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=-14.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SIGNED_OFF_BY,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 756D9C2BB84 for ; Thu, 10 Sep 2020 09:29:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3232121D40 for ; Thu, 10 Sep 2020 09:29:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730551AbgIJJ3C (ORCPT ); Thu, 10 Sep 2020 05:29:02 -0400 Received: from foss.arm.com ([217.140.110.172]:58960 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726760AbgIJJ25 (ORCPT ); Thu, 10 Sep 2020 05:28:57 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 60584101E; Thu, 10 Sep 2020 02:28:57 -0700 (PDT) Received: from [10.163.71.250] (unknown [10.163.71.250]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 7C4ED3F68F; Thu, 10 Sep 2020 02:28:55 -0700 (PDT) Subject: Re: [PATCH 2/2] arm64/mm: Use CONT_SHIFT to define CONT_PTE_SHIFT To: Gavin Shan , linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org, catalin.marinas@arm.com, will@kernel.org, shan.gavin@gmail.com References: <20200908071931.47767-1-gshan@redhat.com> <20200908071931.47767-2-gshan@redhat.com> <459d0f64-fea9-a060-91a5-17a37834fb1b@arm.com> <283283a2-f516-6890-ae25-101d2b1b46a2@redhat.com> From: Anshuman Khandual Message-ID: <966505a6-16f6-8129-804b-fcf890429fb8@arm.com> Date: Thu, 10 Sep 2020 14:58:22 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <283283a2-f516-6890-ae25-101d2b1b46a2@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/10/2020 02:01 PM, Gavin Shan wrote: > Hi Anshuman, > > On 9/10/20 4:17 PM, Anshuman Khandual wrote: >> On 09/08/2020 12:49 PM, Gavin Shan wrote: >>> The macro CONT_PTE_SHIFT actually depends on CONT_SHIFT, which has >>> been defined in page-def.h, based on CONFIG_ARM64_CONT_SHIFT. Lets >>> reflect the dependency. >>> >>> Signed-off-by: Gavin Shan >>> --- >>>   arch/arm64/include/asm/pgtable-hwdef.h | 4 +--- >>>   1 file changed, 1 insertion(+), 3 deletions(-) >>> >>> diff --git a/arch/arm64/include/asm/pgtable-hwdef.h b/arch/arm64/include/asm/pgtable-hwdef.h >>> index 8a399e666837..0bd9469f4323 100644 >>> --- a/arch/arm64/include/asm/pgtable-hwdef.h >>> +++ b/arch/arm64/include/asm/pgtable-hwdef.h >>> @@ -81,14 +81,12 @@ >>>   /* >>>    * Contiguous page definitions. >>>    */ >>> +#define CONT_PTE_SHIFT        (CONT_SHIFT + PAGE_SHIFT) >>>   #ifdef CONFIG_ARM64_64K_PAGES >>> -#define CONT_PTE_SHIFT        (5 + PAGE_SHIFT) >>>   #define CONT_PMD_SHIFT        (5 + PMD_SHIFT) >>>   #elif defined(CONFIG_ARM64_16K_PAGES) >>> -#define CONT_PTE_SHIFT        (7 + PAGE_SHIFT) >>>   #define CONT_PMD_SHIFT        (5 + PMD_SHIFT) >>>   #else >>> -#define CONT_PTE_SHIFT        (4 + PAGE_SHIFT) >>>   #define CONT_PMD_SHIFT        (4 + PMD_SHIFT) >>>   #endif >> Could not a similar CONT_PMD be created from a new CONFIG_ARM64_CONT_PMD >> config option, which would help unify CONT_PMD_SHIFT here as well ? >> > > I was thinking of it, to have CONFIG_ARM64_CONT_PMD and defined the > following macros in arch/arm64/include/asm/page-def.h: > >    #define CONT_PMD_SHIFT    CONFIG_ARM64_CONT_PMD_SHIFT >    #define CONT_PMD_SIZE        (_AC(1, UL) << (CONT_PMD_SHIFT + PMD_SHIFT) >    #define CONT_PMD_MASK        (~(CONT_PMD_SIZE - 1)) > > PMD_SHIFT is variable because PMD could be folded into PUD or PGD, > depending on the kernel configuration. PMD_SHIFT is declared Even CONT_PMD_SHIFT via the new CONFIG_ARM64_CONT_PMD_SHIFT will be a variable as well depending on page size. > in arch/arm64/include/asm/pgtable-types.h, which isn't supposed > to be included in "page-def.h". Are there build failures if is included from ? > > So the peroper way to handle this might be drop the continuous page > macros in page-def.h and introduce the following ones into pgtable-hwdef.h. > I will post v2 to do this if it sounds good to you. Sure, go ahead if that builds. But unifying both these macros seems cleaner. > >    #define CONT_PTE_SHIFT         (CONFIG_ARM64_CONT_PTE_SHIFT + PAGE_SHIFT) >    #define CONT_PMD_SHIFT         (CONFIG_ARM64_CONT_PMD_SHIFT + PMD_SHIFT) > > Thanks, > Gavin > >