On Tue, Sep 28, 2021 at 07:30:41AM +0000, Tian, Kevin wrote: > > Also, don't call it "hint", there is nothing hinty about this, it has > > definitive functional impacts. > > possibly dma_mode (too broad?) or dma_usage You just need a flag to specify if the driver manages DMA ownership itself, or if it requires the driver core to setup kernel ownership DMA_OWNER_KERNEL DMA_OWNER_DRIVER_CONTROLLED ? There is a bool 'suprress_bind_attrs' already so it could be done like this: bool suppress_bind_attrs:1; /* If set the driver must call iommu_XX as the first action in probe() */ bool suppress_dma_owner:1; Which is pretty low cost. Jason
