[PATCH v5 13/25] arm64/mm: ptep_test_and_clear_young(): New layer to manage contig bit

Ryan Roberts
2024-02-02T08:09:06Z

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.

Tested-by: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
---
arch/arm64/include/asm/pgtable.h | 18 +++++++-----------
1 file changed, 7 insertions(+), 11 deletions(-)

diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 5f560326116e..77a8b100e1cd 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -899,8 +899,9 @@ static inline bool pud_user_accessible_page(pud_t pud)
/*
* Atomic pte/pmd modifications.
*/
-#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
-static inline int __ptep_test_and_clear_young(pte_t *ptep)
+static inline int __ptep_test_and_clear_young(struct vm_area_struct *vma,
+ unsigned long address,
+ pte_t *ptep)
{
pte_t old_pte, pte;

@@ -915,18 +916,11 @@ static inline int __ptep_test_and_clear_young(pte_t *ptep)
return pte_young(pte);
}

-static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
- unsigned long address,
- pte_t *ptep)
-{
- return __ptep_test_and_clear_young(ptep);
-}
-
#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)
{
- int young = ptep_test_and_clear_young(vma, address, ptep);
+ int young = __ptep_test_and_clear_young(vma, address, ptep);

if (young) {
/*
@@ -949,7 +943,7 @@ static inline int 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);
+ return __ptep_test_and_clear_young(vma, address, (pte_t *)pmdp);
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */

@@ -1142,6 +1136,8 @@ void vmemmap_update_pte(unsigned long addr, pte_t *ptep, pte_t pte);
#define pte_clear __pte_clear
#define __HAVE_ARCH_PTEP_GET_AND_CLEAR
#define ptep_get_and_clear __ptep_get_and_clear
+#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
+#define ptep_test_and_clear_young __ptep_test_and_clear_young

#endif /* !__ASSEMBLY__ */

--
2.25.1