[PATCH] s390/mm: Use set_pmd() / set_pud() for hugetlb pagetable entries

[Gerald Schaefer <gerald.schaefer@linux.ibm.com>]

hugetlb code is known to view all pagetable entries as PTEs, instead of
corresponding upper levels like PMD or PUD. For s390, with different
pagetable entry layout for different levels, this requires some
conversion action under the hood.

The converted PMD and PUD entries are then written via set_pte()
function, but that might add some PTE-specific modifications.
There is no functional problem with current code, and the clearing of
_PAGE_UNUSED in set_pte(). Avoid future problems by using the set_pmd()
and set_pud() functions instead.

Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
---
 arch/s390/include/asm/hugetlb.h |  4 ++--
 arch/s390/mm/hugetlbpage.c      | 10 ++++++----
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/arch/s390/include/asm/hugetlb.h b/arch/s390/include/asm/hugetlb.h
index e33a5b587ee4..02db08429b7c 100644
--- a/arch/s390/include/asm/hugetlb.h
+++ b/arch/s390/include/asm/hugetlb.h
@@ -42,9 +42,9 @@ static inline void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
 				  pte_t *ptep, unsigned long sz)
 {
 	if ((pte_val(ptep_get(ptep)) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3)
-		set_pte(ptep, __pte(_REGION3_ENTRY_EMPTY));
+		set_pud((pud_t *)ptep, __pud(_REGION3_ENTRY_EMPTY));
 	else
-		set_pte(ptep, __pte(_SEGMENT_ENTRY_EMPTY));
+		set_pmd((pmd_t *)ptep, __pmd(_SEGMENT_ENTRY_EMPTY));
 }
 
 #define __HAVE_ARCH_HUGE_PTEP_CLEAR_FLUSH
diff --git a/arch/s390/mm/hugetlbpage.c b/arch/s390/mm/hugetlbpage.c
index db35d8fe8609..f84aa9265430 100644
--- a/arch/s390/mm/hugetlbpage.c
+++ b/arch/s390/mm/hugetlbpage.c
@@ -147,10 +147,12 @@ void __set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
 		if (likely(pte_present(pte)))
 			rste |= _REGION3_ENTRY_LARGE;
 		rste |= _REGION_ENTRY_TYPE_R3;
-	} else if (likely(pte_present(pte)))
-		rste |= _SEGMENT_ENTRY_LARGE;
-
-	set_pte(ptep, __pte(rste));
+		set_pud((pud_t *)ptep, __pud(rste));
+	} else {
+		if (likely(pte_present(pte)))
+			rste |= _SEGMENT_ENTRY_LARGE;
+		set_pmd((pmd_t *)ptep, __pmd(rste));
+	}
 }
 
 void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
-- 
2.53.0