locking/qrwlock: Implement queue_write_unlock() using smp_store_release()

[uclinux-h8/linux.git] / include / asm-generic / qrwlock.h

diff --git a/include/asm-generic/qrwlock.h b/include/asm-generic/qrwlock.h
index deb9e8b..eb673dd 100644 (file)
--- a/include/asm-generic/qrwlock.h
+++ b/include/asm-generic/qrwlock.h
@@ -134,21 +134,14 @@ static inline void queued_read_unlock(struct qrwlock *lock)
        atomic_sub(_QR_BIAS, &lock->cnts);
 }
 
-#ifndef queued_write_unlock
 /**
  * queued_write_unlock - release write lock of a queue rwlock
  * @lock : Pointer to queue rwlock structure
  */
 static inline void queued_write_unlock(struct qrwlock *lock)
 {
-       /*
-        * If the writer field is atomic, it can be cleared directly.
-        * Otherwise, an atomic subtraction will be used to clear it.
-        */
-       smp_mb__before_atomic();
-       atomic_sub(_QW_LOCKED, &lock->cnts);
+       smp_store_release((u8 *)&lock->cnts, 0);
 }
-#endif
 
 /*
  * Remapping rwlock architecture specific functions to the corresponding