linux-kernel - [PATCH 3/11] cpufreq: governor: Use common global_dbs

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Date:	Thu, 04 Feb 2016 00:22:31 +0100
From:	"Rafael J. Wysocki" <rjw@...ysocki.net>
To:	Linux PM list <linux-pm@...r.kernel.org>
Cc:	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Viresh Kumar <viresh.kumar@...aro.org>,
	Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>,
	Juri Lelli <juri.lelli@....com>,
	Steve Muckle <steve.muckle@...aro.org>,
	Saravana Kannan <skannan@...eaurora.org>
Subject: [PATCH 3/11] cpufreq: governor: Use common global_dbs_data pointer

From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>

If the ondemand and conservative governors cannot use per-policy
tunables (CPUFREQ_HAVE_GOVERNOR_PER_POLICY is not set in the cpufreq
driver), all policy objects point to the same single dbs_data object.
Additionally, that object is pointed to by a global pointer hidden in
the governor's data structures.

There is no reason for that pointer to be buried in those
data structures, though, so make it explicitly global.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
---
 drivers/cpufreq/cpufreq_governor.c |   20 ++++++++++----------
 drivers/cpufreq/cpufreq_governor.h |   20 ++++++++++----------
 2 files changed, 20 insertions(+), 20 deletions(-)

Index: linux-pm/drivers/cpufreq/cpufreq_governor.h
===================================================================
--- linux-pm.orig/drivers/cpufreq/cpufreq_governor.h
+++ linux-pm/drivers/cpufreq/cpufreq_governor.h
@@ -78,7 +78,7 @@ __ATTR(_name, 0644, show_##_name##_gov_p
 static ssize_t show_##file_name##_gov_sys				\
 (struct kobject *kobj, struct attribute *attr, char *buf)		\
 {									\
-	struct _gov##_dbs_tuners *tuners = _gov##_dbs_cdata.gdbs_data->tuners; \
+	struct _gov##_dbs_tuners *tuners = global_dbs_data->tuners; \
 	return sprintf(buf, "%u\n", tuners->file_name);			\
 }									\
 									\
@@ -94,7 +94,7 @@ static ssize_t show_##file_name##_gov_po
 static ssize_t store_##file_name##_gov_sys				\
 (struct kobject *kobj, struct attribute *attr, const char *buf, size_t count) \
 {									\
-	struct dbs_data *dbs_data = _gov##_dbs_cdata.gdbs_data;		\
+	struct dbs_data *dbs_data = global_dbs_data;		\
 	return store_##file_name(dbs_data, buf, count);			\
 }									\
 									\
@@ -201,19 +201,14 @@ struct cs_dbs_tuners {
 /* Common Governor data across policies */
 struct dbs_data;
 struct common_dbs_data {
-	/* Common across governors */
+	struct cpufreq_governor gov;
+
 	#define GOV_ONDEMAND		0
 	#define GOV_CONSERVATIVE	1
 	int governor;
 	struct attribute_group *attr_group_gov_sys; /* one governor - system */
 	struct attribute_group *attr_group_gov_pol; /* one governor - policy */
 
-	/*
-	 * Common data for platforms that don't set
-	 * CPUFREQ_HAVE_GOVERNOR_PER_POLICY
-	 */
-	struct dbs_data *gdbs_data;
-
 	struct cpu_dbs_info *(*get_cpu_cdbs)(int cpu);
 	void *(*get_cpu_dbs_info_s)(int cpu);
 	unsigned int (*gov_dbs_timer)(struct cpufreq_policy *policy);
@@ -233,6 +228,11 @@ struct dbs_data {
 	void *tuners;
 };
 
+/*
+ * Common governor data for platforms without CPUFREQ_HAVE_GOVERNOR_PER_POLICY.
+ */
+extern struct dbs_data *global_dbs_data;
+
 /* Governor specific ops, will be passed to dbs_data->gov_ops */
 struct od_ops {
 	void (*powersave_bias_init_cpu)(int cpu);
@@ -256,7 +256,7 @@ static inline int delay_for_sampling_rat
 static ssize_t show_sampling_rate_min_gov_sys				\
 (struct kobject *kobj, struct attribute *attr, char *buf)		\
 {									\
-	struct dbs_data *dbs_data = _gov##_dbs_cdata.gdbs_data;		\
+	struct dbs_data *dbs_data = global_dbs_data;			\
 	return sprintf(buf, "%u\n", dbs_data->min_sampling_rate);	\
 }									\
 									\
Index: linux-pm/drivers/cpufreq/cpufreq_governor.c
===================================================================
--- linux-pm.orig/drivers/cpufreq/cpufreq_governor.c
+++ linux-pm/drivers/cpufreq/cpufreq_governor.c
@@ -22,6 +22,9 @@
 
 #include "cpufreq_governor.h"
 
+struct dbs_data *global_dbs_data;
+EXPORT_SYMBOL_GPL(global_dbs_data);
+
 DEFINE_MUTEX(dbs_data_mutex);
 EXPORT_SYMBOL_GPL(dbs_data_mutex);
 
@@ -377,22 +380,19 @@ static int cpufreq_governor_init(struct
 					latency * LATENCY_MULTIPLIER));
 
 	if (!have_governor_per_policy())
-		cdata->gdbs_data = dbs_data;
+		global_dbs_data = dbs_data;
 
 	policy->governor_data = dbs_data;
 
 	ret = sysfs_create_group(get_governor_parent_kobj(policy),
 				 get_sysfs_attr(dbs_data));
-	if (ret)
-		goto reset_gdbs_data;
-
-	return 0;
+	if (!ret)
+		return 0;
 
-reset_gdbs_data:
 	policy->governor_data = NULL;
-
 	if (!have_governor_per_policy())
-		cdata->gdbs_data = NULL;
+		global_dbs_data = NULL;
+
 	cdata->exit(dbs_data, !policy->governor->initialized);
 free_common_dbs_info:
 	free_common_dbs_info(policy, cdata);
@@ -418,7 +418,7 @@ static int cpufreq_governor_exit(struct
 		policy->governor_data = NULL;
 
 		if (!have_governor_per_policy())
-			cdata->gdbs_data = NULL;
+			global_dbs_data = NULL;
 
 		cdata->exit(dbs_data, policy->governor->initialized == 1);
 		kfree(dbs_data);
@@ -550,7 +550,7 @@ int cpufreq_governor_dbs(struct cpufreq_
 	if (have_governor_per_policy())
 		dbs_data = policy->governor_data;
 	else
-		dbs_data = cdata->gdbs_data;
+		dbs_data = global_dbs_data;
 
 	if (!dbs_data && (event != CPUFREQ_GOV_POLICY_INIT)) {
 		ret = -EINVAL;