From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753402AbYASSqP (ORCPT ); Sat, 19 Jan 2008 13:46:15 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751266AbYASSqA (ORCPT ); Sat, 19 Jan 2008 13:46:00 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:41031 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750929AbYASSp7 (ORCPT ); Sat, 19 Jan 2008 13:45:59 -0500 Date: Sat, 19 Jan 2008 19:45:43 +0100 From: Ingo Molnar To: Andi Kleen Cc: venkatesh.pallipadi@intel.com, suresh.b.siddha@intel.com, tglx@linutronix.de, linux-kernel@vger.kernel.org Subject: Re: ACPI early ioremap problems Message-ID: <20080119184543.GA3751@elte.hu> References: <20080119030843.GA2028@basil.nowhere.org> <20080119150328.GA32370@elte.hu> <20080119152649.GA1375@one.firstfloor.org> <20080119153055.GA12054@elte.hu> <20080119154651.GA1626@one.firstfloor.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080119154651.GA1626@one.firstfloor.org> User-Agent: Mutt/1.5.17 (2007-11-01) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Andi Kleen wrote: > On Sat, Jan 19, 2008 at 04:30:55PM +0100, Ingo Molnar wrote: > > > > that case it's a 64-bit early_ioremap() bug that we want to find > > > > even if ACPI didnt use early_ioremap(). > > > > > > > > and this all runs before zap_low_mappings(), right? > > > > > > No after. Since some time x86-64 does the equivalent of z_l_m() in > > > head64(); this means before start_kernel and definitely before > > > setup_arch which sets up ACPI. > > > > that would mean early_ioremap() should switch to ioremap() after that > > point. Could you try that, does it resolve the failure you are seeing? > > ioremap() does alloc_page and that won't work before paging_init(). > Early ACPI scan is before paging_init() because paging_init() needs > node discovery at at least; which requires some ACPI tables. hm, so are you saying that on 64-bit there's in essence no usable ioremap facility between zap_low_mappings() and paging_init()? (early_ioremap() is not usable anymore, and ioremap() is not yet usable.) I guess we'll have to pick up the 32-bit early_ioremap() code for 64-bit as well. Ingo