__SWP_OFFSET_MASK  824 arch/arm64/include/asm/pgtable.h #define __SWP_OFFSET_MASK	((1UL << __SWP_OFFSET_BITS) - 1)
__SWP_OFFSET_MASK 1647 arch/s390/include/asm/pgtable.h #define __SWP_OFFSET_MASK	((1UL << 52) - 1)