[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 <linas@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
(cherry picked from e8ca11b460c4c9c7fa6b529be221529ebd770e38 commit)
diff --git a/arch/powerpc/platforms/pseries/eeh_driver.c b/arch/powerpc/platforms/pseries/eeh_driver.c
new file mode 100644
index 0000000..f6cff06
--- /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 ---------- */