From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: [PATCH 23/31] arch,s390: Convert smp_mb__* Date: Wed, 19 Mar 2014 07:47:52 +0100 Message-ID: <20140319065205.008359711@infradead.org> References: <20140319064729.660482086@infradead.org> Return-path: Content-Disposition: inline; filename=peterz-s390-smp_mb__atomic.patch Sender: linux-kernel-owner@vger.kernel.org To: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, mingo@kernel.org, will.deacon@arm.com, paulmck@linux.vnet.ibm.com, Peter Zijlstra List-Id: linux-arch.vger.kernel.org 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 --- arch/s390/include/asm/atomic.h | 6 +----- arch/s390/include/asm/barrier.h | 5 +++-- arch/s390/include/asm/bitops.h | 1 + 3 files changed, 5 insertions(+), 7 deletions(-) --- a/arch/s390/include/asm/atomic.h +++ b/arch/s390/include/asm/atomic.h @@ -16,6 +16,7 @@ #include #include #include +#include #define ATOMIC_INIT(i) { (i) } @@ -398,9 +399,4 @@ static inline long long atomic64_dec_if_ #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__ */ --- 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) --- a/arch/s390/include/asm/bitops.h +++ b/arch/s390/include/asm/bitops.h @@ -47,6 +47,7 @@ #include #include +#include #ifndef CONFIG_64BIT From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from merlin.infradead.org ([205.233.59.134]:53001 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756595AbaCSG4a (ORCPT ); Wed, 19 Mar 2014 02:56:30 -0400 Message-ID: <20140319065205.008359711@infradead.org> Date: Wed, 19 Mar 2014 07:47:52 +0100 From: Peter Zijlstra Subject: [PATCH 23/31] arch,s390: Convert smp_mb__* References: <20140319064729.660482086@infradead.org> Content-Disposition: inline; filename=peterz-s390-smp_mb__atomic.patch Sender: linux-arch-owner@vger.kernel.org List-ID: To: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, mingo@kernel.org, will.deacon@arm.com, paulmck@linux.vnet.ibm.com, Peter Zijlstra Message-ID: <20140319064752.ZHdaliU7LANoQP3YXSlCobeOrebFmalNQAMwhr92KuA@z> 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 --- arch/s390/include/asm/atomic.h | 6 +----- arch/s390/include/asm/barrier.h | 5 +++-- arch/s390/include/asm/bitops.h | 1 + 3 files changed, 5 insertions(+), 7 deletions(-) --- a/arch/s390/include/asm/atomic.h +++ b/arch/s390/include/asm/atomic.h @@ -16,6 +16,7 @@ #include #include #include +#include #define ATOMIC_INIT(i) { (i) } @@ -398,9 +399,4 @@ static inline long long atomic64_dec_if_ #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__ */ --- 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) --- a/arch/s390/include/asm/bitops.h +++ b/arch/s390/include/asm/bitops.h @@ -47,6 +47,7 @@ #include #include +#include #ifndef CONFIG_64BIT