thermal/core: Move the thermal zone lock out of the governors

All the governors throttling ops are taking/releasing the lock at the
beginning and the end of the function.

We can move the mutex to the throttling call site instead.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20220805153834.2510142-4-daniel.lezcano@linaro.org

diff --git a/drivers/thermal/gov_bang_bang.c b/drivers/thermal/gov_bang_bang.c
index f0bff2e..a08bbe3 100644 (file)
--- a/drivers/thermal/gov_bang_bang.c
+++ b/drivers/thermal/gov_bang_bang.c
@@ -96,15 +96,13 @@ static int bang_bang_control(struct thermal_zone_device *tz, int trip)
 {
        struct thermal_instance *instance;
 
-       mutex_lock(&tz->lock);
+       lockdep_assert_held(&tz->lock);
 
        thermal_zone_trip_update(tz, trip);
 
        list_for_each_entry(instance, &tz->thermal_instances, tz_node)
                thermal_cdev_update(instance->cdev);
 
-       mutex_unlock(&tz->lock);
-
        return 0;
 }
 

diff --git a/drivers/thermal/gov_fair_share.c b/drivers/thermal/gov_fair_share.c
index 5d5ddd6..a4ee466 100644 (file)
--- a/drivers/thermal/gov_fair_share.c
+++ b/drivers/thermal/gov_fair_share.c
@@ -82,7 +82,7 @@ static int fair_share_throttle(struct thermal_zone_device *tz, int trip)
        int total_instance = 0;
        int cur_trip_level = get_trip_level(tz);
 
-       mutex_lock(&tz->lock);
+       lockdep_assert_held(&tz->lock);
 
        list_for_each_entry(instance, &tz->thermal_instances, tz_node) {
                if (instance->trip != trip)
@@ -112,8 +112,6 @@ static int fair_share_throttle(struct thermal_zone_device *tz, int trip)
                mutex_unlock(&cdev->lock);
        }
 
-       mutex_unlock(&tz->lock);
-
        return 0;
 }
 

diff --git a/drivers/thermal/gov_power_allocator.c b/drivers/thermal/gov_power_allocator.c
index d3aca23..2d1aeab 100644 (file)
--- a/drivers/thermal/gov_power_allocator.c
+++ b/drivers/thermal/gov_power_allocator.c
@@ -697,19 +697,19 @@ static void power_allocator_unbind(struct thermal_zone_device *tz)
 
 static int power_allocator_throttle(struct thermal_zone_device *tz, int trip)
 {
-       int ret = 0;
+       int ret;
        int switch_on_temp, control_temp;
        struct power_allocator_params *params = tz->governor_data;
        bool update;
 
-       mutex_lock(&tz->lock);
+       lockdep_assert_held(&tz->lock);
 
        /*
         * We get called for every trip point but we only need to do
         * our calculations once
         */
        if (trip != params->trip_max_desired_temperature)
-               goto out;
+               return 0;
 
        ret = tz->ops->get_trip_temp(tz, params->trip_switch_on,
                                     &switch_on_temp);
@@ -718,7 +718,7 @@ static int power_allocator_throttle(struct thermal_zone_device *tz, int trip)
                tz->passive = 0;
                reset_pid_controller(params);
                allow_maximum_power(tz, update);
-               goto out;
+               return 0;
        }
 
        tz->passive = 1;
@@ -729,14 +729,10 @@ static int power_allocator_throttle(struct thermal_zone_device *tz, int trip)
                dev_warn(&tz->device,
                         "Failed to get the maximum desired temperature: %d\n",
                         ret);
-               goto out;
+               return ret;
        }
 
-       ret = allocate_power(tz, control_temp);
-
-       mutex_unlock(&tz->lock);
-out:
-       return ret;
+       return allocate_power(tz, control_temp);
 }
 
 static struct thermal_governor thermal_gov_power_allocator = {

diff --git a/drivers/thermal/gov_step_wise.c b/drivers/thermal/gov_step_wise.c
index 597a0eb..cdd3354 100644 (file)
--- a/drivers/thermal/gov_step_wise.c
+++ b/drivers/thermal/gov_step_wise.c
@@ -160,15 +160,13 @@ static int step_wise_throttle(struct thermal_zone_device *tz, int trip)
 {
        struct thermal_instance *instance;
 
-       mutex_lock(&tz->lock);
+       lockdep_assert_held(&tz->lock);
 
        thermal_zone_trip_update(tz, trip);
 
        list_for_each_entry(instance, &tz->thermal_instances, tz_node)
                thermal_cdev_update(instance->cdev);
 
-       mutex_unlock(&tz->lock);
-
        return 0;
 }
 

diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index 5408e92..fcac28d 100644 (file)
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -311,8 +311,10 @@ static void monitor_thermal_zone(struct thermal_zone_device *tz)
 
 static void handle_non_critical_trips(struct thermal_zone_device *tz, int trip)
 {
+       mutex_lock(&tz->lock);
        tz->governor ? tz->governor->throttle(tz, trip) :
                       def_governor->throttle(tz, trip);
+       mutex_unlock(&tz->lock);
 }
 
 void thermal_zone_device_critical(struct thermal_zone_device *tz)