cpufreq: Allow freq_table to be obtained for offline CPUs

Users of freq table may want to access it for any CPU from
policy->related_cpus mask. One such user is cpu-cooling layer. It gets a
list of 'clip_cpus' (equivalent to policy->related_cpus) during
registration and tries to get freq_table for the first CPU of this mask.

If the CPU, for which it tries to fetch freq_table, is offline,
cpufreq_frequency_get_table() fails. This happens because it relies on
cpufreq_cpu_get_raw() for its functioning which returns policy only for
online CPUs.

The fix is to access the policy data structure for the given CPU
directly (which also returns a valid policy for offline CPUs), but the
policy itself has to be active (meaning that at least one CPU using it
is online) for the frequency table to be returned.

Because we will be using 'cpufreq_cpu_data' now, which is internal to
the cpufreq core, move cpufreq_frequency_get_table() to cpufreq.c.

Reported-and-tested-by: Pi-Cheng Chen <pi-cheng.chen@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 2c22e3902e72368a21d17bd12926b15c7eb962e1..26063afb3eba41a88f68e753689b05f741f82d36 100644 (file)
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -169,6 +169,15 @@ struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy)
 }
 EXPORT_SYMBOL_GPL(get_governor_parent_kobj);
 
+struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu)
+{
+       struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
+
+       return policy && !policy_is_inactive(policy) ?
+               policy->freq_table : NULL;
+}
+EXPORT_SYMBOL_GPL(cpufreq_frequency_get_table);
+
 static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall)
 {
        u64 idle_time;

diff --git a/drivers/cpufreq/freq_table.c b/drivers/cpufreq/freq_table.c
index df14766a8e06b7b692807c08d1bf27d683a339eb..dfbbf981ed56fdfd52b147b5c693f764696a56c8 100644 (file)
--- a/drivers/cpufreq/freq_table.c
+++ b/drivers/cpufreq/freq_table.c
@@ -297,15 +297,6 @@ int cpufreq_table_validate_and_show(struct cpufreq_policy *policy,
 }
 EXPORT_SYMBOL_GPL(cpufreq_table_validate_and_show);
 
-struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu);
-
-struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu)
-{
-       struct cpufreq_policy *policy = cpufreq_cpu_get_raw(cpu);
-       return policy ? policy->freq_table : NULL;
-}
-EXPORT_SYMBOL_GPL(cpufreq_frequency_get_table);
-
 MODULE_AUTHOR("Dominik Brodowski <linux@brodo.de>");
 MODULE_DESCRIPTION("CPUfreq frequency table helpers");
 MODULE_LICENSE("GPL");