1 files changed, 13 insertions, 0 deletions

diff --git a/arch/sparc/mm/gup.c b/arch/sparc/mm/gup.c
index a986b5d05712..afcebac144fb 100644
--- a/arch/sparc/mm/gup.c
+++ b/arch/sparc/mm/gup.c
@@ -12,6 +12,17 @@
 #include <linux/rwsem.h>
 #include <asm/pgtable.h>
 
+static inline void get_huge_page_tail(struct page *page)
+{
+        /*
+         * __split_huge_page_refcount() cannot run
+         * from under us.
+         */
+        VM_BUG_ON(page_mapcount(page) < 0);
+        VM_BUG_ON(atomic_read(&page->_count) != 0);
+        atomic_inc(&page->_mapcount);
+}
+
 /*
  * The performance critical leaf functions are made noinline otherwise gcc
  * inlines everything into a single function which results in too much
@@ -56,6 +67,8 @@ static noinline int gup_pte_range(pmd_t pmd, unsigned long addr,
                         put_page(head);
                         return 0;
                 }
+                if (head != page)
+                        get_huge_page_tail(page);
 
                 pages[*nr] = page;
                 (*nr)++;