Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux

[karo-tx-linux.git] / include / asm-generic / qrwlock.h

diff --git a/include/asm-generic/qrwlock.h b/include/asm-generic/qrwlock.h
index deb9e8b0eb9ef2f5a86638148e76f4c4c74cd0fe..54a8e65e18b622edf10df6d07ca0d84fea9e49ae 100644 (file)
--- a/include/asm-generic/qrwlock.h
+++ b/include/asm-generic/qrwlock.h
@@ -68,7 +68,7 @@ static inline int queued_read_trylock(struct qrwlock *lock)
 
        cnts = atomic_read(&lock->cnts);
        if (likely(!(cnts & _QW_WMASK))) {
-               cnts = (u32)atomic_add_return(_QR_BIAS, &lock->cnts);
+               cnts = (u32)atomic_add_return_acquire(_QR_BIAS, &lock->cnts);
                if (likely(!(cnts & _QW_WMASK)))
                        return 1;
                atomic_sub(_QR_BIAS, &lock->cnts);
@@ -89,8 +89,8 @@ static inline int queued_write_trylock(struct qrwlock *lock)
        if (unlikely(cnts))
                return 0;
 
-       return likely(atomic_cmpxchg(&lock->cnts,
-                                    cnts, cnts | _QW_LOCKED) == cnts);
+       return likely(atomic_cmpxchg_acquire(&lock->cnts,
+                                            cnts, cnts | _QW_LOCKED) == cnts);
 }
 /**
  * queued_read_lock - acquire read lock of a queue rwlock
@@ -100,7 +100,7 @@ static inline void queued_read_lock(struct qrwlock *lock)
 {
        u32 cnts;
 
-       cnts = atomic_add_return(_QR_BIAS, &lock->cnts);
+       cnts = atomic_add_return_acquire(_QR_BIAS, &lock->cnts);
        if (likely(!(cnts & _QW_WMASK)))
                return;
 
@@ -115,7 +115,7 @@ static inline void queued_read_lock(struct qrwlock *lock)
 static inline void queued_write_lock(struct qrwlock *lock)
 {
        /* Optimize for the unfair lock case where the fair flag is 0. */
-       if (atomic_cmpxchg(&lock->cnts, 0, _QW_LOCKED) == 0)
+       if (atomic_cmpxchg_acquire(&lock->cnts, 0, _QW_LOCKED) == 0)
                return;
 
        queued_write_lock_slowpath(lock);
@@ -130,25 +130,17 @@ static inline void queued_read_unlock(struct qrwlock *lock)
        /*
         * Atomically decrement the reader count
         */
-       smp_mb__before_atomic();
-       atomic_sub(_QR_BIAS, &lock->cnts);
+       (void)atomic_sub_return_release(_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