#define store_barrier() asm volatile ("": : :"memory")
#elif defined(__ppc__) || defined(__powerpc__)
#define store_barrier() asm volatile ("eieio" : : : "memory")
+#elif defined(__s390__) || defined(__s390x__)
+#define store_barrier() asm volatile ("bcr 15,0" : : : "memory")
#else
#error Define store_barrier() for your CPU
#endif