From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264358AbTLPExy (ORCPT ); Mon, 15 Dec 2003 23:53:54 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264936AbTLPExy (ORCPT ); Mon, 15 Dec 2003 23:53:54 -0500 Received: from parcelfarce.linux.theplanet.co.uk ([195.92.249.252]:18397 "EHLO www.linux.org.uk") by vger.kernel.org with ESMTP id S264358AbTLPExx (ORCPT ); Mon, 15 Dec 2003 23:53:53 -0500 Message-ID: <3FDE8FD2.2070801@pobox.com> Date: Mon, 15 Dec 2003 23:53:38 -0500 From: Jeff Garzik User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4) Gecko/20030703 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Linus Torvalds CC: Vladimir Kondratiev , linux-kernel@vger.kernel.org, Alan Cox , Marcelo Tosatti Subject: Re: PCI Express support for 2.4 kernel References: <3FDC9DC5.2070302@intel.com> <3FDE1391.7030306@pobox.com> In-Reply-To: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Linus Torvalds wrote: > On Mon, 15 Dec 2003, Jeff Garzik wrote: >>neat. dumb question though... how portable is set_fixmap_nocache()? > Not very. Although it should generally be trivial to port if you need it. [...] > On 64-bit architectures you're not likely to ever need to worry about it, > and then you can just map the whole thing directly (and use some special > large-page mapping for it, at that). Yeah, good point. IA64 with its 1001 different types of mappings and zones can go crazy, for example. Sounds like PCI express needs a per-architecture policy for mapping the 256MB region. Some [64b] arches can direct-map the entire area. IA32 and others can go another route. Jeff