From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933618AbZHDXwl (ORCPT ); Tue, 4 Aug 2009 19:52:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932449AbZHDXwk (ORCPT ); Tue, 4 Aug 2009 19:52:40 -0400 Received: from claw.goop.org ([74.207.240.146]:37206 "EHLO claw.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932435AbZHDXwj (ORCPT ); Tue, 4 Aug 2009 19:52:39 -0400 Message-ID: <4A78C9C6.6010103@goop.org> Date: Tue, 04 Aug 2009 16:52:38 -0700 From: Jeremy Fitzhardinge User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1b3pre) Gecko/20090513 Fedora/3.0-2.3.beta2.fc11 Lightning/1.0pre Thunderbird/3.0b2 MIME-Version: 1.0 To: David Woodhouse CC: Dave Airlie , Keir Fraser , xen-devel@lists.xensource.com, Joerg Roedel , iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Zhenyu Wang Subject: Re: [Xen-devel] Re: [RFC] Make AGP work with IOMMU References: <1248707041.6100.35.camel@macbook.infradead.org> <21d7e9970907282328l4a44b9a2of4500c5c84a3586b@mail.gmail.com> <1248851712.19733.214.camel@macbook.infradead.org> <21d7e9970907290143q6778511cvda1c6b915f61654a@mail.gmail.com> <1248860205.19733.238.camel@macbook.infradead.org> In-Reply-To: <1248860205.19733.238.camel@macbook.infradead.org> X-Enigmail-Version: 0.96a Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/29/09 02:36, David Woodhouse wrote: > On Wed, 2009-07-29 at 18:43 +1000, Dave Airlie wrote: > >>>> don't suppose we want page_to_gart or is the double function nicer? >>>> >>> I pondered that briefly. But then observed that phys_to_gart() and >>> gart_to_phys() _always_ describe an identity mapping, so perhaps they >>> could just be ditched completely? >>> >> Yeah that could work too, no idea why they were introduced, well before my time. >> > > http://git.infradead.org/users/dwmw2/iommu-agp.git?a=commitdiff;h=8bf2f3a9 > > It was introduced by Keir in 2005 for Xen (commit 07eee78e). I suspect > it can die though, and that the right answer there is also to use the > DMA API correctly. > And just when I have patches to use them for their original purpose... Looking back over the thread, are you saying that most users are already using the DMA API correctly for AGP accesses? If that's true then we should be just fine. J