From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 36B37C4743C for ; Mon, 7 Jun 2021 05:49:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1991F610E7 for ; Mon, 7 Jun 2021 05:49:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230097AbhFGFuw (ORCPT ); Mon, 7 Jun 2021 01:50:52 -0400 Received: from pegase1.c-s.fr ([93.17.236.30]:23881 "EHLO pegase1.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229449AbhFGFus (ORCPT ); Mon, 7 Jun 2021 01:50:48 -0400 Received: from localhost (mailhub3.si.c-s.fr [192.168.12.233]) by localhost (Postfix) with ESMTP id 4Fz2Vc3ZsszB9cJ; Mon, 7 Jun 2021 07:48:56 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id vyaOJDm2hiAi; Mon, 7 Jun 2021 07:48:56 +0200 (CEST) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase1.c-s.fr (Postfix) with ESMTP id 4Fz2Vc2XHVzB9Zm; Mon, 7 Jun 2021 07:48:56 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 436848B77F; Mon, 7 Jun 2021 07:48:56 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id KgJWM97gaIvs; Mon, 7 Jun 2021 07:48:56 +0200 (CEST) Received: from [172.25.230.103] (po15451.idsi0.si.c-s.fr [172.25.230.103]) by messagerie.si.c-s.fr (Postfix) with ESMTP id E86C38B763; Mon, 7 Jun 2021 07:48:55 +0200 (CEST) Subject: Re: [PATCH v2 00/15] init_mm: cleanup ARCH's text/data/brk setup code To: Kefeng Wang , Mike Rapoport Cc: uclinux-h8-devel@lists.sourceforge.jp, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, linux-kernel@vger.kernel.org, linux-csky@vger.kernel.org, linux-mm@kvack.org, linux-m68k@lists.linux-m68k.org, openrisc@lists.librecores.org, Andrew Morton , linux-snps-arc@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-arm-kernel@lists.infradead.org References: <20210604070633.32363-1-wangkefeng.wang@huawei.com> <481056ab-686e-9f42-3b8a-b31941f58af6@huawei.com> From: Christophe Leroy Message-ID: <006eb573-5a20-1ac7-6234-338d11346a08@csgroup.eu> Date: Mon, 7 Jun 2021 07:48:54 +0200 User-Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <481056ab-686e-9f42-3b8a-b31941f58af6@huawei.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: fr Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-sh@vger.kernel.org Hi Kefeng, Le 07/06/2021 à 02:55, Kefeng Wang a écrit : > > On 2021/6/7 5:29, Mike Rapoport wrote: >> Hello Kefeng, >> >> On Fri, Jun 04, 2021 at 03:06:18PM +0800, Kefeng Wang wrote: >>> Add setup_initial_init_mm() helper, then use it >>> to cleanup the text, data and brk setup code. >>> >>> v2: >>> - change argument from "char *" to "void *" setup_initial_init_mm() >>>    suggested by Geert Uytterhoeven >>> - use NULL instead of (void *)0 on h8300 and m68k >>> - collect ACKs >>> >>> Cc: linux-snps-arc@lists.infradead.org >>> Cc: linux-arm-kernel@lists.infradead.org >>> Cc: linux-csky@vger.kernel.org >>> Cc: uclinux-h8-devel@lists.sourceforge.jp >>> Cc: linux-m68k@lists.linux-m68k.org >>> Cc: openrisc@lists.librecores.org >>> Cc: linuxppc-dev@lists.ozlabs.org >>> Cc: linux-riscv@lists.infradead.org >>> Cc: linux-sh@vger.kernel.org >>> Cc: linux-s390@vger.kernel.org >>> Kefeng Wang (15): >>>    mm: add setup_initial_init_mm() helper >>>    arc: convert to setup_initial_init_mm() >>>    arm: convert to setup_initial_init_mm() >>>    arm64: convert to setup_initial_init_mm() >>>    csky: convert to setup_initial_init_mm() >>>    h8300: convert to setup_initial_init_mm() >>>    m68k: convert to setup_initial_init_mm() >>>    nds32: convert to setup_initial_init_mm() >>>    nios2: convert to setup_initial_init_mm() >>>    openrisc: convert to setup_initial_init_mm() >>>    powerpc: convert to setup_initial_init_mm() >>>    riscv: convert to setup_initial_init_mm() >>>    s390: convert to setup_initial_init_mm() >>>    sh: convert to setup_initial_init_mm() >>>    x86: convert to setup_initial_init_mm() >> I might be missing something, but AFAIU the init_mm.start_code and other >> fields are not used really early so the new setup_initial_init_mm() >> function can be called in the generic code outside setup_arch(), e.g in >> mm_init(). > > Hi Mike， each architecture has their own value, not the same, eg m68K and > > h8300, also the name of the text/code/brk is different in some arch, so I keep > > unchanged. What you could do is to define a __weak function that architectures can override and call that function from mm_init() as suggested by Mike, Something like: void __weak setup_initial_init_mm(void) { init_mm.start_code = (unsigned long)_stext; init_mm.end_code = (unsigned long)_etext; init_mm.end_data = (unsigned long)_edata; init_mm.brk = (unsigned long)_end; } Then only the few architecture that are different would override it. I see a few archictectures are usigne PAGE_OFFSET to set .start_code, but it is likely that this is equivalent to _stext. Christophe