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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 8E071C433DF for ; Mon, 15 Jun 2020 12:58:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 78F012078A for ; Mon, 15 Jun 2020 12:58:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730199AbgFOM6E (ORCPT ); Mon, 15 Jun 2020 08:58:04 -0400 Received: from pegase1.c-s.fr ([93.17.236.30]:46566 "EHLO pegase1.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729826AbgFOM6A (ORCPT ); Mon, 15 Jun 2020 08:58:00 -0400 Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 49lrwN3hbzz9v1fd; Mon, 15 Jun 2020 14:57:56 +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 Mt02zgRfRhQ2; Mon, 15 Jun 2020 14:57:56 +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 49lrwN2bq2z9v1fM; Mon, 15 Jun 2020 14:57:56 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id B54988B792; Mon, 15 Jun 2020 14:57:56 +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 gAwaiMFxQKLE; Mon, 15 Jun 2020 14:57:56 +0200 (CEST) Received: from pc16570vm.idsi0.si.c-s.fr (po15451.idsi0.si.c-s.fr [172.25.230.104]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 645BB8B75F; Mon, 15 Jun 2020 14:57:56 +0200 (CEST) Received: by pc16570vm.idsi0.si.c-s.fr (Postfix, from userid 0) id F187565B0E; Mon, 15 Jun 2020 12:57:55 +0000 (UTC) Message-Id: From: Christophe Leroy Subject: [PATCH 0/3] Fix build failure with v5.8-rc1 To: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Will Deacon , Andrew Morton , "Peter Zijlstra (Intel)" Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-mm@kvack.org Date: Mon, 15 Jun 2020 12:57:55 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit 2ab3a0a02905 ("READ_ONCE: Enforce atomicity for {READ,WRITE}_ONCE() memory accesses") leads to following build failure on powerpc 8xx. To fix it, this small series introduces a new helper named ptep_get() to replace the direct access with READ_ONCE(). This new helper can be overriden by architectures. CC mm/gup.o In file included from ./include/linux/kernel.h:11:0, from mm/gup.c:2: In function 'gup_hugepte.constprop', inlined from 'gup_huge_pd.isra.79' at mm/gup.c:2465:8: ./include/linux/compiler.h:392:38: error: call to '__compiletime_assert_222' declared with attribute error: Unsupported access size for {READ,WRITE}_ONCE(). _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) ^ ./include/linux/compiler.h:373:4: note: in definition of macro '__compiletime_assert' prefix ## suffix(); \ ^ ./include/linux/compiler.h:392:2: note: in expansion of macro '_compiletime_assert' _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) ^ ./include/linux/compiler.h:405:2: note: in expansion of macro 'compiletime_assert' compiletime_assert(__native_word(t) || sizeof(t) == sizeof(long long), \ ^ ./include/linux/compiler.h:291:2: note: in expansion of macro 'compiletime_assert_rwonce_type' compiletime_assert_rwonce_type(x); \ ^ mm/gup.c:2428:8: note: in expansion of macro 'READ_ONCE' pte = READ_ONCE(*ptep); ^ In function 'gup_get_pte', inlined from 'gup_pte_range' at mm/gup.c:2228:9, inlined from 'gup_pmd_range' at mm/gup.c:2613:15, inlined from 'gup_pud_range' at mm/gup.c:2641:15, inlined from 'gup_p4d_range' at mm/gup.c:2666:15, inlined from 'gup_pgd_range' at mm/gup.c:2694:15, inlined from 'internal_get_user_pages_fast' at mm/gup.c:2795:3: ./include/linux/compiler.h:392:38: error: call to '__compiletime_assert_219' declared with attribute error: Unsupported access size for {READ,WRITE}_ONCE(). _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) ^ ./include/linux/compiler.h:373:4: note: in definition of macro '__compiletime_assert' prefix ## suffix(); \ ^ ./include/linux/compiler.h:392:2: note: in expansion of macro '_compiletime_assert' _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) ^ ./include/linux/compiler.h:405:2: note: in expansion of macro 'compiletime_assert' compiletime_assert(__native_word(t) || sizeof(t) == sizeof(long long), \ ^ ./include/linux/compiler.h:291:2: note: in expansion of macro 'compiletime_assert_rwonce_type' compiletime_assert_rwonce_type(x); \ ^ mm/gup.c:2199:9: note: in expansion of macro 'READ_ONCE' return READ_ONCE(*ptep); ^ make[2]: *** [mm/gup.o] Error 1 Christophe Leroy (3): mm/gup: Use huge_ptep_get() in gup_hugepte() mm: Allow arches to provide ptep_get() powerpc/8xx: Provide ptep_get() with 16k pages arch/powerpc/include/asm/nohash/32/pgtable.h | 10 ++++++++++ include/asm-generic/hugetlb.h | 2 +- include/linux/pgtable.h | 7 +++++++ mm/gup.c | 4 ++-- 4 files changed, 20 insertions(+), 3 deletions(-) -- 2.25.0