diff options
| -rw-r--r-- | drivers/watchdog/watchdog_dev.c | 15 | ||||
| -rw-r--r-- | drivers/watchdog/watchdog_pretimeout.c | 76 | ||||
| -rw-r--r-- | drivers/watchdog/watchdog_pretimeout.h | 8 |
3 files changed, 98 insertions, 1 deletions
diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c index d2d0b5e37a35..3fdbe0ab1365 100644 --- a/drivers/watchdog/watchdog_dev.c +++ b/drivers/watchdog/watchdog_dev.c @@ -497,7 +497,20 @@ static ssize_t pretimeout_governor_show(struct device *dev, return watchdog_pretimeout_governor_get(wdd, buf); } -static DEVICE_ATTR_RO(pretimeout_governor); + +static ssize_t pretimeout_governor_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct watchdog_device *wdd = dev_get_drvdata(dev); + int ret = watchdog_pretimeout_governor_set(wdd, buf); + + if (!ret) + ret = count; + + return ret; +} +static DEVICE_ATTR_RW(pretimeout_governor); static umode_t wdt_is_visible(struct kobject *kobj, struct attribute *attr, int n) diff --git a/drivers/watchdog/watchdog_pretimeout.c b/drivers/watchdog/watchdog_pretimeout.c index 098c965f6c78..c9e4a0326938 100644 --- a/drivers/watchdog/watchdog_pretimeout.c +++ b/drivers/watchdog/watchdog_pretimeout.c @@ -11,6 +11,7 @@ #include <linux/list.h> #include <linux/slab.h> #include <linux/spinlock.h> +#include <linux/string.h> #include <linux/watchdog.h> #include "watchdog_pretimeout.h" @@ -29,6 +30,28 @@ struct watchdog_pretimeout { struct list_head entry; }; +/* The mutex protects governor list and serializes external interfaces */ +static DEFINE_MUTEX(governor_lock); + +/* List of the registered watchdog pretimeout governors */ +static LIST_HEAD(governor_list); + +struct governor_priv { + struct watchdog_governor *gov; + struct list_head entry; +}; + +static struct governor_priv *find_governor_by_name(const char *gov_name) +{ + struct governor_priv *priv; + + list_for_each_entry(priv, &governor_list, entry) + if (sysfs_streq(gov_name, priv->gov->name)) + return priv; + + return NULL; +} + int watchdog_pretimeout_governor_get(struct watchdog_device *wdd, char *buf) { int count = 0; @@ -41,6 +64,28 @@ int watchdog_pretimeout_governor_get(struct watchdog_device *wdd, char *buf) return count; } +int watchdog_pretimeout_governor_set(struct watchdog_device *wdd, + const char *buf) +{ + struct governor_priv *priv; + + mutex_lock(&governor_lock); + + priv = find_governor_by_name(buf); + if (!priv) { + mutex_unlock(&governor_lock); + return -EINVAL; + } + + spin_lock_irq(&pretimeout_lock); + wdd->gov = priv->gov; + spin_unlock_irq(&pretimeout_lock); + + mutex_unlock(&governor_lock); + + return 0; +} + void watchdog_notify_pretimeout(struct watchdog_device *wdd) { unsigned long flags; @@ -59,6 +104,22 @@ EXPORT_SYMBOL_GPL(watchdog_notify_pretimeout); int watchdog_register_governor(struct watchdog_governor *gov) { struct watchdog_pretimeout *p; + struct governor_priv *priv; + + priv = kzalloc(sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + mutex_lock(&governor_lock); + + if (find_governor_by_name(gov->name)) { + mutex_unlock(&governor_lock); + kfree(priv); + return -EBUSY; + } + + priv->gov = gov; + list_add(&priv->entry, &governor_list); if (!strncmp(gov->name, WATCHDOG_PRETIMEOUT_DEFAULT_GOV, WATCHDOG_GOV_NAME_MAXLEN)) { @@ -71,6 +132,8 @@ int watchdog_register_governor(struct watchdog_governor *gov) spin_unlock_irq(&pretimeout_lock); } + mutex_unlock(&governor_lock); + return 0; } EXPORT_SYMBOL(watchdog_register_governor); @@ -78,12 +141,25 @@ EXPORT_SYMBOL(watchdog_register_governor); void watchdog_unregister_governor(struct watchdog_governor *gov) { struct watchdog_pretimeout *p; + struct governor_priv *priv, *t; + + mutex_lock(&governor_lock); + + list_for_each_entry_safe(priv, t, &governor_list, entry) { + if (priv->gov == gov) { + list_del(&priv->entry); + kfree(priv); + break; + } + } spin_lock_irq(&pretimeout_lock); list_for_each_entry(p, &pretimeout_list, entry) if (p->wdd->gov == gov) p->wdd->gov = default_gov; spin_unlock_irq(&pretimeout_lock); + + mutex_unlock(&governor_lock); } EXPORT_SYMBOL(watchdog_unregister_governor); diff --git a/drivers/watchdog/watchdog_pretimeout.h b/drivers/watchdog/watchdog_pretimeout.h index 867492aa7ea6..6cd6c89a411c 100644 --- a/drivers/watchdog/watchdog_pretimeout.h +++ b/drivers/watchdog/watchdog_pretimeout.h @@ -19,6 +19,8 @@ void watchdog_unregister_governor(struct watchdog_governor *gov); int watchdog_register_pretimeout(struct watchdog_device *wdd); void watchdog_unregister_pretimeout(struct watchdog_device *wdd); int watchdog_pretimeout_governor_get(struct watchdog_device *wdd, char *buf); +int watchdog_pretimeout_governor_set(struct watchdog_device *wdd, + const char *buf); #if IS_ENABLED(CONFIG_WATCHDOG_PRETIMEOUT_DEFAULT_GOV_NOOP) #define WATCHDOG_PRETIMEOUT_DEFAULT_GOV "noop" @@ -41,6 +43,12 @@ static inline int watchdog_pretimeout_governor_get(struct watchdog_device *wdd, { return -EINVAL; } + +static inline int watchdog_pretimeout_governor_set(struct watchdog_device *wdd, + const char *buf) +{ + return -EINVAL; +} #endif #endif |