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=-0.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 1E491C43381 for ; Tue, 19 Feb 2019 17:44:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CE7472083E for ; Tue, 19 Feb 2019 17:44:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="D5NgRs11" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726342AbfBSRok (ORCPT ); Tue, 19 Feb 2019 12:44:40 -0500 Received: from mail-pg1-f193.google.com ([209.85.215.193]:36430 "EHLO mail-pg1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725807AbfBSRok (ORCPT ); Tue, 19 Feb 2019 12:44:40 -0500 Received: by mail-pg1-f193.google.com with SMTP id r124so10468526pgr.3 for ; Tue, 19 Feb 2019 09:44:39 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:openpgp:autocrypt:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=LldfT9PqctseLZt9p1W89Wf9GfY+n8WkcL8s0rgEEDk=; b=D5NgRs11KE9oyh9E0gjAdbN/ciPRIA1hHCizOHPctJV4tEPXHqrh2q3Kp/9uj+XPoA ccZpbYTOTZJPzj/EkbiVJmxOzPHS6rXH0P9bPTj4enRJryMCufAcSmVo9PaRWUZHlFQW eOjs+eTGpLhT6s4/TG8QkCaN7hd26CYG01/ZV7+lCnzr/vUAJuG9URa5D0UQKePfSJ9a kpdFslKFTm1vviCtMZkdlXdWKdIBADUm499WQ9ObkjgQ++qaoBA3okJmWg2IvbG7jSdo CyWbE3usviyTzhMFCDSwrf3vEYRR3jGXWFsUL5hd5O406txOFRrQlVqmxCUicpOyMkIF k4Lg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:openpgp:autocrypt :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=LldfT9PqctseLZt9p1W89Wf9GfY+n8WkcL8s0rgEEDk=; b=CXY0NWsQm8oMnU012dah4EaG7tN4kzR+2d32wIOnMtBTSEyB1qW1jC9deWMxFeIcP0 e7d69YPTmRVuP9ESdKljkXPSsN0pn+9z/4FrUj9/OgncdHcmcclNBeqxWnwjpYYyyWyX /vP8SuBG8TAjzAAgaGh7tM7Lq63eraNTAE6Y8kr/cDe9CvZUqRkh1VF+JdXO+Qdjye23 knP9IwJoHKpqfBXd/VpA46eyc4Kb3CYgoiwypXUQkmp09VE0+W3KjcHYRz19mgYhTWTy kpG84FentTILBEFMIA7GsUcAx3gVn/4QXqvqICFkUp4N+brHYrOVoVrmrierC9H5afw2 UGlw== X-Gm-Message-State: AHQUAubgc1si2njc/yZFGEjbQOhTpeMoThe3qgDFvDf3HGcGeZ8Kc8Q4 6o33I7crlAm+jlSdA+p2qEr4ABt3 X-Google-Smtp-Source: AHgI3IZ5CnDqGECXF+ZOApuNLGU2iNH9u2jOukYRtXnfbGjWRfShPPUeUARn7dBrhmO5FxvXOzdRxg== X-Received: by 2002:a62:e04b:: with SMTP id f72mr31120653pfh.41.1550598278267; Tue, 19 Feb 2019 09:44:38 -0800 (PST) Received: from [10.67.49.152] ([192.19.223.250]) by smtp.googlemail.com with ESMTPSA id n75sm35913958pfb.39.2019.02.19.09.44.35 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 19 Feb 2019 09:44:37 -0800 (PST) Subject: Re: [PATCH net-next v2 2/3] net: dsa: mv88e6xxx: add support for bridge flags To: Vivien Didelot , Russell King - ARM Linux admin Cc: Andrew Lunn , Heiner Kallweit , "David S. Miller" , netdev@vger.kernel.org References: <20190217163114.yomawlljyxlqy3ob@shell.armlinux.org.uk> <20190219111612.GF27578@t480s.localdomain> <20190219162435.f5zl5harbarwy6bj@shell.armlinux.org.uk> <20190219120000.GB4140@t480s.localdomain> <20190219171414.cvaiw7u2xnd5zk3g@shell.armlinux.org.uk> <20190219123828.GD10959@t480s.localdomain> From: Florian Fainelli Openpgp: preference=signencrypt Autocrypt: addr=f.fainelli@gmail.com; prefer-encrypt=mutual; keydata= mQGiBEjPuBIRBACW9MxSJU9fvEOCTnRNqG/13rAGsj+vJqontvoDSNxRgmafP8d3nesnqPyR xGlkaOSDuu09rxuW+69Y2f1TzjFuGpBk4ysWOR85O2Nx8AJ6fYGCoeTbovrNlGT1M9obSFGQ X3IzRnWoqlfudjTO5TKoqkbOgpYqIo5n1QbEjCCwCwCg3DOH/4ug2AUUlcIT9/l3pGvoRJ0E AICDzi3l7pmC5IWn2n1mvP5247urtHFs/uusE827DDj3K8Upn2vYiOFMBhGsxAk6YKV6IP0d ZdWX6fqkJJlu9cSDvWtO1hXeHIfQIE/xcqvlRH783KrihLcsmnBqOiS6rJDO2x1eAgC8meAX SAgsrBhcgGl2Rl5gh/jkeA5ykwbxA/9u1eEuL70Qzt5APJmqVXR+kWvrqdBVPoUNy/tQ8mYc nzJJ63ng3tHhnwHXZOu8hL4nqwlYHRa9eeglXYhBqja4ZvIvCEqSmEukfivk+DlIgVoOAJbh qIWgvr3SIEuR6ayY3f5j0f2ejUMYlYYnKdiHXFlF9uXm1ELrb0YX4GMHz7QnRmxvcmlhbiBG YWluZWxsaSA8Zi5mYWluZWxsaUBnbWFpbC5jb20+iGYEExECACYCGyMGCwkIBwMCBBUCCAME FgIDAQIeAQIXgAUCVF/S8QUJHlwd3wAKCRBhV5kVtWN2DvCVAJ4u4/bPF4P3jxb4qEY8I2gS 6hG0gACffNWlqJ2T4wSSn+3o7CCZNd7SLSC5BA0ESM+4EhAQAL/o09boR9D3Vk1Tt7+gpYr3 WQ6hgYVON905q2ndEoA2J0dQxJNRw3snabHDDzQBAcqOvdi7YidfBVdKi0wxHhSuRBfuOppu pdXkb7zxuPQuSveCLqqZWRQ+Cc2QgF7SBqgznbe6Ngout5qXY5Dcagk9LqFNGhJQzUGHAsIs hap1f0B1PoUyUNeEInV98D8Xd/edM3mhO9nRpUXRK9Bvt4iEZUXGuVtZLT52nK6Wv2EZ1TiT OiqZlf1P+vxYLBx9eKmabPdm3yjalhY8yr1S1vL0gSA/C6W1o/TowdieF1rWN/MYHlkpyj9c Rpc281gAO0AP3V1G00YzBEdYyi0gaJbCEQnq8Vz1vDXFxHzyhgGz7umBsVKmYwZgA8DrrB0M oaP35wuGR3RJcaG30AnJpEDkBYHznI2apxdcuTPOHZyEilIRrBGzDwGtAhldzlBoBwE3Z3MY 31TOpACu1ZpNOMysZ6xiE35pWkwc0KYm4hJA5GFfmWSN6DniimW3pmdDIiw4Ifcx8b3mFrRO BbDIW13E51j9RjbO/nAaK9ndZ5LRO1B/8Fwat7bLzmsCiEXOJY7NNpIEpkoNoEUfCcZwmLrU +eOTPzaF6drw6ayewEi5yzPg3TAT6FV3oBsNg3xlwU0gPK3v6gYPX5w9+ovPZ1/qqNfOrbsE FRuiSVsZQ5s3AAMFD/9XjlnnVDh9GX/r/6hjmr4U9tEsM+VQXaVXqZuHKaSmojOLUCP/YVQo 7IiYaNssCS4FCPe4yrL4FJJfJAsbeyDykMN7wAnBcOkbZ9BPJPNCbqU6dowLOiy8AuTYQ48m vIyQ4Ijnb6GTrtxIUDQeOBNuQC/gyyx3nbL/lVlHbxr4tb6YkhkO6shjXhQh7nQb33FjGO4P WU11Nr9i/qoV8QCo12MQEo244RRA6VMud06y/E449rWZFSTwGqb0FS0seTcYNvxt8PB2izX+ HZA8SL54j479ubxhfuoTu5nXdtFYFj5Lj5x34LKPx7MpgAmj0H7SDhpFWF2FzcC1bjiW9mjW HaKaX23Awt97AqQZXegbfkJwX2Y53ufq8Np3e1542lh3/mpiGSilCsaTahEGrHK+lIusl6mz Joil+u3k01ofvJMK0ZdzGUZ/aPMZ16LofjFA+MNxWrZFrkYmiGdv+LG45zSlZyIvzSiG2lKy kuVag+IijCIom78P9jRtB1q1Q5lwZp2TLAJlz92DmFwBg1hyFzwDADjZ2nrDxKUiybXIgZp9 aU2d++ptEGCVJOfEW4qpWCCLPbOT7XBr+g/4H3qWbs3j/cDDq7LuVYIe+wchy/iXEJaQVeTC y5arMQorqTFWlEOgRA8OP47L9knl9i4xuR0euV6DChDrguup2aJVU4hPBBgRAgAPAhsMBQJU X9LxBQkeXB3fAAoJEGFXmRW1Y3YOj4UAn3nrFLPZekMeqX5aD/aq/dsbXSfyAKC45Go0YyxV HGuUuzv+GKZ6nsysJ7kCDQRXG8fwARAA6q/pqBi5PjHcOAUgk2/2LR5LjjesK50bCaD4JuNc YDhFR7Vs108diBtsho3w8WRd9viOqDrhLJTroVckkk74OY8r+3t1E0Dd4wHWHQZsAeUvOwDM PQMqTUBFuMi6ydzTZpFA2wBR9x6ofl8Ax+zaGBcFrRlQnhsuXLnM1uuvS39+pmzIjasZBP2H UPk5ifigXcpelKmj6iskP3c8QN6x6GjUSmYx+xUfs/GNVSU1XOZn61wgPDbgINJd/THGdqiO iJxCLuTMqlSsmh1+E1dSdfYkCb93R/0ZHvMKWlAx7MnaFgBfsG8FqNtZu3PCLfizyVYYjXbV WO1A23riZKqwrSJAATo5iTS65BuYxrFsFNPrf7TitM8E76BEBZk0OZBvZxMuOs6Z1qI8YKVK UrHVGFq3NbuPWCdRul9SX3VfOunr9Gv0GABnJ0ET+K7nspax0xqq7zgnM71QEaiaH17IFYGS sG34V7Wo3vyQzsk7qLf9Ajno0DhJ+VX43g8+AjxOMNVrGCt9RNXSBVpyv2AMTlWCdJ5KI6V4 KEzWM4HJm7QlNKE6RPoBxJVbSQLPd9St3h7mxLcne4l7NK9eNgNnneT7QZL8fL//s9K8Ns1W t60uQNYvbhKDG7+/yLcmJgjF74XkGvxCmTA1rW2bsUriM533nG9gAOUFQjURkwI8jvMAEQEA AYkCaAQYEQIACQUCVxvH8AIbAgIpCRBhV5kVtWN2DsFdIAQZAQIABgUCVxvH8AAKCRCH0Jac RAcHBIkHD/9nmfog7X2ZXMzL9ktT++7x+W/QBrSTCTmq8PK+69+INN1ZDOrY8uz6htfTLV9+ e2W6G8/7zIvODuHk7r+yQ585XbplgP0V5Xc8iBHdBgXbqnY5zBrcH+Q/oQ2STalEvaGHqNoD UGyLQ/fiKoLZTPMur57Fy1c9rTuKiSdMgnT0FPfWVDfpR2Ds0gpqWePlRuRGOoCln5GnREA/ 2MW2rWf+CO9kbIR+66j8b4RUJqIK3dWn9xbENh/aqxfonGTCZQ2zC4sLd25DQA4w1itPo+f5 V/SQxuhnlQkTOCdJ7b/mby/pNRz1lsLkjnXueLILj7gNjwTabZXYtL16z24qkDTI1x3g98R/ xunb3/fQwR8FY5/zRvXJq5us/nLvIvOmVwZFkwXc+AF+LSIajqQz9XbXeIP/BDjlBNXRZNdo dVuSU51ENcMcilPr2EUnqEAqeczsCGpnvRCLfVQeSZr2L9N4svNhhfPOEscYhhpHTh0VPyxI pPBNKq+byuYPMyk3nj814NKhImK0O4gTyCK9b+gZAVvQcYAXvSouCnTZeJRrNHJFTgTgu6E0 caxTGgc5zzQHeX67eMzrGomG3ZnIxmd1sAbgvJUDaD2GrYlulfwGWwWyTNbWRvMighVdPkSF 6XFgQaosWxkV0OELLy2N485YrTr2Uq64VKyxpncLh50e2RnyAJ9Za0Dx0yyp44iD1OvHtkEI M5kY0ACeNhCZJvZ5g4C2Lc9fcTHu8jxmEkI= Message-ID: Date: Tue, 19 Feb 2019 09:44:32 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.4.0 MIME-Version: 1.0 In-Reply-To: <20190219123828.GD10959@t480s.localdomain> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 2/19/19 9:38 AM, Vivien Didelot wrote: > Hi Russell, > > On Tue, 19 Feb 2019 17:14:14 +0000, Russell King - ARM Linux admin wrote: >>>>>> +static unsigned long mv88e6xxx_bridge_flags_support(struct dsa_switch *ds) >>>>>> +{ >>>>>> + struct mv88e6xxx_chip *chip = ds->priv; >>>>>> + unsigned long support = 0; >>>>>> + >>>>>> + if (chip->info->ops->port_set_egress_floods) >>>>>> + support |= BR_FLOOD | BR_MCAST_FLOOD; >>>>>> + >>>>>> + return support; >>>>>> +} >>>>> >>>>> I think that it isn't necessary to propagate the notion of bridge flags down >>>>> to the DSA drivers. It might be just enough to add: >>>>> >>>>> port_egress_flood(dsa_switch *ds, int port, bool uc, bool mc) >>>>> >>>>> to dsa_switch_ops and set BR_FLOOD | BR_MCAST_FLOOD from the DSA core, >>>>> if the targeted driver has ds->ops->port_set_egress_flood. What do you think? >>>> >>>> There are two other flags that I haven't covered which the bridge code >>>> expects to be offloaded, and those are the broadcast flood flag and >>>> the learning flag. >>> >>> I see. What does the bridge code do if these flags are set? Does it expect >>> the underlying devices to handle ff:ff:ff:ff:ff:ff magically or does it >>> program this entry into the bridged ports? >> >> The bridge code defaults to all four flags set. See new_nbp() in >> net/bridge/br_if.c: >> >> p->flags = BR_LEARNING | BR_FLOOD | BR_MCAST_FLOOD | BR_BCAST_FLOOD; >> >> bridge(8) doesn't touch BR_BCAST_FLOOD, but it is made available to >> userspace via netlink and IFLA_BRPORT_BCAST_FLOOD. Hence, there's >> no man page documentation for that flag. >> >> According to br_flood() in net/bridge/br_forward.c, it controls >> whether broadcast frames are flooded to all ports or not. Changing >> this flag is merely handled just like the multicast/unicast flooding >> flags - a call is made to set the offloaded flags, and if it isn't >> returned as being supported, a warning is printed. No attempt is >> made to create or change a forwarding entry for the broadcast MAC >> address. > > OK, thanks for the details. The programming of the broadcast MAC address > must be handled in the core then, I will move this from mv88e6xxx up to the > DSA layer later, but that's totally orthogonal here. I am not sure if it makes sense for us to work hard on supporting BR_BCAST_FLOOD, for instance, on Broadcom switches, there does not appear to be an easy way to specify whether broadcast traffic will be flooded or not, it will be. The only way to tsolve that is to create a MDB/FDB entry with negative logic (e.g.: forward to a non-existing/connected port). Every other bridge flag typically maps 1:1 with a corresponding hardware feature, so we should support them. > >> >> bridge(8) does document BR_LEARNING via IFLA_BRPORT_LEARNING: >> >> learning on or learning off >> Controls whether a given port will learn MAC addresses from >> received traffic or not. If learning if off, the bridge will end >> up flooding any traffic for which it has no FDB entry. By >> default this flag is on. >> >>> In the latter case we have almost nothing to do. In the former case, we can >>> make the core call dsa_port_mdb_add on setup and when a VLAN is added. >>> >>> mv88e6xxx tries to be smart and is already doing that and I'm really not a fan. >>> >>> If tomorrow there's a switch capable of simply toggling a bit to do that, >>> we can add a new ops and skip the port_mdb_add call in the core. >>> >>>> I know that the Marvell switches don't have a bit to control the >>>> broadcast flooding, that appears to be controlled via a static entry >>>> in the ATU which would have to be modified as the broadcast flood flag >>>> is manipulated. I don't know how that is handled in other bridges. >>>> >>>> Do we want to include the broadcast flood in the above prototype? >>>> If we go for this, how do we detect which options a switch supports? >>> >>> If the necessary dsa_switch_ops routine is correctly prototyped, having it >>> implemented by a driver or not should be enough to inform the core that the >>> related feature(s) is/are supported by the switch. >>> >>> I'll try to give a bit more context on why I'd prefer this approach, hoping >>> it makes sense: a switch driver does not need to understand bridge flags >>> per-se, the core should give enough abstraction to this layer (and any other >>> net-specifics). The core just needs to know if a driver can program this or >>> that. More importantly, it can easily become messy to maintain switch-cases >>> of arbitrary flags in all drivers and the core. >> >> So, should we go the other way and have: >> >> int (*port_learning)(struct dsa_switch *ds, int port, bool enable); >> int (*port_egress_flood_uc)(struct dsa_switch *ds, int port, bool enable); >> int (*port_egress_flood_mc)(struct dsa_switch *ds, int port, bool enable); >> int (*port_egress_flood_bc)(struct dsa_switch *ds, int port, bool enable); >> >> rather than trying to combine uc/mc into one? It would mean that we'd >> be performing more bus reads/writes, but I guess that doesn't matter >> for these configuration parameters. > > I like this very much. As long as these flags can be programmed in switch > devices, these ops totally make sense. No objections or preference here, whatever works :) -- Florian