From nobody Mon Feb 9 06:48:38 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B72F3EB64DA for ; Fri, 7 Jul 2023 05:33:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231666AbjGGFd5 (ORCPT ); Fri, 7 Jul 2023 01:33:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47310 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229529AbjGGFdu (ORCPT ); Fri, 7 Jul 2023 01:33:50 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 41925171D; Thu, 6 Jul 2023 22:33:49 -0700 (PDT) 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 C82591063; Thu, 6 Jul 2023 22:34:30 -0700 (PDT) Received: from a077893.arm.com (unknown [10.163.48.50]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id ACB703F740; Thu, 6 Jul 2023 22:33:44 -0700 (PDT) From: Anshuman Khandual To: linux-arm-kernel@lists.infradead.org Cc: Anshuman Khandual , Catalin Marinas , Will Deacon , Ryan Roberts , Mark Rutland , Andrew Morton , David Hildenbrand , Jonathan Corbet , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org Subject: [RFC 1/4] arm64/mm: Add SW and HW dirty state helpers Date: Fri, 7 Jul 2023 11:03:28 +0530 Message-Id: <20230707053331.510041-2-anshuman.khandual@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230707053331.510041-1-anshuman.khandual@arm.com> References: <20230707053331.510041-1-anshuman.khandual@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" This factors out low level SW and HW state changes i.e make and clear into separate helpers making them explicit improving readability. This also adds pte_rdonly() helper as well. No functional change is intended. Cc: Catalin Marinas Cc: Will Deacon Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Anshuman Khandual --- arch/arm64/include/asm/pgtable.h | 52 ++++++++++++++++++++++++++------ 1 file changed, 42 insertions(+), 10 deletions(-) diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgta= ble.h index 0bd18de9fd97..fb03be697819 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -103,6 +103,7 @@ static inline pteval_t __phys_to_pte_val(phys_addr_t ph= ys) #define pte_young(pte) (!!(pte_val(pte) & PTE_AF)) #define pte_special(pte) (!!(pte_val(pte) & PTE_SPECIAL)) #define pte_write(pte) (!!(pte_val(pte) & PTE_WRITE)) +#define pte_rdonly(pte) (!!(pte_val(pte) & PTE_RDONLY)) #define pte_user(pte) (!!(pte_val(pte) & PTE_USER)) #define pte_user_exec(pte) (!(pte_val(pte) & PTE_UXN)) #define pte_cont(pte) (!!(pte_val(pte) & PTE_CONT)) @@ -120,7 +121,7 @@ static inline pteval_t __phys_to_pte_val(phys_addr_t ph= ys) (__boundary - 1 < (end) - 1) ? __boundary : (end); \ }) =20 -#define pte_hw_dirty(pte) (pte_write(pte) && !(pte_val(pte) & PTE_RDONLY)) +#define pte_hw_dirty(pte) (pte_write(pte) && !pte_rdonly(pte)) #define pte_sw_dirty(pte) (!!(pte_val(pte) & PTE_DIRTY)) #define pte_dirty(pte) (pte_sw_dirty(pte) || pte_hw_dirty(pte)) =20 @@ -174,6 +175,39 @@ static inline pmd_t clear_pmd_bit(pmd_t pmd, pgprot_t = prot) return pmd; } =20 +static inline pte_t pte_hw_mkdirty(pte_t pte) +{ + if (pte_write(pte)) + pte =3D clear_pte_bit(pte, __pgprot(PTE_RDONLY)); + + return pte; +} + +static inline pte_t pte_sw_mkdirty(pte_t pte) +{ + return set_pte_bit(pte, __pgprot(PTE_DIRTY)); +} + +static inline __always_unused pte_t pte_hw_clr_dirty(pte_t pte) +{ + return set_pte_bit(pte, __pgprot(PTE_RDONLY)); +} + +static inline pte_t pte_sw_clr_dirty(pte_t pte) +{ + pte =3D clear_pte_bit(pte, __pgprot(PTE_DIRTY)); + + /* + * Clearing the software dirty state requires clearing + * the PTE_DIRTY bit along with setting the PTE_RDONLY + * ensuring a page fault on subsequent write access. + * + * NOTE: Setting the PTE_RDONLY (as a coincident) also + * implies clearing the HW dirty state. + */ + return set_pte_bit(pte, __pgprot(PTE_RDONLY)); +} + static inline pmd_t set_pmd_bit(pmd_t pmd, pgprot_t prot) { pmd_val(pmd) |=3D pgprot_val(prot); @@ -189,19 +223,17 @@ static inline pte_t pte_mkwrite(pte_t pte) =20 static inline pte_t pte_mkclean(pte_t pte) { - pte =3D clear_pte_bit(pte, __pgprot(PTE_DIRTY)); - pte =3D set_pte_bit(pte, __pgprot(PTE_RDONLY)); - - return pte; + /* + * Subsequent call to pte_hw_clr_dirty() is not required + * because pte_sw_clr_dirty() in turn does that as well. + */ + return pte_sw_clr_dirty(pte); } =20 static inline pte_t pte_mkdirty(pte_t pte) { - pte =3D set_pte_bit(pte, __pgprot(PTE_DIRTY)); - - if (pte_write(pte)) - pte =3D clear_pte_bit(pte, __pgprot(PTE_RDONLY)); - + pte =3D pte_sw_mkdirty(pte); + pte =3D pte_hw_mkdirty(pte); return pte; } =20 --=20 2.30.2