sys/dev/sysmon/swwdog.c

   1 /*      $NetBSD: swwdog.c,v 1.6 2007/01/29 01:52:45 hubertf Exp $       */
   2
   3 /*
   4  * Copyright (c) 2004, 2005 Steven M. Bellovin
   5  * All rights reserved.
   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  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. All advertising materials mentioning features or use of this software
  16  *    must display the following acknowledgement:
  17  *      This product includes software developed by Steven M. Bellovin
  18  * 4. The name of the author contributors may not be used to endorse or
  19  *    promote products derived from this software without specific prior
  20  *    written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS
  23  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  24  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  25  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS
  26  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  27  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  28  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  29  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  30  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  31  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  32  * POSSIBILITY OF SUCH DAMAGE.
  33  */
  34
  35 #include <sys/cdefs.h>
  36 __KERNEL_RCSID(0, "$NetBSD: swwdog.c,v 1.6 2007/01/29 01:52:45 hubertf Exp $");
  37
  38 /*
  39  *
  40  * Software watchdog timer
  41  *
  42  */
  43 #include <sys/param.h>
  44 #include <sys/callout.h>
  45 #include <sys/device.h>
  46 #include <sys/kernel.h>
  47 #include <sys/reboot.h>
  48 #include <sys/systm.h>
  49 #include <sys/wdog.h>
  50 #include <dev/sysmon/sysmonvar.h>
  51
  52 #include "swwdog.h"
  53
  54 struct swwdog_softc {
  55         struct sysmon_wdog sc_smw;
  56         struct callout sc_c;
  57         char sc_name[20];
  58         int sc_wdog_armed;
  59 } sc_wdog[NSWWDOG];
  60
  61 void    swwdogattach(int);
  62
  63 static int swwdog_setmode(struct sysmon_wdog *);
  64 static int swwdog_tickle(struct sysmon_wdog *);
  65
  66 static int swwdog_arm(struct swwdog_softc *);
  67 static int swwdog_disarm(struct swwdog_softc *);
  68
  69 static void swwdog_panic(void *);
  70
  71 int swwdog_reboot = 0;          /* set for panic instead of reboot */
  72
  73 #define SWDOG_DEFAULT   60              /* 60-second default period */
  74
  75 void
  76 swwdogattach(int count __unused)
  77 {
  78         int i;
  79
  80         for (i = 0; i < NSWWDOG; i++) {
  81                 struct swwdog_softc *sc = &sc_wdog[i];
  82
  83                 snprintf(sc->sc_name, sizeof sc->sc_name, "swwdog%d", i);
  84                 printf("%s: ", sc->sc_name);
  85                 sc->sc_smw.smw_name = sc->sc_name;
  86                 sc->sc_smw.smw_cookie = sc;
  87                 sc->sc_smw.smw_setmode = swwdog_setmode;
  88                 sc->sc_smw.smw_tickle = swwdog_tickle;
  89                 sc->sc_smw.smw_period = SWDOG_DEFAULT;
  90                 callout_init(&sc->sc_c, 0);
  91                 callout_setfunc(&sc->sc_c, swwdog_panic, sc);
  92
  93                 if (sysmon_wdog_register(&sc->sc_smw) == 0)
  94                         printf("software watchdog initialized\n");
  95                 else
  96                         printf("unable to register software watchdog "
  97                             "with sysmon\n");
  98         }
  99 }
 100
 101 static int
 102 swwdog_setmode(struct sysmon_wdog *smw)
 103 {
 104         struct swwdog_softc *sc = smw->smw_cookie;
 105         int error = 0;
 106
 107         if ((smw->smw_mode & WDOG_MODE_MASK) == WDOG_MODE_DISARMED) {
 108                 error = swwdog_disarm(sc);
 109         } else {
 110                 if (smw->smw_period == 0)
 111                         return EINVAL;
 112                 else if (smw->smw_period == WDOG_PERIOD_DEFAULT)
 113                         sc->sc_smw.smw_period = SWDOG_DEFAULT;
 114                 else
 115                         sc->sc_smw.smw_period = smw->smw_period;
 116                 error = swwdog_arm(sc);
 117         }
 118         return error;
 119 }
 120
 121 static int
 122 swwdog_tickle(struct sysmon_wdog *smw)
 123 {
 124
 125         return swwdog_arm(smw->smw_cookie);
 126 }
 127
 128 static int
 129 swwdog_arm(struct swwdog_softc *sc)
 130 {
 131
 132         callout_schedule(&sc->sc_c, sc->sc_smw.smw_period * hz);
 133         return 0;
 134 }
 135
 136 static int
 137 swwdog_disarm(struct swwdog_softc *sc)
 138 {
 139
 140         callout_stop(&sc->sc_c);
 141         return 0;
 142 }
 143
 144 static void
 145 swwdog_panic(void *vsc)
 146 {
 147         struct swwdog_softc *sc = vsc;
 148         int do_panic;
 149
 150         do_panic = swwdog_reboot;
 151         swwdog_reboot = 1;
 152         callout_schedule(&sc->sc_c, 60 * hz);   /* deliberate double-panic */
 153
 154         printf("%s: %d second timer expired", sc->sc_name,
 155             sc->sc_smw.smw_period);
 156
 157         if (do_panic)
 158                 panic("watchdog timer expired");
 159         else
 160                 cpu_reboot(0, NULL);
 161 }