Function cpufreq_dup_set

freebsd/kern/kern_cpu.c:840–933

}

static struct cf_level *
cpufreq_dup_set(struct cpufreq_softc *sc, struct cf_level *dup,
    struct cf_setting *set)
{
	struct cf_level_lst *list;
	struct cf_level *fill, *itr;
	struct cf_setting *fill_set, *itr_set;
	int i;

	CF_MTX_ASSERT(&sc->lock);

	/*
	 * Create a new level, copy it from the old one, and update the
	 * total frequency and power by the percentage specified in the
	 * relative setting.
	 */
	fill = malloc(sizeof(*fill), M_TEMP, M_NOWAIT);
	if (fill == NULL)
		return (NULL);
	*fill = *dup;
	fill_set = &fill->total_set;
	fill_set->freq =
	    ((uint64_t)fill_set->freq * set->freq) / 10000;
	if (fill_set->power != CPUFREQ_VAL_UNKNOWN) {
		fill_set->power = ((uint64_t)fill_set->power * set->freq)
		    / 10000;
	}
	if (set->lat != CPUFREQ_VAL_UNKNOWN) {
		if (fill_set->lat != CPUFREQ_VAL_UNKNOWN)
			fill_set->lat += set->lat;
		else
			fill_set->lat = set->lat;
	}
	CF_DEBUG("dup set considering derived setting %d\n", fill_set->freq);

	/*
	 * If we copied an old level that we already modified (say, at 100%),
	 * we need to remove that setting before adding this one.  Since we
	 * process each setting array in order, we know any settings for this
	 * driver will be found at the end.
	 */
	for (i = fill->rel_count; i != 0; i--) {
		if (fill->rel_set[i - 1].dev != set->dev)
			break;
		CF_DEBUG("removed last relative driver: %s\n",
		    device_get_nameunit(set->dev));
		fill->rel_count--;
	}

	/*
	 * Insert the new level in sorted order.  If it is a duplicate of an
	 * existing level (1) or has an absolute setting higher than the
	 * existing level (2), do not add it.  We can do this since any such
	 * level is guaranteed use less power.  For example (1), a level with
	 * one absolute setting of 800 Mhz uses less power than one composed
	 * of an absolute setting of 1600 Mhz and a relative setting at 50%.
	 * Also for example (2), a level of 800 Mhz/75% is preferable to
	 * 1600 Mhz/25% even though the latter has a lower total frequency.