ACPICA: Interpreter: Update handling for Alias operator

ACPICA commit 719d0bdd48e3e8e7a62a86c04922b9f41da6def0

Provide common creation code for the Alias operator. All objects
are now handled the same, with the only exception being the
Method() operator. It has a special internal Alias type.

Link: https://github.com/acpica/acpica/commit/719d0bdd
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/acpica/excreate.c

@@ -88,72 +88,39 @@ acpi_status acpi_ex_create_alias(struct acpi_walk_state *walk_state)
 	}
 
 	/* Ensure that the target node is valid */
+
 	if (!target_node) {
 		return_ACPI_STATUS(AE_NULL_OBJECT);
 	}
 
-	/*
-	 * For objects that can never change (i.e., the NS node will
-	 * permanently point to the same object), we can simply attach
-	 * the object to the new NS node. For other objects (such as
-	 * Integers, buffers, etc.), we have to point the Alias node
-	 * to the original Node.
-	 */
-	switch (target_node->type) {
-
-		/* For these types, the sub-object can change dynamically via a Store */
-
-	case ACPI_TYPE_INTEGER:
-	case ACPI_TYPE_STRING:
-	case ACPI_TYPE_BUFFER:
-	case ACPI_TYPE_PACKAGE:
-	case ACPI_TYPE_BUFFER_FIELD:
-		/*
-		 * These types open a new scope, so we need the NS node in order to access
-		 * any children.
-		 */
-	case ACPI_TYPE_DEVICE:
-	case ACPI_TYPE_POWER:
-	case ACPI_TYPE_PROCESSOR:
-	case ACPI_TYPE_THERMAL:
-	case ACPI_TYPE_LOCAL_SCOPE:
-		/*
-		 * The new alias has the type ALIAS and points to the original
-		 * NS node, not the object itself.
-		 */
-		alias_node->type = ACPI_TYPE_LOCAL_ALIAS;
-		alias_node->object =
-		    ACPI_CAST_PTR(union acpi_operand_object, target_node);
-		break;
+	/* Construct the alias object (a namespace node) */
 
+	switch (target_node->type) {
 	case ACPI_TYPE_METHOD:
 		/*
-		 * Control method aliases need to be differentiated
+		 * Control method aliases need to be differentiated with
+		 * a special type
 		 */
 		alias_node->type = ACPI_TYPE_LOCAL_METHOD_ALIAS;
-		alias_node->object =
-		    ACPI_CAST_PTR(union acpi_operand_object, target_node);
 		break;
 
 	default:
-
-		/* Attach the original source object to the new Alias Node */
-
 		/*
-		 * The new alias assumes the type of the target, and it points
-		 * to the same object. The reference count of the object has an
-		 * additional reference to prevent deletion out from under either the
-		 * target node or the alias Node
+		 * All other object types.
+		 *
+		 * The new alias has the type ALIAS and points to the original
+		 * NS node, not the object itself.
 		 */
-		status = acpi_ns_attach_object(alias_node,
-					       acpi_ns_get_attached_object
-					       (target_node),
-					       target_node->type);
+		alias_node->type = ACPI_TYPE_LOCAL_ALIAS;
+		alias_node->object =
+		    ACPI_CAST_PTR(union acpi_operand_object, target_node);
 		break;
 	}
 
 	/* Since both operands are Nodes, we don't need to delete them */
 
+	alias_node->object =
+	    ACPI_CAST_PTR(union acpi_operand_object, target_node);
 	return_ACPI_STATUS(status);
 }