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31#include <linux/module.h>
32#include <linux/moduleparam.h>
33#include <linux/types.h>
34#include <linux/timer.h>
35#include <linux/jiffies.h>
36#include <linux/miscdevice.h>
37#include <linux/watchdog.h>
38#include <linux/fs.h>
39#include <linux/ioport.h>
40#include <linux/notifier.h>
41#include <linux/reboot.h>
42#include <linux/init.h>
43
44#include <asm/io.h>
45#include <asm/uaccess.h>
46#include <asm/system.h>
47
48
49#define ZF_IOBASE 0x218
50#define INDEX 0x218
51#define DATA_B 0x219
52#define DATA_W 0x21A
53#define DATA_D 0x21A
54
55
56#define ZFL_VERSION 0x02
57#define CONTROL 0x10
58#define STATUS 0x12
59#define COUNTER_1 0x0C
60#define COUNTER_2 0x0E
61#define PULSE_LEN 0x0F
62
63
64#define ENABLE_WD1 0x0001
65#define ENABLE_WD2 0x0002
66#define RESET_WD1 0x0010
67#define RESET_WD2 0x0020
68#define GEN_SCI 0x0100
69#define GEN_NMI 0x0200
70#define GEN_SMI 0x0400
71#define GEN_RESET 0x0800
72
73
74
75
76#define WD1 0
77#define WD2 1
78
79#define zf_writew(port, data) { outb(port, INDEX); outw(data, DATA_W); }
80#define zf_writeb(port, data) { outb(port, INDEX); outb(data, DATA_B); }
81#define zf_get_ZFL_version() zf_readw(ZFL_VERSION)
82
83
84static unsigned short zf_readw(unsigned char port)
85{
86 outb(port, INDEX);
87 return inw(DATA_W);
88}
89
90
91MODULE_AUTHOR("Fernando Fuganti <fuganti@conectiva.com.br>");
92MODULE_DESCRIPTION("MachZ ZF-Logic Watchdog driver");
93MODULE_LICENSE("GPL");
94MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
95
96static int nowayout = WATCHDOG_NOWAYOUT;
97module_param(nowayout, int, 0);
98MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
99
100#define PFX "machzwd"
101
102static struct watchdog_info zf_info = {
103 .options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
104 .firmware_version = 1,
105 .identity = "ZF-Logic watchdog",
106};
107
108
109
110
111
112
113
114
115
116
117static int action = 0;
118module_param(action, int, 0);
119MODULE_PARM_DESC(action, "after watchdog resets, generate: 0 = RESET(*) 1 = SMI 2 = NMI 3 = SCI");
120
121static void zf_ping(unsigned long data);
122
123static int zf_action = GEN_RESET;
124static unsigned long zf_is_open;
125static char zf_expect_close;
126static DEFINE_SPINLOCK(zf_lock);
127static DEFINE_SPINLOCK(zf_port_lock);
128static DEFINE_TIMER(zf_timer, zf_ping, 0, 0);
129static unsigned long next_heartbeat = 0;
130
131
132
133#define ZF_USER_TIMEO (HZ*10)
134
135
136#define ZF_HW_TIMEO (HZ/2)
137
138
139#define ZF_CTIMEOUT 0xffff
140
141#ifndef ZF_DEBUG
142# define dprintk(format, args...)
143#else
144# define dprintk(format, args...) printk(KERN_DEBUG PFX ":%s:%d: " format, __FUNCTION__, __LINE__ , ## args)
145#endif
146
147
148static inline void zf_set_status(unsigned char new)
149{
150 zf_writeb(STATUS, new);
151}
152
153
154
155
156static inline unsigned short zf_get_control(void)
157{
158 return zf_readw(CONTROL);
159}
160
161static inline void zf_set_control(unsigned short new)
162{
163 zf_writew(CONTROL, new);
164}
165
166
167
168
169
170
171
172static inline void zf_set_timer(unsigned short new, unsigned char n)
173{
174 switch(n){
175 case WD1:
176 zf_writew(COUNTER_1, new);
177 case WD2:
178 zf_writeb(COUNTER_2, new > 0xff ? 0xff : new);
179 default:
180 return;
181 }
182}
183
184
185
186
187static void zf_timer_off(void)
188{
189 unsigned int ctrl_reg = 0;
190 unsigned long flags;
191
192
193 del_timer_sync(&zf_timer);
194
195 spin_lock_irqsave(&zf_port_lock, flags);
196
197 ctrl_reg = zf_get_control();
198 ctrl_reg |= (ENABLE_WD1|ENABLE_WD2);
199 ctrl_reg &= ~(ENABLE_WD1|ENABLE_WD2);
200 zf_set_control(ctrl_reg);
201 spin_unlock_irqrestore(&zf_port_lock, flags);
202
203 printk(KERN_INFO PFX ": Watchdog timer is now disabled\n");
204}
205
206
207
208
209
210static void zf_timer_on(void)
211{
212 unsigned int ctrl_reg = 0;
213 unsigned long flags;
214
215 spin_lock_irqsave(&zf_port_lock, flags);
216
217 zf_writeb(PULSE_LEN, 0xff);
218
219 zf_set_timer(ZF_CTIMEOUT, WD1);
220
221
222 next_heartbeat = jiffies + ZF_USER_TIMEO;
223
224
225 mod_timer(&zf_timer, jiffies + ZF_HW_TIMEO);
226
227
228 ctrl_reg = zf_get_control();
229 ctrl_reg |= (ENABLE_WD1|zf_action);
230 zf_set_control(ctrl_reg);
231 spin_unlock_irqrestore(&zf_port_lock, flags);
232
233 printk(KERN_INFO PFX ": Watchdog timer is now enabled\n");
234}
235
236
237static void zf_ping(unsigned long data)
238{
239 unsigned int ctrl_reg = 0;
240 unsigned long flags;
241
242 zf_writeb(COUNTER_2, 0xff);
243
244 if(time_before(jiffies, next_heartbeat)){
245
246 dprintk("time_before: %ld\n", next_heartbeat - jiffies);
247
248
249
250
251
252
253 spin_lock_irqsave(&zf_port_lock, flags);
254 ctrl_reg = zf_get_control();
255 ctrl_reg |= RESET_WD1;
256 zf_set_control(ctrl_reg);
257
258
259 ctrl_reg &= ~(RESET_WD1);
260 zf_set_control(ctrl_reg);
261 spin_unlock_irqrestore(&zf_port_lock, flags);
262
263 mod_timer(&zf_timer, jiffies + ZF_HW_TIMEO);
264 }else{
265 printk(KERN_CRIT PFX ": I will reset your machine\n");
266 }
267}
268
269static ssize_t zf_write(struct file *file, const char __user *buf, size_t count,
270 loff_t *ppos)
271{
272
273 if(count){
274
275
276
277
278
279 if (!nowayout) {
280 size_t ofs;
281
282
283
284
285
286 zf_expect_close = 0;
287
288
289 for (ofs = 0; ofs != count; ofs++){
290 char c;
291 if (get_user(c, buf + ofs))
292 return -EFAULT;
293 if (c == 'V'){
294 zf_expect_close = 42;
295 dprintk("zf_expect_close = 42\n");
296 }
297 }
298 }
299
300
301
302
303
304 next_heartbeat = jiffies + ZF_USER_TIMEO;
305 dprintk("user ping at %ld\n", jiffies);
306
307 }
308
309 return count;
310}
311
312static int zf_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
313 unsigned long arg)
314{
315 void __user *argp = (void __user *)arg;
316 int __user *p = argp;
317 switch (cmd) {
318 case WDIOC_GETSUPPORT:
319 if (copy_to_user(argp, &zf_info, sizeof(zf_info)))
320 return -EFAULT;
321 break;
322
323 case WDIOC_GETSTATUS:
324 case WDIOC_GETBOOTSTATUS:
325 return put_user(0, p);
326
327 case WDIOC_KEEPALIVE:
328 zf_ping(0);
329 break;
330
331 default:
332 return -ENOTTY;
333 }
334
335 return 0;
336}
337
338static int zf_open(struct inode *inode, struct file *file)
339{
340 spin_lock(&zf_lock);
341 if(test_and_set_bit(0, &zf_is_open)) {
342 spin_unlock(&zf_lock);
343 return -EBUSY;
344 }
345
346 if (nowayout)
347 __module_get(THIS_MODULE);
348
349 spin_unlock(&zf_lock);
350
351 zf_timer_on();
352
353 return nonseekable_open(inode, file);
354}
355
356static int zf_close(struct inode *inode, struct file *file)
357{
358 if(zf_expect_close == 42){
359 zf_timer_off();
360 } else {
361 del_timer(&zf_timer);
362 printk(KERN_ERR PFX ": device file closed unexpectedly. Will not stop the WDT!\n");
363 }
364
365 spin_lock(&zf_lock);
366 clear_bit(0, &zf_is_open);
367 spin_unlock(&zf_lock);
368
369 zf_expect_close = 0;
370
371 return 0;
372}
373
374
375
376
377
378static int zf_notify_sys(struct notifier_block *this, unsigned long code,
379 void *unused)
380{
381 if(code == SYS_DOWN || code == SYS_HALT){
382 zf_timer_off();
383 }
384
385 return NOTIFY_DONE;
386}
387
388
389
390
391static const struct file_operations zf_fops = {
392 .owner = THIS_MODULE,
393 .llseek = no_llseek,
394 .write = zf_write,
395 .ioctl = zf_ioctl,
396 .open = zf_open,
397 .release = zf_close,
398};
399
400static struct miscdevice zf_miscdev = {
401 .minor = WATCHDOG_MINOR,
402 .name = "watchdog",
403 .fops = &zf_fops,
404};
405
406
407
408
409
410
411static struct notifier_block zf_notifier = {
412 .notifier_call = zf_notify_sys,
413};
414
415static void __init zf_show_action(int act)
416{
417 char *str[] = { "RESET", "SMI", "NMI", "SCI" };
418
419 printk(KERN_INFO PFX ": Watchdog using action = %s\n", str[act]);
420}
421
422static int __init zf_init(void)
423{
424 int ret;
425
426 printk(KERN_INFO PFX ": MachZ ZF-Logic Watchdog driver initializing.\n");
427
428 ret = zf_get_ZFL_version();
429 if ((!ret) || (ret == 0xffff)) {
430 printk(KERN_WARNING PFX ": no ZF-Logic found\n");
431 return -ENODEV;
432 }
433
434 if((action <= 3) && (action >= 0)){
435 zf_action = zf_action>>action;
436 } else
437 action = 0;
438
439 zf_show_action(action);
440
441 if(!request_region(ZF_IOBASE, 3, "MachZ ZFL WDT")){
442 printk(KERN_ERR "cannot reserve I/O ports at %d\n",
443 ZF_IOBASE);
444 ret = -EBUSY;
445 goto no_region;
446 }
447
448 ret = register_reboot_notifier(&zf_notifier);
449 if(ret){
450 printk(KERN_ERR "can't register reboot notifier (err=%d)\n",
451 ret);
452 goto no_reboot;
453 }
454
455 ret = misc_register(&zf_miscdev);
456 if (ret){
457 printk(KERN_ERR "can't misc_register on minor=%d\n",
458 WATCHDOG_MINOR);
459 goto no_misc;
460 }
461
462 zf_set_status(0);
463 zf_set_control(0);
464
465 return 0;
466
467no_misc:
468 unregister_reboot_notifier(&zf_notifier);
469no_reboot:
470 release_region(ZF_IOBASE, 3);
471no_region:
472 return ret;
473}
474
475
476static void __exit zf_exit(void)
477{
478 zf_timer_off();
479
480 misc_deregister(&zf_miscdev);
481 unregister_reboot_notifier(&zf_notifier);
482 release_region(ZF_IOBASE, 3);
483}
484
485module_init(zf_init);
486module_exit(zf_exit);
487