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authorRobin Murphy <robin.murphy@arm.com>2016-11-03 17:39:07 +0000
committerJoerg Roedel <jroedel@suse.de>2016-11-08 14:46:41 +0100
commitec615f43d3b61edcfdc4d8d1f672be1059573d1b (patch)
treeba64026a7ea18e1036634a9664d05782d1f85a81
parentfba4f8e5c49443ddb1511f8f548ac801a693d7b7 (diff)
downloadlinux-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.c25
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)