libata-pmp.c

   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_reset.prereset	= ata_std_prereset,
  19	.pmp_reset.hardreset	= sata_std_hardreset,
  20	.pmp_reset.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 *	@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	u32 *gscr = (void *)dev->sector_buf;
 652	int rc;
 653
 654	ata_eh_about_to_do(link, NULL, ATA_EH_REVALIDATE);
 655
 656	if (!ata_dev_enabled(dev)) {
 657		rc = -ENODEV;
 658		goto fail;
 659	}
 660
 661	/* wrong class? */
 662	if (ata_class_enabled(new_class) && new_class != ATA_DEV_PMP) {
 663		rc = -ENODEV;
 664		goto fail;
 665	}
 666
 667	/* read GSCR */
 668	rc = sata_pmp_read_gscr(dev, gscr);
 669	if (rc)
 670		goto fail;
 671
 672	/* is the pmp still there? */
 673	if (!sata_pmp_same_pmp(dev, gscr)) {
 674		rc = -ENODEV;
 675		goto fail;
 676	}
 677
 678	memcpy(dev->gscr, gscr, sizeof(gscr[0]) * SATA_PMP_GSCR_DWORDS);
 679
 680	rc = sata_pmp_configure(dev, 0);
 681	if (rc)
 682		goto fail;
 683
 684	ata_eh_done(link, NULL, ATA_EH_REVALIDATE);
 685
 686	return 0;
 687
 688 fail:
 689	ata_dev_err(dev, "PMP revalidation failed (errno=%d)\n", rc);
 690	return rc;
 691}
 692
 693/**
 694 *	sata_pmp_revalidate_quick - revalidate SATA PMP quickly
 695 *	@dev: PMP device to revalidate
 696 *
 697 *	Make sure the attached PMP is accessible.
 698 *
 699 *	LOCKING:
 700 *	Kernel thread context (may sleep).
 701 *
 702 *	RETURNS:
 703 *	0 on success, -errno otherwise.
 704 */
 705static int sata_pmp_revalidate_quick(struct ata_device *dev)
 706{
 707	unsigned int err_mask;
 708	u32 prod_id;
 709
 710	err_mask = sata_pmp_read(dev->link, SATA_PMP_GSCR_PROD_ID, &prod_id);
 711	if (err_mask) {
 712		ata_dev_err(dev,
 713			    "failed to read PMP product ID (Emask=0x%x)\n",
 714			    err_mask);
 715		return -EIO;
 716	}
 717
 718	if (prod_id != dev->gscr[SATA_PMP_GSCR_PROD_ID]) {
 719		ata_dev_err(dev, "PMP product ID mismatch\n");
 720		/* something weird is going on, request full PMP recovery */
 721		return -EIO;
 722	}
 723
 724	return 0;
 725}
 726
 727/**
 728 *	sata_pmp_eh_recover_pmp - recover PMP
 729 *	@ap: ATA port PMP is attached to
 730 *	@reset_ops: The set of reset operations to use
 731 *
 732 *	Recover PMP attached to @ap.  Recovery procedure is somewhat
 733 *	similar to that of ata_eh_recover() except that reset should
 734 *	always be performed in hard->soft sequence and recovery
 735 *	failure results in PMP detachment.
 736 *
 737 *	LOCKING:
 738 *	Kernel thread context (may sleep).
 739 *
 740 *	RETURNS:
 741 *	0 on success, -errno on failure.
 742 */
 743static int sata_pmp_eh_recover_pmp(struct ata_port *ap,
 744				   struct ata_reset_operations *reset_ops)
 745{
 746	struct ata_link *link = &ap->link;
 747	struct ata_eh_context *ehc = &link->eh_context;
 748	struct ata_device *dev = link->device;
 749	int tries = ATA_EH_PMP_TRIES;
 750	int detach = 0, rc = 0;
 751	int reval_failed = 0;
 752
 753	if (dev->flags & ATA_DFLAG_DETACH) {
 754		detach = 1;
 755		rc = -ENODEV;
 756		goto fail;
 757	}
 758
 759 retry:
 760	ehc->classes[0] = ATA_DEV_UNKNOWN;
 761
 762	if (ehc->i.action & ATA_EH_RESET) {
 763		struct ata_link *tlink;
 764
 765		/* reset */
 766		rc = ata_eh_reset(link, 0, reset_ops);
 767		if (rc) {
 768			ata_link_err(link, "failed to reset PMP, giving up\n");
 769			goto fail;
 770		}
 771
 772		/* PMP is reset, SErrors cannot be trusted, scan all */
 773		ata_for_each_link(tlink, ap, EDGE) {
 774			struct ata_eh_context *ehc = &tlink->eh_context;
 775
 776			ehc->i.probe_mask |= ATA_ALL_DEVICES;
 777			ehc->i.action |= ATA_EH_RESET;
 778		}
 779	}
 780
 781	/* If revalidation is requested, revalidate and reconfigure;
 782	 * otherwise, do quick revalidation.
 783	 */
 784	if (ehc->i.action & ATA_EH_REVALIDATE)
 785		rc = sata_pmp_revalidate(dev, ehc->classes[0]);
 786	else
 787		rc = sata_pmp_revalidate_quick(dev);
 788
 789	if (rc) {
 790		tries--;
 791
 792		if (rc == -ENODEV) {
 793			ehc->i.probe_mask |= ATA_ALL_DEVICES;
 794			detach = 1;
 795			/* give it just two more chances */
 796			tries = min(tries, 2);
 797		}
 798
 799		if (tries) {
 800			/* consecutive revalidation failures? speed down */
 801			if (reval_failed)
 802				sata_down_spd_limit(link, 0);
 803			else
 804				reval_failed = 1;
 805
 806			ehc->i.action |= ATA_EH_RESET;
 807			goto retry;
 808		} else {
 809			ata_dev_err(dev,
 810				    "failed to recover PMP after %d tries, giving up\n",
 811				    ATA_EH_PMP_TRIES);
 812			goto fail;
 813		}
 814	}
 815
 816	/* okay, PMP resurrected */
 817	ehc->i.flags = 0;
 818
 819	return 0;
 820
 821 fail:
 822	sata_pmp_detach(dev);
 823	if (detach)
 824		ata_eh_detach_dev(dev);
 825	else
 826		ata_dev_disable(dev);
 827
 828	return rc;
 829}
 830
 831static int sata_pmp_eh_handle_disabled_links(struct ata_port *ap)
 832{
 833	struct ata_link *link;
 834	unsigned long flags;
 835	int rc;
 836
 837	spin_lock_irqsave(ap->lock, flags);
 838
 839	ata_for_each_link(link, ap, EDGE) {
 840		if (!(link->flags & ATA_LFLAG_DISABLED))
 841			continue;
 842
 843		spin_unlock_irqrestore(ap->lock, flags);
 844
 845		/* Some PMPs require hardreset sequence to get
 846		 * SError.N working.
 847		 */
 848		sata_link_hardreset(link, sata_deb_timing_normal,
 849				ata_deadline(jiffies, ATA_TMOUT_INTERNAL_QUICK),
 850				NULL, NULL);
 851
 852		/* unconditionally clear SError.N */
 853		rc = sata_scr_write(link, SCR_ERROR, SERR_PHYRDY_CHG);
 854		if (rc) {
 855			ata_link_err(link,
 856				     "failed to clear SError.N (errno=%d)\n",
 857				     rc);
 858			return rc;
 859		}
 860
 861		spin_lock_irqsave(ap->lock, flags);
 862	}
 863
 864	spin_unlock_irqrestore(ap->lock, flags);
 865
 866	return 0;
 867}
 868
 869static int sata_pmp_handle_link_fail(struct ata_link *link, int *link_tries)
 870{
 871	struct ata_port *ap = link->ap;
 872	unsigned long flags;
 873
 874	if (link_tries[link->pmp] && --link_tries[link->pmp])
 875		return 1;
 876
 877	/* disable this link */
 878	if (!(link->flags & ATA_LFLAG_DISABLED)) {
 879		ata_link_warn(link,
 880			"failed to recover link after %d tries, disabling\n",
 881			ATA_EH_PMP_LINK_TRIES);
 882
 883		spin_lock_irqsave(ap->lock, flags);
 884		link->flags |= ATA_LFLAG_DISABLED;
 885		spin_unlock_irqrestore(ap->lock, flags);
 886	}
 887
 888	ata_dev_disable(link->device);
 889	link->eh_context.i.action = 0;
 890
 891	return 0;
 892}
 893
 894/**
 895 *	sata_pmp_eh_recover - recover PMP-enabled port
 896 *	@ap: ATA port to recover
 897 *
 898 *	Drive EH recovery operation for PMP enabled port @ap.  This
 899 *	function recovers host and PMP ports with proper retrials and
 900 *	fallbacks.  Actual recovery operations are performed using
 901 *	ata_eh_recover() and sata_pmp_eh_recover_pmp().
 902 *
 903 *	LOCKING:
 904 *	Kernel thread context (may sleep).
 905 *
 906 *	RETURNS:
 907 *	0 on success, -errno on failure.
 908 */
 909static int sata_pmp_eh_recover(struct ata_port *ap)
 910{
 911	struct ata_port_operations *ops = ap->ops;
 912	int pmp_tries, link_tries[SATA_PMP_MAX_PORTS];
 913	struct ata_link *pmp_link = &ap->link;
 914	struct ata_device *pmp_dev = pmp_link->device;
 915	struct ata_eh_context *pmp_ehc = &pmp_link->eh_context;
 916	u32 *gscr = pmp_dev->gscr;
 917	struct ata_link *link;
 918	struct ata_device *dev;
 919	unsigned int err_mask;
 920	u32 gscr_error, sntf;
 921	int cnt, rc;
 922
 923	pmp_tries = ATA_EH_PMP_TRIES;
 924	ata_for_each_link(link, ap, EDGE)
 925		link_tries[link->pmp] = ATA_EH_PMP_LINK_TRIES;
 926
 927 retry:
 928	/* PMP attached? */
 929	if (!sata_pmp_attached(ap)) {
 930		rc = ata_eh_recover(ap, &ops->reset, NULL);
 931		if (rc) {
 932			ata_for_each_dev(dev, &ap->link, ALL)
 933				ata_dev_disable(dev);
 934			return rc;
 935		}
 936
 937		if (pmp_dev->class != ATA_DEV_PMP)
 938			return 0;
 939
 940		/* new PMP online */
 941		ata_for_each_link(link, ap, EDGE)
 942			link_tries[link->pmp] = ATA_EH_PMP_LINK_TRIES;
 943
 944		/* fall through */
 945	}
 946
 947	/* recover pmp */
 948	rc = sata_pmp_eh_recover_pmp(ap, &ops->reset);
 949	if (rc)
 950		goto pmp_fail;
 951
 952	/* PHY event notification can disturb reset and other recovery
 953	 * operations.  Turn it off.
 954	 */
 955	if (gscr[SATA_PMP_GSCR_FEAT_EN] & SATA_PMP_FEAT_NOTIFY) {
 956		gscr[SATA_PMP_GSCR_FEAT_EN] &= ~SATA_PMP_FEAT_NOTIFY;
 957
 958		err_mask = sata_pmp_write(pmp_link, SATA_PMP_GSCR_FEAT_EN,
 959					  gscr[SATA_PMP_GSCR_FEAT_EN]);
 960		if (err_mask) {
 961			ata_link_warn(pmp_link,
 962				"failed to disable NOTIFY (err_mask=0x%x)\n",
 963				err_mask);
 964			goto pmp_fail;
 965		}
 966	}
 967
 968	/* handle disabled links */
 969	rc = sata_pmp_eh_handle_disabled_links(ap);
 970	if (rc)
 971		goto pmp_fail;
 972
 973	/* recover links */
 974	rc = ata_eh_recover(ap, &ops->pmp_reset, &link);
 975	if (rc)
 976		goto link_fail;
 977
 978	/* clear SNotification */
 979	rc = sata_scr_read(&ap->link, SCR_NOTIFICATION, &sntf);
 980	if (rc == 0)
 981		sata_scr_write(&ap->link, SCR_NOTIFICATION, sntf);
 982
 983	/*
 984	 * If LPM is active on any fan-out port, hotplug wouldn't
 985	 * work.  Return w/ PHY event notification disabled.
 986	 */
 987	ata_for_each_link(link, ap, EDGE)
 988		if (link->lpm_policy > ATA_LPM_MAX_POWER)
 989			return 0;
 990
 991	/*
 992	 * Connection status might have changed while resetting other
 993	 * links, enable notification and check SATA_PMP_GSCR_ERROR
 994	 * before returning.
 995	 */
 996
 997	/* enable notification */
 998	if (pmp_dev->flags & ATA_DFLAG_AN) {
 999		gscr[SATA_PMP_GSCR_FEAT_EN] |= SATA_PMP_FEAT_NOTIFY;
1000
1001		err_mask = sata_pmp_write(pmp_link, SATA_PMP_GSCR_FEAT_EN,
1002					  gscr[SATA_PMP_GSCR_FEAT_EN]);
1003		if (err_mask) {
1004			ata_dev_err(pmp_dev,
1005				    "failed to write PMP_FEAT_EN (Emask=0x%x)\n",
1006				    err_mask);
1007			rc = -EIO;
1008			goto pmp_fail;
1009		}
1010	}
1011
1012	/* check GSCR_ERROR */
1013	err_mask = sata_pmp_read(pmp_link, SATA_PMP_GSCR_ERROR, &gscr_error);
1014	if (err_mask) {
1015		ata_dev_err(pmp_dev,
1016			    "failed to read PMP_GSCR_ERROR (Emask=0x%x)\n",
1017			    err_mask);
1018		rc = -EIO;
1019		goto pmp_fail;
1020	}
1021
1022	cnt = 0;
1023	ata_for_each_link(link, ap, EDGE) {
1024		if (!(gscr_error & (1 << link->pmp)))
1025			continue;
1026
1027		if (sata_pmp_handle_link_fail(link, link_tries)) {
1028			ata_ehi_hotplugged(&link->eh_context.i);
1029			cnt++;
1030		} else {
1031			ata_link_warn(link,
1032				"PHY status changed but maxed out on retries, giving up\n");
1033			ata_link_warn(link,
1034				"Manually issue scan to resume this link\n");
1035		}
1036	}
1037
1038	if (cnt) {
1039		ata_port_info(ap,
1040			"PMP SError.N set for some ports, repeating recovery\n");
1041		goto retry;
1042	}
1043
1044	return 0;
1045
1046 link_fail:
1047	if (sata_pmp_handle_link_fail(link, link_tries)) {
1048		pmp_ehc->i.action |= ATA_EH_RESET;
1049		goto retry;
1050	}
1051
1052	/* fall through */
1053 pmp_fail:
1054	/* Control always ends up here after detaching PMP.  Shut up
1055	 * and return if we're unloading.
1056	 */
1057	if (ap->pflags & ATA_PFLAG_UNLOADING)
1058		return rc;
1059
1060	if (!sata_pmp_attached(ap))
1061		goto retry;
1062
1063	if (--pmp_tries) {
1064		pmp_ehc->i.action |= ATA_EH_RESET;
1065		goto retry;
1066	}
1067
1068	ata_port_err(ap, "failed to recover PMP after %d tries, giving up\n",
1069		     ATA_EH_PMP_TRIES);
1070	sata_pmp_detach(pmp_dev);
1071	ata_dev_disable(pmp_dev);
1072
1073	return rc;
1074}
1075
1076/**
1077 *	sata_pmp_error_handler - do standard error handling for PMP-enabled host
1078 *	@ap: host port to handle error for
1079 *
1080 *	Perform standard error handling sequence for PMP-enabled host
1081 *	@ap.
1082 *
1083 *	LOCKING:
1084 *	Kernel thread context (may sleep).
1085 */
1086void sata_pmp_error_handler(struct ata_port *ap)
1087{
1088	ata_eh_autopsy(ap);
1089	ata_eh_report(ap);
1090	sata_pmp_eh_recover(ap);
1091	ata_eh_finish(ap);
1092}
1093
1094EXPORT_SYMBOL_GPL(sata_pmp_port_ops);
1095EXPORT_SYMBOL_GPL(sata_pmp_qc_defer_cmd_switch);
1096EXPORT_SYMBOL_GPL(sata_pmp_error_handler);