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, 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 739ADC4345B for ; Tue, 28 Jul 2020 05:02:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5026021775 for ; Tue, 28 Jul 2020 05:02:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="FFJEqir1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726953AbgG1FCJ (ORCPT ); Tue, 28 Jul 2020 01:02:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60730 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726929AbgG1FCH (ORCPT ); Tue, 28 Jul 2020 01:02:07 -0400 Received: from mail-pg1-x543.google.com (mail-pg1-x543.google.com [IPv6:2607:f8b0:4864:20::543]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BDD0EC061794 for ; Mon, 27 Jul 2020 22:02:06 -0700 (PDT) Received: by mail-pg1-x543.google.com with SMTP id l63so11190745pge.12 for ; Mon, 27 Jul 2020 22:02:06 -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=quJpJ8MFVCXxN2uUe5uCTDrzupsmhmPuwJ3x/xpP/Nw=; b=FFJEqir1hVkStEtfk+rEgzo8ZUuB5JUH7sJuO0JVeZhFlRfq6eDnq0M4SOi7xAzJNL Lg/B3hHFlX31yqXoVUvS53JbUcgSOfKFc9jlDruvAYag4p2p8uxI5CayvTuyOTxTzb2Y CmbNlaHf7A4Fl7V3TquMd4DohiBBSI7zhVcCs= 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=quJpJ8MFVCXxN2uUe5uCTDrzupsmhmPuwJ3x/xpP/Nw=; b=KZ5uUbwRwJnfcG4JFx4N6PWZ9mUMBCsnkqubcK8H7IQyOpVBtRZtvb8OkyIzmSu1CP v0NCQkP4OJxvZWX43ZKYMaZvaM9sFJaqU8O1SJA3u6fTZnzAVIGemalnoHKfMLnn3M9l naLJVTVuF7kHImwdosuP9Jzr7sz6uchU6SA+0BVnSmVNNf8FBhKwe5qJA0bX5BJsKBqD m6HPU7I/xiPk1wLi5cTovzkO1KbqZ7K5q993eNOoz3n1vdb9mUlvWUBn6AJB2HavqrDc 59CDHcKvtEzu3LtCR+4UR+uRH9ELOxi3zT2BNL+T0NSwStkrR844y6J5xgTELUoTi9I7 9hUQ== X-Gm-Message-State: AOAM53093kun4cnLUKCfMVcpIUKEAwzb/bv0yV0au+X+v+0YhdSRyRq2 VBevQT1dhGs7Ygi+buxIKVd5tQ== X-Google-Smtp-Source: ABdhPJxRMJ3gCBUPChJ2eZ/7cp0FgFLdngDiw44ugrhRF2b1gUjV2mSJdfqzvUQMjkMMzXOG1e/voQ== X-Received: by 2002:a65:428d:: with SMTP id j13mr23297111pgp.211.1595912526277; Mon, 27 Jul 2020 22:02:06 -0700 (PDT) Received: from localhost ([2401:fa00:1:10:3e52:82ff:fe5e:cc9d]) by smtp.gmail.com with ESMTPSA id a26sm17578156pgm.20.2020.07.27.22.02.03 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 27 Jul 2020 22:02:05 -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, drinkcat@chromium.org, tfiga@chromium.org, tientzu@chromium.org Subject: [RFC v2 4/5] dt-bindings: of: Add plumbing for restricted DMA pool Date: Tue, 28 Jul 2020 13:01:39 +0800 Message-Id: <20200728050140.996974-5-tientzu@chromium.org> X-Mailer: git-send-email 2.28.0.rc0.142.g3c755180ce-goog In-Reply-To: <20200728050140.996974-1-tientzu@chromium.org> References: <20200728050140.996974-1-tientzu@chromium.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Introduce the new compatible string, device-swiotlb-pool, for restricted DMA. One can specify the address and length of the device swiotlb memory region by device-swiotlb-pool in the device tree. Signed-off-by: Claire Chang --- .../reserved-memory/reserved-memory.txt | 35 +++++++++++++++++++ 1 file changed, 35 insertions(+) diff --git a/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt b/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt index 4dd20de6977f..78850896e1d0 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. + - device-swiotlb-pool: This indicates a region of memory meant to be + used as a pool of device swiotlb 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 restricted-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 device-swiotlb-pool for regular DMA to/from system + memory, which would be subject to bouncing. 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 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 +135,16 @@ one for multimedia processing (named multimedia-memory@77000000, 64MiB). compatible = "acme,multimedia-memory"; reg = <0x77000000 0x4000000>; }; + + wifi_coherent_mem_region: wifi_coherent_mem_region { + compatible = "shared-dma-pool"; + reg = <0x50000000 0x400000>; + }; + + wifi_device_swiotlb_region: wifi_device_swiotlb_region { + compatible = "device-swiotlb-pool"; + reg = <0x50400000 0x4000000>; + }; }; /* ... */ @@ -135,4 +163,11 @@ one for multimedia processing (named multimedia-memory@77000000, 64MiB). memory-region = <&multimedia_reserved>; /* ... */ }; + + pcie_wifi: pcie_wifi@0,0 { + memory-region = <&wifi_coherent_mem_region>, + <&wifi_device_swiotlb_region>; + restricted-dma = <0>, <1>; + /* ... */ + }; }; -- 2.28.0.rc0.142.g3c755180ce-goog