From patchwork Wed Oct 4 22:43:53 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Linus Walleij X-Patchwork-Id: 13409655 X-Patchwork-Delegate: kuba@kernel.org Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D556510780 for ; Wed, 4 Oct 2023 22:44:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="POYH5bxd" Received: from mail-lf1-x135.google.com (mail-lf1-x135.google.com [IPv6:2a00:1450:4864:20::135]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D2CB0BD for ; Wed, 4 Oct 2023 15:43:58 -0700 (PDT) Received: by mail-lf1-x135.google.com with SMTP id 2adb3069b0e04-5031ccf004cso413862e87.2 for ; Wed, 04 Oct 2023 15:43:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1696459437; x=1697064237; darn=vger.kernel.org; h=cc:to:message-id:content-transfer-encoding:mime-version:subject :date:from:from:to:cc:subject:date:message-id:reply-to; bh=9lwczMSD98fajqNb6/mKrj3RaEEEuYyEsq8ivVzfMMQ=; b=POYH5bxdLtDONsG8xkJhf57vUr666w/IZd8CkVh+HrM9Jgk3jXzlryB7C8j2Fec+4k TVvG6IIVv5bFPzX075hMTB85vcq8TehTWRwD2i75us+1yit6gVi20cECGGUGrXm2b/rz tQnwNOjrHe2y7N8zbnEEOI/E3o7IEfms+uS/hCAVl50nQGeflIcqh78ouiqtlREs0q/z ZjRcNIvvyZCcmSDf1BWPmkCQVIgZTuGIASNCnsnpr744JbgFyWT8bHSMrSnco4EmZ0+D 5kdexPl7+g241TFGsIXyqBb6VvfHXaariezadOkzWwbH4TbFflgYO9v3Iq1JtQt7FXOl PlTw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1696459437; x=1697064237; h=cc:to:message-id:content-transfer-encoding:mime-version:subject :date:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=9lwczMSD98fajqNb6/mKrj3RaEEEuYyEsq8ivVzfMMQ=; b=tR7omT6ICMTIjuWwIjd22qBy3noOmZoE71oDvEeZWPLFku0yatRiBP7BCMLG66XQsf kXwNT1JudEPm1vZL5NQMSnM21Wr65Kb58dT13DetYFGkfW82twS3SZrNWJoqDRC1Xn68 VcBEMJuNckLtJSMyu9zQq3YkVQ6ojvhvgVsR2toMkTtKDJcTJ2DA9LX5v7mU6xSHs+Gx TDnsOIw28vqomG9VKqIgwbIS7kYWS21fAGhF9Yi2EDfrMKVcgPAPnLL9vXnqGr0V3Izb Uhs+PMiCG5UfZhV93cg4ZTUdKIVZSg1DmW5anKVr+ptuv6nqnhh2JcPbTPJ/LbR3lJlt hWPw== X-Gm-Message-State: AOJu0YxNIxRhw1YDO0r238DtUc9KmvPx0BLOcoHh9k1d7qd+p1HEfrrw 78gJ7iXm/ZLTwJgYpagAAb+4ycW4RIcbcpF7NKU= X-Google-Smtp-Source: AGHT+IFVBPiVbnjN/jU9NmwiTjdif63YN8GR8K1uocl6DgAhrT5E0sqBJnT5eMBGql/IHcwqlh5z5g== X-Received: by 2002:a05:6512:10ca:b0:505:6785:d6c6 with SMTP id k10-20020a05651210ca00b005056785d6c6mr4328310lfg.54.1696459436663; Wed, 04 Oct 2023 15:43:56 -0700 (PDT) Received: from [192.168.1.2] (c-21d3225c.014-348-6c756e10.bbcust.telenor.se. [92.34.211.33]) by smtp.gmail.com with ESMTPSA id j13-20020a19f50d000000b005041b7735dbsm41646lfb.53.2023.10.04.15.43.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 04 Oct 2023 15:43:56 -0700 (PDT) From: Linus Walleij Date: Thu, 05 Oct 2023 00:43:53 +0200 Subject: [PATCH net-next v4] net: ixp4xx_eth: Support changing the MTU Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20231005-ixp4xx-eth-mtu-v4-1-08c66ed0bc69@linaro.org> X-B4-Tracking: v=1; b=H4sIAKjqHWUC/3XNSwrDIBgE4KsE17X4SIh21XuULtT8TYTWBLViC bl7xVVK6HIYvpkVBfAWAro0K/KQbLCzK6E9NchMyo2A7VAyYoRxIhnHNi9tzhjihF/xjQ1p6dD DAyRnqKDFw8PmOnhDDiJ2kCO6l2ayIc7+U58Srf2/0UQxxRKE0JIIoJpdn9YpP59nP9atxPa+O 3hWPJfcKKX7zmhy8HzvxcHz4o2mApQiMGj547dt+wKpf1iPNwEAAA== To: Krzysztof Halasa , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Jacob Keller , Linus Walleij X-Mailer: b4 0.12.3 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_BLOCKED, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-Delegate: kuba@kernel.org As we don't specify the MTU in the driver, the framework will fall back to 1500 bytes and this doesn't work very well when we try to attach a DSA switch: eth1: mtu greater than device maximum ixp4xx_eth c800a000.ethernet eth1: error -22 setting MTU to 1504 to include DSA overhead After locating an out-of-tree patch in OpenWrt I found suitable code to set the MTU on the interface and ported it and updated it. Now the MTU gets set properly. Reviewed-by: Jacob Keller Signed-off-by: Linus Walleij --- Changes in v4: - Rebase on the merged patch "net: ixp4xx_eth: Specify min/max MTU" so it can be easily applied. - Link to v3: https://lore.kernel.org/r/20230928-ixp4xx-eth-mtu-v3-1-cb18eaa0edb9@linaro.org Changes in v3: - Fix some coding style and initialization style. - Collect Jacob's review tag. - Link to v2: https://lore.kernel.org/r/20230925-ixp4xx-eth-mtu-v2-1-393caab75cb0@linaro.org Changes in v2: - Don't just set min/max MTU: implement the interface for actually changing it as well. - Link to v1: https://lore.kernel.org/r/20230923-ixp4xx-eth-mtu-v1-1-9e88b908e1b2@linaro.org --- drivers/net/ethernet/xscale/ixp4xx_eth.c | 67 +++++++++++++++++++++++++++++--- 1 file changed, 61 insertions(+), 6 deletions(-) --- base-commit: f22d2ec3d4e72d1f24153533ba0ce8fa926cdd37 change-id: 20230923-ixp4xx-eth-mtu-c041d7efe932 Best regards, diff --git a/drivers/net/ethernet/xscale/ixp4xx_eth.c b/drivers/net/ethernet/xscale/ixp4xx_eth.c index 8f40287c8d58..910094ab553c 100644 --- a/drivers/net/ethernet/xscale/ixp4xx_eth.c +++ b/drivers/net/ethernet/xscale/ixp4xx_eth.c @@ -64,7 +64,15 @@ #define POOL_ALLOC_SIZE (sizeof(struct desc) * (RX_DESCS + TX_DESCS)) #define REGS_SIZE 0x1000 -#define MAX_MRU 1536 /* 0x600 */ + +/* MRU is said to be 14320 in a code dump, the SW manual says that + * MRU/MTU is 16320 and includes VLAN and ethernet headers. + * See "IXP400 Software Programmer's Guide" section 10.3.2, page 161. + * + * FIXME: we have chosen the safe default (14320) but if you can test + * jumboframes, experiment with 16320 and see what happens! + */ +#define MAX_MRU (14320 - VLAN_ETH_HLEN) #define RX_BUFF_SIZE ALIGN((NET_IP_ALIGN) + MAX_MRU, 4) #define NAPI_WEIGHT 16 @@ -1183,6 +1191,54 @@ static void destroy_queues(struct port *port) } } +static int ixp4xx_do_change_mtu(struct net_device *dev, int new_mtu) +{ + struct port *port = netdev_priv(dev); + struct npe *npe = port->npe; + int framesize, chunks; + struct msg msg = {}; + + /* adjust for ethernet headers */ + framesize = new_mtu + VLAN_ETH_HLEN; + /* max rx/tx 64 byte chunks */ + chunks = DIV_ROUND_UP(framesize, 64); + + msg.cmd = NPE_SETMAXFRAMELENGTHS; + msg.eth_id = port->id; + + /* Firmware wants to know buffer size in 64 byte chunks */ + msg.byte2 = chunks << 8; + msg.byte3 = chunks << 8; + + msg.byte4 = msg.byte6 = framesize >> 8; + msg.byte5 = msg.byte7 = framesize & 0xff; + + if (npe_send_recv_message(npe, &msg, "ETH_SET_MAX_FRAME_LENGTH")) + return -EIO; + netdev_dbg(dev, "set MTU on NPE %s to %d bytes\n", + npe_name(npe), new_mtu); + + return 0; +} + +static int ixp4xx_eth_change_mtu(struct net_device *dev, int new_mtu) +{ + int ret; + + /* MTU can only be changed when the interface is up. We also + * set the MTU from dev->mtu when opening the device. + */ + if (dev->flags & IFF_UP) { + ret = ixp4xx_do_change_mtu(dev, new_mtu); + if (ret < 0) + return ret; + } + + dev->mtu = new_mtu; + + return 0; +} + static int eth_open(struct net_device *dev) { struct port *port = netdev_priv(dev); @@ -1233,6 +1289,8 @@ static int eth_open(struct net_device *dev) if (npe_send_recv_message(port->npe, &msg, "ETH_SET_FIREWALL_MODE")) return -EIO; + ixp4xx_do_change_mtu(dev, dev->mtu); + if ((err = request_queues(port)) != 0) return err; @@ -1375,6 +1433,7 @@ static int eth_close(struct net_device *dev) static const struct net_device_ops ixp4xx_netdev_ops = { .ndo_open = eth_open, .ndo_stop = eth_close, + .ndo_change_mtu = ixp4xx_eth_change_mtu, .ndo_start_xmit = eth_xmit, .ndo_set_rx_mode = eth_set_mcast_list, .ndo_eth_ioctl = eth_ioctl, @@ -1489,12 +1548,8 @@ static int ixp4xx_eth_probe(struct platform_device *pdev) ndev->dev.dma_mask = dev->dma_mask; ndev->dev.coherent_dma_mask = dev->coherent_dma_mask; - /* Maximum frame size is 16320 bytes and includes VLAN and - * ethernet headers. See "IXP400 Software Programmer's Guide" - * section 10.3.2, page 161. - */ ndev->min_mtu = ETH_MIN_MTU; - ndev->max_mtu = 16320 - VLAN_ETH_HLEN; + ndev->max_mtu = MAX_MRU; netif_napi_add_weight(ndev, &port->napi, eth_poll, NAPI_WEIGHT);