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) <pet...@infradead.org>
---
arch/frv/include/asm/atomic.h | 32 ++++++++++++--------------------
arch/frv/include/asm/atomic_defs.h | 2 ++
2 files changed, 14 insertions(+), 20 deletions(-)
--- a/arch/frv/include/asm/atomic.h
+++ b/arch/frv/include/asm/atomic.h
@@ -60,16 +60,6 @@ static inline int atomic_add_negative(in
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);
@@ -84,6 +74,8 @@ static inline void atomic_dec(atomic_t *
#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
*/
@@ -136,16 +128,6 @@ static inline long long atomic64_add_neg
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);
@@ -182,11 +164,19 @@ static __inline__ int __atomic_add_unles
}
#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); \
@@ -195,6 +185,8 @@ static inline void atomic64_##op(long lo
ATOMIC_OP(or)
ATOMIC_OP(and)
ATOMIC_OP(xor)
+ATOMIC_OP(add)
+ATOMIC_OP(sub)
#undef ATOMIC_OP
--- a/arch/frv/include/asm/atomic_defs.h
+++ b/arch/frv/include/asm/atomic_defs.h
@@ -162,6 +162,8 @@ ATOMIC_EXPORT(__atomic64_fetch_##op);
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)
