From patchwork Mon Mar 15 18:49:26 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alex Elder X-Patchwork-Id: 400527 Delivered-To: patch@linaro.org Received: by 2002:a02:8562:0:0:0:0:0 with SMTP id g89csp3673800jai; Mon, 15 Mar 2021 11:50:37 -0700 (PDT) X-Google-Smtp-Source: ABdhPJyKll4oSOmt9Cbs5H73m2kaNmkJYdZnXT9T/oQcjYhVvOyGMQsSNaM8po7nQMNH8jk1B68D X-Received: by 2002:a05:6402:518d:: with SMTP id q13mr31735816edd.313.1615834237682; Mon, 15 Mar 2021 11:50:37 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1615834237; cv=none; d=google.com; s=arc-20160816; b=D00UarPEJh9tZOtBbRBXql9Br2FX/8W+TbPcNh7JHwyBJXu93Tj0VhvD8U1QIn7/bv i+WzJDJFAjyx3Ukt8hMIzmRetG+EoDcFqlPywlYpUldNdg6hgAvINnXru6wzjDx/9mQm OvzQS7cLw/ucoFQLxlwTnMfYavIGWvejd/ajt9erdhXvkwNb3HDXNsX9+yosBqRSFaZl UTpJpF5io0hbZ1+7BDZr9EceP4Q1NoNuOO8znAQYiAvOu+3hQvGnoRMsvwu7JkU+HPLq cYGEiazSAXMMRnVK8xtoistWaRpPRic5zit3Gzy0pCpX6j4qlbblEc4rxTtf4prPc0OC V85w== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature; bh=Gzfg71vsx3VY2377GfG2oAcRHO8kBLm5otxChzsZJP0=; b=Ji5bpOY+OpY07lWC6Epqi9uJXV7h2h3X/5vJpJZo9mfaqg3xAe0uBMTS/RkNiSVvdv 9nmcztOcfHNThfyhyplyC1y2Qa4iRVba7efoulunmJHwkexfVV/ZZwR3uurrFVu9g3lB ddoX+0q9PsXDT5vfYGxACyNGMAzu4bjOl9NXVCEJpv5K1c0u8lKtkUsAxzs3VZvzEOza uSOsQuunXumUrx70s9nNo5/bg6kAQgceJ0ciBFPMe6y7YW6k2EVIeaLe08gX8zNVP3Ct mvWh3s3viZUMYHG6FGhjNkJAqlXlWvsyzXDxAuN84jsCMGoVTOsX0V6Rbnt22jmXw8rE bbyg== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b="siTp/EcD"; spf=pass (google.com: domain of netdev-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=netdev-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id x27si11624279ejb.603.2021.03.15.11.50.37; Mon, 15 Mar 2021 11:50:37 -0700 (PDT) Received-SPF: pass (google.com: domain of netdev-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b="siTp/EcD"; spf=pass (google.com: domain of netdev-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=netdev-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232137AbhCOSuF (ORCPT + 8 others); Mon, 15 Mar 2021 14:50:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51654 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231964AbhCOSth (ORCPT ); Mon, 15 Mar 2021 14:49:37 -0400 Received: from mail-io1-xd29.google.com (mail-io1-xd29.google.com [IPv6:2607:f8b0:4864:20::d29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9BF8FC06174A for ; Mon, 15 Mar 2021 11:49:37 -0700 (PDT) Received: by mail-io1-xd29.google.com with SMTP id f20so34480638ioo.10 for ; Mon, 15 Mar 2021 11:49:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=Gzfg71vsx3VY2377GfG2oAcRHO8kBLm5otxChzsZJP0=; b=siTp/EcDCURtedClVwE0kYOM6IqyOaIr3aFJkBce7eWylsrNmhEKOD3/4orkrGH+KA gouAetKh8XjyZMjjGsi3NJd//K7wllrCij7gdrwhVFw/RdkUcmRPoJhQGevQ2Tyqnjb8 Uqxs+YSfV30PLd79wJuG+1LGhamiOG8GbwaRpUYZ2soEx3mPg9YgAveJ8sW9SCy9iyaX r284yDsdz1/3XTn6Mdq2B3vW6WYy/Fkj+ZFApRNcOdHXKqPprY16AqxKF8hoH2BDVb2g /ru7FuQjI63zbgzbe8ylg0qD46nIoNWcgRr07mnGLRe8Eq/uNeDykuo+czdPX/IwJ9Jn PHGQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=Gzfg71vsx3VY2377GfG2oAcRHO8kBLm5otxChzsZJP0=; b=Yn9Zhmb5aOkQ05iZDNFhV1yOBga/a+G5Ju6obAgBzKC1Or43tuZuN7IDlyHqdVPvSy wT4HIGB/Lnfl5TdH4tsuCmQzaolbh6I4qCkH0fC9U7Cyc511c0b7H0KMl9I/CAE7tCtA +YnbMW/ebuPhyeiKukpF/cI7MHz52CBj82kxGigrK+H1hzvlA8awiKBT/xin+pdn/6yR k5T8eiWLRgmXsHXzhvRL3kMlUiDVOEb6uIiURKfekb3zfqGkujlq8NhvJ2ShUWcX8iNx bvTP0yQSghlR3WTNETk+do4skDPvE+kHbfmJORaIXiQeOi5g/GR5CbhkShCqS0TwSr2H +0uw== X-Gm-Message-State: AOAM530py+CkbSSUAOkV91ENM1k4YHrBuopebym2JKsf5t7ZELoNU8Ly XMmzMMXvOqF/Z4yJFlCxrwRc0g== X-Received: by 2002:a02:94a9:: with SMTP id x38mr10824603jah.50.1615834177131; Mon, 15 Mar 2021 11:49:37 -0700 (PDT) Received: from localhost.localdomain (c-73-185-129-58.hsd1.mn.comcast.net. [73.185.129.58]) by smtp.gmail.com with ESMTPSA id a5sm8212162ilk.14.2021.03.15.11.49.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 15 Mar 2021 11:49:36 -0700 (PDT) From: Alex Elder To: subashab@codeaurora.org, stranche@codeaurora.org, davem@davemloft.net, kuba@kernel.org Cc: sharathv@codeaurora.org, bjorn.andersson@linaro.org, evgreen@chromium.org, cpratapa@codeaurora.org, David.Laight@ACULAB.COM, olteanv@gmail.com, alexander.duyck@gmail.com, elder@kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Alexander Duyck Subject: [PATCH net-next v5 4/6] net: qualcomm: rmnet: use masks instead of C bit-fields Date: Mon, 15 Mar 2021 13:49:26 -0500 Message-Id: <20210315184928.2913264-5-elder@linaro.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20210315184928.2913264-1-elder@linaro.org> References: <20210315184928.2913264-1-elder@linaro.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The actual layout of bits defined in C bit-fields (e.g. int foo : 3) is implementation-defined. Structures defined in address this by specifying all bit-fields twice, to cover two possible layouts. I think this pattern is repetitive and noisy, and I find the whole notion of compiler "bitfield endianness" to be non-intuitive. Stop using C bit-fields for the command/data flag and the pad length fields in the rmnet_map structure, and define a single-byte flags field instead. Define a mask for the single-bit "command" flag, and another mask for the encoded pad length. The content of both fields can be accessed using a simple bitwise AND operation. Signed-off-by: Alex Elder Reviewed-by: Bjorn Andersson Reviewed-by: Alexander Duyck --- v4: - Don't use u8_get_bits() to access the pad length - Added BUILD_BUG_ON() to ensure field width is adequate v3: - Use BIT(x) and don't use u8_get_bits() for the command flag .../ethernet/qualcomm/rmnet/rmnet_handlers.c | 4 ++-- .../ethernet/qualcomm/rmnet/rmnet_map_data.c | 4 +++- include/linux/if_rmnet.h | 23 ++++++++----------- 3 files changed, 15 insertions(+), 16 deletions(-) -- 2.27.0 diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c index 2a6b2a609884c..0be5ac7ab2617 100644 --- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c +++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c @@ -61,7 +61,7 @@ __rmnet_map_ingress_handler(struct sk_buff *skb, u16 len, pad; u8 mux_id; - if (map_header->cd_bit) { + if (map_header->flags & MAP_CMD_FLAG) { /* Packet contains a MAP command (not data) */ if (port->data_format & RMNET_FLAGS_INGRESS_MAP_COMMANDS) return rmnet_map_command(skb, port); @@ -70,7 +70,7 @@ __rmnet_map_ingress_handler(struct sk_buff *skb, } mux_id = map_header->mux_id; - pad = map_header->pad_len; + pad = map_header->flags & MAP_PAD_LEN_MASK; len = ntohs(map_header->pkt_len) - pad; if (mux_id >= RMNET_MAX_LOGICAL_EP) diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c index 3af68368fc315..e7d0394cb2979 100644 --- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c +++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c @@ -280,6 +280,7 @@ struct rmnet_map_header *rmnet_map_add_map_header(struct sk_buff *skb, return map_header; } + BUILD_BUG_ON(MAP_PAD_LEN_MASK < 3); padding = ALIGN(map_datalen, 4) - map_datalen; if (padding == 0) @@ -293,7 +294,8 @@ struct rmnet_map_header *rmnet_map_add_map_header(struct sk_buff *skb, done: map_header->pkt_len = htons(map_datalen + padding); - map_header->pad_len = padding & 0x3F; + /* This is a data packet, so the CMD bit is 0 */ + map_header->flags = padding & MAP_PAD_LEN_MASK; return map_header; } diff --git a/include/linux/if_rmnet.h b/include/linux/if_rmnet.h index 8c7845baf3837..a02f0a3df1d9a 100644 --- a/include/linux/if_rmnet.h +++ b/include/linux/if_rmnet.h @@ -6,21 +6,18 @@ #define _LINUX_IF_RMNET_H_ struct rmnet_map_header { -#if defined(__LITTLE_ENDIAN_BITFIELD) - u8 pad_len:6; - u8 reserved_bit:1; - u8 cd_bit:1; -#elif defined (__BIG_ENDIAN_BITFIELD) - u8 cd_bit:1; - u8 reserved_bit:1; - u8 pad_len:6; -#else -#error "Please fix " -#endif - u8 mux_id; - __be16 pkt_len; + u8 flags; /* MAP_CMD_FLAG, MAP_PAD_LEN_MASK */ + u8 mux_id; + __be16 pkt_len; /* Length of packet, including pad */ } __aligned(1); +/* rmnet_map_header flags field: + * PAD_LEN: number of pad bytes following packet data + * CMD: 1 = packet contains a MAP command; 0 = packet contains data + */ +#define MAP_PAD_LEN_MASK GENMASK(5, 0) +#define MAP_CMD_FLAG BIT(7) + struct rmnet_map_dl_csum_trailer { u8 reserved1; #if defined(__LITTLE_ENDIAN_BITFIELD)