Durga,

On 05-02-2013 06:46, Durgadoss R wrote:
This patch creates new APIs to add/remove a
cdev to/from a zone. This patch does not change
the old cooling device implementation.

Same comments on patch 02/08 I want to rise here:

- Consider using linked list
- You may have contention on your index/cdevs array
- overflow on your buffer (carefully check your implementation)
- zone removal condition. can we remove zones with cdevs registered?
- get_by_name, why do we need it? (at least not on this patch)
- Minors on strlcpy, snprintf, devm_ helpers
- documentation in the code for these helper functions and also better naming..


Signed-off-by: Durgadoss R <durgados...@intel.com>
---
  drivers/thermal/thermal_sys.c |   80 +++++++++++++++++++++++++++++++++++++++++
  include/linux/thermal.h       |    9 +++++
  2 files changed, 89 insertions(+)

diff --git a/drivers/thermal/thermal_sys.c b/drivers/thermal/thermal_sys.c
index 838d4fb..bf703b1 100644
--- a/drivers/thermal/thermal_sys.c
+++ b/drivers/thermal/thermal_sys.c
@@ -57,6 +57,7 @@ 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(cdev_list_lock);
  static DEFINE_MUTEX(thermal_governor_lock);

  #define for_each_thermal_sensor(pos) \
@@ -83,6 +84,9 @@ static DEFINE_MUTEX(thermal_governor_lock);
        ret;                                            \
  })

+#define for_each_cdev(pos) \
+       list_for_each_entry(pos, &thermal_cdev_list, node)
+
  static struct thermal_governor *__find_governor(const char *name)
  {
        struct thermal_governor *pos;
@@ -466,6 +470,24 @@ static void remove_sensor_from_zone(struct thermal_zone 
*tz,
        tz->sensor_indx--;
  }

+static void remove_cdev_from_zone(struct thermal_zone *tz,
+                               struct thermal_cooling_device *cdev)
+{
+       int j, indx;
+
+       indx = GET_INDEX(tz, cdev, cdev);
+       if (indx < 0)
+               return;
+
+       sysfs_remove_link(&tz->device.kobj, kobject_name(&cdev->device.kobj));
+
+       /* Shift the entries in the tz->cdevs array */
+       for (j = indx; j < MAX_CDEVS_PER_ZONE - 1; j++)
+               tz->cdevs[j] = tz->cdevs[j + 1];
+
+       tz->cdev_indx--;
+}
+
  /* sys I/F for thermal zone */

  #define to_thermal_zone(_dev) \
@@ -1462,6 +1484,7 @@ void thermal_cooling_device_unregister(struct 
thermal_cooling_device *cdev)
        int i;
        const struct thermal_zone_params *tzp;
        struct thermal_zone_device *tz;
+       struct thermal_zone *tmp_tz;
        struct thermal_cooling_device *pos = NULL;

        if (!cdev)
@@ -1499,6 +1522,13 @@ void thermal_cooling_device_unregister(struct 
thermal_cooling_device *cdev)

        mutex_unlock(&thermal_list_lock);

+       mutex_lock(&zone_list_lock);
+
+       for_each_thermal_zone(tmp_tz)
+               remove_cdev_from_zone(tmp_tz, cdev);
+
+       mutex_unlock(&zone_list_lock);
+
        if (cdev->type[0])
                device_remove_file(&cdev->device, &dev_attr_cdev_type);
        device_remove_file(&cdev->device, &dev_attr_max_state);
@@ -1794,6 +1824,23 @@ exit:
  }
  EXPORT_SYMBOL(remove_thermal_zone);

+struct thermal_cooling_device *get_cdev_by_name(const char *name)
+{
+       struct thermal_cooling_device *pos;
+       struct thermal_cooling_device *cdev = NULL;
+
+       mutex_lock(&cdev_list_lock);
+       for_each_cdev(pos) {
+               if (!strnicmp(pos->type, name, THERMAL_NAME_LENGTH)) {
+                       cdev = pos;
+                       break;
+               }
+       }
+       mutex_unlock(&cdev_list_lock);
+       return cdev;
+}
+EXPORT_SYMBOL(get_cdev_by_name);
+
  struct thermal_sensor *get_sensor_by_name(const char *name)
  {
        struct thermal_sensor *pos;
@@ -1844,6 +1891,39 @@ exit_zone:
  }
  EXPORT_SYMBOL(add_sensor_to_zone);

+int add_cdev_to_zone(struct thermal_zone *tz,
+                       struct thermal_cooling_device *cdev)
+{
+       int ret;
+
+       if (!tz || !cdev)
+               return -EINVAL;
+
+       mutex_lock(&zone_list_lock);
+
+       /* Ensure we are not adding the same cdev again!! */
+       ret = GET_INDEX(tz, cdev, cdev);
+       if (ret >= 0) {
+               ret = -EEXIST;
+               goto exit_zone;
+       }
+
+       mutex_lock(&cdev_list_lock);
+       ret = sysfs_create_link(&tz->device.kobj, &cdev->device.kobj,
+                               kobject_name(&cdev->device.kobj));
+       if (ret)
+               goto exit_cdev;
+
+       tz->cdevs[tz->cdev_indx++] = cdev;
+
+exit_cdev:
+       mutex_unlock(&cdev_list_lock);
+exit_zone:
+       mutex_unlock(&zone_list_lock);
+       return ret;
+}
+EXPORT_SYMBOL(add_cdev_to_zone);
+
  /**
   * thermal_sensor_register - register a new thermal sensor
   * @name:     name of the thermal sensor
diff --git a/include/linux/thermal.h b/include/linux/thermal.h
index 2194519..c841414 100644
--- a/include/linux/thermal.h
+++ b/include/linux/thermal.h
@@ -57,6 +57,8 @@

  #define MAX_SENSORS_PER_ZONE          5

+#define MAX_CDEVS_PER_ZONE             5
+
  struct thermal_sensor;
  struct thermal_zone_device;
  struct thermal_cooling_device;
@@ -217,6 +219,10 @@ struct thermal_zone {
        /* Sensor level information */
        int sensor_indx; /* index into 'sensors' array */
        struct thermal_sensor *sensors[MAX_SENSORS_PER_ZONE];
+
+       /* cdev level information */
+       int cdev_indx; /* index into 'cdevs' array */
+       struct thermal_cooling_device *cdevs[MAX_CDEVS_PER_ZONE];
  };

  /* Structure that holds thermal governor information */
@@ -296,6 +302,9 @@ 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 *);

+int add_cdev_to_zone(struct thermal_zone *, struct thermal_cooling_device *);
+struct thermal_cooling_device *get_cdev_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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