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Message-ID: <20120228224806.8961.2884.stgit@bob.linux.org.uk>
Date: Tue, 28 Feb 2012 22:48:11 +0000
From: Alan Cox <alan@...rguk.ukuu.org.uk>
To: wim@...ana.be, linux-watchdog@...r.kernel.org,
linux-kernel@...r.kernel.org
Subject: [PATCH 3/5] softdog: convert to watchdog core
From: Alan Cox <alan@...ux.intel.com>
This happens to be rather useful for testing multi-device, plus it's handy
to support a software watchdog as backup to the real one
Signed-off-by: Alan Cox <alan@...ux.intel.com>
---
drivers/watchdog/softdog.c | 166 +++++++-------------------------------------
1 files changed, 28 insertions(+), 138 deletions(-)
diff --git a/drivers/watchdog/softdog.c b/drivers/watchdog/softdog.c
index bf16ffb..e2f8ba4 100644
--- a/drivers/watchdog/softdog.c
+++ b/drivers/watchdog/softdog.c
@@ -1,5 +1,5 @@
/*
- * SoftDog 0.07: A Software Watchdog Device
+ * SoftDog: A Software Watchdog Device
*
* (c) Copyright 1996 Alan Cox <alan@...rguk.ukuu.org.uk>,
* All Rights Reserved.
@@ -65,11 +65,7 @@ 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,
@@ -89,9 +85,6 @@ 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 +92,6 @@ 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)
printk(KERN_CRIT PFX "Triggered - Reboot ignored.\n");
else if (soft_panic) {
@@ -118,128 +108,25 @@ 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));
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;
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
*/
@@ -248,7 +135,7 @@ 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;
}
@@ -256,23 +143,28 @@ 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 notifier_block softdog_notifier = {
+ .notifier_call = softdog_notify_sys,
};
-static struct miscdevice softdog_miscdev = {
- .minor = WATCHDOG_MINOR,
- .name = "watchdog",
- .fops = &softdog_fops,
+static struct watchdog_info softdog_info = {
+ .identity = "Software Watchdog",
+ .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
};
-static struct notifier_block softdog_notifier = {
- .notifier_call = softdog_notify_sys,
+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 char banner[] __initdata = KERN_INFO "Software Watchdog Timer: 0.07 "
@@ -285,12 +177,13 @@ static int __init watchdog_init(void)
/* 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) {
printk(KERN_INFO PFX
"soft_margin must be 0 < soft_margin < 65536, using %d\n",
TIMER_MARGIN);
+ return -EINVAL;
}
+ softdog_dev.timeout = soft_margin;
ret = register_reboot_notifier(&softdog_notifier);
if (ret) {
@@ -299,11 +192,8 @@ static int __init watchdog_init(void)
return ret;
}
- ret = misc_register(&softdog_miscdev);
+ ret = watchdog_register_device(&softdog_dev);
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;
}
@@ -315,7 +205,7 @@ 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);
}
--
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