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=-18.9 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, 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 3937CC48BE8 for ; Wed, 16 Jun 2021 03:54:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 236BF61055 for ; Wed, 16 Jun 2021 03:54:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231383AbhFPD4m (ORCPT ); Tue, 15 Jun 2021 23:56:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51164 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231381AbhFPD4d (ORCPT ); Tue, 15 Jun 2021 23:56:33 -0400 Received: from mail-pf1-x42d.google.com (mail-pf1-x42d.google.com [IPv6:2607:f8b0:4864:20::42d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 254C2C06175F for ; Tue, 15 Jun 2021 20:54:28 -0700 (PDT) Received: by mail-pf1-x42d.google.com with SMTP id c12so1110748pfl.3 for ; Tue, 15 Jun 2021 20:54:28 -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=bKNX+61KY+497C18UMf9tzB54BN9JmhN17dgRMarCuH6/YI06HcZUO1rsG8qU0UaJg 9iacuS6rTIiJCommP10+VQN+2EY3YjRv+hgL0/TXA9Ap9/T8W18MYpuKAZHM60A9JzTy NcemwkgEoNzTX8rMbFHfcKVugBejDTMzKi1yI= 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=saBDfS/kZSik4u/wkxiXIAbggZU7acwZDscXASEOLNHkfrLSBt0sC6tmS2Mqr2VKr7 e9ASolPIGKvsPrOoc16NHF5v0N6mWiHBH3szOQnpiO4oVjNFK1cjdh8ft/KiSAiAdxeq ER0omt6naKd9P8wIlaN0p7E1oRd4tm2EuslT03c+g0f5IlJqmE623vQGD57QhPEq8B2m R05yMHNQIzTtAqPkjRohpp2x5J95NOPS+oxdSY/c9/os7J6wWjysfha79AC60685jOuV hYUHIoN9zbv9ZixNtc67BDgGA4ol7M+F7/q7QHfJX/CT1XYZhaxtBVLn24DIRj8g06iw b3GA== X-Gm-Message-State: AOAM53033sy9wLf1FmJ41W0YyV7DSIdMFKlT+FzFgWxpSIZXwuCGbR8a xNSD6wBprpxKHzjryMh/C1Fykg== X-Google-Smtp-Source: ABdhPJyE12O0mP5M3Jhr5nm1IKCwmz9NUZqWaZOhZUHV0/ZLS5Hyi/5IPzyx8nJy3XXN3OzKpotPIA== X-Received: by 2002:a65:58c1:: with SMTP id e1mr2877486pgu.200.1623815667680; Tue, 15 Jun 2021 20:54:27 -0700 (PDT) Received: from localhost ([2401:fa00:95:205:3d52:f252:7393:1992]) by smtp.gmail.com with UTF8SMTPSA id w18sm599561pjg.50.2021.06.15.20.54.20 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 15 Jun 2021 20:54:27 -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 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, rodrigo.vivi@intel.com, thomas.hellstrom@linux.intel.com Subject: [PATCH v11 11/12] dt-bindings: of: Add restricted DMA pool Date: Wed, 16 Jun 2021 11:52:39 +0800 Message-Id: <20210616035240.840463-12-tientzu@chromium.org> X-Mailer: git-send-email 2.32.0.272.g935e593368-goog In-Reply-To: <20210616035240.840463-1-tientzu@chromium.org> References: <20210616035240.840463-1-tientzu@chromium.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 | 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>; + /* ... */ + }; }; -- 2.32.0.272.g935e593368-goog