MMU_TIB_MASK
((unsigned long) (pa) & (MMU_TIA_MASK|MMU_TIB_MASK))
((unsigned long) (pa + MMU_TIB_RANGE - 1) & (MMU_TIA_MASK|MMU_TIB_MASK))
((unsigned long) ((va) & MMU_TIB_MASK) >> MMU_TIB_SHIFT)
c_tbl->ct_va = (va & (MMU_TIA_MASK|MMU_TIB_MASK));