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 B3C0B1607A4 for ; Tue, 24 Feb 2026 05:12:56 +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=1771909978; cv=none; b=Br2t/a1mfWreE/erPwaK+E6DJwcxmYhyCV9kBhfhpxPom7ovq9iNP8ow/bchpHaIGA2un/PKcFPdiUjyLQfhYO3p560VfD5GWLCUPNi0/PyyMHeQdYAbUDajz+b/zUlO3iiqqiASP9DscE15m3rAW6ThLc/hpbh6Ek+81iHPi8k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771909978; c=relaxed/simple; bh=qLvNJ5ac2hzL6uv9+aU17gCV2qIaMbbXMsIEua/eII0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=AxvE97MsU3vgyvarqZTRu0grEKZcG8S+TBLmGiBhweOSzVlekAbU5s3pLd9x1m4l+Z/SxoHnLG4OScQDGow7Uv3hvIYyCLdxNDp6eFKSOREUeGd/GlMAIAUsB3yreQTu4U3qw2PHdMOfbagdcyqH0Ciobdgb1QiVYje0Gd9FQeA= 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; 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 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 CA9A7497; Mon, 23 Feb 2026 21:12:49 -0800 (PST) Received: from a085714.blr.arm.com (a085714.arm.com [10.164.18.87]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id A2A183F7BD; Mon, 23 Feb 2026 21:12:51 -0800 (PST) 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, kasan-dev@googlegroups.com Subject: [RFC V1 06/16] arm64/mm: Convert READ_ONCE() as pudp_get() while accessing PUD Date: Tue, 24 Feb 2026 10:41:43 +0530 Message-ID: <20260224051153.3150613-7-anshuman.khandual@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260224051153.3150613-1-anshuman.khandual@arm.com> References: <20260224051153.3150613-1-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 Convert all READ_ONCE() based PUD accesses as pudp_get() instead which will support both D64 and D128 translation regime going forward. 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 Cc: kasan-dev@googlegroups.com Signed-off-by: Anshuman Khandual --- arch/arm64/include/asm/pgtable.h | 3 ++- arch/arm64/mm/fault.c | 2 +- arch/arm64/mm/fixmap.c | 2 +- arch/arm64/mm/hugetlbpage.c | 4 ++-- arch/arm64/mm/kasan_init.c | 4 ++-- arch/arm64/mm/mmu.c | 20 ++++++++++---------- arch/arm64/mm/pageattr.c | 2 +- arch/arm64/mm/trans_pgd.c | 4 ++-- 8 files changed, 21 insertions(+), 20 deletions(-) diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 4b5bc2c09bf2..93d06b5de34b 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -913,7 +913,8 @@ static inline pmd_t *pud_pgtable(pud_t pud) } /* Find an entry in the second-level page table. */ -#define pmd_offset_phys(dir, addr) (pud_page_paddr(READ_ONCE(*(dir))) + pmd_index(addr) * sizeof(pmd_t)) +#define pmd_offset_phys(dir, addr) (pud_page_paddr(pudp_get(dir)) + \ + pmd_index(addr) * sizeof(pmd_t)) #define pmd_set_fixmap(addr) ((pmd_t *)set_fixmap_offset(FIX_PMD, addr)) #define pmd_set_fixmap_offset(pud, addr) pmd_set_fixmap(pmd_offset_phys(pud, addr)) diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index 1389ba26ec74..64836bc14798 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -171,7 +171,7 @@ static void show_pte(unsigned long addr) break; pudp = pud_offset(p4dp, addr); - pud = READ_ONCE(*pudp); + pud = pudp_get(pudp); pr_cont(", pud=%016llx", pud_val(pud)); if (pud_none(pud) || pud_bad(pud)) break; diff --git a/arch/arm64/mm/fixmap.c b/arch/arm64/mm/fixmap.c index 7a4bbcb39094..dd58af6561e0 100644 --- a/arch/arm64/mm/fixmap.c +++ b/arch/arm64/mm/fixmap.c @@ -56,7 +56,7 @@ static void __init early_fixmap_init_pmd(pud_t *pudp, unsigned long addr, unsigned long end) { unsigned long next; - pud_t pud = READ_ONCE(*pudp); + pud_t pud = pudp_get(pudp); pmd_t *pmdp; if (pud_none(pud)) diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c index 6117aca2bac7..b229c05bfbb6 100644 --- a/arch/arm64/mm/hugetlbpage.c +++ b/arch/arm64/mm/hugetlbpage.c @@ -262,7 +262,7 @@ pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma, WARN_ON(addr & (sz - 1)); ptep = pte_alloc_huge(mm, pmdp, addr); } else if (sz == PMD_SIZE) { - if (want_pmd_share(vma, addr) && pud_none(READ_ONCE(*pudp))) + if (want_pmd_share(vma, addr) && pud_none(pudp_get(pudp))) ptep = huge_pmd_share(mm, vma, addr, pudp); else ptep = (pte_t *)pmd_alloc(mm, pudp, addr); @@ -292,7 +292,7 @@ pte_t *huge_pte_offset(struct mm_struct *mm, return NULL; pudp = pud_offset(p4dp, addr); - pud = READ_ONCE(*pudp); + pud = pudp_get(pudp); if (sz != PUD_SIZE && pud_none(pud)) return NULL; /* hugepage or swap? */ diff --git a/arch/arm64/mm/kasan_init.c b/arch/arm64/mm/kasan_init.c index 709e8ad15603..19492ef5940a 100644 --- a/arch/arm64/mm/kasan_init.c +++ b/arch/arm64/mm/kasan_init.c @@ -76,7 +76,7 @@ static pte_t *__init kasan_pte_offset(pmd_t *pmdp, unsigned long addr, int node, static pmd_t *__init kasan_pmd_offset(pud_t *pudp, unsigned long addr, int node, bool early) { - if (pud_none(READ_ONCE(*pudp))) { + if (pud_none(pudp_get(pudp))) { phys_addr_t pmd_phys = early ? __pa_symbol(kasan_early_shadow_pmd) : kasan_alloc_zeroed_page(node); @@ -150,7 +150,7 @@ static void __init kasan_pud_populate(p4d_t *p4dp, unsigned long addr, do { next = pud_addr_end(addr, end); kasan_pmd_populate(pudp, addr, next, node, early); - } while (pudp++, addr = next, addr != end && pud_none(READ_ONCE(*pudp))); + } while (pudp++, addr = next, addr != end && pud_none(pudp_get(pudp))); } static void __init kasan_p4d_populate(pgd_t *pgdp, unsigned long addr, diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index dea1b595f237..a80d06db4de6 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -297,7 +297,7 @@ static int alloc_init_cont_pmd(pud_t *pudp, unsigned long addr, { int ret; unsigned long next; - pud_t pud = READ_ONCE(*pudp); + pud_t pud = pudp_get(pudp); pmd_t *pmdp; /* @@ -377,7 +377,7 @@ static int alloc_init_pud(p4d_t *p4dp, unsigned long addr, unsigned long end, } do { - pud_t old_pud = READ_ONCE(*pudp); + pud_t old_pud = pudp_get(pudp); next = pud_addr_end(addr, end); @@ -394,7 +394,7 @@ static int alloc_init_pud(p4d_t *p4dp, unsigned long addr, unsigned long end, * only allow updates to the permission attributes. */ BUG_ON(!pgattr_change_is_safe(pud_val(old_pud), - READ_ONCE(pud_val(*pudp)))); + pud_val(pudp_get(pudp)))); } else { ret = alloc_init_cont_pmd(pudp, addr, next, phys, prot, pgtable_alloc, flags); @@ -402,7 +402,7 @@ static int alloc_init_pud(p4d_t *p4dp, unsigned long addr, unsigned long end, goto out; BUG_ON(pud_val(old_pud) != 0 && - pud_val(old_pud) != READ_ONCE(pud_val(*pudp))); + pud_val(old_pud) != pud_val(pudp_get(pudp))); } phys += next - addr; } while (pudp++, addr = next, addr != end); @@ -1508,7 +1508,7 @@ static void unmap_hotplug_pud_range(p4d_t *p4dp, unsigned long addr, do { next = pud_addr_end(addr, end); pudp = pud_offset(p4dp, addr); - pud = READ_ONCE(*pudp); + pud = pudp_get(pudp); if (pud_none(pud)) continue; @@ -1663,7 +1663,7 @@ static void free_empty_pud_table(p4d_t *p4dp, unsigned long addr, do { next = pud_addr_end(addr, end); pudp = pud_offset(p4dp, addr); - pud = READ_ONCE(*pudp); + pud = pudp_get(pudp); if (pud_none(pud)) continue; @@ -1684,7 +1684,7 @@ static void free_empty_pud_table(p4d_t *p4dp, unsigned long addr, */ pudp = pud_offset(p4dp, 0UL); for (i = 0; i < PTRS_PER_PUD; i++) { - if (!pud_none(READ_ONCE(pudp[i]))) + if (!pud_none(pudp_get(pudp + i))) return; } @@ -1796,7 +1796,7 @@ int pud_set_huge(pud_t *pudp, phys_addr_t phys, pgprot_t prot) pud_t new_pud = pfn_pud(__phys_to_pfn(phys), mk_pud_sect_prot(prot)); /* Only allow permission changes for now */ - if (!pgattr_change_is_safe(READ_ONCE(pud_val(*pudp)), + if (!pgattr_change_is_safe(pud_val(pudp_get(pudp)), pud_val(new_pud))) return 0; @@ -1827,7 +1827,7 @@ void p4d_clear_huge(p4d_t *p4dp) int pud_clear_huge(pud_t *pudp) { - if (!pud_sect(READ_ONCE(*pudp))) + if (!pud_sect(pudp_get(pudp))) return 0; pud_clear(pudp); return 1; @@ -1880,7 +1880,7 @@ int pud_free_pmd_page(pud_t *pudp, unsigned long addr) pud_t pud; unsigned long next, end; - pud = READ_ONCE(*pudp); + pud = pudp_get(pudp); if (!pud_table(pud)) { VM_WARN_ON(1); diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c index ed1eec4c757d..581b461d4d15 100644 --- a/arch/arm64/mm/pageattr.c +++ b/arch/arm64/mm/pageattr.c @@ -401,7 +401,7 @@ bool kernel_page_present(struct page *page) return false; pudp = pud_offset(p4dp, addr); - pud = READ_ONCE(*pudp); + pud = pudp_get(pudp); if (pud_none(pud)) return false; if (pud_sect(pud)) diff --git a/arch/arm64/mm/trans_pgd.c b/arch/arm64/mm/trans_pgd.c index ddde0f2983b0..71f489d439ef 100644 --- a/arch/arm64/mm/trans_pgd.c +++ b/arch/arm64/mm/trans_pgd.c @@ -90,7 +90,7 @@ static int copy_pmd(struct trans_pgd_info *info, pud_t *dst_pudp, unsigned long next; unsigned long addr = start; - if (pud_none(READ_ONCE(*dst_pudp))) { + if (pud_none(pudp_get(dst_pudp))) { dst_pmdp = trans_alloc(info); if (!dst_pmdp) return -ENOMEM; @@ -136,7 +136,7 @@ static int copy_pud(struct trans_pgd_info *info, p4d_t *dst_p4dp, src_pudp = pud_offset(src_p4dp, start); do { - pud_t pud = READ_ONCE(*src_pudp); + pud_t pud = pudp_get(src_pudp); next = pud_addr_end(addr, end); if (pud_none(pud)) -- 2.43.0