1 files changed, 551 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/eeh_driver.c b/arch/powerpc/kernel/eeh_driver.c
new file mode 100644
index 000000000000..fb927af9a9ef
--- /dev/null
+++ b/arch/powerpc/kernel/eeh_driver.c
@@ -0,0 +1,551 @@
+/*
+ * 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);
+}
+
+#if 0
+static void print_device_node_tree(struct pci_dn *pdn, int dent)
+{
+	int i;
+	struct device_node *pc;
+
+	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;
+	pc = pdn->node->child;
+	while (pc) {
+		print_device_node_tree(PCI_DN(pc), dent);
+		pc = pc->sibling;
+	}
+}
+#endif
+
+/**
+ * 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;
+		enable_irq(dev->irq);
+	}
+}
+
+/**
+ * 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;
+
+	/* We might not have the associated PCI device,
+	 * then we should continue for next one.
+	 */
+	if (!dev) 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;
+
+	driver = eeh_pcid_get(dev);
+	if (!driver) return NULL;
+
+	if (!driver->err_handler ||
+	    !driver->err_handler->mmio_enabled) {
+		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) 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) {
+		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;
+}
+
+/**
+ * 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) 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) {
+		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) 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;
+}
+
+/**
+ * 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)
+{
+	int cnt, rc;
+
+	/* pcibios will clear the counter; save the value */
+	cnt = pe->freeze_count;
+
+	/*
+	 * 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().
+	 */
+	if (bus)
+		__pcibios_remove_pci_devices(bus, 0);
+
+	/* 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.
+	 */
+	rc = eeh_reset_pe(pe);
+	if (rc)
+		return rc;
+
+	/* Restore PE */
+	eeh_ops->configure_bridge(pe);
+	eeh_pe_restore_bars(pe);
+
+	/* 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);
+	}
+	pe->freeze_count = cnt;
+
+	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 150
+
+/**
+ * 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)
+{
+	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;
+	}
+
+	pe->freeze_count++;
+	if (pe->freeze_count > EEH_MAX_ALLOWED_FREEZES)
+		goto excess_failures;
+	pr_warning("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.
+	 */
+	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) {
+		printk(KERN_WARNING "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.
+	 */
+	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) {
+		rc = eeh_reset_device(pe, frozen_bus);
+		if (rc) {
+			printk(KERN_WARNING "EEH: Unable to reset, rc=%d\n", rc);
+			goto hard_fail;
+		}
+	}
+
+	/* If all devices reported they can proceed, then re-enable MMIO */
+	if (result == PCI_ERS_RESULT_CAN_RECOVER) {
+		rc = eeh_pci_enable(pe, EEH_OPT_THAW_MMIO);
+
+		if (rc < 0)
+			goto hard_fail;
+		if (rc) {
+			result = PCI_ERS_RESULT_NEED_RESET;
+		} else {
+			result = PCI_ERS_RESULT_NONE;
+			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) {
+		rc = eeh_pci_enable(pe, EEH_OPT_THAW_DMA);
+
+		if (rc < 0)
+			goto hard_fail;
+		if (rc)
+			result = PCI_ERS_RESULT_NEED_RESET;
+		else
+			result = PCI_ERS_RESULT_RECOVERED;
+	}
+
+	/* If any device has a hard failure, then shut off everything. */
+	if (result == PCI_ERS_RESULT_DISCONNECT) {
+		printk(KERN_WARNING "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) {
+		rc = eeh_reset_device(pe, NULL);
+		if (rc) {
+			printk(KERN_WARNING "EEH: Cannot reset, rc=%d\n", rc);
+			goto hard_fail;
+		}
+		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)) {
+		printk(KERN_WARNING "EEH: Not recovered\n");
+		goto hard_fail;
+	}
+
+	/* Tell all device drivers that they can resume operations */
+	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);
+
+	/* Shut down the device drivers for good. */
+	if (frozen_bus)
+		pcibios_remove_pci_devices(frozen_bus);
+}