exresolv.c

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/******************************************************************************
 *
 * Module Name: exresolv - 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 "amlcode.h"
#include "acdispat.h"
#include "acinterp.h"
#include "acnamesp.h"

#define _COMPONENT          ACPI_EXECUTER
ACPI_MODULE_NAME("exresolv")

/* Local prototypes */
static acpi_status
acpi_ex_resolve_object_to_value(union acpi_operand_object **stack_ptr,
                struct acpi_walk_state *walk_state);

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_resolve_to_value
 *
 * PARAMETERS:  **stack_ptr         - Points to entry on obj_stack, which can
 *                                    be either an (union acpi_operand_object *)
 *                                    or an acpi_handle.
 *              walk_state          - Current method state
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Convert Reference objects to values
 *
 ******************************************************************************/

acpi_status
acpi_ex_resolve_to_value(union acpi_operand_object **stack_ptr,
             struct acpi_walk_state *walk_state)
{
    acpi_status status;

    ACPI_FUNCTION_TRACE_PTR(ex_resolve_to_value, stack_ptr);

    if (!stack_ptr || !*stack_ptr) {
        ACPI_ERROR((AE_INFO, "Internal - null pointer"));
        return_ACPI_STATUS(AE_AML_NO_OPERAND);
    }

    /*
     * The entity pointed to by the stack_ptr can be either
     * 1) A valid union acpi_operand_object, or
     * 2) A struct acpi_namespace_node (named_obj)
     */
    if (ACPI_GET_DESCRIPTOR_TYPE(*stack_ptr) == ACPI_DESC_TYPE_OPERAND) {
        status = acpi_ex_resolve_object_to_value(stack_ptr, walk_state);
        if (ACPI_FAILURE(status)) {
            return_ACPI_STATUS(status);
        }

        if (!*stack_ptr) {
            ACPI_ERROR((AE_INFO, "Internal - null pointer"));
            return_ACPI_STATUS(AE_AML_NO_OPERAND);
        }
    }

    /*
     * Object on the stack may have changed if acpi_ex_resolve_object_to_value()
     * was called (i.e., we can't use an _else_ here.)
     */
    if (ACPI_GET_DESCRIPTOR_TYPE(*stack_ptr) == ACPI_DESC_TYPE_NAMED) {
        status =
            acpi_ex_resolve_node_to_value(ACPI_CAST_INDIRECT_PTR
                          (struct acpi_namespace_node,
                           stack_ptr), walk_state);
        if (ACPI_FAILURE(status)) {
            return_ACPI_STATUS(status);
        }
    }

    ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Resolved object %p\n", *stack_ptr));
    return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_resolve_object_to_value
 *
 * PARAMETERS:  stack_ptr       - Pointer to an internal object
 *              walk_state      - Current method state
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Retrieve the value from an internal object. The Reference type
 *              uses the associated AML opcode to determine the value.
 *
 ******************************************************************************/

static acpi_status
acpi_ex_resolve_object_to_value(union acpi_operand_object **stack_ptr,
                struct acpi_walk_state *walk_state)
{
    acpi_status status = AE_OK;
    union acpi_operand_object *stack_desc;
    union acpi_operand_object *obj_desc = NULL;
    u8 ref_type;

    ACPI_FUNCTION_TRACE(ex_resolve_object_to_value);

    stack_desc = *stack_ptr;

    /* This is an object of type union acpi_operand_object */

    switch (stack_desc->common.type) {
    case ACPI_TYPE_LOCAL_REFERENCE:

        ref_type = stack_desc->reference.class;

        switch (ref_type) {
        case ACPI_REFCLASS_LOCAL:
        case ACPI_REFCLASS_ARG:

            /*
             * Get the local from the method's state info
             * Note: this increments the local's object reference count
             */
            status = acpi_ds_method_data_get_value(ref_type,
                                   stack_desc->
                                   reference.value,
                                   walk_state,
                                   &obj_desc);
            if (ACPI_FAILURE(status)) {
                return_ACPI_STATUS(status);
            }

            ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
                      "[Arg/Local %X] ValueObj is %p\n",
                      stack_desc->reference.value,
                      obj_desc));

            /*
             * Now we can delete the original Reference Object and
             * replace it with the resolved value
             */
            acpi_ut_remove_reference(stack_desc);
            *stack_ptr = obj_desc;
            break;

        case ACPI_REFCLASS_INDEX:

            switch (stack_desc->reference.target_type) {
            case ACPI_TYPE_BUFFER_FIELD:

                /* Just return - do not dereference */
                break;

            case ACPI_TYPE_PACKAGE:

                /* If method call or copy_object - do not dereference */

                if ((walk_state->opcode ==
                     AML_INT_METHODCALL_OP)
                    || (walk_state->opcode == AML_COPY_OP)) {
                    break;
                }

                /* Otherwise, dereference the package_index to a package element */

                obj_desc = *stack_desc->reference.where;
                if (obj_desc) {
                    /*
                     * Valid object descriptor, copy pointer to return value
                     * (i.e., dereference the package index)
                     * Delete the ref object, increment the returned object
                     */
                    acpi_ut_remove_reference(stack_desc);
                    acpi_ut_add_reference(obj_desc);
                    *stack_ptr = obj_desc;
                } else {
                    /*
                     * A NULL object descriptor means an uninitialized element of
                     * the package, can't dereference it
                     */
                    ACPI_ERROR((AE_INFO,
                            "Attempt to dereference an Index to NULL package element Idx=%p",
                            stack_desc));
                    status = AE_AML_UNINITIALIZED_ELEMENT;
                }
                break;

            default:

                /* Invalid reference object */

                ACPI_ERROR((AE_INFO,
                        "Unknown TargetType 0x%X in Index/Reference object %p",
                        stack_desc->reference.target_type,
                        stack_desc));
                status = AE_AML_INTERNAL;
                break;
            }
            break;

        case ACPI_REFCLASS_REFOF:
        case ACPI_REFCLASS_DEBUG:
        case ACPI_REFCLASS_TABLE:

            /* Just leave the object as-is, do not dereference */

            break;

        case ACPI_REFCLASS_NAME:    /* Reference to a named object */

            /* Dereference the name */

            if ((stack_desc->reference.node->type ==
                 ACPI_TYPE_DEVICE)
                || (stack_desc->reference.node->type ==
                ACPI_TYPE_THERMAL)) {

                /* These node types do not have 'real' subobjects */

                *stack_ptr = (void *)stack_desc->reference.node;
            } else {
                /* Get the object pointed to by the namespace node */

                *stack_ptr =
                    (stack_desc->reference.node)->object;
                acpi_ut_add_reference(*stack_ptr);
            }

            acpi_ut_remove_reference(stack_desc);
            break;

        default:

            ACPI_ERROR((AE_INFO,
                    "Unknown Reference type 0x%X in %p",
                    ref_type, stack_desc));
            status = AE_AML_INTERNAL;
            break;
        }
        break;

    case ACPI_TYPE_BUFFER:

        status = acpi_ds_get_buffer_arguments(stack_desc);
        break;

    case ACPI_TYPE_PACKAGE:

        status = acpi_ds_get_package_arguments(stack_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 SourceDesc=%p Type=%X\n",
                  stack_desc, stack_desc->common.type));

        status =
            acpi_ex_read_data_from_field(walk_state, stack_desc,
                         &obj_desc);

        /* Remove a reference to the original operand, then override */

        acpi_ut_remove_reference(*stack_ptr);
        *stack_ptr = (void *)obj_desc;
        break;

    default:
        break;
    }

    return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_resolve_multiple
 *
 * PARAMETERS:  walk_state          - Current state (contains AML opcode)
 *              operand             - Starting point for resolution
 *              return_type         - Where the object type is returned
 *              return_desc         - Where the resolved object is returned
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Return the base object and type.  Traverse a reference list if
 *              necessary to get to the base object.
 *
 ******************************************************************************/

acpi_status
acpi_ex_resolve_multiple(struct acpi_walk_state *walk_state,
             union acpi_operand_object *operand,
             acpi_object_type * return_type,
             union acpi_operand_object **return_desc)
{
    union acpi_operand_object *obj_desc = (void *)operand;
    struct acpi_namespace_node *node;
    acpi_object_type type;
    acpi_status status;

    ACPI_FUNCTION_TRACE(acpi_ex_resolve_multiple);

    /* Operand can be either a namespace node or an operand descriptor */

    switch (ACPI_GET_DESCRIPTOR_TYPE(obj_desc)) {
    case ACPI_DESC_TYPE_OPERAND:
        type = obj_desc->common.type;
        break;

    case ACPI_DESC_TYPE_NAMED:
        type = ((struct acpi_namespace_node *)obj_desc)->type;
        obj_desc =
            acpi_ns_get_attached_object((struct acpi_namespace_node *)
                        obj_desc);

        /* If we had an Alias node, use the attached object for type info */

        if (type == ACPI_TYPE_LOCAL_ALIAS) {
            type = ((struct acpi_namespace_node *)obj_desc)->type;
            obj_desc =
                acpi_ns_get_attached_object((struct
                             acpi_namespace_node *)
                            obj_desc);
        }
        break;

    default:
        return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
    }

    /* If type is anything other than a reference, we are done */

    if (type != ACPI_TYPE_LOCAL_REFERENCE) {
        goto exit;
    }

    /*
     * For reference objects created via the ref_of, Index, or Load/load_table
     * operators, we need to get to the base object (as per the ACPI
     * specification of the object_type and size_of operators). This means
     * traversing the list of possibly many nested references.
     */
    while (obj_desc->common.type == ACPI_TYPE_LOCAL_REFERENCE) {
        switch (obj_desc->reference.class) {
        case ACPI_REFCLASS_REFOF:
        case ACPI_REFCLASS_NAME:

            /* Dereference the reference pointer */

            if (obj_desc->reference.class == ACPI_REFCLASS_REFOF) {
                node = obj_desc->reference.object;
            } else {    /* AML_INT_NAMEPATH_OP */

                node = obj_desc->reference.node;
            }

            /* All "References" point to a NS node */

            if (ACPI_GET_DESCRIPTOR_TYPE(node) !=
                ACPI_DESC_TYPE_NAMED) {
                ACPI_ERROR((AE_INFO,
                        "Not a namespace node %p [%s]",
                        node,
                        acpi_ut_get_descriptor_name(node)));
                return_ACPI_STATUS(AE_AML_INTERNAL);
            }

            /* Get the attached object */

            obj_desc = acpi_ns_get_attached_object(node);
            if (!obj_desc) {

                /* No object, use the NS node type */

                type = acpi_ns_get_type(node);
                goto exit;
            }

            /* Check for circular references */

            if (obj_desc == operand) {
                return_ACPI_STATUS(AE_AML_CIRCULAR_REFERENCE);
            }
            break;

        case ACPI_REFCLASS_INDEX:

            /* Get the type of this reference (index into another object) */

            type = obj_desc->reference.target_type;
            if (type != ACPI_TYPE_PACKAGE) {
                goto exit;
            }

            /*
             * The main object is a package, we want to get the type
             * of the individual package element that is referenced by
             * the index.
             *
             * This could of course in turn be another reference object.
             */
            obj_desc = *(obj_desc->reference.where);
            if (!obj_desc) {

                /* NULL package elements are allowed */

                type = 0;   /* Uninitialized */
                goto exit;
            }
            break;

        case ACPI_REFCLASS_TABLE:

            type = ACPI_TYPE_DDB_HANDLE;
            goto exit;

        case ACPI_REFCLASS_LOCAL:
        case ACPI_REFCLASS_ARG:

            if (return_desc) {
                status =
                    acpi_ds_method_data_get_value(obj_desc->
                                  reference.
                                  class,
                                  obj_desc->
                                  reference.
                                  value,
                                  walk_state,
                                  &obj_desc);
                if (ACPI_FAILURE(status)) {
                    return_ACPI_STATUS(status);
                }
                acpi_ut_remove_reference(obj_desc);
            } else {
                status =
                    acpi_ds_method_data_get_node(obj_desc->
                                 reference.
                                 class,
                                 obj_desc->
                                 reference.
                                 value,
                                 walk_state,
                                 &node);
                if (ACPI_FAILURE(status)) {
                    return_ACPI_STATUS(status);
                }

                obj_desc = acpi_ns_get_attached_object(node);
                if (!obj_desc) {
                    type = ACPI_TYPE_ANY;
                    goto exit;
                }
            }
            break;

        case ACPI_REFCLASS_DEBUG:

            /* The Debug Object is of type "DebugObject" */

            type = ACPI_TYPE_DEBUG_OBJECT;
            goto exit;

        default:

            ACPI_ERROR((AE_INFO,
                    "Unknown Reference Class 0x%2.2X",
                    obj_desc->reference.class));
            return_ACPI_STATUS(AE_AML_INTERNAL);
        }
    }

    /*
     * Now we are guaranteed to have an object that has not been created
     * via the ref_of or Index operators.
     */
    type = obj_desc->common.type;

      exit:
    /* Convert internal types to external types */

    switch (type) {
    case ACPI_TYPE_LOCAL_REGION_FIELD:
    case ACPI_TYPE_LOCAL_BANK_FIELD:
    case ACPI_TYPE_LOCAL_INDEX_FIELD:

        type = ACPI_TYPE_FIELD_UNIT;
        break;

    case ACPI_TYPE_LOCAL_SCOPE:

        /* Per ACPI Specification, Scope is untyped */

        type = ACPI_TYPE_ANY;
        break;

    default:
        /* No change to Type required */
        break;
    }

    *return_type = type;
    if (return_desc) {
        *return_desc = obj_desc;
    }
    return_ACPI_STATUS(AE_OK);
}