RX_BD
bd_prod = RX_BD(bd_prod);
bd_cons = RX_BD(bd_cons);
rx_buf = &fp_rx->rx_buf_ring[RX_BD(fp_rx->rx_bd_cons)];
start = RX_BD(le16_to_cpu(*fp->rx_cons_sb) - 10);
end = RX_BD(le16_to_cpu(*fp->rx_cons_sb) + 503);
for (j = start; j != end; j = RX_BD(j + 1)) {