Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S940034AbXFHIKT (ORCPT ); Fri, 8 Jun 2007 04:10:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S939877AbXFHH51 (ORCPT ); Fri, 8 Jun 2007 03:57:27 -0400 Received: from pentafluge.infradead.org ([213.146.154.40]:53830 "EHLO pentafluge.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S939670AbXFHH50 (ORCPT ); Fri, 8 Jun 2007 03:57:26 -0400 Date: Fri, 8 Jun 2007 08:57:17 +0100 From: Christoph Hellwig To: carsteno@de.ibm.com Cc: Christoph Hellwig , Jared Hulbert , Nick Piggin , Andrew Morton , richard.griffiths@windriver.com, Richard Griffiths , Linux-kernel@vger.kernel.org Subject: Re: [PATCH 2.6.21] cramfs: add cramfs Linear XIP Message-ID: <20070608075717.GA16927@infradead.org> Mail-Followup-To: Christoph Hellwig , carsteno@de.ibm.com, Jared Hulbert , Nick Piggin , Andrew Morton , richard.griffiths@windriver.com, Richard Griffiths , Linux-kernel@vger.kernel.org References: <46641472.3080802@de.ibm.com> <6934efce0706060413y6e74512s19d5f468106d4b85@mail.gmail.com> <20070606113351.GA11701@infradead.org> <4666DD88.5030708@de.ibm.com> <20070606162305.GA20600@infradead.org> <46683B6A.6030306@de.ibm.com> <20070607193844.GB17144@infradead.org> <4669027E.3070406@de.ibm.com> <20070608072609.GA13115@infradead.org> <46690A39.3010402@de.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <46690A39.3010402@de.ibm.com> User-Agent: Mutt/1.4.2.2i X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1065 Lines: 18 On Fri, Jun 08, 2007 at 09:50:17AM +0200, Carsten Otte wrote: > I see your poing with regard to layering, and I agree to it. > In order to do ioremap/iounmap at least we need a counterpart > put_xip_page thing to do iounmap in that path. Our dcss segments on > 390 did not raise that requirement: they had a permanent kernel mapping. > The quiz question to me is: why don't we establish a permanenet > mapping of the entire thing from mount() to unmount(). That eliminates > the need to do iomap/iounmap, eliminates the need to have > put_xip_page, and eliminates to care about what layer would do this. > Would work for cramfs, won't work for read+write flash filesystems. Jared's patch currently does ioremap on mount (and no iounmap at all). That mapping needs to move from the filesystem to the device driver. - 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/