mm: add new arch_make_huge_pte() method for tile support

The tile support for multiple-size huge pages requires tagging
the hugetlb PTE with a "super" bit for PTEs that are multiples of
the basic size of a pagetable span.  To set that bit properly
we need to tweak the PTe in make_huge_pte() based on the vma.

This change provides the API for a subsequent tile-specific
change to use.

Reviewed-by: Hillf Danton <dhillf@gmail.com>
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>

2 files changed, 9 insertions, 0 deletions

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 000837e126e6..d5d6bbe2259e 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -284,6 +284,14 @@ static inline unsigned int blocks_per_huge_page(struct hstate *h)
 
 #include <asm/hugetlb.h>
 
+#ifndef arch_make_huge_pte
+static inline pte_t arch_make_huge_pte(pte_t entry, struct vm_area_struct *vma,
+                                       struct page *page, int writable)
+{
+        return entry;
+}
+#endif
+
 static inline struct hstate *page_hstate(struct page *page)
 {
         return size_to_hstate(PAGE_SIZE << compound_order(page));
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index ae8f708e3d75..4e28416c47fb 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2213,6 +2213,7 @@ static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page,
         }
         entry = pte_mkyoung(entry);
         entry = pte_mkhuge(entry);
+        entry = arch_make_huge_pte(entry, vma, page, writable);
 
         return entry;
 }