Commit f4fd3797 authored by Lan Tianyu's avatar Lan Tianyu Committed by Rafael J. Wysocki
Browse files

acpi-cpufreq: Add new sysfs attribute freqdomain_cpus

Commits fcf80582 (cpufreq: Simplify cpufreq_add_dev()) and aa77a527
(cpufreq: acpi-cpufreq: Don't set policy->related_cpus from .init())
changed the contents of the "related_cpus" sysfs attribute on systems
where acpi-cpufreq is used and user space can't get the list of CPUs
which are in the same hardware coordination CPU domain (provided by
the ACPI AML method _PSD) via "related_cpus" any more.

To make up for that loss add a new sysfs attribute "freqdomian_cpus"
for the acpi-cpufreq driver which exposes the list of CPUs in the
same domain regardless of whether it is coordinated by hardware or

[rjw: Changelog, documentation]

Reported-by: default avatarJean-Philippe Halimi <>
Signed-off-by: default avatarLan Tianyu <>
Acked-by: default avatarViresh Kumar <>
Signed-off-by: default avatarRafael J. Wysocki <>
parent 7c30ed53
......@@ -144,6 +144,21 @@ Description: Discover and change clock speed of CPUs
to learn how to control the knobs.
What: /sys/devices/system/cpu/cpu#/cpufreq/freqdomain_cpus
Date: June 2013
Description: Discover CPUs in the same CPU frequency coordination domain
freqdomain_cpus is the list of CPUs (online+offline) that share
the same clock/freq domain (possibly at the hardware level).
That information may be hidden from the cpufreq core and the
value of related_cpus may be different from freqdomain_cpus. This
attribute is useful for user space DVFS controllers to get better
power/performance results for platforms using acpi-cpufreq.
This file is only present if the acpi-cpufreq driver is in use.
What: /sys/devices/system/cpu/cpu*/cache/index3/cache_disable_{0,1}
Date: August 2008
KernelVersion: 2.6.27
......@@ -70,6 +70,7 @@ struct acpi_cpufreq_data {
struct cpufreq_frequency_table *freq_table;
unsigned int resume;
unsigned int cpu_feature;
cpumask_var_t freqdomain_cpus;
static DEFINE_PER_CPU(struct acpi_cpufreq_data *, acfreq_data);
......@@ -176,6 +177,15 @@ static struct global_attr global_boost = __ATTR(boost, 0644,
static ssize_t show_freqdomain_cpus(struct cpufreq_policy *policy, char *buf)
struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
return cpufreq_show_cpus(data->freqdomain_cpus, buf);
static ssize_t store_cpb(struct cpufreq_policy *policy, const char *buf,
size_t count)
......@@ -704,6 +714,11 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
if (!data)
return -ENOMEM;
if (!zalloc_cpumask_var(&data->freqdomain_cpus, GFP_KERNEL)) {
result = -ENOMEM;
goto err_free;
data->acpi_data = per_cpu_ptr(acpi_perf_data, cpu);
per_cpu(acfreq_data, cpu) = data;
......@@ -712,7 +727,7 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
result = acpi_processor_register_performance(data->acpi_data, cpu);
if (result)
goto err_free;
goto err_free_mask;
perf = data->acpi_data;
policy->shared_type = perf->shared_type;
......@@ -725,6 +740,7 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
cpumask_copy(policy->cpus, perf->shared_cpu_map);
cpumask_copy(data->freqdomain_cpus, perf->shared_cpu_map);
......@@ -736,6 +752,7 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
if (check_amd_hwpstate_cpu(cpu) && !acpi_pstate_strict) {
cpumask_set_cpu(cpu, policy->cpus);
cpumask_copy(data->freqdomain_cpus, cpu_sibling_mask(cpu));
policy->shared_type = CPUFREQ_SHARED_TYPE_HW;
pr_info_once(PFX "overriding BIOS provided _PSD data\n");
......@@ -870,6 +887,8 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
acpi_processor_unregister_performance(perf, cpu);
per_cpu(acfreq_data, cpu) = NULL;
......@@ -888,6 +907,7 @@ static int acpi_cpufreq_cpu_exit(struct cpufreq_policy *policy)
per_cpu(acfreq_data, policy->cpu) = NULL;
......@@ -908,6 +928,7 @@ static int acpi_cpufreq_resume(struct cpufreq_policy *policy)
static struct freq_attr *acpi_cpufreq_attr[] = {
NULL, /* this is a placeholder for cpb, do not remove */
......@@ -585,7 +585,7 @@ static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy,
return i;
static ssize_t show_cpus(const struct cpumask *mask, char *buf)
ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf)
ssize_t i = 0;
unsigned int cpu;
......@@ -600,6 +600,7 @@ static ssize_t show_cpus(const struct cpumask *mask, char *buf)
i += sprintf(&buf[i], "\n");
return i;
* show_related_cpus - show the CPUs affected by each transition even if
......@@ -607,7 +608,7 @@ static ssize_t show_cpus(const struct cpumask *mask, char *buf)
static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf)
return show_cpus(policy->related_cpus, buf);
return cpufreq_show_cpus(policy->related_cpus, buf);
......@@ -615,7 +616,7 @@ static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf)
static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf)
return show_cpus(policy->cpus, buf);
return cpufreq_show_cpus(policy->cpus, buf);
static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy,
......@@ -439,4 +439,7 @@ void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
void cpufreq_frequency_table_update_policy_cpu(struct cpufreq_policy *policy);
void cpufreq_frequency_table_put_attr(unsigned int cpu);
ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf);
#endif /* _LINUX_CPUFREQ_H */
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