The patch titled
Subject: arm64/mm: ptep_get(): new layer to manage contig bit
has been added to the -mm mm-unstable branch. Its filename is
arm64-mm-ptep_get-new-layer-to-manage-contig-bit.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/arm64-mm-ptep_get-new-layer-to-manage-contig-bit.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Ryan Roberts <ryan.roberts@xxxxxxx>
Subject: arm64/mm: ptep_get(): new layer to manage contig bit
Date: Mon, 18 Dec 2023 10:50:56 +0000
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.
Link: https://lkml.kernel.org/r/20231218105100.172635-13-ryan.roberts@xxxxxxx
Signed-off-by: Ryan Roberts <ryan.roberts@xxxxxxx>
Tested-by: John Hubbard <jhubbard@xxxxxxxxxx>
Cc: Alexander Potapenko <glider@xxxxxxxxxx>
Cc: Alistair Popple <apopple@xxxxxxxxxx>
Cc: Andrey Konovalov <andreyknvl@xxxxxxxxx>
Cc: Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx>
Cc: Anshuman Khandual <anshuman.khandual@xxxxxxx>
Cc: Ard Biesheuvel <ardb@xxxxxxxxxx>
Cc: Barry Song <21cnbao@xxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: James Morse <james.morse@xxxxxxx>
Cc: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Cc: Marc Zyngier <maz@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Oliver Upton <oliver.upton@xxxxxxxxx>
Cc: Suzuki Poulouse <suzuki.poulose@xxxxxxx>
Cc: Vincenzo Frascino <vincenzo.frascino@xxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: Yang Shi <shy828301@xxxxxxxxx>
Cc: Yu Zhao <yuzhao@xxxxxxxxxx>
Cc: Zenghui Yu <yuzenghui@xxxxxxxxxx>
Cc: Zi Yan <ziy@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
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(-)
--- a/arch/arm64/include/asm/pgtable.h~arm64-mm-ptep_get-new-layer-to-manage-contig-bit
+++ a/arch/arm64/include/asm/pgtable.h
@@ -276,6 +276,11 @@ static inline void __set_pte(pte_t *ptep
}
}
+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_upda
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_
{
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(
{
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(stru
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
--- a/arch/arm64/kernel/efi.c~arm64-mm-ptep_get-new-layer-to-manage-contig-bit
+++ a/arch/arm64/kernel/efi.c
@@ -103,7 +103,7 @@ static int __init set_permissions(pte_t
{
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));
--- a/arch/arm64/mm/fault.c~arm64-mm-ptep_get-new-layer-to-manage-contig-bit
+++ a/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_ar
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;
--- a/arch/arm64/mm/hugetlbpage.c~arm64-mm-ptep_get-new-layer-to-manage-contig-bit
+++ a/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_
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_
{
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(p
{
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_s
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_ar
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
* 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);
--- a/arch/arm64/mm/kasan_init.c~arm64-mm-ptep_get-new-layer-to-manage-contig-bit
+++ a/arch/arm64/mm/kasan_init.c
@@ -113,7 +113,7 @@ static void __init kasan_pte_populate(pm
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,
--- a/arch/arm64/mm/mmu.c~arm64-mm-ptep_get-new-layer-to-manage-contig-bit
+++ a/arch/arm64/mm/mmu.c
@@ -176,7 +176,7 @@ static void init_pte(pmd_t *pmdp, unsign
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, unsign
* 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_
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 *
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 *
*/
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_a
* 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);
--- a/arch/arm64/mm/pageattr.c~arm64-mm-ptep_get-new-layer-to-manage-contig-bit
+++ a/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);
@@ -245,5 +245,5 @@ bool kernel_page_present(struct page *pa
return true;
ptep = pte_offset_kernel(pmdp, addr);
- return pte_valid(READ_ONCE(*ptep));
+ return pte_valid(__ptep_get(ptep));
}
--- a/arch/arm64/mm/trans_pgd.c~arm64-mm-ptep_get-new-layer-to-manage-contig-bit
+++ a/arch/arm64/mm/trans_pgd.c
@@ -33,7 +33,7 @@ static void *trans_alloc(struct trans_pg
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)) {
/*
_
Patches currently in -mm which might be from ryan.roberts@xxxxxxx are
mm-allow-deferred-splitting-of-arbitrary-anon-large-folios.patch
mm-non-pmd-mappable-large-folios-for-folio_add_new_anon_rmap.patch
mm-thp-introduce-multi-size-thp-sysfs-interface.patch
mm-thp-introduce-multi-size-thp-sysfs-interface-fix.patch
mm-thp-support-allocation-of-anonymous-multi-size-thp.patch
mm-thp-support-allocation-of-anonymous-multi-size-thp-fix.patch
selftests-mm-kugepaged-restore-thp-settings-at-exit.patch
selftests-mm-factor-out-thp-settings-management.patch
selftests-mm-support-multi-size-thp-interface-in-thp_settings.patch
selftests-mm-khugepaged-enlighten-for-multi-size-thp.patch
selftests-mm-cow-generalize-do_run_with_thp-helper.patch
selftests-mm-cow-add-tests-for-anonymous-multi-size-thp.patch
mm-thp-batch-collapse-pmd-with-set_ptes.patch
mm-batch-copy-pte-ranges-during-fork.patch
mm-batch-clear-pte-ranges-during-zap_pte_range.patch
arm64-mm-set_pte-new-layer-to-manage-contig-bit.patch
arm64-mm-set_ptes-set_pte_at-new-layer-to-manage-contig-bit.patch
arm64-mm-pte_clear-new-layer-to-manage-contig-bit.patch
arm64-mm-ptep_get_and_clear-new-layer-to-manage-contig-bit.patch
arm64-mm-ptep_test_and_clear_young-new-layer-to-manage-contig-bit.patch
arm64-mm-ptep_clear_flush_young-new-layer-to-manage-contig-bit.patch
arm64-mm-ptep_set_wrprotect-new-layer-to-manage-contig-bit.patch
arm64-mm-ptep_set_access_flags-new-layer-to-manage-contig-bit.patch
arm64-mm-ptep_get-new-layer-to-manage-contig-bit.patch
arm64-mm-split-__flush_tlb_range-to-elide-trailing-dsb.patch
arm64-mm-wire-up-pte_cont-for-user-mappings.patch
arm64-mm-implement-new-helpers-to-optimize-fork.patch
arm64-mm-implement-clear_ptes-to-optimize-exit-munmap-dontneed.patch
selftests-mm-log-run_vmtestssh-results-in-tap-format.patch
