)
365 				link->flags |= ATA_LFLAG_NO_SRST |
366 					       ATA_LFLAG_ASSUME_SEMB;
367 		}
368 	} else if (vendor == 0x1095 && (devid == 0x5723 || devid == 0x5733 ||
369 					devid == 0x5734 || devid == 0x5744)) {
370 		/* sil5723/5744 quirks */
371 
372 		/* sil5723/5744 has either two or three downstream
373 		 * ports depending on operation mode.  The last port
374 		 * is empty if any actual IO device is available or
375 		 * occupied by a pseudo configuration device
376 		 * otherwise.  Don't try hard to recover it.
377 		 */
378 		ap->pmp_link[ap->nr_pmp_links - 1].flags |= ATA_LFLAG_NO_RETRY;
379 	}
380 }
381 
382 /**
383  *	sata_pmp_attach - attach a SATA PMP device
384  *	@dev: SATA PMP device to attach
385  *
386  *	Configure and attach SATA PMP device @dev.  This function is
387  *	also responsible for allocating and initializing PMP links.
388  *
389  *	LOCKING:
390  *	Kernel thread context (may sleep).
391  *
392  *	RETURNS:
393  *	0 on success, -errno on failure.
394  */
395 int sata_pmp_attach(struct ata_device *dev)
396 {
397 	struct ata_link *link = dev->link;
398 	struct ata_port *ap = link->ap;
399 	unsigned long flags;
400 	struct ata_link *tlink;
401 	int rc;
402 
403 	/* is it hanging off the right place? */
404 	if (!sata_pmp_supported(ap)) {
405 		ata_dev_printk(dev, KERN_ERR,
406 			       "host does not support Port Multiplier\n");
407 		return -EINVAL;
408 	}
409 
410 	if (!ata_is_host_link(link)) {
411 		ata_dev_printk(dev, KERN_ERR,
412 			       "Port Multipliers cannot be nested\n");
413 		return -EINVAL;
414 	}
415 
416 	if (dev->devno) {
417 		ata_dev_printk(dev, KERN_ERR,
418 			       "Port Multiplier must be the first device\n");
419 		return -EINVAL;
420 	}
421 
422 	WARN_ON(link->pmp != 0);
423 	link->pmp = SATA_PMP_CTRL_PORT;
424 
425 	/* read GSCR block */
426 	rc = sata_pmp_read_gscr(dev, dev->gscr);
427 	if (rc)
428 		goto fail;
429 
430 	/* config PMP */
431 	rc = sata_pmp_configure(dev, 1);
432 	if (rc)
433 		goto fail;
434 
435 	rc = sata_pmp_init_links(ap, sata_pmp_gscr_ports(dev->gscr));
436 	if (rc) {
437 		ata_dev_printk(dev, KERN_INFO,
438 			       "failed to initialize PMP links\n");
439 		goto fail;
440 	}
441 
442 	/* attach it */
443 	spin_lock_irqsave(ap->lock, flags);
444 	WARN_ON(ap->nr_pmp_links);
445 	ap->nr_pmp_links = sata_pmp_gscr_ports(dev->gscr);
446 	spin_unlock_irqrestore(ap->lock, flags);
447 
448 	sata_pmp_quirks(ap);
449 
450 	if (ap->ops->pmp_attach)
451 		ap->ops->pmp_attach(ap);
452 
453 	ata_port_for_each_link(tlink, ap)
454 		sata_link_init_spd(tlink);
455 
456 	ata_acpi_associate_sata_port(ap);
457 
458 	return 0;
459 
460  fail:
461 	link->pmp = 0;
462 	return rc;
463 }
464 
465 /**
466  *	sata_pmp_detach - detach a SATA PMP device
467  *	@dev: SATA PMP device to detach
468  *
469  *	Detach SATA PMP device @dev.  This function is also
470  *	responsible for deconfiguring PMP links.
471  *
472  *	LOCKING:
473  *	Kernel thread context (may sleep).
474  */
475 static void sata_pmp_detach(struct ata_device *dev)
476 {
477 	struct ata_link *link = dev->link;
478 	struct ata_port *ap = link->ap;
479 	struct ata_link *tlink;
480 	unsigned long flags;
481 
482 	ata_dev_printk(dev, KERN_INFO, "Port Multiplier detaching\n");
483 
484 	WARN_ON(!ata_is_host_link(link) || dev->devno ||
485 		link->pmp != SATA_PMP_CTRL_PORT);
486 
487 	if (ap->ops->pmp_detach)
488 		ap->ops->pmp_detach(ap);
489 
490 	ata_port_for_each_link(tlink, ap)
491 		ata_eh_detach_dev(tlink->device);
492 
493 	spin_lock_irqsave(ap->lock, flags);
494 	ap->nr_pmp_links = 0;
495 	link->pmp = 0;
496 	spin_unlock_irqrestore(ap->lock, flags);
497 
498 	ata_acpi_associate_sata_port(ap);
499 }
500 
501 /**
502  *	sata_pmp_same_pmp - does new GSCR matches the configured PMP?
503  *	@dev: PMP device to compare against
504  *	@new_gscr: GSCR block of the new device
505  *
506  *	Compare @new_gscr against @dev and determine whether @dev is
507  *	the PMP described by @new_gscr.
508  *
509  *	LOCKING:
510  *	None.
511  *
512  *	RETURNS:
513  *	1 if @dev matches @new_gscr, 0 otherwise.
514  */
515 static int sata_pmp_same_pmp(struct ata_device *dev, const u32 *new_gscr)
516 {
517 	const u32 *old_gscr = dev->gscr;
518 	u16 old_vendor, new_vendor, old_devid, new_devid;
519 	int old_nr_ports, new_nr_ports;
520 
521 	old_vendor = sata_pmp_gscr_vendor(old_gscr);
522 	new_vendor = sata_pmp_gscr_vendor(new_gscr);
523 	old_devid = sata_pmp_gscr_devid(old_gscr);
524 	new_devid = sata_pmp_gscr_devid(new_gscr);
525 	old_nr_ports = sata_pmp_gscr_ports(old_gscr);
526 	new_nr_ports = sata_pmp_gscr_ports(new_gscr);
527 
528 	if (old_vendor != new_vendor) {
529 		ata_dev_printk(dev, KERN_INFO, "Port Multiplier "
530 			       "vendor mismatch '0x%x' != '0x%x'\n",
531 			       old_vendor, new_vendor);
532 		return 0;
533 	}
534 
535 	if (old_devid != new_devid) {
536 		ata_dev_printk(dev, KERN_INFO, "Port Multiplier "
537 			       "device ID mismatch '0x%x' != '0x%x'\n",
538 			       old_devid, new_devid);
539 		return 0;
540 	}
541 
542 	if (old_nr_ports != new_nr_ports) {
543 		ata_dev_printk(dev, KERN_INFO, "Port Multiplier "
544 			       "nr_ports mismatch '0x%x' != '0x%x'\n",
545 			       old_nr_ports, new_nr_ports);
546 		return 0;
547 	}
548 
549 	return 1;
550 }
551 
552 /**
553  *	sata_pmp_revalidate - revalidate SATA PMP
554  *	@dev: PMP device to revalidate
555  *	@new_class: new class code
556  *
557  *	Re-read GSCR block and make sure @dev is still attached to the
558  *	port and properly configured.
559  *
560  *	LOCKING:
561  *	Kernel thread context (may sleep).
562  *
563  *	RETURNS:
564  *	0 on success, -errno otherwise.
565  */
566 static int sata_pmp_revalidate(struct ata_device *dev, unsigned int new_class)
567 {
568 	struct ata_link *link = dev->link;
569 	struct ata_port *ap = link->ap;
570 	u32 *gscr = (void *)ap->sector_buf;
571 	int rc;
572 
573 	DPRINTK("ENTER\n");
574 
575 	ata_eh_about_to_do(link, NULL, ATA_EH_REVALIDATE);
576 
577 	if (!ata_dev_enabled(dev)) {
578 		rc = -ENODEV;
579 		goto fail;
580 	}
581 
582 	/* wrong class? */
583 	if (ata_class_enabled(new_class) && new_class != ATA_DEV_PMP) {
584 		rc = -ENODEV;
585 		goto fail;
586 	}
587 
588 	/* read GSCR */
589 	rc = sata_pmp_read_gscr(dev, gscr);
590 	if (rc)
591 		goto fail;
592 
593 	/* is the pmp still there? */
594 	if (!sata_pmp_same_pmp(dev, gscr)) {
595 		rc = -ENODEV;
596 		goto fail;
597 	}
598 
599 	memcpy(dev->gscr, gscr, sizeof(gscr[0]) * SATA_PMP_GSCR_DWORDS);
600 
601 	rc = sata_pmp_configure(dev, 0);
602 	if (rc)
603 		goto fail;
604 
605 	ata_eh_done(link, NULL, ATA_EH_REVALIDATE);
606 
607 	DPRINTK("EXIT, rc=0\n");
608 	return 0;
609 
610  fail:
611 	ata_dev_printk(dev, KERN_ERR,
612 		       "PMP revalidation failed (errno=%d)\n", rc);
613 	DPRINTK("EXIT, rc=%d\n", rc);
614 	return rc;
615 }
616 
617 /**
618  *	sata_pmp_revalidate_quick - revalidate SATA PMP quickly
619  *	@dev: PMP device to revalidate
620  *
621  *	Make sure the attached PMP is accessible.
622  *
623  *	LOCKING:
624  *	Kernel thread context (may sleep).
625  *
626  *	RETURNS:
627  *	0 on success, -errno otherwise.
628  */
629 static int sata_pmp_revalidate_quick(struct ata_device *dev)
630 {
631 	unsigned int err_mask;
632 	u32 prod_id;
633 
634 	err_mask = sata_pmp_read(dev->link, SATA_PMP_GSCR_PROD_ID, &prod_id);
635 	if (err_mask) {
636 		ata_dev_printk(dev, KERN_ERR, "failed to read PMP product ID "
637 			       "(Emask=0x%x)\n", err_mask);
638 		return -EIO;
639 	}
640 
641 	if (prod_id != dev->gscr[SATA_PMP_GSCR_PROD_ID]) {
642 		ata_dev_printk(dev, KERN_ERR, "PMP product ID mismatch\n");
643 		/* something weird is going on, request full PMP recovery */
644 		return -EIO;
645 	}
646 
647 	return 0;
648 }
649 
650 /**
651  *	sata_pmp_eh_recover_pmp - recover PMP
652  *	@ap: ATA port PMP is attached to
653  *	@prereset: prereset method (can be NULL)
654  *	@softreset: softreset method
655  *	@hardreset: hardreset method
656  *	@postreset: postreset method (can be NULL)
657  *
658  *	Recover PMP attached to @ap.  Recovery procedure is somewhat
659  *	similar to that of ata_eh_recover() except that reset should
660  *	always be performed in hard->soft sequence and recovery
661  *	failure results in PMP detachment.
662  *
663  *	LOCKING:
664  *	Kernel thread context (may sleep).
665  *
666  *	RETURNS:
667  *	0 on success, -errno on failure.
668  */
669 static int sata_pmp_eh_recover_pmp(struct ata_port *ap,
670 		ata_prereset_fn_t prereset, ata_reset_fn_t softreset,
671 		ata_reset_fn_t hardreset, ata_postreset_fn_t postreset)
672 {
673 	struct ata_link *link = &ap->link;
674 	struct ata_eh_context *ehc = &link->eh_context;
675 	struct ata_device *dev = link->device;
676 	int tries = ATA_EH_PMP_TRIES;
677 	int detach = 0, rc = 0;
678 	int reval_failed = 0;
679 
680 	DPRINTK("ENTER\n");
681 
682 	if (dev->flags & ATA_DFLAG_DETACH) {
683 		detach = 1;
684 		goto fail;
685 	}
686 
687  retry:
688 	ehc->classes[0] = ATA_DEV_UNKNOWN;
689 
690 	if (ehc->i.action & ATA_EH_RESET) {
691 		struct ata_link *tlink;
692 
693 		/* reset */
694 		rc = ata_eh_reset(link, 0, prereset, softreset, hardreset,
695 				  postreset);
696 		if (rc) {
697 			ata_link_printk(link, KERN_ERR,
698 					"failed to reset PMP, giving up\n");
699 			goto fail;
700 		}
701 
702 		/* PMP is reset, SErrors cannot be trusted, scan all */
703 		ata_port_for_each_link(tlink, ap) {
704 			struct ata_eh_context *ehc = &tlink->eh_context;
705 
706 			ehc->i.probe_mask |= ATA_ALL_DEVICES;
707 			ehc->i.action |= ATA_EH_RESET;
708 		}
709 	}
710 
711 	/* If revalidation is requested, revalidate and reconfigure;
712 	 * otherwise, do quick revalidation.
713 	 */
714 	if (ehc->i.action & ATA_EH_REVALIDATE)
715 		rc = sata_pmp_revalidate(dev, ehc->classes[0]);
716 	else
717 		rc = sata_pmp_revalidate_quick(dev);
718 
719 	if (rc) {
720 		tries--;
721 
722 		if (rc == -ENODEV) {
723 			ehc->i.probe_mask |= ATA_ALL_DEVICES;
724 			detach = 1;
725 			/* give it just two more chances */
726 			tries = min(tries, 2);
727 		}
728 
729 		if (tries) {
730 			int sleep = ehc->i.flags & ATA_EHI_DID_RESET;
731 
732 			/* consecutive revalidation failures? speed down */
733 			if (reval_failed)
734 				sata_down_spd_limit(link);
735 			else
736 				reval_failed = 1;
737 
738 			ata_dev_printk(dev, KERN_WARNING,
739 				       "retrying reset%s\n",
740 				       sleep ? " in 5 secs" : "");
741 			if (sleep)
742 				ssleep(5);
743 			ehc->i.action |= ATA_EH_RESET;
744 			goto retry;
745 		} else {
746 			ata_dev_printk(dev, KERN_ERR, "failed to recover PMP "
747 				       "after %d tries, giving up\n",
748 				       ATA_EH_PMP_TRIES);
749 			goto fail;
750 		}
751 	}
752 
753 	/* okay, PMP resurrected */
754 	ehc->i.flags = 0;
755 
756 	DPRINTK("EXIT, rc=0\n");
757 	return 0;
758 
759  fail:
760 	sata_pmp_detach(dev);
761 	if (detach)
762 		ata_eh_detach_dev(dev);
763 	else
764 		ata_dev_disable(dev);
765 
766 	DPRINTK("EXIT, rc=%d\n", rc);
767 	return rc;
768 }
769 
770 static int sata_pmp_eh_handle_disabled_links(struct ata_port *ap)
771 {
772 	struct ata_link *link;
773 	unsigned long flags;
774 	int rc;
775 
776 	spin_lock_irqsave(ap->lock, flags);
777 
778 	ata_port_for_each_link(link, ap) {
779 		if (!(link->flags & ATA_LFLAG_DISABLED))
780 			continue;
781 
782 		spin_unlock_irqrestore(ap->lock, flags);
783 
784 		/* Some PMPs require hardreset sequence to get
785 		 * SError.N working.
786 		 */
787 		sata_link_hardreset(link, sata_deb_timing_normal,
788 				jiffies + ATA_TMOUT_INTERNAL_QUICK, NULL, NULL);
789 
790 		/* unconditionally clear SError.N */
791 		rc = sata_scr_write(link, SCR_ERROR, SERR_PHYRDY_CHG);
792 		if (rc) {
793 			ata_link_printk(link, KERN_ERR, "failed to clear "
794 					"SError.N (errno=%d)\n", rc);
795 			return rc;
796 		}
797 
798 		spin_lock_irqsave(ap->lock, flags);
799 	}
800 
801 	spin_unlock_irqrestore(ap->lock, flags);
802 
803 	return 0;
804 }
805 
806 static int sata_pmp_handle_link_fail(struct ata_link *link, int *link_tries)
807 {
808 	struct ata_port *ap = link->ap;
809 	unsigned long flags;
810 
811 	if (link_tries[link->pmp] && --link_tries[link->pmp])
812 		return 1;
813 
814 	/* disable this link */
815 	if (!(link->flags & ATA_LFLAG_DISABLED)) {
816 		ata_link_printk(link, KERN_WARNING,
817 			"failed to recover link after %d tries, disabling\n",
818 			ATA_EH_PMP_LINK_TRIES);
819 
820 		spin_lock_irqsave(ap->lock, flags);
821 		link->flags |= ATA_LFLAG_DISABLED;
822 		spin_unlock_irqrestore(ap->lock, flags);
823 	}
824 
825 	ata_dev_disable(link->device);
826 	link->eh_context.i.action = 0;
827 
828 	return 0;
829 }
830 
831 /**
832  *	sata_pmp_eh_recover - recover PMP-enabled port
833  *	@ap: ATA port to recover
834  *
835  *	Drive EH recovery operation for PMP enabled port @ap.  This
836  *	function recovers host and PMP ports with proper retrials and
837  *	fallbacks.  Actual recovery operations are performed using
838  *	ata_eh_recover() and sata_pmp_eh_recover_pmp().
839  *
840  *	LOCKING:
841  *	Kernel thread context (may sleep).
842  *
843  *	RETURNS:
844  *	0 on success, -errno on failure.
845  */
846 static int sata_pmp_eh_recover(struct ata_port *ap)
847 {
848 	struct ata_port_operations *ops = ap->ops;
849 	int pmp_tries, link_tries[SATA_PMP_MAX_PORTS];
850 	struct ata_link *pmp_link = &ap->link;
851 	struct ata_device *pmp_dev = pmp_link->device;
852 	struct ata_eh_context *pmp_ehc = &pmp_link->eh_context;
853 	u32 *gscr = pmp_dev->gscr;
854 	struct ata_link *link;
855 	struct ata_device *dev;
856 	unsigned int err_mask;
857 	u32 gscr_error, sntf;
858 	int cnt, rc;
859 
860 	pmp_tries = ATA_EH_PMP_TRIES;
861 	ata_port_for_each_link(link, ap)
862 		link_tries[link->pmp] = ATA_EH_PMP_LINK_TRIES;
863 
864  retry:
865 	/* PMP attached? */
866 	if (!sata_pmp_attached(ap)) {
867 		rc = ata_eh_recover(ap, ops->prereset, ops->softreset,
868 				    ops->hardreset, ops->postreset, NULL);
869 		if (rc) {
870 			ata_link_for_each_dev(dev, &ap->link)
871 				ata_dev_disable(dev);
872 			return rc;
873 		}
874 
875 		if (pmp_dev->class != ATA_DEV_PMP)
876 			return 0;
877 
878 		/* new PMP online */
879 		ata_port_for_each_link(link, ap)
880 			link_tries[link->pmp] = ATA_EH_PMP_LINK_TRIES;
881 
882 		/* fall through */
883 	}
884 
885 	/* recover pmp */
886 	rc = sata_pmp_eh_recover_pmp(ap, ops->prereset, ops->softreset,
887 				     ops->hardreset, ops->postreset);
888 	if (rc)
889 		goto pmp_fail;
890 
891 	/* PHY event notification can disturb reset and other recovery
892 	 * operations.  Turn it off.
893 	 */
894 	if (gscr[SATA_PMP_GSCR_FEAT_EN] & SATA_PMP_FEAT_NOTIFY) {
895 		gscr[SATA_PMP_GSCR_FEAT_EN] &= ~SATA_PMP_FEAT_NOTIFY;
896 
897 		err_mask = sata_pmp_write(pmp_link, SATA_PMP_GSCR_FEAT_EN,
898 					  gscr[SATA_PMP_GSCR_FEAT_EN]);
899 		if (err_mask) {
900 			ata_link_printk(pmp_link, KERN_WARNING,
901 				"failed to disable NOTIFY (err_mask=0x%x)\n",
902 				err_mask);
903 			goto pmp_fail;
904 		}
905 	}
906 
907 	/* handle disabled links */
908 	rc = sata_pmp_eh_handle_disabled_links(ap);
909 	if (rc)
910 		goto pmp_fail;
911 
912 	/* recover links */
913 	rc = ata_eh_recover(ap, ops->pmp_prereset, ops->pmp_softreset,
914 			    ops->pmp_hardreset, ops->pmp_postreset, &link);
915 	if (rc)
916 		goto link_fail;
917 
918 	/* Connection status might have changed while resetting other
919 	 * links, check SATA_PMP_GSCR_ERROR before returning.
920 	 */
921 
922 	/* clear SNotification */
923 	rc = sata_scr_read(&ap->link, SCR_NOTIFICATION, &sntf);
924 	if (rc == 0)
925 		sata_scr_write(&ap->link, SCR_NOTIFICATION, sntf);
926 
927 	/* enable notification */
928 	if (pmp_dev->flags & ATA_DFLAG_AN) {
929 		gscr[SATA_PMP_GSCR_FEAT_EN] |= SATA_PMP_FEAT_NOTIFY;
930 
931 		err_mask = sata_pmp_write(pmp_link, SATA_PMP_GSCR_FEAT_EN,
932 					  gscr[SATA_PMP_GSCR_FEAT_EN]);
933 		if (err_mask) {
934 			ata_dev_printk(pmp_dev, KERN_ERR, "failed to write "
935 				       "PMP_FEAT_EN (Emask=0x%x)\n", err_mask);
936 			rc = -EIO;
937 			goto pmp_fail;
938 		}
939 	}
940 
941 	/* check GSCR_ERROR */
942 	err_mask = sata_pmp_read(pmp_link, SATA_PMP_GSCR_ERROR, &gscr_error);
943 	if (err_mask) {
944 		ata_dev_printk(pmp_dev, KERN_ERR, "failed to read "
945 			       "PMP_GSCR_ERROR (Emask=0x%x)\n", err_mask);
946 		rc = -EIO;
947 		goto pmp_fail;
948 	}
949 
950 	cnt = 0;
951 	ata_port_for_each_link(link, ap) {
952 		if (!(gscr_error & (1 << link->pmp)))
953 			continue;
954 
955 		if (sata_pmp_handle_link_fail(link, link_tries)) {
956 			ata_ehi_hotplugged(&link->eh_context.i);
957 			cnt++;
958 		} else {
959 			ata_link_printk(link, KERN_WARNING,
960 				"PHY status changed but maxed out on retries, "
961 				"giving up\n");
962 			ata_link_printk(link, KERN_WARNING,
963 				"Manully issue scan to resume this link\n");
964 		}
965 	}
966 
967 	if (cnt) {
968 		ata_port_printk(ap, KERN_INFO, "PMP SError.N set for some "
969 				"ports, repeating recovery\n");
970 		goto retry;
971 	}
972 
973 	return 0;
974 
975  link_fail:
976 	if (sata_pmp_handle_link_fail(link, link_tries)) {
977 		pmp_ehc->i.action |= ATA_EH_RESET;
978 		goto retry;
979 	}
980 
981 	/* fall through */
982  pmp_fail:
983 	/* Control always ends up here after detaching PMP.  Shut up
984 	 * and return if we're unloading.
985 	 */
986 	if (ap->pflags & ATA_PFLAG_UNLOADING)
987 		return rc;
988 
989 	if (!sata_pmp_attached(ap))
990 		goto retry;
991 
992 	if (--pmp_tries) {
993 		ata_port_printk(ap, KERN_WARNING,
994 				"failed to recover PMP, retrying in 5 secs\n");
995 		pmp_ehc->i.action |= ATA_EH_RESET;
996 		ssleep(5);
997 		goto retry;
998 	}
999 
1000 	ata_port_printk(ap, KERN_ERR,
1001 			"failed to recover PMP after %d tries, giving up\n",
1002 			ATA_EH_PMP_TRIES);
1003 	sata_pmp_detach(pmp_dev);
1004 	ata_dev_disable(pmp_dev);
1005 
1006 	return rc;
1007 }
1008 
1009 /**
1010  *	sata_pmp_error_handler - do standard error handling for PMP-enabled host
1011  *	@ap: host port to handle error for
1012  *
1013  *	Perform standard error handling sequence for PMP-enabled host
1014  *	@ap.
1015  *
1016  *	LOCKING:
1017  *	Kernel thread context (may sleep).
1018  */
1019 void sata_pmp_error_handler(struct ata_port *ap)
1020 {
1021 	ata_eh_autopsy(ap);
1022 	ata_eh_report(ap);
1023 	sata_pmp_eh_recover(ap);
1024 	ata_eh_finish(ap);
1025 }
1026 
1027 EXPORT_SYMBOL_GPL(sata_pmp_port_ops);
1028 EXPORT_SYMBOL_GPL(sata_pmp_qc_defer_cmd_switch);
1029 EXPORT_SYMBOL_GPL(sata_pmp_error_handler);
1030