static int watchdog_stop(struct watchdog_device *wdd)
{
int err = 0;
if (!watchdog_active(wdd))
return 0;
if (test_bit(WDOG_NO_WAY_OUT, &wdd->status)) {
pr_info("watchdog%d: nowayout prevents watchdog being stopped!\n",
wdd->id);
return -EBUSY;
}
if (wdd->ops->stop) {
clear_bit(WDOG_HW_RUNNING, &wdd->status);
err = wdd->ops->stop(wdd);
} else {
set_bit(WDOG_HW_RUNNING, &wdd->status);
}
if (err == 0) {
clear_bit(WDOG_ACTIVE, &wdd->status);
watchdog_update_worker(wdd);
}
return err;
}
static int __watchdog_ping(struct watchdog_device *wdd)
{
struct watchdog_core_data *wd_data = wdd->wd_data;
ktime_t earliest_keepalive, now;
int err;
earliest_keepalive = ktime_add(wd_data->last_hw_keepalive,
ms_to_ktime(wdd->min_hw_heartbeat_ms));
now = ktime_get();
if (ktime_after(earliest_keepalive, now)) {
hrtimer_start(&wd_data->timer,
ktime_sub(earliest_keepalive, now),
HRTIMER_MODE_REL);
return 0;
}
wd_data->last_hw_keepalive = now;
if (wdd->ops->ping)
err = wdd->ops->ping(wdd); /* ping the watchdog */
else
err = wdd->ops->start(wdd); /* restart watchdog */
watchdog_update_worker(wdd);
return err;
}
static int watchdog_release(struct inode *inode, struct file *file)
{
struct watchdog_core_data *wd_data = file->private_data;
struct watchdog_device *wdd;
int err = -EBUSY;
bool running;
mutex_lock(&wd_data->lock);
wdd = wd_data->wdd;
if (!wdd)
goto done;
/*
* We only stop the watchdog if we received the magic character
* or if WDIOF_MAGICCLOSE is not set. If nowayout was set then
* watchdog_stop will fail.
*/
if (!test_bit(WDOG_ACTIVE, &wdd->status))
err = 0;
else if (test_and_clear_bit(_WDOG_ALLOW_RELEASE, &wd_data->status) ||
!(wdd->info->options & WDIOF_MAGICCLOSE))
err = watchdog_stop(wdd);
/* If the watchdog was not stopped, send a keepalive ping */
if (err < 0) {
pr_crit("watchdog%d: watchdog did not stop!\n", wdd->id);
watchdog_ping(wdd);
}
watchdog_update_worker(wdd);
/* make sure that /dev/watchdog can be re-opened */
clear_bit(_WDOG_DEV_OPEN, &wd_data->status);
done:
running = wdd && watchdog_hw_running(wdd);
mutex_unlock(&wd_data->lock);
/*
* Allow the owner module to be unloaded again unless the watchdog
* is still running. If the watchdog is still running, it can not
* be stopped, and its driver must not be unloaded.
*/
if (!running) {
module_put(wd_data->cdev.owner);
kref_put(&wd_data->kref, watchdog_core_data_release);
}
return 0;
}
static int watchdog_set_timeout(struct watchdog_device *wdd,
unsigned int timeout)
{
int err = 0;
if (!(wdd->info->options & WDIOF_SETTIMEOUT))
return -EOPNOTSUPP;
if (watchdog_timeout_invalid(wdd, timeout))
return -EINVAL;
if (wdd->ops->set_timeout)
err = wdd->ops->set_timeout(wdd, timeout);
else
wdd->timeout = timeout;
watchdog_update_worker(wdd);
return err;
}
static int watchdog_set_timeout(struct watchdog_device *wdd,
unsigned int timeout)
{
int err = 0;
if (!(wdd->info->options & WDIOF_SETTIMEOUT))
return -EOPNOTSUPP;
if (watchdog_timeout_invalid(wdd, timeout))
return -EINVAL;
if (wdd->ops->set_timeout) {
err = wdd->ops->set_timeout(wdd, timeout);
} else {
wdd->timeout = timeout;
/* Disable pretimeout if it doesn't fit the new timeout */
if (wdd->pretimeout >= wdd->timeout)
wdd->pretimeout = 0;
}
watchdog_update_worker(wdd);
return err;
}
static int watchdog_start(struct watchdog_device *wdd)
{
struct watchdog_core_data *wd_data = wdd->wd_data;
unsigned long started_at;
int err;
if (watchdog_active(wdd))
return 0;
set_bit(_WDOG_KEEPALIVE, &wd_data->status);
started_at = jiffies;
if (watchdog_hw_running(wdd) && wdd->ops->ping)
err = wdd->ops->ping(wdd);
else
err = wdd->ops->start(wdd);
if (err == 0) {
set_bit(WDOG_ACTIVE, &wdd->status);
wd_data->last_keepalive = started_at;
watchdog_update_worker(wdd);
}
return err;
}
static int __watchdog_ping(struct watchdog_device *wdd)
{
struct watchdog_core_data *wd_data = wdd->wd_data;
unsigned long earliest_keepalive = wd_data->last_hw_keepalive +
msecs_to_jiffies(wdd->min_hw_heartbeat_ms);
int err;
if (time_is_after_jiffies(earliest_keepalive)) {
mod_delayed_work(watchdog_wq, &wd_data->work,
earliest_keepalive - jiffies);
return 0;
}
wd_data->last_hw_keepalive = jiffies;
if (wdd->ops->ping)
err = wdd->ops->ping(wdd); /* ping the watchdog */
else
err = wdd->ops->start(wdd); /* restart watchdog */
watchdog_update_worker(wdd);
return err;
}
