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 86EBFC0015E for ; Tue, 25 Jul 2023 08:51:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229542AbjGYIvb (ORCPT ); Tue, 25 Jul 2023 04:51:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35500 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232244AbjGYIuv (ORCPT ); Tue, 25 Jul 2023 04:50:51 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BFD1B35AD for ; Tue, 25 Jul 2023 01:48:19 -0700 (PDT) Received: from canpemm500005.china.huawei.com (unknown [172.30.72.56]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4R99Z06KWBzNmgb; Tue, 25 Jul 2023 16:44:24 +0800 (CST) Received: from [10.67.110.73] (10.67.110.73) by canpemm500005.china.huawei.com (7.192.104.229) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.27; Tue, 25 Jul 2023 16:47:47 +0800 Message-ID: <9fcfe47f-9289-8eb5-ce4e-9f66648b0e89@huawei.com> Date: Tue, 25 Jul 2023 16:47:46 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.3.3 Subject: Re: [PATCH -next v2] arm64: fix build warning for ARM64_MEMSTART_SHIFT To: Anshuman Khandual , Catalin Marinas CC: , , , , , , References: <20230724172751.3048501-1-chris.zjh@huawei.com> <4938685e-d293-4970-b964-3b9f560d45dd@arm.com> From: "zhangjianhua (E)" In-Reply-To: <4938685e-d293-4970-b964-3b9f560d45dd@arm.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.67.110.73] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To canpemm500005.china.huawei.com (7.192.104.229) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 在 2023/7/25 12:22, Anshuman Khandual 写道: > > On 7/24/23 20:41, Catalin Marinas wrote: >> On Mon, Jul 24, 2023 at 05:27:51PM +0000, 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 >>> | ^~~~~~~~~~~~~~~~~~~~ >> Another thing that's missing here is that the warning is probably when >> this file is included from asm-offests.h or some .S file. >> >>> diff --git a/arch/arm64/include/asm/kernel-pgtable.h b/arch/arm64/include/asm/kernel-pgtable.h >>> index 577773870b66..51bdce66885d 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 >> That's not the correct fix since PUD_SHIFT should always be defined. >> When CONFIG_PGTABLE_LEVELS == 3, pgtable-types.h includes >> asm-generic/pgtable-nopud.h and this defines PUD_SHIFT. We either got > Right, PUD_SHIFT is always defined irrespective of page table levels. > >> ARM64_MEMSTART_SHIFT defined in the wrong file or kernel-pgtable.h does >> not pull the relevant headers (either directly or via an included >> header). Even if kernel-pgtable.h ends up including the nopud/nopmd >> headers, P*D_SHIFT is guarded by an #indef __ASSEMBLY__ in those files. >> >> Something like below appears to fix this, though I'm not particularly >> fond of guarding the ARM64_MEMSTART_* definitions by #ifndef >> __ASSEMBLY__ for no apparent reason (could add a comment though): >> >> -----------------------8<--------------------------- >> diff --git a/arch/arm64/include/asm/kernel-pgtable.h b/arch/arm64/include/asm/kernel-pgtable.h >> index 577773870b66..fcea7e87a6ca 100644 >> --- a/arch/arm64/include/asm/kernel-pgtable.h >> +++ b/arch/arm64/include/asm/kernel-pgtable.h >> @@ -118,6 +118,8 @@ >> #define SWAPPER_RX_MMUFLAGS (SWAPPER_RW_MMUFLAGS | PTE_RDONLY) >> #endif >> >> +#ifndef __ASSEMBLY__ >> + >> /* >> * To make optimal use of block mappings when laying out the linear >> * mapping, round down the base of physical memory to a size that can >> @@ -145,4 +147,6 @@ >> #define ARM64_MEMSTART_ALIGN (1UL << ARM64_MEMSTART_SHIFT) >> #endif >> >> +#endif /* __ASSEMBLY__ */ >> + >> #endif /* __ASM_KERNEL_PGTABLE_H */ >> diff --git a/arch/arm64/include/asm/pgtable-hwdef.h b/arch/arm64/include/asm/pgtable-hwdef.h >> index e4944d517c99..22b36f2d5d93 100644 >> --- a/arch/arm64/include/asm/pgtable-hwdef.h >> +++ b/arch/arm64/include/asm/pgtable-hwdef.h >> @@ -6,6 +6,7 @@ >> #define __ASM_PGTABLE_HWDEF_H >> >> #include >> +#include >> >> /* >> * Number of page-table levels required to address 'va_bits' wide >> diff --git a/arch/arm64/include/asm/pgtable-types.h b/arch/arm64/include/asm/pgtable-types.h >> index b8f158ae2527..ae86e66fdb11 100644 >> --- a/arch/arm64/include/asm/pgtable-types.h >> +++ b/arch/arm64/include/asm/pgtable-types.h >> @@ -11,6 +11,8 @@ >> >> #include >> >> +#ifndef __ASSEMBLY__ >> + >> typedef u64 pteval_t; >> typedef u64 pmdval_t; >> typedef u64 pudval_t; >> @@ -44,6 +46,8 @@ typedef struct { pteval_t pgprot; } pgprot_t; >> #define pgprot_val(x) ((x).pgprot) >> #define __pgprot(x) ((pgprot_t) { (x) } ) >> >> +#endif /* __ASSEMBLY__ */ >> + >> #if CONFIG_PGTABLE_LEVELS == 2 >> #include >> #elif CONFIG_PGTABLE_LEVELS == 3 >> -----------------------8<--------------------------- >> >> To avoid guarding the ARM64_MEMSTART_* definitions, we could instead >> move the P*D_SHIFT definitions in asm-generic/pgtable-nop*d.h outside >> the #ifndef __ASSEMBLY__ block. > OR could ARM64_MEMSTART_SHIFT and ARM64_MEMSTART_ALIGN computation blocks > be moved inside arch/arm64/mm/init.c, where it is used exclusively. Seems > to be solving the problem as well. This method can avoid the current compilation warning, but does not solve the problem that PUD_SHIFT and PMD_SHIFT undefined in fact, and it is contrary to XXX_SHIFT should always be defined. Maybe it would be more appropriate to solve this issue directly.