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 20:18:09 +1000 Message-ID: <4DAEB2E1.6050404@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> <4DAEA7F5.6080603@snapgear.com> <20110420095529.GC3296@frolo.macqel> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from sncsmrelay2.nai.com ([67.97.80.206]:29090 "EHLO sncsmrelay2.nai.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753717Ab1DTKUz convert rfc822-to-8bit (ORCPT ); Wed, 20 Apr 2011 06:20:55 -0400 In-Reply-To: <20110420095529.GC3296@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 Hi Philippe, On 20/04/11 19:55, Philippe De Muyter wrote: > On Wed, Apr 20, 2011 at 07:31:33PM +1000, Greg Ungerer wrote: >> 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 wr= ote: >>>>> Hi Greg. >>>>> >>>>>> + >>>>>> +#if defined(__mc68020__) || defined(__mc68030__) || \ >>>>>> + =E2=94=9C=C3=AD =E2=94=9C=C3=ADdefined(__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_* >>>>> symbols. >>>>> 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 suppor= t >>>> yet) have that >>>> instruction? >>> >>> Actually, MCF547x& MCF548x (CFv4e family) are integrated but with= out > (*) >>> their >>> limited MMU functionality. >>> >>> freescale had even written an mmu port for 2.6.25 but has not pushe= d it >>> upstream. This port can be found on their site or in the openwrt >>> repository. >> >> 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. > > The 68340 has it also. (And I have an old linux port for this process= or) That is just a SoC that contains a 68020 though, so __mc68020__ would be defined for that. > I surmise the 68360 has it also. I believe that is a SoC with a 68040 cpu core, so I would expect that __mc68040__ would be correct for that. > Philippe > > (*) Greg, there must be something with your mail installation : it ga= rbles > the messages. (or is it mine, but I noticed that only with replies fr= om you ?) Unfortunately mail getting to me goes through an MS exchange server that tends to garble some parts of emails. Not too much I can do about that (at least using the existing gerg@snapgear.com email address). 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