From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f173.google.com (mail-pl1-f173.google.com [209.85.214.173]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9DACD1C5F14; Thu, 23 Jan 2025 10:34:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.173 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737628456; cv=none; b=SYywaFWEPthZETvR6a6ILmhm5PXHtFSHbYVjlR7ti4U2EKblTLhvs3zPzzOOyfdWnPH9yltKp0q+YWcEge4/ZWx3Z3nbfQsnHSc5Tb9RQh2zbcXr3yxgNqFhpzQZsWaGtb4TIXNtoziJ08ReoHLc4KsCJpL2ZtDhnTVdi3d+ZXE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737628456; c=relaxed/simple; bh=gsyxcjrfPRlVRrzpZn06sndNy0fCEKZf+MF9IrWJVv4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=a2nf0gtT6VHIz5DG8pwkrcemMA8+c2BpPScj6i+Wec0bR6lEvahoAotchZtFHF19aFq+qD86wKyxZyIXmIzyDq5Dxfq6VBeGgJRSw/BJe2ccY9OtdzB94gLj1oIWxrdT7mSCrvtIXdPtYTLuC16ChTBo4LjzrYTDpzGJAt5Owpk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=Hj8MOap9; arc=none smtp.client-ip=209.85.214.173 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Hj8MOap9" Received: by mail-pl1-f173.google.com with SMTP id d9443c01a7336-21680814d42so11179975ad.2; Thu, 23 Jan 2025 02:34:14 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1737628454; x=1738233254; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=kta1kpUGyKQ79E+obX3jn+pQXvGIiJLwWQQsshofAyo=; b=Hj8MOap9vOH1Qd67NyQEpwKOmF5na4fDUNNh0dUbX5bVS6uzMpJFj9ZOv8z1IxvR/v +z5VEJekKSBnhWQOlzDV4FWLDfWaKI2Mc1Ev6R8FbfOpk2f7aWaCNZgGbNd1uZ+zQ+DI DCQxrbyKll8QoBHMmeMoawvVqFt2o/geCPHhThfRKpskvKcJCgSuRPiEnII9AlI4Nbh9 oxkPJxRp03AIhfRa0LzpVIhNgeEQWcGZFodNIXwPN98GRnKqBwcknN1mmYv3bUPghDQp s05K0/jJK4bKRd/P4R33DjwuUX8i2+N2aW0hAf3+seKeqPge3Zd/BojtmqH9SMM4iRkP cU7w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1737628454; x=1738233254; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=kta1kpUGyKQ79E+obX3jn+pQXvGIiJLwWQQsshofAyo=; b=McmotIzYre9G1NMKND99iGv7J/AAXNJMdY5zq4lwb3nrySnq265lyZhB6KqUNSg86r CGp/A2pHnQ0tvmePffEntDRoc14a7C04Js3JkchpKBR9Hkl6i+qFK4ko3NKvbgK2twOv wDrDgHBFvfAVDAX5+ujsKWy2kyMsYtT3MUB3LNFAMIqgJuKxZI1eQbq/ppXYt2COyASy hq99H/GdOSiXjQRTzPpRu9/uRHeh7xn63AbdMa09D1iy70B68WK3F2wQpJaP/2dQGv+D Hiho5LuSSUqqwcf9bG0Db2FSvl+mphjrm6lXFeFMn4qQ0F0Fc7eZbwctvgV7WRryqg4d Zjlw== X-Forwarded-Encrypted: i=1; AJvYcCUOzSOfl2ePsIac4jmGRu/9/flh15f9LF6r6SSKrCYfdLtHrVEzJrZsy/vwc03kjyhyUoqsYTuI@vger.kernel.org, AJvYcCWDwxP+vjKNhEUjpxqk0jN/x9jhVQkz7FZKF7YbqpC2Po6Sued+vUcyK7+G5EHcepyJtwGBZ4WXuva98t8=@vger.kernel.org X-Gm-Message-State: AOJu0YyIgVzRe7Za11/+lhQLThHf4SiVsicNJLwpIsq2P3Ren0symTzt zwb8jMS/YJ9BPit2Rq620LL4UwzQxX/lp4P91T/cypiPfcYE9EbcOFlNmg== X-Gm-Gg: ASbGncuekiZwUwmKX4J3Up1FzTmwJOaV6mk+n1Vnq7G2dPpq130bKrVhxvXg7JucVgx znBhS/0lJ7mIw3DwHs+AbKUMQX1MAW14rvmZUK13bDk42RHgMGGhhkmhLyDBbTmDxaFVxkb1j11 Z20lNAMQDyLtxF9ZOU2IFo4Oy/EvyXEzw8bKJmpW258peiSSX5jgC5Ipcf9FMj0yJUYn9jdwvbv dfyt7wuHu8ae0+6hG2TfzccB6s1JZO78Yd5PgRNE62kJfM/SJPLrG2kbE8td4UpBvcH1pJtgFYp Y27mYJRN X-Google-Smtp-Source: AGHT+IFQdN/5La2w5kfygfWxH2hklatSF3XsJgt3pGVejkBczyJ0ommryHlN7Qz3ElnZcfB2zwuP0A== X-Received: by 2002:a17:902:ebcd:b0:21c:7e22:7844 with SMTP id d9443c01a7336-21c7e22789fmr246273405ad.51.1737628453532; Thu, 23 Jan 2025 02:34:13 -0800 (PST) Received: from HOME-PC ([223.185.135.17]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-21c2d3e088bsm109217575ad.173.2025.01.23.02.34.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 23 Jan 2025 02:34:13 -0800 (PST) Date: Thu, 23 Jan 2025 16:04:09 +0530 From: Dheeraj Reddy Jonnalagadda To: Wei Fang Cc: Shenwei Wang , Clark Wang , "andrew+netdev@lunn.ch" , "davem@davemloft.net" , "edumazet@google.com" , "kuba@kernel.org" , "pabeni@redhat.com" , "imx@lists.linux.dev" , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH net] net: fec: remove unnecessary DMA mapping of TSO header Message-ID: References: <20250122104307.138659-1-dheeraj.linuxdev@gmail.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Thu, Jan 23, 2025 at 02:58:32AM +0000, Wei Fang wrote: > > Hi Dheeraj, > > I must admit that I misread it too. There is another case in the TSO > header where txq->tx_bounce may be used in some cases. I think > the most correct fix is to make txq->tso_hdrs aligned to 32/64 bytes > when allocating tso_hdrs, then we do not need to use txq->tx_bounce > in fec_enet_txq_put_hdr_tso(), because (bufaddr) & fep->tx_align) > will not be true. This way we can safely remove dma_map_single() > from fec_enet_txq_put_hdr_tso(). Hi Fang, Simon, Thank you for the feedback. I have a clarification question regarding the alignment of txq->tso_hdrs. In the current code, txq->tso_hdrs is allocated using fec_dma_alloc(), which internally calls dma_alloc_coherent(). As I understand it, dma_alloc_coherent() guarantees that the allocated buffer is properly aligned. Given this, should we remove the alignment check ((unsigned long)bufaddr) & fep->tx_align and the associated dma_map_single() logic entirely from fec_enet_txq_put_hdr_tso() as you have suggested? -Dheeraj