_memset_c_io
extern void _memset_c_io(volatile void __iomem *, unsigned long, long);
_memset_c_io(addr, 0x0101010101010101UL * c, len);
_memset_c_io(addr, 0x0001000100010001UL * c, len);
EXPORT_SYMBOL(_memset_c_io);