Re: [PATCH v2 2/6] arm64: use hw_pte_val for HW PTE atomics
flat view
From: Ryan Roberts <ryan.roberts@arm.com>
Date: 2026-09-24 12:21:49
Also in:
linux-efi, linux-mm, lkml
On 22/09/2026 18:31, Muhammad Usama Anjum wrote:
The low-level atomic PTE update paths take the address of pte_val(*ptep). That assumes HW PTE storage can be passed directly to the SW PTE value accessor and no longer type-checks when hw_pte_t is distinct. Use hw_pte_val() for the lvalues passed to compare-exchange and exchange operations. The atomic operations and their ordering are unchanged. Signed-off-by: Muhammad Usama Anjum <redacted>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
quoted hunk ↗ jump to hunk
--- Chagnes in v2: - Remove comment change - Move hw_pte_val() to generic series --- arch/arm64/include/asm/pgtable.h | 10 +++++----- arch/arm64/mm/fault.c | 2 +- 2 files changed, 6 insertions(+), 6 deletions(-)diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 652ce413be389..4768ec59de555 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h@@ -1303,7 +1303,7 @@ static inline bool __ptep_test_and_clear_young(struct vm_area_struct *vma, do { old_pte = pte; pte = pte_mkold(pte); - pte_val(pte) = cmpxchg_relaxed(&pte_val(*ptep), + pte_val(pte) = cmpxchg_relaxed(&hw_pte_val(*ptep), pte_val(old_pte), pte_val(pte)); } while (pte_val(pte) != pte_val(old_pte));@@ -1346,7 +1346,7 @@ static inline pte_t __ptep_get_and_clear_anysz(struct mm_struct *mm, hw_pte_t *ptep, unsigned long pgsize) { - pte_t pte = __pte(xchg_relaxed(&pte_val(*ptep), 0)); + pte_t pte = __pte(xchg_relaxed(&hw_pte_val(*ptep), 0)); switch (pgsize) { case PAGE_SIZE:@@ -1422,7 +1422,7 @@ static inline void ___ptep_set_wrprotect(struct mm_struct *mm, do { old_pte = pte; pte = pte_wrprotect(pte); - pte_val(pte) = cmpxchg_relaxed(&pte_val(*ptep), + pte_val(pte) = cmpxchg_relaxed(&hw_pte_val(*ptep), pte_val(old_pte), pte_val(pte)); } while (pte_val(pte) != pte_val(old_pte)); }@@ -1460,7 +1460,7 @@ static inline void __clear_young_dirty_pte(struct vm_area_struct *vma, if (flags & CYDP_CLEAR_DIRTY) pte = pte_mkclean(pte); - pte_val(pte) = cmpxchg_relaxed(&pte_val(*ptep), + pte_val(pte) = cmpxchg_relaxed(&hw_pte_val(*ptep), pte_val(old_pte), pte_val(pte)); } while (pte_val(pte) != pte_val(old_pte)); }@@ -1830,7 +1830,7 @@ static inline bool ptep_try_set(hw_pte_t *ptep, pte_t new_pte) { pteval_t old = 0; - if (!try_cmpxchg(&pte_val(*ptep), &old, pte_val(new_pte))) + if (!try_cmpxchg(&hw_pte_val(*ptep), &old, pte_val(new_pte))) return false; /*diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index b77f4be88e3ea..3322f4e7174dc 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c@@ -235,7 +235,7 @@ int __ptep_set_access_flags_anysz(struct vm_area_struct *vma, pteval ^= PTE_RDONLY; pteval |= pte_val(entry); pteval ^= PTE_RDONLY; - pteval = cmpxchg_relaxed(&pte_val(*ptep), old_pteval, pteval); + pteval = cmpxchg_relaxed(&hw_pte_val(*ptep), old_pteval, pteval); } while (pteval != old_pteval); /*