From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755452Ab2LCRE1 (ORCPT ); Mon, 3 Dec 2012 12:04:27 -0500 Received: from co9ehsobe003.messaging.microsoft.com ([207.46.163.26]:53040 "EHLO co9outboundpool.messaging.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754000Ab2LCREZ convert rfc822-to-8bit (ORCPT ); Mon, 3 Dec 2012 12:04:25 -0500 X-Forefront-Antispam-Report: CIP:70.37.183.190;KIP:(null);UIP:(null);IPV:NLI;H:mail.freescale.net;RD:none;EFVD:NLI X-SpamScore: -11 X-BigFish: VS-11(zzbb2dI98dI9371I179dN542I1432Izz1de0h1202h1d1ah1d2ahzz8275dhz2dh2a8h668h839h944hd2bhf0ah1288h12a5h12a9h12bdh137ah139eh13b6h1441h1504h1537h162dh1631h16a6h1155h) Date: Mon, 3 Dec 2012 11:03:43 -0600 From: Scott Wood Subject: Re: [PATCH 3/4 v5] iommu/fsl: Add iommu domain attributes required by fsl PAMU driver. To: Sethi Varun-B16395 CC: Joerg Roedel , "linux-kernel@vger.kernel.org" , "iommu@lists.linux-foundation.org" , Wood Scott-B07421 , "linuxppc-dev@lists.ozlabs.org" , Tabi Timur-B04825 References: <1353419697-31269-1-git-send-email-Varun.Sethi@freescale.com> <1353419697-31269-4-git-send-email-Varun.Sethi@freescale.com> <20121202140323.GO30633@8bytes.org> In-Reply-To: (from B16395@freescale.com on Mon Dec 3 10:57:29 2012) X-Mailer: Balsa 2.4.11 Message-ID: <1354554223.2960.7@snotra> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; delsp=Yes; format=Flowed Content-Disposition: inline Content-Transfer-Encoding: 8BIT X-OriginatorOrg: freescale.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/03/2012 10:57:29 AM, Sethi Varun-B16395 wrote: > > > > -----Original Message----- > > From: iommu-bounces@lists.linux-foundation.org [mailto:iommu- > > bounces@lists.linux-foundation.org] On Behalf Of Joerg Roedel > > Sent: Sunday, December 02, 2012 7:33 PM > > To: Sethi Varun-B16395 > > Cc: linux-kernel@vger.kernel.org; iommu@lists.linux-foundation.org; > Wood > > Scott-B07421; linuxppc-dev@lists.ozlabs.org; Tabi Timur-B04825 > > Subject: Re: [PATCH 3/4 v5] iommu/fsl: Add iommu domain attributes > > required by fsl PAMU driver. > > > > Hmm, we need to work out a good abstraction for this. > > > > On Tue, Nov 20, 2012 at 07:24:56PM +0530, Varun Sethi wrote: > > > Added the following domain attributes required by FSL PAMU driver: > > > 1. Subwindows field added to the iommu domain geometry attribute. > > > > Are the Subwindows mapped with full size or do you map only parts > of the > > subwindows? > > > [Sethi Varun-B16395] It's possible to map a part of the subwindow > i.e. size of the mapping can be less than the sub window size. > > > > + * This attribute indicates number of DMA subwindows supported > by > > > + * the geometry. If there is a single window that maps the > entire > > > + * geometry, attribute must be set to "1". A value of "0" > implies > > > + * that this mechanism is not used at all(normal paging is > used). > > > + * Value other than* "0" or "1" indicates the actual number of > > > + * subwindows. > > > + */ > > > > This semantic is ugly, how about a feature detection mechanism? > > > [Sethi Varun-B16395] A feature mechanism to query the type of IOMMU? A feature mechanism to determine whether this subwindow mechanism is available, and what the limits are. -Scott