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 8F2ACC98317 for ; Thu, 24 Sep 2026 12:21:40 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 9F3B86B008A; Thu, 24 Sep 2026 08:21:39 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 97D866B008C; Thu, 24 Sep 2026 08:21:39 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 86C0B6B0092; Thu, 24 Sep 2026 08:21:39 -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 5E19E6B008A for ; Thu, 24 Sep 2026 08:21:39 -0400 (EDT) Received: from smtpin14.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay01.hostedemail.com (Postfix) with ESMTP id E7C0C1C2698 for ; Thu, 24 Sep 2026 12:21:38 +0000 (UTC) X-FDA: 85248566676.14.446A145 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf01.hostedemail.com (Postfix) with ESMTP id EA3D340005 for ; Thu, 24 Sep 2026 12:21:36 +0000 (UTC) Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=arm.com header.s=foss header.b=RCb6mJCl; spf=pass (imf01.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=1790252497; 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=5xePOy1AI/uAmoNLk2pom3JdMozQVH6qVeKB1dqEvS8=; b=fx5vgqPHHFlcb3q55QxUxAfV6SKNpRz3MfaDPF761DZWuovhjk7+InptdVoHyCWVbUhKhX tNCF2H7Bf8trZlh52XrBdcd6JBPsR78AERT6jhjQilwuVvO9bGRU8M2x7YW2LbfpnQSCqd crZ7YUTAR/xBpfyFbvVaqjEedhpBFwQ= ARC-Authentication-Results: i=1; imf01.hostedemail.com; dkim=pass header.d=arm.com header.s=foss header.b=RCb6mJCl; spf=pass (imf01.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=1790252497; b=4T4EfYwJ7oyZthNykvH/XVeCWkWvHnnqSZtf3CpV1YGXuX0pkYyCdrkrIOLRWV22WU7kzT e20d+fzQdwGyLTPPYKz88ONMqWxz/1psJ7ugxj/C8jH/6fl3/uVS5WKJQaDLs2XpwGhXYA 04CT+BuC8sUfcWPbu/Nhqe9iTtK911w= 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 8687A152B; Thu, 24 Sep 2026 05:21:32 -0700 (PDT) Received: from [10.57.83.110] (unknown [10.57.83.110]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id ABA9B3F86C; Thu, 24 Sep 2026 05:21:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1790252496; bh=rTdcO7n0+nshxu9CDu/EDryDUt+kuTOvFiqhnTEqJCg=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=RCb6mJClIL5UcTql5vFcsex7DxOdojrWEOrsuD+03U/8LnEkoU4WGd4NklebN4L/q i8SAcsH8Z8iDp7GOdFsb2I3V0awYWc2PApLoDAD0UXrSVigZDqp90z2XYQLFkm59o6 Z+aW0c6kZeCZ6al02l/F0iQ5og5z9BpTFQcoNTnk= Message-ID: <7a600128-bf10-4966-8c08-129eeec3fb91@arm.com> Date: Thu, 24 Sep 2026 13:21:29 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 2/6] arm64: use hw_pte_val for HW PTE atomics 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: <20260922-pte0_arm-v2-0-a3f1ddff0a8a@arm.com> <20260922-pte0_arm-v2-2-a3f1ddff0a8a@arm.com> From: Ryan Roberts Content-Language: en-GB In-Reply-To: <20260922-pte0_arm-v2-2-a3f1ddff0a8a@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: EA3D340005 X-Stat-Signature: 5shq55ewymz63xu9rkrbharsjf4hcgn8 X-Rspam-User: X-HE-Tag: 1790252496-486143 X-HE-Meta: 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 nJpDG0NA q5UpESE81V/iaX928TE8oV2dADfV5oWEgg0lFGKczESooPICzTb7R6EbGRsBcYgLwUA0tyWKz4nQF8bvmXVWmvnghj7uZZT/69aWHbwguOLBLIaPwPHLhCvqWXa2KTbIw9jy47HVPmNOCqluidR8G9hsLpntwEfUAhhJHjDtlTIr6c35gxHIRaeP+Am09ynrZN42+XUqUbueaheyJfhRD84vXOJFHoMCYj1mDu27vQxM2ID/1x6/NgJllN8oDGAOrZlCvayLoe7hfDvcCHeaaCdMgE/jP4ispJGmRYYRe9jJAL2q391UlXNMjiiauL7VTPp6j94iaTVobNdTDpj7HlDm2+/w37kxeYs76wJZMldKsmSubpyhvQK0ZQZQBS9+cy+0OMUv/S5Lz0AEyA/xfFMfs0kjfxvW5v/ax Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 22/09/2026 18:31, Muhammad Usama Anjum wrote: > The low-level atomic PTE update paths take the address of > pte_val(*ptep). That assumes HW PTE storage can be passed directly to > the SW PTE value accessor and no longer type-checks when hw_pte_t is > distinct. > > Use hw_pte_val() for the lvalues passed to compare-exchange and exchange > operations. The atomic operations and their ordering are unchanged. > > Signed-off-by: Muhammad Usama Anjum Reviewed-by: Ryan Roberts > --- > Chagnes in v2: > - Remove comment change > - Move hw_pte_val() to generic series > --- > arch/arm64/include/asm/pgtable.h | 10 +++++----- > arch/arm64/mm/fault.c | 2 +- > 2 files changed, 6 insertions(+), 6 deletions(-) > > diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h > index 652ce413be389..4768ec59de555 100644 > --- a/arch/arm64/include/asm/pgtable.h > +++ b/arch/arm64/include/asm/pgtable.h > @@ -1303,7 +1303,7 @@ static inline bool __ptep_test_and_clear_young(struct vm_area_struct *vma, > do { > old_pte = pte; > pte = pte_mkold(pte); > - pte_val(pte) = cmpxchg_relaxed(&pte_val(*ptep), > + pte_val(pte) = cmpxchg_relaxed(&hw_pte_val(*ptep), > pte_val(old_pte), pte_val(pte)); > } while (pte_val(pte) != pte_val(old_pte)); > > @@ -1346,7 +1346,7 @@ static inline pte_t __ptep_get_and_clear_anysz(struct mm_struct *mm, > hw_pte_t *ptep, > unsigned long pgsize) > { > - pte_t pte = __pte(xchg_relaxed(&pte_val(*ptep), 0)); > + pte_t pte = __pte(xchg_relaxed(&hw_pte_val(*ptep), 0)); > > switch (pgsize) { > case PAGE_SIZE: > @@ -1422,7 +1422,7 @@ static inline void ___ptep_set_wrprotect(struct mm_struct *mm, > do { > old_pte = pte; > pte = pte_wrprotect(pte); > - pte_val(pte) = cmpxchg_relaxed(&pte_val(*ptep), > + pte_val(pte) = cmpxchg_relaxed(&hw_pte_val(*ptep), > pte_val(old_pte), pte_val(pte)); > } while (pte_val(pte) != pte_val(old_pte)); > } > @@ -1460,7 +1460,7 @@ static inline void __clear_young_dirty_pte(struct vm_area_struct *vma, > if (flags & CYDP_CLEAR_DIRTY) > pte = pte_mkclean(pte); > > - pte_val(pte) = cmpxchg_relaxed(&pte_val(*ptep), > + pte_val(pte) = cmpxchg_relaxed(&hw_pte_val(*ptep), > pte_val(old_pte), pte_val(pte)); > } while (pte_val(pte) != pte_val(old_pte)); > } > @@ -1830,7 +1830,7 @@ static inline bool ptep_try_set(hw_pte_t *ptep, pte_t new_pte) > { > pteval_t old = 0; > > - if (!try_cmpxchg(&pte_val(*ptep), &old, pte_val(new_pte))) > + if (!try_cmpxchg(&hw_pte_val(*ptep), &old, pte_val(new_pte))) > return false; > > /* > diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c > index b77f4be88e3ea..3322f4e7174dc 100644 > --- a/arch/arm64/mm/fault.c > +++ b/arch/arm64/mm/fault.c > @@ -235,7 +235,7 @@ int __ptep_set_access_flags_anysz(struct vm_area_struct *vma, > pteval ^= PTE_RDONLY; > pteval |= pte_val(entry); > pteval ^= PTE_RDONLY; > - pteval = cmpxchg_relaxed(&pte_val(*ptep), old_pteval, pteval); > + pteval = cmpxchg_relaxed(&hw_pte_val(*ptep), old_pteval, pteval); > } while (pteval != old_pteval); > > /* >