From 00bc5095547ef9878324167fe0c3e56f7b388159 Mon Sep 17 00:00:00 2001 From: Sam Bobroff Date: Tue, 31 Mar 2020 15:12:46 +1100 Subject: [PATCH] vfio-pci/nvlink2: Allow fallback to ibm,mmio-atsd[0] Older versions of skiboot only provide a single value in the device tree property "ibm,mmio-atsd", even when multiple Address Translation Shoot Down (ATSD) registers are present. This prevents NVLink2 devices (other than the first) from being used with vfio-pci because vfio-pci expects to be able to assign a dedicated ATSD register to each NVLink2 device. However, ATSD registers can be shared among devices. This change allows vfio-pci to fall back to sharing the register at index 0 if necessary. Fixes: 7f92891778df ("vfio_pci: Add NVIDIA GV100GL [Tesla V100 SXM2] subdriver") Signed-off-by: Sam Bobroff Reviewed-by: Alexey Kardashevskiy Signed-off-by: Alex Williamson --- drivers/vfio/pci/vfio_pci_nvlink2.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/vfio/pci/vfio_pci_nvlink2.c b/drivers/vfio/pci/vfio_pci_nvlink2.c index df4d96038cd4..ed20d73cc27c 100644 --- a/drivers/vfio/pci/vfio_pci_nvlink2.c +++ b/drivers/vfio/pci/vfio_pci_nvlink2.c @@ -422,8 +422,14 @@ int vfio_pci_ibm_npu2_init(struct vfio_pci_device *vdev) if (of_property_read_u64_index(hose->dn, "ibm,mmio-atsd", nvlink_index, &mmio_atsd)) { - dev_warn(&vdev->pdev->dev, "No available ATSD found\n"); - mmio_atsd = 0; + if (of_property_read_u64_index(hose->dn, "ibm,mmio-atsd", 0, + &mmio_atsd)) { + dev_warn(&vdev->pdev->dev, "No available ATSD found\n"); + mmio_atsd = 0; + } else { + dev_warn(&vdev->pdev->dev, + "Using fallback ibm,mmio-atsd[0] for ATSD.\n"); + } } if (of_property_read_u64(npu_node, "ibm,device-tgt-addr", &tgt)) {