From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754594AbbBKWGU (ORCPT ); Wed, 11 Feb 2015 17:06:20 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:42644 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754444AbbBKWGT (ORCPT ); Wed, 11 Feb 2015 17:06:19 -0500 Date: Wed, 11 Feb 2015 14:06:17 -0800 From: Andrew Morton To: Russell King - ARM Linux Cc: Andre Przywara , catalin.marinas@arm.com, Mel Gorman , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH] arm/mm: fix compiler warning in pmdp_invalidate() (in -next) Message-Id: <20150211140617.9f00465d147fe0db10777dfb@linux-foundation.org> In-Reply-To: <20150130164015.GQ26493@n2100.arm.linux.org.uk> References: <20150130100620.GL2395@suse.de> <1422635852-21569-1-git-send-email-andre.przywara@arm.com> <20150130164015.GQ26493@n2100.arm.linux.org.uk> X-Mailer: Sylpheed 3.4.1 (GTK+ 2.24.23; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 30 Jan 2015 16:40:15 +0000 Russell King - ARM Linux wrote: > On Fri, Jan 30, 2015 at 04:37:32PM +0000, Andre Przywara wrote: > > Commit ff61d185f4e7 ("mm: convert p[te|md]_mknonnuma and remaining > > page table manipulations") removed a check in > > mm/pgtable-generic.c:pmdp_invalidate(), which leaves the > > pmd_mknotpresent macro the only user of the entry variable. > > For ARM/LPAE we use a constant 0 without referencing the argument to > > mark this condition, so the entry variable is no longer used here: > > > > mm/pgtable-generic.c: In function 'pmdp_invalidate': > > mm/pgtable-generic.c:195:8: warning: unused variable 'entry' [-Wunused-variable] > > pmd_t entry = *pmdp; > > ^ > > > > Replace the ARM macro implementation with a static inline function to > > get rid of this warning. > > > > Signed-off-by: Andre Przywara > > --- > > Hi Andrew, > > > > Mel mentioned that I should send that simple fix below to you to > > merge it with his original mmotm patch: > > mm-convert-p_mknonnuma-and-remaining-page-table-manipulations.patch > > The commit message above contains the mmotm-reference to this patch, > > which will break when it hits mainline. > > > > Can you consider this? Given that's only a warning fix I am also > > happy with resending it after -rc1, if you reckon that this arch/arm > > change should not go via mmotm. > > This isn't correct though. > > > /* represent a notpresent pmd by zero, this is used by pmdp_invalidate */ > > -#define pmd_mknotpresent(pmd) (__pmd(0)) > > +static inline pmd_t pmd_mknotpresent(pmd_t pmd) > > +{ > > + return 0; > > +} > > typedef struct { pmdval_t pmd; } pmd_t; > > typedef u32 pmdval_t; > > "0" is not compatible with pmd_t when STRICT_MM_TYPECHECKS is enabled. This? --- a/arch/arm/include/asm/pgtable-3level.h~mm-convert-p_mknonnuma-and-remaining-page-table-manipulations-fix-fix +++ a/arch/arm/include/asm/pgtable-3level.h @@ -259,7 +259,7 @@ PMD_BIT_FUNC(mkyoung, |= PMD_SECT_AF); /* represent a notpresent pmd by zero, this is used by pmdp_invalidate */ static inline pmd_t pmd_mknotpresent(pmd_t pmd) { - return 0; + return __pmd(0); } static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)