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_std_prereset - prepare PMP link for reset
 180  *      @link: link to be reset
 181  *      @deadline: deadline jiffies for the operation
 182  *
 183  *      @link is about to be reset.  Initialize it.
 184  *
 185  *      LOCKING:
 186  *      Kernel thread context (may sleep)
 187  *
 188  *      RETURNS:
 189  *      0 on success, -errno otherwise.
 190  */
 191 int sata_pmp_std_prereset(struct ata_link *link, unsigned long deadline)
 192 {
 193         struct ata_eh_context *ehc = &link->eh_context;
 194         const unsigned long *timing = sata_ehc_deb_timing(ehc);
 195         int rc;
 196
 197         /* if we're about to do hardreset, nothing more to do */
 198         if (ehc->i.action & ATA_EH_HARDRESET)
 199                 return 0;
 200
 201         /* resume link */
 202         rc = sata_link_resume(link, timing, deadline);
 203         if (rc) {
 204                 /* phy resume failed */
 205                 ata_link_printk(link, KERN_WARNING, "failed to resume link "
 206                                 "for reset (errno=%d)\n", rc);
 207                 return rc;
 208         }
 209
 210         /* clear SError bits including .X which blocks the port when set */
 211         rc = sata_scr_write(link, SCR_ERROR, 0xffffffff);
 212         if (rc) {
 213                 ata_link_printk(link, KERN_ERR,
 214                                 "failed to clear SError (errno=%d)\n", rc);
 215                 return rc;
 216         }
 217
 218         return 0;
 219 }
 220
 221 /**
 222  *      sata_pmp_std_hardreset - standard hardreset method for PMP link
 223  *      @link: link to be reset
 224  *      @class: resulting class of attached device
 225  *      @deadline: deadline jiffies for the operation
 226  *
 227  *      Hardreset PMP port @link.  Note that this function doesn't
 228  *      wait for BSY clearance.  There simply isn't a generic way to
 229  *      wait the event.  Instead, this function return -EAGAIN thus
 230  *      telling libata-EH to followup with softreset.
 231  *
 232  *      LOCKING:
 233  *      Kernel thread context (may sleep)
 234  *
 235  *      RETURNS:
 236  *      0 on success, -errno otherwise.
 237  */
 238 int sata_pmp_std_hardreset(struct ata_link *link, unsigned int *class,
 239                            unsigned long deadline)
 240 {
 241         const unsigned long *timing = sata_ehc_deb_timing(&link->eh_context);
 242         u32 tmp;
 243         int rc;
 244
 245         DPRINTK("ENTER\n");
 246
 247         /* do hardreset */
 248         rc = sata_link_hardreset(link, timing, deadline);
 249         if (rc) {
 250                 ata_link_printk(link, KERN_ERR,
 251                                 "COMRESET failed (errno=%d)\n", rc);
 252                 goto out;
 253         }
 254
 255         /* clear SError bits including .X which blocks the port when set */
 256         rc = sata_scr_write(link, SCR_ERROR, 0xffffffff);
 257         if (rc) {
 258                 ata_link_printk(link, KERN_ERR, "failed to clear SError "
 259                                 "during hardreset (errno=%d)\n", rc);
 260                 goto out;
 261         }
 262
 263         /* if device is present, follow up with srst to wait for !BSY */
 264         if (ata_link_online(link))
 265                 rc = -EAGAIN;
 266  out:
 267         /* if SCR isn't accessible, we need to reset the PMP */
 268         if (rc && rc != -EAGAIN && sata_scr_read(link, SCR_STATUS, &tmp))
 269                 rc = -ERESTART;
 270
 271         DPRINTK("EXIT, rc=%d\n", rc);
 272         return rc;
 273 }
 274
 275 /**
 276  *      ata_std_postreset - standard postreset method for PMP link
 277  *      @link: the target ata_link
 278  *      @classes: classes of attached devices
 279  *
 280  *      This function is invoked after a successful reset.  Note that
 281  *      the device might have been reset more than once using
 282  *      different reset methods before postreset is invoked.
 283  *
 284  *      LOCKING:
 285  *      Kernel thread context (may sleep)
 286  */
 287 void sata_pmp_std_postreset(struct ata_link *link, unsigned int *class)
 288 {
 289         u32 serror;
 290
 291         DPRINTK("ENTER\n");
 292
 293         /* clear SError */
 294         if (sata_scr_read(link, SCR_ERROR, &serror) == 0)
 295                 sata_scr_write(link, SCR_ERROR, serror);
 296
 297         /* print link status */
 298         sata_print_link_status(link);
 299
 300         DPRINTK("EXIT\n");
 301 }
 302
 303 /**
 304  *      sata_pmp_read_gscr - read GSCR block of SATA PMP
 305  *      @dev: PMP device
 306  *      @gscr: buffer to read GSCR block into
 307  *
 308  *      Read selected PMP GSCRs from the PMP at @dev.  This will serve
 309  *      as configuration and identification info for the PMP.
 310  *
 311  *      LOCKING:
 312  *      Kernel thread context (may sleep).
 313  *
 314  *      RETURNS:
 315  *      0 on success, -errno on failure.
 316  */
 317 static int sata_pmp_read_gscr(struct ata_device *dev, u32 *gscr)
 318 {
 319         static const int gscr_to_read[] = { 0, 1, 2, 32, 33, 64, 96 };
 320         int i;
 321
 322         for (i = 0; i < ARRAY_SIZE(gscr_to_read); i++) {
 323                 int reg = gscr_to_read[i];
 324                 unsigned int err_mask;
 325
 326                 err_mask = sata_pmp_read(dev->link, reg, &gscr[reg]);
 327                 if (err_mask) {
 328                         ata_dev_printk(dev, KERN_ERR, "failed to read PMP "
 329                                 "GSCR[%d] (Emask=0x%x)\n", reg, err_mask);
 330                         return -EIO;
 331                 }
 332         }
 333
 334         return 0;
 335 }
 336
 337 static const char *sata_pmp_spec_rev_str(const u32 *gscr)
 338 {
 339         u32 rev = gscr[SATA_PMP_GSCR_REV];
 340
 341         if (rev & (1 << 2))
 342                 return "1.1";
 343         if (rev & (1 << 1))
 344                 return "1.0";
 345         return "<unknown>";
 346 }
 347
 348 static int sata_pmp_configure(struct ata_device *dev, int print_info)
 349 {
 350         struct ata_port *ap = dev->link->ap;
 351         u32 *gscr = dev->gscr;
 352         unsigned int err_mask = 0;
 353         const char *reason;
 354         int nr_ports, rc;
 355
 356         nr_ports = sata_pmp_gscr_ports(gscr);
 357
 358         if (nr_ports <= 0 || nr_ports > SATA_PMP_MAX_PORTS) {
 359                 rc = -EINVAL;
 360                 reason = "invalid nr_ports";
 361                 goto fail;
 362         }
 363
 364         if ((ap->flags & ATA_FLAG_AN) &&
 365             (gscr[SATA_PMP_GSCR_FEAT] & SATA_PMP_FEAT_NOTIFY))
 366                 dev->flags |= ATA_DFLAG_AN;
 367
 368         /* monitor SERR_PHYRDY_CHG on fan-out ports */
 369         err_mask = sata_pmp_write(dev->link, SATA_PMP_GSCR_ERROR_EN,
 370                                   SERR_PHYRDY_CHG);
 371         if (err_mask) {
 372                 rc = -EIO;
 373                 reason = "failed to write GSCR_ERROR_EN";
 374                 goto fail;
 375         }
 376
 377         /* turn off notification till fan-out ports are reset and configured */
 378         if (gscr[SATA_PMP_GSCR_FEAT_EN] & SATA_PMP_FEAT_NOTIFY) {
 379                 gscr[SATA_PMP_GSCR_FEAT_EN] &= ~SATA_PMP_FEAT_NOTIFY;
 380
 381                 err_mask = sata_pmp_write(dev->link, SATA_PMP_GSCR_FEAT_EN,
 382                                           gscr[SATA_PMP_GSCR_FEAT_EN]);
 383                 if (err_mask) {
 384                         rc = -EIO;
 385                         reason = "failed to write GSCR_FEAT_EN";
 386                         goto fail;
 387                 }
 388         }
 389
 390         if (print_info) {
 391                 ata_dev_printk(dev, KERN_INFO, "Port Multiplier %s, "
 392                                "0x%04x:0x%04x r%d, %d ports, feat 0x%x/0x%x\n",
 393                                sata_pmp_spec_rev_str(gscr),
 394                                sata_pmp_gscr_vendor(gscr),
 395                                sata_pmp_gscr_devid(gscr),
 396                                sata_pmp_gscr_rev(gscr),
 397                                nr_ports, gscr[SATA_PMP_GSCR_FEAT_EN],
 398                                gscr[SATA_PMP_GSCR_FEAT]);
 399
 400                 if (!(dev->flags & ATA_DFLAG_AN))
 401                         ata_dev_printk(dev, KERN_INFO,
 402                                 "Asynchronous notification not supported, "
 403                                 "hotplug won't\n         work on fan-out "
 404                                 "ports. Use warm-plug instead.\n");
 405         }
 406
 407         return 0;
 408
 409  fail:
 410         ata_dev_printk(dev, KERN_ERR,
 411                        "failed to configure Port Multiplier (%s, Emask=0x%x)\n",
 412                        reason, err_mask);
 413         return rc;
 414 }
 415
 416 static int sata_pmp_init_links(struct ata_port *ap, int nr_ports)
 417 {
 418         struct ata_link *pmp_link = ap->pmp_link;
 419         int i;
 420
 421         if (!pmp_link) {
 422                 pmp_link = kzalloc(sizeof(pmp_link[0]) * SATA_PMP_MAX_PORTS,
 423                                    GFP_NOIO);
 424                 if (!pmp_link)
 425                         return -ENOMEM;
 426
 427                 for (i = 0; i < SATA_PMP_MAX_PORTS; i++)
 428                         ata_link_init(ap, &pmp_link[i], i);
 429
 430                 ap->pmp_link = pmp_link;
 431         }
 432
 433         for (i = 0; i < nr_ports; i++) {
 434                 struct ata_link *link = &pmp_link[i];
 435                 struct ata_eh_context *ehc = &link->eh_context;
 436
 437                 link->flags = 0;
 438                 ehc->i.probe_mask |= ATA_ALL_DEVICES;
 439                 ehc->i.action |= ATA_EH_RESET;
 440         }
 441
 442         return 0;
 443 }
 444
 445 static void sata_pmp_quirks(struct ata_port *ap)
 446 {
 447         u32 *gscr = ap->link.device->gscr;
 448         u16 vendor = sata_pmp_gscr_vendor(gscr);
 449         u16 devid = sata_pmp_gscr_devid(gscr);
 450         struct ata_link *link;
 451
 452         if (vendor == 0x1095 && devid == 0x3726) {
 453                 /* sil3726 quirks */
 454                 ata_port_for_each_link(link, ap) {
 455                         /* class code report is unreliable */
 456                         if (link->pmp < 5)
 457                                 link->flags |= ATA_LFLAG_ASSUME_ATA;
 458
 459                         /* port 5 is for SEMB device and it doesn't like SRST */
 460                         if (link->pmp == 5)
 461                                 link->flags |= ATA_LFLAG_NO_SRST |
 462                                                ATA_LFLAG_ASSUME_SEMB;
 463                 }
 464         } else if (vendor == 0x1095 && devid == 0x4723) {
 465                 /* sil4723 quirks */
 466                 ata_port_for_each_link(link, ap) {
 467                         /* class code report is unreliable */
 468                         if (link->pmp < 2)
 469                                 link->flags |= ATA_LFLAG_ASSUME_ATA;
 470
 471                         /* the config device at port 2 locks up on SRST */
 472                         if (link->pmp == 2)
 473                                 link->flags |= ATA_LFLAG_NO_SRST |
 474                                                ATA_LFLAG_ASSUME_ATA;
 475                 }
 476         } else if (vendor == 0x1095 && devid == 0x4726) {
 477                 /* sil4726 quirks */
 478                 ata_port_for_each_link(link, ap) {
 479                         /* Class code report is unreliable and SRST
 480                          * times out under certain configurations.
 481                          * Config device can be at port 0 or 5 and
 482                          * locks up on SRST.
 483                          */
 484                         if (link->pmp <= 5)
 485                                 link->flags |= ATA_LFLAG_NO_SRST |
 486                                                ATA_LFLAG_ASSUME_ATA;
 487
 488                         /* Port 6 is for SEMB device which doesn't
 489                          * like SRST either.
 490                          */
 491                         if (link->pmp == 6)
 492                                 link->flags |= ATA_LFLAG_NO_SRST |
 493                                                ATA_LFLAG_ASSUME_SEMB;
 494                 }
 495         } else if (vendor == 0x1095 && (devid == 0x5723 || devid == 0x5733 ||
 496                                         devid == 0x5734 || devid == 0x5744)) {
 497                 /* sil5723/5744 quirks */
 498
 499                 /* sil5723/5744 has either two or three downstream
 500                  * ports depending on operation mode.  The last port
 501                  * is empty if any actual IO device is available or
 502                  * occupied by a pseudo configuration device
 503                  * otherwise.  Don't try hard to recover it.
 504                  */
 505                 ap->pmp_link[ap->nr_pmp_links - 1].flags |= ATA_LFLAG_NO_RETRY;
 506         }
 507 }
 508
 509 /**
 510  *      sata_pmp_attach - attach a SATA PMP device
 511  *      @dev: SATA PMP device to attach
 512  *
 513  *      Configure and attach SATA PMP device @dev.  This function is
 514  *      also responsible for allocating and initializing PMP links.
 515  *
 516  *      LOCKING:
 517  *      Kernel thread context (may sleep).
 518  *
 519  *      RETURNS:
 520  *      0 on success, -errno on failure.
 521  */
 522 int sata_pmp_attach(struct ata_device *dev)
 523 {
 524         struct ata_link *link = dev->link;
 525         struct ata_port *ap = link->ap;
 526         unsigned long flags;
 527         struct ata_link *tlink;
 528         int rc;
 529
 530         /* is it hanging off the right place? */
 531         if (!(ap->flags & ATA_FLAG_PMP)) {
 532                 ata_dev_printk(dev, KERN_ERR,
 533                                "host does not support Port Multiplier\n");
 534                 return -EINVAL;
 535         }
 536
 537         if (!ata_is_host_link(link)) {
 538                 ata_dev_printk(dev, KERN_ERR,
 539                                "Port Multipliers cannot be nested\n");
 540                 return -EINVAL;
 541         }
 542
 543         if (dev->devno) {
 544                 ata_dev_printk(dev, KERN_ERR,
 545                                "Port Multiplier must be the first device\n");
 546                 return -EINVAL;
 547         }
 548
 549         WARN_ON(link->pmp != 0);
 550         link->pmp = SATA_PMP_CTRL_PORT;
 551
 552         /* read GSCR block */
 553         rc = sata_pmp_read_gscr(dev, dev->gscr);
 554         if (rc)
 555                 goto fail;
 556
 557         /* config PMP */
 558         rc = sata_pmp_configure(dev, 1);
 559         if (rc)
 560                 goto fail;
 561
 562         rc = sata_pmp_init_links(ap, sata_pmp_gscr_ports(dev->gscr));
 563         if (rc) {
 564                 ata_dev_printk(dev, KERN_INFO,
 565                                "failed to initialize PMP links\n");
 566                 goto fail;
 567         }
 568
 569         /* attach it */
 570         spin_lock_irqsave(ap->lock, flags);
 571         WARN_ON(ap->nr_pmp_links);
 572         ap->nr_pmp_links = sata_pmp_gscr_ports(dev->gscr);
 573         spin_unlock_irqrestore(ap->lock, flags);
 574
 575         sata_pmp_quirks(ap);
 576
 577         if (ap->ops->pmp_attach)
 578                 ap->ops->pmp_attach(ap);
 579
 580         ata_port_for_each_link(tlink, ap)
 581                 sata_link_init_spd(tlink);
 582
 583         ata_acpi_associate_sata_port(ap);
 584
 585         return 0;
 586
 587  fail:
 588         link->pmp = 0;
 589         return rc;
 590 }
 591
 592 /**
 593  *      sata_pmp_detach - detach a SATA PMP device
 594  *      @dev: SATA PMP device to detach
 595  *
 596  *      Detach SATA PMP device @dev.  This function is also
 597  *      responsible for deconfiguring PMP links.
 598  *
 599  *      LOCKING:
 600  *      Kernel thread context (may sleep).
 601  */
 602 static void sata_pmp_detach(struct ata_device *dev)
 603 {
 604         struct ata_link *link = dev->link;
 605         struct ata_port *ap = link->ap;
 606         struct ata_link *tlink;
 607         unsigned long flags;
 608
 609         ata_dev_printk(dev, KERN_INFO, "Port Multiplier detaching\n");
 610
 611         WARN_ON(!ata_is_host_link(link) || dev->devno ||
 612                 link->pmp != SATA_PMP_CTRL_PORT);
 613
 614         if (ap->ops->pmp_detach)
 615                 ap->ops->pmp_detach(ap);
 616
 617         ata_port_for_each_link(tlink, ap)
 618                 ata_eh_detach_dev(tlink->device);
 619
 620         spin_lock_irqsave(ap->lock, flags);
 621         ap->nr_pmp_links = 0;
 622         link->pmp = 0;
 623         spin_unlock_irqrestore(ap->lock, flags);
 624
 625         ata_acpi_associate_sata_port(ap);
 626 }
 627
 628 /**
 629  *      sata_pmp_same_pmp - does new GSCR matches the configured PMP?
 630  *      @dev: PMP device to compare against
 631  *      @new_gscr: GSCR block of the new device
 632  *
 633  *      Compare @new_gscr against @dev and determine whether @dev is
 634  *      the PMP described by @new_gscr.
 635  *
 636  *      LOCKING:
 637  *      None.
 638  *
 639  *      RETURNS:
 640  *      1 if @dev matches @new_gscr, 0 otherwise.
 641  */
 642 static int sata_pmp_same_pmp(struct ata_device *dev, const u32 *new_gscr)
 643 {
 644         const u32 *old_gscr = dev->gscr;
 645         u16 old_vendor, new_vendor, old_devid, new_devid;
 646         int old_nr_ports, new_nr_ports;
 647
 648         old_vendor = sata_pmp_gscr_vendor(old_gscr);
 649         new_vendor = sata_pmp_gscr_vendor(new_gscr);
 650         old_devid = sata_pmp_gscr_devid(old_gscr);
 651         new_devid = sata_pmp_gscr_devid(new_gscr);
 652         old_nr_ports = sata_pmp_gscr_ports(old_gscr);
 653         new_nr_ports = sata_pmp_gscr_ports(new_gscr);
 654
 655         if (old_vendor != new_vendor) {
 656                 ata_dev_printk(dev, KERN_INFO, "Port Multiplier "
 657                                "vendor mismatch '0x%x' != '0x%x'\n",
 658                                old_vendor, new_vendor);
 659                 return 0;
 660         }
 661
 662         if (old_devid != new_devid) {
 663                 ata_dev_printk(dev, KERN_INFO, "Port Multiplier "
 664                                "device ID mismatch '0x%x' != '0x%x'\n",
 665                                old_devid, new_devid);
 666                 return 0;
 667         }
 668
 669         if (old_nr_ports != new_nr_ports) {
 670                 ata_dev_printk(dev, KERN_INFO, "Port Multiplier "
 671                                "nr_ports mismatch '0x%x' != '0x%x'\n",
 672                                old_nr_ports, new_nr_ports);
 673                 return 0;
 674         }
 675
 676         return 1;
 677 }
 678
 679 /**
 680  *      sata_pmp_revalidate - revalidate SATA PMP
 681  *      @dev: PMP device to revalidate
 682  *      @new_class: new class code
 683  *
 684  *      Re-read GSCR block and make sure @dev is still attached to the
 685  *      port and properly configured.
 686  *
 687  *      LOCKING:
 688  *      Kernel thread context (may sleep).
 689  *
 690  *      RETURNS:
 691  *      0 on success, -errno otherwise.
 692  */
 693 static int sata_pmp_revalidate(struct ata_device *dev, unsigned int new_class)
 694 {
 695         struct ata_link *link = dev->link;
 696         struct ata_port *ap = link->ap;
 697         u32 *gscr = (void *)ap->sector_buf;
 698         int rc;
 699
 700         DPRINTK("ENTER\n");
 701
 702         ata_eh_about_to_do(link, NULL, ATA_EH_REVALIDATE);
 703
 704         if (!ata_dev_enabled(dev)) {
 705                 rc = -ENODEV;
 706                 goto fail;
 707         }
 708
 709         /* wrong class? */
 710         if (ata_class_enabled(new_class) && new_class != ATA_DEV_PMP) {
 711                 rc = -ENODEV;
 712                 goto fail;
 713         }
 714
 715         /* read GSCR */
 716         rc = sata_pmp_read_gscr(dev, gscr);
 717         if (rc)
 718                 goto fail;
 719
 720         /* is the pmp still there? */
 721         if (!sata_pmp_same_pmp(dev, gscr)) {
 722                 rc = -ENODEV;
 723                 goto fail;
 724         }
 725
 726         memcpy(dev->gscr, gscr, sizeof(gscr[0]) * SATA_PMP_GSCR_DWORDS);
 727
 728         rc = sata_pmp_configure(dev, 0);
 729         if (rc)
 730                 goto fail;
 731
 732         ata_eh_done(link, NULL, ATA_EH_REVALIDATE);
 733
 734         DPRINTK("EXIT, rc=0\n");
 735         return 0;
 736
 737  fail:
 738         ata_dev_printk(dev, KERN_ERR,
 739                        "PMP revalidation failed (errno=%d)\n", rc);
 740         DPRINTK("EXIT, rc=%d\n", rc);
 741         return rc;
 742 }
 743
 744 /**
 745  *      sata_pmp_revalidate_quick - revalidate SATA PMP quickly
 746  *      @dev: PMP device to revalidate
 747  *
 748  *      Make sure the attached PMP is accessible.
 749  *
 750  *      LOCKING:
 751  *      Kernel thread context (may sleep).
 752  *
 753  *      RETURNS:
 754  *      0 on success, -errno otherwise.
 755  */
 756 static int sata_pmp_revalidate_quick(struct ata_device *dev)
 757 {
 758         unsigned int err_mask;
 759         u32 prod_id;
 760
 761         err_mask = sata_pmp_read(dev->link, SATA_PMP_GSCR_PROD_ID, &prod_id);
 762         if (err_mask) {
 763                 ata_dev_printk(dev, KERN_ERR, "failed to read PMP product ID "
 764                                "(Emask=0x%x)\n", err_mask);
 765                 return -EIO;
 766         }
 767
 768         if (prod_id != dev->gscr[SATA_PMP_GSCR_PROD_ID]) {
 769                 ata_dev_printk(dev, KERN_ERR, "PMP product ID mismatch\n");
 770                 /* something weird is going on, request full PMP recovery */
 771                 return -EIO;
 772         }
 773
 774         return 0;
 775 }
 776
 777 /**
 778  *      sata_pmp_eh_recover_pmp - recover PMP
 779  *      @ap: ATA port PMP is attached to
 780  *      @prereset: prereset method (can be NULL)
 781  *      @softreset: softreset method
 782  *      @hardreset: hardreset method
 783  *      @postreset: postreset method (can be NULL)
 784  *
 785  *      Recover PMP attached to @ap.  Recovery procedure is somewhat
 786  *      similar to that of ata_eh_recover() except that reset should
 787  *      always be performed in hard->soft sequence and recovery
 788  *      failure results in PMP detachment.
 789  *
 790  *      LOCKING:
 791  *      Kernel thread context (may sleep).
 792  *
 793  *      RETURNS:
 794  *      0 on success, -errno on failure.
 795  */
 796 static int sata_pmp_eh_recover_pmp(struct ata_port *ap,
 797                 ata_prereset_fn_t prereset, ata_reset_fn_t softreset,
 798                 ata_reset_fn_t hardreset, ata_postreset_fn_t postreset)
 799 {
 800         struct ata_link *link = &ap->link;
 801         struct ata_eh_context *ehc = &link->eh_context;
 802         struct ata_device *dev = link->device;
 803         int tries = ATA_EH_PMP_TRIES;
 804         int detach = 0, rc = 0;
 805         int reval_failed = 0;
 806
 807         DPRINTK("ENTER\n");
 808
 809         if (dev->flags & ATA_DFLAG_DETACH) {
 810                 detach = 1;
 811                 goto fail;
 812         }
 813
 814  retry:
 815         ehc->classes[0] = ATA_DEV_UNKNOWN;
 816
 817         if (ehc->i.action & ATA_EH_RESET) {
 818                 struct ata_link *tlink;
 819
 820                 ata_eh_freeze_port(ap);
 821
 822                 /* reset */
 823                 rc = ata_eh_reset(link, 0, prereset, softreset, hardreset,
 824                                   postreset);
 825                 if (rc) {
 826                         ata_link_printk(link, KERN_ERR,
 827                                         "failed to reset PMP, giving up\n");
 828                         goto fail;
 829                 }
 830
 831                 ata_eh_thaw_port(ap);
 832
 833                 /* PMP is reset, SErrors cannot be trusted, scan all */
 834                 ata_port_for_each_link(tlink, ap) {
 835                         struct ata_eh_context *ehc = &tlink->eh_context;
 836
 837                         ehc->i.probe_mask |= ATA_ALL_DEVICES;
 838                         ehc->i.action |= ATA_EH_RESET;
 839                 }
 840         }
 841
 842         /* If revalidation is requested, revalidate and reconfigure;
 843          * otherwise, do quick revalidation.
 844          */
 845         if (ehc->i.action & ATA_EH_REVALIDATE)
 846                 rc = sata_pmp_revalidate(dev, ehc->classes[0]);
 847         else
 848                 rc = sata_pmp_revalidate_quick(dev);
 849
 850         if (rc) {
 851                 tries--;
 852
 853                 if (rc == -ENODEV) {
 854                         ehc->i.probe_mask |= ATA_ALL_DEVICES;
 855                         detach = 1;
 856                         /* give it just two more chances */
 857                         tries = min(tries, 2);
 858                 }
 859
 860                 if (tries) {
 861                         int sleep = ehc->i.flags & ATA_EHI_DID_RESET;
 862
 863                         /* consecutive revalidation failures? speed down */
 864                         if (reval_failed)
 865                                 sata_down_spd_limit(link);
 866                         else
 867                                 reval_failed = 1;
 868
 869                         ata_dev_printk(dev, KERN_WARNING,
 870                                        "retrying reset%s\n",
 871                                        sleep ? " in 5 secs" : "");
 872                         if (sleep)
 873                                 ssleep(5);
 874                         ehc->i.action |= ATA_EH_RESET;
 875                         goto retry;
 876                 } else {
 877                         ata_dev_printk(dev, KERN_ERR, "failed to recover PMP "
 878                                        "after %d tries, giving up\n",
 879                                        ATA_EH_PMP_TRIES);
 880                         goto fail;
 881                 }
 882         }
 883
 884         /* okay, PMP resurrected */
 885         ehc->i.flags = 0;
 886
 887         DPRINTK("EXIT, rc=0\n");
 888         return 0;
 889
 890  fail:
 891         sata_pmp_detach(dev);
 892         if (detach)
 893                 ata_eh_detach_dev(dev);
 894         else
 895                 ata_dev_disable(dev);
 896
 897         DPRINTK("EXIT, rc=%d\n", rc);
 898         return rc;
 899 }
 900
 901 static int sata_pmp_eh_handle_disabled_links(struct ata_port *ap)
 902 {
 903         struct ata_link *link;
 904         unsigned long flags;
 905         int rc;
 906
 907         spin_lock_irqsave(ap->lock, flags);
 908
 909         ata_port_for_each_link(link, ap) {
 910                 if (!(link->flags & ATA_LFLAG_DISABLED))
 911                         continue;
 912
 913                 spin_unlock_irqrestore(ap->lock, flags);
 914
 915                 /* Some PMPs require hardreset sequence to get
 916                  * SError.N working.
 917                  */
 918                 sata_link_hardreset(link, sata_deb_timing_normal,
 919                                     jiffies + ATA_TMOUT_INTERNAL_QUICK);
 920
 921                 /* unconditionally clear SError.N */
 922                 rc = sata_scr_write(link, SCR_ERROR, SERR_PHYRDY_CHG);
 923                 if (rc) {
 924                         ata_link_printk(link, KERN_ERR, "failed to clear "
 925                                         "SError.N (errno=%d)\n", rc);
 926                         return rc;
 927                 }
 928
 929                 spin_lock_irqsave(ap->lock, flags);
 930         }
 931
 932         spin_unlock_irqrestore(ap->lock, flags);
 933
 934         return 0;
 935 }
 936
 937 static int sata_pmp_handle_link_fail(struct ata_link *link, int *link_tries)
 938 {
 939         struct ata_port *ap = link->ap;
 940         unsigned long flags;
 941
 942         if (link_tries[link->pmp] && --link_tries[link->pmp])
 943                 return 1;
 944
 945         /* disable this link */
 946         if (!(link->flags & ATA_LFLAG_DISABLED)) {
 947                 ata_link_printk(link, KERN_WARNING,
 948                         "failed to recover link after %d tries, disabling\n",
 949                         ATA_EH_PMP_LINK_TRIES);
 950
 951                 spin_lock_irqsave(ap->lock, flags);
 952                 link->flags |= ATA_LFLAG_DISABLED;
 953                 spin_unlock_irqrestore(ap->lock, flags);
 954         }
 955
 956         ata_dev_disable(link->device);
 957         link->eh_context.i.action = 0;
 958
 959         return 0;
 960 }
 961
 962 /**
 963  *      sata_pmp_eh_recover - recover PMP-enabled port
 964  *      @ap: ATA port to recover
 965  *
 966  *      Drive EH recovery operation for PMP enabled port @ap.  This
 967  *      function recovers host and PMP ports with proper retrials and
 968  *      fallbacks.  Actual recovery operations are performed using
 969  *      ata_eh_recover() and sata_pmp_eh_recover_pmp().
 970  *
 971  *      LOCKING:
 972  *      Kernel thread context (may sleep).
 973  *
 974  *      RETURNS:
 975  *      0 on success, -errno on failure.
 976  */
 977 static int sata_pmp_eh_recover(struct ata_port *ap)
 978 {
 979         struct ata_port_operations *ops = ap->ops;
 980         int pmp_tries, link_tries[SATA_PMP_MAX_PORTS];
 981         struct ata_link *pmp_link = &ap->link;
 982         struct ata_device *pmp_dev = pmp_link->device;
 983         struct ata_eh_context *pmp_ehc = &pmp_link->eh_context;
 984         struct ata_link *link;
 985         struct ata_device *dev;
 986         unsigned int err_mask;
 987         u32 gscr_error, sntf;
 988         int cnt, rc;
 989
 990         pmp_tries = ATA_EH_PMP_TRIES;
 991         ata_port_for_each_link(link, ap)
 992                 link_tries[link->pmp] = ATA_EH_PMP_LINK_TRIES;
 993
 994  retry:
 995         /* PMP attached? */
 996         if (!ap->nr_pmp_links) {
 997                 rc = ata_eh_recover(ap, ops->prereset, ops->softreset,
 998                                     ops->hardreset, ops->postreset, NULL);
 999                 if (rc) {
1000                         ata_link_for_each_dev(dev, &ap->link)
1001                                 ata_dev_disable(dev);
1002                         return rc;
1003                 }
1004
1005                 if (pmp_dev->class != ATA_DEV_PMP)
1006                         return 0;
1007
1008                 /* new PMP online */
1009                 ata_port_for_each_link(link, ap)
1010                         link_tries[link->pmp] = ATA_EH_PMP_LINK_TRIES;
1011
1012                 /* fall through */
1013         }
1014
1015         /* recover pmp */
1016         rc = sata_pmp_eh_recover_pmp(ap, ops->prereset, ops->softreset,
1017                                      ops->hardreset, ops->postreset);
1018         if (rc)
1019                 goto pmp_fail;
1020
1021         /* handle disabled links */
1022         rc = sata_pmp_eh_handle_disabled_links(ap);
1023         if (rc)
1024                 goto pmp_fail;
1025
1026         /* recover links */
1027         rc = ata_eh_recover(ap, ops->pmp_prereset, ops->pmp_softreset,
1028                             ops->pmp_hardreset, ops->pmp_postreset, &link);
1029         if (rc)
1030                 goto link_fail;
1031
1032         /* Connection status might have changed while resetting other
1033          * links, check SATA_PMP_GSCR_ERROR before returning.
1034          */
1035
1036         /* clear SNotification */
1037         rc = sata_scr_read(&ap->link, SCR_NOTIFICATION, &sntf);
1038         if (rc == 0)
1039                 sata_scr_write(&ap->link, SCR_NOTIFICATION, sntf);
1040
1041         /* enable notification */
1042         if (pmp_dev->flags & ATA_DFLAG_AN) {
1043                 pmp_dev->gscr[SATA_PMP_GSCR_FEAT_EN] |= SATA_PMP_FEAT_NOTIFY;
1044
1045                 err_mask = sata_pmp_write(pmp_dev->link, SATA_PMP_GSCR_FEAT_EN,
1046                                           pmp_dev->gscr[SATA_PMP_GSCR_FEAT_EN]);
1047                 if (err_mask) {
1048                         ata_dev_printk(pmp_dev, KERN_ERR, "failed to write "
1049                                        "PMP_FEAT_EN (Emask=0x%x)\n", err_mask);
1050                         rc = -EIO;
1051                         goto pmp_fail;
1052                 }
1053         }
1054
1055         /* check GSCR_ERROR */
1056         err_mask = sata_pmp_read(pmp_link, SATA_PMP_GSCR_ERROR, &gscr_error);
1057         if (err_mask) {
1058                 ata_dev_printk(pmp_dev, KERN_ERR, "failed to read "
1059                                "PMP_GSCR_ERROR (Emask=0x%x)\n", err_mask);
1060                 rc = -EIO;
1061                 goto pmp_fail;
1062         }
1063
1064         cnt = 0;
1065         ata_port_for_each_link(link, ap) {
1066                 if (!(gscr_error & (1 << link->pmp)))
1067                         continue;
1068
1069                 if (sata_pmp_handle_link_fail(link, link_tries)) {
1070                         ata_ehi_hotplugged(&link->eh_context.i);
1071                         cnt++;
1072                 } else {
1073                         ata_link_printk(link, KERN_WARNING,
1074                                 "PHY status changed but maxed out on retries, "
1075                                 "giving up\n");
1076                         ata_link_printk(link, KERN_WARNING,
1077                                 "Manully issue scan to resume this link\n");
1078                 }
1079         }
1080
1081         if (cnt) {
1082                 ata_port_printk(ap, KERN_INFO, "PMP SError.N set for some "
1083                                 "ports, repeating recovery\n");
1084                 goto retry;
1085         }
1086
1087         return 0;
1088
1089  link_fail:
1090         if (sata_pmp_handle_link_fail(link, link_tries)) {
1091                 pmp_ehc->i.action |= ATA_EH_RESET;
1092                 goto retry;
1093         }
1094
1095         /* fall through */
1096  pmp_fail:
1097         /* Control always ends up here after detaching PMP.  Shut up
1098          * and return if we're unloading.
1099          */
1100         if (ap->pflags & ATA_PFLAG_UNLOADING)
1101                 return rc;
1102
1103         if (!ap->nr_pmp_links)
1104                 goto retry;
1105
1106         if (--pmp_tries) {
1107                 ata_port_printk(ap, KERN_WARNING,
1108                                 "failed to recover PMP, retrying in 5 secs\n");
1109                 pmp_ehc->i.action |= ATA_EH_RESET;
1110                 ssleep(5);
1111                 goto retry;
1112         }
1113
1114         ata_port_printk(ap, KERN_ERR,
1115                         "failed to recover PMP after %d tries, giving up\n",
1116                         ATA_EH_PMP_TRIES);
1117         sata_pmp_detach(pmp_dev);
1118         ata_dev_disable(pmp_dev);
1119
1120         return rc;
1121 }
1122
1123 /**
1124  *      sata_pmp_error_handler - do standard error handling for PMP-enabled host
1125  *      @ap: host port to handle error for
1126  *
1127  *      Perform standard error handling sequence for PMP-enabled host
1128  *      @ap.
1129  *
1130  *      LOCKING:
1131  *      Kernel thread context (may sleep).
1132  */
1133 void sata_pmp_error_handler(struct ata_port *ap)
1134 {
1135         ata_eh_autopsy(ap);
1136         ata_eh_report(ap);
1137         sata_pmp_eh_recover(ap);
1138         ata_eh_finish(ap);
1139 }