// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/******************************************************************************
 *
 * Module Name: exstorob - AML object store support, store to object
 *
 * Copyright (C) 2000 - 2025, Intel Corp.
 *
 *****************************************************************************/

#include <acpi/acpi.h>
#include "accommon.h"
#include "acinterp.h"

#define _COMPONENT          ACPI_EXECUTER
ACPI_MODULE_NAME("exstorob")

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_store_buffer_to_buffer
 *
 * PARAMETERS:  source_desc         - Source object to copy
 *              target_desc         - Destination object of the copy
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Copy a buffer object to another buffer object.
 *
 ******************************************************************************/
acpi_status
acpi_ex_store_buffer_to_buffer(union acpi_operand_object *source_desc,
                               union acpi_operand_object *target_desc)
{
        u32 length;
        u8 *buffer;

        ACPI_FUNCTION_TRACE_PTR(ex_store_buffer_to_buffer, source_desc);

        /* If Source and Target are the same, just return */

        if (source_desc == target_desc) {
                return_ACPI_STATUS(AE_OK);
        }

        /* We know that source_desc is a buffer by now */

        buffer = ACPI_CAST_PTR(u8, source_desc->buffer.pointer);
        length = source_desc->buffer.length;

        /*
         * If target is a buffer of length zero or is a static buffer,
         * allocate a new buffer of the proper length
         */
        if ((target_desc->buffer.length == 0) ||
            (target_desc->common.flags & AOPOBJ_STATIC_POINTER)) {
                target_desc->buffer.pointer = ACPI_ALLOCATE(length);
                if (!target_desc->buffer.pointer) {
                        return_ACPI_STATUS(AE_NO_MEMORY);
                }

                target_desc->buffer.length = length;
        }

        /* Copy source buffer to target buffer */

        if (length <= target_desc->buffer.length) {

                /* Clear existing buffer and copy in the new one */

                memset(target_desc->buffer.pointer, 0,
                       target_desc->buffer.length);
                memcpy(target_desc->buffer.pointer, buffer, length);

#ifdef ACPI_OBSOLETE_BEHAVIOR
                /*
                 * NOTE: ACPI versions up to 3.0 specified that the buffer must be
                 * truncated if the string is smaller than the buffer. However, "other"
                 * implementations of ACPI never did this and thus became the defacto
                 * standard. ACPI 3.0A changes this behavior such that the buffer
                 * is no longer truncated.
                 */

                /*
                 * OBSOLETE BEHAVIOR:
                 * If the original source was a string, we must truncate the buffer,
                 * according to the ACPI spec. Integer-to-Buffer and Buffer-to-Buffer
                 * copy must not truncate the original buffer.
                 */
                if (original_src_type == ACPI_TYPE_STRING) {

                        /* Set the new length of the target */

                        target_desc->buffer.length = length;
                }
#endif
        } else {
                /* Truncate the source, copy only what will fit */

                memcpy(target_desc->buffer.pointer, buffer,
                       target_desc->buffer.length);

                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                                  "Truncating source buffer from %X to %X\n",
                                  length, target_desc->buffer.length));
        }

        /* Copy flags */

        target_desc->buffer.flags = source_desc->buffer.flags;
        target_desc->common.flags &= ~AOPOBJ_STATIC_POINTER;
        return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_store_string_to_string
 *
 * PARAMETERS:  source_desc         - Source object to copy
 *              target_desc         - Destination object of the copy
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Copy a String object to another String object
 *
 ******************************************************************************/

acpi_status
acpi_ex_store_string_to_string(union acpi_operand_object *source_desc,
                               union acpi_operand_object *target_desc)
{
        u32 length;
        u8 *buffer;

        ACPI_FUNCTION_TRACE_PTR(ex_store_string_to_string, source_desc);

        /* If Source and Target are the same, just return */

        if (source_desc == target_desc) {
                return_ACPI_STATUS(AE_OK);
        }

        /* We know that source_desc is a string by now */

        buffer = ACPI_CAST_PTR(u8, source_desc->string.pointer);
        length = source_desc->string.length;

        /*
         * Replace existing string value if it will fit and the string
         * pointer is not a static pointer (part of an ACPI table)
         */
        if ((length < target_desc->string.length) &&
            (!(target_desc->common.flags & AOPOBJ_STATIC_POINTER))) {
                /*
                 * String will fit in existing non-static buffer.
                 * Clear old string and copy in the new one
                 */
                memset(target_desc->string.pointer, 0,
                       (acpi_size)target_desc->string.length + 1);
                memcpy(target_desc->string.pointer, buffer, length);
        } else {
                /*
                 * Free the current buffer, then allocate a new buffer
                 * large enough to hold the value
                 */
                if (target_desc->string.pointer &&
                    (!(target_desc->common.flags & AOPOBJ_STATIC_POINTER))) {

                        /* Only free if not a pointer into the DSDT */

                        ACPI_FREE(target_desc->string.pointer);
                }

                target_desc->string.pointer =
                    ACPI_ALLOCATE_ZEROED((acpi_size)length + 1);

                if (!target_desc->string.pointer) {
                        return_ACPI_STATUS(AE_NO_MEMORY);
                }

                target_desc->common.flags &= ~AOPOBJ_STATIC_POINTER;
                memcpy(target_desc->string.pointer, buffer, length);
        }

        /* Set the new target length */

        target_desc->string.length = length;
        return_ACPI_STATUS(AE_OK);
}