diff --git a/arch/powerpc/include/asm/fb.h b/arch/powerpc/include/asm/fb.h
index 5f1a2e5f7654..61e3b8806db6 100644
--- a/arch/powerpc/include/asm/fb.h
+++ b/arch/powerpc/include/asm/fb.h
@@ -9,7 +9,12 @@
 static inline void fb_pgprotect(struct file *file, struct vm_area_struct *vma,
 				unsigned long off)
 {
-	vma->vm_page_prot = phys_mem_access_prot(file, off >> PAGE_SHIFT,
+	/*
+	 * PowerPC's implementation of phys_mem_access_prot() does
+	 * not use the file argument. Set it to NULL in preparation
+	 * of later updates to the interface.
+	 */
+	vma->vm_page_prot = phys_mem_access_prot(NULL, PHYS_PFN(off),
 						 vma->vm_end - vma->vm_start,
 						 vma->vm_page_prot);
 }