From patchwork Wed Jul 27 23:42:05 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mitchel Humpherys X-Patchwork-Id: 9250485 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id C410260867 for ; Wed, 27 Jul 2016 23:43:37 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B4C762522B for ; Wed, 27 Jul 2016 23:43:37 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A989D26530; Wed, 27 Jul 2016 23:43:37 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 69B892522B for ; Wed, 27 Jul 2016 23:43:37 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.85_2 #1 (Red Hat Linux)) id 1bSYT2-0004ZP-Bx; Wed, 27 Jul 2016 23:42:24 +0000 Received: from smtp.codeaurora.org ([198.145.29.96]) by bombadil.infradead.org with esmtps (Exim 4.85_2 #1 (Red Hat Linux)) id 1bSYSp-0004QY-5x for linux-arm-kernel@lists.infradead.org; Wed, 27 Jul 2016 23:42:12 +0000 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id BF3DC61272; Wed, 27 Jul 2016 23:41:52 +0000 (UTC) Received: from mitchelh-linux.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: mitchelh@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id B4C896121D; Wed, 27 Jul 2016 23:41:51 +0000 (UTC) From: Mitchel Humpherys To: Joerg Roedel , iommu@lists.linux-foundation.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Robin Murphy , Will Deacon , Marek Szyprowski Subject: [PATCH v5 3/6] common: DMA-mapping: add DMA_ATTR_PRIVILEGED attribute Date: Wed, 27 Jul 2016 16:42:05 -0700 Message-Id: <20160727234208.2101-4-mitchelh@codeaurora.org> X-Mailer: git-send-email 2.9.0 In-Reply-To: <20160727234208.2101-1-mitchelh@codeaurora.org> References: <20160727234208.2101-1-mitchelh@codeaurora.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160727_164211_374179_C02F58FC X-CRM114-Status: GOOD ( 12.57 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mitchel Humpherys , Patrick Daly , Jeremy Gebben , linux-doc@vger.kernel.org, Jordan Crouse , Pratik Patel , Thomas Zeng MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP This patch adds the DMA_ATTR_PRIVILEGED attribute to the DMA-mapping subsystem. Some advanced peripherals such as remote processors and GPUs perform accesses to DMA buffers in both privileged "supervisor" and unprivileged "user" modes. This attribute is used to indicate to the DMA-mapping subsystem that the buffer is fully accessible at the elevated privilege level (and ideally inaccessible or at least read-only at the lesser-privileged levels). Cc: linux-doc@vger.kernel.org Reviewed-by: Robin Murphy Tested-by: Robin Murphy Signed-off-by: Mitchel Humpherys --- Notes: v2..v3 - Not worrying about executability. Documentation/DMA-attributes.txt | 10 ++++++++++ include/linux/dma-mapping.h | 6 ++++++ 2 files changed, 16 insertions(+) diff --git a/Documentation/DMA-attributes.txt b/Documentation/DMA-attributes.txt index 2d455a5cf671..7728bda278c9 100644 --- a/Documentation/DMA-attributes.txt +++ b/Documentation/DMA-attributes.txt @@ -126,3 +126,13 @@ means that we won't try quite as hard to get them. NOTE: At the moment DMA_ATTR_ALLOC_SINGLE_PAGES is only implemented on ARM, though ARM64 patches will likely be posted soon. + +DMA_ATTR_PRIVILEGED +------------------------------ + +Some advanced peripherals such as remote processors and GPUs perform +accesses to DMA buffers in both privileged "supervisor" and unprivileged +"user" modes. This attribute is used to indicate to the DMA-mapping +subsystem that the buffer is fully accessible at the elevated privilege +level (and ideally inaccessible or at least read-only at the +lesser-privileged levels). diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index 66533e18276c..73f477609262 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -56,6 +56,12 @@ * that gives better TLB efficiency. */ #define DMA_ATTR_ALLOC_SINGLE_PAGES (1UL << 7) +/* + * DMA_ATTR_PRIVILEGED: used to indicate that the buffer is fully + * accessible at an elevated privilege level (and ideally inaccessible or + * at least read-only at lesser-privileged levels). + */ +#define DMA_ATTR_PRIVILEGED (1UL << 8) /* * A dma_addr_t can hold any valid DMA or bus address for the platform.