1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * libata-pmp.c - libata port multiplier support
4 *
5 * Copyright (c) 2007  SUSE Linux Products GmbH
6 * Copyright (c) 2007  Tejun Heo <teheo@suse.de>
7 */
8
9#include <linux/kernel.h>
10#include <linux/export.h>
11#include <linux/libata.h>
12#include <linux/slab.h>
13#include "libata.h"
14#include "libata-transport.h"
15
16const struct ata_port_operations sata_pmp_port_ops = {
17	.inherits		= &sata_port_ops,
18	.pmp_prereset		= ata_std_prereset,
19	.pmp_hardreset		= sata_std_hardreset,
20	.pmp_postreset		= ata_std_postreset,
21	.error_handler		= sata_pmp_error_handler,
22};
23
24/**
25 *	sata_pmp_read - read PMP register
26 *	@link: link to read PMP register for
27 *	@reg: register to read
28 *	@r_val: resulting value
29 *
30 *	Read PMP register.
31 *
32 *	LOCKING:
33 *	Kernel thread context (may sleep).
34 *
35 *	RETURNS:
36 *	0 on success, AC_ERR_* mask on failure.
37 */
38static unsigned int sata_pmp_read(struct ata_link *link, int reg, u32 *r_val)
39{
40	struct ata_port *ap = link->ap;
41	struct ata_device *pmp_dev = ap->link.device;
42	struct ata_taskfile tf;
43	unsigned int err_mask;
44
45	ata_tf_init(pmp_dev, &tf);
46	tf.command = ATA_CMD_PMP_READ;
47	tf.protocol = ATA_PROT_NODATA;
48	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE | ATA_TFLAG_LBA48;
49	tf.feature = reg;
50	tf.device = link->pmp;
51
52	err_mask = ata_exec_internal(pmp_dev, &tf, NULL, DMA_NONE, NULL, 0,
53				     SATA_PMP_RW_TIMEOUT);
54	if (err_mask)
55		return err_mask;
56
57	*r_val = tf.nsect | tf.lbal << 8 | tf.lbam << 16 | tf.lbah << 24;
58	return 0;
59}
60
61/**
62 *	sata_pmp_write - write PMP register
63 *	@link: link to write PMP register for
64 *	@reg: register to write
65 *	@r_val: value to write
66 *
67 *	Write PMP register.
68 *
69 *	LOCKING:
70 *	Kernel thread context (may sleep).
71 *
72 *	RETURNS:
73 *	0 on success, AC_ERR_* mask on failure.
74 */
75static unsigned int sata_pmp_write(struct ata_link *link, int reg, u32 val)
76{
77	struct ata_port *ap = link->ap;
78	struct ata_device *pmp_dev = ap->link.device;
79	struct ata_taskfile tf;
80
81	ata_tf_init(pmp_dev, &tf);
82	tf.command = ATA_CMD_PMP_WRITE;
83	tf.protocol = ATA_PROT_NODATA;
84	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE | ATA_TFLAG_LBA48;
85	tf.feature = reg;
86	tf.device = link->pmp;
87	tf.nsect = val & 0xff;
88	tf.lbal = (val >> 8) & 0xff;
89	tf.lbam = (val >> 16) & 0xff;
90	tf.lbah = (val >> 24) & 0xff;
91
92	return ata_exec_internal(pmp_dev, &tf, NULL, DMA_NONE, NULL, 0,
93				 SATA_PMP_RW_TIMEOUT);
94}
95
96/**
97 *	sata_pmp_qc_defer_cmd_switch - qc_defer for command switching PMP
98 *	@qc: ATA command in question
99 *
100 *	A host which has command switching PMP support cannot issue
101 *	commands to multiple links simultaneously.
102 *
103 *	LOCKING:
104 *	spin_lock_irqsave(host lock)
105 *
106 *	RETURNS:
107 *	ATA_DEFER_* if deferring is needed, 0 otherwise.
108 */
109int sata_pmp_qc_defer_cmd_switch(struct ata_queued_cmd *qc)
110{
111	struct ata_link *link = qc->dev->link;
112	struct ata_port *ap = link->ap;
113
114	if (ap->excl_link == NULL || ap->excl_link == link) {
115		if (ap->nr_active_links == 0 || ata_link_active(link)) {
116			qc->flags |= ATA_QCFLAG_CLEAR_EXCL;
117			return ata_std_qc_defer(qc);
118		}
119
120		ap->excl_link = link;
121	}
122
123	return ATA_DEFER_PORT;
124}
125
126/**
127 *	sata_pmp_scr_read - read PSCR
128 *	@link: ATA link to read PSCR for
129 *	@reg: PSCR to read
130 *	@r_val: resulting value
131 *
132 *	Read PSCR @reg into @r_val for @link, to be called from
133 *	ata_scr_read().
134 *
135 *	LOCKING:
136 *	Kernel thread context (may sleep).
137 *
138 *	RETURNS:
139 *	0 on success, -errno on failure.
140 */
141int sata_pmp_scr_read(struct ata_link *link, int reg, u32 *r_val)
142{
143	unsigned int err_mask;
144
145	if (reg > SATA_PMP_PSCR_CONTROL)
146		return -EINVAL;
147
148	err_mask = sata_pmp_read(link, reg, r_val);
149	if (err_mask) {
150		ata_link_warn(link, "failed to read SCR %d (Emask=0x%x)\n",
151			      reg, err_mask);
152		return -EIO;
153	}
154	return 0;
155}
156
157/**
158 *	sata_pmp_scr_write - write PSCR
159 *	@link: ATA link to write PSCR for
160 *	@reg: PSCR to write
161 *	@val: value to be written
162 *
163 *	Write @val to PSCR @reg for @link, to be called from
164 *	ata_scr_write() and ata_scr_write_flush().
165 *
166 *	LOCKING:
167 *	Kernel thread context (may sleep).
168 *
169 *	RETURNS:
170 *	0 on success, -errno on failure.
171 */
172int sata_pmp_scr_write(struct ata_link *link, int reg, u32 val)
173{
174	unsigned int err_mask;
175
176	if (reg > SATA_PMP_PSCR_CONTROL)
177		return -EINVAL;
178
179	err_mask = sata_pmp_write(link, reg, val);
180	if (err_mask) {
181		ata_link_warn(link, "failed to write SCR %d (Emask=0x%x)\n",
182			      reg, err_mask);
183		return -EIO;
184	}
185	return 0;
186}
187
188/**
189 *	sata_pmp_set_lpm - configure LPM for a PMP link
190 *	@link: PMP link to configure LPM for
191 *	@policy: target LPM policy
192 *	@hints: LPM hints
193 *
194 *	Configure LPM for @link.  This function will contain any PMP
195 *	specific workarounds if necessary.
196 *
197 *	LOCKING:
198 *	EH context.
199 *
200 *	RETURNS:
201 *	0 on success, -errno on failure.
202 */
203int sata_pmp_set_lpm(struct ata_link *link, enum ata_lpm_policy policy,
204		     unsigned hints)
205{
206	return sata_link_scr_lpm(link, policy, true);
207}
208
209/**
210 *	sata_pmp_read_gscr - read GSCR block of SATA PMP
211 *	@dev: PMP device
212 *	@gscr: buffer to read GSCR block into
213 *
214 *	Read selected PMP GSCRs from the PMP at @dev.  This will serve
215 *	as configuration and identification info for the PMP.
216 *
217 *	LOCKING:
218 *	Kernel thread context (may sleep).
219 *
220 *	RETURNS:
221 *	0 on success, -errno on failure.
222 */
223static int sata_pmp_read_gscr(struct ata_device *dev, u32 *gscr)
224{
225	static const int gscr_to_read[] = { 0, 1, 2, 32, 33, 64, 96 };
226	int i;
227
228	for (i = 0; i < ARRAY_SIZE(gscr_to_read); i++) {
229		int reg = gscr_to_read[i];
230		unsigned int err_mask;
231
232		err_mask = sata_pmp_read(dev->link, reg, &gscr[reg]);
233		if (err_mask) {
234			ata_dev_err(dev, "failed to read PMP GSCR[%d] (Emask=0x%x)\n",
235				    reg, err_mask);
236			return -EIO;
237		}
238	}
239
240	return 0;
241}
242
243static const char *sata_pmp_spec_rev_str(const u32 *gscr)
244{
245	u32 rev = gscr[SATA_PMP_GSCR_REV];
246
247	if (rev & (1 << 3))
248		return "1.2";
249	if (rev & (1 << 2))
250		return "1.1";
251	if (rev & (1 << 1))
252		return "1.0";
253	return "<unknown>";
254}
255
256#define PMP_GSCR_SII_POL 129
257
258static int sata_pmp_configure(struct ata_device *dev, int print_info)
259{
260	struct ata_port *ap = dev->link->ap;
261	u32 *gscr = dev->gscr;
262	u16 vendor = sata_pmp_gscr_vendor(gscr);
263	u16 devid = sata_pmp_gscr_devid(gscr);
264	unsigned int err_mask = 0;
265	const char *reason;
266	int nr_ports, rc;
267
268	nr_ports = sata_pmp_gscr_ports(gscr);
269
270	if (nr_ports <= 0 || nr_ports > SATA_PMP_MAX_PORTS) {
271		rc = -EINVAL;
272		reason = "invalid nr_ports";
273		goto fail;
274	}
275
276	if ((ap->flags & ATA_FLAG_AN) &&
277	    (gscr[SATA_PMP_GSCR_FEAT] & SATA_PMP_FEAT_NOTIFY))
278		dev->flags |= ATA_DFLAG_AN;
279
280	/* monitor SERR_PHYRDY_CHG on fan-out ports */
281	err_mask = sata_pmp_write(dev->link, SATA_PMP_GSCR_ERROR_EN,
282				  SERR_PHYRDY_CHG);
283	if (err_mask) {
284		rc = -EIO;
285		reason = "failed to write GSCR_ERROR_EN";
286		goto fail;
287	}
288
289	/* Disable sending Early R_OK.
290	 * With "cached read" HDD testing and multiple ports busy on a SATA
291	 * host controller, 3x26 PMP will very rarely drop a deferred
292	 * R_OK that was intended for the host. Symptom will be all
293	 * 5 drives under test will timeout, get reset, and recover.
294	 */
295	if (vendor == 0x1095 && (devid == 0x3726 || devid == 0x3826)) {
296		u32 reg;
297
298		err_mask = sata_pmp_read(&ap->link, PMP_GSCR_SII_POL, &reg);
299		if (err_mask) {
300			rc = -EIO;
301			reason = "failed to read Sil3x26 Private Register";
302			goto fail;
303		}
304		reg &= ~0x1;
305		err_mask = sata_pmp_write(&ap->link, PMP_GSCR_SII_POL, reg);
306		if (err_mask) {
307			rc = -EIO;
308			reason = "failed to write Sil3x26 Private Register";
309			goto fail;
310		}
311	}
312
313	if (print_info) {
314		ata_dev_info(dev, "Port Multiplier %s, "
315			     "0x%04x:0x%04x r%d, %d ports, feat 0x%x/0x%x\n",
316			     sata_pmp_spec_rev_str(gscr), vendor, devid,
317			     sata_pmp_gscr_rev(gscr),
318			     nr_ports, gscr[SATA_PMP_GSCR_FEAT_EN],
319			     gscr[SATA_PMP_GSCR_FEAT]);
320
321		if (!(dev->flags & ATA_DFLAG_AN))
322			ata_dev_info(dev,
323				"Asynchronous notification not supported, "
324				"hotplug won't work on fan-out ports. Use warm-plug instead.\n");
325	}
326
327	return 0;
328
329 fail:
330	ata_dev_err(dev,
331		    "failed to configure Port Multiplier (%s, Emask=0x%x)\n",
332		    reason, err_mask);
333	return rc;
334}
335
336static int sata_pmp_init_links (struct ata_port *ap, int nr_ports)
337{
338	struct ata_link *pmp_link = ap->pmp_link;
339	int i, err;
340
341	if (!pmp_link) {
342		pmp_link = kcalloc(SATA_PMP_MAX_PORTS, sizeof(pmp_link[0]),
343				   GFP_NOIO);
344		if (!pmp_link)
345			return -ENOMEM;
346
347		for (i = 0; i < SATA_PMP_MAX_PORTS; i++)
348			ata_link_init(ap, &pmp_link[i], i);
349
350		ap->pmp_link = pmp_link;
351
352		for (i = 0; i < SATA_PMP_MAX_PORTS; i++) {
353			err = ata_tlink_add(&pmp_link[i]);
354			if (err) {
355				goto err_tlink;
356			}
357		}
358	}
359
360	for (i = 0; i < nr_ports; i++) {
361		struct ata_link *link = &pmp_link[i];
362		struct ata_eh_context *ehc = &link->eh_context;
363
364		link->flags = 0;
365		ehc->i.probe_mask |= ATA_ALL_DEVICES;
366		ehc->i.action |= ATA_EH_RESET;
367	}
368
369	return 0;
370  err_tlink:
371	while (--i >= 0)
372		ata_tlink_delete(&pmp_link[i]);
373	kfree(pmp_link);
374	ap->pmp_link = NULL;
375	return err;
376}
377
378static void sata_pmp_quirks(struct ata_port *ap)
379{
380	u32 *gscr = ap->link.device->gscr;
381	u16 vendor = sata_pmp_gscr_vendor(gscr);
382	u16 devid = sata_pmp_gscr_devid(gscr);
383	struct ata_link *link;
384
385	if (vendor == 0x1095 && (devid == 0x3726 || devid == 0x3826)) {
386		/* sil3x26 quirks */
387		ata_for_each_link(link, ap, EDGE) {
388			/* link reports offline after LPM */
389			link->flags |= ATA_LFLAG_NO_LPM;
390
391			/*
392			 * Class code report is unreliable and SRST times
393			 * out under certain configurations.
394			 */
395			if (link->pmp < 5)
396				link->flags |= ATA_LFLAG_NO_SRST |
397					       ATA_LFLAG_ASSUME_ATA;
398
399			/* port 5 is for SEMB device and it doesn't like SRST */
400			if (link->pmp == 5)
401				link->flags |= ATA_LFLAG_NO_SRST |
402					       ATA_LFLAG_ASSUME_SEMB;
403		}
404	} else if (vendor == 0x1095 && devid == 0x4723) {
405		/*
406		 * sil4723 quirks
407		 *
408		 * Link reports offline after LPM.  Class code report is
409		 * unreliable.  SIMG PMPs never got SRST reliable and the
410		 * config device at port 2 locks up on SRST.
411		 */
412		ata_for_each_link(link, ap, EDGE)
413			link->flags |= ATA_LFLAG_NO_LPM |
414				       ATA_LFLAG_NO_SRST |
415				       ATA_LFLAG_ASSUME_ATA;
416	} else if (vendor == 0x1095 && devid == 0x4726) {
417		/* sil4726 quirks */
418		ata_for_each_link(link, ap, EDGE) {
419			/* link reports offline after LPM */
420			link->flags |= ATA_LFLAG_NO_LPM;
421
422			/* Class code report is unreliable and SRST
423			 * times out under certain configurations.
424			 * Config device can be at port 0 or 5 and
425			 * locks up on SRST.
426			 */
427			if (link->pmp <= 5)
428				link->flags |= ATA_LFLAG_NO_SRST |
429					       ATA_LFLAG_ASSUME_ATA;
430
431			/* Port 6 is for SEMB device which doesn't
432			 * like SRST either.
433			 */
434			if (link->pmp == 6)
435				link->flags |= ATA_LFLAG_NO_SRST |
436					       ATA_LFLAG_ASSUME_SEMB;
437		}
438	} else if (vendor == 0x1095 && (devid == 0x5723 || devid == 0x5733 ||
439					devid == 0x5734 || devid == 0x5744)) {
440		/* sil5723/5744 quirks */
441
442		/* sil5723/5744 has either two or three downstream
443		 * ports depending on operation mode.  The last port
444		 * is empty if any actual IO device is available or
445		 * occupied by a pseudo configuration device
446		 * otherwise.  Don't try hard to recover it.
447		 */
448		ap->pmp_link[ap->nr_pmp_links - 1].flags |= ATA_LFLAG_NO_RETRY;
449	} else if (vendor == 0x197b && (devid == 0x2352 || devid == 0x0325)) {
450		/*
451		 * 0x2352: found in Thermaltake BlackX Duet, jmicron JMB350?
452		 * 0x0325: jmicron JMB394.
453		 */
454		ata_for_each_link(link, ap, EDGE) {
455			/* SRST breaks detection and disks get misclassified
456			 * LPM disabled to avoid potential problems
457			 */
458			link->flags |= ATA_LFLAG_NO_LPM |
459				       ATA_LFLAG_NO_SRST |
460				       ATA_LFLAG_ASSUME_ATA;
461		}
462	} else if (vendor == 0x11ab && devid == 0x4140) {
463		/* Marvell 4140 quirks */
464		ata_for_each_link(link, ap, EDGE) {
465			/* port 4 is for SEMB device and it doesn't like SRST */
466			if (link->pmp == 4)
467				link->flags |= ATA_LFLAG_DISABLED;
468		}
469	}
470}
471
472/**
473 *	sata_pmp_attach - attach a SATA PMP device
474 *	@dev: SATA PMP device to attach
475 *
476 *	Configure and attach SATA PMP device @dev.  This function is
477 *	also responsible for allocating and initializing PMP links.
478 *
479 *	LOCKING:
480 *	Kernel thread context (may sleep).
481 *
482 *	RETURNS:
483 *	0 on success, -errno on failure.
484 */
485int sata_pmp_attach(struct ata_device *dev)
486{
487	struct ata_link *link = dev->link;
488	struct ata_port *ap = link->ap;
489	unsigned long flags;
490	struct ata_link *tlink;
491	int rc;
492
493	/* is it hanging off the right place? */
494	if (!sata_pmp_supported(ap)) {
495		ata_dev_err(dev, "host does not support Port Multiplier\n");
496		return -EINVAL;
497	}
498
499	if (!ata_is_host_link(link)) {
500		ata_dev_err(dev, "Port Multipliers cannot be nested\n");
501		return -EINVAL;
502	}
503
504	if (dev->devno) {
505		ata_dev_err(dev, "Port Multiplier must be the first device\n");
506		return -EINVAL;
507	}
508
509	WARN_ON(link->pmp != 0);
510	link->pmp = SATA_PMP_CTRL_PORT;
511
512	/* read GSCR block */
513	rc = sata_pmp_read_gscr(dev, dev->gscr);
514	if (rc)
515		goto fail;
516
517	/* config PMP */
518	rc = sata_pmp_configure(dev, 1);
519	if (rc)
520		goto fail;
521
522	rc = sata_pmp_init_links(ap, sata_pmp_gscr_ports(dev->gscr));
523	if (rc) {
524		ata_dev_info(dev, "failed to initialize PMP links\n");
525		goto fail;
526	}
527
528	/* attach it */
529	spin_lock_irqsave(ap->lock, flags);
530	WARN_ON(ap->nr_pmp_links);
531	ap->nr_pmp_links = sata_pmp_gscr_ports(dev->gscr);
532	spin_unlock_irqrestore(ap->lock, flags);
533
534	sata_pmp_quirks(ap);
535
536	if (ap->ops->pmp_attach)
537		ap->ops->pmp_attach(ap);
538
539	ata_for_each_link(tlink, ap, EDGE)
540		sata_link_init_spd(tlink);
541
542	return 0;
543
544 fail:
545	link->pmp = 0;
546	return rc;
547}
548
549/**
550 *	sata_pmp_detach - detach a SATA PMP device
551 *	@dev: SATA PMP device to detach
552 *
553 *	Detach SATA PMP device @dev.  This function is also
554 *	responsible for deconfiguring PMP links.
555 *
556 *	LOCKING:
557 *	Kernel thread context (may sleep).
558 */
559static void sata_pmp_detach(struct ata_device *dev)
560{
561	struct ata_link *link = dev->link;
562	struct ata_port *ap = link->ap;
563	struct ata_link *tlink;
564	unsigned long flags;
565
566	ata_dev_info(dev, "Port Multiplier detaching\n");
567
568	WARN_ON(!ata_is_host_link(link) || dev->devno ||
569		link->pmp != SATA_PMP_CTRL_PORT);
570
571	if (ap->ops->pmp_detach)
572		ap->ops->pmp_detach(ap);
573
574	ata_for_each_link(tlink, ap, EDGE)
575		ata_eh_detach_dev(tlink->device);
576
577	spin_lock_irqsave(ap->lock, flags);
578	ap->nr_pmp_links = 0;
579	link->pmp = 0;
580	spin_unlock_irqrestore(ap->lock, flags);
581}
582
583/**
584 *	sata_pmp_same_pmp - does new GSCR matches the configured PMP?
585 *	@dev: PMP device to compare against
586 *	@new_gscr: GSCR block of the new device
587 *
588 *	Compare @new_gscr against @dev and determine whether @dev is
589 *	the PMP described by @new_gscr.
590 *
591 *	LOCKING:
592 *	None.
593 *
594 *	RETURNS:
595 *	1 if @dev matches @new_gscr, 0 otherwise.
596 */
597static int sata_pmp_same_pmp(struct ata_device *dev, const u32 *new_gscr)
598{
599	const u32 *old_gscr = dev->gscr;
600	u16 old_vendor, new_vendor, old_devid, new_devid;
601	int old_nr_ports, new_nr_ports;
602
603	old_vendor = sata_pmp_gscr_vendor(old_gscr);
604	new_vendor = sata_pmp_gscr_vendor(new_gscr);
605	old_devid = sata_pmp_gscr_devid(old_gscr);
606	new_devid = sata_pmp_gscr_devid(new_gscr);
607	old_nr_ports = sata_pmp_gscr_ports(old_gscr);
608	new_nr_ports = sata_pmp_gscr_ports(new_gscr);
609
610	if (old_vendor != new_vendor) {
611		ata_dev_info(dev,
612			     "Port Multiplier vendor mismatch '0x%x' != '0x%x'\n",
613			     old_vendor, new_vendor);
614		return 0;
615	}
616
617	if (old_devid != new_devid) {
618		ata_dev_info(dev,
619			     "Port Multiplier device ID mismatch '0x%x' != '0x%x'\n",
620			     old_devid, new_devid);
621		return 0;
622	}
623
624	if (old_nr_ports != new_nr_ports) {
625		ata_dev_info(dev,
626			     "Port Multiplier nr_ports mismatch '0x%x' != '0x%x'\n",
627			     old_nr_ports, new_nr_ports);
628		return 0;
629	}
630
631	return 1;
632}
633
634/**
635 *	sata_pmp_revalidate - revalidate SATA PMP
636 *	@dev: PMP device to revalidate
637 *	@new_class: new class code
638 *
639 *	Re-read GSCR block and make sure @dev is still attached to the
640 *	port and properly configured.
641 *
642 *	LOCKING:
643 *	Kernel thread context (may sleep).
644 *
645 *	RETURNS:
646 *	0 on success, -errno otherwise.
647 */
648static int sata_pmp_revalidate(struct ata_device *dev, unsigned int new_class)
649{
650	struct ata_link *link = dev->link;
651	struct ata_port *ap = link->ap;
652	u32 *gscr = (void *)ap->sector_buf;
653	int rc;
654
655	DPRINTK("ENTER\n");
656
657	ata_eh_about_to_do(link, NULL, ATA_EH_REVALIDATE);
658
659	if (!ata_dev_enabled(dev)) {
660		rc = -ENODEV;
661		goto fail;
662	}
663
664	/* wrong class? */
665	if (ata_class_enabled(new_class) && new_class != ATA_DEV_PMP) {
666		rc = -ENODEV;
667		goto fail;
668	}
669
670	/* read GSCR */
671	rc = sata_pmp_read_gscr(dev, gscr);
672	if (rc)
673		goto fail;
674
675	/* is the pmp still there? */
676	if (!sata_pmp_same_pmp(dev, gscr)) {
677		rc = -ENODEV;
678		goto fail;
679	}
680
681	memcpy(dev->gscr, gscr, sizeof(gscr[0]) * SATA_PMP_GSCR_DWORDS);
682
683	rc = sata_pmp_configure(dev, 0);
684	if (rc)
685		goto fail;
686
687	ata_eh_done(link, NULL, ATA_EH_REVALIDATE);
688
689	DPRINTK("EXIT, rc=0\n");
690	return 0;
691
692 fail:
693	ata_dev_err(dev, "PMP revalidation failed (errno=%d)\n", rc);
694	DPRINTK("EXIT, rc=%d\n", rc);
695	return rc;
696}
697
698/**
699 *	sata_pmp_revalidate_quick - revalidate SATA PMP quickly
700 *	@dev: PMP device to revalidate
701 *
702 *	Make sure the attached PMP is accessible.
703 *
704 *	LOCKING:
705 *	Kernel thread context (may sleep).
706 *
707 *	RETURNS:
708 *	0 on success, -errno otherwise.
709 */
710static int sata_pmp_revalidate_quick(struct ata_device *dev)
711{
712	unsigned int err_mask;
713	u32 prod_id;
714
715	err_mask = sata_pmp_read(dev->link, SATA_PMP_GSCR_PROD_ID, &prod_id);
716	if (err_mask) {
717		ata_dev_err(dev,
718			    "failed to read PMP product ID (Emask=0x%x)\n",
719			    err_mask);
720		return -EIO;
721	}
722
723	if (prod_id != dev->gscr[SATA_PMP_GSCR_PROD_ID]) {
724		ata_dev_err(dev, "PMP product ID mismatch\n");
725		/* something weird is going on, request full PMP recovery */
726		return -EIO;
727	}
728
729	return 0;
730}
731
732/**
733 *	sata_pmp_eh_recover_pmp - recover PMP
734 *	@ap: ATA port PMP is attached to
735 *	@prereset: prereset method (can be NULL)
736 *	@softreset: softreset method
737 *	@hardreset: hardreset method
738 *	@postreset: postreset method (can be NULL)
739 *
740 *	Recover PMP attached to @ap.  Recovery procedure is somewhat
741 *	similar to that of ata_eh_recover() except that reset should
742 *	always be performed in hard->soft sequence and recovery
743 *	failure results in PMP detachment.
744 *
745 *	LOCKING:
746 *	Kernel thread context (may sleep).
747 *
748 *	RETURNS:
749 *	0 on success, -errno on failure.
750 */
751static int sata_pmp_eh_recover_pmp(struct ata_port *ap,
752		ata_prereset_fn_t prereset, ata_reset_fn_t softreset,
753		ata_reset_fn_t hardreset, ata_postreset_fn_t postreset)
754{
755	struct ata_link *link = &ap->link;
756	struct ata_eh_context *ehc = &link->eh_context;
757	struct ata_device *dev = link->device;
758	int tries = ATA_EH_PMP_TRIES;
759	int detach = 0, rc = 0;
760	int reval_failed = 0;
761
762	DPRINTK("ENTER\n");
763
764	if (dev->flags & ATA_DFLAG_DETACH) {
765		detach = 1;
766		rc = -ENODEV;
767		goto fail;
768	}
769
770 retry:
771	ehc->classes[0] = ATA_DEV_UNKNOWN;
772
773	if (ehc->i.action & ATA_EH_RESET) {
774		struct ata_link *tlink;
775
776		/* reset */
777		rc = ata_eh_reset(link, 0, prereset, softreset, hardreset,
778				  postreset);
779		if (rc) {
780			ata_link_err(link, "failed to reset PMP, giving up\n");
781			goto fail;
782		}
783
784		/* PMP is reset, SErrors cannot be trusted, scan all */
785		ata_for_each_link(tlink, ap, EDGE) {
786			struct ata_eh_context *ehc = &tlink->eh_context;
787
788			ehc->i.probe_mask |= ATA_ALL_DEVICES;
789			ehc->i.action |= ATA_EH_RESET;
790		}
791	}
792
793	/* If revalidation is requested, revalidate and reconfigure;
794	 * otherwise, do quick revalidation.
795	 */
796	if (ehc->i.action & ATA_EH_REVALIDATE)
797		rc = sata_pmp_revalidate(dev, ehc->classes[0]);
798	else
799		rc = sata_pmp_revalidate_quick(dev);
800
801	if (rc) {
802		tries--;
803
804		if (rc == -ENODEV) {
805			ehc->i.probe_mask |= ATA_ALL_DEVICES;
806			detach = 1;
807			/* give it just two more chances */
808			tries = min(tries, 2);
809		}
810
811		if (tries) {
812			/* consecutive revalidation failures? speed down */
813			if (reval_failed)
814				sata_down_spd_limit(link, 0);
815			else
816				reval_failed = 1;
817
818			ehc->i.action |= ATA_EH_RESET;
819			goto retry;
820		} else {
821			ata_dev_err(dev,
822				    "failed to recover PMP after %d tries, giving up\n",
823				    ATA_EH_PMP_TRIES);
824			goto fail;
825		}
826	}
827
828	/* okay, PMP resurrected */
829	ehc->i.flags = 0;
830
831	DPRINTK("EXIT, rc=0\n");
832	return 0;
833
834 fail:
835	sata_pmp_detach(dev);
836	if (detach)
837		ata_eh_detach_dev(dev);
838	else
839		ata_dev_disable(dev);
840
841	DPRINTK("EXIT, rc=%d\n", rc);
842	return rc;
843}
844
845static int sata_pmp_eh_handle_disabled_links(struct ata_port *ap)
846{
847	struct ata_link *link;
848	unsigned long flags;
849	int rc;
850
851	spin_lock_irqsave(ap->lock, flags);
852
853	ata_for_each_link(link, ap, EDGE) {
854		if (!(link->flags & ATA_LFLAG_DISABLED))
855			continue;
856
857		spin_unlock_irqrestore(ap->lock, flags);
858
859		/* Some PMPs require hardreset sequence to get
860		 * SError.N working.
861		 */
862		sata_link_hardreset(link, sata_deb_timing_normal,
863				ata_deadline(jiffies, ATA_TMOUT_INTERNAL_QUICK),
864				NULL, NULL);
865
866		/* unconditionally clear SError.N */
867		rc = sata_scr_write(link, SCR_ERROR, SERR_PHYRDY_CHG);
868		if (rc) {
869			ata_link_err(link,
870				     "failed to clear SError.N (errno=%d)\n",
871				     rc);
872			return rc;
873		}
874
875		spin_lock_irqsave(ap->lock, flags);
876	}
877
878	spin_unlock_irqrestore(ap->lock, flags);
879
880	return 0;
881}
882
883static int sata_pmp_handle_link_fail(struct ata_link *link, int *link_tries)
884{
885	struct ata_port *ap = link->ap;
886	unsigned long flags;
887
888	if (link_tries[link->pmp] && --link_tries[link->pmp])
889		return 1;
890
891	/* disable this link */
892	if (!(link->flags & ATA_LFLAG_DISABLED)) {
893		ata_link_warn(link,
894			"failed to recover link after %d tries, disabling\n",
895			ATA_EH_PMP_LINK_TRIES);
896
897		spin_lock_irqsave(ap->lock, flags);
898		link->flags |= ATA_LFLAG_DISABLED;
899		spin_unlock_irqrestore(ap->lock, flags);
900	}
901
902	ata_dev_disable(link->device);
903	link->eh_context.i.action = 0;
904
905	return 0;
906}
907
908/**
909 *	sata_pmp_eh_recover - recover PMP-enabled port
910 *	@ap: ATA port to recover
911 *
912 *	Drive EH recovery operation for PMP enabled port @ap.  This
913 *	function recovers host and PMP ports with proper retrials and
914 *	fallbacks.  Actual recovery operations are performed using
915 *	ata_eh_recover() and sata_pmp_eh_recover_pmp().
916 *
917 *	LOCKING:
918 *	Kernel thread context (may sleep).
919 *
920 *	RETURNS:
921 *	0 on success, -errno on failure.
922 */
923static int sata_pmp_eh_recover(struct ata_port *ap)
924{
925	struct ata_port_operations *ops = ap->ops;
926	int pmp_tries, link_tries[SATA_PMP_MAX_PORTS];
927	struct ata_link *pmp_link = &ap->link;
928	struct ata_device *pmp_dev = pmp_link->device;
929	struct ata_eh_context *pmp_ehc = &pmp_link->eh_context;
930	u32 *gscr = pmp_dev->gscr;
931	struct ata_link *link;
932	struct ata_device *dev;
933	unsigned int err_mask;
934	u32 gscr_error, sntf;
935	int cnt, rc;
936
937	pmp_tries = ATA_EH_PMP_TRIES;
938	ata_for_each_link(link, ap, EDGE)
939		link_tries[link->pmp] = ATA_EH_PMP_LINK_TRIES;
940
941 retry:
942	/* PMP attached? */
943	if (!sata_pmp_attached(ap)) {
944		rc = ata_eh_recover(ap, ops->prereset, ops->softreset,
945				    ops->hardreset, ops->postreset, NULL);
946		if (rc) {
947			ata_for_each_dev(dev, &ap->link, ALL)
948				ata_dev_disable(dev);
949			return rc;
950		}
951
952		if (pmp_dev->class != ATA_DEV_PMP)
953			return 0;
954
955		/* new PMP online */
956		ata_for_each_link(link, ap, EDGE)
957			link_tries[link->pmp] = ATA_EH_PMP_LINK_TRIES;
958
959		/* fall through */
960	}
961
962	/* recover pmp */
963	rc = sata_pmp_eh_recover_pmp(ap, ops->prereset, ops->softreset,
964				     ops->hardreset, ops->postreset);
965	if (rc)
966		goto pmp_fail;
967
968	/* PHY event notification can disturb reset and other recovery
969	 * operations.  Turn it off.
970	 */
971	if (gscr[SATA_PMP_GSCR_FEAT_EN] & SATA_PMP_FEAT_NOTIFY) {
972		gscr[SATA_PMP_GSCR_FEAT_EN] &= ~SATA_PMP_FEAT_NOTIFY;
973
974		err_mask = sata_pmp_write(pmp_link, SATA_PMP_GSCR_FEAT_EN,
975					  gscr[SATA_PMP_GSCR_FEAT_EN]);
976		if (err_mask) {
977			ata_link_warn(pmp_link,
978				"failed to disable NOTIFY (err_mask=0x%x)\n",
979				err_mask);
980			goto pmp_fail;
981		}
982	}
983
984	/* handle disabled links */
985	rc = sata_pmp_eh_handle_disabled_links(ap);
986	if (rc)
987		goto pmp_fail;
988
989	/* recover links */
990	rc = ata_eh_recover(ap, ops->pmp_prereset, ops->pmp_softreset,
991			    ops->pmp_hardreset, ops->pmp_postreset, &link);
992	if (rc)
993		goto link_fail;
994
995	/* clear SNotification */
996	rc = sata_scr_read(&ap->link, SCR_NOTIFICATION, &sntf);
997	if (rc == 0)
998		sata_scr_write(&ap->link, SCR_NOTIFICATION, sntf);
999
1000	/*
1001	 * If LPM is active on any fan-out port, hotplug wouldn't
1002	 * work.  Return w/ PHY event notification disabled.
1003	 */
1004	ata_for_each_link(link, ap, EDGE)
1005		if (link->lpm_policy > ATA_LPM_MAX_POWER)
1006			return 0;
1007
1008	/*
1009	 * Connection status might have changed while resetting other
1010	 * links, enable notification and check SATA_PMP_GSCR_ERROR
1011	 * before returning.
1012	 */
1013
1014	/* enable notification */
1015	if (pmp_dev->flags & ATA_DFLAG_AN) {
1016		gscr[SATA_PMP_GSCR_FEAT_EN] |= SATA_PMP_FEAT_NOTIFY;
1017
1018		err_mask = sata_pmp_write(pmp_link, SATA_PMP_GSCR_FEAT_EN,
1019					  gscr[SATA_PMP_GSCR_FEAT_EN]);
1020		if (err_mask) {
1021			ata_dev_err(pmp_dev,
1022				    "failed to write PMP_FEAT_EN (Emask=0x%x)\n",
1023				    err_mask);
1024			rc = -EIO;
1025			goto pmp_fail;
1026		}
1027	}
1028
1029	/* check GSCR_ERROR */
1030	err_mask = sata_pmp_read(pmp_link, SATA_PMP_GSCR_ERROR, &gscr_error);
1031	if (err_mask) {
1032		ata_dev_err(pmp_dev,
1033			    "failed to read PMP_GSCR_ERROR (Emask=0x%x)\n",
1034			    err_mask);
1035		rc = -EIO;
1036		goto pmp_fail;
1037	}
1038
1039	cnt = 0;
1040	ata_for_each_link(link, ap, EDGE) {
1041		if (!(gscr_error & (1 << link->pmp)))
1042			continue;
1043
1044		if (sata_pmp_handle_link_fail(link, link_tries)) {
1045			ata_ehi_hotplugged(&link->eh_context.i);
1046			cnt++;
1047		} else {
1048			ata_link_warn(link,
1049				"PHY status changed but maxed out on retries, giving up\n");
1050			ata_link_warn(link,
1051				"Manually issue scan to resume this link\n");
1052		}
1053	}
1054
1055	if (cnt) {
1056		ata_port_info(ap,
1057			"PMP SError.N set for some ports, repeating recovery\n");
1058		goto retry;
1059	}
1060
1061	return 0;
1062
1063 link_fail:
1064	if (sata_pmp_handle_link_fail(link, link_tries)) {
1065		pmp_ehc->i.action |= ATA_EH_RESET;
1066		goto retry;
1067	}
1068
1069	/* fall through */
1070 pmp_fail:
1071	/* Control always ends up here after detaching PMP.  Shut up
1072	 * and return if we're unloading.
1073	 */
1074	if (ap->pflags & ATA_PFLAG_UNLOADING)
1075		return rc;
1076
1077	if (!sata_pmp_attached(ap))
1078		goto retry;
1079
1080	if (--pmp_tries) {
1081		pmp_ehc->i.action |= ATA_EH_RESET;
1082		goto retry;
1083	}
1084
1085	ata_port_err(ap, "failed to recover PMP after %d tries, giving up\n",
1086		     ATA_EH_PMP_TRIES);
1087	sata_pmp_detach(pmp_dev);
1088	ata_dev_disable(pmp_dev);
1089
1090	return rc;
1091}
1092
1093/**
1094 *	sata_pmp_error_handler - do standard error handling for PMP-enabled host
1095 *	@ap: host port to handle error for
1096 *
1097 *	Perform standard error handling sequence for PMP-enabled host
1098 *	@ap.
1099 *
1100 *	LOCKING:
1101 *	Kernel thread context (may sleep).
1102 */
1103void sata_pmp_error_handler(struct ata_port *ap)
1104{
1105	ata_eh_autopsy(ap);
1106	ata_eh_report(ap);
1107	sata_pmp_eh_recover(ap);
1108	ata_eh_finish(ap);
1109}
1110
1111EXPORT_SYMBOL_GPL(sata_pmp_port_ops);
1112EXPORT_SYMBOL_GPL(sata_pmp_qc_defer_cmd_switch);
1113EXPORT_SYMBOL_GPL(sata_pmp_error_handler);
1114