DMA_CTRL
I915_WRITE(DMA_CTRL, _MASKED_BIT_ENABLE(UOS_MOVE | START_DMA));
ret = __intel_wait_for_register_fw(dev_priv, DMA_CTRL, START_DMA, 0,
I915_WRITE(DMA_CTRL, _MASKED_BIT_ENABLE(HUC_UKERNEL | START_DMA));
ret = intel_wait_for_register_fw(dev_priv, DMA_CTRL, START_DMA, 0, 100);
I915_WRITE(DMA_CTRL, _MASKED_BIT_DISABLE(HUC_UKERNEL));