From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263494AbTKCXoZ (ORCPT ); Mon, 3 Nov 2003 18:44:25 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263497AbTKCXoZ (ORCPT ); Mon, 3 Nov 2003 18:44:25 -0500 Received: from rth.ninka.net ([216.101.162.244]:21633 "EHLO rth.ninka.net") by vger.kernel.org with ESMTP id S263494AbTKCXoY (ORCPT ); Mon, 3 Nov 2003 18:44:24 -0500 Date: Mon, 3 Nov 2003 16:41:16 -0800 From: "David S. Miller" To: davidm@hpl.hp.com Cc: davidm@napali.hpl.hp.com, jes@wildopensource.com, Jamie.Wellnitz@emulex.com, linux-kernel@vger.kernel.org Subject: Re: virt_to_page/pci_map_page vs. pci_map_single Message-Id: <20031103164116.5793a95e.davem@redhat.com> In-Reply-To: <16294.53393.763572.291298@napali.hpl.hp.com> References: <20031102181224.GD2149@ma.emulex.com> <20031103125259.GC16690@ma.emulex.com> <16294.53393.763572.291298@napali.hpl.hp.com> X-Mailer: Sylpheed version 0.9.7 (GTK+ 1.2.10; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 3 Nov 2003 14:02:57 -0800 David Mosberger wrote: > >>>>> On 03 Nov 2003 09:17:59 -0500, Jes Sorensen said: > > Jes> Hmmm, my brain has gotten ia64ified ;-) It's basically the normal > Jes> mappings of the kernel, ie. the kernel text/data/bss segments as well > Jes> as anything you do not get back as a dynamic mapping such as > Jes> ioremap/vmalloc/kmap. > > I don't think it's safe to use virt_to_page() on static kernel > addresses (text, data, and bss). For example, ia64 linux nowadays > uses a virtual mapping for the static kernel memory, so it's not part > of the identity-mapped segment. That's correct and it'll break on sparc64 for similar reasons. It's also not safe to do virt_to_page() on kernel stack addresses either.