The change adds an option to a user with CONFIG_WATCHDOG_SYSFS and
CONFIG_WATCHDOG_PRETIMEOUT_GOV enabled to get information about all
registered watchdog pretimeout governors by reading watchdog device
attribute named "pretimeout_available_governors".
Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@xxxxxxxxxx>
---
Changes from v4 to v5:
* none
Changes from v3 to v4:
* new change, this functional change was removed in v3
Changes from v2 1/4 to v4:
* introduced watchdog_pretimeout_available_governors_get() and moved
device attribute registration to watchdog_dev.c
* made attribute visibility more precise
drivers/watchdog/watchdog_dev.c | 11 ++++++++++-
drivers/watchdog/watchdog_pretimeout.c | 15 +++++++++++++++
drivers/watchdog/watchdog_pretimeout.h | 6 ++++++
3 files changed, 31 insertions(+), 1 deletion(-)
diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
index 3fdbe0ab1365..32930a073a12 100644
--- a/drivers/watchdog/watchdog_dev.c
+++ b/drivers/watchdog/watchdog_dev.c
@@ -489,6 +489,13 @@ static ssize_t state_show(struct device *dev, struct device_attribute *attr,
}
static DEVICE_ATTR_RO(state);
+static ssize_t pretimeout_available_governors_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return watchdog_pretimeout_available_governors_get(buf);
+}
+static DEVICE_ATTR_RO(pretimeout_available_governors);
+
static ssize_t pretimeout_governor_show(struct device *dev,
struct device_attribute *attr,
char *buf)
@@ -524,7 +531,8 @@ static umode_t wdt_is_visible(struct kobject *kobj, struct attribute *attr,
else if (attr == &dev_attr_pretimeout.attr &&
!(wdd->info->options & WDIOF_PRETIMEOUT))
mode = 0;
- else if (attr == &dev_attr_pretimeout_governor.attr &&
+ else if ((attr == &dev_attr_pretimeout_governor.attr ||
+ attr == &dev_attr_pretimeout_available_governors.attr) &&
(!(wdd->info->options & WDIOF_PRETIMEOUT) ||
!IS_ENABLED(CONFIG_WATCHDOG_PRETIMEOUT_GOV)))
mode = 0;
@@ -541,6 +549,7 @@ static struct attribute *wdt_attrs[] = {
&dev_attr_status.attr,
&dev_attr_nowayout.attr,
&dev_attr_pretimeout_governor.attr,
+ &dev_attr_pretimeout_available_governors.attr,
NULL,
};
diff --git a/drivers/watchdog/watchdog_pretimeout.c b/drivers/watchdog/watchdog_pretimeout.c
index c9e4a0326938..9db07bfb4334 100644
--- a/drivers/watchdog/watchdog_pretimeout.c
+++ b/drivers/watchdog/watchdog_pretimeout.c
@@ -52,6 +52,21 @@ static struct governor_priv *find_governor_by_name(const char *gov_name)
return NULL;
}
+int watchdog_pretimeout_available_governors_get(char *buf)
+{
+ struct governor_priv *priv;
+ int count = 0;
+
+ mutex_lock(&governor_lock);
+
+ list_for_each_entry(priv, &governor_list, entry)
+ count += sprintf(buf + count, "%s\n", priv->gov->name);
+
+ mutex_unlock(&governor_lock);
+
+ return count;
+}
+
int watchdog_pretimeout_governor_get(struct watchdog_device *wdd, char *buf)
{
int count = 0;
diff --git a/drivers/watchdog/watchdog_pretimeout.h b/drivers/watchdog/watchdog_pretimeout.h
index afb868eedc65..0166dea234d6 100644
--- a/drivers/watchdog/watchdog_pretimeout.h
+++ b/drivers/watchdog/watchdog_pretimeout.h
@@ -18,6 +18,7 @@ void watchdog_unregister_governor(struct watchdog_governor *gov);
/* Interfaces to watchdog_dev.c */
int watchdog_register_pretimeout(struct watchdog_device *wdd);
void watchdog_unregister_pretimeout(struct watchdog_device *wdd);
+int watchdog_pretimeout_available_governors_get(char *buf);
int watchdog_pretimeout_governor_get(struct watchdog_device *wdd, char *buf);
int watchdog_pretimeout_governor_set(struct watchdog_device *wdd,
const char *buf);
@@ -38,6 +39,11 @@ static inline void watchdog_unregister_pretimeout(struct watchdog_device *wdd)
{
}
+static inline int watchdog_pretimeout_available_governors_get(char *buf)
+{
+ return -EINVAL;
+}
+
static inline int watchdog_pretimeout_governor_get(struct watchdog_device *wdd,
char *buf)
{
--
2.8.1
--
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