static void __init intel_idle_init_cstates_acpi()

in intel_idle.c [1276:1324]

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

static void __init intel_idle_init_cstates_acpi(struct cpuidle_driver *drv)
{
	int cstate, limit = min_t(int, CPUIDLE_STATE_MAX, acpi_state_table.count);

	/*
	 * If limit > 0, intel_idle_cst_usable() has returned 'true', so all of
	 * the interesting states are ACPI_CSTATE_FFH.
	 */
	for (cstate = 1; cstate < limit; cstate++) {
		struct acpi_processor_cx *cx;
		struct cpuidle_state *state;

		if (intel_idle_max_cstate_reached(cstate - 1))
			break;

		cx = &acpi_state_table.states[cstate];

		state = &drv->states[drv->state_count++];

		snprintf(state->name, CPUIDLE_NAME_LEN, "C%d_ACPI", cstate);
		strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
		state->exit_latency = cx->latency;
		/*
		 * For C1-type C-states use the same number for both the exit
		 * latency and target residency, because that is the case for
		 * C1 in the majority of the static C-states tables above.
		 * For the other types of C-states, however, set the target
		 * residency to 3 times the exit latency which should lead to
		 * a reasonable balance between energy-efficiency and
		 * performance in the majority of interesting cases.
		 */
		state->target_residency = cx->latency;
		if (cx->type > ACPI_STATE_C1)
			state->target_residency *= 3;

		state->flags = MWAIT2flg(cx->address);
		if (cx->type > ACPI_STATE_C2)
			state->flags |= CPUIDLE_FLAG_TLB_FLUSHED;

		if (disabled_states_mask & BIT(cstate))
			state->flags |= CPUIDLE_FLAG_OFF;

		if (intel_idle_state_needs_timer_stop(state))
			state->flags |= CPUIDLE_FLAG_TIMER_STOP;

		state->enter = intel_idle;
		state->enter_s2idle = intel_idle_s2idle;
	}
}