From b464d1270a8016edcf1fd20d77cefdecf9b0b73e Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Mon, 30 May 2016 14:32:04 +0200 Subject: locking/barriers, tile: Provide TILE specific smp_acquire__after_ctrl_dep() Since TILE doesn't do read speculation, its control dependencies also guarantee LOAD->LOAD order and we don't need the additional RMB otherwise required to provide ACQUIRE semantics. Signed-off-by: Peter Zijlstra (Intel) Acked-by: Chris Metcalf Cc: Andrew Morton Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar diff --git a/arch/tile/include/asm/barrier.h b/arch/tile/include/asm/barrier.h index d552228..4c419ab 100644 --- a/arch/tile/include/asm/barrier.h +++ b/arch/tile/include/asm/barrier.h @@ -87,6 +87,13 @@ mb_incoherent(void) #define __smp_mb__after_atomic() __smp_mb() #endif +/* + * The TILE architecture does not do speculative reads; this ensures + * that a control dependency also orders against loads and already provides + * a LOAD->{LOAD,STORE} order and can forgo the additional RMB. + */ +#define smp_acquire__after_ctrl_dep() barrier() + #include #endif /* !__ASSEMBLY__ */ -- cgit v0.10.2