[PATCH 20/28] ARCv2: barriers

From: Vineet Gupta
Date: Tue Jun 09 2015 - 07:53:32 EST


Cc: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Signed-off-by: Vineet Gupta <vgupta@xxxxxxxxxxxx>
---
arch/arc/include/asm/Kbuild | 1 -
arch/arc/include/asm/barrier.h | 48 ++++++++++++++++++++++++++++++++++++++++++
2 files changed, 48 insertions(+), 1 deletion(-)
create mode 100644 arch/arc/include/asm/barrier.h

diff --git a/arch/arc/include/asm/Kbuild b/arch/arc/include/asm/Kbuild
index be0c39e76f7c..59e2dd1d434f 100644
--- a/arch/arc/include/asm/Kbuild
+++ b/arch/arc/include/asm/Kbuild
@@ -1,5 +1,4 @@
generic-y += auxvec.h
-generic-y += barrier.h
generic-y += bitsperlong.h
generic-y += bugs.h
generic-y += clkdev.h
diff --git a/arch/arc/include/asm/barrier.h b/arch/arc/include/asm/barrier.h
new file mode 100644
index 000000000000..c6ea2f6af55e
--- /dev/null
+++ b/arch/arc/include/asm/barrier.h
@@ -0,0 +1,48 @@
+/*
+ * Copyright (C) 2014-15 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef __ASM_BARRIER_H
+#define __ASM_BARRIER_H
+
+#ifdef CONFIG_SMP
+
+#ifdef CONFIG_ISA_ARCV2
+
+/*
+ * DMB:
+ * - Ensures that selected memory operation issued before it will complete
+ * before any subsequent memory operation of same type
+ */
+#define smp_mb() asm volatile("dmb 3\n" : : : "memory")
+#define smp_rmb() asm volatile("dmb 1\n" : : : "memory")
+#define smp_wmb() asm volatile("dmb 2\n" : : : "memory")
+
+/*
+ * DSYNC:
+ * - Waits for completion of all outstanding memory operations before any new
+ * operations can begin
+ * - Includes implicit memory operations such as cache/TLB/BPU maintenance ops
+ * - Lighter version of SYNC as it doesn't wait for non-memory operations
+ */
+#define mb() asm volatile("dsync\n" : : : "memory")
+
+#else /* CONFIG_ISA_ARCOMPACT */
+
+/* SYNC:
+ * - Waits for completion of all outstanding memory transactions AND all
+ * previous instructions to reture
+ */
+#define mb() asm volatile("sync\n" : : : "memory")
+
+#endif /* CONFIG_ISA_ARCV2 */
+
+#endif /* CONFIG_SMP */
+
+#include <asm-generic/barrier.h>
+
+#endif
--
1.9.1

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