drm/ttm: export some functions useful to drivers using ttm

These are functions required by nouveau which will be merged later.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/ttm/ttm_bo.c

@@ -185,6 +185,7 @@ int ttm_bo_wait_unreserved(struct ttm_buffer_object *bo, bool interruptible)
 	}
 	return 0;
 }
+EXPORT_SYMBOL(ttm_bo_wait_unreserved);
 
 static void ttm_bo_add_to_lru(struct ttm_buffer_object *bo)
 {
@@ -946,6 +947,7 @@ int ttm_bo_wait_cpu(struct ttm_buffer_object *bo, bool no_wait)
 	return wait_event_interruptible(bo->event_queue,
 					atomic_read(&bo->cpu_writers) == 0);
 }
+EXPORT_SYMBOL(ttm_bo_wait_cpu);
 
 int ttm_bo_move_buffer(struct ttm_buffer_object *bo,
 			struct ttm_placement *placement,
@@ -1727,12 +1729,14 @@ int ttm_bo_synccpu_write_grab(struct ttm_buffer_object *bo, bool no_wait)
 	ttm_bo_unreserve(bo);
 	return ret;
 }
+EXPORT_SYMBOL(ttm_bo_synccpu_write_grab);
 
 void ttm_bo_synccpu_write_release(struct ttm_buffer_object *bo)
 {
 	if (atomic_dec_and_test(&bo->cpu_writers))
 		wake_up_all(&bo->event_queue);
 }
+EXPORT_SYMBOL(ttm_bo_synccpu_write_release);
 
 /**
  * A buffer object shrink method that tries to swap out the first