1 files changed, 50 insertions, 5 deletions

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 60e0e4a..4670ebd 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -267,21 +267,31 @@ static inline int get_page_unless_zero(struct page *page)
 	return atomic_inc_not_zero(&page->_count);
 }
 
+static inline struct page *compound_head(struct page *page)
+{
+	if (unlikely(PageTail(page)))
+		return page->first_page;
+	return page;
+}
+
 static inline int page_count(struct page *page)
 {
-	if (unlikely(PageCompound(page)))
-		page = (struct page *)page_private(page);
-	return atomic_read(&page->_count);
+	return atomic_read(&compound_head(page)->_count);
 }
 
 static inline void get_page(struct page *page)
 {
-	if (unlikely(PageCompound(page)))
-		page = (struct page *)page_private(page);
+	page = compound_head(page);
 	VM_BUG_ON(atomic_read(&page->_count) == 0);
 	atomic_inc(&page->_count);
 }
 
+static inline struct page *virt_to_head_page(const void *x)
+{
+	struct page *page = virt_to_page(x);
+	return compound_head(page);
+}
+
 /*
  * Setup the page count before being freed into the page allocator for
  * the first time (boot or memory hotplug)
@@ -314,6 +324,18 @@ static inline compound_page_dtor *get_compound_page_dtor(struct page *page)
 	return (compound_page_dtor *)page[1].lru.next;
 }
 
+static inline int compound_order(struct page *page)
+{
+	if (!PageHead(page))
+		return 0;
+	return (unsigned long)page[1].lru.prev;
+}
+
+static inline void set_compound_order(struct page *page, unsigned long order)
+{
+	page[1].lru.prev = (void *)order;
+}
+
 /*
  * Multiple processes may "see" the same page. E.g. for untouched
  * mappings of /dev/null, all processes see the same page full of
@@ -850,8 +872,26 @@ static inline int vma_wants_writenotify(struct vm_area_struct *vma)
 
 extern pte_t *FASTCALL(get_locked_pte(struct mm_struct *mm, unsigned long addr, spinlock_t **ptl));
 
+#ifdef __PAGETABLE_PUD_FOLDED
+static inline int __pud_alloc(struct mm_struct *mm, pgd_t *pgd,
+						unsigned long address)
+{
+	return 0;
+}
+#else
 int __pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address);
+#endif
+
+#ifdef __PAGETABLE_PMD_FOLDED
+static inline int __pmd_alloc(struct mm_struct *mm, pud_t *pud,
+						unsigned long address)
+{
+	return 0;
+}
+#else
 int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address);
+#endif
+
 int __pte_alloc(struct mm_struct *mm, pmd_t *pmd, unsigned long address);
 int __pte_alloc_kernel(pmd_t *pmd, unsigned long address);
 
@@ -1130,6 +1170,11 @@ struct page *follow_page(struct vm_area_struct *, unsigned long address,
 #define FOLL_GET	0x04	/* do get_page on page */
 #define FOLL_ANON	0x08	/* give ZERO_PAGE if no pgtable */
 
+typedef int (*pte_fn_t)(pte_t *pte, struct page *pmd_page, unsigned long addr,
+			void *data);
+extern int apply_to_page_range(struct mm_struct *mm, unsigned long address,
+			       unsigned long size, pte_fn_t fn, void *data);
+
 #ifdef CONFIG_PROC_FS
 void vm_stat_account(struct mm_struct *, unsigned long, struct file *, long);
 #else