sys/kern/kern_wdog.c

   1 /*
   2  * Copyright (c) 2009 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by Alex Hornung <ahornung@gmail.com>
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in
  15  *    the documentation and/or other materials provided with the
  16  *    distribution.
  17  * 3. Neither the name of The DragonFly Project nor the names of its
  18  *    contributors may be used to endorse or promote products derived
  19  *    from this software without specific, prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34
  35 #include <sys/param.h>
  36 #include <sys/kernel.h>
  37 #include <sys/systm.h>
  38 #include <sys/malloc.h>
  39 #include <sys/sysproto.h>
  40 #include <sys/spinlock2.h>
  41 #include <sys/conf.h>
  42 #include <sys/device.h>
  43 #include <sys/filedesc.h>
  44 #include <sys/sysctl.h>
  45 #include <sys/unistd.h>
  46 #include <sys/event.h>
  47 #include <sys/queue.h>
  48 #include <sys/wdog.h>
  49 #include <machine/limits.h>
  50
  51 static LIST_HEAD(, watchdog) wdoglist = LIST_HEAD_INITIALIZER(&wdoglist);
  52 static struct spinlock  wdogmtx;
  53 static struct callout   wdog_callout;
  54
  55 static int wdog_auto_enable = 1;
  56 static int wdog_auto_period = WDOG_DEFAULT_PERIOD;
  57
  58 static void wdog_reset_all(void *unused);
  59
  60 void
  61 wdog_register(struct watchdog *wd)
  62 {
  63         spin_lock(&wdogmtx);
  64         wd->period = WDOG_DEFAULT_PERIOD;
  65         LIST_INSERT_HEAD(&wdoglist, wd, link);
  66         spin_unlock(&wdogmtx);
  67
  68         wdog_reset_all(NULL);
  69
  70         kprintf("wdog: Watchdog %s registered, max period = %ds , period = %ds\n",
  71             wd->name, wd->period_max, wd->period);
  72 }
  73
  74 void
  75 wdog_unregister(struct watchdog *wd)
  76 {
  77         spin_lock(&wdogmtx);
  78         LIST_REMOVE(wd, link);
  79         spin_unlock(&wdogmtx);
  80
  81         kprintf("wdog: Watchdog %s unregistered\n", wd->name);
  82 }
  83
  84 static int
  85 wdog_reset(struct watchdog *wd)
  86 {
  87         return (wd->period = wd->wdog_fn(wd->arg, wd->period));
  88 }
  89
  90 static void
  91 wdog_reset_all(void *unused)
  92 {
  93         struct watchdog *wd;
  94         int period, min_period = INT_MAX;
  95
  96         spin_lock(&wdogmtx);
  97         if (LIST_EMPTY(&wdoglist))
  98                 goto done;
  99         LIST_FOREACH(wd, &wdoglist, link) {
 100                 period = wdog_reset(wd);
 101                 if (period < min_period)
 102                         min_period = period;
 103         }
 104         if (wdog_auto_enable)
 105                 callout_reset(&wdog_callout, min_period * hz / 2, wdog_reset_all, NULL);
 106
 107         wdog_auto_period = min_period;
 108
 109 done:
 110         spin_unlock(&wdogmtx);
 111 }
 112
 113 static void
 114 wdog_set_period(int period)
 115 {
 116         struct watchdog *wd;
 117
 118         spin_lock(&wdogmtx);
 119         LIST_FOREACH(wd, &wdoglist, link) {
 120                 /* XXX: check for period_max */
 121                 wd->period = period;
 122         }
 123         spin_unlock(&wdogmtx);
 124 }
 125
 126
 127 static int
 128 wdog_sysctl_auto(SYSCTL_HANDLER_ARGS)
 129 {
 130         int             error;
 131
 132         error = sysctl_handle_int(oidp, &wdog_auto_enable, 1, req);
 133         if (error || req->newptr == NULL)
 134                 return error;
 135
 136         /* has changed, do something */
 137         callout_stop(&wdog_callout);
 138         if (wdog_auto_enable) {
 139                 wdog_reset_all(NULL);
 140         }
 141
 142         kprintf("wdog: In-kernel automatic watchdog reset %s\n",
 143             (wdog_auto_enable)?"enabled":"disabled");
 144
 145         return 0;
 146 }
 147
 148 static int
 149 wdog_sysctl_period(SYSCTL_HANDLER_ARGS)
 150 {
 151         int             error;
 152
 153         error = sysctl_handle_int(oidp, &wdog_auto_period, WDOG_DEFAULT_PERIOD, req);
 154         if (error || req->newptr == NULL)
 155                 return error;
 156
 157         /* has changed, do something */
 158         callout_stop(&wdog_callout);
 159         wdog_set_period(wdog_auto_period);
 160         wdog_reset_all(NULL);
 161
 162         if (wdog_auto_period != 0)
 163                 kprintf("wdog: Watchdog period set to %ds\n", wdog_auto_period);
 164         else
 165                 kprintf("wdog: Disabled watchdog(s)\n");
 166
 167         return 0;
 168 }
 169
 170 void
 171 wdog_disable(void)
 172 {
 173         callout_stop(&wdog_callout);
 174         wdog_set_period(0);
 175         wdog_reset_all(NULL);
 176 }
 177
 178 static SYSCTL_NODE(_kern, OID_AUTO, watchdog, CTLFLAG_RW, 0, "watchdog");
 179 SYSCTL_PROC(_kern_watchdog, OID_AUTO, auto, CTLTYPE_INT | CTLFLAG_RW,
 180                         NULL, 0, wdog_sysctl_auto, "I", "auto in-kernel watchdog reset "
 181                         "(0 = disabled, 1 = enabled)");
 182 SYSCTL_PROC(_kern_watchdog, OID_AUTO, period, CTLTYPE_INT | CTLFLAG_RW,
 183                         NULL, 0, wdog_sysctl_period, "I", "watchdog period "
 184                         "(value in seconds)");
 185
 186
 187 static int
 188 wdog_ioctl(struct dev_ioctl_args *ap)
 189 {
 190         if (wdog_auto_enable)
 191                 return EINVAL;
 192
 193         if (ap->a_cmd == WDIOCRESET) {
 194                 wdog_reset_all(NULL);
 195         } else {
 196                 return EINVAL;
 197         }
 198
 199         return 0;
 200 }
 201
 202 static struct dev_ops wdog_ops = {
 203         { "wdog", 0, 0 },
 204         .d_ioctl =      wdog_ioctl,
 205 };
 206
 207 static void
 208 wdog_init(void)
 209 {
 210         spin_init(&wdogmtx, "wdog");
 211         make_dev(&wdog_ops, 0,
 212             UID_ROOT, GID_WHEEL, 0600, "wdog");
 213         callout_init_mp(&wdog_callout);
 214
 215         kprintf("wdog: In-kernel automatic watchdog reset %s\n",
 216             (wdog_auto_enable)?"enabled":"disabled");
 217 }
 218
 219 static void
 220 wdog_uninit(void)
 221 {
 222         callout_stop(&wdog_callout);
 223         callout_deactivate(&wdog_callout);
 224         dev_ops_remove_all(&wdog_ops);
 225         spin_uninit(&wdogmtx);
 226 }
 227
 228 SYSINIT(wdog_register, SI_SUB_PRE_DRIVERS, SI_ORDER_ANY, wdog_init, NULL);
 229 SYSUNINIT(wdog_register, SI_SUB_PRE_DRIVERS, SI_ORDER_ANY, wdog_uninit, NULL);