Add stats functions to track what is happening in the driver, and put
unit tests to check those.
Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Acked-by: Anatoly Burakov <anatoly.burakov@intel.com>
Acked-by: Jiayu Hu <jiayu.hu@intel.com>
Tested-by: Harry van Haaren <harry.van.haaren@intel.com>