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 BA7B1E81BCF for ; Mon, 9 Feb 2026 14:41:42 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id DE1AD6B00B1; Mon, 9 Feb 2026 09:41:41 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id D988D6B00B3; Mon, 9 Feb 2026 09:41:41 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id CC2126B00B4; Mon, 9 Feb 2026 09:41:41 -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 BAD016B00B1 for ; Mon, 9 Feb 2026 09:41:41 -0500 (EST) Received: from smtpin25.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 6C0841BFE9 for ; Mon, 9 Feb 2026 14:41:41 +0000 (UTC) X-FDA: 84425182002.25.36D9B82 Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf30.hostedemail.com (Postfix) with ESMTP id B65158000D for ; Mon, 9 Feb 2026 14:41:39 +0000 (UTC) Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=IoiSaopD; spf=pass (imf30.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=1770648099; 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=rHeTYlrnqQ8tIjmWDSX04No3xBlUEI/t591IknV/v6Y=; b=pk+VIJS+pTGQE7RsgaGmZU6RTbVzWbb1ofOfmRwQqGxRDO+Pzb7THSwxh8S3pvaAjhFtb5 330jANupwnC5J4Z/uwKpikEv01sYXYa/zEniX6nHOd799otop5fZvZUfJ6wNtnHI79+e6d XnjhKP/aNE3noFaGc11iibAwMCCeyhE= ARC-Authentication-Results: i=1; imf30.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=IoiSaopD; spf=pass (imf30.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-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1770648099; a=rsa-sha256; cv=none; b=ylZR/ixYZiZYFiMa2Qhsh50q+bs97HrZEGZnZ05DIbk+UylssYB/RX/SWurG8yJhDn7rcf IUVIn+O+p3Na8D+qoDqEUlZY/HUlZhsdoX1N0dO40h2tHOfauzHHsFyf4k8JaphRiAA1yD dX9p5WVxbKQtvSVggTf1sFzNwhknyBo= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 4700460008; Mon, 9 Feb 2026 14:41:39 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2D57DC116C6; Mon, 9 Feb 2026 14:41:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1770648099; bh=dIkOhzWY1xuDq5ewEz/XDIyATuNWlEhxlmAB0qWidMk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IoiSaopDKfrfSZ7+rlBU8LjocFAFB8EJgAVaUZ/W+cBxwixSmGT1x/E8BIkMkjYP8 SzhptbW3ELmnRGgPqG0GC6S3X5YQ0NFlsp7/MwlGEwmonjJfjX36w6Zrid+02MdXYD aD13CKitrIkfiTc+tMswjO0GZ7FkCVjL6pg6DrkfeYhc3cdJymj5D1FMzCONDpjNPt CRTH696/5neg33D9wpXGgfmmIGyqUJnxX11v6uXDMEkOIdpDtKcYEzjVktAE2R8WVo jD3MvmL5DA+h5y6UTuTlFtK2d3SzKn7oXhmb/Hq02WBSEx3CHrl4//hhcmH0UMQ0G3 Ad/W6NbiDr+Ig== 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 2/4] mm: rename my_zero_pfn() to zero_pfn() Date: Mon, 9 Feb 2026 16:40:55 +0200 Message-ID: <20260209144058.2092871-3-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-Server: rspam09 X-Rspamd-Queue-Id: B65158000D X-Stat-Signature: 7m61tbwrg34ousnrqtwby8h3w6damydi X-Rspam-User: X-HE-Tag: 1770648099-386207 X-HE-Meta: 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 Z/V2epNi MAYZxQs2lDcwc/7LQ7ztixTL0lRppItlGpBcbk9Rm7ycBhRg8M/Im+cTQI4Pc4tXTTaxp5/Q6LY+33OtJDLPeF9OcnJzzn3WLwS8CKxncUJDezUnle8joFskUrgGwlHHqFpzVBnNOvtPQAx5f1uTgovJdIp0g3dU9zjtKiJyqaA74ddYbeFLUAGQj/x9Na1YIIfALdljmAybfXrM8WpY63IuAUM4PF3OHrVa73pFnv1gFrFl0IJ76R5OSE0IvNcLLF0KDHyIIgPjw1Tkip95DQHEhhbOIK4/iGJM6j2sCR55ZeSgYlrbLUHBe9g== 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)" my_zero_pfn() is a silly name. Rename zero_pfn variable to zero_page_pfn and my_zero_pfn() function to zero_pfn(). While on it, move extern declarations of zero_page_pfn outside the functions that use it and add a comment about what ZERO_PAGE is. Signed-off-by: Mike Rapoport (Microsoft) --- arch/x86/kvm/mmu/spte.h | 2 +- fs/dax.c | 2 +- fs/proc/vmcore.c | 2 +- include/linux/pgtable.h | 25 +++++++++++++++++-------- mm/huge_memory.c | 2 +- mm/memory.c | 2 +- mm/migrate.c | 2 +- mm/mm_init.c | 10 +++++----- mm/userfaultfd.c | 4 ++-- 9 files changed, 30 insertions(+), 21 deletions(-) diff --git a/arch/x86/kvm/mmu/spte.h b/arch/x86/kvm/mmu/spte.h index 91ce29fd6f1b..8c0ffa2cded6 100644 --- a/arch/x86/kvm/mmu/spte.h +++ b/arch/x86/kvm/mmu/spte.h @@ -248,7 +248,7 @@ extern u64 __read_mostly shadow_nonpresent_or_rsvd_lower_gfn_mask; static inline hpa_t kvm_mmu_get_dummy_root(void) { - return my_zero_pfn(0) << PAGE_SHIFT; + return zero_pfn(0) << PAGE_SHIFT; } static inline bool kvm_mmu_is_dummy_root(hpa_t shadow_page) diff --git a/fs/dax.c b/fs/dax.c index 289e6254aa30..b78cff9c91b3 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -1360,7 +1360,7 @@ static vm_fault_t dax_load_hole(struct xa_state *xas, struct vm_fault *vmf, { struct inode *inode = iter->inode; unsigned long vaddr = vmf->address; - unsigned long pfn = my_zero_pfn(vaddr); + unsigned long pfn = zero_pfn(vaddr); vm_fault_t ret; *entry = dax_insert_entry(xas, vmf, iter, *entry, pfn, DAX_ZERO_PAGE); diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c index f188bd900eb2..44d15436439f 100644 --- a/fs/proc/vmcore.c +++ b/fs/proc/vmcore.c @@ -525,7 +525,7 @@ static int remap_oldmem_pfn_checked(struct vm_area_struct *vma, { unsigned long map_size; unsigned long pos_start, pos_end, pos; - unsigned long zeropage_pfn = my_zero_pfn(0); + unsigned long zeropage_pfn = zero_pfn(0); size_t len = 0; pos_start = pfn; diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h index 08a88b0d56e5..a965e2f8b8de 100644 --- a/include/linux/pgtable.h +++ b/include/linux/pgtable.h @@ -1882,27 +1882,36 @@ static inline void pfnmap_setup_cachemode_pfn(unsigned long pfn, pgprot_t *prot) pfnmap_setup_cachemode(pfn, PAGE_SIZE, prot); } +/* + * ZERO_PAGE() is global shared page(s) that is always zero. It is used for + * zero-mapped memory areas, CoW etc. + * + * On architectures that __HAVE_COLOR_ZERO_PAGE there are several such pages + * for different ranges in the virtual address space. + * + * zero_page_pfn identifies the first (or the only) pfn for these pages. + */ +extern unsigned long zero_page_pfn; + #ifdef __HAVE_COLOR_ZERO_PAGE static inline int is_zero_pfn(unsigned long pfn) { - extern unsigned long zero_pfn; - unsigned long offset_from_zero_pfn = pfn - zero_pfn; + unsigned long offset_from_zero_pfn = pfn - zero_page_pfn; + return offset_from_zero_pfn <= (zero_page_mask >> PAGE_SHIFT); } -#define my_zero_pfn(addr) page_to_pfn(ZERO_PAGE(addr)) +#define zero_pfn(addr) page_to_pfn(ZERO_PAGE(addr)) #else static inline int is_zero_pfn(unsigned long pfn) { - extern unsigned long zero_pfn; - return pfn == zero_pfn; + return pfn == zero_page_pfn; } -static inline unsigned long my_zero_pfn(unsigned long addr) +static inline unsigned long zero_pfn(unsigned long addr) { - extern unsigned long zero_pfn; - return zero_pfn; + return zero_page_pfn; } #endif /* __HAVE_COLOR_ZERO_PAGE */ diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 44ff8a648afd..bc15fd152526 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2968,7 +2968,7 @@ static void __split_huge_zero_page_pmd(struct vm_area_struct *vma, for (i = 0, addr = haddr; i < HPAGE_PMD_NR; i++, addr += PAGE_SIZE) { pte_t entry; - entry = pfn_pte(my_zero_pfn(addr), vma->vm_page_prot); + entry = pfn_pte(zero_pfn(addr), vma->vm_page_prot); entry = pte_mkspecial(entry); if (pmd_uffd_wp(old_pmd)) entry = pte_mkuffd_wp(entry); diff --git a/mm/memory.c b/mm/memory.c index 51d2018a387a..ae610afa9cea 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -5165,7 +5165,7 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf) /* Use the zero-page for reads */ if (!(vmf->flags & FAULT_FLAG_WRITE) && !mm_forbids_zeropage(vma->vm_mm)) { - entry = pte_mkspecial(pfn_pte(my_zero_pfn(vmf->address), + entry = pte_mkspecial(pfn_pte(zero_pfn(vmf->address), vma->vm_page_prot)); vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd, vmf->address, &vmf->ptl); diff --git a/mm/migrate.c b/mm/migrate.c index 1bf2cf8c44dd..739c4e03769b 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -321,7 +321,7 @@ static bool try_to_map_unused_to_zeropage(struct page_vma_mapped_walk *pvmw, if (!pages_identical(page, ZERO_PAGE(0))) return false; - newpte = pte_mkspecial(pfn_pte(my_zero_pfn(pvmw->address), + newpte = pte_mkspecial(pfn_pte(zero_pfn(pvmw->address), pvmw->vma->vm_page_prot)); if (pte_swp_soft_dirty(old_pte)) diff --git a/mm/mm_init.c b/mm/mm_init.c index dcf9eff34f83..a0ca236eb4f5 100644 --- a/mm/mm_init.c +++ b/mm/mm_init.c @@ -53,8 +53,8 @@ EXPORT_SYMBOL(mem_map); void *high_memory; EXPORT_SYMBOL(high_memory); -unsigned long zero_pfn __ro_after_init; -EXPORT_SYMBOL(zero_pfn); +unsigned long zero_page_pfn __ro_after_init; +EXPORT_SYMBOL(zero_page_pfn); #ifdef CONFIG_DEBUG_MEMORY_INIT int __meminitdata mminit_loglevel; @@ -2670,12 +2670,12 @@ static void __init mem_init_print_info(void) ); } -static int __init init_zero_pfn(void) +static int __init init_zero_page_pfn(void) { - zero_pfn = page_to_pfn(ZERO_PAGE(0)); + zero_page_pfn = page_to_pfn(ZERO_PAGE(0)); return 0; } -early_initcall(init_zero_pfn); +early_initcall(init_zero_page_pfn); void __init __weak arch_mm_preinit(void) { diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c index 927086bb4a3c..e19872e51878 100644 --- a/mm/userfaultfd.c +++ b/mm/userfaultfd.c @@ -357,7 +357,7 @@ static int mfill_atomic_pte_zeropage(pmd_t *dst_pmd, if (mm_forbids_zeropage(dst_vma->vm_mm)) return mfill_atomic_pte_zeroed_folio(dst_pmd, dst_vma, dst_addr); - _dst_pte = pte_mkspecial(pfn_pte(my_zero_pfn(dst_addr), + _dst_pte = pte_mkspecial(pfn_pte(zero_pfn(dst_addr), dst_vma->vm_page_prot)); ret = -EAGAIN; dst_pte = pte_offset_map_lock(dst_vma->vm_mm, dst_pmd, dst_addr, &ptl); @@ -1229,7 +1229,7 @@ static int move_zeropage_pte(struct mm_struct *mm, return -EAGAIN; } - zero_pte = pte_mkspecial(pfn_pte(my_zero_pfn(dst_addr), + zero_pte = pte_mkspecial(pfn_pte(zero_pfn(dst_addr), dst_vma->vm_page_prot)); ptep_clear_flush(src_vma, src_addr, src_pte); set_pte_at(mm, dst_addr, dst_pte, zero_pte); -- 2.51.0