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>
diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
index 55191cc..76d2572 100644
--- a/drivers/watchdog/watchdog_dev.c
+++ b/drivers/watchdog/watchdog_dev.c
@@ -61,13 +61,18 @@
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_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_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 @@
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 @@
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 @@
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;
}