/*-
* Copyright (c) 2004 Poul-Henning Kamp
* Copyright (c) 2013 iXsystems.com,
* author: Alfred Perlstein <alfred@freebsd.org>
*
* 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 "opt_ddb.h"
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/types.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/uio.h>
#include <sys/kernel.h>
#include <sys/kdb.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/sysctl.h>
#include <sys/syslog.h>
#include <sys/watchdog.h>
#include <sys/bus.h>
#include <machine/bus.h>
#include <sys/syscallsubr.h> /* kern_clock_gettime() */
static int wd_set_pretimeout(int newtimeout, int disableiftoolong);
static void wd_timeout_cb(void *arg);
static struct callout wd_pretimeo_handle;
static int wd_pretimeout;
static int wd_pretimeout_act = WD_SOFT_LOG;
static struct callout wd_softtimeo_handle;
static int wd_softtimer; /* true = use softtimer instead of hardware
watchdog */
static int wd_softtimeout_act = WD_SOFT_LOG; /* action for the software timeout */
static struct cdev *wd_dev;
static volatile u_int wd_last_u; /* last timeout value set by kern_do_pat */
static u_int wd_last_u_sysctl; /* last timeout value set by kern_do_pat */
static u_int wd_last_u_sysctl_secs; /* wd_last_u in seconds */
SYSCTL_NODE(_hw, OID_AUTO, watchdog, CTLFLAG_RD, 0, "Main watchdog device");
SYSCTL_UINT(_hw_watchdog, OID_AUTO, wd_last_u, CTLFLAG_RD,
&wd_last_u_sysctl, 0, "Watchdog last update time");
SYSCTL_UINT(_hw_watchdog, OID_AUTO, wd_last_u_secs, CTLFLAG_RD,
&wd_last_u_sysctl_secs, 0, "Watchdog last update time");
static int wd_lastpat_valid = 0;
static time_t wd_lastpat = 0; /* when the watchdog was last patted */
static void
pow2ns_to_ts(int pow2ns, struct timespec *ts)
{
uint64_t ns;
ns = 1ULL << pow2ns;
ts->tv_sec = ns / 1000000000ULL;
ts->tv_nsec = ns % 1000000000ULL;
}
static int
pow2ns_to_ticks(int pow2ns)
{
struct timeval tv;
struct timespec ts;
pow2ns_to_ts(pow2ns, &ts);
TIMESPEC_TO_TIMEVAL(&tv, &ts);
return (tvtohz(&tv));
}
static int
seconds_to_pow2ns(int seconds)
{
uint64_t power;
uint64_t ns;
uint64_t shifted;
ns = ((uint64_t)seconds) * 1000000000ULL;
power = flsll(ns);
shifted = 1ULL << power;
if (shifted <= ns) {
power++;
}
return (power);
}
int
wdog_kern_pat(u_int utim)
{
int error;
if ((utim & WD_LASTVAL) != 0 && (utim & WD_INTERVAL) > 0)
return (EINVAL);
if ((utim & WD_LASTVAL) != 0) {
/*
* if WD_LASTVAL is set, fill in the bits for timeout
* from the saved value in wd_last_u.
*/
MPASS((wd_last_u & ~WD_INTERVAL) == 0);
utim &= ~WD_LASTVAL;
utim |= wd_last_u;
} else {
/*
* Otherwise save the new interval.
* This can be zero (to disable the watchdog)
*/
wd_last_u = (utim & WD_INTERVAL);
wd_last_u_sysctl = wd_last_u;
wd_last_u_sysctl_secs = pow2ns_to_ticks(wd_last_u) / hz;
}
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;
}
if (wd_softtimer) {
if (utim == 0) {
callout_stop(&wd_softtimeo_handle);
} else {
(void) callout_reset(&wd_softtimeo_handle,
pow2ns_to_ticks(utim), wd_timeout_cb, "soft");
}
error = 0;
} else {
EVENTHANDLER_INVOKE(watchdog_list, utim, &error);
}
wd_set_pretimeout(wd_pretimeout, true);
/*
* If we were able to arm/strobe the watchdog, then
* update the last time it was strobed for WDIOC_GETTIMELEFT
*/
if (!error) {
struct timespec ts;
error = kern_clock_gettime(curthread /* XXX */,
CLOCK_MONOTONIC_FAST, &ts);
if (!error) {
wd_lastpat = ts.tv_sec;
wd_lastpat_valid = 1;
}
}
return (error);
}
static int
wd_valid_act(int act)
{
if ((act & ~(WD_SOFT_MASK)) != 0)
return false;
return true;
}
static int
wd_ioctl_patpat(caddr_t data)
{
u_int u;
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 (wdog_kern_pat(u));
}
static int
wd_get_time_left(struct thread *td, time_t *remainp)
{
struct timespec ts;
int error;
error = kern_clock_gettime(td, CLOCK_MONOTONIC_FAST, &ts);
if (error)
return (error);
if (!wd_lastpat_valid)
return (ENOENT);
*remainp = ts.tv_sec - wd_lastpat;
return (0);
}
static void
wd_timeout_cb(void *arg)
{
const char *type = arg;
#ifdef DDB
if ((wd_pretimeout_act & WD_SOFT_DDB)) {
char kdb_why[80];
snprintf(kdb_why, sizeof(kdb_why), "watchdog %s timeout", type);
kdb_backtrace();
kdb_enter(KDB_WHY_WATCHDOG, kdb_why);
}
#endif
if ((wd_pretimeout_act & WD_SOFT_LOG))
log(LOG_EMERG, "watchdog %s-timeout, WD_SOFT_LOG", type);
if ((wd_pretimeout_act & WD_SOFT_PRINTF))
printf("watchdog %s-timeout, WD_SOFT_PRINTF\n", type);
if ((wd_pretimeout_act & WD_SOFT_PANIC))
panic("watchdog %s-timeout, WD_SOFT_PANIC set", type);
}
/*
* Called to manage timeouts.
* newtimeout needs to be in the range of 0 to actual watchdog timeout.
* if 0, we disable the pre-timeout.
* otherwise we set the pre-timeout provided it's not greater than the
* current actual watchdog timeout.
*/
static int
wd_set_pretimeout(int newtimeout, int disableiftoolong)
{
u_int utime;
struct timespec utime_ts;
int timeout_ticks;
utime = wdog_kern_last_timeout();
pow2ns_to_ts(utime, &utime_ts);
/* do not permit a pre-timeout >= than the timeout. */
if (newtimeout >= utime_ts.tv_sec) {
/*
* If 'disableiftoolong' then just fall through
* so as to disable the pre-watchdog
*/
if (disableiftoolong)
newtimeout = 0;
else
return EINVAL;
}
/* disable the pre-timeout */
if (newtimeout == 0) {
wd_pretimeout = 0;
callout_stop(&wd_pretimeo_handle);
return 0;
}
timeout_ticks = pow2ns_to_ticks(utime) - (hz*newtimeout);
#if 0
printf("wd_set_pretimeout: "
"newtimeout: %d, "
"utime: %d -> utime_ticks: %d, "
"hz*newtimeout: %d, "
"timeout_ticks: %d -> sec: %d\n",
newtimeout,
utime, pow2ns_to_ticks(utime),
hz*newtimeout,
timeout_ticks, timeout_ticks / hz);
#endif
/* We determined the value is sane, so reset the callout */
(void) callout_reset(&wd_pretimeo_handle,
timeout_ticks,
wd_timeout_cb, "pre-timeout");
wd_pretimeout = newtimeout;
return 0;
}
static int
wd_ioctl(struct cdev *dev __unused, u_long cmd, caddr_t data,
int flags __unused, struct thread *td)
{
u_int u;
time_t timeleft;
int error;
error = 0;
switch (cmd) {
case WDIOC_SETSOFT:
u = *(int *)data;
/* do nothing? */
if (u == wd_softtimer)
break;
/* If there is a pending timeout disallow this ioctl */
if (wd_last_u != 0) {
error = EINVAL;
break;
}
wd_softtimer = u;
break;
case WDIOC_SETSOFTTIMEOUTACT:
u = *(int *)data;
if (wd_valid_act(u)) {
wd_softtimeout_act = u;
} else {
error = EINVAL;
}
break;
case WDIOC_SETPRETIMEOUTACT:
u = *(int *)data;
if (wd_valid_act(u)) {
wd_pretimeout_act = u;
} else {
error = EINVAL;
}
break;
case WDIOC_GETPRETIMEOUT:
*(int *)data = (int)wd_pretimeout;
break;
case WDIOC_SETPRETIMEOUT:
error = wd_set_pretimeout(*(int *)data, false);
break;
case WDIOC_GETTIMELEFT:
error = wd_get_time_left(td, &timeleft);
if (error)
break;
*(int *)data = (int)timeleft;
break;
case WDIOC_SETTIMEOUT:
u = *(u_int *)data;
error = wdog_kern_pat(seconds_to_pow2ns(u));
break;
case WDIOC_GETTIMEOUT:
u = wdog_kern_last_timeout();
*(u_int *)data = u;
break;
case WDIOCPATPAT:
error = wd_ioctl_patpat(data);
break;
default:
error = ENOIOCTL;
break;
}
return (error);
}
/*
* Return the last timeout set, this is NOT the seconds from NOW until timeout,
* rather it is the amount of seconds passed to WDIOCPATPAT/WDIOC_SETTIMEOUT.
*/
u_int
wdog_kern_last_timeout(void)
{
return (wd_last_u);
}
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:
callout_init(&wd_pretimeo_handle, 1);
callout_init(&wd_softtimeo_handle, 1);
wd_dev = make_dev(&wd_cdevsw, 0,
UID_ROOT, GID_WHEEL, 0600, _PATH_WATCHDOG);
return 0;
case MOD_UNLOAD:
callout_stop(&wd_pretimeo_handle);
callout_stop(&wd_softtimeo_handle);
callout_drain(&wd_pretimeo_handle);
callout_drain(&wd_softtimeo_handle);
destroy_dev(wd_dev);
return 0;
case MOD_SHUTDOWN:
return 0;
default:
return EOPNOTSUPP;
}
}
DEV_MODULE(watchdog, watchdog_modevent, NULL);
