#include <linux/compiler.h>
#include <asm/processor.h>
+#include <asm/cmpxchg.h>
/*
* Atomic operations that C can't guarantee us. Useful for
* on us. We need to use _exactly_ the address the user gave us,
* not some alias that contains the same information.
*/
-typedef struct { volatile int counter; } atomic_t;
+typedef struct { int counter; } atomic_t;
#define ATOMIC_INIT(i) { (i) }
/* Modern 486+ processor */
__i = i;
__asm__ __volatile__(
- LOCK_PREFIX "xaddl %0, %1;"
- :"=r"(i)
- :"m"(v->counter), "0"(i));
+ LOCK_PREFIX "xaddl %0, %1"
+ :"+r" (i), "+m" (v->counter)
+ : : "memory");
return i + __i;
#ifdef CONFIG_M386
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) (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
+ * atomic_add_unless - add unless the number is already 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.
+ * Atomically adds @a to @v, so long as @v was not already @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); \
- for (;;) { \
- if (unlikely(c == (u))) \
- break; \
- old = atomic_cmpxchg((v), c, c + (a)); \
- if (likely(old == c)) \
- break; \
- 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)
#define atomic_inc_return(v) (atomic_add_return(1,v))