Re: [PATCH v3 6/8] ACPI: thermal: Use trip point table to register thermal zones

Rafael J. Wysocki
2023-07-25T18:08:21Z

On Tuesday, July 25, 2023 2:20:57 PM CEST Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>
> Make the ACPI thermal driver use thermal_zone_device_register_with_trips()
> to register its thermal zones.
>
> For this purpose, make it create a trip point table and pass it to
> thermal_zone_device_register_with_trips() as an argument and use the
> struct thermal_trip_ref introduced previously to connect the generic
> thermal trip structures to the internal data structures representing
> trip points in the driver.
>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> ---
>
> v2 -> v3:
> * Fix error code path memory leak in acpi_thermal_register_thermal_zone().
> * Notice that the critical and hot trips never change after initialization,
> so don't add struct thermal_trip_ref to any of them.
>
> v1 -> v2:
> * Use thermal_zone_device_lock()/thermal_zone_device_unlock() in
> acpi_thermal_check_fn() explicitly and call __thermal_zone_device_update()
> from there without unlocking the thermal zone.
> * Export __thermal_zone_device_update() to modules (so it can be called by
> the ACPI thermal code).
>
> ---
> drivers/acpi/thermal.c | 106 ++++++++++++++++++++++++++++++++++++++---
> drivers/thermal/thermal_core.c | 1
> include/linux/thermal.h | 2
> 3 files changed, 102 insertions(+), 7 deletions(-)
>
> Index: linux-pm/drivers/acpi/thermal.c
> ===================================================================
> --- linux-pm.orig/drivers/acpi/thermal.c
> +++ linux-pm/drivers/acpi/thermal.c
> @@ -107,6 +107,7 @@ struct acpi_thermal_hot {
> };
>
> struct acpi_thermal_passive {
> + struct thermal_trip_ref trip_ref;
> struct acpi_handle_list devices;
> unsigned long temperature;
> unsigned long tc1;
> @@ -116,6 +117,7 @@ struct acpi_thermal_passive {
> };
>
> struct acpi_thermal_active {
> + struct thermal_trip_ref trip_ref;
> struct acpi_handle_list devices;
> unsigned long temperature;
> bool valid;
> @@ -137,6 +139,7 @@ struct acpi_thermal {
> unsigned long polling_frequency;
> volatile u8 zombie;
> struct acpi_thermal_trips trips;
> + struct thermal_trip *trip_table;
> struct acpi_handle_list devices;
> struct thermal_zone_device *thermal_zone;
> int kelvin_offset; /* in millidegrees */
> @@ -190,6 +193,14 @@ static int acpi_thermal_get_polling_freq
> return 0;
> }
>
> +static void acpi_thermal_trip_update_temp(struct acpi_thermal *tz,
> + struct thermal_trip *trip,
> + long temperature)
> +{
> + trip->temperature = deci_kelvin_to_millicelsius_with_offset(temperature,
> + tz->kelvin_offset);
> +}
> +
> static void __acpi_thermal_trips_update(struct acpi_thermal *tz, int flag)
> {
> acpi_status status;
> @@ -756,6 +767,7 @@ static void acpi_thermal_zone_sysfs_remo
>
> static int acpi_thermal_register_thermal_zone(struct acpi_thermal *tz)
> {
> + struct thermal_trip *trip;
> int passive_delay = 0;
> int trip_count = 0;
> int result;
> @@ -776,12 +788,54 @@ static int acpi_thermal_register_thermal
> for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE && tz->trips.active[i].valid; i++)
> trip_count++;
>
> - tz->thermal_zone = thermal_zone_device_register("acpitz", trip_count, 0,
> - tz, &acpi_thermal_zone_ops,
> - NULL, passive_delay,
> - tz->polling_frequency * 100);
> - if (IS_ERR(tz->thermal_zone))
> - return -ENODEV;
> + trip = kcalloc(trip_count, sizeof(*trip), GFP_KERNEL);
> + if (!trip)
> + return -ENOMEM;
> +
> + tz->trip_table = trip;
> +
> + if (tz->trips.critical.valid) {
> + trip->type = THERMAL_TRIP_CRITICAL;
> + acpi_thermal_trip_update_temp(tz, trip,
> + tz->trips.critical.temperature);
> + trip++;
> + }
> +
> + if (tz->trips.hot.valid) {
> + trip->type = THERMAL_TRIP_HOT;
> + acpi_thermal_trip_update_temp(tz, trip,
> + tz->trips.hot.temperature);
> + trip++;
> + }
> +
> + if (tz->trips.passive.valid) {
> + trip->type = THERMAL_TRIP_PASSIVE;
> + acpi_thermal_trip_update_temp(tz, trip,
> + tz->trips.passive.temperature);
> + trip->driver_ref = &tz->trips.passive.trip_ref;
> + trip++;
> + }
> +
> + for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE && tz->trips.active[i].valid; i++) {
> + trip->type = THERMAL_TRIP_ACTIVE;
> + acpi_thermal_trip_update_temp(tz, trip,
> + tz->trips.active[i].temperature);
> + trip->driver_ref = &tz->trips.active[i].trip_ref;
> + trip++;
> + }
> +
> + tz->thermal_zone = thermal_zone_device_register_with_trips("acpitz",
> + tz->trip_table,
> + trip_count,
> + 0, tz,
> + &acpi_thermal_zone_ops,
> + NULL,
> + passive_delay,
> + tz->polling_frequency * 100);
> + if (IS_ERR(tz->thermal_zone)) {
> + result = PTR_ERR(tz->thermal_zone);
> + goto free_trip_table;
> + }
>
> result = acpi_thermal_zone_sysfs_add(tz);
> if (result)
> @@ -809,6 +863,8 @@ remove_links:
> acpi_thermal_zone_sysfs_remove(tz);
> unregister_tzd:
> thermal_zone_device_unregister(tz->thermal_zone);
> +free_trip_table:
> + kfree(tz->trip_table);
>
> return result;
> }
> @@ -817,6 +873,7 @@ static void acpi_thermal_unregister_ther
> {
> acpi_thermal_zone_sysfs_remove(tz);
> thermal_zone_device_unregister(tz->thermal_zone);
> + kfree(tz->trip_table);
> tz->thermal_zone = NULL;
> acpi_bus_detach_private_data(tz->device->handle);
> }
> @@ -950,6 +1007,9 @@ static void acpi_thermal_check_fn(struct
> {
> struct acpi_thermal *tz = container_of(work, struct acpi_thermal,
> thermal_check_work);
> + struct thermal_trip *trip;
> + long temperature;
> + int i;
>
> /*
> * In general, it is not sufficient to check the pending bit, because
> @@ -964,7 +1024,39 @@ static void acpi_thermal_check_fn(struct
>
> mutex_lock(&tz->thermal_check_lock);
>
> - thermal_zone_device_update(tz->thermal_zone, THERMAL_EVENT_UNSPECIFIED);
> + thermal_zone_device_lock(tz->thermal_zone);
> +
> + trip = tz->trips.passive.trip_ref.trip;
> + if (trip) {
> + /*
> + * This means that the passive trip was valid initially, so
> + * update its temperature in case it has changed or the trip
> + * has become invalid.
> + */
> + temperature = tz->trips.passive.valid ?
> + tz->trips.passive.temperature :
> + THERMAL_TEMP_INVALID;
> + acpi_thermal_trip_update_temp(tz, trip, temperature);

This is a mistake, because THERMAL_TEMP_INVALID should not be passed to
acpi_thermal_trip_update_temp() (and same below).

I'll send an update of this patch in a moment.

> + }
> +
> + for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
> + trip = tz->trips.active[i].trip_ref.trip;
> + if (trip) {
> + /*
> + * This means that the active trip #i was valid
> + * initially, so update its temperature in case it has
> + * changed or the trip has become invalid.
> + */
> + temperature = tz->trips.active[i].valid ?
> + tz->trips.active[i].temperature :
> + THERMAL_TEMP_INVALID;
> + acpi_thermal_trip_update_temp(tz, trip, temperature);
> + }
> + }
> +
> + __thermal_zone_device_update(tz->thermal_zone, THERMAL_EVENT_UNSPECIFIED);
> +
> + thermal_zone_device_unlock(tz->thermal_zone);
>
> refcount_inc(&tz->thermal_check_count);
>
> Index: linux-pm/drivers/thermal/thermal_core.c
> ===================================================================
> --- linux-pm.orig/drivers/thermal/thermal_core.c
> +++ linux-pm/drivers/thermal/thermal_core.c
> @@ -429,6 +429,7 @@ void __thermal_zone_device_update(struct
>
> monitor_thermal_zone(tz);
> }
> +EXPORT_SYMBOL_GPL(__thermal_zone_device_update);
>
> static int thermal_zone_device_set_mode(struct thermal_zone_device *tz,
> enum thermal_device_mode mode)
> Index: linux-pm/include/linux/thermal.h
> ===================================================================
> --- linux-pm.orig/include/linux/thermal.h
> +++ linux-pm/include/linux/thermal.h
> @@ -334,6 +334,8 @@ int thermal_zone_bind_cooling_device(str
> unsigned int);
> int thermal_zone_unbind_cooling_device(struct thermal_zone_device *, int,
> struct thermal_cooling_device *);
> +void __thermal_zone_device_update(struct thermal_zone_device *,
> + enum thermal_notify_event);
> void thermal_zone_device_update(struct thermal_zone_device *,
> enum thermal_notify_event);
> void thermal_zone_device_lock(struct thermal_zone_device *tz);
>