[PATCH 8/9] mm: Use common huge_ptep_set_wrprotect() function for riscv/arm64

[Alexandre Ghiti <alexghiti@xxxxxxxxxxxx>]

After some adjustments, both architectures have the same implementation
so move it to the generic code.

Signed-off-by: Alexandre Ghiti <alexghiti@xxxxxxxxxxxx>
---
 arch/arm64/mm/hugetlbpage.c | 27 ---------------------------
 arch/riscv/mm/hugetlbpage.c | 22 ----------------------
 mm/contpte.c                | 21 +++++++++++++++++++++
 3 files changed, 21 insertions(+), 49 deletions(-)

diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
index b8abbd5ace4f..d6ddaf282a94 100644
--- a/arch/arm64/mm/hugetlbpage.c
+++ b/arch/arm64/mm/hugetlbpage.c
@@ -284,33 +284,6 @@ pte_t arch_make_huge_pte(pte_t entry, unsigned int shift, vm_flags_t flags)
 	return entry;
 }
 
-void huge_ptep_set_wrprotect(struct mm_struct *mm,
-			     unsigned long addr, pte_t *ptep)
-{
-	unsigned long pfn, dpfn;
-	pgprot_t hugeprot;
-	int ncontig, i;
-	size_t pgsize;
-	pte_t pte;
-
-	if (!pte_cont(READ_ONCE(*ptep))) {
-		ptep_set_wrprotect(mm, addr, ptep);
-		return;
-	}
-
-	ncontig = find_num_contig(mm, addr, ptep, &pgsize);
-	dpfn = pgsize >> PAGE_SHIFT;
-
-	pte = get_clear_contig_flush(mm, addr, ptep, pgsize, ncontig);
-	pte = pte_wrprotect(pte);
-
-	hugeprot = pte_pgprot(pte);
-	pfn = pte_pfn(pte);
-
-	for (i = 0; i < ncontig; i++, ptep++, addr += pgsize, pfn += dpfn)
-		set_pte_at(mm, addr, ptep, pfn_pte(pfn, hugeprot));
-}
-
 pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
 			    unsigned long addr, pte_t *ptep)
 {
diff --git a/arch/riscv/mm/hugetlbpage.c b/arch/riscv/mm/hugetlbpage.c
index fdb633844d4b..e6cbb6fb2904 100644
--- a/arch/riscv/mm/hugetlbpage.c
+++ b/arch/riscv/mm/hugetlbpage.c
@@ -173,28 +173,6 @@ pte_t arch_make_huge_pte(pte_t entry, unsigned int shift, vm_flags_t flags)
 	return entry;
 }
 
-void huge_ptep_set_wrprotect(struct mm_struct *mm,
-			     unsigned long addr,
-			     pte_t *ptep)
-{
-	pte_t pte = ptep_get(ptep);
-	size_t pgsize;
-	pte_t orig_pte;
-	int pte_num;
-
-	if (!pte_napot(pte)) {
-		ptep_set_wrprotect(mm, addr, ptep);
-		return;
-	}
-
-	pte_num = arch_contpte_get_num_contig(mm, addr, ptep, 0, &pgsize);
-
-	orig_pte = get_clear_contig_flush(mm, addr, ptep, pte_num);
-	orig_pte = pte_wrprotect(orig_pte);
-
-	set_ptes(mm, addr, ptep, orig_pte, pte_num);
-}
-
 pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
 			    unsigned long addr,
 			    pte_t *ptep)
diff --git a/mm/contpte.c b/mm/contpte.c
index 3b65c49c6d4b..f7f26d2cfa23 100644
--- a/mm/contpte.c
+++ b/mm/contpte.c
@@ -22,6 +22,7 @@
  * huge_pte_clear()
  * huge_ptep_get_and_clear()
  * huge_ptep_set_access_flags()
+ * huge_ptep_set_wrprotect()
  */
 
 pte_t huge_ptep_get(pte_t *ptep)
@@ -230,3 +231,23 @@ int huge_ptep_set_access_flags(struct vm_area_struct *vma,
 
 	return 1;
 }
+
+void huge_ptep_set_wrprotect(struct mm_struct *mm,
+			     unsigned long addr, pte_t *ptep)
+{
+	int ncontig;
+	size_t pgsize;
+	pte_t pte;
+
+	if (!pte_cont(ptep_get(ptep))) {
+		ptep_set_wrprotect(mm, addr, ptep);
+		return;
+	}
+
+	ncontig = arch_contpte_get_num_contig(mm, addr, ptep, 0, &pgsize);
+
+	pte = get_clear_contig_flush(mm, addr, ptep, pgsize, ncontig);
+	pte = pte_wrprotect(pte);
+
+	set_contptes(mm, addr, ptep, pte, ncontig, pgsize);
+}
-- 
2.39.2