From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755993Ab3LTKU4 (ORCPT ); Fri, 20 Dec 2013 05:20:56 -0500 Received: from mail-pa0-f50.google.com ([209.85.220.50]:45971 "EHLO mail-pa0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755116Ab3LTKUP (ORCPT ); Fri, 20 Dec 2013 05:20:15 -0500 Message-ID: <52B419DE.8050706@gmail.com> Date: Fri, 20 Dec 2013 18:20:14 +0800 From: Chen Gang User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130625 Thunderbird/17.0.7 MIME-Version: 1.0 To: James Hogan CC: rostedt@goodmis.org, "linux-kernel@vger.kernel.org" , linux-metag@vger.kernel.org Subject: Re: [PATCH] arch: metag: lib: add "umoddi3.S" file for __umoddi3() References: <52B2E0FA.7090805@gmail.com> <52B2E3DB.7010008@imgtec.com> <52B2F6B7.1050802@gmail.com> <52B2F8DC.8060006@imgtec.com> <52B3A0EA.9010801@gmail.com> <52B40E44.9040603@imgtec.com> In-Reply-To: <52B40E44.9040603@imgtec.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/20/2013 05:30 PM, James Hogan wrote: > On 20/12/13 01:44, Chen Gang wrote: >> On 12/19/2013 09:47 PM, James Hogan wrote: >>> No, I believe there shouldn't be any use of the C 64bit division/modulo >>> operations in generic kernel code in the first place, so like I said >>> before the code in question should be fixed to use the proper functions >>> in . >>> >> >> OK, thanks, your idea is one of fix ways. >> >> Hmm... for me, it is still not a bad idea to add "__umoddi3" to metag. > > NAK > > Please read this: > http://yarchive.net/comp/linux/64bit_divide.html > OK, thanks, that sounds reasonable to me. For kernel, we really need treat it carefully. Hmm... but do you know why we need some 64-bit functions which are implemented under "arch/metag/lib/*.S"? can we use instead of them? (e.g 64-bit '/'). And for me, 64-bit '/' and '%' are related operations, if provide one, we also need provide the other (or neither of them are provided). Thanks. -- Chen Gang Open, share and attitude like air, water and life which God blessed