int cpufreq_table_index_unsorted()

in freq_table.c [118:208]

• 85 lines of code
• 21 McCabe index (conditional complexity)

int cpufreq_table_index_unsorted(struct cpufreq_policy *policy,
				 unsigned int target_freq,
				 unsigned int relation)
{
	struct cpufreq_frequency_table optimal = {
		.driver_data = ~0,
		.frequency = 0,
	};
	struct cpufreq_frequency_table suboptimal = {
		.driver_data = ~0,
		.frequency = 0,
	};
	struct cpufreq_frequency_table *pos;
	struct cpufreq_frequency_table *table = policy->freq_table;
	unsigned int freq, diff, i = 0;
	int index;

	pr_debug("request for target %u kHz (relation: %u) for cpu %u\n",
					target_freq, relation, policy->cpu);

	switch (relation) {
	case CPUFREQ_RELATION_H:
		suboptimal.frequency = ~0;
		break;
	case CPUFREQ_RELATION_L:
	case CPUFREQ_RELATION_C:
		optimal.frequency = ~0;
		break;
	}

	cpufreq_for_each_valid_entry_idx(pos, table, i) {
		freq = pos->frequency;

		if ((freq < policy->min) || (freq > policy->max))
			continue;
		if (freq == target_freq) {
			optimal.driver_data = i;
			break;
		}
		switch (relation) {
		case CPUFREQ_RELATION_H:
			if (freq < target_freq) {
				if (freq >= optimal.frequency) {
					optimal.frequency = freq;
					optimal.driver_data = i;
				}
			} else {
				if (freq <= suboptimal.frequency) {
					suboptimal.frequency = freq;
					suboptimal.driver_data = i;
				}
			}
			break;
		case CPUFREQ_RELATION_L:
			if (freq > target_freq) {
				if (freq <= optimal.frequency) {
					optimal.frequency = freq;
					optimal.driver_data = i;
				}
			} else {
				if (freq >= suboptimal.frequency) {
					suboptimal.frequency = freq;
					suboptimal.driver_data = i;
				}
			}
			break;
		case CPUFREQ_RELATION_C:
			diff = abs(freq - target_freq);
			if (diff < optimal.frequency ||
			    (diff == optimal.frequency &&
			     freq > table[optimal.driver_data].frequency)) {
				optimal.frequency = diff;
				optimal.driver_data = i;
			}
			break;
		}
	}
	if (optimal.driver_data > i) {
		if (suboptimal.driver_data > i) {
			WARN(1, "Invalid frequency table: %d\n", policy->cpu);
			return 0;
		}

		index = suboptimal.driver_data;
	} else
		index = optimal.driver_data;

	pr_debug("target index is %u, freq is:%u kHz\n", index,
		 table[index].frequency);
	return index;
}