From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756187AbaICLr1 (ORCPT ); Wed, 3 Sep 2014 07:47:27 -0400 Received: from mail-pa0-f51.google.com ([209.85.220.51]:41219 "EHLO mail-pa0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752112AbaICLr0 (ORCPT ); Wed, 3 Sep 2014 07:47:26 -0400 Message-ID: <5406FFBD.8010207@gmail.com> Date: Wed, 03 Sep 2014 19:47:09 +0800 From: Chen Gang User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.0 MIME-Version: 1.0 To: Paul Gortmaker , "H. Peter Anvin" CC: eparis@redhat.com, paulmck@linux.vnet.ibm.com, Geert Uytterhoeven , zhenglong.cai@cs2c.com.cn, khilman@linaro.org, ak@linux.intel.com, mcgrof@suse.com, fabf@skynet.be, "dhowells@redhat.com" , pefoley2@pefoley.com, mgorman@suse.de, biederm@xmission.com, "akpm@linux-foundation.org" , "linux-kernel@vger.kernel.org" , Arnd Bergmann , Jean Delvare Subject: Re: [PATCH] init/Kconfig: Add ENDIAN attributes for all architectures using References: <540494D6.40701@gmail.com> <20140901160828.GJ26632@windriver.com> <5404A66E.509@zytor.com> <20140902051737.GK26632@windriver.com> <54055FF8.3080907@gmail.com> In-Reply-To: <54055FF8.3080907@gmail.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/02/2014 02:13 PM, Chen Gang wrote: > On 9/2/14 13:17, Paul Gortmaker wrote: >> >> OK, but that was not at _all_ what I thought when looking at this... >> >> Instead I saw a well intentioned, but perhaps not fully thought out >> attempt at fixing a largely irrelevant randconfig/allmodconfig of a >> 1990's vintage ISDN driver coming from that x86-only era, built against >> an architecture that will never use or support it (microblaze). >> >> In today's world, we'd probably not accept a new ethernet driver or >> filesystem if it was incapable of handling both BE and LE (exception >> being SoC ethernet physically bound to one specific CPU, of course.) >> So the justification given in the commit log for expanding the scope to >> better deal with the stuff found in ISDN and the like was questionable. >> > I guess, we are mainly focus on: "Is it worthy enough to add *ENDIAN in init/Kconfig?" It seems really few modules need depend on LE or BE (although I am still not quite sure). If it is true, for me, only for architectures, it is still worthy enough to let all duplicated *ENDIAN to one place. If it is still worthy, maybe this patch need be improvement (especially, for its comments), so please help check when you have time, thanks. Welcome any other members' ideas, suggestions, or completions. Thanks. > After a simple search, for crypto, it may be endian sensitive, and for > architectures may be endian sensitive, in config time. > > bash-3.2# find ./ | grep Kconfig | xargs grep depend | grep ENDIAN > .//arch/arm/mm/Kconfig: depends on ARCH_SUPPORTS_BIG_ENDIAN > .//arch/arm/mm/Kconfig: depends on CPU_BIG_ENDIAN > .//arch/arm/mm/Kconfig: depends on CPU_BIG_ENDIAN > .//arch/arm64/Kconfig: depends on OF && !CPU_BIG_ENDIAN > .//arch/mips/Kconfig: depends on SYS_SUPPORTS_BIG_ENDIAN > .//arch/mips/Kconfig: depends on SYS_SUPPORTS_LITTLE_ENDIAN > .//arch/mips/Kconfig: depends on SGI_IP22 || SGI_IP28 || (SNI_RM && CPU_LITTLE_ENDIAN) > .//arch/powerpc/platforms/Kconfig.cputype: depends on !CPU_LITTLE_ENDIAN > .//arch/powerpc/platforms/Kconfig.cputype: depends on PPC_BOOK3S_64 && !CPU_LITTLE_ENDIAN > .//arch/powerpc/platforms/Kconfig.cputype: depends on PPC_BOOK3S_64 && !CPU_LITTLE_ENDIAN > .//arch/powerpc/platforms/Kconfig.cputype: depends on PPC_BOOK3S_64 && !CPU_LITTLE_ENDIAN > .//arch/powerpc/platforms/Kconfig.cputype: depends on PPC_BOOK3S_64 && !CPU_LITTLE_ENDIAN > .//arch/powerpc/platforms/Kconfig.cputype: depends on CPU_LITTLE_ENDIAN > [...] > .//crypto/Kconfig: depends on ARM && KERNEL_MODE_NEON && !CPU_BIG_ENDIAN > .//crypto/Kconfig: depends on ARM && KERNEL_MODE_NEON && !CPU_BIG_ENDIAN > .//drivers/crypto/Kconfig: depends on PPC64 && IBMVIO && !CPU_LITTLE_ENDIAN > [...] > > It is a simple search, so I am not sure whether have other modules also > need LE or BE. > Thanks. -- Chen Gang Open, share, and attitude like air, water, and life which God blessed