From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 30DB9C6377A for ; Wed, 21 Jul 2021 23:35:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1367E6101E for ; Wed, 21 Jul 2021 23:35:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231241AbhGUWzS (ORCPT ); Wed, 21 Jul 2021 18:55:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41018 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230289AbhGUWzR (ORCPT ); Wed, 21 Jul 2021 18:55:17 -0400 Received: from mail-ed1-x52e.google.com (mail-ed1-x52e.google.com [IPv6:2a00:1450:4864:20::52e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8054FC061575; Wed, 21 Jul 2021 16:35:52 -0700 (PDT) Received: by mail-ed1-x52e.google.com with SMTP id dj21so4566180edb.0; Wed, 21 Jul 2021 16:35:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=uEqLdGKF6+rg1FAbUl0sbtAwny0zoTLNAfMvz3yVKUc=; b=IHRJNobmB50DI1h20Pr7f4uYikBnbtt4dMTHrvLlItiKSyBfPs1MawYLBdF6CGP7RM ex683UPnPIgomHpfLMJpvY5KGrTrqNSvXNlUWm8ktIxoH5Jt65uhiuDhHApFfyA0vGyf 96IbZP2kXwnNns73bc0FMfyrur4k6tZML9tjHeEtU8WcGBt89PaSCoa9ls6RPxymHO3/ azhEm+XTzmnTcMBlJehuAiKuEeNnzeXhu7NZ0uPvmMo4ExSSngKrXQdHVm+lbFHBqkgb cvpK3Ytv5LEhzH7yQZi2EcZ2JIYwm7wtV+PK/FQf8PXvFrO7E5CYy4SowQk5bntPS/yq MnFQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=uEqLdGKF6+rg1FAbUl0sbtAwny0zoTLNAfMvz3yVKUc=; b=fJ4tnmE3aRgnTeHt6yMaRfjaWVf+TyIRPKaA3wcsfd3jG177q7KW+88JK5XLCF7OuQ YYdrgUeLbjvMUa5Xi1SUAdIXcylC8BkHpUAw4/m6p8Tc0HIUnaJA9nBQusebalT9Suhk 7Uz1vWxAS9G7EW9Bl+3ARN850PiWGqBNxpRKwrooo71q8Q5VZTwbEJ6EWTMau6yRc3DE gxECBTwfXsoIPUV0OzHSJZvrVYDXadjAmquOVQCK6J+XY5BQQg0qUtnDOteaoL0TElxJ 25eAp1OJ0lO0HWtHBe1WQfrkAXBzz+GtUPaeETXUH9OjE/YKcrLubiQL2B2MsIXGWM8J jazg== X-Gm-Message-State: AOAM531sPyNhcThoQwQDdh98UsgXvWyNAEHACty5E8ZhvC4gSiYQGi7m LXBfacUP2s+Prvj4snAOjIU= X-Google-Smtp-Source: ABdhPJzUiY8X3xBvpDKKpn7221qkP6gD+e4ElJEdL60keo8TvM/fgy9c/3pQFiH17fa+CZO8hHxKNw== X-Received: by 2002:a05:6402:1546:: with SMTP id p6mr44885499edx.206.1626910551162; Wed, 21 Jul 2021 16:35:51 -0700 (PDT) Received: from skbuf ([82.76.66.29]) by smtp.gmail.com with ESMTPSA id j1sm11479752edl.80.2021.07.21.16.35.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 21 Jul 2021 16:35:50 -0700 (PDT) Date: Thu, 22 Jul 2021 02:35:49 +0300 From: Vladimir Oltean To: Lino Sanfilippo Cc: woojung.huh@microchip.com, UNGLinuxDriver@microchip.com, andrew@lunn.ch, vivien.didelot@gmail.com, f.fainelli@gmail.com, davem@davemloft.net, kuba@kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 1/2] net: dsa: ensure linearized SKBs in case of tail taggers Message-ID: <20210721233549.mhqlrt3l2bbyaawr@skbuf> References: <20210721215642.19866-1-LinoSanfilippo@gmx.de> <20210721215642.19866-2-LinoSanfilippo@gmx.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210721215642.19866-2-LinoSanfilippo@gmx.de> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 21, 2021 at 11:56:41PM +0200, Lino Sanfilippo wrote: > The function skb_put() that is used by tail taggers to make room for the > DSA tag must only be called for linearized SKBS. However in case that the > slave device inherited features like NETIF_F_HW_SG or NETIF_F_FRAGLIST the > SKB passed to the slaves transmit function may not be linearized. > Avoid those SKBs by clearing the NETIF_F_HW_SG and NETIF_F_FRAGLIST flags > for tail taggers. > Furthermore since the tagging protocol can be changed at runtime move the > code for setting up the slaves features into dsa_slave_setup_tagger(). > > Suggested-by: Vladimir Oltean > Signed-off-by: Lino Sanfilippo > --- > net/dsa/slave.c | 14 +++++++++----- > 1 file changed, 9 insertions(+), 5 deletions(-) > > diff --git a/net/dsa/slave.c b/net/dsa/slave.c > index 22ce11cd770e..ae2a648ed9be 100644 > --- a/net/dsa/slave.c > +++ b/net/dsa/slave.c > @@ -1808,6 +1808,7 @@ void dsa_slave_setup_tagger(struct net_device *slave) > struct dsa_slave_priv *p = netdev_priv(slave); > const struct dsa_port *cpu_dp = dp->cpu_dp; > struct net_device *master = cpu_dp->master; > + const struct dsa_switch *ds = dp->ds; > > slave->needed_headroom = cpu_dp->tag_ops->needed_headroom; > slave->needed_tailroom = cpu_dp->tag_ops->needed_tailroom; > @@ -1819,6 +1820,14 @@ void dsa_slave_setup_tagger(struct net_device *slave) > slave->needed_tailroom += master->needed_tailroom; > > p->xmit = cpu_dp->tag_ops->xmit; > + > + slave->features = master->vlan_features | NETIF_F_HW_TC; > + if (ds->ops->port_vlan_add && ds->ops->port_vlan_del) > + slave->features |= NETIF_F_HW_VLAN_CTAG_FILTER; > + slave->hw_features |= NETIF_F_HW_TC; > + slave->features |= NETIF_F_LLTX; > + if (slave->needed_tailroom) > + slave->features &= ~(NETIF_F_SG | NETIF_F_FRAGLIST); > } > > static struct lock_class_key dsa_slave_netdev_xmit_lock_key; > @@ -1881,11 +1890,6 @@ int dsa_slave_create(struct dsa_port *port) > if (slave_dev == NULL) > return -ENOMEM; > > - slave_dev->features = master->vlan_features | NETIF_F_HW_TC; > - if (ds->ops->port_vlan_add && ds->ops->port_vlan_del) > - slave_dev->features |= NETIF_F_HW_VLAN_CTAG_FILTER; > - slave_dev->hw_features |= NETIF_F_HW_TC; > - slave_dev->features |= NETIF_F_LLTX; > slave_dev->ethtool_ops = &dsa_slave_ethtool_ops; > if (!is_zero_ether_addr(port->mac)) > ether_addr_copy(slave_dev->dev_addr, port->mac); > -- > 2.32.0 > I would have probably changed the code in dsa_slave_create just like this: - slave->features = master->vlan_features | NETIF_F_HW_TC; + slave->features = NETIF_F_HW_TC; ... - slave_dev->vlan_features = master->vlan_features; and in dsa_slave_setup_tagger: + vlan_features = master->vlan_features; + slave->features &= ~vlan_features; + if (slave->needed_tailroom) + vlan_features &= ~(NETIF_F_SG | NETIF_F_FRAGLIST); + slave->features |= vlan_features; + slave->vlan_features = vlan_features; no need to move around NETIF_F_HW_TC and NETIF_F_LLTX. Makes sense? And I would probably add: Fixes: 91da11f870f0 ("net: Distributed Switch Architecture protocol support")