From patchwork Thu Apr 22 08:15:07 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Claire Chang X-Patchwork-Id: 12217917 X-Patchwork-Delegate: bhelgaas@google.com 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=-18.8 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, 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 CA7B5C43460 for ; Thu, 22 Apr 2021 08:17:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 976E96144A for ; Thu, 22 Apr 2021 08:17:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235393AbhDVISC (ORCPT ); Thu, 22 Apr 2021 04:18:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38848 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235304AbhDVISC (ORCPT ); Thu, 22 Apr 2021 04:18:02 -0400 Received: from mail-pf1-x429.google.com (mail-pf1-x429.google.com [IPv6:2607:f8b0:4864:20::429]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3C976C06138C for ; Thu, 22 Apr 2021 01:17:27 -0700 (PDT) Received: by mail-pf1-x429.google.com with SMTP id c17so31155520pfn.6 for ; Thu, 22 Apr 2021 01:17:27 -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=RuOOsLHj/oNZjBm4RnvuivSFFV92Va82CrZ+fAg7zfY=; b=SU4sVnlV04xSgoofQca5QyBITV+0IvFAevjbJUPql51e/WJmwt753FvY8Mkg5m2V9K KltjB0Yf/owsba7VaGE5I/jyIpffrwgwzMWGj5OuANSMmX9kAJK1YudQOntlivYBBgBL ojHwCuXZ3zEWizTS3cOusPjXwW4Dim4zSAIxs= 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=RuOOsLHj/oNZjBm4RnvuivSFFV92Va82CrZ+fAg7zfY=; b=smKaiJ8I+klLhRSyM04s10vnxxaWmG2SUMQyKafMYVl68JmuQe9oQHR2TRakHqsCZ/ FzK3CwE9Bsio8iLtu4jNvjn+z1PI65jFTL40Ztv7L6rRfuPLa+VbLjCRuv08PnjaJ3H+ rNEYQfzqHt3Gno5zr1tf2O7aBYTefQlcmuRfzhsAFefwrmLvfcSJ96nlck+ctGrh4cWh 3CPCE4kP+D1Gvu3eJ2sk1a8CoTGtY4PHiMUVx4Wn7NKh6VyRuRDvmvDATYGMrH6W19aZ HLerEWwCYLf7JmR3p96JRIQok3JGnjRctQiKoZ/sx0OSP2wKCP4JZOHxdrdLzmfeJ5Ke 5Epw== X-Gm-Message-State: AOAM530IJfc87a2pDnYEh7XJJWIaM8Vb0gKFrEh3faYP3Xd2SbOnHVuu OjjX7pGkPNfwquSuw6Uup/+1OQ== X-Google-Smtp-Source: ABdhPJwbWgS0cLJAD3Tg8wl4hIiA/h+MeZ9ZtrvoWlgRDwgrWUw8WsaWULCcDmGHjuLEWNOlKJKskA== X-Received: by 2002:aa7:8703:0:b029:261:4680:9723 with SMTP id b3-20020aa787030000b029026146809723mr2287757pfo.70.1619079446787; Thu, 22 Apr 2021 01:17:26 -0700 (PDT) Received: from localhost ([2401:fa00:1:10:1a8e:1bde:f79e:c302]) by smtp.gmail.com with UTF8SMTPSA id i22sm1586646pgj.90.2021.04.22.01.17.19 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 22 Apr 2021 01:17:26 -0700 (PDT) From: Claire Chang To: Joerg Roedel , Will Deacon , Frank Rowand , Konrad Rzeszutek Wilk , boris.ostrovsky@oracle.com, jgross@suse.com, Christoph Hellwig , Marek Szyprowski Cc: benh@kernel.crashing.org, paulus@samba.org, "list@263.net:IOMMU DRIVERS" , sstabellini@kernel.org, Robin Murphy , grant.likely@arm.com, xypron.glpk@gmx.de, Thierry Reding , mingo@kernel.org, bauerman@linux.ibm.com, peterz@infradead.org, Greg KH , Saravana Kannan , "Rafael J . Wysocki" , heikki.krogerus@linux.intel.com, Andy Shevchenko , Randy Dunlap , Dan Williams , Bartosz Golaszewski , linux-devicetree , lkml , linuxppc-dev@lists.ozlabs.org, xen-devel@lists.xenproject.org, Nicolas Boichat , Jim Quinlan , tfiga@chromium.org, bskeggs@redhat.com, bhelgaas@google.com, chris@chris-wilson.co.uk, tientzu@chromium.org, daniel@ffwll.ch, airlied@linux.ie, dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, jani.nikula@linux.intel.com, jxgao@google.com, joonas.lahtinen@linux.intel.com, linux-pci@vger.kernel.org, maarten.lankhorst@linux.intel.com, matthew.auld@intel.com, nouveau@lists.freedesktop.org, rodrigo.vivi@intel.com, thomas.hellstrom@linux.intel.com Subject: [PATCH v5 15/16] dt-bindings: of: Add restricted DMA pool Date: Thu, 22 Apr 2021 16:15:07 +0800 Message-Id: <20210422081508.3942748-16-tientzu@chromium.org> X-Mailer: git-send-email 2.31.1.368.gbe11c130af-goog In-Reply-To: <20210422081508.3942748-1-tientzu@chromium.org> References: <20210422081508.3942748-1-tientzu@chromium.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@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 reserved-memory node. 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..fc9a12c2f679 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 lock down + the memory access, e.g., MPU. - 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>; + /* ... */ + }; };