xref: /kernel/linux/linux-6.6/drivers/acpi/acpica/utuuid.c

// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/******************************************************************************
 *
 * Module Name: utuuid -- UUID support functions
 *
 * Copyright (C) 2000 - 2023, Intel Corp.
 *
 *****************************************************************************/

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

#define _COMPONENT          ACPI_COMPILER
ACPI_MODULE_NAME("utuuid")

#if (defined ACPI_ASL_COMPILER || defined ACPI_EXEC_APP || defined ACPI_HELP_APP)
/*
 * UUID support functions.
 *
 * This table is used to convert an input UUID ascii string to a 16 byte
 * buffer and the reverse. The table maps a UUID buffer index 0-15 to
 * the index within the 36-byte UUID string where the associated 2-byte
 * hex value can be found.
 *
 * 36-byte UUID strings are of the form:
 *     aabbccdd-eeff-gghh-iijj-kkllmmnnoopp
 * Where aa-pp are one byte hex numbers, made up of two hex digits
 *
 * Note: This table is basically the inverse of the string-to-offset table
 * found in the ACPI spec in the description of the to_UUID macro.
 */
const u8 acpi_gbl_map_to_uuid_offset[UUID_BUFFER_LENGTH] = {
	6, 4, 2, 0, 11, 9, 16, 14, 19, 21, 24, 26, 28, 30, 32, 34
};

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_convert_string_to_uuid
 *
 * PARAMETERS:  in_string           - 36-byte formatted UUID string
 *              uuid_buffer         - Where the 16-byte UUID buffer is returned
 *
 * RETURN:      None. Output data is returned in the uuid_buffer
 *
 * DESCRIPTION: Convert a 36-byte formatted UUID string to 16-byte UUID buffer
 *
 ******************************************************************************/

void acpi_ut_convert_string_to_uuid(char *in_string, u8 *uuid_buffer)
{
	u32 i;

	for (i = 0; i < UUID_BUFFER_LENGTH; i++) {
		uuid_buffer[i] =
		    (acpi_ut_ascii_char_to_hex
		     (in_string[acpi_gbl_map_to_uuid_offset[i]]) << 4);

		uuid_buffer[i] |=
		    acpi_ut_ascii_char_to_hex(in_string
					      [acpi_gbl_map_to_uuid_offset[i] +
					       1]);
	}
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_convert_uuid_to_string
 *
 * PARAMETERS:  uuid_buffer         - 16-byte UUID buffer
 *              out_string          - 36-byte formatted UUID string
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Convert 16-byte UUID buffer to 36-byte formatted UUID string
 *              out_string must be 37 bytes to include null terminator.
 *
 ******************************************************************************/

acpi_status acpi_ut_convert_uuid_to_string(char *uuid_buffer, char *out_string)
{
	u32 i;

	if (!uuid_buffer || !out_string) {
		return (AE_BAD_PARAMETER);
	}

	for (i = 0; i < UUID_BUFFER_LENGTH; i++) {
		out_string[acpi_gbl_map_to_uuid_offset[i]] =
		    acpi_ut_hex_to_ascii_char(uuid_buffer[i], 4);

		out_string[acpi_gbl_map_to_uuid_offset[i] + 1] =
		    acpi_ut_hex_to_ascii_char(uuid_buffer[i], 0);
	}

	/* Insert required hyphens (dashes) */

	out_string[UUID_HYPHEN1_OFFSET] =
	    out_string[UUID_HYPHEN2_OFFSET] =
	    out_string[UUID_HYPHEN3_OFFSET] =
	    out_string[UUID_HYPHEN4_OFFSET] = '-';

	out_string[UUID_STRING_LENGTH] = 0;	/* Null terminate */
	return (AE_OK);
}
#endif