From 1cfc05cbe2c9757c6cc36804df96e3ed28e940a1 Mon Sep 17 00:00:00 2001
From: Vineet Gupta <vgupta@synopsys.com>
Date: Mon, 9 Nov 2015 17:48:34 +0530
Subject: [PATCH] ARC: cpu_relax() to be compiler barrier even for UP
cpu_relax() on ARC has been barrier only for SMP (and no-op for UP). Per
recent discussions, it is safer to make it a compiler barrier
unconditionally.
Link: http://lkml.kernel.org/r/53A7D3AA.9020100@synopsys.com
Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
---
arch/arc/include/asm/processor.h | 4 ----
1 file changed, 4 deletions(-)
diff --git a/arch/arc/include/asm/processor.h b/arch/arc/include/asm/processor.h
index 44545354e9e85..1d694c1ef6d6b 100644
--- a/arch/arc/include/asm/processor.h
+++ b/arch/arc/include/asm/processor.h
@@ -57,11 +57,7 @@ struct task_struct;
* A lot of busy-wait loops in SMP are based off of non-volatile data otherwise
* get optimised away by gcc
*/
-#ifdef CONFIG_SMP
#define cpu_relax() __asm__ __volatile__ ("" : : : "memory")
-#else
-#define cpu_relax() do { } while (0)
-#endif
#define cpu_relax_lowlatency() cpu_relax()
--
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