Re: [PATCH 3/8] Thermal: Add APIs to bind cdev to new zone structure
From: Eduardo Valentin
Date: Thu Feb 28 2013 - 14:35:53 EST
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 <durgadoss.r@xxxxxxxxx>
---
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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