s390/hugetlb: switch to generic version of follow_huge_pud()

When pud-sized hugepages were introduced for s390, the generic version of
follow_huge_pud() was using pte_page() instead of pud_page().  This would
be wrong for s390, see also commit 97534127012f ("mm/hugetlb: use
pmd_page() in follow_huge_pmd()").  Therefore, and probably because not
all archs were supporting pud_page() at that time, a private version of
follow_huge_pud() was added for s390, correctly using pud_page().

Since commit 3a194f3f8ad01 ("mm/hugetlb: make pud_huge() and
follow_huge_pud() aware of non-present pud entry"), the generic version of
follow_huge_pud() is now also using pud_page(), and in general behaves
similar to follow_huge_pmd().

Therefore we can now switch to the generic version and get rid of the
s390-specific follow_huge_pud().

Link: https://lkml.kernel.org/r/20220818135717.609eef8a@thinkpad
Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Haiyue Wang <haiyue.wang@intel.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/arch/s390/mm/hugetlbpage.c b/arch/s390/mm/hugetlbpage.c
index 10e51ef9c79a793b658890c71db84e68b07b15c9..c299a18273ffeca9c30f89d75f14b6fdfc5b49ed 100644 (file)
--- a/arch/s390/mm/hugetlbpage.c
+++ b/arch/s390/mm/hugetlbpage.c
@@ -237,16 +237,6 @@ int pud_huge(pud_t pud)
        return pud_large(pud);
 }
 
-struct page *
-follow_huge_pud(struct mm_struct *mm, unsigned long address,
-               pud_t *pud, int flags)
-{
-       if (flags & FOLL_GET)
-               return NULL;
-
-       return pud_page(*pud) + ((address & ~PUD_MASK) >> PAGE_SHIFT);
-}
-
 bool __init arch_hugetlb_valid_size(unsigned long size)
 {
        if (MACHINE_HAS_EDAT1 && size == PMD_SIZE)