From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg Ungerer Subject: Re: [uClinux-dev] [PATCH v2 1/6] m68k: merge mmu and non-mmu versions of muldi3 Date: Wed, 20 Apr 2011 19:31:33 +1000 Message-ID: <4DAEA7F5.6080603@snapgear.com> References: <1303278880-16153-1-git-send-email-gerg@snapgear.com> <1303278880-16153-2-git-send-email-gerg@snapgear.com> <1303278880-16153-3-git-send-email-gerg@snapgear.com> <20110420080609.GA24244@merkur.ravnborg.org> <20110420091216.GB3296@frolo.macqel> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from sncsmrelay2.nai.com ([67.97.80.206]:30530 "EHLO sncsmrelay2.nai.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753715Ab1DTJcJ convert rfc822-to-8bit (ORCPT ); Wed, 20 Apr 2011 05:32:09 -0400 In-Reply-To: <20110420091216.GB3296@frolo.macqel> Sender: linux-m68k-owner@vger.kernel.org List-Id: linux-m68k@vger.kernel.org To: Philippe De Muyter Cc: uClinux development list , linux-m68k@vger.kernel.org, Greg Ungerer On 20/04/11 19:12, Philippe De Muyter wrote: > On Wed, Apr 20, 2011 at 10:55:15AM +0200, Geert Uytterhoeven wrote: >> On Wed, Apr 20, 2011 at 10:06, Sam Ravnborg wrote= : >>> Hi Greg. >>> >>>> + >>>> +#if defined(__mc68020__) || defined(__mc68030__) || \ >>>> + =C3=A1 =C3=A1defined(__mc68040__) || defined(__mc68060__) >>> >>> Why use these to decide if this is MMU or not? >>> This code is not exposed to user-space so we can rely on CONFIG_* s= ymbols. >>> IMO the CONIFG_* symbols is easier to read/maintain. >> >> Because technically it doesn't depend on having a MMU or not, but on= having >> the full 32-bit multiplication instruction or not. >> >> Does Coldfire-with-MMU (for which we haven't integrated the support >> yet) have that >> instruction? > > Actually, MCF547x& MCF548x (CFv4e family) are integrated but without= their > limited MMU functionality. > > freescale had even written an mmu port for 2.6.25 but has not pushed = it > upstream. This port can be found on their site or in the openwrt rep= ository. Part of my plan with the merge of m68k and m68knommu is to make it easy to support the v4e parts with MMU enabled. And certainly as I work through cleaning the individual files up I am doing it with this in mind. Of course most of the code to support the v4e is the same no matter if you have the MMU enabled or not. I have Freescales 2.6.25 kernel, but it is really only a reference point for this work. > MCF547x& MCF548x do not have that instruction. Thats right. I believe the processors listed in the patch are the only ones that currently support the 64bit mul. Regards Greg -----------------------------------------------------------------------= - Greg Ungerer -- Principal Engineer EMAIL: gerg@snapgear.co= m SnapGear Group, McAfee PHONE: +61 7 3435 288= 8 8 Gardner Close FAX: +61 7 3217 532= 3 Milton, QLD, 4064, Australia WEB: http://www.SnapGear.co= m