From 7a87982420e5e126bfefeb42232d1fd92052794e Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Tue, 22 May 2012 11:40:26 +0200 Subject: [PATCH] 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 Signed-off-by: Wim Van Sebroeck --- drivers/watchdog/watchdog_dev.c | 170 ++++++++++++++++++++++++-------- 1 file changed, 130 insertions(+), 40 deletions(-) diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c index 55191cccf026..76d2572fed25 100644 --- a/drivers/watchdog/watchdog_dev.c +++ b/drivers/watchdog/watchdog_dev.c @@ -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; } -- 2.39.5