Disintegrate asm/system.h for H8300

Disintegrate asm/system.h for H8300.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Yoshinori Sato <ysato@users.sourceforge.jp>
diff --git a/arch/h8300/include/asm/barrier.h b/arch/h8300/include/asm/barrier.h
new file mode 100644
index 0000000..c7283c3
--- /dev/null
+++ b/arch/h8300/include/asm/barrier.h
@@ -0,0 +1,27 @@
+#ifndef _H8300_BARRIER_H
+#define _H8300_BARRIER_H
+
+#define nop()  asm volatile ("nop"::)
+
+/*
+ * Force strict CPU ordering.
+ * Not really required on H8...
+ */
+#define mb()   asm volatile (""   : : :"memory")
+#define rmb()  asm volatile (""   : : :"memory")
+#define wmb()  asm volatile (""   : : :"memory")
+#define set_mb(var, value) do { xchg(&var, value); } while (0)
+
+#ifdef CONFIG_SMP
+#define smp_mb()	mb()
+#define smp_rmb()	rmb()
+#define smp_wmb()	wmb()
+#define smp_read_barrier_depends()	read_barrier_depends()
+#else
+#define smp_mb()	barrier()
+#define smp_rmb()	barrier()
+#define smp_wmb()	barrier()
+#define smp_read_barrier_depends()	do { } while(0)
+#endif
+
+#endif /* _H8300_BARRIER_H */