linux/drivers/acpi/acpica/nspredef.c

// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/******************************************************************************
 *
 * Module Name: nspredef - Validation of ACPI predefined methods and objects
 *
 * Copyright (C) 2000 - 2023, Intel Corp.
 *
 *****************************************************************************/

#define ACPI_CREATE_PREDEFINED_TABLE

#include <acpi/acpi.h>
#include "accommon.h"
#include "acnamesp.h"
#include "acpredef.h"

#define _COMPONENT …
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_reference(struct acpi_evaluate_info *info,
			union acpi_operand_object *return_object);

static u32 acpi_ns_get_bitmapped_type(union acpi_operand_object *return_object);

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_check_return_value
 *
 * PARAMETERS:  node            - Namespace node for the method/object
 *              info            - Method execution information block
 *              user_param_count - Number of parameters actually passed
 *              return_status   - Status from the object evaluation
 *              return_object_ptr - Pointer to the object returned from the
 *                                evaluation of a method or object
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Check the value returned from a predefined name.
 *
 ******************************************************************************/

acpi_status
acpi_ns_check_return_value(struct acpi_namespace_node *node,
			   struct acpi_evaluate_info *info,
			   u32 user_param_count,
			   acpi_status return_status,
			   union acpi_operand_object **return_object_ptr)
{ … }

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_check_object_type
 *
 * PARAMETERS:  info            - Method execution information block
 *              return_object_ptr - Pointer to the object returned from the
 *                                evaluation of a method or object
 *              expected_btypes - Bitmap of expected return type(s)
 *              package_index   - Index of object within parent package (if
 *                                applicable - ACPI_NOT_PACKAGE_ELEMENT
 *                                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.
 *
 ******************************************************************************/

acpi_status
acpi_ns_check_object_type(struct acpi_evaluate_info *info,
			  union acpi_operand_object **return_object_ptr,
			  u32 expected_btypes, u32 package_index)
{ … }

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_check_reference
 *
 * PARAMETERS:  info            - Method execution information block
 *              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(struct acpi_evaluate_info *info,
			union acpi_operand_object *return_object)
{ … }

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_get_bitmapped_type
 *
 * PARAMETERS:  return_object   - Object returned from method/obj evaluation
 *
 * RETURN:      Object return type. ACPI_RTYPE_ANY indicates that the object
 *              type is not supported. ACPI_RTYPE_NONE indicates that no
 *              object was returned (return_object is NULL).
 *
 * DESCRIPTION: Convert object type into a bitmapped object return type.
 *
 ******************************************************************************/

static u32 acpi_ns_get_bitmapped_type(union acpi_operand_object *return_object)
{ … }