linux-kernel - [PATCH V2] cpufreq: Allow accessing freq

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Message-Id: <5b275fbf85738095a6045ddd7d470cc99a795664.1436346340.git.viresh.kumar@linaro.org>
Date:	Wed,  8 Jul 2015 14:38:41 +0530
From:	Viresh Kumar <viresh.kumar@...aro.org>
To:	Rafael Wysocki <rjw@...ysocki.net>
Cc:	linaro-kernel@...ts.linaro.org, linux-pm@...r.kernel.org,
	rui.zhang@...el.com, edubezval@...il.com, javi.merino@....com,
	pi-cheng.chen@...aro.org, Viresh Kumar <viresh.kumar@...aro.org>,
	linux-kernel@...r.kernel.org (open list)
Subject: [PATCH V2] cpufreq: Allow accessing freq_table 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.

Fix this by considering offline CPUs, but with a restriction that the
policy is active at that time.

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

Reported-and-tested-by: Pi-Cheng Chen <pi-cheng.chen@...aro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@...aro.org>
---
V2: Get rid of cpufreq_cpu_data()'s declaration as well.. Thanks Javi.

 drivers/cpufreq/cpufreq.c    | 9 +++++++++
 drivers/cpufreq/freq_table.c | 9 ---------
 2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 2c22e3902e72..26063afb3eba 100644
--- 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 df14766a8e06..dfbbf981ed56 100644
--- 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@...do.de>");
 MODULE_DESCRIPTION("CPUfreq frequency table helpers");
 MODULE_LICENSE("GPL");
-- 
2.4.0

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