Upgrade to 4.4.50-rt62

[kvmfornfv.git] / kernel / include / asm-generic / qspinlock.h

diff --git a/kernel/include/asm-generic/qspinlock.h b/kernel/include/asm-generic/qspinlock.h
index e2aadbc..1885fc4 100644 (file)
--- a/kernel/include/asm-generic/qspinlock.h
+++ b/kernel/include/asm-generic/qspinlock.h
@@ -20,15 +20,34 @@
 
 #include <asm-generic/qspinlock_types.h>
 
+/**
+ * queued_spin_unlock_wait - wait until the _current_ lock holder releases the lock
+ * @lock : Pointer to queued spinlock structure
+ *
+ * There is a very slight possibility of live-lock if the lockers keep coming
+ * and the waiter is just unfortunate enough to not see any unlock state.
+ */
+#ifndef queued_spin_unlock_wait
+extern void queued_spin_unlock_wait(struct qspinlock *lock);
+#endif
+
 /**
  * queued_spin_is_locked - is the spinlock locked?
  * @lock: Pointer to queued spinlock structure
  * Return: 1 if it is locked, 0 otherwise
  */
+#ifndef queued_spin_is_locked
 static __always_inline int queued_spin_is_locked(struct qspinlock *lock)
 {
+       /*
+        * See queued_spin_unlock_wait().
+        *
+        * Any !0 state indicates it is locked, even if _Q_LOCKED_VAL
+        * isn't immediately observable.
+        */
        return atomic_read(&lock->val);
 }
+#endif
 
 /**
  * queued_spin_value_unlocked - is the spinlock structure unlocked?
@@ -98,19 +117,6 @@ static __always_inline void queued_spin_unlock(struct qspinlock *lock)
 }
 #endif
 
-/**
- * queued_spin_unlock_wait - wait until current lock holder releases the lock
- * @lock : Pointer to queued spinlock structure
- *
- * There is a very slight possibility of live-lock if the lockers keep coming
- * and the waiter is just unfortunate enough to not see any unlock state.
- */
-static inline void queued_spin_unlock_wait(struct qspinlock *lock)
-{
-       while (atomic_read(&lock->val) & _Q_LOCKED_MASK)
-               cpu_relax();
-}
-
 #ifndef virt_spin_lock
 static __always_inline bool virt_spin_lock(struct qspinlock *lock)
 {