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
software.

[rjw: Changelog, documentation]
References: https://bugzilla.kernel.org/show_bug.cgi?id=58761


Reported-by: default avatarJean-Philippe Halimi <jean-philippe.halimi@exascale-computing.eu>
Signed-off-by: default avatarLan Tianyu <tianyu.lan@intel.com>
Acked-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 7c30ed53

Documentation/ABI/testing/sysfs-devices-system-cpu

+15 −0
Original line number Diff line number Diff line
@@ -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

drivers/cpufreq/acpi-cpufreq.c

+22 −1
Original line number Diff line number Diff line
@@ -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,

};

drivers/cpufreq/cpufreq.c

+4 −3
Original line number Diff line number Diff line
@@ -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,

include/linux/cpufreq.h

+3 −0
Original line number Diff line number Diff line
@@ -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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