TX_BD
uint16_t bd_idx = TX_BD(tx_buf->first_bd);
pkt_cons = TX_BD(sw_cons);
tx_buf = &fp->tx_mbuf_chain[TX_BD(pkt_prod)];
tx_start_bd = &fp->tx_chain[TX_BD(bd_prod)].start_bd;
pbd_e2 = &fp->tx_chain[TX_BD(bd_prod)].parse_bd_e2;
pbd_e1x = &fp->tx_chain[TX_BD(bd_prod)].parse_bd_e1x;
tx_data_bd = &fp->tx_chain[TX_BD(bd_prod)].reg_bd;
tx_data_bd = &fp->tx_chain[TX_BD(bd_prod)].reg_bd;
tx_data_bd = &fp->tx_chain[TX_BD(tmp_bd)].reg_bd;