Hi Will/Robin/Joerg, I am s/w engineer from NXP India Pvt. Ltd. We are using SMMU-V3 in one of NXP SOC. I have a question about the SMMU Stream ID allocation in linux.
Right now the Stream IDs allocated to a device are mapped via device tree to the device. https://elixir.bootlin.com/linux/latest/source/Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt#L39 As the device tree is passed from bootloader to linux, we detect all the stream IDs needed by a device in bootloader and add their IDs in respective device nodes. For each PCIE Endpoint (a unique BDF (Bus Device Function)) on PCIE bus, we are assigning a unique Stream ID in bootloader. However, this poses an issue with PCIE hot plug. If we plug in a pcie device while linux is running, a unique BDF is assigned to the device, for which there is no stream ID in device tree. How can this problem be solved in linux? Is there a way to assign (and revoke) stream IDs at run time? Regards, Pankaj Bansal _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
