From patchwork Mon May 10 09:50:25 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Claire Chang X-Patchwork-Id: 12247363 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=-16.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 4FEBAC43460 for ; Mon, 10 May 2021 09:52:43 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id F399461582 for ; Mon, 10 May 2021 09:52:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F399461582 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=chromium.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 0DD606E85A; Mon, 10 May 2021 09:52:42 +0000 (UTC) Received: from mail-pg1-x52a.google.com (mail-pg1-x52a.google.com [IPv6:2607:f8b0:4864:20::52a]) by gabe.freedesktop.org (Postfix) with ESMTPS id 610276E878 for ; Mon, 10 May 2021 09:52:41 +0000 (UTC) Received: by mail-pg1-x52a.google.com with SMTP id i5so8156771pgm.0 for ; Mon, 10 May 2021 02:52:41 -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=TI//+rWs2AonD6qoX7ur8OGwRk/rsyDr2ocu0NzNq5I=; b=OeemdSgPmia6P5EsXKkEzN0OL4fVLwcXTd/CieenRMdBKHxFqUP4Df4joJbySWSSMc NQa62kYUP6NBQhMfe69O4Y1TVNyiYjME1kHrojL7NiW2Og6QvxSOkeGdpSahkdmKkkLI olHy6atIMBhauJm3Bf+RxBbMLkFko3Ac9JTU8= 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=TI//+rWs2AonD6qoX7ur8OGwRk/rsyDr2ocu0NzNq5I=; b=GqD6zNFCsO8BafvNNJe0dHRnSy9gcYzrX+84w+nyYjxsNPqtyJBGti7F2sacq2xL1D KarIeJSwSrZaGwTIvVZAL2QtpB0uPOBYDnFYXiOj0IS98qgUdN5meNIjCyi8tNWWtxun FoZXR8Thmu/oe827AfCP6VbQ8x+ENKO0+mNQN/ZcG7ulPcoP1twgnKWgVFGujYWL4WZ8 gr8JmYA+Wxzrb94pmMLwQEXeTBuUyXokOeRA/ordmUBCS5oYld4v9pFZh4Ii+1djIlTE +DvurTHrPabrYDxp2ABdRUyKc5qIQBaXzrmqqZiknHXyvg0fZNBX78T8YG6lCzv+3vIq dCAQ== X-Gm-Message-State: AOAM532gKYs7kgHUygaDk79LqgvzF+B1x40v42M9i6jdDLjfxQxDN2To KOjHjQCJ7jzv+cXBPeVJB8l9Pg== X-Google-Smtp-Source: ABdhPJx3NolYg0tYgQE7hrG22fSVZg4paXFqQrFAkVZpowUqVebMyfoHJdLoW9aBQ5hSJPVDYKavFA== X-Received: by 2002:a63:5160:: with SMTP id r32mr23960989pgl.83.1620640360984; Mon, 10 May 2021 02:52:40 -0700 (PDT) Received: from localhost ([2401:fa00:95:205:a524:abe8:94e3:5601]) by smtp.gmail.com with UTF8SMTPSA id q7sm9111446pfq.172.2021.05.10.02.52.33 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 10 May 2021 02:52:40 -0700 (PDT) From: Claire Chang To: Rob Herring , mpe@ellerman.id.au, Joerg Roedel , Will Deacon , Frank Rowand , Konrad Rzeszutek Wilk , boris.ostrovsky@oracle.com, jgross@suse.com, Christoph Hellwig , Marek Szyprowski Subject: [PATCH v6 14/15] dt-bindings: of: Add restricted DMA pool Date: Mon, 10 May 2021 17:50:25 +0800 Message-Id: <20210510095026.3477496-15-tientzu@chromium.org> X-Mailer: git-send-email 2.31.1.607.g51e8a6a459-goog In-Reply-To: <20210510095026.3477496-1-tientzu@chromium.org> References: <20210510095026.3477496-1-tientzu@chromium.org> MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: heikki.krogerus@linux.intel.com, thomas.hellstrom@linux.intel.com, peterz@infradead.org, dri-devel@lists.freedesktop.org, chris@chris-wilson.co.uk, grant.likely@arm.com, paulus@samba.org, mingo@kernel.org, jxgao@google.com, sstabellini@kernel.org, Saravana Kannan , xypron.glpk@gmx.de, "Rafael J . Wysocki" , Bartosz Golaszewski , bskeggs@redhat.com, linux-pci@vger.kernel.org, xen-devel@lists.xenproject.org, Thierry Reding , intel-gfx@lists.freedesktop.org, matthew.auld@intel.com, linux-devicetree , airlied@linux.ie, Robin Murphy , Nicolas Boichat , rodrigo.vivi@intel.com, bhelgaas@google.com, tientzu@chromium.org, Dan Williams , Andy Shevchenko , nouveau@lists.freedesktop.org, Greg KH , Randy Dunlap , lkml , tfiga@chromium.org, "list@263.net:IOMMU DRIVERS" , Jim Quinlan , linuxppc-dev@lists.ozlabs.org, bauerman@linux.ibm.com Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" 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 | 27 +++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt b/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt index e8d3096d922c..284aea659015 100644 --- a/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt +++ b/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt @@ -51,6 +51,23 @@ 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. Note that since coherent allocation + needs remapping, one must set up another device coherent pool by + shared-dma-pool and use dma_alloc_from_dev_coherent instead for atomic + coherent allocation. - vendor specific string in the form ,[-] no-map (optional) - empty property - Indicates the operating system must not create a virtual mapping @@ -120,6 +137,11 @@ 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 +160,9 @@ 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>; + /* ... */ + }; };