x86: Use xadd helper more widely

This covers the trivial cases from open-coded xadd to the xadd macros.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Link: http://lkml.kernel.org/r/4E5BCC40.3030501@goop.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

arch/x86/include/asm/atomic.h

@@ -172,18 +172,14 @@ static inline int atomic_add_negative(int i, atomic_t *v)
  */
 static inline int atomic_add_return(int i, atomic_t *v)
 {
-	int __i;
 #ifdef CONFIG_M386
+	int __i;
 	unsigned long flags;
 	if (unlikely(boot_cpu_data.x86 <= 3))
 		goto no_xadd;
 #endif
 	/* Modern 486+ processor */
-	__i = i;
+	return i + xadd(&v->counter, i);
-	asm volatile(LOCK_PREFIX "xaddl %0, %1"
-		     : "+r" (i), "+m" (v->counter)
-		     : : "memory");
-	return i + __i;
 
 #ifdef CONFIG_M386
 no_xadd: /* Legacy 386 processor */

arch/x86/include/asm/atomic64_64.h

@@ -170,11 +170,7 @@ static inline int atomic64_add_negative(long i, atomic64_t *v)
  */
 static inline long atomic64_add_return(long i, atomic64_t *v)
 {
-	long __i = i;
+	return i + xadd(&v->counter, i);
-	asm volatile(LOCK_PREFIX "xaddq %0, %1;"
-		     : "+r" (i), "+m" (v->counter)
-		     : : "memory");
-	return i + __i;
 }
 
 static inline long atomic64_sub_return(long i, atomic64_t *v)

arch/x86/include/asm/rwsem.h

@@ -204,13 +204,7 @@ static inline void rwsem_atomic_add(long delta, struct rw_semaphore *sem)
  */
 static inline long rwsem_atomic_update(long delta, struct rw_semaphore *sem)
 {
-	long tmp = delta;
+	return delta + xadd(&sem->count, delta);
-
-	asm volatile(LOCK_PREFIX "xadd %0,%1"
-		     : "+r" (tmp), "+m" (sem->count)
-		     : : "memory");
-
-	return tmp + delta;
 }
 
 #endif /* __KERNEL__ */

arch/x86/include/asm/uv/uv_bau.h

@@ -656,11 +656,7 @@ static inline int atomic_read_short(const struct atomic_short *v)
  */
 static inline int atom_asr(short i, struct atomic_short *v)
 {
-	short __i = i;
+	return i + xadd(&v->counter, i);
-	asm volatile(LOCK_PREFIX "xaddw %0, %1"
-			: "+r" (i), "+m" (v->counter)
-			: : "memory");
-	return i + __i;
 }
 
 /*