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authorJosé Pekkarinen <jose.pekkarinen@nokia.com>2016-04-11 10:41:07 +0300
committerJosé Pekkarinen <jose.pekkarinen@nokia.com>2016-04-13 08:17:18 +0300
commite09b41010ba33a20a87472ee821fa407a5b8da36 (patch)
treed10dc367189862e7ca5c592f033dc3726e1df4e3 /kernel/arch/arc/include/asm/barrier.h
parentf93b97fd65072de626c074dbe099a1fff05ce060 (diff)
These changes are the raw update to linux-4.4.6-rt14. Kernel sources
are taken from kernel.org, and rt patch from the rt wiki download page. During the rebasing, the following patch collided: Force tick interrupt and get rid of softirq magic(I70131fb85). Collisions have been removed because its logic was found on the source already. Change-Id: I7f57a4081d9deaa0d9ccfc41a6c8daccdee3b769 Signed-off-by: José Pekkarinen <jose.pekkarinen@nokia.com>
Diffstat (limited to 'kernel/arch/arc/include/asm/barrier.h')
-rw-r--r--kernel/arch/arc/include/asm/barrier.h48
1 files changed, 48 insertions, 0 deletions
diff --git a/kernel/arch/arc/include/asm/barrier.h b/kernel/arch/arc/include/asm/barrier.h
new file mode 100644
index 000000000..a7209983e
--- /dev/null
+++ b/kernel/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_ISA_ARCV2
+
+/*
+ * ARCv2 based HS38 cores are in-order issue, but still weakly ordered
+ * due to micro-arch buffering/queuing of load/store, cache hit vs. miss ...
+ *
+ * Explicit barrier provided by DMB instruction
+ * - Operand supports fine grained load/store/load+store semantics
+ * - Ensures that selected memory operation issued before it will complete
+ * before any subsequent memory operation of same type
+ * - DMB guarantees SMP as well as local barrier semantics
+ * (asm-generic/barrier.h ensures sane smp_*mb if not defined here, i.e.
+ * UP: barrier(), SMP: smp_*mb == *mb)
+ * - DSYNC provides DMB+completion_of_cache_bpu_maintenance_ops hence not needed
+ * in the general case. Plus it only provides full barrier.
+ */
+
+#define mb() asm volatile("dmb 3\n" : : : "memory")
+#define rmb() asm volatile("dmb 1\n" : : : "memory")
+#define wmb() asm volatile("dmb 2\n" : : : "memory")
+
+#endif
+
+#ifdef CONFIG_ISA_ARCOMPACT
+
+/*
+ * ARCompact based cores (ARC700) only have SYNC instruction which is super
+ * heavy weight as it flushes the pipeline as well.
+ * There are no real SMP implementations of such cores.
+ */
+
+#define mb() asm volatile("sync\n" : : : "memory")
+#endif
+
+#include <asm-generic/barrier.h>
+
+#endif