diff options
Diffstat (limited to 'arch/powerpc/platforms/pseries/eeh_driver.c')
| -rw-r--r-- | arch/powerpc/platforms/pseries/eeh_driver.c | 366 |
1 files changed, 366 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/pseries/eeh_driver.c b/arch/powerpc/platforms/pseries/eeh_driver.c new file mode 100644 index 0000000000000..f6cff065d89dd --- /dev/null +++ b/arch/powerpc/platforms/pseries/eeh_driver.c @@ -0,0 +1,366 @@ +/* + * PCI Error Recovery Driver for RPA-compliant PPC64 platform. + * Copyright (C) 2004, 2005 Linas Vepstas <linas@linas.org> + * + * 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 feedback to <linas@us.ibm.com> + * + */ +#include <linux/delay.h> +#include <linux/irq.h> +#include <linux/interrupt.h> +#include <linux/notifier.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->dev.driver) + return pdev->dev.driver->name; + return ""; +} + +/** + * Return the "partitionable endpoint" (pe) under which this device lies + */ +static struct device_node * find_device_pe(struct device_node *dn) +{ + while ((dn->parent) && PCI_DN(dn->parent) && + (PCI_DN(dn->parent)->eeh_mode & EEH_MODE_SUPPORTED)) { + dn = dn->parent; + } + return dn; +} + + +#ifdef DEBUG +static void print_device_node_tree (struct pci_dn *pdn, int dent) +{ + int i; + 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; + struct device_node *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_report_error - report an EEH error to each device, + * collect up and merge the device responses. + */ + +static void eeh_report_error(struct pci_dev *dev, void *userdata) +{ + enum pcierr_result rc, *res = userdata; + struct pci_driver *driver = dev->driver; + + dev->error_state = pci_channel_io_frozen; + + if (!driver) + return; + + if (irq_in_use (dev->irq)) { + struct device_node *dn = pci_device_to_OF_node(dev); + PCI_DN(dn)->eeh_mode |= EEH_MODE_IRQ_DISABLED; + disable_irq_nosync(dev->irq); + } + if (!driver->err_handler) + return; + if (!driver->err_handler->error_detected) + return; + + rc = driver->err_handler->error_detected (dev, pci_channel_io_frozen); + if (*res == PCIERR_RESULT_NONE) *res = rc; + if (*res == PCIERR_RESULT_NEED_RESET) return; + if (*res == PCIERR_RESULT_DISCONNECT && + rc == PCIERR_RESULT_NEED_RESET) *res = rc; +} + +/** eeh_report_reset -- tell this device that the pci slot + * has been reset. + */ + +static void eeh_report_reset(struct pci_dev *dev, void *userdata) +{ + struct pci_driver *driver = dev->driver; + struct device_node *dn = pci_device_to_OF_node(dev); + + if (!driver) + return; + + if ((PCI_DN(dn)->eeh_mode) & EEH_MODE_IRQ_DISABLED) { + PCI_DN(dn)->eeh_mode &= ~EEH_MODE_IRQ_DISABLED; + enable_irq(dev->irq); + } + if (!driver->err_handler) + return; + if (!driver->err_handler->slot_reset) + return; + + driver->err_handler->slot_reset(dev); +} + +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; + if (!driver->err_handler) + return; + if (!driver->err_handler->resume) + return; + + driver->err_handler->resume(dev); +} + +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; + + if (irq_in_use (dev->irq)) { + struct device_node *dn = pci_device_to_OF_node(dev); + PCI_DN(dn)->eeh_mode |= EEH_MODE_IRQ_DISABLED; + disable_irq_nosync(dev->irq); + } + if (!driver->err_handler) + return; + if (!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 + * occuring 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 + * Args: 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 void eeh_reset_device (struct pci_dn *pe_dn, struct pci_bus *bus) +{ + if (bus) + pcibios_remove_pci_devices(bus); + + /* Reset the pci controller. (Asserts RST#; resets config space). + * Reconfigure bridges and devices */ + rtas_set_slot_reset(pe_dn); + + /* Walk over all functions on this device */ + rtas_configure_bridge(pe_dn); + eeh_restore_bars(pe_dn); + + /* 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); + } +} + +/* The longest amount of time to wait for a pci device + * to come back on line, in seconds. + */ +#define MAX_WAIT_FOR_RECOVERY 15 + +void handle_eeh_events (struct eeh_event *event) +{ + struct device_node *frozen_dn; + struct pci_dn *frozen_pdn; + struct pci_bus *frozen_bus; + int perm_failure = 0; + + frozen_dn = find_device_pe(event->dn); + frozen_bus = pcibios_find_pci_bus(frozen_dn); + + if (!frozen_dn) { + printk(KERN_ERR "EEH: Error: Cannot find partition endpoint for %s\n", + pci_name(event->dev)); + return; + } + + /* 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 %s\n", + frozen_dn->full_name); + return; + } + +#if 0 + /* We may get "permanent failure" messages on empty slots. + * These are false alarms. Empty slots have no child dn. */ + if ((event->state == pci_channel_io_perm_failure) && (frozen_device == NULL)) + return; +#endif + + frozen_pdn = PCI_DN(frozen_dn); + frozen_pdn->eeh_freeze_count++; + + if (frozen_pdn->eeh_freeze_count > EEH_MAX_ALLOWED_FREEZES) + perm_failure = 1; + + /* If the reset state is a '5' and the time to reset is 0 (infinity) + * or is more then 15 seconds, then mark this as a permanent failure. + */ + if ((event->state == pci_channel_io_perm_failure) && + ((event->time_unavail <= 0) || + (event->time_unavail > MAX_WAIT_FOR_RECOVERY*1000))) + { + perm_failure = 1; + } + + /* Log the error with the rtas logger. */ + if (perm_failure) { + /* + * 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 %s - %s has failed %d times \n" + "and has been permanently disabled. Please try reseating\n" + "this device or replacing it.\n", + pci_name (frozen_pdn->pcidev), + pcid_name(frozen_pdn->pcidev), + frozen_pdn->eeh_freeze_count); + + eeh_slot_error_detail(frozen_pdn, 2 /* Permanent Error */); + + /* Notify all devices that they're about to go down. */ + pci_walk_bus(frozen_bus, eeh_report_failure, 0); + + /* Shut down the device drivers for good. */ + pcibios_remove_pci_devices(frozen_bus); + return; + } + + eeh_slot_error_detail(frozen_pdn, 1 /* Temporary Error */); + printk(KERN_WARNING + "EEH: This PCI device has failed %d times since last reboot: %s - %s\n", + frozen_pdn->eeh_freeze_count, + pci_name (frozen_pdn->pcidev), + pcid_name(frozen_pdn->pcidev)); + + /* 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. + */ + enum pcierr_result result = PCIERR_RESULT_NONE; + pci_walk_bus(frozen_bus, eeh_report_error, &result); + + /* 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 == PCIERR_RESULT_NONE) { + eeh_reset_device(frozen_pdn, frozen_bus); + } + + /* If any device called out for a reset, then reset the slot */ + if (result == PCIERR_RESULT_NEED_RESET) { + eeh_reset_device(frozen_pdn, NULL); + pci_walk_bus(frozen_bus, eeh_report_reset, 0); + } + + /* If all devices reported they can proceed, the re-enable PIO */ + if (result == PCIERR_RESULT_CAN_RECOVER) { + /* XXX Not supported; we brute-force reset the device */ + eeh_reset_device(frozen_pdn, NULL); + pci_walk_bus(frozen_bus, eeh_report_reset, 0); + } + + /* Tell all device drivers that they can resume operations */ + pci_walk_bus(frozen_bus, eeh_report_resume, 0); +} + +/* ---------- end of file ---------- */ |