From 9d664c0aec3bfdb77fcf7de61cfe1febbecdd389 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 9 Jun 2017 13:05:06 +0200 Subject: locking/atomic: Fix atomic_set_release() for 'funny' architectures Those architectures that have a special atomic_set implementation also need a special atomic_set_release(), because for the very same reason WRITE_ONCE() is broken for them, smp_store_release() is too. The vast majority is architectures that have spinlock hash based atomic implementation except hexagon which seems to have a hardware 'feature'. The spinlock based atomics should be SC, that is, none of them appear to place extra barriers in atomic_cmpxchg() or any of the other SC atomic primitives and therefore seem to rely on their spinlock implementation being SC (I did not fully validate all that). Therefore, the normal atomic_set() is SC and can be used at atomic_set_release(). Signed-off-by: Peter Zijlstra (Intel) Acked-by: Chris Metcalf [for tile] Cc: Boqun Feng Cc: Linus Torvalds Cc: Paul McKenney Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Will Deacon Cc: davem@davemloft.net Cc: james.hogan@imgtec.com Cc: jejb@parisc-linux.org Cc: rkuo@codeaurora.org Cc: vgupta@synopsys.com Link: http://lkml.kernel.org/r/20170609110506.yod47flaav3wgoj5@hirez.programming.kicks-ass.net Signed-off-by: Ingo Molnar --- arch/arc/include/asm/atomic.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/arc/include') diff --git a/arch/arc/include/asm/atomic.h b/arch/arc/include/asm/atomic.h index 54b54da6384c..11859287c52a 100644 --- a/arch/arc/include/asm/atomic.h +++ b/arch/arc/include/asm/atomic.h @@ -123,6 +123,8 @@ static inline void atomic_set(atomic_t *v, int i) atomic_ops_unlock(flags); } +#define atomic_set_release(v, i) atomic_set((v), (i)) + #endif /* -- cgit v1.2.3