Initial import

1 files changed, 208 insertions, 0 deletions

diff --git a/drivers/watchdog/softdog.c b/drivers/watchdog/softdog.c
new file mode 100644
index 000000000..0dc5e323d
--- /dev/null
+++ b/drivers/watchdog/softdog.c
@@ -0,0 +1,208 @@
+/*
+ *	SoftDog:	A Software Watchdog Device
+ *
+ *	(c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>,
+ *							All Rights Reserved.
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ *
+ *	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.
+ *
+ *  03/96: Angelo Haritsis <ah@doc.ic.ac.uk> :
+ *	Modularised.
+ *	Added soft_margin; use upon insmod to change the timer delay.
+ *	NB: uses same minor as wdt (WATCHDOG_MINOR); we could use separate
+ *	    minors.
+ *
+ *  19980911 Alan Cox
+ *	Made SMP safe for 2.3.x
+ *
+ *  20011127 Joel Becker (jlbec@evilplan.org>
+ *	Added soft_noboot; Allows testing the softdog trigger without
+ *	requiring a recompile.
+ *	Added WDIOC_GETTIMEOUT and WDIOC_SETTIMOUT.
+ *
+ *  20020530 Joel Becker <joel.becker@oracle.com>
+ *	Added Matt Domsch's nowayout module option.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/types.h>
+#include <linux/timer.h>
+#include <linux/watchdog.h>
+#include <linux/notifier.h>
+#include <linux/reboot.h>
+#include <linux/init.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.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)");
+
+/*
+ *	Our timer
+ */
+
+static void watchdog_fire(unsigned long);
+
+static struct timer_list watchdog_ticktock =
+		TIMER_INITIALIZER(watchdog_fire, 0, 0);
+
+/*
+ *	If the timer expires..
+ */
+
+static void watchdog_fire(unsigned long data)
+{
+	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");
+	}
+}
+
+/*
+ *	Softdog operations
+ */
+
+static int softdog_ping(struct watchdog_device *w)
+{
+	mod_timer(&watchdog_ticktock, jiffies+(w->timeout*HZ));
+	return 0;
+}
+
+static int softdog_stop(struct watchdog_device *w)
+{
+	del_timer(&watchdog_ticktock);
+	return 0;
+}
+
+static int softdog_set_timeout(struct watchdog_device *w, unsigned int t)
+{
+	w->timeout = t;
+	return 0;
+}
+
+/*
+ *	Notifier for system down
+ */
+
+static int softdog_notify_sys(struct notifier_block *this, unsigned long code,
+	void *unused)
+{
+	if (code == SYS_DOWN || code == SYS_HALT)
+		/* Turn the WDT off */
+		softdog_stop(NULL);
+	return NOTIFY_DONE;
+}
+
+/*
+ *	Kernel Interfaces
+ */
+
+static struct notifier_block softdog_notifier = {
+	.notifier_call	= softdog_notify_sys,
+};
+
+static struct watchdog_info softdog_info = {
+	.identity = "Software Watchdog",
+	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
+};
+
+static struct watchdog_ops softdog_ops = {
+	.owner = THIS_MODULE,
+	.start = softdog_ping,
+	.stop = softdog_stop,
+	.set_timeout = softdog_set_timeout,
+};
+
+static struct watchdog_device softdog_dev = {
+	.info = &softdog_info,
+	.ops = &softdog_ops,
+	.min_timeout = 1,
+	.max_timeout = 0xFFFF
+};
+
+static int __init watchdog_init(void)
+{
+	int ret;
+
+	/* Check that the soft_margin value is within it's range;
+	   if not reset to the default */
+	if (soft_margin < 1 || soft_margin > 65535) {
+		pr_info("soft_margin must be 0 < soft_margin < 65536, using %d\n",
+			TIMER_MARGIN);
+		return -EINVAL;
+	}
+	softdog_dev.timeout = soft_margin;
+
+	watchdog_set_nowayout(&softdog_dev, nowayout);
+
+	ret = register_reboot_notifier(&softdog_notifier);
+	if (ret) {
+		pr_err("cannot register reboot notifier (err=%d)\n", ret);
+		return ret;
+	}
+
+	ret = watchdog_register_device(&softdog_dev);
+	if (ret) {
+		unregister_reboot_notifier(&softdog_notifier);
+		return ret;
+	}
+
+	pr_info("Software Watchdog Timer: 0.08 initialized. soft_noboot=%d soft_margin=%d sec soft_panic=%d (nowayout=%d)\n",
+		soft_noboot, soft_margin, soft_panic, nowayout);
+
+	return 0;
+}
+
+static void __exit watchdog_exit(void)
+{
+	watchdog_unregister_device(&softdog_dev);
+	unregister_reboot_notifier(&softdog_notifier);
+}
+
+module_init(watchdog_init);
+module_exit(watchdog_exit);
+
+MODULE_AUTHOR("Alan Cox");
+MODULE_DESCRIPTION("Software Watchdog Device Driver");
+MODULE_LICENSE("GPL");