From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753957Ab2A3G1g (ORCPT ); Mon, 30 Jan 2012 01:27:36 -0500 Received: from ch1ehsobe004.messaging.microsoft.com ([216.32.181.184]:23607 "EHLO ch1outboundpool.messaging.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752584Ab2A3G1f convert rfc822-to-8bit (ORCPT ); Mon, 30 Jan 2012 01:27:35 -0500 X-SpamScore: -13 X-BigFish: VS-13(zzbb2dI9371I542M1432N98dKzz1202hzzz2dhc1bhc31hc1ah2a8h668h839h8e2h8e3h944hbe9k) X-Forefront-Antispam-Report: CIP:70.37.183.190;KIP:(null);UIP:(null);IPV:NLI;H:mail.freescale.net;RD:none;EFVD:NLI From: Sethi Varun-B16395 To: Joerg Roedel , Wood Scott-B07421 CC: "iommu@lists.linux-foundation.org" , Ohad Ben-Cohen , Tony Lindgren , Hiroshi DOYU , "linux-kernel@vger.kernel.org" , Laurent Pinchart , Wood Scott-B07421 , David Brown , David Woodhouse Subject: RE: [PATCH 2/5] iommu/amd: Implement DOMAIN_ATTR_GEOMETRY attribute Thread-Topic: [PATCH 2/5] iommu/amd: Implement DOMAIN_ATTR_GEOMETRY attribute Thread-Index: AQHM1rbj1rZDtR84OEuq1/Qi58+pfJYT5niggAHq2gCACZWbAIAAAZsAgAADCwCAAAJ5gIAFCoQg Date: Mon, 30 Jan 2012 06:27:30 +0000 Message-ID: References: <1326983405-319-1-git-send-email-joerg.roedel@amd.com> <1326983405-319-3-git-send-email-joerg.roedel@amd.com> <20120120160344.GG2205@amd.com> <4F219A9C.8000400@freescale.com> <20120126183116.GI19255@amd.com> <4F219E82.106@freescale.com> <20120126185101.GJ19255@amd.com> In-Reply-To: <20120126185101.GJ19255@amd.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.232.134.90] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 X-OriginatorOrg: freescale.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > -----Original Message----- > From: Joerg Roedel [mailto:joerg.roedel@amd.com] > Sent: Friday, January 27, 2012 12:21 AM > To: Wood Scott-B07421 > Cc: Sethi Varun-B16395; iommu@lists.linux-foundation.org; Ohad Ben-Cohen; > Tony Lindgren; Hiroshi DOYU; linux-kernel@vger.kernel.org; Laurent > Pinchart; Wood Scott-B07421; David Brown; David Woodhouse > Subject: Re: [PATCH 2/5] iommu/amd: Implement DOMAIN_ATTR_GEOMETRY > attribute > > On Thu, Jan 26, 2012 at 12:42:10PM -0600, Scott Wood wrote: > > On 01/26/2012 12:31 PM, Joerg Roedel wrote: > > > The force_aperture flag indicated whether DMA is only allowed > > > between aperture_start and apertuer_end or if DMA is allowed outside > > > of this range too (unmapped in this case). > > > > > > The AMD GART for example would set this flag to false because it > > > does not enforce DMA to be in the aperture-range. > > > > Why is this not an AMD GART specific attribute? Is there any feature > > reporting mechanism by which a user would know if that flag is > supported? > > Because this is a flag that makes sense for all IOMMU. Every IOMMU either > allows DMA outside its aperture or it doesn't. > > Another reason why it must be in the generic struct is the intended > generic dma-ops layer on-top. This code can decide on this flag wheter a > address needs to be remapped at all. Can you please explain how would IOMMU remapping be used, based on the force_aperture flag. -Varun