summaryrefslogtreecommitdiffstats
path: root/kernel/arch/sh/include/asm/barrier.h
diff options
context:
space:
mode:
authorYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 12:17:53 -0700
committerYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 15:44:42 -0700
commit9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch)
tree1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/arch/sh/include/asm/barrier.h
parent98260f3884f4a202f9ca5eabed40b1354c489b29 (diff)
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/arch/sh/include/asm/barrier.h')
-rw-r--r--kernel/arch/sh/include/asm/barrier.h39
1 files changed, 39 insertions, 0 deletions
diff --git a/kernel/arch/sh/include/asm/barrier.h b/kernel/arch/sh/include/asm/barrier.h
new file mode 100644
index 000000000..43715308b
--- /dev/null
+++ b/kernel/arch/sh/include/asm/barrier.h
@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima
+ * Copyright (C) 2002 Paul Mundt
+ */
+#ifndef __ASM_SH_BARRIER_H
+#define __ASM_SH_BARRIER_H
+
+#if defined(CONFIG_CPU_SH4A) || defined(CONFIG_CPU_SH5)
+#include <asm/cache_insns.h>
+#endif
+
+/*
+ * A brief note on ctrl_barrier(), the control register write barrier.
+ *
+ * Legacy SH cores typically require a sequence of 8 nops after
+ * modification of a control register in order for the changes to take
+ * effect. On newer cores (like the sh4a and sh5) this is accomplished
+ * with icbi.
+ *
+ * Also note that on sh4a in the icbi case we can forego a synco for the
+ * write barrier, as it's not necessary for control registers.
+ *
+ * Historically we have only done this type of barrier for the MMUCR, but
+ * it's also necessary for the CCR, so we make it generic here instead.
+ */
+#if defined(CONFIG_CPU_SH4A) || defined(CONFIG_CPU_SH5)
+#define mb() __asm__ __volatile__ ("synco": : :"memory")
+#define rmb() mb()
+#define wmb() mb()
+#define ctrl_barrier() __icbi(PAGE_OFFSET)
+#else
+#define ctrl_barrier() __asm__ __volatile__ ("nop;nop;nop;nop;nop;nop;nop;nop")
+#endif
+
+#define set_mb(var, value) do { (void)xchg(&var, value); } while (0)
+
+#include <asm-generic/barrier.h>
+
+#endif /* __ASM_SH_BARRIER_H */