int cpufreq_dbs_governor_init()

in cpufreq_governor.c [391:474]

• 58 lines of code
• 10 McCabe index (conditional complexity)

int cpufreq_dbs_governor_init(struct cpufreq_policy *policy)
{
	struct dbs_governor *gov = dbs_governor_of(policy);
	struct dbs_data *dbs_data;
	struct policy_dbs_info *policy_dbs;
	int ret = 0;

	/* State should be equivalent to EXIT */
	if (policy->governor_data)
		return -EBUSY;

	policy_dbs = alloc_policy_dbs_info(policy, gov);
	if (!policy_dbs)
		return -ENOMEM;

	/* Protect gov->gdbs_data against concurrent updates. */
	mutex_lock(&gov_dbs_data_mutex);

	dbs_data = gov->gdbs_data;
	if (dbs_data) {
		if (WARN_ON(have_governor_per_policy())) {
			ret = -EINVAL;
			goto free_policy_dbs_info;
		}
		policy_dbs->dbs_data = dbs_data;
		policy->governor_data = policy_dbs;

		gov_attr_set_get(&dbs_data->attr_set, &policy_dbs->list);
		goto out;
	}

	dbs_data = kzalloc(sizeof(*dbs_data), GFP_KERNEL);
	if (!dbs_data) {
		ret = -ENOMEM;
		goto free_policy_dbs_info;
	}

	gov_attr_set_init(&dbs_data->attr_set, &policy_dbs->list);

	ret = gov->init(dbs_data);
	if (ret)
		goto free_policy_dbs_info;

	/*
	 * The sampling interval should not be less than the transition latency
	 * of the CPU and it also cannot be too small for dbs_update() to work
	 * correctly.
	 */
	dbs_data->sampling_rate = max_t(unsigned int,
					CPUFREQ_DBS_MIN_SAMPLING_INTERVAL,
					cpufreq_policy_transition_delay_us(policy));

	if (!have_governor_per_policy())
		gov->gdbs_data = dbs_data;

	policy_dbs->dbs_data = dbs_data;
	policy->governor_data = policy_dbs;

	gov->kobj_type.sysfs_ops = &governor_sysfs_ops;
	ret = kobject_init_and_add(&dbs_data->attr_set.kobj, &gov->kobj_type,
				   get_governor_parent_kobj(policy),
				   "%s", gov->gov.name);
	if (!ret)
		goto out;

	/* Failure, so roll back. */
	pr_err("initialization failed (dbs_data kobject init error %d)\n", ret);

	kobject_put(&dbs_data->attr_set.kobj);

	policy->governor_data = NULL;

	if (!have_governor_per_policy())
		gov->gdbs_data = NULL;
	gov->exit(dbs_data);
	kfree(dbs_data);

free_policy_dbs_info:
	free_policy_dbs_info(policy_dbs, gov);

out:
	mutex_unlock(&gov_dbs_data_mutex);
	return ret;
}