diff options
| author | dp-arm <dimitris.papastamos@arm.com> | 2017-01-31 13:01:04 +0000 |
|---|---|---|
| committer | dp-arm <dimitris.papastamos@arm.com> | 2017-02-13 14:33:06 +0000 |
| commit | 04c1db1e574604081bfdcec3d26e662535812eaa (patch) | |
| tree | cf2764a5c729dd413c74f5d1abf5ea306957ea8e /docs/user-guide.md | |
| parent | bab16f9912c6a2ea7600e8d713c1eebf8f0c11d7 (diff) | |
PSCI: Decouple PSCI stat residency calculation from PMF
This patch introduces the following three platform interfaces:
* void plat_psci_stat_accounting_start(const psci_power_state_t *state_info)
This is an optional hook that platforms can implement in order
to perform accounting before entering a low power state. This
typically involves capturing a timestamp.
* void plat_psci_stat_accounting_stop(const psci_power_state_t *state_info)
This is an optional hook that platforms can implement in order
to perform accounting after exiting from a low power state. This
typically involves capturing a timestamp.
* u_register_t plat_psci_stat_get_residency(unsigned int lvl,
const psci_power_state_t *state_info,
unsigned int last_cpu_index)
This is an optional hook that platforms can implement in order
to calculate the PSCI stat residency.
If any of these interfaces are overridden by the platform, it is
recommended that all of them are.
By default `ENABLE_PSCI_STAT` is disabled. If `ENABLE_PSCI_STAT`
is set but `ENABLE_PMF` is not set then an alternative PSCI stat
collection backend must be provided. If both are set, then default
weak definitions of these functions are provided, using PMF to
calculate the residency.
NOTE: Previously, platforms did not have to explicitly set
`ENABLE_PMF` since this was automatically done by the top-level
Makefile.
Change-Id: I17b47804dea68c77bc284df15ee1ccd66bc4b79b
Signed-off-by: dp-arm <dimitris.papastamos@arm.com>
Diffstat (limited to 'docs/user-guide.md')
| -rw-r--r-- | docs/user-guide.md | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/docs/user-guide.md b/docs/user-guide.md index ebdb5a25..265061c4 100644 --- a/docs/user-guide.md +++ b/docs/user-guide.md @@ -274,8 +274,9 @@ performed. * `ENABLE_PSCI_STAT`: Boolean option to enable support for optional PSCI functions `PSCI_STAT_RESIDENCY` and `PSCI_STAT_COUNT`. Default is 0. - Enabling this option enables the `ENABLE_PMF` build option as well. - The PMF is used for collecting the statistics. + In the absence of an alternate stat collection backend, `ENABLE_PMF` must + be enabled. If `ENABLE_PMF` is set, the residency statistics are tracked in + software. * `ENABLE_RUNTIME_INSTRUMENTATION`: Boolean option to enable runtime instrumentation which injects timestamp collection points into |