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-rw-r--r--include/asm-arm/atomic.h11
1 files changed, 11 insertions, 0 deletions
diff --git a/include/asm-arm/atomic.h b/include/asm-arm/atomic.h
index 8ab1689ef56..75b80271972 100644
--- a/include/asm-arm/atomic.h
+++ b/include/asm-arm/atomic.h
@@ -173,6 +173,17 @@ static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr)
#endif /* __LINUX_ARM_ARCH__ */
+static inline int atomic_add_unless(atomic_t *v, int a, int u)
+{
+ int c, old;
+
+ c = atomic_read(v);
+ while (c != u && (old = atomic_cmpxchg((v), c, c + a)) != c)
+ c = old;
+ return c != u;
+}
+#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
+
#define atomic_add(i, v) (void) atomic_add_return(i, v)
#define atomic_inc(v) (void) atomic_add_return(1, v)
#define atomic_sub(i, v) (void) atomic_sub_return(i, v)