watchdog: softdog: convert to watchdog core

Convert softdog.c to the new watchdog API.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
This commit is contained in:
Alan Cox 2012-02-28 22:48:11 +00:00 committed by Wim Van Sebroeck
parent a0f3683365
commit a5132cafc0
2 changed files with 39 additions and 148 deletions

View file

@ -55,6 +55,7 @@ comment "Watchdog Device Drivers"
config SOFT_WATCHDOG
tristate "Software watchdog"
select WATCHDOG_CORE
help
A software monitoring watchdog. This will fail to reboot your system
from some situations that the hardware watchdog will recover

View file

@ -1,5 +1,5 @@
/*
* SoftDog 0.07: A Software Watchdog Device
* SoftDog: A Software Watchdog Device
*
* (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>,
* All Rights Reserved.
@ -44,17 +44,15 @@
#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>
#include <linux/kernel.h>
#define TIMER_MARGIN 60 /* Default is 60 seconds */
static int soft_margin = TIMER_MARGIN; /* in seconds */
module_param(soft_margin, int, 0);
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) ")");
@ -65,16 +63,10 @@ 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)");
"Softdog action, set to 1 to ignore reboots, 0 to reboot (default=0)");
static int soft_panic;
module_param(soft_panic, int, 0);
@ -89,9 +81,6 @@ 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..
@ -99,9 +88,6 @@ static char expect_close;
static void watchdog_fire(unsigned long data)
{
if (test_and_clear_bit(0, &orphan_timer))
module_put(THIS_MODULE);
if (soft_noboot)
pr_crit("Triggered - Reboot ignored\n");
else if (soft_panic) {
@ -118,126 +104,24 @@ static void watchdog_fire(unsigned long data)
* Softdog operations
*/
static int softdog_keepalive(void)
static int softdog_ping(struct watchdog_device *w)
{
mod_timer(&watchdog_ticktock, jiffies+(soft_margin*HZ));
mod_timer(&watchdog_ticktock, jiffies+(w->timeout*HZ));
return 0;
}
static int softdog_stop(void)
static int softdog_stop(struct watchdog_device *w)
{
del_timer(&watchdog_ticktock);
return 0;
}
static int softdog_set_heartbeat(int t)
static int softdog_set_timeout(struct watchdog_device *w, unsigned int t)
{
if ((t < 0x0001) || (t > 0xFFFF))
return -EINVAL;
soft_margin = t;
w->timeout = 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 {
pr_crit("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
*/
@ -247,7 +131,7 @@ static int softdog_notify_sys(struct notifier_block *this, unsigned long code,
{
if (code == SYS_DOWN || code == SYS_HALT)
/* Turn the WDT off */
softdog_stop();
softdog_stop(NULL);
return NOTIFY_DONE;
}
@ -255,36 +139,44 @@ static int softdog_notify_sys(struct notifier_block *this, unsigned long code,
* 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 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,
.ping = softdog_ping,
.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 (softdog_set_heartbeat(soft_margin)) {
softdog_set_heartbeat(TIMER_MARGIN);
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) {
@ -292,15 +184,13 @@ static int __init watchdog_init(void)
return ret;
}
ret = misc_register(&softdog_miscdev);
ret = watchdog_register_device(&softdog_dev);
if (ret) {
pr_err("cannot register miscdev on minor=%d (err=%d)\n",
WATCHDOG_MINOR, ret);
unregister_reboot_notifier(&softdog_notifier);
return ret;
}
pr_info("Software Watchdog Timer: 0.07 initialized. soft_noboot=%d soft_margin=%d sec soft_panic=%d (nowayout= %d)\n",
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;
@ -308,7 +198,7 @@ static int __init watchdog_init(void)
static void __exit watchdog_exit(void)
{
misc_deregister(&softdog_miscdev);
watchdog_unregister_device(&softdog_dev);
unregister_reboot_notifier(&softdog_notifier);
}