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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 3B661C10F0E for ; Tue, 9 Apr 2019 13:59:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1204E2084F for ; Tue, 9 Apr 2019 13:59:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726512AbfDIN7h (ORCPT ); Tue, 9 Apr 2019 09:59:37 -0400 Received: from verein.lst.de ([213.95.11.211]:50624 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726112AbfDIN7g (ORCPT ); Tue, 9 Apr 2019 09:59:36 -0400 Received: by newverein.lst.de (Postfix, from userid 2407) id B7C7268B02; Tue, 9 Apr 2019 15:59:24 +0200 (CEST) Date: Tue, 9 Apr 2019 15:59:24 +0200 From: Christoph Hellwig To: David Woodhouse , Joerg Roedel Cc: iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: per-device dma_map_ops for intel-iommu? Message-ID: <20190409135924.GA11431@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi David and Joerg, do you remember a good reason why intel-iommu is not using per-device dma_map_ops like the AMD iommu or the various ARM iommus? Right now intel-iommu.c contains a half-asses reimplementation of the dma direct code for the iommu_no_mapping() case, and it would seem much nicer to just fall back to that case and not even call into intel-iommu in that case.