atomic.h: atomic_add_unless as inline. Remove system.h atomic.h circular dependency

atomic_add_unless as inline. Remove system.h atomic.h circular dependency.
I agree (with Andi Kleen) this typeof is not needed and more error
prone. All the original atomic.h code that uses cmpxchg (which includes
the atomic_add_unless) uses defines instead of inline functions,
probably to circumvent a circular dependency between system.h and
atomic.h on powerpc (which my patch addresses). Therefore, it makes
sense to use inline functions that will provide type checking.

atomic_add_unless as inline. Remove system.h atomic.h circular dependency.
Digging into the FRV architecture shows me that it is also affected by
such a circular dependency. Here is the diff applying this against the
rest of my atomic.h patches.

It applies over the atomic.h standardization patches.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 15 insertions, 8 deletions

diff --git a/include/asm-xtensa/atomic.h b/include/asm-xtensa/atomic.h
index 5c2672021068..b3b23540f14d 100644
--- a/include/asm-xtensa/atomic.h
+++ b/include/asm-xtensa/atomic.h
@@ -234,14 +234,21 @@ static inline int atomic_sub_return(int i, atomic_t * v)
  * 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);                                               \
-})
+static __inline__ int atomic_add_unless(atomic_t *v, int a, int u)
+{
+        int c, old;
+        c = atomic_read(v);
+        for (;;) {
+                if (unlikely(c == (u)))
+                        break;
+                old = atomic_cmpxchg((v), c, c + (a));
+                if (likely(old == c))
+                        break;
+                c = old;
+        }
+        return 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)