AL_ETH_RX_RING_IDX_NEXT
next_to_use = AL_ETH_RX_RING_IDX_NEXT(rx_ring, next_to_use);
*next_to_clean = AL_ETH_RX_RING_IDX_NEXT(rx_ring,
*next_to_clean = AL_ETH_RX_RING_IDX_NEXT(rx_ring,
*next_to_clean = AL_ETH_RX_RING_IDX_NEXT(rx_ring, *next_to_clean);