From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261572AbVG1QTZ (ORCPT ); Thu, 28 Jul 2005 12:19:25 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261456AbVG1QRw (ORCPT ); Thu, 28 Jul 2005 12:17:52 -0400 Received: from lyle.provo.novell.com ([137.65.81.174]:22372 "EHLO lyle.provo.novell.com") by vger.kernel.org with ESMTP id S261556AbVG1QRf (ORCPT ); Thu, 28 Jul 2005 12:17:35 -0400 Date: Thu, 28 Jul 2005 09:17:20 -0700 From: Greg KH To: Ian Pratt Cc: Roland Dreier , "Michael S. Tsirkin" , linux-pci@atrey.karlin.mff.cuni.cz, openib-general@openib.org, linux-kernel@vger.kernel.org, mj@ucw.cz, ian.pratt@cl.cam.ac.uk Subject: Re: [openib-general] Re: [PATCH] arch/xx/pci: remap_pfn_range -> io_remap_pfn_range Message-ID: <20050728161720.GA23507@suse.de> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.8i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 28, 2005 at 12:57:51PM +0100, Ian Pratt wrote: > > > Greg> Hm, you do realize that io_remap_pfn_range() is the same > > > Greg> thing as remap_pfn_range() on i386, right? > > > > > > Greg> So, why would this patch change anything? > > > > > > It's not the same thing under Xen. I think this patch > > fixes userspace > > > access to PCI memory for XenLinux. > > > > But Xen is a separate arch, and hence, will get different pci > > arch specific functions, right? > > > > In short, what is this patch trying to fix? What is the > > problem anyone is seeing with the existing code? > > As I understand it, remap_pfn_range should be used for mapping pages > that are backed by memory, and io_remap_pfn_range should be used for > mapping MMIO regions. > There's a distinciton between the two for architectures like Sparc and > xen/x86. I agree, but not for i386, which is what the patch was trying to change. If this is a fix for xen, fine, then say so in the changelog information for the patch, as it is, no such information was given. thanks, greg k-h