From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 912E13F0765 for ; Mon, 7 Sep 2026 03:50:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788753045; cv=none; b=IeEkAgsmbA0MISkJTFUspUN1UUoYV3YSjraqFqBEh6ljUMszfok1R3+TL19qmSePhBH7S3wXdx45IKb9fqLfw7muED5Ogb5HhS6tpmYGcwtcIwpj0r9UbS4HUM3BqEoz2+wUFCq3gzjFCMg64wg4cU2wRYePTOnHmD+1Jh6OqRk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788753045; c=relaxed/simple; bh=u0NC425vYyHxLP7hQ6qnyzz+8iyaNNOtn3y2ra/8hTA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=M3Dk2rPzEIE2LBdAhwb/4qlB1zCuzE4mEvu1bYdCPMBRcfkgt8aMd2bRK22ncR+2+zebwKzorn8mea9g/JU0TbHata8isIFIdTYuqgM5gBC7r4BayNW98oDOE6y89ghqhuhH/nzpjLrYkRb/Yt+mLTJmb/brY3BWSl02MkzPhS8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=Hsxe98q8; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="Hsxe98q8" 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 64D0D1BA8; Sun, 6 Sep 2026 20:50:38 -0700 (PDT) Received: from localhost (a085714.arm.com [10.164.19.28]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 5CCC43F7B4; Sun, 6 Sep 2026 20:50:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1788753042; bh=u0NC425vYyHxLP7hQ6qnyzz+8iyaNNOtn3y2ra/8hTA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Hsxe98q84/3K+kWyhkJqja1wgsnGC3YeYfKTHgB+lv+0kg19pwmcx4WqvGbsmzzic 7c+COfU5ZnvixdveYZQPHnggpyxcqQm5iVzOhATDAyQ75LDL7OrBLrYkwvkpo89Pje x638FHhR/9el/45Wd5MBVq7S0rfhZ5JXSoFkoHw4= From: Anshuman Khandual To: linux-arm-kernel@lists.infradead.org Cc: Anshuman Khandual , Catalin Marinas , Will Deacon , Ryan Roberts , Mark Rutland , Lorenzo Stoakes , Andrew Morton , David Hildenbrand , Mike Rapoport , Linu Cherian , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH V2 02/14] arm64/mm: Route all pgtable reads via ptval_get() Date: Mon, 7 Sep 2026 09:20:17 +0530 Message-ID: <20260907035030.2839978-3-anshuman.khandual@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260907035030.2839978-1-anshuman.khandual@arm.com> References: <20260907035030.2839978-1-anshuman.khandual@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Define arm64 platform specific implementations for new pxdp_get() helpers. These resolve into READ_ONCE(), thus ensuring required single copy atomic semantics for the page table entry reads. In future this infrastructure can be used for D128 to maintain single copy atomicity semantics with inline asm blocks. Cc: Catalin Marinas Cc: Will Deacon Cc: Ryan Roberts Cc: Mark Rutland Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Anshuman Khandual --- arch/arm64/include/asm/pgtable.h | 38 +++++++++++++++++++++++++++----- 1 file changed, 32 insertions(+), 6 deletions(-) diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 83087b70f192..f764132ca34e 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -84,6 +84,32 @@ static inline void arch_leave_lazy_mmu_mode(void) arch_flush_lazy_mmu_mode(); } +#define ptval_get(x) READ_ONCE(x) + +#define pmdp_get pmdp_get +static inline pmd_t pmdp_get(pmd_t *pmdp) +{ + return ptval_get(*pmdp); +} + +#define pudp_get pudp_get +static inline pud_t pudp_get(pud_t *pudp) +{ + return ptval_get(*pudp); +} + +#define p4dp_get p4dp_get +static inline p4d_t p4dp_get(p4d_t *p4dp) +{ + return ptval_get(*p4dp); +} + +#define pgdp_get pgdp_get +static inline pgd_t pgdp_get(pgd_t *pgdp) +{ + return ptval_get(*pgdp); +} + #ifdef CONFIG_TRANSPARENT_HUGEPAGE #define __HAVE_ARCH_FLUSH_PMD_TLB_RANGE @@ -381,7 +407,7 @@ static inline void __set_pte(pte_t *ptep, pte_t pte) static inline pte_t __ptep_get(pte_t *ptep) { - return READ_ONCE(*ptep); + return ptval_get(*ptep); } extern void __sync_icache_dcache(pte_t pteval); @@ -958,7 +984,7 @@ static inline phys_addr_t pud_offset_phys(p4d_t *p4dp, unsigned long addr) { VM_WARN_ON_ONCE(!pgtable_l4_enabled()); - return p4d_page_paddr(READ_ONCE(*p4dp)) + pud_index(addr) * sizeof(pud_t); + return p4d_page_paddr(p4dp_get(p4dp)) + pud_index(addr) * sizeof(pud_t); } static inline @@ -972,7 +998,7 @@ pud_t *pud_offset_lockless(p4d_t *p4dp, p4d_t p4d, unsigned long addr) static inline pud_t *pud_offset(p4d_t *p4dp, unsigned long addr) { - return pud_offset_lockless(p4dp, READ_ONCE(*p4dp), addr); + return pud_offset_lockless(p4dp, p4dp_get(p4dp), addr); } #define pud_offset pud_offset @@ -1078,7 +1104,7 @@ static inline phys_addr_t p4d_offset_phys(pgd_t *pgdp, unsigned long addr) { VM_WARN_ON_ONCE(!pgtable_l5_enabled()); - return pgd_page_paddr(READ_ONCE(*pgdp)) + p4d_index(addr) * sizeof(p4d_t); + return pgd_page_paddr(pgdp_get(pgdp)) + p4d_index(addr) * sizeof(p4d_t); } static inline @@ -1092,7 +1118,7 @@ p4d_t *p4d_offset_lockless(pgd_t *pgdp, pgd_t pgd, unsigned long addr) static inline p4d_t *p4d_offset(pgd_t *pgdp, unsigned long addr) { - return p4d_offset_lockless(pgdp, READ_ONCE(*pgdp), addr); + return p4d_offset_lockless(pgdp, pgdp_get(pgdp), addr); } static inline p4d_t *p4d_set_fixmap(unsigned long addr) @@ -1287,7 +1313,7 @@ static inline bool pmdp_test_and_clear_young(struct vm_area_struct *vma, unsigned long address, pmd_t *pmdp) { /* Operation applies to PMD table entry only if FEAT_HAFT is enabled */ - VM_WARN_ON(pmd_table(READ_ONCE(*pmdp)) && !system_supports_haft()); + VM_WARN_ON(pmd_table(pmdp_get(pmdp)) && !system_supports_haft()); return __ptep_test_and_clear_young(vma, address, (pte_t *)pmdp); } #endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG */ -- 2.43.0