// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/******************************************************************************
 *
 * Module Name: nspredef - Validation of ACPI predefined methods and objects
 *
 * Copyright (C) 2000 - 2020, Intel Corp.
 *
 *****************************************************************************/

#define ACPI_CREATE_PREDEFINED_TABLE

#include <acpi/acpi.h>
#include "accommon.h"
#include "acnamesp.h"
#include "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_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)
{
	acpi_status status;
	const union acpi_predefined_info *predefined;

	/* If not a predefined name, we cannot validate the return object */

	predefined = info->predefined;
	if (!predefined) {
		return (AE_OK);
	}

	/*
	 * If the method failed or did not actually return an object, we cannot
	 * validate the return object
	 */
	if ((return_status != AE_OK) && (return_status != AE_CTRL_RETURN_VALUE)) {
		return (AE_OK);
	}

	/*
	 * Return value validation and possible repair.
	 *
	 * 1) Don't perform return value validation/repair if this feature
	 * has been disabled via a global option.
	 *
	 * 2) We have a return value, but if one wasn't expected, just exit,
	 * this is not a problem. For example, if the "Implicit Return"
	 * feature is enabled, methods will always return a value.
	 *
	 * 3) If the return value can be of any type, then we cannot perform
	 * any validation, just exit.
	 */
	if (acpi_gbl_disable_auto_repair ||
	    (!predefined->info.expected_btypes) ||
	    (predefined->info.expected_btypes == ACPI_RTYPE_ALL)) {
		return (AE_OK);
	}

	/*
	 * Check that the type of the main return object is what is expected
	 * for this predefined name
	 */
	status = acpi_ns_check_object_type(info, return_object_ptr,
					   predefined->info.expected_btypes,
					   ACPI_NOT_PACKAGE_ELEMENT);
	if (ACPI_FAILURE(status)) {
		goto exit;
	}

	/*
	 *
	 * 4) If there is no return value and it is optional, just return
	 * AE_OK (_WAK).
	 */
	if (!(*return_object_ptr)) {
		goto exit;
	}

	/*
	 * For returned Package objects, check the type of all sub-objects.
	 * Note: Package may have been newly created by call above.
	 */
	if ((*return_object_ptr)->common.type == ACPI_TYPE_PACKAGE) {
		info->parent_package = *return_object_ptr;
		status = acpi_ns_check_package(info, return_object_ptr);
		if (ACPI_FAILURE(status)) {

			/* We might be able to fix some errors */

			if ((status != AE_AML_OPERAND_TYPE) &&
			    (status != AE_AML_OPERAND_VALUE)) {
				goto exit;
			}
		}
	}

	/*
	 * The return object was OK, or it was successfully repaired above.
	 * Now make some additional checks such as verifying that package
	 * objects are sorted correctly (if required) or buffer objects have
	 * the correct data width (bytes vs. dwords). These repairs are
	 * performed on a per-name basis, i.e., the code is specific to
	 * particular predefined names.
	 */
	status = acpi_ns_complex_repairs(info, node, status, return_object_ptr);

exit:
	/*
	 * If the object validation failed or if we successfully repaired one
	 * or more objects, mark the parent node to suppress further warning
	 * messages during the next evaluation of the same method/object.
	 */
	if (ACPI_FAILURE(status) || (info->return_flags & ACPI_OBJECT_REPAIRED)) {
		node->flags |= ANOBJ_EVALUATED;
	}

	return (status);
}

/*******************************************************************************
 *
 * 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)
{
	union acpi_operand_object *return_object = *return_object_ptr;
	acpi_status status = AE_OK;
	char type_buffer[96];	/* Room for 10 types */

	/* A Namespace node should not get here, but make sure */

	if (return_object &&
	    ACPI_GET_DESCRIPTOR_TYPE(return_object) == ACPI_DESC_TYPE_NAMED) {
		ACPI_WARN_PREDEFINED((AE_INFO, info->full_pathname,
				      info->node_flags,
				      "Invalid return type - Found a Namespace node [%4.4s] type %s",
				      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)
	 */
	info->return_btype = acpi_ns_get_bitmapped_type(return_object);
	if (info->return_btype == ACPI_RTYPE_ANY) {

		/* Not one of the supported objects, must be incorrect */
		goto type_error_exit;
	}

	/* For reference objects, check that the reference type is correct */

	if ((info->return_btype & expected_btypes) == ACPI_RTYPE_REFERENCE) {
		status = acpi_ns_check_reference(info, return_object);
		return (status);
	}

	/* Attempt simple repair of the returned object if necessary */

	status = acpi_ns_simple_repair(info, expected_btypes,
				       package_index, return_object_ptr);
	if (ACPI_SUCCESS(status)) {
		return (AE_OK);	/* Successful repair */
	}

type_error_exit:

	/* Create a string with all expected types for this predefined object */

	acpi_ut_get_expected_return_types(type_buffer, expected_btypes);

	if (!return_object) {
		ACPI_WARN_PREDEFINED((AE_INFO, info->full_pathname,
				      info->node_flags,
				      "Expected return object of type %s",
				      type_buffer));
	} else if (package_index == ACPI_NOT_PACKAGE_ELEMENT) {
		ACPI_WARN_PREDEFINED((AE_INFO, info->full_pathname,
				      info->node_flags,
				      "Return type mismatch - found %s, expected %s",
				      acpi_ut_get_object_type_name
				      (return_object), type_buffer));
	} else {
		ACPI_WARN_PREDEFINED((AE_INFO, info->full_pathname,
				      info->node_flags,
				      "Return Package type mismatch at index %u - "
				      "found %s, expected %s", package_index,
				      acpi_ut_get_object_type_name
				      (return_object), type_buffer));
	}

	return (AE_AML_OPERAND_TYPE);
}

/*******************************************************************************
 *
 * 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)
{

	/*
	 * Check the reference object for the correct reference type (opcode).
	 * The only type of reference that can be converted to a 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_WARN_PREDEFINED((AE_INFO, info->full_pathname, info->node_flags,
			      "Return type mismatch - unexpected reference object type [%s] %2.2X",
			      acpi_ut_get_reference_name(return_object),
			      return_object->reference.class));

	return (AE_AML_OPERAND_TYPE);
}

/*******************************************************************************
 *
 * 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)
{
	u32 return_btype;

	if (!return_object) {
		return (ACPI_RTYPE_NONE);
	}

	/* Map acpi_object_type to internal bitmapped type */

	switch (return_object->common.type) {
	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 */

		return_btype = ACPI_RTYPE_ANY;
		break;
	}

	return (return_btype);
}
