From 5a1b26d7c629915446222ebe77d16567c98426ff Mon Sep 17 00:00:00 2001 From: Davidlohr Bueso Date: Thu, 31 Dec 2015 12:09:13 +0200 Subject: [PATCH] lcoking/barriers, arch: Use smp barriers in smp_store_release() With commit b92b8b35a2e ("locking/arch: Rename set_mb() to smp_store_mb()") it was made clear that the context of this call (and thus set_mb) is strictly for CPU ordering, as opposed to IO. As such all archs should use the smp variant of mb(), respecting the semantics and saving a mandatory barrier on UP. Signed-off-by: Davidlohr Bueso Signed-off-by: Peter Zijlstra (Intel) Cc: Cc: Andrew Morton Cc: Benjamin Herrenschmidt Cc: Heiko Carstens Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Tony Luck Cc: dave@stgolabs.net Link: http://lkml.kernel.org/r/1445975631-17047-3-git-send-email-dave@stgolabs.net Signed-off-by: Ingo Molnar Reviewed-by: Paul E. McKenney --- arch/ia64/include/asm/barrier.h | 2 +- arch/powerpc/include/asm/barrier.h | 2 +- arch/s390/include/asm/barrier.h | 2 +- include/asm-generic/barrier.h | 2 +- 4 files changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/ia64/include/asm/barrier.h b/arch/ia64/include/asm/barrier.h index df896a1c41d3..209c4b817c95 100644 --- a/arch/ia64/include/asm/barrier.h +++ b/arch/ia64/include/asm/barrier.h @@ -77,7 +77,7 @@ do { \ ___p1; \ }) -#define smp_store_mb(var, value) do { WRITE_ONCE(var, value); mb(); } while (0) +#define smp_store_mb(var, value) do { WRITE_ONCE(var, value); smp_mb(); } while (0) /* * The group barrier in front of the rsm & ssm are necessary to ensure diff --git a/arch/powerpc/include/asm/barrier.h b/arch/powerpc/include/asm/barrier.h index 0eca6efc0631..a7af5fb7b914 100644 --- a/arch/powerpc/include/asm/barrier.h +++ b/arch/powerpc/include/asm/barrier.h @@ -34,7 +34,7 @@ #define rmb() __asm__ __volatile__ ("sync" : : : "memory") #define wmb() __asm__ __volatile__ ("sync" : : : "memory") -#define smp_store_mb(var, value) do { WRITE_ONCE(var, value); mb(); } while (0) +#define smp_store_mb(var, value) do { WRITE_ONCE(var, value); smp_mb(); } while (0) #ifdef __SUBARCH_HAS_LWSYNC # define SMPWMB LWSYNC diff --git a/arch/s390/include/asm/barrier.h b/arch/s390/include/asm/barrier.h index d68e11e0df5e..7ffd0b19135c 100644 --- a/arch/s390/include/asm/barrier.h +++ b/arch/s390/include/asm/barrier.h @@ -36,7 +36,7 @@ #define smp_mb__before_atomic() smp_mb() #define smp_mb__after_atomic() smp_mb() -#define smp_store_mb(var, value) do { WRITE_ONCE(var, value); mb(); } while (0) +#define smp_store_mb(var, value) do { WRITE_ONCE(var, value); smp_mb(); } while (0) #define smp_store_release(p, v) \ do { \ diff --git a/include/asm-generic/barrier.h b/include/asm-generic/barrier.h index b42afada1280..0f45f93ef692 100644 --- a/include/asm-generic/barrier.h +++ b/include/asm-generic/barrier.h @@ -93,7 +93,7 @@ #endif /* CONFIG_SMP */ #ifndef smp_store_mb -#define smp_store_mb(var, value) do { WRITE_ONCE(var, value); mb(); } while (0) +#define smp_store_mb(var, value) do { WRITE_ONCE(var, value); smp_mb(); } while (0) #endif #ifndef smp_mb__before_atomic -- 2.20.1