From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422926AbXDXTdW (ORCPT ); Tue, 24 Apr 2007 15:33:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1423063AbXDXTdW (ORCPT ); Tue, 24 Apr 2007 15:33:22 -0400 Received: from mx1.suse.de ([195.135.220.2]:35039 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1422926AbXDXTdV (ORCPT ); Tue, 24 Apr 2007 15:33:21 -0400 From: Andi Kleen Organization: SUSE Linux Products GmbH, Nuernberg, GF: Markus Rex, HRB 16746 (AG Nuernberg) To: Ashok Raj Subject: Re: [Intel IOMMU][patch 8/8] Preserve some Virtual Address when devices cannot address entire range. Date: Tue, 24 Apr 2007 21:33:15 +0200 User-Agent: KMail/1.9.6 Cc: linux-kernel@vger.kernel.org, akpm@osdl.org, gregkh@suse.de, muli@il.ibm.com, asit.k.mallick@intel.com, suresh.b.siddha@intel.com, anil.s.keshavamurthy@intel.com, arjan@linux.intel.com, shaohua.li@intel.com References: <20070424060259.426374000@intel.com> <20070424061038.389587000@intel.com> In-Reply-To: <20070424061038.389587000@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200704242133.16219.ak@suse.de> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tuesday 24 April 2007 08:03:07 Ashok Raj wrote: > Some devices may not support entire 64bit DMA. In a situation where such > devices are co-located in a shared domain, we need to ensure there is some > address space reserved for such devices without the low addresses getting > depleted by other devices capable of handling high dma addresses. Sorry, but you need to find some way to make this usually work without special options. Otherwise users will be unhappy. An possible way would be to allocate space upside down from the limit of the device. Then the lower areas should be usually free. -Andi