From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933586AbYDUNdw (ORCPT ); Mon, 21 Apr 2008 09:33:52 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932876AbYDUN1X (ORCPT ); Mon, 21 Apr 2008 09:27:23 -0400 Received: from terminus.zytor.com ([198.137.202.10]:46653 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932663AbYDUN1W (ORCPT ); Mon, 21 Apr 2008 09:27:22 -0400 Message-ID: <480C9215.7070905@zytor.com> Date: Mon, 21 Apr 2008 09:09:41 -0400 From: "H. Peter Anvin" User-Agent: Thunderbird 2.0.0.12 (X11/20080226) MIME-Version: 1.0 To: Mitch Bradley CC: Andres Salomon , Yinghai Lu , "Eric W. Biederman" , Ingo Molnar , Andrew Morton , Joseph Fannin , linux-kernel@vger.kernel.org, jordan.crouse@amd.com Subject: Re: [PATCH 1/2] OLPC: Add support for calling into Open Firmware References: <20080418014757.52fb4a4f.akpm@linux-foundation.org> <20080419031024.GC3503@nineveh.local> <20080418202925.b18452c5.akpm@linux-foundation.org> <20080419092544.378664a8@ephemeral> <20080419133909.5aa6b63e@ephemeral> <86802c440804200334t5cdcd100rfc41e9b1bf379109@mail.gmail.com> <480B321B.5020802@zytor.com> <20080420135948.61bdb4c9@ephemeral> <480B8E9F.8000701@firmworks.com> <480B95B4.5030203@zytor.com> <480C0C5B.2050403@firmworks.com> <480C7C4E.6070309@zytor.com> In-Reply-To: <480C7C4E.6070309@zytor.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Okay, stepping back a few steps, it's pretty clear that most of my objections aren't really an issue for Geode/OLPC; however, I *really* don't want others to pick it up as being "the" Open Firmware interface. Within those constraints it makes sense to set up the PDEs in swapper_pg_dir and let them propagate using the normal mechanisms. ** This is assuming that your OF interface does not rely on a 1:1 mapping of low memory being present at the time it makes a call. If it *does*, then a separate page directory needs to be maintained for the OF class. ** Thus, I'm willing to accept this with these changes: - Please name things specific to the interface (as opposed to Open Firmware in general, like the device tree) olpc_ofw or olpcfw, to denote that this is an OLPC-specific interface. Thus, CONFIG_OLPC_OPEN_FIRMWARE or something along those lines. - Make it explicit in Kconfig that OLPC_OPEN_FIRMWARE conflicts with X86_PAE, 64BIT, or X86_PAT. - Change VMALLOC_END in include/asm-x86/pgtable_32.h so the kernel will know to avoid this virtual memory range. - Add a memory region to arch/x86/mm/dump_tabletables.c. -hpa