From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roopa Prabhu Subject: Re: [PATCH 2/3] bridge: offload bridge port attributes to switch asic if feature flag set Date: Thu, 04 Dec 2014 23:10:06 -0800 Message-ID: <54815A4E.3020806@cumulusnetworks.com> References: <1417746401-8140-3-git-send-email-roopa@cumulusnetworks.com> <548156C8.5060602@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: Scott Feldman , =?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: John Fastabend Return-path: Received: from ext3.cumulusnetworks.com ([198.211.106.187]:38709 "EHLO ext3.cumulusnetworks.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751258AbaLEHKM (ORCPT ); Fri, 5 Dec 2014 02:10:12 -0500 In-Reply-To: <548156C8.5060602@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: On 12/4/14, 10:55 PM, John Fastabend wrote: > 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. yes, thought about this and when i looked at iproute2 code, it is either master or self today and i don't think anybody else uses both flags with the current kernel implementation. But yes, that does not stop anybody from setting both flags. I will handle it better in v2. > >> >>> + 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. ok... thanks, Roopa