Index: sys/compat/linuxkpi/common/include/linux/bitops.h
===================================================================
--- sys/compat/linuxkpi/common/include/linux/bitops.h
+++ sys/compat/linuxkpi/common/include/linux/bitops.h
@@ -275,6 +275,13 @@
 #define	test_bit(i, a)							\
     !!(READ_ONCE(((volatile const unsigned long *)(a))[BIT_WORD(i)]) & BIT_MASK(i))
 
+static inline void
+clear_bit_unlock(long bit, volatile unsigned long *var)
+{
+	clear_bit(bit, var);
+	wmb();
+}
+
 static inline int
 test_and_clear_bit(long bit, volatile unsigned long *var)
 {