Commit e33df1d2 authored by Javi Merino's avatar Javi Merino Committed by Eduardo Valentin

thermal: let governors have private data for each thermal zone

A governor may need to store its current state between calls to
throttle().  That state depends on the thermal zone, so store it as
private data in struct thermal_zone_device.

The governors may have two new ops: bind_to_tz() and unbind_from_tz().
When provided, these functions let governors do some initialization
and teardown when they are bound/unbound to a tz and possibly store that
information in the governor_data field of the struct
thermal_zone_device.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: default avatarJavi Merino <javi.merino@arm.com>
Signed-off-by: default avatarEduardo Valentin <edubezval@gmail.com>
parent c610afaa
......@@ -75,6 +75,58 @@ static struct thermal_governor *__find_governor(const char *name)
return NULL;
}
/**
* bind_previous_governor() - bind the previous governor of the thermal zone
* @tz: a valid pointer to a struct thermal_zone_device
* @failed_gov_name: the name of the governor that failed to register
*
* Register the previous governor of the thermal zone after a new
* governor has failed to be bound.
*/
static void bind_previous_governor(struct thermal_zone_device *tz,
const char *failed_gov_name)
{
if (tz->governor && tz->governor->bind_to_tz) {
if (tz->governor->bind_to_tz(tz)) {
dev_err(&tz->device,
"governor %s failed to bind and the previous one (%s) failed to bind again, thermal zone %s has no governor\n",
failed_gov_name, tz->governor->name, tz->type);
tz->governor = NULL;
}
}
}
/**
* thermal_set_governor() - Switch to another governor
* @tz: a valid pointer to a struct thermal_zone_device
* @new_gov: pointer to the new governor
*
* Change the governor of thermal zone @tz.
*
* Return: 0 on success, an error if the new governor's bind_to_tz() failed.
*/
static int thermal_set_governor(struct thermal_zone_device *tz,
struct thermal_governor *new_gov)
{
int ret = 0;
if (tz->governor && tz->governor->unbind_from_tz)
tz->governor->unbind_from_tz(tz);
if (new_gov && new_gov->bind_to_tz) {
ret = new_gov->bind_to_tz(tz);
if (ret) {
bind_previous_governor(tz, new_gov->name);
return ret;
}
}
tz->governor = new_gov;
return ret;
}
int thermal_register_governor(struct thermal_governor *governor)
{
int err;
......@@ -107,8 +159,15 @@ int thermal_register_governor(struct thermal_governor *governor)
name = pos->tzp->governor_name;
if (!strncasecmp(name, governor->name, THERMAL_NAME_LENGTH))
pos->governor = governor;
if (!strncasecmp(name, governor->name, THERMAL_NAME_LENGTH)) {
int ret;
ret = thermal_set_governor(pos, governor);
if (ret)
dev_err(&pos->device,
"Failed to set governor %s for thermal zone %s: %d\n",
governor->name, pos->type, ret);
}
}
mutex_unlock(&thermal_list_lock);
......@@ -134,7 +193,7 @@ void thermal_unregister_governor(struct thermal_governor *governor)
list_for_each_entry(pos, &thermal_tz_list, node) {
if (!strncasecmp(pos->governor->name, governor->name,
THERMAL_NAME_LENGTH))
pos->governor = NULL;
thermal_set_governor(pos, NULL);
}
mutex_unlock(&thermal_list_lock);
......@@ -770,7 +829,8 @@ policy_store(struct device *dev, struct device_attribute *attr,
if (!gov)
goto exit;
tz->governor = gov;
ret = thermal_set_governor(tz, gov);
if (!ret)
ret = count;
exit:
......@@ -1512,6 +1572,7 @@ struct thermal_zone_device *thermal_zone_device_register(const char *type,
int result;
int count;
int passive = 0;
struct thermal_governor *governor;
if (type && strlen(type) >= THERMAL_NAME_LENGTH)
return ERR_PTR(-EINVAL);
......@@ -1602,9 +1663,15 @@ struct thermal_zone_device *thermal_zone_device_register(const char *type,
mutex_lock(&thermal_governor_lock);
if (tz->tzp)
tz->governor = __find_governor(tz->tzp->governor_name);
governor = __find_governor(tz->tzp->governor_name);
else
tz->governor = def_governor;
governor = def_governor;
result = thermal_set_governor(tz, governor);
if (result) {
mutex_unlock(&thermal_governor_lock);
goto unregister;
}
mutex_unlock(&thermal_governor_lock);
......@@ -1693,7 +1760,7 @@ void thermal_zone_device_unregister(struct thermal_zone_device *tz)
device_remove_file(&tz->device, &dev_attr_mode);
device_remove_file(&tz->device, &dev_attr_policy);
remove_trip_attrs(tz);
tz->governor = NULL;
thermal_set_governor(tz, NULL);
thermal_remove_hwmon_sysfs(tz);
release_idr(&thermal_tz_idr, &thermal_idr_lock, tz->id);
......
......@@ -165,6 +165,7 @@ struct thermal_attr {
* @ops: operations this &thermal_zone_device supports
* @tzp: thermal zone parameters
* @governor: pointer to the governor for this thermal zone
* @governor_data: private pointer for governor data
* @thermal_instances: list of &struct thermal_instance of this thermal zone
* @idr: &struct idr to generate unique id for this zone's cooling
* devices
......@@ -191,6 +192,7 @@ struct thermal_zone_device {
struct thermal_zone_device_ops *ops;
const struct thermal_zone_params *tzp;
struct thermal_governor *governor;
void *governor_data;
struct list_head thermal_instances;
struct idr idr;
struct mutex lock;
......@@ -201,12 +203,19 @@ struct thermal_zone_device {
/**
* struct thermal_governor - structure that holds thermal governor information
* @name: name of the governor
* @bind_to_tz: callback called when binding to a thermal zone. If it
* returns 0, the governor is bound to the thermal zone,
* otherwise it fails.
* @unbind_from_tz: callback called when a governor is unbound from a
* thermal zone.
* @throttle: callback called for every trip point even if temperature is
* below the trip point temperature
* @governor_list: node in thermal_governor_list (in thermal_core.c)
*/
struct thermal_governor {
char name[THERMAL_NAME_LENGTH];
int (*bind_to_tz)(struct thermal_zone_device *tz);
void (*unbind_from_tz)(struct thermal_zone_device *tz);
int (*throttle)(struct thermal_zone_device *tz, int trip);
struct list_head governor_list;
};
......
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