1 /* 2 * ipmi_watchdog.c 3 * 4 * A watchdog timer based upon the IPMI interface. 5 * 6 * Author: MontaVista Software, Inc. 7 * Corey Minyard <minyard@mvista.com> 8 * source@mvista.com 9 * 10 * Copyright 2002 MontaVista Software Inc. 11 * 12 * This program is free software; you can redistribute it and/or modify it 13 * under the terms of the GNU General Public License as published by the 14 * Free Software Foundation; either version 2 of the License, or (at your 15 * option) any later version. 16 * 17 * 18 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED 19 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 20 * 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, 23 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 24 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 25 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR 26 * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE 27 * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 * 29 * You should have received a copy of the GNU General Public License along 30 * with this program; if not, write to the Free Software Foundation, Inc., 31 * 675 Mass Ave, Cambridge, MA 02139, USA. 32 */ 33 34 #include <linux/module.h> 35 #include <linux/moduleparam.h> 36 #include <linux/ipmi.h> 37 #include <linux/ipmi_smi.h> 38 #include <linux/mutex.h> 39 #include <linux/watchdog.h> 40 #include <linux/miscdevice.h> 41 #include <linux/init.h> 42 #include <linux/completion.h> 43 #include <linux/kdebug.h> 44 #include <linux/rwsem.h> 45 #include <linux/errno.h> 46 #include <linux/uaccess.h> 47 #include <linux/notifier.h> 48 #include <linux/nmi.h> 49 #include <linux/reboot.h> 50 #include <linux/wait.h> 51 #include <linux/poll.h> 52 #include <linux/string.h> 53 #include <linux/ctype.h> 54 #include <linux/delay.h> 55 #include <linux/atomic.h> 56 #include <linux/sched/signal.h> 57 58 #ifdef CONFIG_X86 59 /* 60 * This is ugly, but I've determined that x86 is the only architecture 61 * that can reasonably support the IPMI NMI watchdog timeout at this 62 * time. If another architecture adds this capability somehow, it 63 * will have to be a somewhat different mechanism and I have no idea 64 * how it will work. So in the unlikely event that another 65 * architecture supports this, we can figure out a good generic 66 * mechanism for it at that time. 67 */ 68 #include <asm/kdebug.h> 69 #include <asm/nmi.h> 70 #define HAVE_DIE_NMI 71 #endif 72 73 #define PFX "IPMI Watchdog: " 74 75 /* 76 * The IPMI command/response information for the watchdog timer. 77 */ 78 79 /* values for byte 1 of the set command, byte 2 of the get response. */ 80 #define WDOG_DONT_LOG (1 << 7) 81 #define WDOG_DONT_STOP_ON_SET (1 << 6) 82 #define WDOG_SET_TIMER_USE(byte, use) \ 83 byte = ((byte) & 0xf8) | ((use) & 0x7) 84 #define WDOG_GET_TIMER_USE(byte) ((byte) & 0x7) 85 #define WDOG_TIMER_USE_BIOS_FRB2 1 86 #define WDOG_TIMER_USE_BIOS_POST 2 87 #define WDOG_TIMER_USE_OS_LOAD 3 88 #define WDOG_TIMER_USE_SMS_OS 4 89 #define WDOG_TIMER_USE_OEM 5 90 91 /* values for byte 2 of the set command, byte 3 of the get response. */ 92 #define WDOG_SET_PRETIMEOUT_ACT(byte, use) \ 93 byte = ((byte) & 0x8f) | (((use) & 0x7) << 4) 94 #define WDOG_GET_PRETIMEOUT_ACT(byte) (((byte) >> 4) & 0x7) 95 #define WDOG_PRETIMEOUT_NONE 0 96 #define WDOG_PRETIMEOUT_SMI 1 97 #define WDOG_PRETIMEOUT_NMI 2 98 #define WDOG_PRETIMEOUT_MSG_INT 3 99 100 /* Operations that can be performed on a pretimout. */ 101 #define WDOG_PREOP_NONE 0 102 #define WDOG_PREOP_PANIC 1 103 /* Cause data to be available to read. Doesn't work in NMI mode. */ 104 #define WDOG_PREOP_GIVE_DATA 2 105 106 /* Actions to perform on a full timeout. */ 107 #define WDOG_SET_TIMEOUT_ACT(byte, use) \ 108 byte = ((byte) & 0xf8) | ((use) & 0x7) 109 #define WDOG_GET_TIMEOUT_ACT(byte) ((byte) & 0x7) 110 #define WDOG_TIMEOUT_NONE 0 111 #define WDOG_TIMEOUT_RESET 1 112 #define WDOG_TIMEOUT_POWER_DOWN 2 113 #define WDOG_TIMEOUT_POWER_CYCLE 3 114 115 /* 116 * Byte 3 of the get command, byte 4 of the get response is the 117 * pre-timeout in seconds. 118 */ 119 120 /* Bits for setting byte 4 of the set command, byte 5 of the get response. */ 121 #define WDOG_EXPIRE_CLEAR_BIOS_FRB2 (1 << 1) 122 #define WDOG_EXPIRE_CLEAR_BIOS_POST (1 << 2) 123 #define WDOG_EXPIRE_CLEAR_OS_LOAD (1 << 3) 124 #define WDOG_EXPIRE_CLEAR_SMS_OS (1 << 4) 125 #define WDOG_EXPIRE_CLEAR_OEM (1 << 5) 126 127 /* 128 * Setting/getting the watchdog timer value. This is for bytes 5 and 129 * 6 (the timeout time) of the set command, and bytes 6 and 7 (the 130 * timeout time) and 8 and 9 (the current countdown value) of the 131 * response. The timeout value is given in seconds (in the command it 132 * is 100ms intervals). 133 */ 134 #define WDOG_SET_TIMEOUT(byte1, byte2, val) \ 135 (byte1) = (((val) * 10) & 0xff), (byte2) = (((val) * 10) >> 8) 136 #define WDOG_GET_TIMEOUT(byte1, byte2) \ 137 (((byte1) | ((byte2) << 8)) / 10) 138 139 #define IPMI_WDOG_RESET_TIMER 0x22 140 #define IPMI_WDOG_SET_TIMER 0x24 141 #define IPMI_WDOG_GET_TIMER 0x25 142 143 #define IPMI_WDOG_TIMER_NOT_INIT_RESP 0x80 144 145 static DEFINE_MUTEX(ipmi_watchdog_mutex); 146 static bool nowayout = WATCHDOG_NOWAYOUT; 147 148 static ipmi_user_t watchdog_user; 149 static int watchdog_ifnum; 150 151 /* Default the timeout to 10 seconds. */ 152 static int timeout = 10; 153 154 /* The pre-timeout is disabled by default. */ 155 static int pretimeout; 156 157 /* Default timeout to set on panic */ 158 static int panic_wdt_timeout = 255; 159 160 /* Default action is to reset the board on a timeout. */ 161 static unsigned char action_val = WDOG_TIMEOUT_RESET; 162 163 static char action[16] = "reset"; 164 165 static unsigned char preaction_val = WDOG_PRETIMEOUT_NONE; 166 167 static char preaction[16] = "pre_none"; 168 169 static unsigned char preop_val = WDOG_PREOP_NONE; 170 171 static char preop[16] = "preop_none"; 172 static DEFINE_SPINLOCK(ipmi_read_lock); 173 static char data_to_read; 174 static DECLARE_WAIT_QUEUE_HEAD(read_q); 175 static struct fasync_struct *fasync_q; 176 static char pretimeout_since_last_heartbeat; 177 static char expect_close; 178 179 static int ifnum_to_use = -1; 180 181 /* Parameters to ipmi_set_timeout */ 182 #define IPMI_SET_TIMEOUT_NO_HB 0 183 #define IPMI_SET_TIMEOUT_HB_IF_NECESSARY 1 184 #define IPMI_SET_TIMEOUT_FORCE_HB 2 185 186 static int ipmi_set_timeout(int do_heartbeat); 187 static void ipmi_register_watchdog(int ipmi_intf); 188 static void ipmi_unregister_watchdog(int ipmi_intf); 189 190 /* 191 * If true, the driver will start running as soon as it is configured 192 * and ready. 193 */ 194 static int start_now; 195 196 static int set_param_timeout(const char *val, const struct kernel_param *kp) 197 { 198 char *endp; 199 int l; 200 int rv = 0; 201 202 if (!val) 203 return -EINVAL; 204 l = simple_strtoul(val, &endp, 0); 205 if (endp == val) 206 return -EINVAL; 207 208 *((int *)kp->arg) = l; 209 if (watchdog_user) 210 rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY); 211 212 return rv; 213 } 214 215 static const struct kernel_param_ops param_ops_timeout = { 216 .set = set_param_timeout, 217 .get = param_get_int, 218 }; 219 #define param_check_timeout param_check_int 220 221 typedef int (*action_fn)(const char *intval, char *outval); 222 223 static int action_op(const char *inval, char *outval); 224 static int preaction_op(const char *inval, char *outval); 225 static int preop_op(const char *inval, char *outval); 226 static void check_parms(void); 227 228 static int set_param_str(const char *val, const struct kernel_param *kp) 229 { 230 action_fn fn = (action_fn) kp->arg; 231 int rv = 0; 232 char valcp[16]; 233 char *s; 234 235 strncpy(valcp, val, 16); 236 valcp[15] = '\0'; 237 238 s = strstrip(valcp); 239 240 rv = fn(s, NULL); 241 if (rv) 242 goto out; 243 244 check_parms(); 245 if (watchdog_user) 246 rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY); 247 248 out: 249 return rv; 250 } 251 252 static int get_param_str(char *buffer, const struct kernel_param *kp) 253 { 254 action_fn fn = (action_fn) kp->arg; 255 int rv; 256 257 rv = fn(NULL, buffer); 258 if (rv) 259 return rv; 260 return strlen(buffer); 261 } 262 263 264 static int set_param_wdog_ifnum(const char *val, const struct kernel_param *kp) 265 { 266 int rv = param_set_int(val, kp); 267 if (rv) 268 return rv; 269 if ((ifnum_to_use < 0) || (ifnum_to_use == watchdog_ifnum)) 270 return 0; 271 272 ipmi_unregister_watchdog(watchdog_ifnum); 273 ipmi_register_watchdog(ifnum_to_use); 274 return 0; 275 } 276 277 static const struct kernel_param_ops param_ops_wdog_ifnum = { 278 .set = set_param_wdog_ifnum, 279 .get = param_get_int, 280 }; 281 282 #define param_check_wdog_ifnum param_check_int 283 284 static const struct kernel_param_ops param_ops_str = { 285 .set = set_param_str, 286 .get = get_param_str, 287 }; 288 289 module_param(ifnum_to_use, wdog_ifnum, 0644); 290 MODULE_PARM_DESC(ifnum_to_use, "The interface number to use for the watchdog " 291 "timer. Setting to -1 defaults to the first registered " 292 "interface"); 293 294 module_param(timeout, timeout, 0644); 295 MODULE_PARM_DESC(timeout, "Timeout value in seconds."); 296 297 module_param(pretimeout, timeout, 0644); 298 MODULE_PARM_DESC(pretimeout, "Pretimeout value in seconds."); 299 300 module_param(panic_wdt_timeout, timeout, 0644); 301 MODULE_PARM_DESC(timeout, "Timeout value on kernel panic in seconds."); 302 303 module_param_cb(action, ¶m_ops_str, action_op, 0644); 304 MODULE_PARM_DESC(action, "Timeout action. One of: " 305 "reset, none, power_cycle, power_off."); 306 307 module_param_cb(preaction, ¶m_ops_str, preaction_op, 0644); 308 MODULE_PARM_DESC(preaction, "Pretimeout action. One of: " 309 "pre_none, pre_smi, pre_nmi, pre_int."); 310 311 module_param_cb(preop, ¶m_ops_str, preop_op, 0644); 312 MODULE_PARM_DESC(preop, "Pretimeout driver operation. One of: " 313 "preop_none, preop_panic, preop_give_data."); 314 315 module_param(start_now, int, 0444); 316 MODULE_PARM_DESC(start_now, "Set to 1 to start the watchdog as" 317 "soon as the driver is loaded."); 318 319 module_param(nowayout, bool, 0644); 320 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started " 321 "(default=CONFIG_WATCHDOG_NOWAYOUT)"); 322 323 /* Default state of the timer. */ 324 static unsigned char ipmi_watchdog_state = WDOG_TIMEOUT_NONE; 325 326 /* If shutting down via IPMI, we ignore the heartbeat. */ 327 static int ipmi_ignore_heartbeat; 328 329 /* Is someone using the watchdog? Only one user is allowed. */ 330 static unsigned long ipmi_wdog_open; 331 332 /* 333 * If set to 1, the heartbeat command will set the state to reset and 334 * start the timer. The timer doesn't normally run when the driver is 335 * first opened until the heartbeat is set the first time, this 336 * variable is used to accomplish this. 337 */ 338 static int ipmi_start_timer_on_heartbeat; 339 340 /* IPMI version of the BMC. */ 341 static unsigned char ipmi_version_major; 342 static unsigned char ipmi_version_minor; 343 344 /* If a pretimeout occurs, this is used to allow only one panic to happen. */ 345 static atomic_t preop_panic_excl = ATOMIC_INIT(-1); 346 347 #ifdef HAVE_DIE_NMI 348 static int testing_nmi; 349 static int nmi_handler_registered; 350 #endif 351 352 static int ipmi_heartbeat(void); 353 354 /* 355 * We use a mutex to make sure that only one thing can send a set 356 * timeout at one time, because we only have one copy of the data. 357 * The mutex is claimed when the set_timeout is sent and freed 358 * when both messages are free. 359 */ 360 static atomic_t set_timeout_tofree = ATOMIC_INIT(0); 361 static DEFINE_MUTEX(set_timeout_lock); 362 static DECLARE_COMPLETION(set_timeout_wait); 363 static void set_timeout_free_smi(struct ipmi_smi_msg *msg) 364 { 365 if (atomic_dec_and_test(&set_timeout_tofree)) 366 complete(&set_timeout_wait); 367 } 368 static void set_timeout_free_recv(struct ipmi_recv_msg *msg) 369 { 370 if (atomic_dec_and_test(&set_timeout_tofree)) 371 complete(&set_timeout_wait); 372 } 373 static struct ipmi_smi_msg set_timeout_smi_msg = { 374 .done = set_timeout_free_smi 375 }; 376 static struct ipmi_recv_msg set_timeout_recv_msg = { 377 .done = set_timeout_free_recv 378 }; 379 380 static int i_ipmi_set_timeout(struct ipmi_smi_msg *smi_msg, 381 struct ipmi_recv_msg *recv_msg, 382 int *send_heartbeat_now) 383 { 384 struct kernel_ipmi_msg msg; 385 unsigned char data[6]; 386 int rv; 387 struct ipmi_system_interface_addr addr; 388 int hbnow = 0; 389 390 391 /* These can be cleared as we are setting the timeout. */ 392 pretimeout_since_last_heartbeat = 0; 393 394 data[0] = 0; 395 WDOG_SET_TIMER_USE(data[0], WDOG_TIMER_USE_SMS_OS); 396 397 if ((ipmi_version_major > 1) 398 || ((ipmi_version_major == 1) && (ipmi_version_minor >= 5))) { 399 /* This is an IPMI 1.5-only feature. */ 400 data[0] |= WDOG_DONT_STOP_ON_SET; 401 } else if (ipmi_watchdog_state != WDOG_TIMEOUT_NONE) { 402 /* 403 * In ipmi 1.0, setting the timer stops the watchdog, we 404 * need to start it back up again. 405 */ 406 hbnow = 1; 407 } 408 409 data[1] = 0; 410 WDOG_SET_TIMEOUT_ACT(data[1], ipmi_watchdog_state); 411 if ((pretimeout > 0) && (ipmi_watchdog_state != WDOG_TIMEOUT_NONE)) { 412 WDOG_SET_PRETIMEOUT_ACT(data[1], preaction_val); 413 data[2] = pretimeout; 414 } else { 415 WDOG_SET_PRETIMEOUT_ACT(data[1], WDOG_PRETIMEOUT_NONE); 416 data[2] = 0; /* No pretimeout. */ 417 } 418 data[3] = 0; 419 WDOG_SET_TIMEOUT(data[4], data[5], timeout); 420 421 addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE; 422 addr.channel = IPMI_BMC_CHANNEL; 423 addr.lun = 0; 424 425 msg.netfn = 0x06; 426 msg.cmd = IPMI_WDOG_SET_TIMER; 427 msg.data = data; 428 msg.data_len = sizeof(data); 429 rv = ipmi_request_supply_msgs(watchdog_user, 430 (struct ipmi_addr *) &addr, 431 0, 432 &msg, 433 NULL, 434 smi_msg, 435 recv_msg, 436 1); 437 if (rv) { 438 printk(KERN_WARNING PFX "set timeout error: %d\n", 439 rv); 440 } 441 442 if (send_heartbeat_now) 443 *send_heartbeat_now = hbnow; 444 445 return rv; 446 } 447 448 static int ipmi_set_timeout(int do_heartbeat) 449 { 450 int send_heartbeat_now; 451 int rv; 452 453 454 /* We can only send one of these at a time. */ 455 mutex_lock(&set_timeout_lock); 456 457 atomic_set(&set_timeout_tofree, 2); 458 459 rv = i_ipmi_set_timeout(&set_timeout_smi_msg, 460 &set_timeout_recv_msg, 461 &send_heartbeat_now); 462 if (rv) { 463 mutex_unlock(&set_timeout_lock); 464 goto out; 465 } 466 467 wait_for_completion(&set_timeout_wait); 468 469 mutex_unlock(&set_timeout_lock); 470 471 if ((do_heartbeat == IPMI_SET_TIMEOUT_FORCE_HB) 472 || ((send_heartbeat_now) 473 && (do_heartbeat == IPMI_SET_TIMEOUT_HB_IF_NECESSARY))) 474 rv = ipmi_heartbeat(); 475 476 out: 477 return rv; 478 } 479 480 static atomic_t panic_done_count = ATOMIC_INIT(0); 481 482 static void panic_smi_free(struct ipmi_smi_msg *msg) 483 { 484 atomic_dec(&panic_done_count); 485 } 486 static void panic_recv_free(struct ipmi_recv_msg *msg) 487 { 488 atomic_dec(&panic_done_count); 489 } 490 491 static struct ipmi_smi_msg panic_halt_heartbeat_smi_msg = { 492 .done = panic_smi_free 493 }; 494 static struct ipmi_recv_msg panic_halt_heartbeat_recv_msg = { 495 .done = panic_recv_free 496 }; 497 498 static void panic_halt_ipmi_heartbeat(void) 499 { 500 struct kernel_ipmi_msg msg; 501 struct ipmi_system_interface_addr addr; 502 int rv; 503 504 /* 505 * Don't reset the timer if we have the timer turned off, that 506 * re-enables the watchdog. 507 */ 508 if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE) 509 return; 510 511 addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE; 512 addr.channel = IPMI_BMC_CHANNEL; 513 addr.lun = 0; 514 515 msg.netfn = 0x06; 516 msg.cmd = IPMI_WDOG_RESET_TIMER; 517 msg.data = NULL; 518 msg.data_len = 0; 519 atomic_add(1, &panic_done_count); 520 rv = ipmi_request_supply_msgs(watchdog_user, 521 (struct ipmi_addr *) &addr, 522 0, 523 &msg, 524 NULL, 525 &panic_halt_heartbeat_smi_msg, 526 &panic_halt_heartbeat_recv_msg, 527 1); 528 if (rv) 529 atomic_sub(1, &panic_done_count); 530 } 531 532 static struct ipmi_smi_msg panic_halt_smi_msg = { 533 .done = panic_smi_free 534 }; 535 static struct ipmi_recv_msg panic_halt_recv_msg = { 536 .done = panic_recv_free 537 }; 538 539 /* 540 * Special call, doesn't claim any locks. This is only to be called 541 * at panic or halt time, in run-to-completion mode, when the caller 542 * is the only CPU and the only thing that will be going is these IPMI 543 * calls. 544 */ 545 static void panic_halt_ipmi_set_timeout(void) 546 { 547 int send_heartbeat_now; 548 int rv; 549 550 /* Wait for the messages to be free. */ 551 while (atomic_read(&panic_done_count) != 0) 552 ipmi_poll_interface(watchdog_user); 553 atomic_add(1, &panic_done_count); 554 rv = i_ipmi_set_timeout(&panic_halt_smi_msg, 555 &panic_halt_recv_msg, 556 &send_heartbeat_now); 557 if (rv) { 558 atomic_sub(1, &panic_done_count); 559 printk(KERN_WARNING PFX 560 "Unable to extend the watchdog timeout."); 561 } else { 562 if (send_heartbeat_now) 563 panic_halt_ipmi_heartbeat(); 564 } 565 while (atomic_read(&panic_done_count) != 0) 566 ipmi_poll_interface(watchdog_user); 567 } 568 569 /* 570 * We use a mutex to make sure that only one thing can send a 571 * heartbeat at one time, because we only have one copy of the data. 572 * The semaphore is claimed when the set_timeout is sent and freed 573 * when both messages are free. 574 */ 575 static atomic_t heartbeat_tofree = ATOMIC_INIT(0); 576 static DEFINE_MUTEX(heartbeat_lock); 577 static DECLARE_COMPLETION(heartbeat_wait); 578 static void heartbeat_free_smi(struct ipmi_smi_msg *msg) 579 { 580 if (atomic_dec_and_test(&heartbeat_tofree)) 581 complete(&heartbeat_wait); 582 } 583 static void heartbeat_free_recv(struct ipmi_recv_msg *msg) 584 { 585 if (atomic_dec_and_test(&heartbeat_tofree)) 586 complete(&heartbeat_wait); 587 } 588 static struct ipmi_smi_msg heartbeat_smi_msg = { 589 .done = heartbeat_free_smi 590 }; 591 static struct ipmi_recv_msg heartbeat_recv_msg = { 592 .done = heartbeat_free_recv 593 }; 594 595 static int ipmi_heartbeat(void) 596 { 597 struct kernel_ipmi_msg msg; 598 int rv; 599 struct ipmi_system_interface_addr addr; 600 int timeout_retries = 0; 601 602 if (ipmi_ignore_heartbeat) 603 return 0; 604 605 if (ipmi_start_timer_on_heartbeat) { 606 ipmi_start_timer_on_heartbeat = 0; 607 ipmi_watchdog_state = action_val; 608 return ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB); 609 } else if (pretimeout_since_last_heartbeat) { 610 /* 611 * A pretimeout occurred, make sure we set the timeout. 612 * We don't want to set the action, though, we want to 613 * leave that alone (thus it can't be combined with the 614 * above operation. 615 */ 616 return ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY); 617 } 618 619 mutex_lock(&heartbeat_lock); 620 621 restart: 622 atomic_set(&heartbeat_tofree, 2); 623 624 /* 625 * Don't reset the timer if we have the timer turned off, that 626 * re-enables the watchdog. 627 */ 628 if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE) { 629 mutex_unlock(&heartbeat_lock); 630 return 0; 631 } 632 633 addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE; 634 addr.channel = IPMI_BMC_CHANNEL; 635 addr.lun = 0; 636 637 msg.netfn = 0x06; 638 msg.cmd = IPMI_WDOG_RESET_TIMER; 639 msg.data = NULL; 640 msg.data_len = 0; 641 rv = ipmi_request_supply_msgs(watchdog_user, 642 (struct ipmi_addr *) &addr, 643 0, 644 &msg, 645 NULL, 646 &heartbeat_smi_msg, 647 &heartbeat_recv_msg, 648 1); 649 if (rv) { 650 mutex_unlock(&heartbeat_lock); 651 printk(KERN_WARNING PFX "heartbeat failure: %d\n", 652 rv); 653 return rv; 654 } 655 656 /* Wait for the heartbeat to be sent. */ 657 wait_for_completion(&heartbeat_wait); 658 659 if (heartbeat_recv_msg.msg.data[0] == IPMI_WDOG_TIMER_NOT_INIT_RESP) { 660 timeout_retries++; 661 if (timeout_retries > 3) { 662 printk(KERN_ERR PFX ": Unable to restore the IPMI" 663 " watchdog's settings, giving up.\n"); 664 rv = -EIO; 665 goto out_unlock; 666 } 667 668 /* 669 * The timer was not initialized, that means the BMC was 670 * probably reset and lost the watchdog information. Attempt 671 * to restore the timer's info. Note that we still hold 672 * the heartbeat lock, to keep a heartbeat from happening 673 * in this process, so must say no heartbeat to avoid a 674 * deadlock on this mutex. 675 */ 676 rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB); 677 if (rv) { 678 printk(KERN_ERR PFX ": Unable to send the command to" 679 " set the watchdog's settings, giving up.\n"); 680 goto out_unlock; 681 } 682 683 /* We might need a new heartbeat, so do it now */ 684 goto restart; 685 } else if (heartbeat_recv_msg.msg.data[0] != 0) { 686 /* 687 * Got an error in the heartbeat response. It was already 688 * reported in ipmi_wdog_msg_handler, but we should return 689 * an error here. 690 */ 691 rv = -EINVAL; 692 } 693 694 out_unlock: 695 mutex_unlock(&heartbeat_lock); 696 697 return rv; 698 } 699 700 static struct watchdog_info ident = { 701 .options = 0, /* WDIOF_SETTIMEOUT, */ 702 .firmware_version = 1, 703 .identity = "IPMI" 704 }; 705 706 static int ipmi_ioctl(struct file *file, 707 unsigned int cmd, unsigned long arg) 708 { 709 void __user *argp = (void __user *)arg; 710 int i; 711 int val; 712 713 switch (cmd) { 714 case WDIOC_GETSUPPORT: 715 i = copy_to_user(argp, &ident, sizeof(ident)); 716 return i ? -EFAULT : 0; 717 718 case WDIOC_SETTIMEOUT: 719 i = copy_from_user(&val, argp, sizeof(int)); 720 if (i) 721 return -EFAULT; 722 timeout = val; 723 return ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY); 724 725 case WDIOC_GETTIMEOUT: 726 i = copy_to_user(argp, &timeout, sizeof(timeout)); 727 if (i) 728 return -EFAULT; 729 return 0; 730 731 case WDIOC_SETPRETIMEOUT: 732 i = copy_from_user(&val, argp, sizeof(int)); 733 if (i) 734 return -EFAULT; 735 pretimeout = val; 736 return ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY); 737 738 case WDIOC_GETPRETIMEOUT: 739 i = copy_to_user(argp, &pretimeout, sizeof(pretimeout)); 740 if (i) 741 return -EFAULT; 742 return 0; 743 744 case WDIOC_KEEPALIVE: 745 return ipmi_heartbeat(); 746 747 case WDIOC_SETOPTIONS: 748 i = copy_from_user(&val, argp, sizeof(int)); 749 if (i) 750 return -EFAULT; 751 if (val & WDIOS_DISABLECARD) { 752 ipmi_watchdog_state = WDOG_TIMEOUT_NONE; 753 ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB); 754 ipmi_start_timer_on_heartbeat = 0; 755 } 756 757 if (val & WDIOS_ENABLECARD) { 758 ipmi_watchdog_state = action_val; 759 ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB); 760 } 761 return 0; 762 763 case WDIOC_GETSTATUS: 764 val = 0; 765 i = copy_to_user(argp, &val, sizeof(val)); 766 if (i) 767 return -EFAULT; 768 return 0; 769 770 default: 771 return -ENOIOCTLCMD; 772 } 773 } 774 775 static long ipmi_unlocked_ioctl(struct file *file, 776 unsigned int cmd, 777 unsigned long arg) 778 { 779 int ret; 780 781 mutex_lock(&ipmi_watchdog_mutex); 782 ret = ipmi_ioctl(file, cmd, arg); 783 mutex_unlock(&ipmi_watchdog_mutex); 784 785 return ret; 786 } 787 788 static ssize_t ipmi_write(struct file *file, 789 const char __user *buf, 790 size_t len, 791 loff_t *ppos) 792 { 793 int rv; 794 795 if (len) { 796 if (!nowayout) { 797 size_t i; 798 799 /* In case it was set long ago */ 800 expect_close = 0; 801 802 for (i = 0; i != len; i++) { 803 char c; 804 805 if (get_user(c, buf + i)) 806 return -EFAULT; 807 if (c == 'V') 808 expect_close = 42; 809 } 810 } 811 rv = ipmi_heartbeat(); 812 if (rv) 813 return rv; 814 } 815 return len; 816 } 817 818 static ssize_t ipmi_read(struct file *file, 819 char __user *buf, 820 size_t count, 821 loff_t *ppos) 822 { 823 int rv = 0; 824 wait_queue_entry_t wait; 825 826 if (count <= 0) 827 return 0; 828 829 /* 830 * Reading returns if the pretimeout has gone off, and it only does 831 * it once per pretimeout. 832 */ 833 spin_lock(&ipmi_read_lock); 834 if (!data_to_read) { 835 if (file->f_flags & O_NONBLOCK) { 836 rv = -EAGAIN; 837 goto out; 838 } 839 840 init_waitqueue_entry(&wait, current); 841 add_wait_queue(&read_q, &wait); 842 while (!data_to_read) { 843 set_current_state(TASK_INTERRUPTIBLE); 844 spin_unlock(&ipmi_read_lock); 845 schedule(); 846 spin_lock(&ipmi_read_lock); 847 } 848 remove_wait_queue(&read_q, &wait); 849 850 if (signal_pending(current)) { 851 rv = -ERESTARTSYS; 852 goto out; 853 } 854 } 855 data_to_read = 0; 856 857 out: 858 spin_unlock(&ipmi_read_lock); 859 860 if (rv == 0) { 861 if (copy_to_user(buf, &data_to_read, 1)) 862 rv = -EFAULT; 863 else 864 rv = 1; 865 } 866 867 return rv; 868 } 869 870 static int ipmi_open(struct inode *ino, struct file *filep) 871 { 872 switch (iminor(ino)) { 873 case WATCHDOG_MINOR: 874 if (test_and_set_bit(0, &ipmi_wdog_open)) 875 return -EBUSY; 876 877 878 /* 879 * Don't start the timer now, let it start on the 880 * first heartbeat. 881 */ 882 ipmi_start_timer_on_heartbeat = 1; 883 return nonseekable_open(ino, filep); 884 885 default: 886 return (-ENODEV); 887 } 888 } 889 890 static unsigned int ipmi_poll(struct file *file, poll_table *wait) 891 { 892 unsigned int mask = 0; 893 894 poll_wait(file, &read_q, wait); 895 896 spin_lock(&ipmi_read_lock); 897 if (data_to_read) 898 mask |= (POLLIN | POLLRDNORM); 899 spin_unlock(&ipmi_read_lock); 900 901 return mask; 902 } 903 904 static int ipmi_fasync(int fd, struct file *file, int on) 905 { 906 int result; 907 908 result = fasync_helper(fd, file, on, &fasync_q); 909 910 return (result); 911 } 912 913 static int ipmi_close(struct inode *ino, struct file *filep) 914 { 915 if (iminor(ino) == WATCHDOG_MINOR) { 916 if (expect_close == 42) { 917 ipmi_watchdog_state = WDOG_TIMEOUT_NONE; 918 ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB); 919 } else { 920 printk(KERN_CRIT PFX 921 "Unexpected close, not stopping watchdog!\n"); 922 ipmi_heartbeat(); 923 } 924 clear_bit(0, &ipmi_wdog_open); 925 } 926 927 expect_close = 0; 928 929 return 0; 930 } 931 932 static const struct file_operations ipmi_wdog_fops = { 933 .owner = THIS_MODULE, 934 .read = ipmi_read, 935 .poll = ipmi_poll, 936 .write = ipmi_write, 937 .unlocked_ioctl = ipmi_unlocked_ioctl, 938 .open = ipmi_open, 939 .release = ipmi_close, 940 .fasync = ipmi_fasync, 941 .llseek = no_llseek, 942 }; 943 944 static struct miscdevice ipmi_wdog_miscdev = { 945 .minor = WATCHDOG_MINOR, 946 .name = "watchdog", 947 .fops = &ipmi_wdog_fops 948 }; 949 950 static void ipmi_wdog_msg_handler(struct ipmi_recv_msg *msg, 951 void *handler_data) 952 { 953 if (msg->msg.cmd == IPMI_WDOG_RESET_TIMER && 954 msg->msg.data[0] == IPMI_WDOG_TIMER_NOT_INIT_RESP) 955 printk(KERN_INFO PFX "response: The IPMI controller appears" 956 " to have been reset, will attempt to reinitialize" 957 " the watchdog timer\n"); 958 else if (msg->msg.data[0] != 0) 959 printk(KERN_ERR PFX "response: Error %x on cmd %x\n", 960 msg->msg.data[0], 961 msg->msg.cmd); 962 963 ipmi_free_recv_msg(msg); 964 } 965 966 static void ipmi_wdog_pretimeout_handler(void *handler_data) 967 { 968 if (preaction_val != WDOG_PRETIMEOUT_NONE) { 969 if (preop_val == WDOG_PREOP_PANIC) { 970 if (atomic_inc_and_test(&preop_panic_excl)) 971 panic("Watchdog pre-timeout"); 972 } else if (preop_val == WDOG_PREOP_GIVE_DATA) { 973 spin_lock(&ipmi_read_lock); 974 data_to_read = 1; 975 wake_up_interruptible(&read_q); 976 kill_fasync(&fasync_q, SIGIO, POLL_IN); 977 978 spin_unlock(&ipmi_read_lock); 979 } 980 } 981 982 /* 983 * On some machines, the heartbeat will give an error and not 984 * work unless we re-enable the timer. So do so. 985 */ 986 pretimeout_since_last_heartbeat = 1; 987 } 988 989 static const struct ipmi_user_hndl ipmi_hndlrs = { 990 .ipmi_recv_hndl = ipmi_wdog_msg_handler, 991 .ipmi_watchdog_pretimeout = ipmi_wdog_pretimeout_handler 992 }; 993 994 static void ipmi_register_watchdog(int ipmi_intf) 995 { 996 int rv = -EBUSY; 997 998 if (watchdog_user) 999 goto out; 1000 1001 if ((ifnum_to_use >= 0) && (ifnum_to_use != ipmi_intf)) 1002 goto out; 1003 1004 watchdog_ifnum = ipmi_intf; 1005 1006 rv = ipmi_create_user(ipmi_intf, &ipmi_hndlrs, NULL, &watchdog_user); 1007 if (rv < 0) { 1008 printk(KERN_CRIT PFX "Unable to register with ipmi\n"); 1009 goto out; 1010 } 1011 1012 ipmi_get_version(watchdog_user, 1013 &ipmi_version_major, 1014 &ipmi_version_minor); 1015 1016 rv = misc_register(&ipmi_wdog_miscdev); 1017 if (rv < 0) { 1018 ipmi_destroy_user(watchdog_user); 1019 watchdog_user = NULL; 1020 printk(KERN_CRIT PFX "Unable to register misc device\n"); 1021 } 1022 1023 #ifdef HAVE_DIE_NMI 1024 if (nmi_handler_registered) { 1025 int old_pretimeout = pretimeout; 1026 int old_timeout = timeout; 1027 int old_preop_val = preop_val; 1028 1029 /* 1030 * Set the pretimeout to go off in a second and give 1031 * ourselves plenty of time to stop the timer. 1032 */ 1033 ipmi_watchdog_state = WDOG_TIMEOUT_RESET; 1034 preop_val = WDOG_PREOP_NONE; /* Make sure nothing happens */ 1035 pretimeout = 99; 1036 timeout = 100; 1037 1038 testing_nmi = 1; 1039 1040 rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB); 1041 if (rv) { 1042 printk(KERN_WARNING PFX "Error starting timer to" 1043 " test NMI: 0x%x. The NMI pretimeout will" 1044 " likely not work\n", rv); 1045 rv = 0; 1046 goto out_restore; 1047 } 1048 1049 msleep(1500); 1050 1051 if (testing_nmi != 2) { 1052 printk(KERN_WARNING PFX "IPMI NMI didn't seem to" 1053 " occur. The NMI pretimeout will" 1054 " likely not work\n"); 1055 } 1056 out_restore: 1057 testing_nmi = 0; 1058 preop_val = old_preop_val; 1059 pretimeout = old_pretimeout; 1060 timeout = old_timeout; 1061 } 1062 #endif 1063 1064 out: 1065 if ((start_now) && (rv == 0)) { 1066 /* Run from startup, so start the timer now. */ 1067 start_now = 0; /* Disable this function after first startup. */ 1068 ipmi_watchdog_state = action_val; 1069 ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB); 1070 printk(KERN_INFO PFX "Starting now!\n"); 1071 } else { 1072 /* Stop the timer now. */ 1073 ipmi_watchdog_state = WDOG_TIMEOUT_NONE; 1074 ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB); 1075 } 1076 } 1077 1078 static void ipmi_unregister_watchdog(int ipmi_intf) 1079 { 1080 int rv; 1081 1082 if (!watchdog_user) 1083 goto out; 1084 1085 if (watchdog_ifnum != ipmi_intf) 1086 goto out; 1087 1088 /* Make sure no one can call us any more. */ 1089 misc_deregister(&ipmi_wdog_miscdev); 1090 1091 /* 1092 * Wait to make sure the message makes it out. The lower layer has 1093 * pointers to our buffers, we want to make sure they are done before 1094 * we release our memory. 1095 */ 1096 while (atomic_read(&set_timeout_tofree)) 1097 schedule_timeout_uninterruptible(1); 1098 1099 /* Disconnect from IPMI. */ 1100 rv = ipmi_destroy_user(watchdog_user); 1101 if (rv) { 1102 printk(KERN_WARNING PFX "error unlinking from IPMI: %d\n", 1103 rv); 1104 } 1105 watchdog_user = NULL; 1106 1107 out: 1108 return; 1109 } 1110 1111 #ifdef HAVE_DIE_NMI 1112 static int 1113 ipmi_nmi(unsigned int val, struct pt_regs *regs) 1114 { 1115 /* 1116 * If we get here, it's an NMI that's not a memory or I/O 1117 * error. We can't truly tell if it's from IPMI or not 1118 * without sending a message, and sending a message is almost 1119 * impossible because of locking. 1120 */ 1121 1122 if (testing_nmi) { 1123 testing_nmi = 2; 1124 return NMI_HANDLED; 1125 } 1126 1127 /* If we are not expecting a timeout, ignore it. */ 1128 if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE) 1129 return NMI_DONE; 1130 1131 if (preaction_val != WDOG_PRETIMEOUT_NMI) 1132 return NMI_DONE; 1133 1134 /* 1135 * If no one else handled the NMI, we assume it was the IPMI 1136 * watchdog. 1137 */ 1138 if (preop_val == WDOG_PREOP_PANIC) { 1139 /* On some machines, the heartbeat will give 1140 an error and not work unless we re-enable 1141 the timer. So do so. */ 1142 pretimeout_since_last_heartbeat = 1; 1143 if (atomic_inc_and_test(&preop_panic_excl)) 1144 nmi_panic(regs, PFX "pre-timeout"); 1145 } 1146 1147 return NMI_HANDLED; 1148 } 1149 #endif 1150 1151 static int wdog_reboot_handler(struct notifier_block *this, 1152 unsigned long code, 1153 void *unused) 1154 { 1155 static int reboot_event_handled; 1156 1157 if ((watchdog_user) && (!reboot_event_handled)) { 1158 /* Make sure we only do this once. */ 1159 reboot_event_handled = 1; 1160 1161 if (code == SYS_POWER_OFF || code == SYS_HALT) { 1162 /* Disable the WDT if we are shutting down. */ 1163 ipmi_watchdog_state = WDOG_TIMEOUT_NONE; 1164 ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB); 1165 } else if (ipmi_watchdog_state != WDOG_TIMEOUT_NONE) { 1166 /* Set a long timer to let the reboot happen or 1167 reset if it hangs, but only if the watchdog 1168 timer was already running. */ 1169 if (timeout < 120) 1170 timeout = 120; 1171 pretimeout = 0; 1172 ipmi_watchdog_state = WDOG_TIMEOUT_RESET; 1173 ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB); 1174 } 1175 } 1176 return NOTIFY_OK; 1177 } 1178 1179 static struct notifier_block wdog_reboot_notifier = { 1180 .notifier_call = wdog_reboot_handler, 1181 .next = NULL, 1182 .priority = 0 1183 }; 1184 1185 static int wdog_panic_handler(struct notifier_block *this, 1186 unsigned long event, 1187 void *unused) 1188 { 1189 static int panic_event_handled; 1190 1191 /* On a panic, if we have a panic timeout, make sure to extend 1192 the watchdog timer to a reasonable value to complete the 1193 panic, if the watchdog timer is running. Plus the 1194 pretimeout is meaningless at panic time. */ 1195 if (watchdog_user && !panic_event_handled && 1196 ipmi_watchdog_state != WDOG_TIMEOUT_NONE) { 1197 /* Make sure we do this only once. */ 1198 panic_event_handled = 1; 1199 1200 timeout = panic_wdt_timeout; 1201 pretimeout = 0; 1202 panic_halt_ipmi_set_timeout(); 1203 } 1204 1205 return NOTIFY_OK; 1206 } 1207 1208 static struct notifier_block wdog_panic_notifier = { 1209 .notifier_call = wdog_panic_handler, 1210 .next = NULL, 1211 .priority = 150 /* priority: INT_MAX >= x >= 0 */ 1212 }; 1213 1214 1215 static void ipmi_new_smi(int if_num, struct device *device) 1216 { 1217 ipmi_register_watchdog(if_num); 1218 } 1219 1220 static void ipmi_smi_gone(int if_num) 1221 { 1222 ipmi_unregister_watchdog(if_num); 1223 } 1224 1225 static struct ipmi_smi_watcher smi_watcher = { 1226 .owner = THIS_MODULE, 1227 .new_smi = ipmi_new_smi, 1228 .smi_gone = ipmi_smi_gone 1229 }; 1230 1231 static int action_op(const char *inval, char *outval) 1232 { 1233 if (outval) 1234 strcpy(outval, action); 1235 1236 if (!inval) 1237 return 0; 1238 1239 if (strcmp(inval, "reset") == 0) 1240 action_val = WDOG_TIMEOUT_RESET; 1241 else if (strcmp(inval, "none") == 0) 1242 action_val = WDOG_TIMEOUT_NONE; 1243 else if (strcmp(inval, "power_cycle") == 0) 1244 action_val = WDOG_TIMEOUT_POWER_CYCLE; 1245 else if (strcmp(inval, "power_off") == 0) 1246 action_val = WDOG_TIMEOUT_POWER_DOWN; 1247 else 1248 return -EINVAL; 1249 strcpy(action, inval); 1250 return 0; 1251 } 1252 1253 static int preaction_op(const char *inval, char *outval) 1254 { 1255 if (outval) 1256 strcpy(outval, preaction); 1257 1258 if (!inval) 1259 return 0; 1260 1261 if (strcmp(inval, "pre_none") == 0) 1262 preaction_val = WDOG_PRETIMEOUT_NONE; 1263 else if (strcmp(inval, "pre_smi") == 0) 1264 preaction_val = WDOG_PRETIMEOUT_SMI; 1265 #ifdef HAVE_DIE_NMI 1266 else if (strcmp(inval, "pre_nmi") == 0) 1267 preaction_val = WDOG_PRETIMEOUT_NMI; 1268 #endif 1269 else if (strcmp(inval, "pre_int") == 0) 1270 preaction_val = WDOG_PRETIMEOUT_MSG_INT; 1271 else 1272 return -EINVAL; 1273 strcpy(preaction, inval); 1274 return 0; 1275 } 1276 1277 static int preop_op(const char *inval, char *outval) 1278 { 1279 if (outval) 1280 strcpy(outval, preop); 1281 1282 if (!inval) 1283 return 0; 1284 1285 if (strcmp(inval, "preop_none") == 0) 1286 preop_val = WDOG_PREOP_NONE; 1287 else if (strcmp(inval, "preop_panic") == 0) 1288 preop_val = WDOG_PREOP_PANIC; 1289 else if (strcmp(inval, "preop_give_data") == 0) 1290 preop_val = WDOG_PREOP_GIVE_DATA; 1291 else 1292 return -EINVAL; 1293 strcpy(preop, inval); 1294 return 0; 1295 } 1296 1297 static void check_parms(void) 1298 { 1299 #ifdef HAVE_DIE_NMI 1300 int do_nmi = 0; 1301 int rv; 1302 1303 if (preaction_val == WDOG_PRETIMEOUT_NMI) { 1304 do_nmi = 1; 1305 if (preop_val == WDOG_PREOP_GIVE_DATA) { 1306 printk(KERN_WARNING PFX "Pretimeout op is to give data" 1307 " but NMI pretimeout is enabled, setting" 1308 " pretimeout op to none\n"); 1309 preop_op("preop_none", NULL); 1310 do_nmi = 0; 1311 } 1312 } 1313 if (do_nmi && !nmi_handler_registered) { 1314 rv = register_nmi_handler(NMI_UNKNOWN, ipmi_nmi, 0, 1315 "ipmi"); 1316 if (rv) { 1317 printk(KERN_WARNING PFX 1318 "Can't register nmi handler\n"); 1319 return; 1320 } else 1321 nmi_handler_registered = 1; 1322 } else if (!do_nmi && nmi_handler_registered) { 1323 unregister_nmi_handler(NMI_UNKNOWN, "ipmi"); 1324 nmi_handler_registered = 0; 1325 } 1326 #endif 1327 } 1328 1329 static int __init ipmi_wdog_init(void) 1330 { 1331 int rv; 1332 1333 if (action_op(action, NULL)) { 1334 action_op("reset", NULL); 1335 printk(KERN_INFO PFX "Unknown action '%s', defaulting to" 1336 " reset\n", action); 1337 } 1338 1339 if (preaction_op(preaction, NULL)) { 1340 preaction_op("pre_none", NULL); 1341 printk(KERN_INFO PFX "Unknown preaction '%s', defaulting to" 1342 " none\n", preaction); 1343 } 1344 1345 if (preop_op(preop, NULL)) { 1346 preop_op("preop_none", NULL); 1347 printk(KERN_INFO PFX "Unknown preop '%s', defaulting to" 1348 " none\n", preop); 1349 } 1350 1351 check_parms(); 1352 1353 register_reboot_notifier(&wdog_reboot_notifier); 1354 atomic_notifier_chain_register(&panic_notifier_list, 1355 &wdog_panic_notifier); 1356 1357 rv = ipmi_smi_watcher_register(&smi_watcher); 1358 if (rv) { 1359 #ifdef HAVE_DIE_NMI 1360 if (nmi_handler_registered) 1361 unregister_nmi_handler(NMI_UNKNOWN, "ipmi"); 1362 #endif 1363 atomic_notifier_chain_unregister(&panic_notifier_list, 1364 &wdog_panic_notifier); 1365 unregister_reboot_notifier(&wdog_reboot_notifier); 1366 printk(KERN_WARNING PFX "can't register smi watcher\n"); 1367 return rv; 1368 } 1369 1370 printk(KERN_INFO PFX "driver initialized\n"); 1371 1372 return 0; 1373 } 1374 1375 static void __exit ipmi_wdog_exit(void) 1376 { 1377 ipmi_smi_watcher_unregister(&smi_watcher); 1378 ipmi_unregister_watchdog(watchdog_ifnum); 1379 1380 #ifdef HAVE_DIE_NMI 1381 if (nmi_handler_registered) 1382 unregister_nmi_handler(NMI_UNKNOWN, "ipmi"); 1383 #endif 1384 1385 atomic_notifier_chain_unregister(&panic_notifier_list, 1386 &wdog_panic_notifier); 1387 unregister_reboot_notifier(&wdog_reboot_notifier); 1388 } 1389 module_exit(ipmi_wdog_exit); 1390 module_init(ipmi_wdog_init); 1391 MODULE_LICENSE("GPL"); 1392 MODULE_AUTHOR("Corey Minyard <minyard@mvista.com>"); 1393 MODULE_DESCRIPTION("watchdog timer based upon the IPMI interface."); 1394