diff --git a/sys/dev/drm2/drmP.h b/sys/dev/drm2/drmP.h
index dbf5277..4f86372 100644
--- a/sys/dev/drm2/drmP.h
+++ b/sys/dev/drm2/drmP.h
@@ -1432,6 +1432,8 @@ void drm_gem_pager_dtr(void *obj);
 struct ttm_bo_device;
 int ttm_bo_mmap_single(struct ttm_bo_device *bdev, vm_ooffset_t *offset,
     vm_size_t size, struct vm_object **obj_res, int nprot);
+struct ttm_buffer_object;
+void ttm_bo_mmap_release(struct ttm_buffer_object *bo);
 
 void drm_device_lock_mtx(struct drm_device *dev);
 void drm_device_unlock_mtx(struct drm_device *dev);
diff --git a/sys/dev/drm2/ttm/ttm_bo.c b/sys/dev/drm2/ttm/ttm_bo.c
index 8bd8af9..8676113 100644
--- a/sys/dev/drm2/ttm/ttm_bo.c
+++ b/sys/dev/drm2/ttm/ttm_bo.c
@@ -523,6 +523,8 @@ static void ttm_bo_cleanup_memtype_use(struct ttm_buffer_object *bo)
 		bo->bdev->driver->move_notify(bo, NULL);
 
 	if (bo->ttm) {
+		ttm_bo_mmap_release(bo);
+
 		ttm_tt_unbind(bo->ttm);
 		ttm_tt_destroy(bo->ttm);
 		bo->ttm = NULL;
diff --git a/sys/dev/drm2/ttm/ttm_bo_util.c b/sys/dev/drm2/ttm/ttm_bo_util.c
index bca0ad3..e334ac3 100644
--- a/sys/dev/drm2/ttm/ttm_bo_util.c
+++ b/sys/dev/drm2/ttm/ttm_bo_util.c
@@ -655,8 +655,19 @@ int ttm_bo_move_accel_cleanup(struct ttm_buffer_object *bo,
 
 		if (!(man->flags & TTM_MEMTYPE_FLAG_FIXED))
 			ghost_obj->ttm = NULL;
-		else
+		else {
+			/*
+			 * Release mmap for this buffer object, because
+			 * bo->ttm is transferred to the ghost object.
+			 *
+			 * ttm_bo_mmap_release() will be called again
+			 * on ghost_obj but it'll be a no-op, as the
+			 * vm_object_t is already deallocated.
+			 */
+			ttm_bo_mmap_release(bo);
+
 			bo->ttm = NULL;
+		}
 
 		ttm_bo_unreserve(ghost_obj);
 		ttm_bo_unref(&ghost_obj);
diff --git a/sys/dev/drm2/ttm/ttm_bo_vm.c b/sys/dev/drm2/ttm/ttm_bo_vm.c
index 2eba4c3..eef4d7f 100644
--- a/sys/dev/drm2/ttm/ttm_bo_vm.c
+++ b/sys/dev/drm2/ttm/ttm_bo_vm.c
@@ -337,6 +337,32 @@ out_unref:
 	return ret;
 }
 
+void
+ttm_bo_mmap_release(struct ttm_buffer_object *bo)
+{
+	vm_object_t vm_obj;
+	vm_page_t m;
+	int i;
+
+	vm_obj = cdev_pager_lookup(bo);
+	if (vm_obj == NULL) {
+		return;
+	}
+
+	VM_OBJECT_WLOCK(vm_obj);
+retry:
+	for (i = 0; i < bo->num_pages; i++) {
+		m = vm_page_lookup(vm_obj, i);
+		if (m == NULL)
+			continue;
+		if (vm_page_sleep_if_busy(m, true, "ttm_unm"))
+			goto retry;
+		cdev_pager_free_page(vm_obj, m);
+	}
+	VM_OBJECT_WUNLOCK(vm_obj);
+	vm_object_deallocate(vm_obj);
+}
+
 #if 0
 int ttm_fbdev_mmap(struct vm_area_struct *vma, struct ttm_buffer_object *bo)
 {