mm: export prep_compound_page to mm

hugetlb will need to get compound pages from bootmem to handle the case of
them being greater than or equal to MAX_ORDER.  Export the constructor
function needed for this.

Acked-by: Adam Litke <agl@us.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 3 insertions, 1 deletions

diff --git a/mm/internal.h b/mm/internal.h
index 858ad01864dc..1f43f7416972 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -16,6 +16,8 @@
 void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma,
                 unsigned long floor, unsigned long ceiling);
 
+extern void prep_compound_page(struct page *page, unsigned long order);
+
 static inline void set_page_count(struct page *page, int v)
 {
         atomic_set(&page->_count, v);
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index e43aae135b38..eaa86671ebbd 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -264,7 +264,7 @@ static void free_compound_page(struct page *page)
         __free_pages_ok(page, compound_order(page));
 }
 
-static void prep_compound_page(struct page *page, unsigned long order)
+void prep_compound_page(struct page *page, unsigned long order)
 {
         int i;
         int nr_pages = 1 << order;