Function cf_levels_method

freebsd/kern/kern_cpu.c:632–724

}

static int
cf_levels_method(device_t dev, struct cf_level *levels, int *count)
{
	struct cf_setting_array *set_arr;
	struct cf_setting_lst rel_sets;
	struct cpufreq_softc *sc;
	struct cf_level *lev;
	struct pcpu *pc;
	int error, i;
	uint64_t rate;

	if (levels == NULL || count == NULL)
		return (EINVAL);

	TAILQ_INIT(&rel_sets);
	sc = device_get_softc(dev);

	CF_MTX_LOCK(&sc->lock);
	error = cpufreq_add_levels(sc->dev, &rel_sets);
	if (error)
		goto out;

	/*
	 * If there are no absolute levels, create a fake one at 100%.  We
	 * then cache the clockrate for later use as our base frequency.
	 */
	if (TAILQ_EMPTY(&sc->all_levels)) {
		struct cf_setting set;

		CF_DEBUG("No absolute levels returned by driver\n");

		if (sc->max_mhz == CPUFREQ_VAL_UNKNOWN) {
			sc->max_mhz = cpu_get_nominal_mhz(dev);
			/*
			 * If the CPU can't report a rate for 100%, hope
			 * the CPU is running at its nominal rate right now,
			 * and use that instead.
			 */
			if (sc->max_mhz <= 0) {
				pc = cpu_get_pcpu(dev);
				cpu_est_clockrate(pc->pc_cpuid, &rate);
				sc->max_mhz = rate / 1000000;
			}
		}
		memset(&set, CPUFREQ_VAL_UNKNOWN, sizeof(set));
		set.freq = sc->max_mhz;
		set.dev = NULL;
		error = cpufreq_insert_abs(sc, &set, 1);
		if (error)
			goto out;
	}

	/* Create a combined list of absolute + relative levels. */
	TAILQ_FOREACH(set_arr, &rel_sets, link)
		cpufreq_expand_set(sc, set_arr);

	/* If the caller doesn't have enough space, return the actual count. */
	if (sc->all_count > *count) {