1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/acpi/acpica/acglobal.h b/drivers/acpi/acpica/acglobal.h
index f3e87ba43dbe..f431b997d2f8 100644
--- a/drivers/acpi/acpica/acglobal.h
+++ b/drivers/acpi/acpica/acglobal.h
@@ -165,6 +165,10 @@ ACPI_EXTERN u8 acpi_gbl_integer_bit_width;
 ACPI_EXTERN u8 acpi_gbl_integer_byte_width;
 ACPI_EXTERN u8 acpi_gbl_integer_nybble_width;
 
+/* Reader/Writer lock is used for namespace walk and dynamic table unload */
+
+ACPI_EXTERN struct acpi_rw_lock acpi_gbl_namespace_rw_lock;
+
 /*****************************************************************************
  *
  * Mutual exlusion within ACPICA subsystem