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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 BF1BCC43331 for ; Wed, 6 Jan 2021 03:43:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9CA3122DBF for ; Wed, 6 Jan 2021 03:43:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726631AbhAFDnB (ORCPT ); Tue, 5 Jan 2021 22:43:01 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40876 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726614AbhAFDnA (ORCPT ); Tue, 5 Jan 2021 22:43:00 -0500 Received: from mail-pj1-x1035.google.com (mail-pj1-x1035.google.com [IPv6:2607:f8b0:4864:20::1035]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0AF91C061360 for ; Tue, 5 Jan 2021 19:42:10 -0800 (PST) Received: by mail-pj1-x1035.google.com with SMTP id b5so890623pjk.2 for ; Tue, 05 Jan 2021 19:42:10 -0800 (PST) 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=FZGRSIKNWZAaAhyn9I46mv2qEvPmwpxpVmXsznFggAw=; b=gGxBXOihHsm3ZVDHLv31fDSdj1SXhYQbdn9k5cmAoncGt12QQUfM/c3IHcaEnDkA5J ocQxp+U8gmPg/aUt1mhhV6zZJ8VXZG4qoywct4SKLATrpd2CnwkRGzp6iVjwWvWh4uPB 8z3i8pIB+5J9HuYE/Sxl8iNS0nIPHFjKwJX1c= 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=FZGRSIKNWZAaAhyn9I46mv2qEvPmwpxpVmXsznFggAw=; b=kycDCBSnT3g+8FuBmy6KQru7gS278nUU3dbkbwaZ2C4FQqw4sHU6wW/0kInTcWQhpg lLB3f83LFCe4K0siLyXE9IINPOYYHUDknOU3ZoSrqo1C/092OOMakYcV/pgdrDk2WPau wC/ko1/41qMGyNOJZ7bhhkFtKz09QZ3jOarJirHWZeuc3dI8AZlhOrovXVw/epq8gFyy Ud6t+4NoJ0LqF6KVaVD1wLcUhde0zY4h6hkCx4qS1lFr2SpnAnxP8GQFfdpT8QoSEGTX SwHpjmmoCvkp5WQbqXphNd2eXplLb1LUPLluX7tKIrZiyN2I3MIFGrIEb2N8KNN//npD 1Pcg== X-Gm-Message-State: AOAM530AeYx3zbB3ry910sEID5C1NzGu9WfcpRPIVpOv1zOxZIT+NGCm lSWJ1IduZX/0X2gvLDLXvKSgog== X-Google-Smtp-Source: ABdhPJz3c69cs7bN5kIpvTYTxsM3wMIyOYfyNKD7ypyEM9IFVwp2OokHNuXw3jIYJjMTgHoQH4pU0Q== X-Received: by 2002:a17:90a:5802:: with SMTP id h2mr2368082pji.68.1609904529594; Tue, 05 Jan 2021 19:42:09 -0800 (PST) Received: from localhost ([2401:fa00:1:10:3e52:82ff:fe5e:cc9d]) by smtp.gmail.com with ESMTPSA id f7sm581725pjs.25.2021.01.05.19.42.04 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 05 Jan 2021 19:42:09 -0800 (PST) From: Claire Chang To: robh+dt@kernel.org, mpe@ellerman.id.au, benh@kernel.crashing.org, paulus@samba.org, joro@8bytes.org, will@kernel.org, frowand.list@gmail.com, konrad.wilk@oracle.com, boris.ostrovsky@oracle.com, jgross@suse.com, sstabellini@kernel.org, hch@lst.de, m.szyprowski@samsung.com, robin.murphy@arm.com Cc: grant.likely@arm.com, xypron.glpk@gmx.de, treding@nvidia.com, mingo@kernel.org, bauerman@linux.ibm.com, peterz@infradead.org, gregkh@linuxfoundation.org, saravanak@google.com, rafael.j.wysocki@intel.com, heikki.krogerus@linux.intel.com, andriy.shevchenko@linux.intel.com, rdunlap@infradead.org, dan.j.williams@intel.com, bgolaszewski@baylibre.com, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, iommu@lists.linux-foundation.org, xen-devel@lists.xenproject.org, tfiga@chromium.org, drinkcat@chromium.org, Claire Chang Subject: [RFC PATCH v3 5/6] dt-bindings: of: Add restricted DMA pool Date: Wed, 6 Jan 2021 11:41:23 +0800 Message-Id: <20210106034124.30560-6-tientzu@chromium.org> X-Mailer: git-send-email 2.29.2.729.g45daf8777d-goog In-Reply-To: <20210106034124.30560-1-tientzu@chromium.org> References: <20210106034124.30560-1-tientzu@chromium.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Introduce the new compatible string, restricted-dma-pool, for restricted DMA. One can specify the address and length of the restricted DMA memory region by restricted-dma-pool in the device tree. Signed-off-by: Claire Chang --- .../reserved-memory/reserved-memory.txt | 24 +++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt b/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt index e8d3096d922c..44975e2a1fd2 100644 --- a/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt +++ b/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt @@ -51,6 +51,20 @@ 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. + - restricted-dma-pool: This indicates a region of memory meant to be + used as a pool of restricted DMA buffers for a set of devices. The + memory region would be the only region accessible to those devices. + 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. The main purpose for restricted 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 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 @@ -120,6 +134,11 @@ one for multimedia processing (named multimedia-memory@77000000, 64MiB). compatible = "acme,multimedia-memory"; reg = <0x77000000 0x4000000>; }; + + restricted_dma_mem_reserved: restricted_dma_mem_reserved { + compatible = "restricted-dma-pool"; + reg = <0x50000000 0x400000>; + }; }; /* ... */ @@ -138,4 +157,9 @@ one for multimedia processing (named multimedia-memory@77000000, 64MiB). memory-region = <&multimedia_reserved>; /* ... */ }; + + pcie_device: pcie_device@0,0 { + memory-region = <&restricted_dma_mem_reserved>; + /* ... */ + }; }; -- 2.29.2.729.g45daf8777d-goog