From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753142Ab1H2MZa (ORCPT ); Mon, 29 Aug 2011 08:25:30 -0400 Received: from ch1ehsobe002.messaging.microsoft.com ([216.32.181.182]:33022 "EHLO ch1outboundpool.messaging.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752896Ab1H2MZZ (ORCPT ); Mon, 29 Aug 2011 08:25:25 -0400 X-SpamScore: -21 X-BigFish: VPS-21(zz9371K1432N98dKzz1202hzz15d4R8275bhz32i668h839h944h62h) X-Spam-TCS-SCL: 1:0 X-Forefront-Antispam-Report: CIP:163.181.249.108;KIP:(null);UIP:(null);IPVD:NLI;H:ausb3twp01.amd.com;RD:none;EFVD:NLI X-WSS-ID: 0LQOVU6-01-8PL-02 X-M-MSG: Date: Mon, 29 Aug 2011 14:25:16 +0200 From: "Roedel, Joerg" To: Ohad Ben-Cohen CC: "iommu@lists.linux-foundation.org" , Stepan Moskovchenko , David Woodhouse , "linux-kernel@vger.kernel.org" , David Brown Subject: Re: [PATCH] iommu: Remove stub functions for !CONFIG_IOMMU_API Message-ID: <20110829122516.GB9730@amd.com> References: <1314364839-28492-1-git-send-email-joerg.roedel@amd.com> <20110829101550.GT1923@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) X-OriginatorOrg: amd.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Aug 29, 2011 at 06:59:05AM -0400, Ohad Ben-Cohen wrote: > On Mon, Aug 29, 2011 at 1:15 PM, Roedel, Joerg wrote: > > Isn't the abstraction that the drivers use the dma-api? There should be > > an implementation that doesn't require the iommu-api for such devices, > > no? > > Before we boot a remote processor device we often need to map it to > some (specific) bus addresses (e.g. to allow the processor access to > certain peripheral devices), and we're doing it directly with the > IOMMU API. > > Do you think this kind of functionality should be added to the DMA API as well ? > > IIRC, it was suggested awhile ago but you supported using the IOMMU > API directly in this case. Right, when the system has an iommu then the iommu-api is the right choice to do that. But how to you handle this on systems without an iommu? Joerg -- AMD Operating System Research Center Advanced Micro Devices GmbH Einsteinring 24 85609 Dornach General Managers: Alberto Bozzo, Andrew Bowd Registration: Dornach, Landkr. Muenchen; Registerger. Muenchen, HRB Nr. 43632