thermal/core: Precompute the delays from msecs to jiffies

The delays are stored in ms units and when the polling function is
called this delay is converted into jiffies at each call.

Instead of doing the conversion again and again, compute the jiffies
at init time and use the value directly when setting the polling.

Cc: Thara Gopinath <thara.gopinath@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Reviewed-by: Thara Gopinath <thara.gopinath@linaro.org>
Link: https://lore.kernel.org/r/20201216220337.839878-1-daniel.lezcano@linaro.org

drivers/thermal/thermal_core.c

@@ -1315,6 +1315,9 @@ thermal_zone_device_register(const char *type, int trips, int mask,
 	tz->passive_delay = passive_delay;
 	tz->polling_delay = polling_delay;
 
+	thermal_set_delay_jiffies(&tz->passive_delay_jiffies, passive_delay);
+	thermal_set_delay_jiffies(&tz->polling_delay_jiffies, polling_delay);
+
 	/* sys I/F */
 	/* Add nodes that are always present via .groups */
 	result = thermal_zone_create_device_groups(tz, mask);

drivers/thermal/thermal_core.h

@@ -123,6 +123,7 @@ int thermal_build_list_of_policies(char *buf);
 
 /* Helpers */
 void thermal_zone_set_trips(struct thermal_zone_device *tz);
+void thermal_set_delay_jiffies(unsigned long *delay_jiffies, int delay_ms);
 
 /* sysfs I/F */
 int thermal_zone_create_device_groups(struct thermal_zone_device *, int);

drivers/thermal/thermal_helpers.c

@@ -175,6 +175,13 @@ void thermal_zone_set_trips(struct thermal_zone_device *tz)
 	mutex_unlock(&tz->lock);
 }
 
+void thermal_set_delay_jiffies(unsigned long *delay_jiffies, int delay_ms)
+{
+	*delay_jiffies = msecs_to_jiffies(delay_ms);
+	if (delay_ms > 1000)
+		*delay_jiffies = round_jiffies(*delay_jiffies);
+}
+
 static void thermal_cdev_set_cur_state(struct thermal_cooling_device *cdev,
 				       int target)
 {

include/linux/thermal.h

@@ -117,9 +117,14 @@ struct thermal_cooling_device {
  * @trips_disabled;	bitmap for disabled trips
  * @passive_delay:	number of milliseconds to wait between polls when
  *			performing passive cooling.
+ * @passive_delay_jiffies: number of jiffies to wait between polls when
+ *			performing passive cooling.
  * @polling_delay:	number of milliseconds to wait between polls when
  *			checking whether trip points have been crossed (0 for
  *			interrupt driven systems)
+ * @polling_delay_jiffies: number of jiffies to wait between polls when
+ *			checking whether trip points have been crossed (0 for
+ *			interrupt driven systems)
  * @temperature:	current temperature.  This is only for core code,
  *			drivers should use thermal_zone_get_temp() to get the
  *			current temperature
@@ -155,6 +160,8 @@ struct thermal_zone_device {
 	void *devdata;
 	int trips;
 	unsigned long trips_disabled;	/* bitmap for disabled trips */
+	unsigned long passive_delay_jiffies;
+	unsigned long polling_delay_jiffies;
 	int passive_delay;
 	int polling_delay;
 	int temperature;