#define wmb() asm volatile("" ::: "memory")
#endif
#define read_barrier_depends() do {} while(0)
-#define set_mb(var, value) do { xchg(&var, value); } while (0)
+#define set_mb(var, value) do { (void) xchg(&var, value); } while (0)
#define set_wmb(var, value) do { var = value; wmb(); } while (0)
#define warn_if_not_ulong(x) do { unsigned long foo; (void) (&(x) == &foo); } while (0)