linux/drivers/watchdog/softdog.c
Guenter Roeck d017327893 watchdog: convert remaining drivers to use SPDX license identifier
This gets rid of the unnecessary license boilerplate, and avoids
having to deal with individual patches one by one.

No functional changes.

Reviewed-by: Jerry Hoemann <jerry.hoemann@hpe.com>
Acked-by: Sylvain Lemieux <slemieux.tyco@gmail.com>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2019-07-08 20:35:11 +02:00

168 lines
4.3 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* SoftDog: A Software Watchdog Device
*
* (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>,
* All Rights Reserved.
*
* Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
* warranty for any of this software. This material is provided
* "AS-IS" and at no charge.
*
* (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk>
*
* Software only watchdog driver. Unlike its big brother the WDT501P
* driver this won't always recover a failed machine.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/hrtimer.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/reboot.h>
#include <linux/types.h>
#include <linux/watchdog.h>
#define TIMER_MARGIN 60 /* Default is 60 seconds */
static unsigned int soft_margin = TIMER_MARGIN; /* in seconds */
module_param(soft_margin, uint, 0);
MODULE_PARM_DESC(soft_margin,
"Watchdog soft_margin in seconds. (0 < soft_margin < 65536, default="
__MODULE_STRING(TIMER_MARGIN) ")");
static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout,
"Watchdog cannot be stopped once started (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
static int soft_noboot;
module_param(soft_noboot, int, 0);
MODULE_PARM_DESC(soft_noboot,
"Softdog action, set to 1 to ignore reboots, 0 to reboot (default=0)");
static int soft_panic;
module_param(soft_panic, int, 0);
MODULE_PARM_DESC(soft_panic,
"Softdog action, set to 1 to panic, 0 to reboot (default=0)");
static struct hrtimer softdog_ticktock;
static struct hrtimer softdog_preticktock;
static enum hrtimer_restart softdog_fire(struct hrtimer *timer)
{
module_put(THIS_MODULE);
if (soft_noboot) {
pr_crit("Triggered - Reboot ignored\n");
} else if (soft_panic) {
pr_crit("Initiating panic\n");
panic("Software Watchdog Timer expired");
} else {
pr_crit("Initiating system reboot\n");
emergency_restart();
pr_crit("Reboot didn't ?????\n");
}
return HRTIMER_NORESTART;
}
static struct watchdog_device softdog_dev;
static enum hrtimer_restart softdog_pretimeout(struct hrtimer *timer)
{
watchdog_notify_pretimeout(&softdog_dev);
return HRTIMER_NORESTART;
}
static int softdog_ping(struct watchdog_device *w)
{
if (!hrtimer_active(&softdog_ticktock))
__module_get(THIS_MODULE);
hrtimer_start(&softdog_ticktock, ktime_set(w->timeout, 0),
HRTIMER_MODE_REL);
if (IS_ENABLED(CONFIG_SOFT_WATCHDOG_PRETIMEOUT)) {
if (w->pretimeout)
hrtimer_start(&softdog_preticktock,
ktime_set(w->timeout - w->pretimeout, 0),
HRTIMER_MODE_REL);
else
hrtimer_cancel(&softdog_preticktock);
}
return 0;
}
static int softdog_stop(struct watchdog_device *w)
{
if (hrtimer_cancel(&softdog_ticktock))
module_put(THIS_MODULE);
if (IS_ENABLED(CONFIG_SOFT_WATCHDOG_PRETIMEOUT))
hrtimer_cancel(&softdog_preticktock);
return 0;
}
static struct watchdog_info softdog_info = {
.identity = "Software Watchdog",
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
};
static const struct watchdog_ops softdog_ops = {
.owner = THIS_MODULE,
.start = softdog_ping,
.stop = softdog_stop,
};
static struct watchdog_device softdog_dev = {
.info = &softdog_info,
.ops = &softdog_ops,
.min_timeout = 1,
.max_timeout = 65535,
.timeout = TIMER_MARGIN,
};
static int __init softdog_init(void)
{
int ret;
watchdog_init_timeout(&softdog_dev, soft_margin, NULL);
watchdog_set_nowayout(&softdog_dev, nowayout);
watchdog_stop_on_reboot(&softdog_dev);
hrtimer_init(&softdog_ticktock, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
softdog_ticktock.function = softdog_fire;
if (IS_ENABLED(CONFIG_SOFT_WATCHDOG_PRETIMEOUT)) {
softdog_info.options |= WDIOF_PRETIMEOUT;
hrtimer_init(&softdog_preticktock, CLOCK_MONOTONIC,
HRTIMER_MODE_REL);
softdog_preticktock.function = softdog_pretimeout;
}
ret = watchdog_register_device(&softdog_dev);
if (ret)
return ret;
pr_info("initialized. soft_noboot=%d soft_margin=%d sec soft_panic=%d (nowayout=%d)\n",
soft_noboot, softdog_dev.timeout, soft_panic, nowayout);
return 0;
}
module_init(softdog_init);
static void __exit softdog_exit(void)
{
watchdog_unregister_device(&softdog_dev);
}
module_exit(softdog_exit);
MODULE_AUTHOR("Alan Cox");
MODULE_DESCRIPTION("Software Watchdog Device Driver");
MODULE_LICENSE("GPL");