-static inline unsigned long
-__cmpxchg(volatile void *ptr, unsigned long expected, unsigned long new)
-{
- unsigned long prev;
-
- /*
- * Explicit full memory barrier needed before/after as
- * LLOCK/SCOND themselves don't provide any such semantics
- */
- smp_mb();
-
- __asm__ __volatile__(
- "1: llock %0, [%1] \n"
- " brne %0, %2, 2f \n"
- " scond %3, [%1] \n"
- " bnz 1b \n"
- "2: \n"
- : "=&r"(prev) /* Early clobber, to prevent reg reuse */
- : "r"(ptr), /* Not "m": llock only supports reg direct addr mode */
- "ir"(expected),
- "r"(new) /* can't be "ir". scond can't take LIMM for "b" */
- : "cc", "memory"); /* so that gcc knows memory is being written here */
-
- smp_mb();
-
- return prev;
-}
-
-#else /* !CONFIG_ARC_HAS_LLSC */
-
-static inline unsigned long
-__cmpxchg(volatile void *ptr, unsigned long expected, unsigned long new)
-{
- unsigned long flags;
- int prev;
- volatile unsigned long *p = ptr;
-
- /*
- * spin lock/unlock provide the needed smp_mb() before/after
- */
- atomic_ops_lock(flags);
- prev = *p;
- if (prev == expected)
- *p = new;
- atomic_ops_unlock(flags);
- return prev;
-}
-
-#endif
+/*
+ * if (*ptr == @old)
+ * *ptr = @new
+ */
+#define __cmpxchg(ptr, old, new) \
+({ \
+ __typeof__(*(ptr)) _prev; \
+ \
+ __asm__ __volatile__( \
+ "1: llock %0, [%1] \n" \
+ " brne %0, %2, 2f \n" \
+ " scond %3, [%1] \n" \
+ " bnz 1b \n" \
+ "2: \n" \
+ : "=&r"(_prev) /* Early clobber prevent reg reuse */ \
+ : "r"(ptr), /* Not "m": llock only supports reg */ \
+ "ir"(old), \
+ "r"(new) /* Not "ir": scond can't take LIMM */ \
+ : "cc", \
+ "memory"); /* gcc knows memory is clobbered */ \
+ \
+ _prev; \
+})