// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/******************************************************************************
 *
 * Module Name: exresolv - AML Interpreter object resolution
 *
 * Copyright (C) 2000 - 2025, Intel Corp.
 *
 *****************************************************************************/

#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_OBJECT_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_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 = ACPI_CAST_PTR(void, operand);
        struct acpi_namespace_node *node =
            ACPI_CAST_PTR(struct acpi_namespace_node, operand);
        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(node);

                /* 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);
                }

                switch (type) {
                case ACPI_TYPE_DEVICE:
                case ACPI_TYPE_THERMAL:

                        /* These types have no attached subobject */
                        break;

                default:

                        /* All other types require a subobject */

                        if (!obj_desc) {
                                ACPI_ERROR((AE_INFO,
                                            "[%4.4s] Node is unresolved or uninitialized",
                                            acpi_ut_get_node_name(node)));
                                return_ACPI_STATUS(AE_AML_UNINITIALIZED_NODE);
                        }
                        break;
                }
                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);
}