swwdog.c revision 1.13
1 /* $NetBSD: swwdog.c,v 1.13 2014/04/13 13:19:50 pgoyette 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 1.13 2014/04/13 13:19:50 pgoyette 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 pmf_device_deregister(self); 166 swwdog_disarm(sc); 167 callout_destroy(&sc->sc_c); 168 sysctl_teardown(&swwdog_sysctllog); 169 workqueue_destroy(wq); 170 171 return 1; 172 } 173 174 static bool 175 swwdog_suspend(device_t dev, const pmf_qual_t *qual) 176 { 177 struct swwdog_softc *sc = device_private(dev); 178 179 /* Don't allow suspend if watchdog is armed */ 180 if ((sc->sc_smw.smw_mode & WDOG_MODE_MASK) != WDOG_MODE_DISARMED) 181 return false; 182 return true; 183 } 184 185 static int 186 swwdog_setmode(struct sysmon_wdog *smw) 187 { 188 struct swwdog_softc *sc = smw->smw_cookie; 189 int error = 0; 190 191 if ((smw->smw_mode & WDOG_MODE_MASK) == WDOG_MODE_DISARMED) { 192 error = swwdog_disarm(sc); 193 } else { 194 if (smw->smw_period == 0) 195 return EINVAL; 196 else if (smw->smw_period == WDOG_PERIOD_DEFAULT) 197 sc->sc_smw.smw_period = SWDOG_DEFAULT; 198 else 199 sc->sc_smw.smw_period = smw->smw_period; 200 error = swwdog_arm(sc); 201 } 202 return error; 203 } 204 205 static int 206 swwdog_tickle(struct sysmon_wdog *smw) 207 { 208 209 return swwdog_arm(smw->smw_cookie); 210 } 211 212 static int 213 swwdog_arm(struct swwdog_softc *sc) 214 { 215 216 callout_schedule(&sc->sc_c, sc->sc_smw.smw_period * hz); 217 return 0; 218 } 219 220 static int 221 swwdog_disarm(struct swwdog_softc *sc) 222 { 223 224 callout_stop(&sc->sc_c); 225 return 0; 226 } 227 228 static void 229 swwdog_panic(void *vsc) 230 { 231 struct swwdog_softc *sc = vsc; 232 static struct work wk; /* we'll need it max once */ 233 bool do_panic; 234 235 do_panic = !swwdog_reboot; 236 swwdog_reboot = false; 237 callout_schedule(&sc->sc_c, 60 * hz); /* deliberate double-panic */ 238 239 printf("%s: %d second timer expired\n", device_xname(sc->sc_dev), 240 sc->sc_smw.smw_period); 241 242 if (do_panic) 243 panic("watchdog timer expired"); 244 else 245 workqueue_enqueue(wq, &wk, NULL); 246 } 247 248 static void 249 swwdog_sysctl_setup(void) 250 { 251 const struct sysctlnode *me; 252 253 KASSERT(swwdog_sysctllog == NULL); 254 255 sysctl_createv(&swwdog_sysctllog, 0, NULL, &me, CTLFLAG_READWRITE, 256 CTLTYPE_NODE, "swwdog", NULL, 257 NULL, 0, NULL, 0, 258 CTL_HW, CTL_CREATE, CTL_EOL); 259 sysctl_createv(&swwdog_sysctllog, 0, NULL, NULL, CTLFLAG_READWRITE, 260 CTLTYPE_BOOL, "reboot", "reboot if timer expires", 261 NULL, 0, &swwdog_reboot, sizeof(bool), 262 CTL_HW, me->sysctl_num, CTL_CREATE, CTL_EOL); 263 } 264
Indexes created Thu Oct 02 01:09:59 GMT 2025