dev_priv->gtt.base.clear_range(&dev_priv->gtt.base,
dev_priv->gtt.base.start / PAGE_SIZE,
dev_priv->gtt.base.total / PAGE_SIZE,
dev_priv->gtt.base.clear_range(&dev_priv->gtt.base,
dev_priv->gtt.base.start / PAGE_SIZE,
dev_priv->gtt.base.total / PAGE_SIZE,