return;
 
 out:
-       exynos_gem_unmap_sgt_from_dma(drm_dev, g2d_userptr->sgt,
-                                       DMA_BIDIRECTIONAL);
+       dma_unmap_sg(to_dma_dev(drm_dev), g2d_userptr->sgt->sgl,
+                       g2d_userptr->sgt->nents, DMA_BIDIRECTIONAL);
 
        pages = frame_vector_pages(g2d_userptr->vec);
        if (!IS_ERR(pages)) {
 
        g2d_userptr->sgt = sgt;
 
-       ret = exynos_gem_map_sgt_with_dma(drm_dev, g2d_userptr->sgt,
-                                               DMA_BIDIRECTIONAL);
-       if (ret < 0) {
+       if (!dma_map_sg(to_dma_dev(drm_dev), sgt->sgl, sgt->nents,
+                               DMA_BIDIRECTIONAL)) {
                DRM_ERROR("failed to map sgt with dma region.\n");
+               ret = -ENOMEM;
                goto err_sg_free_table;
        }
 
 
        return 0;
 }
 
-int exynos_gem_map_sgt_with_dma(struct drm_device *drm_dev,
-                               struct sg_table *sgt,
-                               enum dma_data_direction dir)
-{
-       int nents;
-
-       nents = dma_map_sg(to_dma_dev(drm_dev), sgt->sgl, sgt->nents, dir);
-       if (!nents) {
-               DRM_ERROR("failed to map sgl with dma.\n");
-               return nents;
-       }
-
-       return 0;
-}
-
-void exynos_gem_unmap_sgt_from_dma(struct drm_device *drm_dev,
-                               struct sg_table *sgt,
-                               enum dma_data_direction dir)
-{
-       dma_unmap_sg(to_dma_dev(drm_dev), sgt->sgl, sgt->nents, dir);
-}
-
 void exynos_drm_gem_free_object(struct drm_gem_object *obj)
 {
        exynos_drm_gem_destroy(to_exynos_gem(obj));
 
 /* set vm_flags and we can change the vm attribute to other one at here. */
 int exynos_drm_gem_mmap(struct file *filp, struct vm_area_struct *vma);
 
-/* map sgt with dma region. */
-int exynos_gem_map_sgt_with_dma(struct drm_device *drm_dev,
-                               struct sg_table *sgt,
-                               enum dma_data_direction dir);
-
-/* unmap sgt from dma region. */
-void exynos_gem_unmap_sgt_from_dma(struct drm_device *drm_dev,
-                               struct sg_table *sgt,
-                               enum dma_data_direction dir);
-
 /* low-level interface prime helpers */
 struct sg_table *exynos_drm_gem_prime_get_sg_table(struct drm_gem_object *obj);
 struct drm_gem_object *