1 /* $NetBSD: swwdog.c,v 1.7 2007/07/09 21:01:23 ad 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 1.7 2007/07/09 21:01:23 ad 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 } 162