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 <asm/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 57 #ifdef CONFIG_X86 58 /* 59 * This is ugly, but I've determined that x86 is the only architecture 60 * that can reasonably support the IPMI NMI watchdog timeout at this 61 * time. If another architecture adds this capability somehow, it 62 * will have to be a somewhat different mechanism and I have no idea 63 * how it will work. So in the unlikely event that another 64 * architecture supports this, we can figure out a good generic 65 * mechanism for it at that time. 66 */ 67 #include <asm/kdebug.h> 68 #define HAVE_DIE_NMI 69 #endif 70 71 #define PFX "IPMI Watchdog: " 72 73 /* 74 * The IPMI command/response information for the watchdog timer. 75 */ 76 77 /* values for byte 1 of the set command, byte 2 of the get response. */ 78 #define WDOG_DONT_LOG (1 << 7) 79 #define WDOG_DONT_STOP_ON_SET (1 << 6) 80 #define WDOG_SET_TIMER_USE(byte, use) \ 81 byte = ((byte) & 0xf8) | ((use) & 0x7) 82 #define WDOG_GET_TIMER_USE(byte) ((byte) & 0x7) 83 #define WDOG_TIMER_USE_BIOS_FRB2 1 84 #define WDOG_TIMER_USE_BIOS_POST 2 85 #define WDOG_TIMER_USE_OS_LOAD 3 86 #define WDOG_TIMER_USE_SMS_OS 4 87 #define WDOG_TIMER_USE_OEM 5 88 89 /* values for byte 2 of the set command, byte 3 of the get response. */ 90 #define WDOG_SET_PRETIMEOUT_ACT(byte, use) \ 91 byte = ((byte) & 0x8f) | (((use) & 0x7) << 4) 92 #define WDOG_GET_PRETIMEOUT_ACT(byte) (((byte) >> 4) & 0x7) 93 #define WDOG_PRETIMEOUT_NONE 0 94 #define WDOG_PRETIMEOUT_SMI 1 95 #define WDOG_PRETIMEOUT_NMI 2 96 #define WDOG_PRETIMEOUT_MSG_INT 3 97 98 /* Operations that can be performed on a pretimout. */ 99 #define WDOG_PREOP_NONE 0 100 #define WDOG_PREOP_PANIC 1 101 /* Cause data to be available to read. Doesn't work in NMI mode. */ 102 #define WDOG_PREOP_GIVE_DATA 2 103 104 /* Actions to perform on a full timeout. */ 105 #define WDOG_SET_TIMEOUT_ACT(byte, use) \ 106 byte = ((byte) & 0xf8) | ((use) & 0x7) 107 #define WDOG_GET_TIMEOUT_ACT(byte) ((byte) & 0x7) 108 #define WDOG_TIMEOUT_NONE 0 109 #define WDOG_TIMEOUT_RESET 1 110 #define WDOG_TIMEOUT_POWER_DOWN 2 111 #define WDOG_TIMEOUT_POWER_CYCLE 3 112 113 /* 114 * Byte 3 of the get command, byte 4 of the get response is the 115 * pre-timeout in seconds. 116 */ 117 118 /* Bits for setting byte 4 of the set command, byte 5 of the get response. */ 119 #define WDOG_EXPIRE_CLEAR_BIOS_FRB2 (1 << 1) 120 #define WDOG_EXPIRE_CLEAR_BIOS_POST (1 << 2) 121 #define WDOG_EXPIRE_CLEAR_OS_LOAD (1 << 3) 122 #define WDOG_EXPIRE_CLEAR_SMS_OS (1 << 4) 123 #define WDOG_EXPIRE_CLEAR_OEM (1 << 5) 124 125 /* 126 * Setting/getting the watchdog timer value. This is for bytes 5 and 127 * 6 (the timeout time) of the set command, and bytes 6 and 7 (the 128 * timeout time) and 8 and 9 (the current countdown value) of the 129 * response. The timeout value is given in seconds (in the command it 130 * is 100ms intervals). 131 */ 132 #define WDOG_SET_TIMEOUT(byte1, byte2, val) \ 133 (byte1) = (((val) * 10) & 0xff), (byte2) = (((val) * 10) >> 8) 134 #define WDOG_GET_TIMEOUT(byte1, byte2) \ 135 (((byte1) | ((byte2) << 8)) / 10) 136 137 #define IPMI_WDOG_RESET_TIMER 0x22 138 #define IPMI_WDOG_SET_TIMER 0x24 139 #define IPMI_WDOG_GET_TIMER 0x25 140 141 /* These are here until the real ones get into the watchdog.h interface. */ 142 #ifndef WDIOC_GETTIMEOUT 143 #define WDIOC_GETTIMEOUT _IOW(WATCHDOG_IOCTL_BASE, 20, int) 144 #endif 145 #ifndef WDIOC_SET_PRETIMEOUT 146 #define WDIOC_SET_PRETIMEOUT _IOW(WATCHDOG_IOCTL_BASE, 21, int) 147 #endif 148 #ifndef WDIOC_GET_PRETIMEOUT 149 #define WDIOC_GET_PRETIMEOUT _IOW(WATCHDOG_IOCTL_BASE, 22, int) 150 #endif 151 152 static DEFINE_MUTEX(ipmi_watchdog_mutex); 153 static int nowayout = WATCHDOG_NOWAYOUT; 154 155 static ipmi_user_t watchdog_user; 156 static int watchdog_ifnum; 157 158 /* Default the timeout to 10 seconds. */ 159 static int timeout = 10; 160 161 /* The pre-timeout is disabled by default. */ 162 static int pretimeout; 163 164 /* Default action is to reset the board on a timeout. */ 165 static unsigned char action_val = WDOG_TIMEOUT_RESET; 166 167 static char action[16] = "reset"; 168 169 static unsigned char preaction_val = WDOG_PRETIMEOUT_NONE; 170 171 static char preaction[16] = "pre_none"; 172 173 static unsigned char preop_val = WDOG_PREOP_NONE; 174 175 static char preop[16] = "preop_none"; 176 static DEFINE_SPINLOCK(ipmi_read_lock); 177 static char data_to_read; 178 static DECLARE_WAIT_QUEUE_HEAD(read_q); 179 static struct fasync_struct *fasync_q; 180 static char pretimeout_since_last_heartbeat; 181 static char expect_close; 182 183 static int ifnum_to_use = -1; 184 185 /* Parameters to ipmi_set_timeout */ 186 #define IPMI_SET_TIMEOUT_NO_HB 0 187 #define IPMI_SET_TIMEOUT_HB_IF_NECESSARY 1 188 #define IPMI_SET_TIMEOUT_FORCE_HB 2 189 190 static int ipmi_set_timeout(int do_heartbeat); 191 static void ipmi_register_watchdog(int ipmi_intf); 192 static void ipmi_unregister_watchdog(int ipmi_intf); 193 194 /* 195 * If true, the driver will start running as soon as it is configured 196 * and ready. 197 */ 198 static int start_now; 199 200 static int set_param_timeout(const char *val, const struct kernel_param *kp) 201 { 202 char *endp; 203 int l; 204 int rv = 0; 205 206 if (!val) 207 return -EINVAL; 208 l = simple_strtoul(val, &endp, 0); 209 if (endp == val) 210 return -EINVAL; 211 212 *((int *)kp->arg) = l; 213 if (watchdog_user) 214 rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY); 215 216 return rv; 217 } 218 219 static struct kernel_param_ops param_ops_timeout = { 220 .set = set_param_timeout, 221 .get = param_get_int, 222 }; 223 #define param_check_timeout param_check_int 224 225 typedef int (*action_fn)(const char *intval, char *outval); 226 227 static int action_op(const char *inval, char *outval); 228 static int preaction_op(const char *inval, char *outval); 229 static int preop_op(const char *inval, char *outval); 230 static void check_parms(void); 231 232 static int set_param_str(const char *val, const struct kernel_param *kp) 233 { 234 action_fn fn = (action_fn) kp->arg; 235 int rv = 0; 236 char valcp[16]; 237 char *s; 238 239 strncpy(valcp, val, 16); 240 valcp[15] = '\0'; 241 242 s = strstrip(valcp); 243 244 rv = fn(s, NULL); 245 if (rv) 246 goto out; 247 248 check_parms(); 249 if (watchdog_user) 250 rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY); 251 252 out: 253 return rv; 254 } 255 256 static int get_param_str(char *buffer, const struct kernel_param *kp) 257 { 258 action_fn fn = (action_fn) kp->arg; 259 int rv; 260 261 rv = fn(NULL, buffer); 262 if (rv) 263 return rv; 264 return strlen(buffer); 265 } 266 267 268 static int set_param_wdog_ifnum(const char *val, const struct kernel_param *kp) 269 { 270 int rv = param_set_int(val, kp); 271 if (rv) 272 return rv; 273 if ((ifnum_to_use < 0) || (ifnum_to_use == watchdog_ifnum)) 274 return 0; 275 276 ipmi_unregister_watchdog(watchdog_ifnum); 277 ipmi_register_watchdog(ifnum_to_use); 278 return 0; 279 } 280 281 static struct kernel_param_ops param_ops_wdog_ifnum = { 282 .set = set_param_wdog_ifnum, 283 .get = param_get_int, 284 }; 285 286 #define param_check_wdog_ifnum param_check_int 287 288 static struct kernel_param_ops param_ops_str = { 289 .set = set_param_str, 290 .get = get_param_str, 291 }; 292 293 module_param(ifnum_to_use, wdog_ifnum, 0644); 294 MODULE_PARM_DESC(ifnum_to_use, "The interface number to use for the watchdog " 295 "timer. Setting to -1 defaults to the first registered " 296 "interface"); 297 298 module_param(timeout, timeout, 0644); 299 MODULE_PARM_DESC(timeout, "Timeout value in seconds."); 300 301 module_param(pretimeout, timeout, 0644); 302 MODULE_PARM_DESC(pretimeout, "Pretimeout value in seconds."); 303 304 module_param_cb(action, ¶m_ops_str, action_op, 0644); 305 MODULE_PARM_DESC(action, "Timeout action. One of: " 306 "reset, none, power_cycle, power_off."); 307 308 module_param_cb(preaction, ¶m_ops_str, preaction_op, 0644); 309 MODULE_PARM_DESC(preaction, "Pretimeout action. One of: " 310 "pre_none, pre_smi, pre_nmi, pre_int."); 311 312 module_param_cb(preop, ¶m_ops_str, preop_op, 0644); 313 MODULE_PARM_DESC(preop, "Pretimeout driver operation. One of: " 314 "preop_none, preop_panic, preop_give_data."); 315 316 module_param(start_now, int, 0444); 317 MODULE_PARM_DESC(start_now, "Set to 1 to start the watchdog as" 318 "soon as the driver is loaded."); 319 320 module_param(nowayout, int, 0644); 321 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started " 322 "(default=CONFIG_WATCHDOG_NOWAYOUT)"); 323 324 /* Default state of the timer. */ 325 static unsigned char ipmi_watchdog_state = WDOG_TIMEOUT_NONE; 326 327 /* If shutting down via IPMI, we ignore the heartbeat. */ 328 static int ipmi_ignore_heartbeat; 329 330 /* Is someone using the watchdog? Only one user is allowed. */ 331 static unsigned long ipmi_wdog_open; 332 333 /* 334 * If set to 1, the heartbeat command will set the state to reset and 335 * start the timer. The timer doesn't normally run when the driver is 336 * first opened until the heartbeat is set the first time, this 337 * variable is used to accomplish this. 338 */ 339 static int ipmi_start_timer_on_heartbeat; 340 341 /* IPMI version of the BMC. */ 342 static unsigned char ipmi_version_major; 343 static unsigned char ipmi_version_minor; 344 345 /* If a pretimeout occurs, this is used to allow only one panic to happen. */ 346 static atomic_t preop_panic_excl = ATOMIC_INIT(-1); 347 348 #ifdef HAVE_DIE_NMI 349 static int testing_nmi; 350 static int nmi_handler_registered; 351 #endif 352 353 static int ipmi_heartbeat(void); 354 355 /* 356 * We use a mutex to make sure that only one thing can send a set 357 * timeout at one time, because we only have one copy of the data. 358 * The mutex is claimed when the set_timeout is sent and freed 359 * when both messages are free. 360 */ 361 static atomic_t set_timeout_tofree = ATOMIC_INIT(0); 362 static DEFINE_MUTEX(set_timeout_lock); 363 static DECLARE_COMPLETION(set_timeout_wait); 364 static void set_timeout_free_smi(struct ipmi_smi_msg *msg) 365 { 366 if (atomic_dec_and_test(&set_timeout_tofree)) 367 complete(&set_timeout_wait); 368 } 369 static void set_timeout_free_recv(struct ipmi_recv_msg *msg) 370 { 371 if (atomic_dec_and_test(&set_timeout_tofree)) 372 complete(&set_timeout_wait); 373 } 374 static struct ipmi_smi_msg set_timeout_smi_msg = { 375 .done = set_timeout_free_smi 376 }; 377 static struct ipmi_recv_msg set_timeout_recv_msg = { 378 .done = set_timeout_free_recv 379 }; 380 381 static int i_ipmi_set_timeout(struct ipmi_smi_msg *smi_msg, 382 struct ipmi_recv_msg *recv_msg, 383 int *send_heartbeat_now) 384 { 385 struct kernel_ipmi_msg msg; 386 unsigned char data[6]; 387 int rv; 388 struct ipmi_system_interface_addr addr; 389 int hbnow = 0; 390 391 392 /* These can be cleared as we are setting the timeout. */ 393 pretimeout_since_last_heartbeat = 0; 394 395 data[0] = 0; 396 WDOG_SET_TIMER_USE(data[0], WDOG_TIMER_USE_SMS_OS); 397 398 if ((ipmi_version_major > 1) 399 || ((ipmi_version_major == 1) && (ipmi_version_minor >= 5))) { 400 /* This is an IPMI 1.5-only feature. */ 401 data[0] |= WDOG_DONT_STOP_ON_SET; 402 } else if (ipmi_watchdog_state != WDOG_TIMEOUT_NONE) { 403 /* 404 * In ipmi 1.0, setting the timer stops the watchdog, we 405 * need to start it back up again. 406 */ 407 hbnow = 1; 408 } 409 410 data[1] = 0; 411 WDOG_SET_TIMEOUT_ACT(data[1], ipmi_watchdog_state); 412 if ((pretimeout > 0) && (ipmi_watchdog_state != WDOG_TIMEOUT_NONE)) { 413 WDOG_SET_PRETIMEOUT_ACT(data[1], preaction_val); 414 data[2] = pretimeout; 415 } else { 416 WDOG_SET_PRETIMEOUT_ACT(data[1], WDOG_PRETIMEOUT_NONE); 417 data[2] = 0; /* No pretimeout. */ 418 } 419 data[3] = 0; 420 WDOG_SET_TIMEOUT(data[4], data[5], timeout); 421 422 addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE; 423 addr.channel = IPMI_BMC_CHANNEL; 424 addr.lun = 0; 425 426 msg.netfn = 0x06; 427 msg.cmd = IPMI_WDOG_SET_TIMER; 428 msg.data = data; 429 msg.data_len = sizeof(data); 430 rv = ipmi_request_supply_msgs(watchdog_user, 431 (struct ipmi_addr *) &addr, 432 0, 433 &msg, 434 NULL, 435 smi_msg, 436 recv_msg, 437 1); 438 if (rv) { 439 printk(KERN_WARNING PFX "set timeout error: %d\n", 440 rv); 441 } 442 443 if (send_heartbeat_now) 444 *send_heartbeat_now = hbnow; 445 446 return rv; 447 } 448 449 static int ipmi_set_timeout(int do_heartbeat) 450 { 451 int send_heartbeat_now; 452 int rv; 453 454 455 /* We can only send one of these at a time. */ 456 mutex_lock(&set_timeout_lock); 457 458 atomic_set(&set_timeout_tofree, 2); 459 460 rv = i_ipmi_set_timeout(&set_timeout_smi_msg, 461 &set_timeout_recv_msg, 462 &send_heartbeat_now); 463 if (rv) { 464 mutex_unlock(&set_timeout_lock); 465 goto out; 466 } 467 468 wait_for_completion(&set_timeout_wait); 469 470 mutex_unlock(&set_timeout_lock); 471 472 if ((do_heartbeat == IPMI_SET_TIMEOUT_FORCE_HB) 473 || ((send_heartbeat_now) 474 && (do_heartbeat == IPMI_SET_TIMEOUT_HB_IF_NECESSARY))) 475 rv = ipmi_heartbeat(); 476 477 out: 478 return rv; 479 } 480 481 static atomic_t panic_done_count = ATOMIC_INIT(0); 482 483 static void panic_smi_free(struct ipmi_smi_msg *msg) 484 { 485 atomic_dec(&panic_done_count); 486 } 487 static void panic_recv_free(struct ipmi_recv_msg *msg) 488 { 489 atomic_dec(&panic_done_count); 490 } 491 492 static struct ipmi_smi_msg panic_halt_heartbeat_smi_msg = { 493 .done = panic_smi_free 494 }; 495 static struct ipmi_recv_msg panic_halt_heartbeat_recv_msg = { 496 .done = panic_recv_free 497 }; 498 499 static void panic_halt_ipmi_heartbeat(void) 500 { 501 struct kernel_ipmi_msg msg; 502 struct ipmi_system_interface_addr addr; 503 int rv; 504 505 /* 506 * Don't reset the timer if we have the timer turned off, that 507 * re-enables the watchdog. 508 */ 509 if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE) 510 return; 511 512 addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE; 513 addr.channel = IPMI_BMC_CHANNEL; 514 addr.lun = 0; 515 516 msg.netfn = 0x06; 517 msg.cmd = IPMI_WDOG_RESET_TIMER; 518 msg.data = NULL; 519 msg.data_len = 0; 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_add(2, &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 rv = i_ipmi_set_timeout(&panic_halt_smi_msg, 554 &panic_halt_recv_msg, 555 &send_heartbeat_now); 556 if (!rv) { 557 atomic_add(2, &panic_done_count); 558 if (send_heartbeat_now) 559 panic_halt_ipmi_heartbeat(); 560 } else 561 printk(KERN_WARNING PFX 562 "Unable to extend the watchdog timeout."); 563 while (atomic_read(&panic_done_count) != 0) 564 ipmi_poll_interface(watchdog_user); 565 } 566 567 /* 568 * We use a mutex to make sure that only one thing can send a 569 * heartbeat at one time, because we only have one copy of the data. 570 * The semaphore is claimed when the set_timeout is sent and freed 571 * when both messages are free. 572 */ 573 static atomic_t heartbeat_tofree = ATOMIC_INIT(0); 574 static DEFINE_MUTEX(heartbeat_lock); 575 static DECLARE_COMPLETION(heartbeat_wait); 576 static void heartbeat_free_smi(struct ipmi_smi_msg *msg) 577 { 578 if (atomic_dec_and_test(&heartbeat_tofree)) 579 complete(&heartbeat_wait); 580 } 581 static void heartbeat_free_recv(struct ipmi_recv_msg *msg) 582 { 583 if (atomic_dec_and_test(&heartbeat_tofree)) 584 complete(&heartbeat_wait); 585 } 586 static struct ipmi_smi_msg heartbeat_smi_msg = { 587 .done = heartbeat_free_smi 588 }; 589 static struct ipmi_recv_msg heartbeat_recv_msg = { 590 .done = heartbeat_free_recv 591 }; 592 593 static int ipmi_heartbeat(void) 594 { 595 struct kernel_ipmi_msg msg; 596 int rv; 597 struct ipmi_system_interface_addr addr; 598 599 if (ipmi_ignore_heartbeat) 600 return 0; 601 602 if (ipmi_start_timer_on_heartbeat) { 603 ipmi_start_timer_on_heartbeat = 0; 604 ipmi_watchdog_state = action_val; 605 return ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB); 606 } else if (pretimeout_since_last_heartbeat) { 607 /* 608 * A pretimeout occurred, make sure we set the timeout. 609 * We don't want to set the action, though, we want to 610 * leave that alone (thus it can't be combined with the 611 * above operation. 612 */ 613 return ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY); 614 } 615 616 mutex_lock(&heartbeat_lock); 617 618 atomic_set(&heartbeat_tofree, 2); 619 620 /* 621 * Don't reset the timer if we have the timer turned off, that 622 * re-enables the watchdog. 623 */ 624 if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE) { 625 mutex_unlock(&heartbeat_lock); 626 return 0; 627 } 628 629 addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE; 630 addr.channel = IPMI_BMC_CHANNEL; 631 addr.lun = 0; 632 633 msg.netfn = 0x06; 634 msg.cmd = IPMI_WDOG_RESET_TIMER; 635 msg.data = NULL; 636 msg.data_len = 0; 637 rv = ipmi_request_supply_msgs(watchdog_user, 638 (struct ipmi_addr *) &addr, 639 0, 640 &msg, 641 NULL, 642 &heartbeat_smi_msg, 643 &heartbeat_recv_msg, 644 1); 645 if (rv) { 646 mutex_unlock(&heartbeat_lock); 647 printk(KERN_WARNING PFX "heartbeat failure: %d\n", 648 rv); 649 return rv; 650 } 651 652 /* Wait for the heartbeat to be sent. */ 653 wait_for_completion(&heartbeat_wait); 654 655 if (heartbeat_recv_msg.msg.data[0] != 0) { 656 /* 657 * Got an error in the heartbeat response. It was already 658 * reported in ipmi_wdog_msg_handler, but we should return 659 * an error here. 660 */ 661 rv = -EINVAL; 662 } 663 664 mutex_unlock(&heartbeat_lock); 665 666 return rv; 667 } 668 669 static struct watchdog_info ident = { 670 .options = 0, /* WDIOF_SETTIMEOUT, */ 671 .firmware_version = 1, 672 .identity = "IPMI" 673 }; 674 675 static int ipmi_ioctl(struct file *file, 676 unsigned int cmd, unsigned long arg) 677 { 678 void __user *argp = (void __user *)arg; 679 int i; 680 int val; 681 682 switch (cmd) { 683 case WDIOC_GETSUPPORT: 684 i = copy_to_user(argp, &ident, sizeof(ident)); 685 return i ? -EFAULT : 0; 686 687 case WDIOC_SETTIMEOUT: 688 i = copy_from_user(&val, argp, sizeof(int)); 689 if (i) 690 return -EFAULT; 691 timeout = val; 692 return ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY); 693 694 case WDIOC_GETTIMEOUT: 695 i = copy_to_user(argp, &timeout, sizeof(timeout)); 696 if (i) 697 return -EFAULT; 698 return 0; 699 700 case WDIOC_SET_PRETIMEOUT: 701 case WDIOC_SETPRETIMEOUT: 702 i = copy_from_user(&val, argp, sizeof(int)); 703 if (i) 704 return -EFAULT; 705 pretimeout = val; 706 return ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY); 707 708 case WDIOC_GET_PRETIMEOUT: 709 case WDIOC_GETPRETIMEOUT: 710 i = copy_to_user(argp, &pretimeout, sizeof(pretimeout)); 711 if (i) 712 return -EFAULT; 713 return 0; 714 715 case WDIOC_KEEPALIVE: 716 return ipmi_heartbeat(); 717 718 case WDIOC_SETOPTIONS: 719 i = copy_from_user(&val, argp, sizeof(int)); 720 if (i) 721 return -EFAULT; 722 if (val & WDIOS_DISABLECARD) { 723 ipmi_watchdog_state = WDOG_TIMEOUT_NONE; 724 ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB); 725 ipmi_start_timer_on_heartbeat = 0; 726 } 727 728 if (val & WDIOS_ENABLECARD) { 729 ipmi_watchdog_state = action_val; 730 ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB); 731 } 732 return 0; 733 734 case WDIOC_GETSTATUS: 735 val = 0; 736 i = copy_to_user(argp, &val, sizeof(val)); 737 if (i) 738 return -EFAULT; 739 return 0; 740 741 default: 742 return -ENOIOCTLCMD; 743 } 744 } 745 746 static long ipmi_unlocked_ioctl(struct file *file, 747 unsigned int cmd, 748 unsigned long arg) 749 { 750 int ret; 751 752 mutex_lock(&ipmi_watchdog_mutex); 753 ret = ipmi_ioctl(file, cmd, arg); 754 mutex_unlock(&ipmi_watchdog_mutex); 755 756 return ret; 757 } 758 759 static ssize_t ipmi_write(struct file *file, 760 const char __user *buf, 761 size_t len, 762 loff_t *ppos) 763 { 764 int rv; 765 766 if (len) { 767 if (!nowayout) { 768 size_t i; 769 770 /* In case it was set long ago */ 771 expect_close = 0; 772 773 for (i = 0; i != len; i++) { 774 char c; 775 776 if (get_user(c, buf + i)) 777 return -EFAULT; 778 if (c == 'V') 779 expect_close = 42; 780 } 781 } 782 rv = ipmi_heartbeat(); 783 if (rv) 784 return rv; 785 } 786 return len; 787 } 788 789 static ssize_t ipmi_read(struct file *file, 790 char __user *buf, 791 size_t count, 792 loff_t *ppos) 793 { 794 int rv = 0; 795 wait_queue_t wait; 796 797 if (count <= 0) 798 return 0; 799 800 /* 801 * Reading returns if the pretimeout has gone off, and it only does 802 * it once per pretimeout. 803 */ 804 spin_lock(&ipmi_read_lock); 805 if (!data_to_read) { 806 if (file->f_flags & O_NONBLOCK) { 807 rv = -EAGAIN; 808 goto out; 809 } 810 811 init_waitqueue_entry(&wait, current); 812 add_wait_queue(&read_q, &wait); 813 while (!data_to_read) { 814 set_current_state(TASK_INTERRUPTIBLE); 815 spin_unlock(&ipmi_read_lock); 816 schedule(); 817 spin_lock(&ipmi_read_lock); 818 } 819 remove_wait_queue(&read_q, &wait); 820 821 if (signal_pending(current)) { 822 rv = -ERESTARTSYS; 823 goto out; 824 } 825 } 826 data_to_read = 0; 827 828 out: 829 spin_unlock(&ipmi_read_lock); 830 831 if (rv == 0) { 832 if (copy_to_user(buf, &data_to_read, 1)) 833 rv = -EFAULT; 834 else 835 rv = 1; 836 } 837 838 return rv; 839 } 840 841 static int ipmi_open(struct inode *ino, struct file *filep) 842 { 843 switch (iminor(ino)) { 844 case WATCHDOG_MINOR: 845 if (test_and_set_bit(0, &ipmi_wdog_open)) 846 return -EBUSY; 847 848 849 /* 850 * Don't start the timer now, let it start on the 851 * first heartbeat. 852 */ 853 ipmi_start_timer_on_heartbeat = 1; 854 return nonseekable_open(ino, filep); 855 856 default: 857 return (-ENODEV); 858 } 859 } 860 861 static unsigned int ipmi_poll(struct file *file, poll_table *wait) 862 { 863 unsigned int mask = 0; 864 865 poll_wait(file, &read_q, wait); 866 867 spin_lock(&ipmi_read_lock); 868 if (data_to_read) 869 mask |= (POLLIN | POLLRDNORM); 870 spin_unlock(&ipmi_read_lock); 871 872 return mask; 873 } 874 875 static int ipmi_fasync(int fd, struct file *file, int on) 876 { 877 int result; 878 879 result = fasync_helper(fd, file, on, &fasync_q); 880 881 return (result); 882 } 883 884 static int ipmi_close(struct inode *ino, struct file *filep) 885 { 886 if (iminor(ino) == WATCHDOG_MINOR) { 887 if (expect_close == 42) { 888 ipmi_watchdog_state = WDOG_TIMEOUT_NONE; 889 ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB); 890 } else { 891 printk(KERN_CRIT PFX 892 "Unexpected close, not stopping watchdog!\n"); 893 ipmi_heartbeat(); 894 } 895 clear_bit(0, &ipmi_wdog_open); 896 } 897 898 expect_close = 0; 899 900 return 0; 901 } 902 903 static const struct file_operations ipmi_wdog_fops = { 904 .owner = THIS_MODULE, 905 .read = ipmi_read, 906 .poll = ipmi_poll, 907 .write = ipmi_write, 908 .unlocked_ioctl = ipmi_unlocked_ioctl, 909 .open = ipmi_open, 910 .release = ipmi_close, 911 .fasync = ipmi_fasync, 912 .llseek = no_llseek, 913 }; 914 915 static struct miscdevice ipmi_wdog_miscdev = { 916 .minor = WATCHDOG_MINOR, 917 .name = "watchdog", 918 .fops = &ipmi_wdog_fops 919 }; 920 921 static void ipmi_wdog_msg_handler(struct ipmi_recv_msg *msg, 922 void *handler_data) 923 { 924 if (msg->msg.data[0] != 0) { 925 printk(KERN_ERR PFX "response: Error %x on cmd %x\n", 926 msg->msg.data[0], 927 msg->msg.cmd); 928 } 929 930 ipmi_free_recv_msg(msg); 931 } 932 933 static void ipmi_wdog_pretimeout_handler(void *handler_data) 934 { 935 if (preaction_val != WDOG_PRETIMEOUT_NONE) { 936 if (preop_val == WDOG_PREOP_PANIC) { 937 if (atomic_inc_and_test(&preop_panic_excl)) 938 panic("Watchdog pre-timeout"); 939 } else if (preop_val == WDOG_PREOP_GIVE_DATA) { 940 spin_lock(&ipmi_read_lock); 941 data_to_read = 1; 942 wake_up_interruptible(&read_q); 943 kill_fasync(&fasync_q, SIGIO, POLL_IN); 944 945 spin_unlock(&ipmi_read_lock); 946 } 947 } 948 949 /* 950 * On some machines, the heartbeat will give an error and not 951 * work unless we re-enable the timer. So do so. 952 */ 953 pretimeout_since_last_heartbeat = 1; 954 } 955 956 static struct ipmi_user_hndl ipmi_hndlrs = { 957 .ipmi_recv_hndl = ipmi_wdog_msg_handler, 958 .ipmi_watchdog_pretimeout = ipmi_wdog_pretimeout_handler 959 }; 960 961 static void ipmi_register_watchdog(int ipmi_intf) 962 { 963 int rv = -EBUSY; 964 965 if (watchdog_user) 966 goto out; 967 968 if ((ifnum_to_use >= 0) && (ifnum_to_use != ipmi_intf)) 969 goto out; 970 971 watchdog_ifnum = ipmi_intf; 972 973 rv = ipmi_create_user(ipmi_intf, &ipmi_hndlrs, NULL, &watchdog_user); 974 if (rv < 0) { 975 printk(KERN_CRIT PFX "Unable to register with ipmi\n"); 976 goto out; 977 } 978 979 ipmi_get_version(watchdog_user, 980 &ipmi_version_major, 981 &ipmi_version_minor); 982 983 rv = misc_register(&ipmi_wdog_miscdev); 984 if (rv < 0) { 985 ipmi_destroy_user(watchdog_user); 986 watchdog_user = NULL; 987 printk(KERN_CRIT PFX "Unable to register misc device\n"); 988 } 989 990 #ifdef HAVE_DIE_NMI 991 if (nmi_handler_registered) { 992 int old_pretimeout = pretimeout; 993 int old_timeout = timeout; 994 int old_preop_val = preop_val; 995 996 /* 997 * Set the pretimeout to go off in a second and give 998 * ourselves plenty of time to stop the timer. 999 */ 1000 ipmi_watchdog_state = WDOG_TIMEOUT_RESET; 1001 preop_val = WDOG_PREOP_NONE; /* Make sure nothing happens */ 1002 pretimeout = 99; 1003 timeout = 100; 1004 1005 testing_nmi = 1; 1006 1007 rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB); 1008 if (rv) { 1009 printk(KERN_WARNING PFX "Error starting timer to" 1010 " test NMI: 0x%x. The NMI pretimeout will" 1011 " likely not work\n", rv); 1012 rv = 0; 1013 goto out_restore; 1014 } 1015 1016 msleep(1500); 1017 1018 if (testing_nmi != 2) { 1019 printk(KERN_WARNING PFX "IPMI NMI didn't seem to" 1020 " occur. The NMI pretimeout will" 1021 " likely not work\n"); 1022 } 1023 out_restore: 1024 testing_nmi = 0; 1025 preop_val = old_preop_val; 1026 pretimeout = old_pretimeout; 1027 timeout = old_timeout; 1028 } 1029 #endif 1030 1031 out: 1032 if ((start_now) && (rv == 0)) { 1033 /* Run from startup, so start the timer now. */ 1034 start_now = 0; /* Disable this function after first startup. */ 1035 ipmi_watchdog_state = action_val; 1036 ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB); 1037 printk(KERN_INFO PFX "Starting now!\n"); 1038 } else { 1039 /* Stop the timer now. */ 1040 ipmi_watchdog_state = WDOG_TIMEOUT_NONE; 1041 ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB); 1042 } 1043 } 1044 1045 static void ipmi_unregister_watchdog(int ipmi_intf) 1046 { 1047 int rv; 1048 1049 if (!watchdog_user) 1050 goto out; 1051 1052 if (watchdog_ifnum != ipmi_intf) 1053 goto out; 1054 1055 /* Make sure no one can call us any more. */ 1056 misc_deregister(&ipmi_wdog_miscdev); 1057 1058 /* 1059 * Wait to make sure the message makes it out. The lower layer has 1060 * pointers to our buffers, we want to make sure they are done before 1061 * we release our memory. 1062 */ 1063 while (atomic_read(&set_timeout_tofree)) 1064 schedule_timeout_uninterruptible(1); 1065 1066 /* Disconnect from IPMI. */ 1067 rv = ipmi_destroy_user(watchdog_user); 1068 if (rv) { 1069 printk(KERN_WARNING PFX "error unlinking from IPMI: %d\n", 1070 rv); 1071 } 1072 watchdog_user = NULL; 1073 1074 out: 1075 return; 1076 } 1077 1078 #ifdef HAVE_DIE_NMI 1079 static int 1080 ipmi_nmi(struct notifier_block *self, unsigned long val, void *data) 1081 { 1082 struct die_args *args = data; 1083 1084 if (val != DIE_NMIUNKNOWN) 1085 return NOTIFY_OK; 1086 1087 /* Hack, if it's a memory or I/O error, ignore it. */ 1088 if (args->err & 0xc0) 1089 return NOTIFY_OK; 1090 1091 /* 1092 * If we get here, it's an NMI that's not a memory or I/O 1093 * error. We can't truly tell if it's from IPMI or not 1094 * without sending a message, and sending a message is almost 1095 * impossible because of locking. 1096 */ 1097 1098 if (testing_nmi) { 1099 testing_nmi = 2; 1100 return NOTIFY_STOP; 1101 } 1102 1103 /* If we are not expecting a timeout, ignore it. */ 1104 if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE) 1105 return NOTIFY_OK; 1106 1107 if (preaction_val != WDOG_PRETIMEOUT_NMI) 1108 return NOTIFY_OK; 1109 1110 /* 1111 * If no one else handled the NMI, we assume it was the IPMI 1112 * watchdog. 1113 */ 1114 if (preop_val == WDOG_PREOP_PANIC) { 1115 /* On some machines, the heartbeat will give 1116 an error and not work unless we re-enable 1117 the timer. So do so. */ 1118 pretimeout_since_last_heartbeat = 1; 1119 if (atomic_inc_and_test(&preop_panic_excl)) 1120 panic(PFX "pre-timeout"); 1121 } 1122 1123 return NOTIFY_STOP; 1124 } 1125 1126 static struct notifier_block ipmi_nmi_handler = { 1127 .notifier_call = ipmi_nmi 1128 }; 1129 #endif 1130 1131 static int wdog_reboot_handler(struct notifier_block *this, 1132 unsigned long code, 1133 void *unused) 1134 { 1135 static int reboot_event_handled; 1136 1137 if ((watchdog_user) && (!reboot_event_handled)) { 1138 /* Make sure we only do this once. */ 1139 reboot_event_handled = 1; 1140 1141 if (code == SYS_POWER_OFF || code == SYS_HALT) { 1142 /* Disable the WDT if we are shutting down. */ 1143 ipmi_watchdog_state = WDOG_TIMEOUT_NONE; 1144 panic_halt_ipmi_set_timeout(); 1145 } else if (ipmi_watchdog_state != WDOG_TIMEOUT_NONE) { 1146 /* Set a long timer to let the reboot happens, but 1147 reboot if it hangs, but only if the watchdog 1148 timer was already running. */ 1149 timeout = 120; 1150 pretimeout = 0; 1151 ipmi_watchdog_state = WDOG_TIMEOUT_RESET; 1152 panic_halt_ipmi_set_timeout(); 1153 } 1154 } 1155 return NOTIFY_OK; 1156 } 1157 1158 static struct notifier_block wdog_reboot_notifier = { 1159 .notifier_call = wdog_reboot_handler, 1160 .next = NULL, 1161 .priority = 0 1162 }; 1163 1164 static int wdog_panic_handler(struct notifier_block *this, 1165 unsigned long event, 1166 void *unused) 1167 { 1168 static int panic_event_handled; 1169 1170 /* On a panic, if we have a panic timeout, make sure to extend 1171 the watchdog timer to a reasonable value to complete the 1172 panic, if the watchdog timer is running. Plus the 1173 pretimeout is meaningless at panic time. */ 1174 if (watchdog_user && !panic_event_handled && 1175 ipmi_watchdog_state != WDOG_TIMEOUT_NONE) { 1176 /* Make sure we do this only once. */ 1177 panic_event_handled = 1; 1178 1179 timeout = 255; 1180 pretimeout = 0; 1181 panic_halt_ipmi_set_timeout(); 1182 } 1183 1184 return NOTIFY_OK; 1185 } 1186 1187 static struct notifier_block wdog_panic_notifier = { 1188 .notifier_call = wdog_panic_handler, 1189 .next = NULL, 1190 .priority = 150 /* priority: INT_MAX >= x >= 0 */ 1191 }; 1192 1193 1194 static void ipmi_new_smi(int if_num, struct device *device) 1195 { 1196 ipmi_register_watchdog(if_num); 1197 } 1198 1199 static void ipmi_smi_gone(int if_num) 1200 { 1201 ipmi_unregister_watchdog(if_num); 1202 } 1203 1204 static struct ipmi_smi_watcher smi_watcher = { 1205 .owner = THIS_MODULE, 1206 .new_smi = ipmi_new_smi, 1207 .smi_gone = ipmi_smi_gone 1208 }; 1209 1210 static int action_op(const char *inval, char *outval) 1211 { 1212 if (outval) 1213 strcpy(outval, action); 1214 1215 if (!inval) 1216 return 0; 1217 1218 if (strcmp(inval, "reset") == 0) 1219 action_val = WDOG_TIMEOUT_RESET; 1220 else if (strcmp(inval, "none") == 0) 1221 action_val = WDOG_TIMEOUT_NONE; 1222 else if (strcmp(inval, "power_cycle") == 0) 1223 action_val = WDOG_TIMEOUT_POWER_CYCLE; 1224 else if (strcmp(inval, "power_off") == 0) 1225 action_val = WDOG_TIMEOUT_POWER_DOWN; 1226 else 1227 return -EINVAL; 1228 strcpy(action, inval); 1229 return 0; 1230 } 1231 1232 static int preaction_op(const char *inval, char *outval) 1233 { 1234 if (outval) 1235 strcpy(outval, preaction); 1236 1237 if (!inval) 1238 return 0; 1239 1240 if (strcmp(inval, "pre_none") == 0) 1241 preaction_val = WDOG_PRETIMEOUT_NONE; 1242 else if (strcmp(inval, "pre_smi") == 0) 1243 preaction_val = WDOG_PRETIMEOUT_SMI; 1244 #ifdef HAVE_DIE_NMI 1245 else if (strcmp(inval, "pre_nmi") == 0) 1246 preaction_val = WDOG_PRETIMEOUT_NMI; 1247 #endif 1248 else if (strcmp(inval, "pre_int") == 0) 1249 preaction_val = WDOG_PRETIMEOUT_MSG_INT; 1250 else 1251 return -EINVAL; 1252 strcpy(preaction, inval); 1253 return 0; 1254 } 1255 1256 static int preop_op(const char *inval, char *outval) 1257 { 1258 if (outval) 1259 strcpy(outval, preop); 1260 1261 if (!inval) 1262 return 0; 1263 1264 if (strcmp(inval, "preop_none") == 0) 1265 preop_val = WDOG_PREOP_NONE; 1266 else if (strcmp(inval, "preop_panic") == 0) 1267 preop_val = WDOG_PREOP_PANIC; 1268 else if (strcmp(inval, "preop_give_data") == 0) 1269 preop_val = WDOG_PREOP_GIVE_DATA; 1270 else 1271 return -EINVAL; 1272 strcpy(preop, inval); 1273 return 0; 1274 } 1275 1276 static void check_parms(void) 1277 { 1278 #ifdef HAVE_DIE_NMI 1279 int do_nmi = 0; 1280 int rv; 1281 1282 if (preaction_val == WDOG_PRETIMEOUT_NMI) { 1283 do_nmi = 1; 1284 if (preop_val == WDOG_PREOP_GIVE_DATA) { 1285 printk(KERN_WARNING PFX "Pretimeout op is to give data" 1286 " but NMI pretimeout is enabled, setting" 1287 " pretimeout op to none\n"); 1288 preop_op("preop_none", NULL); 1289 do_nmi = 0; 1290 } 1291 } 1292 if (do_nmi && !nmi_handler_registered) { 1293 rv = register_die_notifier(&ipmi_nmi_handler); 1294 if (rv) { 1295 printk(KERN_WARNING PFX 1296 "Can't register nmi handler\n"); 1297 return; 1298 } else 1299 nmi_handler_registered = 1; 1300 } else if (!do_nmi && nmi_handler_registered) { 1301 unregister_die_notifier(&ipmi_nmi_handler); 1302 nmi_handler_registered = 0; 1303 } 1304 #endif 1305 } 1306 1307 static int __init ipmi_wdog_init(void) 1308 { 1309 int rv; 1310 1311 if (action_op(action, NULL)) { 1312 action_op("reset", NULL); 1313 printk(KERN_INFO PFX "Unknown action '%s', defaulting to" 1314 " reset\n", action); 1315 } 1316 1317 if (preaction_op(preaction, NULL)) { 1318 preaction_op("pre_none", NULL); 1319 printk(KERN_INFO PFX "Unknown preaction '%s', defaulting to" 1320 " none\n", preaction); 1321 } 1322 1323 if (preop_op(preop, NULL)) { 1324 preop_op("preop_none", NULL); 1325 printk(KERN_INFO PFX "Unknown preop '%s', defaulting to" 1326 " none\n", preop); 1327 } 1328 1329 check_parms(); 1330 1331 register_reboot_notifier(&wdog_reboot_notifier); 1332 atomic_notifier_chain_register(&panic_notifier_list, 1333 &wdog_panic_notifier); 1334 1335 rv = ipmi_smi_watcher_register(&smi_watcher); 1336 if (rv) { 1337 #ifdef HAVE_DIE_NMI 1338 if (nmi_handler_registered) 1339 unregister_die_notifier(&ipmi_nmi_handler); 1340 #endif 1341 atomic_notifier_chain_unregister(&panic_notifier_list, 1342 &wdog_panic_notifier); 1343 unregister_reboot_notifier(&wdog_reboot_notifier); 1344 printk(KERN_WARNING PFX "can't register smi watcher\n"); 1345 return rv; 1346 } 1347 1348 printk(KERN_INFO PFX "driver initialized\n"); 1349 1350 return 0; 1351 } 1352 1353 static void __exit ipmi_wdog_exit(void) 1354 { 1355 ipmi_smi_watcher_unregister(&smi_watcher); 1356 ipmi_unregister_watchdog(watchdog_ifnum); 1357 1358 #ifdef HAVE_DIE_NMI 1359 if (nmi_handler_registered) 1360 unregister_die_notifier(&ipmi_nmi_handler); 1361 #endif 1362 1363 atomic_notifier_chain_unregister(&panic_notifier_list, 1364 &wdog_panic_notifier); 1365 unregister_reboot_notifier(&wdog_reboot_notifier); 1366 } 1367 module_exit(ipmi_wdog_exit); 1368 module_init(ipmi_wdog_init); 1369 MODULE_LICENSE("GPL"); 1370 MODULE_AUTHOR("Corey Minyard <minyard@mvista.com>"); 1371 MODULE_DESCRIPTION("watchdog timer based upon the IPMI interface."); 1372