[PATCH v2 4/4] riscv: Use accessors to page table entries instead of direct dereference

From: Alexandre Ghiti
Date: Wed Dec 13 2023 - 15:34:33 EST

As very well explained in commit 20a004e7b017 ("arm64: mm: Use
READ_ONCE/WRITE_ONCE when accessing page tables"), an architecture whose
page table walker can modify the PTE in parallel must use
READ_ONCE()/WRITE_ONCE() macro to avoid any compiler transformation.

So apply that to riscv which is such architecture.

Signed-off-by: Alexandre Ghiti <alexghiti@xxxxxxxxxxxx>
---
arch/riscv/include/asm/kfence.h | 4 +--
arch/riscv/include/asm/pgtable-64.h | 16 ++-------
arch/riscv/include/asm/pgtable.h | 29 ++++------------
arch/riscv/kernel/efi.c | 2 +-
arch/riscv/kvm/mmu.c | 22 ++++++-------
arch/riscv/mm/fault.c | 16 ++++-----
arch/riscv/mm/hugetlbpage.c | 12 +++----
arch/riscv/mm/kasan_init.c | 45 +++++++++++++------------
arch/riscv/mm/pageattr.c | 44 ++++++++++++-------------
arch/riscv/mm/pgtable.c | 51 ++++++++++++++++++++++++++---
10 files changed, 128 insertions(+), 113 deletions(-)

diff --git a/arch/riscv/include/asm/kfence.h b/arch/riscv/include/asm/kfence.h
index 0bbffd528096..7388edd88986 100644
--- a/arch/riscv/include/asm/kfence.h
+++ b/arch/riscv/include/asm/kfence.h
@@ -18,9 +18,9 @@ static inline bool kfence_protect_page(unsigned long addr, bool protect)
pte_t *pte = virt_to_kpte(addr);

if (protect)
- set_pte(pte, __pte(pte_val(*pte) & ~_PAGE_PRESENT));
+ set_pte(pte, __pte(pte_val(ptep_get(pte)) & ~_PAGE_PRESENT));
else
- set_pte(pte, __pte(pte_val(*pte) | _PAGE_PRESENT));
+ set_pte(pte, __pte(pte_val(ptep_get(pte)) | _PAGE_PRESENT));

flush_tlb_kernel_range(addr, addr + PAGE_SIZE);

diff --git a/arch/riscv/include/asm/pgtable-64.h b/arch/riscv/include/asm/pgtable-64.h
index 5d8431a390dd..b42017d76924 100644
--- a/arch/riscv/include/asm/pgtable-64.h
+++ b/arch/riscv/include/asm/pgtable-64.h
@@ -340,13 +340,7 @@ static inline struct page *p4d_page(p4d_t p4d)
#define pud_index(addr) (((addr) >> PUD_SHIFT) & (PTRS_PER_PUD - 1))

#define pud_offset pud_offset
-static inline pud_t *pud_offset(p4d_t *p4d, unsigned long address)
-{
- if (pgtable_l4_enabled)
- return p4d_pgtable(*p4d) + pud_index(address);
-
- return (pud_t *)p4d;
-}
+pud_t *pud_offset(p4d_t *p4d, unsigned long address);

static inline void set_pgd(pgd_t *pgdp, pgd_t pgd)
{
@@ -404,12 +398,6 @@ static inline struct page *pgd_page(pgd_t pgd)
#define p4d_index(addr) (((addr) >> P4D_SHIFT) & (PTRS_PER_P4D - 1))

#define p4d_offset p4d_offset
-static inline p4d_t *p4d_offset(pgd_t *pgd, unsigned long address)
-{
- if (pgtable_l5_enabled)
- return pgd_pgtable(*pgd) + p4d_index(address);
-
- return (p4d_t *)pgd;
-}
+p4d_t *p4d_offset(pgd_t *pgd, unsigned long address);

#endif /* _ASM_RISCV_PGTABLE_64_H */
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index c9f4b250b4ee..3773f454f0fa 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -544,19 +544,12 @@ static inline void pte_clear(struct mm_struct *mm,
__set_pte_at(ptep, __pte(0));
}

-#define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
-static inline int ptep_set_access_flags(struct vm_area_struct *vma,
- unsigned long address, pte_t *ptep,
- pte_t entry, int dirty)
-{
- if (!pte_same(*ptep, entry))
- __set_pte_at(ptep, entry);
- /*
- * update_mmu_cache will unconditionally execute, handling both
- * the case that the PTE changed and the spurious fault case.
- */
- return true;
-}
+#define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS /* defined in mm/pgtable.c */
+extern int ptep_set_access_flags(struct vm_area_struct *vma, unsigned long address,
+ pte_t *ptep, pte_t entry, int dirty);
+#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG /* defined in mm/pgtable.c */
+extern int ptep_test_and_clear_young(struct vm_area_struct *vma, unsigned long address,
+ pte_t *ptep);

#define __HAVE_ARCH_PTEP_GET_AND_CLEAR
static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
@@ -569,16 +562,6 @@ static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
return pte;
}

-#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
-static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
- unsigned long address,
- pte_t *ptep)
-{
- if (!pte_young(*ptep))
- return 0;
- return test_and_clear_bit(_PAGE_ACCESSED_OFFSET, &pte_val(*ptep));
-}
-
#define __HAVE_ARCH_PTEP_SET_WRPROTECT
static inline void ptep_set_wrprotect(struct mm_struct *mm,
unsigned long address, pte_t *ptep)
diff --git a/arch/riscv/kernel/efi.c b/arch/riscv/kernel/efi.c
index aa6209a74c83..b64bf1624a05 100644
--- a/arch/riscv/kernel/efi.c
+++ b/arch/riscv/kernel/efi.c
@@ -60,7 +60,7 @@ int __init efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md)
static int __init set_permissions(pte_t *ptep, unsigned long addr, void *data)
{
efi_memory_desc_t *md = data;
- pte_t pte = READ_ONCE(*ptep);
+ pte_t pte = ptep_get(ptep);
unsigned long val;

if (md->attribute & EFI_MEMORY_RO) {
diff --git a/arch/riscv/kvm/mmu.c b/arch/riscv/kvm/mmu.c
index 068c74593871..a9e2fd7245e1 100644
--- a/arch/riscv/kvm/mmu.c
+++ b/arch/riscv/kvm/mmu.c
@@ -103,7 +103,7 @@ static bool gstage_get_leaf_entry(struct kvm *kvm, gpa_t addr,
*ptep_level = current_level;
ptep = (pte_t *)kvm->arch.pgd;
ptep = &ptep[gstage_pte_index(addr, current_level)];
- while (ptep && pte_val(*ptep)) {
+ while (ptep && pte_val(ptep_get(ptep))) {
if (gstage_pte_leaf(ptep)) {
*ptep_level = current_level;
*ptepp = ptep;
@@ -113,7 +113,7 @@ static bool gstage_get_leaf_entry(struct kvm *kvm, gpa_t addr,
if (current_level) {
current_level--;
*ptep_level = current_level;
- ptep = (pte_t *)gstage_pte_page_vaddr(*ptep);
+ ptep = (pte_t *)gstage_pte_page_vaddr(ptep_get(ptep));
ptep = &ptep[gstage_pte_index(addr, current_level)];
} else {
ptep = NULL;
@@ -149,25 +149,25 @@ static int gstage_set_pte(struct kvm *kvm, u32 level,
if (gstage_pte_leaf(ptep))
return -EEXIST;

- if (!pte_val(*ptep)) {
+ if (!pte_val(ptep_get(ptep))) {
if (!pcache)
return -ENOMEM;
next_ptep = kvm_mmu_memory_cache_alloc(pcache);
if (!next_ptep)
return -ENOMEM;
- *ptep = pfn_pte(PFN_DOWN(__pa(next_ptep)),
- __pgprot(_PAGE_TABLE));
+ set_pte(ptep, pfn_pte(PFN_DOWN(__pa(next_ptep)),
+ __pgprot(_PAGE_TABLE)));
} else {
if (gstage_pte_leaf(ptep))
return -EEXIST;
- next_ptep = (pte_t *)gstage_pte_page_vaddr(*ptep);
+ next_ptep = (pte_t *)gstage_pte_page_vaddr(ptep_get(ptep));
}

current_level--;
ptep = &next_ptep[gstage_pte_index(addr, current_level)];
}

- *ptep = *new_pte;
+ set_pte(ptep, *new_pte);
if (gstage_pte_leaf(ptep))
gstage_remote_tlb_flush(kvm, current_level, addr);

@@ -239,11 +239,11 @@ static void gstage_op_pte(struct kvm *kvm, gpa_t addr,

BUG_ON(addr & (page_size - 1));

- if (!pte_val(*ptep))
+ if (!pte_val(ptep_get(ptep)))
return;

if (ptep_level && !gstage_pte_leaf(ptep)) {
- next_ptep = (pte_t *)gstage_pte_page_vaddr(*ptep);
+ next_ptep = (pte_t *)gstage_pte_page_vaddr(ptep_get(ptep));
next_ptep_level = ptep_level - 1;
ret = gstage_level_to_page_size(next_ptep_level,
&next_page_size);
@@ -261,7 +261,7 @@ static void gstage_op_pte(struct kvm *kvm, gpa_t addr,
if (op == GSTAGE_OP_CLEAR)
set_pte(ptep, __pte(0));
else if (op == GSTAGE_OP_WP)
- set_pte(ptep, __pte(pte_val(*ptep) & ~_PAGE_WRITE));
+ set_pte(ptep, __pte(pte_val(ptep_get(ptep)) & ~_PAGE_WRITE));
gstage_remote_tlb_flush(kvm, ptep_level, addr);
}
}
@@ -603,7 +603,7 @@ bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
&ptep, &ptep_level))
return false;

- return pte_young(*ptep);
+ return pte_young(ptep_get(ptep));
}

int kvm_riscv_gstage_map(struct kvm_vcpu *vcpu,
diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c
index 90d4ba36d1d0..76f1df709a21 100644
--- a/arch/riscv/mm/fault.c
+++ b/arch/riscv/mm/fault.c
@@ -136,24 +136,24 @@ static inline void vmalloc_fault(struct pt_regs *regs, int code, unsigned long a
pgd = (pgd_t *)pfn_to_virt(pfn) + index;
pgd_k = init_mm.pgd + index;

- if (!pgd_present(*pgd_k)) {
+ if (!pgd_present(pgdp_get(pgd_k))) {
no_context(regs, addr);
return;
}
- set_pgd(pgd, *pgd_k);
+ set_pgd(pgd, pgdp_get(pgd_k));

p4d_k = p4d_offset(pgd_k, addr);
- if (!p4d_present(*p4d_k)) {
+ if (!p4d_present(p4dp_get(p4d_k))) {
no_context(regs, addr);
return;
}

pud_k = pud_offset(p4d_k, addr);
- if (!pud_present(*pud_k)) {
+ if (!pud_present(pudp_get(pud_k))) {
no_context(regs, addr);
return;
}
- if (pud_leaf(*pud_k))
+ if (pud_leaf(pudp_get(pud_k)))
goto flush_tlb;

/*
@@ -161,11 +161,11 @@ static inline void vmalloc_fault(struct pt_regs *regs, int code, unsigned long a
* to copy individual PTEs
*/
pmd_k = pmd_offset(pud_k, addr);
- if (!pmd_present(*pmd_k)) {
+ if (!pmd_present(pmdp_get(pmd_k))) {
no_context(regs, addr);
return;
}
- if (pmd_leaf(*pmd_k))
+ if (pmd_leaf(pmdp_get(pmd_k)))
goto flush_tlb;

/*
@@ -175,7 +175,7 @@ static inline void vmalloc_fault(struct pt_regs *regs, int code, unsigned long a
* silently loop forever.
*/
pte_k = pte_offset_kernel(pmd_k, addr);
- if (!pte_present(*pte_k)) {
+ if (!pte_present(ptep_get(pte_k))) {
no_context(regs, addr);
return;
}
diff --git a/arch/riscv/mm/hugetlbpage.c b/arch/riscv/mm/hugetlbpage.c
index b52f0210481f..431596c0e20e 100644
--- a/arch/riscv/mm/hugetlbpage.c
+++ b/arch/riscv/mm/hugetlbpage.c
@@ -54,7 +54,7 @@ pte_t *huge_pte_alloc(struct mm_struct *mm,
}

if (sz == PMD_SIZE) {
- if (want_pmd_share(vma, addr) && pud_none(*pud))
+ if (want_pmd_share(vma, addr) && pud_none(pudp_get(pud)))
pte = huge_pmd_share(mm, vma, addr, pud);
else
pte = (pte_t *)pmd_alloc(mm, pud, addr);
@@ -93,11 +93,11 @@ pte_t *huge_pte_offset(struct mm_struct *mm,
pmd_t *pmd;

pgd = pgd_offset(mm, addr);
- if (!pgd_present(*pgd))
+ if (!pgd_present(pgdp_get(pgd)))
return NULL;

p4d = p4d_offset(pgd, addr);
- if (!p4d_present(*p4d))
+ if (!p4d_present(p4dp_get(p4d)))
return NULL;

pud = pud_offset(p4d, addr);
@@ -105,7 +105,7 @@ pte_t *huge_pte_offset(struct mm_struct *mm,
/* must be pud huge, non-present or none */
return (pte_t *)pud;

- if (!pud_present(*pud))
+ if (!pud_present(pudp_get(pud)))
return NULL;

pmd = pmd_offset(pud, addr);
@@ -113,7 +113,7 @@ pte_t *huge_pte_offset(struct mm_struct *mm,
/* must be pmd huge, non-present or none */
return (pte_t *)pmd;

- if (!pmd_present(*pmd))
+ if (!pmd_present(pmdp_get(pmd)))
return NULL;

for_each_napot_order(order) {
@@ -293,7 +293,7 @@ void huge_pte_clear(struct mm_struct *mm,
pte_t *ptep,
unsigned long sz)
{
- pte_t pte = READ_ONCE(*ptep);
+ pte_t pte = ptep_get(ptep);
int i, pte_num;

if (!pte_napot(pte)) {
diff --git a/arch/riscv/mm/kasan_init.c b/arch/riscv/mm/kasan_init.c
index 5e39dcf23fdb..e96251853037 100644
--- a/arch/riscv/mm/kasan_init.c
+++ b/arch/riscv/mm/kasan_init.c
@@ -31,7 +31,7 @@ static void __init kasan_populate_pte(pmd_t *pmd, unsigned long vaddr, unsigned
phys_addr_t phys_addr;
pte_t *ptep, *p;

- if (pmd_none(*pmd)) {
+ if (pmd_none(pmdp_get(pmd))) {
p = memblock_alloc(PTRS_PER_PTE * sizeof(pte_t), PAGE_SIZE);
set_pmd(pmd, pfn_pmd(PFN_DOWN(__pa(p)), PAGE_TABLE));
}
@@ -39,7 +39,7 @@ static void __init kasan_populate_pte(pmd_t *pmd, unsigned long vaddr, unsigned
ptep = pte_offset_kernel(pmd, vaddr);

do {
- if (pte_none(*ptep)) {
+ if (pte_none(ptep_get(ptep))) {
phys_addr = memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
set_pte(ptep, pfn_pte(PFN_DOWN(phys_addr), PAGE_KERNEL));
memset(__va(phys_addr), KASAN_SHADOW_INIT, PAGE_SIZE);
@@ -53,7 +53,7 @@ static void __init kasan_populate_pmd(pud_t *pud, unsigned long vaddr, unsigned
pmd_t *pmdp, *p;
unsigned long next;

- if (pud_none(*pud)) {
+ if (pud_none(pudp_get(pud))) {
p = memblock_alloc(PTRS_PER_PMD * sizeof(pmd_t), PAGE_SIZE);
set_pud(pud, pfn_pud(PFN_DOWN(__pa(p)), PAGE_TABLE));
}
@@ -63,7 +63,8 @@ static void __init kasan_populate_pmd(pud_t *pud, unsigned long vaddr, unsigned
do {
next = pmd_addr_end(vaddr, end);

- if (pmd_none(*pmdp) && IS_ALIGNED(vaddr, PMD_SIZE) && (next - vaddr) >= PMD_SIZE) {
+ if (pmd_none(pmdp_get(pmdp)) && IS_ALIGNED(vaddr, PMD_SIZE) &&
+ (next - vaddr) >= PMD_SIZE) {
phys_addr = memblock_phys_alloc(PMD_SIZE, PMD_SIZE);
if (phys_addr) {
set_pmd(pmdp, pfn_pmd(PFN_DOWN(phys_addr), PAGE_KERNEL));
@@ -83,7 +84,7 @@ static void __init kasan_populate_pud(p4d_t *p4d,
pud_t *pudp, *p;
unsigned long next;

- if (p4d_none(*p4d)) {
+ if (p4d_none(p4dp_get(p4d))) {
p = memblock_alloc(PTRS_PER_PUD * sizeof(pud_t), PAGE_SIZE);
set_p4d(p4d, pfn_p4d(PFN_DOWN(__pa(p)), PAGE_TABLE));
}
@@ -93,7 +94,8 @@ static void __init kasan_populate_pud(p4d_t *p4d,
do {
next = pud_addr_end(vaddr, end);

- if (pud_none(*pudp) && IS_ALIGNED(vaddr, PUD_SIZE) && (next - vaddr) >= PUD_SIZE) {
+ if (pud_none(pudp_get(pudp)) && IS_ALIGNED(vaddr, PUD_SIZE) &&
+ (next - vaddr) >= PUD_SIZE) {
phys_addr = memblock_phys_alloc(PUD_SIZE, PUD_SIZE);
if (phys_addr) {
set_pud(pudp, pfn_pud(PFN_DOWN(phys_addr), PAGE_KERNEL));
@@ -113,7 +115,7 @@ static void __init kasan_populate_p4d(pgd_t *pgd,
p4d_t *p4dp, *p;
unsigned long next;

- if (pgd_none(*pgd)) {
+ if (pgd_none(pgdp_get(pgd))) {
p = memblock_alloc(PTRS_PER_P4D * sizeof(p4d_t), PAGE_SIZE);
set_pgd(pgd, pfn_pgd(PFN_DOWN(__pa(p)), PAGE_TABLE));
}
@@ -123,7 +125,8 @@ static void __init kasan_populate_p4d(pgd_t *pgd,
do {
next = p4d_addr_end(vaddr, end);

- if (p4d_none(*p4dp) && IS_ALIGNED(vaddr, P4D_SIZE) && (next - vaddr) >= P4D_SIZE) {
+ if (p4d_none(p4dp_get(p4dp)) && IS_ALIGNED(vaddr, P4D_SIZE) &&
+ (next - vaddr) >= P4D_SIZE) {
phys_addr = memblock_phys_alloc(P4D_SIZE, P4D_SIZE);
if (phys_addr) {
set_p4d(p4dp, pfn_p4d(PFN_DOWN(phys_addr), PAGE_KERNEL));
@@ -145,7 +148,7 @@ static void __init kasan_populate_pgd(pgd_t *pgdp,
do {
next = pgd_addr_end(vaddr, end);

- if (pgd_none(*pgdp) && IS_ALIGNED(vaddr, PGDIR_SIZE) &&
+ if (pgd_none(pgdp_get(pgdp)) && IS_ALIGNED(vaddr, PGDIR_SIZE) &&
(next - vaddr) >= PGDIR_SIZE) {
phys_addr = memblock_phys_alloc(PGDIR_SIZE, PGDIR_SIZE);
if (phys_addr) {
@@ -168,7 +171,7 @@ static void __init kasan_early_clear_pud(p4d_t *p4dp,
if (!pgtable_l4_enabled) {
pudp = (pud_t *)p4dp;
} else {
- base_pud = pt_ops.get_pud_virt(pfn_to_phys(_p4d_pfn(*p4dp)));
+ base_pud = pt_ops.get_pud_virt(pfn_to_phys(_p4d_pfn(p4dp_get(p4dp))));
pudp = base_pud + pud_index(vaddr);
}

@@ -193,7 +196,7 @@ static void __init kasan_early_clear_p4d(pgd_t *pgdp,
if (!pgtable_l5_enabled) {
p4dp = (p4d_t *)pgdp;
} else {
- base_p4d = pt_ops.get_p4d_virt(pfn_to_phys(_pgd_pfn(*pgdp)));
+ base_p4d = pt_ops.get_p4d_virt(pfn_to_phys(_pgd_pfn(pgdp_get(pgdp))));
p4dp = base_p4d + p4d_index(vaddr);
}

@@ -239,14 +242,14 @@ static void __init kasan_early_populate_pud(p4d_t *p4dp,
if (!pgtable_l4_enabled) {
pudp = (pud_t *)p4dp;
} else {
- base_pud = pt_ops.get_pud_virt(pfn_to_phys(_p4d_pfn(*p4dp)));
+ base_pud = pt_ops.get_pud_virt(pfn_to_phys(_p4d_pfn(p4dp_get(p4dp))));
pudp = base_pud + pud_index(vaddr);
}

do {
next = pud_addr_end(vaddr, end);

- if (pud_none(*pudp) && IS_ALIGNED(vaddr, PUD_SIZE) &&
+ if (pud_none(pudp_get(pudp)) && IS_ALIGNED(vaddr, PUD_SIZE) &&
(next - vaddr) >= PUD_SIZE) {
phys_addr = __pa((uintptr_t)kasan_early_shadow_pmd);
set_pud(pudp, pfn_pud(PFN_DOWN(phys_addr), PAGE_TABLE));
@@ -277,14 +280,14 @@ static void __init kasan_early_populate_p4d(pgd_t *pgdp,
if (!pgtable_l5_enabled) {
p4dp = (p4d_t *)pgdp;
} else {
- base_p4d = pt_ops.get_p4d_virt(pfn_to_phys(_pgd_pfn(*pgdp)));
+ base_p4d = pt_ops.get_p4d_virt(pfn_to_phys(_pgd_pfn(pgdp_get(pgdp))));
p4dp = base_p4d + p4d_index(vaddr);
}

do {
next = p4d_addr_end(vaddr, end);

- if (p4d_none(*p4dp) && IS_ALIGNED(vaddr, P4D_SIZE) &&
+ if (p4d_none(p4dp_get(p4dp)) && IS_ALIGNED(vaddr, P4D_SIZE) &&
(next - vaddr) >= P4D_SIZE) {
phys_addr = __pa((uintptr_t)kasan_early_shadow_pud);
set_p4d(p4dp, pfn_p4d(PFN_DOWN(phys_addr), PAGE_TABLE));
@@ -305,7 +308,7 @@ static void __init kasan_early_populate_pgd(pgd_t *pgdp,
do {
next = pgd_addr_end(vaddr, end);

- if (pgd_none(*pgdp) && IS_ALIGNED(vaddr, PGDIR_SIZE) &&
+ if (pgd_none(pgdp_get(pgdp)) && IS_ALIGNED(vaddr, PGDIR_SIZE) &&
(next - vaddr) >= PGDIR_SIZE) {
phys_addr = __pa((uintptr_t)kasan_early_shadow_p4d);
set_pgd(pgdp, pfn_pgd(PFN_DOWN(phys_addr), PAGE_TABLE));
@@ -381,7 +384,7 @@ static void __init kasan_shallow_populate_pud(p4d_t *p4d,
do {
next = pud_addr_end(vaddr, end);

- if (pud_none(*pud_k)) {
+ if (pud_none(pudp_get(pud_k))) {
p = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
set_pud(pud_k, pfn_pud(PFN_DOWN(__pa(p)), PAGE_TABLE));
continue;
@@ -401,7 +404,7 @@ static void __init kasan_shallow_populate_p4d(pgd_t *pgd,
do {
next = p4d_addr_end(vaddr, end);

- if (p4d_none(*p4d_k)) {
+ if (p4d_none(p4dp_get(p4d_k))) {
p = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
set_p4d(p4d_k, pfn_p4d(PFN_DOWN(__pa(p)), PAGE_TABLE));
continue;
@@ -420,7 +423,7 @@ static void __init kasan_shallow_populate_pgd(unsigned long vaddr, unsigned long
do {
next = pgd_addr_end(vaddr, end);

- if (pgd_none(*pgd_k)) {
+ if (pgd_none(pgdp_get(pgd_k))) {
p = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
set_pgd(pgd_k, pfn_pgd(PFN_DOWN(__pa(p)), PAGE_TABLE));
continue;
@@ -451,7 +454,7 @@ static void __init create_tmp_mapping(void)

/* Copy the last p4d since it is shared with the kernel mapping. */
if (pgtable_l5_enabled) {
- ptr = (p4d_t *)pgd_page_vaddr(*pgd_offset_k(KASAN_SHADOW_END));
+ ptr = (p4d_t *)pgd_page_vaddr(pgdp_get(pgd_offset_k(KASAN_SHADOW_END)));
memcpy(tmp_p4d, ptr, sizeof(p4d_t) * PTRS_PER_P4D);
set_pgd(&tmp_pg_dir[pgd_index(KASAN_SHADOW_END)],
pfn_pgd(PFN_DOWN(__pa(tmp_p4d)), PAGE_TABLE));
@@ -462,7 +465,7 @@ static void __init create_tmp_mapping(void)

/* Copy the last pud since it is shared with the kernel mapping. */
if (pgtable_l4_enabled) {
- ptr = (pud_t *)p4d_page_vaddr(*(base_p4d + p4d_index(KASAN_SHADOW_END)));
+ ptr = (pud_t *)p4d_page_vaddr(p4dp_get(base_p4d + p4d_index(KASAN_SHADOW_END)));
memcpy(tmp_pud, ptr, sizeof(pud_t) * PTRS_PER_PUD);
set_p4d(&base_p4d[p4d_index(KASAN_SHADOW_END)],
pfn_p4d(PFN_DOWN(__pa(tmp_pud)), PAGE_TABLE));
diff --git a/arch/riscv/mm/pageattr.c b/arch/riscv/mm/pageattr.c
index fc5fc4f785c4..0b5e38e018c8 100644
--- a/arch/riscv/mm/pageattr.c
+++ b/arch/riscv/mm/pageattr.c
@@ -29,7 +29,7 @@ static unsigned long set_pageattr_masks(unsigned long val, struct mm_walk *walk)
static int pageattr_p4d_entry(p4d_t *p4d, unsigned long addr,
unsigned long next, struct mm_walk *walk)
{
- p4d_t val = READ_ONCE(*p4d);
+ p4d_t val = p4dp_get(p4d);

if (p4d_leaf(val)) {
val = __p4d(set_pageattr_masks(p4d_val(val), walk));
@@ -42,7 +42,7 @@ static int pageattr_p4d_entry(p4d_t *p4d, unsigned long addr,
static int pageattr_pud_entry(pud_t *pud, unsigned long addr,
unsigned long next, struct mm_walk *walk)
{
- pud_t val = READ_ONCE(*pud);
+ pud_t val = pudp_get(pud);

if (pud_leaf(val)) {
val = __pud(set_pageattr_masks(pud_val(val), walk));
@@ -55,7 +55,7 @@ static int pageattr_pud_entry(pud_t *pud, unsigned long addr,
static int pageattr_pmd_entry(pmd_t *pmd, unsigned long addr,
unsigned long next, struct mm_walk *walk)
{
- pmd_t val = READ_ONCE(*pmd);
+ pmd_t val = pmdp_get(pmd);

if (pmd_leaf(val)) {
val = __pmd(set_pageattr_masks(pmd_val(val), walk));
@@ -68,7 +68,7 @@ static int pageattr_pmd_entry(pmd_t *pmd, unsigned long addr,
static int pageattr_pte_entry(pte_t *pte, unsigned long addr,
unsigned long next, struct mm_walk *walk)
{
- pte_t val = READ_ONCE(*pte);
+ pte_t val = ptep_get(pte);

val = __pte(set_pageattr_masks(pte_val(val), walk));
set_pte(pte, val);
@@ -108,10 +108,10 @@ static int __split_linear_mapping_pmd(pud_t *pudp,
vaddr <= (vaddr & PMD_MASK) && end >= next)
continue;

- if (pmd_leaf(*pmdp)) {
+ if (pmd_leaf(pmdp_get(pmdp))) {
struct page *pte_page;
- unsigned long pfn = _pmd_pfn(*pmdp);
- pgprot_t prot = __pgprot(pmd_val(*pmdp) & ~_PAGE_PFN_MASK);
+ unsigned long pfn = _pmd_pfn(pmdp_get(pmdp));
+ pgprot_t prot = __pgprot(pmd_val(pmdp_get(pmdp)) & ~_PAGE_PFN_MASK);
pte_t *ptep_new;
int i;

@@ -148,10 +148,10 @@ static int __split_linear_mapping_pud(p4d_t *p4dp,
vaddr <= (vaddr & PUD_MASK) && end >= next)
continue;

- if (pud_leaf(*pudp)) {
+ if (pud_leaf(pudp_get(pudp))) {
struct page *pmd_page;
- unsigned long pfn = _pud_pfn(*pudp);
- pgprot_t prot = __pgprot(pud_val(*pudp) & ~_PAGE_PFN_MASK);
+ unsigned long pfn = _pud_pfn(pudp_get(pudp));
+ pgprot_t prot = __pgprot(pud_val(pudp_get(pudp)) & ~_PAGE_PFN_MASK);
pmd_t *pmdp_new;
int i;

@@ -197,10 +197,10 @@ static int __split_linear_mapping_p4d(pgd_t *pgdp,
vaddr <= (vaddr & P4D_MASK) && end >= next)
continue;

- if (p4d_leaf(*p4dp)) {
+ if (p4d_leaf(p4dp_get(p4dp))) {
struct page *pud_page;
- unsigned long pfn = _p4d_pfn(*p4dp);
- pgprot_t prot = __pgprot(p4d_val(*p4dp) & ~_PAGE_PFN_MASK);
+ unsigned long pfn = _p4d_pfn(p4dp_get(p4dp));
+ pgprot_t prot = __pgprot(p4d_val(p4dp_get(p4dp)) & ~_PAGE_PFN_MASK);
pud_t *pudp_new;
int i;

@@ -406,29 +406,29 @@ bool kernel_page_present(struct page *page)
pte_t *pte;

pgd = pgd_offset_k(addr);
- if (!pgd_present(*pgd))
+ if (!pgd_present(pgdp_get(pgd)))
return false;
- if (pgd_leaf(*pgd))
+ if (pgd_leaf(pgdp_get(pgd)))
return true;

p4d = p4d_offset(pgd, addr);
- if (!p4d_present(*p4d))
+ if (!p4d_present(p4dp_get(p4d)))
return false;
- if (p4d_leaf(*p4d))
+ if (p4d_leaf(p4dp_get(p4d)))
return true;

pud = pud_offset(p4d, addr);
- if (!pud_present(*pud))
+ if (!pud_present(pudp_get(pud)))
return false;
- if (pud_leaf(*pud))
+ if (pud_leaf(pudp_get(pud)))
return true;

pmd = pmd_offset(pud, addr);
- if (!pmd_present(*pmd))
+ if (!pmd_present(pmdp_get(pmd)))
return false;
- if (pmd_leaf(*pmd))
+ if (pmd_leaf(pmdp_get(pmd)))
return true;

pte = pte_offset_kernel(pmd, addr);
- return pte_present(*pte);
+ return pte_present(ptep_get(pte));
}
diff --git a/arch/riscv/mm/pgtable.c b/arch/riscv/mm/pgtable.c
index fef4e7328e49..ef887efcb679 100644
--- a/arch/riscv/mm/pgtable.c
+++ b/arch/riscv/mm/pgtable.c
@@ -5,6 +5,47 @@
#include <linux/kernel.h>
#include <linux/pgtable.h>

+int ptep_set_access_flags(struct vm_area_struct *vma,
+ unsigned long address, pte_t *ptep,
+ pte_t entry, int dirty)
+{
+ if (!pte_same(ptep_get(ptep), entry))
+ __set_pte_at(ptep, entry);
+ /*
+ * update_mmu_cache will unconditionally execute, handling both
+ * the case that the PTE changed and the spurious fault case.
+ */
+ return true;
+}
+
+int ptep_test_and_clear_young(struct vm_area_struct *vma,
+ unsigned long address,
+ pte_t *ptep)
+{
+ if (!pte_young(ptep_get(ptep)))
+ return 0;
+ return test_and_clear_bit(_PAGE_ACCESSED_OFFSET, &pte_val(*ptep));
+}
+EXPORT_SYMBOL_GPL(ptep_test_and_clear_young);
+
+#ifdef CONFIG_64BIT
+pud_t *pud_offset(p4d_t *p4d, unsigned long address)
+{
+ if (pgtable_l4_enabled)
+ return p4d_pgtable(p4dp_get(p4d)) + pud_index(address);
+
+ return (pud_t *)p4d;
+}
+
+p4d_t *p4d_offset(pgd_t *pgd, unsigned long address)
+{
+ if (pgtable_l5_enabled)
+ return pgd_pgtable(pgdp_get(pgd)) + p4d_index(address);
+
+ return (p4d_t *)pgd;
+}
+#endif
+
#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
int p4d_set_huge(p4d_t *p4d, phys_addr_t addr, pgprot_t prot)
{
@@ -25,7 +66,7 @@ int pud_set_huge(pud_t *pud, phys_addr_t phys, pgprot_t prot)

int pud_clear_huge(pud_t *pud)
{
- if (!pud_leaf(READ_ONCE(*pud)))
+ if (!pud_leaf(pudp_get(pud)))
return 0;
pud_clear(pud);
return 1;
@@ -33,7 +74,7 @@ int pud_clear_huge(pud_t *pud)

int pud_free_pmd_page(pud_t *pud, unsigned long addr)
{
- pmd_t *pmd = pud_pgtable(*pud);
+ pmd_t *pmd = pud_pgtable(pudp_get(pud));
int i;

pud_clear(pud);
@@ -63,7 +104,7 @@ int pmd_set_huge(pmd_t *pmd, phys_addr_t phys, pgprot_t prot)

int pmd_clear_huge(pmd_t *pmd)
{
- if (!pmd_leaf(READ_ONCE(*pmd)))
+ if (!pmd_leaf(pmdp_get(pmd)))
return 0;
pmd_clear(pmd);
return 1;
@@ -71,7 +112,7 @@ int pmd_clear_huge(pmd_t *pmd)

int pmd_free_pte_page(pmd_t *pmd, unsigned long addr)
{
- pte_t *pte = (pte_t *)pmd_page_vaddr(*pmd);
+ pte_t *pte = (pte_t *)pmd_page_vaddr(pmdp_get(pmd));

pmd_clear(pmd);

@@ -88,7 +129,7 @@ pmd_t pmdp_collapse_flush(struct vm_area_struct *vma,
pmd_t pmd = pmdp_huge_get_and_clear(vma->vm_mm, address, pmdp);

VM_BUG_ON(address & ~HPAGE_PMD_MASK);
- VM_BUG_ON(pmd_trans_huge(*pmdp));
+ VM_BUG_ON(pmd_trans_huge(pmdp_get(pmdp)));
/*
* When leaf PTE entries (regular pages) are collapsed into a leaf
* PMD entry (huge page), a valid non-leaf PTE is converted into a
--
2.39.2