1 /*- 2 * Copyright (c) 2004 Poul-Henning Kamp 3 * Copyright (c) 2013 iXsystems.com, 4 * author: Alfred Perlstein <alfred@freebsd.org> 5 * 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer 13 * in this position and unchanged. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 * 29 */ 30 31 #include "opt_ddb.h" 32 33 #include <sys/cdefs.h> 34 __FBSDID("$FreeBSD$"); 35 36 #include <sys/param.h> 37 #include <sys/types.h> 38 #include <sys/systm.h> 39 #include <sys/conf.h> 40 #include <sys/uio.h> 41 #include <sys/kernel.h> 42 #include <sys/kdb.h> 43 #include <sys/malloc.h> 44 #include <sys/module.h> 45 #include <sys/sysctl.h> 46 #include <sys/syslog.h> 47 #include <sys/watchdog.h> 48 #include <sys/bus.h> 49 #include <machine/bus.h> 50 51 #include <sys/syscallsubr.h> /* kern_clock_gettime() */ 52 53 static int wd_set_pretimeout(int newtimeout, int disableiftoolong); 54 static void wd_timeout_cb(void *arg); 55 56 static struct callout wd_pretimeo_handle; 57 static int wd_pretimeout; 58 static int wd_pretimeout_act = WD_SOFT_LOG; 59 60 static struct callout wd_softtimeo_handle; 61 static int wd_softtimer; /* true = use softtimer instead of hardware 62 watchdog */ 63 static int wd_softtimeout_act = WD_SOFT_LOG; /* action for the software timeout */ 64 65 static struct cdev *wd_dev; 66 static volatile u_int wd_last_u; /* last timeout value set by kern_do_pat */ 67 static u_int wd_last_u_sysctl; /* last timeout value set by kern_do_pat */ 68 static u_int wd_last_u_sysctl_secs; /* wd_last_u in seconds */ 69 70 SYSCTL_NODE(_hw, OID_AUTO, watchdog, CTLFLAG_RD, 0, "Main watchdog device"); 71 SYSCTL_UINT(_hw_watchdog, OID_AUTO, wd_last_u, CTLFLAG_RD, 72 &wd_last_u_sysctl, 0, "Watchdog last update time"); 73 SYSCTL_UINT(_hw_watchdog, OID_AUTO, wd_last_u_secs, CTLFLAG_RD, 74 &wd_last_u_sysctl_secs, 0, "Watchdog last update time"); 75 76 static int wd_lastpat_valid = 0; 77 static time_t wd_lastpat = 0; /* when the watchdog was last patted */ 78 79 static void 80 pow2ns_to_ts(int pow2ns, struct timespec *ts) 81 { 82 uint64_t ns; 83 84 ns = 1ULL << pow2ns; 85 ts->tv_sec = ns / 1000000000ULL; 86 ts->tv_nsec = ns % 1000000000ULL; 87 } 88 89 static int 90 pow2ns_to_ticks(int pow2ns) 91 { 92 struct timeval tv; 93 struct timespec ts; 94 95 pow2ns_to_ts(pow2ns, &ts); 96 TIMESPEC_TO_TIMEVAL(&tv, &ts); 97 return (tvtohz(&tv)); 98 } 99 100 static int 101 seconds_to_pow2ns(int seconds) 102 { 103 uint64_t power; 104 uint64_t ns; 105 uint64_t shifted; 106 107 ns = ((uint64_t)seconds) * 1000000000ULL; 108 power = flsll(ns); 109 shifted = 1ULL << power; 110 if (shifted <= ns) { 111 power++; 112 } 113 return (power); 114 } 115 116 117 int 118 wdog_kern_pat(u_int utim) 119 { 120 int error; 121 122 if ((utim & WD_LASTVAL) != 0 && (utim & WD_INTERVAL) > 0) 123 return (EINVAL); 124 125 if ((utim & WD_LASTVAL) != 0) { 126 /* 127 * if WD_LASTVAL is set, fill in the bits for timeout 128 * from the saved value in wd_last_u. 129 */ 130 MPASS((wd_last_u & ~WD_INTERVAL) == 0); 131 utim &= ~WD_LASTVAL; 132 utim |= wd_last_u; 133 } else { 134 /* 135 * Otherwise save the new interval. 136 * This can be zero (to disable the watchdog) 137 */ 138 wd_last_u = (utim & WD_INTERVAL); 139 wd_last_u_sysctl = wd_last_u; 140 wd_last_u_sysctl_secs = pow2ns_to_ticks(wd_last_u) / hz; 141 } 142 if ((utim & WD_INTERVAL) == WD_TO_NEVER) { 143 utim = 0; 144 145 /* Assume all is well; watchdog signals failure. */ 146 error = 0; 147 } else { 148 /* Assume no watchdog available; watchdog flags success */ 149 error = EOPNOTSUPP; 150 } 151 if (wd_softtimer) { 152 if (utim == 0) { 153 callout_stop(&wd_softtimeo_handle); 154 } else { 155 (void) callout_reset(&wd_softtimeo_handle, 156 pow2ns_to_ticks(utim), wd_timeout_cb, "soft"); 157 } 158 error = 0; 159 } else { 160 EVENTHANDLER_INVOKE(watchdog_list, utim, &error); 161 } 162 wd_set_pretimeout(wd_pretimeout, true); 163 /* 164 * If we were able to arm/strobe the watchdog, then 165 * update the last time it was strobed for WDIOC_GETTIMELEFT 166 */ 167 if (!error) { 168 struct timespec ts; 169 170 error = kern_clock_gettime(curthread /* XXX */, 171 CLOCK_MONOTONIC_FAST, &ts); 172 if (!error) { 173 wd_lastpat = ts.tv_sec; 174 wd_lastpat_valid = 1; 175 } 176 } 177 return (error); 178 } 179 180 static int 181 wd_valid_act(int act) 182 { 183 184 if ((act & ~(WD_SOFT_MASK)) != 0) 185 return false; 186 return true; 187 } 188 189 static int 190 wd_ioctl_patpat(caddr_t data) 191 { 192 u_int u; 193 194 u = *(u_int *)data; 195 if (u & ~(WD_ACTIVE | WD_PASSIVE | WD_LASTVAL | WD_INTERVAL)) 196 return (EINVAL); 197 if ((u & (WD_ACTIVE | WD_PASSIVE)) == (WD_ACTIVE | WD_PASSIVE)) 198 return (EINVAL); 199 if ((u & (WD_ACTIVE | WD_PASSIVE)) == 0 && ((u & WD_INTERVAL) > 0 || 200 (u & WD_LASTVAL) != 0)) 201 return (EINVAL); 202 if (u & WD_PASSIVE) 203 return (ENOSYS); /* XXX Not implemented yet */ 204 u &= ~(WD_ACTIVE | WD_PASSIVE); 205 206 return (wdog_kern_pat(u)); 207 } 208 209 static int 210 wd_get_time_left(struct thread *td, time_t *remainp) 211 { 212 struct timespec ts; 213 int error; 214 215 error = kern_clock_gettime(td, CLOCK_MONOTONIC_FAST, &ts); 216 if (error) 217 return (error); 218 if (!wd_lastpat_valid) 219 return (ENOENT); 220 *remainp = ts.tv_sec - wd_lastpat; 221 return (0); 222 } 223 224 static void 225 wd_timeout_cb(void *arg) 226 { 227 const char *type = arg; 228 229 #ifdef DDB 230 if ((wd_pretimeout_act & WD_SOFT_DDB)) { 231 char kdb_why[80]; 232 snprintf(kdb_why, sizeof(kdb_why), "watchdog %s-timeout", type); 233 kdb_backtrace(); 234 kdb_enter(KDB_WHY_WATCHDOG, kdb_why); 235 } 236 #endif 237 if ((wd_pretimeout_act & WD_SOFT_LOG)) 238 log(LOG_EMERG, "watchdog %s-timeout, WD_SOFT_LOG\n", type); 239 if ((wd_pretimeout_act & WD_SOFT_PRINTF)) 240 printf("watchdog %s-timeout, WD_SOFT_PRINTF\n", type); 241 if ((wd_pretimeout_act & WD_SOFT_PANIC)) 242 panic("watchdog %s-timeout, WD_SOFT_PANIC set", type); 243 } 244 245 /* 246 * Called to manage timeouts. 247 * newtimeout needs to be in the range of 0 to actual watchdog timeout. 248 * if 0, we disable the pre-timeout. 249 * otherwise we set the pre-timeout provided it's not greater than the 250 * current actual watchdog timeout. 251 */ 252 static int 253 wd_set_pretimeout(int newtimeout, int disableiftoolong) 254 { 255 u_int utime; 256 struct timespec utime_ts; 257 int timeout_ticks; 258 259 utime = wdog_kern_last_timeout(); 260 pow2ns_to_ts(utime, &utime_ts); 261 /* do not permit a pre-timeout >= than the timeout. */ 262 if (newtimeout >= utime_ts.tv_sec) { 263 /* 264 * If 'disableiftoolong' then just fall through 265 * so as to disable the pre-watchdog 266 */ 267 if (disableiftoolong) 268 newtimeout = 0; 269 else 270 return EINVAL; 271 } 272 273 /* disable the pre-timeout */ 274 if (newtimeout == 0) { 275 wd_pretimeout = 0; 276 callout_stop(&wd_pretimeo_handle); 277 return 0; 278 } 279 280 timeout_ticks = pow2ns_to_ticks(utime) - (hz*newtimeout); 281 #if 0 282 printf("wd_set_pretimeout: " 283 "newtimeout: %d, " 284 "utime: %d -> utime_ticks: %d, " 285 "hz*newtimeout: %d, " 286 "timeout_ticks: %d -> sec: %d\n", 287 newtimeout, 288 utime, pow2ns_to_ticks(utime), 289 hz*newtimeout, 290 timeout_ticks, timeout_ticks / hz); 291 #endif 292 293 /* We determined the value is sane, so reset the callout */ 294 (void) callout_reset(&wd_pretimeo_handle, 295 timeout_ticks, wd_timeout_cb, "pre"); 296 wd_pretimeout = newtimeout; 297 return 0; 298 } 299 300 static int 301 wd_ioctl(struct cdev *dev __unused, u_long cmd, caddr_t data, 302 int flags __unused, struct thread *td) 303 { 304 u_int u; 305 time_t timeleft; 306 int error; 307 308 error = 0; 309 310 switch (cmd) { 311 case WDIOC_SETSOFT: 312 u = *(int *)data; 313 /* do nothing? */ 314 if (u == wd_softtimer) 315 break; 316 /* If there is a pending timeout disallow this ioctl */ 317 if (wd_last_u != 0) { 318 error = EINVAL; 319 break; 320 } 321 wd_softtimer = u; 322 break; 323 case WDIOC_SETSOFTTIMEOUTACT: 324 u = *(int *)data; 325 if (wd_valid_act(u)) { 326 wd_softtimeout_act = u; 327 } else { 328 error = EINVAL; 329 } 330 break; 331 case WDIOC_SETPRETIMEOUTACT: 332 u = *(int *)data; 333 if (wd_valid_act(u)) { 334 wd_pretimeout_act = u; 335 } else { 336 error = EINVAL; 337 } 338 break; 339 case WDIOC_GETPRETIMEOUT: 340 *(int *)data = (int)wd_pretimeout; 341 break; 342 case WDIOC_SETPRETIMEOUT: 343 error = wd_set_pretimeout(*(int *)data, false); 344 break; 345 case WDIOC_GETTIMELEFT: 346 error = wd_get_time_left(td, &timeleft); 347 if (error) 348 break; 349 *(int *)data = (int)timeleft; 350 break; 351 case WDIOC_SETTIMEOUT: 352 u = *(u_int *)data; 353 error = wdog_kern_pat(seconds_to_pow2ns(u)); 354 break; 355 case WDIOC_GETTIMEOUT: 356 u = wdog_kern_last_timeout(); 357 *(u_int *)data = u; 358 break; 359 case WDIOCPATPAT: 360 error = wd_ioctl_patpat(data); 361 break; 362 default: 363 error = ENOIOCTL; 364 break; 365 } 366 return (error); 367 } 368 369 /* 370 * Return the last timeout set, this is NOT the seconds from NOW until timeout, 371 * rather it is the amount of seconds passed to WDIOCPATPAT/WDIOC_SETTIMEOUT. 372 */ 373 u_int 374 wdog_kern_last_timeout(void) 375 { 376 377 return (wd_last_u); 378 } 379 380 static struct cdevsw wd_cdevsw = { 381 .d_version = D_VERSION, 382 .d_ioctl = wd_ioctl, 383 .d_name = "watchdog", 384 }; 385 386 static int 387 watchdog_modevent(module_t mod __unused, int type, void *data __unused) 388 { 389 switch(type) { 390 case MOD_LOAD: 391 callout_init(&wd_pretimeo_handle, 1); 392 callout_init(&wd_softtimeo_handle, 1); 393 wd_dev = make_dev(&wd_cdevsw, 0, 394 UID_ROOT, GID_WHEEL, 0600, _PATH_WATCHDOG); 395 return 0; 396 case MOD_UNLOAD: 397 callout_stop(&wd_pretimeo_handle); 398 callout_stop(&wd_softtimeo_handle); 399 callout_drain(&wd_pretimeo_handle); 400 callout_drain(&wd_softtimeo_handle); 401 destroy_dev(wd_dev); 402 return 0; 403 case MOD_SHUTDOWN: 404 return 0; 405 default: 406 return EOPNOTSUPP; 407 } 408 } 409 410 DEV_MODULE(watchdog, watchdog_modevent, NULL); 411