diff options
| author | Robin Murphy <robin.murphy@arm.com> | 2016-11-03 17:39:07 +0000 |
|---|---|---|
| committer | Joerg Roedel <jroedel@suse.de> | 2016-11-08 14:46:41 +0100 |
| commit | ec615f43d3b61edcfdc4d8d1f672be1059573d1b (patch) | |
| tree | ba64026a7ea18e1036634a9664d05782d1f85a81 | |
| parent | fba4f8e5c49443ddb1511f8f548ac801a693d7b7 (diff) | |
| download | linux-ec615f43d3b61edcfdc4d8d1f672be1059573d1b.tar.bz2 | |
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: 08d4ca2a672b ("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>
| -rw-r--r-- | drivers/iommu/arm-smmu-v3.c | 25 |
1 files changed, 17 insertions, 8 deletions
diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c index 15c01c3cd540..e6f9b2d745ca 100644 --- a/drivers/iommu/arm-smmu-v3.c +++ b/drivers/iommu/arm-smmu-v3.c @@ -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 - pci_request_acs(); - ret = bus_set_iommu(&pci_bus_type, &arm_smmu_ops); - if (ret) - return ret; + 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 - ret = bus_set_iommu(&amba_bustype, &arm_smmu_ops); - if (ret) - return ret; + 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) |