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 BB679C624D7 for ; Thu, 3 Sep 2026 10:31:00 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 9F8FB6B00BE; Thu, 3 Sep 2026 06:30:59 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 9D1216B00BF; Thu, 3 Sep 2026 06:30:59 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8E78A6B00C0; Thu, 3 Sep 2026 06:30:59 -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 69AA46B00BE for ; Thu, 3 Sep 2026 06:30:59 -0400 (EDT) Received: from smtpin09.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay08.hostedemail.com (Postfix) with ESMTP id EE7DA1404A7 for ; Thu, 3 Sep 2026 10:30:58 +0000 (UTC) X-FDA: 85172082996.09.90F8A9E Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf12.hostedemail.com (Postfix) with ESMTP id 26FC940003 for ; Thu, 3 Sep 2026 10:30:57 +0000 (UTC) Authentication-Results: imf12.hostedemail.com; dkim=pass header.d=arm.com header.s=foss header.b=OCqN0IM7; spf=pass (imf12.hostedemail.com: domain of usama.anjum@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=usama.anjum@arm.com; dmarc=pass (policy=none) header.from=arm.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1788431457; 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=boIbdWY3njDuq8O0ZC5c3wai0+LDy2ZAyOHaVP6lhx4=; b=osEBy+8/tSblQ/HQOMah30kv/kX2+PezCxXPLO2+Asn7dIoCKCNkM8Rjjk8jSOZMr7WpQS TnWc+tq7rQ6jpo3t3Qe0KoJS39sd1N+JEeFIhN0cu6fbmm29El/EHqn4NFrI6ZAevMEjdo rerSXtFdtCe1pq8sQiItbseVlPPhJHc= ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1788431457; b=MsgAgNeJbmWNO3GoL+ud9D/gepv9a7LkswBvzwd0/IyaEFqO5mMM6alDYqse0e4NkwUWeM WdDeeXOaDcg4bmUN0kjDtajqijajKNwJCi/5HGFxbXjzF+/xt2HRquv0FqXp0/kNjQMy0E aoam1To167q7QurtZt4XbrO/aC11Jg0= ARC-Authentication-Results: i=1; imf12.hostedemail.com; dkim=pass header.d=arm.com header.s=foss header.b=OCqN0IM7; spf=pass (imf12.hostedemail.com: domain of usama.anjum@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=usama.anjum@arm.com; dmarc=pass (policy=none) header.from=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 993991F02; Thu, 3 Sep 2026 03:30:52 -0700 (PDT) Received: from e142334-100.cambridge.arm.com (e142334-100.cambridge.arm.com [10.2.198.93]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 3AE423F673; Thu, 3 Sep 2026 03:30:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1788431456; bh=DEt3KlUchGpFfzI7cFYM3vauHOwXVIVRP1eSVCB1rgM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OCqN0IM73DlVeIFEnlcCIuqR18FAoouHSGHhXNucYr8rONtG/PWo24UoFAmagMzIb 8r48Ezf7p4wr9UIjQ4++anmaFeiCydvVPqtUevaAhHfgY9il6/+hvRvy7PKAcpAA/e wapcW/7pqB0l6aY7tSwko5ZNforUusnJFwU24SHs= From: Muhammad Usama Anjum To: Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , Tvrtko Ursulin , David Airlie , Simona Vetter , Dimitri Sivanich , Arnd Bergmann , Greg Kroah-Hartman , "James E.J. Bottomley" , Helge Deller , Juergen Gross , Stefano Stabellini , Muchun Song , Oscar Salvador , Andrew Morton , "Liam R. Howlett" , Lorenzo Stoakes , Will Deacon , "Aneesh Kumar K.V" , Nick Piggin , Peter Zijlstra , Andrey Ryabinin , David Hildenbrand , Pasha Tatashin , Chris Li , Kairui Song , Uladzislau Rezki , Steven Rostedt , Masami Hiramatsu , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Eduard Zingerman , Kumar Kartikeya Dwivedi , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , SJ Park , "Matthew Wilcox (Oracle)" , Jan Kara , Jason Gunthorpe , Leon Romanovsky , Miaohe Lin , Dennis Zhou , Tejun Heo , Christoph Lameter , Mike Rapoport , Johannes Weiner , ziy@nvidia.com, pfalcato@suse.de, agordeev@linux.ibm.com, ryan.roberts@arm.com Cc: Muhammad Usama Anjum , linux-kernel@vger.kernel.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-parisc@vger.kernel.org, xen-devel@lists.xenproject.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, kasan-dev@googlegroups.com, linux-trace-kernel@vger.kernel.org, bpf@vger.kernel.org, linux-perf-users@vger.kernel.org, damon@lists.linux.dev Subject: [PATCH v2 1/8] mm: introduce hw_pte_t for PTE table storage Date: Thu, 3 Sep 2026 11:29:53 +0100 Message-ID: <20260903103002.1091859-2-usama.anjum@arm.com> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260903103002.1091859-1-usama.anjum@arm.com> References: <20260903103002.1091859-1-usama.anjum@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Stat-Signature: so5h3ubinqk9ju1fpjtkugquz4zjmp3i X-Rspamd-Queue-Id: 26FC940003 X-Rspamd-Server: rspam02 X-Rspam-User: X-HE-Tag: 1788431457-74708 X-HE-Meta: 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 6t/fbaBT EnOjmzJx1H6IDRZToJJgcaneVol2XGBd38/pjXq5ltQ4QwNF3aaLZ2F11XPMQUsXtU9hZpvSWM2XF5izzHypKWef7xj66ixuTQNz+gyHg5luvqHdTwJqDXof6ts2F+0kR2c5ujyIlFq6sOIK6udy6J3ux/fOT0LEXs413Ck7KyM4AADTitM3N9njt1QRWAdPzu+VTvG1FAoeYougv4z8oruR9GgTb62ZuUwDM3yPtZPrHjtfRUIms33jrTG196O77NZ3U/PK1wAVyfu5TL+ENg3NeIg8x8ofBY51juUg+3clXN1T8tcVzbhPMTKOyYmFE6eK4/tcO6/3kO/qXtCTQr0RO7yh55B4wE++SxaZGhINjOv0= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: pte_t is used both for software PTE values and for entries stored in a PTE table, so pte_t * does not distinguish a pointer to a software PTE value from a pointer to table storage. Introduce hw_pte_t as the generic name for a PTE table element. Define it as a macro alias of pte_t by default. When an architecture selects ARCH_HAS_HW_PTE_T, define it as a structure containing a pte_t instead. This preserves the representation while allowing converted architectures to enforce the distinction at compile time. Name the generic wrapper structure __hw_pte_t so architectures can forward-declare it when pgtable_t must be defined before the generic hw_pte_t typedef is visible. This avoids header-order dependencies. Keep the C type definitions behind an __ASSEMBLY__ check because architecture assembly sources can include this header indirectly. Include asm/page.h so consumers such as linux/vmalloc.h retain the page definitions they previously obtained from that header. Signed-off-by: Muhammad Usama Anjum --- Changes since v1: - Name the generic wrapper structure __hw_pte_t so architectures can forward-declare it, and explain why this is required. - Use software PTE value terminology. Changes since RFC v1: - Add the ARCH_HAS_HW_PTE_T opt-in and generic wrapper definition. - Exclude the C type definitions from assembly sources. - Update the description for the new opt-in model. --- MAINTAINERS | 1 + include/linux/pgtable_types.h | 17 +++++++++++++++++ mm/Kconfig | 3 +++ 3 files changed, 21 insertions(+) create mode 100644 include/linux/pgtable_types.h diff --git a/MAINTAINERS b/MAINTAINERS index 2133aec4a2004..da60a8bdcddb5 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -17140,6 +17140,7 @@ F: include/linux/mmu_notifier.h F: include/linux/pagewalk.h F: include/linux/pgalloc.h F: include/linux/pgtable.h +F: include/linux/pgtable_types.h F: include/linux/ptdump.h F: include/linux/vmpressure.h F: include/linux/vmstat.h diff --git a/include/linux/pgtable_types.h b/include/linux/pgtable_types.h new file mode 100644 index 0000000000000..07da05d375c2c --- /dev/null +++ b/include/linux/pgtable_types.h @@ -0,0 +1,17 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_PGTABLE_TYPES_H +#define _LINUX_PGTABLE_TYPES_H + +#include + +#ifndef __ASSEMBLY__ + +#ifdef CONFIG_ARCH_HAS_HW_PTE_T +typedef struct __hw_pte_t { pte_t __pte; } hw_pte_t; +#else +#define hw_pte_t pte_t +#endif + +#endif /* !__ASSEMBLY__ */ + +#endif /* _LINUX_PGTABLE_TYPES_H */ diff --git a/mm/Kconfig b/mm/Kconfig index c1ddf59c0d71a..5f462ec6fa5e5 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -1312,6 +1312,9 @@ comment "GUP_TEST needs to have DEBUG_FS enabled" config GUP_GET_PXX_LOW_HIGH bool +config ARCH_HAS_HW_PTE_T + bool + config DMAPOOL_TEST tristate "Enable a module to run time tests on dma_pool" depends on HAS_DMA -- 2.47.3