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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/export.h>
12#include <linux/libata.h>
13#include <linux/slab.h>
14#include "libata.h"
15#include "libata-transport.h"
16
17const struct ata_port_operations sata_pmp_port_ops = {
18	.inherits		= &sata_port_ops,
19	.pmp_prereset		= ata_std_prereset,
20	.pmp_hardreset		= sata_std_hardreset,
21	.pmp_postreset		= ata_std_postreset,
22	.error_handler		= sata_pmp_error_handler,
23};
24
25/**
26 *	sata_pmp_read - read PMP register
27 *	@link: link to read PMP register for
28 *	@reg: register to read
29 *	@r_val: resulting value
30 *
31 *	Read PMP register.
32 *
33 *	LOCKING:
34 *	Kernel thread context (may sleep).
35 *
36 *	RETURNS:
37 *	0 on success, AC_ERR_* mask on failure.
38 */
39static unsigned int sata_pmp_read(struct ata_link *link, int reg, u32 *r_val)
40{
41	struct ata_port *ap = link->ap;
42	struct ata_device *pmp_dev = ap->link.device;
43	struct ata_taskfile tf;
44	unsigned int err_mask;
45
46	ata_tf_init(pmp_dev, &tf);
47	tf.command = ATA_CMD_PMP_READ;
48	tf.protocol = ATA_PROT_NODATA;
49	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE | ATA_TFLAG_LBA48;
50	tf.feature = reg;
51	tf.device = link->pmp;
52
53	err_mask = ata_exec_internal(pmp_dev, &tf, NULL, DMA_NONE, NULL, 0,
54				     SATA_PMP_RW_TIMEOUT);
55	if (err_mask)
56		return err_mask;
57
58	*r_val = tf.nsect | tf.lbal << 8 | tf.lbam << 16 | tf.lbah << 24;
59	return 0;
60}
61
62/**
63 *	sata_pmp_write - write PMP register
64 *	@link: link to write PMP register for
65 *	@reg: register to write
66 *	@r_val: value to write
67 *
68 *	Write PMP register.
69 *
70 *	LOCKING:
71 *	Kernel thread context (may sleep).
72 *
73 *	RETURNS:
74 *	0 on success, AC_ERR_* mask on failure.
75 */
76static unsigned int sata_pmp_write(struct ata_link *link, int reg, u32 val)
77{
78	struct ata_port *ap = link->ap;
79	struct ata_device *pmp_dev = ap->link.device;
80	struct ata_taskfile tf;
81
82	ata_tf_init(pmp_dev, &tf);
83	tf.command = ATA_CMD_PMP_WRITE;
84	tf.protocol = ATA_PROT_NODATA;
85	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE | ATA_TFLAG_LBA48;
86	tf.feature = reg;
87	tf.device = link->pmp;
88	tf.nsect = val & 0xff;
89	tf.lbal = (val >> 8) & 0xff;
90	tf.lbam = (val >> 16) & 0xff;
91	tf.lbah = (val >> 24) & 0xff;
92
93	return ata_exec_internal(pmp_dev, &tf, NULL, DMA_NONE, NULL, 0,
94				 SATA_PMP_RW_TIMEOUT);
95}
96
97/**
98 *	sata_pmp_qc_defer_cmd_switch - qc_defer for command switching PMP
99 *	@qc: ATA command in question
100 *
101 *	A host which has command switching PMP support cannot issue
102 *	commands to multiple links simultaneously.
103 *
104 *	LOCKING:
105 *	spin_lock_irqsave(host lock)
106 *
107 *	RETURNS:
108 *	ATA_DEFER_* if deferring is needed, 0 otherwise.
109 */
110int sata_pmp_qc_defer_cmd_switch(struct ata_queued_cmd *qc)
111{
112	struct ata_link *link = qc->dev->link;
113	struct ata_port *ap = link->ap;
114
115	if (ap->excl_link == NULL || ap->excl_link == link) {
116		if (ap->nr_active_links == 0 || ata_link_active(link)) {
117			qc->flags |= ATA_QCFLAG_CLEAR_EXCL;
118			return ata_std_qc_defer(qc);
119		}
120
121		ap->excl_link = link;
122	}
123
124	return ATA_DEFER_PORT;
125}
126
127/**
128 *	sata_pmp_scr_read - read PSCR
129 *	@link: ATA link to read PSCR for
130 *	@reg: PSCR to read
131 *	@r_val: resulting value
132 *
133 *	Read PSCR @reg into @r_val for @link, to be called from
134 *	ata_scr_read().
135 *
136 *	LOCKING:
137 *	Kernel thread context (may sleep).
138 *
139 *	RETURNS:
140 *	0 on success, -errno on failure.
141 */
142int sata_pmp_scr_read(struct ata_link *link, int reg, u32 *r_val)
143{
144	unsigned int err_mask;
145
146	if (reg > SATA_PMP_PSCR_CONTROL)
147		return -EINVAL;
148
149	err_mask = sata_pmp_read(link, reg, r_val);
150	if (err_mask) {
151		ata_link_warn(link, "failed to read SCR %d (Emask=0x%x)\n",
152			      reg, err_mask);
153		return -EIO;
154	}
155	return 0;
156}
157
158/**
159 *	sata_pmp_scr_write - write PSCR
160 *	@link: ATA link to write PSCR for
161 *	@reg: PSCR to write
162 *	@val: value to be written
163 *
164 *	Write @val to PSCR @reg for @link, to be called from
165 *	ata_scr_write() and ata_scr_write_flush().
166 *
167 *	LOCKING:
168 *	Kernel thread context (may sleep).
169 *
170 *	RETURNS:
171 *	0 on success, -errno on failure.
172 */
173int sata_pmp_scr_write(struct ata_link *link, int reg, u32 val)
174{
175	unsigned int err_mask;
176
177	if (reg > SATA_PMP_PSCR_CONTROL)
178		return -EINVAL;
179
180	err_mask = sata_pmp_write(link, reg, val);
181	if (err_mask) {
182		ata_link_warn(link, "failed to write SCR %d (Emask=0x%x)\n",
183			      reg, err_mask);
184		return -EIO;
185	}
186	return 0;
187}
188
189/**
190 *	sata_pmp_set_lpm - configure LPM for a PMP link
191 *	@link: PMP link to configure LPM for
192 *	@policy: target LPM policy
193 *	@hints: LPM hints
194 *
195 *	Configure LPM for @link.  This function will contain any PMP
196 *	specific workarounds if necessary.
197 *
198 *	LOCKING:
199 *	EH context.
200 *
201 *	RETURNS:
202 *	0 on success, -errno on failure.
203 */
204int sata_pmp_set_lpm(struct ata_link *link, enum ata_lpm_policy policy,
205		     unsigned hints)
206{
207	return sata_link_scr_lpm(link, policy, true);
208}
209
210/**
211 *	sata_pmp_read_gscr - read GSCR block of SATA PMP
212 *	@dev: PMP device
213 *	@gscr: buffer to read GSCR block into
214 *
215 *	Read selected PMP GSCRs from the PMP at @dev.  This will serve
216 *	as configuration and identification info for the PMP.
217 *
218 *	LOCKING:
219 *	Kernel thread context (may sleep).
220 *
221 *	RETURNS:
222 *	0 on success, -errno on failure.
223 */
224static int sata_pmp_read_gscr(struct ata_device *dev, u32 *gscr)
225{
226	static const int gscr_to_read[] = { 0, 1, 2, 32, 33, 64, 96 };
227	int i;
228
229	for (i = 0; i < ARRAY_SIZE(gscr_to_read); i++) {
230		int reg = gscr_to_read[i];
231		unsigned int err_mask;
232
233		err_mask = sata_pmp_read(dev->link, reg, &gscr[reg]);
234		if (err_mask) {
235			ata_dev_err(dev, "failed to read PMP GSCR[%d] (Emask=0x%x)\n",
236				    reg, err_mask);
237			return -EIO;
238		}
239	}
240
241	return 0;
242}
243
244static const char *sata_pmp_spec_rev_str(const u32 *gscr)
245{
246	u32 rev = gscr[SATA_PMP_GSCR_REV];
247
248	if (rev & (1 << 3))
249		return "1.2";
250	if (rev & (1 << 2))
251		return "1.1";
252	if (rev & (1 << 1))
253		return "1.0";
254	return "<unknown>";
255}
256
257#define PMP_GSCR_SII_POL 129
258
259static int sata_pmp_configure(struct ata_device *dev, int print_info)
260{
261	struct ata_port *ap = dev->link->ap;
262	u32 *gscr = dev->gscr;
263	u16 vendor = sata_pmp_gscr_vendor(gscr);
264	u16 devid = sata_pmp_gscr_devid(gscr);
265	unsigned int err_mask = 0;
266	const char *reason;
267	int nr_ports, rc;
268
269	nr_ports = sata_pmp_gscr_ports(gscr);
270
271	if (nr_ports <= 0 || nr_ports > SATA_PMP_MAX_PORTS) {
272		rc = -EINVAL;
273		reason = "invalid nr_ports";
274		goto fail;
275	}
276
277	if ((ap->flags & ATA_FLAG_AN) &&
278	    (gscr[SATA_PMP_GSCR_FEAT] & SATA_PMP_FEAT_NOTIFY))
279		dev->flags |= ATA_DFLAG_AN;
280
281	/* monitor SERR_PHYRDY_CHG on fan-out ports */
282	err_mask = sata_pmp_write(dev->link, SATA_PMP_GSCR_ERROR_EN,
283				  SERR_PHYRDY_CHG);
284	if (err_mask) {
285		rc = -EIO;
286		reason = "failed to write GSCR_ERROR_EN";
287		goto fail;
288	}
289
290	/* Disable sending Early R_OK.
291	 * With "cached read" HDD testing and multiple ports busy on a SATA
292	 * host controller, 3x26 PMP will very rarely drop a deferred
293	 * R_OK that was intended for the host. Symptom will be all
294	 * 5 drives under test will timeout, get reset, and recover.
295	 */
296	if (vendor == 0x1095 && (devid == 0x3726 || devid == 0x3826)) {
297		u32 reg;
298
299		err_mask = sata_pmp_read(&ap->link, PMP_GSCR_SII_POL, &reg);
300		if (err_mask) {
301			rc = -EIO;
302			reason = "failed to read Sil3x26 Private Register";
303			goto fail;
304		}
305		reg &= ~0x1;
306		err_mask = sata_pmp_write(&ap->link, PMP_GSCR_SII_POL, reg);
307		if (err_mask) {
308			rc = -EIO;
309			reason = "failed to write Sil3x26 Private Register";
310			goto fail;
311		}
312	}
313
314	if (print_info) {
315		ata_dev_info(dev, "Port Multiplier %s, "
316			     "0x%04x:0x%04x r%d, %d ports, feat 0x%x/0x%x\n",
317			     sata_pmp_spec_rev_str(gscr), vendor, devid,
318			     sata_pmp_gscr_rev(gscr),
319			     nr_ports, gscr[SATA_PMP_GSCR_FEAT_EN],
320			     gscr[SATA_PMP_GSCR_FEAT]);
321
322		if (!(dev->flags & ATA_DFLAG_AN))
323			ata_dev_info(dev,
324				"Asynchronous notification not supported, "
325				"hotplug won't work on fan-out ports. Use warm-plug instead.\n");
326	}
327
328	return 0;
329
330 fail:
331	ata_dev_err(dev,
332		    "failed to configure Port Multiplier (%s, Emask=0x%x)\n",
333		    reason, err_mask);
334	return rc;
335}
336
337static int sata_pmp_init_links (struct ata_port *ap, int nr_ports)
338{
339	struct ata_link *pmp_link = ap->pmp_link;
340	int i, err;
341
342	if (!pmp_link) {
343		pmp_link = kzalloc(sizeof(pmp_link[0]) * SATA_PMP_MAX_PORTS,
344				   GFP_NOIO);
345		if (!pmp_link)
346			return -ENOMEM;
347
348		for (i = 0; i < SATA_PMP_MAX_PORTS; i++)
349			ata_link_init(ap, &pmp_link[i], i);
350
351		ap->pmp_link = pmp_link;
352
353		for (i = 0; i < SATA_PMP_MAX_PORTS; i++) {
354			err = ata_tlink_add(&pmp_link[i]);
355			if (err) {
356				goto err_tlink;
357			}
358		}
359	}
360
361	for (i = 0; i < nr_ports; i++) {
362		struct ata_link *link = &pmp_link[i];
363		struct ata_eh_context *ehc = &link->eh_context;
364
365		link->flags = 0;
366		ehc->i.probe_mask |= ATA_ALL_DEVICES;
367		ehc->i.action |= ATA_EH_RESET;
368	}
369
370	return 0;
371  err_tlink:
372	while (--i >= 0)
373		ata_tlink_delete(&pmp_link[i]);
374	kfree(pmp_link);
375	ap->pmp_link = NULL;
376	return err;
377}
378
379static void sata_pmp_quirks(struct ata_port *ap)
380{
381	u32 *gscr = ap->link.device->gscr;
382	u16 vendor = sata_pmp_gscr_vendor(gscr);
383	u16 devid = sata_pmp_gscr_devid(gscr);
384	struct ata_link *link;
385
386	if (vendor == 0x1095 && (devid == 0x3726 || devid == 0x3826)) {
387		/* sil3x26 quirks */
388		ata_for_each_link(link, ap, EDGE) {
389			/* link reports offline after LPM */
390			link->flags |= ATA_LFLAG_NO_LPM;
391
392			/*
393			 * Class code report is unreliable and SRST times
394			 * out under certain configurations.
395			 */
396			if (link->pmp < 5)
397				link->flags |= ATA_LFLAG_NO_SRST |
398					       ATA_LFLAG_ASSUME_ATA;
399
400			/* port 5 is for SEMB device and it doesn't like SRST */
401			if (link->pmp == 5)
402				link->flags |= ATA_LFLAG_NO_SRST |
403					       ATA_LFLAG_ASSUME_SEMB;
404		}
405	} else if (vendor == 0x1095 && devid == 0x4723) {
406		/*
407		 * sil4723 quirks
408		 *
409		 * Link reports offline after LPM.  Class code report is
410		 * unreliable.  SIMG PMPs never got SRST reliable and the
411		 * config device at port 2 locks up on SRST.
412		 */
413		ata_for_each_link(link, ap, EDGE)
414			link->flags |= ATA_LFLAG_NO_LPM |
415				       ATA_LFLAG_NO_SRST |
416				       ATA_LFLAG_ASSUME_ATA;
417	} else if (vendor == 0x1095 && devid == 0x4726) {
418		/* sil4726 quirks */
419		ata_for_each_link(link, ap, EDGE) {
420			/* link reports offline after LPM */
421			link->flags |= ATA_LFLAG_NO_LPM;
422
423			/* Class code report is unreliable and SRST
424			 * times out under certain configurations.
425			 * Config device can be at port 0 or 5 and
426			 * locks up on SRST.
427			 */
428			if (link->pmp <= 5)
429				link->flags |= ATA_LFLAG_NO_SRST |
430					       ATA_LFLAG_ASSUME_ATA;
431
432			/* Port 6 is for SEMB device which doesn't
433			 * like SRST either.
434			 */
435			if (link->pmp == 6)
436				link->flags |= ATA_LFLAG_NO_SRST |
437					       ATA_LFLAG_ASSUME_SEMB;
438		}
439	} else if (vendor == 0x1095 && (devid == 0x5723 || devid == 0x5733 ||
440					devid == 0x5734 || devid == 0x5744)) {
441		/* sil5723/5744 quirks */
442
443		/* sil5723/5744 has either two or three downstream
444		 * ports depending on operation mode.  The last port
445		 * is empty if any actual IO device is available or
446		 * occupied by a pseudo configuration device
447		 * otherwise.  Don't try hard to recover it.
448		 */
449		ap->pmp_link[ap->nr_pmp_links - 1].flags |= ATA_LFLAG_NO_RETRY;
450	} else if (vendor == 0x197b && (devid == 0x2352 || devid == 0x0325)) {
451		/*
452		 * 0x2352: found in Thermaltake BlackX Duet, jmicron JMB350?
453		 * 0x0325: jmicron JMB394.
454		 */
455		ata_for_each_link(link, ap, EDGE) {
456			/* SRST breaks detection and disks get misclassified
457			 * LPM disabled to avoid potential problems
458			 */
459			link->flags |= ATA_LFLAG_NO_LPM |
460				       ATA_LFLAG_NO_SRST |
461				       ATA_LFLAG_ASSUME_ATA;
462		}
463	}
464}
465
466/**
467 *	sata_pmp_attach - attach a SATA PMP device
468 *	@dev: SATA PMP device to attach
469 *
470 *	Configure and attach SATA PMP device @dev.  This function is
471 *	also responsible for allocating and initializing PMP links.
472 *
473 *	LOCKING:
474 *	Kernel thread context (may sleep).
475 *
476 *	RETURNS:
477 *	0 on success, -errno on failure.
478 */
479int sata_pmp_attach(struct ata_device *dev)
480{
481	struct ata_link *link = dev->link;
482	struct ata_port *ap = link->ap;
483	unsigned long flags;
484	struct ata_link *tlink;
485	int rc;
486
487	/* is it hanging off the right place? */
488	if (!sata_pmp_supported(ap)) {
489		ata_dev_err(dev, "host does not support Port Multiplier\n");
490		return -EINVAL;
491	}
492
493	if (!ata_is_host_link(link)) {
494		ata_dev_err(dev, "Port Multipliers cannot be nested\n");
495		return -EINVAL;
496	}
497
498	if (dev->devno) {
499		ata_dev_err(dev, "Port Multiplier must be the first device\n");
500		return -EINVAL;
501	}
502
503	WARN_ON(link->pmp != 0);
504	link->pmp = SATA_PMP_CTRL_PORT;
505
506	/* read GSCR block */
507	rc = sata_pmp_read_gscr(dev, dev->gscr);
508	if (rc)
509		goto fail;
510
511	/* config PMP */
512	rc = sata_pmp_configure(dev, 1);
513	if (rc)
514		goto fail;
515
516	rc = sata_pmp_init_links(ap, sata_pmp_gscr_ports(dev->gscr));
517	if (rc) {
518		ata_dev_info(dev, "failed to initialize PMP links\n");
519		goto fail;
520	}
521
522	/* attach it */
523	spin_lock_irqsave(ap->lock, flags);
524	WARN_ON(ap->nr_pmp_links);
525	ap->nr_pmp_links = sata_pmp_gscr_ports(dev->gscr);
526	spin_unlock_irqrestore(ap->lock, flags);
527
528	sata_pmp_quirks(ap);
529
530	if (ap->ops->pmp_attach)
531		ap->ops->pmp_attach(ap);
532
533	ata_for_each_link(tlink, ap, EDGE)
534		sata_link_init_spd(tlink);
535
536	return 0;
537
538 fail:
539	link->pmp = 0;
540	return rc;
541}
542
543/**
544 *	sata_pmp_detach - detach a SATA PMP device
545 *	@dev: SATA PMP device to detach
546 *
547 *	Detach SATA PMP device @dev.  This function is also
548 *	responsible for deconfiguring PMP links.
549 *
550 *	LOCKING:
551 *	Kernel thread context (may sleep).
552 */
553static void sata_pmp_detach(struct ata_device *dev)
554{
555	struct ata_link *link = dev->link;
556	struct ata_port *ap = link->ap;
557	struct ata_link *tlink;
558	unsigned long flags;
559
560	ata_dev_info(dev, "Port Multiplier detaching\n");
561
562	WARN_ON(!ata_is_host_link(link) || dev->devno ||
563		link->pmp != SATA_PMP_CTRL_PORT);
564
565	if (ap->ops->pmp_detach)
566		ap->ops->pmp_detach(ap);
567
568	ata_for_each_link(tlink, ap, EDGE)
569		ata_eh_detach_dev(tlink->device);
570
571	spin_lock_irqsave(ap->lock, flags);
572	ap->nr_pmp_links = 0;
573	link->pmp = 0;
574	spin_unlock_irqrestore(ap->lock, flags);
575}
576
577/**
578 *	sata_pmp_same_pmp - does new GSCR matches the configured PMP?
579 *	@dev: PMP device to compare against
580 *	@new_gscr: GSCR block of the new device
581 *
582 *	Compare @new_gscr against @dev and determine whether @dev is
583 *	the PMP described by @new_gscr.
584 *
585 *	LOCKING:
586 *	None.
587 *
588 *	RETURNS:
589 *	1 if @dev matches @new_gscr, 0 otherwise.
590 */
591static int sata_pmp_same_pmp(struct ata_device *dev, const u32 *new_gscr)
592{
593	const u32 *old_gscr = dev->gscr;
594	u16 old_vendor, new_vendor, old_devid, new_devid;
595	int old_nr_ports, new_nr_ports;
596
597	old_vendor = sata_pmp_gscr_vendor(old_gscr);
598	new_vendor = sata_pmp_gscr_vendor(new_gscr);
599	old_devid = sata_pmp_gscr_devid(old_gscr);
600	new_devid = sata_pmp_gscr_devid(new_gscr);
601	old_nr_ports = sata_pmp_gscr_ports(old_gscr);
602	new_nr_ports = sata_pmp_gscr_ports(new_gscr);
603
604	if (old_vendor != new_vendor) {
605		ata_dev_info(dev,
606			     "Port Multiplier vendor mismatch '0x%x' != '0x%x'\n",
607			     old_vendor, new_vendor);
608		return 0;
609	}
610
611	if (old_devid != new_devid) {
612		ata_dev_info(dev,
613			     "Port Multiplier device ID mismatch '0x%x' != '0x%x'\n",
614			     old_devid, new_devid);
615		return 0;
616	}
617
618	if (old_nr_ports != new_nr_ports) {
619		ata_dev_info(dev,
620			     "Port Multiplier nr_ports mismatch '0x%x' != '0x%x'\n",
621			     old_nr_ports, new_nr_ports);
622		return 0;
623	}
624
625	return 1;
626}
627
628/**
629 *	sata_pmp_revalidate - revalidate SATA PMP
630 *	@dev: PMP device to revalidate
631 *	@new_class: new class code
632 *
633 *	Re-read GSCR block and make sure @dev is still attached to the
634 *	port and properly configured.
635 *
636 *	LOCKING:
637 *	Kernel thread context (may sleep).
638 *
639 *	RETURNS:
640 *	0 on success, -errno otherwise.
641 */
642static int sata_pmp_revalidate(struct ata_device *dev, unsigned int new_class)
643{
644	struct ata_link *link = dev->link;
645	struct ata_port *ap = link->ap;
646	u32 *gscr = (void *)ap->sector_buf;
647	int rc;
648
649	DPRINTK("ENTER\n");
650
651	ata_eh_about_to_do(link, NULL, ATA_EH_REVALIDATE);
652
653	if (!ata_dev_enabled(dev)) {
654		rc = -ENODEV;
655		goto fail;
656	}
657
658	/* wrong class? */
659	if (ata_class_enabled(new_class) && new_class != ATA_DEV_PMP) {
660		rc = -ENODEV;
661		goto fail;
662	}
663
664	/* read GSCR */
665	rc = sata_pmp_read_gscr(dev, gscr);
666	if (rc)
667		goto fail;
668
669	/* is the pmp still there? */
670	if (!sata_pmp_same_pmp(dev, gscr)) {
671		rc = -ENODEV;
672		goto fail;
673	}
674
675	memcpy(dev->gscr, gscr, sizeof(gscr[0]) * SATA_PMP_GSCR_DWORDS);
676
677	rc = sata_pmp_configure(dev, 0);
678	if (rc)
679		goto fail;
680
681	ata_eh_done(link, NULL, ATA_EH_REVALIDATE);
682
683	DPRINTK("EXIT, rc=0\n");
684	return 0;
685
686 fail:
687	ata_dev_err(dev, "PMP revalidation failed (errno=%d)\n", rc);
688	DPRINTK("EXIT, rc=%d\n", rc);
689	return rc;
690}
691
692/**
693 *	sata_pmp_revalidate_quick - revalidate SATA PMP quickly
694 *	@dev: PMP device to revalidate
695 *
696 *	Make sure the attached PMP is accessible.
697 *
698 *	LOCKING:
699 *	Kernel thread context (may sleep).
700 *
701 *	RETURNS:
702 *	0 on success, -errno otherwise.
703 */
704static int sata_pmp_revalidate_quick(struct ata_device *dev)
705{
706	unsigned int err_mask;
707	u32 prod_id;
708
709	err_mask = sata_pmp_read(dev->link, SATA_PMP_GSCR_PROD_ID, &prod_id);
710	if (err_mask) {
711		ata_dev_err(dev,
712			    "failed to read PMP product ID (Emask=0x%x)\n",
713			    err_mask);
714		return -EIO;
715	}
716
717	if (prod_id != dev->gscr[SATA_PMP_GSCR_PROD_ID]) {
718		ata_dev_err(dev, "PMP product ID mismatch\n");
719		/* something weird is going on, request full PMP recovery */
720		return -EIO;
721	}
722
723	return 0;
724}
725
726/**
727 *	sata_pmp_eh_recover_pmp - recover PMP
728 *	@ap: ATA port PMP is attached to
729 *	@prereset: prereset method (can be NULL)
730 *	@softreset: softreset method
731 *	@hardreset: hardreset method
732 *	@postreset: postreset method (can be NULL)
733 *
734 *	Recover PMP attached to @ap.  Recovery procedure is somewhat
735 *	similar to that of ata_eh_recover() except that reset should
736 *	always be performed in hard->soft sequence and recovery
737 *	failure results in PMP detachment.
738 *
739 *	LOCKING:
740 *	Kernel thread context (may sleep).
741 *
742 *	RETURNS:
743 *	0 on success, -errno on failure.
744 */
745static int sata_pmp_eh_recover_pmp(struct ata_port *ap,
746		ata_prereset_fn_t prereset, ata_reset_fn_t softreset,
747		ata_reset_fn_t hardreset, ata_postreset_fn_t postreset)
748{
749	struct ata_link *link = &ap->link;
750	struct ata_eh_context *ehc = &link->eh_context;
751	struct ata_device *dev = link->device;
752	int tries = ATA_EH_PMP_TRIES;
753	int detach = 0, rc = 0;
754	int reval_failed = 0;
755
756	DPRINTK("ENTER\n");
757
758	if (dev->flags & ATA_DFLAG_DETACH) {
759		detach = 1;
760		goto fail;
761	}
762
763 retry:
764	ehc->classes[0] = ATA_DEV_UNKNOWN;
765
766	if (ehc->i.action & ATA_EH_RESET) {
767		struct ata_link *tlink;
768
769		/* reset */
770		rc = ata_eh_reset(link, 0, prereset, softreset, hardreset,
771				  postreset);
772		if (rc) {
773			ata_link_err(link, "failed to reset PMP, giving up\n");
774			goto fail;
775		}
776
777		/* PMP is reset, SErrors cannot be trusted, scan all */
778		ata_for_each_link(tlink, ap, EDGE) {
779			struct ata_eh_context *ehc = &tlink->eh_context;
780
781			ehc->i.probe_mask |= ATA_ALL_DEVICES;
782			ehc->i.action |= ATA_EH_RESET;
783		}
784	}
785
786	/* If revalidation is requested, revalidate and reconfigure;
787	 * otherwise, do quick revalidation.
788	 */
789	if (ehc->i.action & ATA_EH_REVALIDATE)
790		rc = sata_pmp_revalidate(dev, ehc->classes[0]);
791	else
792		rc = sata_pmp_revalidate_quick(dev);
793
794	if (rc) {
795		tries--;
796
797		if (rc == -ENODEV) {
798			ehc->i.probe_mask |= ATA_ALL_DEVICES;
799			detach = 1;
800			/* give it just two more chances */
801			tries = min(tries, 2);
802		}
803
804		if (tries) {
805			/* consecutive revalidation failures? speed down */
806			if (reval_failed)
807				sata_down_spd_limit(link, 0);
808			else
809				reval_failed = 1;
810
811			ehc->i.action |= ATA_EH_RESET;
812			goto retry;
813		} else {
814			ata_dev_err(dev,
815				    "failed to recover PMP after %d tries, giving up\n",
816				    ATA_EH_PMP_TRIES);
817			goto fail;
818		}
819	}
820
821	/* okay, PMP resurrected */
822	ehc->i.flags = 0;
823
824	DPRINTK("EXIT, rc=0\n");
825	return 0;
826
827 fail:
828	sata_pmp_detach(dev);
829	if (detach)
830		ata_eh_detach_dev(dev);
831	else
832		ata_dev_disable(dev);
833
834	DPRINTK("EXIT, rc=%d\n", rc);
835	return rc;
836}
837
838static int sata_pmp_eh_handle_disabled_links(struct ata_port *ap)
839{
840	struct ata_link *link;
841	unsigned long flags;
842	int rc;
843
844	spin_lock_irqsave(ap->lock, flags);
845
846	ata_for_each_link(link, ap, EDGE) {
847		if (!(link->flags & ATA_LFLAG_DISABLED))
848			continue;
849
850		spin_unlock_irqrestore(ap->lock, flags);
851
852		/* Some PMPs require hardreset sequence to get
853		 * SError.N working.
854		 */
855		sata_link_hardreset(link, sata_deb_timing_normal,
856				ata_deadline(jiffies, ATA_TMOUT_INTERNAL_QUICK),
857				NULL, NULL);
858
859		/* unconditionally clear SError.N */
860		rc = sata_scr_write(link, SCR_ERROR, SERR_PHYRDY_CHG);
861		if (rc) {
862			ata_link_err(link,
863				     "failed to clear SError.N (errno=%d)\n",
864				     rc);
865			return rc;
866		}
867
868		spin_lock_irqsave(ap->lock, flags);
869	}
870
871	spin_unlock_irqrestore(ap->lock, flags);
872
873	return 0;
874}
875
876static int sata_pmp_handle_link_fail(struct ata_link *link, int *link_tries)
877{
878	struct ata_port *ap = link->ap;
879	unsigned long flags;
880
881	if (link_tries[link->pmp] && --link_tries[link->pmp])
882		return 1;
883
884	/* disable this link */
885	if (!(link->flags & ATA_LFLAG_DISABLED)) {
886		ata_link_warn(link,
887			"failed to recover link after %d tries, disabling\n",
888			ATA_EH_PMP_LINK_TRIES);
889
890		spin_lock_irqsave(ap->lock, flags);
891		link->flags |= ATA_LFLAG_DISABLED;
892		spin_unlock_irqrestore(ap->lock, flags);
893	}
894
895	ata_dev_disable(link->device);
896	link->eh_context.i.action = 0;
897
898	return 0;
899}
900
901/**
902 *	sata_pmp_eh_recover - recover PMP-enabled port
903 *	@ap: ATA port to recover
904 *
905 *	Drive EH recovery operation for PMP enabled port @ap.  This
906 *	function recovers host and PMP ports with proper retrials and
907 *	fallbacks.  Actual recovery operations are performed using
908 *	ata_eh_recover() and sata_pmp_eh_recover_pmp().
909 *
910 *	LOCKING:
911 *	Kernel thread context (may sleep).
912 *
913 *	RETURNS:
914 *	0 on success, -errno on failure.
915 */
916static int sata_pmp_eh_recover(struct ata_port *ap)
917{
918	struct ata_port_operations *ops = ap->ops;
919	int pmp_tries, link_tries[SATA_PMP_MAX_PORTS];
920	struct ata_link *pmp_link = &ap->link;
921	struct ata_device *pmp_dev = pmp_link->device;
922	struct ata_eh_context *pmp_ehc = &pmp_link->eh_context;
923	u32 *gscr = pmp_dev->gscr;
924	struct ata_link *link;
925	struct ata_device *dev;
926	unsigned int err_mask;
927	u32 gscr_error, sntf;
928	int cnt, rc;
929
930	pmp_tries = ATA_EH_PMP_TRIES;
931	ata_for_each_link(link, ap, EDGE)
932		link_tries[link->pmp] = ATA_EH_PMP_LINK_TRIES;
933
934 retry:
935	/* PMP attached? */
936	if (!sata_pmp_attached(ap)) {
937		rc = ata_eh_recover(ap, ops->prereset, ops->softreset,
938				    ops->hardreset, ops->postreset, NULL);
939		if (rc) {
940			ata_for_each_dev(dev, &ap->link, ALL)
941				ata_dev_disable(dev);
942			return rc;
943		}
944
945		if (pmp_dev->class != ATA_DEV_PMP)
946			return 0;
947
948		/* new PMP online */
949		ata_for_each_link(link, ap, EDGE)
950			link_tries[link->pmp] = ATA_EH_PMP_LINK_TRIES;
951
952		/* fall through */
953	}
954
955	/* recover pmp */
956	rc = sata_pmp_eh_recover_pmp(ap, ops->prereset, ops->softreset,
957				     ops->hardreset, ops->postreset);
958	if (rc)
959		goto pmp_fail;
960
961	/* PHY event notification can disturb reset and other recovery
962	 * operations.  Turn it off.
963	 */
964	if (gscr[SATA_PMP_GSCR_FEAT_EN] & SATA_PMP_FEAT_NOTIFY) {
965		gscr[SATA_PMP_GSCR_FEAT_EN] &= ~SATA_PMP_FEAT_NOTIFY;
966
967		err_mask = sata_pmp_write(pmp_link, SATA_PMP_GSCR_FEAT_EN,
968					  gscr[SATA_PMP_GSCR_FEAT_EN]);
969		if (err_mask) {
970			ata_link_warn(pmp_link,
971				"failed to disable NOTIFY (err_mask=0x%x)\n",
972				err_mask);
973			goto pmp_fail;
974		}
975	}
976
977	/* handle disabled links */
978	rc = sata_pmp_eh_handle_disabled_links(ap);
979	if (rc)
980		goto pmp_fail;
981
982	/* recover links */
983	rc = ata_eh_recover(ap, ops->pmp_prereset, ops->pmp_softreset,
984			    ops->pmp_hardreset, ops->pmp_postreset, &link);
985	if (rc)
986		goto link_fail;
987
988	/* clear SNotification */
989	rc = sata_scr_read(&ap->link, SCR_NOTIFICATION, &sntf);
990	if (rc == 0)
991		sata_scr_write(&ap->link, SCR_NOTIFICATION, sntf);
992
993	/*
994	 * If LPM is active on any fan-out port, hotplug wouldn't
995	 * work.  Return w/ PHY event notification disabled.
996	 */
997	ata_for_each_link(link, ap, EDGE)
998		if (link->lpm_policy > ATA_LPM_MAX_POWER)
999			return 0;
1000
1001	/*
1002	 * Connection status might have changed while resetting other
1003	 * links, enable notification and check SATA_PMP_GSCR_ERROR
1004	 * before returning.
1005	 */
1006
1007	/* enable notification */
1008	if (pmp_dev->flags & ATA_DFLAG_AN) {
1009		gscr[SATA_PMP_GSCR_FEAT_EN] |= SATA_PMP_FEAT_NOTIFY;
1010
1011		err_mask = sata_pmp_write(pmp_link, SATA_PMP_GSCR_FEAT_EN,
1012					  gscr[SATA_PMP_GSCR_FEAT_EN]);
1013		if (err_mask) {
1014			ata_dev_err(pmp_dev,
1015				    "failed to write PMP_FEAT_EN (Emask=0x%x)\n",
1016				    err_mask);
1017			rc = -EIO;
1018			goto pmp_fail;
1019		}
1020	}
1021
1022	/* check GSCR_ERROR */
1023	err_mask = sata_pmp_read(pmp_link, SATA_PMP_GSCR_ERROR, &gscr_error);
1024	if (err_mask) {
1025		ata_dev_err(pmp_dev,
1026			    "failed to read PMP_GSCR_ERROR (Emask=0x%x)\n",
1027			    err_mask);
1028		rc = -EIO;
1029		goto pmp_fail;
1030	}
1031
1032	cnt = 0;
1033	ata_for_each_link(link, ap, EDGE) {
1034		if (!(gscr_error & (1 << link->pmp)))
1035			continue;
1036
1037		if (sata_pmp_handle_link_fail(link, link_tries)) {
1038			ata_ehi_hotplugged(&link->eh_context.i);
1039			cnt++;
1040		} else {
1041			ata_link_warn(link,
1042				"PHY status changed but maxed out on retries, giving up\n");
1043			ata_link_warn(link,
1044				"Manually issue scan to resume this link\n");
1045		}
1046	}
1047
1048	if (cnt) {
1049		ata_port_info(ap,
1050			"PMP SError.N set for some ports, repeating recovery\n");
1051		goto retry;
1052	}
1053
1054	return 0;
1055
1056 link_fail:
1057	if (sata_pmp_handle_link_fail(link, link_tries)) {
1058		pmp_ehc->i.action |= ATA_EH_RESET;
1059		goto retry;
1060	}
1061
1062	/* fall through */
1063 pmp_fail:
1064	/* Control always ends up here after detaching PMP.  Shut up
1065	 * and return if we're unloading.
1066	 */
1067	if (ap->pflags & ATA_PFLAG_UNLOADING)
1068		return rc;
1069
1070	if (!sata_pmp_attached(ap))
1071		goto retry;
1072
1073	if (--pmp_tries) {
1074		pmp_ehc->i.action |= ATA_EH_RESET;
1075		goto retry;
1076	}
1077
1078	ata_port_err(ap, "failed to recover PMP after %d tries, giving up\n",
1079		     ATA_EH_PMP_TRIES);
1080	sata_pmp_detach(pmp_dev);
1081	ata_dev_disable(pmp_dev);
1082
1083	return rc;
1084}
1085
1086/**
1087 *	sata_pmp_error_handler - do standard error handling for PMP-enabled host
1088 *	@ap: host port to handle error for
1089 *
1090 *	Perform standard error handling sequence for PMP-enabled host
1091 *	@ap.
1092 *
1093 *	LOCKING:
1094 *	Kernel thread context (may sleep).
1095 */
1096void sata_pmp_error_handler(struct ata_port *ap)
1097{
1098	ata_eh_autopsy(ap);
1099	ata_eh_report(ap);
1100	sata_pmp_eh_recover(ap);
1101	ata_eh_finish(ap);
1102}
1103
1104EXPORT_SYMBOL_GPL(sata_pmp_port_ops);
1105EXPORT_SYMBOL_GPL(sata_pmp_qc_defer_cmd_switch);
1106EXPORT_SYMBOL_GPL(sata_pmp_error_handler);
1107