From 0e530747c69f1e191f101a925bb4051894e5c7b0 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 13 Mar 2014 19:00:35 +0100 Subject: [PATCH] arch,s390: Convert smp_mb__*() As per the existing implementation; implement the new one using smp_mb(). AFAICT the s390 compare-and-swap does imply a barrier, however there are some immediate ops that seem to be singly-copy atomic and do not imply a barrier. One such is the "ni" op (which would be and-immediate) which is used for the constant clear_bit implementation. Therefore s390 needs full barriers for the {before,after} atomic ops. Signed-off-by: Peter Zijlstra Acked-by: Paul E. McKenney Link: http://lkml.kernel.org/n/tip-kme5dz5hcobpnufnnkh1ech2@git.kernel.org Cc: Chen Gang Cc: Heiko Carstens Cc: Linus Torvalds Cc: Martin Schwidefsky Cc: Will Deacon Cc: linux390@de.ibm.com Cc: linux-kernel@vger.kernel.org Cc: linux-s390@vger.kernel.org Signed-off-by: Ingo Molnar --- arch/s390/include/asm/atomic.h | 5 ----- arch/s390/include/asm/barrier.h | 5 +++-- 2 files changed, 3 insertions(+), 7 deletions(-) diff --git a/arch/s390/include/asm/atomic.h b/arch/s390/include/asm/atomic.h index 1d47061..fa934fe 100644 --- a/arch/s390/include/asm/atomic.h +++ b/arch/s390/include/asm/atomic.h @@ -412,9 +412,4 @@ static inline long long atomic64_dec_if_positive(atomic64_t *v) #define atomic64_dec_and_test(_v) (atomic64_sub_return(1, _v) == 0) #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0) -#define smp_mb__before_atomic_dec() smp_mb() -#define smp_mb__after_atomic_dec() smp_mb() -#define smp_mb__before_atomic_inc() smp_mb() -#define smp_mb__after_atomic_inc() smp_mb() - #endif /* __ARCH_S390_ATOMIC__ */ diff --git a/arch/s390/include/asm/barrier.h b/arch/s390/include/asm/barrier.h index 578680f..19ff956 100644 --- a/arch/s390/include/asm/barrier.h +++ b/arch/s390/include/asm/barrier.h @@ -27,8 +27,9 @@ #define smp_rmb() rmb() #define smp_wmb() wmb() #define smp_read_barrier_depends() read_barrier_depends() -#define smp_mb__before_clear_bit() smp_mb() -#define smp_mb__after_clear_bit() smp_mb() + +#define smp_mb__before_atomic() smp_mb() +#define smp_mb__after_atomic() smp_mb() #define set_mb(var, value) do { var = value; mb(); } while (0) -- 2.7.4