diff --git a/sys/compat/linuxkpi/common/include/linux/mod_devicetable.h b/sys/compat/linuxkpi/common/include/linux/mod_devicetable.h
index 5becc12ef960..87bd6ec24bce 100644
--- a/sys/compat/linuxkpi/common/include/linux/mod_devicetable.h
+++ b/sys/compat/linuxkpi/common/include/linux/mod_devicetable.h
@@ -1,81 +1,83 @@
 /*-
  * Copyright (c) 2020 The FreeBSD Foundation
  *
  * This software was developed by Emmanuel Vadot under sponsorship
  * from the FreeBSD Foundation.
  *
  * 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.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, 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 DAMAGE.
  */
 
 #ifndef __LINUXKPI_LINUX_MOD_DEVICETABLE_H__
 #define	__LINUXKPI_LINUX_MOD_DEVICETABLE_H__
 
 #include <linux/types.h>
 
 enum dmi_field {
 	DMI_NONE,
 	DMI_BIOS_VENDOR,
 	DMI_BIOS_VERSION,
 	DMI_BIOS_DATE,
 	DMI_BIOS_RELEASE,
 	DMI_EC_FIRMWARE_RELEASE,
 	DMI_SYS_VENDOR,
 	DMI_PRODUCT_NAME,
 	DMI_PRODUCT_VERSION,
 	DMI_PRODUCT_SERIAL,
 	DMI_PRODUCT_UUID,
 	DMI_PRODUCT_SKU,
 	DMI_PRODUCT_FAMILY,
 	DMI_BOARD_VENDOR,
 	DMI_BOARD_NAME,
 	DMI_BOARD_VERSION,
 	DMI_BOARD_SERIAL,
 	DMI_BOARD_ASSET_TAG,
 	DMI_CHASSIS_VENDOR,
 	DMI_CHASSIS_TYPE,
 	DMI_CHASSIS_VERSION,
 	DMI_CHASSIS_SERIAL,
 	DMI_CHASSIS_ASSET_TAG,
 	DMI_STRING_MAX,
 	DMI_OEM_STRING,
 };
 
 struct dmi_strmatch {
 	unsigned char slot : 7;
 	unsigned char exact_match : 1;
 	char substr[79];
 };
 
 struct dmi_system_id {
 	int (*callback)(const struct dmi_system_id *);
 	const char *ident;
 	struct dmi_strmatch matches[4];
 	void *driver_data;
 };
 
 #define DMI_MATCH(a, b) { .slot = a, .substr = b }
 #define DMI_EXACT_MATCH(a, b)   { .slot = a, .substr = b, .exact_match = 1 }
 
 #define	I2C_NAME_SIZE		20
 #define	I2C_MODULE_PREFIX	"i2c:"
 
+#define	ACPI_ID_LEN		16
+
 #endif	/* __LINUXKPI_LINUX_MOD_DEVICETABLE_H__ */