From 56fefbbc3f13ad8cc9f502dbc6b5c9ddc8c4395e Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Mon, 18 Apr 2016 01:16:05 +0200 Subject: [PATCH] locking/atomic, arch/s390: 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) Acked-by: Martin Schwidefsky Cc: Andrew Morton Cc: Heiko Carstens Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-arch@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-s390@vger.kernel.org Signed-off-by: Ingo Molnar --- arch/s390/include/asm/atomic.h | 42 ++++++++++++++++++++++++++-------- 1 file changed, 32 insertions(+), 10 deletions(-) diff --git a/arch/s390/include/asm/atomic.h b/arch/s390/include/asm/atomic.h index 911064aa59b2..2324e759b544 100644 --- a/arch/s390/include/asm/atomic.h +++ b/arch/s390/include/asm/atomic.h @@ -93,6 +93,11 @@ static inline int atomic_add_return(int i, atomic_t *v) return __ATOMIC_LOOP(v, i, __ATOMIC_ADD, __ATOMIC_BARRIER) + i; } +static inline int atomic_fetch_add(int i, atomic_t *v) +{ + return __ATOMIC_LOOP(v, i, __ATOMIC_ADD, __ATOMIC_BARRIER); +} + static inline void atomic_add(int i, atomic_t *v) { #ifdef CONFIG_HAVE_MARCH_Z196_FEATURES @@ -114,22 +119,29 @@ static inline void atomic_add(int i, atomic_t *v) #define atomic_inc_and_test(_v) (atomic_add_return(1, _v) == 0) #define atomic_sub(_i, _v) atomic_add(-(int)(_i), _v) #define atomic_sub_return(_i, _v) atomic_add_return(-(int)(_i), _v) +#define atomic_fetch_sub(_i, _v) atomic_fetch_add(-(int)(_i), _v) #define atomic_sub_and_test(_i, _v) (atomic_sub_return(_i, _v) == 0) #define atomic_dec(_v) atomic_sub(1, _v) #define atomic_dec_return(_v) atomic_sub_return(1, _v) #define atomic_dec_and_test(_v) (atomic_sub_return(1, _v) == 0) -#define ATOMIC_OP(op, OP) \ +#define ATOMIC_OPS(op, OP) \ static inline void atomic_##op(int i, atomic_t *v) \ { \ __ATOMIC_LOOP(v, i, __ATOMIC_##OP, __ATOMIC_NO_BARRIER); \ +} \ +static inline int atomic_fetch_##op(int i, atomic_t *v) \ +{ \ + return __ATOMIC_LOOP(v, i, __ATOMIC_##OP, __ATOMIC_BARRIER); \ } -ATOMIC_OP(and, AND) -ATOMIC_OP(or, OR) -ATOMIC_OP(xor, XOR) +#define atomic_fetch_or atomic_fetch_or + +ATOMIC_OPS(and, AND) +ATOMIC_OPS(or, OR) +ATOMIC_OPS(xor, XOR) -#undef ATOMIC_OP +#undef ATOMIC_OPS #define atomic_xchg(v, new) (xchg(&((v)->counter), new)) @@ -236,6 +248,11 @@ static inline long long atomic64_add_return(long long i, atomic64_t *v) return __ATOMIC64_LOOP(v, i, __ATOMIC64_ADD, __ATOMIC64_BARRIER) + i; } +static inline long long atomic64_fetch_add(long long i, atomic64_t *v) +{ + return __ATOMIC64_LOOP(v, i, __ATOMIC64_ADD, __ATOMIC64_BARRIER); +} + static inline void atomic64_add(long long i, atomic64_t *v) { #ifdef CONFIG_HAVE_MARCH_Z196_FEATURES @@ -264,17 +281,21 @@ static inline long long atomic64_cmpxchg(atomic64_t *v, return old; } -#define ATOMIC64_OP(op, OP) \ +#define ATOMIC64_OPS(op, OP) \ static inline void atomic64_##op(long i, atomic64_t *v) \ { \ __ATOMIC64_LOOP(v, i, __ATOMIC64_##OP, __ATOMIC64_NO_BARRIER); \ +} \ +static inline long atomic64_fetch_##op(long i, atomic64_t *v) \ +{ \ + return __ATOMIC64_LOOP(v, i, __ATOMIC64_##OP, __ATOMIC64_BARRIER); \ } -ATOMIC64_OP(and, AND) -ATOMIC64_OP(or, OR) -ATOMIC64_OP(xor, XOR) +ATOMIC64_OPS(and, AND) +ATOMIC64_OPS(or, OR) +ATOMIC64_OPS(xor, XOR) -#undef ATOMIC64_OP +#undef ATOMIC64_OPS #undef __ATOMIC64_LOOP static inline int atomic64_add_unless(atomic64_t *v, long long i, long long u) @@ -315,6 +336,7 @@ static inline long long atomic64_dec_if_positive(atomic64_t *v) #define atomic64_inc_return(_v) atomic64_add_return(1, _v) #define atomic64_inc_and_test(_v) (atomic64_add_return(1, _v) == 0) #define atomic64_sub_return(_i, _v) atomic64_add_return(-(long long)(_i), _v) +#define atomic64_fetch_sub(_i, _v) atomic64_fetch_add(-(long long)(_i), _v) #define atomic64_sub(_i, _v) atomic64_add(-(long long)(_i), _v) #define atomic64_sub_and_test(_i, _v) (atomic64_sub_return(_i, _v) == 0) #define atomic64_dec(_v) atomic64_sub(1, _v) -- 2.20.1