Re: [PATCH v2 11/11] thermal: core: Manage thermal_governor_lock using a mutex guard

Lukasz Luba
2024-10-22T22:34:02Z

On 10/10/24 23:22, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>
> Switch over the thermal core to using a mutex guard for
> thermal_governor_lock management.
>
> 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/863177860.0ifERbkFSE@rjwysocki.net/
>
> ---
> drivers/thermal/thermal_core.c | 40 +++++++++++++---------------------------
> 1 file changed, 13 insertions(+), 27 deletions(-)
>
> Index: linux-pm/drivers/thermal/thermal_core.c
> ===================================================================
> --- linux-pm.orig/drivers/thermal/thermal_core.c
> +++ linux-pm/drivers/thermal/thermal_core.c
> @@ -124,7 +124,7 @@ int thermal_register_governor(struct the
> if (!governor)
> return -EINVAL;
>
> - mutex_lock(&thermal_governor_lock);
> + guard(mutex)(&thermal_governor_lock);
>
> err = -EBUSY;
> if (!__find_governor(governor->name)) {
> @@ -163,8 +163,6 @@ int thermal_register_governor(struct the
> }
> }
>
> - mutex_unlock(&thermal_governor_lock);
> -
> return err;
> }
>
> @@ -175,10 +173,10 @@ void thermal_unregister_governor(struct
> if (!governor)
> return;
>
> - mutex_lock(&thermal_governor_lock);
> + guard(mutex)(&thermal_governor_lock);
>
> if (!__find_governor(governor->name))
> - goto exit;
> + return;
>
> list_del(&governor->governor_list);
>
> @@ -189,9 +187,6 @@ void thermal_unregister_governor(struct
> THERMAL_NAME_LENGTH))
> thermal_set_governor(pos, NULL);
> }
> -
> -exit:
> - mutex_unlock(&thermal_governor_lock);
> }
>
> int thermal_zone_device_set_policy(struct thermal_zone_device *tz,
> @@ -200,16 +195,13 @@ int thermal_zone_device_set_policy(struc
> struct thermal_governor *gov;
> int ret = -EINVAL;
>
> - mutex_lock(&thermal_governor_lock);
> -
> + guard(mutex)(&thermal_governor_lock);
> guard(thermal_zone)(tz);
>
> gov = __find_governor(strim(policy));
> if (gov)
> ret = thermal_set_governor(tz, gov);
>
> - mutex_unlock(&thermal_governor_lock);
> -
> thermal_notify_tz_gov_change(tz, policy);
>
> return ret;
> @@ -220,15 +212,13 @@ int thermal_build_list_of_policies(char
> struct thermal_governor *pos;
> ssize_t count = 0;
>
> - mutex_lock(&thermal_governor_lock);
> + guard(mutex)(&thermal_governor_lock);
>
> list_for_each_entry(pos, &thermal_governor_list, governor_list) {
> count += sysfs_emit_at(buf, count, "%s ", pos->name);
> }
> count += sysfs_emit_at(buf, count, "\n");
>
> - mutex_unlock(&thermal_governor_lock);
> -
> return count;
> }
>
> @@ -668,17 +658,18 @@ int for_each_thermal_governor(int (*cb)(
> void *data)
> {
> struct thermal_governor *gov;
> - int ret = 0;
>
> - mutex_lock(&thermal_governor_lock);
> + guard(mutex)(&thermal_governor_lock);
> +
> list_for_each_entry(gov, &thermal_governor_list, governor_list) {
> + int ret;
> +
> ret = cb(gov, data);
> if (ret)
> - break;
> + return ret;
> }
> - mutex_unlock(&thermal_governor_lock);
>
> - return ret;
> + return 0;
> }
>
> int for_each_thermal_cooling_device(int (*cb)(struct thermal_cooling_device *,
> @@ -1346,20 +1337,15 @@ EXPORT_SYMBOL_GPL(thermal_zone_get_crit_
> static int thermal_zone_init_governor(struct thermal_zone_device *tz)
> {
> struct thermal_governor *governor;
> - int ret;
>
> - mutex_lock(&thermal_governor_lock);
> + guard(mutex)(&thermal_governor_lock);
>
> if (tz->tzp)
> governor = __find_governor(tz->tzp->governor_name);
> else
> governor = def_governor;
>
> - ret = thermal_set_governor(tz, governor);
> -
> - mutex_unlock(&thermal_governor_lock);
> -
> - return ret;
> + return thermal_set_governor(tz, governor);
> }
>
> static void thermal_zone_init_complete(struct thermal_zone_device *tz)
>
>
>

Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>