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Subject[PATCHv5 04/10] Thermal: Create zone level APIs
Date
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_core_new.c | 268 ++++++++++++++++++++++++++++++++++++
include/linux/thermal.h | 23 ++++
2 files changed, 291 insertions(+)

diff --git a/drivers/thermal/thermal_core_new.c b/drivers/thermal/thermal_core_new.c
index ba38438..4f84cb5 100644
--- a/drivers/thermal/thermal_core_new.c
+++ b/drivers/thermal/thermal_core_new.c
@@ -40,13 +40,16 @@ MODULE_LICENSE("GPL v2");

static DEFINE_IDR(thermal_sensor_idr);
static DEFINE_IDR(thermal_cdev_idr);
+static DEFINE_IDR(thermal_zone_idr);

static LIST_HEAD(thermal_sensor_list);
static LIST_HEAD(thermal_cdev_list);
+static LIST_HEAD(thermal_zone_list);

static DEFINE_MUTEX(thermal_idr_lock);
static DEFINE_MUTEX(sensor_list_lock);
static DEFINE_MUTEX(cdev_list_lock);
+static DEFINE_MUTEX(zone_list_lock);

#define to_thermal_sensor(_dev) \
container_of(_dev, struct thermal_sensor, device)
@@ -54,6 +57,35 @@ static DEFINE_MUTEX(cdev_list_lock);
#define to_cooling_device(_dev) \
container_of(_dev, struct thermal_cooling_device, device)

+#define to_thermal_zone(_dev) \
+ container_of(_dev, struct thermal_zone, device)
+
+#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(&tz->lock); \
+ 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); \
+ mutex_unlock(&tz->lock); \
+ } while (0); \
+ ret; \
+})
+
static int get_idr(struct idr *idr, int *id)
{
int ret;
@@ -228,6 +260,14 @@ cur_state_store(struct device *dev, struct device_attribute *attr,
return ret ? ret : count;
}

+static ssize_t
+zone_name_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct thermal_zone *tz = to_thermal_zone(dev);
+
+ return sprintf(buf, "%s\n", tz->name);
+}
+
/* Thermal sensor attributes */
static DEVICE_ATTR_RO(name);
static DEVICE_ATTR_RO(temp);
@@ -237,6 +277,30 @@ static DEVICE_ATTR_RO(type);
static DEVICE_ATTR_RO(max_state);
static DEVICE_ATTR_RW(cur_state);

+/* Thermal zone attributes */
+static DEVICE_ATTR_RO(zone_name);
+
+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));
+
+ mutex_lock(&tz->lock);
+
+ /* 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--;
+ mutex_unlock(&tz->lock);
+}
+
/**
* thermal_create_sensor_sysfs - create sysfs nodes for sensorX
* @ts: the thermal sensor
@@ -391,6 +455,7 @@ EXPORT_SYMBOL_GPL(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;

@@ -410,6 +475,13 @@ 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) {
@@ -549,3 +621,199 @@ void thermal_cdev_unregister(struct thermal_cooling_device *cdev)
return;
}
EXPORT_SYMBOL_GPL(thermal_cdev_unregister);
+
+/**
+ * thermal_create_thermal_zone - create sysfs nodes for thermal zone
+ * @name: Name of the thermla zone
+ * @devdata: Data supplied by the caller
+ *
+ * On Success returns a thermal zone reference, otherwise:
+ * -EINVAL for invalid parameters,
+ * -ENOMEM for insufficient memory cases,
+ */
+struct thermal_zone *thermal_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, &tz->id);
+ if (ret)
+ goto exit_free;
+
+ mutex_init(&tz->lock);
+ strlcpy(tz->name, name, sizeof(tz->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:
+ mutex_destroy(&tz->lock);
+ release_idr(&thermal_zone_idr, tz->id);
+exit_free:
+ kfree(tz);
+ return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(thermal_create_thermal_zone);
+
+/**
+ * thermal_remove_thermal_zone - removes the sysfs nodes for given tz
+ * @tz: Thermal zone to be removed.
+ */
+void thermal_remove_thermal_zone(struct thermal_zone *tz)
+{
+ struct thermal_zone *pos, *next;
+ struct thermal_sensor *ts;
+ 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;
+
+ for_each_thermal_sensor(ts)
+ remove_sensor_from_zone(tz, ts);
+
+ device_remove_file(&tz->device, &dev_attr_zone_name);
+
+ mutex_destroy(&tz->lock);
+ release_idr(&thermal_zone_idr, tz->id);
+ idr_destroy(&tz->idr);
+
+ device_unregister(&tz->device);
+ kfree(tz);
+exit:
+ mutex_unlock(&zone_list_lock);
+ return;
+}
+EXPORT_SYMBOL_GPL(thermal_remove_thermal_zone);
+
+/**
+ * thermal_get_sensor_by_name() - search for a sensor and return its reference
+ * @name: thermal sensor name to fetch the reference
+ *
+ * On success returns a reference to a unique sensor with
+ * name matching that of @name, an ERR_PTR otherwise:
+ * -EINVAL for invalid paramenters
+ * -ENODEV for sensor not found
+ * -EEXIST for multiple matches
+ */
+struct thermal_sensor *thermal_get_sensor_by_name(const char *name)
+{
+ int found = 0;
+ struct thermal_sensor *pos;
+ struct thermal_sensor *ts = ERR_PTR(-EINVAL);
+
+ if (!name)
+ return ts;
+
+ mutex_lock(&sensor_list_lock);
+ for_each_thermal_sensor(pos) {
+ if (!strnicmp(pos->name, name, THERMAL_NAME_LENGTH)) {
+ found++;
+ ts = pos;
+ }
+ }
+ mutex_unlock(&sensor_list_lock);
+
+ if (found == 0)
+ ts = ERR_PTR(-ENODEV);
+ else if (found > 1)
+ ts = ERR_PTR(-EEXIST);
+
+ return ts;
+}
+EXPORT_SYMBOL_GPL(thermal_get_sensor_by_name);
+
+/**
+ * thermal_add_sensor_to_zone - Add @ts to thermal zone @tz
+ * @tz: Thermal zone reference
+ * @ts: Thermal sensor reference
+ *
+ * Returns 0 on success, otherwise
+ * -EINVAL for invalid paramenters
+ * -EINVAL when trying to add more zones than MAX_SENSORS_PER_ZONE
+ * -EEXIST when trying add existing thermal sensor again
+ */
+int thermal_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;
+ }
+
+ /* Protect against 'ts' being unregistered */
+ 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;
+
+ mutex_lock(&tz->lock);
+
+ if (tz->sensor_indx >= MAX_SENSORS_PER_ZONE - 1) {
+ dev_err(&tz->device, "Only %d sensors allowed per zone\n",
+ MAX_SENSORS_PER_ZONE);
+ sysfs_remove_link(&tz->device.kobj,
+ kobject_name(&ts->device.kobj));
+ ret = -EINVAL;
+ goto exit_indx_check;
+ }
+
+ tz->sensors[tz->sensor_indx++] = ts;
+
+exit_indx_check:
+ mutex_unlock(&tz->lock);
+exit_sensor:
+ mutex_unlock(&sensor_list_lock);
+exit_zone:
+ mutex_unlock(&zone_list_lock);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(thermal_add_sensor_to_zone);
diff --git a/include/linux/thermal.h b/include/linux/thermal.h
index 46d7dc3..2afc483 100644
--- a/include/linux/thermal.h
+++ b/include/linux/thermal.h
@@ -59,6 +59,8 @@
#define DEFAULT_THERMAL_GOVERNOR "user_space"
#endif

+#define MAX_SENSORS_PER_ZONE 5
+
struct thermal_sensor;
struct thermal_zone_device;
struct thermal_cooling_device;
@@ -210,6 +212,22 @@ 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 mutex lock; /* protect elements of this structure */
+ 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];
@@ -320,6 +338,11 @@ struct thermal_instance *get_thermal_instance(struct thermal_zone_device *,
void thermal_cdev_update(struct thermal_cooling_device *);
void thermal_notify_framework(struct thermal_zone_device *, int);

+struct thermal_zone *thermal_create_thermal_zone(const char *, void *);
+void thermal_remove_thermal_zone(struct thermal_zone *);
+int thermal_add_sensor_to_zone(struct thermal_zone *, struct thermal_sensor *);
+struct thermal_sensor *thermal_get_sensor_by_name(const char *);
+
#ifdef CONFIG_NET
extern int thermal_generate_netlink_event(struct thermal_zone_device *tz,
enum events event);
--
1.7.9.5


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