taglinefilesource code
_IOC_NRBITS20include/asm-alpha/ioctl.h#define _IOC_NRMASK  ((1 << _IOC_NRBITS)-1)
_IOC_NRBITS26include/asm-alpha/ioctl.h#define _IOC_TYPESHIFT  (_IOC_NRSHIFT+_IOC_NRBITS)