Commit b464d127 authored May 30, 2016 by Peter Zijlstra Committed by Ingo Molnar Jun 14, 2016

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) <peterz@infradead.org>
Acked-by: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent 7cb45c0f

arch/tile/include/asm/barrier.h

+7 −0

Original line number	Diff line number	Diff line
		@@ -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 <asm-generic/barrier.h>

		#endif /* !__ASSEMBLY__ */