From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Gallatin Subject: [PATCH v3 net-next 2/2] myri10ge: Add vlan rx for better GRO perf. Date: Thu, 29 Nov 2012 16:07:32 -0500 Message-ID: <50B7CE94.6000203@myri.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: netdev To: David Miller Return-path: Received: from mail-gh0-f174.google.com ([209.85.160.174]:63251 "EHLO mail-gh0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753382Ab2K2VHf (ORCPT ); Thu, 29 Nov 2012 16:07:35 -0500 Received: by mail-gh0-f174.google.com with SMTP id g15so2603302ghb.19 for ; Thu, 29 Nov 2012 13:07:35 -0800 (PST) Sender: netdev-owner@vger.kernel.org List-ID: Unlike LRO, GRO requires that vlan tags be removed before aggregation can occur. Since the myri10ge NIC does not support hardware vlan tag offload, we must remove the tag in the driver to achieve performance comparable to LRO for vlan tagged frames. Thanks to Eric Duzamet for his help simplifying the original patch. Signed-off-by: Andrew Gallatin --- drivers/net/ethernet/myricom/myri10ge/myri10ge.c | 41 ++++++++++++++++++++++ 1 file changed, 41 insertions(+) diff --git a/drivers/net/ethernet/myricom/myri10ge/myri10ge.c b/drivers/net/ethernet/myricom/myri10ge/myri10ge.c index 84207c0..2fc984a 100644 --- a/drivers/net/ethernet/myricom/myri10ge/myri10ge.c +++ b/drivers/net/ethernet/myricom/myri10ge/myri10ge.c @@ -1264,6 +1264,42 @@ myri10ge_unmap_rx_page(struct pci_dev *pdev, } } +/* + * GRO does not support acceleration of tagged vlan frames, and + * this NIC does not support vlan tag offload, so we must pop + * the tag ourselves to be able to achieve GRO performance that + * is comparable to LRO. + */ + +static inline void +myri10ge_vlan_rx(struct net_device *dev, void *addr, struct sk_buff *skb) +{ + u8 *va; + struct vlan_ethhdr *veh; + struct skb_frag_struct *frag; + __wsum vsum; + + va = addr; + va += MXGEFW_PAD; + veh = (struct vlan_ethhdr *)va; + if ((dev->features & NETIF_F_HW_VLAN_RX) == NETIF_F_HW_VLAN_RX && + veh->h_vlan_proto == ntohs(ETH_P_8021Q)) { + /* fixup csum if needed */ + if (skb->ip_summed == CHECKSUM_COMPLETE) { + vsum = csum_partial(va + ETH_HLEN, VLAN_HLEN, 0); + skb->csum = csum_sub(skb->csum, vsum); + } + /* pop tag */ + __vlan_hwaccel_put_tag(skb, ntohs(veh->h_vlan_TCI)); + memmove(va + VLAN_HLEN, va, 2 * ETH_ALEN); + skb->len -= VLAN_HLEN; + skb->data_len -= VLAN_HLEN; + frag = skb_shinfo(skb)->frags; + frag->page_offset += VLAN_HLEN; + skb_frag_size_set(frag, skb_frag_size(frag) - VLAN_HLEN); + } +} + static inline int myri10ge_rx_done(struct myri10ge_slice_state *ss, int len, __wsum csum) { @@ -1326,6 +1362,7 @@ myri10ge_rx_done(struct myri10ge_slice_state *ss, int len, __wsum csum) skb->ip_summed = CHECKSUM_COMPLETE; skb->csum = csum; } + myri10ge_vlan_rx(mgp->dev, va, skb); skb_record_rx_queue(skb, ss - &mgp->ss[0]); napi_gro_frags(&ss->napi); @@ -3851,6 +3888,10 @@ static int myri10ge_probe(struct pci_dev *pdev, const struct pci_device_id *ent) netdev->netdev_ops = &myri10ge_netdev_ops; netdev->mtu = myri10ge_initial_mtu; netdev->hw_features = mgp->features | NETIF_F_RXCSUM; + + /* fake NETIF_F_HW_VLAN_RX for good GRO performance */ + netdev->hw_features |= NETIF_F_HW_VLAN_RX; + netdev->features = netdev->hw_features; if (dac_enabled) -- 1.7.9.5