ACPICA: Add a lock to the internal object reference count mechanism

Certain external interfaces need to update object references
without holding the interpreter or namespace mutex objects. To
prevent race conditions, add a spinlock around the increment
and decrement of the reference counts for internal ACPI
objects. Reported by Andriy Gapon (avg@FreeBSD.org).

Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Andriy Gapon <avg@FreeBSD.org>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/acpi/acpica/acglobal.h b/drivers/acpi/acpica/acglobal.h
index 833fbc5be2d6..07160928ca25 100644
--- a/drivers/acpi/acpica/acglobal.h
+++ b/drivers/acpi/acpica/acglobal.h
@@ -224,6 +224,7 @@ ACPI_EXTERN u8 acpi_gbl_global_lock_pending;
  */
 ACPI_EXTERN acpi_spinlock acpi_gbl_gpe_lock;    /* For GPE data structs and registers */
 ACPI_EXTERN acpi_spinlock acpi_gbl_hardware_lock;       /* For ACPI H/W except GPE registers */
+ACPI_EXTERN acpi_spinlock acpi_gbl_reference_count_lock;
 
 /* Mutex for _OSI support */