1 /* $NetBSD: swwdog.c,v 1.12 2010/11/11 21:55:04 pooka 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 1.12 2010/11/11 21:55:04 pooka 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/kmem.h> 48 #include <sys/reboot.h> 49 #include <sys/systm.h> 50 #include <sys/sysctl.h> 51 #include <sys/wdog.h> 52 #include <sys/workqueue.h> 53 #include <dev/sysmon/sysmonvar.h> 54 55 #include "ioconf.h" 56 57 struct swwdog_softc { 58 device_t sc_dev; 59 struct sysmon_wdog sc_smw; 60 struct callout sc_c; 61 int sc_wdog_armed; 62 }; 63 64 void swwdogattach(int); 65 66 static int swwdog_match(device_t, cfdata_t, void *); 67 static void swwdog_attach(device_t, device_t, void *); 68 static int swwdog_detach(device_t, int); 69 static bool swwdog_suspend(device_t, const pmf_qual_t *); 70 71 static int swwdog_setmode(struct sysmon_wdog *); 72 static int swwdog_tickle(struct sysmon_wdog *); 73 74 static int swwdog_arm(struct swwdog_softc *); 75 static int swwdog_disarm(struct swwdog_softc *); 76 77 static void swwdog_panic(void *); 78 79 bool swwdog_reboot = false; /* set for panic instead of reboot */ 80 81 #define SWDOG_DEFAULT 60 /* 60-second default period */ 82 83 CFATTACH_DECL_NEW(swwdog, sizeof(struct swwdog_softc), 84 swwdog_match, swwdog_attach, swwdog_detach, NULL); 85 86 static void swwdog_sysctl_setup(void); 87 static struct sysctllog *swwdog_sysctllog; 88 89 static void 90 doreboot(struct work *wrkwrkwrk, void *p) 91 { 92 93 cpu_reboot(0, NULL); 94 } 95 96 static struct workqueue *wq; 97 98 void 99 swwdogattach(int n __unused) 100 { 101 int err; 102 static struct cfdata cf; 103 104 if (workqueue_create(&wq, "swwreboot", doreboot, NULL, 105 PRI_NONE, IPL_NONE, 0) != 0) { 106 aprint_error("failed to create swwdog reboot wq"); 107 } 108 109 err = config_cfattach_attach(swwdog_cd.cd_name, &swwdog_ca); 110 if (err) { 111 aprint_error("%s: couldn't register cfattach: %d\n", 112 swwdog_cd.cd_name, err); 113 config_cfdriver_detach(&swwdog_cd); 114 workqueue_destroy(wq); 115 return; 116 } 117 118 cf.cf_name = swwdog_cd.cd_name; 119 cf.cf_atname = swwdog_cd.cd_name; 120 cf.cf_unit = 0; 121 cf.cf_fstate = FSTATE_STAR; 122 123 (void)config_attach_pseudo(&cf); 124 125 return; 126 } 127 128 static int 129 swwdog_match(device_t parent, cfdata_t data, void *aux) 130 { 131 return 1; 132 } 133 134 static void 135 swwdog_attach(device_t parent, device_t self, void *aux) 136 { 137 struct swwdog_softc *sc = device_private(self); 138 139 sc->sc_dev = self; 140 sc->sc_smw.smw_name = device_xname(self); 141 sc->sc_smw.smw_cookie = sc; 142 sc->sc_smw.smw_setmode = swwdog_setmode; 143 sc->sc_smw.smw_tickle = swwdog_tickle; 144 sc->sc_smw.smw_period = SWDOG_DEFAULT; 145 callout_init(&sc->sc_c, 0); 146 callout_setfunc(&sc->sc_c, swwdog_panic, sc); 147 148 if (sysmon_wdog_register(&sc->sc_smw) == 0) 149 aprint_normal_dev(self, "software watchdog initialized\n"); 150 else 151 aprint_error_dev(self, "unable to register software " 152 "watchdog with sysmon\n"); 153 154 if (!pmf_device_register(self, swwdog_suspend, NULL)) 155 aprint_error_dev(self, "couldn't establish power handler\n"); 156 157 swwdog_sysctl_setup(); 158 } 159 160 static int 161 swwdog_detach(device_t self, int flags) 162 { 163 struct swwdog_softc *sc = device_private(self); 164 165 swwdog_disarm(sc); 166 callout_destroy(&sc->sc_c); 167 sysctl_teardown(&swwdog_sysctllog); 168 workqueue_destroy(wq); 169 170 return 1; 171 } 172 173 static bool 174 swwdog_suspend(device_t dev, const pmf_qual_t *qual) 175 { 176 struct swwdog_softc *sc = device_private(dev); 177 178 /* Don't allow suspend if watchdog is armed */ 179 if ((sc->sc_smw.smw_mode & WDOG_MODE_MASK) != WDOG_MODE_DISARMED) 180 return false; 181 return true; 182 } 183 184 static int 185 swwdog_setmode(struct sysmon_wdog *smw) 186 { 187 struct swwdog_softc *sc = smw->smw_cookie; 188 int error = 0; 189 190 if ((smw->smw_mode & WDOG_MODE_MASK) == WDOG_MODE_DISARMED) { 191 error = swwdog_disarm(sc); 192 } else { 193 if (smw->smw_period == 0) 194 return EINVAL; 195 else if (smw->smw_period == WDOG_PERIOD_DEFAULT) 196 sc->sc_smw.smw_period = SWDOG_DEFAULT; 197 else 198 sc->sc_smw.smw_period = smw->smw_period; 199 error = swwdog_arm(sc); 200 } 201 return error; 202 } 203 204 static int 205 swwdog_tickle(struct sysmon_wdog *smw) 206 { 207 208 return swwdog_arm(smw->smw_cookie); 209 } 210 211 static int 212 swwdog_arm(struct swwdog_softc *sc) 213 { 214 215 callout_schedule(&sc->sc_c, sc->sc_smw.smw_period * hz); 216 return 0; 217 } 218 219 static int 220 swwdog_disarm(struct swwdog_softc *sc) 221 { 222 223 callout_stop(&sc->sc_c); 224 return 0; 225 } 226 227 static void 228 swwdog_panic(void *vsc) 229 { 230 struct swwdog_softc *sc = vsc; 231 static struct work wk; /* we'll need it max once */ 232 bool do_panic; 233 234 do_panic = !swwdog_reboot; 235 swwdog_reboot = false; 236 callout_schedule(&sc->sc_c, 60 * hz); /* deliberate double-panic */ 237 238 printf("%s: %d second timer expired\n", device_xname(sc->sc_dev), 239 sc->sc_smw.smw_period); 240 241 if (do_panic) 242 panic("watchdog timer expired"); 243 else 244 workqueue_enqueue(wq, &wk, NULL); 245 } 246 247 static void 248 swwdog_sysctl_setup(void) 249 { 250 const struct sysctlnode *me; 251 252 KASSERT(swwdog_sysctllog == NULL); 253 254 sysctl_createv(&swwdog_sysctllog, 0, NULL, &me, CTLFLAG_READWRITE, 255 CTLTYPE_NODE, "swwdog", NULL, 256 NULL, 0, NULL, 0, 257 CTL_HW, CTL_CREATE, CTL_EOL); 258 sysctl_createv(&swwdog_sysctllog, 0, NULL, NULL, CTLFLAG_READWRITE, 259 CTLTYPE_BOOL, "reboot", "reboot if timer expires", 260 NULL, 0, &swwdog_reboot, sizeof(bool), 261 CTL_HW, me->sysctl_num, CTL_CREATE, CTL_EOL); 262 } 263