iommu/arm-smmu: Correct group reference count
The basic flow for add a device:
arm_smmu_add_device
|->iommu_group_get_for_dev
|->iommu_group_get
return group; (1)
|->ops->device_group : Init/increase reference count to/by 1.
|->iommu_group_add_device : Increase reference count by 1.
return group (2)
|->return 0;
Since we are adding one device, the flow is (2) and the group reference
count will be increased by 2. So, we need to add iommu_group_put at the
end of arm_smmu_add_device to decrease the count by 1.
Also take the failure path into consideration when fail to add a device.
Signed-off-by: Peng Fan <van.freenix@gmail.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2 files changed