From 77bd741561016134d1761d6101c4f0361025062f Mon Sep 17 00:00:00 2001 From: Linas Vepstas Date: Thu, 3 Nov 2005 18:52:49 -0600 Subject: [PATCH] [PATCH] powerpc: PCI Error Recovery: PPC64 core recovery routines Various PCI bus errors can be signaled by newer PCI controllers. The core error recovery routines are architecture dependent. This patch adds a recovery infrastructure for the PPC64 pSeries systems. Signed-off-by: Linas Vepstas Signed-off-by: Paul Mackerras (cherry picked from e8ca11b460c4c9c7fa6b529be221529ebd770e38 commit) --- arch/powerpc/platforms/pseries/Makefile | 2 +- arch/powerpc/platforms/pseries/eeh.c | 17 +- arch/powerpc/platforms/pseries/eeh_driver.c | 366 ++++++++++++++++++++ arch/powerpc/platforms/pseries/eeh_event.c | 39 +-- include/asm-powerpc/eeh.h | 8 +- include/asm-powerpc/eeh_event.h | 7 +- include/asm-powerpc/ppc-pci.h | 9 + 7 files changed, 413 insertions(+), 35 deletions(-) create mode 100644 arch/powerpc/platforms/pseries/eeh_driver.c diff --git a/arch/powerpc/platforms/pseries/Makefile b/arch/powerpc/platforms/pseries/Makefile index 6accdd1555..0b7d5cb641 100644 --- a/arch/powerpc/platforms/pseries/Makefile +++ b/arch/powerpc/platforms/pseries/Makefile @@ -4,7 +4,7 @@ obj-$(CONFIG_SMP) += smp.o obj-$(CONFIG_IBMVIO) += vio.o obj-$(CONFIG_XICS) += xics.o obj-$(CONFIG_SCANLOG) += scanlog.o -obj-$(CONFIG_EEH) += eeh.o eeh_event.o +obj-$(CONFIG_EEH) += eeh.o eeh_driver.o eeh_event.o obj-$(CONFIG_HVC_CONSOLE) += hvconsole.o obj-$(CONFIG_HVCS) += hvcserver.o diff --git a/arch/powerpc/platforms/pseries/eeh.c b/arch/powerpc/platforms/pseries/eeh.c index 7fbfd16d72..d6560c4563 100644 --- a/arch/powerpc/platforms/pseries/eeh.c +++ b/arch/powerpc/platforms/pseries/eeh.c @@ -485,6 +485,11 @@ static void __eeh_mark_slot (struct device_node *dn, int mode_flag) if (PCI_DN(dn)) { PCI_DN(dn)->eeh_mode |= mode_flag; + /* Mark the pci device driver too */ + struct pci_dev *dev = PCI_DN(dn)->pcidev; + if (dev && dev->driver) + dev->error_state = pci_channel_io_frozen; + if (dn->child) __eeh_mark_slot (dn->child, mode_flag); } @@ -544,6 +549,7 @@ int eeh_dn_check_failure(struct device_node *dn, struct pci_dev *dev) int rets[3]; unsigned long flags; struct pci_dn *pdn; + enum pci_channel_state state; int rc = 0; __get_cpu_var(total_mmio_ffs)++; @@ -648,8 +654,13 @@ int eeh_dn_check_failure(struct device_node *dn, struct pci_dev *dev) eeh_mark_slot (dn, EEH_MODE_ISOLATED); spin_unlock_irqrestore(&confirm_error_lock, flags); - eeh_send_failure_event (dn, dev, rets[0], rets[2]); - + state = pci_channel_io_normal; + if ((rets[0] == 2) || (rets[0] == 4)) + state = pci_channel_io_frozen; + if (rets[0] == 5) + state = pci_channel_io_perm_failure; + eeh_send_failure_event (dn, dev, state, rets[2]); + /* Most EEH events are due to device driver bugs. Having * a stack trace will help the device-driver authors figure * out what happened. So print that out. */ @@ -953,8 +964,10 @@ static void *early_enable_eeh(struct device_node *dn, void *data) * But there are a few cases like display devices that make sense. */ enable = 1; /* i.e. we will do checking */ +#if 0 if ((*class_code >> 16) == PCI_BASE_CLASS_DISPLAY) enable = 0; +#endif if (!enable) pdn->eeh_mode |= EEH_MODE_NOCHECK; diff --git a/arch/powerpc/platforms/pseries/eeh_driver.c b/arch/powerpc/platforms/pseries/eeh_driver.c new file mode 100644 index 0000000000..f6cff065d8 --- /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 + * + * 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 + * + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + + +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;inode->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 ---------- */ diff --git a/arch/powerpc/platforms/pseries/eeh_event.c b/arch/powerpc/platforms/pseries/eeh_event.c index 92497333c2..9a9961f274 100644 --- a/arch/powerpc/platforms/pseries/eeh_event.c +++ b/arch/powerpc/platforms/pseries/eeh_event.c @@ -21,6 +21,7 @@ #include #include #include +#include /** Overview: * EEH error states may be detected within exception handlers; @@ -36,31 +37,6 @@ LIST_HEAD(eeh_eventlist); static void eeh_thread_launcher(void *); DECLARE_WORK(eeh_event_wq, eeh_thread_launcher, NULL); -/** - * eeh_panic - call panic() for an eeh event that cannot be handled. - * The philosophy of this routine is that it is better to panic and - * halt the OS than it is to risk possible data corruption by - * oblivious device drivers that don't know better. - * - * @dev pci device that had an eeh event - * @reset_state current reset state of the device slot - */ -static void eeh_panic(struct pci_dev *dev, int reset_state) -{ - /* - * Since the panic_on_oops sysctl is used to halt the system - * in light of potential corruption, we can use it here. - */ - if (panic_on_oops) { - panic("EEH: MMIO failure (%d) on device:%s\n", reset_state, - pci_name(dev)); - } - else { - printk(KERN_INFO "EEH: Ignored MMIO failure (%d) on device:%s\n", - reset_state, pci_name(dev)); - } -} - /** * eeh_event_handler - dispatch EEH events. The detection of a frozen * slot can occur inside an interrupt, where it can be hard to do @@ -82,10 +58,16 @@ static int eeh_event_handler(void * dummy) spin_lock_irqsave(&eeh_eventlist_lock, flags); event = NULL; + + /* Unqueue the event, get ready to process. */ if (!list_empty(&eeh_eventlist)) { event = list_entry(eeh_eventlist.next, struct eeh_event, list); list_del(&event->list); } + + if (event) + eeh_mark_slot(event->dn, EEH_MODE_RECOVERING); + spin_unlock_irqrestore(&eeh_eventlist_lock, flags); if (event == NULL) break; @@ -93,8 +75,11 @@ static int eeh_event_handler(void * dummy) printk(KERN_INFO "EEH: Detected PCI bus error on device %s\n", pci_name(event->dev)); - eeh_panic (event->dev, event->state); + handle_eeh_events(event); + + eeh_clear_slot(event->dn, EEH_MODE_RECOVERING); + pci_dev_put(event->dev); kfree(event); } @@ -122,7 +107,7 @@ static void eeh_thread_launcher(void *dummy) */ int eeh_send_failure_event (struct device_node *dn, struct pci_dev *dev, - int state, + enum pci_channel_state state, int time_unavail) { unsigned long flags; diff --git a/include/asm-powerpc/eeh.h b/include/asm-powerpc/eeh.h index 4395b7bc1e..b263fb2fa6 100644 --- a/include/asm-powerpc/eeh.h +++ b/include/asm-powerpc/eeh.h @@ -34,9 +34,11 @@ struct device_node; extern int eeh_subsystem_enabled; /* Values for eeh_mode bits in device_node */ -#define EEH_MODE_SUPPORTED (1<<0) -#define EEH_MODE_NOCHECK (1<<1) -#define EEH_MODE_ISOLATED (1<<2) +#define EEH_MODE_SUPPORTED (1<<0) +#define EEH_MODE_NOCHECK (1<<1) +#define EEH_MODE_ISOLATED (1<<2) +#define EEH_MODE_RECOVERING (1<<3) +#define EEH_MODE_IRQ_DISABLED (1<<4) /* Max number of EEH freezes allowed before we consider the device * to be permanently disabled. */ diff --git a/include/asm-powerpc/eeh_event.h b/include/asm-powerpc/eeh_event.h index 5e11a00b6f..93d55a2beb 100644 --- a/include/asm-powerpc/eeh_event.h +++ b/include/asm-powerpc/eeh_event.h @@ -30,7 +30,7 @@ struct eeh_event { struct list_head list; struct device_node *dn; /* struct device node */ struct pci_dev *dev; /* affected device */ - int state; + enum pci_channel_state state; /* PCI bus state for the affected device */ int time_unavail; /* milliseconds until device might be available */ }; @@ -47,8 +47,11 @@ struct eeh_event { */ int eeh_send_failure_event (struct device_node *dn, struct pci_dev *dev, - int reset_state, + enum pci_channel_state state, int time_unavail); +/* Main recovery function */ +void handle_eeh_events (struct eeh_event *); + #endif /* __KERNEL__ */ #endif /* ASM_PPC64_EEH_EVENT_H */ diff --git a/include/asm-powerpc/ppc-pci.h b/include/asm-powerpc/ppc-pci.h index bdef312900..caf67a3bcb 100644 --- a/include/asm-powerpc/ppc-pci.h +++ b/include/asm-powerpc/ppc-pci.h @@ -52,6 +52,15 @@ extern unsigned long pci_probe_only; /* ---- EEH internal-use-only related routines ---- */ #ifdef CONFIG_EEH +/** + * eeh_slot_error_detail -- record and EEH error condition to the log + * @severity: 1 if temporary, 2 if permanent failure. + * + * Obtains the the EEH error details from the RTAS subsystem, + * and then logs these details with the RTAS error log system. + */ +void eeh_slot_error_detail (struct pci_dn *pdn, int severity); + /** * rtas_set_slot_reset -- unfreeze a frozen slot * -- 2.39.5