exresnte.c

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/******************************************************************************
 *
 * Module Name: exresnte - AML Interpreter object resolution
 *
 *****************************************************************************/

/*
 * Copyright (C) 2000 - 2012, 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 "accommon.h"
#include "acdispat.h"
#include "acinterp.h"
#include "acnamesp.h"

#define _COMPONENT          ACPI_EXECUTER
ACPI_MODULE_NAME("exresnte")

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_resolve_node_to_value
 *
 * PARAMETERS:  object_ptr      - Pointer to a location that contains
 *                                a pointer to a NS node, and will receive a
 *                                pointer to the resolved object.
 *              walk_state      - Current state.  Valid only if executing AML
 *                                code.  NULL if simply resolving an object
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Resolve a Namespace node to a valued object
 *
 * Note: for some of the data types, the pointer attached to the Node
 * can be either a pointer to an actual internal object or a pointer into the
 * AML stream itself.  These types are currently:
 *
 *      ACPI_TYPE_INTEGER
 *      ACPI_TYPE_STRING
 *      ACPI_TYPE_BUFFER
 *      ACPI_TYPE_MUTEX
 *      ACPI_TYPE_PACKAGE
 *
 ******************************************************************************/
acpi_status
acpi_ex_resolve_node_to_value(struct acpi_namespace_node **object_ptr,
                  struct acpi_walk_state *walk_state)
{
    acpi_status status = AE_OK;
    union acpi_operand_object *source_desc;
    union acpi_operand_object *obj_desc = NULL;
    struct acpi_namespace_node *node;
    acpi_object_type entry_type;

    ACPI_FUNCTION_TRACE(ex_resolve_node_to_value);

    /*
     * The stack pointer points to a struct acpi_namespace_node (Node).  Get the
     * object that is attached to the Node.
     */
    node = *object_ptr;
    source_desc = acpi_ns_get_attached_object(node);
    entry_type = acpi_ns_get_type((acpi_handle) node);

    ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Entry=%p SourceDesc=%p [%s]\n",
              node, source_desc,
              acpi_ut_get_type_name(entry_type)));

    if ((entry_type == ACPI_TYPE_LOCAL_ALIAS) ||
        (entry_type == ACPI_TYPE_LOCAL_METHOD_ALIAS)) {

        /* There is always exactly one level of indirection */

        node = ACPI_CAST_PTR(struct acpi_namespace_node, node->object);
        source_desc = acpi_ns_get_attached_object(node);
        entry_type = acpi_ns_get_type((acpi_handle) node);
        *object_ptr = node;
    }

    /*
     * Several object types require no further processing:
     * 1) Device/Thermal objects don't have a "real" subobject, return the Node
     * 2) Method locals and arguments have a pseudo-Node
     * 3) 10/2007: Added method type to assist with Package construction.
     */
    if ((entry_type == ACPI_TYPE_DEVICE) ||
        (entry_type == ACPI_TYPE_THERMAL) ||
        (entry_type == ACPI_TYPE_METHOD) ||
        (node->flags & (ANOBJ_METHOD_ARG | ANOBJ_METHOD_LOCAL))) {
        return_ACPI_STATUS(AE_OK);
    }

    if (!source_desc) {
        ACPI_ERROR((AE_INFO, "No object attached to node %p", node));
        return_ACPI_STATUS(AE_AML_NO_OPERAND);
    }

    /*
     * Action is based on the type of the Node, which indicates the type
     * of the attached object or pointer
     */
    switch (entry_type) {
    case ACPI_TYPE_PACKAGE:

        if (source_desc->common.type != ACPI_TYPE_PACKAGE) {
            ACPI_ERROR((AE_INFO, "Object not a Package, type %s",
                    acpi_ut_get_object_type_name(source_desc)));
            return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
        }

        status = acpi_ds_get_package_arguments(source_desc);
        if (ACPI_SUCCESS(status)) {

            /* Return an additional reference to the object */

            obj_desc = source_desc;
            acpi_ut_add_reference(obj_desc);
        }
        break;

    case ACPI_TYPE_BUFFER:

        if (source_desc->common.type != ACPI_TYPE_BUFFER) {
            ACPI_ERROR((AE_INFO, "Object not a Buffer, type %s",
                    acpi_ut_get_object_type_name(source_desc)));
            return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
        }

        status = acpi_ds_get_buffer_arguments(source_desc);
        if (ACPI_SUCCESS(status)) {

            /* Return an additional reference to the object */

            obj_desc = source_desc;
            acpi_ut_add_reference(obj_desc);
        }
        break;

    case ACPI_TYPE_STRING:

        if (source_desc->common.type != ACPI_TYPE_STRING) {
            ACPI_ERROR((AE_INFO, "Object not a String, type %s",
                    acpi_ut_get_object_type_name(source_desc)));
            return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
        }

        /* Return an additional reference to the object */

        obj_desc = source_desc;
        acpi_ut_add_reference(obj_desc);
        break;

    case ACPI_TYPE_INTEGER:

        if (source_desc->common.type != ACPI_TYPE_INTEGER) {
            ACPI_ERROR((AE_INFO, "Object not a Integer, type %s",
                    acpi_ut_get_object_type_name(source_desc)));
            return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
        }

        /* Return an additional reference to the object */

        obj_desc = source_desc;
        acpi_ut_add_reference(obj_desc);
        break;

    case ACPI_TYPE_BUFFER_FIELD:
    case ACPI_TYPE_LOCAL_REGION_FIELD:
    case ACPI_TYPE_LOCAL_BANK_FIELD:
    case ACPI_TYPE_LOCAL_INDEX_FIELD:

        ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
                  "FieldRead Node=%p SourceDesc=%p Type=%X\n",
                  node, source_desc, entry_type));

        status =
            acpi_ex_read_data_from_field(walk_state, source_desc,
                         &obj_desc);
        break;

        /* For these objects, just return the object attached to the Node */

    case ACPI_TYPE_MUTEX:
    case ACPI_TYPE_POWER:
    case ACPI_TYPE_PROCESSOR:
    case ACPI_TYPE_EVENT:
    case ACPI_TYPE_REGION:

        /* Return an additional reference to the object */

        obj_desc = source_desc;
        acpi_ut_add_reference(obj_desc);
        break;

        /* TYPE_ANY is untyped, and thus there is no object associated with it */

    case ACPI_TYPE_ANY:

        ACPI_ERROR((AE_INFO,
                "Untyped entry %p, no attached object!", node));

        return_ACPI_STATUS(AE_AML_OPERAND_TYPE);    /* Cannot be AE_TYPE */

    case ACPI_TYPE_LOCAL_REFERENCE:

        switch (source_desc->reference.class) {
        case ACPI_REFCLASS_TABLE:   /* This is a ddb_handle */
        case ACPI_REFCLASS_REFOF:
        case ACPI_REFCLASS_INDEX:

            /* Return an additional reference to the object */

            obj_desc = source_desc;
            acpi_ut_add_reference(obj_desc);
            break;

        default:
            /* No named references are allowed here */

            ACPI_ERROR((AE_INFO,
                    "Unsupported Reference type 0x%X",
                    source_desc->reference.class));

            return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
        }
        break;

    default:

        /* Default case is for unknown types */

        ACPI_ERROR((AE_INFO,
                "Node %p - Unknown object type 0x%X",
                node, entry_type));

        return_ACPI_STATUS(AE_AML_OPERAND_TYPE);

    }           /* switch (entry_type) */

    /* Return the object descriptor */

    *object_ptr = (void *)obj_desc;
    return_ACPI_STATUS(status);
}