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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 8E1C0C3A589 for ; Thu, 15 Aug 2019 15:48:50 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (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 5F93A20665 for ; Thu, 15 Aug 2019 15:48:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5F93A20665 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=8bytes.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id 0D0ACEEB; Thu, 15 Aug 2019 15:48:50 +0000 (UTC) Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 8BF85EE8 for ; Thu, 15 Aug 2019 15:48:48 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from theia.8bytes.org (8bytes.org [81.169.241.247]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id E492B8A0 for ; Thu, 15 Aug 2019 15:48:47 +0000 (UTC) Received: by theia.8bytes.org (Postfix, from userid 1000) id 9919C3AA; Thu, 15 Aug 2019 17:48:45 +0200 (CEST) Date: Thu, 15 Aug 2019 17:48:45 +0200 From: Joerg Roedel To: Lu Baolu Subject: Re: [PATCH v6 5/8] iommu: Add bounce page APIs Message-ID: <20190815154845.GA18327@8bytes.org> References: <20190730045229.3826-1-baolu.lu@linux.intel.com> <20190730045229.3826-6-baolu.lu@linux.intel.com> <20190814083842.GB22669@8bytes.org> <445624e7-eb57-8089-8eb3-8687a65b1258@linux.intel.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <445624e7-eb57-8089-8eb3-8687a65b1258@linux.intel.com> User-Agent: Mutt/1.9.4 (2018-02-28) Cc: alan.cox@intel.com, Christoph Hellwig , Stefano Stabellini , ashok.raj@intel.com, Jonathan Corbet , pengfei.xu@intel.com, Ingo Molnar , David Woodhouse , kevin.tian@intel.com, Konrad Rzeszutek Wilk , Steven Rostedt , Bjorn Helgaas , Boris Ostrovsky , mika.westerberg@linux.intel.com, Alan Cox , Juergen Gross , Greg Kroah-Hartman , Mika Westerberg , linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, jacob.jun.pan@intel.com, Robin Murphy X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: iommu-bounces@lists.linux-foundation.org Errors-To: iommu-bounces@lists.linux-foundation.org On Thu, Aug 15, 2019 at 02:15:32PM +0800, Lu Baolu wrote: > iommu_map/unmap() APIs haven't parameters for dma direction and > attributions. These parameters are elementary for DMA APIs. Say, > after map, if the dma direction is TO_DEVICE and a bounce buffer is > used, we must sync the data from the original dma buffer to the bounce > buffer; In the opposite direction, if dma is FROM_DEVICE, before unmap, > we need to sync the data from the bounce buffer onto the original > buffer. The DMA direction from DMA-API maps to the protections in iommu_map(): DMA_FROM_DEVICE: IOMMU_WRITE DMA_TO_DEVICE: IOMMU_READ DMA_BIDIRECTIONAL IOMMU_READ | IOMMU_WRITE And for the sync DMA-API also has separate functions for either direction. So I don't see why these extra functions are needed in the IOMMU-API. Regards, Joerg _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu