// SPDX-License-Identifier: GPL-2.0-or-later /* * PCI Error Recovery Driver for RPA-compliant PPC64 platform. * Copyright IBM Corp. 2004 2005 * Copyright Linas Vepstas <linas@linas.org> 2004, 2005 * * Send comments and feedback to Linas Vepstas <linas@austin.ibm.com> */ #include <linux/delay.h> #include <linux/interrupt.h> #include <linux/irq.h> #include <linux/module.h> #include <linux/pci.h> #include <linux/pci_hotplug.h> #include <asm/eeh.h> #include <asm/eeh_event.h> #include <asm/ppc-pci.h> #include <asm/pci-bridge.h> #include <asm/rtas.h> struct eeh_rmv_data { struct list_head removed_vf_list; int removed_dev_count; }; static int eeh_result_priority(enum pci_ers_result result) { switch (result) { case PCI_ERS_RESULT_NONE: return 1; case PCI_ERS_RESULT_NO_AER_DRIVER: return 2; case PCI_ERS_RESULT_RECOVERED: return 3; case PCI_ERS_RESULT_CAN_RECOVER: return 4; case PCI_ERS_RESULT_DISCONNECT: return 5; case PCI_ERS_RESULT_NEED_RESET: return 6; default: WARN_ONCE(1, "Unknown pci_ers_result value: %d\n", (int)result); return 0; } }; static const char *pci_ers_result_name(enum pci_ers_result result) { switch (result) { case PCI_ERS_RESULT_NONE: return "none"; case PCI_ERS_RESULT_CAN_RECOVER: return "can recover"; case PCI_ERS_RESULT_NEED_RESET: return "need reset"; case PCI_ERS_RESULT_DISCONNECT: return "disconnect"; case PCI_ERS_RESULT_RECOVERED: return "recovered"; case PCI_ERS_RESULT_NO_AER_DRIVER: return "no AER driver"; default: WARN_ONCE(1, "Unknown result type: %d\n", (int)result); return "unknown"; } }; static enum pci_ers_result pci_ers_merge_result(enum pci_ers_result old, enum pci_ers_result new) { if (eeh_result_priority(new) > eeh_result_priority(old)) return new; return old; } static bool eeh_dev_removed(struct eeh_dev *edev) { return !edev || (edev->mode & EEH_DEV_REMOVED); } static bool eeh_edev_actionable(struct eeh_dev *edev) { if (!edev->pdev) return false; if (edev->pdev->error_state == pci_channel_io_perm_failure) return false; if (eeh_dev_removed(edev)) return false; if (eeh_pe_passed(edev->pe)) return false; return true; } /** * 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->dev.driver) return NULL; if (!try_module_get(pdev->dev.driver->owner)) return NULL; return to_pci_driver(pdev->dev.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->dev.driver) return; module_put(pdev->dev.driver->owner); } /** * 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 eeh_dev *edev) { /* Don't disable MSI and MSI-X interrupts. They are * effectively disabled by the DMA Stopped state * when an EEH error occurs. */ if (edev->pdev->msi_enabled || edev->pdev->msix_enabled) return; if (!irq_has_action(edev->pdev->irq)) return; edev->mode |= EEH_DEV_IRQ_DISABLED; disable_irq_nosync(edev->pdev->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 eeh_dev *edev) { if ((edev->mode) & EEH_DEV_IRQ_DISABLED) { edev->mode &= ~EEH_DEV_IRQ_DISABLED; /* * FIXME !!!!! * * This is just ass backwards. This maze has * unbalanced irq_enable/disable calls. So instead of * finding the root cause it works around the warning * in the irq_enable code by conditionally calling * into it. * * That's just wrong.The warning in the core code is * there to tell people to fix their asymmetries in * their own code, not by abusing the core information * to avoid it. * * I so wish that the assymetry would be the other way * round and a few more irq_disable calls render that * shit unusable forever. * * tglx */ if (irqd_irq_disabled(irq_get_irq_data(edev->pdev->irq))) enable_irq(edev->pdev->irq); } } static void eeh_dev_save_state(struct eeh_dev *edev, void *userdata) { struct pci_dev *pdev; if (!edev) return; /* * We cannot access the config space on some adapters. * Otherwise, it will cause fenced PHB. We don't save * the content in their config space and will restore * from the initial config space saved when the EEH * device is created. */ if (edev->pe && (edev->pe->state & EEH_PE_CFG_RESTRICTED)) return; pdev = eeh_dev_to_pci_dev(edev); if (!pdev) return; pci_save_state(pdev); } static void eeh_set_channel_state(struct eeh_pe *root, pci_channel_state_t s) { struct eeh_pe *pe; struct eeh_dev *edev, *tmp; eeh_for_each_pe(root, pe) eeh_pe_for_each_dev(pe, edev, tmp) if (eeh_edev_actionable(edev)) edev->pdev->error_state = s; } static void eeh_set_irq_state(struct eeh_pe *root, bool enable) { struct eeh_pe *pe; struct eeh_dev *edev, *tmp; eeh_for_each_pe(root, pe) { eeh_pe_for_each_dev(pe, edev, tmp) { if (!eeh_edev_actionable(edev)) continue; if (!eeh_pcid_get(edev->pdev)) continue; if (enable) eeh_enable_irq(edev); else eeh_disable_irq(edev); eeh_pcid_put(edev->pdev); } } } typedef enum pci_ers_result (*eeh_report_fn)(struct eeh_dev *, struct pci_dev *, struct pci_driver *); static void eeh_pe_report_edev(struct eeh_dev *edev, eeh_report_fn fn, enum pci_ers_result *result) { struct pci_dev *pdev; struct pci_driver *driver; enum pci_ers_result new_result; pci_lock_rescan_remove(); pdev = edev->pdev; if (pdev) get_device(&pdev->dev); pci_unlock_rescan_remove(); if (!pdev) { eeh_edev_info(edev, "no device"); return; } device_lock(&pdev->dev); if (eeh_edev_actionable(edev)) { driver = eeh_pcid_get(pdev); if (!driver) eeh_edev_info(edev, "no driver"); else if (!driver->err_handler) eeh_edev_info(edev, "driver not EEH aware"); else if (edev->mode & EEH_DEV_NO_HANDLER) eeh_edev_info(edev, "driver bound too late"); else { new_result = fn(edev, pdev, driver); eeh_edev_info(edev, "%s driver reports: '%s'", driver->name, pci_ers_result_name(new_result)); if (result) *result = pci_ers_merge_result(*result, new_result); } if (driver) eeh_pcid_put(pdev); } else { eeh_edev_info(edev, "not actionable (%d,%d,%d)", !!pdev, !eeh_dev_removed(edev), !eeh_pe_passed(edev->pe)); } device_unlock(&pdev->dev); if (edev->pdev != pdev) eeh_edev_warn(edev, "Device changed during processing!\n"); put_device(&pdev->dev); } static void eeh_pe_report(const char *name, struct eeh_pe *root, eeh_report_fn fn, enum pci_ers_result *result) { struct eeh_pe *pe; struct eeh_dev *edev, *tmp; pr_info("EEH: Beginning: '%s'\n", name); eeh_for_each_pe(root, pe) eeh_pe_for_each_dev(pe, edev, tmp) eeh_pe_report_edev(edev, fn, result); if (result) pr_info("EEH: Finished:'%s' with aggregate recovery state:'%s'\n", name, pci_ers_result_name(*result)); else pr_info("EEH: Finished:'%s'", name); } /** * eeh_report_error - Report pci error to each device driver * @edev: eeh device * @driver: device's PCI driver * * Report an EEH error to each device driver. */ static enum pci_ers_result eeh_report_error(struct eeh_dev *edev, struct pci_dev *pdev, struct pci_driver *driver) { enum pci_ers_result rc; if (!driver->err_handler->error_detected) return PCI_ERS_RESULT_NONE; eeh_edev_info(edev, "Invoking %s->error_detected(IO frozen)", driver->name); rc = driver->err_handler->error_detected(pdev, pci_channel_io_frozen); edev->in_error = true; pci_uevent_ers(pdev, PCI_ERS_RESULT_NONE); return rc; } /** * eeh_report_mmio_enabled - Tell drivers that MMIO has been enabled * @edev: eeh device * @driver: device's PCI driver * * Tells each device driver that IO ports, MMIO and config space I/O * are now enabled. */ static enum pci_ers_result eeh_report_mmio_enabled(struct eeh_dev *edev, struct pci_dev *pdev, struct pci_driver *driver) { if (!driver->err_handler->mmio_enabled) return PCI_ERS_RESULT_NONE; eeh_edev_info(edev, "Invoking %s->mmio_enabled()", driver->name); return driver->err_handler->mmio_enabled(pdev); } /** * eeh_report_reset - Tell device that slot has been reset * @edev: eeh device * @driver: device's PCI driver * * 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 enum pci_ers_result eeh_report_reset(struct eeh_dev *edev, struct pci_dev *pdev, struct pci_driver *driver) { if (!driver->err_handler->slot_reset || !edev->in_error) return PCI_ERS_RESULT_NONE; eeh_edev_info(edev, "Invoking %s->slot_reset()", driver->name); return driver->err_handler->slot_reset(pdev); } static void eeh_dev_restore_state(struct eeh_dev *edev, void *userdata) { struct pci_dev *pdev; if (!edev) return; /* * The content in the config space isn't saved because * the blocked config space on some adapters. We have * to restore the initial saved config space when the * EEH device is created. */ if (edev->pe && (edev->pe->state & EEH_PE_CFG_RESTRICTED)) { if (list_is_last(&edev->entry, &edev->pe->edevs)) eeh_pe_restore_bars(edev->pe); return; } pdev = eeh_dev_to_pci_dev(edev); if (!pdev) return; pci_restore_state(pdev); } /** * eeh_report_resume - Tell device to resume normal operations * @edev: eeh device * @driver: device's PCI driver * * 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 enum pci_ers_result eeh_report_resume(struct eeh_dev *edev, struct pci_dev *pdev, struct pci_driver *driver) { if (!driver->err_handler->resume || !edev->in_error) return PCI_ERS_RESULT_NONE; eeh_edev_info(edev, "Invoking %s->resume()", driver->name); driver->err_handler->resume(pdev); pci_uevent_ers(edev->pdev, PCI_ERS_RESULT_RECOVERED); #ifdef CONFIG_PCI_IOV if (eeh_ops->notify_resume) eeh_ops->notify_resume(edev); #endif return PCI_ERS_RESULT_NONE; } /** * eeh_report_failure - Tell device driver that device is dead. * @edev: eeh device * @driver: device's PCI driver * * This informs the device driver that the device is permanently * dead, and that no further recovery attempts will be made on it. */ static enum pci_ers_result eeh_report_failure(struct eeh_dev *edev, struct pci_dev *pdev, struct pci_driver *driver) { enum pci_ers_result rc; if (!driver->err_handler->error_detected) return PCI_ERS_RESULT_NONE; eeh_edev_info(edev, "Invoking %s->error_detected(permanent failure)", driver->name); rc = driver->err_handler->error_detected(pdev, pci_channel_io_perm_failure); pci_uevent_ers(pdev, PCI_ERS_RESULT_DISCONNECT); return rc; } static void *eeh_add_virt_device(struct eeh_dev *edev) { struct pci_driver *driver; struct pci_dev *dev = eeh_dev_to_pci_dev(edev); if (!(edev->physfn)) { eeh_edev_warn(edev, "Not for VF\n"); return NULL; } driver = eeh_pcid_get(dev); if (driver) { if (driver->err_handler) { eeh_pcid_put(dev); return NULL; } eeh_pcid_put(dev); } #ifdef CONFIG_PCI_IOV pci_iov_add_virtfn(edev->physfn, edev->vf_index); #endif return NULL; } static void eeh_rmv_device(struct eeh_dev *edev, void *userdata) { struct pci_driver *driver; struct pci_dev *dev = eeh_dev_to_pci_dev(edev); struct eeh_rmv_data *rmv_data = (struct eeh_rmv_data *)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 (!eeh_edev_actionable(edev) || (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE)) return; if (rmv_data) { driver = eeh_pcid_get(dev); if (driver) { if (driver->err_handler && driver->err_handler->error_detected && driver->err_handler->slot_reset) { eeh_pcid_put(dev); return; } eeh_pcid_put(dev); } } /* Remove it from PCI subsystem */ pr_info("EEH: Removing %s without EEH sensitive driver\n", pci_name(dev)); edev->mode |= EEH_DEV_DISCONNECTED; if (rmv_data) rmv_data->removed_dev_count++; if (edev->physfn) { #ifdef CONFIG_PCI_IOV pci_iov_remove_virtfn(edev->physfn, edev->vf_index); edev->pdev = NULL; #endif if (rmv_data) list_add(&edev->rmv_entry, &rmv_data->removed_vf_list); } else { pci_lock_rescan_remove(); pci_stop_and_remove_bus_device(dev); pci_unlock_rescan_remove(); } } static void *eeh_pe_detach_dev(struct eeh_pe *pe, void *userdata) { 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_pe_tree_remove(edev); } return NULL; } /* * Explicitly clear PE's frozen state for PowerNV where * we have frozen PE until BAR restore is completed. It's * harmless to clear it for pSeries. To be consistent with * PE reset (for 3 times), we try to clear the frozen state * for 3 times as well. */ static int eeh_clear_pe_frozen_state(struct eeh_pe *root, bool include_passed) { struct eeh_pe *pe; int i; eeh_for_each_pe(root, pe) { if (include_passed || !eeh_pe_passed(pe)) { for (i = 0; i < 3; i++) if (!eeh_unfreeze_pe(pe)) break; if (i >= 3) return -EIO; } } eeh_pe_state_clear(root, EEH_PE_ISOLATED, include_passed); return 0; } int eeh_pe_reset_and_recover(struct eeh_pe *pe) { int ret; /* Bail if the PE is being recovered */ if (pe->state & EEH_PE_RECOVERING) return 0; /* Put the PE into recovery mode */ eeh_pe_state_mark(pe, EEH_PE_RECOVERING); /* Save states */ eeh_pe_dev_traverse(pe, eeh_dev_save_state, NULL); /* Issue reset */ ret = eeh_pe_reset_full(pe, true); if (ret) { eeh_pe_state_clear(pe, EEH_PE_RECOVERING, true); return ret; } /* Unfreeze the PE */ ret = eeh_clear_pe_frozen_state(pe, true); if (ret) { eeh_pe_state_clear(pe, EEH_PE_RECOVERING, true); return ret; } /* Restore device state */ eeh_pe_dev_traverse(pe, eeh_dev_restore_state, NULL); /* Clear recovery mode */ eeh_pe_state_clear(pe, EEH_PE_RECOVERING, true); return 0; } /** * eeh_reset_device - Perform actual reset of a pci slot * @driver_eeh_aware: Does the device's driver provide EEH support? * @pe: EEH PE * @bus: PCI bus corresponding to the isolcated slot * @rmv_data: Optional, list to record removed devices * * 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 eeh_rmv_data *rmv_data, bool driver_eeh_aware) { time64_t tstamp; int cnt, rc; struct eeh_dev *edev; struct eeh_pe *tmp_pe; bool any_passed = false; eeh_for_each_pe(pe, tmp_pe) any_passed |= eeh_pe_passed(tmp_pe); /* 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 pci_hp_add_devices(). */ eeh_pe_state_mark(pe, EEH_PE_KEEP); if (any_passed || driver_eeh_aware || (pe->type & EEH_PE_VF)) { eeh_pe_dev_traverse(pe, eeh_rmv_device, rmv_data); } else { pci_lock_rescan_remove(); pci_hp_remove_devices(bus); pci_unlock_rescan_remove(); } /* * 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. * * During the reset, it's very dangerous to have uncontrolled PCI * config accesses. So we prefer to block them. However, controlled * PCI config accesses initiated from EEH itself are allowed. */ rc = eeh_pe_reset_full(pe, false); if (rc) return rc; pci_lock_rescan_remove(); /* Restore PE */ eeh_ops->configure_bridge(pe); eeh_pe_restore_bars(pe); /* Clear frozen state */ rc = eeh_clear_pe_frozen_state(pe, false); if (rc) { pci_unlock_rescan_remove(); return rc; } /* 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 (!driver_eeh_aware || rmv_data->removed_dev_count) { pr_info("EEH: Sleep 5s ahead of %s hotplug\n", (driver_eeh_aware ? "partial" : "complete")); 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. */ edev = list_first_entry(&pe->edevs, struct eeh_dev, entry); eeh_pe_traverse(pe, eeh_pe_detach_dev, NULL); if (pe->type & EEH_PE_VF) { eeh_add_virt_device(edev); } else { if (!driver_eeh_aware) eeh_pe_state_clear(pe, EEH_PE_PRI_BUS, true); pci_hp_add_devices(bus); } } eeh_pe_state_clear(pe, EEH_PE_KEEP, true); 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 /* Walks the PE tree after processing an event to remove any stale PEs. * * NB: This needs to be recursive to ensure the leaf PEs get removed * before their parents do. Although this is possible to do recursively * we don't since this is easier to read and we need to garantee * the leaf nodes will be handled first. */ static void eeh_pe_cleanup(struct eeh_pe *pe) { struct eeh_pe *child_pe, *tmp; list_for_each_entry_safe(child_pe, tmp, &pe->child_list, child) eeh_pe_cleanup(child_pe); if (pe->state & EEH_PE_KEEP) return; if (!(pe->state & EEH_PE_INVALID)) return; if (list_empty(&pe->edevs) && list_empty(&pe->child_list)) { list_del(&pe->child); kfree(pe); } } /** * eeh_check_slot_presence - Check if a device is still present in a slot * @pdev: pci_dev to check * * This function may return a false positive if we can't determine the slot's * presence state. This might happen for for PCIe slots if the PE containing * the upstream bridge is also frozen, or the bridge is part of the same PE * as the device. * * This shouldn't happen often, but you might see it if you hotplug a PCIe * switch. */ static bool eeh_slot_presence_check(struct pci_dev *pdev) { const struct hotplug_slot_ops *ops; struct pci_slot *slot; u8 state; int rc; if (!pdev) return false; if (pdev->error_state == pci_channel_io_perm_failure) return false; slot = pdev->slot; if (!slot || !slot->hotplug) return true; ops = slot->hotplug->ops; if (!ops || !ops->get_adapter_status) return true; /* set the attention indicator while we've got the slot ops */ if (ops->set_attention_status) ops->set_attention_status(slot->hotplug, 1); rc = ops->get_adapter_status(slot->hotplug, &state); if (rc) return true; return !!state; } static void eeh_clear_slot_attention(struct pci_dev *pdev) { const struct hotplug_slot_ops *ops; struct pci_slot *slot; if (!pdev) return; if (pdev->error_state == pci_channel_io_perm_failure) return; slot = pdev->slot; if (!slot || !slot->hotplug) return; ops = slot->hotplug->ops; if (!ops || !ops->set_attention_status) return; ops->set_attention_status(slot->hotplug, 0); } /** * eeh_handle_normal_event - Handle EEH events on a specific PE * @pe: EEH PE - which should not be used after we return, as it may * have been invalidated. * * Attempts to recover the given PE. If recovery fails or the PE has failed * too many times, remove the 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_normal_event(struct eeh_pe *pe) { struct pci_bus *bus; struct eeh_dev *edev, *tmp; struct eeh_pe *tmp_pe; int rc = 0; enum pci_ers_result result = PCI_ERS_RESULT_NONE; struct eeh_rmv_data rmv_data = {LIST_HEAD_INIT(rmv_data.removed_vf_list), 0}; int devices = 0; bus = eeh_pe_bus_get(pe); if (!bus) { pr_err("%s: Cannot find PCI bus for PHB#%x-PE#%x\n", __func__, pe->phb->global_number, pe->addr); return; } /* * When devices are hot-removed we might get an EEH due to * a driver attempting to touch the MMIO space of a removed * device. In this case we don't have a device to recover * so suppress the event if we can't find any present devices. * * The hotplug driver should take care of tearing down the * device itself. */ eeh_for_each_pe(pe, tmp_pe) eeh_pe_for_each_dev(tmp_pe, edev, tmp) if (eeh_slot_presence_check(edev->pdev)) devices++; if (!devices) { pr_debug("EEH: Frozen PHB#%x-PE#%x is empty!\n", pe->phb->global_number, pe->addr); goto out; /* nothing to recover */ } /* Log the event */ if (pe->type & EEH_PE_PHB) { pr_err("EEH: Recovering PHB#%x, location: %s\n", pe->phb->global_number, eeh_pe_loc_get(pe)); } else { struct eeh_pe *phb_pe = eeh_phb_pe_get(pe->phb); pr_err("EEH: Recovering PHB#%x-PE#%x\n", pe->phb->global_number, pe->addr); pr_err("EEH: PE location: %s, PHB location: %s\n", eeh_pe_loc_get(pe), eeh_pe_loc_get(phb_pe)); } #ifdef CONFIG_STACKTRACE /* * Print the saved stack trace now that we've verified there's * something to recover. */ if (pe->trace_entries) { void **ptrs = (void **) pe->stack_trace; int i; pr_err("EEH: Frozen PHB#%x-PE#%x detected\n", pe->phb->global_number, pe->addr); /* FIXME: Use the same format as dump_stack() */ pr_err("EEH: Call Trace:\n"); for (i = 0; i < pe->trace_entries; i++) pr_err("EEH: [%pK] %pS\n", ptrs[i], ptrs[i]); pe->trace_entries = 0; } #endif /* CONFIG_STACKTRACE */ eeh_for_each_pe(pe, tmp_pe) eeh_pe_for_each_dev(tmp_pe, edev, tmp) edev->mode &= ~EEH_DEV_NO_HANDLER; eeh_pe_update_time_stamp(pe); pe->freeze_count++; if (pe->freeze_count > eeh_max_freezes) { pr_err("EEH: PHB#%x-PE#%x has failed %d times in the last hour and has been permanently disabled.\n", pe->phb->global_number, pe->addr, pe->freeze_count); goto recover_failed; } /* 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. * * When the PHB is fenced, we have to issue a reset to recover from * the error. Override the result if necessary to have partially * hotplug for this case. */ pr_warn("EEH: This PCI device has failed %d times in the last hour and will be permanently disabled after %d failures.\n", pe->freeze_count, eeh_max_freezes); pr_info("EEH: Notify device drivers to shutdown\n"); eeh_set_channel_state(pe, pci_channel_io_frozen); eeh_set_irq_state(pe, false); eeh_pe_report("error_detected(IO frozen)", pe, eeh_report_error, &result); if (result == PCI_ERS_RESULT_DISCONNECT) goto recover_failed; /* * Error logged on a PHB are always fences which need a full * PHB reset to clear so force that to happen. */ if ((pe->type & EEH_PE_PHB) && result != PCI_ERS_RESULT_NONE) result = PCI_ERS_RESULT_NEED_RESET; /* Get the current PCI slot state. This can take a long time, * sometimes over 300 seconds for certain systems. */ rc = eeh_wait_state(pe, MAX_WAIT_FOR_RECOVERY * 1000); if (rc < 0 || rc == EEH_STATE_NOT_SUPPORT) { pr_warn("EEH: Permanent failure\n"); goto recover_failed; } /* 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, bus, NULL, false); if (rc) { pr_warn("%s: Unable to reset, err=%d\n", __func__, rc); goto recover_failed; } } /* 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 recover_failed; if (rc) { result = PCI_ERS_RESULT_NEED_RESET; } else { pr_info("EEH: Notify device drivers to resume I/O\n"); eeh_pe_report("mmio_enabled", pe, eeh_report_mmio_enabled, &result); } } 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 recover_failed; if (rc) { result = PCI_ERS_RESULT_NEED_RESET; } else { /* * We didn't do PE reset for the case. The PE * is still in frozen state. Clear it before * resuming the PE. */ eeh_pe_state_clear(pe, EEH_PE_ISOLATED, true); result = PCI_ERS_RESULT_RECOVERED; } } /* 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, bus, &rmv_data, true); if (rc) { pr_warn("%s: Cannot reset, err=%d\n", __func__, rc); goto recover_failed; } result = PCI_ERS_RESULT_NONE; eeh_set_channel_state(pe, pci_channel_io_normal); eeh_set_irq_state(pe, true); eeh_pe_report("slot_reset", pe, eeh_report_reset, &result); } if ((result == PCI_ERS_RESULT_RECOVERED) || (result == PCI_ERS_RESULT_NONE)) { /* * For those hot removed VFs, we should add back them after PF * get recovered properly. */ list_for_each_entry_safe(edev, tmp, &rmv_data.removed_vf_list, rmv_entry) { eeh_add_virt_device(edev); list_del(&edev->rmv_entry); } /* Tell all device drivers that they can resume operations */ pr_info("EEH: Notify device driver to resume\n"); eeh_set_channel_state(pe, pci_channel_io_normal); eeh_set_irq_state(pe, true); eeh_pe_report("resume", pe, eeh_report_resume, NULL); eeh_for_each_pe(pe, tmp_pe) { eeh_pe_for_each_dev(tmp_pe, edev, tmp) { edev->mode &= ~EEH_DEV_NO_HANDLER; edev->in_error = false; } } pr_info("EEH: Recovery successful.\n"); goto out; } recover_failed: /* * 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: Unable to recover from failure from PHB#%x-PE#%x.\n" "Please try reseating or replacing it\n", pe->phb->global_number, pe->addr); eeh_slot_error_detail(pe, EEH_LOG_PERM); /* Notify all devices that they're about to go down. */ eeh_set_channel_state(pe, pci_channel_io_perm_failure); eeh_set_irq_state(pe, false); eeh_pe_report("error_detected(permanent failure)", pe, eeh_report_failure, NULL); /* Mark the PE to be removed permanently */ eeh_pe_state_mark(pe, EEH_PE_REMOVED); /* * Shut down the device drivers for good. We mark * all removed devices correctly to avoid access * the their PCI config any more. */ if (pe->type & EEH_PE_VF) { eeh_pe_dev_traverse(pe, eeh_rmv_device, NULL); eeh_pe_dev_mode_mark(pe, EEH_DEV_REMOVED); } else { eeh_pe_state_clear(pe, EEH_PE_PRI_BUS, true); eeh_pe_dev_mode_mark(pe, EEH_DEV_REMOVED); pci_lock_rescan_remove(); pci_hp_remove_devices(bus); pci_unlock_rescan_remove(); /* The passed PE should no longer be used */ return; } out: /* * Clean up any PEs without devices. While marked as EEH_PE_RECOVERYING * we don't want to modify the PE tree structure so we do it here. */ eeh_pe_cleanup(pe); /* clear the slot attention LED for all recovered devices */ eeh_for_each_pe(pe, tmp_pe) eeh_pe_for_each_dev(tmp_pe, edev, tmp) eeh_clear_slot_attention(edev->pdev); eeh_pe_state_clear(pe, EEH_PE_RECOVERING, true); } /** * eeh_handle_special_event - Handle EEH events without a specific failing PE * * Called when an EEH event is detected but can't be narrowed down to a * specific PE. Iterates through possible failures and handles them as * necessary. */ void eeh_handle_special_event(void) { struct eeh_pe *pe, *phb_pe, *tmp_pe; struct eeh_dev *edev, *tmp_edev; 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, true); list_for_each_entry(hose, &hose_list, list_node) { phb_pe = eeh_phb_pe_get(hose); if (!phb_pe) continue; eeh_pe_mark_isolated(phb_pe); } 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, true); if (rc != EEH_NEXT_ERR_DEAD_PHB) eeh_pe_state_mark(pe, EEH_PE_RECOVERING); eeh_pe_mark_isolated(pe); 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_pe_state_mark(pe, EEH_PE_RECOVERING); eeh_handle_normal_event(pe); } else { eeh_for_each_pe(pe, tmp_pe) eeh_pe_for_each_dev(tmp_pe, edev, tmp_edev) edev->mode &= ~EEH_DEV_NO_HANDLER; /* Notify all devices to be down */ eeh_pe_state_clear(pe, EEH_PE_PRI_BUS, true); eeh_set_channel_state(pe, pci_channel_io_perm_failure); eeh_pe_report( "error_detected(permanent failure)", pe, eeh_report_failure, NULL); 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_ISOLATED) || (phb_pe->state & EEH_PE_RECOVERING)) continue; bus = eeh_pe_bus_get(phb_pe); if (!bus) { pr_err("%s: Cannot find PCI bus for " "PHB#%x-PE#%x\n", __func__, pe->phb->global_number, pe->addr); break; } pci_hp_remove_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); }