[tesla-dev] c-state info kstat implementation

[Li, Aubrey]

kstat for c-state info is implemented as below:

changelog: add c-state info kstat implementation 

io/cpu_idle.c  |   78
++++++++++++++++++++++++++++++++++++++++++++++++++++++---
sys/cpu_idle.h |    8 +++++
2 files changed, 82 insertions(+), 4 deletions(-)

Any suggestions and comments are really welcome!

Thanks,
-Aubrey

================
[aubrey-sz330p at cpupm-gate]kstat | grep max_cstate
        supported_max_cstates           2
        supported_max_cstates           2

[aubrey-sz330p at cpupm-gate]kstat -m cpudrv
module: cpudrv                          instance: 0     
name:   c1                              class:    misc
        address_space_id                SystemIO
        crtime                          30.895350977
        latency                         1
        power                           1000
        snaptime                        750.118353972

module: cpudrv                          instance: 0     
name:   c2                              class:    misc
        address_space_id                SystemIO
        crtime                          30.895354847
        latency                         1
        power                           500
        snaptime                        750.118719027

module: cpudrv                          instance: 1     
name:   c1                              class:    misc
        address_space_id                SystemIO
        crtime                          36.93058991
        latency                         1
        power                           1000
        snaptime                        750.118903351

module: cpudrv                          instance: 1     
name:   c2                              class:    misc
        address_space_id                SystemIO
        crtime                          36.930593576
        latency                         1
        power                           500
        snaptime                        750.119070612
================