ACPICA: Add support for multiple notify handlers

This change adds support to allow multiple notify handlers on
Device, ThermalZone, and Processor objects. Also re-worked
and restructured the entire notify support code for handler
installation, handler removal, notify event queuing, and notify
dispatch to handler.

Extends and updates original commit 3f0be67("ACPI / ACPICA: Multiple
system notify handlers per device") by Rafael Wysocki.

Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 145 insertions, 295 deletions

diff --git a/drivers/acpi/acpica/evxface.c b/drivers/acpi/acpica/evxface.c
index 44bef5744ebb..90ae6d193645 100644
--- a/drivers/acpi/acpica/evxface.c
+++ b/drivers/acpi/acpica/evxface.c
@@ -54,86 +54,25 @@ ACPI_MODULE_NAME("evxface")
 
 /*******************************************************************************
  *
- * FUNCTION:    acpi_populate_handler_object
- *
- * PARAMETERS:  handler_obj        - Handler object to populate
- *              handler_type       - The type of handler:
- *                                  ACPI_SYSTEM_NOTIFY: system_handler (00-7f)
- *                                  ACPI_DEVICE_NOTIFY: driver_handler (80-ff)
- *                                  ACPI_ALL_NOTIFY:  both system and device
- *              handler            - Address of the handler
- *              context            - Value passed to the handler on each GPE
- *              next               - Address of a handler object to link to
- *
- * RETURN:      None
- *
- * DESCRIPTION: Populate a handler object.
- *
- ******************************************************************************/
-static void
-acpi_populate_handler_object(struct acpi_object_notify_handler *handler_obj,
-			     u32 handler_type,
-			     acpi_notify_handler handler, void *context,
-			     struct acpi_object_notify_handler *next)
-{
-	handler_obj->handler_type = handler_type;
-	handler_obj->handler = handler;
-	handler_obj->context = context;
-	handler_obj->next = next;
-}
-
-/*******************************************************************************
- *
- * FUNCTION:    acpi_add_handler_object
- *
- * PARAMETERS:  parent_obj         - Parent of the new object
- *              handler            - Address of the handler
- *              context            - Value passed to the handler on each GPE
- *
- * RETURN:      Status
- *
- * DESCRIPTION: Create a new handler object and populate it.
- *
- ******************************************************************************/
-static acpi_status
-acpi_add_handler_object(struct acpi_object_notify_handler *parent_obj,
-			acpi_notify_handler handler, void *context)
-{
-	struct acpi_object_notify_handler *handler_obj;
-
-	/* The parent must not be a defice notify handler object. */
-	if (parent_obj->handler_type & ACPI_DEVICE_NOTIFY)
-		return AE_BAD_PARAMETER;
-
-	handler_obj = ACPI_ALLOCATE_ZEROED(sizeof(*handler_obj));
-	if (!handler_obj)
-		return AE_NO_MEMORY;
-
-	acpi_populate_handler_object(handler_obj,
-					ACPI_SYSTEM_NOTIFY,
-					handler, context,
-					parent_obj->next);
-	parent_obj->next = handler_obj;
-
-	return AE_OK;
-}
-
-
-/*******************************************************************************
- *
  * FUNCTION:    acpi_install_notify_handler
  *
  * PARAMETERS:  Device          - The device for which notifies will be handled
  *              handler_type    - The type of handler:
- *                                  ACPI_SYSTEM_NOTIFY: system_handler (00-7f)
- *                                  ACPI_DEVICE_NOTIFY: driver_handler (80-ff)
- *                                  ACPI_ALL_NOTIFY:  both system and device
+ *                                  ACPI_SYSTEM_NOTIFY: System Handler (00-7F)
+ *                                  ACPI_DEVICE_NOTIFY: Device Handler (80-FF)
+ *                                  ACPI_ALL_NOTIFY:    Both System and Device
  *              Handler         - Address of the handler
  *              Context         - Value passed to the handler on each GPE
  *
  * RETURN:      Status
  *
- * DESCRIPTION: Install a handler for notifies on an ACPI device
+ * DESCRIPTION: Install a handler for notifications on an ACPI Device,
+ *              thermal_zone, or Processor object.
+ *
+ * NOTES:       The Root namespace object may have only one handler for each
+ *              type of notify (System/Device). Device/Thermal/Processor objects
+ *              may have one device notify handler, and multiple system notify
+ *              handlers.
  *
  ******************************************************************************/
 acpi_status
@@ -141,17 +80,19 @@ acpi_install_notify_handler(acpi_handle device,
 			    u32 handler_type,
 			    acpi_notify_handler handler, void *context)
 {
+	struct acpi_namespace_node *node =
+	    ACPI_CAST_PTR(struct acpi_namespace_node, device);
 	union acpi_operand_object *obj_desc;
-	union acpi_operand_object *notify_obj;
-	struct acpi_namespace_node *node;
+	union acpi_operand_object *handler_obj;
 	acpi_status status;
+	u32 i;
 
 	ACPI_FUNCTION_TRACE(acpi_install_notify_handler);
 
 	/* Parameter validation */
 
-	if ((!device) ||
-	    (!handler) || (handler_type > ACPI_MAX_NOTIFY_HANDLER_TYPE)) {
+	if ((!device) || (!handler) || (!handler_type) ||
+	    (handler_type > ACPI_MAX_NOTIFY_HANDLER_TYPE)) {
 		return_ACPI_STATUS(AE_BAD_PARAMETER);
 	}
 
@@ -160,144 +101,112 @@ acpi_install_notify_handler(acpi_handle device,
 		return_ACPI_STATUS(status);
 	}
 
-	/* Convert and validate the device handle */
-
-	node = acpi_ns_validate_handle(device);
-	if (!node) {
-		status = AE_BAD_PARAMETER;
-		goto unlock_and_exit;
-	}
-
 	/*
 	 * Root Object:
 	 * Registering a notify handler on the root object indicates that the
 	 * caller wishes to receive notifications for all objects. Note that
-	 * only one <external> global handler can be regsitered (per notify type).
+	 * only one global handler can be registered per notify type.
+	 * Ensure that a handler is not already installed.
 	 */
 	if (device == ACPI_ROOT_OBJECT) {
+		for (i = 0; i < ACPI_NUM_NOTIFY_TYPES; i++) {
+			if (handler_type & (i + 1)) {
+				if (acpi_gbl_global_notify[i].handler) {
+					status = AE_ALREADY_EXISTS;
+					goto unlock_and_exit;
+				}
 
-		/* Make sure the handler is not already installed */
-
-		if (((handler_type & ACPI_SYSTEM_NOTIFY) &&
-		     acpi_gbl_system_notify.handler) ||
-		    ((handler_type & ACPI_DEVICE_NOTIFY) &&
-		     acpi_gbl_device_notify.handler)) {
-			status = AE_ALREADY_EXISTS;
-			goto unlock_and_exit;
-		}
-
-		if (handler_type & ACPI_SYSTEM_NOTIFY) {
-			acpi_gbl_system_notify.node = node;
-			acpi_gbl_system_notify.handler = handler;
-			acpi_gbl_system_notify.context = context;
-		}
-
-		if (handler_type & ACPI_DEVICE_NOTIFY) {
-			acpi_gbl_device_notify.node = node;
-			acpi_gbl_device_notify.handler = handler;
-			acpi_gbl_device_notify.context = context;
+				acpi_gbl_global_notify[i].handler = handler;
+				acpi_gbl_global_notify[i].context = context;
+			}
 		}
 
-		/* Global notify handler installed */
+		goto unlock_and_exit;	/* Global notify handler installed, all done */
 	}
 
 	/*
 	 * All Other Objects:
-	 * Caller will only receive notifications specific to the target object.
-	 * Note that only certain object types can receive notifications.
+	 * Caller will only receive notifications specific to the target
+	 * object. Note that only certain object types are allowed to
+	 * receive notifications.
 	 */
-	else {
-		/* Notifies allowed on this object? */
 
-		if (!acpi_ev_is_notify_object(node)) {
-			status = AE_TYPE;
-			goto unlock_and_exit;
-		}
+	/* Are Notifies allowed on this object? */
 
-		/* Check for an existing internal object */
+	if (!acpi_ev_is_notify_object(node)) {
+		status = AE_TYPE;
+		goto unlock_and_exit;
+	}
 
-		obj_desc = acpi_ns_get_attached_object(node);
-		if (obj_desc) {
+	/* Check for an existing internal object, might not exist */
 
-			/* Object exists. */
+	obj_desc = acpi_ns_get_attached_object(node);
+	if (!obj_desc) {
 
-			/* For a device notify, make sure there's no handler. */
-			if ((handler_type & ACPI_DEVICE_NOTIFY) &&
-			     obj_desc->common_notify.device_notify) {
-				status = AE_ALREADY_EXISTS;
-				goto unlock_and_exit;
-			}
+		/* Create a new object */
 
-			/* System notifies may have more handlers installed. */
-			notify_obj = obj_desc->common_notify.system_notify;
+		obj_desc = acpi_ut_create_internal_object(node->type);
+		if (!obj_desc) {
+			status = AE_NO_MEMORY;
+			goto unlock_and_exit;
+		}
 
-			if ((handler_type & ACPI_SYSTEM_NOTIFY) && notify_obj) {
-				struct acpi_object_notify_handler *parent_obj;
+		/* Attach new object to the Node, remove local reference */
 
-				if (handler_type & ACPI_DEVICE_NOTIFY) {
+		status = acpi_ns_attach_object(device, obj_desc, node->type);
+		acpi_ut_remove_reference(obj_desc);
+		if (ACPI_FAILURE(status)) {
+			goto unlock_and_exit;
+		}
+	}
+
+	/* Ensure that the handler is not already installed in the lists */
+
+	for (i = 0; i < ACPI_NUM_NOTIFY_TYPES; i++) {
+		if (handler_type & (i + 1)) {
+			handler_obj = obj_desc->common_notify.notify_list[i];
+			while (handler_obj) {
+				if (handler_obj->notify.handler == handler) {
 					status = AE_ALREADY_EXISTS;
 					goto unlock_and_exit;
 				}
 
-				parent_obj = &notify_obj->notify;
-				status = acpi_add_handler_object(parent_obj,
-								 handler,
-								 context);
-				goto unlock_and_exit;
-			}
-		} else {
-			/* Create a new object */
-
-			obj_desc = acpi_ut_create_internal_object(node->type);
-			if (!obj_desc) {
-				status = AE_NO_MEMORY;
-				goto unlock_and_exit;
-			}
-
-			/* Attach new object to the Node */
-
-			status =
-			    acpi_ns_attach_object(device, obj_desc, node->type);
-
-			/* Remove local reference to the object */
-
-			acpi_ut_remove_reference(obj_desc);
-			if (ACPI_FAILURE(status)) {
-				goto unlock_and_exit;
+				handler_obj = handler_obj->notify.next[i];
 			}
 		}
+	}
 
-		/* Install the handler */
+	/* Create and populate a new notify handler object */
 
-		notify_obj =
-		    acpi_ut_create_internal_object(ACPI_TYPE_LOCAL_NOTIFY);
-		if (!notify_obj) {
-			status = AE_NO_MEMORY;
-			goto unlock_and_exit;
-		}
+	handler_obj = acpi_ut_create_internal_object(ACPI_TYPE_LOCAL_NOTIFY);
+	if (!handler_obj) {
+		status = AE_NO_MEMORY;
+		goto unlock_and_exit;
+	}
 
-		acpi_populate_handler_object(&notify_obj->notify,
-						handler_type,
-						handler, context,
-						NULL);
+	handler_obj->notify.node = node;
+	handler_obj->notify.handler_type = handler_type;
+	handler_obj->notify.handler = handler;
+	handler_obj->notify.context = context;
 
-		if (handler_type & ACPI_SYSTEM_NOTIFY) {
-			obj_desc->common_notify.system_notify = notify_obj;
-		}
+	/* Install the handler at the list head(s) */
 
-		if (handler_type & ACPI_DEVICE_NOTIFY) {
-			obj_desc->common_notify.device_notify = notify_obj;
-		}
+	for (i = 0; i < ACPI_NUM_NOTIFY_TYPES; i++) {
+		if (handler_type & (i + 1)) {
+			handler_obj->notify.next[i] =
+			    obj_desc->common_notify.notify_list[i];
 
-		if (handler_type == ACPI_ALL_NOTIFY) {
+			obj_desc->common_notify.notify_list[i] = handler_obj;
+		}
+	}
 
-			/* Extra ref if installed in both */
+	/* Add an extra reference if handler was installed in both lists */
 
-			acpi_ut_add_reference(notify_obj);
-		}
+	if (handler_type == ACPI_ALL_NOTIFY) {
+		acpi_ut_add_reference(handler_obj);
 	}
 
-      unlock_and_exit:
+unlock_and_exit:
 	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
 	return_ACPI_STATUS(status);
 }
@@ -308,11 +217,11 @@ ACPI_EXPORT_SYMBOL(acpi_install_notify_handler)
  *
  * FUNCTION:    acpi_remove_notify_handler
  *
- * PARAMETERS:  Device          - The device for which notifies will be handled
+ * PARAMETERS:  Device          - The device for which the handler is installed
  *              handler_type    - The type of handler:
- *                                  ACPI_SYSTEM_NOTIFY: system_handler (00-7f)
- *                                  ACPI_DEVICE_NOTIFY: driver_handler (80-ff)
- *                                  ACPI_ALL_NOTIFY:  both system and device
+ *                                  ACPI_SYSTEM_NOTIFY: System Handler (00-7F)
+ *                                  ACPI_DEVICE_NOTIFY: Device Handler (80-FF)
+ *                                  ACPI_ALL_NOTIFY:    Both System and Device
  *              Handler         - Address of the handler
  *
  * RETURN:      Status
@@ -324,165 +233,106 @@ acpi_status
 acpi_remove_notify_handler(acpi_handle device,
 			   u32 handler_type, acpi_notify_handler handler)
 {
-	union acpi_operand_object *notify_obj;
+	struct acpi_namespace_node *node =
+	    ACPI_CAST_PTR(struct acpi_namespace_node, device);
 	union acpi_operand_object *obj_desc;
-	struct acpi_namespace_node *node;
+	union acpi_operand_object *handler_obj;
+	union acpi_operand_object *previous_handler_obj;
 	acpi_status status;
+	u32 i;
 
 	ACPI_FUNCTION_TRACE(acpi_remove_notify_handler);
 
 	/* Parameter validation */
 
-	if ((!device) ||
-	    (!handler) || (handler_type > ACPI_MAX_NOTIFY_HANDLER_TYPE)) {
-		status = AE_BAD_PARAMETER;
-		goto exit;
+	if ((!device) || (!handler) || (!handler_type) ||
+	    (handler_type > ACPI_MAX_NOTIFY_HANDLER_TYPE)) {
+		return_ACPI_STATUS(AE_BAD_PARAMETER);
 	}
-
-
 	/* Make sure all deferred tasks are completed */
+
 	acpi_os_wait_events_complete(NULL);
 
 	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
 	if (ACPI_FAILURE(status)) {
-		goto exit;
-	}
-
-	/* Convert and validate the device handle */
-
-	node = acpi_ns_validate_handle(device);
-	if (!node) {
-		status = AE_BAD_PARAMETER;
-		goto unlock_and_exit;
+		return_ACPI_STATUS(status);
 	}
 
-	/* Root Object */
+	/* Root Object. Global handlers are removed here */
 
 	if (device == ACPI_ROOT_OBJECT) {
-		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
-				  "Removing notify handler for namespace root object\n"));
+		for (i = 0; i < ACPI_NUM_NOTIFY_TYPES; i++) {
+			if (handler_type & (i + 1)) {
+				if (!acpi_gbl_global_notify[i].handler ||
+				    (acpi_gbl_global_notify[i].handler !=
+				     handler)) {
+					status = AE_NOT_EXIST;
+					goto unlock_and_exit;
+				}
 
-		if (((handler_type & ACPI_SYSTEM_NOTIFY) &&
-		     !acpi_gbl_system_notify.handler) ||
-		    ((handler_type & ACPI_DEVICE_NOTIFY) &&
-		     !acpi_gbl_device_notify.handler)) {
-			status = AE_NOT_EXIST;
-			goto unlock_and_exit;
-		}
+				ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+						  "Removing global notify handler\n"));
 
-		if (handler_type & ACPI_SYSTEM_NOTIFY) {
-			acpi_gbl_system_notify.node = NULL;
-			acpi_gbl_system_notify.handler = NULL;
-			acpi_gbl_system_notify.context = NULL;
+				acpi_gbl_global_notify[i].handler = NULL;
+				acpi_gbl_global_notify[i].context = NULL;
+			}
 		}
 
-		if (handler_type & ACPI_DEVICE_NOTIFY) {
-			acpi_gbl_device_notify.node = NULL;
-			acpi_gbl_device_notify.handler = NULL;
-			acpi_gbl_device_notify.context = NULL;
-		}
+		goto unlock_and_exit;
 	}
 
-	/* All Other Objects */
-
-	else {
-		/* Notifies allowed on this object? */
+	/* All other objects: Are Notifies allowed on this object? */
 
-		if (!acpi_ev_is_notify_object(node)) {
-			status = AE_TYPE;
-			goto unlock_and_exit;
-		}
+	if (!acpi_ev_is_notify_object(node)) {
+		status = AE_TYPE;
+		goto unlock_and_exit;
+	}
 
-		/* Check for an existing internal object */
+	/* Must have an existing internal object */
 
-		obj_desc = acpi_ns_get_attached_object(node);
-		if (!obj_desc) {
-			status = AE_NOT_EXIST;
-			goto unlock_and_exit;
-		}
+	obj_desc = acpi_ns_get_attached_object(node);
+	if (!obj_desc) {
+		status = AE_NOT_EXIST;
+		goto unlock_and_exit;
+	}
 
-		/* Object exists - make sure there's an existing handler */
+	/* Internal object exists. Find the handler and remove it */
 
-		if (handler_type & ACPI_SYSTEM_NOTIFY) {
-			struct acpi_object_notify_handler *handler_obj;
-			struct acpi_object_notify_handler *parent_obj;
+	for (i = 0; i < ACPI_NUM_NOTIFY_TYPES; i++) {
+		if (handler_type & (i + 1)) {
+			handler_obj = obj_desc->common_notify.notify_list[i];
+			previous_handler_obj = NULL;
 
-			notify_obj = obj_desc->common_notify.system_notify;
-			if (!notify_obj) {
-				status = AE_NOT_EXIST;
-				goto unlock_and_exit;
-			}
+			/* Attempt to find the handler in the handler list */
 
-			handler_obj = &notify_obj->notify;
-			parent_obj = NULL;
-			while (handler_obj->handler != handler) {
-				if (handler_obj->next) {
-					parent_obj = handler_obj;
-					handler_obj = handler_obj->next;
-				} else {
-					break;
-				}
+			while (handler_obj &&
+			       (handler_obj->notify.handler != handler)) {
+				previous_handler_obj = handler_obj;
+				handler_obj = handler_obj->notify.next[i];
 			}
 
-			if (handler_obj->handler != handler) {
-				status = AE_BAD_PARAMETER;
+			if (!handler_obj) {
+				status = AE_NOT_EXIST;
 				goto unlock_and_exit;
 			}
 
-			/*
-			 * Remove the handler.  There are three possible cases.
-			 * First, we may need to remove a non-embedded object.
-			 * Second, we may need to remove the embedded object's
-			 * handler data, while non-embedded objects exist.
-			 * Finally, we may need to remove the embedded object
-			 * entirely along with its container.
-			 */
-			if (parent_obj) {
-				/* Non-embedded object is being removed. */
-				parent_obj->next = handler_obj->next;
-				ACPI_FREE(handler_obj);
-			} else if (notify_obj->notify.next) {
-				/*
-				 * The handler matches the embedded object, but
-				 * there are more handler objects in the list.
-				 * Replace the embedded object's data with the
-				 * first next object's data and remove that
-				 * object.
-				 */
-				parent_obj = &notify_obj->notify;
-				handler_obj = notify_obj->notify.next;
-				*parent_obj = *handler_obj;
-				ACPI_FREE(handler_obj);
-			} else {
-				/* No more handler objects in the list. */
-				obj_desc->common_notify.system_notify = NULL;
-				acpi_ut_remove_reference(notify_obj);
-			}
-		}
+			/* Remove the handler object from the list */
 
-		if (handler_type & ACPI_DEVICE_NOTIFY) {
-			notify_obj = obj_desc->common_notify.device_notify;
-			if (!notify_obj) {
-				status = AE_NOT_EXIST;
-				goto unlock_and_exit;
-			}
+			if (previous_handler_obj) {	/* Handler is not at the list head */
+				previous_handler_obj->notify.next[i] =
+				    handler_obj->notify.next[i];
+			} else {	/* Handler is at the list head */
 
-			if (notify_obj->notify.handler != handler) {
-				status = AE_BAD_PARAMETER;
-				goto unlock_and_exit;
+				obj_desc->common_notify.notify_list[i] =
+				    handler_obj->notify.next[i];
 			}
 
-			/* Remove the handler */
-			obj_desc->common_notify.device_notify = NULL;
-			acpi_ut_remove_reference(notify_obj);
+			acpi_ut_remove_reference(handler_obj);
 		}
 	}
 
-      unlock_and_exit:
+unlock_and_exit:
 	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
-      exit:
-	if (ACPI_FAILURE(status))
-		ACPI_EXCEPTION((AE_INFO, status, "Removing notify handler"));
 	return_ACPI_STATUS(status);
 }