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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 34CC5EB64DD for ; Mon, 24 Jul 2023 03:26:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230016AbjGXD0N (ORCPT ); Sun, 23 Jul 2023 23:26:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37662 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229506AbjGXD0K (ORCPT ); Sun, 23 Jul 2023 23:26:10 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id D8B3F1B0 for ; Sun, 23 Jul 2023 20:26:08 -0700 (PDT) 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 880E8DE0; Sun, 23 Jul 2023 20:26:51 -0700 (PDT) Received: from [10.162.41.7] (unknown [10.162.41.7]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 965193F6C4; Sun, 23 Jul 2023 20:26:05 -0700 (PDT) Message-ID: Date: Mon, 24 Jul 2023 08:56:02 +0530 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.11.0 Subject: Re: [PATCH -next] arm64: fix -Wundef warning for PUD_SHIFT Content-Language: en-US To: Zhang Jianhua , catalin.marinas@arm.com, will@kernel.org, joey.gouly@arm.com, mark.rutland@arm.com, ardb@kernel.org Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <20230724103055.2379274-1-chris.zjh@huawei.com> From: Anshuman Khandual In-Reply-To: <20230724103055.2379274-1-chris.zjh@huawei.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 7/24/23 16:00, Zhang Jianhua wrote: > When building with W=1, the following warning occurs. > > arch/arm64/include/asm/kernel-pgtable.h:129:41: error: "PUD_SHIFT" is not defined, evaluates to 0 [-Werror=undef] > 129 | #define ARM64_MEMSTART_SHIFT PUD_SHIFT > | ^~~~~~~~~ > arch/arm64/include/asm/kernel-pgtable.h:142:5: note: in expansion of macro ‘ARM64_MEMSTART_SHIFT’ > 142 | #if ARM64_MEMSTART_SHIFT < SECTION_SIZE_BITS > | ^~~~~~~~~~~~~~~~~~~~ > > The reason is that PUD_SHIFT isn't defined if CONFIG_PGTABLE_LEVELS == > 3, and at this time PUD_SHIFT is equal to PGDIR_SHIFT, so define it. CONFIG_PGTABLE_LEVELS equals 3 only with CONFIG_VA_BITS = 39. > > Fixes: 06e9bf2fd9b3 ("arm64: choose memstart_addr based on minimum sparsemem section alignment") This is not a fix, ARM64_MEMSTART_ALIGN would fallback being (1UL << SECTION_SIZE_BITS) when PUD_SHIFT is undefined (aka 0) but agreed that it's not clean. > Signed-off-by: Zhang Jianhua > --- > v2: > Define PUD_SHIFT before use it instead of judgement > --- > --- > arch/arm64/include/asm/kernel-pgtable.h | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/arch/arm64/include/asm/kernel-pgtable.h b/arch/arm64/include/asm/kernel-pgtable.h > index 577773870b66..996a144e2929 100644 > --- a/arch/arm64/include/asm/kernel-pgtable.h > +++ b/arch/arm64/include/asm/kernel-pgtable.h > @@ -59,6 +59,10 @@ > #define EARLY_KASLR (0) > #endif > > +#ifndef PUD_SHIFT > +#define PUD_SHIFT PGDIR_SHIFT > +#endif Rather ARM64_MEMSTART_SHIFT block needs to be re-written in a more pgtable levels agnostic manner ? OR maybe something like this. diff --git a/arch/arm64/include/asm/kernel-pgtable.h b/arch/arm64/include/asm/kernel-pgtable.h index 577773870b66..5a83b4b249e8 100644 --- a/arch/arm64/include/asm/kernel-pgtable.h +++ b/arch/arm64/include/asm/kernel-pgtable.h @@ -125,12 +125,14 @@ * (64k granule), or a multiple that can be mapped using contiguous bits * in the page tables: 32 * PMD_SIZE (16k granule) */ -#if defined(CONFIG_ARM64_4K_PAGES) +#if defined(CONFIG_ARM64_4K_PAGES) && defined(PUD_SHIFT) #define ARM64_MEMSTART_SHIFT PUD_SHIFT -#elif defined(CONFIG_ARM64_16K_PAGES) +#elif defined(CONFIG_ARM64_16K_PAGES) && defined(CONT_PMD_SHIFT) #define ARM64_MEMSTART_SHIFT CONT_PMD_SHIFT -#else +#elif defined(CONFIG_AR64_64K_PAGES) && defined(PMD_SHIFT) #define ARM64_MEMSTART_SHIFT PMD_SHIFT +#else +#define ARM64_MEMSTART_SHIFT PGDIR_SHIFT #endif The only cases where PUD_SHIFT or PMD_SHIFT (along with CONT_PMD_SHIFT) would not be defined is when XXX_SHIFT level itself matches PGDIR_SHIFT. > + > #define SPAN_NR_ENTRIES(vstart, vend, shift) \ > ((((vend) - 1) >> (shift)) - ((vstart) >> (shift)) + 1) >