[PATCH 13/13]: PCI Err: RPA-PHP-specific error recovery driver
Linas Vepstas
linas at austin.ibm.com
Wed Jun 29 10:00:27 EST 2005
pci-err-13-rpaphp-eeh.patch
PCI Error recovery driver, ppc64-specific implementation.
For various historical reasons, this driver is in the pci
hotplug directory, although it could be moved to arch/ppc64
It is here because the driver falls back to using the pci
hotplug routines if the device driver does not support
native error recovery.
Signed-off-by: Linas Vepstas <linas at linas.org>
-------------- next part --------------
--- linux-2.6.12-git10/drivers/pci/hotplug/rpaphp.h.linas-orig 2005-06-17 14:48:29.000000000 -0500
+++ linux-2.6.12-git10/drivers/pci/hotplug/rpaphp.h 2005-06-22 15:28:29.000000000 -0500
@@ -113,6 +113,8 @@ extern int rpaphp_enable_pci_slot(struct
extern int register_pci_slot(struct slot *slot);
extern int rpaphp_unconfig_pci_adapter(struct slot *slot);
extern int rpaphp_get_pci_adapter_status(struct slot *slot, int is_init, u8 * value);
+extern void init_eeh_handler (void);
+extern void exit_eeh_handler (void);
/* rpaphp_core.c */
extern int rpaphp_add_slot(struct device_node *dn);
--- linux-2.6.12-git10/drivers/pci/hotplug/rpaphp_core.c.linas-orig 2005-06-17 14:48:29.000000000 -0500
+++ linux-2.6.12-git10/drivers/pci/hotplug/rpaphp_core.c 2005-06-22 15:28:29.000000000 -0500
@@ -460,12 +460,18 @@ static int __init rpaphp_init(void)
{
info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
+ /* Get set to handle EEH events. */
+ init_eeh_handler();
+
/* read all the PRA info from the system */
return init_rpa();
}
static void __exit rpaphp_exit(void)
{
+ /* Let EEH know we are going away. */
+ exit_eeh_handler();
+
cleanup_slots();
}
--- drivers/pci/hotplug/rpaphp_eeh.c.linas-orig 2005-06-28 12:47:20.000000000 -0500
+++ drivers/pci/hotplug/rpaphp_eeh.c 2005-06-28 17:36:17.000000000 -0500
@@ -0,0 +1,383 @@
+/*
+ * PCI Hot Plug Controller Driver for RPA-compliant PPC64 platform.
+ * Copyright (C) 2004, 2005 Linas Vepstas <linas at 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 at us.ibm.com>
+ *
+ */
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/notifier.h>
+#include <linux/pci.h>
+#include <asm/eeh.h>
+#include <asm/pci-bridge.h>
+#include <asm/prom.h>
+#include <asm/rtas.h>
+
+#include "../pci.h"
+#include "rpaphp.h"
+
+/**
+ * pci_search_bus_for_dev - return 1 if device is under this bus, else 0
+ * @bus: the bus to search for this device.
+ * @dev: the pci device we are looking for.
+ *
+ * XXX should this be moved to drivers/pci/search.c ?
+ */
+static int pci_search_bus_for_dev (struct pci_bus *bus, struct pci_dev *dev)
+{
+ struct list_head *ln;
+
+ if (!bus) return 0;
+
+ for (ln = bus->devices.next; ln != &bus->devices; ln = ln->next) {
+ struct pci_dev *pdev = pci_dev_b(ln);
+ if (pdev == dev)
+ return 1;
+ if (pdev->subordinate) {
+ int rc;
+ rc = pci_search_bus_for_dev (pdev->subordinate, dev);
+ if (rc)
+ return 1;
+ }
+ }
+ return 0;
+}
+
+/** pci_walk_bus - walk bus under this device, calling callback.
+ * @top device whose peers should be walked
+ * @cb callback to be called for each device found
+ * @userdata arbitrary pointer to be passed to callback.
+ *
+ * Walk the bus on which this device sits, including any
+ * bridged devices on busses under this bus. Call the provided
+ * callback on each device found.
+ */
+typedef void (*pci_buswalk_cb)(struct pci_dev *, void *);
+
+static void
+pci_walk_bus (struct pci_dev *top, pci_buswalk_cb cb, void *userdata)
+{
+ struct pci_dev *dev, *tmp;
+
+ spin_lock(&pci_bus_lock);
+ list_for_each_entry_safe (dev, tmp, &top->bus->devices, bus_list) {
+ pci_dev_get(dev);
+ spin_unlock(&pci_bus_lock);
+
+ /* Run device routines with the bus unlocked */
+ cb (dev, userdata);
+ if (dev->subordinate) {
+ pci_walk_bus (pci_dev_b(&dev->subordinate->devices), cb, userdata);
+ }
+ spin_lock(&pci_bus_lock);
+ pci_dev_put(dev);
+ }
+ spin_unlock(&pci_bus_lock);
+}
+
+/**
+ * rpaphp_find_slot - find and return the slot holding the device
+ * @dev: pci device for which we want the slot structure.
+ */
+static struct slot *rpaphp_find_slot(struct pci_dev *dev)
+{
+ struct list_head *tmp, *n;
+ struct slot *slot;
+
+ list_for_each_safe(tmp, n, &rpaphp_slot_head) {
+ struct pci_bus *bus;
+
+ slot = list_entry(tmp, struct slot, rpaphp_slot_list);
+
+ /* PHB's don't have bridges. */
+ if (slot->bridge == NULL)
+ continue;
+
+ /* The PCI device could be the slot itself. */
+ if (slot->bridge == dev)
+ return slot;
+
+ bus = slot->bridge->subordinate;
+ if (!bus) {
+ printk (KERN_WARNING "PCI bridge is missing bus: %s %s\n",
+ pci_name (slot->bridge), pci_pretty_name (slot->bridge));
+ continue; /* should never happen? */
+ }
+
+ if (pci_search_bus_for_dev (bus, dev))
+ return slot;
+ }
+ return NULL;
+}
+
+/* ------------------------------------------------------- */
+/** 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;
+
+ if (!driver)
+ return;
+ driver->err_handler.error_state = pci_channel_io_frozen;
+ 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;
+
+ if (!driver)
+ 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;
+
+ if (!driver)
+ return;
+ driver->err_handler.error_state = pci_channel_io_normal;
+ 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;
+
+ if (!driver)
+ return;
+ driver->err_handler.error_state = pci_channel_io_perm_failure;
+ 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).
+ */
+
+int eeh_reset_device (struct pci_dev *dev, struct device_node *dn, int reconfig)
+{
+ struct slot *frozen_slot= NULL;
+
+ if (!dev)
+ return 1;
+
+ if (reconfig)
+ frozen_slot = rpaphp_find_slot(dev);
+
+ if (reconfig && frozen_slot) rpaphp_unconfig_pci_adapter (frozen_slot);
+
+ /* Reset the pci controller. (Asserts RST#; resets config space).
+ * Reconfigure bridges and devices */
+ rtas_set_slot_reset (dn->child);
+
+ /* Walk over all functions on this device */
+ struct device_node *peer = dn->child;
+ while (peer) {
+ rtas_configure_bridge(peer);
+ eeh_restore_bars(peer);
+ peer = peer->sibling;
+ }
+
+ /* Give the system 5 seconds to finish running the user-space
+ * hotplug scripts, e.g. ifdown for ethernet. Yes, this is a hack,
+ * but if we don't do this, weird things happen.
+ */
+ if (reconfig && frozen_slot) {
+ ssleep (5);
+ rpaphp_enable_pci_slot (frozen_slot);
+ }
+ 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 15
+
+int handle_eeh_events (struct notifier_block *self,
+ unsigned long reason, void *ev)
+{
+ int freeze_count=0;
+ struct device_node *frozen_device;
+ struct peh_event *event = ev;
+ struct pci_dev *dev = event->dev;
+ int perm_failure = 0;
+
+ if (!dev)
+ {
+ printk ("EEH: EEH error caught, but no PCI device specified!\n");
+ return 1;
+ }
+
+ frozen_device = pci_bus_to_OF_node(dev->bus);
+ if (!frozen_device)
+ {
+ printk (KERN_ERR "EEH: Cannot find PCI controller for %s %s\n",
+ pci_name(dev), pci_pretty_name (dev));
+
+ return 1;
+ }
+ BUG_ON (frozen_device->phb==NULL);
+
+ /* We 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 0;
+
+ if (frozen_device)
+ freeze_count = frozen_device->eeh_freeze_count;
+ freeze_count ++;
+ if (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: 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 (dev),
+ pci_pretty_name (dev),
+ freeze_count);
+
+ eeh_slot_error_detail (frozen_device, 2 /* Permanent Error */);
+
+ /* Notify all devices that they're about to go down. */
+ pci_walk_bus (dev, eeh_report_failure, 0);
+
+ /* If there's a hotplug slot, unconfigure it */
+ // XXX we need alternate way to deconfigure non-hotplug slots.
+ struct slot * frozen_slot = rpaphp_find_slot(dev);
+ if (frozen_slot)
+ rpaphp_unconfig_pci_adapter (frozen_slot);
+ return 1;
+ } else {
+ eeh_slot_error_detail (frozen_device, 1 /* Temporary Error */);
+ }
+
+ printk (KERN_WARNING
+ "EEH: This device has failed %d times since last reboot: %s:%s\n",
+ freeze_count,
+ pci_name (dev),
+ pci_pretty_name (dev));
+
+ /* Walk the various device drivers attached to this slot,
+ * letting each know about the EEH bug.
+ */
+ enum pcierr_result result = PCIERR_RESULT_NONE;
+ pci_walk_bus (dev, eeh_report_error, &result);
+
+ /* If all device drivers were EEH-unaware, then pci hotplug
+ * the device, and hope that clears the error. */
+ if (result == PCIERR_RESULT_NONE) {
+ eeh_reset_device (dev, frozen_device, 1);
+ }
+
+ /* If any device called out for a reset, then reset the slot */
+ if (result == PCIERR_RESULT_NEED_RESET) {
+ eeh_reset_device (dev, frozen_device, 0);
+ pci_walk_bus (dev, 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 (dev, frozen_device, 0);
+ pci_walk_bus (dev, eeh_report_reset, 0);
+ }
+
+ /* Tell all device drivers that they can resume operations */
+ pci_walk_bus (dev, eeh_report_resume, 0);
+
+ /* Store the freeze count with the pci adapter, and not the slot.
+ * This way, if the device is replaced, the count is cleared.
+ */
+ frozen_device->eeh_freeze_count = freeze_count;
+
+ return 1;
+}
+
+static struct notifier_block eeh_block;
+
+void __init init_eeh_handler (void)
+{
+ eeh_block.notifier_call = handle_eeh_events;
+ peh_register_notifier (&eeh_block);
+}
+
+void __exit exit_eeh_handler (void)
+{
+ peh_unregister_notifier (&eeh_block);
+}
+
--- linux-2.6.12-git10/drivers/pci/hotplug/Makefile.linas-orig 2005-06-17 14:48:29.000000000 -0500
+++ linux-2.6.12-git10/drivers/pci/hotplug/Makefile 2005-06-22 15:28:29.000000000 -0500
@@ -41,6 +41,7 @@ acpiphp-objs := acpiphp_core.o \
acpiphp_res.o
rpaphp-objs := rpaphp_core.o \
+ rpaphp_eeh.o \
rpaphp_pci.o \
rpaphp_slot.o \
rpaphp_vio.o
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