root/drivers/acpi/acpica/utobject.c
// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/******************************************************************************
 *
 * Module Name: utobject - ACPI object create/delete/size/cache routines
 *
 * Copyright (C) 2000 - 2026, Intel Corp.
 *
 *****************************************************************************/

#include <acpi/acpi.h>
#include <linux/kmemleak.h>
#include "accommon.h"
#include "acnamesp.h"

#define _COMPONENT          ACPI_UTILITIES
ACPI_MODULE_NAME("utobject")

/* Local prototypes */
static acpi_status
acpi_ut_get_simple_object_size(union acpi_operand_object *obj,
                               acpi_size *obj_length);

static acpi_status
acpi_ut_get_package_object_size(union acpi_operand_object *obj,
                                acpi_size *obj_length);

static acpi_status
acpi_ut_get_element_length(u8 object_type,
                           union acpi_operand_object *source_object,
                           union acpi_generic_state *state, void *context);

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_create_internal_object_dbg
 *
 * PARAMETERS:  module_name         - Source file name of caller
 *              line_number         - Line number of caller
 *              component_id        - Component type of caller
 *              type                - ACPI Type of the new object
 *
 * RETURN:      A new internal object, null on failure
 *
 * DESCRIPTION: Create and initialize a new internal object.
 *
 * NOTE:        We always allocate the worst-case object descriptor because
 *              these objects are cached, and we want them to be
 *              one-size-satisfies-any-request. This in itself may not be
 *              the most memory efficient, but the efficiency of the object
 *              cache should more than make up for this!
 *
 ******************************************************************************/

union acpi_operand_object *acpi_ut_create_internal_object_dbg(const char
                                                              *module_name,
                                                              u32 line_number,
                                                              u32 component_id,
                                                              acpi_object_type
                                                              type)
{
        union acpi_operand_object *object;
        union acpi_operand_object *second_object;

        ACPI_FUNCTION_TRACE_STR(ut_create_internal_object_dbg,
                                acpi_ut_get_type_name(type));

        /* Allocate the raw object descriptor */

        object =
            acpi_ut_allocate_object_desc_dbg(module_name, line_number,
                                             component_id);
        if (!object) {
                return_PTR(NULL);
        }
        kmemleak_not_leak(object);

        switch (type) {
        case ACPI_TYPE_REGION:
        case ACPI_TYPE_BUFFER_FIELD:
        case ACPI_TYPE_LOCAL_BANK_FIELD:

                /* These types require a secondary object */

                second_object =
                    acpi_ut_allocate_object_desc_dbg(module_name, line_number,
                                                     component_id);
                if (!second_object) {
                        acpi_ut_delete_object_desc(object);
                        return_PTR(NULL);
                }

                second_object->common.type = ACPI_TYPE_LOCAL_EXTRA;
                second_object->common.reference_count = 1;

                /* Link the second object to the first */

                object->common.next_object = second_object;
                break;

        default:

                /* All others have no secondary object */
                break;
        }

        /* Save the object type in the object descriptor */

        object->common.type = (u8) type;

        /* Init the reference count */

        object->common.reference_count = 1;

        /* Any per-type initialization should go here */

        return_PTR(object);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_create_package_object
 *
 * PARAMETERS:  count               - Number of package elements
 *
 * RETURN:      Pointer to a new Package object, null on failure
 *
 * DESCRIPTION: Create a fully initialized package object
 *
 ******************************************************************************/

union acpi_operand_object *acpi_ut_create_package_object(u32 count)
{
        union acpi_operand_object *package_desc;
        union acpi_operand_object **package_elements;

        ACPI_FUNCTION_TRACE_U32(ut_create_package_object, count);

        /* Create a new Package object */

        package_desc = acpi_ut_create_internal_object(ACPI_TYPE_PACKAGE);
        if (!package_desc) {
                return_PTR(NULL);
        }

        /*
         * Create the element array. Count+1 allows the array to be null
         * terminated.
         */
        package_elements = ACPI_ALLOCATE_ZEROED(((acpi_size)count +
                                                 1) * sizeof(void *));
        if (!package_elements) {
                acpi_ut_delete_object_desc(package_desc);
                return_PTR(NULL);
        }

        package_desc->package.count = count;
        package_desc->package.elements = package_elements;
        return_PTR(package_desc);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_create_integer_object
 *
 * PARAMETERS:  initial_value       - Initial value for the integer
 *
 * RETURN:      Pointer to a new Integer object, null on failure
 *
 * DESCRIPTION: Create an initialized integer object
 *
 ******************************************************************************/

union acpi_operand_object *acpi_ut_create_integer_object(u64 initial_value)
{
        union acpi_operand_object *integer_desc;

        ACPI_FUNCTION_TRACE(ut_create_integer_object);

        /* Create and initialize a new integer object */

        integer_desc = acpi_ut_create_internal_object(ACPI_TYPE_INTEGER);
        if (!integer_desc) {
                return_PTR(NULL);
        }

        integer_desc->integer.value = initial_value;
        return_PTR(integer_desc);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_create_buffer_object
 *
 * PARAMETERS:  buffer_size            - Size of buffer to be created
 *
 * RETURN:      Pointer to a new Buffer object, null on failure
 *
 * DESCRIPTION: Create a fully initialized buffer object
 *
 ******************************************************************************/

union acpi_operand_object *acpi_ut_create_buffer_object(acpi_size buffer_size)
{
        union acpi_operand_object *buffer_desc;
        u8 *buffer = NULL;

        ACPI_FUNCTION_TRACE_U32(ut_create_buffer_object, buffer_size);

        /* Create a new Buffer object */

        buffer_desc = acpi_ut_create_internal_object(ACPI_TYPE_BUFFER);
        if (!buffer_desc) {
                return_PTR(NULL);
        }

        /* Create an actual buffer only if size > 0 */

        if (buffer_size > 0) {

                /* Allocate the actual buffer */

                buffer = ACPI_ALLOCATE_ZEROED(buffer_size);
                if (!buffer) {
                        ACPI_ERROR((AE_INFO, "Could not allocate size %u",
                                    (u32)buffer_size));

                        acpi_ut_remove_reference(buffer_desc);
                        return_PTR(NULL);
                }
        }

        /* Complete buffer object initialization */

        buffer_desc->buffer.flags |= AOPOBJ_DATA_VALID;
        buffer_desc->buffer.pointer = buffer;
        buffer_desc->buffer.length = (u32) buffer_size;

        /* Return the new buffer descriptor */

        return_PTR(buffer_desc);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_create_string_object
 *
 * PARAMETERS:  string_size         - Size of string to be created. Does not
 *                                    include NULL terminator, this is added
 *                                    automatically.
 *
 * RETURN:      Pointer to a new String object
 *
 * DESCRIPTION: Create a fully initialized string object
 *
 ******************************************************************************/

union acpi_operand_object *acpi_ut_create_string_object(acpi_size string_size)
{
        union acpi_operand_object *string_desc;
        char *string;

        ACPI_FUNCTION_TRACE_U32(ut_create_string_object, string_size);

        /* Create a new String object */

        string_desc = acpi_ut_create_internal_object(ACPI_TYPE_STRING);
        if (!string_desc) {
                return_PTR(NULL);
        }

        /*
         * Allocate the actual string buffer -- (Size + 1) for NULL terminator.
         * NOTE: Zero-length strings are NULL terminated
         */
        string = ACPI_ALLOCATE_ZEROED(string_size + 1);
        if (!string) {
                ACPI_ERROR((AE_INFO, "Could not allocate size %u",
                            (u32)string_size));

                acpi_ut_remove_reference(string_desc);
                return_PTR(NULL);
        }

        /* Complete string object initialization */

        string_desc->string.pointer = string;
        string_desc->string.length = (u32) string_size;

        /* Return the new string descriptor */

        return_PTR(string_desc);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_valid_internal_object
 *
 * PARAMETERS:  object              - Object to be validated
 *
 * RETURN:      TRUE if object is valid, FALSE otherwise
 *
 * DESCRIPTION: Validate a pointer to be of type union acpi_operand_object
 *
 ******************************************************************************/

u8 acpi_ut_valid_internal_object(void *object)
{

        ACPI_FUNCTION_NAME(ut_valid_internal_object);

        /* Check for a null pointer */

        if (!object) {
                ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "**** Null Object Ptr\n"));
                return (FALSE);
        }

        /* Check the descriptor type field */

        switch (ACPI_GET_DESCRIPTOR_TYPE(object)) {
        case ACPI_DESC_TYPE_OPERAND:

                /* The object appears to be a valid union acpi_operand_object */

                return (TRUE);

        default:

                ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
                                  "%p is not an ACPI operand obj [%s]\n",
                                  object, acpi_ut_get_descriptor_name(object)));
                break;
        }

        return (FALSE);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_allocate_object_desc_dbg
 *
 * PARAMETERS:  module_name         - Caller's module name (for error output)
 *              line_number         - Caller's line number (for error output)
 *              component_id        - Caller's component ID (for error output)
 *
 * RETURN:      Pointer to newly allocated object descriptor. Null on error
 *
 * DESCRIPTION: Allocate a new object descriptor. Gracefully handle
 *              error conditions.
 *
 ******************************************************************************/

void *acpi_ut_allocate_object_desc_dbg(const char *module_name,
                                       u32 line_number, u32 component_id)
{
        union acpi_operand_object *object;

        ACPI_FUNCTION_TRACE(ut_allocate_object_desc_dbg);

        object = acpi_os_acquire_object(acpi_gbl_operand_cache);
        if (!object) {
                ACPI_ERROR((module_name, line_number,
                            "Could not allocate an object descriptor"));

                return_PTR(NULL);
        }

        /* Mark the descriptor type */

        ACPI_SET_DESCRIPTOR_TYPE(object, ACPI_DESC_TYPE_OPERAND);

        ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS, "%p Size %X\n",
                          object, (u32) sizeof(union acpi_operand_object)));

        return_PTR(object);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_delete_object_desc
 *
 * PARAMETERS:  object          - An Acpi internal object to be deleted
 *
 * RETURN:      None.
 *
 * DESCRIPTION: Free an ACPI object descriptor or add it to the object cache
 *
 ******************************************************************************/

void acpi_ut_delete_object_desc(union acpi_operand_object *object)
{
        ACPI_FUNCTION_TRACE_PTR(ut_delete_object_desc, object);

        /* Object must be of type union acpi_operand_object */

        if (ACPI_GET_DESCRIPTOR_TYPE(object) != ACPI_DESC_TYPE_OPERAND) {
                ACPI_ERROR((AE_INFO,
                            "%p is not an ACPI Operand object [%s]", object,
                            acpi_ut_get_descriptor_name(object)));
                return_VOID;
        }

        (void)acpi_os_release_object(acpi_gbl_operand_cache, object);
        return_VOID;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_get_simple_object_size
 *
 * PARAMETERS:  internal_object    - An ACPI operand object
 *              obj_length         - Where the length is returned
 *
 * RETURN:      Status
 *
 * DESCRIPTION: This function is called to determine the space required to
 *              contain a simple object for return to an external user.
 *
 *              The length includes the object structure plus any additional
 *              needed space.
 *
 ******************************************************************************/

static acpi_status
acpi_ut_get_simple_object_size(union acpi_operand_object *internal_object,
                               acpi_size *obj_length)
{
        acpi_size length;
        acpi_size size;
        acpi_status status = AE_OK;

        ACPI_FUNCTION_TRACE_PTR(ut_get_simple_object_size, internal_object);

        /* Start with the length of the (external) Acpi object */

        length = sizeof(union acpi_object);

        /* A NULL object is allowed, can be a legal uninitialized package element */

        if (!internal_object) {
        /*
                 * Object is NULL, just return the length of union acpi_object
                 * (A NULL union acpi_object is an object of all zeroes.)
         */
                *obj_length = ACPI_ROUND_UP_TO_NATIVE_WORD(length);
                return_ACPI_STATUS(AE_OK);
        }

        /* A Namespace Node should never appear here */

        if (ACPI_GET_DESCRIPTOR_TYPE(internal_object) == ACPI_DESC_TYPE_NAMED) {

                /* A namespace node should never get here */

                ACPI_ERROR((AE_INFO,
                            "Received a namespace node [%4.4s] "
                            "where an operand object is required",
                            ACPI_CAST_PTR(struct acpi_namespace_node,
                                          internal_object)->name.ascii));
                return_ACPI_STATUS(AE_AML_INTERNAL);
        }

        /*
         * The final length depends on the object type
         * Strings and Buffers are packed right up against the parent object and
         * must be accessed bytewise or there may be alignment problems on
         * certain processors
         */
        switch (internal_object->common.type) {
        case ACPI_TYPE_STRING:

                length += (acpi_size)internal_object->string.length + 1;
                break;

        case ACPI_TYPE_BUFFER:

                length += (acpi_size)internal_object->buffer.length;
                break;

        case ACPI_TYPE_INTEGER:
        case ACPI_TYPE_PROCESSOR:
        case ACPI_TYPE_POWER:

                /* No extra data for these types */

                break;

        case ACPI_TYPE_LOCAL_REFERENCE:

                switch (internal_object->reference.class) {
                case ACPI_REFCLASS_NAME:
                        /*
                         * Get the actual length of the full pathname to this object.
                         * The reference will be converted to the pathname to the object
                         */
                        size =
                            acpi_ns_get_pathname_length(internal_object->
                                                        reference.node);
                        if (!size) {
                                return_ACPI_STATUS(AE_BAD_PARAMETER);
                        }

                        length += ACPI_ROUND_UP_TO_NATIVE_WORD(size);
                        break;

                default:
                        /*
                         * No other reference opcodes are supported.
                         * Notably, Locals and Args are not supported, but this may be
                         * required eventually.
                         */
                        ACPI_ERROR((AE_INFO,
                                    "Cannot convert to external object - "
                                    "unsupported Reference Class [%s] 0x%X in object %p",
                                    acpi_ut_get_reference_name(internal_object),
                                    internal_object->reference.class,
                                    internal_object));
                        status = AE_TYPE;
                        break;
                }
                break;

        default:

                ACPI_ERROR((AE_INFO, "Cannot convert to external object - "
                            "unsupported type [%s] 0x%X in object %p",
                            acpi_ut_get_object_type_name(internal_object),
                            internal_object->common.type, internal_object));
                status = AE_TYPE;
                break;
        }

        /*
         * Account for the space required by the object rounded up to the next
         * multiple of the machine word size. This keeps each object aligned
         * on a machine word boundary. (preventing alignment faults on some
         * machines.)
         */
        *obj_length = ACPI_ROUND_UP_TO_NATIVE_WORD(length);
        return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_get_element_length
 *
 * PARAMETERS:  acpi_pkg_callback
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Get the length of one package element.
 *
 ******************************************************************************/

static acpi_status
acpi_ut_get_element_length(u8 object_type,
                           union acpi_operand_object *source_object,
                           union acpi_generic_state *state, void *context)
{
        acpi_status status = AE_OK;
        struct acpi_pkg_info *info = (struct acpi_pkg_info *)context;
        acpi_size object_space;

        switch (object_type) {
        case ACPI_COPY_TYPE_SIMPLE:
                /*
                 * Simple object - just get the size (Null object/entry is handled
                 * here also) and sum it into the running package length
                 */
                status =
                    acpi_ut_get_simple_object_size(source_object,
                                                   &object_space);
                if (ACPI_FAILURE(status)) {
                        return (status);
                }

                info->length += object_space;
                break;

        case ACPI_COPY_TYPE_PACKAGE:

                /* Package object - nothing much to do here, let the walk handle it */

                info->num_packages++;
                state->pkg.this_target_obj = NULL;
                break;

        default:

                /* No other types allowed */

                return (AE_BAD_PARAMETER);
        }

        return (status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_get_package_object_size
 *
 * PARAMETERS:  internal_object     - An ACPI internal object
 *              obj_length          - Where the length is returned
 *
 * RETURN:      Status
 *
 * DESCRIPTION: This function is called to determine the space required to
 *              contain a package object for return to an external user.
 *
 *              This is moderately complex since a package contains other
 *              objects including packages.
 *
 ******************************************************************************/

static acpi_status
acpi_ut_get_package_object_size(union acpi_operand_object *internal_object,
                                acpi_size *obj_length)
{
        acpi_status status;
        struct acpi_pkg_info info;

        ACPI_FUNCTION_TRACE_PTR(ut_get_package_object_size, internal_object);

        info.length = 0;
        info.object_space = 0;
        info.num_packages = 1;

        status =
            acpi_ut_walk_package_tree(internal_object, NULL,
                                      acpi_ut_get_element_length, &info);
        if (ACPI_FAILURE(status)) {
                return_ACPI_STATUS(status);
        }

        /*
         * We have handled all of the objects in all levels of the package.
         * just add the length of the package objects themselves.
         * Round up to the next machine word.
         */
        info.length +=
            ACPI_ROUND_UP_TO_NATIVE_WORD(sizeof(union acpi_object)) *
            (acpi_size)info.num_packages;

        /* Return the total package length */

        *obj_length = info.length;
        return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_get_object_size
 *
 * PARAMETERS:  internal_object     - An ACPI internal object
 *              obj_length          - Where the length will be returned
 *
 * RETURN:      Status
 *
 * DESCRIPTION: This function is called to determine the space required to
 *              contain an object for return to an API user.
 *
 ******************************************************************************/

acpi_status
acpi_ut_get_object_size(union acpi_operand_object *internal_object,
                        acpi_size *obj_length)
{
        acpi_status status;

        ACPI_FUNCTION_ENTRY();

        if ((ACPI_GET_DESCRIPTOR_TYPE(internal_object) ==
             ACPI_DESC_TYPE_OPERAND) &&
            (internal_object->common.type == ACPI_TYPE_PACKAGE)) {
                status =
                    acpi_ut_get_package_object_size(internal_object,
                                                    obj_length);
        } else {
                status =
                    acpi_ut_get_simple_object_size(internal_object, obj_length);
        }

        return (status);
}