Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751595Ab3JSHtW (ORCPT ); Sat, 19 Oct 2013 03:49:22 -0400 Received: from mail-pb0-f44.google.com ([209.85.160.44]:59623 "EHLO mail-pb0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751017Ab3JSHtV (ORCPT ); Sat, 19 Oct 2013 03:49:21 -0400 MIME-Version: 1.0 In-Reply-To: References: <1382080184-19115-1-git-send-email-geert@linux-m68k.org> <172f2b40c29a29a470215c14250a559e@biophys.uni-duesseldorf.de> Date: Sat, 19 Oct 2013 09:49:20 +0200 X-Google-Sender-Auth: jfmIvmKjKWB1dZT8QeFgx4tZRT8 Message-ID: Subject: Re: [PATCH] m68k/atari: Call paging_init() before nf_init() From: Geert Uytterhoeven To: Michael Schmitz Cc: linux-m68k , "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2053 Lines: 49 On Sat, Oct 19, 2013 at 2:33 AM, Michael Schmitz wrote: >> With the DISCONTIGMEM memory model, the kernel must be stored in the >> first memory block. As ST-RAM is before FastRAM in memory, you cannot >> have the kernel in FastRAM without losing ST-RAM (as main memory --- >> you can still e.g. ioremap() it for atafb, and use the rest of it as >> swap through >> a block device like z2ram. This is basically what we do on Amiga with Chip >> RAM >> and Z2 RAM). > > As long as we can ioremap() the ST-RAM frame buffer, we ought to be fine in > the first instance. How useful ST-RAM as swap may be is debatable so I'd > leave that aside for now. > > Main benefits would be for users of TTs that have been left out with recent > kernel sizes. > > OK - how would I go about ioremaping a chunk of ST-RAM when that has been > left out of the mm setup because it violates the discontigmem layout rules? > Set up a kernel private mapping for all of ST-RAM, and make that available > to the stram allocator? Just call ioremap(), that takes care of the kernel private mapping. ioremap() is meant to map anything that is not part of the mm setup. >> With the SPARSEMEM memory model, you should be able to store the kernel >> in FastRAM and have ST-RAM, too. > > I can still remember the headache I got when last playing with the mm code, > I think I'll pass. But "we" probably have to do that anyway, to please the Amiga BigRAM users. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- 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/