/*
* acpi_cpufreq_early_init - initialize ACPI P-States library
*
* Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c)
* in order to determine correct frequency and voltage pairings. We can
* do _PDC and _PSD and find out the processor dependency for the
* actual init that will happen later...
*/
static int __init acpi_cpufreq_early_init(void)
{
unsigned int i;
pr_debug("acpi_cpufreq_early_init\n");
acpi_perf_data = alloc_percpu(struct acpi_processor_performance);
if (!acpi_perf_data) {
pr_debug("Memory allocation error for acpi_perf_data.\n");
return -ENOMEM;
}
for_each_possible_cpu(i) {
if (!zalloc_cpumask_var_node(
&per_cpu_ptr(acpi_perf_data, i)->shared_cpu_map,
GFP_KERNEL, cpu_to_node(i))) {
/* Freeing a NULL pointer is OK: alloc_percpu zeroes. */
free_acpi_perf_data();
return -ENOMEM;
}
}
/* Do initialization in ACPI core */
acpi_processor_preregister_performance(acpi_perf_data);
return 0;
}
static void __exit acpi_cpufreq_exit(void)
{
pr_debug("acpi_cpufreq_exit\n");
acpi_cpufreq_boost_exit();
cpufreq_unregister_driver(&acpi_cpufreq_driver);
free_acpi_perf_data();
}
static int __init acpi_cpufreq_init(void)
{
int ret;
if (acpi_disabled)
return -ENODEV;
/* don't keep reloading if cpufreq_driver exists */
if (cpufreq_get_current_driver())
return -EEXIST;
pr_debug("acpi_cpufreq_init\n");
ret = acpi_cpufreq_early_init();
if (ret)
return ret;
#ifdef CONFIG_X86_ACPI_CPUFREQ_CPB
/* this is a sysfs file with a strange name and an even stranger
* semantic - per CPU instantiation, but system global effect.
* Lets enable it only on AMD CPUs for compatibility reasons and
* only if configured. This is considered legacy code, which
* will probably be removed at some point in the future.
*/
if (!check_amd_hwpstate_cpu(0)) {
struct freq_attr **attr;
pr_debug("CPB unsupported, do not expose it\n");
for (attr = acpi_cpufreq_attr; *attr; attr++)
if (*attr == &cpb) {
*attr = NULL;
break;
}
}
#endif
acpi_cpufreq_boost_init();
ret = cpufreq_register_driver(&acpi_cpufreq_driver);
if (ret) {
free_acpi_perf_data();
acpi_cpufreq_boost_exit();
}
return ret;
}
static int __init acpi_cpufreq_init(void)
{
int ret;
if (acpi_disabled)
return -ENODEV;
/* don't keep reloading if cpufreq_driver exists */
if (cpufreq_get_current_driver())
return -EEXIST;
pr_debug("acpi_cpufreq_init\n");
ret = acpi_cpufreq_early_init();
if (ret)
return ret;
#ifdef CONFIG_X86_ACPI_CPUFREQ_CPB
/* this is a sysfs file with a strange name and an even stranger
* semantic - per CPU instantiation, but system global effect.
* Lets enable it only on AMD CPUs for compatibility reasons and
* only if configured. This is considered legacy code, which
* will probably be removed at some point in the future.
*/
if (check_amd_hwpstate_cpu(0)) {
struct freq_attr **iter;
pr_debug("adding sysfs entry for cpb\n");
for (iter = acpi_cpufreq_attr; *iter != NULL; iter++)
;
/* make sure there is a terminator behind it */
if (iter[1] == NULL)
*iter = &cpb;
}
#endif
acpi_cpufreq_boost_init();
ret = cpufreq_register_driver(&acpi_cpufreq_driver);
if (ret)
free_acpi_perf_data();
return ret;
}
