diff options
author | Wim Van Sebroeck <wim@iguana.be> | 2007-08-17 04:38:02 -0400 |
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committer | Wim Van Sebroeck <wim@iguana.be> | 2007-10-18 06:39:03 -0400 |
commit | b7e04f8c61a46d742de23af5d7ca2b41b33e40ac (patch) | |
tree | c52a7ea568648e2d8ed0d423098b42298de2058b /drivers/watchdog/softdog.c | |
parent | d85714d81cc0408daddb68c10f7fd69eafe7c213 (diff) |
mv watchdog tree under drivers
move watchdog tree from drivers/char/watchdog to drivers/watchdog.
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Diffstat (limited to 'drivers/watchdog/softdog.c')
-rw-r--r-- | drivers/watchdog/softdog.c | 310 |
1 files changed, 310 insertions, 0 deletions
diff --git a/drivers/watchdog/softdog.c b/drivers/watchdog/softdog.c new file mode 100644 index 000000000000..9c3694909243 --- /dev/null +++ b/drivers/watchdog/softdog.c | |||
@@ -0,0 +1,310 @@ | |||
1 | /* | ||
2 | * SoftDog 0.07: A Software Watchdog Device | ||
3 | * | ||
4 | * (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved. | ||
5 | * http://www.redhat.com | ||
6 | * | ||
7 | * This program is free software; you can redistribute it and/or | ||
8 | * modify it under the terms of the GNU General Public License | ||
9 | * as published by the Free Software Foundation; either version | ||
10 | * 2 of the License, or (at your option) any later version. | ||
11 | * | ||
12 | * Neither Alan Cox nor CymruNet Ltd. admit liability nor provide | ||
13 | * warranty for any of this software. This material is provided | ||
14 | * "AS-IS" and at no charge. | ||
15 | * | ||
16 | * (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk> | ||
17 | * | ||
18 | * Software only watchdog driver. Unlike its big brother the WDT501P | ||
19 | * driver this won't always recover a failed machine. | ||
20 | * | ||
21 | * 03/96: Angelo Haritsis <ah@doc.ic.ac.uk> : | ||
22 | * Modularised. | ||
23 | * Added soft_margin; use upon insmod to change the timer delay. | ||
24 | * NB: uses same minor as wdt (WATCHDOG_MINOR); we could use separate | ||
25 | * minors. | ||
26 | * | ||
27 | * 19980911 Alan Cox | ||
28 | * Made SMP safe for 2.3.x | ||
29 | * | ||
30 | * 20011127 Joel Becker (jlbec@evilplan.org> | ||
31 | * Added soft_noboot; Allows testing the softdog trigger without | ||
32 | * requiring a recompile. | ||
33 | * Added WDIOC_GETTIMEOUT and WDIOC_SETTIMOUT. | ||
34 | * | ||
35 | * 20020530 Joel Becker <joel.becker@oracle.com> | ||
36 | * Added Matt Domsch's nowayout module option. | ||
37 | */ | ||
38 | |||
39 | #include <linux/module.h> | ||
40 | #include <linux/moduleparam.h> | ||
41 | #include <linux/types.h> | ||
42 | #include <linux/timer.h> | ||
43 | #include <linux/miscdevice.h> | ||
44 | #include <linux/watchdog.h> | ||
45 | #include <linux/fs.h> | ||
46 | #include <linux/notifier.h> | ||
47 | #include <linux/reboot.h> | ||
48 | #include <linux/init.h> | ||
49 | #include <linux/jiffies.h> | ||
50 | |||
51 | #include <asm/uaccess.h> | ||
52 | |||
53 | #define PFX "SoftDog: " | ||
54 | |||
55 | #define TIMER_MARGIN 60 /* Default is 60 seconds */ | ||
56 | static int soft_margin = TIMER_MARGIN; /* in seconds */ | ||
57 | module_param(soft_margin, int, 0); | ||
58 | MODULE_PARM_DESC(soft_margin, "Watchdog soft_margin in seconds. (0<soft_margin<65536, default=" __MODULE_STRING(TIMER_MARGIN) ")"); | ||
59 | |||
60 | static int nowayout = WATCHDOG_NOWAYOUT; | ||
61 | module_param(nowayout, int, 0); | ||
62 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | ||
63 | |||
64 | #ifdef ONLY_TESTING | ||
65 | static int soft_noboot = 1; | ||
66 | #else | ||
67 | static int soft_noboot = 0; | ||
68 | #endif /* ONLY_TESTING */ | ||
69 | |||
70 | module_param(soft_noboot, int, 0); | ||
71 | MODULE_PARM_DESC(soft_noboot, "Softdog action, set to 1 to ignore reboots, 0 to reboot (default depends on ONLY_TESTING)"); | ||
72 | |||
73 | /* | ||
74 | * Our timer | ||
75 | */ | ||
76 | |||
77 | static void watchdog_fire(unsigned long); | ||
78 | |||
79 | static struct timer_list watchdog_ticktock = | ||
80 | TIMER_INITIALIZER(watchdog_fire, 0, 0); | ||
81 | static unsigned long driver_open, orphan_timer; | ||
82 | static char expect_close; | ||
83 | |||
84 | |||
85 | /* | ||
86 | * If the timer expires.. | ||
87 | */ | ||
88 | |||
89 | static void watchdog_fire(unsigned long data) | ||
90 | { | ||
91 | if (test_and_clear_bit(0, &orphan_timer)) | ||
92 | module_put(THIS_MODULE); | ||
93 | |||
94 | if (soft_noboot) | ||
95 | printk(KERN_CRIT PFX "Triggered - Reboot ignored.\n"); | ||
96 | else | ||
97 | { | ||
98 | printk(KERN_CRIT PFX "Initiating system reboot.\n"); | ||
99 | emergency_restart(); | ||
100 | printk(KERN_CRIT PFX "Reboot didn't ?????\n"); | ||
101 | } | ||
102 | } | ||
103 | |||
104 | /* | ||
105 | * Softdog operations | ||
106 | */ | ||
107 | |||
108 | static int softdog_keepalive(void) | ||
109 | { | ||
110 | mod_timer(&watchdog_ticktock, jiffies+(soft_margin*HZ)); | ||
111 | return 0; | ||
112 | } | ||
113 | |||
114 | static int softdog_stop(void) | ||
115 | { | ||
116 | del_timer(&watchdog_ticktock); | ||
117 | return 0; | ||
118 | } | ||
119 | |||
120 | static int softdog_set_heartbeat(int t) | ||
121 | { | ||
122 | if ((t < 0x0001) || (t > 0xFFFF)) | ||
123 | return -EINVAL; | ||
124 | |||
125 | soft_margin = t; | ||
126 | return 0; | ||
127 | } | ||
128 | |||
129 | /* | ||
130 | * /dev/watchdog handling | ||
131 | */ | ||
132 | |||
133 | static int softdog_open(struct inode *inode, struct file *file) | ||
134 | { | ||
135 | if (test_and_set_bit(0, &driver_open)) | ||
136 | return -EBUSY; | ||
137 | if (!test_and_clear_bit(0, &orphan_timer)) | ||
138 | __module_get(THIS_MODULE); | ||
139 | /* | ||
140 | * Activate timer | ||
141 | */ | ||
142 | softdog_keepalive(); | ||
143 | return nonseekable_open(inode, file); | ||
144 | } | ||
145 | |||
146 | static int softdog_release(struct inode *inode, struct file *file) | ||
147 | { | ||
148 | /* | ||
149 | * Shut off the timer. | ||
150 | * Lock it in if it's a module and we set nowayout | ||
151 | */ | ||
152 | if (expect_close == 42) { | ||
153 | softdog_stop(); | ||
154 | module_put(THIS_MODULE); | ||
155 | } else { | ||
156 | printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n"); | ||
157 | set_bit(0, &orphan_timer); | ||
158 | softdog_keepalive(); | ||
159 | } | ||
160 | clear_bit(0, &driver_open); | ||
161 | expect_close = 0; | ||
162 | return 0; | ||
163 | } | ||
164 | |||
165 | static ssize_t softdog_write(struct file *file, const char __user *data, size_t len, loff_t *ppos) | ||
166 | { | ||
167 | /* | ||
168 | * Refresh the timer. | ||
169 | */ | ||
170 | if(len) { | ||
171 | if (!nowayout) { | ||
172 | size_t i; | ||
173 | |||
174 | /* In case it was set long ago */ | ||
175 | expect_close = 0; | ||
176 | |||
177 | for (i = 0; i != len; i++) { | ||
178 | char c; | ||
179 | |||
180 | if (get_user(c, data + i)) | ||
181 | return -EFAULT; | ||
182 | if (c == 'V') | ||
183 | expect_close = 42; | ||
184 | } | ||
185 | } | ||
186 | softdog_keepalive(); | ||
187 | } | ||
188 | return len; | ||
189 | } | ||
190 | |||
191 | static int softdog_ioctl(struct inode *inode, struct file *file, | ||
192 | unsigned int cmd, unsigned long arg) | ||
193 | { | ||
194 | void __user *argp = (void __user *)arg; | ||
195 | int __user *p = argp; | ||
196 | int new_margin; | ||
197 | static struct watchdog_info ident = { | ||
198 | .options = WDIOF_SETTIMEOUT | | ||
199 | WDIOF_KEEPALIVEPING | | ||
200 | WDIOF_MAGICCLOSE, | ||
201 | .firmware_version = 0, | ||
202 | .identity = "Software Watchdog", | ||
203 | }; | ||
204 | switch (cmd) { | ||
205 | default: | ||
206 | return -ENOTTY; | ||
207 | case WDIOC_GETSUPPORT: | ||
208 | return copy_to_user(argp, &ident, | ||
209 | sizeof(ident)) ? -EFAULT : 0; | ||
210 | case WDIOC_GETSTATUS: | ||
211 | case WDIOC_GETBOOTSTATUS: | ||
212 | return put_user(0, p); | ||
213 | case WDIOC_KEEPALIVE: | ||
214 | softdog_keepalive(); | ||
215 | return 0; | ||
216 | case WDIOC_SETTIMEOUT: | ||
217 | if (get_user(new_margin, p)) | ||
218 | return -EFAULT; | ||
219 | if (softdog_set_heartbeat(new_margin)) | ||
220 | return -EINVAL; | ||
221 | softdog_keepalive(); | ||
222 | /* Fall */ | ||
223 | case WDIOC_GETTIMEOUT: | ||
224 | return put_user(soft_margin, p); | ||
225 | } | ||
226 | } | ||
227 | |||
228 | /* | ||
229 | * Notifier for system down | ||
230 | */ | ||
231 | |||
232 | static int softdog_notify_sys(struct notifier_block *this, unsigned long code, | ||
233 | void *unused) | ||
234 | { | ||
235 | if(code==SYS_DOWN || code==SYS_HALT) { | ||
236 | /* Turn the WDT off */ | ||
237 | softdog_stop(); | ||
238 | } | ||
239 | return NOTIFY_DONE; | ||
240 | } | ||
241 | |||
242 | /* | ||
243 | * Kernel Interfaces | ||
244 | */ | ||
245 | |||
246 | static const struct file_operations softdog_fops = { | ||
247 | .owner = THIS_MODULE, | ||
248 | .llseek = no_llseek, | ||
249 | .write = softdog_write, | ||
250 | .ioctl = softdog_ioctl, | ||
251 | .open = softdog_open, | ||
252 | .release = softdog_release, | ||
253 | }; | ||
254 | |||
255 | static struct miscdevice softdog_miscdev = { | ||
256 | .minor = WATCHDOG_MINOR, | ||
257 | .name = "watchdog", | ||
258 | .fops = &softdog_fops, | ||
259 | }; | ||
260 | |||
261 | static struct notifier_block softdog_notifier = { | ||
262 | .notifier_call = softdog_notify_sys, | ||
263 | }; | ||
264 | |||
265 | static char banner[] __initdata = KERN_INFO "Software Watchdog Timer: 0.07 initialized. soft_noboot=%d soft_margin=%d sec (nowayout= %d)\n"; | ||
266 | |||
267 | static int __init watchdog_init(void) | ||
268 | { | ||
269 | int ret; | ||
270 | |||
271 | /* Check that the soft_margin value is within it's range ; if not reset to the default */ | ||
272 | if (softdog_set_heartbeat(soft_margin)) { | ||
273 | softdog_set_heartbeat(TIMER_MARGIN); | ||
274 | printk(KERN_INFO PFX "soft_margin value must be 0<soft_margin<65536, using %d\n", | ||
275 | TIMER_MARGIN); | ||
276 | } | ||
277 | |||
278 | ret = register_reboot_notifier(&softdog_notifier); | ||
279 | if (ret) { | ||
280 | printk (KERN_ERR PFX "cannot register reboot notifier (err=%d)\n", | ||
281 | ret); | ||
282 | return ret; | ||
283 | } | ||
284 | |||
285 | ret = misc_register(&softdog_miscdev); | ||
286 | if (ret) { | ||
287 | printk (KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n", | ||
288 | WATCHDOG_MINOR, ret); | ||
289 | unregister_reboot_notifier(&softdog_notifier); | ||
290 | return ret; | ||
291 | } | ||
292 | |||
293 | printk(banner, soft_noboot, soft_margin, nowayout); | ||
294 | |||
295 | return 0; | ||
296 | } | ||
297 | |||
298 | static void __exit watchdog_exit(void) | ||
299 | { | ||
300 | misc_deregister(&softdog_miscdev); | ||
301 | unregister_reboot_notifier(&softdog_notifier); | ||
302 | } | ||
303 | |||
304 | module_init(watchdog_init); | ||
305 | module_exit(watchdog_exit); | ||
306 | |||
307 | MODULE_AUTHOR("Alan Cox"); | ||
308 | MODULE_DESCRIPTION("Software Watchdog Device Driver"); | ||
309 | MODULE_LICENSE("GPL"); | ||
310 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | ||