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SubjectRe: [PATCH 2/8] Thermal: Create zone level APIs
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On Tue, 2013-02-05 at 16:16 +0530, Durgadoss R wrote:
> This patch adds a new thermal_zone structure to
> thermal.h. Also, adds zone level APIs to the thermal
> framework.
>
> A thermal zone is a hot spot on the platform, which
> can have one or more sensors and cooling devices attached
> to it. These sensors can be mapped to a set of cooling
> devices, which when throttled, can help to bring down
> the temperature of the hot spot.
>
> Signed-off-by: Durgadoss R <durgadoss.r@intel.com>
> ---
> drivers/thermal/thermal_sys.c | 196 +++++++++++++++++++++++++++++++++++++++++
> include/linux/thermal.h | 22 +++++
> 2 files changed, 218 insertions(+)
>
> diff --git a/drivers/thermal/thermal_sys.c b/drivers/thermal/thermal_sys.c
> index cb94497..838d4fb 100644
> --- a/drivers/thermal/thermal_sys.c
> +++ b/drivers/thermal/thermal_sys.c
> @@ -43,19 +43,46 @@ MODULE_DESCRIPTION("Generic thermal management sysfs support");
> MODULE_LICENSE("GPL");
>
> static DEFINE_IDR(thermal_tz_idr);
> +static DEFINE_IDR(thermal_zone_idr);
> static DEFINE_IDR(thermal_cdev_idr);
> static DEFINE_IDR(thermal_sensor_idr);
> static DEFINE_MUTEX(thermal_idr_lock);
>
> static LIST_HEAD(thermal_tz_list);
> static LIST_HEAD(thermal_sensor_list);
> +static LIST_HEAD(thermal_zone_list);
> static LIST_HEAD(thermal_cdev_list);
> static LIST_HEAD(thermal_governor_list);
>
> static DEFINE_MUTEX(thermal_list_lock);
> static DEFINE_MUTEX(sensor_list_lock);
> +static DEFINE_MUTEX(zone_list_lock);
> static DEFINE_MUTEX(thermal_governor_lock);
>
> +#define for_each_thermal_sensor(pos) \
> + list_for_each_entry(pos, &thermal_sensor_list, node)
> +
> +#define for_each_thermal_zone(pos) \
> + list_for_each_entry(pos, &thermal_zone_list, node)
> +
> +#define GET_INDEX(tz, ptr, type) \
> +({ \
> + int i, ret = -EINVAL; \
> + do { \
> + if (!tz || !ptr) \
> + break; \
> + mutex_lock(&type##_list_lock); \
> + for (i = 0; i < tz->type##_indx; i++) { \
> + if (tz->type##s[i] == ptr) { \
> + ret = i; \
> + break; \
> + } \
> + } \
> + mutex_unlock(&type##_list_lock); \
> + } while (0); \
> + ret; \
> +})
> +
> static struct thermal_governor *__find_governor(const char *name)
> {
> struct thermal_governor *pos;
> @@ -421,15 +448,44 @@ static void thermal_zone_device_check(struct work_struct *work)
> thermal_zone_device_update(tz);
> }
>
> +static void remove_sensor_from_zone(struct thermal_zone *tz,
> + struct thermal_sensor *ts)
> +{
> + int j, indx;
> +
> + indx = GET_INDEX(tz, ts, sensor);
> + if (indx < 0)
> + return;
> +
> + sysfs_remove_link(&tz->device.kobj, kobject_name(&ts->device.kobj));
> +
> + /* Shift the entries in the tz->sensors array */
> + for (j = indx; j < MAX_SENSORS_PER_ZONE - 1; j++)
> + tz->sensors[j] = tz->sensors[j + 1];
> +
> + tz->sensor_indx--;
> +}
> +
> /* sys I/F for thermal zone */
>
> #define to_thermal_zone(_dev) \
> container_of(_dev, struct thermal_zone_device, device)
>
> +#define to_zone(_dev) \
> + container_of(_dev, struct thermal_zone, device)
> +
> #define to_thermal_sensor(_dev) \
> container_of(_dev, struct thermal_sensor, device)
>
> static ssize_t
> +zone_name_show(struct device *dev, struct device_attribute *attr, char *buf)
> +{
> + struct thermal_zone *tz = to_zone(dev);
> +
> + return sprintf(buf, "%s\n", tz->name);
> +}
> +
> +static ssize_t
> sensor_name_show(struct device *dev, struct device_attribute *attr, char *buf)
> {
> struct thermal_sensor *ts = to_thermal_sensor(dev);
> @@ -811,6 +867,8 @@ static DEVICE_ATTR(policy, S_IRUGO | S_IWUSR, policy_show, policy_store);
> static DEVICE_ATTR(sensor_name, 0444, sensor_name_show, NULL);
> static DEVICE_ATTR(temp_input, 0444, sensor_temp_show, NULL);
>
> +static DEVICE_ATTR(zone_name, 0444, zone_name_show, NULL);
> +
> /* sys I/F for cooling device */
> #define to_cooling_device(_dev) \
> container_of(_dev, struct thermal_cooling_device, device)
> @@ -1656,6 +1714,136 @@ static int enable_sensor_thresholds(struct thermal_sensor *ts, int count)
> return 0;
> }
>
> +struct thermal_zone *create_thermal_zone(const char *name, void *devdata)
> +{
> + struct thermal_zone *tz;
> + int ret;
> +
> + if (!name || (name && strlen(name) >= THERMAL_NAME_LENGTH))
> + return ERR_PTR(-EINVAL);
> +
> + tz = kzalloc(sizeof(*tz), GFP_KERNEL);
> + if (!tz)
> + return ERR_PTR(-ENOMEM);
> +
> + idr_init(&tz->idr);
> + ret = get_idr(&thermal_zone_idr, &thermal_idr_lock, &tz->id);
> + if (ret)
> + goto exit_free;
> +
> + strcpy(tz->name, name);
> + tz->devdata = devdata;
> + tz->device.class = &thermal_class;
> +
> + dev_set_name(&tz->device, "zone%d", tz->id);
> + ret = device_register(&tz->device);
> + if (ret)
> + goto exit_idr;
> +
> + ret = device_create_file(&tz->device, &dev_attr_zone_name);
> + if (ret)
> + goto exit_unregister;
> +
> + /* Add this zone to the global list of thermal zones */
> + mutex_lock(&zone_list_lock);
> + list_add_tail(&tz->node, &thermal_zone_list);
> + mutex_unlock(&zone_list_lock);
> + return tz;
> +
> +exit_unregister:
> + device_unregister(&tz->device);
> +exit_idr:
> + release_idr(&thermal_zone_idr, &thermal_idr_lock, tz->id);
> +exit_free:
> + kfree(tz);
> + return ERR_PTR(ret);
> +}
> +EXPORT_SYMBOL(create_thermal_zone);
> +
> +void remove_thermal_zone(struct thermal_zone *tz)
> +{
> + struct thermal_zone *pos, *next;
> + bool found = false;
> +
> + if (!tz)
> + return;
> +
> + mutex_lock(&zone_list_lock);
> +
> + list_for_each_entry_safe(pos, next, &thermal_zone_list, node) {
> + if (pos == tz) {
> + list_del(&tz->node);
> + found = true;
> + break;
> + }
> + }
> +
> + if (!found)
> + goto exit;
> +
> + device_remove_file(&tz->device, &dev_attr_zone_name);
> +
> + release_idr(&thermal_zone_idr, &thermal_idr_lock, tz->id);
> + idr_destroy(&tz->idr);
> +
> + device_unregister(&tz->device);
> + kfree(tz);
> +exit:
> + mutex_unlock(&zone_list_lock);
> + return;
> +}
> +EXPORT_SYMBOL(remove_thermal_zone);
> +
> +struct thermal_sensor *get_sensor_by_name(const char *name)
> +{
> + struct thermal_sensor *pos;
> + struct thermal_sensor *ts = NULL;
> +
> + mutex_lock(&sensor_list_lock);
> + for_each_thermal_sensor(pos) {
> + if (!strnicmp(pos->name, name, THERMAL_NAME_LENGTH)) {
> + ts = pos;
> + break;

this function depends on the assumption that all the sensor names are
unique.
thus I prefer to go through all the list and return -EINVAL if duplicate
names found, because in this case, the pointer returned may be not the
sensor we want to get.

thanks,
rui
> + }
> + }
> + mutex_unlock(&sensor_list_lock);
> + return ts;
> +}
> +EXPORT_SYMBOL(get_sensor_by_name);
> +
> +int add_sensor_to_zone(struct thermal_zone *tz, struct thermal_sensor *ts)
> +{
> + int ret;
> +
> + if (!tz || !ts)
> + return -EINVAL;
> +
> + mutex_lock(&zone_list_lock);
> +
> + /* Ensure we are not adding the same sensor again!! */
> + ret = GET_INDEX(tz, ts, sensor);
> + if (ret >= 0) {
> + ret = -EEXIST;
> + goto exit_zone;
> + }
> +
> + mutex_lock(&sensor_list_lock);
> +
> + ret = sysfs_create_link(&tz->device.kobj, &ts->device.kobj,
> + kobject_name(&ts->device.kobj));
> + if (ret)
> + goto exit_sensor;
> +
> + tz->sensors[tz->sensor_indx++] = ts;
> +
> +exit_sensor:
> + mutex_unlock(&sensor_list_lock);
> +exit_zone:
> + mutex_unlock(&zone_list_lock);
> + return ret;
> +}
> +EXPORT_SYMBOL(add_sensor_to_zone);
> +
> /**
> * thermal_sensor_register - register a new thermal sensor
> * @name: name of the thermal sensor
> @@ -1732,6 +1920,7 @@ EXPORT_SYMBOL(thermal_sensor_register);
> void thermal_sensor_unregister(struct thermal_sensor *ts)
> {
> int i;
> + struct thermal_zone *tz;
> struct thermal_sensor *pos, *next;
> bool found = false;
>
> @@ -1751,6 +1940,13 @@ void thermal_sensor_unregister(struct thermal_sensor *ts)
> if (!found)
> return;
>
> + mutex_lock(&zone_list_lock);
> +
> + for_each_thermal_zone(tz)
> + remove_sensor_from_zone(tz, ts);
> +
> + mutex_unlock(&zone_list_lock);
> +
> for (i = 0; i < ts->thresholds; i++) {
> device_remove_file(&ts->device, &ts->thresh_attrs[i].attr);
> if (ts->ops->get_hyst) {
> diff --git a/include/linux/thermal.h b/include/linux/thermal.h
> index 5470dae..2194519 100644
> --- a/include/linux/thermal.h
> +++ b/include/linux/thermal.h
> @@ -55,6 +55,8 @@
> #define DEFAULT_THERMAL_GOVERNOR "user_space"
> #endif
>
> +#define MAX_SENSORS_PER_ZONE 5
> +
> struct thermal_sensor;
> struct thermal_zone_device;
> struct thermal_cooling_device;
> @@ -202,6 +204,21 @@ struct thermal_zone_device {
> struct delayed_work poll_queue;
> };
>
> +struct thermal_zone {
> + char name[THERMAL_NAME_LENGTH];
> + int id;
> + void *devdata;
> + struct thermal_zone *ops;
> + struct thermal_governor *governor;
> + struct idr idr;
> + struct device device;
> + struct list_head node;
> +
> + /* Sensor level information */
> + int sensor_indx; /* index into 'sensors' array */
> + struct thermal_sensor *sensors[MAX_SENSORS_PER_ZONE];
> +};
> +
> /* Structure that holds thermal governor information */
> struct thermal_governor {
> char name[THERMAL_NAME_LENGTH];
> @@ -274,6 +291,11 @@ struct thermal_sensor *thermal_sensor_register(const char *, int,
> struct thermal_sensor_ops *, void *);
> void thermal_sensor_unregister(struct thermal_sensor *);
>
> +struct thermal_zone *create_thermal_zone(const char *, void *);
> +void remove_thermal_zone(struct thermal_zone *);
> +int add_sensor_to_zone(struct thermal_zone *, struct thermal_sensor *);
> +struct thermal_sensor *get_sensor_by_name(const char *);
> +
> #ifdef CONFIG_NET
> extern int thermal_generate_netlink_event(struct thermal_zone_device *tz,
> enum events event);




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