[PATCH v2 03/11] thermal: core: Separate code running under thermal_list_lock

Rafael J. Wysocki
2024-10-10T22:22:35Z

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

To prepare for a subsequent change that will switch over the thermal
core to using a mutex guard for thermal_list_lock management, move the
code running under thermal_list_lock during the initialization and
unregistration of cooling devices into separate functions.

While at it, drop some comments that do not add value.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---

This is a resend of

https://lore.kernel.org/linux-pm/1822468.VLH7GnMWUR@rjwysocki.net/

---
drivers/thermal/thermal_core.c | 64 +++++++++++++++++++++++------------------
1 file changed, 36 insertions(+), 28 deletions(-)

Index: linux-pm/drivers/thermal/thermal_core.c
===================================================================
--- linux-pm.orig/drivers/thermal/thermal_core.c
+++ linux-pm/drivers/thermal/thermal_core.c
@@ -965,6 +965,20 @@ static void thermal_zone_cdev_bind(struc
__thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
}

+static void thermal_cooling_device_init_complete(struct thermal_cooling_device *cdev)
+{
+ struct thermal_zone_device *tz;
+
+ mutex_lock(&thermal_list_lock);
+
+ list_add(&cdev->node, &thermal_cdev_list);
+
+ list_for_each_entry(tz, &thermal_tz_list, node)
+ thermal_zone_cdev_bind(tz, cdev);
+
+ mutex_unlock(&thermal_list_lock);
+}
+
/**
* __thermal_cooling_device_register() - register a new thermal cooling device
* @np: a pointer to a device tree node.
@@ -987,7 +1001,6 @@ __thermal_cooling_device_register(struct
const struct thermal_cooling_device_ops *ops)
{
struct thermal_cooling_device *cdev;
- struct thermal_zone_device *pos;
unsigned long current_state;
int id, ret;

@@ -1054,16 +1067,7 @@ __thermal_cooling_device_register(struct
if (current_state <= cdev->max_state)
thermal_debug_cdev_add(cdev, current_state);

- /* Add 'this' new cdev to the global cdev list */
- mutex_lock(&thermal_list_lock);
-
- list_add(&cdev->node, &thermal_cdev_list);
-
- /* Update binding information for 'this' new cdev */
- list_for_each_entry(pos, &thermal_tz_list, node)
- thermal_zone_cdev_bind(pos, cdev);
-
- mutex_unlock(&thermal_list_lock);
+ thermal_cooling_device_init_complete(cdev);

return cdev;

@@ -1274,38 +1278,42 @@ static void thermal_zone_cdev_unbind(str
__thermal_zone_cdev_unbind(tz, cdev);
}

-/**
- * thermal_cooling_device_unregister - removes a thermal cooling device
- * @cdev: the thermal cooling device to remove.
- *
- * thermal_cooling_device_unregister() must be called when a registered
- * thermal cooling device is no longer needed.
- */
-void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev)
+static bool thermal_cooling_device_exit(struct thermal_cooling_device *cdev)
{
struct thermal_zone_device *tz;
-
- if (!cdev)
- return;
-
- thermal_debug_cdev_remove(cdev);
+ bool ret = true;

mutex_lock(&thermal_list_lock);

if (!thermal_cooling_device_present(cdev)) {
- mutex_unlock(&thermal_list_lock);
- return;
+ ret = false;
+ goto unlock;
}

list_del(&cdev->node);

- /* Unbind all thermal zones associated with 'this' cdev */
list_for_each_entry(tz, &thermal_tz_list, node)
thermal_zone_cdev_unbind(tz, cdev);

+unlock:
mutex_unlock(&thermal_list_lock);

- device_unregister(&cdev->device);
+ return ret;
+}
+
+/**
+ * thermal_cooling_device_unregister() - removes a thermal cooling device
+ * @cdev: Thermal cooling device to remove.
+ */
+void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev)
+{
+ if (!cdev)
+ return;
+
+ thermal_debug_cdev_remove(cdev);
+
+ if (thermal_cooling_device_exit(cdev))
+ device_unregister(&cdev->device);
}
EXPORT_SYMBOL_GPL(thermal_cooling_device_unregister);