From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 9 Jan 2001 11:29:52 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 9 Jan 2001 11:29:42 -0500 Received: from monza.monza.org ([209.102.105.34]:62221 "EHLO monza.monza.org") by vger.kernel.org with ESMTP id ; Tue, 9 Jan 2001 11:29:26 -0500 Date: Tue, 9 Jan 2001 08:27:49 -0800 From: Tim Wright To: Matti Aarnio Cc: Venkatesh Ramamurthy , "'Pavel Machek'" , adefacc@tin.it, linux-kernel@vger.kernel.org Subject: Re: Confirmation request about new 2.4.x. kernel limits Message-ID: <20010109082749.A2971@scutter.internal.splhi.com> Reply-To: timw@splhi.com Mail-Followup-To: Matti Aarnio , Venkatesh Ramamurthy , 'Pavel Machek' , adefacc@tin.it, linux-kernel@vger.kernel.org In-Reply-To: <1355693A51C0D211B55A00105ACCFE64E95137@ATL_MS1> <20010109142156.L25659@mea-ext.zmailer.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <20010109142156.L25659@mea-ext.zmailer.org>; from matti.aarnio@zmailer.org on Tue, Jan 09, 2001 at 02:21:56PM +0200 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 09, 2001 at 02:21:56PM +0200, Matti Aarnio wrote: [...] > > For IO on usual systems you have 32 bit address space PCI busmasters, > so those can access only the lowest 4GB of address space, and to have > a block of data in upper area, it needs to be "bounced", that is, CPU > must copy it. Linux 2.4.0 system doesn't support 64-bit PCI addresses > at 32-bit systems (not at 64-bit Alpha either, I recall.) > On the other hand, Alpha systems and SPARC systems have IOMMU hardware, > and we do support that (to some extent), but 32-bit intel world doesn't > have similar things. > Hi Matti, you are correct in saying that ia32 systems don't have IOMMU hardware, but it's unfortunate that we don't support 64-bit PCI bus master cards, since they're inexpensive and fairly common now. For instance, the Qlogic ISP SCSI cards can do 64-bit addressing, as can many others. Has anybody taken a look at enabling this ? Tim -- Tim Wright - timw@splhi.com or timw@aracnet.com or twright@us.ibm.com IBM Linux Technology Center, Beaverton, Oregon "Nobody ever said I was charming, they said "Rimmer, you're a git!"" RD VI - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/