drm/radeon/kms: add support for new fault callback V7

This add the support for the new fault callback and also the
infrastructure for supporting unmappable VRAM.

V2 validate BO with no_wait = true
V3 don't derefence bo->mem.mm_node as it's not NULL only for
   VRAM or GTT
V4 update to splitted no_wait ttm change
V5 update to new balanced io_mem_reserve/free change
V6 callback is responsible for iomapping memory
V7 move back iomapping to ttm

Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/radeon_object.h b/drivers/gpu/drm/radeon/radeon_object.h
index 7ab43de..353998d 100644
--- a/drivers/gpu/drm/radeon/radeon_object.h
+++ b/drivers/gpu/drm/radeon/radeon_object.h
@@ -168,6 +168,6 @@
 				bool force_drop);
 extern void radeon_bo_move_notify(struct ttm_buffer_object *bo,
 					struct ttm_mem_reg *mem);
-extern void radeon_bo_fault_reserve_notify(struct ttm_buffer_object *bo);
+extern int radeon_bo_fault_reserve_notify(struct ttm_buffer_object *bo);
 extern int radeon_bo_get_surface_reg(struct radeon_bo *bo);
 #endif