1 files changed, 10 insertions, 2 deletions

diff --git a/include/linux/iommu-helper.h b/include/linux/iommu-helper.h
index 64d1b638745d..86bdeffe43ad 100644
--- a/include/linux/iommu-helper.h
+++ b/include/linux/iommu-helper.h
@@ -1,6 +1,8 @@
 #ifndef _LINUX_IOMMU_HELPER_H
 #define _LINUX_IOMMU_HELPER_H
 
+#include <linux/kernel.h>
+
 static inline unsigned long iommu_device_max_index(unsigned long size,
                                                    unsigned long offset,
                                                    u64 dma_mask)
@@ -20,7 +22,13 @@ extern unsigned long iommu_area_alloc(unsigned long *map, unsigned long size,
                                       unsigned long boundary_size,
                                       unsigned long align_mask);
 
-extern unsigned long iommu_num_pages(unsigned long addr, unsigned long len,
-                                     unsigned long io_page_size);
+static inline unsigned long iommu_num_pages(unsigned long addr,
+                                            unsigned long len,
+                                            unsigned long io_page_size)
+{
+        unsigned long size = (addr & (io_page_size - 1)) + len;
+
+        return DIV_ROUND_UP(size, io_page_size);
+}
 
 #endif