[PATCH] iommu/arm-smmu: Expunge redundant iommu_present() checks
From: robin.murphy@arm.com (Robin Murphy)
Date: 2016-10-26 10:37:39
Also in:
linux-iommu
Subsystem:
iommu subsystem, the rest · Maintainers:
Joerg Roedel, Will Deacon, Linus Torvalds
The first thing bus_set_iommu() does is check if iommu_ops are already installed on the given bus, and immediately return -EBUSY if so. Since the return value makes no difference as we ignore it anyway, there is no need to redundantly duplicate that check by explicitly calling iommu_present() beforehand. This does bring the slight change that we may now end up calling pci_request_acs() multiple times, but as that does nothing but set a variable to 1, the impact should be effectively zero. Signed-off-by: Robin Murphy <robin.murphy@arm.com> --- drivers/iommu/arm-smmu.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-)
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index c841eb7a1a74..ef978db2bb54 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c@@ -2000,17 +2000,13 @@ static int arm_smmu_device_dt_probe(struct platform_device *pdev) arm_smmu_device_reset(smmu); /* Oh, for a proper bus abstraction */ - if (!iommu_present(&platform_bus_type)) - bus_set_iommu(&platform_bus_type, &arm_smmu_ops); + bus_set_iommu(&platform_bus_type, &arm_smmu_ops); #ifdef CONFIG_ARM_AMBA - if (!iommu_present(&amba_bustype)) - bus_set_iommu(&amba_bustype, &arm_smmu_ops); + bus_set_iommu(&amba_bustype, &arm_smmu_ops); #endif #ifdef CONFIG_PCI - if (!iommu_present(&pci_bus_type)) { - pci_request_acs(); - bus_set_iommu(&pci_bus_type, &arm_smmu_ops); - } + pci_request_acs(); + bus_set_iommu(&pci_bus_type, &arm_smmu_ops); #endif return 0; }
--
1.9.1