Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757899AbYF1Okj (ORCPT ); Sat, 28 Jun 2008 10:40:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753295AbYF1Oka (ORCPT ); Sat, 28 Jun 2008 10:40:30 -0400 Received: from outbound-sin.frontbridge.com ([207.46.51.80]:58074 "EHLO SG2EHSOBE001.bigfish.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753235AbYF1Ok3 convert rfc822-to-8bit (ORCPT ); Sat, 28 Jun 2008 10:40:29 -0400 X-BigFish: VPS-38(zz1432R98dR7efV1805M1442Jzzzzz32i6bh43j61h) X-Spam-TCS-SCL: 0:0 X-WSS-ID: 0K36GQY-02-HOC-01 x-mimeole: Produced By Microsoft Exchange V6.5 Content-Class: urn:content-classes:message MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT Subject: RE: [PATCH 01/34] AMD IOMMU: add Kconfig entry Date: Sat, 28 Jun 2008 09:40:57 -0500 Message-ID: <6453C3CB8E2B3646B0D020C1126132730120C518@sausexmb4.amd.com> In-Reply-To: <20080628110426.GJ10197@8bytes.org> X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: [PATCH 01/34] AMD IOMMU: add Kconfig entry Thread-Index: AcjZDsZMy19Ey33QRYKOW7BROMrBfgAHYGIw References: <20080627170546.GE10197@8bytes.org> <6453C3CB8E2B3646B0D020C1126132730120C444@sausexmb4.amd.com> <20080627222931.GB7201@il.ibm.com> <6453C3CB8E2B3646B0D020C1126132730120C4EE@sausexmb4.amd.com> <20080628110426.GJ10197@8bytes.org> From: "Duran, Leo" To: "Joerg Roedel" CC: "Muli Ben-Yehuda" , "Adrian Bunk" , "Richter, Robert" , , , "Andi Kleen" , "Biemueller, Sebastian" , , , "Sarathy, Bhavna" X-OriginalArrivalTime: 28 Jun 2008 14:40:17.0568 (UTC) FILETIME=[E2214A00:01C8D92C] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1017 Lines: 30 On Saturday, June 28, 2008 6:04 AM, Joerg Roedel wrote: > Yes, there is only one exclusion range per IOMMU. The problem is that > an > exclusion range from 64MB to the end may not be possible because there > is > an exclusion range already configured in the ACPI table. On my System > for > example the exclusion range is somewhere in the first megabyte of RAM. > In this case the direct mapping using page tables is needed. If there > is > no exclusion range defined in ACPI this idea would work of course. > > Joerg > Direct 1:1 mappings have a couple of issues: 1) They don't provide a performance optimization (i.e., table-walk still required) 2) Your aperture would have to be large enough so that virtual==physical (i.e., lots of memory for page-tables) Leo. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/