map_pt_dma
ret = map_pt_dma(vm, vm->scratch[1]);
ret = map_pt_dma(vm, obj);
err = map_pt_dma(vm, pde->pt.base);
err = map_pt_dma(vm, pd->pt.base);
if (map_pt_dma(vm, obj))
int map_pt_dma(struct i915_address_space *vm, struct drm_i915_gem_object *obj);