static int nds32_pmu_event_init()

in kernel/perf_event_cpu.c [857:886]

• 21 lines of code
• 7 McCabe index (conditional complexity)

static int nds32_pmu_event_init(struct perf_event *event)
{
	struct nds32_pmu *nds32_pmu = to_nds32_pmu(event->pmu);
	int err = 0;
	atomic_t *active_events = &nds32_pmu->active_events;

	/* does not support taken branch sampling */
	if (has_branch_stack(event))
		return -EOPNOTSUPP;

	if (nds32_pmu->map_event(event) == -ENOENT)
		return -ENOENT;

	if (!atomic_inc_not_zero(active_events)) {
		if (atomic_read(active_events) == 0) {
			/* Register irq handler */
			err = nds32_pmu_reserve_hardware(nds32_pmu);
		}

		if (!err)
			atomic_inc(active_events);
	}

	if (err)
		return err;

	err = __hw_perf_event_init(event);

	return err;
}