swwdog.c revision 1.14
1 /* $NetBSD: swwdog.c,v 1.14 2015/04/18 10:49:31 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 1.14 2015/04/18 10:49:31 pgoyette Exp $"); 37 38 /* 39 * 40 * Software watchdog timer 41 * 42 */ 43 #include <sys/param.h> 44 #include <sys/device.h> 45 #include <sys/callout.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 <sys/module.h> 54 #include <dev/sysmon/sysmonvar.h> 55 56 #ifndef _MODULE 57 #include "opt_modular.h" 58 #endif 59 60 struct swwdog_softc { 61 device_t sc_dev; 62 struct sysmon_wdog sc_smw; 63 struct callout sc_c; 64 int sc_armed; 65 }; 66 67 bool swwdog_reboot = false; /* false --> panic , true --> reboot */ 68 69 static struct workqueue *wq; 70 static device_t swwdog_dev; 71 72 MODULE(MODULE_CLASS_DRIVER, swwdog, NULL); 73 74 #ifdef _LKM 75 CFDRIVER_DECL(swwdog, DV_DULL, NULL); 76 #endif 77 78 int swwdogattach(int); 79 80 static int swwdog_setmode(struct sysmon_wdog *); 81 static int swwdog_tickle(struct sysmon_wdog *); 82 static bool swwdog_suspend(device_t, const pmf_qual_t *); 83 static int swwdog_arm(struct swwdog_softc *); 84 static int swwdog_disarm(struct swwdog_softc *); 85 86 static void swwdog_panic(void *); 87 88 static void swwdog_sysctl_setup(void); 89 static struct sysctllog *swwdog_sysctllog = NULL; 90 91 static int swwdog_match(device_t, cfdata_t, void *); 92 static void swwdog_attach(device_t, device_t, void *); 93 static int swwdog_detach(device_t, int); 94 static bool swwdog_suspend(device_t, const pmf_qual_t *); 95 96 static int swwdog_init(void *); 97 static int swwdog_fini(void *); 98 static int swwdog_modcmd(modcmd_t, void *); 99 100 CFATTACH_DECL_NEW(swwdog, sizeof(struct swwdog_softc), 101 swwdog_match, swwdog_attach, swwdog_detach, NULL); 102 extern struct cfdriver swwdog_cd; 103 104 #define SWDOG_DEFAULT 60 /* 60-second default period */ 105 106 static void 107 doreboot(struct work *wrkwrkwrk, void *p) 108 { 109 110 cpu_reboot(0, NULL); 111 } 112 113 int 114 swwdogattach(int n __unused) 115 { 116 int error; 117 static struct cfdata cf; 118 119 printf("%s: entered\n", __func__); /* XXX PRG */ 120 if (workqueue_create(&wq, "swwreboot", doreboot, NULL, 121 PRI_NONE, IPL_NONE, 0) != 0) { 122 aprint_error("failed to create swwdog reboot wq"); 123 return 1; 124 } 125 126 error = config_cfattach_attach(swwdog_cd.cd_name, &swwdog_ca); 127 if (error) { 128 aprint_error("%s: unable to attach cfattach\n", 129 swwdog_cd.cd_name); 130 workqueue_destroy(wq); 131 return error; 132 } 133 134 cf.cf_name = swwdog_cd.cd_name; 135 cf.cf_atname = swwdog_cd.cd_name; 136 cf.cf_unit = 0; 137 cf.cf_fstate = FSTATE_STAR; 138 cf.cf_pspec = NULL; 139 cf.cf_loc = NULL; 140 cf.cf_flags = 0; 141 142 swwdog_dev = config_attach_pseudo(&cf); 143 144 printf("%s: swwdog_dev = 0x%p\n", __func__, swwdog_dev); /* XXX PRG */ 145 if (swwdog_dev == NULL) { 146 config_cfattach_detach(swwdog_cd.cd_name, &swwdog_ca); 147 workqueue_destroy(wq); 148 return 1; 149 } 150 return 0; 151 } 152 153 static int 154 swwdog_match(device_t parent, cfdata_t data, void *aux) 155 { 156 157 printf("%s: entered\n", __func__); /* XXX PRG */ 158 return 1; 159 } 160 161 static void 162 swwdog_attach(device_t parent, device_t self, void *aux) 163 { 164 struct swwdog_softc *sc = device_private(self); 165 166 printf("%s: entered\n", __func__); /* XXX PRG */ 167 if (workqueue_create(&wq, "swwreboot", doreboot, NULL, 168 PRI_NONE, IPL_NONE, 0) != 0) { 169 aprint_error_dev(self, "failed to create reboot workqueue"); 170 } 171 172 sc->sc_dev = self; 173 sc->sc_smw.smw_name = device_xname(self); 174 sc->sc_smw.smw_cookie = sc; 175 sc->sc_smw.smw_setmode = swwdog_setmode; 176 sc->sc_smw.smw_tickle = swwdog_tickle; 177 sc->sc_smw.smw_period = SWDOG_DEFAULT; 178 179 callout_init(&sc->sc_c, 0); 180 callout_setfunc(&sc->sc_c, swwdog_panic, sc); 181 182 if (sysmon_wdog_register(&sc->sc_smw) == 0) 183 aprint_normal_dev(self, "software watchdog initialized\n"); 184 else { 185 aprint_error_dev(self, "unable to register software " 186 "watchdog with sysmon\n"); 187 callout_destroy(&sc->sc_c); 188 workqueue_destroy(wq); 189 return; 190 } 191 192 if (!pmf_device_register(self, swwdog_suspend, NULL)) 193 aprint_error_dev(self, "couldn't establish power handler\n"); 194 195 swwdog_sysctl_setup(); 196 } 197 198 static int 199 swwdog_detach(device_t self, int flags) 200 { 201 struct swwdog_softc *sc = device_private(self); 202 203 printf("%s: entered\n", __func__); /* XXX PRG */ 204 pmf_device_deregister(self); 205 swwdog_disarm(sc); 206 sysctl_teardown(&swwdog_sysctllog); 207 sysmon_wdog_unregister(&sc->sc_smw); 208 callout_destroy(&sc->sc_c); 209 workqueue_destroy(wq); 210 211 return 0; 212 } 213 214 static bool 215 swwdog_suspend(device_t dev, const pmf_qual_t *qual) 216 { 217 struct swwdog_softc *sc = device_private(dev); 218 219 /* Don't allow suspend if watchdog is armed */ 220 if ((sc->sc_smw.smw_mode & WDOG_MODE_MASK) != WDOG_MODE_DISARMED) 221 return false; 222 return true; 223 } 224 225 static int 226 swwdog_setmode(struct sysmon_wdog *smw) 227 { 228 struct swwdog_softc *sc = smw->smw_cookie; 229 int error = 0; 230 231 if ((smw->smw_mode & WDOG_MODE_MASK) == WDOG_MODE_DISARMED) { 232 error = swwdog_disarm(sc); 233 } else { 234 if (smw->smw_period == 0) 235 return EINVAL; 236 else if (smw->smw_period == WDOG_PERIOD_DEFAULT) 237 sc->sc_smw.smw_period = SWDOG_DEFAULT; 238 else 239 sc->sc_smw.smw_period = smw->smw_period; 240 error = swwdog_arm(sc); 241 } 242 return error; 243 } 244 245 static int 246 swwdog_tickle(struct sysmon_wdog *smw) 247 { 248 249 return swwdog_arm(smw->smw_cookie); 250 } 251 252 static int 253 swwdog_arm(struct swwdog_softc *sc) 254 { 255 256 callout_schedule(&sc->sc_c, sc->sc_smw.smw_period * hz); 257 return 0; 258 } 259 260 static int 261 swwdog_disarm(struct swwdog_softc *sc) 262 { 263 264 callout_stop(&sc->sc_c); 265 return 0; 266 } 267 268 static void 269 swwdog_panic(void *vsc) 270 { 271 struct swwdog_softc *sc = vsc; 272 static struct work wk; /* we'll need it max once */ 273 bool do_panic; 274 275 do_panic = !swwdog_reboot; 276 swwdog_reboot = false; 277 callout_schedule(&sc->sc_c, 60 * hz); /* deliberate double-panic */ 278 279 printf("%s: %d second timer expired\n", "swwdog", 280 sc->sc_smw.smw_period); 281 282 if (do_panic) 283 panic("watchdog timer expired"); 284 else 285 workqueue_enqueue(wq, &wk, NULL); 286 } 287 288 static void 289 swwdog_sysctl_setup(void) 290 { 291 const struct sysctlnode *me; 292 293 KASSERT(swwdog_sysctllog == NULL); 294 295 sysctl_createv(&swwdog_sysctllog, 0, NULL, &me, CTLFLAG_READWRITE, 296 CTLTYPE_NODE, "swwdog", NULL, 297 NULL, 0, NULL, 0, 298 CTL_HW, CTL_CREATE, CTL_EOL); 299 sysctl_createv(&swwdog_sysctllog, 0, NULL, NULL, CTLFLAG_READWRITE, 300 CTLTYPE_BOOL, "reboot", "reboot if timer expires", 301 NULL, 0, &swwdog_reboot, sizeof(bool), 302 CTL_HW, me->sysctl_num, CTL_CREATE, CTL_EOL); 303 } 304 305 /* 306 * Module management 307 */ 308 309 static 310 int 311 swwdog_init(void *arg) 312 { 313 #ifdef _LKM 314 /* 315 * Merge the driver info into the kernel tables and attach the 316 * pseudo-device 317 */ 318 int error; 319 320 error = config_cfdriver_attach(&swwdog_cd); 321 if (error) { 322 aprint_error("%s: unable to attach cfdriver\n", 323 swwdog_cd.cd_name); 324 return error; 325 } 326 error = swwdogattach(1); 327 if (error) { 328 aprint_error("%s: device attach failed\n", swwdog_cd.cd_name); 329 config_cfdriver_detach(&swwdog_cd); 330 } 331 332 return error; 333 #else 334 335 return 0; 336 #endif 337 } 338 339 static 340 int 341 swwdog_fini(void *arg) 342 { 343 int error; 344 345 error = config_detach(swwdog_dev, 0); 346 347 error = config_cfattach_detach(swwdog_cd.cd_name, &swwdog_ca); 348 if (error) 349 aprint_error("%s: error detaching cfattach: %d\n", 350 swwdog_cd.cd_name, error); 351 352 #ifdef _LKM 353 error = config_cfdriver_detach(&swwdog_cd); 354 if (error) 355 aprint_error("%s: error detaching cfdriver: %d\n", 356 swwdog_cd.cd_name, error); 357 #endif 358 359 return error; 360 } 361 362 static 363 int 364 swwdog_modcmd(modcmd_t cmd, void *arg) 365 { 366 int ret; 367 368 printf("%s: cmd %d\n", __func__, cmd); /* XXX PRG */ 369 switch (cmd) { 370 case MODULE_CMD_INIT: 371 ret = swwdog_init(arg); 372 break; 373 374 case MODULE_CMD_FINI: 375 ret = swwdog_fini(arg); 376 break; 377 378 case MODULE_CMD_STAT: 379 default: 380 ret = ENOTTY; 381 } 382 383 return ret; 384 } 385 386
Indexes created Thu Oct 02 01:09:59 GMT 2025