In the sysvad example, I have added a IOControlHandler to the driver after
the call to PcInitializeAdapterDriver() :
DriverObject->MajorFunction[IRP_MJ_DEVICE_CONTROL] = DeviceControlHandler;
From the DeviceControlHandler callback, I can get a handle to the common
adapter via DeviceObject->DeviceExtension.
How can I determine which subdevice in the m_SubdeviceCache is being
referenced using the available parameters (DEVICE_OBJECT and IRP)