On Tue, Mar 27, 2018 at 2:21 PM, Eric Dumazet <eduma...@google.com> wrote: > Refine the RX check summing handling to propagate the > hardware provided checksum so that we do not have to > compute it later in software. > > Signed-off-by: Eric Dumazet <eduma...@google.com> > Cc: Willem de Bruijn <will...@google.com> > Cc: Tariq Toukan <tar...@mellanox.com> > --- > drivers/net/ethernet/mellanox/mlx4/en_rx.c | 10 ++++------ > 1 file changed, 4 insertions(+), 6 deletions(-) > > diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c > b/drivers/net/ethernet/mellanox/mlx4/en_rx.c > index > 05787efef492b1c0c6ce540ef73647fad91ce282..5c613c6663da51a4ae792eeb4d8956b54655786b > 100644 > --- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c > +++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c > @@ -821,14 +821,12 @@ int mlx4_en_process_rx_cq(struct net_device *dev, > struct mlx4_en_cq *cq, int bud > skb_record_rx_queue(skb, cq_ring); > > if (likely(dev->features & NETIF_F_RXCSUM)) { > - if (cqe->status & cpu_to_be16(MLX4_CQE_STATUS_TCP | > - MLX4_CQE_STATUS_UDP)) { > + if ((cqe->status & cpu_to_be16(MLX4_CQE_STATUS_TCP | > + MLX4_CQE_STATUS_UDP)) > && > + (cqe->status & cpu_to_be16(MLX4_CQE_STATUS_IPOK)) > && > + cqe->checksum == cpu_to_be16(0xffff)) { > bool l2_tunnel; >
LGTM, this code even aligns better with the mlx4 HW documentation: "When L4_CSUM field is not supported, L4 checksum for TCP/UDP packets can be validated by: (IP_OK && (TCP || UDP)) && (checksum == 0xFFFF))." in the code we don't even consider L4_CSUM at the moment, As a future patch, it could be a nice acceleration for the above 3 steps condition. Small comment, if we expect that cqe->checksum is NOT likely to be 0xffff for UDP/TCP packets, maybe it is better performance wise to move (cqe->checksum == cpu_to_be16(0xffff)) to be evaluated first in the condition. > - if (!((cqe->status & > cpu_to_be16(MLX4_CQE_STATUS_IPOK)) && > - cqe->checksum == cpu_to_be16(0xffff))) > - goto csum_none; > - > l2_tunnel = (dev->hw_enc_features & > NETIF_F_RXCSUM) && > (cqe->vlan_my_qpn & > cpu_to_be32(MLX4_CQE_L2_TUNNEL)); > ip_summed = CHECKSUM_UNNECESSARY; > -- > 2.17.0.rc1.321.gba9d0f2565-goog >