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-rw-r--r--arch/powerpc/kernel/eeh_driver.c918
1 files changed, 918 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/eeh_driver.c b/arch/powerpc/kernel/eeh_driver.c
new file mode 100644
index 000000000..24768ff3c
--- /dev/null
+++ b/arch/powerpc/kernel/eeh_driver.c
@@ -0,0 +1,918 @@
+/*
+ * 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/module.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>
+
+/**
+ * eeh_pcid_name - Retrieve name of PCI device driver
+ * @pdev: PCI device
+ *
+ * This routine is used to retrieve the name of PCI device driver
+ * if that's valid.
+ */
+static inline const char *eeh_pcid_name(struct pci_dev *pdev)
+{
+ if (pdev && pdev->dev.driver)
+ return pdev->dev.driver->name;
+ return "";
+}
+
+/**
+ * eeh_pcid_get - Get the PCI device driver
+ * @pdev: PCI device
+ *
+ * The function is used to retrieve the PCI device driver for
+ * the indicated PCI device. Besides, we will increase the reference
+ * of the PCI device driver to prevent that being unloaded on
+ * the fly. Otherwise, kernel crash would be seen.
+ */
+static inline struct pci_driver *eeh_pcid_get(struct pci_dev *pdev)
+{
+ if (!pdev || !pdev->driver)
+ return NULL;
+
+ if (!try_module_get(pdev->driver->driver.owner))
+ return NULL;
+
+ return pdev->driver;
+}
+
+/**
+ * eeh_pcid_put - Dereference on the PCI device driver
+ * @pdev: PCI device
+ *
+ * The function is called to do dereference on the PCI device
+ * driver of the indicated PCI device.
+ */
+static inline void eeh_pcid_put(struct pci_dev *pdev)
+{
+ if (!pdev || !pdev->driver)
+ return;
+
+ module_put(pdev->driver->driver.owner);
+}
+
+/**
+ * eeh_disable_irq - Disable interrupt for the recovering device
+ * @dev: PCI device
+ *
+ * This routine must be called when reporting temporary or permanent
+ * error to the particular PCI device to disable interrupt of that
+ * device. If the device has enabled MSI or MSI-X interrupt, we needn't
+ * do real work because EEH should freeze DMA transfers for those PCI
+ * devices encountering EEH errors, which includes MSI or MSI-X.
+ */
+static void eeh_disable_irq(struct pci_dev *dev)
+{
+ struct eeh_dev *edev = pci_dev_to_eeh_dev(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_has_action(dev->irq))
+ return;
+
+ edev->mode |= EEH_DEV_IRQ_DISABLED;
+ disable_irq_nosync(dev->irq);
+}
+
+/**
+ * eeh_enable_irq - Enable interrupt for the recovering device
+ * @dev: PCI device
+ *
+ * This routine must be called to enable interrupt while failed
+ * device could be resumed.
+ */
+static void eeh_enable_irq(struct pci_dev *dev)
+{
+ struct eeh_dev *edev = pci_dev_to_eeh_dev(dev);
+
+ if ((edev->mode) & EEH_DEV_IRQ_DISABLED) {
+ edev->mode &= ~EEH_DEV_IRQ_DISABLED;
+ /*
+ * FIXME !!!!!
+ *
+ * This is just ass backwards. This maze has
+ * unbalanced irq_enable/disable calls. So instead of
+ * finding the root cause it works around the warning
+ * in the irq_enable code by conditionally calling
+ * into it.
+ *
+ * That's just wrong.The warning in the core code is
+ * there to tell people to fix their assymetries in
+ * their own code, not by abusing the core information
+ * to avoid it.
+ *
+ * I so wish that the assymetry would be the other way
+ * round and a few more irq_disable calls render that
+ * shit unusable forever.
+ *
+ * tglx
+ */
+ if (irqd_irq_disabled(irq_get_irq_data(dev->irq)))
+ enable_irq(dev->irq);
+ }
+}
+
+static bool eeh_dev_removed(struct eeh_dev *edev)
+{
+ /* EEH device removed ? */
+ if (!edev || (edev->mode & EEH_DEV_REMOVED))
+ return true;
+
+ return false;
+}
+
+static void *eeh_dev_save_state(void *data, void *userdata)
+{
+ struct eeh_dev *edev = data;
+ struct pci_dev *pdev;
+
+ if (!edev)
+ return NULL;
+
+ pdev = eeh_dev_to_pci_dev(edev);
+ if (!pdev)
+ return NULL;
+
+ pci_save_state(pdev);
+ return NULL;
+}
+
+/**
+ * eeh_report_error - Report pci error to each device driver
+ * @data: eeh device
+ * @userdata: return value
+ *
+ * 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(void *data, void *userdata)
+{
+ struct eeh_dev *edev = (struct eeh_dev *)data;
+ struct pci_dev *dev = eeh_dev_to_pci_dev(edev);
+ enum pci_ers_result rc, *res = userdata;
+ struct pci_driver *driver;
+
+ if (!dev || eeh_dev_removed(edev))
+ return NULL;
+ dev->error_state = pci_channel_io_frozen;
+
+ driver = eeh_pcid_get(dev);
+ if (!driver) return NULL;
+
+ eeh_disable_irq(dev);
+
+ if (!driver->err_handler ||
+ !driver->err_handler->error_detected) {
+ eeh_pcid_put(dev);
+ return NULL;
+ }
+
+ 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_pcid_put(dev);
+ return NULL;
+}
+
+/**
+ * eeh_report_mmio_enabled - Tell drivers that MMIO has been enabled
+ * @data: eeh device
+ * @userdata: return value
+ *
+ * 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(void *data, void *userdata)
+{
+ struct eeh_dev *edev = (struct eeh_dev *)data;
+ struct pci_dev *dev = eeh_dev_to_pci_dev(edev);
+ enum pci_ers_result rc, *res = userdata;
+ struct pci_driver *driver;
+
+ if (!dev || eeh_dev_removed(edev))
+ return NULL;
+
+ driver = eeh_pcid_get(dev);
+ if (!driver) return NULL;
+
+ if (!driver->err_handler ||
+ !driver->err_handler->mmio_enabled ||
+ (edev->mode & EEH_DEV_NO_HANDLER)) {
+ eeh_pcid_put(dev);
+ return NULL;
+ }
+
+ 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_pcid_put(dev);
+ return NULL;
+}
+
+/**
+ * eeh_report_reset - Tell device that slot has been reset
+ * @data: eeh device
+ * @userdata: return value
+ *
+ * This routine must be called while EEH tries to reset particular
+ * PCI device so that the associated PCI device driver could take
+ * some actions, usually to save data the driver needs so that the
+ * driver can work again while the device is recovered.
+ */
+static void *eeh_report_reset(void *data, void *userdata)
+{
+ struct eeh_dev *edev = (struct eeh_dev *)data;
+ struct pci_dev *dev = eeh_dev_to_pci_dev(edev);
+ enum pci_ers_result rc, *res = userdata;
+ struct pci_driver *driver;
+
+ if (!dev || eeh_dev_removed(edev))
+ return NULL;
+ dev->error_state = pci_channel_io_normal;
+
+ driver = eeh_pcid_get(dev);
+ if (!driver) return NULL;
+
+ eeh_enable_irq(dev);
+
+ if (!driver->err_handler ||
+ !driver->err_handler->slot_reset ||
+ (edev->mode & EEH_DEV_NO_HANDLER)) {
+ eeh_pcid_put(dev);
+ return NULL;
+ }
+
+ 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_pcid_put(dev);
+ return NULL;
+}
+
+static void *eeh_dev_restore_state(void *data, void *userdata)
+{
+ struct eeh_dev *edev = data;
+ struct pci_dev *pdev;
+
+ if (!edev)
+ return NULL;
+
+ pdev = eeh_dev_to_pci_dev(edev);
+ if (!pdev)
+ return NULL;
+
+ pci_restore_state(pdev);
+ return NULL;
+}
+
+/**
+ * eeh_report_resume - Tell device to resume normal operations
+ * @data: eeh device
+ * @userdata: return value
+ *
+ * This routine must be called to notify the device driver that it
+ * could resume so that the device driver can do some initialization
+ * to make the recovered device work again.
+ */
+static void *eeh_report_resume(void *data, void *userdata)
+{
+ struct eeh_dev *edev = (struct eeh_dev *)data;
+ struct pci_dev *dev = eeh_dev_to_pci_dev(edev);
+ struct pci_driver *driver;
+
+ if (!dev || eeh_dev_removed(edev))
+ return NULL;
+ dev->error_state = pci_channel_io_normal;
+
+ driver = eeh_pcid_get(dev);
+ if (!driver) return NULL;
+
+ eeh_enable_irq(dev);
+
+ if (!driver->err_handler ||
+ !driver->err_handler->resume ||
+ (edev->mode & EEH_DEV_NO_HANDLER)) {
+ edev->mode &= ~EEH_DEV_NO_HANDLER;
+ eeh_pcid_put(dev);
+ return NULL;
+ }
+
+ driver->err_handler->resume(dev);
+
+ eeh_pcid_put(dev);
+ return NULL;
+}
+
+/**
+ * eeh_report_failure - Tell device driver that device is dead.
+ * @data: eeh device
+ * @userdata: return value
+ *
+ * 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(void *data, void *userdata)
+{
+ struct eeh_dev *edev = (struct eeh_dev *)data;
+ struct pci_dev *dev = eeh_dev_to_pci_dev(edev);
+ struct pci_driver *driver;
+
+ if (!dev || eeh_dev_removed(edev))
+ return NULL;
+ dev->error_state = pci_channel_io_perm_failure;
+
+ driver = eeh_pcid_get(dev);
+ if (!driver) return NULL;
+
+ eeh_disable_irq(dev);
+
+ if (!driver->err_handler ||
+ !driver->err_handler->error_detected) {
+ eeh_pcid_put(dev);
+ return NULL;
+ }
+
+ driver->err_handler->error_detected(dev, pci_channel_io_perm_failure);
+
+ eeh_pcid_put(dev);
+ return NULL;
+}
+
+static void *eeh_rmv_device(void *data, void *userdata)
+{
+ struct pci_driver *driver;
+ struct eeh_dev *edev = (struct eeh_dev *)data;
+ struct pci_dev *dev = eeh_dev_to_pci_dev(edev);
+ int *removed = (int *)userdata;
+
+ /*
+ * Actually, we should remove the PCI bridges as well.
+ * However, that's lots of complexity to do that,
+ * particularly some of devices under the bridge might
+ * support EEH. So we just care about PCI devices for
+ * simplicity here.
+ */
+ if (!dev || (dev->hdr_type & PCI_HEADER_TYPE_BRIDGE))
+ return NULL;
+
+ /*
+ * We rely on count-based pcibios_release_device() to
+ * detach permanently offlined PEs. Unfortunately, that's
+ * not reliable enough. We might have the permanently
+ * offlined PEs attached, but we needn't take care of
+ * them and their child devices.
+ */
+ if (eeh_dev_removed(edev))
+ return NULL;
+
+ driver = eeh_pcid_get(dev);
+ if (driver) {
+ eeh_pcid_put(dev);
+ if (driver->err_handler)
+ return NULL;
+ }
+
+ /* Remove it from PCI subsystem */
+ pr_debug("EEH: Removing %s without EEH sensitive driver\n",
+ pci_name(dev));
+ edev->bus = dev->bus;
+ edev->mode |= EEH_DEV_DISCONNECTED;
+ (*removed)++;
+
+ pci_lock_rescan_remove();
+ pci_stop_and_remove_bus_device(dev);
+ pci_unlock_rescan_remove();
+
+ return NULL;
+}
+
+static void *eeh_pe_detach_dev(void *data, void *userdata)
+{
+ struct eeh_pe *pe = (struct eeh_pe *)data;
+ struct eeh_dev *edev, *tmp;
+
+ eeh_pe_for_each_dev(pe, edev, tmp) {
+ if (!(edev->mode & EEH_DEV_DISCONNECTED))
+ continue;
+
+ edev->mode &= ~(EEH_DEV_DISCONNECTED | EEH_DEV_IRQ_DISABLED);
+ eeh_rmv_from_parent_pe(edev);
+ }
+
+ return NULL;
+}
+
+/*
+ * Explicitly clear PE's frozen state for PowerNV where
+ * we have frozen PE until BAR restore is completed. It's
+ * harmless to clear it for pSeries. To be consistent with
+ * PE reset (for 3 times), we try to clear the frozen state
+ * for 3 times as well.
+ */
+static void *__eeh_clear_pe_frozen_state(void *data, void *flag)
+{
+ struct eeh_pe *pe = (struct eeh_pe *)data;
+ bool *clear_sw_state = flag;
+ int i, rc = 1;
+
+ for (i = 0; rc && i < 3; i++)
+ rc = eeh_unfreeze_pe(pe, clear_sw_state);
+
+ /* Stop immediately on any errors */
+ if (rc) {
+ pr_warn("%s: Failure %d unfreezing PHB#%x-PE#%x\n",
+ __func__, rc, pe->phb->global_number, pe->addr);
+ return (void *)pe;
+ }
+
+ return NULL;
+}
+
+static int eeh_clear_pe_frozen_state(struct eeh_pe *pe,
+ bool clear_sw_state)
+{
+ void *rc;
+
+ rc = eeh_pe_traverse(pe, __eeh_clear_pe_frozen_state, &clear_sw_state);
+ if (!rc)
+ eeh_pe_state_clear(pe, EEH_PE_ISOLATED);
+
+ return rc ? -EIO : 0;
+}
+
+int eeh_pe_reset_and_recover(struct eeh_pe *pe)
+{
+ int result, ret;
+
+ /* Bail if the PE is being recovered */
+ if (pe->state & EEH_PE_RECOVERING)
+ return 0;
+
+ /* Put the PE into recovery mode */
+ eeh_pe_state_mark(pe, EEH_PE_RECOVERING);
+
+ /* Save states */
+ eeh_pe_dev_traverse(pe, eeh_dev_save_state, NULL);
+
+ /* Report error */
+ eeh_pe_dev_traverse(pe, eeh_report_error, &result);
+
+ /* Issue reset */
+ ret = eeh_reset_pe(pe);
+ if (ret) {
+ eeh_pe_state_clear(pe, EEH_PE_RECOVERING);
+ return ret;
+ }
+
+ /* Unfreeze the PE */
+ ret = eeh_clear_pe_frozen_state(pe, true);
+ if (ret) {
+ eeh_pe_state_clear(pe, EEH_PE_RECOVERING);
+ return ret;
+ }
+
+ /* Notify completion of reset */
+ eeh_pe_dev_traverse(pe, eeh_report_reset, &result);
+
+ /* Restore device state */
+ eeh_pe_dev_traverse(pe, eeh_dev_restore_state, NULL);
+
+ /* Resume */
+ eeh_pe_dev_traverse(pe, eeh_report_resume, NULL);
+
+ /* Clear recovery mode */
+ eeh_pe_state_clear(pe, EEH_PE_RECOVERING);
+
+ return 0;
+}
+
+/**
+ * eeh_reset_device - Perform actual reset of a pci slot
+ * @pe: EEH PE
+ * @bus: PCI bus corresponding to the isolcated slot
+ *
+ * This routine must be called to do reset on the indicated PE.
+ * During the reset, udev might be invoked because those affected
+ * PCI devices will be removed and then added.
+ */
+static int eeh_reset_device(struct eeh_pe *pe, struct pci_bus *bus)
+{
+ struct pci_bus *frozen_bus = eeh_pe_bus_get(pe);
+ struct timeval tstamp;
+ int cnt, rc, removed = 0;
+
+ /* pcibios will clear the counter; save the value */
+ cnt = pe->freeze_count;
+ tstamp = pe->tstamp;
+
+ /*
+ * We don't remove the corresponding PE instances because
+ * we need the information afterwords. The attached EEH
+ * devices are expected to be attached soon when calling
+ * into pcibios_add_pci_devices().
+ */
+ eeh_pe_state_mark(pe, EEH_PE_KEEP);
+ if (bus) {
+ pci_lock_rescan_remove();
+ pcibios_remove_pci_devices(bus);
+ pci_unlock_rescan_remove();
+ } else if (frozen_bus) {
+ eeh_pe_dev_traverse(pe, eeh_rmv_device, &removed);
+ }
+
+ /*
+ * 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.
+ *
+ * During the reset, it's very dangerous to have uncontrolled PCI
+ * config accesses. So we prefer to block them. However, controlled
+ * PCI config accesses initiated from EEH itself are allowed.
+ */
+ rc = eeh_reset_pe(pe);
+ if (rc)
+ return rc;
+
+ pci_lock_rescan_remove();
+
+ /* Restore PE */
+ eeh_ops->configure_bridge(pe);
+ eeh_pe_restore_bars(pe);
+
+ /* Clear frozen state */
+ rc = eeh_clear_pe_frozen_state(pe, false);
+ if (rc)
+ return rc;
+
+ /* 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) {
+ pr_info("EEH: Sleep 5s ahead of complete hotplug\n");
+ ssleep(5);
+
+ /*
+ * The EEH device is still connected with its parent
+ * PE. We should disconnect it so the binding can be
+ * rebuilt when adding PCI devices.
+ */
+ eeh_pe_traverse(pe, eeh_pe_detach_dev, NULL);
+ pcibios_add_pci_devices(bus);
+ } else if (frozen_bus && removed) {
+ pr_info("EEH: Sleep 5s ahead of partial hotplug\n");
+ ssleep(5);
+
+ eeh_pe_traverse(pe, eeh_pe_detach_dev, NULL);
+ pcibios_add_pci_devices(frozen_bus);
+ }
+ eeh_pe_state_clear(pe, EEH_PE_KEEP);
+
+ pe->tstamp = tstamp;
+ pe->freeze_count = cnt;
+
+ pci_unlock_rescan_remove();
+ 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 300
+
+static void eeh_handle_normal_event(struct eeh_pe *pe)
+{
+ struct pci_bus *frozen_bus;
+ int rc = 0;
+ enum pci_ers_result result = PCI_ERS_RESULT_NONE;
+
+ frozen_bus = eeh_pe_bus_get(pe);
+ if (!frozen_bus) {
+ pr_err("%s: Cannot find PCI bus for PHB#%d-PE#%x\n",
+ __func__, pe->phb->global_number, pe->addr);
+ return;
+ }
+
+ eeh_pe_update_time_stamp(pe);
+ pe->freeze_count++;
+ if (pe->freeze_count > eeh_max_freezes)
+ goto excess_failures;
+ pr_warn("EEH: This PCI device has failed %d times in the last hour\n",
+ pe->freeze_count);
+
+ /* 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.
+ */
+ pr_info("EEH: Notify device drivers to shutdown\n");
+ eeh_pe_dev_traverse(pe, 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_ops->wait_state(pe, MAX_WAIT_FOR_RECOVERY*1000);
+ if (rc < 0 || rc == EEH_STATE_NOT_SUPPORT) {
+ pr_warn("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.
+ */
+ pr_info("EEH: Collect temporary log\n");
+ eeh_slot_error_detail(pe, EEH_LOG_TEMP);
+
+ /* 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) {
+ pr_info("EEH: Reset with hotplug activity\n");
+ rc = eeh_reset_device(pe, frozen_bus);
+ if (rc) {
+ pr_warn("%s: Unable to reset, err=%d\n",
+ __func__, rc);
+ goto hard_fail;
+ }
+ }
+
+ /* If all devices reported they can proceed, then re-enable MMIO */
+ if (result == PCI_ERS_RESULT_CAN_RECOVER) {
+ pr_info("EEH: Enable I/O for affected devices\n");
+ rc = eeh_pci_enable(pe, EEH_OPT_THAW_MMIO);
+
+ if (rc < 0)
+ goto hard_fail;
+ if (rc) {
+ result = PCI_ERS_RESULT_NEED_RESET;
+ } else {
+ pr_info("EEH: Notify device drivers to resume I/O\n");
+ eeh_pe_dev_traverse(pe, eeh_report_mmio_enabled, &result);
+ }
+ }
+
+ /* If all devices reported they can proceed, then re-enable DMA */
+ if (result == PCI_ERS_RESULT_CAN_RECOVER) {
+ pr_info("EEH: Enabled DMA for affected devices\n");
+ rc = eeh_pci_enable(pe, EEH_OPT_THAW_DMA);
+
+ if (rc < 0)
+ goto hard_fail;
+ if (rc) {
+ result = PCI_ERS_RESULT_NEED_RESET;
+ } else {
+ /*
+ * We didn't do PE reset for the case. The PE
+ * is still in frozen state. Clear it before
+ * resuming the PE.
+ */
+ eeh_pe_state_clear(pe, EEH_PE_ISOLATED);
+ result = PCI_ERS_RESULT_RECOVERED;
+ }
+ }
+
+ /* If any device has a hard failure, then shut off everything. */
+ if (result == PCI_ERS_RESULT_DISCONNECT) {
+ pr_warn("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) {
+ pr_info("EEH: Reset without hotplug activity\n");
+ rc = eeh_reset_device(pe, NULL);
+ if (rc) {
+ pr_warn("%s: Cannot reset, err=%d\n",
+ __func__, rc);
+ goto hard_fail;
+ }
+
+ pr_info("EEH: Notify device drivers "
+ "the completion of reset\n");
+ result = PCI_ERS_RESULT_NONE;
+ eeh_pe_dev_traverse(pe, eeh_report_reset, &result);
+ }
+
+ /* All devices should claim they have recovered by now. */
+ if ((result != PCI_ERS_RESULT_RECOVERED) &&
+ (result != PCI_ERS_RESULT_NONE)) {
+ pr_warn("EEH: Not recovered\n");
+ goto hard_fail;
+ }
+
+ /* Tell all device drivers that they can resume operations */
+ pr_info("EEH: Notify device driver to resume\n");
+ eeh_pe_dev_traverse(pe, eeh_report_resume, NULL);
+
+ return;
+
+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.
+ */
+ pr_err("EEH: PHB#%d-PE#%x has failed %d times in the\n"
+ "last hour and has been permanently disabled.\n"
+ "Please try reseating or replacing it.\n",
+ pe->phb->global_number, pe->addr,
+ pe->freeze_count);
+ goto perm_error;
+
+hard_fail:
+ pr_err("EEH: Unable to recover from failure from PHB#%d-PE#%x.\n"
+ "Please try reseating or replacing it\n",
+ pe->phb->global_number, pe->addr);
+
+perm_error:
+ eeh_slot_error_detail(pe, EEH_LOG_PERM);
+
+ /* Notify all devices that they're about to go down. */
+ eeh_pe_dev_traverse(pe, eeh_report_failure, NULL);
+
+ /* Mark the PE to be removed permanently */
+ eeh_pe_state_mark(pe, EEH_PE_REMOVED);
+
+ /*
+ * Shut down the device drivers for good. We mark
+ * all removed devices correctly to avoid access
+ * the their PCI config any more.
+ */
+ if (frozen_bus) {
+ eeh_pe_dev_mode_mark(pe, EEH_DEV_REMOVED);
+
+ pci_lock_rescan_remove();
+ pcibios_remove_pci_devices(frozen_bus);
+ pci_unlock_rescan_remove();
+ }
+}
+
+static void eeh_handle_special_event(void)
+{
+ struct eeh_pe *pe, *phb_pe;
+ struct pci_bus *bus;
+ struct pci_controller *hose;
+ unsigned long flags;
+ int rc;
+
+
+ do {
+ rc = eeh_ops->next_error(&pe);
+
+ switch (rc) {
+ case EEH_NEXT_ERR_DEAD_IOC:
+ /* Mark all PHBs in dead state */
+ eeh_serialize_lock(&flags);
+
+ /* Purge all events */
+ eeh_remove_event(NULL, true);
+
+ list_for_each_entry(hose, &hose_list, list_node) {
+ phb_pe = eeh_phb_pe_get(hose);
+ if (!phb_pe) continue;
+
+ eeh_pe_state_mark(phb_pe, EEH_PE_ISOLATED);
+ }
+
+ eeh_serialize_unlock(flags);
+
+ break;
+ case EEH_NEXT_ERR_FROZEN_PE:
+ case EEH_NEXT_ERR_FENCED_PHB:
+ case EEH_NEXT_ERR_DEAD_PHB:
+ /* Mark the PE in fenced state */
+ eeh_serialize_lock(&flags);
+
+ /* Purge all events of the PHB */
+ eeh_remove_event(pe, true);
+
+ if (rc == EEH_NEXT_ERR_DEAD_PHB)
+ eeh_pe_state_mark(pe, EEH_PE_ISOLATED);
+ else
+ eeh_pe_state_mark(pe,
+ EEH_PE_ISOLATED | EEH_PE_RECOVERING);
+
+ eeh_serialize_unlock(flags);
+
+ break;
+ case EEH_NEXT_ERR_NONE:
+ return;
+ default:
+ pr_warn("%s: Invalid value %d from next_error()\n",
+ __func__, rc);
+ return;
+ }
+
+ /*
+ * For fenced PHB and frozen PE, it's handled as normal
+ * event. We have to remove the affected PHBs for dead
+ * PHB and IOC
+ */
+ if (rc == EEH_NEXT_ERR_FROZEN_PE ||
+ rc == EEH_NEXT_ERR_FENCED_PHB) {
+ eeh_handle_normal_event(pe);
+ eeh_pe_state_clear(pe, EEH_PE_RECOVERING);
+ } else {
+ pci_lock_rescan_remove();
+ list_for_each_entry(hose, &hose_list, list_node) {
+ phb_pe = eeh_phb_pe_get(hose);
+ if (!phb_pe ||
+ !(phb_pe->state & EEH_PE_ISOLATED) ||
+ (phb_pe->state & EEH_PE_RECOVERING))
+ continue;
+
+ /* Notify all devices to be down */
+ bus = eeh_pe_bus_get(phb_pe);
+ eeh_pe_dev_traverse(pe,
+ eeh_report_failure, NULL);
+ pcibios_remove_pci_devices(bus);
+ }
+ pci_unlock_rescan_remove();
+ }
+
+ /*
+ * If we have detected dead IOC, we needn't proceed
+ * any more since all PHBs would have been removed
+ */
+ if (rc == EEH_NEXT_ERR_DEAD_IOC)
+ break;
+ } while (rc != EEH_NEXT_ERR_NONE);
+}
+
+/**
+ * eeh_handle_event - Reset a PCI device after hard lockup.
+ * @pe: EEH PE
+ *
+ * While PHB detects address or data parity errors on particular PCI
+ * slot, the associated PE will be frozen. Besides, DMA's occurring
+ * to wild addresses (which usually happen due to bugs in device
+ * drivers or in PCI adapter firmware) can cause EEH error. #SERR,
+ * #PERR or other misc PCI-related errors also can trigger EEH errors.
+ *
+ * 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).
+ */
+void eeh_handle_event(struct eeh_pe *pe)
+{
+ if (pe)
+ eeh_handle_normal_event(pe);
+ else
+ eeh_handle_special_event();
+}
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-11-04 21:49:37 +0000