sh: Support for SH-4A memory barriers.
SH-4A supports 'synco' as a barrier, sprinkle it around
the cache ops as necessary..
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/include/asm-sh/system.h b/include/asm-sh/system.h
index e89728d..eb4902e 100644
--- a/include/asm-sh/system.h
+++ b/include/asm-sh/system.h
@@ -84,10 +84,17 @@
extern void __xchg_called_with_bad_pointer(void);
+#ifdef CONFIG_CPU_SH4A
+#define mb() __asm__ __volatile__ ("synco": : :"memory")
+#define rmb() mb()
+#define wmb() __asm__ __volatile__ ("synco": : :"memory")
+#define read_barrier_depends() do { } while(0)
+#else
#define mb() __asm__ __volatile__ ("": : :"memory")
#define rmb() mb()
#define wmb() __asm__ __volatile__ ("": : :"memory")
#define read_barrier_depends() do { } while(0)
+#endif
#ifdef CONFIG_SMP
#define smp_mb() mb()