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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT 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 CFF08C43381 for ; Thu, 21 Feb 2019 13:52:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AA0A92084F for ; Thu, 21 Feb 2019 13:52:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728191AbfBUNwH (ORCPT ); Thu, 21 Feb 2019 08:52:07 -0500 Received: from foss.arm.com ([217.140.101.70]:44884 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725385AbfBUNwG (ORCPT ); Thu, 21 Feb 2019 08:52:06 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6E47680D; Thu, 21 Feb 2019 05:52:06 -0800 (PST) Received: from lakrids.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 14BE13F5C1; Thu, 21 Feb 2019 05:52:02 -0800 (PST) Date: Thu, 21 Feb 2019 13:52:00 +0000 From: Mark Rutland To: Steven Price Cc: linux-mm@kvack.org, Andy Lutomirski , Ard Biesheuvel , Arnd Bergmann , Borislav Petkov , Catalin Marinas , Dave Hansen , Ingo Molnar , James Morse , =?utf-8?B?SsOpcsO0bWU=?= Glisse , Peter Zijlstra , Thomas Gleixner , Will Deacon , x86@kernel.org, "H. Peter Anvin" , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, "Liang, Kan" Subject: Re: [PATCH v2 01/13] arm64: mm: Add p?d_large() definitions Message-ID: <20190221135200.GG33673@lakrids.cambridge.arm.com> References: <20190221113502.54153-1-steven.price@arm.com> <20190221113502.54153-2-steven.price@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190221113502.54153-2-steven.price@arm.com> User-Agent: Mutt/1.11.1+11 (2f07cb52) (2018-12-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Feb 21, 2019 at 11:34:50AM +0000, Steven Price wrote: > From: James Morse > > Exposing the pud/pgd levels of the page tables to walk_page_range() means > we may come across the exotic large mappings that come with large areas > of contiguous memory (such as the kernel's linear map). > > Expose p?d_large() from each architecture to detect these large mappings. > > arm64 already has these macros defined, but with a different name. > p?d_large() is used by s390, sparc and x86. Only arm/arm64 use p?d_sect(). > Add a macro to allow both names. So that we can avoid conflciting terminology, could we reword this as: A generic walk_page_range() needs to handle exotic leaf entries at arbitrary depths in the page tables (e.g. section mappings in the kernel's linear map, or huge pages in userspace page tables). Currently there is no generic API to detect such entries, but s390, sparc, and x86 have all aligned on p?d_large(). Let's implement the same for arm64 atop of p?d_cont(). With that: Acked-by: Mark Rutland Thanks, Mark. > > Signed-off-by: James Morse > Signed-off-by: Steven Price > --- > arch/arm64/include/asm/pgtable.h | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h > index de70c1eabf33..09d308921625 100644 > --- a/arch/arm64/include/asm/pgtable.h > +++ b/arch/arm64/include/asm/pgtable.h > @@ -428,6 +428,7 @@ extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, > PMD_TYPE_TABLE) > #define pmd_sect(pmd) ((pmd_val(pmd) & PMD_TYPE_MASK) == \ > PMD_TYPE_SECT) > +#define pmd_large(x) pmd_sect(x) > > #if defined(CONFIG_ARM64_64K_PAGES) || CONFIG_PGTABLE_LEVELS < 3 > #define pud_sect(pud) (0) > @@ -435,6 +436,7 @@ extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, > #else > #define pud_sect(pud) ((pud_val(pud) & PUD_TYPE_MASK) == \ > PUD_TYPE_SECT) > +#define pud_large(x) pud_sect(x) > #define pud_table(pud) ((pud_val(pud) & PUD_TYPE_MASK) == \ > PUD_TYPE_TABLE) > #endif > -- > 2.20.1 >