[PATCH 28/48] thermal: Add event notification to thermal framework

Len Brown
2011-01-12T18:00:35Z

From: R.Durgadoss <durgadoss.r@intel.com>

This patch adds event notification support to the generic
thermal sysfs framework in the kernel. The notification is in the
form of a netlink event.

Signed-off-by: R.Durgadoss <durgadoss.r@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
---
Documentation/ABI/stable/thermal-notification | 4 +
Documentation/thermal/sysfs-api.txt | 12 +++
drivers/thermal/Kconfig | 1 +
drivers/thermal/thermal_sys.c | 103 ++++++++++++++++++++++++-
include/linux/thermal.h | 32 ++++++++
5 files changed, 151 insertions(+), 1 deletions(-)
create mode 100644 Documentation/ABI/stable/thermal-notification

diff --git a/Documentation/ABI/stable/thermal-notification b/Documentation/ABI/stable/thermal-notification
new file mode 100644
index 0000000..9723e8b
--- /dev/null
+++ b/Documentation/ABI/stable/thermal-notification
@@ -0,0 +1,4 @@
+What: A notification mechanism for thermal related events
+Description:
+ This interface enables notification for thermal related events.
+ The notification is in the form of a netlink event.
diff --git a/Documentation/thermal/sysfs-api.txt b/Documentation/thermal/sysfs-api.txt
index cb3d15b..b61e46f 100644
--- a/Documentation/thermal/sysfs-api.txt
+++ b/Documentation/thermal/sysfs-api.txt
@@ -278,3 +278,15 @@ method, the sys I/F structure will be built like this:
|---name: acpitz
|---temp1_input: 37000
|---temp1_crit: 100000
+
+4. Event Notification
+
+The framework includes a simple notification mechanism, in the form of a
+netlink event. Netlink socket initialization is done during the _init_
+of the framework. Drivers which intend to use the notification mechanism
+just need to call generate_netlink_event() with two arguments viz
+(originator, event). Typically the originator will be an integer assigned
+to a thermal_zone_device when it registers itself with the framework. The
+event will be one of:{THERMAL_AUX0, THERMAL_AUX1, THERMAL_CRITICAL,
+THERMAL_DEV_FAULT}. Notification can be sent when the current temperature
+crosses any of the configured thresholds.
diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index bf7c687..f7a5dba 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -4,6 +4,7 @@

menuconfig THERMAL
tristate "Generic Thermal sysfs driver"
+ depends on NET
help
Generic Thermal Sysfs driver offers a generic mechanism for
thermal management. Usually it's made up of one or more thermal
diff --git a/drivers/thermal/thermal_sys.c b/drivers/thermal/thermal_sys.c
index 13c72c6..760e045 100644
--- a/drivers/thermal/thermal_sys.c
+++ b/drivers/thermal/thermal_sys.c
@@ -32,6 +32,8 @@
#include <linux/thermal.h>
#include <linux/spinlock.h>
#include <linux/reboot.h>
+#include <net/netlink.h>
+#include <net/genetlink.h>

MODULE_AUTHOR("Zhang Rui");
MODULE_DESCRIPTION("Generic thermal management sysfs support");
@@ -58,6 +60,22 @@ static LIST_HEAD(thermal_tz_list);
static LIST_HEAD(thermal_cdev_list);
static DEFINE_MUTEX(thermal_list_lock);

+static unsigned int thermal_event_seqnum;
+
+static struct genl_family thermal_event_genl_family = {
+ .id = GENL_ID_GENERATE,
+ .name = THERMAL_GENL_FAMILY_NAME,
+ .version = THERMAL_GENL_VERSION,
+ .maxattr = THERMAL_GENL_ATTR_MAX,
+};
+
+static struct genl_multicast_group thermal_event_mcgrp = {
+ .name = THERMAL_GENL_MCAST_GROUP_NAME,
+};
+
+static int genetlink_init(void);
+static void genetlink_exit(void);
+
static int get_idr(struct idr *idr, struct mutex *lock, int *id)
{
int err;
@@ -1214,6 +1232,82 @@ void thermal_zone_device_unregister(struct thermal_zone_device *tz)

EXPORT_SYMBOL(thermal_zone_device_unregister);

+int generate_netlink_event(u32 orig, enum events event)
+{
+ struct sk_buff *skb;
+ struct nlattr *attr;
+ struct thermal_genl_event *thermal_event;
+ void *msg_header;
+ int size;
+ int result;
+
+ /* allocate memory */
+ size = nla_total_size(sizeof(struct thermal_genl_event)) + \
+ nla_total_size(0);
+
+ skb = genlmsg_new(size, GFP_ATOMIC);
+ if (!skb)
+ return -ENOMEM;
+
+ /* add the genetlink message header */
+ msg_header = genlmsg_put(skb, 0, thermal_event_seqnum++,
+ &thermal_event_genl_family, 0,
+ THERMAL_GENL_CMD_EVENT);
+ if (!msg_header) {
+ nlmsg_free(skb);
+ return -ENOMEM;
+ }
+
+ /* fill the data */
+ attr = nla_reserve(skb, THERMAL_GENL_ATTR_EVENT, \
+ sizeof(struct thermal_genl_event));
+
+ if (!attr) {
+ nlmsg_free(skb);
+ return -EINVAL;
+ }
+
+ thermal_event = nla_data(attr);
+ if (!thermal_event) {
+ nlmsg_free(skb);
+ return -EINVAL;
+ }
+
+ memset(thermal_event, 0, sizeof(struct thermal_genl_event));
+
+ thermal_event->orig = orig;
+ thermal_event->event = event;
+
+ /* send multicast genetlink message */
+ result = genlmsg_end(skb, msg_header);
+ if (result < 0) {
+ nlmsg_free(skb);
+ return result;
+ }
+
+ result = genlmsg_multicast(skb, 0, thermal_event_mcgrp.id, GFP_ATOMIC);
+ if (result)
+ printk(KERN_INFO "failed to send netlink event:%d", result);
+
+ return result;
+}
+EXPORT_SYMBOL(generate_netlink_event);
+
+static int genetlink_init(void)
+{
+ int result;
+
+ result = genl_register_family(&thermal_event_genl_family);
+ if (result)
+ return result;
+
+ result = genl_register_mc_group(&thermal_event_genl_family,
+ &thermal_event_mcgrp);
+ if (result)
+ genl_unregister_family(&thermal_event_genl_family);
+ return result;
+}
+
static int __init thermal_init(void)
{
int result = 0;
@@ -1225,9 +1319,15 @@ static int __init thermal_init(void)
mutex_destroy(&thermal_idr_lock);
mutex_destroy(&thermal_list_lock);
}
+ result = genetlink_init();
return result;
}

+static void genetlink_exit(void)
+{
+ genl_unregister_family(&thermal_event_genl_family);
+}
+
static void __exit thermal_exit(void)
{
class_unregister(&thermal_class);
@@ -1235,7 +1335,8 @@ static void __exit thermal_exit(void)
idr_destroy(&thermal_cdev_idr);
mutex_destroy(&thermal_idr_lock);
mutex_destroy(&thermal_list_lock);
+ genetlink_exit();
}

-subsys_initcall(thermal_init);
+fs_initcall(thermal_init);
module_exit(thermal_exit);
diff --git a/include/linux/thermal.h b/include/linux/thermal.h
index 1de8b9e..7846449 100644
--- a/include/linux/thermal.h
+++ b/include/linux/thermal.h
@@ -127,6 +127,37 @@ struct thermal_zone_device {
struct thermal_hwmon_attr temp_crit; /* hwmon sys attr */
#endif
};
+/* Adding event notification support elements */
+#define THERMAL_GENL_FAMILY_NAME "thermal_event"
+#define THERMAL_GENL_VERSION 0x01
+#define THERMAL_GENL_MCAST_GROUP_NAME "thermal_mc_group"
+
+enum events {
+ THERMAL_AUX0,
+ THERMAL_AUX1,
+ THERMAL_CRITICAL,
+ THERMAL_DEV_FAULT,
+};
+
+struct thermal_genl_event {
+ u32 orig;
+ enum events event;
+};
+/* attributes of thermal_genl_family */
+enum {
+ THERMAL_GENL_ATTR_UNSPEC,
+ THERMAL_GENL_ATTR_EVENT,
+ __THERMAL_GENL_ATTR_MAX,
+};
+#define THERMAL_GENL_ATTR_MAX (__THERMAL_GENL_ATTR_MAX - 1)
+
+/* commands supported by the thermal_genl_family */
+enum {
+ THERMAL_GENL_CMD_UNSPEC,
+ THERMAL_GENL_CMD_EVENT,
+ __THERMAL_GENL_CMD_MAX,
+};
+#define THERMAL_GENL_CMD_MAX (__THERMAL_GENL_CMD_MAX - 1)

struct thermal_zone_device *thermal_zone_device_register(char *, int, void *,
struct
@@ -146,5 +177,6 @@ struct thermal_cooling_device *thermal_cooling_device_register(char *, void *,
thermal_cooling_device_ops
*);
void thermal_cooling_device_unregister(struct thermal_cooling_device *);
+extern int generate_netlink_event(u32 orig, enum events event);

#endif /* __THERMAL_H__ */
--
1.7.4.rc1.7.g2cf08