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 E582C1099B43 for ; Fri, 20 Mar 2026 22:14:41 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 5F0CE6B00F4; Fri, 20 Mar 2026 18:14:41 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 5C8BA6B00F5; Fri, 20 Mar 2026 18:14:41 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 506406B00F6; Fri, 20 Mar 2026 18:14:41 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 40D9D6B00F4 for ; Fri, 20 Mar 2026 18:14:41 -0400 (EDT) Received: from smtpin22.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 14EE11D9B9 for ; Fri, 20 Mar 2026 22:14:41 +0000 (UTC) X-FDA: 84567846762.22.C8A3AA7 Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf02.hostedemail.com (Postfix) with ESMTP id 73ED78000F for ; Fri, 20 Mar 2026 22:14:39 +0000 (UTC) Authentication-Results: imf02.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=TslszDhS; spf=pass (imf02.hostedemail.com: domain of david@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=david@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=1774044879; 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-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=x/1ctJgZFjwJnEt9D488YF1w3aSO7eSWrdVytrypd5Q=; b=Jmm5OQjTEsZiZxgLEy0KtiQTJy889lms+W/kwQl5kMGgsjqit7R4skWdhpJTEiQ4+3uSsN rOPJh0UsBpB8WDg6DZ4LxTdGHJh/Gu4A11iMFIEYRtoTnpI1Ro77nRv2GSaPmxGiEpeSjG 3AsRLP/27jA9/h7sYGkYdyt5/kVbAwI= ARC-Authentication-Results: i=1; imf02.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=TslszDhS; spf=pass (imf02.hostedemail.com: domain of david@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=david@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1774044879; a=rsa-sha256; cv=none; b=2YVYEM++CBJX4l1kUkPcj5HrrlFpv/0COGxv/4+fX2N99EzEPnAiGO8Sq6Km96qfs+IMPw 3qd/TcqOJ/yRZTCTRanJJNAj5r0agHwBu5FLi4lUjLlUG6T5aUurXVcPUsCvDRkINUvUxe MpNRMw/B77Uw5glFw7hPiYBhSK1xdHA= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id F1CE46111B; Fri, 20 Mar 2026 22:14:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B066CC4CEF7; Fri, 20 Mar 2026 22:14:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1774044878; bh=y3sgZkTrQ7ucF18Vg7qRa+O7aPCnDHgstTSd5M9UBOY=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=TslszDhSAzMDVRIyuMv6paGVgSsd2CzTi2m+XDZauLL+oMPD8nN2y19WOg5QAxcN8 MJkxnPJI13xWM/TQBuUVFa8i2WBfcrPqP1pN4JyiIYxzvSpK68kow0YUXzxMwjLIvA PZfMcLRp38aeBp/XZ/scY6XOVW8u6R2Vl2bxg7ZCjPYl5+Zw1cWeOJK9ueZjsjOuBI /f+WZSPbGmI8Ms+0wdaf/gI3Ef6Dwbp58ZS76mf9o54sv2J4dxehoWLmTRoayHRyve UXsBVGWUjpn8Bff33KBzLTvQ6RK33x76NgUJDEqM9svExTt2X8h0wOTNQ+4FrOCJLF 6X7zc7Xpdr5tg== From: "David Hildenbrand (Arm)" Date: Fri, 20 Mar 2026 23:13:45 +0100 Subject: [PATCH v2 13/15] mm/sparse: move sparse_init_one_section() to internal.h MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260320-sparsemem_cleanups-v2-13-096addc8800d@kernel.org> References: <20260320-sparsemem_cleanups-v2-0-096addc8800d@kernel.org> In-Reply-To: <20260320-sparsemem_cleanups-v2-0-096addc8800d@kernel.org> To: linux-kernel@vger.kernel.org Cc: Andrew Morton , Oscar Salvador , Axel Rasmussen , Yuanchu Xie , Wei Xu , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Sidhartha Kumar , linux-mm@kvack.org, linux-cxl@vger.kernel.org, linux-riscv@lists.infradead.org, "David Hildenbrand (Arm)" X-Mailer: b4 0.13.0 X-Stat-Signature: kbuxyhdidwpoq9scdzoyyy9pq779zk1m X-Rspamd-Server: rspam09 X-Rspam-User: X-Rspamd-Queue-Id: 73ED78000F X-HE-Tag: 1774044879-446762 X-HE-Meta: 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 9nZJvXEW ZEiw0wPAKC531r6HZtY3i5Rgvt25//mYsi8M4+Iv1zY1TxsPRFJIXagd57fLlb2C3ZZgRAKp/UuggoKjE2KrlGPfWfAoP+keXLcAAsWkbLzdgj/p0Fzcicc+IWsjH5jwojAy08MD3LJvlfwokrM+llSCADuiQaroVzivg1w5NRUTXlVmcB8QrhNoufwdAdDXQAEPrIbHXKaA29rDVz1nKunvQxpNu3v5g/RUDS9PlaLEzg4u3Aeh+1i6oLMq+qKu4IFaL Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: While at it, convert the BUG_ON to a VM_WARN_ON_ONCE, avoid long lines, and merge sparse_encode_mem_map() into its only caller sparse_init_one_section(). Clarify the comment a bit, pointing at page_to_pfn(). Reviewed-by: Lorenzo Stoakes (Oracle) Reviewed-by: Mike Rapoport (Microsoft) Signed-off-by: David Hildenbrand (Arm) --- include/linux/mmzone.h | 2 +- mm/internal.h | 22 ++++++++++++++++++++++ mm/sparse.c | 24 ------------------------ 3 files changed, 23 insertions(+), 25 deletions(-) diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index b694c69dee04..dcbbf36ed88c 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -2008,7 +2008,7 @@ struct mem_section { /* * This is, logically, a pointer to an array of struct * pages. However, it is stored with some other magic. - * (see sparse.c::sparse_init_one_section()) + * (see sparse_init_one_section()) * * Additionally during early boot we encode node id of * the location of the section here to guide allocation. diff --git a/mm/internal.h b/mm/internal.h index 5f5c45d80aca..2f188f7702f7 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -965,6 +965,28 @@ void memmap_init_range(unsigned long, int, unsigned long, unsigned long, */ #ifdef CONFIG_SPARSEMEM void sparse_init(void); + +static inline void sparse_init_one_section(struct mem_section *ms, + unsigned long pnum, struct page *mem_map, + struct mem_section_usage *usage, unsigned long flags) +{ + unsigned long coded_mem_map; + + BUILD_BUG_ON(SECTION_MAP_LAST_BIT > PFN_SECTION_SHIFT); + + /* + * We encode the start PFN of the section into the mem_map such that + * page_to_pfn() on !CONFIG_SPARSEMEM_VMEMMAP can simply subtract it + * from the page pointer to obtain the PFN. + */ + coded_mem_map = (unsigned long)(mem_map - section_nr_to_pfn(pnum)); + VM_WARN_ON(coded_mem_map & ~SECTION_MAP_MASK); + + ms->section_mem_map &= ~SECTION_MAP_MASK; + ms->section_mem_map |= coded_mem_map; + ms->section_mem_map |= flags | SECTION_HAS_MEM_MAP; + ms->usage = usage; +} #else static inline void sparse_init(void) {} #endif /* CONFIG_SPARSEMEM */ diff --git a/mm/sparse.c b/mm/sparse.c index 5c9cad390282..ed5de1a25f04 100644 --- a/mm/sparse.c +++ b/mm/sparse.c @@ -256,30 +256,6 @@ static void __init memblocks_present(void) memory_present(nid, start, end); } -/* - * Subtle, we encode the real pfn into the mem_map such that - * the identity pfn - section_mem_map will return the actual - * physical page frame number. - */ -static unsigned long sparse_encode_mem_map(struct page *mem_map, unsigned long pnum) -{ - unsigned long coded_mem_map = - (unsigned long)(mem_map - (section_nr_to_pfn(pnum))); - BUILD_BUG_ON(SECTION_MAP_LAST_BIT > PFN_SECTION_SHIFT); - BUG_ON(coded_mem_map & ~SECTION_MAP_MASK); - return coded_mem_map; -} - -static void __meminit sparse_init_one_section(struct mem_section *ms, - unsigned long pnum, struct page *mem_map, - struct mem_section_usage *usage, unsigned long flags) -{ - ms->section_mem_map &= ~SECTION_MAP_MASK; - ms->section_mem_map |= sparse_encode_mem_map(mem_map, pnum) - | SECTION_HAS_MEM_MAP | flags; - ms->usage = usage; -} - static unsigned long usemap_size(void) { return BITS_TO_LONGS(SECTION_BLOCKFLAGS_BITS) * sizeof(unsigned long); -- 2.43.0