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Wed, 15 Nov 2023 08:31:02 -0800 (PST) From: Ryan Roberts To: Catalin Marinas , Will Deacon , Ard Biesheuvel , Marc Zyngier , Oliver Upton , James Morse , Suzuki K Poulose , Zenghui Yu , Andrey Ryabinin , Alexander Potapenko , Andrey Konovalov , Dmitry Vyukov , Vincenzo Frascino , Andrew Morton , Anshuman Khandual , Matthew Wilcox , Yu Zhao , Mark Rutland , David Hildenbrand , Kefeng Wang , John Hubbard , Zi Yan Cc: Ryan Roberts , linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 10/14] arm64/mm: ptep_get(): New layer to manage contig bit Date: Wed, 15 Nov 2023 16:30:14 +0000 Message-Id: <20231115163018.1303287-11-ryan.roberts@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20231115163018.1303287-1-ryan.roberts@arm.com> References: <20231115163018.1303287-1-ryan.roberts@arm.com> MIME-Version: 1.0 X-Rspamd-Queue-Id: 9626D1C002D X-Rspam-User: X-Rspamd-Server: rspam04 X-Stat-Signature: 1mm1kn7ahn3ytb4wwrfeh74zd8osnxs4 X-HE-Tag: 1700065867-119900 X-HE-Meta: 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 qIqlVdI5 7MhpnLzA2Xv+IoL8HHGSWZJgKbJ2SCLpCBOXWOVbYQK//SgwrayXR7CgS4Pw33guEsUbUD2VElpGl7NBcYNF3ky12q1AJmJEPewQbN0NvtWBwqmn7FnO3gh3yJY+FASvg/HH/hP4FO8qpKYuYdlaSb5OcQWZ1rYPLP+5lu0QyObuuVAaIA/HcFxXeGFsqxPGltv+0j6mOEZGpD7YZAWueXR+EhzwbdrFb3PKHomkZ19O5MT5bVUa2yETrX2p4DIWbhXOXxY8mPZfmMT9ydUT0EjGgpw== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Create a new layer for the in-table PTE manipulation APIs. For now, The existing API is prefixed with double underscore to become the arch-private API and the public API is just a simple wrapper that calls the private API. The public API implementation will subsequently be used to transparently manipulate the contiguous bit where appropriate. But since there are already some contig-aware users (e.g. hugetlb, kernel mapper), we must first ensure those users use the private API directly so that the future contig-bit manipulations in the public API do not interfere with those existing uses. arm64 did not previously define an arch-specific ptep_get(), so override the default version in the arch code, and also define the private __ptep_get() version. Currently they both do the same thing that the default version does (READ_ONCE()). Some arch users (hugetlb) were already using ptep_get() so convert those to the private API. While other callsites were doing direct READ_ONCE(), so convert those to use the appropriate (public/private) API too. Signed-off-by: Ryan Roberts --- arch/arm64/include/asm/pgtable.h | 12 +++++++++--- arch/arm64/kernel/efi.c | 2 +- arch/arm64/mm/fault.c | 4 ++-- arch/arm64/mm/hugetlbpage.c | 18 +++++++++--------- arch/arm64/mm/kasan_init.c | 2 +- arch/arm64/mm/mmu.c | 12 ++++++------ arch/arm64/mm/pageattr.c | 4 ++-- arch/arm64/mm/trans_pgd.c | 2 +- 8 files changed, 31 insertions(+), 25 deletions(-) diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 85010c2d4dfa..6930c14f062f 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -276,6 +276,11 @@ static inline void __set_pte(pte_t *ptep, pte_t pte) } } +static inline pte_t __ptep_get(pte_t *ptep) +{ + return READ_ONCE(*ptep); +} + extern void __sync_icache_dcache(pte_t pteval); bool pgattr_change_is_safe(u64 old, u64 new); @@ -303,7 +308,7 @@ static inline void __check_safe_pte_update(struct mm_struct *mm, pte_t *ptep, if (!IS_ENABLED(CONFIG_DEBUG_VM)) return; - old_pte = READ_ONCE(*ptep); + old_pte = __ptep_get(ptep); if (!pte_valid(old_pte) || !pte_valid(pte)) return; @@ -893,7 +898,7 @@ static inline int __ptep_test_and_clear_young(struct vm_area_struct *vma, { pte_t old_pte, pte; - pte = READ_ONCE(*ptep); + pte = __ptep_get(ptep); do { old_pte = pte; pte = pte_mkold(pte); @@ -966,7 +971,7 @@ static inline void __ptep_set_wrprotect(struct mm_struct *mm, { pte_t old_pte, pte; - pte = READ_ONCE(*ptep); + pte = __ptep_get(ptep); do { old_pte = pte; pte = pte_wrprotect(pte); @@ -1111,6 +1116,7 @@ extern void ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep, pte_t old_pte, pte_t new_pte); +#define ptep_get __ptep_get #define set_pte __set_pte #define set_ptes __set_ptes #define pte_clear __pte_clear diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c index 44288a12fc6c..9afcc690fe73 100644 --- a/arch/arm64/kernel/efi.c +++ b/arch/arm64/kernel/efi.c @@ -103,7 +103,7 @@ static int __init set_permissions(pte_t *ptep, unsigned long addr, void *data) { struct set_perm_data *spd = data; const efi_memory_desc_t *md = spd->md; - pte_t pte = READ_ONCE(*ptep); + pte_t pte = __ptep_get(ptep); if (md->attribute & EFI_MEMORY_RO) pte = set_pte_bit(pte, __pgprot(PTE_RDONLY)); diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index 7cebd9847aae..d63f3a0a7251 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -191,7 +191,7 @@ static void show_pte(unsigned long addr) if (!ptep) break; - pte = READ_ONCE(*ptep); + pte = __ptep_get(ptep); pr_cont(", pte=%016llx", pte_val(pte)); pte_unmap(ptep); } while(0); @@ -214,7 +214,7 @@ int __ptep_set_access_flags(struct vm_area_struct *vma, pte_t entry, int dirty) { pteval_t old_pteval, pteval; - pte_t pte = READ_ONCE(*ptep); + pte_t pte = __ptep_get(ptep); if (pte_same(pte, entry)) return 0; diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c index 627a9717e98c..52fb767607e0 100644 --- a/arch/arm64/mm/hugetlbpage.c +++ b/arch/arm64/mm/hugetlbpage.c @@ -152,14 +152,14 @@ pte_t huge_ptep_get(pte_t *ptep) { int ncontig, i; size_t pgsize; - pte_t orig_pte = ptep_get(ptep); + pte_t orig_pte = __ptep_get(ptep); if (!pte_present(orig_pte) || !pte_cont(orig_pte)) return orig_pte; ncontig = num_contig_ptes(page_size(pte_page(orig_pte)), &pgsize); for (i = 0; i < ncontig; i++, ptep++) { - pte_t pte = ptep_get(ptep); + pte_t pte = __ptep_get(ptep); if (pte_dirty(pte)) orig_pte = pte_mkdirty(orig_pte); @@ -184,7 +184,7 @@ static pte_t get_clear_contig(struct mm_struct *mm, unsigned long pgsize, unsigned long ncontig) { - pte_t orig_pte = ptep_get(ptep); + pte_t orig_pte = __ptep_get(ptep); unsigned long i; for (i = 0; i < ncontig; i++, addr += pgsize, ptep++) { @@ -408,7 +408,7 @@ pte_t huge_ptep_get_and_clear(struct mm_struct *mm, { int ncontig; size_t pgsize; - pte_t orig_pte = ptep_get(ptep); + pte_t orig_pte = __ptep_get(ptep); if (!pte_cont(orig_pte)) return __ptep_get_and_clear(mm, addr, ptep); @@ -431,11 +431,11 @@ static int __cont_access_flags_changed(pte_t *ptep, pte_t pte, int ncontig) { int i; - if (pte_write(pte) != pte_write(ptep_get(ptep))) + if (pte_write(pte) != pte_write(__ptep_get(ptep))) return 1; for (i = 0; i < ncontig; i++) { - pte_t orig_pte = ptep_get(ptep + i); + pte_t orig_pte = __ptep_get(ptep + i); if (pte_dirty(pte) != pte_dirty(orig_pte)) return 1; @@ -492,7 +492,7 @@ void huge_ptep_set_wrprotect(struct mm_struct *mm, size_t pgsize; pte_t pte; - if (!pte_cont(READ_ONCE(*ptep))) { + if (!pte_cont(__ptep_get(ptep))) { __ptep_set_wrprotect(mm, addr, ptep); return; } @@ -517,7 +517,7 @@ pte_t huge_ptep_clear_flush(struct vm_area_struct *vma, size_t pgsize; int ncontig; - if (!pte_cont(READ_ONCE(*ptep))) + if (!pte_cont(__ptep_get(ptep))) return ptep_clear_flush(vma, addr, ptep); ncontig = find_num_contig(mm, addr, ptep, &pgsize); @@ -550,7 +550,7 @@ pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr * when the permission changes from executable to non-executable * in cases where cpu is affected with errata #2645198. */ - if (pte_user_exec(READ_ONCE(*ptep))) + if (pte_user_exec(__ptep_get(ptep))) return huge_ptep_clear_flush(vma, addr, ptep); } return huge_ptep_get_and_clear(vma->vm_mm, addr, ptep); diff --git a/arch/arm64/mm/kasan_init.c b/arch/arm64/mm/kasan_init.c index 5eade712e9e5..5274c317d775 100644 --- a/arch/arm64/mm/kasan_init.c +++ b/arch/arm64/mm/kasan_init.c @@ -113,7 +113,7 @@ static void __init kasan_pte_populate(pmd_t *pmdp, unsigned long addr, memset(__va(page_phys), KASAN_SHADOW_INIT, PAGE_SIZE); next = addr + PAGE_SIZE; __set_pte(ptep, pfn_pte(__phys_to_pfn(page_phys), PAGE_KERNEL)); - } while (ptep++, addr = next, addr != end && pte_none(READ_ONCE(*ptep))); + } while (ptep++, addr = next, addr != end && pte_none(__ptep_get(ptep))); } static void __init kasan_pmd_populate(pud_t *pudp, unsigned long addr, diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 080e9b50f595..784f1e312447 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -176,7 +176,7 @@ static void init_pte(pmd_t *pmdp, unsigned long addr, unsigned long end, ptep = pte_set_fixmap_offset(pmdp, addr); do { - pte_t old_pte = READ_ONCE(*ptep); + pte_t old_pte = __ptep_get(ptep); __set_pte(ptep, pfn_pte(__phys_to_pfn(phys), prot)); @@ -185,7 +185,7 @@ static void init_pte(pmd_t *pmdp, unsigned long addr, unsigned long end, * only allow updates to the permission attributes. */ BUG_ON(!pgattr_change_is_safe(pte_val(old_pte), - READ_ONCE(pte_val(*ptep)))); + pte_val(__ptep_get(ptep)))); phys += PAGE_SIZE; } while (ptep++, addr += PAGE_SIZE, addr != end); @@ -854,7 +854,7 @@ static void unmap_hotplug_pte_range(pmd_t *pmdp, unsigned long addr, do { ptep = pte_offset_kernel(pmdp, addr); - pte = READ_ONCE(*ptep); + pte = __ptep_get(ptep); if (pte_none(pte)) continue; @@ -987,7 +987,7 @@ static void free_empty_pte_table(pmd_t *pmdp, unsigned long addr, do { ptep = pte_offset_kernel(pmdp, addr); - pte = READ_ONCE(*ptep); + pte = __ptep_get(ptep); /* * This is just a sanity check here which verifies that @@ -1006,7 +1006,7 @@ static void free_empty_pte_table(pmd_t *pmdp, unsigned long addr, */ ptep = pte_offset_kernel(pmdp, 0UL); for (i = 0; i < PTRS_PER_PTE; i++) { - if (!pte_none(READ_ONCE(ptep[i]))) + if (!pte_none(__ptep_get(&ptep[i]))) return; } @@ -1475,7 +1475,7 @@ pte_t ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr, pte * when the permission changes from executable to non-executable * in cases where cpu is affected with errata #2645198. */ - if (pte_user_exec(READ_ONCE(*ptep))) + if (pte_user_exec(ptep_get(ptep))) return ptep_clear_flush(vma, addr, ptep); } return ptep_get_and_clear(vma->vm_mm, addr, ptep); diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c index 057097acf9e0..624b0b0982e3 100644 --- a/arch/arm64/mm/pageattr.c +++ b/arch/arm64/mm/pageattr.c @@ -36,7 +36,7 @@ bool can_set_direct_map(void) static int change_page_range(pte_t *ptep, unsigned long addr, void *data) { struct page_change_data *cdata = data; - pte_t pte = READ_ONCE(*ptep); + pte_t pte = __ptep_get(ptep); pte = clear_pte_bit(pte, cdata->clear_mask); pte = set_pte_bit(pte, cdata->set_mask); @@ -246,5 +246,5 @@ bool kernel_page_present(struct page *page) return true; ptep = pte_offset_kernel(pmdp, addr); - return pte_valid(READ_ONCE(*ptep)); + return pte_valid(__ptep_get(ptep)); } diff --git a/arch/arm64/mm/trans_pgd.c b/arch/arm64/mm/trans_pgd.c index 230b607cf881..5139a28130c0 100644 --- a/arch/arm64/mm/trans_pgd.c +++ b/arch/arm64/mm/trans_pgd.c @@ -33,7 +33,7 @@ static void *trans_alloc(struct trans_pgd_info *info) static void _copy_pte(pte_t *dst_ptep, pte_t *src_ptep, unsigned long addr) { - pte_t pte = READ_ONCE(*src_ptep); + pte_t pte = __ptep_get(src_ptep); if (pte_valid(pte)) { /*