[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>

3 files changed, 3 insertions, 3 deletions

diff --git a/include/asm-s390/dma.h b/include/asm-s390/dma.h
index 02720c449cd8..7425c6af6cd4 100644
--- a/include/asm-s390/dma.h
+++ b/include/asm-s390/dma.h
@@ -11,6 +11,6 @@
 
 #define MAX_DMA_ADDRESS         0x80000000
 
-#define free_dma(x)
+#define free_dma(x)     do { } while (0)
 
 #endif /* _ASM_DMA_H */
diff --git a/include/asm-s390/io.h b/include/asm-s390/io.h
index d4614b35f423..a6cc27e77007 100644
--- a/include/asm-s390/io.h
+++ b/include/asm-s390/io.h
@@ -116,7 +116,7 @@ extern void iounmap(void *addr);
 #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
diff --git a/include/asm-s390/smp.h b/include/asm-s390/smp.h
index 657646054c5e..9fb02e9779c9 100644
--- a/include/asm-s390/smp.h
+++ b/include/asm-s390/smp.h
@@ -104,7 +104,7 @@ smp_call_function_on(void (*func) (void *info), void *info,
 #define smp_cpu_not_running(cpu)        1
 #define smp_get_cpu(cpu) ({ 0; })
 #define smp_put_cpu(cpu) ({ 0; })
-#define smp_setup_cpu_possible_map()
+#define smp_setup_cpu_possible_map()    do { } while (0)
 #endif
 
 #endif