1 files changed, 57 insertions, 13 deletions

diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c
index cd929aed3613..7c7a388c85ab 100644
--- a/drivers/pci/hotplug/acpiphp_glue.c
+++ b/drivers/pci/hotplug/acpiphp_glue.c
@@ -210,10 +210,29 @@ static void post_dock_fixups(acpi_handle not_used, u32 event, void *data)
 	}
 }
 
+static void dock_event(acpi_handle handle, u32 type, void *data)
+{
+	struct acpiphp_context *context;
+
+	mutex_lock(&acpiphp_context_lock);
+	context = acpiphp_get_context(handle);
+	if (!context || WARN_ON(context->handle != handle)
+	    || context->func.parent->is_going_away) {
+		mutex_unlock(&acpiphp_context_lock);
+		return;
+	}
+	get_bridge(context->func.parent);
+	acpiphp_put_context(context);
+	mutex_unlock(&acpiphp_context_lock);
+
+	hotplug_event(handle, type, data);
+
+	put_bridge(context->func.parent);
+}
 
 static const struct acpi_dock_ops acpiphp_dock_ops = {
 	.fixup = post_dock_fixups,
-	.handler = hotplug_event,
+	.handler = dock_event,
 };
 
 /* Check whether the PCI device is managed by native PCIe hotplug driver */
@@ -441,7 +460,9 @@ static void cleanup_bridge(struct acpiphp_bridge *bridge)
 	list_del(&bridge->list);
 	mutex_unlock(&bridge_mutex);
 
+	mutex_lock(&acpiphp_context_lock);
 	bridge->is_going_away = true;
+	mutex_unlock(&acpiphp_context_lock);
 }
 
 /**
@@ -709,6 +730,17 @@ static unsigned int get_slot_status(struct acpiphp_slot *slot)
 	return (unsigned int)sta;
 }
 
+static inline bool device_status_valid(unsigned int sta)
+{
+	/*
+	 * ACPI spec says that _STA may return bit 0 clear with bit 3 set
+	 * if the device is valid but does not require a device driver to be
+	 * loaded (Section 6.3.7 of ACPI 5.0A).
+	 */
+	unsigned int mask = ACPI_STA_DEVICE_ENABLED | ACPI_STA_DEVICE_FUNCTIONING;
+	return (sta & mask) == mask;
+}
+
 /**
  * trim_stale_devices - remove PCI devices that are not responding.
  * @dev: PCI device to start walking the hierarchy from.
@@ -724,7 +756,7 @@ static void trim_stale_devices(struct pci_dev *dev)
 		unsigned long long sta;
 
 		status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
-		alive = (ACPI_SUCCESS(status) && sta == ACPI_STA_ALL)
+		alive = (ACPI_SUCCESS(status) && device_status_valid(sta))
 			|| acpiphp_no_hotplug(handle);
 	}
 	if (!alive) {
@@ -742,7 +774,7 @@ static void trim_stale_devices(struct pci_dev *dev)
 
 		/* The device is a bridge. so check the bus below it. */
 		pm_runtime_get_sync(&dev->dev);
-		list_for_each_entry_safe(child, tmp, &bus->devices, bus_list)
+		list_for_each_entry_safe_reverse(child, tmp, &bus->devices, bus_list)
 			trim_stale_devices(child);
 
 		pm_runtime_put(&dev->dev);
@@ -771,10 +803,10 @@ static void acpiphp_check_bridge(struct acpiphp_bridge *bridge)
 		mutex_lock(&slot->crit_sect);
 		if (slot_no_hotplug(slot)) {
 			; /* do nothing */
-		} else if (get_slot_status(slot) == ACPI_STA_ALL) {
+		} else if (device_status_valid(get_slot_status(slot))) {
 			/* remove stale devices if any */
-			list_for_each_entry_safe(dev, tmp, &bus->devices,
-						 bus_list)
+			list_for_each_entry_safe_reverse(dev, tmp,
+							 &bus->devices, bus_list)
 				if (PCI_SLOT(dev->devfn) == slot->device)
 					trim_stale_devices(dev);
 
@@ -805,7 +837,7 @@ static void acpiphp_sanitize_bus(struct pci_bus *bus)
 	int i;
 	unsigned long type_mask = IORESOURCE_IO | IORESOURCE_MEM;
 
-	list_for_each_entry_safe(dev, tmp, &bus->devices, bus_list) {
+	list_for_each_entry_safe_reverse(dev, tmp, &bus->devices, bus_list) {
 		for (i=0; i<PCI_BRIDGE_RESOURCES; i++) {
 			struct resource *res = &dev->resource[i];
 			if ((res->flags & type_mask) && !res->start &&
@@ -829,7 +861,11 @@ void acpiphp_check_host_bridge(acpi_handle handle)
 
 	bridge = acpiphp_handle_to_bridge(handle);
 	if (bridge) {
+		pci_lock_rescan_remove();
+
 		acpiphp_check_bridge(bridge);
+
+		pci_unlock_rescan_remove();
 		put_bridge(bridge);
 	}
 }
@@ -852,6 +888,7 @@ static void hotplug_event(acpi_handle handle, u32 type, void *data)
 
 	mutex_unlock(&acpiphp_context_lock);
 
+	pci_lock_rescan_remove();
 	acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
 
 	switch (type) {
@@ -905,6 +942,7 @@ static void hotplug_event(acpi_handle handle, u32 type, void *data)
 		break;
 	}
 
+	pci_unlock_rescan_remove();
 	if (bridge)
 		put_bridge(bridge);
 }
@@ -915,11 +953,9 @@ static void hotplug_event_work(void *data, u32 type)
 	acpi_handle handle = context->handle;
 
 	acpi_scan_lock_acquire();
-	pci_lock_rescan_remove();
 
 	hotplug_event(handle, type, context);
 
-	pci_unlock_rescan_remove();
 	acpi_scan_lock_release();
 	acpi_evaluate_hotplug_ost(handle, type, ACPI_OST_SC_SUCCESS, NULL);
 	put_bridge(context->func.parent);
@@ -937,6 +973,7 @@ static void handle_hotplug_event(acpi_handle handle, u32 type, void *data)
 {
 	struct acpiphp_context *context;
 	u32 ost_code = ACPI_OST_SC_SUCCESS;
+	acpi_status status;
 
 	switch (type) {
 	case ACPI_NOTIFY_BUS_CHECK:
@@ -972,13 +1009,20 @@ static void handle_hotplug_event(acpi_handle handle, u32 type, void *data)
 
 	mutex_lock(&acpiphp_context_lock);
 	context = acpiphp_get_context(handle);
-	if (context && !WARN_ON(context->handle != handle)) {
-		get_bridge(context->func.parent);
-		acpiphp_put_context(context);
-		acpi_hotplug_execute(hotplug_event_work, context, type);
+	if (!context || WARN_ON(context->handle != handle)
+	    || context->func.parent->is_going_away)
+		goto err_out;
+
+	get_bridge(context->func.parent);
+	acpiphp_put_context(context);
+	status = acpi_hotplug_execute(hotplug_event_work, context, type);
+	if (ACPI_SUCCESS(status)) {
 		mutex_unlock(&acpiphp_context_lock);
 		return;
 	}
+	put_bridge(context->func.parent);
+
+ err_out:
 	mutex_unlock(&acpiphp_context_lock);
 	ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;