_IOC_SIZEMASK 88 include/uapi/asm-generic/ioctl.h #define _IOC_SIZE(nr) (((nr) >> _IOC_SIZESHIFT) & _IOC_SIZEMASK) _IOC_SIZEMASK 95 include/uapi/asm-generic/ioctl.h #define IOCSIZE_MASK (_IOC_SIZEMASK << _IOC_SIZESHIFT)