summaryrefslogtreecommitdiffstats
path: root/sys/dev/watchdog/watchdog.c
blob: e7edf31c4b7a17b4d698c3b8ae3e1102ff06c52e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
/*-
 * Copyright (c) 2004 Poul-Henning Kamp
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer
 *    in this position and unchanged.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/uio.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/watchdog.h>
#include <sys/bus.h>
#include <machine/bus.h>

static struct cdev *wd_dev;
static volatile u_int wd_last_u;

static int
kern_do_pat(u_int utim)
{
	int error;

	if ((utim & WD_LASTVAL) != 0 && (utim & WD_INTERVAL) > 0)
		return (EINVAL);

	if ((utim & WD_LASTVAL) != 0) {
		MPASS((wd_last_u & ~WD_INTERVAL) == 0);
		utim &= ~WD_LASTVAL;
		utim |= wd_last_u;
	} else
		wd_last_u = (utim & WD_INTERVAL);
	if ((utim & WD_INTERVAL) == WD_TO_NEVER) {
		utim = 0;

		/* Assume all is well; watchdog signals failure. */
		error = 0;
	} else {
		/* Assume no watchdog available; watchdog flags success */
		error = EOPNOTSUPP;
	}
	EVENTHANDLER_INVOKE(watchdog_list, utim, &error);
	return (error);
}

static int
wd_ioctl(struct cdev *dev __unused, u_long cmd, caddr_t data,
    int flags __unused, struct thread *td)
{
	u_int u;

	if (cmd != WDIOCPATPAT)
		return (ENOIOCTL);
	u = *(u_int *)data;
	if (u & ~(WD_ACTIVE | WD_PASSIVE | WD_LASTVAL | WD_INTERVAL))
		return (EINVAL);
	if ((u & (WD_ACTIVE | WD_PASSIVE)) == (WD_ACTIVE | WD_PASSIVE))
		return (EINVAL);
	if ((u & (WD_ACTIVE | WD_PASSIVE)) == 0 && ((u & WD_INTERVAL) > 0 ||
	    (u & WD_LASTVAL) != 0))
		return (EINVAL);
	if (u & WD_PASSIVE)
		return (ENOSYS);	/* XXX Not implemented yet */
	u &= ~(WD_ACTIVE | WD_PASSIVE);

	return (kern_do_pat(u));
}

u_int
wdog_kern_last_timeout(void)
{

	return (wd_last_u);
}

int
wdog_kern_pat(u_int utim)
{

	if (utim & ~(WD_LASTVAL | WD_INTERVAL))
		return (EINVAL);

	return (kern_do_pat(utim));
}

static struct cdevsw wd_cdevsw = {
	.d_version =	D_VERSION,
	.d_ioctl =	wd_ioctl,
	.d_name =	"watchdog",
};

static int
watchdog_modevent(module_t mod __unused, int type, void *data __unused)
{
	switch(type) {
	case MOD_LOAD:
		wd_dev = make_dev(&wd_cdevsw, 0,
		    UID_ROOT, GID_WHEEL, 0600, _PATH_WATCHDOG);
		return 0;
	case MOD_UNLOAD:
		destroy_dev(wd_dev);
		return 0;
	case MOD_SHUTDOWN:
		return 0;
	default:
		return EOPNOTSUPP;
	}
}

DEV_MODULE(watchdog, watchdog_modevent, NULL);
OpenPOWER on IntegriCloud