Disintegrate asm/system.h for M68K

Disintegrate asm/system.h for M68K.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Greg Ungerer <gerg@uclinux.org>
cc: linux-m68k@lists.linux-m68k.org
diff --git a/arch/m68k/include/asm/barrier.h b/arch/m68k/include/asm/barrier.h
new file mode 100644
index 0000000..445ce22
--- /dev/null
+++ b/arch/m68k/include/asm/barrier.h
@@ -0,0 +1,20 @@
+#ifndef _M68K_BARRIER_H
+#define _M68K_BARRIER_H
+
+/*
+ * Force strict CPU ordering.
+ * Not really required on m68k...
+ */
+#define nop()		do { asm volatile ("nop"); barrier(); } while (0)
+#define mb()		barrier()
+#define rmb()		barrier()
+#define wmb()		barrier()
+#define read_barrier_depends()	((void)0)
+#define set_mb(var, value)	({ (var) = (value); wmb(); })
+
+#define smp_mb()	barrier()
+#define smp_rmb()	barrier()
+#define smp_wmb()	barrier()
+#define smp_read_barrier_depends()	((void)0)
+
+#endif /* _M68K_BARRIER_H */