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 28C18E81BCB for ; Mon, 9 Feb 2026 14:41:30 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 8DE3B6B00AF; Mon, 9 Feb 2026 09:41:29 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 8C5216B00B1; Mon, 9 Feb 2026 09:41:29 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7BEB56B00B2; Mon, 9 Feb 2026 09:41:29 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 688D56B00AF for ; Mon, 9 Feb 2026 09:41:29 -0500 (EST) Received: from smtpin10.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 2E93887807 for ; Mon, 9 Feb 2026 14:41:29 +0000 (UTC) X-FDA: 84425181498.10.8D6DCFF Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf20.hostedemail.com (Postfix) with ESMTP id 87A0D1C0011 for ; Mon, 9 Feb 2026 14:41:27 +0000 (UTC) Authentication-Results: imf20.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=APyMK8Xc; spf=pass (imf20.hostedemail.com: domain of rppt@kernel.org designates 172.105.4.254 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=1770648087; 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=N5xBaAj7lna5raddfKT8/+jMhKcidLEmzo6nFiKMBPB+dtA0T1SFRfstL3y/Xig4c+oplG i7ftwvLYs6yEk5T1DHdrbG0ux9jOk829ogsCi62LLndeDJOv27zN61+z0pX8hzpFQnomMa /44sOXsCOHwK08hr+N0McnOQ+exX8ns= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1770648087; a=rsa-sha256; cv=none; b=bYj8Dd5WDo/Mf+ZbjIT9jDlAl2N+ULZXmkIX+x/1HZd6RUKTb3PyD3Hs5gS6KbcuBjbXtH sE1b2FwcpyWQlbl411AswFU4bGABirZeCvzpRQ0EWtiwhCaSUKwITqtlUxBXYv+NNAi1Dx 4TaXEpynCjCUDLQ7JGgeKIcpHb6FacE= ARC-Authentication-Results: i=1; imf20.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=APyMK8Xc; spf=pass (imf20.hostedemail.com: domain of rppt@kernel.org designates 172.105.4.254 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 tor.source.kernel.org (Postfix) with ESMTP id EA41A6013E; Mon, 9 Feb 2026 14:41:26 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D4BD7C16AAE; Mon, 9 Feb 2026 14:41:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1770648086; bh=IrP0HcvbxJyr+QPUUgTWRvTOZExBIyn/P520HSFeTE0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=APyMK8Xcr0Pj/4H/7ScdM60IKK2Af+gkFXGdQhPjdHsnmzLsJm02Nchy+jJL23anM bNBnoHk9xK2QiZTV+rQY/KLwerxB3VnzQfxzTkQc1iH70KMN3Z0GuLpljati7S0tf8 ls86zRd33YVz+J6pURgPRqvGX5Q/n+dPhzCqdL5yV63J60pinW1+OsSd3d1xFDgsvS 6up5zQsE5HXsLq3bdag17WhUQCgbBwXYJxsH7xLXV9rnrG9HIsZoWR0mYcQZNF9Lk2 3fCjxQBhoGvtiYzXnS5lcX8tXcaTibT8zTyCBbpHKv+p0HdsmTNf1IjvNxObtwAPb6 sxyY+fXDu7Mnw== 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 v2 1/4] mm: don't special case !MMU for is_zero_pfn() and my_zero_pfn() Date: Mon, 9 Feb 2026 16:40:54 +0200 Message-ID: <20260209144058.2092871-2-rppt@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260209144058.2092871-1-rppt@kernel.org> References: <20260209144058.2092871-1-rppt@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 87A0D1C0011 X-Rspam-User: X-Rspamd-Server: rspam05 X-Stat-Signature: 8exf1mkc3eitjb9u3prxoey1yrp1fd5h X-HE-Tag: 1770648087-719907 X-HE-Meta: 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 v+yUWY7b +c8JsHyaRczb6eul9xag8CTAxG5TZiX39kOA3tuIYifydsVNSav9DkeO76G7UYSNP/Ac8m6LeR0+b0F3mQUrO/wKwE/TJuop70x30k1FsQ5nmhcxs+YL0biBgcu2iW+mN41aLLd6gg7uxn+i3f/9Qz4Vh8SA3zrayO38MDpV7/lFF6m5n2dfzUfBm3s9L/NSxgcukcJFnGTy9oc3Z9uR3b59bCEIqzYnpOSfVZh5P0BUJtIlgn9XOtp7CxoY9Rs5k80MLBpzR7vbpdUEJ6byelFeCTMCP5UJSJhiOHh7O5ULMr0EzT44DnNK3bDB5ehWSQhLbGh9jJlsXFurVBsu0Ril08lMtgmHlSJbp 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