cpufreq: governor: Implement per policy instances of governors

Currently, there can't be multiple instances of single governor_type.
If we have a multi-package system, where we have multiple instances
of struct policy (per package), we can't have multiple instances of
same governor. i.e. We can't have multiple instances of ondemand
governor for multiple packages.

Governors directory in sysfs is created at /sys/devices/system/cpu/cpufreq/
governor-name/. Which again reflects that there can be only one
instance of a governor_type in the system.

This is a bottleneck for multicluster system, where we want different
packages to use same governor type, but with different tunables.

This patch uses the infrastructure provided by earlier patch and
implements init/exit routines for ondemand and conservative
governors.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index b7393b56f552..4bbc572dd521 100644
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -232,6 +232,13 @@ struct cpufreq_driver {
         struct module           *owner;
         char                    name[CPUFREQ_NAME_LEN];
         u8                      flags;
+        /*
+         * This should be set by platforms having multiple clock-domains, i.e.
+         * supporting multiple policies. With this sysfs directories of governor
+         * would be created in cpu/cpu<num>/cpufreq/ directory and so they can
+         * use the same governor with different tunables for different clusters.
+         */
+        bool                    have_governor_per_policy;
 
         /* needed by all drivers */
         int     (*init)         (struct cpufreq_policy *policy);
@@ -332,6 +339,7 @@ const char *cpufreq_get_current_driver(void);
  *********************************************************************/
 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
 int cpufreq_update_policy(unsigned int cpu);
+bool have_governor_per_policy(void);
 
 #ifdef CONFIG_CPU_FREQ
 /* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */