[S390] empty function defines.
Use do { } while (0) constructs instead of empty defines to avoid
subtle compile bugs.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/include/asm-s390/io.h b/include/asm-s390/io.h
index d4614b3..a6cc27e 100644
--- a/include/asm-s390/io.h
+++ b/include/asm-s390/io.h
@@ -116,7 +116,7 @@
#define outb(x,addr) ((void) writeb(x,addr))
#define outb_p(x,addr) outb(x,addr)
-#define mmiowb()
+#define mmiowb() do { } while (0)
/*
* Convert a physical pointer to a virtual kernel pointer for /dev/mem