diff --git a/include/asm-s390/processor.h b/include/asm-s390/processor.h
index c5cbc4bd8414..5b71d3731723 100644
--- a/include/asm-s390/processor.h
+++ b/include/asm-s390/processor.h
@@ -199,15 +199,13 @@ unsigned long get_wchan(struct task_struct *p);
 /*
  * Give up the time slice of the virtual PU.
  */
-#ifndef __s390x__
-# define cpu_relax()	asm volatile ("diag 0,0,68" : : : "memory")
-#else /* __s390x__ */
-# define cpu_relax() \
-	do { \
-		if (MACHINE_HAS_DIAG44) \
-			asm volatile ("diag 0,0,68" : : : "memory"); \
-	} while (0)
-#endif /* __s390x__ */
+static inline void cpu_relax(void)
+{
+	if (MACHINE_HAS_DIAG44)
+		asm volatile ("diag 0,0,68" : : : "memory");
+	else
+		barrier();
+}
 
 /*
  * Set PSW to specified value.
diff --git a/include/asm-s390/setup.h b/include/asm-s390/setup.h
index da3fd4a7bb32..19e31979309a 100644
--- a/include/asm-s390/setup.h
+++ b/include/asm-s390/setup.h
@@ -40,15 +40,16 @@ extern unsigned long machine_flags;
 #define MACHINE_IS_VM		(machine_flags & 1)
 #define MACHINE_IS_P390		(machine_flags & 4)
 #define MACHINE_HAS_MVPG	(machine_flags & 16)
-#define MACHINE_HAS_DIAG44	(machine_flags & 32)
 #define MACHINE_HAS_IDTE	(machine_flags & 128)
 
 #ifndef __s390x__
 #define MACHINE_HAS_IEEE	(machine_flags & 2)
 #define MACHINE_HAS_CSP		(machine_flags & 8)
+#define MACHINE_HAS_DIAG44	(1)
 #else /* __s390x__ */
 #define MACHINE_HAS_IEEE	(1)
 #define MACHINE_HAS_CSP		(1)
+#define MACHINE_HAS_DIAG44	(machine_flags & 32)
 #endif /* __s390x__ */