Merge commit 'v2.6.28-rc2' into tracing/urgent

1 files changed, 900 insertions, 0 deletions

diff --git a/drivers/acpi/namespace/nspredef.c b/drivers/acpi/namespace/nspredef.c
new file mode 100644
index 000000000000..0f17cf0898c9
--- /dev/null
+++ b/drivers/acpi/namespace/nspredef.c
@@ -0,0 +1,900 @@
+/******************************************************************************
+ *
+ * Module Name: nspredef - Validation of ACPI predefined methods and objects
+ *              $Revision: 1.1 $
+ *
+ *****************************************************************************/
+
+/*
+ * Copyright (C) 2000 - 2008, Intel Corp.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions, and the following disclaimer,
+ *    without modification.
+ * 2. Redistributions in binary form must reproduce at minimum a disclaimer
+ *    substantially similar to the "NO WARRANTY" disclaimer below
+ *    ("Disclaimer") and any redistribution must be conditioned upon
+ *    including a substantially similar Disclaimer requirement for further
+ *    binary redistribution.
+ * 3. Neither the names of the above-listed copyright holders nor the names
+ *    of any contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2 as published by the Free
+ * Software Foundation.
+ *
+ * NO WARRANTY
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGES.
+ */
+
+#include <acpi/acpi.h>
+#include <acpi/acnamesp.h>
+#include <acpi/acpredef.h>
+
+#define _COMPONENT          ACPI_NAMESPACE
+ACPI_MODULE_NAME("nspredef")
+
+/*******************************************************************************
+ *
+ * This module validates predefined ACPI objects that appear in the namespace,
+ * at the time they are evaluated (via acpi_evaluate_object). The purpose of this
+ * validation is to detect problems with BIOS-exposed predefined ACPI objects
+ * before the results are returned to the ACPI-related drivers.
+ *
+ * There are several areas that are validated:
+ *
+ *  1) The number of input arguments as defined by the method/object in the
+ *      ASL is validated against the ACPI specification.
+ *  2) The type of the return object (if any) is validated against the ACPI
+ *      specification.
+ *  3) For returned package objects, the count of package elements is
+ *      validated, as well as the type of each package element. Nested
+ *      packages are supported.
+ *
+ * For any problems found, a warning message is issued.
+ *
+ ******************************************************************************/
+/* Local prototypes */
+static acpi_status
+acpi_ns_check_package(char *pathname,
+		      union acpi_operand_object *return_object,
+		      const union acpi_predefined_info *predefined);
+
+static acpi_status
+acpi_ns_check_package_elements(char *pathname,
+			       union acpi_operand_object **elements,
+			       u8 type1, u32 count1, u8 type2, u32 count2);
+
+static acpi_status
+acpi_ns_check_object_type(char *pathname,
+			  union acpi_operand_object *return_object,
+			  u32 expected_btypes, u32 package_index);
+
+static acpi_status
+acpi_ns_check_reference(char *pathname,
+			union acpi_operand_object *return_object);
+
+/*
+ * Names for the types that can be returned by the predefined objects.
+ * Used for warning messages. Must be in the same order as the ACPI_RTYPEs
+ */
+static const char *acpi_rtype_names[] = {
+	"/Integer",
+	"/String",
+	"/Buffer",
+	"/Package",
+	"/Reference",
+};
+
+#define ACPI_NOT_PACKAGE    ACPI_UINT32_MAX
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ns_check_predefined_names
+ *
+ * PARAMETERS:  Node            - Namespace node for the method/object
+ *              return_object   - Object returned from the evaluation of this
+ *                                method/object
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Check an ACPI name for a match in the predefined name list.
+ *
+ ******************************************************************************/
+
+acpi_status
+acpi_ns_check_predefined_names(struct acpi_namespace_node *node,
+			       union acpi_operand_object *return_object)
+{
+	acpi_status status = AE_OK;
+	const union acpi_predefined_info *predefined;
+	char *pathname;
+
+	/* Match the name for this method/object against the predefined list */
+
+	predefined = acpi_ns_check_for_predefined_name(node);
+	if (!predefined) {
+
+		/* Name was not one of the predefined names */
+
+		return (AE_OK);
+	}
+
+	/* Get the full pathname to the object, for use in error messages */
+
+	pathname = acpi_ns_get_external_pathname(node);
+	if (!pathname) {
+		pathname = ACPI_CAST_PTR(char, predefined->info.name);
+	}
+
+	/*
+	 * Check that the parameter count for this method is in accordance
+	 * with the ACPI specification.
+	 */
+	acpi_ns_check_parameter_count(pathname, node, predefined);
+
+	/*
+	 * If there is no return value, check if we require a return value for
+	 * this predefined name. Either one return value is expected, or none,
+	 * for both methods and other objects.
+	 *
+	 * Exit now if there is no return object. Warning if one was expected.
+	 */
+	if (!return_object) {
+		if ((predefined->info.expected_btypes) &&
+		    (!(predefined->info.expected_btypes & ACPI_RTYPE_NONE))) {
+			ACPI_ERROR((AE_INFO,
+				    "%s: Missing expected return value",
+				    pathname));
+
+			status = AE_AML_NO_RETURN_VALUE;
+		}
+		goto exit;
+	}
+
+	/*
+	 * We have a return value, but if one wasn't expected, just exit, this is
+	 * not a problem
+	 *
+	 * For example, if "Implicit return value" is enabled, methods will
+	 * always return a value
+	 */
+	if (!predefined->info.expected_btypes) {
+		goto exit;
+	}
+
+	/*
+	 * Check that the type of the return object is what is expected for
+	 * this predefined name
+	 */
+	status = acpi_ns_check_object_type(pathname, return_object,
+					   predefined->info.expected_btypes,
+					   ACPI_NOT_PACKAGE);
+	if (ACPI_FAILURE(status)) {
+		goto exit;
+	}
+
+	/* For returned Package objects, check the type of all sub-objects */
+
+	if (ACPI_GET_OBJECT_TYPE(return_object) == ACPI_TYPE_PACKAGE) {
+		status =
+		    acpi_ns_check_package(pathname, return_object, predefined);
+	}
+
+      exit:
+	if (pathname) {
+		ACPI_FREE(pathname);
+	}
+
+	return (status);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ns_check_parameter_count
+ *
+ * PARAMETERS:  Pathname        - Full pathname to the node (for error msgs)
+ *              Node            - Namespace node for the method/object
+ *              Predefined      - Pointer to entry in predefined name table
+ *
+ * RETURN:      None
+ *
+ * DESCRIPTION: Check that the declared (in ASL/AML) parameter count for a
+ *              predefined name is what is expected (i.e., what is defined in
+ *              the ACPI specification for this predefined name.)
+ *
+ ******************************************************************************/
+
+void
+acpi_ns_check_parameter_count(char *pathname,
+			      struct acpi_namespace_node *node,
+			      const union acpi_predefined_info *predefined)
+{
+	u32 param_count;
+	u32 required_params_current;
+	u32 required_params_old;
+
+	/*
+	 * Check that the ASL-defined parameter count is what is expected for
+	 * this predefined name.
+	 *
+	 * Methods have 0-7 parameters. All other types have zero.
+	 */
+	param_count = 0;
+	if (node->type == ACPI_TYPE_METHOD) {
+		param_count = node->object->method.param_count;
+	}
+
+	/* Validate parameter count - allow two different legal counts (_SCP) */
+
+	required_params_current = predefined->info.param_count & 0x0F;
+	required_params_old = predefined->info.param_count >> 4;
+
+	if ((param_count != required_params_current) &&
+	    (param_count != required_params_old)) {
+		ACPI_WARNING((AE_INFO,
+			      "%s: Parameter count mismatch - ASL declared %d, expected %d",
+			      pathname, param_count, required_params_current));
+	}
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ns_check_for_predefined_name
+ *
+ * PARAMETERS:  Node            - Namespace node for the method/object
+ *
+ * RETURN:      Pointer to entry in predefined table. NULL indicates not found.
+ *
+ * DESCRIPTION: Check an object name against the predefined object list.
+ *
+ ******************************************************************************/
+
+const union acpi_predefined_info *acpi_ns_check_for_predefined_name(struct
+								    acpi_namespace_node
+								    *node)
+{
+	const union acpi_predefined_info *this_name;
+
+	/* Quick check for a predefined name, first character must be underscore */
+
+	if (node->name.ascii[0] != '_') {
+		return (NULL);
+	}
+
+	/* Search info table for a predefined method/object name */
+
+	this_name = predefined_names;
+	while (this_name->info.name[0]) {
+		if (ACPI_COMPARE_NAME(node->name.ascii, this_name->info.name)) {
+
+			/* Return pointer to this table entry */
+
+			return (this_name);
+		}
+
+		/*
+		 * Skip next entry in the table if this name returns a Package
+		 * (next entry contains the package info)
+		 */
+		if (this_name->info.expected_btypes & ACPI_RTYPE_PACKAGE) {
+			this_name++;
+		}
+
+		this_name++;
+	}
+
+	return (NULL);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ns_check_package
+ *
+ * PARAMETERS:  Pathname        - Full pathname to the node (for error msgs)
+ *              return_object   - Object returned from the evaluation of a
+ *                                method or object
+ *              Predefined      - Pointer to entry in predefined name table
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Check a returned package object for the correct count and
+ *              correct type of all sub-objects.
+ *
+ ******************************************************************************/
+
+static acpi_status
+acpi_ns_check_package(char *pathname,
+		      union acpi_operand_object *return_object,
+		      const union acpi_predefined_info *predefined)
+{
+	const union acpi_predefined_info *package;
+	union acpi_operand_object *sub_package;
+	union acpi_operand_object **elements;
+	union acpi_operand_object **sub_elements;
+	acpi_status status;
+	u32 expected_count;
+	u32 count;
+	u32 i;
+	u32 j;
+
+	ACPI_FUNCTION_NAME(ns_check_package);
+
+	/* The package info for this name is in the next table entry */
+
+	package = predefined + 1;
+
+	ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
+			  "%s Validating return Package of Type %X, Count %X\n",
+			  pathname, package->ret_info.type,
+			  return_object->package.count));
+
+	/* Extract package count and elements array */
+
+	elements = return_object->package.elements;
+	count = return_object->package.count;
+
+	/* The package must have at least one element, else invalid */
+
+	if (!count) {
+		ACPI_WARNING((AE_INFO,
+			      "%s: Return Package has no elements (empty)",
+			      pathname));
+
+		return (AE_AML_OPERAND_VALUE);
+	}
+
+	/*
+	 * Decode the type of the expected package contents
+	 *
+	 * PTYPE1 packages contain no subpackages
+	 * PTYPE2 packages contain sub-packages
+	 */
+	switch (package->ret_info.type) {
+	case ACPI_PTYPE1_FIXED:
+
+		/*
+		 * The package count is fixed and there are no sub-packages
+		 *
+		 * If package is too small, exit.
+		 * If package is larger than expected, issue warning but continue
+		 */
+		expected_count =
+		    package->ret_info.count1 + package->ret_info.count2;
+		if (count < expected_count) {
+			goto package_too_small;
+		} else if (count > expected_count) {
+			ACPI_WARNING((AE_INFO,
+				      "%s: Return Package is larger than needed - "
+				      "found %u, expected %u", pathname, count,
+				      expected_count));
+		}
+
+		/* Validate all elements of the returned package */
+
+		status = acpi_ns_check_package_elements(pathname, elements,
+							package->ret_info.
+							object_type1,
+							package->ret_info.
+							count1,
+							package->ret_info.
+							object_type2,
+							package->ret_info.
+							count2);
+		if (ACPI_FAILURE(status)) {
+			return (status);
+		}
+		break;
+
+	case ACPI_PTYPE1_VAR:
+
+		/*
+		 * The package count is variable, there are no sub-packages, and all
+		 * elements must be of the same type
+		 */
+		for (i = 0; i < count; i++) {
+			status = acpi_ns_check_object_type(pathname, *elements,
+							   package->ret_info.
+							   object_type1, i);
+			if (ACPI_FAILURE(status)) {
+				return (status);
+			}
+			elements++;
+		}
+		break;
+
+	case ACPI_PTYPE1_OPTION:
+
+		/*
+		 * The package count is variable, there are no sub-packages. There are
+		 * a fixed number of required elements, and a variable number of
+		 * optional elements.
+		 *
+		 * Check if package is at least as large as the minimum required
+		 */
+		expected_count = package->ret_info3.count;
+		if (count < expected_count) {
+			goto package_too_small;
+		}
+
+		/* Variable number of sub-objects */
+
+		for (i = 0; i < count; i++) {
+			if (i < package->ret_info3.count) {
+
+				/* These are the required package elements (0, 1, or 2) */
+
+				status =
+				    acpi_ns_check_object_type(pathname,
+							      *elements,
+							      package->
+							      ret_info3.
+							      object_type[i],
+							      i);
+				if (ACPI_FAILURE(status)) {
+					return (status);
+				}
+			} else {
+				/* These are the optional package elements */
+
+				status =
+				    acpi_ns_check_object_type(pathname,
+							      *elements,
+							      package->
+							      ret_info3.
+							      tail_object_type,
+							      i);
+				if (ACPI_FAILURE(status)) {
+					return (status);
+				}
+			}
+			elements++;
+		}
+		break;
+
+	case ACPI_PTYPE2_PKG_COUNT:
+
+		/* First element is the (Integer) count of sub-packages to follow */
+
+		status = acpi_ns_check_object_type(pathname, *elements,
+						   ACPI_RTYPE_INTEGER, 0);
+		if (ACPI_FAILURE(status)) {
+			return (status);
+		}
+
+		/*
+		 * Count cannot be larger than the parent package length, but allow it
+		 * to be smaller. The >= accounts for the Integer above.
+		 */
+		expected_count = (u32) (*elements)->integer.value;
+		if (expected_count >= count) {
+			goto package_too_small;
+		}
+
+		count = expected_count;
+		elements++;
+
+		/* Now we can walk the sub-packages */
+
+		/*lint -fallthrough */
+
+	case ACPI_PTYPE2:
+	case ACPI_PTYPE2_FIXED:
+	case ACPI_PTYPE2_MIN:
+	case ACPI_PTYPE2_COUNT:
+
+		/*
+		 * These types all return a single package that consists of a variable
+		 * number of sub-packages
+		 */
+		for (i = 0; i < count; i++) {
+			sub_package = *elements;
+			sub_elements = sub_package->package.elements;
+
+			/* Each sub-object must be of type Package */
+
+			status =
+			    acpi_ns_check_object_type(pathname, sub_package,
+						      ACPI_RTYPE_PACKAGE, i);
+			if (ACPI_FAILURE(status)) {
+				return (status);
+			}
+
+			/* Examine the different types of sub-packages */
+
+			switch (package->ret_info.type) {
+			case ACPI_PTYPE2:
+			case ACPI_PTYPE2_PKG_COUNT:
+
+				/* Each subpackage has a fixed number of elements */
+
+				expected_count =
+				    package->ret_info.count1 +
+				    package->ret_info.count2;
+				if (sub_package->package.count !=
+				    expected_count) {
+					count = sub_package->package.count;
+					goto package_too_small;
+				}
+
+				status =
+				    acpi_ns_check_package_elements(pathname,
+								   sub_elements,
+								   package->
+								   ret_info.
+								   object_type1,
+								   package->
+								   ret_info.
+								   count1,
+								   package->
+								   ret_info.
+								   object_type2,
+								   package->
+								   ret_info.
+								   count2);
+				if (ACPI_FAILURE(status)) {
+					return (status);
+				}
+				break;
+
+			case ACPI_PTYPE2_FIXED:
+
+				/* Each sub-package has a fixed length */
+
+				expected_count = package->ret_info2.count;
+				if (sub_package->package.count < expected_count) {
+					count = sub_package->package.count;
+					goto package_too_small;
+				}
+
+				/* Check the type of each sub-package element */
+
+				for (j = 0; j < expected_count; j++) {
+					status =
+					    acpi_ns_check_object_type(pathname,
+								      sub_elements
+								      [j],
+								      package->
+								      ret_info2.
+								      object_type
+								      [j], j);
+					if (ACPI_FAILURE(status)) {
+						return (status);
+					}
+				}
+				break;
+
+			case ACPI_PTYPE2_MIN:
+
+				/* Each sub-package has a variable but minimum length */
+
+				expected_count = package->ret_info.count1;
+				if (sub_package->package.count < expected_count) {
+					count = sub_package->package.count;
+					goto package_too_small;
+				}
+
+				/* Check the type of each sub-package element */
+
+				status =
+				    acpi_ns_check_package_elements(pathname,
+								   sub_elements,
+								   package->
+								   ret_info.
+								   object_type1,
+								   sub_package->
+								   package.
+								   count, 0, 0);
+				if (ACPI_FAILURE(status)) {
+					return (status);
+				}
+				break;
+
+			case ACPI_PTYPE2_COUNT:
+
+				/* First element is the (Integer) count of elements to follow */
+
+				status =
+				    acpi_ns_check_object_type(pathname,
+							      *sub_elements,
+							      ACPI_RTYPE_INTEGER,
+							      0);
+				if (ACPI_FAILURE(status)) {
+					return (status);
+				}
+
+				/* Make sure package is large enough for the Count */
+
+				expected_count =
+				    (u32) (*sub_elements)->integer.value;
+				if (sub_package->package.count < expected_count) {
+					count = sub_package->package.count;
+					goto package_too_small;
+				}
+
+				/* Check the type of each sub-package element */
+
+				status =
+				    acpi_ns_check_package_elements(pathname,
+								   (sub_elements
+								    + 1),
+								   package->
+								   ret_info.
+								   object_type1,
+								   (expected_count
+								    - 1), 0, 0);
+				if (ACPI_FAILURE(status)) {
+					return (status);
+				}
+				break;
+
+			default:
+				break;
+			}
+
+			elements++;
+		}
+		break;
+
+	default:
+
+		/* Should not get here if predefined info table is correct */
+
+		ACPI_WARNING((AE_INFO,
+			      "%s: Invalid internal return type in table entry: %X",
+			      pathname, package->ret_info.type));
+
+		return (AE_AML_INTERNAL);
+	}
+
+	return (AE_OK);
+
+      package_too_small:
+
+	/* Error exit for the case with an incorrect package count */
+
+	ACPI_WARNING((AE_INFO, "%s: Return Package is too small - "
+		      "found %u, expected %u", pathname, count,
+		      expected_count));
+
+	return (AE_AML_OPERAND_VALUE);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ns_check_package_elements
+ *
+ * PARAMETERS:  Pathname        - Full pathname to the node (for error msgs)
+ *              Elements        - Pointer to the package elements array
+ *              Type1           - Object type for first group
+ *              Count1          - Count for first group
+ *              Type2           - Object type for second group
+ *              Count2          - Count for second group
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Check that all elements of a package are of the correct object
+ *              type. Supports up to two groups of different object types.
+ *
+ ******************************************************************************/
+
+static acpi_status
+acpi_ns_check_package_elements(char *pathname,
+			       union acpi_operand_object **elements,
+			       u8 type1, u32 count1, u8 type2, u32 count2)
+{
+	union acpi_operand_object **this_element = elements;
+	acpi_status status;
+	u32 i;
+
+	/*
+	 * Up to two groups of package elements are supported by the data
+	 * structure. All elements in each group must be of the same type.
+	 * The second group can have a count of zero.
+	 */
+	for (i = 0; i < count1; i++) {
+		status = acpi_ns_check_object_type(pathname, *this_element,
+						   type1, i);
+		if (ACPI_FAILURE(status)) {
+			return (status);
+		}
+		this_element++;
+	}
+
+	for (i = 0; i < count2; i++) {
+		status = acpi_ns_check_object_type(pathname, *this_element,
+						   type2, (i + count1));
+		if (ACPI_FAILURE(status)) {
+			return (status);
+		}
+		this_element++;
+	}
+
+	return (AE_OK);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ns_check_object_type
+ *
+ * PARAMETERS:  Pathname        - Full pathname to the node (for error msgs)
+ *              return_object   - Object return from the execution of this
+ *                                method/object
+ *              expected_btypes - Bitmap of expected return type(s)
+ *              package_index   - Index of object within parent package (if
+ *                                applicable - ACPI_NOT_PACKAGE otherwise)
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Check the type of the return object against the expected object
+ *              type(s). Use of Btype allows multiple expected object types.
+ *
+ ******************************************************************************/
+
+static acpi_status
+acpi_ns_check_object_type(char *pathname,
+			  union acpi_operand_object *return_object,
+			  u32 expected_btypes, u32 package_index)
+{
+	acpi_status status = AE_OK;
+	u32 return_btype;
+	char type_buffer[48];	/* Room for 5 types */
+	u32 this_rtype;
+	u32 i;
+	u32 j;
+
+	/*
+	 * If we get a NULL return_object here, it is a NULL package element,
+	 * and this is always an error.
+	 */
+	if (!return_object) {
+		goto type_error_exit;
+	}
+
+	/* A Namespace node should not get here, but make sure */
+
+	if (ACPI_GET_DESCRIPTOR_TYPE(return_object) == ACPI_DESC_TYPE_NAMED) {
+		ACPI_WARNING((AE_INFO,
+			      "%s: Invalid return type - Found a Namespace node [%4.4s] type %s",
+			      pathname, return_object->node.name.ascii,
+			      acpi_ut_get_type_name(return_object->node.type)));
+		return (AE_AML_OPERAND_TYPE);
+	}
+
+	/*
+	 * Convert the object type (ACPI_TYPE_xxx) to a bitmapped object type.
+	 * The bitmapped type allows multiple possible return types.
+	 *
+	 * Note, the cases below must handle all of the possible types returned
+	 * from all of the predefined names (including elements of returned
+	 * packages)
+	 */
+	switch (ACPI_GET_OBJECT_TYPE(return_object)) {
+	case ACPI_TYPE_INTEGER:
+		return_btype = ACPI_RTYPE_INTEGER;
+		break;
+
+	case ACPI_TYPE_BUFFER:
+		return_btype = ACPI_RTYPE_BUFFER;
+		break;
+
+	case ACPI_TYPE_STRING:
+		return_btype = ACPI_RTYPE_STRING;
+		break;
+
+	case ACPI_TYPE_PACKAGE:
+		return_btype = ACPI_RTYPE_PACKAGE;
+		break;
+
+	case ACPI_TYPE_LOCAL_REFERENCE:
+		return_btype = ACPI_RTYPE_REFERENCE;
+		break;
+
+	default:
+		/* Not one of the supported objects, must be incorrect */
+
+		goto type_error_exit;
+	}
+
+	/* Is the object one of the expected types? */
+
+	if (!(return_btype & expected_btypes)) {
+		goto type_error_exit;
+	}
+
+	/* For reference objects, check that the reference type is correct */
+
+	if (ACPI_GET_OBJECT_TYPE(return_object) == ACPI_TYPE_LOCAL_REFERENCE) {
+		status = acpi_ns_check_reference(pathname, return_object);
+	}
+
+	return (status);
+
+      type_error_exit:
+
+	/* Create a string with all expected types for this predefined object */
+
+	j = 1;
+	type_buffer[0] = 0;
+	this_rtype = ACPI_RTYPE_INTEGER;
+
+	for (i = 0; i < ACPI_NUM_RTYPES; i++) {
+
+		/* If one of the expected types, concatenate the name of this type */
+
+		if (expected_btypes & this_rtype) {
+			ACPI_STRCAT(type_buffer, &acpi_rtype_names[i][j]);
+			j = 0;	/* Use name separator from now on */
+		}
+		this_rtype <<= 1;	/* Next Rtype */
+	}
+
+	if (package_index == ACPI_NOT_PACKAGE) {
+		ACPI_WARNING((AE_INFO,
+			      "%s: Return type mismatch - found %s, expected %s",
+			      pathname,
+			      acpi_ut_get_object_type_name(return_object),
+			      type_buffer));
+	} else {
+		ACPI_WARNING((AE_INFO,
+			      "%s: Return Package type mismatch at index %u - "
+			      "found %s, expected %s", pathname, package_index,
+			      acpi_ut_get_object_type_name(return_object),
+			      type_buffer));
+	}
+
+	return (AE_AML_OPERAND_TYPE);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ns_check_reference
+ *
+ * PARAMETERS:  Pathname        - Full pathname to the node (for error msgs)
+ *              return_object   - Object returned from the evaluation of a
+ *                                method or object
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Check a returned reference object for the correct reference
+ *              type. The only reference type that can be returned from a
+ *              predefined method is a named reference. All others are invalid.
+ *
+ ******************************************************************************/
+
+static acpi_status
+acpi_ns_check_reference(char *pathname,
+			union acpi_operand_object *return_object)
+{
+
+	/*
+	 * Check the reference object for the correct reference type (opcode).
+	 * The only type of reference that can be converted to an union acpi_object is
+	 * a reference to a named object (reference class: NAME)
+	 */
+	if (return_object->reference.class == ACPI_REFCLASS_NAME) {
+		return (AE_OK);
+	}
+
+	ACPI_WARNING((AE_INFO,
+		      "%s: Return type mismatch - unexpected reference object type [%s] %2.2X",
+		      pathname, acpi_ut_get_reference_name(return_object),
+		      return_object->reference.class));
+
+	return (AE_AML_OPERAND_TYPE);
+}