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 BA8BDC982DE for ; Mon, 21 Sep 2026 09:51:17 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id D34986B0088; Mon, 21 Sep 2026 05:51:16 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id CE58C6B00DB; Mon, 21 Sep 2026 05:51:16 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BD3886B00DF; Mon, 21 Sep 2026 05:51:16 -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 8D4EF6B0088 for ; Mon, 21 Sep 2026 05:51:16 -0400 (EDT) Received: from smtpin21.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay08.hostedemail.com (Postfix) with ESMTP id D482D140535 for ; Mon, 21 Sep 2026 09:51:15 +0000 (UTC) X-FDA: 85237301310.21.3E055C8 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf02.hostedemail.com (Postfix) with ESMTP id E9B7C80003 for ; Mon, 21 Sep 2026 09:51:13 +0000 (UTC) Authentication-Results: imf02.hostedemail.com; dkim=pass header.d=arm.com header.s=foss header.b=PwNXaD+0; spf=pass (imf02.hostedemail.com: domain of ryan.roberts@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=ryan.roberts@arm.com; dmarc=pass (policy=none) header.from=arm.com ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1789984274; b=wjvfshEjbyZ0ZYkYt5xP1rVnvEvPU0tU5onOfvsbuE5bdWehQDwIZ+fuxYmz38GgoMra7g egxMZ0Kt4NDS6IpjKMGCvd+wlRLIAtB7jVnXFDO8wOol+3ysTLCc9mrdFa/FNCCajgwM5k 5+tOFUtwysE/7iZ6D53wpEb9l9IIqFw= ARC-Authentication-Results: i=1; imf02.hostedemail.com; dkim=pass header.d=arm.com header.s=foss header.b=PwNXaD+0; spf=pass (imf02.hostedemail.com: domain of ryan.roberts@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=ryan.roberts@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=1789984274; 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=zd1jRqYPXZwU2hXU1MHVfUpexFL0QG0Ad5Vt2W87lxs=; b=TKUAAyOTZxrXJCTGONPQanKGCMhkzDhKFKxEOsxZFLVzPmY7fDu0Z/Nr8Wkmw5VcadXNFu o5Vqr8dmbMwYpyEIM0cXV3ZdthZmC3K4Kqr7GAQYUVI/qph2ZurFprO4bAVr8rjguUsTH2 e0alPOCoV8XGH7o8TBgZsOOYDNCIOoM= 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 8A778153B; Mon, 21 Sep 2026 02:51:09 -0700 (PDT) Received: from [10.57.83.12] (unknown [10.57.83.12]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 2F7573F86F; Mon, 21 Sep 2026 02:51:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1789984273; bh=Yh04mAUW/tMDEOlWdN+OXJwoGQ3qq3vUxi4DFjfm1GY=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=PwNXaD+0WUdgUn9Bq7v/HPrz6iSdG1Ka6YECPv9iF0/ZzjF26pxz1O08q0ccMYQOB bwL5+mucY5hunLe30UlgLiO6VVb5ARI9CGDPOGyQ+uv4FlLL6YtNVCUQHpoIMJEw4b NXAtZ3P9Af5w6Y40kU8Ymb3s0bMrOwUXnW+78CFE= Message-ID: <27fb625b-7117-4666-9a34-3b8aa9a43833@arm.com> Date: Mon, 21 Sep 2026 10:51:07 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 0/6] arm64: distinguish HW PTE pointers from SW PTE value pointers To: Muhammad Usama Anjum , Catalin Marinas , Will Deacon , Mark Rutland , Ard Biesheuvel , Ilias Apalodimas , Andrey Ryabinin , Alexander Potapenko , Andrey Konovalov , Dmitry Vyukov , Vincenzo Frascino , Andrew Morton , David Hildenbrand , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-efi@vger.kernel.org, kasan-dev@googlegroups.com, linux-mm@kvack.org References: <20260914-pte0_arm-v1-0-bb53b663e396@arm.com> From: Ryan Roberts Content-Language: en-GB In-Reply-To: <20260914-pte0_arm-v1-0-bb53b663e396@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: E9B7C80003 X-Rspam-User: X-Stat-Signature: 1sy5fkh48s49gsjqpp1t86wsy1juf3ss X-HE-Tag: 1789984273-274634 X-HE-Meta: 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 Ln/pFGK3 v/Xt7Y6h5i147AAomowQEUccvYyln+yZ18zaEva2jx0jYmJikPAJ1xIC+yLk41PTCT6i/l9RnaeuUdKNMyPHZKJQSZrJ5jEhe0BLt//zs+1oeO4q4Jithjkl45R0WfRfJzY4tyPzm22lSu2ikmjiNEuad6aBs7YpCt5gAVva8DQMXFKx4mlQp+klUK8/hMIWsAw+HVTEUr/fAKDj19Oqc9q8uGbzQRLPze1bGStS2YLGCJx3QugH6VSTxZp04yNTIOdOE20+0oIjzI6Jo1RBxA4HnZwmcNmGzEhpQe7o2Sgg2JRXkV56LrHIzjYXr/n94gSzqaHvkjn+74y8K/2F1gv0xoikoZIvnZ+uYszbJ82WEIHucDzzqfkSkLwNvwmkXtHck0te65iOlQ70= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 14/09/2026 14:51, Muhammad Usama Anjum wrote: > Hi, > > The generic series introduces hw_pte_t for HW PTEs, while SW PTE values > use pte_t. This series enables the distinct type on arm64 so the > compiler can distinguish HW PTE pointers (hw_pte_t *) from SW PTE value > pointers (pte_t *). > > The conversion updates HW PTE pointers and accessors, including atomic > updates, fixmap, and early page-table construction, before selecting > ARCH_HAS_HW_PTE_T. Higher-level entry types remain out of scope, and > shared helpers retain explicit casts. > > The linked generic series is a prerequisite. Its cover contains the > Coccinelle script used for most pointer conversions; the remaining sites > were converted by hand. > > Link: https://lore.kernel.org/all/20260903103002.1091859-1-usama.anjum@arm.com/ > Signed-off-by: Muhammad Usama Anjum I've been through this as best I can and provided some minor comments. This all looks ok over all. But given the number of small changes, it would probably be wise to go big on testing; what level of testing has been performed? I'd suggest mm selftests (with all the magic to make all the tests actually run) at minimum and all the fastpath benchmarks as a stress test. I think it's quite ugly (and adds a bit to the cognitive load) to have this intermediate state where only ptes are converted. But I understand the need to do this incrementally. Hopefully you can follow up with the other levels soon :) Thanks, Ryan > --- > Muhammad Usama Anjum (6): > arm64: use hw_pte_t for HW PTE pointers > arm64: use hw_pte_val for HW PTE atomics > arm64: convert between HW PTEs and SW PTE values > arm64: use hw_pte_t for fixmap HW PTEs > arm64: use HW PTE accessors in early map_range() > arm64: enable a distinct type for HW PTEs > > arch/arm64/Kconfig | 1 + > arch/arm64/include/asm/hugetlb.h | 19 ++--- > arch/arm64/include/asm/pgalloc.h | 2 +- > arch/arm64/include/asm/pgtable.h | 157 ++++++++++++++++++++------------------ > arch/arm64/include/asm/vmalloc.h | 2 +- > arch/arm64/kernel/efi.c | 3 +- > arch/arm64/kernel/pi/map_kernel.c | 4 +- > arch/arm64/kernel/pi/map_range.c | 20 +++-- > arch/arm64/kernel/pi/pi.h | 3 +- > arch/arm64/mm/contpte.c | 49 ++++++------ > arch/arm64/mm/fault.c | 11 +-- > arch/arm64/mm/fixmap.c | 8 +- > arch/arm64/mm/hugetlbpage.c | 48 ++++++------ > arch/arm64/mm/kasan_init.c | 4 +- > arch/arm64/mm/mmu.c | 46 ++++++----- > arch/arm64/mm/pageattr.c | 4 +- > arch/arm64/mm/trans_pgd.c | 4 +- > include/linux/pgtable_types.h | 6 ++ > 18 files changed, 215 insertions(+), 176 deletions(-) > --- > base-commit: ead700ca770c82167af32622cf8b68c9f87c3c7c > change-id: 20260911-pte0_arm-f1b7df7c0b51 > prerequisite-message-id: 20260903103002.1091859-1-usama.anjum@arm.com > prerequisite-patch-id: 0114fcc6ab0dbb739b5bb6fc0fe6b1c8f1fa37a1 > prerequisite-patch-id: 09fcf65970074620dd3a9cce6850b901beb01db8 > prerequisite-patch-id: 9b2fdab97c99effabb85526fa7f141c933b3aa23 > prerequisite-patch-id: 1aa309a26d98a1e93a54742705a03567ee93be71 > prerequisite-patch-id: ebe32f52c95ad0542982f0b37798d209595e25e1 > prerequisite-patch-id: a60d249f52d092524176851b2570d7245bb24434 > prerequisite-patch-id: 81ebd1378e25d40a1771b53973abcc4defa87535 > prerequisite-patch-id: d982f2b00c5eddb2459f69008a73e4f4ae4d8299 > > Best regards, > -- > Usama >