/*
* External function declarations
*/
-extern void queue_read_lock_slowpath(struct qrwlock *lock);
-extern void queue_write_lock_slowpath(struct qrwlock *lock);
+extern void queued_read_lock_slowpath(struct qrwlock *lock, u32 cnts);
+extern void queued_write_lock_slowpath(struct qrwlock *lock);
/**
- * queue_read_can_lock- would read_trylock() succeed?
+ * queued_read_can_lock- would read_trylock() succeed?
* @lock: Pointer to queue rwlock structure
*/
-static inline int queue_read_can_lock(struct qrwlock *lock)
+static inline int queued_read_can_lock(struct qrwlock *lock)
{
return !(atomic_read(&lock->cnts) & _QW_WMASK);
}
/**
- * queue_write_can_lock- would write_trylock() succeed?
+ * queued_write_can_lock- would write_trylock() succeed?
* @lock: Pointer to queue rwlock structure
*/
-static inline int queue_write_can_lock(struct qrwlock *lock)
+static inline int queued_write_can_lock(struct qrwlock *lock)
{
return !atomic_read(&lock->cnts);
}
/**
- * queue_read_trylock - try to acquire read lock of a queue rwlock
+ * queued_read_trylock - try to acquire read lock of a queue rwlock
* @lock : Pointer to queue rwlock structure
* Return: 1 if lock acquired, 0 if failed
*/
-static inline int queue_read_trylock(struct qrwlock *lock)
+static inline int queued_read_trylock(struct qrwlock *lock)
{
u32 cnts;
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);
}
/**
- * queue_write_trylock - try to acquire write lock of a queue rwlock
+ * queued_write_trylock - try to acquire write lock of a queue rwlock
* @lock : Pointer to queue rwlock structure
* Return: 1 if lock acquired, 0 if failed
*/
-static inline int queue_write_trylock(struct qrwlock *lock)
+static inline int queued_write_trylock(struct qrwlock *lock)
{
u32 cnts;
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);
}
/**
- * queue_read_lock - acquire read lock of a queue rwlock
+ * queued_read_lock - acquire read lock of a queue rwlock
* @lock: Pointer to queue rwlock structure
*/
-static inline void queue_read_lock(struct qrwlock *lock)
+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;
/* The slowpath will decrement the reader count, if necessary. */
- queue_read_lock_slowpath(lock);
+ queued_read_lock_slowpath(lock, cnts);
}
/**
- * queue_write_lock - acquire write lock of a queue rwlock
+ * queued_write_lock - acquire write lock of a queue rwlock
* @lock : Pointer to queue rwlock structure
*/
-static inline void queue_write_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;
- queue_write_lock_slowpath(lock);
+ queued_write_lock_slowpath(lock);
}
/**
- * queue_read_unlock - release read lock of a queue rwlock
+ * queued_read_unlock - release read lock of a queue rwlock
* @lock : Pointer to queue rwlock structure
*/
-static inline void queue_read_unlock(struct qrwlock *lock)
+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 queue_write_unlock
/**
- * queue_write_unlock - release write lock of a queue rwlock
+ * queued_write_unlock - release write lock of a queue rwlock
* @lock : Pointer to queue rwlock structure
*/
-static inline void queue_write_unlock(struct qrwlock *lock)
+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
* queue rwlock functions.
*/
-#define arch_read_can_lock(l) queue_read_can_lock(l)
-#define arch_write_can_lock(l) queue_write_can_lock(l)
-#define arch_read_lock(l) queue_read_lock(l)
-#define arch_write_lock(l) queue_write_lock(l)
-#define arch_read_trylock(l) queue_read_trylock(l)
-#define arch_write_trylock(l) queue_write_trylock(l)
-#define arch_read_unlock(l) queue_read_unlock(l)
-#define arch_write_unlock(l) queue_write_unlock(l)
+#define arch_read_can_lock(l) queued_read_can_lock(l)
+#define arch_write_can_lock(l) queued_write_can_lock(l)
+#define arch_read_lock(l) queued_read_lock(l)
+#define arch_write_lock(l) queued_write_lock(l)
+#define arch_read_trylock(l) queued_read_trylock(l)
+#define arch_write_trylock(l) queued_write_trylock(l)
+#define arch_read_unlock(l) queued_read_unlock(l)
+#define arch_write_unlock(l) queued_write_unlock(l)
#endif /* __ASM_GENERIC_QRWLOCK_H */
Code Review / kvmfornfv.git / blobdiff