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