xref: /linux/drivers/ata/libata-pmp.c (revision 4dc7ccf7e9d9bca1989b840be9e8e84911387cf2)
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 <linux/slab.h>
13 #include "libata.h"
14 
15 const struct ata_port_operations sata_pmp_port_ops = {
16 	.inherits		= &sata_port_ops,
17 	.pmp_prereset		= ata_std_prereset,
18 	.pmp_hardreset		= sata_std_hardreset,
19 	.pmp_postreset		= ata_std_postreset,
20 	.error_handler		= sata_pmp_error_handler,
21 };
22 
23 /**
24  *	sata_pmp_read - read PMP register
25  *	@link: link to read PMP register for
26  *	@reg: register to read
27  *	@r_val: resulting value
28  *
29  *	Read PMP register.
30  *
31  *	LOCKING:
32  *	Kernel thread context (may sleep).
33  *
34  *	RETURNS:
35  *	0 on success, AC_ERR_* mask on failure.
36  */
37 static unsigned int sata_pmp_read(struct ata_link *link, int reg, u32 *r_val)
38 {
39 	struct ata_port *ap = link->ap;
40 	struct ata_device *pmp_dev = ap->link.device;
41 	struct ata_taskfile tf;
42 	unsigned int err_mask;
43 
44 	ata_tf_init(pmp_dev, &tf);
45 	tf.command = ATA_CMD_PMP_READ;
46 	tf.protocol = ATA_PROT_NODATA;
47 	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE | ATA_TFLAG_LBA48;
48 	tf.feature = reg;
49 	tf.device = link->pmp;
50 
51 	err_mask = ata_exec_internal(pmp_dev, &tf, NULL, DMA_NONE, NULL, 0,
52 				     SATA_PMP_RW_TIMEOUT);
53 	if (err_mask)
54 		return err_mask;
55 
56 	*r_val = tf.nsect | tf.lbal << 8 | tf.lbam << 16 | tf.lbah << 24;
57 	return 0;
58 }
59 
60 /**
61  *	sata_pmp_write - write PMP register
62  *	@link: link to write PMP register for
63  *	@reg: register to write
64  *	@r_val: value to write
65  *
66  *	Write PMP register.
67  *
68  *	LOCKING:
69  *	Kernel thread context (may sleep).
70  *
71  *	RETURNS:
72  *	0 on success, AC_ERR_* mask on failure.
73  */
74 static unsigned int sata_pmp_write(struct ata_link *link, int reg, u32 val)
75 {
76 	struct ata_port *ap = link->ap;
77 	struct ata_device *pmp_dev = ap->link.device;
78 	struct ata_taskfile tf;
79 
80 	ata_tf_init(pmp_dev, &tf);
81 	tf.command = ATA_CMD_PMP_WRITE;
82 	tf.protocol = ATA_PROT_NODATA;
83 	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE | ATA_TFLAG_LBA48;
84 	tf.feature = reg;
85 	tf.device = link->pmp;
86 	tf.nsect = val & 0xff;
87 	tf.lbal = (val >> 8) & 0xff;
88 	tf.lbam = (val >> 16) & 0xff;
89 	tf.lbah = (val >> 24) & 0xff;
90 
91 	return ata_exec_internal(pmp_dev, &tf, NULL, DMA_NONE, NULL, 0,
92 				 SATA_PMP_RW_TIMEOUT);
93 }
94 
95 /**
96  *	sata_pmp_qc_defer_cmd_switch - qc_defer for command switching PMP
97  *	@qc: ATA command in question
98  *
99  *	A host which has command switching PMP support cannot issue
100  *	commands to multiple links simultaneously.
101  *
102  *	LOCKING:
103  *	spin_lock_irqsave(host lock)
104  *
105  *	RETURNS:
106  *	ATA_DEFER_* if deferring is needed, 0 otherwise.
107  */
108 int sata_pmp_qc_defer_cmd_switch(struct ata_queued_cmd *qc)
109 {
110 	struct ata_link *link = qc->dev->link;
111 	struct ata_port *ap = link->ap;
112 
113 	if (ap->excl_link == NULL || ap->excl_link == link) {
114 		if (ap->nr_active_links == 0 || ata_link_active(link)) {
115 			qc->flags |= ATA_QCFLAG_CLEAR_EXCL;
116 			return ata_std_qc_defer(qc);
117 		}
118 
119 		ap->excl_link = link;
120 	}
121 
122 	return ATA_DEFER_PORT;
123 }
124 
125 /**
126  *	sata_pmp_scr_read - read PSCR
127  *	@link: ATA link to read PSCR for
128  *	@reg: PSCR to read
129  *	@r_val: resulting value
130  *
131  *	Read PSCR @reg into @r_val for @link, to be called from
132  *	ata_scr_read().
133  *
134  *	LOCKING:
135  *	Kernel thread context (may sleep).
136  *
137  *	RETURNS:
138  *	0 on success, -errno on failure.
139  */
140 int sata_pmp_scr_read(struct ata_link *link, int reg, u32 *r_val)
141 {
142 	unsigned int err_mask;
143 
144 	if (reg > SATA_PMP_PSCR_CONTROL)
145 		return -EINVAL;
146 
147 	err_mask = sata_pmp_read(link, reg, r_val);
148 	if (err_mask) {
149 		ata_link_printk(link, KERN_WARNING, "failed to read SCR %d "
150 				"(Emask=0x%x)\n", reg, err_mask);
151 		return -EIO;
152 	}
153 	return 0;
154 }
155 
156 /**
157  *	sata_pmp_scr_write - write PSCR
158  *	@link: ATA link to write PSCR for
159  *	@reg: PSCR to write
160  *	@val: value to be written
161  *
162  *	Write @val to PSCR @reg for @link, to be called from
163  *	ata_scr_write() and ata_scr_write_flush().
164  *
165  *	LOCKING:
166  *	Kernel thread context (may sleep).
167  *
168  *	RETURNS:
169  *	0 on success, -errno on failure.
170  */
171 int sata_pmp_scr_write(struct ata_link *link, int reg, u32 val)
172 {
173 	unsigned int err_mask;
174 
175 	if (reg > SATA_PMP_PSCR_CONTROL)
176 		return -EINVAL;
177 
178 	err_mask = sata_pmp_write(link, reg, val);
179 	if (err_mask) {
180 		ata_link_printk(link, KERN_WARNING, "failed to write SCR %d "
181 				"(Emask=0x%x)\n", reg, err_mask);
182 		return -EIO;
183 	}
184 	return 0;
185 }
186 
187 /**
188  *	sata_pmp_read_gscr - read GSCR block of SATA PMP
189  *	@dev: PMP device
190  *	@gscr: buffer to read GSCR block into
191  *
192  *	Read selected PMP GSCRs from the PMP at @dev.  This will serve
193  *	as configuration and identification info for the PMP.
194  *
195  *	LOCKING:
196  *	Kernel thread context (may sleep).
197  *
198  *	RETURNS:
199  *	0 on success, -errno on failure.
200  */
201 static int sata_pmp_read_gscr(struct ata_device *dev, u32 *gscr)
202 {
203 	static const int gscr_to_read[] = { 0, 1, 2, 32, 33, 64, 96 };
204 	int i;
205 
206 	for (i = 0; i < ARRAY_SIZE(gscr_to_read); i++) {
207 		int reg = gscr_to_read[i];
208 		unsigned int err_mask;
209 
210 		err_mask = sata_pmp_read(dev->link, reg, &gscr[reg]);
211 		if (err_mask) {
212 			ata_dev_printk(dev, KERN_ERR, "failed to read PMP "
213 				"GSCR[%d] (Emask=0x%x)\n", reg, err_mask);
214 			return -EIO;
215 		}
216 	}
217 
218 	return 0;
219 }
220 
221 static const char *sata_pmp_spec_rev_str(const u32 *gscr)
222 {
223 	u32 rev = gscr[SATA_PMP_GSCR_REV];
224 
225 	if (rev & (1 << 3))
226 		return "1.2";
227 	if (rev & (1 << 2))
228 		return "1.1";
229 	if (rev & (1 << 1))
230 		return "1.0";
231 	return "<unknown>";
232 }
233 
234 static int sata_pmp_configure(struct ata_device *dev, int print_info)
235 {
236 	struct ata_port *ap = dev->link->ap;
237 	u32 *gscr = dev->gscr;
238 	unsigned int err_mask = 0;
239 	const char *reason;
240 	int nr_ports, rc;
241 
242 	nr_ports = sata_pmp_gscr_ports(gscr);
243 
244 	if (nr_ports <= 0 || nr_ports > SATA_PMP_MAX_PORTS) {
245 		rc = -EINVAL;
246 		reason = "invalid nr_ports";
247 		goto fail;
248 	}
249 
250 	if ((ap->flags & ATA_FLAG_AN) &&
251 	    (gscr[SATA_PMP_GSCR_FEAT] & SATA_PMP_FEAT_NOTIFY))
252 		dev->flags |= ATA_DFLAG_AN;
253 
254 	/* monitor SERR_PHYRDY_CHG on fan-out ports */
255 	err_mask = sata_pmp_write(dev->link, SATA_PMP_GSCR_ERROR_EN,
256 				  SERR_PHYRDY_CHG);
257 	if (err_mask) {
258 		rc = -EIO;
259 		reason = "failed to write GSCR_ERROR_EN";
260 		goto fail;
261 	}
262 
263 	if (print_info) {
264 		ata_dev_printk(dev, KERN_INFO, "Port Multiplier %s, "
265 			       "0x%04x:0x%04x r%d, %d ports, feat 0x%x/0x%x\n",
266 			       sata_pmp_spec_rev_str(gscr),
267 			       sata_pmp_gscr_vendor(gscr),
268 			       sata_pmp_gscr_devid(gscr),
269 			       sata_pmp_gscr_rev(gscr),
270 			       nr_ports, gscr[SATA_PMP_GSCR_FEAT_EN],
271 			       gscr[SATA_PMP_GSCR_FEAT]);
272 
273 		if (!(dev->flags & ATA_DFLAG_AN))
274 			ata_dev_printk(dev, KERN_INFO,
275 				"Asynchronous notification not supported, "
276 				"hotplug won't\n         work on fan-out "
277 				"ports. Use warm-plug instead.\n");
278 	}
279 
280 	return 0;
281 
282  fail:
283 	ata_dev_printk(dev, KERN_ERR,
284 		       "failed to configure Port Multiplier (%s, Emask=0x%x)\n",
285 		       reason, err_mask);
286 	return rc;
287 }
288 
289 static int sata_pmp_init_links(struct ata_port *ap, int nr_ports)
290 {
291 	struct ata_link *pmp_link = ap->pmp_link;
292 	int i;
293 
294 	if (!pmp_link) {
295 		pmp_link = kzalloc(sizeof(pmp_link[0]) * SATA_PMP_MAX_PORTS,
296 				   GFP_NOIO);
297 		if (!pmp_link)
298 			return -ENOMEM;
299 
300 		for (i = 0; i < SATA_PMP_MAX_PORTS; i++)
301 			ata_link_init(ap, &pmp_link[i], i);
302 
303 		ap->pmp_link = pmp_link;
304 	}
305 
306 	for (i = 0; i < nr_ports; i++) {
307 		struct ata_link *link = &pmp_link[i];
308 		struct ata_eh_context *ehc = &link->eh_context;
309 
310 		link->flags = 0;
311 		ehc->i.probe_mask |= ATA_ALL_DEVICES;
312 		ehc->i.action |= ATA_EH_RESET;
313 	}
314 
315 	return 0;
316 }
317 
318 static void sata_pmp_quirks(struct ata_port *ap)
319 {
320 	u32 *gscr = ap->link.device->gscr;
321 	u16 vendor = sata_pmp_gscr_vendor(gscr);
322 	u16 devid = sata_pmp_gscr_devid(gscr);
323 	struct ata_link *link;
324 
325 	if (vendor == 0x1095 && devid == 0x3726) {
326 		/* sil3726 quirks */
327 		ata_for_each_link(link, ap, EDGE) {
328 			/* Class code report is unreliable and SRST
329 			 * times out under certain configurations.
330 			 */
331 			if (link->pmp < 5)
332 				link->flags |= ATA_LFLAG_NO_SRST |
333 					       ATA_LFLAG_ASSUME_ATA;
334 
335 			/* port 5 is for SEMB device and it doesn't like SRST */
336 			if (link->pmp == 5)
337 				link->flags |= ATA_LFLAG_NO_SRST |
338 					       ATA_LFLAG_ASSUME_SEMB;
339 		}
340 	} else if (vendor == 0x1095 && devid == 0x4723) {
341 		/* sil4723 quirks */
342 		ata_for_each_link(link, ap, EDGE) {
343 			/* class code report is unreliable */
344 			if (link->pmp < 2)
345 				link->flags |= ATA_LFLAG_ASSUME_ATA;
346 
347 			/* the config device at port 2 locks up on SRST */
348 			if (link->pmp == 2)
349 				link->flags |= ATA_LFLAG_NO_SRST |
350 					       ATA_LFLAG_ASSUME_ATA;
351 		}
352 	} else if (vendor == 0x1095 && devid == 0x4726) {
353 		/* sil4726 quirks */
354 		ata_for_each_link(link, ap, EDGE) {
355 			/* Class code report is unreliable and SRST
356 			 * times out under certain configurations.
357 			 * Config device can be at port 0 or 5 and
358 			 * locks up on SRST.
359 			 */
360 			if (link->pmp <= 5)
361 				link->flags |= ATA_LFLAG_NO_SRST |
362 					       ATA_LFLAG_ASSUME_ATA;
363 
364 			/* Port 6 is for SEMB device which doesn't
365 			 * like SRST either.
366 			 */
367 			if (link->pmp == 6)
368 				link->flags |= ATA_LFLAG_NO_SRST |
369 					       ATA_LFLAG_ASSUME_SEMB;
370 		}
371 	} else if (vendor == 0x1095 && (devid == 0x5723 || devid == 0x5733 ||
372 					devid == 0x5734 || devid == 0x5744)) {
373 		/* sil5723/5744 quirks */
374 
375 		/* sil5723/5744 has either two or three downstream
376 		 * ports depending on operation mode.  The last port
377 		 * is empty if any actual IO device is available or
378 		 * occupied by a pseudo configuration device
379 		 * otherwise.  Don't try hard to recover it.
380 		 */
381 		ap->pmp_link[ap->nr_pmp_links - 1].flags |= ATA_LFLAG_NO_RETRY;
382 	}
383 }
384 
385 /**
386  *	sata_pmp_attach - attach a SATA PMP device
387  *	@dev: SATA PMP device to attach
388  *
389  *	Configure and attach SATA PMP device @dev.  This function is
390  *	also responsible for allocating and initializing PMP links.
391  *
392  *	LOCKING:
393  *	Kernel thread context (may sleep).
394  *
395  *	RETURNS:
396  *	0 on success, -errno on failure.
397  */
398 int sata_pmp_attach(struct ata_device *dev)
399 {
400 	struct ata_link *link = dev->link;
401 	struct ata_port *ap = link->ap;
402 	unsigned long flags;
403 	struct ata_link *tlink;
404 	int rc;
405 
406 	/* is it hanging off the right place? */
407 	if (!sata_pmp_supported(ap)) {
408 		ata_dev_printk(dev, KERN_ERR,
409 			       "host does not support Port Multiplier\n");
410 		return -EINVAL;
411 	}
412 
413 	if (!ata_is_host_link(link)) {
414 		ata_dev_printk(dev, KERN_ERR,
415 			       "Port Multipliers cannot be nested\n");
416 		return -EINVAL;
417 	}
418 
419 	if (dev->devno) {
420 		ata_dev_printk(dev, KERN_ERR,
421 			       "Port Multiplier must be the first device\n");
422 		return -EINVAL;
423 	}
424 
425 	WARN_ON(link->pmp != 0);
426 	link->pmp = SATA_PMP_CTRL_PORT;
427 
428 	/* read GSCR block */
429 	rc = sata_pmp_read_gscr(dev, dev->gscr);
430 	if (rc)
431 		goto fail;
432 
433 	/* config PMP */
434 	rc = sata_pmp_configure(dev, 1);
435 	if (rc)
436 		goto fail;
437 
438 	rc = sata_pmp_init_links(ap, sata_pmp_gscr_ports(dev->gscr));
439 	if (rc) {
440 		ata_dev_printk(dev, KERN_INFO,
441 			       "failed to initialize PMP links\n");
442 		goto fail;
443 	}
444 
445 	/* attach it */
446 	spin_lock_irqsave(ap->lock, flags);
447 	WARN_ON(ap->nr_pmp_links);
448 	ap->nr_pmp_links = sata_pmp_gscr_ports(dev->gscr);
449 	spin_unlock_irqrestore(ap->lock, flags);
450 
451 	sata_pmp_quirks(ap);
452 
453 	if (ap->ops->pmp_attach)
454 		ap->ops->pmp_attach(ap);
455 
456 	ata_for_each_link(tlink, ap, EDGE)
457 		sata_link_init_spd(tlink);
458 
459 	ata_acpi_associate_sata_port(ap);
460 
461 	return 0;
462 
463  fail:
464 	link->pmp = 0;
465 	return rc;
466 }
467 
468 /**
469  *	sata_pmp_detach - detach a SATA PMP device
470  *	@dev: SATA PMP device to detach
471  *
472  *	Detach SATA PMP device @dev.  This function is also
473  *	responsible for deconfiguring PMP links.
474  *
475  *	LOCKING:
476  *	Kernel thread context (may sleep).
477  */
478 static void sata_pmp_detach(struct ata_device *dev)
479 {
480 	struct ata_link *link = dev->link;
481 	struct ata_port *ap = link->ap;
482 	struct ata_link *tlink;
483 	unsigned long flags;
484 
485 	ata_dev_printk(dev, KERN_INFO, "Port Multiplier detaching\n");
486 
487 	WARN_ON(!ata_is_host_link(link) || dev->devno ||
488 		link->pmp != SATA_PMP_CTRL_PORT);
489 
490 	if (ap->ops->pmp_detach)
491 		ap->ops->pmp_detach(ap);
492 
493 	ata_for_each_link(tlink, ap, EDGE)
494 		ata_eh_detach_dev(tlink->device);
495 
496 	spin_lock_irqsave(ap->lock, flags);
497 	ap->nr_pmp_links = 0;
498 	link->pmp = 0;
499 	spin_unlock_irqrestore(ap->lock, flags);
500 
501 	ata_acpi_associate_sata_port(ap);
502 }
503 
504 /**
505  *	sata_pmp_same_pmp - does new GSCR matches the configured PMP?
506  *	@dev: PMP device to compare against
507  *	@new_gscr: GSCR block of the new device
508  *
509  *	Compare @new_gscr against @dev and determine whether @dev is
510  *	the PMP described by @new_gscr.
511  *
512  *	LOCKING:
513  *	None.
514  *
515  *	RETURNS:
516  *	1 if @dev matches @new_gscr, 0 otherwise.
517  */
518 static int sata_pmp_same_pmp(struct ata_device *dev, const u32 *new_gscr)
519 {
520 	const u32 *old_gscr = dev->gscr;
521 	u16 old_vendor, new_vendor, old_devid, new_devid;
522 	int old_nr_ports, new_nr_ports;
523 
524 	old_vendor = sata_pmp_gscr_vendor(old_gscr);
525 	new_vendor = sata_pmp_gscr_vendor(new_gscr);
526 	old_devid = sata_pmp_gscr_devid(old_gscr);
527 	new_devid = sata_pmp_gscr_devid(new_gscr);
528 	old_nr_ports = sata_pmp_gscr_ports(old_gscr);
529 	new_nr_ports = sata_pmp_gscr_ports(new_gscr);
530 
531 	if (old_vendor != new_vendor) {
532 		ata_dev_printk(dev, KERN_INFO, "Port Multiplier "
533 			       "vendor mismatch '0x%x' != '0x%x'\n",
534 			       old_vendor, new_vendor);
535 		return 0;
536 	}
537 
538 	if (old_devid != new_devid) {
539 		ata_dev_printk(dev, KERN_INFO, "Port Multiplier "
540 			       "device ID mismatch '0x%x' != '0x%x'\n",
541 			       old_devid, new_devid);
542 		return 0;
543 	}
544 
545 	if (old_nr_ports != new_nr_ports) {
546 		ata_dev_printk(dev, KERN_INFO, "Port Multiplier "
547 			       "nr_ports mismatch '0x%x' != '0x%x'\n",
548 			       old_nr_ports, new_nr_ports);
549 		return 0;
550 	}
551 
552 	return 1;
553 }
554 
555 /**
556  *	sata_pmp_revalidate - revalidate SATA PMP
557  *	@dev: PMP device to revalidate
558  *	@new_class: new class code
559  *
560  *	Re-read GSCR block and make sure @dev is still attached to the
561  *	port and properly configured.
562  *
563  *	LOCKING:
564  *	Kernel thread context (may sleep).
565  *
566  *	RETURNS:
567  *	0 on success, -errno otherwise.
568  */
569 static int sata_pmp_revalidate(struct ata_device *dev, unsigned int new_class)
570 {
571 	struct ata_link *link = dev->link;
572 	struct ata_port *ap = link->ap;
573 	u32 *gscr = (void *)ap->sector_buf;
574 	int rc;
575 
576 	DPRINTK("ENTER\n");
577 
578 	ata_eh_about_to_do(link, NULL, ATA_EH_REVALIDATE);
579 
580 	if (!ata_dev_enabled(dev)) {
581 		rc = -ENODEV;
582 		goto fail;
583 	}
584 
585 	/* wrong class? */
586 	if (ata_class_enabled(new_class) && new_class != ATA_DEV_PMP) {
587 		rc = -ENODEV;
588 		goto fail;
589 	}
590 
591 	/* read GSCR */
592 	rc = sata_pmp_read_gscr(dev, gscr);
593 	if (rc)
594 		goto fail;
595 
596 	/* is the pmp still there? */
597 	if (!sata_pmp_same_pmp(dev, gscr)) {
598 		rc = -ENODEV;
599 		goto fail;
600 	}
601 
602 	memcpy(dev->gscr, gscr, sizeof(gscr[0]) * SATA_PMP_GSCR_DWORDS);
603 
604 	rc = sata_pmp_configure(dev, 0);
605 	if (rc)
606 		goto fail;
607 
608 	ata_eh_done(link, NULL, ATA_EH_REVALIDATE);
609 
610 	DPRINTK("EXIT, rc=0\n");
611 	return 0;
612 
613  fail:
614 	ata_dev_printk(dev, KERN_ERR,
615 		       "PMP revalidation failed (errno=%d)\n", rc);
616 	DPRINTK("EXIT, rc=%d\n", rc);
617 	return rc;
618 }
619 
620 /**
621  *	sata_pmp_revalidate_quick - revalidate SATA PMP quickly
622  *	@dev: PMP device to revalidate
623  *
624  *	Make sure the attached PMP is accessible.
625  *
626  *	LOCKING:
627  *	Kernel thread context (may sleep).
628  *
629  *	RETURNS:
630  *	0 on success, -errno otherwise.
631  */
632 static int sata_pmp_revalidate_quick(struct ata_device *dev)
633 {
634 	unsigned int err_mask;
635 	u32 prod_id;
636 
637 	err_mask = sata_pmp_read(dev->link, SATA_PMP_GSCR_PROD_ID, &prod_id);
638 	if (err_mask) {
639 		ata_dev_printk(dev, KERN_ERR, "failed to read PMP product ID "
640 			       "(Emask=0x%x)\n", err_mask);
641 		return -EIO;
642 	}
643 
644 	if (prod_id != dev->gscr[SATA_PMP_GSCR_PROD_ID]) {
645 		ata_dev_printk(dev, KERN_ERR, "PMP product ID mismatch\n");
646 		/* something weird is going on, request full PMP recovery */
647 		return -EIO;
648 	}
649 
650 	return 0;
651 }
652 
653 /**
654  *	sata_pmp_eh_recover_pmp - recover PMP
655  *	@ap: ATA port PMP is attached to
656  *	@prereset: prereset method (can be NULL)
657  *	@softreset: softreset method
658  *	@hardreset: hardreset method
659  *	@postreset: postreset method (can be NULL)
660  *
661  *	Recover PMP attached to @ap.  Recovery procedure is somewhat
662  *	similar to that of ata_eh_recover() except that reset should
663  *	always be performed in hard->soft sequence and recovery
664  *	failure results in PMP detachment.
665  *
666  *	LOCKING:
667  *	Kernel thread context (may sleep).
668  *
669  *	RETURNS:
670  *	0 on success, -errno on failure.
671  */
672 static int sata_pmp_eh_recover_pmp(struct ata_port *ap,
673 		ata_prereset_fn_t prereset, ata_reset_fn_t softreset,
674 		ata_reset_fn_t hardreset, ata_postreset_fn_t postreset)
675 {
676 	struct ata_link *link = &ap->link;
677 	struct ata_eh_context *ehc = &link->eh_context;
678 	struct ata_device *dev = link->device;
679 	int tries = ATA_EH_PMP_TRIES;
680 	int detach = 0, rc = 0;
681 	int reval_failed = 0;
682 
683 	DPRINTK("ENTER\n");
684 
685 	if (dev->flags & ATA_DFLAG_DETACH) {
686 		detach = 1;
687 		goto fail;
688 	}
689 
690  retry:
691 	ehc->classes[0] = ATA_DEV_UNKNOWN;
692 
693 	if (ehc->i.action & ATA_EH_RESET) {
694 		struct ata_link *tlink;
695 
696 		/* reset */
697 		rc = ata_eh_reset(link, 0, prereset, softreset, hardreset,
698 				  postreset);
699 		if (rc) {
700 			ata_link_printk(link, KERN_ERR,
701 					"failed to reset PMP, giving up\n");
702 			goto fail;
703 		}
704 
705 		/* PMP is reset, SErrors cannot be trusted, scan all */
706 		ata_for_each_link(tlink, ap, EDGE) {
707 			struct ata_eh_context *ehc = &tlink->eh_context;
708 
709 			ehc->i.probe_mask |= ATA_ALL_DEVICES;
710 			ehc->i.action |= ATA_EH_RESET;
711 		}
712 	}
713 
714 	/* If revalidation is requested, revalidate and reconfigure;
715 	 * otherwise, do quick revalidation.
716 	 */
717 	if (ehc->i.action & ATA_EH_REVALIDATE)
718 		rc = sata_pmp_revalidate(dev, ehc->classes[0]);
719 	else
720 		rc = sata_pmp_revalidate_quick(dev);
721 
722 	if (rc) {
723 		tries--;
724 
725 		if (rc == -ENODEV) {
726 			ehc->i.probe_mask |= ATA_ALL_DEVICES;
727 			detach = 1;
728 			/* give it just two more chances */
729 			tries = min(tries, 2);
730 		}
731 
732 		if (tries) {
733 			/* consecutive revalidation failures? speed down */
734 			if (reval_failed)
735 				sata_down_spd_limit(link, 0);
736 			else
737 				reval_failed = 1;
738 
739 			ehc->i.action |= ATA_EH_RESET;
740 			goto retry;
741 		} else {
742 			ata_dev_printk(dev, KERN_ERR, "failed to recover PMP "
743 				       "after %d tries, giving up\n",
744 				       ATA_EH_PMP_TRIES);
745 			goto fail;
746 		}
747 	}
748 
749 	/* okay, PMP resurrected */
750 	ehc->i.flags = 0;
751 
752 	DPRINTK("EXIT, rc=0\n");
753 	return 0;
754 
755  fail:
756 	sata_pmp_detach(dev);
757 	if (detach)
758 		ata_eh_detach_dev(dev);
759 	else
760 		ata_dev_disable(dev);
761 
762 	DPRINTK("EXIT, rc=%d\n", rc);
763 	return rc;
764 }
765 
766 static int sata_pmp_eh_handle_disabled_links(struct ata_port *ap)
767 {
768 	struct ata_link *link;
769 	unsigned long flags;
770 	int rc;
771 
772 	spin_lock_irqsave(ap->lock, flags);
773 
774 	ata_for_each_link(link, ap, EDGE) {
775 		if (!(link->flags & ATA_LFLAG_DISABLED))
776 			continue;
777 
778 		spin_unlock_irqrestore(ap->lock, flags);
779 
780 		/* Some PMPs require hardreset sequence to get
781 		 * SError.N working.
782 		 */
783 		sata_link_hardreset(link, sata_deb_timing_normal,
784 				ata_deadline(jiffies, ATA_TMOUT_INTERNAL_QUICK),
785 				NULL, NULL);
786 
787 		/* unconditionally clear SError.N */
788 		rc = sata_scr_write(link, SCR_ERROR, SERR_PHYRDY_CHG);
789 		if (rc) {
790 			ata_link_printk(link, KERN_ERR, "failed to clear "
791 					"SError.N (errno=%d)\n", rc);
792 			return rc;
793 		}
794 
795 		spin_lock_irqsave(ap->lock, flags);
796 	}
797 
798 	spin_unlock_irqrestore(ap->lock, flags);
799 
800 	return 0;
801 }
802 
803 static int sata_pmp_handle_link_fail(struct ata_link *link, int *link_tries)
804 {
805 	struct ata_port *ap = link->ap;
806 	unsigned long flags;
807 
808 	if (link_tries[link->pmp] && --link_tries[link->pmp])
809 		return 1;
810 
811 	/* disable this link */
812 	if (!(link->flags & ATA_LFLAG_DISABLED)) {
813 		ata_link_printk(link, KERN_WARNING,
814 			"failed to recover link after %d tries, disabling\n",
815 			ATA_EH_PMP_LINK_TRIES);
816 
817 		spin_lock_irqsave(ap->lock, flags);
818 		link->flags |= ATA_LFLAG_DISABLED;
819 		spin_unlock_irqrestore(ap->lock, flags);
820 	}
821 
822 	ata_dev_disable(link->device);
823 	link->eh_context.i.action = 0;
824 
825 	return 0;
826 }
827 
828 /**
829  *	sata_pmp_eh_recover - recover PMP-enabled port
830  *	@ap: ATA port to recover
831  *
832  *	Drive EH recovery operation for PMP enabled port @ap.  This
833  *	function recovers host and PMP ports with proper retrials and
834  *	fallbacks.  Actual recovery operations are performed using
835  *	ata_eh_recover() and sata_pmp_eh_recover_pmp().
836  *
837  *	LOCKING:
838  *	Kernel thread context (may sleep).
839  *
840  *	RETURNS:
841  *	0 on success, -errno on failure.
842  */
843 static int sata_pmp_eh_recover(struct ata_port *ap)
844 {
845 	struct ata_port_operations *ops = ap->ops;
846 	int pmp_tries, link_tries[SATA_PMP_MAX_PORTS];
847 	struct ata_link *pmp_link = &ap->link;
848 	struct ata_device *pmp_dev = pmp_link->device;
849 	struct ata_eh_context *pmp_ehc = &pmp_link->eh_context;
850 	u32 *gscr = pmp_dev->gscr;
851 	struct ata_link *link;
852 	struct ata_device *dev;
853 	unsigned int err_mask;
854 	u32 gscr_error, sntf;
855 	int cnt, rc;
856 
857 	pmp_tries = ATA_EH_PMP_TRIES;
858 	ata_for_each_link(link, ap, EDGE)
859 		link_tries[link->pmp] = ATA_EH_PMP_LINK_TRIES;
860 
861  retry:
862 	/* PMP attached? */
863 	if (!sata_pmp_attached(ap)) {
864 		rc = ata_eh_recover(ap, ops->prereset, ops->softreset,
865 				    ops->hardreset, ops->postreset, NULL);
866 		if (rc) {
867 			ata_for_each_dev(dev, &ap->link, ALL)
868 				ata_dev_disable(dev);
869 			return rc;
870 		}
871 
872 		if (pmp_dev->class != ATA_DEV_PMP)
873 			return 0;
874 
875 		/* new PMP online */
876 		ata_for_each_link(link, ap, EDGE)
877 			link_tries[link->pmp] = ATA_EH_PMP_LINK_TRIES;
878 
879 		/* fall through */
880 	}
881 
882 	/* recover pmp */
883 	rc = sata_pmp_eh_recover_pmp(ap, ops->prereset, ops->softreset,
884 				     ops->hardreset, ops->postreset);
885 	if (rc)
886 		goto pmp_fail;
887 
888 	/* PHY event notification can disturb reset and other recovery
889 	 * operations.  Turn it off.
890 	 */
891 	if (gscr[SATA_PMP_GSCR_FEAT_EN] & SATA_PMP_FEAT_NOTIFY) {
892 		gscr[SATA_PMP_GSCR_FEAT_EN] &= ~SATA_PMP_FEAT_NOTIFY;
893 
894 		err_mask = sata_pmp_write(pmp_link, SATA_PMP_GSCR_FEAT_EN,
895 					  gscr[SATA_PMP_GSCR_FEAT_EN]);
896 		if (err_mask) {
897 			ata_link_printk(pmp_link, KERN_WARNING,
898 				"failed to disable NOTIFY (err_mask=0x%x)\n",
899 				err_mask);
900 			goto pmp_fail;
901 		}
902 	}
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 		gscr[SATA_PMP_GSCR_FEAT_EN] |= SATA_PMP_FEAT_NOTIFY;
927 
928 		err_mask = sata_pmp_write(pmp_link, SATA_PMP_GSCR_FEAT_EN,
929 					  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_for_each_link(link, ap, EDGE) {
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 		pmp_ehc->i.action |= ATA_EH_RESET;
991 		goto retry;
992 	}
993 
994 	ata_port_printk(ap, KERN_ERR,
995 			"failed to recover PMP after %d tries, giving up\n",
996 			ATA_EH_PMP_TRIES);
997 	sata_pmp_detach(pmp_dev);
998 	ata_dev_disable(pmp_dev);
999 
1000 	return rc;
1001 }
1002 
1003 /**
1004  *	sata_pmp_error_handler - do standard error handling for PMP-enabled host
1005  *	@ap: host port to handle error for
1006  *
1007  *	Perform standard error handling sequence for PMP-enabled host
1008  *	@ap.
1009  *
1010  *	LOCKING:
1011  *	Kernel thread context (may sleep).
1012  */
1013 void sata_pmp_error_handler(struct ata_port *ap)
1014 {
1015 	ata_eh_autopsy(ap);
1016 	ata_eh_report(ap);
1017 	sata_pmp_eh_recover(ap);
1018 	ata_eh_finish(ap);
1019 }
1020 
1021 EXPORT_SYMBOL_GPL(sata_pmp_port_ops);
1022 EXPORT_SYMBOL_GPL(sata_pmp_qc_defer_cmd_switch);
1023 EXPORT_SYMBOL_GPL(sata_pmp_error_handler);
1024