From febdbfe8a91ce0d11939d4940b592eb0dba8d663 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 6 Feb 2014 18:16:07 +0100 Subject: arch: Prepare for smp_mb__{before,after}_atomic() Since the smp_mb__{before,after}*() ops are fundamentally dependent on how an arch can implement atomics it doesn't make sense to have 3 variants of them. They must all be the same. Furthermore, the 3 variants suggest they're only valid for those 3 atomic ops, while we have many more where they could be applied. So move away from smp_mb__{before,after}_{atomic,clear}_{dec,inc,bit}() and reduce the interface to just the two: smp_mb__{before,after}_atomic(). This patch prepares the way by introducing default implementations in asm-generic/barrier.h that default to a full barrier and providing __deprecated inlines for the previous 6 barriers if they're not provided by the arch. This should allow for a mostly painless transition (lots of deprecated warns in the interim). Signed-off-by: Peter Zijlstra Acked-by: Paul E. McKenney Link: http://lkml.kernel.org/n/tip-wr59327qdyi9mbzn6x937s4e@git.kernel.org Cc: Arnd Bergmann Cc: "Chen, Gong" Cc: John Sullivan Cc: Linus Torvalds Cc: Mauro Carvalho Chehab Cc: Srinivas Pandruvada Cc: "Theodore Ts'o" Cc: linux-arch@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar --- include/asm-generic/barrier.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include/asm-generic/barrier.h') diff --git a/include/asm-generic/barrier.h b/include/asm-generic/barrier.h index 6f692f8ac664..1402fa855388 100644 --- a/include/asm-generic/barrier.h +++ b/include/asm-generic/barrier.h @@ -62,6 +62,14 @@ #define set_mb(var, value) do { (var) = (value); mb(); } while (0) #endif +#ifndef smp_mb__before_atomic +#define smp_mb__before_atomic() smp_mb() +#endif + +#ifndef smp_mb__after_atomic +#define smp_mb__after_atomic() smp_mb() +#endif + #define smp_store_release(p, v) \ do { \ compiletime_assert_atomic_type(*p); \ -- cgit v1.2.3-59-g8ed1b