1 files changed, 236 insertions, 98 deletions

diff --git a/arch/powerpc/kernel/eeh_driver.c b/arch/powerpc/kernel/eeh_driver.c
index 36bed5a1275..420da61d4ce 100644
--- a/arch/powerpc/kernel/eeh_driver.c
+++ b/arch/powerpc/kernel/eeh_driver.c
@@ -143,17 +143,43 @@ static void eeh_disable_irq(struct pci_dev *dev)
 static void eeh_enable_irq(struct pci_dev *dev)
 {
 	struct eeh_dev *edev = pci_dev_to_eeh_dev(dev);
-	struct irq_desc *desc;
 
 	if ((edev->mode) & EEH_DEV_IRQ_DISABLED) {
 		edev->mode &= ~EEH_DEV_IRQ_DISABLED;
-
-		desc = irq_to_desc(dev->irq);
-		if (desc && desc->depth > 0)
+		/*
+		 * 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;
+}
+
 /**
  * eeh_report_error - Report pci error to each device driver
  * @data: eeh device
@@ -170,10 +196,8 @@ static void *eeh_report_error(void *data, void *userdata)
 	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;
+	if (!dev || eeh_dev_removed(edev))
+		return NULL;
 	dev->error_state = pci_channel_io_frozen;
 
 	driver = eeh_pcid_get(dev);
@@ -213,11 +237,15 @@ static void *eeh_report_mmio_enabled(void *data, void *userdata)
 	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) {
+	    !driver->err_handler->mmio_enabled ||
+	    (edev->mode & EEH_DEV_NO_HANDLER)) {
 		eeh_pcid_put(dev);
 		return NULL;
 	}
@@ -249,7 +277,8 @@ static void *eeh_report_reset(void *data, void *userdata)
 	enum pci_ers_result rc, *res = userdata;
 	struct pci_driver *driver;
 
-	if (!dev) return NULL;
+	if (!dev || eeh_dev_removed(edev))
+		return NULL;
 	dev->error_state = pci_channel_io_normal;
 
 	driver = eeh_pcid_get(dev);
@@ -258,7 +287,8 @@ static void *eeh_report_reset(void *data, void *userdata)
 	eeh_enable_irq(dev);
 
 	if (!driver->err_handler ||
-	    !driver->err_handler->slot_reset) {
+	    !driver->err_handler->slot_reset ||
+	    (edev->mode & EEH_DEV_NO_HANDLER)) {
 		eeh_pcid_put(dev);
 		return NULL;
 	}
@@ -288,7 +318,8 @@ static void *eeh_report_resume(void *data, void *userdata)
 	struct pci_dev *dev = eeh_dev_to_pci_dev(edev);
 	struct pci_driver *driver;
 
-	if (!dev) return NULL;
+	if (!dev || eeh_dev_removed(edev))
+		return NULL;
 	dev->error_state = pci_channel_io_normal;
 
 	driver = eeh_pcid_get(dev);
@@ -297,7 +328,9 @@ static void *eeh_report_resume(void *data, void *userdata)
 	eeh_enable_irq(dev);
 
 	if (!driver->err_handler ||
-	    !driver->err_handler->resume) {
+	    !driver->err_handler->resume ||
+	    (edev->mode & EEH_DEV_NO_HANDLER)) {
+		edev->mode &= ~EEH_DEV_NO_HANDLER;
 		eeh_pcid_put(dev);
 		return NULL;
 	}
@@ -322,7 +355,8 @@ static void *eeh_report_failure(void *data, void *userdata)
 	struct pci_dev *dev = eeh_dev_to_pci_dev(edev);
 	struct pci_driver *driver;
 
-	if (!dev) return NULL;
+	if (!dev || eeh_dev_removed(edev))
+		return NULL;
 	dev->error_state = pci_channel_io_perm_failure;
 
 	driver = eeh_pcid_get(dev);
@@ -358,10 +392,24 @@ static void *eeh_rmv_device(void *data, void *userdata)
 	 */
 	if (!dev || (dev->hdr_type & PCI_HEADER_TYPE_BRIDGE))
 		return NULL;
-	driver = eeh_pcid_get(dev);
-	if (driver && driver->err_handler)
+
+	/*
+	 * 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));
@@ -369,7 +417,9 @@ static void *eeh_rmv_device(void *data, void *userdata)
 	edev->mode |= EEH_DEV_DISCONNECTED;
 	(*removed)++;
 
+	pci_lock_rescan_remove();
 	pci_stop_and_remove_bus_device(dev);
+	pci_unlock_rescan_remove();
 
 	return NULL;
 }
@@ -390,6 +440,48 @@ static void *eeh_pe_detach_dev(void *data, void *userdata)
 	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;
+	int i, rc;
+
+	for (i = 0; i < 3; i++) {
+		rc = eeh_pci_enable(pe, EEH_OPT_THAW_MMIO);
+		if (rc)
+			continue;
+		rc = eeh_pci_enable(pe, EEH_OPT_THAW_DMA);
+		if (!rc)
+			break;
+	}
+
+	/* The PE has been isolated, clear it */
+	if (rc) {
+		pr_warn("%s: Can't clear frozen PHB#%x-PE#%x (%d)\n",
+			__func__, pe->phb->global_number, pe->addr, rc);
+		return (void *)pe;
+	}
+
+	return NULL;
+}
+
+static int eeh_clear_pe_frozen_state(struct eeh_pe *pe)
+{
+	void *rc;
+
+	rc = eeh_pe_traverse(pe, __eeh_clear_pe_frozen_state, NULL);
+	if (!rc)
+		eeh_pe_state_clear(pe, EEH_PE_ISOLATED);
+
+	return rc ? -EIO : 0;
+}
+
 /**
  * eeh_reset_device - Perform actual reset of a pci slot
  * @pe: EEH PE
@@ -416,22 +508,41 @@ static int eeh_reset_device(struct eeh_pe *pe, struct pci_bus *bus)
 	 * into pcibios_add_pci_devices().
 	 */
 	eeh_pe_state_mark(pe, EEH_PE_KEEP);
-	if (bus)
+	if (bus) {
+		pci_lock_rescan_remove();
 		pcibios_remove_pci_devices(bus);
-	else if (frozen_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).
+	/*
+	 * 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.
 	 */
+	eeh_pe_state_mark(pe, EEH_PE_RESET);
 	rc = eeh_reset_pe(pe);
-	if (rc)
+	if (rc) {
+		eeh_pe_state_clear(pe, EEH_PE_RESET);
 		return rc;
+	}
+
+	pci_lock_rescan_remove();
 
 	/* Restore PE */
 	eeh_ops->configure_bridge(pe);
 	eeh_pe_restore_bars(pe);
+	eeh_pe_state_clear(pe, EEH_PE_RESET);
+
+	/* Clear frozen state */
+	rc = eeh_clear_pe_frozen_state(pe);
+	if (rc)
+		return rc;
 
 	/* Give the system 5 seconds to finish running the user-space
 	 * hotplug shutdown scripts, e.g. ifdown for ethernet.  Yes,
@@ -462,13 +573,14 @@ static int eeh_reset_device(struct eeh_pe *pe, struct pci_bus *bus)
 	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 150
+#define MAX_WAIT_FOR_RECOVERY 300
 
 static void eeh_handle_normal_event(struct eeh_pe *pe)
 {
@@ -540,7 +652,6 @@ static void eeh_handle_normal_event(struct eeh_pe *pe)
 			result = PCI_ERS_RESULT_NEED_RESET;
 		} else {
 			pr_info("EEH: Notify device drivers to resume I/O\n");
-			result = PCI_ERS_RESULT_NONE;
 			eeh_pe_dev_traverse(pe, eeh_report_mmio_enabled, &result);
 		}
 	}
@@ -552,10 +663,17 @@ static void eeh_handle_normal_event(struct eeh_pe *pe)
 
 		if (rc < 0)
 			goto hard_fail;
-		if (rc)
+		if (rc) {
 			result = PCI_ERS_RESULT_NEED_RESET;
-		else
+		} 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. */
@@ -617,93 +735,113 @@ perm_error:
 	/* 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)
+	/* Mark the PE to be removed permanently */
+	pe->freeze_count = EEH_MAX_ALLOWED_FREEZES + 1;
+
+	/*
+	 * 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, *tmp;
+	struct pci_controller *hose;
 	unsigned long flags;
-	int rc = 0;
+	int rc;
 
-	/*
-	 * The return value from next_error() has been classified as follows.
-	 * It might be good to enumerate them. However, next_error() is only
-	 * supported by PowerNV platform for now. So it would be fine to use
-	 * integer directly:
-	 *
-	 * 4 - Dead IOC           3 - Dead PHB
-	 * 2 - Fenced PHB         1 - Frozen PE
-	 * 0 - No error found
-	 *
-	 */
-	rc = eeh_ops->next_error(&pe);
-	if (rc <= 0)
-		return;
 
-	switch (rc) {
-	case 4:
-		/* Mark all PHBs in dead state */
-		eeh_serialize_lock(&flags);
-		list_for_each_entry_safe(hose, tmp,
-				&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_PE_PHB_DEAD);
+	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;
 		}
-		eeh_serialize_unlock(flags);
-
-		/* Purge all events */
-		eeh_remove_event(NULL);
-		break;
-	case 3:
-	case 2:
-	case 1:
-		/* Mark the PE in fenced state */
-		eeh_serialize_lock(&flags);
-		if (rc == 3)
-			eeh_pe_state_mark(pe,
-				EEH_PE_ISOLATED | EEH_PE_PHB_DEAD);
-		else
-			eeh_pe_state_mark(pe,
-				EEH_PE_ISOLATED | EEH_PE_RECOVERING);
-		eeh_serialize_unlock(flags);
-
-		/* Purge all events of the PHB */
-		eeh_remove_event(pe);
-		break;
-	default:
-		pr_err("%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 == 2 || rc == 1)
-		eeh_handle_normal_event(pe);
-	else {
-		list_for_each_entry_safe(hose, tmp,
-			&hose_list, list_node) {
-			phb_pe = eeh_phb_pe_get(hose);
-			if (!phb_pe || !(phb_pe->state & EEH_PE_PHB_DEAD))
-				continue;
-
-			bus = eeh_pe_bus_get(phb_pe);
-			/* Notify all devices that they're about to go down. */
-			eeh_pe_dev_traverse(pe, eeh_report_failure, NULL);
-			pcibios_remove_pci_devices(bus);
+		/*
+		 * 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);
 }
 
 /**