From b7e04f8c61a46d742de23af5d7ca2b41b33e40ac Mon Sep 17 00:00:00 2001 From: Wim Van Sebroeck Date: Fri, 17 Aug 2007 08:38:02 +0000 Subject: mv watchdog tree under drivers move watchdog tree from drivers/char/watchdog to drivers/watchdog. Signed-off-by: Wim Van Sebroeck --- drivers/watchdog/softdog.c | 310 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 310 insertions(+) create mode 100644 drivers/watchdog/softdog.c (limited to 'drivers/watchdog/softdog.c') diff --git a/drivers/watchdog/softdog.c b/drivers/watchdog/softdog.c new file mode 100644 index 00000000000..9c369490924 --- /dev/null +++ b/drivers/watchdog/softdog.c @@ -0,0 +1,310 @@ +/* + * SoftDog 0.07: A Software Watchdog Device + * + * (c) Copyright 1996 Alan Cox , All Rights Reserved. + * http://www.redhat.com + * + * 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 + * + * Software only watchdog driver. Unlike its big brother the WDT501P + * driver this won't always recover a failed machine. + * + * 03/96: Angelo Haritsis : + * 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 + * Added Matt Domsch's nowayout module option. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#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 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 int softdog_ioctl(struct inode *inode, struct file *file, + unsigned int cmd, unsigned long arg) +{ + void __user *argp = (void __user *)arg; + int __user *p = argp; + int new_margin; + static struct watchdog_info ident = { + .options = WDIOF_SETTIMEOUT | + WDIOF_KEEPALIVEPING | + WDIOF_MAGICCLOSE, + .firmware_version = 0, + .identity = "Software Watchdog", + }; + switch (cmd) { + default: + return -ENOTTY; + 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); + } +} + +/* + * 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, + .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 value must be 0