MAX_PG_PAGES
sc->pg_pages = min((sc->rx_pages * 4), MAX_PG_PAGES);
#define MAX_PG_BD_AVAIL (MAX_PG_PAGES * TOTAL_PG_BD_PER_PAGE)
bus_dmamap_t pg_bd_chain_map[MAX_PG_PAGES];
struct rx_bd *pg_bd_chain[MAX_PG_PAGES];
bus_addr_t pg_bd_chain_paddr[MAX_PG_PAGES];