diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index 6021c4087a08..ca1956608261 100644
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -1267,6 +1267,7 @@ drm_gem_object_lookup_at_offset(struct file *filp, unsigned long start,
 	return obj;
 }
 
+#ifdef CONFIG_MMU
 /**
  * drm_gem_get_unmapped_area - get memory mapping region routine for GEM objects
  * @filp: DRM file pointer
@@ -1309,6 +1310,7 @@ unsigned long drm_gem_get_unmapped_area(struct file *filp, unsigned long uaddr,
 	return ret;
 }
 EXPORT_SYMBOL_GPL(drm_gem_get_unmapped_area);
+#endif
 
 /**
  * drm_gem_mmap - memory map routine for GEM objects
diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h
index cca815dc87f3..f4da8ed0d630 100644
--- a/include/drm/drm_gem.h
+++ b/include/drm/drm_gem.h
@@ -537,9 +537,14 @@ void drm_gem_vm_close(struct vm_area_struct *vma);
 int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size,
 		     struct vm_area_struct *vma);
 int drm_gem_mmap(struct file *filp, struct vm_area_struct *vma);
+
+#ifdef CONFIG_MMU
 unsigned long drm_gem_get_unmapped_area(struct file *filp, unsigned long uaddr,
 					unsigned long len, unsigned long pgoff,
 					unsigned long flags);
+#else
+#define drm_gem_get_unmapped_area NULL
+#endif
 
 /**
  * drm_gem_object_get - acquire a GEM buffer object reference