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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 4A652C433B4 for ; Wed, 14 Apr 2021 06:11:21 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 868C561166 for ; Wed, 14 Apr 2021 06:11:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 868C561166 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=csgroup.eu Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4FKsYL6qBdz3btS for ; Wed, 14 Apr 2021 16:11:18 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=csgroup.eu (client-ip=93.17.236.30; helo=pegase1.c-s.fr; envelope-from=christophe.leroy@csgroup.eu; receiver=) Received: from pegase1.c-s.fr (pegase1.c-s.fr [93.17.236.30]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4FKsXy3ptxz303C for ; Wed, 14 Apr 2021 16:10:55 +1000 (AEST) Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 4FKsXp6CPzzB09bD; Wed, 14 Apr 2021 08:10:50 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [192.168.12.234]) (amavisd-new, port 10024) with ESMTP id bgEX-Y99N3ka; Wed, 14 Apr 2021 08:10:50 +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 4FKsXp513xzB09bB; Wed, 14 Apr 2021 08:10:50 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 8F6CC8B7B6; Wed, 14 Apr 2021 08:10:51 +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 8t_hMitD6rsU; Wed, 14 Apr 2021 08:10:51 +0200 (CEST) Received: from [192.168.4.90] (unknown [192.168.4.90]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 62A328B75F; Wed, 14 Apr 2021 08:10:50 +0200 (CEST) Subject: Re: [PATCH] mm: Define ARCH_HAS_FIRST_USER_ADDRESS To: Anshuman Khandual , linux-mm@kvack.org, akpm@linux-foundation.org References: <1618368899-20311-1-git-send-email-anshuman.khandual@arm.com> <6d24d3cc-b2df-f0d7-f4bf-f505f679c77e@arm.com> From: Christophe Leroy Message-ID: Date: Wed, 14 Apr 2021 08:10:49 +0200 User-Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.9.1 MIME-Version: 1.0 In-Reply-To: <6d24d3cc-b2df-f0d7-f4bf-f505f679c77e@arm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: fr Content-Transfer-Encoding: 8bit X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-s390@vger.kernel.org, linux-ia64@vger.kernel.org, linux-parisc@vger.kernel.org, linux-xtensa@linux-xtensa.org, linux-sh@vger.kernel.org, linux-hexagon@vger.kernel.org, x86@kernel.org, linux-um@lists.infradead.org, linux-mips@vger.kernel.org, linux-csky@vger.kernel.org, linux-kernel@vger.kernel.org, linux-m68k@lists.linux-m68k.org, openrisc@lists.librecores.org, linux-alpha@vger.kernel.org, sparclinux@vger.kernel.org, linux-riscv@lists.infradead.org, linux-snps-arc@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Le 14/04/2021 à 07:59, Anshuman Khandual a écrit : > > > On 4/14/21 10:52 AM, Christophe Leroy wrote: >> >> >> Le 14/04/2021 à 04:54, Anshuman Khandual a écrit : >>> Currently most platforms define FIRST_USER_ADDRESS as 0UL duplicating the >>> same code all over. Instead define a new option ARCH_HAS_FIRST_USER_ADDRESS >>> for those platforms which would override generic default FIRST_USER_ADDRESS >>> value 0UL. This makes it much cleaner with reduced code. >>> >>> Cc: linux-alpha@vger.kernel.org >>> Cc: linux-snps-arc@lists.infradead.org >>> Cc: linux-arm-kernel@lists.infradead.org >>> Cc: linux-csky@vger.kernel.org >>> Cc: linux-hexagon@vger.kernel.org >>> Cc: linux-ia64@vger.kernel.org >>> Cc: linux-m68k@lists.linux-m68k.org >>> Cc: linux-mips@vger.kernel.org >>> Cc: openrisc@lists.librecores.org >>> Cc: linux-parisc@vger.kernel.org >>> Cc: linuxppc-dev@lists.ozlabs.org >>> Cc: linux-riscv@lists.infradead.org >>> Cc: linux-s390@vger.kernel.org >>> Cc: linux-sh@vger.kernel.org >>> Cc: sparclinux@vger.kernel.org >>> Cc: linux-um@lists.infradead.org >>> Cc: linux-xtensa@linux-xtensa.org >>> Cc: x86@kernel.org >>> Cc: linux-mm@kvack.org >>> Cc: linux-kernel@vger.kernel.org >>> Signed-off-by: Anshuman Khandual >>> --- >>> arch/alpha/include/asm/pgtable.h | 1 - >>> arch/arc/include/asm/pgtable.h | 6 ------ >>> arch/arm/Kconfig | 1 + >>> arch/arm64/include/asm/pgtable.h | 2 -- >>> arch/csky/include/asm/pgtable.h | 1 - >>> arch/hexagon/include/asm/pgtable.h | 3 --- >>> arch/ia64/include/asm/pgtable.h | 1 - >>> arch/m68k/include/asm/pgtable_mm.h | 1 - >>> arch/microblaze/include/asm/pgtable.h | 2 -- >>> arch/mips/include/asm/pgtable-32.h | 1 - >>> arch/mips/include/asm/pgtable-64.h | 1 - >>> arch/nds32/Kconfig | 1 + >>> arch/nios2/include/asm/pgtable.h | 2 -- >>> arch/openrisc/include/asm/pgtable.h | 1 - >>> arch/parisc/include/asm/pgtable.h | 2 -- >>> arch/powerpc/include/asm/book3s/pgtable.h | 1 - >>> arch/powerpc/include/asm/nohash/32/pgtable.h | 1 - >>> arch/powerpc/include/asm/nohash/64/pgtable.h | 2 -- >>> arch/riscv/include/asm/pgtable.h | 2 -- >>> arch/s390/include/asm/pgtable.h | 2 -- >>> arch/sh/include/asm/pgtable.h | 2 -- >>> arch/sparc/include/asm/pgtable_32.h | 1 - >>> arch/sparc/include/asm/pgtable_64.h | 3 --- >>> arch/um/include/asm/pgtable-2level.h | 1 - >>> arch/um/include/asm/pgtable-3level.h | 1 - >>> arch/x86/include/asm/pgtable_types.h | 2 -- >>> arch/xtensa/include/asm/pgtable.h | 1 - >>> include/linux/mm.h | 4 ++++ >>> mm/Kconfig | 4 ++++ >>> 29 files changed, 10 insertions(+), 43 deletions(-) >>> >>> diff --git a/include/linux/mm.h b/include/linux/mm.h >>> index 8ba434287387..47098ccd715e 100644 >>> --- a/include/linux/mm.h >>> +++ b/include/linux/mm.h >>> @@ -46,6 +46,10 @@ extern int sysctl_page_lock_unfairness; >>> void init_mm_internals(void); >>> +#ifndef ARCH_HAS_FIRST_USER_ADDRESS >> >> I guess you didn't test it ..... :) > > In fact I did :) Though just booted it on arm64 and cross compiled on > multiple others platforms. > >> >> should be #ifndef CONFIG_ARCH_HAS_FIRST_USER_ADDRESS > > Right, meant that instead. > >> >>> +#define FIRST_USER_ADDRESS 0UL >>> +#endif >> >> But why do we need a config option at all for that ? >> >> Why not just: >> >> #ifndef FIRST_USER_ADDRESS >> #define FIRST_USER_ADDRESS 0UL >> #endif > > This sounds simpler. But just wondering, would not there be any possibility > of build problems due to compilation sequence between arch and generic code ? > For sure it has to be addresses carefully, but there are already a lot of stuff like that around pgtables.h For instance, pte_offset_kernel() has a generic definition in linux/pgtables.h based on whether it is already defined or not. Taking into account that FIRST_USER_ADDRESS is today in the architectures's asm/pgtables.h, I think putting the fallback definition in linux/pgtable.h would do the trick.