dma_direct_get_required_mask
u64 bypass_mask = dma_direct_get_required_mask(dev);
.get_required_mask = dma_direct_get_required_mask,
u64 dma_direct_get_required_mask(struct device *dev);
dma_direct_get_required_mask(dev);
return dma_direct_get_required_mask(dev);