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/libata.h>
  12 #include "libata.h"
  13
  14 /**
  15  *      sata_pmp_read - read PMP register
  16  *      @link: link to read PMP register for
  17  *      @reg: register to read
  18  *      @r_val: resulting value
  19  *
  20  *      Read PMP register.
  21  *
  22  *      LOCKING:
  23  *      Kernel thread context (may sleep).
  24  *
  25  *      RETURNS:
  26  *      0 on success, AC_ERR_* mask on failure.
  27  */
  28 static unsigned int sata_pmp_read(struct ata_link *link, int reg, u32 *r_val)
  29 {
  30         struct ata_port *ap = link->ap;
  31         struct ata_device *pmp_dev = ap->link.device;
  32         struct ata_taskfile tf;
  33         unsigned int err_mask;
  34
  35         ata_tf_init(pmp_dev, &tf);
  36         tf.command = ATA_CMD_PMP_READ;
  37         tf.protocol = ATA_PROT_NODATA;
  38         tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE | ATA_TFLAG_LBA48;
  39         tf.feature = reg;
  40         tf.device = link->pmp;
  41
  42         err_mask = ata_exec_internal(pmp_dev, &tf, NULL, DMA_NONE, NULL, 0,
  43                                      SATA_PMP_SCR_TIMEOUT);
  44         if (err_mask)
  45                 return err_mask;
  46
  47         *r_val = tf.nsect | tf.lbal << 8 | tf.lbam << 16 | tf.lbah << 24;
  48         return 0;
  49 }
  50
  51 /**
  52  *      sata_pmp_write - write PMP register
  53  *      @link: link to write PMP register for
  54  *      @reg: register to write
  55  *      @r_val: value to write
  56  *
  57  *      Write PMP register.
  58  *
  59  *      LOCKING:
  60  *      Kernel thread context (may sleep).
  61  *
  62  *      RETURNS:
  63  *      0 on success, AC_ERR_* mask on failure.
  64  */
  65 static unsigned int sata_pmp_write(struct ata_link *link, int reg, u32 val)
  66 {
  67         struct ata_port *ap = link->ap;
  68         struct ata_device *pmp_dev = ap->link.device;
  69         struct ata_taskfile tf;
  70
  71         ata_tf_init(pmp_dev, &tf);
  72         tf.command = ATA_CMD_PMP_WRITE;
  73         tf.protocol = ATA_PROT_NODATA;
  74         tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE | ATA_TFLAG_LBA48;
  75         tf.feature = reg;
  76         tf.device = link->pmp;
  77         tf.nsect = val & 0xff;
  78         tf.lbal = (val >> 8) & 0xff;
  79         tf.lbam = (val >> 16) & 0xff;
  80         tf.lbah = (val >> 24) & 0xff;
  81
  82         return ata_exec_internal(pmp_dev, &tf, NULL, DMA_NONE, NULL, 0,
  83                                  SATA_PMP_SCR_TIMEOUT);
  84 }
  85
  86 /**
  87  *      sata_pmp_qc_defer_cmd_switch - qc_defer for command switching PMP
  88  *      @qc: ATA command in question
  89  *
  90  *      A host which has command switching PMP support cannot issue
  91  *      commands to multiple links simultaneously.
  92  *
  93  *      LOCKING:
  94  *      spin_lock_irqsave(host lock)
  95  *
  96  *      RETURNS:
  97  *      ATA_DEFER_* if deferring is needed, 0 otherwise.
  98  */
  99 int sata_pmp_qc_defer_cmd_switch(struct ata_queued_cmd *qc)
 100 {
 101         struct ata_link *link = qc->dev->link;
 102         struct ata_port *ap = link->ap;
 103
 104         if (ap->excl_link == NULL || ap->excl_link == link) {
 105                 if (ap->nr_active_links == 0 || ata_link_active(link)) {
 106                         qc->flags |= ATA_QCFLAG_CLEAR_EXCL;
 107                         return ata_std_qc_defer(qc);
 108                 }
 109
 110                 ap->excl_link = link;
 111         }
 112
 113         return ATA_DEFER_PORT;
 114 }
 115
 116 /**
 117  *      sata_pmp_scr_read - read PSCR
 118  *      @link: ATA link to read PSCR for
 119  *      @reg: PSCR to read
 120  *      @r_val: resulting value
 121  *
 122  *      Read PSCR @reg into @r_val for @link, to be called from
 123  *      ata_scr_read().
 124  *
 125  *      LOCKING:
 126  *      Kernel thread context (may sleep).
 127  *
 128  *      RETURNS:
 129  *      0 on success, -errno on failure.
 130  */
 131 int sata_pmp_scr_read(struct ata_link *link, int reg, u32 *r_val)
 132 {
 133         unsigned int err_mask;
 134
 135         if (reg > SATA_PMP_PSCR_CONTROL)
 136                 return -EINVAL;
 137
 138         err_mask = sata_pmp_read(link, reg, r_val);
 139         if (err_mask) {
 140                 ata_link_printk(link, KERN_WARNING, "failed to read SCR %d "
 141                                 "(Emask=0x%x)\n", reg, err_mask);
 142                 return -EIO;
 143         }
 144         return 0;
 145 }
 146
 147 /**
 148  *      sata_pmp_scr_write - write PSCR
 149  *      @link: ATA link to write PSCR for
 150  *      @reg: PSCR to write
 151  *      @val: value to be written
 152  *
 153  *      Write @val to PSCR @reg for @link, to be called from
 154  *      ata_scr_write() and ata_scr_write_flush().
 155  *
 156  *      LOCKING:
 157  *      Kernel thread context (may sleep).
 158  *
 159  *      RETURNS:
 160  *      0 on success, -errno on failure.
 161  */
 162 int sata_pmp_scr_write(struct ata_link *link, int reg, u32 val)
 163 {
 164         unsigned int err_mask;
 165
 166         if (reg > SATA_PMP_PSCR_CONTROL)
 167                 return -EINVAL;
 168
 169         err_mask = sata_pmp_write(link, reg, val);
 170         if (err_mask) {
 171                 ata_link_printk(link, KERN_WARNING, "failed to write SCR %d "
 172                                 "(Emask=0x%x)\n", reg, err_mask);
 173                 return -EIO;
 174         }
 175         return 0;
 176 }
 177
 178 /**
 179  *      sata_pmp_read_gscr - read GSCR block of SATA PMP
 180  *      @dev: PMP device
 181  *      @gscr: buffer to read GSCR block into
 182  *
 183  *      Read selected PMP GSCRs from the PMP at @dev.  This will serve
 184  *      as configuration and identification info for the PMP.
 185  *
 186  *      LOCKING:
 187  *      Kernel thread context (may sleep).
 188  *
 189  *      RETURNS:
 190  *      0 on success, -errno on failure.
 191  */
 192 static int sata_pmp_read_gscr(struct ata_device *dev, u32 *gscr)
 193 {
 194         static const int gscr_to_read[] = { 0, 1, 2, 32, 33, 64, 96 };
 195         int i;
 196
 197         for (i = 0; i < ARRAY_SIZE(gscr_to_read); i++) {
 198                 int reg = gscr_to_read[i];
 199                 unsigned int err_mask;
 200
 201                 err_mask = sata_pmp_read(dev->link, reg, &gscr[reg]);
 202                 if (err_mask) {
 203                         ata_dev_printk(dev, KERN_ERR, "failed to read PMP "
 204                                 "GSCR[%d] (Emask=0x%x)\n", reg, err_mask);
 205                         return -EIO;
 206                 }
 207         }
 208
 209         return 0;
 210 }
 211
 212 static const char *sata_pmp_spec_rev_str(const u32 *gscr)
 213 {
 214         u32 rev = gscr[SATA_PMP_GSCR_REV];
 215
 216         if (rev & (1 << 2))
 217                 return "1.1";
 218         if (rev & (1 << 1))
 219                 return "1.0";
 220         return "<unknown>";
 221 }
 222
 223 static int sata_pmp_configure(struct ata_device *dev, int print_info)
 224 {
 225         struct ata_port *ap = dev->link->ap;
 226         u32 *gscr = dev->gscr;
 227         unsigned int err_mask = 0;
 228         const char *reason;
 229         int nr_ports, rc;
 230
 231         nr_ports = sata_pmp_gscr_ports(gscr);
 232
 233         if (nr_ports <= 0 || nr_ports > SATA_PMP_MAX_PORTS) {
 234                 rc = -EINVAL;
 235                 reason = "invalid nr_ports";
 236                 goto fail;
 237         }
 238
 239         if ((ap->flags & ATA_FLAG_AN) &&
 240             (gscr[SATA_PMP_GSCR_FEAT] & SATA_PMP_FEAT_NOTIFY))
 241                 dev->flags |= ATA_DFLAG_AN;
 242
 243         /* monitor SERR_PHYRDY_CHG on fan-out ports */
 244         err_mask = sata_pmp_write(dev->link, SATA_PMP_GSCR_ERROR_EN,
 245                                   SERR_PHYRDY_CHG);
 246         if (err_mask) {
 247                 rc = -EIO;
 248                 reason = "failed to write GSCR_ERROR_EN";
 249                 goto fail;
 250         }
 251
 252         /* turn off notification till fan-out ports are reset and configured */
 253         if (gscr[SATA_PMP_GSCR_FEAT_EN] & SATA_PMP_FEAT_NOTIFY) {
 254                 gscr[SATA_PMP_GSCR_FEAT_EN] &= ~SATA_PMP_FEAT_NOTIFY;
 255
 256                 err_mask = sata_pmp_write(dev->link, SATA_PMP_GSCR_FEAT_EN,
 257                                           gscr[SATA_PMP_GSCR_FEAT_EN]);
 258                 if (err_mask) {
 259                         rc = -EIO;
 260                         reason = "failed to write GSCR_FEAT_EN";
 261                         goto fail;
 262                 }
 263         }
 264
 265         if (print_info) {
 266                 ata_dev_printk(dev, KERN_INFO, "Port Multiplier %s, "
 267                                "0x%04x:0x%04x r%d, %d ports, feat 0x%x/0x%x\n",
 268                                sata_pmp_spec_rev_str(gscr),
 269                                sata_pmp_gscr_vendor(gscr),
 270                                sata_pmp_gscr_devid(gscr),
 271                                sata_pmp_gscr_rev(gscr),
 272                                nr_ports, gscr[SATA_PMP_GSCR_FEAT_EN],
 273                                gscr[SATA_PMP_GSCR_FEAT]);
 274
 275                 if (!(dev->flags & ATA_DFLAG_AN))
 276                         ata_dev_printk(dev, KERN_INFO,
 277                                 "Asynchronous notification not supported, "
 278                                 "hotplug won't\n         work on fan-out "
 279                                 "ports. Use warm-plug instead.\n");
 280         }
 281
 282         return 0;
 283
 284  fail:
 285         ata_dev_printk(dev, KERN_ERR,
 286                        "failed to configure Port Multiplier (%s, Emask=0x%x)\n",
 287                        reason, err_mask);
 288         return rc;
 289 }
 290
 291 static int sata_pmp_init_links(struct ata_port *ap, int nr_ports)
 292 {
 293         struct ata_link *pmp_link = ap->pmp_link;
 294         int i;
 295
 296         if (!pmp_link) {
 297                 pmp_link = kzalloc(sizeof(pmp_link[0]) * SATA_PMP_MAX_PORTS,
 298                                    GFP_NOIO);
 299                 if (!pmp_link)
 300                         return -ENOMEM;
 301
 302                 for (i = 0; i < SATA_PMP_MAX_PORTS; i++)
 303                         ata_link_init(ap, &pmp_link[i], i);
 304
 305                 ap->pmp_link = pmp_link;
 306         }
 307
 308         for (i = 0; i < nr_ports; i++) {
 309                 struct ata_link *link = &pmp_link[i];
 310                 struct ata_eh_context *ehc = &link->eh_context;
 311
 312                 link->flags = 0;
 313                 ehc->i.probe_mask |= ATA_ALL_DEVICES;
 314                 ehc->i.action |= ATA_EH_RESET;
 315         }
 316
 317         return 0;
 318 }
 319
 320 static void sata_pmp_quirks(struct ata_port *ap)
 321 {
 322         u32 *gscr = ap->link.device->gscr;
 323         u16 vendor = sata_pmp_gscr_vendor(gscr);
 324         u16 devid = sata_pmp_gscr_devid(gscr);
 325         struct ata_link *link;
 326
 327         if (vendor == 0x1095 && devid == 0x3726) {
 328                 /* sil3726 quirks */
 329                 ata_port_for_each_link(link, ap) {
 330                         /* class code report is unreliable */
 331                         if (link->pmp < 5)
 332                                 link->flags |= ATA_LFLAG_ASSUME_ATA;
 333
 334                         /* port 5 is for SEMB device and it doesn't like SRST */
 335                         if (link->pmp == 5)
 336                                 link->flags |= ATA_LFLAG_NO_SRST |
 337                                                ATA_LFLAG_ASSUME_SEMB;
 338                 }
 339         } else if (vendor == 0x1095 && devid == 0x4723) {
 340                 /* sil4723 quirks */
 341                 ata_port_for_each_link(link, ap) {
 342                         /* class code report is unreliable */
 343                         if (link->pmp < 2)
 344                                 link->flags |= ATA_LFLAG_ASSUME_ATA;
 345
 346                         /* the config device at port 2 locks up on SRST */
 347                         if (link->pmp == 2)
 348                                 link->flags |= ATA_LFLAG_NO_SRST |
 349                                                ATA_LFLAG_ASSUME_ATA;
 350                 }
 351         } else if (vendor == 0x1095 && devid == 0x4726) {
 352                 /* sil4726 quirks */
 353                 ata_port_for_each_link(link, ap) {
 354                         /* Class code report is unreliable and SRST
 355                          * times out under certain configurations.
 356                          * Config device can be at port 0 or 5 and
 357                          * locks up on SRST.
 358                          */
 359                         if (link->pmp <= 5)
 360                                 link->flags |= ATA_LFLAG_NO_SRST |
 361                                                ATA_LFLAG_ASSUME_ATA;
 362
 363                         /* Port 6 is for SEMB device which doesn't
 364                          * like SRST either.
 365                          */
 366                         if (link->pmp == 6)
 367                                 link->flags |= ATA_LFLAG_NO_SRST |
 368                                                ATA_LFLAG_ASSUME_SEMB;
 369                 }
 370         } else if (vendor == 0x1095 && (devid == 0x5723 || devid == 0x5733 ||
 371                                         devid == 0x5734 || devid == 0x5744)) {
 372                 /* sil5723/5744 quirks */
 373
 374                 /* sil5723/5744 has either two or three downstream
 375                  * ports depending on operation mode.  The last port
 376                  * is empty if any actual IO device is available or
 377                  * occupied by a pseudo configuration device
 378                  * otherwise.  Don't try hard to recover it.
 379                  */
 380                 ap->pmp_link[ap->nr_pmp_links - 1].flags |= ATA_LFLAG_NO_RETRY;
 381         }
 382 }
 383
 384 /**
 385  *      sata_pmp_attach - attach a SATA PMP device
 386  *      @dev: SATA PMP device to attach
 387  *
 388  *      Configure and attach SATA PMP device @dev.  This function is
 389  *      also responsible for allocating and initializing PMP links.
 390  *
 391  *      LOCKING:
 392  *      Kernel thread context (may sleep).
 393  *
 394  *      RETURNS:
 395  *      0 on success, -errno on failure.
 396  */
 397 int sata_pmp_attach(struct ata_device *dev)
 398 {
 399         struct ata_link *link = dev->link;
 400         struct ata_port *ap = link->ap;
 401         unsigned long flags;
 402         struct ata_link *tlink;
 403         int rc;
 404
 405         /* is it hanging off the right place? */
 406         if (!(ap->flags & ATA_FLAG_PMP)) {
 407                 ata_dev_printk(dev, KERN_ERR,
 408                                "host does not support Port Multiplier\n");
 409                 return -EINVAL;
 410         }
 411
 412         if (!ata_is_host_link(link)) {
 413                 ata_dev_printk(dev, KERN_ERR,
 414                                "Port Multipliers cannot be nested\n");
 415                 return -EINVAL;
 416         }
 417
 418         if (dev->devno) {
 419                 ata_dev_printk(dev, KERN_ERR,
 420                                "Port Multiplier must be the first device\n");
 421                 return -EINVAL;
 422         }
 423
 424         WARN_ON(link->pmp != 0);
 425         link->pmp = SATA_PMP_CTRL_PORT;
 426
 427         /* read GSCR block */
 428         rc = sata_pmp_read_gscr(dev, dev->gscr);
 429         if (rc)
 430                 goto fail;
 431
 432         /* config PMP */
 433         rc = sata_pmp_configure(dev, 1);
 434         if (rc)
 435                 goto fail;
 436
 437         rc = sata_pmp_init_links(ap, sata_pmp_gscr_ports(dev->gscr));
 438         if (rc) {
 439                 ata_dev_printk(dev, KERN_INFO,
 440                                "failed to initialize PMP links\n");
 441                 goto fail;
 442         }
 443
 444         /* attach it */
 445         spin_lock_irqsave(ap->lock, flags);
 446         WARN_ON(ap->nr_pmp_links);
 447         ap->nr_pmp_links = sata_pmp_gscr_ports(dev->gscr);
 448         spin_unlock_irqrestore(ap->lock, flags);
 449
 450         sata_pmp_quirks(ap);
 451
 452         if (ap->ops->pmp_attach)
 453                 ap->ops->pmp_attach(ap);
 454
 455         ata_port_for_each_link(tlink, ap)
 456                 sata_link_init_spd(tlink);
 457
 458         ata_acpi_associate_sata_port(ap);
 459
 460         return 0;
 461
 462  fail:
 463         link->pmp = 0;
 464         return rc;
 465 }
 466
 467 /**
 468  *      sata_pmp_detach - detach a SATA PMP device
 469  *      @dev: SATA PMP device to detach
 470  *
 471  *      Detach SATA PMP device @dev.  This function is also
 472  *      responsible for deconfiguring PMP links.
 473  *
 474  *      LOCKING:
 475  *      Kernel thread context (may sleep).
 476  */
 477 static void sata_pmp_detach(struct ata_device *dev)
 478 {
 479         struct ata_link *link = dev->link;
 480         struct ata_port *ap = link->ap;
 481         struct ata_link *tlink;
 482         unsigned long flags;
 483
 484         ata_dev_printk(dev, KERN_INFO, "Port Multiplier detaching\n");
 485
 486         WARN_ON(!ata_is_host_link(link) || dev->devno ||
 487                 link->pmp != SATA_PMP_CTRL_PORT);
 488
 489         if (ap->ops->pmp_detach)
 490                 ap->ops->pmp_detach(ap);
 491
 492         ata_port_for_each_link(tlink, ap)
 493                 ata_eh_detach_dev(tlink->device);
 494
 495         spin_lock_irqsave(ap->lock, flags);
 496         ap->nr_pmp_links = 0;
 497         link->pmp = 0;
 498         spin_unlock_irqrestore(ap->lock, flags);
 499
 500         ata_acpi_associate_sata_port(ap);
 501 }
 502
 503 /**
 504  *      sata_pmp_same_pmp - does new GSCR matches the configured PMP?
 505  *      @dev: PMP device to compare against
 506  *      @new_gscr: GSCR block of the new device
 507  *
 508  *      Compare @new_gscr against @dev and determine whether @dev is
 509  *      the PMP described by @new_gscr.
 510  *
 511  *      LOCKING:
 512  *      None.
 513  *
 514  *      RETURNS:
 515  *      1 if @dev matches @new_gscr, 0 otherwise.
 516  */
 517 static int sata_pmp_same_pmp(struct ata_device *dev, const u32 *new_gscr)
 518 {
 519         const u32 *old_gscr = dev->gscr;
 520         u16 old_vendor, new_vendor, old_devid, new_devid;
 521         int old_nr_ports, new_nr_ports;
 522
 523         old_vendor = sata_pmp_gscr_vendor(old_gscr);
 524         new_vendor = sata_pmp_gscr_vendor(new_gscr);
 525         old_devid = sata_pmp_gscr_devid(old_gscr);
 526         new_devid = sata_pmp_gscr_devid(new_gscr);
 527         old_nr_ports = sata_pmp_gscr_ports(old_gscr);
 528         new_nr_ports = sata_pmp_gscr_ports(new_gscr);
 529
 530         if (old_vendor != new_vendor) {
 531                 ata_dev_printk(dev, KERN_INFO, "Port Multiplier "
 532                                "vendor mismatch '0x%x' != '0x%x'\n",
 533                                old_vendor, new_vendor);
 534                 return 0;
 535         }
 536
 537         if (old_devid != new_devid) {
 538                 ata_dev_printk(dev, KERN_INFO, "Port Multiplier "
 539                                "device ID mismatch '0x%x' != '0x%x'\n",
 540                                old_devid, new_devid);
 541                 return 0;
 542         }
 543
 544         if (old_nr_ports != new_nr_ports) {
 545                 ata_dev_printk(dev, KERN_INFO, "Port Multiplier "
 546                                "nr_ports mismatch '0x%x' != '0x%x'\n",
 547                                old_nr_ports, new_nr_ports);
 548                 return 0;
 549         }
 550
 551         return 1;
 552 }
 553
 554 /**
 555  *      sata_pmp_revalidate - revalidate SATA PMP
 556  *      @dev: PMP device to revalidate
 557  *      @new_class: new class code
 558  *
 559  *      Re-read GSCR block and make sure @dev is still attached to the
 560  *      port and properly configured.
 561  *
 562  *      LOCKING:
 563  *      Kernel thread context (may sleep).
 564  *
 565  *      RETURNS:
 566  *      0 on success, -errno otherwise.
 567  */
 568 static int sata_pmp_revalidate(struct ata_device *dev, unsigned int new_class)
 569 {
 570         struct ata_link *link = dev->link;
 571         struct ata_port *ap = link->ap;
 572         u32 *gscr = (void *)ap->sector_buf;
 573         int rc;
 574
 575         DPRINTK("ENTER\n");
 576
 577         ata_eh_about_to_do(link, NULL, ATA_EH_REVALIDATE);
 578
 579         if (!ata_dev_enabled(dev)) {
 580                 rc = -ENODEV;
 581                 goto fail;
 582         }
 583
 584         /* wrong class? */
 585         if (ata_class_enabled(new_class) && new_class != ATA_DEV_PMP) {
 586                 rc = -ENODEV;
 587                 goto fail;
 588         }
 589
 590         /* read GSCR */
 591         rc = sata_pmp_read_gscr(dev, gscr);
 592         if (rc)
 593                 goto fail;
 594
 595         /* is the pmp still there? */
 596         if (!sata_pmp_same_pmp(dev, gscr)) {
 597                 rc = -ENODEV;
 598                 goto fail;
 599         }
 600
 601         memcpy(dev->gscr, gscr, sizeof(gscr[0]) * SATA_PMP_GSCR_DWORDS);
 602
 603         rc = sata_pmp_configure(dev, 0);
 604         if (rc)
 605                 goto fail;
 606
 607         ata_eh_done(link, NULL, ATA_EH_REVALIDATE);
 608
 609         DPRINTK("EXIT, rc=0\n");
 610         return 0;
 611
 612  fail:
 613         ata_dev_printk(dev, KERN_ERR,
 614                        "PMP revalidation failed (errno=%d)\n", rc);
 615         DPRINTK("EXIT, rc=%d\n", rc);
 616         return rc;
 617 }
 618
 619 /**
 620  *      sata_pmp_revalidate_quick - revalidate SATA PMP quickly
 621  *      @dev: PMP device to revalidate
 622  *
 623  *      Make sure the attached PMP is accessible.
 624  *
 625  *      LOCKING:
 626  *      Kernel thread context (may sleep).
 627  *
 628  *      RETURNS:
 629  *      0 on success, -errno otherwise.
 630  */
 631 static int sata_pmp_revalidate_quick(struct ata_device *dev)
 632 {
 633         unsigned int err_mask;
 634         u32 prod_id;
 635
 636         err_mask = sata_pmp_read(dev->link, SATA_PMP_GSCR_PROD_ID, &prod_id);
 637         if (err_mask) {
 638                 ata_dev_printk(dev, KERN_ERR, "failed to read PMP product ID "
 639                                "(Emask=0x%x)\n", err_mask);
 640                 return -EIO;
 641         }
 642
 643         if (prod_id != dev->gscr[SATA_PMP_GSCR_PROD_ID]) {
 644                 ata_dev_printk(dev, KERN_ERR, "PMP product ID mismatch\n");
 645                 /* something weird is going on, request full PMP recovery */
 646                 return -EIO;
 647         }
 648
 649         return 0;
 650 }
 651
 652 /**
 653  *      sata_pmp_eh_recover_pmp - recover PMP
 654  *      @ap: ATA port PMP is attached to
 655  *      @prereset: prereset method (can be NULL)
 656  *      @softreset: softreset method
 657  *      @hardreset: hardreset method
 658  *      @postreset: postreset method (can be NULL)
 659  *
 660  *      Recover PMP attached to @ap.  Recovery procedure is somewhat
 661  *      similar to that of ata_eh_recover() except that reset should
 662  *      always be performed in hard->soft sequence and recovery
 663  *      failure results in PMP detachment.
 664  *
 665  *      LOCKING:
 666  *      Kernel thread context (may sleep).
 667  *
 668  *      RETURNS:
 669  *      0 on success, -errno on failure.
 670  */
 671 static int sata_pmp_eh_recover_pmp(struct ata_port *ap,
 672                 ata_prereset_fn_t prereset, ata_reset_fn_t softreset,
 673                 ata_reset_fn_t hardreset, ata_postreset_fn_t postreset)
 674 {
 675         struct ata_link *link = &ap->link;
 676         struct ata_eh_context *ehc = &link->eh_context;
 677         struct ata_device *dev = link->device;
 678         int tries = ATA_EH_PMP_TRIES;
 679         int detach = 0, rc = 0;
 680         int reval_failed = 0;
 681
 682         DPRINTK("ENTER\n");
 683
 684         if (dev->flags & ATA_DFLAG_DETACH) {
 685                 detach = 1;
 686                 goto fail;
 687         }
 688
 689  retry:
 690         ehc->classes[0] = ATA_DEV_UNKNOWN;
 691
 692         if (ehc->i.action & ATA_EH_RESET) {
 693                 struct ata_link *tlink;
 694
 695                 ata_eh_freeze_port(ap);
 696
 697                 /* reset */
 698                 rc = ata_eh_reset(link, 0, prereset, softreset, hardreset,
 699                                   postreset);
 700                 if (rc) {
 701                         ata_link_printk(link, KERN_ERR,
 702                                         "failed to reset PMP, giving up\n");
 703                         goto fail;
 704                 }
 705
 706                 ata_eh_thaw_port(ap);
 707
 708                 /* PMP is reset, SErrors cannot be trusted, scan all */
 709                 ata_port_for_each_link(tlink, ap) {
 710                         struct ata_eh_context *ehc = &tlink->eh_context;
 711
 712                         ehc->i.probe_mask |= ATA_ALL_DEVICES;
 713                         ehc->i.action |= ATA_EH_RESET;
 714                 }
 715         }
 716
 717         /* If revalidation is requested, revalidate and reconfigure;
 718          * otherwise, do quick revalidation.
 719          */
 720         if (ehc->i.action & ATA_EH_REVALIDATE)
 721                 rc = sata_pmp_revalidate(dev, ehc->classes[0]);
 722         else
 723                 rc = sata_pmp_revalidate_quick(dev);
 724
 725         if (rc) {
 726                 tries--;
 727
 728                 if (rc == -ENODEV) {
 729                         ehc->i.probe_mask |= ATA_ALL_DEVICES;
 730                         detach = 1;
 731                         /* give it just two more chances */
 732                         tries = min(tries, 2);
 733                 }
 734
 735                 if (tries) {
 736                         int sleep = ehc->i.flags & ATA_EHI_DID_RESET;
 737
 738                         /* consecutive revalidation failures? speed down */
 739                         if (reval_failed)
 740                                 sata_down_spd_limit(link);
 741                         else
 742                                 reval_failed = 1;
 743
 744                         ata_dev_printk(dev, KERN_WARNING,
 745                                        "retrying reset%s\n",
 746                                        sleep ? " in 5 secs" : "");
 747                         if (sleep)
 748                                 ssleep(5);
 749                         ehc->i.action |= ATA_EH_RESET;
 750                         goto retry;
 751                 } else {
 752                         ata_dev_printk(dev, KERN_ERR, "failed to recover PMP "
 753                                        "after %d tries, giving up\n",
 754                                        ATA_EH_PMP_TRIES);
 755                         goto fail;
 756                 }
 757         }
 758
 759         /* okay, PMP resurrected */
 760         ehc->i.flags = 0;
 761
 762         DPRINTK("EXIT, rc=0\n");
 763         return 0;
 764
 765  fail:
 766         sata_pmp_detach(dev);
 767         if (detach)
 768                 ata_eh_detach_dev(dev);
 769         else
 770                 ata_dev_disable(dev);
 771
 772         DPRINTK("EXIT, rc=%d\n", rc);
 773         return rc;
 774 }
 775
 776 static int sata_pmp_eh_handle_disabled_links(struct ata_port *ap)
 777 {
 778         struct ata_link *link;
 779         unsigned long flags;
 780         int rc;
 781
 782         spin_lock_irqsave(ap->lock, flags);
 783
 784         ata_port_for_each_link(link, ap) {
 785                 if (!(link->flags & ATA_LFLAG_DISABLED))
 786                         continue;
 787
 788                 spin_unlock_irqrestore(ap->lock, flags);
 789
 790                 /* Some PMPs require hardreset sequence to get
 791                  * SError.N working.
 792                  */
 793                 sata_link_hardreset(link, sata_deb_timing_normal,
 794                                 jiffies + ATA_TMOUT_INTERNAL_QUICK, NULL, NULL);
 795
 796                 /* unconditionally clear SError.N */
 797                 rc = sata_scr_write(link, SCR_ERROR, SERR_PHYRDY_CHG);
 798                 if (rc) {
 799                         ata_link_printk(link, KERN_ERR, "failed to clear "
 800                                         "SError.N (errno=%d)\n", rc);
 801                         return rc;
 802                 }
 803
 804                 spin_lock_irqsave(ap->lock, flags);
 805         }
 806
 807         spin_unlock_irqrestore(ap->lock, flags);
 808
 809         return 0;
 810 }
 811
 812 static int sata_pmp_handle_link_fail(struct ata_link *link, int *link_tries)
 813 {
 814         struct ata_port *ap = link->ap;
 815         unsigned long flags;
 816
 817         if (link_tries[link->pmp] && --link_tries[link->pmp])
 818                 return 1;
 819
 820         /* disable this link */
 821         if (!(link->flags & ATA_LFLAG_DISABLED)) {
 822                 ata_link_printk(link, KERN_WARNING,
 823                         "failed to recover link after %d tries, disabling\n",
 824                         ATA_EH_PMP_LINK_TRIES);
 825
 826                 spin_lock_irqsave(ap->lock, flags);
 827                 link->flags |= ATA_LFLAG_DISABLED;
 828                 spin_unlock_irqrestore(ap->lock, flags);
 829         }
 830
 831         ata_dev_disable(link->device);
 832         link->eh_context.i.action = 0;
 833
 834         return 0;
 835 }
 836
 837 /**
 838  *      sata_pmp_eh_recover - recover PMP-enabled port
 839  *      @ap: ATA port to recover
 840  *
 841  *      Drive EH recovery operation for PMP enabled port @ap.  This
 842  *      function recovers host and PMP ports with proper retrials and
 843  *      fallbacks.  Actual recovery operations are performed using
 844  *      ata_eh_recover() and sata_pmp_eh_recover_pmp().
 845  *
 846  *      LOCKING:
 847  *      Kernel thread context (may sleep).
 848  *
 849  *      RETURNS:
 850  *      0 on success, -errno on failure.
 851  */
 852 static int sata_pmp_eh_recover(struct ata_port *ap)
 853 {
 854         struct ata_port_operations *ops = ap->ops;
 855         int pmp_tries, link_tries[SATA_PMP_MAX_PORTS];
 856         struct ata_link *pmp_link = &ap->link;
 857         struct ata_device *pmp_dev = pmp_link->device;
 858         struct ata_eh_context *pmp_ehc = &pmp_link->eh_context;
 859         struct ata_link *link;
 860         struct ata_device *dev;
 861         unsigned int err_mask;
 862         u32 gscr_error, sntf;
 863         int cnt, rc;
 864
 865         pmp_tries = ATA_EH_PMP_TRIES;
 866         ata_port_for_each_link(link, ap)
 867                 link_tries[link->pmp] = ATA_EH_PMP_LINK_TRIES;
 868
 869  retry:
 870         /* PMP attached? */
 871         if (!ap->nr_pmp_links) {
 872                 rc = ata_eh_recover(ap, ops->prereset, ops->softreset,
 873                                     ops->hardreset, ops->postreset, NULL);
 874                 if (rc) {
 875                         ata_link_for_each_dev(dev, &ap->link)
 876                                 ata_dev_disable(dev);
 877                         return rc;
 878                 }
 879
 880                 if (pmp_dev->class != ATA_DEV_PMP)
 881                         return 0;
 882
 883                 /* new PMP online */
 884                 ata_port_for_each_link(link, ap)
 885                         link_tries[link->pmp] = ATA_EH_PMP_LINK_TRIES;
 886
 887                 /* fall through */
 888         }
 889
 890         /* recover pmp */
 891         rc = sata_pmp_eh_recover_pmp(ap, ops->prereset, ops->softreset,
 892                                      ops->hardreset, ops->postreset);
 893         if (rc)
 894                 goto pmp_fail;
 895
 896         /* handle disabled links */
 897         rc = sata_pmp_eh_handle_disabled_links(ap);
 898         if (rc)
 899                 goto pmp_fail;
 900
 901         /* recover links */
 902         rc = ata_eh_recover(ap, ops->pmp_prereset, ops->pmp_softreset,
 903                             ops->pmp_hardreset, ops->pmp_postreset, &link);
 904         if (rc)
 905                 goto link_fail;
 906
 907         /* Connection status might have changed while resetting other
 908          * links, check SATA_PMP_GSCR_ERROR before returning.
 909          */
 910
 911         /* clear SNotification */
 912         rc = sata_scr_read(&ap->link, SCR_NOTIFICATION, &sntf);
 913         if (rc == 0)
 914                 sata_scr_write(&ap->link, SCR_NOTIFICATION, sntf);
 915
 916         /* enable notification */
 917         if (pmp_dev->flags & ATA_DFLAG_AN) {
 918                 pmp_dev->gscr[SATA_PMP_GSCR_FEAT_EN] |= SATA_PMP_FEAT_NOTIFY;
 919
 920                 err_mask = sata_pmp_write(pmp_dev->link, SATA_PMP_GSCR_FEAT_EN,
 921                                           pmp_dev->gscr[SATA_PMP_GSCR_FEAT_EN]);
 922                 if (err_mask) {
 923                         ata_dev_printk(pmp_dev, KERN_ERR, "failed to write "
 924                                        "PMP_FEAT_EN (Emask=0x%x)\n", err_mask);
 925                         rc = -EIO;
 926                         goto pmp_fail;
 927                 }
 928         }
 929
 930         /* check GSCR_ERROR */
 931         err_mask = sata_pmp_read(pmp_link, SATA_PMP_GSCR_ERROR, &gscr_error);
 932         if (err_mask) {
 933                 ata_dev_printk(pmp_dev, KERN_ERR, "failed to read "
 934                                "PMP_GSCR_ERROR (Emask=0x%x)\n", err_mask);
 935                 rc = -EIO;
 936                 goto pmp_fail;
 937         }
 938
 939         cnt = 0;
 940         ata_port_for_each_link(link, ap) {
 941                 if (!(gscr_error & (1 << link->pmp)))
 942                         continue;
 943
 944                 if (sata_pmp_handle_link_fail(link, link_tries)) {
 945                         ata_ehi_hotplugged(&link->eh_context.i);
 946                         cnt++;
 947                 } else {
 948                         ata_link_printk(link, KERN_WARNING,
 949                                 "PHY status changed but maxed out on retries, "
 950                                 "giving up\n");
 951                         ata_link_printk(link, KERN_WARNING,
 952                                 "Manully issue scan to resume this link\n");
 953                 }
 954         }
 955
 956         if (cnt) {
 957                 ata_port_printk(ap, KERN_INFO, "PMP SError.N set for some "
 958                                 "ports, repeating recovery\n");
 959                 goto retry;
 960         }
 961
 962         return 0;
 963
 964  link_fail:
 965         if (sata_pmp_handle_link_fail(link, link_tries)) {
 966                 pmp_ehc->i.action |= ATA_EH_RESET;
 967                 goto retry;
 968         }
 969
 970         /* fall through */
 971  pmp_fail:
 972         /* Control always ends up here after detaching PMP.  Shut up
 973          * and return if we're unloading.
 974          */
 975         if (ap->pflags & ATA_PFLAG_UNLOADING)
 976                 return rc;
 977
 978         if (!ap->nr_pmp_links)
 979                 goto retry;
 980
 981         if (--pmp_tries) {
 982                 ata_port_printk(ap, KERN_WARNING,
 983                                 "failed to recover PMP, retrying in 5 secs\n");
 984                 pmp_ehc->i.action |= ATA_EH_RESET;
 985                 ssleep(5);
 986                 goto retry;
 987         }
 988
 989         ata_port_printk(ap, KERN_ERR,
 990                         "failed to recover PMP after %d tries, giving up\n",
 991                         ATA_EH_PMP_TRIES);
 992         sata_pmp_detach(pmp_dev);
 993         ata_dev_disable(pmp_dev);
 994
 995         return rc;
 996 }
 997
 998 /**
 999  *      sata_pmp_error_handler - do standard error handling for PMP-enabled host
1000  *      @ap: host port to handle error for
1001  *
1002  *      Perform standard error handling sequence for PMP-enabled host
1003  *      @ap.
1004  *
1005  *      LOCKING:
1006  *      Kernel thread context (may sleep).
1007  */
1008 void sata_pmp_error_handler(struct ata_port *ap)
1009 {
1010         ata_eh_autopsy(ap);
1011         ata_eh_report(ap);
1012         sata_pmp_eh_recover(ap);
1013         ata_eh_finish(ap);
1014 }