dn_provider
if ((dnp->dn_provider = dt_provider_lookup(dtp, name)) != NULL)
else if ((dnp->dn_provider = dt_provider_create(dtp, name)) == NULL)
dnp->dn_provider->pv_flags |= DT_PROVIDER_INTF;
lnp->dn_link = dnp->dn_provider->pv_nodes;
dnp->dn_provider->pv_nodes = yypcb->pcb_list;
dt_provider_t *pvp = dnp->dn_provider;