_pmap_pdp_addref
_pmap_pdp_addref(pm, pdppa0, pdppg0); /* L1 occupancy++ */
_pmap_pdp_addref(pm, pdppa0, pdppg0); /* L2 occupancy++ */
_pmap_pdp_addref(pm, pdppa, pdppg); /* L3 occupancy++ */