/*
- * asm-generic/mutex-dec.h
+ * include/asm-generic/mutex-dec.h
*
* Generic implementation of the mutex fastpath, based on atomic
* decrement/increment.
* it wasn't 1 originally. This function MUST leave the value lower than
* 1 even when the "1" assertion wasn't true.
*/
-#define __mutex_fastpath_lock(count, fail_fn) \
-do { \
- if (unlikely(atomic_dec_return(count) < 0)) \
- fail_fn(count); \
- else \
- smp_mb(); \
-} while (0)
+static inline void
+__mutex_fastpath_lock(atomic_t *count, void (*fail_fn)(atomic_t *))
+{
+ if (unlikely(atomic_dec_return(count) < 0))
+ fail_fn(count);
+}
/**
* __mutex_fastpath_lock_retval - try to take the lock by moving the count
{
if (unlikely(atomic_dec_return(count) < 0))
return fail_fn(count);
- else {
- smp_mb();
- return 0;
- }
+ return 0;
}
/**
* __mutex_slowpath_needs_to_unlock() macro needs to return 1, it needs
* to return 0 otherwise.
*/
-#define __mutex_fastpath_unlock(count, fail_fn) \
-do { \
- smp_mb(); \
- if (unlikely(atomic_inc_return(count) <= 0)) \
- fail_fn(count); \
-} while (0)
+static inline void
+__mutex_fastpath_unlock(atomic_t *count, void (*fail_fn)(atomic_t *))
+{
+ if (unlikely(atomic_inc_return(count) <= 0))
+ fail_fn(count);
+}
#define __mutex_slowpath_needs_to_unlock() 1
static inline int
__mutex_fastpath_trylock(atomic_t *count, int (*fail_fn)(atomic_t *))
{
- /*
- * We have two variants here. The cmpxchg based one is the best one
- * because it never induce a false contention state. It is included
- * here because architectures using the inc/dec algorithms over the
- * xchg ones are much more likely to support cmpxchg natively.
- *
- * If not we fall back to the spinlock based variant - that is
- * just as efficient (and simpler) as a 'destructive' probing of
- * the mutex state would be.
- */
-#ifdef __HAVE_ARCH_CMPXCHG
- if (likely(atomic_cmpxchg(count, 1, 0) == 1)) {
- smp_mb();
+ if (likely(atomic_cmpxchg(count, 1, 0) == 1))
return 1;
- }
return 0;
-#else
- return fail_fn(count);
-#endif
}
#endif