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=-15.5 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=ham 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 5A1CAC2B9F4 for ; Thu, 17 Jun 2021 07:00:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 35A23613F3 for ; Thu, 17 Jun 2021 07:00:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229972AbhFQHCs (ORCPT ); Thu, 17 Jun 2021 03:02:48 -0400 Received: from pegase1.c-s.fr ([93.17.236.30]:19612 "EHLO pegase1.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229931AbhFQHCq (ORCPT ); Thu, 17 Jun 2021 03:02:46 -0400 Received: from localhost (mailhub3.si.c-s.fr [192.168.12.233]) by localhost (Postfix) with ESMTP id 4G5Cck6knBzB9Kg; Thu, 17 Jun 2021 09:00:38 +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 QJPdcHdgEBZK; Thu, 17 Jun 2021 09:00:38 +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 4G5Cck5nnwzB9JP; Thu, 17 Jun 2021 09:00:38 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id BB7508B803; Thu, 17 Jun 2021 09:00:38 +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 v7kr536TYdhu; Thu, 17 Jun 2021 09:00:38 +0200 (CEST) Received: from [192.168.4.90] (unknown [192.168.4.90]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 0BA158B801; Thu, 17 Jun 2021 09:00:37 +0200 (CEST) Subject: Re: [PATCH v14 3/4] mm: define default MAX_PTRS_PER_* in include/pgtable.h To: Daniel Axtens , linux-kernel@vger.kernel.org, linux-mm@kvack.org, kasan-dev@googlegroups.com, elver@google.com, akpm@linux-foundation.org, andreyknvl@gmail.com Cc: linuxppc-dev@lists.ozlabs.org, aneesh.kumar@linux.ibm.com, bsingharora@gmail.com References: <20210617063956.94061-1-dja@axtens.net> <20210617063956.94061-4-dja@axtens.net> From: Christophe Leroy Message-ID: Date: Thu, 17 Jun 2021 09:00:35 +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: <20210617063956.94061-4-dja@axtens.net> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: fr Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le 17/06/2021 à 08:39, Daniel Axtens a écrit : > Commit c65e774fb3f6 ("x86/mm: Make PGDIR_SHIFT and PTRS_PER_P4D variable") > made PTRS_PER_P4D variable on x86 and introduced MAX_PTRS_PER_P4D as a > constant for cases which need a compile-time constant (e.g. fixed-size > arrays). > > powerpc likewise has boot-time selectable MMU features which can cause > other mm "constants" to vary. For KASAN, we have some static > PTE/PMD/PUD/P4D arrays so we need compile-time maximums for all these > constants. Extend the MAX_PTRS_PER_ idiom, and place default definitions > in include/pgtable.h. These define MAX_PTRS_PER_x to be PTRS_PER_x unless > an architecture has defined MAX_PTRS_PER_x in its arch headers. > > Clean up pgtable-nop4d.h and s390's MAX_PTRS_PER_P4D definitions while > we're at it: both can just pick up the default now. > > Signed-off-by: Daniel Axtens Reviewed-by: Christophe Leroy > > --- > > s390 was compile tested only. > --- > arch/s390/include/asm/pgtable.h | 2 -- > include/asm-generic/pgtable-nop4d.h | 1 - > include/linux/pgtable.h | 22 ++++++++++++++++++++++ > 3 files changed, 22 insertions(+), 3 deletions(-) > > diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h > index 7c66ae5d7e32..cf05954ce013 100644 > --- a/arch/s390/include/asm/pgtable.h > +++ b/arch/s390/include/asm/pgtable.h > @@ -342,8 +342,6 @@ static inline int is_module_addr(void *addr) > #define PTRS_PER_P4D _CRST_ENTRIES > #define PTRS_PER_PGD _CRST_ENTRIES > > -#define MAX_PTRS_PER_P4D PTRS_PER_P4D > - > /* > * Segment table and region3 table entry encoding > * (R = read-only, I = invalid, y = young bit): > diff --git a/include/asm-generic/pgtable-nop4d.h b/include/asm-generic/pgtable-nop4d.h > index ce2cbb3c380f..2f6b1befb129 100644 > --- a/include/asm-generic/pgtable-nop4d.h > +++ b/include/asm-generic/pgtable-nop4d.h > @@ -9,7 +9,6 @@ > typedef struct { pgd_t pgd; } p4d_t; > > #define P4D_SHIFT PGDIR_SHIFT > -#define MAX_PTRS_PER_P4D 1 > #define PTRS_PER_P4D 1 > #define P4D_SIZE (1UL << P4D_SHIFT) > #define P4D_MASK (~(P4D_SIZE-1)) > diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h > index 9e6f71265f72..69700e3e615f 100644 > --- a/include/linux/pgtable.h > +++ b/include/linux/pgtable.h > @@ -1625,4 +1625,26 @@ typedef unsigned int pgtbl_mod_mask; > #define pte_leaf_size(x) PAGE_SIZE > #endif > > +/* > + * Some architectures have MMUs that are configurable or selectable at boot > + * time. These lead to variable PTRS_PER_x. For statically allocated arrays it > + * helps to have a static maximum value. > + */ > + > +#ifndef MAX_PTRS_PER_PTE > +#define MAX_PTRS_PER_PTE PTRS_PER_PTE > +#endif > + > +#ifndef MAX_PTRS_PER_PMD > +#define MAX_PTRS_PER_PMD PTRS_PER_PMD > +#endif > + > +#ifndef MAX_PTRS_PER_PUD > +#define MAX_PTRS_PER_PUD PTRS_PER_PUD > +#endif > + > +#ifndef MAX_PTRS_PER_P4D > +#define MAX_PTRS_PER_P4D PTRS_PER_P4D > +#endif > + > #endif /* _LINUX_PGTABLE_H */ >