[PATCH 3/9] atomic.h : i386 "64 bits" ready fix.

Mathieu Desnoyers
2006-12-21T00:08:16Z

This patch changes the cmpxchg, xchg and add_unless atomic operations on i386 so
they will still work if, for instance, they are cut'n'pasted to operate of
atomic64_t types. The correct fix might be to create inline functions for
cmpxchg for every architecture, but until then, it looks safer to put this kind
of automatic typing instead of using an integer.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>

--- a/include/asm-i386/atomic.h
+++ b/include/asm-i386/atomic.h
@@ -207,8 +207,9 @@ static __inline__ int atomic_sub_return(
return atomic_add_return(-i,v);
}

-#define atomic_cmpxchg(v, old, new) ((int)cmpxchg(&((v)->counter), old, new))
-#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
+#define atomic_cmpxchg(v, old, new) \
+ ((__typeof__((v)->counter))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
@@ -221,7 +222,7 @@ #define atomic_xchg(v, new) (xchg(&((v)-
*/
#define atomic_add_unless(v, a, u) \
({ \
- int c, old; \
+ __typeof__((v)->counter) c, old; \
c = atomic_read(v); \
for (;;) { \
if (unlikely(c == (u))) \