[Skiboot] [PATCH v3] occ/prd/opal-prd: Queue OCC_RESET event message to host in OpenPOWER

[Shilpasri G Bhat]

Hi,

On 04/18/2016 04:46 PM, Shilpasri G Bhat wrote:
> During an OCC reset cycle the system is forced to Psafe pstate.
> When OCC becomes active, the system has to be restored to its
> last pstate as requested by host. So host needs to be notified
> of OCC_RESET event or else system will continue to remian in
> Psafe state until host requests a new pstate after the OCC
> reset cycle.
> 
> This patch defines 'OPAL_PRD_MSG_TYPE_OCC_RESET_NOTIFY' to
> notify OPAL when opal-prd issues OCC reset. OPAL will queue
> OCC_RESET message to host when it receives opal_prd_msg of
> type '*_OCC_RESET_NOTIFY'.
> 
> Signed-off-by: Shilpasri G Bhat <shilpa.bhat at linux.vnet.ibm.com>
> ---

Below are the test results:

- Set all cores to nominal frequency using userspace governor.
# echo userspace | tee /sys/devices/system/cpu/cpufreq/policy*/scaling_governor
userspace
# cat /sys/devices/system/cpu/cpufreq/policy0/cpuinfo_nominal_freq | tee
/sys/devices/system/cpu/cpufreq/policy*/scaling_setspeed
2926000

- Issue OCC reset using opal-prd

I) Without patch:
root at fir01:/home/shilpa/skiboot/external/xscom-utils# for i in
{2,3,4,5,6,A,B,D,E}; do ./getscom -c 0 0x1${i}0F0153; done
efefd50008000000
efefd50008000000
efefd50008000000
efefd50008000000
efefd50008000000
efefd50008000000
efefd50008000000
efefd50008000000
efefd50008000000
root at fir01:/home/shilpa/skiboot/external/xscom-utils# opal-prd occ reset
root at fir01:/home/shilpa/skiboot/external/xscom-utils# for i in
{1,3,4,5,6,9,A,B,E}; do ./getscom -c 8 0x1${i}0F0153; done
d4d4d50008000000
d4d4d50008000000
d4d4d50008000000
d4d4d50008000000
d4d4d50008000000
d4d4d50008000000
d4d4d50008000000
d4d4d50008000000
d4d4d50008000000


II) With patch:

root at fir01:/home/shilpa/skiboot/external/xscom-utils# ../opal-prd/opal-prd occ reset
root at fir01:/home/shilpa/skiboot/external/xscom-utils# dmesg | grep pufreq
[    3.693786] powernv-cpufreq: cpufreq pstate min -43 nominal -17 max 0
[  357.743916] powernv-cpufreq: OCC (On Chip Controller - enforces hard
thermal/power limits) Resetting
[  357.743920] powernv-cpufreq: CPU frequency is throttled for duration
[  366.573778] powernv-cpufreq: OCC Active, CPU frequency is no longer throttled
root at fir01:/home/shilpa/skiboot/external/xscom-utils# for i in
{1,3,4,5,6,9,A,B,E}; do ./getscom -c 8 0x1${i}0F0153; done
efefd50008000000
efefd50008000000
efefd50008000000
efefd50008000000
efefd50008000000
efefd50008000000
efefd50008000000
efefd50008000000
efefd50008000000

Thanks and Regards,
Shilpa