tree 456974555d3eb0b9a704198235884b9dd2314545
parent 9518d02f12181ab91b401ae4eb5ada204b67a2f9
author Yatharth Kochar <yatharth.kochar@arm.com> 1462814795 +0100
committer Soby Mathew <soby.mathew@arm.com> 1466063700 +0100

Add optional PSCI STAT residency & count functions

This patch adds following optional PSCI STAT functions:

- PSCI_STAT_RESIDENCY: This call returns the amount of time spent
  in power_state in microseconds, by the node represented by the
  `target_cpu` and the highest level of `power_state`.

- PSCI_STAT_COUNT: This call returns the number of times a
  `power_state` has been used by the node represented by the
  `target_cpu` and the highest power level of `power_state`.

These APIs provides residency statistics for power states that has
been used by the platform. They are implemented according to v1.0
of the PSCI specification.

By default this optional feature is disabled in the PSCI
implementation. To enable it, set the boolean flag
`ENABLE_PSCI_STAT` to 1. This also sets `ENABLE_PMF` to 1.

Change-Id: Ie62e9d37d6d416ccb1813acd7f616d1ddd3e8aff