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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0F6AFC433EF for ; Thu, 3 Feb 2022 12:53:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238168AbiBCMxj (ORCPT ); Thu, 3 Feb 2022 07:53:39 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35580 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232231AbiBCMxh (ORCPT ); Thu, 3 Feb 2022 07:53:37 -0500 Received: from mail-ej1-x62c.google.com (mail-ej1-x62c.google.com [IPv6:2a00:1450:4864:20::62c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DC175C061714; Thu, 3 Feb 2022 04:53:36 -0800 (PST) Received: by mail-ej1-x62c.google.com with SMTP id h7so8587725ejf.1; Thu, 03 Feb 2022 04:53:36 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=bDH9Nk0+/o9mu2Zgni8eu8F6PQOKs9CYbDD3SvAHg8A=; b=XEbXPW9KabqAF3OHMNpKhGUnfjAi6TBWYOnpFQS4Qc6f/uXr2FWlZjLROnjc/Vcw79 Ox1N7aLBYBG9RzZLUGdpR4QJmvZxhVbWyxBV8kpq8plQMZaxykSKAkW+PkUqxE1pe5lb VZKP3L8r1/VFNrzX5w6yJzcAIumgTIf6WjboojHnG5AbVHSH93Cg4KfQiv5ujxME4fUB f4i/XVwkBhHB7PDcuBgWn7XjWCA3okBfBqQlbBrf/Hb9/5YjE4kEK/OaSTu55ViArPBv Dn3J3jqVxORlOSZinimMRQg2ff93TeTDw4AwIfto0ZFKHRLj7qwhaX3ECmo0prFXKiXu 7UZA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=bDH9Nk0+/o9mu2Zgni8eu8F6PQOKs9CYbDD3SvAHg8A=; b=pBk3uY0BEcMWyRL3BdKxrOwFwRIFETH46AtVcRgCnao1lGzwhWReAgo9cZyhz/KY9K eFCmkmsrrEjhrAuB4o/JnKGKnIkNvGrFByupsES0cubQzf8FIWTiY+Gpfw5N5mXIfcoq 7OpIkVimVCxTrMPJzI4K/bqarXvHsQtPotZChUKYebZHMgwIJzY8bpiu32c5fY8lgJEP CmcgyZJDkFldj1nxaRH8z9vTUwy4cNU+Lc83EkEIEDGLl8RiCw8uwTZZoZkJYjNNDVah vzRpHnUl9swWJKmpiOL/fQvlFnkTDfsP/u3TZAr7vDloyGtzUf0bw6tRJPmP0UJ5Tlma L4Uw== X-Gm-Message-State: AOAM530s9EIREZ6YCVTRHp3WrnO40bdwzyKMozhJAP2UjY5KvXXBla0J 2RPQq/QIj5sVTz8mQ9wtN8I= X-Google-Smtp-Source: ABdhPJxMhYsIAPnM9xbeZ03tbimYEosXOSoqgAl1R/iWmgu5qN4zQVs87oCvzh/0WbouCUlAUPTQqA== X-Received: by 2002:a17:907:6da1:: with SMTP id sb33mr28868085ejc.18.1643892815436; Thu, 03 Feb 2022 04:53:35 -0800 (PST) Received: from skbuf ([188.27.184.105]) by smtp.gmail.com with ESMTPSA id h19sm15752224edv.90.2022.02.03.04.53.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 03 Feb 2022 04:53:34 -0800 (PST) Date: Thu, 3 Feb 2022 14:53:33 +0200 From: Vladimir Oltean To: Tobias Waldekranz Cc: davem@davemloft.net, kuba@kernel.org, netdev@vger.kernel.org, Andrew Lunn , Vivien Didelot , Florian Fainelli , linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 net-next 4/5] net: dsa: mv88e6xxx: Improve multichip isolation of standalone ports Message-ID: <20220203125333.swap2es7rt4gt2yl@skbuf> References: <20220203101657.990241-1-tobias@waldekranz.com> <20220203101657.990241-5-tobias@waldekranz.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220203101657.990241-5-tobias@waldekranz.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Feb 03, 2022 at 11:16:56AM +0100, Tobias Waldekranz wrote: > Given that standalone ports are now configured to bypass the ATU and > forward all frames towards the upstream port, extend the ATU bypass to > multichip systems. > > Load VID 0 (standalone) into the VTU with the policy bit set. Since > VID 4095 (bridged) is already loaded, we now know that all VIDs in use > are always available in all VTUs. Therefore, we can safely enable > 802.1Q on DSA ports. > > Setting the DSA ports' VTU policy to TRAP means that all incoming > frames on VID 0 will be classified as MGMT - as a result, the ATU is > bypassed on all subsequent switches. > > With this isolation in place, we are able to support configurations > that are simultaneously very quirky and very useful. Quirky because it > involves looping cables between local switchports like in this > example: > > CPU > | .------. > .---0---. | .----0----. > | sw0 | | | sw1 | > '-1-2-3-' | '-1-2-3-4-' > $ @ '---' $ @ % % > > We have three physically looped pairs ($, @, and %). > > This is very useful because it allows us to run the kernel's > kselftests for the bridge on mv88e6xxx hardware. > > Signed-off-by: Tobias Waldekranz > --- Reviewed-by: Vladimir Oltean