Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932150AbXF1XCX (ORCPT ); Thu, 28 Jun 2007 19:02:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759461AbXF1XCO (ORCPT ); Thu, 28 Jun 2007 19:02:14 -0400 Received: from smtp2.linux-foundation.org ([207.189.120.14]:48204 "EHLO smtp2.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755669AbXF1XCN (ORCPT ); Thu, 28 Jun 2007 19:02:13 -0400 Date: Thu, 28 Jun 2007 16:01:52 -0700 From: Andrew Morton To: Jeff Dike Cc: Alan Cox , Geert Uytterhoeven , Heiko Carstens , linux-kernel@vger.kernel.org, Martin Schwidefsky , Roman Zippel Subject: Re: [patch -mm] Make check_signature() depend on CONFIG_HAS_IOMEM Message-Id: <20070628160152.3f36af82.akpm@linux-foundation.org> In-Reply-To: <20070628224511.GA12447@c2.user-mode-linux.org> References: <20070628034321.38c9f12b.akpm@linux-foundation.org> <20070628133715.GA4343@osiris.boeblingen.de.ibm.com> <20070628110644.a530cfef.akpm@linux-foundation.org> <20070628113819.c24e592d.akpm@linux-foundation.org> <20070628132947.e3378811.akpm@linux-foundation.org> <20070628232537.02ced21c@the-village.bc.nu> <20070628224511.GA12447@c2.user-mode-linux.org> X-Mailer: Sylpheed version 2.2.7 (GTK+ 2.8.6; 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 Content-Length: 1482 Lines: 37 On Thu, 28 Jun 2007 18:45:11 -0400 Jeff Dike wrote: > On Thu, Jun 28, 2007 at 11:25:37PM +0100, Alan Cox wrote: > > This completely bogus. readb() should be present on M68K, fix the > > platform to implement readb() for MMIO, even if your MMIO readb is a > > moveb instruction. > > > > check_signature is relevant for anything with MMIO space (for example you > > can legitimately want to check_signature a MAC68K Nubus ROM). > > > > S/390 is a bit of a special case as no S/390 usage of check_signature > > appears sane but equally it isn't used so you can stub it out. > > This is a problem for UML too. > > I have a patch in my tree, which basically stubs readb, waiting to see > how this is fixed for the other arches. > What a mess. I guess we could add an empty readb() implementation to lib/lib.a so the arch will pick that up if all else fails. But it's pretty stinky. And it won't work either because we don't know at compile-time to declare the prototype for that thing appropriately. So... what's the proper fix here? "The arch must implement readb"? That's bad: if the arch really cannot implement readb(), we want builds to fail if someone tries to use it. I think I'll go shopping instead. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/