arch/powerpc/kernel/eeh_driver.c

   1 /*
   2  * PCI Error Recovery Driver for RPA-compliant PPC64 platform.
   3  * Copyright IBM Corp. 2004 2005
   4  * Copyright Linas Vepstas <linas@linas.org> 2004, 2005
   5  *
   6  * All rights reserved.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or (at
  11  * your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  16  * NON INFRINGEMENT.  See the GNU General Public License for more
  17  * details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22  *
  23  * Send comments and feedback to Linas Vepstas <linas@austin.ibm.com>
  24  */
  25 #include <linux/delay.h>
  26 #include <linux/interrupt.h>
  27 #include <linux/irq.h>
  28 #include <linux/module.h>
  29 #include <linux/pci.h>
  30 #include <asm/eeh.h>
  31 #include <asm/eeh_event.h>
  32 #include <asm/ppc-pci.h>
  33 #include <asm/pci-bridge.h>
  34 #include <asm/prom.h>
  35 #include <asm/rtas.h>
  36
  37 /**
  38  * eeh_pcid_name - Retrieve name of PCI device driver
  39  * @pdev: PCI device
  40  *
  41  * This routine is used to retrieve the name of PCI device driver
  42  * if that's valid.
  43  */
  44 static inline const char *eeh_pcid_name(struct pci_dev *pdev)
  45 {
  46         if (pdev && pdev->dev.driver)
  47                 return pdev->dev.driver->name;
  48         return "";
  49 }
  50
  51 /**
  52  * eeh_pcid_get - Get the PCI device driver
  53  * @pdev: PCI device
  54  *
  55  * The function is used to retrieve the PCI device driver for
  56  * the indicated PCI device. Besides, we will increase the reference
  57  * of the PCI device driver to prevent that being unloaded on
  58  * the fly. Otherwise, kernel crash would be seen.
  59  */
  60 static inline struct pci_driver *eeh_pcid_get(struct pci_dev *pdev)
  61 {
  62         if (!pdev || !pdev->driver)
  63                 return NULL;
  64
  65         if (!try_module_get(pdev->driver->driver.owner))
  66                 return NULL;
  67
  68         return pdev->driver;
  69 }
  70
  71 /**
  72  * eeh_pcid_put - Dereference on the PCI device driver
  73  * @pdev: PCI device
  74  *
  75  * The function is called to do dereference on the PCI device
  76  * driver of the indicated PCI device.
  77  */
  78 static inline void eeh_pcid_put(struct pci_dev *pdev)
  79 {
  80         if (!pdev || !pdev->driver)
  81                 return;
  82
  83         module_put(pdev->driver->driver.owner);
  84 }
  85
  86 #if 0
  87 static void print_device_node_tree(struct pci_dn *pdn, int dent)
  88 {
  89         int i;
  90         struct device_node *pc;
  91
  92         if (!pdn)
  93                 return;
  94         for (i = 0; i < dent; i++)
  95                 printk(" ");
  96         printk("dn=%s mode=%x \tcfg_addr=%x pe_addr=%x \tfull=%s\n",
  97                 pdn->node->name, pdn->eeh_mode, pdn->eeh_config_addr,
  98                 pdn->eeh_pe_config_addr, pdn->node->full_name);
  99         dent += 3;
 100         pc = pdn->node->child;
 101         while (pc) {
 102                 print_device_node_tree(PCI_DN(pc), dent);
 103                 pc = pc->sibling;
 104         }
 105 }
 106 #endif
 107
 108 /**
 109  * eeh_disable_irq - Disable interrupt for the recovering device
 110  * @dev: PCI device
 111  *
 112  * This routine must be called when reporting temporary or permanent
 113  * error to the particular PCI device to disable interrupt of that
 114  * device. If the device has enabled MSI or MSI-X interrupt, we needn't
 115  * do real work because EEH should freeze DMA transfers for those PCI
 116  * devices encountering EEH errors, which includes MSI or MSI-X.
 117  */
 118 static void eeh_disable_irq(struct pci_dev *dev)
 119 {
 120         struct eeh_dev *edev = pci_dev_to_eeh_dev(dev);
 121
 122         /* Don't disable MSI and MSI-X interrupts. They are
 123          * effectively disabled by the DMA Stopped state
 124          * when an EEH error occurs.
 125          */
 126         if (dev->msi_enabled || dev->msix_enabled)
 127                 return;
 128
 129         if (!irq_has_action(dev->irq))
 130                 return;
 131
 132         edev->mode |= EEH_DEV_IRQ_DISABLED;
 133         disable_irq_nosync(dev->irq);
 134 }
 135
 136 /**
 137  * eeh_enable_irq - Enable interrupt for the recovering device
 138  * @dev: PCI device
 139  *
 140  * This routine must be called to enable interrupt while failed
 141  * device could be resumed.
 142  */
 143 static void eeh_enable_irq(struct pci_dev *dev)
 144 {
 145         struct eeh_dev *edev = pci_dev_to_eeh_dev(dev);
 146
 147         if ((edev->mode) & EEH_DEV_IRQ_DISABLED) {
 148                 edev->mode &= ~EEH_DEV_IRQ_DISABLED;
 149                 /*
 150                  * FIXME !!!!!
 151                  *
 152                  * This is just ass backwards. This maze has
 153                  * unbalanced irq_enable/disable calls. So instead of
 154                  * finding the root cause it works around the warning
 155                  * in the irq_enable code by conditionally calling
 156                  * into it.
 157                  *
 158                  * That's just wrong.The warning in the core code is
 159                  * there to tell people to fix their assymetries in
 160                  * their own code, not by abusing the core information
 161                  * to avoid it.
 162                  *
 163                  * I so wish that the assymetry would be the other way
 164                  * round and a few more irq_disable calls render that
 165                  * shit unusable forever.
 166                  *
 167                  *      tglx
 168                  */
 169                 if (irqd_irq_disabled(irq_get_irq_data(dev->irq)))
 170                         enable_irq(dev->irq);
 171         }
 172 }
 173
 174 /**
 175  * eeh_report_error - Report pci error to each device driver
 176  * @data: eeh device
 177  * @userdata: return value
 178  *
 179  * Report an EEH error to each device driver, collect up and
 180  * merge the device driver responses. Cumulative response
 181  * passed back in "userdata".
 182  */
 183 static void *eeh_report_error(void *data, void *userdata)
 184 {
 185         struct eeh_dev *edev = (struct eeh_dev *)data;
 186         struct pci_dev *dev = eeh_dev_to_pci_dev(edev);
 187         enum pci_ers_result rc, *res = userdata;
 188         struct pci_driver *driver;
 189
 190         /* We might not have the associated PCI device,
 191          * then we should continue for next one.
 192          */
 193         if (!dev) return NULL;
 194         dev->error_state = pci_channel_io_frozen;
 195
 196         driver = eeh_pcid_get(dev);
 197         if (!driver) return NULL;
 198
 199         eeh_disable_irq(dev);
 200
 201         if (!driver->err_handler ||
 202             !driver->err_handler->error_detected) {
 203                 eeh_pcid_put(dev);
 204                 return NULL;
 205         }
 206
 207         rc = driver->err_handler->error_detected(dev, pci_channel_io_frozen);
 208
 209         /* A driver that needs a reset trumps all others */
 210         if (rc == PCI_ERS_RESULT_NEED_RESET) *res = rc;
 211         if (*res == PCI_ERS_RESULT_NONE) *res = rc;
 212
 213         eeh_pcid_put(dev);
 214         return NULL;
 215 }
 216
 217 /**
 218  * eeh_report_mmio_enabled - Tell drivers that MMIO has been enabled
 219  * @data: eeh device
 220  * @userdata: return value
 221  *
 222  * Tells each device driver that IO ports, MMIO and config space I/O
 223  * are now enabled. Collects up and merges the device driver responses.
 224  * Cumulative response passed back in "userdata".
 225  */
 226 static void *eeh_report_mmio_enabled(void *data, void *userdata)
 227 {
 228         struct eeh_dev *edev = (struct eeh_dev *)data;
 229         struct pci_dev *dev = eeh_dev_to_pci_dev(edev);
 230         enum pci_ers_result rc, *res = userdata;
 231         struct pci_driver *driver;
 232
 233         driver = eeh_pcid_get(dev);
 234         if (!driver) return NULL;
 235
 236         if (!driver->err_handler ||
 237             !driver->err_handler->mmio_enabled ||
 238             (edev->mode & EEH_DEV_NO_HANDLER)) {
 239                 eeh_pcid_put(dev);
 240                 return NULL;
 241         }
 242
 243         rc = driver->err_handler->mmio_enabled(dev);
 244
 245         /* A driver that needs a reset trumps all others */
 246         if (rc == PCI_ERS_RESULT_NEED_RESET) *res = rc;
 247         if (*res == PCI_ERS_RESULT_NONE) *res = rc;
 248
 249         eeh_pcid_put(dev);
 250         return NULL;
 251 }
 252
 253 /**
 254  * eeh_report_reset - Tell device that slot has been reset
 255  * @data: eeh device
 256  * @userdata: return value
 257  *
 258  * This routine must be called while EEH tries to reset particular
 259  * PCI device so that the associated PCI device driver could take
 260  * some actions, usually to save data the driver needs so that the
 261  * driver can work again while the device is recovered.
 262  */
 263 static void *eeh_report_reset(void *data, void *userdata)
 264 {
 265         struct eeh_dev *edev = (struct eeh_dev *)data;
 266         struct pci_dev *dev = eeh_dev_to_pci_dev(edev);
 267         enum pci_ers_result rc, *res = userdata;
 268         struct pci_driver *driver;
 269
 270         if (!dev) return NULL;
 271         dev->error_state = pci_channel_io_normal;
 272
 273         driver = eeh_pcid_get(dev);
 274         if (!driver) return NULL;
 275
 276         eeh_enable_irq(dev);
 277
 278         if (!driver->err_handler ||
 279             !driver->err_handler->slot_reset ||
 280             (edev->mode & EEH_DEV_NO_HANDLER)) {
 281                 eeh_pcid_put(dev);
 282                 return NULL;
 283         }
 284
 285         rc = driver->err_handler->slot_reset(dev);
 286         if ((*res == PCI_ERS_RESULT_NONE) ||
 287             (*res == PCI_ERS_RESULT_RECOVERED)) *res = rc;
 288         if (*res == PCI_ERS_RESULT_DISCONNECT &&
 289              rc == PCI_ERS_RESULT_NEED_RESET) *res = rc;
 290
 291         eeh_pcid_put(dev);
 292         return NULL;
 293 }
 294
 295 /**
 296  * eeh_report_resume - Tell device to resume normal operations
 297  * @data: eeh device
 298  * @userdata: return value
 299  *
 300  * This routine must be called to notify the device driver that it
 301  * could resume so that the device driver can do some initialization
 302  * to make the recovered device work again.
 303  */
 304 static void *eeh_report_resume(void *data, void *userdata)
 305 {
 306         struct eeh_dev *edev = (struct eeh_dev *)data;
 307         struct pci_dev *dev = eeh_dev_to_pci_dev(edev);
 308         struct pci_driver *driver;
 309
 310         if (!dev) return NULL;
 311         dev->error_state = pci_channel_io_normal;
 312
 313         driver = eeh_pcid_get(dev);
 314         if (!driver) return NULL;
 315
 316         eeh_enable_irq(dev);
 317
 318         if (!driver->err_handler ||
 319             !driver->err_handler->resume ||
 320             (edev->mode & EEH_DEV_NO_HANDLER)) {
 321                 edev->mode &= ~EEH_DEV_NO_HANDLER;
 322                 eeh_pcid_put(dev);
 323                 return NULL;
 324         }
 325
 326         driver->err_handler->resume(dev);
 327
 328         eeh_pcid_put(dev);
 329         return NULL;
 330 }
 331
 332 /**
 333  * eeh_report_failure - Tell device driver that device is dead.
 334  * @data: eeh device
 335  * @userdata: return value
 336  *
 337  * This informs the device driver that the device is permanently
 338  * dead, and that no further recovery attempts will be made on it.
 339  */
 340 static void *eeh_report_failure(void *data, void *userdata)
 341 {
 342         struct eeh_dev *edev = (struct eeh_dev *)data;
 343         struct pci_dev *dev = eeh_dev_to_pci_dev(edev);
 344         struct pci_driver *driver;
 345
 346         if (!dev) return NULL;
 347         dev->error_state = pci_channel_io_perm_failure;
 348
 349         driver = eeh_pcid_get(dev);
 350         if (!driver) return NULL;
 351
 352         eeh_disable_irq(dev);
 353
 354         if (!driver->err_handler ||
 355             !driver->err_handler->error_detected) {
 356                 eeh_pcid_put(dev);
 357                 return NULL;
 358         }
 359
 360         driver->err_handler->error_detected(dev, pci_channel_io_perm_failure);
 361
 362         eeh_pcid_put(dev);
 363         return NULL;
 364 }
 365
 366 static void *eeh_rmv_device(void *data, void *userdata)
 367 {
 368         struct pci_driver *driver;
 369         struct eeh_dev *edev = (struct eeh_dev *)data;
 370         struct pci_dev *dev = eeh_dev_to_pci_dev(edev);
 371         int *removed = (int *)userdata;
 372
 373         /*
 374          * Actually, we should remove the PCI bridges as well.
 375          * However, that's lots of complexity to do that,
 376          * particularly some of devices under the bridge might
 377          * support EEH. So we just care about PCI devices for
 378          * simplicity here.
 379          */
 380         if (!dev || (dev->hdr_type & PCI_HEADER_TYPE_BRIDGE))
 381                 return NULL;
 382
 383         driver = eeh_pcid_get(dev);
 384         if (driver) {
 385                 eeh_pcid_put(dev);
 386                 if (driver->err_handler)
 387                         return NULL;
 388         }
 389
 390         /* Remove it from PCI subsystem */
 391         pr_debug("EEH: Removing %s without EEH sensitive driver\n",
 392                  pci_name(dev));
 393         edev->bus = dev->bus;
 394         edev->mode |= EEH_DEV_DISCONNECTED;
 395         (*removed)++;
 396
 397         pci_lock_rescan_remove();
 398         pci_stop_and_remove_bus_device(dev);
 399         pci_unlock_rescan_remove();
 400
 401         return NULL;
 402 }
 403
 404 static void *eeh_pe_detach_dev(void *data, void *userdata)
 405 {
 406         struct eeh_pe *pe = (struct eeh_pe *)data;
 407         struct eeh_dev *edev, *tmp;
 408
 409         eeh_pe_for_each_dev(pe, edev, tmp) {
 410                 if (!(edev->mode & EEH_DEV_DISCONNECTED))
 411                         continue;
 412
 413                 edev->mode &= ~(EEH_DEV_DISCONNECTED | EEH_DEV_IRQ_DISABLED);
 414                 eeh_rmv_from_parent_pe(edev);
 415         }
 416
 417         return NULL;
 418 }
 419
 420 /**
 421  * eeh_reset_device - Perform actual reset of a pci slot
 422  * @pe: EEH PE
 423  * @bus: PCI bus corresponding to the isolcated slot
 424  *
 425  * This routine must be called to do reset on the indicated PE.
 426  * During the reset, udev might be invoked because those affected
 427  * PCI devices will be removed and then added.
 428  */
 429 static int eeh_reset_device(struct eeh_pe *pe, struct pci_bus *bus)
 430 {
 431         struct pci_bus *frozen_bus = eeh_pe_bus_get(pe);
 432         struct timeval tstamp;
 433         int cnt, rc, removed = 0;
 434
 435         /* pcibios will clear the counter; save the value */
 436         cnt = pe->freeze_count;
 437         tstamp = pe->tstamp;
 438
 439         /*
 440          * We don't remove the corresponding PE instances because
 441          * we need the information afterwords. The attached EEH
 442          * devices are expected to be attached soon when calling
 443          * into pcibios_add_pci_devices().
 444          */
 445         eeh_pe_state_mark(pe, EEH_PE_KEEP);
 446         if (bus) {
 447                 pci_lock_rescan_remove();
 448                 pcibios_remove_pci_devices(bus);
 449                 pci_unlock_rescan_remove();
 450         } else if (frozen_bus) {
 451                 eeh_pe_dev_traverse(pe, eeh_rmv_device, &removed);
 452         }
 453
 454         /* Reset the pci controller. (Asserts RST#; resets config space).
 455          * Reconfigure bridges and devices. Don't try to bring the system
 456          * up if the reset failed for some reason.
 457          */
 458         rc = eeh_reset_pe(pe);
 459         if (rc)
 460                 return rc;
 461
 462         pci_lock_rescan_remove();
 463
 464         /* Restore PE */
 465         eeh_ops->configure_bridge(pe);
 466         eeh_pe_restore_bars(pe);
 467
 468         /* Give the system 5 seconds to finish running the user-space
 469          * hotplug shutdown scripts, e.g. ifdown for ethernet.  Yes,
 470          * this is a hack, but if we don't do this, and try to bring
 471          * the device up before the scripts have taken it down,
 472          * potentially weird things happen.
 473          */
 474         if (bus) {
 475                 pr_info("EEH: Sleep 5s ahead of complete hotplug\n");
 476                 ssleep(5);
 477
 478                 /*
 479                  * The EEH device is still connected with its parent
 480                  * PE. We should disconnect it so the binding can be
 481                  * rebuilt when adding PCI devices.
 482                  */
 483                 eeh_pe_traverse(pe, eeh_pe_detach_dev, NULL);
 484                 pcibios_add_pci_devices(bus);
 485         } else if (frozen_bus && removed) {
 486                 pr_info("EEH: Sleep 5s ahead of partial hotplug\n");
 487                 ssleep(5);
 488
 489                 eeh_pe_traverse(pe, eeh_pe_detach_dev, NULL);
 490                 pcibios_add_pci_devices(frozen_bus);
 491         }
 492         eeh_pe_state_clear(pe, EEH_PE_KEEP);
 493
 494         pe->tstamp = tstamp;
 495         pe->freeze_count = cnt;
 496
 497         pci_unlock_rescan_remove();
 498         return 0;
 499 }
 500
 501 /* The longest amount of time to wait for a pci device
 502  * to come back on line, in seconds.
 503  */
 504 #define MAX_WAIT_FOR_RECOVERY 300
 505
 506 static void eeh_handle_normal_event(struct eeh_pe *pe)
 507 {
 508         struct pci_bus *frozen_bus;
 509         int rc = 0;
 510         enum pci_ers_result result = PCI_ERS_RESULT_NONE;
 511
 512         frozen_bus = eeh_pe_bus_get(pe);
 513         if (!frozen_bus) {
 514                 pr_err("%s: Cannot find PCI bus for PHB#%d-PE#%x\n",
 515                         __func__, pe->phb->global_number, pe->addr);
 516                 return;
 517         }
 518
 519         eeh_pe_update_time_stamp(pe);
 520         pe->freeze_count++;
 521         if (pe->freeze_count > EEH_MAX_ALLOWED_FREEZES)
 522                 goto excess_failures;
 523         pr_warning("EEH: This PCI device has failed %d times in the last hour\n",
 524                 pe->freeze_count);
 525
 526         /* Walk the various device drivers attached to this slot through
 527          * a reset sequence, giving each an opportunity to do what it needs
 528          * to accomplish the reset.  Each child gets a report of the
 529          * status ... if any child can't handle the reset, then the entire
 530          * slot is dlpar removed and added.
 531          */
 532         pr_info("EEH: Notify device drivers to shutdown\n");
 533         eeh_pe_dev_traverse(pe, eeh_report_error, &result);
 534
 535         /* Get the current PCI slot state. This can take a long time,
 536          * sometimes over 3 seconds for certain systems.
 537          */
 538         rc = eeh_ops->wait_state(pe, MAX_WAIT_FOR_RECOVERY*1000);
 539         if (rc < 0 || rc == EEH_STATE_NOT_SUPPORT) {
 540                 pr_warning("EEH: Permanent failure\n");
 541                 goto hard_fail;
 542         }
 543
 544         /* Since rtas may enable MMIO when posting the error log,
 545          * don't post the error log until after all dev drivers
 546          * have been informed.
 547          */
 548         pr_info("EEH: Collect temporary log\n");
 549         eeh_slot_error_detail(pe, EEH_LOG_TEMP);
 550
 551         /* If all device drivers were EEH-unaware, then shut
 552          * down all of the device drivers, and hope they
 553          * go down willingly, without panicing the system.
 554          */
 555         if (result == PCI_ERS_RESULT_NONE) {
 556                 pr_info("EEH: Reset with hotplug activity\n");
 557                 rc = eeh_reset_device(pe, frozen_bus);
 558                 if (rc) {
 559                         pr_warning("%s: Unable to reset, err=%d\n",
 560                                    __func__, rc);
 561                         goto hard_fail;
 562                 }
 563         }
 564
 565         /* If all devices reported they can proceed, then re-enable MMIO */
 566         if (result == PCI_ERS_RESULT_CAN_RECOVER) {
 567                 pr_info("EEH: Enable I/O for affected devices\n");
 568                 rc = eeh_pci_enable(pe, EEH_OPT_THAW_MMIO);
 569
 570                 if (rc < 0)
 571                         goto hard_fail;
 572                 if (rc) {
 573                         result = PCI_ERS_RESULT_NEED_RESET;
 574                 } else {
 575                         pr_info("EEH: Notify device drivers to resume I/O\n");
 576                         result = PCI_ERS_RESULT_NONE;
 577                         eeh_pe_dev_traverse(pe, eeh_report_mmio_enabled, &result);
 578                 }
 579         }
 580
 581         /* If all devices reported they can proceed, then re-enable DMA */
 582         if (result == PCI_ERS_RESULT_CAN_RECOVER) {
 583                 pr_info("EEH: Enabled DMA for affected devices\n");
 584                 rc = eeh_pci_enable(pe, EEH_OPT_THAW_DMA);
 585
 586                 if (rc < 0)
 587                         goto hard_fail;
 588                 if (rc)
 589                         result = PCI_ERS_RESULT_NEED_RESET;
 590                 else
 591                         result = PCI_ERS_RESULT_RECOVERED;
 592         }
 593
 594         /* If any device has a hard failure, then shut off everything. */
 595         if (result == PCI_ERS_RESULT_DISCONNECT) {
 596                 pr_warning("EEH: Device driver gave up\n");
 597                 goto hard_fail;
 598         }
 599
 600         /* If any device called out for a reset, then reset the slot */
 601         if (result == PCI_ERS_RESULT_NEED_RESET) {
 602                 pr_info("EEH: Reset without hotplug activity\n");
 603                 rc = eeh_reset_device(pe, NULL);
 604                 if (rc) {
 605                         pr_warning("%s: Cannot reset, err=%d\n",
 606                                    __func__, rc);
 607                         goto hard_fail;
 608                 }
 609
 610                 pr_info("EEH: Notify device drivers "
 611                         "the completion of reset\n");
 612                 result = PCI_ERS_RESULT_NONE;
 613                 eeh_pe_dev_traverse(pe, eeh_report_reset, &result);
 614         }
 615
 616         /* All devices should claim they have recovered by now. */
 617         if ((result != PCI_ERS_RESULT_RECOVERED) &&
 618             (result != PCI_ERS_RESULT_NONE)) {
 619                 pr_warning("EEH: Not recovered\n");
 620                 goto hard_fail;
 621         }
 622
 623         /* Tell all device drivers that they can resume operations */
 624         pr_info("EEH: Notify device driver to resume\n");
 625         eeh_pe_dev_traverse(pe, eeh_report_resume, NULL);
 626
 627         return;
 628
 629 excess_failures:
 630         /*
 631          * About 90% of all real-life EEH failures in the field
 632          * are due to poorly seated PCI cards. Only 10% or so are
 633          * due to actual, failed cards.
 634          */
 635         pr_err("EEH: PHB#%d-PE#%x has failed %d times in the\n"
 636                "last hour and has been permanently disabled.\n"
 637                "Please try reseating or replacing it.\n",
 638                 pe->phb->global_number, pe->addr,
 639                 pe->freeze_count);
 640         goto perm_error;
 641
 642 hard_fail:
 643         pr_err("EEH: Unable to recover from failure from PHB#%d-PE#%x.\n"
 644                "Please try reseating or replacing it\n",
 645                 pe->phb->global_number, pe->addr);
 646
 647 perm_error:
 648         eeh_slot_error_detail(pe, EEH_LOG_PERM);
 649
 650         /* Notify all devices that they're about to go down. */
 651         eeh_pe_dev_traverse(pe, eeh_report_failure, NULL);
 652
 653         /* Shut down the device drivers for good. */
 654         if (frozen_bus) {
 655                 pci_lock_rescan_remove();
 656                 pcibios_remove_pci_devices(frozen_bus);
 657                 pci_unlock_rescan_remove();
 658         }
 659 }
 660
 661 static void eeh_handle_special_event(void)
 662 {
 663         struct eeh_pe *pe, *phb_pe;
 664         struct pci_bus *bus;
 665         struct pci_controller *hose;
 666         unsigned long flags;
 667         int rc;
 668
 669
 670         do {
 671                 rc = eeh_ops->next_error(&pe);
 672
 673                 switch (rc) {
 674                 case EEH_NEXT_ERR_DEAD_IOC:
 675                         /* Mark all PHBs in dead state */
 676                         eeh_serialize_lock(&flags);
 677
 678                         /* Purge all events */
 679                         eeh_remove_event(NULL);
 680
 681                         list_for_each_entry(hose, &hose_list, list_node) {
 682                                 phb_pe = eeh_phb_pe_get(hose);
 683                                 if (!phb_pe) continue;
 684
 685                                 eeh_pe_state_mark(phb_pe,
 686                                         EEH_PE_ISOLATED | EEH_PE_PHB_DEAD);
 687                         }
 688
 689                         eeh_serialize_unlock(flags);
 690
 691                         break;
 692                 case EEH_NEXT_ERR_FROZEN_PE:
 693                 case EEH_NEXT_ERR_FENCED_PHB:
 694                 case EEH_NEXT_ERR_DEAD_PHB:
 695                         /* Mark the PE in fenced state */
 696                         eeh_serialize_lock(&flags);
 697
 698                         /* Purge all events of the PHB */
 699                         eeh_remove_event(pe);
 700
 701                         if (rc == EEH_NEXT_ERR_DEAD_PHB)
 702                                 eeh_pe_state_mark(pe,
 703                                         EEH_PE_ISOLATED | EEH_PE_PHB_DEAD);
 704                         else
 705                                 eeh_pe_state_mark(pe,
 706                                         EEH_PE_ISOLATED | EEH_PE_RECOVERING);
 707
 708                         eeh_serialize_unlock(flags);
 709
 710                         break;
 711                 case EEH_NEXT_ERR_NONE:
 712                         return;
 713                 default:
 714                         pr_warn("%s: Invalid value %d from next_error()\n",
 715                                 __func__, rc);
 716                         return;
 717                 }
 718
 719                 /*
 720                  * For fenced PHB and frozen PE, it's handled as normal
 721                  * event. We have to remove the affected PHBs for dead
 722                  * PHB and IOC
 723                  */
 724                 if (rc == EEH_NEXT_ERR_FROZEN_PE ||
 725                     rc == EEH_NEXT_ERR_FENCED_PHB) {
 726                         eeh_handle_normal_event(pe);
 727                 } else {
 728                         pci_lock_rescan_remove();
 729                         list_for_each_entry(hose, &hose_list, list_node) {
 730                                 phb_pe = eeh_phb_pe_get(hose);
 731                                 if (!phb_pe ||
 732                                     !(phb_pe->state & EEH_PE_PHB_DEAD))
 733                                         continue;
 734
 735                                 /* Notify all devices to be down */
 736                                 bus = eeh_pe_bus_get(phb_pe);
 737                                 eeh_pe_dev_traverse(pe,
 738                                         eeh_report_failure, NULL);
 739                                 pcibios_remove_pci_devices(bus);
 740                         }
 741                         pci_unlock_rescan_remove();
 742                 }
 743
 744                 /*
 745                  * If we have detected dead IOC, we needn't proceed
 746                  * any more since all PHBs would have been removed
 747                  */
 748                 if (rc == EEH_NEXT_ERR_DEAD_IOC)
 749                         break;
 750         } while (rc != EEH_NEXT_ERR_NONE);
 751 }
 752
 753 /**
 754  * eeh_handle_event - Reset a PCI device after hard lockup.
 755  * @pe: EEH PE
 756  *
 757  * While PHB detects address or data parity errors on particular PCI
 758  * slot, the associated PE will be frozen. Besides, DMA's occurring
 759  * to wild addresses (which usually happen due to bugs in device
 760  * drivers or in PCI adapter firmware) can cause EEH error. #SERR,
 761  * #PERR or other misc PCI-related errors also can trigger EEH errors.
 762  *
 763  * Recovery process consists of unplugging the device driver (which
 764  * generated hotplug events to userspace), then issuing a PCI #RST to
 765  * the device, then reconfiguring the PCI config space for all bridges
 766  * & devices under this slot, and then finally restarting the device
 767  * drivers (which cause a second set of hotplug events to go out to
 768  * userspace).
 769  */
 770 void eeh_handle_event(struct eeh_pe *pe)
 771 {
 772         if (pe)
 773                 eeh_handle_normal_event(pe);
 774         else
 775                 eeh_handle_special_event();
 776 }