[PATCH 31/45] mm/mincore: Create mincore_pud_range to handle PUD-mapped hugetlb vmas

[Oscar Salvador]

Normal THP cannot be PUD-mapped (besides devmap), but hugetlb can, so create
mincore_pud_range in order to handle PUD-mapped hugetlb vmas.

Signed-off-by: Oscar Salvador <osalvador@xxxxxxx>
---
 mm/mincore.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/mm/mincore.c b/mm/mincore.c
index 5154bc705f60..786df7246899 100644
--- a/mm/mincore.c
+++ b/mm/mincore.c
@@ -98,6 +98,25 @@ static int mincore_unmapped_range(unsigned long addr, unsigned long end,
 	return 0;
 }
 
+static int mincore_pud_range(pud_t *pud, unsigned long addr, unsigned long end,
+			     struct mm_walk *walk)
+{
+#ifdef CONFIG_PGTABLE_HAS_HUGE_LEAVES
+	spinlock_t *ptl;
+	unsigned char *vec = walk->private;
+	int nr = (end - addr) >> PAGE_SHIFT;
+	struct vm_area_struct *vma = walk->vma;
+
+	ptl = pud_huge_lock(pud, vma);
+	if (!ptl)
+		return 0;
+
+	memset(vec, 1, nr);
+	spin_unlock(ptl);
+#endif
+	return 0;
+}
+
 static int mincore_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
 			struct mm_walk *walk)
 {
@@ -175,6 +194,7 @@ static inline bool can_do_mincore(struct vm_area_struct *vma)
 }
 
 static const struct mm_walk_ops mincore_walk_ops = {
+	.pud_entry		= mincore_pud_range,
 	.pmd_entry		= mincore_pte_range,
 	.pte_hole		= mincore_unmapped_range,
 	.hugetlb_entry		= mincore_hugetlb,
-- 
2.26.2