When unmapping a hugepage range, huge_pte_clear() is used to clear the
page table entries that are marked as not present. huge_pte_clear()
internally just ends up calling pte_clear() which does not correctly
deal with hugepages consisting of contiguous page table entries.

Add a size argument to address this issue and allow architectures to
override huge_pte_clear() by wrapping it in a #ifndef block.

Update s390 implementation with the size parameter as well.

Note that the change only affects huge_pte_clear() - the other generic
hugetlb functions don't need any change.

Signed-off-by: Punit Agrawal <redacted>
Cc: Martin Schwidefsky <redacted>
Cc: Heiko Carstens <redacted>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "Aneesh Kumar K.V" <redacted>
Cc: Mike Kravetz <redacted>
---

Changes since v3

* Drop weak function and use #ifndef block to allow architecture override
* Drop unnecessary move of s390 function definition

 arch/s390/include/asm/hugetlb.h | 2 +-
 include/asm-generic/hugetlb.h   | 4 +++-
 mm/hugetlb.c                    | 2 +-
 3 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/arch/s390/include/asm/hugetlb.h b/arch/s390/include/asm/hugetlb.h
index cd546a245c68..c0443500baec 100644
--- a/arch/s390/include/asm/hugetlb.h
+++ b/arch/s390/include/asm/hugetlb.h

@@ -39,7 +39,7 @@ static inline int prepare_hugepage_range(struct file *file,
 #define arch_clear_hugepage_flags(page)		do { } while (0)

 static inline void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
-				  pte_t *ptep)
+				  pte_t *ptep, unsigned long sz)
 {
 	if ((pte_val(*ptep) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3)
 		pte_val(*ptep) = _REGION3_ENTRY_EMPTY;