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 65C23C43458 for ; Mon, 29 Jun 2026 12:24:54 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 8A3B16B00C4; Mon, 29 Jun 2026 08:24:43 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 82C516B00C3; Mon, 29 Jun 2026 08:24:43 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6CDE46B00C4; Mon, 29 Jun 2026 08:24:43 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 3BE2D6B00C2 for ; Mon, 29 Jun 2026 08:24:43 -0400 (EDT) Received: from smtpin08.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay01.hostedemail.com (Postfix) with ESMTP id B25811C3555 for ; Mon, 29 Jun 2026 12:24:42 +0000 (UTC) X-FDA: 84932868804.08.4661AE0 Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf31.hostedemail.com (Postfix) with ESMTP id 2036520004 for ; Mon, 29 Jun 2026 12:24:40 +0000 (UTC) Authentication-Results: imf31.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=h2YtNTBC; spf=pass (imf31.hostedemail.com: domain of ljs@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=ljs@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1782735881; b=mMQnbx79QeQSAWahwPMtoDC9nobnuGqpxKrMIPWsnkGiOQX0gRRQncX5aVeBjuFUFC+AP+ Wf0Q3EDq5YNm4i57LxtOftN7fJJGzTEgO14xQNOmzE6PWYWaKnh4aQCe7ZaSLkG0CJ1FV+ JPcsrdKjgVuvEkBoS5RWipZhDqenTts= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1782735881; 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=+of2eJHuR5dNuNJiS3cZuvLehUoHg8ljbLqq9Ah0AQ4=; b=PVyY8qxaylMxYrk+760x33xDfQTFUKCyU+z8Ft9Wq1pxa7PQ3lHSS0u/KjrXkm/1V2nnou QkWr4Kz4UDPeNYIMdl5fkqSUB1vDhM6hUjH+SwI2dRhEWaj3NkDFbQeXLp3V+vYKlg/cmC iKz1no/RhlvF7bF86ymrSz7WVsehKwE= ARC-Authentication-Results: i=1; imf31.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=h2YtNTBC; spf=pass (imf31.hostedemail.com: domain of ljs@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=ljs@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id AD0A9600D8; Mon, 29 Jun 2026 12:24:40 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8B4A81F000E9; Mon, 29 Jun 2026 12:24:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1782735880; bh=+of2eJHuR5dNuNJiS3cZuvLehUoHg8ljbLqq9Ah0AQ4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=h2YtNTBCsJFLeuggkXoygsgvXPGBhgysE1dL0jJxSBgEibKwxrxBKBVkCF7H7B5B9 CMBhr61zOts8FtzvxLocHIiLkQyF7/jaK21luzc0jjR0RUO8+CMng45Jp6ysrpb9aM uY84Roia6rA0mFTBZlwUW/I/+znMt4CVrXrjXH2ChKSWcrSjCWtYc2HfuwM1FyISP8 vbmjmSzlxQ8mXIczOsJ5mRC89LLsZAg8F2I6xVLDYMZyT40OqQHfzXKe2Yb0HZTEpY wC9fvuVgpJy/8Haqy9b9YseUpf27o/EwJ556JfcxFLzbHK5HwMwqJpR9v6i99Gr9TJ w7K5/x0UhwFYQ== From: Lorenzo Stoakes To: Andrew Morton Cc: Russell King , Dinh Nguyen , Simon Schuster , "James E . J . Bottomley" , Helge Deller , Jarkko Sakkinen , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, Ian Abbott , H Hartley Sweeten , Lucas Stach , David Airlie , Simona Vetter , Patrik Jakobsson , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , Rob Clark , Dmitry Baryshkov , Tomi Valkeinen , Thierry Reding , Mikko Perttunen , Jonathan Hunter , Christian Koenig , Huang Rui , Ankit Agrawal , Alex Williamson , Alexander Viro , Christian Brauner , Dan Williams , Muchun Song , Oscar Salvador , David Hildenbrand , Suren Baghdasaryan , "Liam R . Howlett" , Matthew Wilcox , Marek Szyprowski , Peter Zijlstra , Arnaldo Carvalho de Melo , Namhyung Kim , Masami Hiramatsu , Oleg Nesterov , Steven Rostedt , SeongJae Park , Miaohe Lin , Hugh Dickins , Mike Rapoport , Kees Cook , Paolo Bonzini , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-parisc@vger.kernel.org, linux-sgx@vger.kernel.org, etnaviv@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-arm-msm@vger.kernel.org, freedreno@lists.freedesktop.org, linux-tegra@vger.kernel.org, kvm@vger.kernel.org, linux-fsdevel@vger.kernel.org, nvdimm@lists.linux.dev, linux-mm@kvack.org, iommu@lists.linux.dev, linux-perf-users@vger.kernel.org, linux-trace-kernel@vger.kernel.org, kasan-dev@googlegroups.com, damon@lists.linux.dev, Pedro Falcato , Rik van Riel , Harry Yoo , Jann Horn Subject: [PATCH 15/30] mm: introduce and use linear_page_delta() Date: Mon, 29 Jun 2026 13:23:26 +0100 Message-ID: X-Mailer: git-send-email 2.54.0 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: 2036520004 X-Rspam-User: X-Stat-Signature: 391oa5c63w3twpripynfum368xepe7ch X-HE-Tag: 1782735880-407593 X-HE-Meta: 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 AyH8hP8O +5Gm69CA+Q3UDykeQTXwLkvW6FbGGopk+YTkmnLxqSftxbjpKPfT3pjHChvSfcphgPo+25sxQgDOk71ZkWy6xnb5j/Sbz7HKZ4J3tsXQoioZQp1KK8jcMBKM0nydRZ4aKzPSdQUniCXG4vv/HFCVC2/DHonDpM26LI2wOf4HzvYllKzm6ayLjD7vWVGKidP1IXllj3w8mEAN9hlJ2OIVaS8STIY477QDl1o8GDrMIHuHm0dIXiz4XfV253DxUBhLa9SCnf03pxaJEWDhElGzUVrYs/ThaT9UfRdQqRSiX2PcX+Ri6EilRyySnhG2q4XroHTYy+TmLcjXJ7fvfXupZjwE88JBHJn+TvITZ Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: It's often useful to obtain the number of pages a given address lies at within a VMA. Add linear_page_delta() to determine this and update linear_page_index() to make use of it. Add comments to describe both linear_page_delta() and linear_page_index(). No functional change intended. Signed-off-by: Lorenzo Stoakes --- include/linux/pagemap.h | 37 +++++++++++++++++++++++++++++++++++-- 1 file changed, 35 insertions(+), 2 deletions(-) diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 2c3718d592d6..644c0f25ae73 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -1063,11 +1063,44 @@ static inline pgoff_t folio_pgoff(const struct folio *folio) return folio->index; } +/** + * linear_page_delta() - Determine the relative page offset of @address within + * @vma. + * @vma: The VMA in which @address resides. + * @address: The address whose relative page offset is required. + * + * The result is identical for both file-backed and anonymous mappings and + * simply determines how many pages @address lies from @vma->vm_start. + * + * Returns: The number of pages @address is offset by within @vma. + */ +static inline pgoff_t linear_page_delta(const struct vm_area_struct *vma, + const unsigned long address) +{ + return (address - vma->vm_start) >> PAGE_SHIFT; +} + +/** + * linear_page_index() - Determine the absolute page offset of @address within + * @vma. + * @vma: The VMA in which @address resides. + * @address: The address whose absolute page offset is required. + * + * For file-backed mappings, this returns the page offset of @address within the + * file. + * + * For anonymous mappings, this returns the virtual page offset of @address, + * which is the page offset the address possessed at the time the VMA was first + * faulted. + * + * Returns: The absolute page offset of @address within @vma. + */ static inline pgoff_t linear_page_index(const struct vm_area_struct *vma, const unsigned long address) { pgoff_t pgoff; - pgoff = (address - vma->vm_start) >> PAGE_SHIFT; + + pgoff = linear_page_delta(vma, address); pgoff += vma->vm_pgoff; return pgoff; } @@ -1219,7 +1252,7 @@ static inline vm_fault_t folio_lock_or_retry(struct folio *folio, void folio_wait_bit(struct folio *folio, int bit_nr); int folio_wait_bit_killable(struct folio *folio, int bit_nr); -/* +/* * Wait for a folio to be unlocked. * * This must be called with the caller "holding" the folio, -- 2.54.0