diff options
Diffstat (limited to 'drivers/bus')
| -rw-r--r-- | drivers/bus/arm-cci.c | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/drivers/bus/arm-cci.c b/drivers/bus/arm-cci.c index d28903712eb8..7ce7da0a17c7 100644 --- a/drivers/bus/arm-cci.c +++ b/drivers/bus/arm-cci.c @@ -719,6 +719,44 @@ static void pmu_set_event(struct cci_pmu *cci_pmu, int idx, unsigned long event) } /* + * For all counters on the CCI-PMU, disable any 'enabled' counters, + * saving the changed counters in the mask, so that we can restore + * it later using pmu_restore_counters. The mask is private to the + * caller. We cannot rely on the used_mask maintained by the CCI_PMU + * as it only tells us if the counter is assigned to perf_event or not. + * The state of the perf_event cannot be locked by the PMU layer, hence + * we check the individual counter status (which can be locked by + * cci_pm->hw_events->pmu_lock). + * + * @mask should be initialised to empty by the caller. + */ +static void __maybe_unused +pmu_save_counters(struct cci_pmu *cci_pmu, unsigned long *mask) +{ + int i; + + for (i = 0; i < cci_pmu->num_cntrs; i++) { + if (pmu_counter_is_enabled(cci_pmu, i)) { + set_bit(i, mask); + pmu_disable_counter(cci_pmu, i); + } + } +} + +/* + * Restore the status of the counters. Reversal of the pmu_save_counters(). + * For each counter set in the mask, enable the counter back. + */ +static void __maybe_unused +pmu_restore_counters(struct cci_pmu *cci_pmu, unsigned long *mask) +{ + int i; + + for_each_set_bit(i, mask, cci_pmu->num_cntrs) + pmu_enable_counter(cci_pmu, i); +} + +/* * Returns the number of programmable counters actually implemented * by the cci */ |