/* * PCI Error Recovery Driver for RPA-compliant PPC64 platform. * Copyright IBM Corp. 2004 2005 * Copyright Linas Vepstas 2004, 2005 * * All rights reserved. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or (at * your option) any later version. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or * NON INFRINGEMENT. See the GNU General Public License for more * details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. * * Send comments and feedback to Linas Vepstas */ #include #include #include #include #include #include #include #include #include #include #include /** * eeh_pcid_name - Retrieve name of PCI device driver * @pdev: PCI device * * This routine is used to retrieve the name of PCI device driver * if that's valid. */ static inline const char *eeh_pcid_name(struct pci_dev *pdev) { if (pdev && pdev->dev.driver) return pdev->dev.driver->name; return ""; } /** * eeh_pcid_get - Get the PCI device driver * @pdev: PCI device * * The function is used to retrieve the PCI device driver for * the indicated PCI device. Besides, we will increase the reference * of the PCI device driver to prevent that being unloaded on * the fly. Otherwise, kernel crash would be seen. */ static inline struct pci_driver *eeh_pcid_get(struct pci_dev *pdev) { if (!pdev || !pdev->driver) return NULL; if (!try_module_get(pdev->driver->driver.owner)) return NULL; return pdev->driver; } /** * eeh_pcid_put - Dereference on the PCI device driver * @pdev: PCI device * * The function is called to do dereference on the PCI device * driver of the indicated PCI device. */ static inline void eeh_pcid_put(struct pci_dev *pdev) { if (!pdev || !pdev->driver) return; module_put(pdev->driver->driver.owner); } #if 0 static void print_device_node_tree(struct pci_dn *pdn, int dent) { int i; struct device_node *pc; if (!pdn) return; for (i = 0; i < dent; i++) printk(" "); printk("dn=%s mode=%x \tcfg_addr=%x pe_addr=%x \tfull=%s\n", pdn->node->name, pdn->eeh_mode, pdn->eeh_config_addr, pdn->eeh_pe_config_addr, pdn->node->full_name); dent += 3; pc = pdn->node->child; while (pc) { print_device_node_tree(PCI_DN(pc), dent); pc = pc->sibling; } } #endif /** * eeh_disable_irq - Disable interrupt for the recovering device * @dev: PCI device * * This routine must be called when reporting temporary or permanent * error to the particular PCI device to disable interrupt of that * device. If the device has enabled MSI or MSI-X interrupt, we needn't * do real work because EEH should freeze DMA transfers for those PCI * devices encountering EEH errors, which includes MSI or MSI-X. */ static void eeh_disable_irq(struct pci_dev *dev) { struct eeh_dev *edev = pci_dev_to_eeh_dev(dev); /* Don't disable MSI and MSI-X interrupts. They are * effectively disabled by the DMA Stopped state * when an EEH error occurs. */ if (dev->msi_enabled || dev->msix_enabled) return; if (!irq_has_action(dev->irq)) return; edev->mode |= EEH_DEV_IRQ_DISABLED; disable_irq_nosync(dev->irq); } /** * eeh_enable_irq - Enable interrupt for the recovering device * @dev: PCI device * * This routine must be called to enable interrupt while failed * device could be resumed. */ static void eeh_enable_irq(struct pci_dev *dev) { struct eeh_dev *edev = pci_dev_to_eeh_dev(dev); struct irq_desc *desc; if ((edev->mode) & EEH_DEV_IRQ_DISABLED) { edev->mode &= ~EEH_DEV_IRQ_DISABLED; desc = irq_to_desc(dev->irq); if (desc && desc->depth > 0) enable_irq(dev->irq); } } /** * eeh_report_error - Report pci error to each device driver * @data: eeh device * @userdata: return value * * Report an EEH error to each device driver, collect up and * merge the device driver responses. Cumulative response * passed back in "userdata". */ static void *eeh_report_error(void *data, void *userdata) { struct eeh_dev *edev = (struct eeh_dev *)data; struct pci_dev *dev = eeh_dev_to_pci_dev(edev); enum pci_ers_result rc, *res = userdata; struct pci_driver *driver; /* We might not have the associated PCI device, * then we should continue for next one. */ if (!dev) return NULL; dev->error_state = pci_channel_io_frozen; driver = eeh_pcid_get(dev); if (!driver) return NULL; eeh_disable_irq(dev); if (!driver->err_handler || !driver->err_handler->error_detected) { eeh_pcid_put(dev); return NULL; } rc = driver->err_handler->error_detected(dev, pci_channel_io_frozen); /* A driver that needs a reset trumps all others */ if (rc == PCI_ERS_RESULT_NEED_RESET) *res = rc; if (*res == PCI_ERS_RESULT_NONE) *res = rc; eeh_pcid_put(dev); return NULL; } /** * eeh_report_mmio_enabled - Tell drivers that MMIO has been enabled * @data: eeh device * @userdata: return value * * Tells each device driver that IO ports, MMIO and config space I/O * are now enabled. Collects up and merges the device driver responses. * Cumulative response passed back in "userdata". */ static void *eeh_report_mmio_enabled(void *data, void *userdata) { struct eeh_dev *edev = (struct eeh_dev *)data; struct pci_dev *dev = eeh_dev_to_pci_dev(edev); enum pci_ers_result rc, *res = userdata; struct pci_driver *driver; driver = eeh_pcid_get(dev); if (!driver) return NULL; if (!driver->err_handler || !driver->err_handler->mmio_enabled || (edev->mode & EEH_DEV_NO_HANDLER)) { eeh_pcid_put(dev); return NULL; } rc = driver->err_handler->mmio_enabled(dev); /* A driver that needs a reset trumps all others */ if (rc == PCI_ERS_RESULT_NEED_RESET) *res = rc; if (*res == PCI_ERS_RESULT_NONE) *res = rc; eeh_pcid_put(dev); return NULL; } /** * eeh_report_reset - Tell device that slot has been reset * @data: eeh device * @userdata: return value * * This routine must be called while EEH tries to reset particular * PCI device so that the associated PCI device driver could take * some actions, usually to save data the driver needs so that the * driver can work again while the device is recovered. */ static void *eeh_report_reset(void *data, void *userdata) { struct eeh_dev *edev = (struct eeh_dev *)data; struct pci_dev *dev = eeh_dev_to_pci_dev(edev); enum pci_ers_result rc, *res = userdata; struct pci_driver *driver; if (!dev) return NULL; dev->error_state = pci_channel_io_normal; driver = eeh_pcid_get(dev); if (!driver) return NULL; eeh_enable_irq(dev); if (!driver->err_handler || !driver->err_handler->slot_reset || (edev->mode & EEH_DEV_NO_HANDLER)) { eeh_pcid_put(dev); return NULL; } rc = driver->err_handler->slot_reset(dev); if ((*res == PCI_ERS_RESULT_NONE) || (*res == PCI_ERS_RESULT_RECOVERED)) *res = rc; if (*res == PCI_ERS_RESULT_DISCONNECT && rc == PCI_ERS_RESULT_NEED_RESET) *res = rc; eeh_pcid_put(dev); return NULL; } /** * eeh_report_resume - Tell device to resume normal operations * @data: eeh device * @userdata: return value * * This routine must be called to notify the device driver that it * could resume so that the device driver can do some initialization * to make the recovered device work again. */ static void *eeh_report_resume(void *data, void *userdata) { struct eeh_dev *edev = (struct eeh_dev *)data; struct pci_dev *dev = eeh_dev_to_pci_dev(edev); struct pci_driver *driver; if (!dev) return NULL; dev->error_state = pci_channel_io_normal; driver = eeh_pcid_get(dev); if (!driver) return NULL; eeh_enable_irq(dev); if (!driver->err_handler || !driver->err_handler->resume || (edev->mode & EEH_DEV_NO_HANDLER)) { edev->mode &= ~EEH_DEV_NO_HANDLER; eeh_pcid_put(dev); return NULL; } driver->err_handler->resume(dev); eeh_pcid_put(dev); return NULL; } /** * eeh_report_failure - Tell device driver that device is dead. * @data: eeh device * @userdata: return value * * This informs the device driver that the device is permanently * dead, and that no further recovery attempts will be made on it. */ static void *eeh_report_failure(void *data, void *userdata) { struct eeh_dev *edev = (struct eeh_dev *)data; struct pci_dev *dev = eeh_dev_to_pci_dev(edev); struct pci_driver *driver; if (!dev) return NULL; dev->error_state = pci_channel_io_perm_failure; driver = eeh_pcid_get(dev); if (!driver) return NULL; eeh_disable_irq(dev); if (!driver->err_handler || !driver->err_handler->error_detected) { eeh_pcid_put(dev); return NULL; } driver->err_handler->error_detected(dev, pci_channel_io_perm_failure); eeh_pcid_put(dev); return NULL; } static void *eeh_rmv_device(void *data, void *userdata) { struct pci_driver *driver; struct eeh_dev *edev = (struct eeh_dev *)data; struct pci_dev *dev = eeh_dev_to_pci_dev(edev); int *removed = (int *)userdata; /* * Actually, we should remove the PCI bridges as well. * However, that's lots of complexity to do that, * particularly some of devices under the bridge might * support EEH. So we just care about PCI devices for * simplicity here. */ if (!dev || (dev->hdr_type & PCI_HEADER_TYPE_BRIDGE)) return NULL; driver = eeh_pcid_get(dev); if (driver) { eeh_pcid_put(dev); if (driver->err_handler) return NULL; } /* Remove it from PCI subsystem */ pr_debug("EEH: Removing %s without EEH sensitive driver\n", pci_name(dev)); edev->bus = dev->bus; edev->mode |= EEH_DEV_DISCONNECTED; (*removed)++; pci_lock_rescan_remove(); pci_stop_and_remove_bus_device(dev); pci_unlock_rescan_remove(); return NULL; } static void *eeh_pe_detach_dev(void *data, void *userdata) { struct eeh_pe *pe = (struct eeh_pe *)data; struct eeh_dev *edev, *tmp; eeh_pe_for_each_dev(pe, edev, tmp) { if (!(edev->mode & EEH_DEV_DISCONNECTED)) continue; edev->mode &= ~(EEH_DEV_DISCONNECTED | EEH_DEV_IRQ_DISABLED); eeh_rmv_from_parent_pe(edev); } return NULL; } /** * eeh_reset_device - Perform actual reset of a pci slot * @pe: EEH PE * @bus: PCI bus corresponding to the isolcated slot * * This routine must be called to do reset on the indicated PE. * During the reset, udev might be invoked because those affected * PCI devices will be removed and then added. */ static int eeh_reset_device(struct eeh_pe *pe, struct pci_bus *bus) { struct pci_bus *frozen_bus = eeh_pe_bus_get(pe); struct timeval tstamp; int cnt, rc, removed = 0; /* pcibios will clear the counter; save the value */ cnt = pe->freeze_count; tstamp = pe->tstamp; /* * We don't remove the corresponding PE instances because * we need the information afterwords. The attached EEH * devices are expected to be attached soon when calling * into pcibios_add_pci_devices(). */ eeh_pe_state_mark(pe, EEH_PE_KEEP); if (bus) { pci_lock_rescan_remove(); pcibios_remove_pci_devices(bus); pci_unlock_rescan_remove(); } else if (frozen_bus) { eeh_pe_dev_traverse(pe, eeh_rmv_device, &removed); } /* Reset the pci controller. (Asserts RST#; resets config space). * Reconfigure bridges and devices. Don't try to bring the system * up if the reset failed for some reason. */ rc = eeh_reset_pe(pe); if (rc) return rc; pci_lock_rescan_remove(); /* Restore PE */ eeh_ops->configure_bridge(pe); eeh_pe_restore_bars(pe); /* Give the system 5 seconds to finish running the user-space * hotplug shutdown scripts, e.g. ifdown for ethernet. Yes, * this is a hack, but if we don't do this, and try to bring * the device up before the scripts have taken it down, * potentially weird things happen. */ if (bus) { pr_info("EEH: Sleep 5s ahead of complete hotplug\n"); ssleep(5); /* * The EEH device is still connected with its parent * PE. We should disconnect it so the binding can be * rebuilt when adding PCI devices. */ eeh_pe_traverse(pe, eeh_pe_detach_dev, NULL); pcibios_add_pci_devices(bus); } else if (frozen_bus && removed) { pr_info("EEH: Sleep 5s ahead of partial hotplug\n"); ssleep(5); eeh_pe_traverse(pe, eeh_pe_detach_dev, NULL); pcibios_add_pci_devices(frozen_bus); } eeh_pe_state_clear(pe, EEH_PE_KEEP); pe->tstamp = tstamp; pe->freeze_count = cnt; pci_unlock_rescan_remove(); return 0; } /* The longest amount of time to wait for a pci device * to come back on line, in seconds. */ #define MAX_WAIT_FOR_RECOVERY 300 static void eeh_handle_normal_event(struct eeh_pe *pe) { struct pci_bus *frozen_bus; int rc = 0; enum pci_ers_result result = PCI_ERS_RESULT_NONE; frozen_bus = eeh_pe_bus_get(pe); if (!frozen_bus) { pr_err("%s: Cannot find PCI bus for PHB#%d-PE#%x\n", __func__, pe->phb->global_number, pe->addr); return; } eeh_pe_update_time_stamp(pe); pe->freeze_count++; if (pe->freeze_count > EEH_MAX_ALLOWED_FREEZES) goto excess_failures; pr_warning("EEH: This PCI device has failed %d times in the last hour\n", pe->freeze_count); /* Walk the various device drivers attached to this slot through * a reset sequence, giving each an opportunity to do what it needs * to accomplish the reset. Each child gets a report of the * status ... if any child can't handle the reset, then the entire * slot is dlpar removed and added. */ pr_info("EEH: Notify device drivers to shutdown\n"); eeh_pe_dev_traverse(pe, eeh_report_error, &result); /* Get the current PCI slot state. This can take a long time, * sometimes over 3 seconds for certain systems. */ rc = eeh_ops->wait_state(pe, MAX_WAIT_FOR_RECOVERY*1000); if (rc < 0 || rc == EEH_STATE_NOT_SUPPORT) { pr_warning("EEH: Permanent failure\n"); goto hard_fail; } /* Since rtas may enable MMIO when posting the error log, * don't post the error log until after all dev drivers * have been informed. */ pr_info("EEH: Collect temporary log\n"); eeh_slot_error_detail(pe, EEH_LOG_TEMP); /* If all device drivers were EEH-unaware, then shut * down all of the device drivers, and hope they * go down willingly, without panicing the system. */ if (result == PCI_ERS_RESULT_NONE) { pr_info("EEH: Reset with hotplug activity\n"); rc = eeh_reset_device(pe, frozen_bus); if (rc) { pr_warning("%s: Unable to reset, err=%d\n", __func__, rc); goto hard_fail; } } /* If all devices reported they can proceed, then re-enable MMIO */ if (result == PCI_ERS_RESULT_CAN_RECOVER) { pr_info("EEH: Enable I/O for affected devices\n"); rc = eeh_pci_enable(pe, EEH_OPT_THAW_MMIO); if (rc < 0) goto hard_fail; if (rc) { result = PCI_ERS_RESULT_NEED_RESET; } else { pr_info("EEH: Notify device drivers to resume I/O\n"); result = PCI_ERS_RESULT_NONE; eeh_pe_dev_traverse(pe, eeh_report_mmio_enabled, &result); } } /* If all devices reported they can proceed, then re-enable DMA */ if (result == PCI_ERS_RESULT_CAN_RECOVER) { pr_info("EEH: Enabled DMA for affected devices\n"); rc = eeh_pci_enable(pe, EEH_OPT_THAW_DMA); if (rc < 0) goto hard_fail; if (rc) result = PCI_ERS_RESULT_NEED_RESET; else result = PCI_ERS_RESULT_RECOVERED; } /* If any device has a hard failure, then shut off everything. */ if (result == PCI_ERS_RESULT_DISCONNECT) { pr_warning("EEH: Device driver gave up\n"); goto hard_fail; } /* If any device called out for a reset, then reset the slot */ if (result == PCI_ERS_RESULT_NEED_RESET) { pr_info("EEH: Reset without hotplug activity\n"); rc = eeh_reset_device(pe, NULL); if (rc) { pr_warning("%s: Cannot reset, err=%d\n", __func__, rc); goto hard_fail; } pr_info("EEH: Notify device drivers " "the completion of reset\n"); result = PCI_ERS_RESULT_NONE; eeh_pe_dev_traverse(pe, eeh_report_reset, &result); } /* All devices should claim they have recovered by now. */ if ((result != PCI_ERS_RESULT_RECOVERED) && (result != PCI_ERS_RESULT_NONE)) { pr_warning("EEH: Not recovered\n"); goto hard_fail; } /* Tell all device drivers that they can resume operations */ pr_info("EEH: Notify device driver to resume\n"); eeh_pe_dev_traverse(pe, eeh_report_resume, NULL); return; excess_failures: /* * About 90% of all real-life EEH failures in the field * are due to poorly seated PCI cards. Only 10% or so are * due to actual, failed cards. */ pr_err("EEH: PHB#%d-PE#%x has failed %d times in the\n" "last hour and has been permanently disabled.\n" "Please try reseating or replacing it.\n", pe->phb->global_number, pe->addr, pe->freeze_count); goto perm_error; hard_fail: pr_err("EEH: Unable to recover from failure from PHB#%d-PE#%x.\n" "Please try reseating or replacing it\n", pe->phb->global_number, pe->addr); perm_error: eeh_slot_error_detail(pe, EEH_LOG_PERM); /* Notify all devices that they're about to go down. */ eeh_pe_dev_traverse(pe, eeh_report_failure, NULL); /* Shut down the device drivers for good. */ if (frozen_bus) { pci_lock_rescan_remove(); pcibios_remove_pci_devices(frozen_bus); pci_unlock_rescan_remove(); } } static void eeh_handle_special_event(void) { struct eeh_pe *pe, *phb_pe; struct pci_bus *bus; struct pci_controller *hose; unsigned long flags; int rc; do { rc = eeh_ops->next_error(&pe); switch (rc) { case EEH_NEXT_ERR_DEAD_IOC: /* Mark all PHBs in dead state */ eeh_serialize_lock(&flags); /* Purge all events */ eeh_remove_event(NULL); list_for_each_entry(hose, &hose_list, list_node) { phb_pe = eeh_phb_pe_get(hose); if (!phb_pe) continue; eeh_pe_state_mark(phb_pe, EEH_PE_ISOLATED | EEH_PE_PHB_DEAD); } eeh_serialize_unlock(flags); break; case EEH_NEXT_ERR_FROZEN_PE: case EEH_NEXT_ERR_FENCED_PHB: case EEH_NEXT_ERR_DEAD_PHB: /* Mark the PE in fenced state */ eeh_serialize_lock(&flags); /* Purge all events of the PHB */ eeh_remove_event(pe); if (rc == EEH_NEXT_ERR_DEAD_PHB) eeh_pe_state_mark(pe, EEH_PE_ISOLATED | EEH_PE_PHB_DEAD); else eeh_pe_state_mark(pe, EEH_PE_ISOLATED | EEH_PE_RECOVERING); eeh_serialize_unlock(flags); break; case EEH_NEXT_ERR_NONE: return; default: pr_warn("%s: Invalid value %d from next_error()\n", __func__, rc); return; } /* * For fenced PHB and frozen PE, it's handled as normal * event. We have to remove the affected PHBs for dead * PHB and IOC */ if (rc == EEH_NEXT_ERR_FROZEN_PE || rc == EEH_NEXT_ERR_FENCED_PHB) { eeh_handle_normal_event(pe); } else { pci_lock_rescan_remove(); list_for_each_entry(hose, &hose_list, list_node) { phb_pe = eeh_phb_pe_get(hose); if (!phb_pe || !(phb_pe->state & EEH_PE_PHB_DEAD)) continue; /* Notify all devices to be down */ bus = eeh_pe_bus_get(phb_pe); eeh_pe_dev_traverse(pe, eeh_report_failure, NULL); pcibios_remove_pci_devices(bus); } pci_unlock_rescan_remove(); } /* * If we have detected dead IOC, we needn't proceed * any more since all PHBs would have been removed */ if (rc == EEH_NEXT_ERR_DEAD_IOC) break; } while (rc != EEH_NEXT_ERR_NONE); } /** * eeh_handle_event - Reset a PCI device after hard lockup. * @pe: EEH PE * * While PHB detects address or data parity errors on particular PCI * slot, the associated PE will be frozen. Besides, DMA's occurring * to wild addresses (which usually happen due to bugs in device * drivers or in PCI adapter firmware) can cause EEH error. #SERR, * #PERR or other misc PCI-related errors also can trigger EEH errors. * * Recovery process consists of unplugging the device driver (which * generated hotplug events to userspace), then issuing a PCI #RST to * the device, then reconfiguring the PCI config space for all bridges * & devices under this slot, and then finally restarting the device * drivers (which cause a second set of hotplug events to go out to * userspace). */ void eeh_handle_event(struct eeh_pe *pe) { if (pe) eeh_handle_normal_event(pe); else eeh_handle_special_event(); }