[PATCH 07/45] arch/s390: Enable __s390_enable_skey_pmd to handle hugetlb vmas

[Oscar Salvador]

__s390_enable_skey_pmd does nothing for THP, but will handle pmd-leafs
hugetlb vmas from now onwards, so teach it how to handle those.

Signed-off-by: Oscar Salvador <osalvador@xxxxxxx>
---
 arch/s390/mm/gmap.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
index 474a25ca5c48..e1d098dc7f07 100644
--- a/arch/s390/mm/gmap.c
+++ b/arch/s390/mm/gmap.c
@@ -2723,6 +2723,20 @@ static int __s390_enable_skey_pte(pte_t *pte, unsigned long addr,
 static int __s390_enable_skey_pmd(pmd_t *pmd, unsigned long addr,
 				  unsigned long next, struct mm_walk *walk)
 {
+	if (pmd_leaf(*pmd) && is_vm_hugetlb_page(vma))
+		unsigned long start, end;
+		struct page *page = pmd_page(*pmd);
+
+		if (pmd_val(*pmd) & _SEGMENT_ENTRY_INVALID ||
+		    !(pmd_val(*pmd) & _SEGMENT_ENTRY_WRITE))
+			return 0;
+
+		start = pmd_val(*pmd) & HPAGE_MASK;
+		end = start + HPAGE_SIZE;
+		__storage_key_init_range(start, end);
+		set_bit(PG_arch_1, &page->flags);
+	}
+
 	cond_resched();
 	return 0;
 }
-- 
2.26.2