static int ddr_perf_event_init()

in fsl_imx8_ddr_perf.c [368:413]

• 33 lines of code
• 12 McCabe index (conditional complexity)

static int ddr_perf_event_init(struct perf_event *event)
{
	struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
	struct hw_perf_event *hwc = &event->hw;
	struct perf_event *sibling;

	if (event->attr.type != event->pmu->type)
		return -ENOENT;

	if (is_sampling_event(event) || event->attach_state & PERF_ATTACH_TASK)
		return -EOPNOTSUPP;

	if (event->cpu < 0) {
		dev_warn(pmu->dev, "Can't provide per-task data!\n");
		return -EOPNOTSUPP;
	}

	/*
	 * We must NOT create groups containing mixed PMUs, although software
	 * events are acceptable (for example to create a CCN group
	 * periodically read when a hrtimer aka cpu-clock leader triggers).
	 */
	if (event->group_leader->pmu != event->pmu &&
			!is_software_event(event->group_leader))
		return -EINVAL;

	if (pmu->devtype_data->quirks & DDR_CAP_AXI_ID_FILTER) {
		if (!ddr_perf_filters_compatible(event, event->group_leader))
			return -EINVAL;
		for_each_sibling_event(sibling, event->group_leader) {
			if (!ddr_perf_filters_compatible(event, sibling))
				return -EINVAL;
		}
	}

	for_each_sibling_event(sibling, event->group_leader) {
		if (sibling->pmu != event->pmu &&
				!is_software_event(sibling))
			return -EINVAL;
	}

	event->cpu = pmu->cpu;
	hwc->idx = -1;

	return 0;
}