linux/drivers/ata/libata-pmp.c
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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, 3726 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) {
 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 Sil3726 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 Sil3726 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) {
 387                /* sil3726 quirks */
 388                ata_for_each_link(link, ap, EDGE) {
 389                        /* link reports offline after LPM */
 390                        link->flags |= ATA_LFLAG_NO_LPM;
 391
 392                        /* Class code report is unreliable. */
 393                        if (link->pmp < 5)
 394                                link->flags |= ATA_LFLAG_ASSUME_ATA;
 395
 396                        /* port 5 is for SEMB device and it doesn't like SRST */
 397                        if (link->pmp == 5)
 398                                link->flags |= ATA_LFLAG_NO_SRST |
 399                                               ATA_LFLAG_ASSUME_SEMB;
 400                }
 401        } else if (vendor == 0x1095 && devid == 0x4723) {
 402                /* sil4723 quirks */
 403                ata_for_each_link(link, ap, EDGE) {
 404                        /* link reports offline after LPM */
 405                        link->flags |= ATA_LFLAG_NO_LPM;
 406
 407                        /* class code report is unreliable */
 408                        if (link->pmp < 2)
 409                                link->flags |= ATA_LFLAG_ASSUME_ATA;
 410
 411                        /* the config device at port 2 locks up on SRST */
 412                        if (link->pmp == 2)
 413                                link->flags |= ATA_LFLAG_NO_SRST |
 414                                               ATA_LFLAG_ASSUME_ATA;
 415                }
 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) {
 450                /* chip found in Thermaltake BlackX Duet, jmicron JMB350? */
 451                ata_for_each_link(link, ap, EDGE) {
 452                        /* SRST breaks detection and disks get misclassified
 453                         * LPM disabled to avoid potential problems
 454                         */
 455                        link->flags |= ATA_LFLAG_NO_LPM |
 456                                       ATA_LFLAG_NO_SRST |
 457                                       ATA_LFLAG_ASSUME_ATA;
 458                }
 459        }
 460}
 461
 462/**
 463 *      sata_pmp_attach - attach a SATA PMP device
 464 *      @dev: SATA PMP device to attach
 465 *
 466 *      Configure and attach SATA PMP device @dev.  This function is
 467 *      also responsible for allocating and initializing PMP links.
 468 *
 469 *      LOCKING:
 470 *      Kernel thread context (may sleep).
 471 *
 472 *      RETURNS:
 473 *      0 on success, -errno on failure.
 474 */
 475int sata_pmp_attach(struct ata_device *dev)
 476{
 477        struct ata_link *link = dev->link;
 478        struct ata_port *ap = link->ap;
 479        unsigned long flags;
 480        struct ata_link *tlink;
 481        int rc;
 482
 483        /* is it hanging off the right place? */
 484        if (!sata_pmp_supported(ap)) {
 485                ata_dev_err(dev, "host does not support Port Multiplier\n");
 486                return -EINVAL;
 487        }
 488
 489        if (!ata_is_host_link(link)) {
 490                ata_dev_err(dev, "Port Multipliers cannot be nested\n");
 491                return -EINVAL;
 492        }
 493
 494        if (dev->devno) {
 495                ata_dev_err(dev, "Port Multiplier must be the first device\n");
 496                return -EINVAL;
 497        }
 498
 499        WARN_ON(link->pmp != 0);
 500        link->pmp = SATA_PMP_CTRL_PORT;
 501
 502        /* read GSCR block */
 503        rc = sata_pmp_read_gscr(dev, dev->gscr);
 504        if (rc)
 505                goto fail;
 506
 507        /* config PMP */
 508        rc = sata_pmp_configure(dev, 1);
 509        if (rc)
 510                goto fail;
 511
 512        rc = sata_pmp_init_links(ap, sata_pmp_gscr_ports(dev->gscr));
 513        if (rc) {
 514                ata_dev_info(dev, "failed to initialize PMP links\n");
 515                goto fail;
 516        }
 517
 518        /* attach it */
 519        spin_lock_irqsave(ap->lock, flags);
 520        WARN_ON(ap->nr_pmp_links);
 521        ap->nr_pmp_links = sata_pmp_gscr_ports(dev->gscr);
 522        spin_unlock_irqrestore(ap->lock, flags);
 523
 524        sata_pmp_quirks(ap);
 525
 526        if (ap->ops->pmp_attach)
 527                ap->ops->pmp_attach(ap);
 528
 529        ata_for_each_link(tlink, ap, EDGE)
 530                sata_link_init_spd(tlink);
 531
 532        return 0;
 533
 534 fail:
 535        link->pmp = 0;
 536        return rc;
 537}
 538
 539/**
 540 *      sata_pmp_detach - detach a SATA PMP device
 541 *      @dev: SATA PMP device to detach
 542 *
 543 *      Detach SATA PMP device @dev.  This function is also
 544 *      responsible for deconfiguring PMP links.
 545 *
 546 *      LOCKING:
 547 *      Kernel thread context (may sleep).
 548 */
 549static void sata_pmp_detach(struct ata_device *dev)
 550{
 551        struct ata_link *link = dev->link;
 552        struct ata_port *ap = link->ap;
 553        struct ata_link *tlink;
 554        unsigned long flags;
 555
 556        ata_dev_info(dev, "Port Multiplier detaching\n");
 557
 558        WARN_ON(!ata_is_host_link(link) || dev->devno ||
 559                link->pmp != SATA_PMP_CTRL_PORT);
 560
 561        if (ap->ops->pmp_detach)
 562                ap->ops->pmp_detach(ap);
 563
 564        ata_for_each_link(tlink, ap, EDGE)
 565                ata_eh_detach_dev(tlink->device);
 566
 567        spin_lock_irqsave(ap->lock, flags);
 568        ap->nr_pmp_links = 0;
 569        link->pmp = 0;
 570        spin_unlock_irqrestore(ap->lock, flags);
 571}
 572
 573/**
 574 *      sata_pmp_same_pmp - does new GSCR matches the configured PMP?
 575 *      @dev: PMP device to compare against
 576 *      @new_gscr: GSCR block of the new device
 577 *
 578 *      Compare @new_gscr against @dev and determine whether @dev is
 579 *      the PMP described by @new_gscr.
 580 *
 581 *      LOCKING:
 582 *      None.
 583 *
 584 *      RETURNS:
 585 *      1 if @dev matches @new_gscr, 0 otherwise.
 586 */
 587static int sata_pmp_same_pmp(struct ata_device *dev, const u32 *new_gscr)
 588{
 589        const u32 *old_gscr = dev->gscr;
 590        u16 old_vendor, new_vendor, old_devid, new_devid;
 591        int old_nr_ports, new_nr_ports;
 592
 593        old_vendor = sata_pmp_gscr_vendor(old_gscr);
 594        new_vendor = sata_pmp_gscr_vendor(new_gscr);
 595        old_devid = sata_pmp_gscr_devid(old_gscr);
 596        new_devid = sata_pmp_gscr_devid(new_gscr);
 597        old_nr_ports = sata_pmp_gscr_ports(old_gscr);
 598        new_nr_ports = sata_pmp_gscr_ports(new_gscr);
 599
 600        if (old_vendor != new_vendor) {
 601                ata_dev_info(dev,
 602                             "Port Multiplier vendor mismatch '0x%x' != '0x%x'\n",
 603                             old_vendor, new_vendor);
 604                return 0;
 605        }
 606
 607        if (old_devid != new_devid) {
 608                ata_dev_info(dev,
 609                             "Port Multiplier device ID mismatch '0x%x' != '0x%x'\n",
 610                             old_devid, new_devid);
 611                return 0;
 612        }
 613
 614        if (old_nr_ports != new_nr_ports) {
 615                ata_dev_info(dev,
 616                             "Port Multiplier nr_ports mismatch '0x%x' != '0x%x'\n",
 617                             old_nr_ports, new_nr_ports);
 618                return 0;
 619        }
 620
 621        return 1;
 622}
 623
 624/**
 625 *      sata_pmp_revalidate - revalidate SATA PMP
 626 *      @dev: PMP device to revalidate
 627 *      @new_class: new class code
 628 *
 629 *      Re-read GSCR block and make sure @dev is still attached to the
 630 *      port and properly configured.
 631 *
 632 *      LOCKING:
 633 *      Kernel thread context (may sleep).
 634 *
 635 *      RETURNS:
 636 *      0 on success, -errno otherwise.
 637 */
 638static int sata_pmp_revalidate(struct ata_device *dev, unsigned int new_class)
 639{
 640        struct ata_link *link = dev->link;
 641        struct ata_port *ap = link->ap;
 642        u32 *gscr = (void *)ap->sector_buf;
 643        int rc;
 644
 645        DPRINTK("ENTER\n");
 646
 647        ata_eh_about_to_do(link, NULL, ATA_EH_REVALIDATE);
 648
 649        if (!ata_dev_enabled(dev)) {
 650                rc = -ENODEV;
 651                goto fail;
 652        }
 653
 654        /* wrong class? */
 655        if (ata_class_enabled(new_class) && new_class != ATA_DEV_PMP) {
 656                rc = -ENODEV;
 657                goto fail;
 658        }
 659
 660        /* read GSCR */
 661        rc = sata_pmp_read_gscr(dev, gscr);
 662        if (rc)
 663                goto fail;
 664
 665        /* is the pmp still there? */
 666        if (!sata_pmp_same_pmp(dev, gscr)) {
 667                rc = -ENODEV;
 668                goto fail;
 669        }
 670
 671        memcpy(dev->gscr, gscr, sizeof(gscr[0]) * SATA_PMP_GSCR_DWORDS);
 672
 673        rc = sata_pmp_configure(dev, 0);
 674        if (rc)
 675                goto fail;
 676
 677        ata_eh_done(link, NULL, ATA_EH_REVALIDATE);
 678
 679        DPRINTK("EXIT, rc=0\n");
 680        return 0;
 681
 682 fail:
 683        ata_dev_err(dev, "PMP revalidation failed (errno=%d)\n", rc);
 684        DPRINTK("EXIT, rc=%d\n", rc);
 685        return rc;
 686}
 687
 688/**
 689 *      sata_pmp_revalidate_quick - revalidate SATA PMP quickly
 690 *      @dev: PMP device to revalidate
 691 *
 692 *      Make sure the attached PMP is accessible.
 693 *
 694 *      LOCKING:
 695 *      Kernel thread context (may sleep).
 696 *
 697 *      RETURNS:
 698 *      0 on success, -errno otherwise.
 699 */
 700static int sata_pmp_revalidate_quick(struct ata_device *dev)
 701{
 702        unsigned int err_mask;
 703        u32 prod_id;
 704
 705        err_mask = sata_pmp_read(dev->link, SATA_PMP_GSCR_PROD_ID, &prod_id);
 706        if (err_mask) {
 707                ata_dev_err(dev,
 708                            "failed to read PMP product ID (Emask=0x%x)\n",
 709                            err_mask);
 710                return -EIO;
 711        }
 712
 713        if (prod_id != dev->gscr[SATA_PMP_GSCR_PROD_ID]) {
 714                ata_dev_err(dev, "PMP product ID mismatch\n");
 715                /* something weird is going on, request full PMP recovery */
 716                return -EIO;
 717        }
 718
 719        return 0;
 720}
 721
 722/**
 723 *      sata_pmp_eh_recover_pmp - recover PMP
 724 *      @ap: ATA port PMP is attached to
 725 *      @prereset: prereset method (can be NULL)
 726 *      @softreset: softreset method
 727 *      @hardreset: hardreset method
 728 *      @postreset: postreset method (can be NULL)
 729 *
 730 *      Recover PMP attached to @ap.  Recovery procedure is somewhat
 731 *      similar to that of ata_eh_recover() except that reset should
 732 *      always be performed in hard->soft sequence and recovery
 733 *      failure results in PMP detachment.
 734 *
 735 *      LOCKING:
 736 *      Kernel thread context (may sleep).
 737 *
 738 *      RETURNS:
 739 *      0 on success, -errno on failure.
 740 */
 741static int sata_pmp_eh_recover_pmp(struct ata_port *ap,
 742                ata_prereset_fn_t prereset, ata_reset_fn_t softreset,
 743                ata_reset_fn_t hardreset, ata_postreset_fn_t postreset)
 744{
 745        struct ata_link *link = &ap->link;
 746        struct ata_eh_context *ehc = &link->eh_context;
 747        struct ata_device *dev = link->device;
 748        int tries = ATA_EH_PMP_TRIES;
 749        int detach = 0, rc = 0;
 750        int reval_failed = 0;
 751
 752        DPRINTK("ENTER\n");
 753
 754        if (dev->flags & ATA_DFLAG_DETACH) {
 755                detach = 1;
 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, prereset, softreset, hardreset,
 767                                  postreset);
 768                if (rc) {
 769                        ata_link_err(link, "failed to reset PMP, giving up\n");
 770                        goto fail;
 771                }
 772
 773                /* PMP is reset, SErrors cannot be trusted, scan all */
 774                ata_for_each_link(tlink, ap, EDGE) {
 775                        struct ata_eh_context *ehc = &tlink->eh_context;
 776
 777                        ehc->i.probe_mask |= ATA_ALL_DEVICES;
 778                        ehc->i.action |= ATA_EH_RESET;
 779                }
 780        }
 781
 782        /* If revalidation is requested, revalidate and reconfigure;
 783         * otherwise, do quick revalidation.
 784         */
 785        if (ehc->i.action & ATA_EH_REVALIDATE)
 786                rc = sata_pmp_revalidate(dev, ehc->classes[0]);
 787        else
 788                rc = sata_pmp_revalidate_quick(dev);
 789
 790        if (rc) {
 791                tries--;
 792
 793                if (rc == -ENODEV) {
 794                        ehc->i.probe_mask |= ATA_ALL_DEVICES;
 795                        detach = 1;
 796                        /* give it just two more chances */
 797                        tries = min(tries, 2);
 798                }
 799
 800                if (tries) {
 801                        /* consecutive revalidation failures? speed down */
 802                        if (reval_failed)
 803                                sata_down_spd_limit(link, 0);
 804                        else
 805                                reval_failed = 1;
 806
 807                        ehc->i.action |= ATA_EH_RESET;
 808                        goto retry;
 809                } else {
 810                        ata_dev_err(dev,
 811                                    "failed to recover PMP after %d tries, giving up\n",
 812                                    ATA_EH_PMP_TRIES);
 813                        goto fail;
 814                }
 815        }
 816
 817        /* okay, PMP resurrected */
 818        ehc->i.flags = 0;
 819
 820        DPRINTK("EXIT, rc=0\n");
 821        return 0;
 822
 823 fail:
 824        sata_pmp_detach(dev);
 825        if (detach)
 826                ata_eh_detach_dev(dev);
 827        else
 828                ata_dev_disable(dev);
 829
 830        DPRINTK("EXIT, rc=%d\n", rc);
 831        return rc;
 832}
 833
 834static int sata_pmp_eh_handle_disabled_links(struct ata_port *ap)
 835{
 836        struct ata_link *link;
 837        unsigned long flags;
 838        int rc;
 839
 840        spin_lock_irqsave(ap->lock, flags);
 841
 842        ata_for_each_link(link, ap, EDGE) {
 843                if (!(link->flags & ATA_LFLAG_DISABLED))
 844                        continue;
 845
 846                spin_unlock_irqrestore(ap->lock, flags);
 847
 848                /* Some PMPs require hardreset sequence to get
 849                 * SError.N working.
 850                 */
 851                sata_link_hardreset(link, sata_deb_timing_normal,
 852                                ata_deadline(jiffies, ATA_TMOUT_INTERNAL_QUICK),
 853                                NULL, NULL);
 854
 855                /* unconditionally clear SError.N */
 856                rc = sata_scr_write(link, SCR_ERROR, SERR_PHYRDY_CHG);
 857                if (rc) {
 858                        ata_link_err(link,
 859                                     "failed to clear SError.N (errno=%d)\n",
 860                                     rc);
 861                        return rc;
 862                }
 863
 864                spin_lock_irqsave(ap->lock, flags);
 865        }
 866
 867        spin_unlock_irqrestore(ap->lock, flags);
 868
 869        return 0;
 870}
 871
 872static int sata_pmp_handle_link_fail(struct ata_link *link, int *link_tries)
 873{
 874        struct ata_port *ap = link->ap;
 875        unsigned long flags;
 876
 877        if (link_tries[link->pmp] && --link_tries[link->pmp])
 878                return 1;
 879
 880        /* disable this link */
 881        if (!(link->flags & ATA_LFLAG_DISABLED)) {
 882                ata_link_warn(link,
 883                        "failed to recover link after %d tries, disabling\n",
 884                        ATA_EH_PMP_LINK_TRIES);
 885
 886                spin_lock_irqsave(ap->lock, flags);
 887                link->flags |= ATA_LFLAG_DISABLED;
 888                spin_unlock_irqrestore(ap->lock, flags);
 889        }
 890
 891        ata_dev_disable(link->device);
 892        link->eh_context.i.action = 0;
 893
 894        return 0;
 895}
 896
 897/**
 898 *      sata_pmp_eh_recover - recover PMP-enabled port
 899 *      @ap: ATA port to recover
 900 *
 901 *      Drive EH recovery operation for PMP enabled port @ap.  This
 902 *      function recovers host and PMP ports with proper retrials and
 903 *      fallbacks.  Actual recovery operations are performed using
 904 *      ata_eh_recover() and sata_pmp_eh_recover_pmp().
 905 *
 906 *      LOCKING:
 907 *      Kernel thread context (may sleep).
 908 *
 909 *      RETURNS:
 910 *      0 on success, -errno on failure.
 911 */
 912static int sata_pmp_eh_recover(struct ata_port *ap)
 913{
 914        struct ata_port_operations *ops = ap->ops;
 915        int pmp_tries, link_tries[SATA_PMP_MAX_PORTS];
 916        struct ata_link *pmp_link = &ap->link;
 917        struct ata_device *pmp_dev = pmp_link->device;
 918        struct ata_eh_context *pmp_ehc = &pmp_link->eh_context;
 919        u32 *gscr = pmp_dev->gscr;
 920        struct ata_link *link;
 921        struct ata_device *dev;
 922        unsigned int err_mask;
 923        u32 gscr_error, sntf;
 924        int cnt, rc;
 925
 926        pmp_tries = ATA_EH_PMP_TRIES;
 927        ata_for_each_link(link, ap, EDGE)
 928                link_tries[link->pmp] = ATA_EH_PMP_LINK_TRIES;
 929
 930 retry:
 931        /* PMP attached? */
 932        if (!sata_pmp_attached(ap)) {
 933                rc = ata_eh_recover(ap, ops->prereset, ops->softreset,
 934                                    ops->hardreset, ops->postreset, NULL);
 935                if (rc) {
 936                        ata_for_each_dev(dev, &ap->link, ALL)
 937                                ata_dev_disable(dev);
 938                        return rc;
 939                }
 940
 941                if (pmp_dev->class != ATA_DEV_PMP)
 942                        return 0;
 943
 944                /* new PMP online */
 945                ata_for_each_link(link, ap, EDGE)
 946                        link_tries[link->pmp] = ATA_EH_PMP_LINK_TRIES;
 947
 948                /* fall through */
 949        }
 950
 951        /* recover pmp */
 952        rc = sata_pmp_eh_recover_pmp(ap, ops->prereset, ops->softreset,
 953                                     ops->hardreset, ops->postreset);
 954        if (rc)
 955                goto pmp_fail;
 956
 957        /* PHY event notification can disturb reset and other recovery
 958         * operations.  Turn it off.
 959         */
 960        if (gscr[SATA_PMP_GSCR_FEAT_EN] & SATA_PMP_FEAT_NOTIFY) {
 961                gscr[SATA_PMP_GSCR_FEAT_EN] &= ~SATA_PMP_FEAT_NOTIFY;
 962
 963                err_mask = sata_pmp_write(pmp_link, SATA_PMP_GSCR_FEAT_EN,
 964                                          gscr[SATA_PMP_GSCR_FEAT_EN]);
 965                if (err_mask) {
 966                        ata_link_warn(pmp_link,
 967                                "failed to disable NOTIFY (err_mask=0x%x)\n",
 968                                err_mask);
 969                        goto pmp_fail;
 970                }
 971        }
 972
 973        /* handle disabled links */
 974        rc = sata_pmp_eh_handle_disabled_links(ap);
 975        if (rc)
 976                goto pmp_fail;
 977
 978        /* recover links */
 979        rc = ata_eh_recover(ap, ops->pmp_prereset, ops->pmp_softreset,
 980                            ops->pmp_hardreset, ops->pmp_postreset, &link);
 981        if (rc)
 982                goto link_fail;
 983
 984        /* clear SNotification */
 985        rc = sata_scr_read(&ap->link, SCR_NOTIFICATION, &sntf);
 986        if (rc == 0)
 987                sata_scr_write(&ap->link, SCR_NOTIFICATION, sntf);
 988
 989        /*
 990         * If LPM is active on any fan-out port, hotplug wouldn't
 991         * work.  Return w/ PHY event notification disabled.
 992         */
 993        ata_for_each_link(link, ap, EDGE)
 994                if (link->lpm_policy > ATA_LPM_MAX_POWER)
 995                        return 0;
 996
 997        /*
 998         * Connection status might have changed while resetting other
 999         * links, enable notification and check SATA_PMP_GSCR_ERROR
1000         * before returning.
1001         */
1002
1003        /* enable notification */
1004        if (pmp_dev->flags & ATA_DFLAG_AN) {
1005                gscr[SATA_PMP_GSCR_FEAT_EN] |= SATA_PMP_FEAT_NOTIFY;
1006
1007                err_mask = sata_pmp_write(pmp_link, SATA_PMP_GSCR_FEAT_EN,
1008                                          gscr[SATA_PMP_GSCR_FEAT_EN]);
1009                if (err_mask) {
1010                        ata_dev_err(pmp_dev,
1011                                    "failed to write PMP_FEAT_EN (Emask=0x%x)\n",
1012                                    err_mask);
1013                        rc = -EIO;
1014                        goto pmp_fail;
1015                }
1016        }
1017
1018        /* check GSCR_ERROR */
1019        err_mask = sata_pmp_read(pmp_link, SATA_PMP_GSCR_ERROR, &gscr_error);
1020        if (err_mask) {
1021                ata_dev_err(pmp_dev,
1022                            "failed to read PMP_GSCR_ERROR (Emask=0x%x)\n",
1023                            err_mask);
1024                rc = -EIO;
1025                goto pmp_fail;
1026        }
1027
1028        cnt = 0;
1029        ata_for_each_link(link, ap, EDGE) {
1030                if (!(gscr_error & (1 << link->pmp)))
1031                        continue;
1032
1033                if (sata_pmp_handle_link_fail(link, link_tries)) {
1034                        ata_ehi_hotplugged(&link->eh_context.i);
1035                        cnt++;
1036                } else {
1037                        ata_link_warn(link,
1038                                "PHY status changed but maxed out on retries, giving up\n");
1039                        ata_link_warn(link,
1040                                "Manually issue scan to resume this link\n");
1041                }
1042        }
1043
1044        if (cnt) {
1045                ata_port_info(ap,
1046                        "PMP SError.N set for some ports, repeating recovery\n");
1047                goto retry;
1048        }
1049
1050        return 0;
1051
1052 link_fail:
1053        if (sata_pmp_handle_link_fail(link, link_tries)) {
1054                pmp_ehc->i.action |= ATA_EH_RESET;
1055                goto retry;
1056        }
1057
1058        /* fall through */
1059 pmp_fail:
1060        /* Control always ends up here after detaching PMP.  Shut up
1061         * and return if we're unloading.
1062         */
1063        if (ap->pflags & ATA_PFLAG_UNLOADING)
1064                return rc;
1065
1066        if (!sata_pmp_attached(ap))
1067                goto retry;
1068
1069        if (--pmp_tries) {
1070                pmp_ehc->i.action |= ATA_EH_RESET;
1071                goto retry;
1072        }
1073
1074        ata_port_err(ap, "failed to recover PMP after %d tries, giving up\n",
1075                     ATA_EH_PMP_TRIES);
1076        sata_pmp_detach(pmp_dev);
1077        ata_dev_disable(pmp_dev);
1078
1079        return rc;
1080}
1081
1082/**
1083 *      sata_pmp_error_handler - do standard error handling for PMP-enabled host
1084 *      @ap: host port to handle error for
1085 *
1086 *      Perform standard error handling sequence for PMP-enabled host
1087 *      @ap.
1088 *
1089 *      LOCKING:
1090 *      Kernel thread context (may sleep).
1091 */
1092void sata_pmp_error_handler(struct ata_port *ap)
1093{
1094        ata_eh_autopsy(ap);
1095        ata_eh_report(ap);
1096        sata_pmp_eh_recover(ap);
1097        ata_eh_finish(ap);
1098}
1099
1100EXPORT_SYMBOL_GPL(sata_pmp_port_ops);
1101EXPORT_SYMBOL_GPL(sata_pmp_qc_defer_cmd_switch);
1102EXPORT_SYMBOL_GPL(sata_pmp_error_handler);
1103
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