libata-pmp.c revision 31f88384443b3e0d7e2c9d36a96647b7e82edad3
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/**
15 *	sata_pmp_read - read PMP register
16 *	@link: link to read PMP register for
17 *	@reg: register to read
18 *	@r_val: resulting value
19 *
20 *	Wrapper around ap->ops->pmp_read to make it easier to call and
21 *	nomarlize error return value.
22 *
23 *	LOCKING:
24 *	Kernel thread context (may sleep).
25 *
26 *	RETURNS:
27 *	0 on success, -errno on failure.
28 */
29static int sata_pmp_read(struct ata_link *link, int reg, u32 *r_val)
30{
31	struct ata_port *ap = link->ap;
32	struct ata_device *pmp_dev = ap->link.device;
33	int rc;
34
35	might_sleep();
36
37	rc = ap->ops->pmp_read(pmp_dev, link->pmp, reg, r_val);
38	if (rc)
39		rc = -EIO;
40	return rc;
41}
42
43/**
44 *	sata_pmp_write - write PMP register
45 *	@link: link to write PMP register for
46 *	@reg: register to write
47 *	@r_val: value to write
48 *
49 *	Wrapper around ap->ops->pmp_write to make it easier to call
50 *	and nomarlize error return value.
51 *
52 *	LOCKING:
53 *	Kernel thread context (may sleep).
54 *
55 *	RETURNS:
56 *	0 on success, -errno on failure.
57 */
58static int sata_pmp_write(struct ata_link *link, int reg, u32 val)
59{
60	struct ata_port *ap = link->ap;
61	struct ata_device *pmp_dev = ap->link.device;
62	int rc;
63
64	might_sleep();
65
66	rc = ap->ops->pmp_write(pmp_dev, link->pmp, reg, val);
67	if (rc)
68		rc = -EIO;
69	return rc;
70}
71
72/**
73 *	sata_pmp_qc_defer_cmd_switch - qc_defer for command switching PMP
74 *	@qc: ATA command in question
75 *
76 *	A host which has command switching PMP support cannot issue
77 *	commands to multiple links simultaneously.
78 *
79 *	LOCKING:
80 *	spin_lock_irqsave(host lock)
81 *
82 *	RETURNS:
83 *	ATA_DEFER_* if deferring is needed, 0 otherwise.
84 */
85int sata_pmp_qc_defer_cmd_switch(struct ata_queued_cmd *qc)
86{
87	struct ata_link *link = qc->dev->link;
88	struct ata_port *ap = link->ap;
89
90	if (ap->excl_link == NULL || ap->excl_link == link) {
91		if (ap->nr_active_links == 0 || ata_link_active(link)) {
92			qc->flags |= ATA_QCFLAG_CLEAR_EXCL;
93			return ata_std_qc_defer(qc);
94		}
95
96		ap->excl_link = link;
97	}
98
99	return ATA_DEFER_PORT;
100}
101
102/**
103 *	sata_pmp_read_init_tf - initialize TF for PMP read
104 *	@tf: taskfile to initialize
105 *	@dev: PMP dev
106 *	@pmp: port multiplier port number
107 *	@reg: register to read
108 *
109 *	Initialize @tf for PMP read command.
110 *
111 *	LOCKING:
112 *	None.
113 */
114void sata_pmp_read_init_tf(struct ata_taskfile *tf,
115			   struct ata_device *dev, int pmp, int reg)
116{
117	ata_tf_init(dev, tf);
118	tf->command = ATA_CMD_PMP_READ;
119	tf->protocol = ATA_PROT_NODATA;
120	tf->flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
121	tf->feature = reg;
122	tf->device = pmp;
123}
124
125/**
126 *	sata_pmp_read_val - extract PMP read result from TF
127 *	@tf: target TF
128 *
129 *	Determine PMP read result from @tf.
130 *
131 *	LOCKING:
132 *	None.
133 */
134u32 sata_pmp_read_val(const struct ata_taskfile *tf)
135{
136	return tf->nsect | tf->lbal << 8 | tf->lbam << 16 | tf->lbah << 24;
137}
138
139/**
140 *	sata_pmp_read_init_tf - initialize TF for PMP write
141 *	@tf: taskfile to initialize
142 *	@dev: PMP dev
143 *	@pmp: port multiplier port number
144 *	@reg: register to read
145 *	@val: value to write
146 *
147 *	Initialize @tf for PMP write command.
148 *
149 *	LOCKING:
150 *	None.
151 */
152void sata_pmp_write_init_tf(struct ata_taskfile *tf,
153			    struct ata_device *dev, int pmp, int reg, u32 val)
154{
155	ata_tf_init(dev, tf);
156	tf->command = ATA_CMD_PMP_WRITE;
157	tf->protocol = ATA_PROT_NODATA;
158	tf->flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
159	tf->feature = reg;
160	tf->device = pmp;
161	tf->nsect = val & 0xff;
162	tf->lbal = (val >> 8) & 0xff;
163	tf->lbam = (val >> 16) & 0xff;
164	tf->lbah = (val >> 24) & 0xff;
165}
166
167/**
168 *	sata_pmp_scr_read - read PSCR
169 *	@link: ATA link to read PSCR for
170 *	@reg: PSCR to read
171 *	@r_val: resulting value
172 *
173 *	Read PSCR @reg into @r_val for @link, to be called from
174 *	ata_scr_read().
175 *
176 *	LOCKING:
177 *	Kernel thread context (may sleep).
178 *
179 *	RETURNS:
180 *	0 on success, -errno on failure.
181 */
182int sata_pmp_scr_read(struct ata_link *link, int reg, u32 *r_val)
183{
184	if (reg > SATA_PMP_PSCR_CONTROL)
185		return -EINVAL;
186
187	return sata_pmp_read(link, reg, r_val);
188}
189
190/**
191 *	sata_pmp_scr_write - write PSCR
192 *	@link: ATA link to write PSCR for
193 *	@reg: PSCR to write
194 *	@val: value to be written
195 *
196 *	Write @val to PSCR @reg for @link, to be called from
197 *	ata_scr_write() and ata_scr_write_flush().
198 *
199 *	LOCKING:
200 *	Kernel thread context (may sleep).
201 *
202 *	RETURNS:
203 *	0 on success, -errno on failure.
204 */
205int sata_pmp_scr_write(struct ata_link *link, int reg, u32 val)
206{
207	if (reg > SATA_PMP_PSCR_CONTROL)
208		return -EINVAL;
209
210	return sata_pmp_write(link, reg, val);
211}
212
213/**
214 *	sata_pmp_std_prereset - prepare PMP link for reset
215 *	@link: link to be reset
216 *	@deadline: deadline jiffies for the operation
217 *
218 *	@link is about to be reset.  Initialize it.
219 *
220 *	LOCKING:
221 *	Kernel thread context (may sleep)
222 *
223 *	RETURNS:
224 *	0 on success, -errno otherwise.
225 */
226int sata_pmp_std_prereset(struct ata_link *link, unsigned long deadline)
227{
228	struct ata_eh_context *ehc = &link->eh_context;
229	const unsigned long *timing = sata_ehc_deb_timing(ehc);
230	int rc;
231
232	/* force HRST? */
233	if (link->flags & ATA_LFLAG_NO_SRST)
234		ehc->i.action |= ATA_EH_HARDRESET;
235
236	/* handle link resume */
237	if ((ehc->i.flags & ATA_EHI_RESUME_LINK) &&
238	    (link->flags & ATA_LFLAG_HRST_TO_RESUME))
239		ehc->i.action |= ATA_EH_HARDRESET;
240
241	/* if we're about to do hardreset, nothing more to do */
242	if (ehc->i.action & ATA_EH_HARDRESET)
243		return 0;
244
245	/* resume link */
246	rc = sata_link_resume(link, timing, deadline);
247	if (rc) {
248		/* phy resume failed */
249		ata_link_printk(link, KERN_WARNING, "failed to resume link "
250				"for reset (errno=%d)\n", rc);
251		return rc;
252	}
253
254	/* clear SError bits including .X which blocks the port when set */
255	rc = sata_scr_write(link, SCR_ERROR, 0xffffffff);
256	if (rc) {
257		ata_link_printk(link, KERN_ERR,
258				"failed to clear SError (errno=%d)\n", rc);
259		return rc;
260	}
261
262	return 0;
263}
264
265/**
266 *	sata_pmp_std_hardreset - standard hardreset method for PMP link
267 *	@link: link to be reset
268 *	@class: resulting class of attached device
269 *	@deadline: deadline jiffies for the operation
270 *
271 *	Hardreset PMP port @link.  Note that this function doesn't
272 *	wait for BSY clearance.  There simply isn't a generic way to
273 *	wait the event.  Instead, this function return -EAGAIN thus
274 *	telling libata-EH to followup with softreset.
275 *
276 *	LOCKING:
277 *	Kernel thread context (may sleep)
278 *
279 *	RETURNS:
280 *	0 on success, -errno otherwise.
281 */
282int sata_pmp_std_hardreset(struct ata_link *link, unsigned int *class,
283			   unsigned long deadline)
284{
285	const unsigned long *timing = sata_ehc_deb_timing(&link->eh_context);
286	u32 tmp;
287	int rc;
288
289	DPRINTK("ENTER\n");
290
291	/* do hardreset */
292	rc = sata_link_hardreset(link, timing, deadline);
293	if (rc) {
294		ata_link_printk(link, KERN_ERR,
295				"COMRESET failed (errno=%d)\n", rc);
296		goto out;
297	}
298
299	/* clear SError bits including .X which blocks the port when set */
300	rc = sata_scr_write(link, SCR_ERROR, 0xffffffff);
301	if (rc) {
302		ata_link_printk(link, KERN_ERR, "failed to clear SError "
303				"during hardreset (errno=%d)\n", rc);
304		goto out;
305	}
306
307	/* if device is present, follow up with srst to wait for !BSY */
308	if (ata_link_online(link))
309		rc = -EAGAIN;
310 out:
311	/* if SCR isn't accessible, we need to reset the PMP */
312	if (rc && rc != -EAGAIN && sata_scr_read(link, SCR_STATUS, &tmp))
313		rc = -ERESTART;
314
315	DPRINTK("EXIT, rc=%d\n", rc);
316	return rc;
317}
318
319/**
320 *	ata_std_postreset - standard postreset method for PMP link
321 *	@link: the target ata_link
322 *	@classes: classes of attached devices
323 *
324 *	This function is invoked after a successful reset.  Note that
325 *	the device might have been reset more than once using
326 *	different reset methods before postreset is invoked.
327 *
328 *	LOCKING:
329 *	Kernel thread context (may sleep)
330 */
331void sata_pmp_std_postreset(struct ata_link *link, unsigned int *class)
332{
333	u32 serror;
334
335	DPRINTK("ENTER\n");
336
337	/* clear SError */
338	if (sata_scr_read(link, SCR_ERROR, &serror) == 0)
339		sata_scr_write(link, SCR_ERROR, serror);
340
341	/* print link status */
342	sata_print_link_status(link);
343
344	DPRINTK("EXIT\n");
345}
346
347/**
348 *	sata_pmp_read_gscr - read GSCR block of SATA PMP
349 *	@dev: PMP device
350 *	@gscr: buffer to read GSCR block into
351 *
352 *	Read selected PMP GSCRs from the PMP at @dev.  This will serve
353 *	as configuration and identification info for the PMP.
354 *
355 *	LOCKING:
356 *	Kernel thread context (may sleep).
357 *
358 *	RETURNS:
359 *	0 on success, -errno on failure.
360 */
361static int sata_pmp_read_gscr(struct ata_device *dev, u32 *gscr)
362{
363	static const int gscr_to_read[] = { 0, 1, 2, 32, 33, 64, 96 };
364	int i, rc;
365
366	for (i = 0; i < ARRAY_SIZE(gscr_to_read); i++) {
367		int reg = gscr_to_read[i];
368
369		rc = sata_pmp_read(dev->link, reg, &gscr[reg]);
370		if (rc) {
371			ata_dev_printk(dev, KERN_ERR, "failed to read "
372				       "PMP GSCR[%d] (errno=%d)\n", reg, rc);
373			return rc;
374		}
375	}
376
377	return 0;
378}
379
380static const char *sata_pmp_spec_rev_str(const u32 *gscr)
381{
382	u32 rev = gscr[SATA_PMP_GSCR_REV];
383
384	if (rev & (1 << 2))
385		return "1.1";
386	if (rev & (1 << 1))
387		return "1.0";
388	return "<unknown>";
389}
390
391static int sata_pmp_configure(struct ata_device *dev, int print_info)
392{
393	struct ata_port *ap = dev->link->ap;
394	u32 *gscr = dev->gscr;
395	const char *reason;
396	int nr_ports, rc;
397
398	nr_ports = sata_pmp_gscr_ports(gscr);
399
400	if (nr_ports <= 0 || nr_ports > SATA_PMP_MAX_PORTS) {
401		rc = -EINVAL;
402		reason = "invalid nr_ports";
403		goto fail;
404	}
405
406	if ((ap->flags & ATA_FLAG_AN) &&
407	    (gscr[SATA_PMP_GSCR_FEAT] & SATA_PMP_FEAT_NOTIFY))
408		dev->flags |= ATA_DFLAG_AN;
409
410	/* monitor SERR_PHYRDY_CHG on fan-out ports */
411	rc = sata_pmp_write(dev->link, SATA_PMP_GSCR_ERROR_EN, SERR_PHYRDY_CHG);
412	if (rc) {
413		reason = "failed to write GSCR_ERROR_EN";
414		goto fail;
415	}
416
417	/* turn off notification till fan-out ports are reset and configured */
418	if (gscr[SATA_PMP_GSCR_FEAT_EN] & SATA_PMP_FEAT_NOTIFY) {
419		gscr[SATA_PMP_GSCR_FEAT_EN] &= ~SATA_PMP_FEAT_NOTIFY;
420
421		rc = sata_pmp_write(dev->link, SATA_PMP_GSCR_FEAT_EN,
422				    gscr[SATA_PMP_GSCR_FEAT_EN]);
423		if (rc) {
424			reason = "failed to write GSCR_FEAT_EN";
425			goto fail;
426		}
427	}
428
429	if (print_info) {
430		ata_dev_printk(dev, KERN_INFO, "Port Multiplier %s, "
431			       "0x%04x:0x%04x r%d, %d ports, feat 0x%x/0x%x\n",
432			       sata_pmp_spec_rev_str(gscr),
433			       sata_pmp_gscr_vendor(gscr),
434			       sata_pmp_gscr_devid(gscr),
435			       sata_pmp_gscr_rev(gscr),
436			       nr_ports, gscr[SATA_PMP_GSCR_FEAT_EN],
437			       gscr[SATA_PMP_GSCR_FEAT]);
438
439		if (!(dev->flags & ATA_DFLAG_AN))
440			ata_dev_printk(dev, KERN_INFO,
441				"Asynchronous notification not supported, "
442				"hotplug won't\n         work on fan-out "
443				"ports. Use warm-plug instead.\n");
444	}
445
446	return 0;
447
448 fail:
449	ata_dev_printk(dev, KERN_ERR,
450		       "failed to configure Port Multiplier (%s)\n", reason);
451	return rc;
452}
453
454static int sata_pmp_init_links(struct ata_port *ap, int nr_ports)
455{
456	struct ata_link *pmp_link = ap->pmp_link;
457	int i;
458
459	if (!pmp_link) {
460		pmp_link = kzalloc(sizeof(pmp_link[0]) * SATA_PMP_MAX_PORTS,
461				   GFP_NOIO);
462		if (!pmp_link)
463			return -ENOMEM;
464
465		for (i = 0; i < SATA_PMP_MAX_PORTS; i++)
466			ata_link_init(ap, &pmp_link[i], i);
467
468		ap->pmp_link = pmp_link;
469	}
470
471	for (i = 0; i < nr_ports; i++) {
472		struct ata_link *link = &pmp_link[i];
473		struct ata_eh_context *ehc = &link->eh_context;
474
475		link->flags = 0;
476		ehc->i.probe_mask |= 1;
477		ehc->i.action |= ATA_EH_SOFTRESET;
478		ehc->i.flags |= ATA_EHI_RESUME_LINK;
479	}
480
481	return 0;
482}
483
484static void sata_pmp_quirks(struct ata_port *ap)
485{
486	u32 *gscr = ap->link.device->gscr;
487	u16 vendor = sata_pmp_gscr_vendor(gscr);
488	u16 devid = sata_pmp_gscr_devid(gscr);
489	struct ata_link *link;
490
491	if (vendor == 0x1095 && devid == 0x3726) {
492		/* sil3726 quirks */
493		ata_port_for_each_link(link, ap) {
494			/* SError.N need a kick in the ass to get working */
495			link->flags |= ATA_LFLAG_HRST_TO_RESUME;
496
497			/* class code report is unreliable */
498			if (link->pmp < 5)
499				link->flags |= ATA_LFLAG_ASSUME_ATA;
500
501			/* port 5 is for SEMB device and it doesn't like SRST */
502			if (link->pmp == 5)
503				link->flags |= ATA_LFLAG_NO_SRST |
504					       ATA_LFLAG_ASSUME_SEMB;
505		}
506	} else if (vendor == 0x1095 && devid == 0x4723) {
507		/* sil4723 quirks */
508		ata_port_for_each_link(link, ap) {
509			/* SError.N need a kick in the ass to get working */
510			link->flags |= ATA_LFLAG_HRST_TO_RESUME;
511
512			/* class code report is unreliable */
513			if (link->pmp < 2)
514				link->flags |= ATA_LFLAG_ASSUME_ATA;
515
516			/* the config device at port 2 locks up on SRST */
517			if (link->pmp == 2)
518				link->flags |= ATA_LFLAG_NO_SRST |
519					       ATA_LFLAG_ASSUME_ATA;
520		}
521	} else if (vendor == 0x1095 && devid == 0x4726) {
522		/* sil4726 quirks */
523		ata_port_for_each_link(link, ap) {
524			/* SError.N need a kick in the ass to get working */
525			link->flags |= ATA_LFLAG_HRST_TO_RESUME;
526
527			/* class code report is unreliable */
528			if (link->pmp < 5)
529				link->flags |= ATA_LFLAG_ASSUME_ATA;
530
531			/* The config device, which can be either at
532			 * port 0 or 5, locks up on SRST.
533			 */
534			if (link->pmp == 0 || link->pmp == 5)
535				link->flags |= ATA_LFLAG_NO_SRST |
536					       ATA_LFLAG_ASSUME_ATA;
537
538			/* Port 6 is for SEMB device which doesn't
539			 * like SRST either.
540			 */
541			if (link->pmp == 6)
542				link->flags |= ATA_LFLAG_NO_SRST |
543					       ATA_LFLAG_ASSUME_SEMB;
544		}
545	} else if (vendor == 0x1095 && (devid == 0x5723 || devid == 0x5733 ||
546					devid == 0x5734 || devid == 0x5744)) {
547		/* sil5723/5744 quirks */
548
549		/* sil5723/5744 has either two or three downstream
550		 * ports depending on operation mode.  The last port
551		 * is empty if any actual IO device is available or
552		 * occupied by a pseudo configuration device
553		 * otherwise.  Don't try hard to recover it.
554		 */
555		ap->pmp_link[ap->nr_pmp_links - 1].flags |= ATA_LFLAG_NO_RETRY;
556	} else if (vendor == 0x11ab && devid == 0x4140) {
557		/* Marvell 88SM4140 quirks.  Fan-out ports require PHY
558		 * reset to work; other than that, it behaves very
559		 * nicely.
560		 */
561		ata_port_for_each_link(link, ap)
562			link->flags |= ATA_LFLAG_HRST_TO_RESUME;
563	}
564}
565
566/**
567 *	sata_pmp_attach - attach a SATA PMP device
568 *	@dev: SATA PMP device to attach
569 *
570 *	Configure and attach SATA PMP device @dev.  This function is
571 *	also responsible for allocating and initializing PMP links.
572 *
573 *	LOCKING:
574 *	Kernel thread context (may sleep).
575 *
576 *	RETURNS:
577 *	0 on success, -errno on failure.
578 */
579int sata_pmp_attach(struct ata_device *dev)
580{
581	struct ata_link *link = dev->link;
582	struct ata_port *ap = link->ap;
583	unsigned long flags;
584	struct ata_link *tlink;
585	int rc;
586
587	/* is it hanging off the right place? */
588	if (!(ap->flags & ATA_FLAG_PMP)) {
589		ata_dev_printk(dev, KERN_ERR,
590			       "host does not support Port Multiplier\n");
591		return -EINVAL;
592	}
593
594	if (!ata_is_host_link(link)) {
595		ata_dev_printk(dev, KERN_ERR,
596			       "Port Multipliers cannot be nested\n");
597		return -EINVAL;
598	}
599
600	if (dev->devno) {
601		ata_dev_printk(dev, KERN_ERR,
602			       "Port Multiplier must be the first device\n");
603		return -EINVAL;
604	}
605
606	WARN_ON(link->pmp != 0);
607	link->pmp = SATA_PMP_CTRL_PORT;
608
609	/* read GSCR block */
610	rc = sata_pmp_read_gscr(dev, dev->gscr);
611	if (rc)
612		goto fail;
613
614	/* config PMP */
615	rc = sata_pmp_configure(dev, 1);
616	if (rc)
617		goto fail;
618
619	rc = sata_pmp_init_links(ap, sata_pmp_gscr_ports(dev->gscr));
620	if (rc) {
621		ata_dev_printk(dev, KERN_INFO,
622			       "failed to initialize PMP links\n");
623		goto fail;
624	}
625
626	/* attach it */
627	spin_lock_irqsave(ap->lock, flags);
628	WARN_ON(ap->nr_pmp_links);
629	ap->nr_pmp_links = sata_pmp_gscr_ports(dev->gscr);
630	spin_unlock_irqrestore(ap->lock, flags);
631
632	sata_pmp_quirks(ap);
633
634	if (ap->ops->pmp_attach)
635		ap->ops->pmp_attach(ap);
636
637	ata_port_for_each_link(tlink, ap)
638		sata_link_init_spd(tlink);
639
640	ata_acpi_associate_sata_port(ap);
641
642	return 0;
643
644 fail:
645	link->pmp = 0;
646	return rc;
647}
648
649/**
650 *	sata_pmp_detach - detach a SATA PMP device
651 *	@dev: SATA PMP device to detach
652 *
653 *	Detach SATA PMP device @dev.  This function is also
654 *	responsible for deconfiguring PMP links.
655 *
656 *	LOCKING:
657 *	Kernel thread context (may sleep).
658 */
659static void sata_pmp_detach(struct ata_device *dev)
660{
661	struct ata_link *link = dev->link;
662	struct ata_port *ap = link->ap;
663	struct ata_link *tlink;
664	unsigned long flags;
665
666	ata_dev_printk(dev, KERN_INFO, "Port Multiplier detaching\n");
667
668	WARN_ON(!ata_is_host_link(link) || dev->devno ||
669		link->pmp != SATA_PMP_CTRL_PORT);
670
671	if (ap->ops->pmp_detach)
672		ap->ops->pmp_detach(ap);
673
674	ata_port_for_each_link(tlink, ap)
675		ata_eh_detach_dev(tlink->device);
676
677	spin_lock_irqsave(ap->lock, flags);
678	ap->nr_pmp_links = 0;
679	link->pmp = 0;
680	spin_unlock_irqrestore(ap->lock, flags);
681
682	ata_acpi_associate_sata_port(ap);
683}
684
685/**
686 *	sata_pmp_same_pmp - does new GSCR matches the configured PMP?
687 *	@dev: PMP device to compare against
688 *	@new_gscr: GSCR block of the new device
689 *
690 *	Compare @new_gscr against @dev and determine whether @dev is
691 *	the PMP described by @new_gscr.
692 *
693 *	LOCKING:
694 *	None.
695 *
696 *	RETURNS:
697 *	1 if @dev matches @new_gscr, 0 otherwise.
698 */
699static int sata_pmp_same_pmp(struct ata_device *dev, const u32 *new_gscr)
700{
701	const u32 *old_gscr = dev->gscr;
702	u16 old_vendor, new_vendor, old_devid, new_devid;
703	int old_nr_ports, new_nr_ports;
704
705	old_vendor = sata_pmp_gscr_vendor(old_gscr);
706	new_vendor = sata_pmp_gscr_vendor(new_gscr);
707	old_devid = sata_pmp_gscr_devid(old_gscr);
708	new_devid = sata_pmp_gscr_devid(new_gscr);
709	old_nr_ports = sata_pmp_gscr_ports(old_gscr);
710	new_nr_ports = sata_pmp_gscr_ports(new_gscr);
711
712	if (old_vendor != new_vendor) {
713		ata_dev_printk(dev, KERN_INFO, "Port Multiplier "
714			       "vendor mismatch '0x%x' != '0x%x'\n",
715			       old_vendor, new_vendor);
716		return 0;
717	}
718
719	if (old_devid != new_devid) {
720		ata_dev_printk(dev, KERN_INFO, "Port Multiplier "
721			       "device ID mismatch '0x%x' != '0x%x'\n",
722			       old_devid, new_devid);
723		return 0;
724	}
725
726	if (old_nr_ports != new_nr_ports) {
727		ata_dev_printk(dev, KERN_INFO, "Port Multiplier "
728			       "nr_ports mismatch '0x%x' != '0x%x'\n",
729			       old_nr_ports, new_nr_ports);
730		return 0;
731	}
732
733	return 1;
734}
735
736/**
737 *	sata_pmp_revalidate - revalidate SATA PMP
738 *	@dev: PMP device to revalidate
739 *	@new_class: new class code
740 *
741 *	Re-read GSCR block and make sure @dev is still attached to the
742 *	port and properly configured.
743 *
744 *	LOCKING:
745 *	Kernel thread context (may sleep).
746 *
747 *	RETURNS:
748 *	0 on success, -errno otherwise.
749 */
750static int sata_pmp_revalidate(struct ata_device *dev, unsigned int new_class)
751{
752	struct ata_link *link = dev->link;
753	struct ata_port *ap = link->ap;
754	u32 *gscr = (void *)ap->sector_buf;
755	int rc;
756
757	DPRINTK("ENTER\n");
758
759	ata_eh_about_to_do(link, NULL, ATA_EH_REVALIDATE);
760
761	if (!ata_dev_enabled(dev)) {
762		rc = -ENODEV;
763		goto fail;
764	}
765
766	/* wrong class? */
767	if (ata_class_enabled(new_class) && new_class != ATA_DEV_PMP) {
768		rc = -ENODEV;
769		goto fail;
770	}
771
772	/* read GSCR */
773	rc = sata_pmp_read_gscr(dev, gscr);
774	if (rc)
775		goto fail;
776
777	/* is the pmp still there? */
778	if (!sata_pmp_same_pmp(dev, gscr)) {
779		rc = -ENODEV;
780		goto fail;
781	}
782
783	memcpy(dev->gscr, gscr, sizeof(gscr[0]) * SATA_PMP_GSCR_DWORDS);
784
785	rc = sata_pmp_configure(dev, 0);
786	if (rc)
787		goto fail;
788
789	ata_eh_done(link, NULL, ATA_EH_REVALIDATE);
790
791	DPRINTK("EXIT, rc=0\n");
792	return 0;
793
794 fail:
795	ata_dev_printk(dev, KERN_ERR,
796		       "PMP revalidation failed (errno=%d)\n", rc);
797	DPRINTK("EXIT, rc=%d\n", rc);
798	return rc;
799}
800
801/**
802 *	sata_pmp_revalidate_quick - revalidate SATA PMP quickly
803 *	@dev: PMP device to revalidate
804 *
805 *	Make sure the attached PMP is accessible.
806 *
807 *	LOCKING:
808 *	Kernel thread context (may sleep).
809 *
810 *	RETURNS:
811 *	0 on success, -errno otherwise.
812 */
813static int sata_pmp_revalidate_quick(struct ata_device *dev)
814{
815	u32 prod_id;
816	int rc;
817
818	rc = sata_pmp_read(dev->link, SATA_PMP_GSCR_PROD_ID, &prod_id);
819	if (rc) {
820		ata_dev_printk(dev, KERN_ERR, "failed to read PMP product ID\n");
821		return rc;
822	}
823
824	if (prod_id != dev->gscr[SATA_PMP_GSCR_PROD_ID]) {
825		ata_dev_printk(dev, KERN_ERR, "PMP product ID mismatch\n");
826		/* something weird is going on, request full PMP recovery */
827		return -EIO;
828	}
829
830	return 0;
831}
832
833/**
834 *	sata_pmp_eh_recover_pmp - recover PMP
835 *	@ap: ATA port PMP is attached to
836 *	@prereset: prereset method (can be NULL)
837 *	@softreset: softreset method
838 *	@hardreset: hardreset method
839 *	@postreset: postreset method (can be NULL)
840 *
841 *	Recover PMP attached to @ap.  Recovery procedure is somewhat
842 *	similar to that of ata_eh_recover() except that reset should
843 *	always be performed in hard->soft sequence and recovery
844 *	failure results in PMP detachment.
845 *
846 *	LOCKING:
847 *	Kernel thread context (may sleep).
848 *
849 *	RETURNS:
850 *	0 on success, -errno on failure.
851 */
852static int sata_pmp_eh_recover_pmp(struct ata_port *ap,
853		ata_prereset_fn_t prereset, ata_reset_fn_t softreset,
854		ata_reset_fn_t hardreset, ata_postreset_fn_t postreset)
855{
856	struct ata_link *link = &ap->link;
857	struct ata_eh_context *ehc = &link->eh_context;
858	struct ata_device *dev = link->device;
859	int tries = ATA_EH_PMP_TRIES;
860	int detach = 0, rc = 0;
861	int reval_failed = 0;
862
863	DPRINTK("ENTER\n");
864
865	if (dev->flags & ATA_DFLAG_DETACH) {
866		detach = 1;
867		goto fail;
868	}
869
870 retry:
871	ehc->classes[0] = ATA_DEV_UNKNOWN;
872
873	if (ehc->i.action & ATA_EH_RESET_MASK) {
874		struct ata_link *tlink;
875
876		ata_eh_freeze_port(ap);
877
878		/* reset */
879		ehc->i.action = ATA_EH_HARDRESET;
880		rc = ata_eh_reset(link, 0, prereset, softreset, hardreset,
881				  postreset);
882		if (rc) {
883			ata_link_printk(link, KERN_ERR,
884					"failed to reset PMP, giving up\n");
885			goto fail;
886		}
887
888		ata_eh_thaw_port(ap);
889
890		/* PMP is reset, SErrors cannot be trusted, scan all */
891		ata_port_for_each_link(tlink, ap)
892			ata_ehi_schedule_probe(&tlink->eh_context.i);
893	}
894
895	/* If revalidation is requested, revalidate and reconfigure;
896	 * otherwise, do quick revalidation.
897	 */
898	if (ehc->i.action & ATA_EH_REVALIDATE)
899		rc = sata_pmp_revalidate(dev, ehc->classes[0]);
900	else
901		rc = sata_pmp_revalidate_quick(dev);
902
903	if (rc) {
904		tries--;
905
906		if (rc == -ENODEV) {
907			ehc->i.probe_mask |= 1;
908			detach = 1;
909			/* give it just two more chances */
910			tries = min(tries, 2);
911		}
912
913		if (tries) {
914			int sleep = ehc->i.flags & ATA_EHI_DID_RESET;
915
916			/* consecutive revalidation failures? speed down */
917			if (reval_failed)
918				sata_down_spd_limit(link);
919			else
920				reval_failed = 1;
921
922			ata_dev_printk(dev, KERN_WARNING,
923				       "retrying hardreset%s\n",
924				       sleep ? " in 5 secs" : "");
925			if (sleep)
926				ssleep(5);
927			ehc->i.action |= ATA_EH_HARDRESET;
928			goto retry;
929		} else {
930			ata_dev_printk(dev, KERN_ERR, "failed to recover PMP "
931				       "after %d tries, giving up\n",
932				       ATA_EH_PMP_TRIES);
933			goto fail;
934		}
935	}
936
937	/* okay, PMP resurrected */
938	ehc->i.flags = 0;
939
940	DPRINTK("EXIT, rc=0\n");
941	return 0;
942
943 fail:
944	sata_pmp_detach(dev);
945	if (detach)
946		ata_eh_detach_dev(dev);
947	else
948		ata_dev_disable(dev);
949
950	DPRINTK("EXIT, rc=%d\n", rc);
951	return rc;
952}
953
954static int sata_pmp_eh_handle_disabled_links(struct ata_port *ap)
955{
956	struct ata_link *link;
957	unsigned long flags;
958	int rc;
959
960	spin_lock_irqsave(ap->lock, flags);
961
962	ata_port_for_each_link(link, ap) {
963		if (!(link->flags & ATA_LFLAG_DISABLED))
964			continue;
965
966		spin_unlock_irqrestore(ap->lock, flags);
967
968		/* Some PMPs require hardreset sequence to get
969		 * SError.N working.
970		 */
971		if ((link->flags & ATA_LFLAG_HRST_TO_RESUME) &&
972		    (link->eh_context.i.flags & ATA_EHI_RESUME_LINK))
973			sata_link_hardreset(link, sata_deb_timing_normal,
974					    jiffies + ATA_TMOUT_INTERNAL_QUICK);
975
976		/* unconditionally clear SError.N */
977		rc = sata_scr_write(link, SCR_ERROR, SERR_PHYRDY_CHG);
978		if (rc) {
979			ata_link_printk(link, KERN_ERR, "failed to clear "
980					"SError.N (errno=%d)\n", rc);
981			return rc;
982		}
983
984		spin_lock_irqsave(ap->lock, flags);
985	}
986
987	spin_unlock_irqrestore(ap->lock, flags);
988
989	return 0;
990}
991
992static int sata_pmp_handle_link_fail(struct ata_link *link, int *link_tries)
993{
994	struct ata_port *ap = link->ap;
995	unsigned long flags;
996
997	if (link_tries[link->pmp] && --link_tries[link->pmp])
998		return 1;
999
1000	/* disable this link */
1001	if (!(link->flags & ATA_LFLAG_DISABLED)) {
1002		ata_link_printk(link, KERN_WARNING,
1003			"failed to recover link after %d tries, disabling\n",
1004			ATA_EH_PMP_LINK_TRIES);
1005
1006		spin_lock_irqsave(ap->lock, flags);
1007		link->flags |= ATA_LFLAG_DISABLED;
1008		spin_unlock_irqrestore(ap->lock, flags);
1009	}
1010
1011	ata_dev_disable(link->device);
1012	link->eh_context.i.action = 0;
1013
1014	return 0;
1015}
1016
1017/**
1018 *	sata_pmp_eh_recover - recover PMP-enabled port
1019 *	@ap: ATA port to recover
1020 *	@prereset: prereset method (can be NULL)
1021 *	@softreset: softreset method
1022 *	@hardreset: hardreset method
1023 *	@postreset: postreset method (can be NULL)
1024 *	@pmp_prereset: PMP prereset method (can be NULL)
1025 *	@pmp_softreset: PMP softreset method (can be NULL)
1026 *	@pmp_hardreset: PMP hardreset method (can be NULL)
1027 *	@pmp_postreset: PMP postreset method (can be NULL)
1028 *
1029 *	Drive EH recovery operation for PMP enabled port @ap.  This
1030 *	function recovers host and PMP ports with proper retrials and
1031 *	fallbacks.  Actual recovery operations are performed using
1032 *	ata_eh_recover() and sata_pmp_eh_recover_pmp().
1033 *
1034 *	LOCKING:
1035 *	Kernel thread context (may sleep).
1036 *
1037 *	RETURNS:
1038 *	0 on success, -errno on failure.
1039 */
1040static int sata_pmp_eh_recover(struct ata_port *ap,
1041		ata_prereset_fn_t prereset, ata_reset_fn_t softreset,
1042		ata_reset_fn_t hardreset, ata_postreset_fn_t postreset,
1043		ata_prereset_fn_t pmp_prereset, ata_reset_fn_t pmp_softreset,
1044		ata_reset_fn_t pmp_hardreset, ata_postreset_fn_t pmp_postreset)
1045{
1046	int pmp_tries, link_tries[SATA_PMP_MAX_PORTS];
1047	struct ata_link *pmp_link = &ap->link;
1048	struct ata_device *pmp_dev = pmp_link->device;
1049	struct ata_eh_context *pmp_ehc = &pmp_link->eh_context;
1050	struct ata_link *link;
1051	struct ata_device *dev;
1052	u32 gscr_error, sntf;
1053	int cnt, rc;
1054
1055	pmp_tries = ATA_EH_PMP_TRIES;
1056	ata_port_for_each_link(link, ap)
1057		link_tries[link->pmp] = ATA_EH_PMP_LINK_TRIES;
1058
1059 retry:
1060	/* PMP attached? */
1061	if (!ap->nr_pmp_links) {
1062		rc = ata_eh_recover(ap, prereset, softreset, hardreset,
1063				    postreset, NULL);
1064		if (rc) {
1065			ata_link_for_each_dev(dev, &ap->link)
1066				ata_dev_disable(dev);
1067			return rc;
1068		}
1069
1070		if (pmp_dev->class != ATA_DEV_PMP)
1071			return 0;
1072
1073		/* new PMP online */
1074		ata_port_for_each_link(link, ap)
1075			link_tries[link->pmp] = ATA_EH_PMP_LINK_TRIES;
1076
1077		/* fall through */
1078	}
1079
1080	/* recover pmp */
1081	rc = sata_pmp_eh_recover_pmp(ap, prereset, softreset, hardreset,
1082				     postreset);
1083	if (rc)
1084		goto pmp_fail;
1085
1086	/* handle disabled links */
1087	rc = sata_pmp_eh_handle_disabled_links(ap);
1088	if (rc)
1089		goto pmp_fail;
1090
1091	/* recover links */
1092	rc = ata_eh_recover(ap, pmp_prereset, pmp_softreset, pmp_hardreset,
1093			    pmp_postreset, &link);
1094	if (rc)
1095		goto link_fail;
1096
1097	/* Connection status might have changed while resetting other
1098	 * links, check SATA_PMP_GSCR_ERROR before returning.
1099	 */
1100
1101	/* clear SNotification */
1102	rc = sata_scr_read(&ap->link, SCR_NOTIFICATION, &sntf);
1103	if (rc == 0)
1104		sata_scr_write(&ap->link, SCR_NOTIFICATION, sntf);
1105
1106	/* enable notification */
1107	if (pmp_dev->flags & ATA_DFLAG_AN) {
1108		pmp_dev->gscr[SATA_PMP_GSCR_FEAT_EN] |= SATA_PMP_FEAT_NOTIFY;
1109
1110		rc = sata_pmp_write(pmp_dev->link, SATA_PMP_GSCR_FEAT_EN,
1111				    pmp_dev->gscr[SATA_PMP_GSCR_FEAT_EN]);
1112		if (rc) {
1113			ata_dev_printk(pmp_dev, KERN_ERR,
1114				       "failed to write PMP_FEAT_EN\n");
1115			goto pmp_fail;
1116		}
1117	}
1118
1119	/* check GSCR_ERROR */
1120	rc = sata_pmp_read(pmp_link, SATA_PMP_GSCR_ERROR, &gscr_error);
1121	if (rc) {
1122		ata_dev_printk(pmp_dev, KERN_ERR,
1123			       "failed to read PMP_GSCR_ERROR\n");
1124		goto pmp_fail;
1125	}
1126
1127	cnt = 0;
1128	ata_port_for_each_link(link, ap) {
1129		if (!(gscr_error & (1 << link->pmp)))
1130			continue;
1131
1132		if (sata_pmp_handle_link_fail(link, link_tries)) {
1133			ata_ehi_hotplugged(&link->eh_context.i);
1134			cnt++;
1135		} else {
1136			ata_link_printk(link, KERN_WARNING,
1137				"PHY status changed but maxed out on retries, "
1138				"giving up\n");
1139			ata_link_printk(link, KERN_WARNING,
1140				"Manully issue scan to resume this link\n");
1141		}
1142	}
1143
1144	if (cnt) {
1145		ata_port_printk(ap, KERN_INFO, "PMP SError.N set for some "
1146				"ports, repeating recovery\n");
1147		goto retry;
1148	}
1149
1150	return 0;
1151
1152 link_fail:
1153	if (sata_pmp_handle_link_fail(link, link_tries)) {
1154		pmp_ehc->i.action |= ATA_EH_HARDRESET;
1155		goto retry;
1156	}
1157
1158	/* fall through */
1159 pmp_fail:
1160	/* Control always ends up here after detaching PMP.  Shut up
1161	 * and return if we're unloading.
1162	 */
1163	if (ap->pflags & ATA_PFLAG_UNLOADING)
1164		return rc;
1165
1166	if (!ap->nr_pmp_links)
1167		goto retry;
1168
1169	if (--pmp_tries) {
1170		ata_port_printk(ap, KERN_WARNING,
1171				"failed to recover PMP, retrying in 5 secs\n");
1172		pmp_ehc->i.action |= ATA_EH_HARDRESET;
1173		ssleep(5);
1174		goto retry;
1175	}
1176
1177	ata_port_printk(ap, KERN_ERR,
1178			"failed to recover PMP after %d tries, giving up\n",
1179			ATA_EH_PMP_TRIES);
1180	sata_pmp_detach(pmp_dev);
1181	ata_dev_disable(pmp_dev);
1182
1183	return rc;
1184}
1185
1186/**
1187 *	sata_pmp_do_eh - do standard error handling for PMP-enabled host
1188 *	@ap: host port to handle error for
1189 *	@prereset: prereset method (can be NULL)
1190 *	@softreset: softreset method
1191 *	@hardreset: hardreset method
1192 *	@postreset: postreset method (can be NULL)
1193 *	@pmp_prereset: PMP prereset method (can be NULL)
1194 *	@pmp_softreset: PMP softreset method (can be NULL)
1195 *	@pmp_hardreset: PMP hardreset method (can be NULL)
1196 *	@pmp_postreset: PMP postreset method (can be NULL)
1197 *
1198 *	Perform standard error handling sequence for PMP-enabled host
1199 *	@ap.
1200 *
1201 *	LOCKING:
1202 *	Kernel thread context (may sleep).
1203 */
1204void sata_pmp_do_eh(struct ata_port *ap,
1205		ata_prereset_fn_t prereset, ata_reset_fn_t softreset,
1206		ata_reset_fn_t hardreset, ata_postreset_fn_t postreset,
1207		ata_prereset_fn_t pmp_prereset, ata_reset_fn_t pmp_softreset,
1208		ata_reset_fn_t pmp_hardreset, ata_postreset_fn_t pmp_postreset)
1209{
1210	ata_eh_autopsy(ap);
1211	ata_eh_report(ap);
1212	sata_pmp_eh_recover(ap, prereset, softreset, hardreset, postreset,
1213			    pmp_prereset, pmp_softreset, pmp_hardreset,
1214			    pmp_postreset);
1215	ata_eh_finish(ap);
1216}
1217