int acpi_processor_preregister_performance()

in processor_perflib.c [568:716]

• 111 lines of code
• 26 McCabe index (conditional complexity)

int acpi_processor_preregister_performance(
		struct acpi_processor_performance __percpu *performance)
{
	int count_target;
	int retval = 0;
	unsigned int i, j;
	cpumask_var_t covered_cpus;
	struct acpi_processor *pr;
	struct acpi_psd_package *pdomain;
	struct acpi_processor *match_pr;
	struct acpi_psd_package *match_pdomain;

	if (!zalloc_cpumask_var(&covered_cpus, GFP_KERNEL))
		return -ENOMEM;

	mutex_lock(&performance_mutex);

	/*
	 * Check if another driver has already registered, and abort before
	 * changing pr->performance if it has. Check input data as well.
	 */
	for_each_possible_cpu(i) {
		pr = per_cpu(processors, i);
		if (!pr) {
			/* Look only at processors in ACPI namespace */
			continue;
		}

		if (pr->performance) {
			retval = -EBUSY;
			goto err_out;
		}

		if (!performance || !per_cpu_ptr(performance, i)) {
			retval = -EINVAL;
			goto err_out;
		}
	}

	/* Call _PSD for all CPUs */
	for_each_possible_cpu(i) {
		pr = per_cpu(processors, i);
		if (!pr)
			continue;

		pr->performance = per_cpu_ptr(performance, i);
		pdomain = &(pr->performance->domain_info);
		if (acpi_processor_get_psd(pr->handle, pdomain)) {
			retval = -EINVAL;
			continue;
		}
	}
	if (retval)
		goto err_ret;

	/*
	 * Now that we have _PSD data from all CPUs, lets setup P-state
	 * domain info.
	 */
	for_each_possible_cpu(i) {
		pr = per_cpu(processors, i);
		if (!pr)
			continue;

		if (cpumask_test_cpu(i, covered_cpus))
			continue;

		pdomain = &(pr->performance->domain_info);
		cpumask_set_cpu(i, pr->performance->shared_cpu_map);
		cpumask_set_cpu(i, covered_cpus);
		if (pdomain->num_processors <= 1)
			continue;

		/* Validate the Domain info */
		count_target = pdomain->num_processors;
		if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ALL)
			pr->performance->shared_type = CPUFREQ_SHARED_TYPE_ALL;
		else if (pdomain->coord_type == DOMAIN_COORD_TYPE_HW_ALL)
			pr->performance->shared_type = CPUFREQ_SHARED_TYPE_HW;
		else if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ANY)
			pr->performance->shared_type = CPUFREQ_SHARED_TYPE_ANY;

		for_each_possible_cpu(j) {
			if (i == j)
				continue;

			match_pr = per_cpu(processors, j);
			if (!match_pr)
				continue;

			match_pdomain = &(match_pr->performance->domain_info);
			if (match_pdomain->domain != pdomain->domain)
				continue;

			/* Here i and j are in the same domain */

			if (match_pdomain->num_processors != count_target) {
				retval = -EINVAL;
				goto err_ret;
			}

			if (pdomain->coord_type != match_pdomain->coord_type) {
				retval = -EINVAL;
				goto err_ret;
			}

			cpumask_set_cpu(j, covered_cpus);
			cpumask_set_cpu(j, pr->performance->shared_cpu_map);
		}

		for_each_possible_cpu(j) {
			if (i == j)
				continue;

			match_pr = per_cpu(processors, j);
			if (!match_pr)
				continue;

			match_pdomain = &(match_pr->performance->domain_info);
			if (match_pdomain->domain != pdomain->domain)
				continue;

			match_pr->performance->shared_type =
					pr->performance->shared_type;
			cpumask_copy(match_pr->performance->shared_cpu_map,
				     pr->performance->shared_cpu_map);
		}
	}

err_ret:
	for_each_possible_cpu(i) {
		pr = per_cpu(processors, i);
		if (!pr || !pr->performance)
			continue;

		/* Assume no coordination on any error parsing domain info */
		if (retval) {
			cpumask_clear(pr->performance->shared_cpu_map);
			cpumask_set_cpu(i, pr->performance->shared_cpu_map);
			pr->performance->shared_type = CPUFREQ_SHARED_TYPE_NONE;
		}
		pr->performance = NULL; /* Will be set for real in register */
	}

err_out:
	mutex_unlock(&performance_mutex);
	free_cpumask_var(covered_cpus);
	return retval;
}