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
diff --git a/services/std_svc/psci/psci_common.c b/services/std_svc/psci/psci_common.c
index 8a2b81c..5090037 100644
--- a/services/std_svc/psci/psci_common.c
+++ b/services/std_svc/psci/psci_common.c
@@ -711,6 +711,16 @@
psci_acquire_pwr_domain_locks(end_pwrlvl,
cpu_idx);
+#if ENABLE_PSCI_STAT
+ /*
+ * Capture power up time-stamp.
+ * No cache maintenance is required as caches are off
+ * and writes are direct to the main memory.
+ */
+ PMF_CAPTURE_TIMESTAMP(psci_svc, PSCI_STAT_ID_EXIT_LOW_PWR,
+ PMF_NO_CACHE_MAINT);
+#endif
+
psci_get_target_local_pwr_states(end_pwrlvl, &state_info);
/*
@@ -736,6 +746,16 @@
*/
psci_set_pwr_domains_to_run(end_pwrlvl);
+#if ENABLE_PSCI_STAT
+ /*
+ * Update PSCI stats.
+ * Caches are off when writing stats data on the power down path.
+ * Since caches are now enabled, it's necessary to do cache
+ * maintenance before reading that same data.
+ */
+ psci_stats_update_pwr_up(end_pwrlvl, &state_info, PMF_CACHE_MAINT);
+#endif
+
/*
* This loop releases the lock corresponding to each power level
* in the reverse order to which they were acquired.