pmap_alloc_pdp
pm->pm_l0table_pa = pmap_alloc_pdp(pm, NULL, 0, true);
pdppa = pmap_alloc_pdp(pm, &pdppg, flags, false); /* L1 pdp */
pdppa = pmap_alloc_pdp(pm, &pdppg, flags, false); /* L2 pdp */
pdppa = pmap_alloc_pdp(pm, &pdppg, flags, false); /* L3 pdp */