Merge branch 'master'

[mv-sheeva.git] / include / asm-xtensa / atomic.h

diff --git a/include/asm-xtensa/atomic.h b/include/asm-xtensa/atomic.h
index cd40c5e75160302e3e75d3af55febf513a3c04e2..3670cc7695dad79d3326323e8c974abf417851f6 100644 (file)
--- a/include/asm-xtensa/atomic.h
+++ b/include/asm-xtensa/atomic.h
@@ -225,6 +225,25 @@ static inline int atomic_sub_return(int i, atomic_t * v)
 
 #define atomic_cmpxchg(v, o, n) ((int)cmpxchg(&((v)->counter), (o), (n)))
 
+/**
+ * atomic_add_unless - add unless the number is a given value
+ * @v: pointer of type atomic_t
+ * @a: the amount to add to v...
+ * @u: ...unless v is equal to u.
+ *
+ * Atomically adds @a to @v, so long as it was not @u.
+ * Returns non-zero if @v was not @u, and zero otherwise.
+ */
+#define atomic_add_unless(v, a, u)                             \
+({                                                             \
+       int c, old;                                             \
+       c = atomic_read(v);                                     \
+       while (c != (u) && (old = atomic_cmpxchg((v), c, c + (a))) != c) \
+               c = old;                                        \
+       c != (u);                                               \
+})
+#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
+
 static inline void atomic_clear_mask(unsigned int mask, atomic_t *v)
 {
     unsigned int all_f = -1;