damon: use pmdp_get instead of drectly dereferencing pmd

As ptep_get, Use the pmdp_get wrapper when we accessing pmdval instead of
directly dereferencing pmd.

Link: https://lkml.kernel.org/r/20230727212157.2985025-1-ppbuk5246@gmail.comSigned-off-by: Levi Yun <ppbuk5246@gmail.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/damon/ops-common.c

@@ -54,7 +54,7 @@ void damon_ptep_mkold(pte_t *pte, struct vm_area_struct *vma, unsigned long addr
 void damon_pmdp_mkold(pmd_t *pmd, struct vm_area_struct *vma, unsigned long addr)
 {
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
-	struct folio *folio = damon_get_folio(pmd_pfn(*pmd));
+	struct folio *folio = damon_get_folio(pmd_pfn(pmdp_get(pmd)));
 
 	if (!folio)
 		return;

mm/damon/paddr.c

@@ -94,7 +94,7 @@ static bool __damon_pa_young(struct folio *folio, struct vm_area_struct *vma,
 				mmu_notifier_test_young(vma->vm_mm, addr);
 		} else {
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
-			*accessed = pmd_young(*pvmw.pmd) ||
+			*accessed = pmd_young(pmdp_get(pvmw.pmd)) ||
 				!folio_test_idle(folio) ||
 				mmu_notifier_test_young(vma->vm_mm, addr);
 #else

mm/damon/vaddr.c

@@ -301,16 +301,19 @@ static int damon_mkold_pmd_entry(pmd_t *pmd, unsigned long addr,
 		unsigned long next, struct mm_walk *walk)
 {
 	pte_t *pte;
+	pmd_t pmde;
 	spinlock_t *ptl;
 
-	if (pmd_trans_huge(*pmd)) {
+	if (pmd_trans_huge(pmdp_get(pmd))) {
 		ptl = pmd_lock(walk->mm, pmd);
-		if (!pmd_present(*pmd)) {
+		pmde = pmdp_get(pmd);
+
+		if (!pmd_present(pmde)) {
 			spin_unlock(ptl);
 			return 0;
 		}
 
-		if (pmd_trans_huge(*pmd)) {
+		if (pmd_trans_huge(pmde)) {
 			damon_pmdp_mkold(pmd, walk->vma, addr);
 			spin_unlock(ptl);
 			return 0;
@@ -439,21 +442,25 @@ static int damon_young_pmd_entry(pmd_t *pmd, unsigned long addr,
 	struct damon_young_walk_private *priv = walk->private;
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
-	if (pmd_trans_huge(*pmd)) {
+	if (pmd_trans_huge(pmdp_get(pmd))) {
+		pmd_t pmde;
+
 		ptl = pmd_lock(walk->mm, pmd);
-		if (!pmd_present(*pmd)) {
+		pmde = pmdp_get(pmd);
+
+		if (!pmd_present(pmde)) {
 			spin_unlock(ptl);
 			return 0;
 		}
 
-		if (!pmd_trans_huge(*pmd)) {
+		if (!pmd_trans_huge(pmde)) {
 			spin_unlock(ptl);
 			goto regular_page;
 		}
-		folio = damon_get_folio(pmd_pfn(*pmd));
+		folio = damon_get_folio(pmd_pfn(pmde));
 		if (!folio)
 			goto huge_out;
-		if (pmd_young(*pmd) || !folio_test_idle(folio) ||
+		if (pmd_young(pmde) || !folio_test_idle(folio) ||
 					mmu_notifier_test_young(walk->mm,
 						addr))
 			priv->young = true;