From nobody Sun Feb 8 12:14:30 2026 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 991FC2E6CA5 for ; Tue, 30 Dec 2025 10:16:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767089766; cv=none; b=BK7n2pxzTWnWFaodCW5eul2FPRHn00Ku+M0nF2czjb1ffQ9WEQQs+ojhmVQSC40P4NrMJuiiVvZDG7GVWvcGmkzOcS4MC1951dhYwtwc/7RaG3VdNk4eja2AzUxg0tXW7/wlB0ARhnganUMXey/j3NBE0pxNCaSHUeVd4w+VO44= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767089766; c=relaxed/simple; bh=3EF4beueqssYSrJr7jAiyWtRxi/ynmIi31SbgxtAbxk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=J3+TxGQ4LBTyHDx+1Pmdpctw2Jsnz2KLAej85dHTlodzdOPJfmxwzJPCamMy302pbr/VLixAxjFfdkV2/UkFY7zmREwc8fmpvYfNHnmfKAl/lYMikQEg2+3dG2FJH37O+cFoA+qFK7VRGSojzNSvehHVnd53L30R3ynDDeDnJSQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=Ig5ep5oQ; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b=Z7FQ8isQ; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Ig5ep5oQ"; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b="Z7FQ8isQ" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1767089763; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=jlkdUJvLxIuG9RkypEQ1odBgc8hsD/vyeqVzWJtThQg=; b=Ig5ep5oQfWTSijshrhmphh1kZkOF0/D3T4IO0PkmzcUJ9LMbjzNp+u6jZ10CCW4QVl+zOX Tya5yn+N8eUQwS6+O8S7fVAFMqh66YiNsMIbM3BzPQPZVUlRDLR/1xsJMoY6lRsszddlWC jG9Ke2bvMqJsbN/EmJMgf0wOxMckYuI= Received: from mail-wr1-f70.google.com (mail-wr1-f70.google.com [209.85.221.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-392-gvxps1pJPMuqj9XMCJYQTQ-1; Tue, 30 Dec 2025 05:16:02 -0500 X-MC-Unique: gvxps1pJPMuqj9XMCJYQTQ-1 X-Mimecast-MFC-AGG-ID: gvxps1pJPMuqj9XMCJYQTQ_1767089761 Received: by mail-wr1-f70.google.com with SMTP id ffacd0b85a97d-430fdaba167so5224335f8f.3 for ; Tue, 30 Dec 2025 02:16:01 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=google; t=1767089760; x=1767694560; 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=jlkdUJvLxIuG9RkypEQ1odBgc8hsD/vyeqVzWJtThQg=; b=Z7FQ8isQq14I1KaSH1zw/UXjxfl4vbX2ZEFt82yb0xF9HrF5cGDa24nsifnCDpFx+d ZJVEGcAaQcquK7ruSxLov+mmtNZm6Z1cY1l5h155mMjVQFrApi3LDOd28jAvqGiPFSet LdpFwLkIn/ZjyF4pQkW4zmY53q3amnxzSS9IUxJai+v6NViiTMCFUhYnCxRcxm5uZESt Aw1V9bQXYW7Fl52Vl/JGM8eclURT8majQKzcf5P/SfKE9+ou1xx5sGSTMLsUXNKdhfjL R5z2Dr7EADU/6enDMzGahCI5t7S/9eDh/HfytF8+YyTZ1fvM3mPQmNW/lQt+yUskX7rr 0rRw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1767089760; x=1767694560; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-gg:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=jlkdUJvLxIuG9RkypEQ1odBgc8hsD/vyeqVzWJtThQg=; b=KmvsL+Iz0MRzPZAJS4OyZkanlZqy5Lv0Ssixj5aAbejFG3PLI/rrk+Gv3prT04WFmE WC3+BK4dZKd0WuXP26HKBfSemHYAtSq9Whc21fh21X2afa7ooKzGw+KHnpSYNEadaXV/ fLS/u+nhg5E1HGFsWCT/4Z1Lw7Wt7hiE8aeCoS1gDt058Jicw9eU7TmJqaqQusEusKar +qOiLfcVsxrF2226IU7m0aPiOtNib54wCWvJdTCDWTQVxzBQDWnKB5pUsnuLWeQ+ONz0 WGknRy0cR7HsR1LTebCQ5ktv3BlXPC3TGfRaH5FGAfU66XMejkH+7UN27aVZTphIv1RP ElIQ== X-Gm-Message-State: AOJu0YwTCT1GIaRq0RKB76CKmH/gE3PjwIYJMkBD/ndaYNedrkl2CJVA 1jLBeNrz3gcWWEbODgU+YasDQwMe08DBsc3aMQqZCcFsdkz578BFbczqzlKJNmaaRTs6IGD6Xh/ KLjcOr/B9M8g0MwsHlZBeo1uLk/AidgKtCVFJUL1GM4K7fFevDTzuqxWPrqmMh5ZX8xkFdiQGMq 6F8TMFvqWtjX/dMXQjfFMOhBIiIfWqth6KkIwIMIDvTiE= X-Gm-Gg: AY/fxX5lN5jcoSYXq0VXonKEkXUkdu2wylyszXeGmsTGl29BqwTuryZfUJpeSUtlTAc j9uKwdr6pCs7ZvrBLD4py5U94ohYcNhTGI5v5WIAJCBHd3rMoUnRFLFwu17dVkaRNkAn2Mh47tU 0k2mZy7PxL8G9/3QMt3igwqBmwj7/TwnL8q1z9gxbzTkCQRjZmPYwxHL0EgeLObdKeH5SLsSGOi xHwhHI2scEP04W4e+32UB+rIl9W0elqHv4kfFJisVTS4klU6ebqAbNEOwDycxGtrfu8LkoDwwaH JUbaIDpI8vaz5kf3lgPIWWo9L1hy6xCuEWEx6govCqOWyUJHHmK15N4KLuspGAb3S/9XYjZz9j7 JZ613CtN/7iqQLZoMBIv5vO6GFnp4vXKPoA== X-Received: by 2002:a05:6000:2906:b0:430:fd84:3171 with SMTP id ffacd0b85a97d-4324e4c9e98mr39750144f8f.22.1767089760516; Tue, 30 Dec 2025 02:16:00 -0800 (PST) X-Google-Smtp-Source: AGHT+IHondA4WovcXdLOT45Lj3uVr7rduhIOKgQxT45AJwE7sF5CS5LqWM7ii/WKiPGqmcKK8QLbHQ== X-Received: by 2002:a05:6000:2906:b0:430:fd84:3171 with SMTP id ffacd0b85a97d-4324e4c9e98mr39750079f8f.22.1767089759925; Tue, 30 Dec 2025 02:15:59 -0800 (PST) Received: from redhat.com (IGLD-80-230-31-118.inter.net.il. [80.230.31.118]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-4324ea830fesm68448837f8f.20.2025.12.30.02.15.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 30 Dec 2025 02:15:59 -0800 (PST) Date: Tue, 30 Dec 2025 05:15:56 -0500 From: "Michael S. Tsirkin" To: linux-kernel@vger.kernel.org Cc: Cong Wang , Jonathan Corbet , Olivia Mackall , Herbert Xu , Jason Wang , Paolo Bonzini , Stefan Hajnoczi , Eugenio =?utf-8?B?UMOpcmV6?= , "James E.J. Bottomley" , "Martin K. Petersen" , Gerd Hoffmann , Xuan Zhuo , Marek Szyprowski , Robin Murphy , Stefano Garzarella , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Petr Tesarik , Leon Romanovsky , Jason Gunthorpe , linux-doc@vger.kernel.org, linux-crypto@vger.kernel.org, virtualization@lists.linux.dev, linux-scsi@vger.kernel.org, iommu@lists.linux.dev, kvm@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH RFC 04/13] docs: dma-api: document DMA_ATTR_CPU_CACHE_CLEAN Message-ID: <818c7ea78e43b93d1bb3995738a217e5e414e208.1767089672.git.mst@redhat.com> References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-Mailer: git-send-email 2.27.0.106.g8ac3dc51b1 X-Mutt-Fcc: =sent Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Document DMA_ATTR_CPU_CACHE_CLEAN as implemented in the previous patch. Signed-off-by: Michael S. Tsirkin --- Documentation/core-api/dma-attributes.rst | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/Documentation/core-api/dma-attributes.rst b/Documentation/core= -api/dma-attributes.rst index 0bdc2be65e57..1d7bfad73b1c 100644 --- a/Documentation/core-api/dma-attributes.rst +++ b/Documentation/core-api/dma-attributes.rst @@ -148,3 +148,12 @@ DMA_ATTR_MMIO is appropriate. For architectures that require cache flushing for DMA coherence DMA_ATTR_MMIO will not perform any cache flushing. The address provided must never be mapped cacheable into the CPU. + +DMA_ATTR_CPU_CACHE_CLEAN +------------------------ + +This attribute indicates the CPU will not dirty any cacheline overlapping = this +DMA_FROM_DEVICE/DMA_BIDIRECTIONAL buffer while it is mapped. This allows +multiple small buffers to safely share a cacheline without risk of data +corruption, suppressing DMA debug warnings about overlapping mappings. +All mappings sharing a cacheline should have this attribute. --=20 MST