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authorPeter Zijlstra <peterz@infradead.org>2016-05-30 14:32:04 +0200
committerIngo Molnar <mingo@kernel.org>2016-06-14 11:55:15 +0200
commitb464d1270a8016edcf1fd20d77cefdecf9b0b73e (patch)
tree2648743895f108c3e2aa9157313c8449404b5883 /arch/tile
parent7cb45c0fe9858f92cc264f6bf9d2f6a0e7d3b249 (diff)
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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>
Diffstat (limited to 'arch/tile')
-rw-r--r--arch/tile/include/asm/barrier.h7
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/tile/include/asm/barrier.h b/arch/tile/include/asm/barrier.h
index d55222806c2f..4c419ab95ab7 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 <asm-generic/barrier.h>
#endif /* !__ASSEMBLY__ */