PMD_FRAG_SIZE_SHIFT  227 arch/powerpc/include/asm/book3s/64/pgtable.h #define PMD_FRAG_SIZE (1UL << PMD_FRAG_SIZE_SHIFT)
PMD_FRAG_SIZE_SHIFT  232 arch/powerpc/mm/book3s64/mmu_context.c 	count = ((unsigned long)pmd_frag & ~PAGE_MASK) >> PMD_FRAG_SIZE_SHIFT;