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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 2A611EA8125 for ; Wed, 11 Feb 2026 10:32:18 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 889006B0089; Wed, 11 Feb 2026 05:32:17 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 836FD6B008A; Wed, 11 Feb 2026 05:32:17 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 736A86B008C; Wed, 11 Feb 2026 05:32:17 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 634106B0089 for ; Wed, 11 Feb 2026 05:32:17 -0500 (EST) Received: from smtpin15.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 141A858475 for ; Wed, 11 Feb 2026 10:32:17 +0000 (UTC) X-FDA: 84431811114.15.E24B72D Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf04.hostedemail.com (Postfix) with ESMTP id 57E9A4000C for ; Wed, 11 Feb 2026 10:32:15 +0000 (UTC) Authentication-Results: imf04.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b="TFe7/nLN"; spf=pass (imf04.hostedemail.com: domain of rppt@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=rppt@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1770805935; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=8fVTXwM0zNvbjsVMJfP4P1PkSZuOtnuFk6QAlesaSE0=; b=Mk42b9cdi0Uyn5fJcQM7QSJmYN0Lq2hdLLkusP3xLCYKVJ0qrdUYBHRaySFscHATGTAjkx g5npupqa2tyHAT714APSoyOe1QC6YyvYdzRpSNcraVFQKy9bzQ2uXwXc1gXh+twkxnig91 pBhKZV0gn8t501C9nU4wIxUaP5I55Jk= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1770805935; a=rsa-sha256; cv=none; b=YrBn/PhfKgRAVx/iD5GgrZVzoJy437QvwNT0wYTyP+vjjwF5xM5g8PS56IBwjoVFwa6md4 2oSDF8zUL7jl/h18me2UjrtezkTCuNCXdStVeNuvRrH0YXvDjKbxiOQASBXAaDZWMpWPeo lbpE3QEFFPJWtg7xYiIggWRae1IPI6c= ARC-Authentication-Results: i=1; imf04.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b="TFe7/nLN"; spf=pass (imf04.hostedemail.com: domain of rppt@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=rppt@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 7659543D75; Wed, 11 Feb 2026 10:32:14 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D7BD6C4CEF7; Wed, 11 Feb 2026 10:32:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1770805934; bh=IrP0HcvbxJyr+QPUUgTWRvTOZExBIyn/P520HSFeTE0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TFe7/nLN+rKkMzW67S9vCNdZrax/kPne+WpMF87k95gqGlUzqF+fR5WSEUhJQdT3j pPxb8u1Ax2zDRwbXDSOUkXQnSyyGT9ATA7S3mMXNx2TRCmDY+UML8uqdt2x5uN5KOn Myw0c7iyqZfsQ6nIDluj/Ct6feChieIpAVe31sKpg0gTQ8BQT8IA1FdMJRou60J6Id rBVyOi00C1KINFPks7VJijlaVTWk5jn2wnNxzaifUW5ZIAAy72z1/aL01QcnnfNWRP Oom4Kb7P8HeZb9qPQLur3tBkv0FhMqGVt2yWCiPLRGAsku2RHRh3DuKoejRqRBa2Dx Gdc7juu6vCfng== From: Mike Rapoport To: Andrew Morton Cc: Andreas Larsson , Borislav Petkov , Brian Cain , Catalin Marinas , "Christophe Leroy (CS GROUP)" , "David S. Miller" , Dave Hansen , David Hildenbrand , Dinh Nguyen , Geert Uytterhoeven , Guo Ren , Helge Deller , Huacai Chen , Ingo Molnar , Johannes Berg , John Paul Adrian Glaubitz , "Liam R. Howlett" , Lorenzo Stoakes , Madhavan Srinivasan , Magnus Lindholm , Matt Turner , Max Filippov , Michael Ellerman , Michal Hocko , Michal Simek , Mike Rapoport , Palmer Dabbelt , Richard Weinberger , Russell King , Stafford Horne , Suren Baghdasaryan , Thomas Gleixner , Vineet Gupta , Vlastimil Babka , Will Deacon , linux-alpha@vger.kernel.org, linux-kernel@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-csky@vger.kernel.org, linux-hexagon@vger.kernel.org, loongarch@lists.linux.dev, linux-m68k@lists.linux-m68k.org, linux-openrisc@vger.kernel.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-um@lists.infradead.org, linux-mm@kvack.org, x86@kernel.org Subject: [PATCH v3 1/4] mm: don't special case !MMU for is_zero_pfn() and my_zero_pfn() Date: Wed, 11 Feb 2026 12:31:38 +0200 Message-ID: <20260211103141.3215197-2-rppt@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260211103141.3215197-1-rppt@kernel.org> References: <20260211103141.3215197-1-rppt@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 57E9A4000C X-Rspam-User: X-Rspamd-Server: rspam05 X-Stat-Signature: p7wfmkik45j5kp4ydpfqo85ornw5nz9o X-HE-Tag: 1770805935-568169 X-HE-Meta: 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 XjwrGBGH 9Rk4I53W8/cot9RD7Nso/gtYw38ctX3ChkIdik8r0b4DrWjpGtiGt6Ztv0j98xj2NOySKoANPKlPTlWR8WKmCj0tlh8ZLBM6RXxPfCCNCYchnegnDbq5ZbA3qGLLrEoUY/HgXaJq9Twmjwzq5ZNihvY3t+FyE0uIIipy/kYcslBBPJzBemWPrUFswCbrXGnNRjmvpFGCtOJURivX8kAXyFmyE/yGI8XSc6FQV29USo/lrhOxNAVVALkUTGN6yJ2DbfGjAs7bz6gyye6c6fMNrstS7tNj4Ua5nCn+gme74W7PBPH59NdANVmCOv3FNHWs2Ym3a5qJQJQ5oAFgb7Vf8v/v38vFMB5ZwYP777Whn/V0c09I= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: From: "Mike Rapoport (Microsoft)" nommu architectures have empty_zero_page and define ZERO_PAGE() and although they don't really use it to populate page tables, there is no reason to hardwire !MMU implementation of is_zero_pfn() and my_zero_pfn() to 0. Drop #ifdef CONFIG_MMU around implementations of is_zero_pfn() and my_zero_pfn() and remove !MMU version. While on it, make zero_pfn __ro_after_init. Signed-off-by: Mike Rapoport (Microsoft) --- include/linux/pgtable.h | 14 +------------- mm/memory.c | 13 ------------- mm/mm_init.c | 10 ++++++++++ 3 files changed, 11 insertions(+), 26 deletions(-) diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h index 827dca25c0bc..08a88b0d56e5 100644 --- a/include/linux/pgtable.h +++ b/include/linux/pgtable.h @@ -1882,7 +1882,6 @@ static inline void pfnmap_setup_cachemode_pfn(unsigned long pfn, pgprot_t *prot) pfnmap_setup_cachemode(pfn, PAGE_SIZE, prot); } -#ifdef CONFIG_MMU #ifdef __HAVE_COLOR_ZERO_PAGE static inline int is_zero_pfn(unsigned long pfn) { @@ -1905,18 +1904,7 @@ static inline unsigned long my_zero_pfn(unsigned long addr) extern unsigned long zero_pfn; return zero_pfn; } -#endif -#else -static inline int is_zero_pfn(unsigned long pfn) -{ - return 0; -} - -static inline unsigned long my_zero_pfn(unsigned long addr) -{ - return 0; -} -#endif /* CONFIG_MMU */ +#endif /* __HAVE_COLOR_ZERO_PAGE */ #ifdef CONFIG_MMU diff --git a/mm/memory.c b/mm/memory.c index 187f16b7e996..51d2018a387a 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -162,21 +162,8 @@ static int __init disable_randmaps(char *s) } __setup("norandmaps", disable_randmaps); -unsigned long zero_pfn __read_mostly; -EXPORT_SYMBOL(zero_pfn); - unsigned long highest_memmap_pfn __read_mostly; -/* - * CONFIG_MMU architectures set up ZERO_PAGE in their paging_init() - */ -static int __init init_zero_pfn(void) -{ - zero_pfn = page_to_pfn(ZERO_PAGE(0)); - return 0; -} -early_initcall(init_zero_pfn); - void mm_trace_rss_stat(struct mm_struct *mm, int member) { trace_rss_stat(mm, member); diff --git a/mm/mm_init.c b/mm/mm_init.c index 1a29a719af58..dcf9eff34f83 100644 --- a/mm/mm_init.c +++ b/mm/mm_init.c @@ -53,6 +53,9 @@ EXPORT_SYMBOL(mem_map); void *high_memory; EXPORT_SYMBOL(high_memory); +unsigned long zero_pfn __ro_after_init; +EXPORT_SYMBOL(zero_pfn); + #ifdef CONFIG_DEBUG_MEMORY_INIT int __meminitdata mminit_loglevel; @@ -2667,6 +2670,13 @@ static void __init mem_init_print_info(void) ); } +static int __init init_zero_pfn(void) +{ + zero_pfn = page_to_pfn(ZERO_PAGE(0)); + return 0; +} +early_initcall(init_zero_pfn); + void __init __weak arch_mm_preinit(void) { } -- 2.51.0