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0bd971676e
At the moment the powernv platform registers an IOMMU group for each PE. There is an exception though: an NVLink bridge which is attached to the corresponding GPU's IOMMU group making it a master. Now we have POWER9 systems with GPUs connected to each other directly bypassing PCI. At the moment we do not control state of these links so we have to put such interconnected GPUs to one IOMMU group which means that the old scheme with one GPU as a master won't work - there will be up to 3 GPUs in such group. This introduces a npu_comp struct which represents a compound IOMMU group made of multiple PEs - PCI PEs (for GPUs) and NPU PEs (for NVLink bridges). This converts the existing NVLink1 code to use the new scheme. >From now on, each PE must have a valid iommu_table_group_ops which will either be called directly (for a single PE group) or indirectly from a compound group handlers. This moves IOMMU group registration for NVLink-connected GPUs to npu-dma.c. For POWER8, this stores a new compound group pointer in the PE (so a GPU is still a master); for POWER9 the new group pointer is stored in an NPU (which is allocated per a PCI host controller). Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> [mpe: Initialise npdev to NULL in pnv_try_setup_npu_table_group()] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> |
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