[PATCH v2 3/10] cpufreq: governor: Avoid passing dbs_data pointers around unnecessarily

From: Rafael J. Wysocki
Date: Thu Feb 04 2016 - 21:23:38 EST


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

Do not pass struct dbs_data pointers to the family of functions
implementing governor operations in cpufreq_governor.c as they can
take that pointer from policy->governor by themselves.

The cpufreq_governor_init() case is slightly more complicated, since
policy->governor may be NULL when it is invoked, but then it can reach
the pointer in question via its cdata argument just fine.

While at it, rework cpufreq_governor_dbs() to avoid a pointless
policy_governor check in the CPUFREQ_GOV_POLICY_INIT case.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
drivers/cpufreq/cpufreq_governor.c | 68 ++++++++++++++-----------------------
1 file changed, 27 insertions(+), 41 deletions(-)

Index: linux-pm/drivers/cpufreq/cpufreq_governor.c
===================================================================
--- linux-pm.orig/drivers/cpufreq/cpufreq_governor.c
+++ linux-pm/drivers/cpufreq/cpufreq_governor.c
@@ -325,9 +325,9 @@ static void free_common_dbs_info(struct
}

static int cpufreq_governor_init(struct cpufreq_policy *policy,
- struct dbs_data *dbs_data,
struct common_dbs_data *cdata)
{
+ struct dbs_data *dbs_data = cdata->gdbs_data;
unsigned int latency;
int ret;

@@ -399,9 +399,9 @@ free_dbs_data:
return ret;
}

-static int cpufreq_governor_exit(struct cpufreq_policy *policy,
- struct dbs_data *dbs_data)
+static int cpufreq_governor_exit(struct cpufreq_policy *policy)
{
+ struct dbs_data *dbs_data = policy->governor_data;
struct common_dbs_data *cdata = dbs_data->cdata;
struct cpu_dbs_info *cdbs = cdata->get_cpu_cdbs(policy->cpu);

@@ -428,9 +428,9 @@ static int cpufreq_governor_exit(struct
return 0;
}

-static int cpufreq_governor_start(struct cpufreq_policy *policy,
- struct dbs_data *dbs_data)
+static int cpufreq_governor_start(struct cpufreq_policy *policy)
{
+ struct dbs_data *dbs_data = policy->governor_data;
struct common_dbs_data *cdata = dbs_data->cdata;
unsigned int sampling_rate, ignore_nice, j, cpu = policy->cpu;
struct cpu_dbs_info *cdbs = cdata->get_cpu_cdbs(cpu);
@@ -497,9 +497,9 @@ static int cpufreq_governor_start(struct
return 0;
}

-static int cpufreq_governor_stop(struct cpufreq_policy *policy,
- struct dbs_data *dbs_data)
+static int cpufreq_governor_stop(struct cpufreq_policy *policy)
{
+ struct dbs_data *dbs_data = policy->governor_data;
struct cpu_dbs_info *cdbs = dbs_data->cdata->get_cpu_cdbs(policy->cpu);
struct cpu_common_dbs_info *shared = cdbs->shared;

@@ -513,9 +513,9 @@ static int cpufreq_governor_stop(struct
return 0;
}

-static int cpufreq_governor_limits(struct cpufreq_policy *policy,
- struct dbs_data *dbs_data)
+static int cpufreq_governor_limits(struct cpufreq_policy *policy)
{
+ struct dbs_data *dbs_data = policy->governor_data;
struct common_dbs_data *cdata = dbs_data->cdata;
unsigned int cpu = policy->cpu;
struct cpu_dbs_info *cdbs = cdata->get_cpu_cdbs(cpu);
@@ -540,45 +540,31 @@ static int cpufreq_governor_limits(struc
int cpufreq_governor_dbs(struct cpufreq_policy *policy,
struct common_dbs_data *cdata, unsigned int event)
{
- struct dbs_data *dbs_data;
- int ret;
+ int ret = -EINVAL;

/* Lock governor to block concurrent initialization of governor */
mutex_lock(&dbs_data_mutex);

- if (have_governor_per_policy())
- dbs_data = policy->governor_data;
- else
- dbs_data = cdata->gdbs_data;
-
- if (!dbs_data && (event != CPUFREQ_GOV_POLICY_INIT)) {
- ret = -EINVAL;
- goto unlock;
- }
-
- switch (event) {
- case CPUFREQ_GOV_POLICY_INIT:
- ret = cpufreq_governor_init(policy, dbs_data, cdata);
- break;
- case CPUFREQ_GOV_POLICY_EXIT:
- ret = cpufreq_governor_exit(policy, dbs_data);
- break;
- case CPUFREQ_GOV_START:
- ret = cpufreq_governor_start(policy, dbs_data);
- break;
- case CPUFREQ_GOV_STOP:
- ret = cpufreq_governor_stop(policy, dbs_data);
- break;
- case CPUFREQ_GOV_LIMITS:
- ret = cpufreq_governor_limits(policy, dbs_data);
- break;
- default:
- ret = -EINVAL;
+ if (event == CPUFREQ_GOV_POLICY_INIT) {
+ ret = cpufreq_governor_init(policy, cdata);
+ } else if (policy->governor_data) {
+ switch (event) {
+ case CPUFREQ_GOV_POLICY_EXIT:
+ ret = cpufreq_governor_exit(policy);
+ break;
+ case CPUFREQ_GOV_START:
+ ret = cpufreq_governor_start(policy);
+ break;
+ case CPUFREQ_GOV_STOP:
+ ret = cpufreq_governor_stop(policy);
+ break;
+ case CPUFREQ_GOV_LIMITS:
+ ret = cpufreq_governor_limits(policy);
+ break;
+ }
}

-unlock:
mutex_unlock(&dbs_data_mutex);
-
return ret;
}
EXPORT_SYMBOL_GPL(cpufreq_governor_dbs);