static int arm_cmn_event_add()

in arm-cmn.c [1287:1392]

• 82 lines of code
• 19 McCabe index (conditional complexity)

static int arm_cmn_event_add(struct perf_event *event, int flags)
{
	struct arm_cmn *cmn = to_cmn(event->pmu);
	struct arm_cmn_hw_event *hw = to_cmn_hw(event);
	struct arm_cmn_dtc *dtc = &cmn->dtc[0];
	struct arm_cmn_node *dn;
	enum cmn_node_type type = CMN_EVENT_TYPE(event);
	unsigned int i, dtc_idx, input_sel;

	if (type == CMN_TYPE_DTC) {
		i = 0;
		while (cmn->dtc[i].cycles)
			if (++i == cmn->num_dtcs)
				return -ENOSPC;

		cmn->dtc[i].cycles = event;
		hw->dtc_idx = CMN_DT_NUM_COUNTERS;
		hw->dtcs_used = 1U << i;

		if (flags & PERF_EF_START)
			arm_cmn_event_start(event, 0);
		return 0;
	}

	/* Grab a free global counter first... */
	dtc_idx = 0;
	while (dtc->counters[dtc_idx])
		if (++dtc_idx == CMN_DT_NUM_COUNTERS)
			return -ENOSPC;

	hw->dtc_idx = dtc_idx;

	/* ...then the local counters to feed it. */
	for_each_hw_dn(hw, dn, i) {
		struct arm_cmn_dtm *dtm = &cmn->dtms[dn->dtm] + hw->dtm_offset;
		unsigned int dtm_idx, shift;
		u64 reg;

		dtm_idx = 0;
		while (dtm->pmu_config_low & CMN__PMEVCNT_PAIRED(dtm_idx))
			if (++dtm_idx == CMN_DTM_NUM_COUNTERS)
				goto free_dtms;

		if (type == CMN_TYPE_XP) {
			input_sel = CMN__PMEVCNT0_INPUT_SEL_XP + dtm_idx;
		} else if (type == CMN_TYPE_WP) {
			int tmp, wp_idx = arm_cmn_wp_idx(event);
			u32 cfg = arm_cmn_wp_config(event);

			if (dtm->wp_event[wp_idx] >= 0)
				goto free_dtms;

			tmp = dtm->wp_event[wp_idx ^ 1];
			if (tmp >= 0 && CMN_EVENT_WP_COMBINE(event) !=
					CMN_EVENT_WP_COMBINE(dtc->counters[tmp]))
				goto free_dtms;

			input_sel = CMN__PMEVCNT0_INPUT_SEL_WP + wp_idx;
			dtm->wp_event[wp_idx] = dtc_idx;
			writel_relaxed(cfg, dtm->base + CMN_DTM_WPn_CONFIG(wp_idx));
		} else {
			struct arm_cmn_nodeid nid = arm_cmn_nid(cmn, dn->id);

			if (cmn->multi_dtm)
				nid.port %= 2;

			input_sel = CMN__PMEVCNT0_INPUT_SEL_DEV + dtm_idx +
				    (nid.port << 4) + (nid.dev << 2);

			if (arm_cmn_is_occup_event(cmn->model, type, CMN_EVENT_EVENTID(event))) {
				u8 occupid = CMN_EVENT_OCCUPID(event);

				if (dn->occupid_count == 0) {
					dn->occupid_val = occupid;
					writel_relaxed(occupid,
						       dn->pmu_base + CMN_PMU_EVENT_SEL + 4);
				} else if (dn->occupid_val != occupid) {
					goto free_dtms;
				}
				dn->occupid_count++;
			}
		}

		arm_cmn_set_index(hw->dtm_idx, i, dtm_idx);

		dtm->input_sel[dtm_idx] = input_sel;
		shift = CMN__PMEVCNTn_GLOBAL_NUM_SHIFT(dtm_idx);
		dtm->pmu_config_low &= ~(CMN__PMEVCNT0_GLOBAL_NUM << shift);
		dtm->pmu_config_low |= FIELD_PREP(CMN__PMEVCNT0_GLOBAL_NUM, dtc_idx) << shift;
		dtm->pmu_config_low |= CMN__PMEVCNT_PAIRED(dtm_idx);
		reg = (u64)le32_to_cpu(dtm->pmu_config_high) << 32 | dtm->pmu_config_low;
		writeq_relaxed(reg, dtm->base + CMN_DTM_PMU_CONFIG);
	}

	/* Go go go! */
	arm_cmn_init_counter(event);

	if (flags & PERF_EF_START)
		arm_cmn_event_start(event, 0);

	return 0;

free_dtms:
	arm_cmn_event_clear(cmn, event, i);
	return -ENOSPC;
}