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Commit ec615f43 authored by Robin Murphy's avatar Robin Murphy Committed by Joerg Roedel
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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: default avatarRobin Murphy <robin.murphy@arm.com>
Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent fba4f8e5

drivers/iommu/arm-smmu-v3.c

+17 −8
Original line number Original line 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! */

	/* And we're up. Go go go! */

	of_iommu_set_ops(dev->of_node, &arm_smmu_ops);

	of_iommu_set_ops(dev->of_node, &arm_smmu_ops);

#ifdef CONFIG_PCI

#ifdef CONFIG_PCI

	if (pci_bus_type.iommu_ops != &arm_smmu_ops) {

		pci_request_acs();

		pci_request_acs();

		ret = bus_set_iommu(&pci_bus_type, &arm_smmu_ops);

		ret = bus_set_iommu(&pci_bus_type, &arm_smmu_ops);

		if (ret)

		if (ret)

			return ret;

			return ret;

	}

#endif

#endif

#ifdef CONFIG_ARM_AMBA

#ifdef CONFIG_ARM_AMBA

	if (amba_bustype.iommu_ops != &arm_smmu_ops) {

		ret = bus_set_iommu(&amba_bustype, &arm_smmu_ops);

		ret = bus_set_iommu(&amba_bustype, &arm_smmu_ops);

		if (ret)

		if (ret)

			return ret;

			return ret;

	}

#endif

#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)

static int arm_smmu_device_remove(struct platform_device *pdev)