Commit ec615f43 authored Nov 03, 2016 by Robin Murphy Committed by Joerg Roedel Nov 08, 2016

iommu/arm-smmu: Don't inadvertently reject multiple SMMUv3s



We now delay installing our per-bus iommu_ops until we know an SMMU has
successfully probed, as they don't serve much purpose beforehand, and
doing so also avoids fights between multiple IOMMU drivers in a single
kernel. However, the upshot of passing the return value of bus_set_iommu()
back from our probe function is that if there happens to be more than
one SMMUv3 device in a system, the second and subsequent probes will
wind up returning -EBUSY to the driver core and getting torn down again.

Avoid re-setting ops if ours are already installed, so that any genuine
failures stand out.

Fixes: 08d4ca2a ("iommu/arm-smmu: Support non-PCI devices with SMMUv3")
CC: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
CC: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

parent fba4f8e5

drivers/iommu/arm-smmu-v3.c

+17 −8

Original line number	Diff line number	Diff line
		@@ -2636,17 +2636,26 @@ static int arm_smmu_device_dt_probe(struct platform_device *pdev)
		/* And we're up. Go go go! */
		of_iommu_set_ops(dev->of_node, &arm_smmu_ops);
		#ifdef CONFIG_PCI
		if (pci_bus_type.iommu_ops != &arm_smmu_ops) {
		pci_request_acs();
		ret = bus_set_iommu(&pci_bus_type, &arm_smmu_ops);
		if (ret)
		return ret;
		}
		#endif
		#ifdef CONFIG_ARM_AMBA
		if (amba_bustype.iommu_ops != &arm_smmu_ops) {
		ret = bus_set_iommu(&amba_bustype, &arm_smmu_ops);
		if (ret)
		return ret;
		}
		#endif
		return bus_set_iommu(&platform_bus_type, &arm_smmu_ops);
		if (platform_bus_type.iommu_ops != &arm_smmu_ops) {
		ret = bus_set_iommu(&platform_bus_type, &arm_smmu_ops);
		if (ret)
		return ret;
		}
		return 0;
		}

		static int arm_smmu_device_remove(struct platform_device *pdev)

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