From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Fastabend Subject: Re: [PATCH 2/3] bridge: offload bridge port attributes to switch asic if feature flag set Date: Thu, 04 Dec 2014 22:55:04 -0800 Message-ID: <548156C8.5060602@gmail.com> References: <1417746401-8140-3-git-send-email-roopa@cumulusnetworks.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: Roopa Prabhu , =?UTF-8?B?SmnFmcOtIFDDrXJrbw==?= , Jamal Hadi Salim , Benjamin LaHaise , Thomas Graf , "stephen@networkplumber.org" , John Linville , "nhorman@tuxdriver.com" , Nicolas Dichtel , "vyasevic@redhat.com" , Florian Fainelli , "buytenh@wantstofly.org" , Aviad Raveh , Netdev , "David S. Miller" , shm@cumulusnetworks.com, Andy Gospodarek To: Scott Feldman Return-path: Received: from mail-ob0-f174.google.com ([209.85.214.174]:55110 "EHLO mail-ob0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750877AbaLEGza (ORCPT ); Fri, 5 Dec 2014 01:55:30 -0500 Received: by mail-ob0-f174.google.com with SMTP id nt9so91002obb.19 for ; Thu, 04 Dec 2014 22:55:30 -0800 (PST) In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On 12/04/2014 10:41 PM, Scott Feldman wrote: > On Thu, Dec 4, 2014 at 6:26 PM, wrote: >> From: Roopa Prabhu >> >> This allows offloading to switch asic without having the user to set >> any flag. And this is done in the bridge driver to rollback kernel settings >> on hw offload failure if required in the future. >> >> With this, it also makes sure a notification goes out only after the >> attributes are set both in the kernel and hw. > > I like this approach as it streamlines the steps for the user in > setting port flags. There is one case for FLOODING where you'll have > to turn off flooding for both, and then turn on flooding in hw. You > don't want flooding turned on on kernel and hw. > >> --- >> net/bridge/br_netlink.c | 27 ++++++++++++++++++++++++++- >> 1 file changed, 26 insertions(+), 1 deletion(-) >> >> diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c >> index 9f5eb55..ce173f0 100644 >> --- a/net/bridge/br_netlink.c >> +++ b/net/bridge/br_netlink.c >> @@ -407,9 +407,21 @@ int br_setlink(struct net_device *dev, struct nlmsghdr *nlh) >> afspec, RTM_SETLINK); >> } >> >> + if ((dev->features & NETIF_F_HW_SWITCH_OFFLOAD) && >> + dev->netdev_ops->ndo_bridge_setlink) { >> + int ret = dev->netdev_ops->ndo_bridge_setlink(dev, nlh); > > I think you want to up-level this to net/core/rtnetlink.c because > you're only enabling the feature for one instance of a driver that > implements ndo_bridge_setlink: the bridge driver. If another driver > was MASTER and implemented ndo_bridge_setlink, you'd want same check > to push setting down to SELF port driver. Also if the user set SELF && MASTER flags && had HW_SWITCH_OFFLOAD bit set we would call ndo_bridge_setlink twice on the dev. Maybe you can catch this case in rtnetlink.c and only call it once. > >> + if (ret && ret != -EOPNOTSUPP) { >> + /* XXX Fix this in the future to rollback >> + * kernel settings and return error >> + */ > > The future is now. Let's fix this now for the rollback case (again up > in rtnetlink.c). So then a general question comes to mind: for these > dual target sets, is it best to try HW first and then SW, or the other > way around? Either way, on failure on second you need to rollback > first. And, on failure, you need to know rollback value for first, so > you have to do a getlink on first before attempting set. It might be helpful to return some indication of what object failed as well. > >> + br_warn(p->br, "error offloading bridge attributes " >> + "on port %u(%s)\n", (unsigned int) p->port_no, >> + p->dev->name); >> + } >> + } >> + >> if (err == 0) >> br_ifinfo_notify(RTM_NEWLINK, p); >> - >> out: >> return err; >> } >> @@ -433,6 +445,19 @@ int br_dellink(struct net_device *dev, struct nlmsghdr *nlh) >> err = br_afspec((struct net_bridge *)netdev_priv(dev), p, >> afspec, RTM_DELLINK); >> >> + if (dev->features & NETIF_F_HW_SWITCH_OFFLOAD >> + && dev->netdev_ops->ndo_bridge_setlink) { >> + int ret = dev->netdev_ops->ndo_bridge_dellink(dev, nlh); >> + if (ret && ret != -EOPNOTSUPP) { >> + /* XXX Fix this in the future to rollback >> + * kernel settings and return error >> + */ >> + br_warn(p->br, "error offloading bridge attributes " >> + "on port %u(%s)\n", (unsigned int) p->port_no, >> + p->dev->name); >> + } >> + } >> + > > Same comments as setlink above. > >> return err; >> } >> static int br_validate(struct nlattr *tb[], struct nlattr *data[]) >> -- >> 1.7.10.4 >> -- John Fastabend Intel Corporation