[PATCH v2 0/6] change young flag check functions to return bool

[PATCH v2 0/6] change young flag check functions to return bool

[Baolin Wang]

This is a cleanup patchset to change all young flag check functions to
return bool, as discussed with David in the previous thread[1]. Since
callers only care about whether the young flag was set, returning bool
makes the intention clearer. No functional changes intended.

Ran mm selftests on Arm64 and x86 machines, and no issues were found.

Note that I only CC'd the arch mailing lists to avoid disturbing too
many people.

[1] https://lore.kernel.org/all/d172d6bf-c60c-4cf5-9da9-f30de38cdfed@kernel.org/

Changes from v1:
 - Add reviewed tag from Lorenzo and Ritesh. Thanks.
 - Drop extern and use 2 tabs indentation, per Lorenzo.
 - Fix the incorrect conversion of the 'id' variable.

Baolin Wang (6):
  mm: change to return bool for ptep_test_and_clear_young()
  mm: change to return bool for
    ptep_clear_flush_young()/clear_flush_young_ptes()
  mm: change to return bool for pmdp_test_and_clear_young()
  mm: change to return bool for pmdp_clear_flush_young()
  mm: change to return bool for pudp_test_and_clear_young()
  mm: change to return bool for the MMU notifier's young flag check

 arch/arm64/include/asm/pgtable.h             | 38 +++++-----
 arch/arm64/mm/contpte.c                      | 14 ++--
 arch/microblaze/include/asm/pgtable.h        |  2 +-
 arch/parisc/include/asm/pgtable.h            |  9 +--
 arch/parisc/kernel/cache.c                   |  8 +--
 arch/powerpc/include/asm/book3s/32/pgtable.h |  4 +-
 arch/powerpc/include/asm/book3s/64/pgtable.h | 26 +++----
 arch/powerpc/include/asm/nohash/64/pgtable.h |  2 +-
 arch/powerpc/include/asm/nohash/pgtable.h    |  4 +-
 arch/powerpc/mm/book3s64/pgtable.c           |  8 +--
 arch/riscv/include/asm/pgtable.h             | 16 ++---
 arch/riscv/mm/pgtable.c                      |  7 +-
 arch/s390/include/asm/pgtable.h              | 16 ++---
 arch/x86/include/asm/pgtable.h               | 20 +++---
 arch/x86/mm/pgtable.c                        | 28 ++++----
 arch/xtensa/include/asm/pgtable.h            |  9 ++-
 include/linux/mmu_notifier.h                 | 76 +++++++++-----------
 include/linux/pgtable.h                      | 53 +++++++-------
 mm/internal.h                                | 16 ++---
 mm/mmu_notifier.c                            | 23 +++---
 mm/pgtable-generic.c                         | 14 ++--
 virt/kvm/kvm_main.c                          | 31 +++-----
 22 files changed, 202 insertions(+), 222 deletions(-)

-- 
2.47.3

[PATCH v2 1/6] mm: change to return bool for ptep_test_and_clear_young()

[Baolin Wang]

Callers use ptep_test_and_clear_young() to clear the young flag and check
whether it was set. Change the return type to bool to make the intention
clearer.

Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
---
 arch/arm64/include/asm/pgtable.h             | 16 +++++++---------
 arch/arm64/mm/contpte.c                      |  7 +++----
 arch/microblaze/include/asm/pgtable.h        |  2 +-
 arch/parisc/include/asm/pgtable.h            |  7 ++++---
 arch/powerpc/include/asm/book3s/32/pgtable.h |  4 ++--
 arch/powerpc/include/asm/book3s/64/pgtable.h |  6 +++---
 arch/powerpc/include/asm/nohash/pgtable.h    |  4 ++--
 arch/riscv/include/asm/pgtable.h             |  4 ++--
 arch/riscv/mm/pgtable.c                      |  7 +++----
 arch/s390/include/asm/pgtable.h              |  4 ++--
 arch/x86/include/asm/pgtable.h               |  4 ++--
 arch/x86/mm/pgtable.c                        |  6 +++---
 arch/xtensa/include/asm/pgtable.h            |  9 ++++-----
 include/linux/pgtable.h                      | 16 ++++++++--------
 14 files changed, 46 insertions(+), 50 deletions(-)

diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index ab451d20e4c5..79596cc05dcb 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -1282,9 +1282,8 @@ static inline void __pte_clear(struct mm_struct *mm,
 	__set_pte(ptep, __pte(0));
 }
 
-static inline int __ptep_test_and_clear_young(struct vm_area_struct *vma,
-					      unsigned long address,
-					      pte_t *ptep)
+static inline bool __ptep_test_and_clear_young(struct vm_area_struct *vma,
+		unsigned long address, pte_t *ptep)
 {
 	pte_t old_pte, pte;
 
@@ -1646,7 +1645,7 @@ extern void contpte_clear_full_ptes(struct mm_struct *mm, unsigned long addr,
 extern pte_t contpte_get_and_clear_full_ptes(struct mm_struct *mm,
 				unsigned long addr, pte_t *ptep,
 				unsigned int nr, int full);
-int contpte_test_and_clear_young_ptes(struct vm_area_struct *vma,
+bool contpte_test_and_clear_young_ptes(struct vm_area_struct *vma,
 				unsigned long addr, pte_t *ptep, unsigned int nr);
 int contpte_clear_flush_young_ptes(struct vm_area_struct *vma,
 				unsigned long addr, pte_t *ptep, unsigned int nr);
@@ -1813,9 +1812,8 @@ static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
 }
 
 #define test_and_clear_young_ptes test_and_clear_young_ptes
-static inline int test_and_clear_young_ptes(struct vm_area_struct *vma,
-					    unsigned long addr, pte_t *ptep,
-					    unsigned int nr)
+static inline bool test_and_clear_young_ptes(struct vm_area_struct *vma,
+		unsigned long addr, pte_t *ptep, unsigned int nr)
 {
 	if (likely(nr == 1 && !pte_cont(__ptep_get(ptep))))
 		return __ptep_test_and_clear_young(vma, addr, ptep);
@@ -1824,8 +1822,8 @@ static inline int test_and_clear_young_ptes(struct vm_area_struct *vma,
 }
 
 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
-static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
-				unsigned long addr, pte_t *ptep)
+static inline bool ptep_test_and_clear_young(struct vm_area_struct *vma,
+		unsigned long addr, pte_t *ptep)
 {
 	return test_and_clear_young_ptes(vma, addr, ptep, 1);
 }
diff --git a/arch/arm64/mm/contpte.c b/arch/arm64/mm/contpte.c
index 1519d090d5ea..a31cae78f712 100644
--- a/arch/arm64/mm/contpte.c
+++ b/arch/arm64/mm/contpte.c
@@ -508,9 +508,8 @@ pte_t contpte_get_and_clear_full_ptes(struct mm_struct *mm,
 }
 EXPORT_SYMBOL_GPL(contpte_get_and_clear_full_ptes);
 
-int contpte_test_and_clear_young_ptes(struct vm_area_struct *vma,
-					unsigned long addr, pte_t *ptep,
-					unsigned int nr)
+bool contpte_test_and_clear_young_ptes(struct vm_area_struct *vma,
+		unsigned long addr, pte_t *ptep, unsigned int nr)
 {
 	/*
 	 * ptep_clear_flush_young() technically requires us to clear the access
@@ -525,7 +524,7 @@ int contpte_test_and_clear_young_ptes(struct vm_area_struct *vma,
 	 */
 
 	unsigned long end = addr + nr * PAGE_SIZE;
-	int young = 0;
+	bool young = false;
 
 	ptep = contpte_align_addr_ptep(&addr, &end, ptep, nr);
 	for (; addr != end; ptep++, addr += PAGE_SIZE)
diff --git a/arch/microblaze/include/asm/pgtable.h b/arch/microblaze/include/asm/pgtable.h
index ea72291de553..7678c040a2fd 100644
--- a/arch/microblaze/include/asm/pgtable.h
+++ b/arch/microblaze/include/asm/pgtable.h
@@ -318,7 +318,7 @@ static inline void set_pte(pte_t *ptep, pte_t pte)
 
 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
 struct vm_area_struct;
-static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
+static inline bool ptep_test_and_clear_young(struct vm_area_struct *vma,
 		unsigned long address, pte_t *ptep)
 {
 	return (pte_update(ptep, _PAGE_ACCESSED, 0) & _PAGE_ACCESSED) != 0;
diff --git a/arch/parisc/include/asm/pgtable.h b/arch/parisc/include/asm/pgtable.h
index f6fb99cb94d9..7097c785f690 100644
--- a/arch/parisc/include/asm/pgtable.h
+++ b/arch/parisc/include/asm/pgtable.h
@@ -438,16 +438,17 @@ static inline pte_t ptep_get(pte_t *ptep)
 }
 #define ptep_get ptep_get
 
-static inline int ptep_test_and_clear_young(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
+static inline bool ptep_test_and_clear_young(struct vm_area_struct *vma,
+		unsigned long addr, pte_t *ptep)
 {
 	pte_t pte;
 
 	pte = ptep_get(ptep);
 	if (!pte_young(pte)) {
-		return 0;
+		return false;
 	}
 	set_pte_at(vma->vm_mm, addr, ptep, pte_mkold(pte));
-	return 1;
+	return true;
 }
 
 int ptep_clear_flush_young(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep);
diff --git a/arch/powerpc/include/asm/book3s/32/pgtable.h b/arch/powerpc/include/asm/book3s/32/pgtable.h
index 001e28f9eabc..4a271318dee8 100644
--- a/arch/powerpc/include/asm/book3s/32/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/32/pgtable.h
@@ -295,8 +295,8 @@ static inline pte_basic_t pte_update(struct mm_struct *mm, unsigned long addr, p
  * for our hash-based implementation, we fix that up here.
  */
 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
-static inline int __ptep_test_and_clear_young(struct mm_struct *mm,
-					      unsigned long addr, pte_t *ptep)
+static inline bool __ptep_test_and_clear_young(struct mm_struct *mm,
+		unsigned long addr, pte_t *ptep)
 {
 	unsigned long old;
 	old = pte_update(mm, addr, ptep, _PAGE_ACCESSED, 0, 0);
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index 1a91762b455d..c049a2e26e25 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -349,13 +349,13 @@ static inline unsigned long pte_update(struct mm_struct *mm, unsigned long addr,
  * For radix: H_PAGE_HASHPTE should be zero. Hence we can use the same
  * function for both hash and radix.
  */
-static inline int __ptep_test_and_clear_young(struct mm_struct *mm,
-					      unsigned long addr, pte_t *ptep)
+static inline bool __ptep_test_and_clear_young(struct mm_struct *mm,
+		unsigned long addr, pte_t *ptep)
 {
 	unsigned long old;
 
 	if ((pte_raw(*ptep) & cpu_to_be64(_PAGE_ACCESSED | H_PAGE_HASHPTE)) == 0)
-		return 0;
+		return false;
 	old = pte_update(mm, addr, ptep, _PAGE_ACCESSED, 0, 0);
 	return (old & _PAGE_ACCESSED) != 0;
 }
diff --git a/arch/powerpc/include/asm/nohash/pgtable.h b/arch/powerpc/include/asm/nohash/pgtable.h
index e6da5eaccff6..3a6f20a1c800 100644
--- a/arch/powerpc/include/asm/nohash/pgtable.h
+++ b/arch/powerpc/include/asm/nohash/pgtable.h
@@ -101,8 +101,8 @@ static inline pte_basic_t pte_update(struct mm_struct *mm, unsigned long addr, p
 }
 #endif
 
-static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
-					    unsigned long addr, pte_t *ptep)
+static inline bool ptep_test_and_clear_young(struct vm_area_struct *vma,
+		unsigned long addr, pte_t *ptep)
 {
 	unsigned long old;
 
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index ab4ce1cc9d9c..643d12481b02 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -659,8 +659,8 @@ static inline void pte_clear(struct mm_struct *mm,
 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);
+bool 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,
diff --git a/arch/riscv/mm/pgtable.c b/arch/riscv/mm/pgtable.c
index b1ed2f14dc3a..9c4427d0b187 100644
--- a/arch/riscv/mm/pgtable.c
+++ b/arch/riscv/mm/pgtable.c
@@ -29,12 +29,11 @@ int ptep_set_access_flags(struct vm_area_struct *vma,
 	return true;
 }
 
-int ptep_test_and_clear_young(struct vm_area_struct *vma,
-			      unsigned long address,
-			      pte_t *ptep)
+bool 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 false;
 	return test_and_clear_bit(_PAGE_ACCESSED_OFFSET, &pte_val(*ptep));
 }
 EXPORT_SYMBOL_GPL(ptep_test_and_clear_young);
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index 1c3c3be93be9..ef4748ee3a2b 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -1164,8 +1164,8 @@ pte_t ptep_xchg_direct(struct mm_struct *, unsigned long, pte_t *, pte_t);
 pte_t ptep_xchg_lazy(struct mm_struct *, unsigned long, pte_t *, pte_t);
 
 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
-static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
-					    unsigned long addr, pte_t *ptep)
+static inline bool ptep_test_and_clear_young(struct vm_area_struct *vma,
+		unsigned long addr, pte_t *ptep)
 {
 	pte_t pte = *ptep;
 
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 54289f4587a4..1d86fb33239f 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -1232,8 +1232,8 @@ extern int ptep_set_access_flags(struct vm_area_struct *vma,
 				 pte_t entry, int dirty);
 
 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
-extern int ptep_test_and_clear_young(struct vm_area_struct *vma,
-				     unsigned long addr, pte_t *ptep);
+bool ptep_test_and_clear_young(struct vm_area_struct *vma,
+		unsigned long addr, pte_t *ptep);
 
 #define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
 extern int ptep_clear_flush_young(struct vm_area_struct *vma,
diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
index 2e5ecfdce73c..5ee38dda9124 100644
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c
@@ -443,10 +443,10 @@ int pudp_set_access_flags(struct vm_area_struct *vma, unsigned long address,
 }
 #endif
 
-int ptep_test_and_clear_young(struct vm_area_struct *vma,
-			      unsigned long addr, pte_t *ptep)
+bool ptep_test_and_clear_young(struct vm_area_struct *vma,
+		unsigned long addr, pte_t *ptep)
 {
-	int ret = 0;
+	bool ret = false;
 
 	if (pte_young(*ptep))
 		ret = test_and_clear_bit(_PAGE_BIT_ACCESSED,
diff --git a/arch/xtensa/include/asm/pgtable.h b/arch/xtensa/include/asm/pgtable.h
index 61f07d981a94..f00a879dc298 100644
--- a/arch/xtensa/include/asm/pgtable.h
+++ b/arch/xtensa/include/asm/pgtable.h
@@ -304,15 +304,14 @@ set_pmd(pmd_t *pmdp, pmd_t pmdval)
 
 struct vm_area_struct;
 
-static inline int
-ptep_test_and_clear_young(struct vm_area_struct *vma, unsigned long addr,
-			  pte_t *ptep)
+static inline bool ptep_test_and_clear_young(struct vm_area_struct *vma,
+		unsigned long addr, pte_t *ptep)
 {
 	pte_t pte = *ptep;
 	if (!pte_young(pte))
-		return 0;
+		return false;
 	update_pte(ptep, pte_mkold(pte));
-	return 1;
+	return true;
 }
 
 static inline pte_t
diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index 17d961c612fc..8e75dc9f7932 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
@@ -491,17 +491,17 @@ static inline pgd_t pgdp_get(pgd_t *pgdp)
 #endif
 
 #ifndef __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)
+static inline bool ptep_test_and_clear_young(struct vm_area_struct *vma,
+		unsigned long address, pte_t *ptep)
 {
 	pte_t pte = ptep_get(ptep);
-	int r = 1;
+	bool young = true;
+
 	if (!pte_young(pte))
-		r = 0;
+		young = false;
 	else
 		set_pte_at(vma->vm_mm, address, ptep, pte_mkold(pte));
-	return r;
+	return young;
 }
 #endif
 
@@ -1123,10 +1123,10 @@ static inline int clear_flush_young_ptes(struct vm_area_struct *vma,
  *
  * Returns: whether any PTE was young.
  */
-static inline int test_and_clear_young_ptes(struct vm_area_struct *vma,
+static inline bool test_and_clear_young_ptes(struct vm_area_struct *vma,
 		unsigned long addr, pte_t *ptep, unsigned int nr)
 {
-	int young = 0;
+	bool young = false;
 
 	for (;;) {
 		young |= ptep_test_and_clear_young(vma, addr, ptep);
-- 
2.47.3

[PATCH v2 2/6] mm: change to return bool for ptep_clear_flush_young()/clear_flush_young_ptes()

[Baolin Wang]

The ptep_clear_flush_young() and clear_flush_young_ptes() are used to clear
the young flag and flush the TLB, returning whether the young flag was set.
Change the return type to bool to make the intention clearer.

Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
---
 arch/arm64/include/asm/pgtable.h             | 17 ++++++++---------
 arch/arm64/mm/contpte.c                      |  7 +++----
 arch/parisc/include/asm/pgtable.h            |  2 +-
 arch/parisc/kernel/cache.c                   |  8 ++++----
 arch/powerpc/include/asm/nohash/64/pgtable.h |  2 +-
 arch/riscv/include/asm/pgtable.h             |  4 ++--
 arch/s390/include/asm/pgtable.h              |  4 ++--
 arch/x86/include/asm/pgtable.h               |  4 ++--
 arch/x86/mm/pgtable.c                        |  4 ++--
 include/linux/pgtable.h                      |  8 ++++----
 mm/pgtable-generic.c                         |  7 ++++---
 11 files changed, 33 insertions(+), 34 deletions(-)

diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 79596cc05dcb..1009f719b157 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -1298,10 +1298,10 @@ static inline bool __ptep_test_and_clear_young(struct vm_area_struct *vma,
 	return pte_young(pte);
 }
 
-static inline int __ptep_clear_flush_young(struct vm_area_struct *vma,
-					 unsigned long address, pte_t *ptep)
+static inline bool __ptep_clear_flush_young(struct vm_area_struct *vma,
+		unsigned long address, pte_t *ptep)
 {
-	int young = __ptep_test_and_clear_young(vma, address, ptep);
+	bool young = __ptep_test_and_clear_young(vma, address, ptep);
 
 	if (young) {
 		/*
@@ -1647,7 +1647,7 @@ extern pte_t contpte_get_and_clear_full_ptes(struct mm_struct *mm,
 				unsigned int nr, int full);
 bool contpte_test_and_clear_young_ptes(struct vm_area_struct *vma,
 				unsigned long addr, pte_t *ptep, unsigned int nr);
-int contpte_clear_flush_young_ptes(struct vm_area_struct *vma,
+bool contpte_clear_flush_young_ptes(struct vm_area_struct *vma,
 				unsigned long addr, pte_t *ptep, unsigned int nr);
 extern void contpte_wrprotect_ptes(struct mm_struct *mm, unsigned long addr,
 				pte_t *ptep, unsigned int nr);
@@ -1829,8 +1829,8 @@ static inline bool ptep_test_and_clear_young(struct vm_area_struct *vma,
 }
 
 #define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
-static inline int ptep_clear_flush_young(struct vm_area_struct *vma,
-				unsigned long addr, pte_t *ptep)
+static inline bool ptep_clear_flush_young(struct vm_area_struct *vma,
+		unsigned long addr, pte_t *ptep)
 {
 	pte_t orig_pte = __ptep_get(ptep);
 
@@ -1841,9 +1841,8 @@ static inline int ptep_clear_flush_young(struct vm_area_struct *vma,
 }
 
 #define clear_flush_young_ptes clear_flush_young_ptes
-static inline int clear_flush_young_ptes(struct vm_area_struct *vma,
-					 unsigned long addr, pte_t *ptep,
-					 unsigned int nr)
+static inline bool clear_flush_young_ptes(struct vm_area_struct *vma,
+		unsigned long addr, pte_t *ptep, unsigned int nr)
 {
 	if (likely(nr == 1 && !pte_cont(__ptep_get(ptep))))
 		return __ptep_clear_flush_young(vma, addr, ptep);
diff --git a/arch/arm64/mm/contpte.c b/arch/arm64/mm/contpte.c
index a31cae78f712..2dc1b8ad71e8 100644
--- a/arch/arm64/mm/contpte.c
+++ b/arch/arm64/mm/contpte.c
@@ -534,11 +534,10 @@ bool contpte_test_and_clear_young_ptes(struct vm_area_struct *vma,
 }
 EXPORT_SYMBOL_GPL(contpte_test_and_clear_young_ptes);
 
-int contpte_clear_flush_young_ptes(struct vm_area_struct *vma,
-				unsigned long addr, pte_t *ptep,
-				unsigned int nr)
+bool contpte_clear_flush_young_ptes(struct vm_area_struct *vma,
+		unsigned long addr, pte_t *ptep, unsigned int nr)
 {
-	int young;
+	bool young;
 
 	young = contpte_test_and_clear_young_ptes(vma, addr, ptep, nr);
 
diff --git a/arch/parisc/include/asm/pgtable.h b/arch/parisc/include/asm/pgtable.h
index 7097c785f690..467b8547ac8b 100644
--- a/arch/parisc/include/asm/pgtable.h
+++ b/arch/parisc/include/asm/pgtable.h
@@ -451,7 +451,7 @@ static inline bool ptep_test_and_clear_young(struct vm_area_struct *vma,
 	return true;
 }
 
-int ptep_clear_flush_young(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep);
+bool ptep_clear_flush_young(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep);
 pte_t ptep_clear_flush(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep);
 
 struct mm_struct;
diff --git a/arch/parisc/kernel/cache.c b/arch/parisc/kernel/cache.c
index 4c5240d3a3c7..349b2bf89bb2 100644
--- a/arch/parisc/kernel/cache.c
+++ b/arch/parisc/kernel/cache.c
@@ -781,18 +781,18 @@ void flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned lon
 	__flush_cache_page(vma, vmaddr, PFN_PHYS(page_to_pfn(page)));
 }
 
-int ptep_clear_flush_young(struct vm_area_struct *vma, unsigned long addr,
-			   pte_t *ptep)
+bool ptep_clear_flush_young(struct vm_area_struct *vma,
+		unsigned long addr, pte_t *ptep)
 {
 	pte_t pte = ptep_get(ptep);
 
 	if (!pte_young(pte))
-		return 0;
+		return false;
 	set_pte(ptep, pte_mkold(pte));
 #if CONFIG_FLUSH_PAGE_ACCESSED
 	__flush_cache_page(vma, addr, PFN_PHYS(pte_pfn(pte)));
 #endif
-	return 1;
+	return true;
 }
 
 /*
diff --git a/arch/powerpc/include/asm/nohash/64/pgtable.h b/arch/powerpc/include/asm/nohash/64/pgtable.h
index 2deb955b7bc8..661eb3820d12 100644
--- a/arch/powerpc/include/asm/nohash/64/pgtable.h
+++ b/arch/powerpc/include/asm/nohash/64/pgtable.h
@@ -155,7 +155,7 @@ static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
 #define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
 #define ptep_clear_flush_young(__vma, __address, __ptep)		\
 ({									\
-	int __young = ptep_test_and_clear_young(__vma, __address, __ptep);\
+	bool __young = ptep_test_and_clear_young(__vma, __address, __ptep);\
 	__young;							\
 })
 
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 643d12481b02..b9dacfc280b1 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -695,8 +695,8 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm,
 }
 
 #define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
-static inline int ptep_clear_flush_young(struct vm_area_struct *vma,
-					 unsigned long address, pte_t *ptep)
+static inline bool ptep_clear_flush_young(struct vm_area_struct *vma,
+		unsigned long address, pte_t *ptep)
 {
 	/*
 	 * This comment is borrowed from x86, but applies equally to RISC-V:
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index ef4748ee3a2b..ac74b5076d8f 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -1174,8 +1174,8 @@ static inline bool ptep_test_and_clear_young(struct vm_area_struct *vma,
 }
 
 #define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
-static inline int ptep_clear_flush_young(struct vm_area_struct *vma,
-					 unsigned long address, pte_t *ptep)
+static inline bool ptep_clear_flush_young(struct vm_area_struct *vma,
+		unsigned long address, pte_t *ptep)
 {
 	return ptep_test_and_clear_young(vma, address, ptep);
 }
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 1d86fb33239f..3993657e0a35 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -1236,8 +1236,8 @@ bool ptep_test_and_clear_young(struct vm_area_struct *vma,
 		unsigned long addr, pte_t *ptep);
 
 #define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
-extern int ptep_clear_flush_young(struct vm_area_struct *vma,
-				  unsigned long address, pte_t *ptep);
+bool ptep_clear_flush_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, unsigned long addr,
diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
index 5ee38dda9124..1348384a3bb9 100644
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c
@@ -483,8 +483,8 @@ int pudp_test_and_clear_young(struct vm_area_struct *vma,
 }
 #endif
 
-int ptep_clear_flush_young(struct vm_area_struct *vma,
-			   unsigned long address, pte_t *ptep)
+bool ptep_clear_flush_young(struct vm_area_struct *vma,
+		unsigned long address, pte_t *ptep)
 {
 	/*
 	 * On x86 CPUs, clearing the accessed bit without a TLB flush
diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index 8e75dc9f7932..99450a3b0705 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
@@ -531,8 +531,8 @@ static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
 #endif
 
 #ifndef __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
-int ptep_clear_flush_young(struct vm_area_struct *vma,
-			   unsigned long address, pte_t *ptep);
+bool ptep_clear_flush_young(struct vm_area_struct *vma,
+		unsigned long address, pte_t *ptep);
 #endif
 
 #ifndef __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH
@@ -1086,10 +1086,10 @@ static inline void wrprotect_ptes(struct mm_struct *mm, unsigned long addr,
  * Context: The caller holds the page table lock.  The PTEs map consecutive
  * pages that belong to the same folio.  The PTEs are all in the same PMD.
  */
-static inline int clear_flush_young_ptes(struct vm_area_struct *vma,
+static inline bool clear_flush_young_ptes(struct vm_area_struct *vma,
 		unsigned long addr, pte_t *ptep, unsigned int nr)
 {
-	int young = 0;
+	bool young = false;
 
 	for (;;) {
 		young |= ptep_clear_flush_young(vma, addr, ptep);
diff --git a/mm/pgtable-generic.c b/mm/pgtable-generic.c
index af7966169d69..db0ee918b08a 100644
--- a/mm/pgtable-generic.c
+++ b/mm/pgtable-generic.c
@@ -81,10 +81,11 @@ int ptep_set_access_flags(struct vm_area_struct *vma,
 #endif
 
 #ifndef __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
-int ptep_clear_flush_young(struct vm_area_struct *vma,
-			   unsigned long address, pte_t *ptep)
+bool ptep_clear_flush_young(struct vm_area_struct *vma,
+		unsigned long address, pte_t *ptep)
 {
-	int young;
+	bool young;
+
 	young = ptep_test_and_clear_young(vma, address, ptep);
 	if (young)
 		flush_tlb_page(vma, address);
-- 
2.47.3

[PATCH v2 3/6] mm: change to return bool for pmdp_test_and_clear_young()

[Baolin Wang]

Callers use pmdp_test_and_clear_young() to clear the young flag and check
whether it was set for this PMD entry. Change the return type to bool to
make the intention clearer.

Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
---
 arch/arm64/include/asm/pgtable.h             |  5 ++---
 arch/powerpc/include/asm/book3s/64/pgtable.h | 10 +++++-----
 arch/powerpc/mm/book3s64/pgtable.c           |  4 ++--
 arch/riscv/include/asm/pgtable.h             |  4 ++--
 arch/s390/include/asm/pgtable.h              |  4 ++--
 arch/x86/include/asm/pgtable.h               |  4 ++--
 arch/x86/mm/pgtable.c                        |  6 +++---
 include/linux/pgtable.h                      | 19 +++++++++----------
 8 files changed, 27 insertions(+), 29 deletions(-)

diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 1009f719b157..52bafe79c10a 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -1320,9 +1320,8 @@ static inline bool __ptep_clear_flush_young(struct vm_area_struct *vma,
 
 #if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG)
 #define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
-static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
-					    unsigned long address,
-					    pmd_t *pmdp)
+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());
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index c049a2e26e25..8b354e81ab22 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -1161,13 +1161,13 @@ pud_hugepage_update(struct mm_struct *mm, unsigned long addr, pud_t *pudp,
  * For radix we should always find H_PAGE_HASHPTE zero. Hence
  * the below will work for radix too
  */
-static inline int __pmdp_test_and_clear_young(struct mm_struct *mm,
-					      unsigned long addr, pmd_t *pmdp)
+static inline bool __pmdp_test_and_clear_young(struct mm_struct *mm,
+		unsigned long addr, pmd_t *pmdp)
 {
 	unsigned long old;
 
 	if ((pmd_raw(*pmdp) & cpu_to_be64(_PAGE_ACCESSED | H_PAGE_HASHPTE)) == 0)
-		return 0;
+		return false;
 	old = pmd_hugepage_update(mm, addr, pmdp, _PAGE_ACCESSED, 0);
 	return ((old & _PAGE_ACCESSED) != 0);
 }
@@ -1300,8 +1300,8 @@ extern int pudp_set_access_flags(struct vm_area_struct *vma,
 				 pud_t entry, int dirty);
 
 #define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
-extern int pmdp_test_and_clear_young(struct vm_area_struct *vma,
-				     unsigned long address, pmd_t *pmdp);
+bool pmdp_test_and_clear_young(struct vm_area_struct *vma,
+		unsigned long address, pmd_t *pmdp);
 #define __HAVE_ARCH_PUDP_TEST_AND_CLEAR_YOUNG
 extern int pudp_test_and_clear_young(struct vm_area_struct *vma,
 				     unsigned long address, pud_t *pudp);
diff --git a/arch/powerpc/mm/book3s64/pgtable.c b/arch/powerpc/mm/book3s64/pgtable.c
index 4b09c04654a8..c584321e3d41 100644
--- a/arch/powerpc/mm/book3s64/pgtable.c
+++ b/arch/powerpc/mm/book3s64/pgtable.c
@@ -98,8 +98,8 @@ int pudp_set_access_flags(struct vm_area_struct *vma, unsigned long address,
 }
 
 
-int pmdp_test_and_clear_young(struct vm_area_struct *vma,
-			      unsigned long address, pmd_t *pmdp)
+bool pmdp_test_and_clear_young(struct vm_area_struct *vma,
+		unsigned long address, pmd_t *pmdp)
 {
 	return __pmdp_test_and_clear_young(vma->vm_mm, address, pmdp);
 }
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index b9dacfc280b1..67e7746e3fbe 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -1015,8 +1015,8 @@ static inline int pmdp_set_access_flags(struct vm_area_struct *vma,
 }
 
 #define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
-static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
-					unsigned long address, pmd_t *pmdp)
+static inline bool pmdp_test_and_clear_young(struct vm_area_struct *vma,
+		unsigned long address, pmd_t *pmdp)
 {
 	return ptep_test_and_clear_young(vma, address, (pte_t *)pmdp);
 }
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index ac74b5076d8f..87a5082da28e 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -1683,8 +1683,8 @@ static inline int pmdp_set_access_flags(struct vm_area_struct *vma,
 }
 
 #define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
-static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
-					    unsigned long addr, pmd_t *pmdp)
+static inline bool pmdp_test_and_clear_young(struct vm_area_struct *vma,
+		unsigned long addr, pmd_t *pmdp)
 {
 	pmd_t pmd = *pmdp;
 
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 3993657e0a35..ba867bac6096 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -1295,8 +1295,8 @@ extern int pudp_set_access_flags(struct vm_area_struct *vma,
 				 pud_t entry, int dirty);
 
 #define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
-extern int pmdp_test_and_clear_young(struct vm_area_struct *vma,
-				     unsigned long addr, pmd_t *pmdp);
+bool pmdp_test_and_clear_young(struct vm_area_struct *vma,
+		unsigned long addr, pmd_t *pmdp);
 extern int pudp_test_and_clear_young(struct vm_area_struct *vma,
 				     unsigned long addr, pud_t *pudp);
 
diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
index 1348384a3bb9..b09e8c5dadf9 100644
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c
@@ -456,10 +456,10 @@ bool ptep_test_and_clear_young(struct vm_area_struct *vma,
 }
 
 #if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG)
-int pmdp_test_and_clear_young(struct vm_area_struct *vma,
-			      unsigned long addr, pmd_t *pmdp)
+bool pmdp_test_and_clear_young(struct vm_area_struct *vma,
+		unsigned long addr, pmd_t *pmdp)
 {
-	int ret = 0;
+	bool ret = false;
 
 	if (pmd_young(*pmdp))
 		ret = test_and_clear_bit(_PAGE_BIT_ACCESSED,
diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index 99450a3b0705..6db900a5d38b 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
@@ -507,25 +507,24 @@ static inline bool ptep_test_and_clear_young(struct vm_area_struct *vma,
 
 #ifndef __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
 #if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG)
-static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
-					    unsigned long address,
-					    pmd_t *pmdp)
+static inline bool pmdp_test_and_clear_young(struct vm_area_struct *vma,
+		unsigned long address, pmd_t *pmdp)
 {
 	pmd_t pmd = *pmdp;
-	int r = 1;
+	bool young = true;
+
 	if (!pmd_young(pmd))
-		r = 0;
+		young = false;
 	else
 		set_pmd_at(vma->vm_mm, address, pmdp, pmd_mkold(pmd));
-	return r;
+	return young;
 }
 #else
-static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
-					    unsigned long address,
-					    pmd_t *pmdp)
+static inline bool pmdp_test_and_clear_young(struct vm_area_struct *vma,
+		unsigned long address, pmd_t *pmdp)
 {
 	BUILD_BUG();
-	return 0;
+	return false;
 }
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG */
 #endif
-- 
2.47.3

[PATCH v2 4/6] mm: change to return bool for pmdp_clear_flush_young()

[Baolin Wang]

The pmdp_clear_flush_young() is used to clear the young flag and flush the
TLB, returning whether the young flag was set for this PMD entry. Change
the return type to bool to make the intention clearer.

Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
---
 arch/s390/include/asm/pgtable.h |  4 ++--
 arch/x86/include/asm/pgtable.h  |  4 ++--
 arch/x86/mm/pgtable.c           |  6 +++---
 include/linux/pgtable.h         | 10 +++++-----
 mm/pgtable-generic.c            |  7 ++++---
 5 files changed, 16 insertions(+), 15 deletions(-)

diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index 87a5082da28e..40a6fb19dd1d 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -1693,8 +1693,8 @@ static inline bool pmdp_test_and_clear_young(struct vm_area_struct *vma,
 }
 
 #define __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH
-static inline int pmdp_clear_flush_young(struct vm_area_struct *vma,
-					 unsigned long addr, pmd_t *pmdp)
+static inline bool pmdp_clear_flush_young(struct vm_area_struct *vma,
+		unsigned long addr, pmd_t *pmdp)
 {
 	VM_BUG_ON(addr & ~HPAGE_MASK);
 	return pmdp_test_and_clear_young(vma, addr, pmdp);
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index ba867bac6096..6c8f2b17d3f9 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -1301,8 +1301,8 @@ extern int pudp_test_and_clear_young(struct vm_area_struct *vma,
 				     unsigned long addr, pud_t *pudp);
 
 #define __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH
-extern int pmdp_clear_flush_young(struct vm_area_struct *vma,
-				  unsigned long address, pmd_t *pmdp);
+bool pmdp_clear_flush_young(struct vm_area_struct *vma,
+		unsigned long address, pmd_t *pmdp);
 
 
 #define __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR
diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
index b09e8c5dadf9..fc1c996c5b2d 100644
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c
@@ -503,10 +503,10 @@ bool ptep_clear_flush_young(struct vm_area_struct *vma,
 }
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
-int pmdp_clear_flush_young(struct vm_area_struct *vma,
-			   unsigned long address, pmd_t *pmdp)
+bool pmdp_clear_flush_young(struct vm_area_struct *vma,
+		unsigned long address, pmd_t *pmdp)
 {
-	int young;
+	bool young;
 
 	VM_BUG_ON(address & ~HPAGE_PMD_MASK);
 
diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index 6db900a5d38b..cdd68ed3ae1a 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
@@ -536,18 +536,18 @@ bool ptep_clear_flush_young(struct vm_area_struct *vma,
 
 #ifndef __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
-extern int pmdp_clear_flush_young(struct vm_area_struct *vma,
-				  unsigned long address, pmd_t *pmdp);
+bool pmdp_clear_flush_young(struct vm_area_struct *vma,
+		unsigned long address, pmd_t *pmdp);
 #else
 /*
  * Despite relevant to THP only, this API is called from generic rmap code
  * under PageTransHuge(), hence needs a dummy implementation for !THP
  */
-static inline int pmdp_clear_flush_young(struct vm_area_struct *vma,
-					 unsigned long address, pmd_t *pmdp)
+static inline bool pmdp_clear_flush_young(struct vm_area_struct *vma,
+		unsigned long address, pmd_t *pmdp)
 {
 	BUILD_BUG();
-	return 0;
+	return false;
 }
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 #endif
diff --git a/mm/pgtable-generic.c b/mm/pgtable-generic.c
index db0ee918b08a..b91b1a98029c 100644
--- a/mm/pgtable-generic.c
+++ b/mm/pgtable-generic.c
@@ -124,10 +124,11 @@ int pmdp_set_access_flags(struct vm_area_struct *vma,
 #endif
 
 #ifndef __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH
-int pmdp_clear_flush_young(struct vm_area_struct *vma,
-			   unsigned long address, pmd_t *pmdp)
+bool pmdp_clear_flush_young(struct vm_area_struct *vma,
+		unsigned long address, pmd_t *pmdp)
 {
-	int young;
+	bool young;
+
 	VM_BUG_ON(address & ~HPAGE_PMD_MASK);
 	young = pmdp_test_and_clear_young(vma, address, pmdp);
 	if (young)
-- 
2.47.3

[PATCH v2 5/6] mm: change to return bool for pudp_test_and_clear_young()

[Baolin Wang]

The pudp_test_and_clear_young() is used to clear the young flag,
returning whether the young flag was set for this PUD entry. Change
the return type to bool to make the intention clearer.

Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
---
 arch/powerpc/include/asm/book3s/64/pgtable.h | 10 +++++-----
 arch/powerpc/mm/book3s64/pgtable.c           |  4 ++--
 arch/riscv/include/asm/pgtable.h             |  4 ++--
 arch/x86/include/asm/pgtable.h               |  4 ++--
 arch/x86/mm/pgtable.c                        |  6 +++---
 5 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index 8b354e81ab22..60e283cf22be 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -1172,13 +1172,13 @@ static inline bool __pmdp_test_and_clear_young(struct mm_struct *mm,
 	return ((old & _PAGE_ACCESSED) != 0);
 }
 
-static inline int __pudp_test_and_clear_young(struct mm_struct *mm,
-					      unsigned long addr, pud_t *pudp)
+static inline bool __pudp_test_and_clear_young(struct mm_struct *mm,
+		unsigned long addr, pud_t *pudp)
 {
 	unsigned long old;
 
 	if ((pud_raw(*pudp) & cpu_to_be64(_PAGE_ACCESSED | H_PAGE_HASHPTE)) == 0)
-		return 0;
+		return false;
 	old = pud_hugepage_update(mm, addr, pudp, _PAGE_ACCESSED, 0);
 	return ((old & _PAGE_ACCESSED) != 0);
 }
@@ -1303,8 +1303,8 @@ extern int pudp_set_access_flags(struct vm_area_struct *vma,
 bool pmdp_test_and_clear_young(struct vm_area_struct *vma,
 		unsigned long address, pmd_t *pmdp);
 #define __HAVE_ARCH_PUDP_TEST_AND_CLEAR_YOUNG
-extern int pudp_test_and_clear_young(struct vm_area_struct *vma,
-				     unsigned long address, pud_t *pudp);
+bool pudp_test_and_clear_young(struct vm_area_struct *vma,
+		unsigned long address, pud_t *pudp);
 
 
 #define __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR
diff --git a/arch/powerpc/mm/book3s64/pgtable.c b/arch/powerpc/mm/book3s64/pgtable.c
index c584321e3d41..ddc766e95855 100644
--- a/arch/powerpc/mm/book3s64/pgtable.c
+++ b/arch/powerpc/mm/book3s64/pgtable.c
@@ -104,8 +104,8 @@ bool pmdp_test_and_clear_young(struct vm_area_struct *vma,
 	return __pmdp_test_and_clear_young(vma->vm_mm, address, pmdp);
 }
 
-int pudp_test_and_clear_young(struct vm_area_struct *vma,
-			      unsigned long address, pud_t *pudp)
+bool pudp_test_and_clear_young(struct vm_area_struct *vma,
+		unsigned long address, pud_t *pudp)
 {
 	return __pudp_test_and_clear_young(vma->vm_mm, address, pudp);
 }
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 67e7746e3fbe..a6e0eaba2653 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -1109,8 +1109,8 @@ static inline int pudp_set_access_flags(struct vm_area_struct *vma,
 	return ptep_set_access_flags(vma, address, (pte_t *)pudp, pud_pte(entry), dirty);
 }
 
-static inline int pudp_test_and_clear_young(struct vm_area_struct *vma,
-					    unsigned long address, pud_t *pudp)
+static inline bool pudp_test_and_clear_young(struct vm_area_struct *vma,
+		unsigned long address, pud_t *pudp)
 {
 	return ptep_test_and_clear_young(vma, address, (pte_t *)pudp);
 }
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 6c8f2b17d3f9..13e3e9a054cb 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -1297,8 +1297,8 @@ extern int pudp_set_access_flags(struct vm_area_struct *vma,
 #define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
 bool pmdp_test_and_clear_young(struct vm_area_struct *vma,
 		unsigned long addr, pmd_t *pmdp);
-extern int pudp_test_and_clear_young(struct vm_area_struct *vma,
-				     unsigned long addr, pud_t *pudp);
+bool pudp_test_and_clear_young(struct vm_area_struct *vma,
+		unsigned long addr, pud_t *pudp);
 
 #define __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH
 bool pmdp_clear_flush_young(struct vm_area_struct *vma,
diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
index fc1c996c5b2d..da7f0a03cf90 100644
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c
@@ -470,10 +470,10 @@ bool pmdp_test_and_clear_young(struct vm_area_struct *vma,
 #endif
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
-int pudp_test_and_clear_young(struct vm_area_struct *vma,
-			      unsigned long addr, pud_t *pudp)
+bool pudp_test_and_clear_young(struct vm_area_struct *vma,
+		unsigned long addr, pud_t *pudp)
 {
-	int ret = 0;
+	bool ret = false;
 
 	if (pud_young(*pudp))
 		ret = test_and_clear_bit(_PAGE_BIT_ACCESSED,
-- 
2.47.3

[PATCH v2 6/6] mm: change to return bool for the MMU notifier's young flag check

[Baolin Wang]

The MMU notifier young flag check related functions only return whether
the young flag was set. Change the return type to bool to make the
intention clearer.

Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
---
 include/linux/mmu_notifier.h | 76 +++++++++++++++++-------------------
 mm/internal.h                | 16 ++++----
 mm/mmu_notifier.c            | 23 +++++------
 virt/kvm/kvm_main.c          | 31 ++++++---------
 4 files changed, 66 insertions(+), 80 deletions(-)

diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h
index 3705d350c863..17f2cdc77dd5 100644
--- a/include/linux/mmu_notifier.h
+++ b/include/linux/mmu_notifier.h
@@ -97,20 +97,20 @@ struct mmu_notifier_ops {
 	 * Start-end is necessary in case the secondary MMU is mapping the page
 	 * at a smaller granularity than the primary MMU.
 	 */
-	int (*clear_flush_young)(struct mmu_notifier *subscription,
-				 struct mm_struct *mm,
-				 unsigned long start,
-				 unsigned long end);
+	bool (*clear_flush_young)(struct mmu_notifier *subscription,
+				  struct mm_struct *mm,
+				  unsigned long start,
+				  unsigned long end);
 
 	/*
 	 * clear_young is a lightweight version of clear_flush_young. Like the
 	 * latter, it is supposed to test-and-clear the young/accessed bitflag
 	 * in the secondary pte, but it may omit flushing the secondary tlb.
 	 */
-	int (*clear_young)(struct mmu_notifier *subscription,
-			   struct mm_struct *mm,
-			   unsigned long start,
-			   unsigned long end);
+	bool (*clear_young)(struct mmu_notifier *subscription,
+			    struct mm_struct *mm,
+			    unsigned long start,
+			    unsigned long end);
 
 	/*
 	 * test_young is called to check the young/accessed bitflag in
@@ -118,9 +118,9 @@ struct mmu_notifier_ops {
 	 * frequently used without actually clearing the flag or tearing
 	 * down the secondary mapping on the page.
 	 */
-	int (*test_young)(struct mmu_notifier *subscription,
-			  struct mm_struct *mm,
-			  unsigned long address);
+	bool (*test_young)(struct mmu_notifier *subscription,
+			   struct mm_struct *mm,
+			   unsigned long address);
 
 	/*
 	 * invalidate_range_start() and invalidate_range_end() must be
@@ -376,14 +376,12 @@ mmu_interval_check_retry(struct mmu_interval_notifier *interval_sub,
 
 extern void __mmu_notifier_subscriptions_destroy(struct mm_struct *mm);
 extern void __mmu_notifier_release(struct mm_struct *mm);
-extern int __mmu_notifier_clear_flush_young(struct mm_struct *mm,
-					  unsigned long start,
-					  unsigned long end);
-extern int __mmu_notifier_clear_young(struct mm_struct *mm,
-				      unsigned long start,
-				      unsigned long end);
-extern int __mmu_notifier_test_young(struct mm_struct *mm,
-				     unsigned long address);
+bool __mmu_notifier_clear_flush_young(struct mm_struct *mm,
+		unsigned long start, unsigned long end);
+bool __mmu_notifier_clear_young(struct mm_struct *mm,
+		unsigned long start, unsigned long end);
+bool __mmu_notifier_test_young(struct mm_struct *mm,
+		unsigned long address);
 extern int __mmu_notifier_invalidate_range_start(struct mmu_notifier_range *r);
 extern void __mmu_notifier_invalidate_range_end(struct mmu_notifier_range *r);
 extern void __mmu_notifier_arch_invalidate_secondary_tlbs(struct mm_struct *mm,
@@ -403,30 +401,28 @@ static inline void mmu_notifier_release(struct mm_struct *mm)
 		__mmu_notifier_release(mm);
 }
 
-static inline int mmu_notifier_clear_flush_young(struct mm_struct *mm,
-					  unsigned long start,
-					  unsigned long end)
+static inline bool mmu_notifier_clear_flush_young(struct mm_struct *mm,
+		unsigned long start, unsigned long end)
 {
 	if (mm_has_notifiers(mm))
 		return __mmu_notifier_clear_flush_young(mm, start, end);
-	return 0;
+	return false;
 }
 
-static inline int mmu_notifier_clear_young(struct mm_struct *mm,
-					   unsigned long start,
-					   unsigned long end)
+static inline bool mmu_notifier_clear_young(struct mm_struct *mm,
+		unsigned long start, unsigned long end)
 {
 	if (mm_has_notifiers(mm))
 		return __mmu_notifier_clear_young(mm, start, end);
-	return 0;
+	return false;
 }
 
-static inline int mmu_notifier_test_young(struct mm_struct *mm,
-					  unsigned long address)
+static inline bool mmu_notifier_test_young(struct mm_struct *mm,
+		unsigned long address)
 {
 	if (mm_has_notifiers(mm))
 		return __mmu_notifier_test_young(mm, address);
-	return 0;
+	return false;
 }
 
 static inline void
@@ -552,24 +548,22 @@ static inline void mmu_notifier_release(struct mm_struct *mm)
 {
 }
 
-static inline int mmu_notifier_clear_flush_young(struct mm_struct *mm,
-					  unsigned long start,
-					  unsigned long end)
+static inline bool mmu_notifier_clear_flush_young(struct mm_struct *mm,
+		unsigned long start, unsigned long end)
 {
-	return 0;
+	return false;
 }
 
-static inline int mmu_notifier_clear_young(struct mm_struct *mm,
-					   unsigned long start,
-					   unsigned long end)
+static inline bool mmu_notifier_clear_young(struct mm_struct *mm,
+		unsigned long start, unsigned long end)
 {
-	return 0;
+	return false;
 }
 
-static inline int mmu_notifier_test_young(struct mm_struct *mm,
-					  unsigned long address)
+static inline bool mmu_notifier_test_young(struct mm_struct *mm,
+		unsigned long address)
 {
-	return 0;
+	return false;
 }
 
 static inline void
diff --git a/mm/internal.h b/mm/internal.h
index 0eaca2f0eb6a..3d6eba216364 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -1831,10 +1831,10 @@ static inline int io_remap_pfn_range_complete(struct vm_area_struct *vma,
 }
 
 #ifdef CONFIG_MMU_NOTIFIER
-static inline int clear_flush_young_ptes_notify(struct vm_area_struct *vma,
+static inline bool clear_flush_young_ptes_notify(struct vm_area_struct *vma,
 		unsigned long addr, pte_t *ptep, unsigned int nr)
 {
-	int young;
+	bool young;
 
 	young = clear_flush_young_ptes(vma, addr, ptep, nr);
 	young |= mmu_notifier_clear_flush_young(vma->vm_mm, addr,
@@ -1842,30 +1842,30 @@ static inline int clear_flush_young_ptes_notify(struct vm_area_struct *vma,
 	return young;
 }
 
-static inline int pmdp_clear_flush_young_notify(struct vm_area_struct *vma,
+static inline bool pmdp_clear_flush_young_notify(struct vm_area_struct *vma,
 		unsigned long addr, pmd_t *pmdp)
 {
-	int young;
+	bool young;
 
 	young = pmdp_clear_flush_young(vma, addr, pmdp);
 	young |= mmu_notifier_clear_flush_young(vma->vm_mm, addr, addr + PMD_SIZE);
 	return young;
 }
 
-static inline int test_and_clear_young_ptes_notify(struct vm_area_struct *vma,
+static inline bool test_and_clear_young_ptes_notify(struct vm_area_struct *vma,
 		unsigned long addr, pte_t *ptep, unsigned int nr)
 {
-	int young;
+	bool young;
 
 	young = test_and_clear_young_ptes(vma, addr, ptep, nr);
 	young |= mmu_notifier_clear_young(vma->vm_mm, addr, addr + nr * PAGE_SIZE);
 	return young;
 }
 
-static inline int pmdp_test_and_clear_young_notify(struct vm_area_struct *vma,
+static inline bool pmdp_test_and_clear_young_notify(struct vm_area_struct *vma,
 		unsigned long addr, pmd_t *pmdp)
 {
-	int young;
+	bool young;
 
 	young = pmdp_test_and_clear_young(vma, addr, pmdp);
 	young |= mmu_notifier_clear_young(vma->vm_mm, addr, addr + PMD_SIZE);
diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c
index 2502474b83b6..dc6f78d559f7 100644
--- a/mm/mmu_notifier.c
+++ b/mm/mmu_notifier.c
@@ -364,12 +364,12 @@ void __mmu_notifier_release(struct mm_struct *mm)
  * unmap the address and return 1 or 0 depending if the mapping previously
  * existed or not.
  */
-int __mmu_notifier_clear_flush_young(struct mm_struct *mm,
-					unsigned long start,
-					unsigned long end)
+bool __mmu_notifier_clear_flush_young(struct mm_struct *mm,
+		unsigned long start, unsigned long end)
 {
 	struct mmu_notifier *subscription;
-	int young = 0, id;
+	bool young = false;
+	int id;
 
 	id = srcu_read_lock(&srcu);
 	hlist_for_each_entry_srcu(subscription,
@@ -384,12 +384,12 @@ int __mmu_notifier_clear_flush_young(struct mm_struct *mm,
 	return young;
 }
 
-int __mmu_notifier_clear_young(struct mm_struct *mm,
-			       unsigned long start,
-			       unsigned long end)
+bool __mmu_notifier_clear_young(struct mm_struct *mm,
+		unsigned long start, unsigned long end)
 {
 	struct mmu_notifier *subscription;
-	int young = 0, id;
+	bool young = false;
+	int id;
 
 	id = srcu_read_lock(&srcu);
 	hlist_for_each_entry_srcu(subscription,
@@ -404,11 +404,12 @@ int __mmu_notifier_clear_young(struct mm_struct *mm,
 	return young;
 }
 
-int __mmu_notifier_test_young(struct mm_struct *mm,
-			      unsigned long address)
+bool __mmu_notifier_test_young(struct mm_struct *mm,
+		unsigned long address)
 {
 	struct mmu_notifier *subscription;
-	int young = 0, id;
+	bool young = false;
+	int id;
 
 	id = srcu_read_lock(&srcu);
 	hlist_for_each_entry_srcu(subscription,
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index d0ab29672c71..82433f46c438 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -646,11 +646,9 @@ static __always_inline kvm_mn_ret_t kvm_handle_hva_range(struct kvm *kvm,
 	return r;
 }
 
-static __always_inline int kvm_age_hva_range(struct mmu_notifier *mn,
-						unsigned long start,
-						unsigned long end,
-						gfn_handler_t handler,
-						bool flush_on_ret)
+static __always_inline bool kvm_age_hva_range(struct mmu_notifier *mn,
+		unsigned long start, unsigned long end, gfn_handler_t handler,
+		bool flush_on_ret)
 {
 	struct kvm *kvm = mmu_notifier_to_kvm(mn);
 	const struct kvm_mmu_notifier_range range = {
@@ -666,10 +664,8 @@ static __always_inline int kvm_age_hva_range(struct mmu_notifier *mn,
 	return kvm_handle_hva_range(kvm, &range).ret;
 }
 
-static __always_inline int kvm_age_hva_range_no_flush(struct mmu_notifier *mn,
-						      unsigned long start,
-						      unsigned long end,
-						      gfn_handler_t handler)
+static __always_inline bool kvm_age_hva_range_no_flush(struct mmu_notifier *mn,
+		unsigned long start, unsigned long end, gfn_handler_t handler)
 {
 	return kvm_age_hva_range(mn, start, end, handler, false);
 }
@@ -829,10 +825,8 @@ static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn,
 		rcuwait_wake_up(&kvm->mn_memslots_update_rcuwait);
 }
 
-static int kvm_mmu_notifier_clear_flush_young(struct mmu_notifier *mn,
-					      struct mm_struct *mm,
-					      unsigned long start,
-					      unsigned long end)
+static bool kvm_mmu_notifier_clear_flush_young(struct mmu_notifier *mn,
+		struct mm_struct *mm, unsigned long start, unsigned long end)
 {
 	trace_kvm_age_hva(start, end);
 
@@ -840,10 +834,8 @@ static int kvm_mmu_notifier_clear_flush_young(struct mmu_notifier *mn,
 				 !IS_ENABLED(CONFIG_KVM_ELIDE_TLB_FLUSH_IF_YOUNG));
 }
 
-static int kvm_mmu_notifier_clear_young(struct mmu_notifier *mn,
-					struct mm_struct *mm,
-					unsigned long start,
-					unsigned long end)
+static bool kvm_mmu_notifier_clear_young(struct mmu_notifier *mn,
+		struct mm_struct *mm, unsigned long start, unsigned long end)
 {
 	trace_kvm_age_hva(start, end);
 
@@ -863,9 +855,8 @@ static int kvm_mmu_notifier_clear_young(struct mmu_notifier *mn,
 	return kvm_age_hva_range_no_flush(mn, start, end, kvm_age_gfn);
 }
 
-static int kvm_mmu_notifier_test_young(struct mmu_notifier *mn,
-				       struct mm_struct *mm,
-				       unsigned long address)
+static bool kvm_mmu_notifier_test_young(struct mmu_notifier *mn,
+		struct mm_struct *mm, unsigned long address)
 {
 	trace_kvm_test_age_hva(address);
 
-- 
2.47.3