/* * PCI Error Recovery Driver for RPA-compliant PPC64 platform. * Copyright IBM Corp. 2004 2005 * Copyright Linas Vepstas <linas@linas.org> 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 <linas@austin.ibm.com> */ #include <linux/delay.h> #include <linux/interrupt.h> #include <linux/irq.h> #include <linux/pci.h> #include <asm/eeh.h> #include <asm/eeh_event.h> #include <asm/ppc-pci.h> #include <asm/pci-bridge.h> #include <asm/prom.h> #include <asm/rtas.h> static inline const char * pcid_name (struct pci_dev *pdev) { if (pdev && pdev->dev.driver) return pdev->dev.driver->name; return ""; } #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 /** * irq_in_use - return true if this irq is being used */ static int irq_in_use(unsigned int irq) { int rc = 0; unsigned long flags; struct irq_desc *desc = irq_desc + irq; spin_lock_irqsave(&desc->lock, flags); if (desc->action) rc = 1; spin_unlock_irqrestore(&desc->lock, flags); return rc; } /** * eeh_disable_irq - disable interrupt for the recovering device */ static void eeh_disable_irq(struct pci_dev *dev) { struct device_node *dn = pci_device_to_OF_node(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_in_use(dev->irq)) return; PCI_DN(dn)->eeh_mode |= EEH_MODE_IRQ_DISABLED; disable_irq_nosync(dev->irq); } /** * eeh_enable_irq - enable interrupt for the recovering device */ static void eeh_enable_irq(struct pci_dev *dev) { struct device_node *dn = pci_device_to_OF_node(dev); if ((PCI_DN(dn)->eeh_mode) & EEH_MODE_IRQ_DISABLED) { PCI_DN(dn)->eeh_mode &= ~EEH_MODE_IRQ_DISABLED; enable_irq(dev->irq); } } /* ------------------------------------------------------- */ /** * eeh_report_error - report pci error to each device driver * * 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(struct pci_dev *dev, void *userdata) { enum pci_ers_result rc, *res = userdata; struct pci_driver *driver = dev->driver; dev->error_state = pci_channel_io_frozen; if (!driver) return; eeh_disable_irq(dev); if (!driver->err_handler || !driver->err_handler->error_detected) return; 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_report_mmio_enabled - tell drivers that MMIO has been enabled * * 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(struct pci_dev *dev, void *userdata) { enum pci_ers_result rc, *res = userdata; struct pci_driver *driver = dev->driver; if (!driver || !driver->err_handler || !driver->err_handler->mmio_enabled) return; 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_report_reset - tell device that slot has been reset */ static void eeh_report_reset(struct pci_dev *dev, void *userdata) { enum pci_ers_result rc, *res = userdata; struct pci_driver *driver = dev->driver; if (!driver) return; dev->error_state = pci_channel_io_normal; eeh_enable_irq(dev); if (!driver->err_handler || !driver->err_handler->slot_reset) return; 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_report_resume - tell device to resume normal operations */ static void eeh_report_resume(struct pci_dev *dev, void *userdata) { struct pci_driver *driver = dev->driver; dev->error_state = pci_channel_io_normal; if (!driver) return; eeh_enable_irq(dev); if (!driver->err_handler || !driver->err_handler->resume) return; driver->err_handler->resume(dev); } /** * eeh_report_failure - tell device driver that device is dead. * * 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(struct pci_dev *dev, void *userdata) { struct pci_driver *driver = dev->driver; dev->error_state = pci_channel_io_perm_failure; if (!driver) return; eeh_disable_irq(dev); if (!driver->err_handler || !driver->err_handler->error_detected) return; driver->err_handler->error_detected(dev, pci_channel_io_perm_failure); } /* ------------------------------------------------------- */ /** * handle_eeh_events -- reset a PCI device after hard lockup. * * pSeries systems will isolate a PCI slot if the PCI-Host * bridge detects address or data parity errors, DMA's * occurring to wild addresses (which usually happen due to * bugs in device drivers or in PCI adapter firmware). * Slot isolations also occur if #SERR, #PERR or other misc * PCI-related errors are detected. * * 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). */ /** * eeh_reset_device() -- perform actual reset of a pci slot * @bus: pointer to the pci bus structure corresponding * to the isolated slot. A non-null value will * cause all devices under the bus to be removed * and then re-added. * @pe_dn: pointer to a "Partionable Endpoint" device node. * This is the top-level structure on which pci * bus resets can be performed. */ static int eeh_reset_device (struct pci_dn *pe_dn, struct pci_bus *bus) { struct device_node *dn; int cnt, rc; /* pcibios will clear the counter; save the value */ cnt = pe_dn->eeh_freeze_count; if (bus) pcibios_remove_pci_devices(bus); /* 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 = rtas_set_slot_reset(pe_dn); if (rc) return rc; /* Walk over all functions on this device. */ dn = pe_dn->node; if (!pcibios_find_pci_bus(dn) && PCI_DN(dn->parent)) dn = dn->parent->child; while (dn) { struct pci_dn *ppe = PCI_DN(dn); /* On Power4, always true because eeh_pe_config_addr=0 */ if (pe_dn->eeh_pe_config_addr == ppe->eeh_pe_config_addr) { rtas_configure_bridge(ppe); eeh_restore_bars(ppe); } dn = dn->sibling; } /* 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) { ssleep (5); pcibios_add_pci_devices(bus); } pe_dn->eeh_freeze_count = cnt; 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 150 struct pci_dn * handle_eeh_events (struct eeh_event *event) { struct device_node *frozen_dn; struct pci_dn *frozen_pdn; struct pci_bus *frozen_bus; int rc = 0; enum pci_ers_result result = PCI_ERS_RESULT_NONE; const char *location, *pci_str, *drv_str; frozen_dn = find_device_pe(event->dn); if (!frozen_dn) { location = of_get_property(event->dn, "ibm,loc-code", NULL); location = location ? location : "unknown"; printk(KERN_ERR "EEH: Error: Cannot find partition endpoint " "for location=%s pci addr=%s\n", location, pci_name(event->dev)); return NULL; } frozen_bus = pcibios_find_pci_bus(frozen_dn); location = of_get_property(frozen_dn, "ibm,loc-code", NULL); location = location ? location : "unknown"; /* There are two different styles for coming up with the PE. * In the old style, it was the highest EEH-capable device * which was always an EADS pci bridge. In the new style, * there might not be any EADS bridges, and even when there are, * the firmware marks them as "EEH incapable". So another * two-step is needed to find the pci bus.. */ if (!frozen_bus) frozen_bus = pcibios_find_pci_bus (frozen_dn->parent); if (!frozen_bus) { printk(KERN_ERR "EEH: Cannot find PCI bus " "for location=%s dn=%s\n", location, frozen_dn->full_name); return NULL; } frozen_pdn = PCI_DN(frozen_dn); frozen_pdn->eeh_freeze_count++; if (frozen_pdn->pcidev) { pci_str = pci_name (frozen_pdn->pcidev); drv_str = pcid_name (frozen_pdn->pcidev); } else { pci_str = pci_name (event->dev); drv_str = pcid_name (event->dev); } if (frozen_pdn->eeh_freeze_count > EEH_MAX_ALLOWED_FREEZES) goto excess_failures; printk(KERN_WARNING "EEH: This PCI device has failed %d times in the last hour:\n", frozen_pdn->eeh_freeze_count); printk(KERN_WARNING "EEH: location=%s driver=%s pci addr=%s\n", location, drv_str, pci_str); /* 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. */ pci_walk_bus(frozen_bus, 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_wait_for_slot_status (frozen_pdn, MAX_WAIT_FOR_RECOVERY*1000); if (rc < 0) { printk(KERN_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. */ eeh_slot_error_detail(frozen_pdn, EEH_LOG_TEMP_FAILURE); /* 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) { rc = eeh_reset_device(frozen_pdn, frozen_bus); if (rc) { printk(KERN_WARNING "EEH: Unable to reset, rc=%d\n", rc); goto hard_fail; } } /* If all devices reported they can proceed, then re-enable MMIO */ if (result == PCI_ERS_RESULT_CAN_RECOVER) { rc = rtas_pci_enable(frozen_pdn, EEH_THAW_MMIO); if (rc < 0) goto hard_fail; if (rc) { result = PCI_ERS_RESULT_NEED_RESET; } else { result = PCI_ERS_RESULT_NONE; pci_walk_bus(frozen_bus, eeh_report_mmio_enabled, &result); } } /* If all devices reported they can proceed, then re-enable DMA */ if (result == PCI_ERS_RESULT_CAN_RECOVER) { rc = rtas_pci_enable(frozen_pdn, EEH_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) { printk(KERN_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) { rc = eeh_reset_device(frozen_pdn, NULL); if (rc) { printk(KERN_WARNING "EEH: Cannot reset, rc=%d\n", rc); goto hard_fail; } result = PCI_ERS_RESULT_NONE; pci_walk_bus(frozen_bus, eeh_report_reset, &result); } /* All devices should claim they have recovered by now. */ if ((result != PCI_ERS_RESULT_RECOVERED) && (result != PCI_ERS_RESULT_NONE)) { printk(KERN_WARNING "EEH: Not recovered\n"); goto hard_fail; } /* Tell all device drivers that they can resume operations */ pci_walk_bus(frozen_bus, eeh_report_resume, NULL); return frozen_pdn; 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. */ printk(KERN_ERR "EEH: PCI device at location=%s driver=%s pci addr=%s \n" "has failed %d times in the last hour " "and has been permanently disabled. \n" "Please try reseating this device or replacing it.\n", location, drv_str, pci_str, frozen_pdn->eeh_freeze_count); goto perm_error; hard_fail: printk(KERN_ERR "EEH: Unable to recover from failure of PCI device " "at location=%s driver=%s pci addr=%s \n" "Please try reseating this device or replacing it.\n", location, drv_str, pci_str); perm_error: eeh_slot_error_detail(frozen_pdn, EEH_LOG_PERM_FAILURE); /* Notify all devices that they're about to go down. */ pci_walk_bus(frozen_bus, eeh_report_failure, NULL); /* Shut down the device drivers for good. */ pcibios_remove_pci_devices(frozen_bus); return NULL; } /* ---------- end of file ---------- */