diff --git a/drivers/gpu/drm/loongson/lsdc_drv.c b/drivers/gpu/drm/loongson/lsdc_drv.c
index abf5bf68eec2..1ece1ea42f78 100644
--- a/drivers/gpu/drm/loongson/lsdc_drv.c
+++ b/drivers/gpu/drm/loongson/lsdc_drv.c
@@ -13,6 +13,7 @@
 #include <drm/drm_drv.h>
 #include <drm/drm_fbdev_ttm.h>
 #include <drm/drm_gem_framebuffer_helper.h>
+#include <drm/drm_gem_ttm_helper.h>
 #include <drm/drm_ioctl.h>
 #include <drm/drm_modeset_helper.h>
 #include <drm/drm_print.h>
@@ -45,7 +46,7 @@ static const struct drm_driver lsdc_drm_driver = {
 
 	.debugfs_init = lsdc_debugfs_init,
 	.dumb_create = lsdc_dumb_create,
-	.dumb_map_offset = lsdc_dumb_map_offset,
+	.dumb_map_offset = drm_gem_ttm_dumb_map_offset,
 	.gem_prime_import_sg_table = lsdc_prime_import_sg_table,
 	DRM_FBDEV_TTM_DRIVER_OPS,
 };
diff --git a/drivers/gpu/drm/loongson/lsdc_gem.c b/drivers/gpu/drm/loongson/lsdc_gem.c
index 6372db2d3093..2fb03487c983 100644
--- a/drivers/gpu/drm/loongson/lsdc_gem.c
+++ b/drivers/gpu/drm/loongson/lsdc_gem.c
@@ -234,21 +234,6 @@ int lsdc_dumb_create(struct drm_file *file, struct drm_device *ddev,
 	return 0;
 }
 
-int lsdc_dumb_map_offset(struct drm_file *filp, struct drm_device *ddev,
-			 u32 handle, uint64_t *offset)
-{
-	struct drm_gem_object *gobj;
-
-	gobj = drm_gem_object_lookup(filp, handle);
-	if (!gobj)
-		return -ENOENT;
-
-	*offset = drm_vma_node_offset_addr(&gobj->vma_node);
-
-	drm_gem_object_put(gobj);
-
-	return 0;
-}
 
 void lsdc_gem_init(struct drm_device *ddev)
 {
diff --git a/drivers/gpu/drm/loongson/lsdc_gem.h b/drivers/gpu/drm/loongson/lsdc_gem.h
index 92cbb10e6e13..96729b3eebec 100644
--- a/drivers/gpu/drm/loongson/lsdc_gem.h
+++ b/drivers/gpu/drm/loongson/lsdc_gem.h
@@ -14,10 +14,6 @@ lsdc_prime_import_sg_table(struct drm_device *ddev,
 			   struct dma_buf_attachment *attach,
 			   struct sg_table *sg);
 
-int lsdc_dumb_map_offset(struct drm_file *file,
-			 struct drm_device *dev,
-			 u32 handle,
-			 uint64_t *offset);
 
 int lsdc_dumb_create(struct drm_file *file,
 		     struct drm_device *ddev,