pagemap: pass mm into pagewalkers

We need this at least for huge page detection for now, because powerpc
needs the vm_area_struct to be able to determine whether a virtual address
is referring to a huge page (its pmd_huge() doesn't work).

It might also come in handy for some of the other users.

Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Acked-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/mm.h b/include/linux/mm.h
index c31a9cd..586a943 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -760,16 +760,17 @@
  * (see walk_page_range for more details)
  */
 struct mm_walk {
-	int (*pgd_entry)(pgd_t *, unsigned long, unsigned long, void *);
-	int (*pud_entry)(pud_t *, unsigned long, unsigned long, void *);
-	int (*pmd_entry)(pmd_t *, unsigned long, unsigned long, void *);
-	int (*pte_entry)(pte_t *, unsigned long, unsigned long, void *);
-	int (*pte_hole)(unsigned long, unsigned long, void *);
+	int (*pgd_entry)(pgd_t *, unsigned long, unsigned long, struct mm_walk *);
+	int (*pud_entry)(pud_t *, unsigned long, unsigned long, struct mm_walk *);
+	int (*pmd_entry)(pmd_t *, unsigned long, unsigned long, struct mm_walk *);
+	int (*pte_entry)(pte_t *, unsigned long, unsigned long, struct mm_walk *);
+	int (*pte_hole)(unsigned long, unsigned long, struct mm_walk *);
+	struct mm_struct *mm;
+	void *private;
 };
 
-int walk_page_range(const struct mm_struct *, unsigned long addr,
-		    unsigned long end, const struct mm_walk *walk,
-		    void *private);
+int walk_page_range(unsigned long addr, unsigned long end,
+		struct mm_walk *walk);
 void free_pgd_range(struct mmu_gather **tlb, unsigned long addr,
 		unsigned long end, unsigned long floor, unsigned long ceiling);
 void free_pgtables(struct mmu_gather **tlb, struct vm_area_struct *start_vma,