From patchwork Wed Jun 16 06:21:56 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Claire Chang X-Patchwork-Id: 12324101 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,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 660CFC48BE8 for ; Wed, 16 Jun 2021 06:23:45 +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 3788D6101B for ; Wed, 16 Jun 2021 06:23:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3788D6101B 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 871F56E50C; Wed, 16 Jun 2021 06:23:44 +0000 (UTC) Received: from mail-pg1-x531.google.com (mail-pg1-x531.google.com [IPv6:2607:f8b0:4864:20::531]) by gabe.freedesktop.org (Postfix) with ESMTPS id 100A06E50C for ; Wed, 16 Jun 2021 06:23:44 +0000 (UTC) Received: by mail-pg1-x531.google.com with SMTP id e20so1172542pgg.0 for ; Tue, 15 Jun 2021 23:23:44 -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=GymVnULBeJ03m5EPo7c7VEX7DSqoBwMT6L2fMWoeeEc=; b=U3eun+ENVyocWxLJj29G6RCpfONi9/U6hPEIyZyKw371lsv5ZvHOuZIFA51JbRET1+ Op95gA7j695YxlxlvZL3RhiG4sat3KCnGzJWEyj6V60Tnw5upJgOTBhRDMBdHFtlUqmv mWPc8X3tmbnhBe3Nq+XG0xr87l9VopnL/TOas= 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=GymVnULBeJ03m5EPo7c7VEX7DSqoBwMT6L2fMWoeeEc=; b=UdjflKUsvhCt+gi965eyF+lEn6Hl+HSZTHze61uXx7HcUBUcFF89RC7zd6IJtKs1UY oqOpBlMhG7Ftj/6frFUcfiWUvccL18jjStvw3MzXVHrielu6d5MGqQlkZrYXMAE9t/sW dQZ4KqmCM3RvHb8RXGMsPijEAfwH9z/JlCOJR2mIoiFNMBQ5N9+wHzL/4DE5WvNhToDY EJgvWaV6P/+BTB0BgouKbpuIIe07FyCxgt+VoDHFVAkWFgFes/c1tQ1wA7v5K8IUSpYm eNtYdpUDd+i6DSP0fsrDZMe5mWuYE4ltl32Ji7T6g35OKUXIskaxPwq321tyr0O9fggC qLjQ== X-Gm-Message-State: AOAM5304k1HGDQOlRF1RRdpx8CgVTxv1vFPX/aMDukpQCKIzk/t1wlI4 176ghvR4HOuvo/hNFag0s0FIDg== X-Google-Smtp-Source: ABdhPJzos0AE316eqwE5bukVSiSBXorK5IVepm+pS66FYVRIq/CQ/YuE4vEFUrrRi3iREp0s0X/Ddw== X-Received: by 2002:a63:6e87:: with SMTP id j129mr3484297pgc.45.1623824623702; Tue, 15 Jun 2021 23:23:43 -0700 (PDT) Received: from localhost ([2401:fa00:95:205:3d52:f252:7393:1992]) by smtp.gmail.com with UTF8SMTPSA id s37sm1040984pfg.90.2021.06.15.23.23.36 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 15 Jun 2021 23:23:43 -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 v12 11/12] dt-bindings: of: Add restricted DMA pool Date: Wed, 16 Jun 2021 14:21:56 +0800 Message-Id: <20210616062157.953777-12-tientzu@chromium.org> X-Mailer: git-send-email 2.32.0.272.g935e593368-goog In-Reply-To: <20210616062157.953777-1-tientzu@chromium.org> References: <20210616062157.953777-1-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 , 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 | 36 +++++++++++++++++-- 1 file changed, 33 insertions(+), 3 deletions(-) diff --git a/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt b/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt index e8d3096d922c..46804f24df05 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 @@ -85,10 +102,11 @@ memory-region-names (optional) - a list of names, one for each corresponding Example ------- -This example defines 3 contiguous regions are defined for Linux kernel: +This example defines 4 contiguous regions for Linux kernel: one default of all device drivers (named linux,cma@72000000 and 64MiB in size), -one dedicated to the framebuffer device (named framebuffer@78000000, 8MiB), and -one for multimedia processing (named multimedia-memory@77000000, 64MiB). +one dedicated to the framebuffer device (named framebuffer@78000000, 8MiB), +one for multimedia processing (named multimedia-memory@77000000, 64MiB), and +one for restricted dma pool (named restricted_dma_reserved@0x50000000, 64MiB). / { #address-cells = <1>; @@ -120,6 +138,11 @@ one for multimedia processing (named multimedia-memory@77000000, 64MiB). compatible = "acme,multimedia-memory"; reg = <0x77000000 0x4000000>; }; + + restricted_dma_reserved: restricted_dma_reserved { + compatible = "restricted-dma-pool"; + reg = <0x50000000 0x4000000>; + }; }; /* ... */ @@ -138,4 +161,11 @@ one for multimedia processing (named multimedia-memory@77000000, 64MiB). memory-region = <&multimedia_reserved>; /* ... */ }; + + pcie_device: pcie_device@0,0 { + reg = <0x83010000 0x0 0x00000000 0x0 0x00100000 + 0x83010000 0x0 0x00100000 0x0 0x00100000>; + memory-region = <&restricted_dma_mem_reserved>; + /* ... */ + }; };