mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-05 18:36:41 +07:00
143a2e54bf
Some more cleaning-up of the watchdog drivers. Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
316 lines
7.2 KiB
C
316 lines
7.2 KiB
C
/*
|
|
* SoftDog 0.07: 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.
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/moduleparam.h>
|
|
#include <linux/types.h>
|
|
#include <linux/timer.h>
|
|
#include <linux/miscdevice.h>
|
|
#include <linux/watchdog.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/notifier.h>
|
|
#include <linux/reboot.h>
|
|
#include <linux/init.h>
|
|
#include <linux/jiffies.h>
|
|
#include <linux/uaccess.h>
|
|
|
|
#define PFX "SoftDog: "
|
|
|
|
#define TIMER_MARGIN 60 /* Default is 60 seconds */
|
|
static int soft_margin = TIMER_MARGIN; /* in seconds */
|
|
module_param(soft_margin, int, 0);
|
|
MODULE_PARM_DESC(soft_margin,
|
|
"Watchdog soft_margin in seconds. (0 < soft_margin < 65536, default="
|
|
__MODULE_STRING(TIMER_MARGIN) ")");
|
|
|
|
static int nowayout = WATCHDOG_NOWAYOUT;
|
|
module_param(nowayout, int, 0);
|
|
MODULE_PARM_DESC(nowayout,
|
|
"Watchdog cannot be stopped once started (default="
|
|
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
|
|
|
|
#ifdef ONLY_TESTING
|
|
static int soft_noboot = 1;
|
|
#else
|
|
static int soft_noboot = 0;
|
|
#endif /* ONLY_TESTING */
|
|
|
|
module_param(soft_noboot, int, 0);
|
|
MODULE_PARM_DESC(soft_noboot, "Softdog action, set to 1 to ignore reboots, 0 to reboot (default depends on ONLY_TESTING)");
|
|
|
|
/*
|
|
* Our timer
|
|
*/
|
|
|
|
static void watchdog_fire(unsigned long);
|
|
|
|
static struct timer_list watchdog_ticktock =
|
|
TIMER_INITIALIZER(watchdog_fire, 0, 0);
|
|
static unsigned long driver_open, orphan_timer;
|
|
static char expect_close;
|
|
|
|
|
|
/*
|
|
* If the timer expires..
|
|
*/
|
|
|
|
static void watchdog_fire(unsigned long data)
|
|
{
|
|
if (test_and_clear_bit(0, &orphan_timer))
|
|
module_put(THIS_MODULE);
|
|
|
|
if (soft_noboot)
|
|
printk(KERN_CRIT PFX "Triggered - Reboot ignored.\n");
|
|
else {
|
|
printk(KERN_CRIT PFX "Initiating system reboot.\n");
|
|
emergency_restart();
|
|
printk(KERN_CRIT PFX "Reboot didn't ?????\n");
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Softdog operations
|
|
*/
|
|
|
|
static int softdog_keepalive(void)
|
|
{
|
|
mod_timer(&watchdog_ticktock, jiffies+(soft_margin*HZ));
|
|
return 0;
|
|
}
|
|
|
|
static int softdog_stop(void)
|
|
{
|
|
del_timer(&watchdog_ticktock);
|
|
return 0;
|
|
}
|
|
|
|
static int softdog_set_heartbeat(int t)
|
|
{
|
|
if ((t < 0x0001) || (t > 0xFFFF))
|
|
return -EINVAL;
|
|
|
|
soft_margin = t;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* /dev/watchdog handling
|
|
*/
|
|
|
|
static int softdog_open(struct inode *inode, struct file *file)
|
|
{
|
|
if (test_and_set_bit(0, &driver_open))
|
|
return -EBUSY;
|
|
if (!test_and_clear_bit(0, &orphan_timer))
|
|
__module_get(THIS_MODULE);
|
|
/*
|
|
* Activate timer
|
|
*/
|
|
softdog_keepalive();
|
|
return nonseekable_open(inode, file);
|
|
}
|
|
|
|
static int softdog_release(struct inode *inode, struct file *file)
|
|
{
|
|
/*
|
|
* Shut off the timer.
|
|
* Lock it in if it's a module and we set nowayout
|
|
*/
|
|
if (expect_close == 42) {
|
|
softdog_stop();
|
|
module_put(THIS_MODULE);
|
|
} else {
|
|
printk(KERN_CRIT PFX
|
|
"Unexpected close, not stopping watchdog!\n");
|
|
set_bit(0, &orphan_timer);
|
|
softdog_keepalive();
|
|
}
|
|
clear_bit(0, &driver_open);
|
|
expect_close = 0;
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t softdog_write(struct file *file, const char __user *data,
|
|
size_t len, loff_t *ppos)
|
|
{
|
|
/*
|
|
* Refresh the timer.
|
|
*/
|
|
if (len) {
|
|
if (!nowayout) {
|
|
size_t i;
|
|
|
|
/* In case it was set long ago */
|
|
expect_close = 0;
|
|
|
|
for (i = 0; i != len; i++) {
|
|
char c;
|
|
|
|
if (get_user(c, data + i))
|
|
return -EFAULT;
|
|
if (c == 'V')
|
|
expect_close = 42;
|
|
}
|
|
}
|
|
softdog_keepalive();
|
|
}
|
|
return len;
|
|
}
|
|
|
|
static long softdog_ioctl(struct file *file, unsigned int cmd,
|
|
unsigned long arg)
|
|
{
|
|
void __user *argp = (void __user *)arg;
|
|
int __user *p = argp;
|
|
int new_margin;
|
|
static const struct watchdog_info ident = {
|
|
.options = WDIOF_SETTIMEOUT |
|
|
WDIOF_KEEPALIVEPING |
|
|
WDIOF_MAGICCLOSE,
|
|
.firmware_version = 0,
|
|
.identity = "Software Watchdog",
|
|
};
|
|
switch (cmd) {
|
|
case WDIOC_GETSUPPORT:
|
|
return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
|
|
case WDIOC_GETSTATUS:
|
|
case WDIOC_GETBOOTSTATUS:
|
|
return put_user(0, p);
|
|
case WDIOC_KEEPALIVE:
|
|
softdog_keepalive();
|
|
return 0;
|
|
case WDIOC_SETTIMEOUT:
|
|
if (get_user(new_margin, p))
|
|
return -EFAULT;
|
|
if (softdog_set_heartbeat(new_margin))
|
|
return -EINVAL;
|
|
softdog_keepalive();
|
|
/* Fall */
|
|
case WDIOC_GETTIMEOUT:
|
|
return put_user(soft_margin, p);
|
|
default:
|
|
return -ENOTTY;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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();
|
|
return NOTIFY_DONE;
|
|
}
|
|
|
|
/*
|
|
* Kernel Interfaces
|
|
*/
|
|
|
|
static const struct file_operations softdog_fops = {
|
|
.owner = THIS_MODULE,
|
|
.llseek = no_llseek,
|
|
.write = softdog_write,
|
|
.unlocked_ioctl = softdog_ioctl,
|
|
.open = softdog_open,
|
|
.release = softdog_release,
|
|
};
|
|
|
|
static struct miscdevice softdog_miscdev = {
|
|
.minor = WATCHDOG_MINOR,
|
|
.name = "watchdog",
|
|
.fops = &softdog_fops,
|
|
};
|
|
|
|
static struct notifier_block softdog_notifier = {
|
|
.notifier_call = softdog_notify_sys,
|
|
};
|
|
|
|
static char banner[] __initdata = KERN_INFO "Software Watchdog Timer: 0.07 initialized. soft_noboot=%d soft_margin=%d sec (nowayout= %d)\n";
|
|
|
|
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 (softdog_set_heartbeat(soft_margin)) {
|
|
softdog_set_heartbeat(TIMER_MARGIN);
|
|
printk(KERN_INFO PFX
|
|
"soft_margin must be 0 < soft_margin < 65536, using %d\n",
|
|
TIMER_MARGIN);
|
|
}
|
|
|
|
ret = register_reboot_notifier(&softdog_notifier);
|
|
if (ret) {
|
|
printk(KERN_ERR PFX
|
|
"cannot register reboot notifier (err=%d)\n", ret);
|
|
return ret;
|
|
}
|
|
|
|
ret = misc_register(&softdog_miscdev);
|
|
if (ret) {
|
|
printk(KERN_ERR PFX
|
|
"cannot register miscdev on minor=%d (err=%d)\n",
|
|
WATCHDOG_MINOR, ret);
|
|
unregister_reboot_notifier(&softdog_notifier);
|
|
return ret;
|
|
}
|
|
|
|
printk(banner, soft_noboot, soft_margin, nowayout);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void __exit watchdog_exit(void)
|
|
{
|
|
misc_deregister(&softdog_miscdev);
|
|
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");
|
|
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
|