[PATCH v2 2/6] arm64: use hw_pte_val for HW PTE atomics

[Muhammad Usama Anjum]

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 <usama.anjum at arm.com>
---
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);
 
 	/*

-- 
2.47.3