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acpi-cpufreq: Add new sysfs attribute freqdomain_cpus 

Commits fcf8058 (cpufreq: Simplify cpufreq_add_dev()) and aa77a52
(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
software.

[rjw: Changelog, documentation]
References: https://bugzilla.kernel.org/show_bug.cgi?id=58761
Reported-by: Jean-Philippe Halimi <jean-philippe.halimi@exascale-computing.eu>
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Lan Tianyu 2013-06-27 15:08:54 +08:00 committed by Rafael J. Wysocki
parent 7c30ed532c
commit f4fd379784
4 changed files with 44 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
Documentation/ABI/testing/sysfs-devices-system-cpu
View File

@ -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
Contact: cpufreq@vger.kernel.org
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

23
drivers/cpufreq/acpi-cpufreq.c
View File

@ -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,
show_global_boost,
store_global_boost);
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);
}
cpufreq_freq_attr_ro(freqdomain_cpus);
#ifdef CONFIG_X86_ACPI_CPUFREQ_CPB
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);
#ifdef CONFIG_SMP
dmi_check_system(sw_any_bug_dmi_table);
@ -736,6 +752,7 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
if (check_amd_hwpstate_cpu(cpu) && !acpi_pstate_strict) {
cpumask_clear(policy->cpus);
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 @@ err_freqfree:
kfree(data->freq_table);
err_unreg:
acpi_processor_unregister_performance(perf, cpu);
err_free_mask:
free_cpumask_var(data->freqdomain_cpus);
err_free:
kfree(data);
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;
acpi_processor_unregister_performance(data->acpi_data,
policy->cpu);
free_cpumask_var(data->freqdomain_cpus);
kfree(data->freq_table);
kfree(data);
}
@ -908,6 +928,7 @@ static int acpi_cpufreq_resume(struct cpufreq_policy *policy)
static struct freq_attr *acpi_cpufreq_attr[] = {
&cpufreq_freq_attr_scaling_available_freqs,
&freqdomain_cpus,
NULL, /* this is a placeholder for cpb, do not remove */
NULL,
};

7
drivers/cpufreq/cpufreq.c
View File

@ -585,7 +585,7 @@ out:
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;
}
EXPORT_SYMBOL_GPL(cpufreq_show_cpus);
/**
* 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,

3
include/linux/cpufreq.h
View File

@ -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 */