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 C78C5C001DE for ; Tue, 25 Jul 2023 10:15:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232561AbjGYKP2 (ORCPT ); Tue, 25 Jul 2023 06:15:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40336 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232443AbjGYKPZ (ORCPT ); Tue, 25 Jul 2023 06:15:25 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 87BD61728 for ; Tue, 25 Jul 2023 03:15:21 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id B29C2615F1 for ; Tue, 25 Jul 2023 10:15:20 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7B7E7C433D9; Tue, 25 Jul 2023 10:15:14 +0000 (UTC) Date: Tue, 25 Jul 2023 11:15:11 +0100 From: Catalin Marinas To: "zhangjianhua (E)" Cc: Anshuman Khandual , will@kernel.org, ryan.roberts@arm.com, joey.gouly@arm.com, ardb@kernel.org, mark.rutland@arm.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH -next v2] arm64: fix build warning for ARM64_MEMSTART_SHIFT Message-ID: References: <20230724172751.3048501-1-chris.zjh@huawei.com> <4938685e-d293-4970-b964-3b9f560d45dd@arm.com> <9fcfe47f-9289-8eb5-ce4e-9f66648b0e89@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <9fcfe47f-9289-8eb5-ce4e-9f66648b0e89@huawei.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 25, 2023 at 04:47:46PM +0800, zhangjianhua (E) wrote: > 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. That's fine by me, better than adding the #ifndef __ASSEMBLY__ around them. > 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. For .c files, we can solve this by including asm/pgtable-types.h in asm/pgtable-hwdef.h. This still leaves P*D_SHIFT undefined for .S files since the generic nop*d.h headers guard the shifts with !__ASSEMBLY__ but do we really care about this? I haven't seen any other warning of P*D_SHIFT not being defined. If you do want to solve these, just go and change the generic headers to take the shift out of the asm guard. I don't think it's worth it. -- Catalin