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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
15const 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 */
37static 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 */
74static 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 */
108int 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 */
140int 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 */
171int 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 */
201static 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
221static 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#define PMP_GSCR_SII_POL 129
235
236static int sata_pmp_configure(struct ata_device *dev, int print_info)
237{
238	struct ata_port *ap = dev->link->ap;
239	u32 *gscr = dev->gscr;
240	u16 vendor = sata_pmp_gscr_vendor(gscr);
241	u16 devid = sata_pmp_gscr_devid(gscr);
242	unsigned int err_mask = 0;
243	const char *reason;
244	int nr_ports, rc;
245
246	nr_ports = sata_pmp_gscr_ports(gscr);
247
248	if (nr_ports <= 0 || nr_ports > SATA_PMP_MAX_PORTS) {
249		rc = -EINVAL;
250		reason = "invalid nr_ports";
251		goto fail;
252	}
253
254	if ((ap->flags & ATA_FLAG_AN) &&
255	    (gscr[SATA_PMP_GSCR_FEAT] & SATA_PMP_FEAT_NOTIFY))
256		dev->flags |= ATA_DFLAG_AN;
257
258	/* monitor SERR_PHYRDY_CHG on fan-out ports */
259	err_mask = sata_pmp_write(dev->link, SATA_PMP_GSCR_ERROR_EN,
260				  SERR_PHYRDY_CHG);
261	if (err_mask) {
262		rc = -EIO;
263		reason = "failed to write GSCR_ERROR_EN";
264		goto fail;
265	}
266
267	/* Disable sending Early R_OK.
268	 * With "cached read" HDD testing and multiple ports busy on a SATA
269	 * host controller, 3726 PMP will very rarely drop a deferred
270	 * R_OK that was intended for the host. Symptom will be all
271	 * 5 drives under test will timeout, get reset, and recover.
272	 */
273	if (vendor == 0x1095 && devid == 0x3726) {
274		u32 reg;
275
276		err_mask = sata_pmp_read(&ap->link, PMP_GSCR_SII_POL, &reg);
277		if (err_mask) {
278			rc = -EIO;
279			reason = "failed to read Sil3726 Private Register";
280			goto fail;
281		}
282		reg &= ~0x1;
283		err_mask = sata_pmp_write(&ap->link, PMP_GSCR_SII_POL, reg);
284		if (err_mask) {
285			rc = -EIO;
286			reason = "failed to write Sil3726 Private Register";
287			goto fail;
288		}
289	}
290
291	if (print_info) {
292		ata_dev_printk(dev, KERN_INFO, "Port Multiplier %s, "
293			       "0x%04x:0x%04x r%d, %d ports, feat 0x%x/0x%x\n",
294			       sata_pmp_spec_rev_str(gscr), vendor, devid,
295			       sata_pmp_gscr_rev(gscr),
296			       nr_ports, gscr[SATA_PMP_GSCR_FEAT_EN],
297			       gscr[SATA_PMP_GSCR_FEAT]);
298
299		if (!(dev->flags & ATA_DFLAG_AN))
300			ata_dev_printk(dev, KERN_INFO,
301				"Asynchronous notification not supported, "
302				"hotplug won't\n         work on fan-out "
303				"ports. Use warm-plug instead.\n");
304	}
305
306	return 0;
307
308 fail:
309	ata_dev_printk(dev, KERN_ERR,
310		       "failed to configure Port Multiplier (%s, Emask=0x%x)\n",
311		       reason, err_mask);
312	return rc;
313}
314
315static int sata_pmp_init_links(struct ata_port *ap, int nr_ports)
316{
317	struct ata_link *pmp_link = ap->pmp_link;
318	int i;
319
320	if (!pmp_link) {
321		pmp_link = kzalloc(sizeof(pmp_link[0]) * SATA_PMP_MAX_PORTS,
322				   GFP_NOIO);
323		if (!pmp_link)
324			return -ENOMEM;
325
326		for (i = 0; i < SATA_PMP_MAX_PORTS; i++)
327			ata_link_init(ap, &pmp_link[i], i);
328
329		ap->pmp_link = pmp_link;
330	}
331
332	for (i = 0; i < nr_ports; i++) {
333		struct ata_link *link = &pmp_link[i];
334		struct ata_eh_context *ehc = &link->eh_context;
335
336		link->flags = 0;
337		ehc->i.probe_mask |= ATA_ALL_DEVICES;
338		ehc->i.action |= ATA_EH_RESET;
339	}
340
341	return 0;
342}
343
344static void sata_pmp_quirks(struct ata_port *ap)
345{
346	u32 *gscr = ap->link.device->gscr;
347	u16 vendor = sata_pmp_gscr_vendor(gscr);
348	u16 devid = sata_pmp_gscr_devid(gscr);
349	struct ata_link *link;
350
351	if (vendor == 0x1095 && devid == 0x3726) {
352		/* sil3726 quirks */
353		ata_for_each_link(link, ap, EDGE) {
354			/* Class code report is unreliable and SRST
355			 * times out under certain configurations.
356			 */
357			if (link->pmp < 5)
358				link->flags |= ATA_LFLAG_NO_SRST |
359					       ATA_LFLAG_ASSUME_ATA;
360
361			/* port 5 is for SEMB device and it doesn't like SRST */
362			if (link->pmp == 5)
363				link->flags |= ATA_LFLAG_NO_SRST |
364					       ATA_LFLAG_ASSUME_SEMB;
365		}
366	} else if (vendor == 0x1095 && devid == 0x4723) {
367		/* sil4723 quirks */
368		ata_for_each_link(link, ap, EDGE) {
369			/* class code report is unreliable */
370			if (link->pmp < 2)
371				link->flags |= ATA_LFLAG_ASSUME_ATA;
372
373			/* the config device at port 2 locks up on SRST */
374			if (link->pmp == 2)
375				link->flags |= ATA_LFLAG_NO_SRST |
376					       ATA_LFLAG_ASSUME_ATA;
377		}
378	} else if (vendor == 0x1095 && devid == 0x4726) {
379		/* sil4726 quirks */
380		ata_for_each_link(link, ap, EDGE) {
381			/* Class code report is unreliable and SRST
382			 * times out under certain configurations.
383			 * Config device can be at port 0 or 5 and
384			 * locks up on SRST.
385			 */
386			if (link->pmp <= 5)
387				link->flags |= ATA_LFLAG_NO_SRST |
388					       ATA_LFLAG_ASSUME_ATA;
389
390			/* Port 6 is for SEMB device which doesn't
391			 * like SRST either.
392			 */
393			if (link->pmp == 6)
394				link->flags |= ATA_LFLAG_NO_SRST |
395					       ATA_LFLAG_ASSUME_SEMB;
396		}
397	} else if (vendor == 0x1095 && (devid == 0x5723 || devid == 0x5733 ||
398					devid == 0x5734 || devid == 0x5744)) {
399		/* sil5723/5744 quirks */
400
401		/* sil5723/5744 has either two or three downstream
402		 * ports depending on operation mode.  The last port
403		 * is empty if any actual IO device is available or
404		 * occupied by a pseudo configuration device
405		 * otherwise.  Don't try hard to recover it.
406		 */
407		ap->pmp_link[ap->nr_pmp_links - 1].flags |= ATA_LFLAG_NO_RETRY;
408	}
409}
410
411/**
412 *	sata_pmp_attach - attach a SATA PMP device
413 *	@dev: SATA PMP device to attach
414 *
415 *	Configure and attach SATA PMP device @dev.  This function is
416 *	also responsible for allocating and initializing PMP links.
417 *
418 *	LOCKING:
419 *	Kernel thread context (may sleep).
420 *
421 *	RETURNS:
422 *	0 on success, -errno on failure.
423 */
424int sata_pmp_attach(struct ata_device *dev)
425{
426	struct ata_link *link = dev->link;
427	struct ata_port *ap = link->ap;
428	unsigned long flags;
429	struct ata_link *tlink;
430	int rc;
431
432	/* is it hanging off the right place? */
433	if (!sata_pmp_supported(ap)) {
434		ata_dev_printk(dev, KERN_ERR,
435			       "host does not support Port Multiplier\n");
436		return -EINVAL;
437	}
438
439	if (!ata_is_host_link(link)) {
440		ata_dev_printk(dev, KERN_ERR,
441			       "Port Multipliers cannot be nested\n");
442		return -EINVAL;
443	}
444
445	if (dev->devno) {
446		ata_dev_printk(dev, KERN_ERR,
447			       "Port Multiplier must be the first device\n");
448		return -EINVAL;
449	}
450
451	WARN_ON(link->pmp != 0);
452	link->pmp = SATA_PMP_CTRL_PORT;
453
454	/* read GSCR block */
455	rc = sata_pmp_read_gscr(dev, dev->gscr);
456	if (rc)
457		goto fail;
458
459	/* config PMP */
460	rc = sata_pmp_configure(dev, 1);
461	if (rc)
462		goto fail;
463
464	rc = sata_pmp_init_links(ap, sata_pmp_gscr_ports(dev->gscr));
465	if (rc) {
466		ata_dev_printk(dev, KERN_INFO,
467			       "failed to initialize PMP links\n");
468		goto fail;
469	}
470
471	/* attach it */
472	spin_lock_irqsave(ap->lock, flags);
473	WARN_ON(ap->nr_pmp_links);
474	ap->nr_pmp_links = sata_pmp_gscr_ports(dev->gscr);
475	spin_unlock_irqrestore(ap->lock, flags);
476
477	sata_pmp_quirks(ap);
478
479	if (ap->ops->pmp_attach)
480		ap->ops->pmp_attach(ap);
481
482	ata_for_each_link(tlink, ap, EDGE)
483		sata_link_init_spd(tlink);
484
485	ata_acpi_associate_sata_port(ap);
486
487	return 0;
488
489 fail:
490	link->pmp = 0;
491	return rc;
492}
493
494/**
495 *	sata_pmp_detach - detach a SATA PMP device
496 *	@dev: SATA PMP device to detach
497 *
498 *	Detach SATA PMP device @dev.  This function is also
499 *	responsible for deconfiguring PMP links.
500 *
501 *	LOCKING:
502 *	Kernel thread context (may sleep).
503 */
504static void sata_pmp_detach(struct ata_device *dev)
505{
506	struct ata_link *link = dev->link;
507	struct ata_port *ap = link->ap;
508	struct ata_link *tlink;
509	unsigned long flags;
510
511	ata_dev_printk(dev, KERN_INFO, "Port Multiplier detaching\n");
512
513	WARN_ON(!ata_is_host_link(link) || dev->devno ||
514		link->pmp != SATA_PMP_CTRL_PORT);
515
516	if (ap->ops->pmp_detach)
517		ap->ops->pmp_detach(ap);
518
519	ata_for_each_link(tlink, ap, EDGE)
520		ata_eh_detach_dev(tlink->device);
521
522	spin_lock_irqsave(ap->lock, flags);
523	ap->nr_pmp_links = 0;
524	link->pmp = 0;
525	spin_unlock_irqrestore(ap->lock, flags);
526
527	ata_acpi_associate_sata_port(ap);
528}
529
530/**
531 *	sata_pmp_same_pmp - does new GSCR matches the configured PMP?
532 *	@dev: PMP device to compare against
533 *	@new_gscr: GSCR block of the new device
534 *
535 *	Compare @new_gscr against @dev and determine whether @dev is
536 *	the PMP described by @new_gscr.
537 *
538 *	LOCKING:
539 *	None.
540 *
541 *	RETURNS:
542 *	1 if @dev matches @new_gscr, 0 otherwise.
543 */
544static int sata_pmp_same_pmp(struct ata_device *dev, const u32 *new_gscr)
545{
546	const u32 *old_gscr = dev->gscr;
547	u16 old_vendor, new_vendor, old_devid, new_devid;
548	int old_nr_ports, new_nr_ports;
549
550	old_vendor = sata_pmp_gscr_vendor(old_gscr);
551	new_vendor = sata_pmp_gscr_vendor(new_gscr);
552	old_devid = sata_pmp_gscr_devid(old_gscr);
553	new_devid = sata_pmp_gscr_devid(new_gscr);
554	old_nr_ports = sata_pmp_gscr_ports(old_gscr);
555	new_nr_ports = sata_pmp_gscr_ports(new_gscr);
556
557	if (old_vendor != new_vendor) {
558		ata_dev_printk(dev, KERN_INFO, "Port Multiplier "
559			       "vendor mismatch '0x%x' != '0x%x'\n",
560			       old_vendor, new_vendor);
561		return 0;
562	}
563
564	if (old_devid != new_devid) {
565		ata_dev_printk(dev, KERN_INFO, "Port Multiplier "
566			       "device ID mismatch '0x%x' != '0x%x'\n",
567			       old_devid, new_devid);
568		return 0;
569	}
570
571	if (old_nr_ports != new_nr_ports) {
572		ata_dev_printk(dev, KERN_INFO, "Port Multiplier "
573			       "nr_ports mismatch '0x%x' != '0x%x'\n",
574			       old_nr_ports, new_nr_ports);
575		return 0;
576	}
577
578	return 1;
579}
580
581/**
582 *	sata_pmp_revalidate - revalidate SATA PMP
583 *	@dev: PMP device to revalidate
584 *	@new_class: new class code
585 *
586 *	Re-read GSCR block and make sure @dev is still attached to the
587 *	port and properly configured.
588 *
589 *	LOCKING:
590 *	Kernel thread context (may sleep).
591 *
592 *	RETURNS:
593 *	0 on success, -errno otherwise.
594 */
595static int sata_pmp_revalidate(struct ata_device *dev, unsigned int new_class)
596{
597	struct ata_link *link = dev->link;
598	struct ata_port *ap = link->ap;
599	u32 *gscr = (void *)ap->sector_buf;
600	int rc;
601
602	DPRINTK("ENTER\n");
603
604	ata_eh_about_to_do(link, NULL, ATA_EH_REVALIDATE);
605
606	if (!ata_dev_enabled(dev)) {
607		rc = -ENODEV;
608		goto fail;
609	}
610
611	/* wrong class? */
612	if (ata_class_enabled(new_class) && new_class != ATA_DEV_PMP) {
613		rc = -ENODEV;
614		goto fail;
615	}
616
617	/* read GSCR */
618	rc = sata_pmp_read_gscr(dev, gscr);
619	if (rc)
620		goto fail;
621
622	/* is the pmp still there? */
623	if (!sata_pmp_same_pmp(dev, gscr)) {
624		rc = -ENODEV;
625		goto fail;
626	}
627
628	memcpy(dev->gscr, gscr, sizeof(gscr[0]) * SATA_PMP_GSCR_DWORDS);
629
630	rc = sata_pmp_configure(dev, 0);
631	if (rc)
632		goto fail;
633
634	ata_eh_done(link, NULL, ATA_EH_REVALIDATE);
635
636	DPRINTK("EXIT, rc=0\n");
637	return 0;
638
639 fail:
640	ata_dev_printk(dev, KERN_ERR,
641		       "PMP revalidation failed (errno=%d)\n", rc);
642	DPRINTK("EXIT, rc=%d\n", rc);
643	return rc;
644}
645
646/**
647 *	sata_pmp_revalidate_quick - revalidate SATA PMP quickly
648 *	@dev: PMP device to revalidate
649 *
650 *	Make sure the attached PMP is accessible.
651 *
652 *	LOCKING:
653 *	Kernel thread context (may sleep).
654 *
655 *	RETURNS:
656 *	0 on success, -errno otherwise.
657 */
658static int sata_pmp_revalidate_quick(struct ata_device *dev)
659{
660	unsigned int err_mask;
661	u32 prod_id;
662
663	err_mask = sata_pmp_read(dev->link, SATA_PMP_GSCR_PROD_ID, &prod_id);
664	if (err_mask) {
665		ata_dev_printk(dev, KERN_ERR, "failed to read PMP product ID "
666			       "(Emask=0x%x)\n", err_mask);
667		return -EIO;
668	}
669
670	if (prod_id != dev->gscr[SATA_PMP_GSCR_PROD_ID]) {
671		ata_dev_printk(dev, KERN_ERR, "PMP product ID mismatch\n");
672		/* something weird is going on, request full PMP recovery */
673		return -EIO;
674	}
675
676	return 0;
677}
678
679/**
680 *	sata_pmp_eh_recover_pmp - recover PMP
681 *	@ap: ATA port PMP is attached to
682 *	@prereset: prereset method (can be NULL)
683 *	@softreset: softreset method
684 *	@hardreset: hardreset method
685 *	@postreset: postreset method (can be NULL)
686 *
687 *	Recover PMP attached to @ap.  Recovery procedure is somewhat
688 *	similar to that of ata_eh_recover() except that reset should
689 *	always be performed in hard->soft sequence and recovery
690 *	failure results in PMP detachment.
691 *
692 *	LOCKING:
693 *	Kernel thread context (may sleep).
694 *
695 *	RETURNS:
696 *	0 on success, -errno on failure.
697 */
698static int sata_pmp_eh_recover_pmp(struct ata_port *ap,
699		ata_prereset_fn_t prereset, ata_reset_fn_t softreset,
700		ata_reset_fn_t hardreset, ata_postreset_fn_t postreset)
701{
702	struct ata_link *link = &ap->link;
703	struct ata_eh_context *ehc = &link->eh_context;
704	struct ata_device *dev = link->device;
705	int tries = ATA_EH_PMP_TRIES;
706	int detach = 0, rc = 0;
707	int reval_failed = 0;
708
709	DPRINTK("ENTER\n");
710
711	if (dev->flags & ATA_DFLAG_DETACH) {
712		detach = 1;
713		goto fail;
714	}
715
716 retry:
717	ehc->classes[0] = ATA_DEV_UNKNOWN;
718
719	if (ehc->i.action & ATA_EH_RESET) {
720		struct ata_link *tlink;
721
722		/* reset */
723		rc = ata_eh_reset(link, 0, prereset, softreset, hardreset,
724				  postreset);
725		if (rc) {
726			ata_link_printk(link, KERN_ERR,
727					"failed to reset PMP, giving up\n");
728			goto fail;
729		}
730
731		/* PMP is reset, SErrors cannot be trusted, scan all */
732		ata_for_each_link(tlink, ap, EDGE) {
733			struct ata_eh_context *ehc = &tlink->eh_context;
734
735			ehc->i.probe_mask |= ATA_ALL_DEVICES;
736			ehc->i.action |= ATA_EH_RESET;
737		}
738	}
739
740	/* If revalidation is requested, revalidate and reconfigure;
741	 * otherwise, do quick revalidation.
742	 */
743	if (ehc->i.action & ATA_EH_REVALIDATE)
744		rc = sata_pmp_revalidate(dev, ehc->classes[0]);
745	else
746		rc = sata_pmp_revalidate_quick(dev);
747
748	if (rc) {
749		tries--;
750
751		if (rc == -ENODEV) {
752			ehc->i.probe_mask |= ATA_ALL_DEVICES;
753			detach = 1;
754			/* give it just two more chances */
755			tries = min(tries, 2);
756		}
757
758		if (tries) {
759			/* consecutive revalidation failures? speed down */
760			if (reval_failed)
761				sata_down_spd_limit(link, 0);
762			else
763				reval_failed = 1;
764
765			ehc->i.action |= ATA_EH_RESET;
766			goto retry;
767		} else {
768			ata_dev_printk(dev, KERN_ERR, "failed to recover PMP "
769				       "after %d tries, giving up\n",
770				       ATA_EH_PMP_TRIES);
771			goto fail;
772		}
773	}
774
775	/* okay, PMP resurrected */
776	ehc->i.flags = 0;
777
778	DPRINTK("EXIT, rc=0\n");
779	return 0;
780
781 fail:
782	sata_pmp_detach(dev);
783	if (detach)
784		ata_eh_detach_dev(dev);
785	else
786		ata_dev_disable(dev);
787
788	DPRINTK("EXIT, rc=%d\n", rc);
789	return rc;
790}
791
792static int sata_pmp_eh_handle_disabled_links(struct ata_port *ap)
793{
794	struct ata_link *link;
795	unsigned long flags;
796	int rc;
797
798	spin_lock_irqsave(ap->lock, flags);
799
800	ata_for_each_link(link, ap, EDGE) {
801		if (!(link->flags & ATA_LFLAG_DISABLED))
802			continue;
803
804		spin_unlock_irqrestore(ap->lock, flags);
805
806		/* Some PMPs require hardreset sequence to get
807		 * SError.N working.
808		 */
809		sata_link_hardreset(link, sata_deb_timing_normal,
810				ata_deadline(jiffies, ATA_TMOUT_INTERNAL_QUICK),
811				NULL, NULL);
812
813		/* unconditionally clear SError.N */
814		rc = sata_scr_write(link, SCR_ERROR, SERR_PHYRDY_CHG);
815		if (rc) {
816			ata_link_printk(link, KERN_ERR, "failed to clear "
817					"SError.N (errno=%d)\n", rc);
818			return rc;
819		}
820
821		spin_lock_irqsave(ap->lock, flags);
822	}
823
824	spin_unlock_irqrestore(ap->lock, flags);
825
826	return 0;
827}
828
829static int sata_pmp_handle_link_fail(struct ata_link *link, int *link_tries)
830{
831	struct ata_port *ap = link->ap;
832	unsigned long flags;
833
834	if (link_tries[link->pmp] && --link_tries[link->pmp])
835		return 1;
836
837	/* disable this link */
838	if (!(link->flags & ATA_LFLAG_DISABLED)) {
839		ata_link_printk(link, KERN_WARNING,
840			"failed to recover link after %d tries, disabling\n",
841			ATA_EH_PMP_LINK_TRIES);
842
843		spin_lock_irqsave(ap->lock, flags);
844		link->flags |= ATA_LFLAG_DISABLED;
845		spin_unlock_irqrestore(ap->lock, flags);
846	}
847
848	ata_dev_disable(link->device);
849	link->eh_context.i.action = 0;
850
851	return 0;
852}
853
854/**
855 *	sata_pmp_eh_recover - recover PMP-enabled port
856 *	@ap: ATA port to recover
857 *
858 *	Drive EH recovery operation for PMP enabled port @ap.  This
859 *	function recovers host and PMP ports with proper retrials and
860 *	fallbacks.  Actual recovery operations are performed using
861 *	ata_eh_recover() and sata_pmp_eh_recover_pmp().
862 *
863 *	LOCKING:
864 *	Kernel thread context (may sleep).
865 *
866 *	RETURNS:
867 *	0 on success, -errno on failure.
868 */
869static int sata_pmp_eh_recover(struct ata_port *ap)
870{
871	struct ata_port_operations *ops = ap->ops;
872	int pmp_tries, link_tries[SATA_PMP_MAX_PORTS];
873	struct ata_link *pmp_link = &ap->link;
874	struct ata_device *pmp_dev = pmp_link->device;
875	struct ata_eh_context *pmp_ehc = &pmp_link->eh_context;
876	u32 *gscr = pmp_dev->gscr;
877	struct ata_link *link;
878	struct ata_device *dev;
879	unsigned int err_mask;
880	u32 gscr_error, sntf;
881	int cnt, rc;
882
883	pmp_tries = ATA_EH_PMP_TRIES;
884	ata_for_each_link(link, ap, EDGE)
885		link_tries[link->pmp] = ATA_EH_PMP_LINK_TRIES;
886
887 retry:
888	/* PMP attached? */
889	if (!sata_pmp_attached(ap)) {
890		rc = ata_eh_recover(ap, ops->prereset, ops->softreset,
891				    ops->hardreset, ops->postreset, NULL);
892		if (rc) {
893			ata_for_each_dev(dev, &ap->link, ALL)
894				ata_dev_disable(dev);
895			return rc;
896		}
897
898		if (pmp_dev->class != ATA_DEV_PMP)
899			return 0;
900
901		/* new PMP online */
902		ata_for_each_link(link, ap, EDGE)
903			link_tries[link->pmp] = ATA_EH_PMP_LINK_TRIES;
904
905		/* fall through */
906	}
907
908	/* recover pmp */
909	rc = sata_pmp_eh_recover_pmp(ap, ops->prereset, ops->softreset,
910				     ops->hardreset, ops->postreset);
911	if (rc)
912		goto pmp_fail;
913
914	/* PHY event notification can disturb reset and other recovery
915	 * operations.  Turn it off.
916	 */
917	if (gscr[SATA_PMP_GSCR_FEAT_EN] & SATA_PMP_FEAT_NOTIFY) {
918		gscr[SATA_PMP_GSCR_FEAT_EN] &= ~SATA_PMP_FEAT_NOTIFY;
919
920		err_mask = sata_pmp_write(pmp_link, SATA_PMP_GSCR_FEAT_EN,
921					  gscr[SATA_PMP_GSCR_FEAT_EN]);
922		if (err_mask) {
923			ata_link_printk(pmp_link, KERN_WARNING,
924				"failed to disable NOTIFY (err_mask=0x%x)\n",
925				err_mask);
926			goto pmp_fail;
927		}
928	}
929
930	/* handle disabled links */
931	rc = sata_pmp_eh_handle_disabled_links(ap);
932	if (rc)
933		goto pmp_fail;
934
935	/* recover links */
936	rc = ata_eh_recover(ap, ops->pmp_prereset, ops->pmp_softreset,
937			    ops->pmp_hardreset, ops->pmp_postreset, &link);
938	if (rc)
939		goto link_fail;
940
941	/* Connection status might have changed while resetting other
942	 * links, check SATA_PMP_GSCR_ERROR before returning.
943	 */
944
945	/* clear SNotification */
946	rc = sata_scr_read(&ap->link, SCR_NOTIFICATION, &sntf);
947	if (rc == 0)
948		sata_scr_write(&ap->link, SCR_NOTIFICATION, sntf);
949
950	/* enable notification */
951	if (pmp_dev->flags & ATA_DFLAG_AN) {
952		gscr[SATA_PMP_GSCR_FEAT_EN] |= SATA_PMP_FEAT_NOTIFY;
953
954		err_mask = sata_pmp_write(pmp_link, SATA_PMP_GSCR_FEAT_EN,
955					  gscr[SATA_PMP_GSCR_FEAT_EN]);
956		if (err_mask) {
957			ata_dev_printk(pmp_dev, KERN_ERR, "failed to write "
958				       "PMP_FEAT_EN (Emask=0x%x)\n", err_mask);
959			rc = -EIO;
960			goto pmp_fail;
961		}
962	}
963
964	/* check GSCR_ERROR */
965	err_mask = sata_pmp_read(pmp_link, SATA_PMP_GSCR_ERROR, &gscr_error);
966	if (err_mask) {
967		ata_dev_printk(pmp_dev, KERN_ERR, "failed to read "
968			       "PMP_GSCR_ERROR (Emask=0x%x)\n", err_mask);
969		rc = -EIO;
970		goto pmp_fail;
971	}
972
973	cnt = 0;
974	ata_for_each_link(link, ap, EDGE) {
975		if (!(gscr_error & (1 << link->pmp)))
976			continue;
977
978		if (sata_pmp_handle_link_fail(link, link_tries)) {
979			ata_ehi_hotplugged(&link->eh_context.i);
980			cnt++;
981		} else {
982			ata_link_printk(link, KERN_WARNING,
983				"PHY status changed but maxed out on retries, "
984				"giving up\n");
985			ata_link_printk(link, KERN_WARNING,
986				"Manully issue scan to resume this link\n");
987		}
988	}
989
990	if (cnt) {
991		ata_port_printk(ap, KERN_INFO, "PMP SError.N set for some "
992				"ports, repeating recovery\n");
993		goto retry;
994	}
995
996	return 0;
997
998 link_fail:
999	if (sata_pmp_handle_link_fail(link, link_tries)) {
1000		pmp_ehc->i.action |= ATA_EH_RESET;
1001		goto retry;
1002	}
1003
1004	/* fall through */
1005 pmp_fail:
1006	/* Control always ends up here after detaching PMP.  Shut up
1007	 * and return if we're unloading.
1008	 */
1009	if (ap->pflags & ATA_PFLAG_UNLOADING)
1010		return rc;
1011
1012	if (!sata_pmp_attached(ap))
1013		goto retry;
1014
1015	if (--pmp_tries) {
1016		pmp_ehc->i.action |= ATA_EH_RESET;
1017		goto retry;
1018	}
1019
1020	ata_port_printk(ap, KERN_ERR,
1021			"failed to recover PMP after %d tries, giving up\n",
1022			ATA_EH_PMP_TRIES);
1023	sata_pmp_detach(pmp_dev);
1024	ata_dev_disable(pmp_dev);
1025
1026	return rc;
1027}
1028
1029/**
1030 *	sata_pmp_error_handler - do standard error handling for PMP-enabled host
1031 *	@ap: host port to handle error for
1032 *
1033 *	Perform standard error handling sequence for PMP-enabled host
1034 *	@ap.
1035 *
1036 *	LOCKING:
1037 *	Kernel thread context (may sleep).
1038 */
1039void sata_pmp_error_handler(struct ata_port *ap)
1040{
1041	ata_eh_autopsy(ap);
1042	ata_eh_report(ap);
1043	sata_pmp_eh_recover(ap);
1044	ata_eh_finish(ap);
1045}
1046
1047EXPORT_SYMBOL_GPL(sata_pmp_port_ops);
1048EXPORT_SYMBOL_GPL(sata_pmp_qc_defer_cmd_switch);
1049EXPORT_SYMBOL_GPL(sata_pmp_error_handler);
1050