diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.c b/drivers/gpu/drm/exynos/exynos_drm_gem.c
index 67e17ce112b69..0e6fe000578c0 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_gem.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_gem.c
@@ -164,6 +164,27 @@ void exynos_drm_gem_destroy(struct exynos_drm_gem_obj *exynos_gem_obj)
 	exynos_gem_obj = NULL;
 }
 
+unsigned long exynos_drm_gem_get_size(struct drm_device *dev,
+						unsigned int gem_handle,
+						struct drm_file *file_priv)
+{
+	struct exynos_drm_gem_obj *exynos_gem_obj;
+	struct drm_gem_object *obj;
+
+	obj = drm_gem_object_lookup(dev, file_priv, gem_handle);
+	if (!obj) {
+		DRM_ERROR("failed to lookup gem object.\n");
+		return 0;
+	}
+
+	exynos_gem_obj = to_exynos_gem_obj(obj);
+
+	drm_gem_object_unreference_unlocked(obj);
+
+	return exynos_gem_obj->buffer->size;
+}
+
+
 struct exynos_drm_gem_obj *exynos_drm_gem_init(struct drm_device *dev,
 						      unsigned long size)
 {
diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.h b/drivers/gpu/drm/exynos/exynos_drm_gem.h
index 35ebac47dc2ba..468766bee4508 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_gem.h
+++ b/drivers/gpu/drm/exynos/exynos_drm_gem.h
@@ -130,6 +130,11 @@ int exynos_drm_gem_userptr_ioctl(struct drm_device *dev, void *data,
 int exynos_drm_gem_get_ioctl(struct drm_device *dev, void *data,
 				      struct drm_file *file_priv);
 
+/* get buffer size to gem handle. */
+unsigned long exynos_drm_gem_get_size(struct drm_device *dev,
+						unsigned int gem_handle,
+						struct drm_file *file_priv);
+
 /* initialize gem object. */
 int exynos_drm_gem_init_object(struct drm_gem_object *obj);