1 /* $NetBSD: swwdog.c,v 1.4 2005/12/11 12:23:56 christos 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 1.4 2005/12/11 12:23:56 christos Exp $"); 37 38 /* 39 * 40 * Software watchdog timer 41 * 42 */ 43 #include <sys/param.h> 44 #include <sys/callout.h> 45 #include <sys/cdefs.h> 46 #include <sys/device.h> 47 #include <sys/kernel.h> 48 #include <sys/reboot.h> 49 #include <sys/systm.h> 50 #include <sys/wdog.h> 51 #include <dev/sysmon/sysmonvar.h> 52 53 #include "swwdog.h" 54 55 struct swwdog_softc { 56 struct sysmon_wdog sc_smw; 57 struct callout sc_c; 58 char sc_name[20]; 59 int sc_wdog_armed; 60 } sc_wdog[NSWWDOG]; 61 62 void swwdogattach(int); 63 64 static int swwdog_setmode(struct sysmon_wdog *); 65 static int swwdog_tickle(struct sysmon_wdog *); 66 67 static int swwdog_arm(struct swwdog_softc *); 68 static int swwdog_disarm(struct swwdog_softc *); 69 70 static void swwdog_panic(void *); 71 72 int swwdog_reboot = 0; /* set for panic instead of reboot */ 73 74 #define SWDOG_DEFAULT 60 /* 60-second default period */ 75 76 void 77 swwdogattach(int count) 78 { 79 int i; 80 81 for (i = 0; i < NSWWDOG; i++) { 82 struct swwdog_softc *sc = &sc_wdog[i]; 83 84 snprintf(sc->sc_name, sizeof sc->sc_name, "swwdog%d", i); 85 printf("%s: ", sc->sc_name); 86 sc->sc_smw.smw_name = sc->sc_name; 87 sc->sc_smw.smw_cookie = sc; 88 sc->sc_smw.smw_setmode = swwdog_setmode; 89 sc->sc_smw.smw_tickle = swwdog_tickle; 90 sc->sc_smw.smw_period = SWDOG_DEFAULT; 91 callout_init(&sc->sc_c); 92 callout_setfunc(&sc->sc_c, swwdog_panic, sc); 93 94 if (sysmon_wdog_register(&sc->sc_smw) == 0) 95 printf("software watchdog initialized\n"); 96 else 97 printf("unable to register software watchdog " 98 "with sysmon\n"); 99 } 100 } 101 102 static int 103 swwdog_setmode(struct sysmon_wdog *smw) 104 { 105 struct swwdog_softc *sc = smw->smw_cookie; 106 int error = 0; 107 108 if ((smw->smw_mode & WDOG_MODE_MASK) == WDOG_MODE_DISARMED) { 109 error = swwdog_disarm(sc); 110 } else { 111 if (smw->smw_period == 0) 112 return EINVAL; 113 else if (smw->smw_period == WDOG_PERIOD_DEFAULT) 114 sc->sc_smw.smw_period = SWDOG_DEFAULT; 115 else 116 sc->sc_smw.smw_period = smw->smw_period; 117 error = swwdog_arm(sc); 118 } 119 return error; 120 } 121 122 static int 123 swwdog_tickle(struct sysmon_wdog *smw) 124 { 125 126 return swwdog_arm(smw->smw_cookie); 127 } 128 129 static int 130 swwdog_arm(struct swwdog_softc *sc) 131 { 132 133 callout_schedule(&sc->sc_c, sc->sc_smw.smw_period * hz); 134 return 0; 135 } 136 137 static int 138 swwdog_disarm(struct swwdog_softc *sc) 139 { 140 141 callout_stop(&sc->sc_c); 142 return 0; 143 } 144 145 static void 146 swwdog_panic(void *vsc) 147 { 148 struct swwdog_softc *sc = vsc; 149 int do_panic; 150 151 do_panic = swwdog_reboot; 152 swwdog_reboot = 1; 153 callout_schedule(&sc->sc_c, 60 * hz); /* deliberate double-panic */ 154 155 printf("%s: %d second timer expired", sc->sc_name, 156 sc->sc_smw.smw_period); 157 158 if (do_panic) 159 panic("watchdog timer expired"); 160 else 161 cpu_reboot(0, NULL); 162 } 163