atomic.h: add atomic64 cmpxchg, xchg and add_unless to alpha

[powerpc.git] / include / asm-alpha / atomic.h

diff --git a/include/asm-alpha/atomic.h b/include/asm-alpha/atomic.h
index fc77f74..7b4fba8 100644 (file)
--- a/include/asm-alpha/atomic.h
+++ b/include/asm-alpha/atomic.h
@@ -175,19 +175,62 @@ static __inline__ long atomic64_sub_return(long i, atomic64_t * v)
        return result;
 }
 
-#define atomic_cmpxchg(v, o, n) ((int)cmpxchg(&((v)->counter), (o), (n)))
+#define atomic64_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new))
+#define atomic64_xchg(v, new) (xchg(&((v)->counter), new))
+
+#define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new))
 #define atomic_xchg(v, new) (xchg(&((v)->counter), new))
 
+/**
+ * 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;                                             \
+       __typeof__((v)->counter) c, old;                        \
        c = atomic_read(v);                                     \
-       while (c != (u) && (old = atomic_cmpxchg((v), c, c + (a))) != c) \
+       for (;;) {                                              \
+               if (unlikely(c == (u)))                         \
+                       break;                                  \
+               old = atomic_cmpxchg((v), c, c + (a));          \
+               if (likely(old == c))                           \
+                       break;                                  \
                c = old;                                        \
+       }                                                       \
        c != (u);                                               \
 })
 #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
 
+/**
+ * atomic64_add_unless - add unless the number is a given value
+ * @v: pointer of type atomic64_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 atomic64_add_unless(v, a, u)                           \
+({                                                             \
+       __typeof__((v)->counter) c, old;                        \
+       c = atomic64_read(v);                                   \
+       for (;;) {                                              \
+               if (unlikely(c == (u)))                         \
+                       break;                                  \
+               old = atomic64_cmpxchg((v), c, c + (a));        \
+               if (likely(old == c))                           \
+                       break;                                  \
+               c = old;                                        \
+       }                                                       \
+       c != (u);                                               \
+})
+#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
+
 #define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0)
 #define atomic64_add_negative(a, v) (atomic64_add_return((a), (v)) < 0)