H_KERN_MAP_SIZE    23 arch/powerpc/include/asm/book3s/64/hash-4k.h #define H_KERN_MAP_SIZE		(ASM_CONST(1) << REGION_SHIFT)
H_KERN_MAP_SIZE    21 arch/powerpc/include/asm/book3s/64/hash-64k.h #define H_KERN_MAP_SIZE		(1UL << MAX_EA_BITS_PER_CONTEXT)