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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A2CABD5AE41 for ; Sat, 13 Dec 2025 12:46:15 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id B2B9010EC2E; Sat, 13 Dec 2025 12:42:15 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=permerror (0-bit key) header.d=gmail.com header.i=@gmail.com header.b="MFAsxLEG"; dkim-atps=neutral Received: from mail-qv1-f51.google.com (mail-qv1-f51.google.com [209.85.219.51]) by gabe.freedesktop.org (Postfix) with ESMTPS id 4426410E83B for ; Wed, 8 Oct 2025 14:28:19 +0000 (UTC) Received: by mail-qv1-f51.google.com with SMTP id 6a1803df08f44-791875a9071so73520246d6.1 for ; Wed, 08 Oct 2025 07:28:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1759933698; x=1760538498; darn=lists.freedesktop.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=C3nyMQNps0AyLL97xzttuk+phB0DdoZh7JjDzOjB4po=; b=MFAsxLEGjCRTAdsXcqihNtVC6waBb8ZYlCNYSdQlhMwUM8A83fJpW0lpgIPTODBtrk FPjjNaKjD24dI8fbVDpcBBhTT90YCn6fwVMnrGk/HnQ2STGx2tMi1O+dNb+/AkunXV+b mFx8+0o8LMkIglLKMAgUU5lXRWpOXFIjCMqlB+aGYrT7Mg3TgTspT4+nJsqAthqvb9Gi ODmc78XC2Jn1v69t7tTqVyFIHmkVWlPxCGyeCWy6CCITohfuwoQk8yyjvwox9D7W8SY0 N+sHpM7qiv/TSrdYendR4j5ss/Op4gypgH8on+NiAH/ci1naS2PHbfHNZdE9+rrmB5D7 5qNQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1759933698; x=1760538498; 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=C3nyMQNps0AyLL97xzttuk+phB0DdoZh7JjDzOjB4po=; b=gFSatKeR1aZSyV3O53PCFIeknLwZRls4HmXeH7kJXgxweCH95RPHL3DtzC3p7+nKOj RD/tSpo1OjrTYSO8dA4xrGKtgHRzDtTGPy+MOrHAM+RYJncyKdfadjJFboglWci/GD0E Lqj/z8UNCk/Wp4iHCdY4FjSbmqZWlplrQRTg7NVVHU9LYmkGbQu/KqxoVN3Sooac8MrC xI7FupCSPGL+e5+tzTB+gXyPNxzuVrrVulK9qUju/70h+7USHwpR+p3nNxbMTu8SdruJ kmdu51iPC5fh2iWABvNu6m1Nl33I+mvj+f6FJ7mMOBnqAmAvhBSD+szycNiHZvtll6D4 kPzA== X-Forwarded-Encrypted: i=1; AJvYcCW+KJs87q0ZTPcEL7sSiPumGylec3FuEuaixaRjDK/EGoYtxGEp0RG6LbQKnGYSyO/h4p6+Z4W2@lists.freedesktop.org X-Gm-Message-State: AOJu0YxEFL3N/mmH+dHMmhnWlBmc0do0SmMp2wdmroRl/HuvMk5z2J3E rMg6cjJv7dYxZIyDmrfdqcWHGc0WiLxGW+tb9y0XRm9lOadDvD50YC4z X-Gm-Gg: ASbGncu00puOeUxg/Xyp8g4GtEwpv0BEcgRJynTBYt9YsQsx6VgJqgPqgiZYYZUviIh bWBtNLzTpHsXAFE52i2mkh/Hq7Z1FgFNw8NoI4Q7KF8O+18wPEri+x0T0DaNtDhhpcDfexv6uAB zXXM4xcXTbndWYVjBVPhKVgDxEBUnNv6Y2OR7cl4070ouIHPSqCaTWceaZskNSN8eyGwaiSKrSn xTRIQCe0nHWIsTOGCM+V03UXTEn0HQ5MhcxOiyUvmZcM9F+rT1/X6NQo12xiv67Sd/kRWSN0xY6 ycDGTCP9uN2IhwIijuzJy+yJYPeXoCRKKs1S3cvnNzttwixjO/+WGWmTHMKc4P7okNeqFMGlo5Z Q0WQuixZ/a95RMco/sdNUm22ayWLfDnuoIOAVRVyz3SI= X-Google-Smtp-Source: AGHT+IFntZefp3Ss0mi+6jECEAXuwb7eOj/bzue7nh8gRQKVbgbOiMWHYq2oEKWHI2USmbbKcqsDDg== X-Received: by 2002:a05:6214:2a87:b0:789:d698:d384 with SMTP id 6a1803df08f44-87b2103104bmr48809406d6.20.1759933697907; Wed, 08 Oct 2025 07:28:17 -0700 (PDT) Received: from localhost ([12.22.141.131]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-878be61f6bcsm163723216d6.65.2025.10.08.07.28.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 08 Oct 2025 07:28:17 -0700 (PDT) Date: Wed, 8 Oct 2025 10:28:15 -0400 From: Yury Norov To: Danilo Krummrich Cc: Joel Fernandes , Alexandre Courbot , linux-kernel@vger.kernel.org, rust-for-linux@vger.kernel.org, dri-devel@lists.freedesktop.org, Alistair Popple , Miguel Ojeda , Alex Gaynor , Boqun Feng , Gary Guo , bjorn3_gh@protonmail.com, Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross , David Airlie , Simona Vetter , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , John Hubbard , Timur Tabi , joel@joelfernandes.org, Elle Rhumsaa , Daniel Almeida , Andrea Righi , nouveau@lists.freedesktop.org Subject: Re: [PATCH v6 0/5] Introduce bitfield and move register macro to rust/kernel/ Message-ID: References: <20251003154748.1687160-1-joelagnelf@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Mailman-Approved-At: Sat, 13 Dec 2025 12:40:49 +0000 X-BeenThere: nouveau@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Nouveau development list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: nouveau-bounces@lists.freedesktop.org Sender: "Nouveau" On Wed, Oct 08, 2025 at 12:08:59AM +0200, Danilo Krummrich wrote: > Regarding the bitfields for page table management: Are we > sure that we can use raw bitfields for this? As per my current understanding we can't. Bitfields are not suitable for direct I/O and considered as a data storage. In the current scheme: regs::NV_PFALCON_FALCON_DMATRFBASE::default() .set_base((dma_start >> 8) as u32) .write(bar, &E::ID); we account for endianess in the .write() method, which would be a part of register API, not bitfields. FYI: ARM64 is in process of dropping BE, and Linus announced the end of BE support for RISC-V: https://lore.kernel.org/all/CAHk-=wgYcOiFvsJzFb+HfB4n6Wj6zM5H5EghUMfpXSCzyQVSfA@mail.gmail.com/ Thanks, Yury