diff --git a/include/linux/iommu-helper.h b/include/linux/iommu-helper.h
index 64d1b638745d63bc0ac7569427e583db3236a0cc..86bdeffe43ad69e3dba2781eeed06b8cbe847a69 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
diff --git a/lib/iommu-helper.c b/lib/iommu-helper.c
index c0251f4ad08b05fec688f97ea2e771095cfdb89c..da053313ee5c089e099d02c9a368eb4f4aacaf56 100644
--- a/lib/iommu-helper.c
+++ b/lib/iommu-helper.c
@@ -38,12 +38,3 @@ unsigned long iommu_area_alloc(unsigned long *map, unsigned long size,
 	return -1;
 }
 EXPORT_SYMBOL(iommu_area_alloc);
-
-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);
-}
-EXPORT_SYMBOL(iommu_num_pages);