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 X-Spam-Level: X-Spam-Status: No, score=-13.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4428AC433E8 for ; Mon, 13 Jul 2020 09:12:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1B41720702 for ; Mon, 13 Jul 2020 09:12:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="e67OPwf1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729341AbgGMJMv (ORCPT ); Mon, 13 Jul 2020 05:12:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35442 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726523AbgGMJMu (ORCPT ); Mon, 13 Jul 2020 05:12:50 -0400 Received: from mail-pf1-x442.google.com (mail-pf1-x442.google.com [IPv6:2607:f8b0:4864:20::442]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 08DD3C061755 for ; Mon, 13 Jul 2020 02:12:50 -0700 (PDT) Received: by mail-pf1-x442.google.com with SMTP id z3so5714285pfn.12 for ; Mon, 13 Jul 2020 02:12:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=+P8dd4dsLzR3swPupkVuVT/gmICFutJbXFpV5NolUAQ=; b=e67OPwf1HIbj3XR4EOfuTCpxuygeGjjAfXvsgSif0nsuT/tPms6AxxDckXWU9kQ4el HVxOOk1iLRoQoAHU1WwmubXO5KyvzzdzXKmHm2RMInBlI1sC1gw6YiMKd4GHMPeZjcyk CxiYiu9iHJ53DICoiCsewCTgy6pX9Yf2fElGo= 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=+P8dd4dsLzR3swPupkVuVT/gmICFutJbXFpV5NolUAQ=; b=R0JtQ/gQ+qxvUETJJjERqxG3AJechXXp6cwMow0cvYvnY+OmNbtTkM1lcZO5JTR8xy IKc5n9M+mrTNmnYLaHDwGrztf4fPAyzDTLkKrX6G1zKFDGWL9vZAz+obOluU5rNjnbVM HgzuLauLGqlKHaAn6xqYbyC9AxV/NSJY8cpeWmkAAY3I+zVSuph+/qrzcHBaP62P6x22 6+hbeWjhVILguir38s4RdoJi+XeM0CN2Tyx2duRwA2EiguxBNwoTz9A/Hf6GUHDDZE4b U4f9ovMuloRBz1JOksT5HZylAe0wwXqZv7PRhn3T5hMnC8xtDxgDyY8vOQaZ0WOABlCg sB1A== X-Gm-Message-State: AOAM530vjvcWORcO5pQ9I8AYr+0pvSAnjfRliEgtCzuzA8k+KzuLVXOX nJWWNxoDGiVfnn2o1aH9HKYpIw== X-Google-Smtp-Source: ABdhPJwiVcgRHj8QaLGk5eyRoZthzOPp5a/LkxFv7ElLZgecHc8H4MvmE9E/lcRqY9ykY343uYMmDg== X-Received: by 2002:a63:1104:: with SMTP id g4mr66811073pgl.369.1594631569568; Mon, 13 Jul 2020 02:12:49 -0700 (PDT) Received: from localhost ([2401:fa00:1:10:3e52:82ff:fe5e:cc9d]) by smtp.gmail.com with ESMTPSA id i132sm13807520pfe.9.2020.07.13.02.12.46 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 13 Jul 2020 02:12:48 -0700 (PDT) From: Claire Chang To: robh+dt@kernel.org, frowand.list@gmail.com, hch@lst.de, m.szyprowski@samsung.com, robin.murphy@arm.com Cc: treding@nvidia.com, gregkh@linuxfoundation.org, saravanak@google.com, suzuki.poulose@arm.com, dan.j.williams@intel.com, heikki.krogerus@linux.intel.com, bgolaszewski@baylibre.com, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, tfiga@chromium.org, drinkcat@chromium.org, Claire Chang Subject: [PATCH 3/4] dt-bindings: of: Add plumbing for bounced DMA pool Date: Mon, 13 Jul 2020 17:12:10 +0800 Message-Id: <20200713091211.2183368-4-tientzu@chromium.org> X-Mailer: git-send-email 2.27.0.383.g050319c2ae-goog In-Reply-To: <20200713091211.2183368-1-tientzu@chromium.org> References: <20200713091211.2183368-1-tientzu@chromium.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Introduce the new compatible string, bounced-dma-pool, for bounced DMA. One can specify the address and length of the bounced memory region by bounced-dma-pool in the device tree. Signed-off-by: Claire Chang --- .../reserved-memory/reserved-memory.txt | 36 +++++++++++++++++++ 1 file changed, 36 insertions(+) diff --git a/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt b/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt index 4dd20de6977f..45b3134193ea 100644 --- a/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt +++ b/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt @@ -51,6 +51,24 @@ compatible (optional) - standard definition used as a shared pool of DMA buffers for a set of devices. It can be used by an operating system to instantiate the necessary pool management subsystem if necessary. + - bounced-dma-pool: This indicates a region of memory meant to be used + as a pool of DMA bounce buffers for a given device. When using this, + the no-map and reusable properties must not be set, so the operating + system can create a virtual mapping that will be used for + synchronization. Also, there must be a bounced-dma property in the + device node to specify the indexes of reserved-memory nodes. One can + specify two reserved-memory nodes in the device tree. One with + shared-dma-pool to handle the coherent DMA buffer allocation, and + another one with bounced-dma-pool for regular DMA to/from system + memory, which would be subject to bouncing. The main purpose for + bounced DMA is to mitigate the lack of DMA access control on systems + without an IOMMU, which could result in the DMA accessing the system + memory at unexpected times and/or unexpected addresses, possibly + leading to data leakage or corruption. The feature on its own provides + a basic level of protection against the DMA overwriting buffer + contents at unexpected times. However, to protect against general data + leakage and system memory corruption, the system needs to provide a + way to restrict the DMA to a predefined memory region. - vendor specific string in the form ,[-] no-map (optional) - empty property - Indicates the operating system must not create a virtual mapping @@ -117,6 +135,17 @@ one for multimedia processing (named multimedia-memory@77000000, 64MiB). compatible = "acme,multimedia-memory"; reg = <0x77000000 0x4000000>; }; + + wifi_bounced_dma_mem_region: wifi_bounced_dma_mem_region { + compatible = "bounced-dma-pool"; + reg = <0x50000000 0x4000000>; + }; + + wifi_coherent_mem_region: wifi_coherent_mem_region { + compatible = "shared-dma-pool"; + reg = <0x54000000 0x400000>; + }; + }; /* ... */ @@ -135,4 +164,11 @@ one for multimedia processing (named multimedia-memory@77000000, 64MiB). memory-region = <&multimedia_reserved>; /* ... */ }; + + pcie_wifi: pcie_wifi@0,0 { + memory-region = <&wifi_bounced_dma_mem_region>, + <&wifi_coherent_mem_region>; + bounced-dma = <0>, <1>; + /* ... */ + }; }; -- 2.27.0.383.g050319c2ae-goog