From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michael Chan Subject: [PATCH net-next v2 2/5] net: Disable GRO_HW when generic XDP is installed on a device. Date: Thu, 7 Dec 2017 03:03:32 -0500 Message-ID: <1512633815-25037-3-git-send-email-michael.chan@broadcom.com> References: <1512633815-25037-1-git-send-email-michael.chan@broadcom.com> Cc: netdev@vger.kernel.org, andrew.gospodarek@broadcom.com, Ariel Elior , everest-linux-l2@cavium.com To: davem@davemloft.net Return-path: Received: from mail-qt0-f193.google.com ([209.85.216.193]:42651 "EHLO mail-qt0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752312AbdLGIDy (ORCPT ); Thu, 7 Dec 2017 03:03:54 -0500 Received: by mail-qt0-f193.google.com with SMTP id g9so15424277qth.9 for ; Thu, 07 Dec 2017 00:03:54 -0800 (PST) In-Reply-To: <1512633815-25037-1-git-send-email-michael.chan@broadcom.com> Sender: netdev-owner@vger.kernel.org List-ID: Hardware should not aggregate any packets when generic XDP is installed. Cc: Ariel Elior Cc: everest-linux-l2@cavium.com Signed-off-by: Michael Chan --- net/core/dev.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/net/core/dev.c b/net/core/dev.c index 7242e5e..7087f34 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1542,6 +1542,29 @@ void dev_disable_lro(struct net_device *dev) } EXPORT_SYMBOL(dev_disable_lro); +/** + * dev_disable_gro_hw - disable HW Generic Receive Offload on a device + * @dev: device + * + * Disable HW Generic Receive Offload (GRO_HW) on a net device. Must be + * called under RTNL. This is needed if Generic XDP is installed on + * the device. + */ +static void dev_disable_gro_hw(struct net_device *dev) +{ + struct net_device *lower_dev; + struct list_head *iter; + + dev->wanted_features &= ~NETIF_F_GRO_HW; + netdev_update_features(dev); + + if (unlikely(dev->features & NETIF_F_GRO_HW)) + netdev_WARN(dev, "failed to disable GRO_HW!\n"); + + netdev_for_each_lower_dev(dev, lower_dev, iter) + dev_disable_gro_hw(lower_dev); +} + static int call_netdevice_notifier(struct notifier_block *nb, unsigned long val, struct net_device *dev) { @@ -4545,6 +4568,7 @@ static int generic_xdp_install(struct net_device *dev, struct netdev_bpf *xdp) } else if (new && !old) { static_key_slow_inc(&generic_xdp_needed); dev_disable_lro(dev); + dev_disable_gro_hw(dev); } break; -- 1.8.3.1