watchdog: watchdog_dev: Rewrite wrapper code

Rewrite and extend the wrapper code so that we can easily introduce
locking (this to be able to prevent potential multithreading issues).

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
This commit is contained in:
Hans de Goede 2012-05-22 11:40:26 +02:00 committed by Wim Van Sebroeck
parent 3dfd6218da
commit 7a87982420

View file

@ -61,13 +61,18 @@ static struct watchdog_device *old_wdd;
static int watchdog_ping(struct watchdog_device *wddev)
{
if (watchdog_active(wddev)) {
if (wddev->ops->ping)
return wddev->ops->ping(wddev); /* ping the watchdog */
else
return wddev->ops->start(wddev); /* restart watchdog */
}
return 0;
int err = 0;
if (!watchdog_active(wddev))
goto out_ping;
if (wddev->ops->ping)
err = wddev->ops->ping(wddev); /* ping the watchdog */
else
err = wddev->ops->start(wddev); /* restart watchdog */
out_ping:
return err;
}
/*
@ -81,16 +86,17 @@ static int watchdog_ping(struct watchdog_device *wddev)
static int watchdog_start(struct watchdog_device *wddev)
{
int err;
int err = 0;
if (!watchdog_active(wddev)) {
err = wddev->ops->start(wddev);
if (err < 0)
return err;
if (watchdog_active(wddev))
goto out_start;
err = wddev->ops->start(wddev);
if (err == 0)
set_bit(WDOG_ACTIVE, &wddev->status);
}
return 0;
out_start:
return err;
}
/*
@ -105,21 +111,111 @@ static int watchdog_start(struct watchdog_device *wddev)
static int watchdog_stop(struct watchdog_device *wddev)
{
int err = -EBUSY;
int err = 0;
if (!watchdog_active(wddev))
goto out_stop;
if (test_bit(WDOG_NO_WAY_OUT, &wddev->status)) {
dev_info(wddev->dev, "nowayout prevents watchdog being stopped!\n");
return err;
err = -EBUSY;
goto out_stop;
}
if (watchdog_active(wddev)) {
err = wddev->ops->stop(wddev);
if (err < 0)
return err;
err = wddev->ops->stop(wddev);
if (err == 0)
clear_bit(WDOG_ACTIVE, &wddev->status);
}
return 0;
out_stop:
return err;
}
/*
* watchdog_get_status: wrapper to get the watchdog status
* @wddev: the watchdog device to get the status from
* @status: the status of the watchdog device
*
* Get the watchdog's status flags.
*/
static int watchdog_get_status(struct watchdog_device *wddev,
unsigned int *status)
{
int err = 0;
*status = 0;
if (!wddev->ops->status)
return -EOPNOTSUPP;
*status = wddev->ops->status(wddev);
return err;
}
/*
* watchdog_set_timeout: set the watchdog timer timeout
* @wddev: the watchdog device to set the timeout for
* @timeout: timeout to set in seconds
*/
static int watchdog_set_timeout(struct watchdog_device *wddev,
unsigned int timeout)
{
int err;
if ((wddev->ops->set_timeout == NULL) ||
!(wddev->info->options & WDIOF_SETTIMEOUT))
return -EOPNOTSUPP;
if ((wddev->max_timeout != 0) &&
(timeout < wddev->min_timeout || timeout > wddev->max_timeout))
return -EINVAL;
err = wddev->ops->set_timeout(wddev, timeout);
return err;
}
/*
* watchdog_get_timeleft: wrapper to get the time left before a reboot
* @wddev: the watchdog device to get the remaining time from
* @timeleft: the time that's left
*
* Get the time before a watchdog will reboot (if not pinged).
*/
static int watchdog_get_timeleft(struct watchdog_device *wddev,
unsigned int *timeleft)
{
int err = 0;
*timeleft = 0;
if (!wddev->ops->get_timeleft)
return -EOPNOTSUPP;
*timeleft = wddev->ops->get_timeleft(wddev);
return err;
}
/*
* watchdog_ioctl_op: call the watchdog drivers ioctl op if defined
* @wddev: the watchdog device to do the ioctl on
* @cmd: watchdog command
* @arg: argument pointer
*/
static int watchdog_ioctl_op(struct watchdog_device *wddev, unsigned int cmd,
unsigned long arg)
{
int err;
if (!wddev->ops->ioctl)
return -ENOIOCTLCMD;
err = wddev->ops->ioctl(wddev, cmd, arg);
return err;
}
/*
@ -183,18 +279,18 @@ static long watchdog_ioctl(struct file *file, unsigned int cmd,
unsigned int val;
int err;
if (wdd->ops->ioctl) {
err = wdd->ops->ioctl(wdd, cmd, arg);
if (err != -ENOIOCTLCMD)
return err;
}
err = watchdog_ioctl_op(wdd, cmd, arg);
if (err != -ENOIOCTLCMD)
return err;
switch (cmd) {
case WDIOC_GETSUPPORT:
return copy_to_user(argp, wdd->info,
sizeof(struct watchdog_info)) ? -EFAULT : 0;
case WDIOC_GETSTATUS:
val = wdd->ops->status ? wdd->ops->status(wdd) : 0;
err = watchdog_get_status(wdd, &val);
if (err)
return err;
return put_user(val, p);
case WDIOC_GETBOOTSTATUS:
return put_user(wdd->bootstatus, p);
@ -218,15 +314,9 @@ static long watchdog_ioctl(struct file *file, unsigned int cmd,
watchdog_ping(wdd);
return 0;
case WDIOC_SETTIMEOUT:
if ((wdd->ops->set_timeout == NULL) ||
!(wdd->info->options & WDIOF_SETTIMEOUT))
return -EOPNOTSUPP;
if (get_user(val, p))
return -EFAULT;
if ((wdd->max_timeout != 0) &&
(val < wdd->min_timeout || val > wdd->max_timeout))
return -EINVAL;
err = wdd->ops->set_timeout(wdd, val);
err = watchdog_set_timeout(wdd, val);
if (err < 0)
return err;
/* If the watchdog is active then we send a keepalive ping
@ -240,10 +330,10 @@ static long watchdog_ioctl(struct file *file, unsigned int cmd,
return -EOPNOTSUPP;
return put_user(wdd->timeout, p);
case WDIOC_GETTIMELEFT:
if (!wdd->ops->get_timeleft)
return -EOPNOTSUPP;
return put_user(wdd->ops->get_timeleft(wdd), p);
err = watchdog_get_timeleft(wdd, &val);
if (err)
return err;
return put_user(val, p);
default:
return -ENOTTY;
}