drivers/ata/libata-pmp.c

   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
  17 const 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  */
  39 static 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  */
  76 static 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  */
 110 int 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  */
 142 int 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  */
 173 int 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  */
 204 int 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  */
 224 static 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
 244 static 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
 259 static int sata_pmp_configure(struct ata_device *dev, int print_info)
 260 {
 261         struct ata_port *ap = dev->link->ap;
 262         u32 *gscr = dev->gscr;
 263         u16 vendor = sata_pmp_gscr_vendor(gscr);
 264         u16 devid = sata_pmp_gscr_devid(gscr);
 265         unsigned int err_mask = 0;
 266         const char *reason;
 267         int nr_ports, rc;
 268
 269         nr_ports = sata_pmp_gscr_ports(gscr);
 270
 271         if (nr_ports <= 0 || nr_ports > SATA_PMP_MAX_PORTS) {
 272                 rc = -EINVAL;
 273                 reason = "invalid nr_ports";
 274                 goto fail;
 275         }
 276
 277         if ((ap->flags & ATA_FLAG_AN) &&
 278             (gscr[SATA_PMP_GSCR_FEAT] & SATA_PMP_FEAT_NOTIFY))
 279                 dev->flags |= ATA_DFLAG_AN;
 280
 281         /* monitor SERR_PHYRDY_CHG on fan-out ports */
 282         err_mask = sata_pmp_write(dev->link, SATA_PMP_GSCR_ERROR_EN,
 283                                   SERR_PHYRDY_CHG);
 284         if (err_mask) {
 285                 rc = -EIO;
 286                 reason = "failed to write GSCR_ERROR_EN";
 287                 goto fail;
 288         }
 289
 290         /* Disable sending Early R_OK.
 291          * With "cached read" HDD testing and multiple ports busy on a SATA
 292          * host controller, 3x26 PMP will very rarely drop a deferred
 293          * R_OK that was intended for the host. Symptom will be all
 294          * 5 drives under test will timeout, get reset, and recover.
 295          */
 296         if (vendor == 0x1095 && (devid == 0x3726 || devid == 0x3826)) {
 297                 u32 reg;
 298
 299                 err_mask = sata_pmp_read(&ap->link, PMP_GSCR_SII_POL, &reg);
 300                 if (err_mask) {
 301                         rc = -EIO;
 302                         reason = "failed to read Sil3x26 Private Register";
 303                         goto fail;
 304                 }
 305                 reg &= ~0x1;
 306                 err_mask = sata_pmp_write(&ap->link, PMP_GSCR_SII_POL, reg);
 307                 if (err_mask) {
 308                         rc = -EIO;
 309                         reason = "failed to write Sil3x26 Private Register";
 310                         goto fail;
 311                 }
 312         }
 313
 314         if (print_info) {
 315                 ata_dev_info(dev, "Port Multiplier %s, "
 316                              "0x%04x:0x%04x r%d, %d ports, feat 0x%x/0x%x\n",
 317                              sata_pmp_spec_rev_str(gscr), vendor, devid,
 318                              sata_pmp_gscr_rev(gscr),
 319                              nr_ports, gscr[SATA_PMP_GSCR_FEAT_EN],
 320                              gscr[SATA_PMP_GSCR_FEAT]);
 321
 322                 if (!(dev->flags & ATA_DFLAG_AN))
 323                         ata_dev_info(dev,
 324                                 "Asynchronous notification not supported, "
 325                                 "hotplug won't work on fan-out ports. Use warm-plug instead.\n");
 326         }
 327
 328         return 0;
 329
 330  fail:
 331         ata_dev_err(dev,
 332                     "failed to configure Port Multiplier (%s, Emask=0x%x)\n",
 333                     reason, err_mask);
 334         return rc;
 335 }
 336
 337 static 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
 379 static void sata_pmp_quirks(struct ata_port *ap)
 380 {
 381         u32 *gscr = ap->link.device->gscr;
 382         u16 vendor = sata_pmp_gscr_vendor(gscr);
 383         u16 devid = sata_pmp_gscr_devid(gscr);
 384         struct ata_link *link;
 385
 386         if (vendor == 0x1095 && (devid == 0x3726 || devid == 0x3826)) {
 387                 /* sil3x26 quirks */
 388                 ata_for_each_link(link, ap, EDGE) {
 389                         /* link reports offline after LPM */
 390                         link->flags |= ATA_LFLAG_NO_LPM;
 391
 392                         /*
 393                          * Class code report is unreliable and SRST times
 394                          * out under certain configurations.
 395                          */
 396                         if (link->pmp < 5)
 397                                 link->flags |= ATA_LFLAG_NO_SRST |
 398                                                ATA_LFLAG_ASSUME_ATA;
 399
 400                         /* port 5 is for SEMB device and it doesn't like SRST */
 401                         if (link->pmp == 5)
 402                                 link->flags |= ATA_LFLAG_NO_SRST |
 403                                                ATA_LFLAG_ASSUME_SEMB;
 404                 }
 405         } else if (vendor == 0x1095 && devid == 0x4723) {
 406                 /*
 407                  * sil4723 quirks
 408                  *
 409                  * Link reports offline after LPM.  Class code report is
 410                  * unreliable.  SIMG PMPs never got SRST reliable and the
 411                  * config device at port 2 locks up on SRST.
 412                  */
 413                 ata_for_each_link(link, ap, EDGE)
 414                         link->flags |= ATA_LFLAG_NO_LPM |
 415                                        ATA_LFLAG_NO_SRST |
 416                                        ATA_LFLAG_ASSUME_ATA;
 417         } else if (vendor == 0x1095 && devid == 0x4726) {
 418                 /* sil4726 quirks */
 419                 ata_for_each_link(link, ap, EDGE) {
 420                         /* link reports offline after LPM */
 421                         link->flags |= ATA_LFLAG_NO_LPM;
 422
 423                         /* Class code report is unreliable and SRST
 424                          * times out under certain configurations.
 425                          * Config device can be at port 0 or 5 and
 426                          * locks up on SRST.
 427                          */
 428                         if (link->pmp <= 5)
 429                                 link->flags |= ATA_LFLAG_NO_SRST |
 430                                                ATA_LFLAG_ASSUME_ATA;
 431
 432                         /* Port 6 is for SEMB device which doesn't
 433                          * like SRST either.
 434                          */
 435                         if (link->pmp == 6)
 436                                 link->flags |= ATA_LFLAG_NO_SRST |
 437                                                ATA_LFLAG_ASSUME_SEMB;
 438                 }
 439         } else if (vendor == 0x1095 && (devid == 0x5723 || devid == 0x5733 ||
 440                                         devid == 0x5734 || devid == 0x5744)) {
 441                 /* sil5723/5744 quirks */
 442
 443                 /* sil5723/5744 has either two or three downstream
 444                  * ports depending on operation mode.  The last port
 445                  * is empty if any actual IO device is available or
 446                  * occupied by a pseudo configuration device
 447                  * otherwise.  Don't try hard to recover it.
 448                  */
 449                 ap->pmp_link[ap->nr_pmp_links - 1].flags |= ATA_LFLAG_NO_RETRY;
 450         } else if (vendor == 0x197b && devid == 0x2352) {
 451                 /* chip found in Thermaltake BlackX Duet, jmicron JMB350? */
 452                 ata_for_each_link(link, ap, EDGE) {
 453                         /* SRST breaks detection and disks get misclassified
 454                          * LPM disabled to avoid potential problems
 455                          */
 456                         link->flags |= ATA_LFLAG_NO_LPM |
 457                                        ATA_LFLAG_NO_SRST |
 458                                        ATA_LFLAG_ASSUME_ATA;
 459                 }
 460         }
 461 }
 462
 463 /**
 464  *      sata_pmp_attach - attach a SATA PMP device
 465  *      @dev: SATA PMP device to attach
 466  *
 467  *      Configure and attach SATA PMP device @dev.  This function is
 468  *      also responsible for allocating and initializing PMP links.
 469  *
 470  *      LOCKING:
 471  *      Kernel thread context (may sleep).
 472  *
 473  *      RETURNS:
 474  *      0 on success, -errno on failure.
 475  */
 476 int sata_pmp_attach(struct ata_device *dev)
 477 {
 478         struct ata_link *link = dev->link;
 479         struct ata_port *ap = link->ap;
 480         unsigned long flags;
 481         struct ata_link *tlink;
 482         int rc;
 483
 484         /* is it hanging off the right place? */
 485         if (!sata_pmp_supported(ap)) {
 486                 ata_dev_err(dev, "host does not support Port Multiplier\n");
 487                 return -EINVAL;
 488         }
 489
 490         if (!ata_is_host_link(link)) {
 491                 ata_dev_err(dev, "Port Multipliers cannot be nested\n");
 492                 return -EINVAL;
 493         }
 494
 495         if (dev->devno) {
 496                 ata_dev_err(dev, "Port Multiplier must be the first device\n");
 497                 return -EINVAL;
 498         }
 499
 500         WARN_ON(link->pmp != 0);
 501         link->pmp = SATA_PMP_CTRL_PORT;
 502
 503         /* read GSCR block */
 504         rc = sata_pmp_read_gscr(dev, dev->gscr);
 505         if (rc)
 506                 goto fail;
 507
 508         /* config PMP */
 509         rc = sata_pmp_configure(dev, 1);
 510         if (rc)
 511                 goto fail;
 512
 513         rc = sata_pmp_init_links(ap, sata_pmp_gscr_ports(dev->gscr));
 514         if (rc) {
 515                 ata_dev_info(dev, "failed to initialize PMP links\n");
 516                 goto fail;
 517         }
 518
 519         /* attach it */
 520         spin_lock_irqsave(ap->lock, flags);
 521         WARN_ON(ap->nr_pmp_links);
 522         ap->nr_pmp_links = sata_pmp_gscr_ports(dev->gscr);
 523         spin_unlock_irqrestore(ap->lock, flags);
 524
 525         sata_pmp_quirks(ap);
 526
 527         if (ap->ops->pmp_attach)
 528                 ap->ops->pmp_attach(ap);
 529
 530         ata_for_each_link(tlink, ap, EDGE)
 531                 sata_link_init_spd(tlink);
 532
 533         return 0;
 534
 535  fail:
 536         link->pmp = 0;
 537         return rc;
 538 }
 539
 540 /**
 541  *      sata_pmp_detach - detach a SATA PMP device
 542  *      @dev: SATA PMP device to detach
 543  *
 544  *      Detach SATA PMP device @dev.  This function is also
 545  *      responsible for deconfiguring PMP links.
 546  *
 547  *      LOCKING:
 548  *      Kernel thread context (may sleep).
 549  */
 550 static void sata_pmp_detach(struct ata_device *dev)
 551 {
 552         struct ata_link *link = dev->link;
 553         struct ata_port *ap = link->ap;
 554         struct ata_link *tlink;
 555         unsigned long flags;
 556
 557         ata_dev_info(dev, "Port Multiplier detaching\n");
 558
 559         WARN_ON(!ata_is_host_link(link) || dev->devno ||
 560                 link->pmp != SATA_PMP_CTRL_PORT);
 561
 562         if (ap->ops->pmp_detach)
 563                 ap->ops->pmp_detach(ap);
 564
 565         ata_for_each_link(tlink, ap, EDGE)
 566                 ata_eh_detach_dev(tlink->device);
 567
 568         spin_lock_irqsave(ap->lock, flags);
 569         ap->nr_pmp_links = 0;
 570         link->pmp = 0;
 571         spin_unlock_irqrestore(ap->lock, flags);
 572 }
 573
 574 /**
 575  *      sata_pmp_same_pmp - does new GSCR matches the configured PMP?
 576  *      @dev: PMP device to compare against
 577  *      @new_gscr: GSCR block of the new device
 578  *
 579  *      Compare @new_gscr against @dev and determine whether @dev is
 580  *      the PMP described by @new_gscr.
 581  *
 582  *      LOCKING:
 583  *      None.
 584  *
 585  *      RETURNS:
 586  *      1 if @dev matches @new_gscr, 0 otherwise.
 587  */
 588 static int sata_pmp_same_pmp(struct ata_device *dev, const u32 *new_gscr)
 589 {
 590         const u32 *old_gscr = dev->gscr;
 591         u16 old_vendor, new_vendor, old_devid, new_devid;
 592         int old_nr_ports, new_nr_ports;
 593
 594         old_vendor = sata_pmp_gscr_vendor(old_gscr);
 595         new_vendor = sata_pmp_gscr_vendor(new_gscr);
 596         old_devid = sata_pmp_gscr_devid(old_gscr);
 597         new_devid = sata_pmp_gscr_devid(new_gscr);
 598         old_nr_ports = sata_pmp_gscr_ports(old_gscr);
 599         new_nr_ports = sata_pmp_gscr_ports(new_gscr);
 600
 601         if (old_vendor != new_vendor) {
 602                 ata_dev_info(dev,
 603                              "Port Multiplier vendor mismatch '0x%x' != '0x%x'\n",
 604                              old_vendor, new_vendor);
 605                 return 0;
 606         }
 607
 608         if (old_devid != new_devid) {
 609                 ata_dev_info(dev,
 610                              "Port Multiplier device ID mismatch '0x%x' != '0x%x'\n",
 611                              old_devid, new_devid);
 612                 return 0;
 613         }
 614
 615         if (old_nr_ports != new_nr_ports) {
 616                 ata_dev_info(dev,
 617                              "Port Multiplier nr_ports mismatch '0x%x' != '0x%x'\n",
 618                              old_nr_ports, new_nr_ports);
 619                 return 0;
 620         }
 621
 622         return 1;
 623 }
 624
 625 /**
 626  *      sata_pmp_revalidate - revalidate SATA PMP
 627  *      @dev: PMP device to revalidate
 628  *      @new_class: new class code
 629  *
 630  *      Re-read GSCR block and make sure @dev is still attached to the
 631  *      port and properly configured.
 632  *
 633  *      LOCKING:
 634  *      Kernel thread context (may sleep).
 635  *
 636  *      RETURNS:
 637  *      0 on success, -errno otherwise.
 638  */
 639 static int sata_pmp_revalidate(struct ata_device *dev, unsigned int new_class)
 640 {
 641         struct ata_link *link = dev->link;
 642         struct ata_port *ap = link->ap;
 643         u32 *gscr = (void *)ap->sector_buf;
 644         int rc;
 645
 646         DPRINTK("ENTER\n");
 647
 648         ata_eh_about_to_do(link, NULL, ATA_EH_REVALIDATE);
 649
 650         if (!ata_dev_enabled(dev)) {
 651                 rc = -ENODEV;
 652                 goto fail;
 653         }
 654
 655         /* wrong class? */
 656         if (ata_class_enabled(new_class) && new_class != ATA_DEV_PMP) {
 657                 rc = -ENODEV;
 658                 goto fail;
 659         }
 660
 661         /* read GSCR */
 662         rc = sata_pmp_read_gscr(dev, gscr);
 663         if (rc)
 664                 goto fail;
 665
 666         /* is the pmp still there? */
 667         if (!sata_pmp_same_pmp(dev, gscr)) {
 668                 rc = -ENODEV;
 669                 goto fail;
 670         }
 671
 672         memcpy(dev->gscr, gscr, sizeof(gscr[0]) * SATA_PMP_GSCR_DWORDS);
 673
 674         rc = sata_pmp_configure(dev, 0);
 675         if (rc)
 676                 goto fail;
 677
 678         ata_eh_done(link, NULL, ATA_EH_REVALIDATE);
 679
 680         DPRINTK("EXIT, rc=0\n");
 681         return 0;
 682
 683  fail:
 684         ata_dev_err(dev, "PMP revalidation failed (errno=%d)\n", rc);
 685         DPRINTK("EXIT, rc=%d\n", rc);
 686         return rc;
 687 }
 688
 689 /**
 690  *      sata_pmp_revalidate_quick - revalidate SATA PMP quickly
 691  *      @dev: PMP device to revalidate
 692  *
 693  *      Make sure the attached PMP is accessible.
 694  *
 695  *      LOCKING:
 696  *      Kernel thread context (may sleep).
 697  *
 698  *      RETURNS:
 699  *      0 on success, -errno otherwise.
 700  */
 701 static int sata_pmp_revalidate_quick(struct ata_device *dev)
 702 {
 703         unsigned int err_mask;
 704         u32 prod_id;
 705
 706         err_mask = sata_pmp_read(dev->link, SATA_PMP_GSCR_PROD_ID, &prod_id);
 707         if (err_mask) {
 708                 ata_dev_err(dev,
 709                             "failed to read PMP product ID (Emask=0x%x)\n",
 710                             err_mask);
 711                 return -EIO;
 712         }
 713
 714         if (prod_id != dev->gscr[SATA_PMP_GSCR_PROD_ID]) {
 715                 ata_dev_err(dev, "PMP product ID mismatch\n");
 716                 /* something weird is going on, request full PMP recovery */
 717                 return -EIO;
 718         }
 719
 720         return 0;
 721 }
 722
 723 /**
 724  *      sata_pmp_eh_recover_pmp - recover PMP
 725  *      @ap: ATA port PMP is attached to
 726  *      @prereset: prereset method (can be NULL)
 727  *      @softreset: softreset method
 728  *      @hardreset: hardreset method
 729  *      @postreset: postreset method (can be NULL)
 730  *
 731  *      Recover PMP attached to @ap.  Recovery procedure is somewhat
 732  *      similar to that of ata_eh_recover() except that reset should
 733  *      always be performed in hard->soft sequence and recovery
 734  *      failure results in PMP detachment.
 735  *
 736  *      LOCKING:
 737  *      Kernel thread context (may sleep).
 738  *
 739  *      RETURNS:
 740  *      0 on success, -errno on failure.
 741  */
 742 static int sata_pmp_eh_recover_pmp(struct ata_port *ap,
 743                 ata_prereset_fn_t prereset, ata_reset_fn_t softreset,
 744                 ata_reset_fn_t hardreset, ata_postreset_fn_t postreset)
 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         DPRINTK("ENTER\n");
 754
 755         if (dev->flags & ATA_DFLAG_DETACH) {
 756                 detach = 1;
 757                 goto fail;
 758         }
 759
 760  retry:
 761         ehc->classes[0] = ATA_DEV_UNKNOWN;
 762
 763         if (ehc->i.action & ATA_EH_RESET) {
 764                 struct ata_link *tlink;
 765
 766                 /* reset */
 767                 rc = ata_eh_reset(link, 0, prereset, softreset, hardreset,
 768                                   postreset);
 769                 if (rc) {
 770                         ata_link_err(link, "failed to reset PMP, giving up\n");
 771                         goto fail;
 772                 }
 773
 774                 /* PMP is reset, SErrors cannot be trusted, scan all */
 775                 ata_for_each_link(tlink, ap, EDGE) {
 776                         struct ata_eh_context *ehc = &tlink->eh_context;
 777
 778                         ehc->i.probe_mask |= ATA_ALL_DEVICES;
 779                         ehc->i.action |= ATA_EH_RESET;
 780                 }
 781         }
 782
 783         /* If revalidation is requested, revalidate and reconfigure;
 784          * otherwise, do quick revalidation.
 785          */
 786         if (ehc->i.action & ATA_EH_REVALIDATE)
 787                 rc = sata_pmp_revalidate(dev, ehc->classes[0]);
 788         else
 789                 rc = sata_pmp_revalidate_quick(dev);
 790
 791         if (rc) {
 792                 tries--;
 793
 794                 if (rc == -ENODEV) {
 795                         ehc->i.probe_mask |= ATA_ALL_DEVICES;
 796                         detach = 1;
 797                         /* give it just two more chances */
 798                         tries = min(tries, 2);
 799                 }
 800
 801                 if (tries) {
 802                         /* consecutive revalidation failures? speed down */
 803                         if (reval_failed)
 804                                 sata_down_spd_limit(link, 0);
 805                         else
 806                                 reval_failed = 1;
 807
 808                         ehc->i.action |= ATA_EH_RESET;
 809                         goto retry;
 810                 } else {
 811                         ata_dev_err(dev,
 812                                     "failed to recover PMP after %d tries, giving up\n",
 813                                     ATA_EH_PMP_TRIES);
 814                         goto fail;
 815                 }
 816         }
 817
 818         /* okay, PMP resurrected */
 819         ehc->i.flags = 0;
 820
 821         DPRINTK("EXIT, rc=0\n");
 822         return 0;
 823
 824  fail:
 825         sata_pmp_detach(dev);
 826         if (detach)
 827                 ata_eh_detach_dev(dev);
 828         else
 829                 ata_dev_disable(dev);
 830
 831         DPRINTK("EXIT, rc=%d\n", rc);
 832         return rc;
 833 }
 834
 835 static int sata_pmp_eh_handle_disabled_links(struct ata_port *ap)
 836 {
 837         struct ata_link *link;
 838         unsigned long flags;
 839         int rc;
 840
 841         spin_lock_irqsave(ap->lock, flags);
 842
 843         ata_for_each_link(link, ap, EDGE) {
 844                 if (!(link->flags & ATA_LFLAG_DISABLED))
 845                         continue;
 846
 847                 spin_unlock_irqrestore(ap->lock, flags);
 848
 849                 /* Some PMPs require hardreset sequence to get
 850                  * SError.N working.
 851                  */
 852                 sata_link_hardreset(link, sata_deb_timing_normal,
 853                                 ata_deadline(jiffies, ATA_TMOUT_INTERNAL_QUICK),
 854                                 NULL, NULL);
 855
 856                 /* unconditionally clear SError.N */
 857                 rc = sata_scr_write(link, SCR_ERROR, SERR_PHYRDY_CHG);
 858                 if (rc) {
 859                         ata_link_err(link,
 860                                      "failed to clear SError.N (errno=%d)\n",
 861                                      rc);
 862                         return rc;
 863                 }
 864
 865                 spin_lock_irqsave(ap->lock, flags);
 866         }
 867
 868         spin_unlock_irqrestore(ap->lock, flags);
 869
 870         return 0;
 871 }
 872
 873 static int sata_pmp_handle_link_fail(struct ata_link *link, int *link_tries)
 874 {
 875         struct ata_port *ap = link->ap;
 876         unsigned long flags;
 877
 878         if (link_tries[link->pmp] && --link_tries[link->pmp])
 879                 return 1;
 880
 881         /* disable this link */
 882         if (!(link->flags & ATA_LFLAG_DISABLED)) {
 883                 ata_link_warn(link,
 884                         "failed to recover link after %d tries, disabling\n",
 885                         ATA_EH_PMP_LINK_TRIES);
 886
 887                 spin_lock_irqsave(ap->lock, flags);
 888                 link->flags |= ATA_LFLAG_DISABLED;
 889                 spin_unlock_irqrestore(ap->lock, flags);
 890         }
 891
 892         ata_dev_disable(link->device);
 893         link->eh_context.i.action = 0;
 894
 895         return 0;
 896 }
 897
 898 /**
 899  *      sata_pmp_eh_recover - recover PMP-enabled port
 900  *      @ap: ATA port to recover
 901  *
 902  *      Drive EH recovery operation for PMP enabled port @ap.  This
 903  *      function recovers host and PMP ports with proper retrials and
 904  *      fallbacks.  Actual recovery operations are performed using
 905  *      ata_eh_recover() and sata_pmp_eh_recover_pmp().
 906  *
 907  *      LOCKING:
 908  *      Kernel thread context (may sleep).
 909  *
 910  *      RETURNS:
 911  *      0 on success, -errno on failure.
 912  */
 913 static int sata_pmp_eh_recover(struct ata_port *ap)
 914 {
 915         struct ata_port_operations *ops = ap->ops;
 916         int pmp_tries, link_tries[SATA_PMP_MAX_PORTS];
 917         struct ata_link *pmp_link = &ap->link;
 918         struct ata_device *pmp_dev = pmp_link->device;
 919         struct ata_eh_context *pmp_ehc = &pmp_link->eh_context;
 920         u32 *gscr = pmp_dev->gscr;
 921         struct ata_link *link;
 922         struct ata_device *dev;
 923         unsigned int err_mask;
 924         u32 gscr_error, sntf;
 925         int cnt, rc;
 926
 927         pmp_tries = ATA_EH_PMP_TRIES;
 928         ata_for_each_link(link, ap, EDGE)
 929                 link_tries[link->pmp] = ATA_EH_PMP_LINK_TRIES;
 930
 931  retry:
 932         /* PMP attached? */
 933         if (!sata_pmp_attached(ap)) {
 934                 rc = ata_eh_recover(ap, ops->prereset, ops->softreset,
 935                                     ops->hardreset, ops->postreset, NULL);
 936                 if (rc) {
 937                         ata_for_each_dev(dev, &ap->link, ALL)
 938                                 ata_dev_disable(dev);
 939                         return rc;
 940                 }
 941
 942                 if (pmp_dev->class != ATA_DEV_PMP)
 943                         return 0;
 944
 945                 /* new PMP online */
 946                 ata_for_each_link(link, ap, EDGE)
 947                         link_tries[link->pmp] = ATA_EH_PMP_LINK_TRIES;
 948
 949                 /* fall through */
 950         }
 951
 952         /* recover pmp */
 953         rc = sata_pmp_eh_recover_pmp(ap, ops->prereset, ops->softreset,
 954                                      ops->hardreset, ops->postreset);
 955         if (rc)
 956                 goto pmp_fail;
 957
 958         /* PHY event notification can disturb reset and other recovery
 959          * operations.  Turn it off.
 960          */
 961         if (gscr[SATA_PMP_GSCR_FEAT_EN] & SATA_PMP_FEAT_NOTIFY) {
 962                 gscr[SATA_PMP_GSCR_FEAT_EN] &= ~SATA_PMP_FEAT_NOTIFY;
 963
 964                 err_mask = sata_pmp_write(pmp_link, SATA_PMP_GSCR_FEAT_EN,
 965                                           gscr[SATA_PMP_GSCR_FEAT_EN]);
 966                 if (err_mask) {
 967                         ata_link_warn(pmp_link,
 968                                 "failed to disable NOTIFY (err_mask=0x%x)\n",
 969                                 err_mask);
 970                         goto pmp_fail;
 971                 }
 972         }
 973
 974         /* handle disabled links */
 975         rc = sata_pmp_eh_handle_disabled_links(ap);
 976         if (rc)
 977                 goto pmp_fail;
 978
 979         /* recover links */
 980         rc = ata_eh_recover(ap, ops->pmp_prereset, ops->pmp_softreset,
 981                             ops->pmp_hardreset, ops->pmp_postreset, &link);
 982         if (rc)
 983                 goto link_fail;
 984
 985         /* clear SNotification */
 986         rc = sata_scr_read(&ap->link, SCR_NOTIFICATION, &sntf);
 987         if (rc == 0)
 988                 sata_scr_write(&ap->link, SCR_NOTIFICATION, sntf);
 989
 990         /*
 991          * If LPM is active on any fan-out port, hotplug wouldn't
 992          * work.  Return w/ PHY event notification disabled.
 993          */
 994         ata_for_each_link(link, ap, EDGE)
 995                 if (link->lpm_policy > ATA_LPM_MAX_POWER)
 996                         return 0;
 997
 998         /*
 999          * Connection status might have changed while resetting other
1000          * links, enable notification and check SATA_PMP_GSCR_ERROR
1001          * before returning.
1002          */
1003
1004         /* enable notification */
1005         if (pmp_dev->flags & ATA_DFLAG_AN) {
1006                 gscr[SATA_PMP_GSCR_FEAT_EN] |= SATA_PMP_FEAT_NOTIFY;
1007
1008                 err_mask = sata_pmp_write(pmp_link, SATA_PMP_GSCR_FEAT_EN,
1009                                           gscr[SATA_PMP_GSCR_FEAT_EN]);
1010                 if (err_mask) {
1011                         ata_dev_err(pmp_dev,
1012                                     "failed to write PMP_FEAT_EN (Emask=0x%x)\n",
1013                                     err_mask);
1014                         rc = -EIO;
1015                         goto pmp_fail;
1016                 }
1017         }
1018
1019         /* check GSCR_ERROR */
1020         err_mask = sata_pmp_read(pmp_link, SATA_PMP_GSCR_ERROR, &gscr_error);
1021         if (err_mask) {
1022                 ata_dev_err(pmp_dev,
1023                             "failed to read PMP_GSCR_ERROR (Emask=0x%x)\n",
1024                             err_mask);
1025                 rc = -EIO;
1026                 goto pmp_fail;
1027         }
1028
1029         cnt = 0;
1030         ata_for_each_link(link, ap, EDGE) {
1031                 if (!(gscr_error & (1 << link->pmp)))
1032                         continue;
1033
1034                 if (sata_pmp_handle_link_fail(link, link_tries)) {
1035                         ata_ehi_hotplugged(&link->eh_context.i);
1036                         cnt++;
1037                 } else {
1038                         ata_link_warn(link,
1039                                 "PHY status changed but maxed out on retries, giving up\n");
1040                         ata_link_warn(link,
1041                                 "Manually issue scan to resume this link\n");
1042                 }
1043         }
1044
1045         if (cnt) {
1046                 ata_port_info(ap,
1047                         "PMP SError.N set for some ports, repeating recovery\n");
1048                 goto retry;
1049         }
1050
1051         return 0;
1052
1053  link_fail:
1054         if (sata_pmp_handle_link_fail(link, link_tries)) {
1055                 pmp_ehc->i.action |= ATA_EH_RESET;
1056                 goto retry;
1057         }
1058
1059         /* fall through */
1060  pmp_fail:
1061         /* Control always ends up here after detaching PMP.  Shut up
1062          * and return if we're unloading.
1063          */
1064         if (ap->pflags & ATA_PFLAG_UNLOADING)
1065                 return rc;
1066
1067         if (!sata_pmp_attached(ap))
1068                 goto retry;
1069
1070         if (--pmp_tries) {
1071                 pmp_ehc->i.action |= ATA_EH_RESET;
1072                 goto retry;
1073         }
1074
1075         ata_port_err(ap, "failed to recover PMP after %d tries, giving up\n",
1076                      ATA_EH_PMP_TRIES);
1077         sata_pmp_detach(pmp_dev);
1078         ata_dev_disable(pmp_dev);
1079
1080         return rc;
1081 }
1082
1083 /**
1084  *      sata_pmp_error_handler - do standard error handling for PMP-enabled host
1085  *      @ap: host port to handle error for
1086  *
1087  *      Perform standard error handling sequence for PMP-enabled host
1088  *      @ap.
1089  *
1090  *      LOCKING:
1091  *      Kernel thread context (may sleep).
1092  */
1093 void sata_pmp_error_handler(struct ata_port *ap)
1094 {
1095         ata_eh_autopsy(ap);
1096         ata_eh_report(ap);
1097         sata_pmp_eh_recover(ap);
1098         ata_eh_finish(ap);
1099 }
1100
1101 EXPORT_SYMBOL_GPL(sata_pmp_port_ops);
1102 EXPORT_SYMBOL_GPL(sata_pmp_qc_defer_cmd_switch);
1103 EXPORT_SYMBOL_GPL(sata_pmp_error_handler);