locking/atomic, arch/frv: Implement atomic{,64}_fetch_{add,sub,and,or,xor}()

Implement FETCH-OP atomic primitives, these are very similar to the
existing OP-RETURN primitives we already have, except they return the
value of the atomic variable _before_ modification.

This is especially useful for irreversible operations -- such as
bitops (because it becomes impossible to reconstruct the state prior
to modification).

Signed-off-by: Peter Zijlstra (Intel) <[e-mail]>
Cc: Andrew Morton <[e-mail]>
Cc: Linus Torvalds <[e-mail]>
Cc: Paul E. McKenney <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Thomas Gleixner <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Signed-off-by: Ingo Molnar <[e-mail]>

arch/frv/include/asm/atomic.h

···
 	return atomic_add_return(i, v) < 0;
 }
 
-static inline void atomic_add(int i, atomic_t *v)
-{
-	atomic_add_return(i, v);
-}
-
-static inline void atomic_sub(int i, atomic_t *v)
-{
-	atomic_sub_return(i, v);
-}
-
 static inline void atomic_inc(atomic_t *v)
 {
 	atomic_inc_return(v);
···
 #define atomic_sub_and_test(i,v)	(atomic_sub_return((i), (v)) == 0)
 #define atomic_dec_and_test(v)		(atomic_sub_return(1, (v)) == 0)
 #define atomic_inc_and_test(v)		(atomic_add_return(1, (v)) == 0)
+
+#define atomic_fetch_or atomic_fetch_or
 
 /*
  * 64-bit atomic ops
···
 	return atomic64_add_return(i, v) < 0;
 }
 
-static inline void atomic64_add(long long i, atomic64_t *v)
-{
-	atomic64_add_return(i, v);
-}
-
-static inline void atomic64_sub(long long i, atomic64_t *v)
-{
-	atomic64_sub_return(i, v);
-}
-
 static inline void atomic64_inc(atomic64_t *v)
 {
 	atomic64_inc_return(v);
···
 }
 
 #define ATOMIC_OP(op)							\
+static inline int atomic_fetch_##op(int i, atomic_t *v)			\
+{									\
+	return __atomic32_fetch_##op(i, &v->counter);			\
+}									\
 static inline void atomic_##op(int i, atomic_t *v)			\
 {									\
 	(void)__atomic32_fetch_##op(i, &v->counter);			\
 }									\
 									\
+static inline long long atomic64_fetch_##op(long long i, atomic64_t *v)	\
+{									\
+	return __atomic64_fetch_##op(i, &v->counter);			\
+}									\
 static inline void atomic64_##op(long long i, atomic64_t *v)		\
 {									\
 	(void)__atomic64_fetch_##op(i, &v->counter);			\
···
 ATOMIC_OP(or)
 ATOMIC_OP(and)
 ATOMIC_OP(xor)
+ATOMIC_OP(add)
+ATOMIC_OP(sub)
 
 #undef ATOMIC_OP
 

arch/frv/include/asm/atomic_defs.h

···
 ATOMIC_FETCH_OP(or)
 ATOMIC_FETCH_OP(and)
 ATOMIC_FETCH_OP(xor)
+ATOMIC_FETCH_OP(add)
+ATOMIC_FETCH_OP(sub)
 
 ATOMIC_OP_RETURN(add)
 ATOMIC_OP_RETURN(sub)