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 /* These are here until the real ones get into the watchdog.h interface. */ 143 #ifndef WDIOC_GETTIMEOUT 144 #define WDIOC_GETTIMEOUT _IOW(WATCHDOG_IOCTL_BASE, 20, int) 145 #endif 146 #ifndef WDIOC_SET_PRETIMEOUT 147 #define WDIOC_SET_PRETIMEOUT _IOW(WATCHDOG_IOCTL_BASE, 21, int) 148 #endif 149 #ifndef WDIOC_GET_PRETIMEOUT 150 #define WDIOC_GET_PRETIMEOUT _IOW(WATCHDOG_IOCTL_BASE, 22, int) 151 #endif 152 153 static DEFINE_MUTEX(ipmi_watchdog_mutex); 154 static int nowayout = WATCHDOG_NOWAYOUT; 155 156 static ipmi_user_t watchdog_user; 157 static int watchdog_ifnum; 158 159 /* Default the timeout to 10 seconds. */ 160 static int timeout = 10; 161 162 /* The pre-timeout is disabled by default. */ 163 static int pretimeout; 164 165 /* Default action is to reset the board on a timeout. */ 166 static unsigned char action_val = WDOG_TIMEOUT_RESET; 167 168 static char action[16] = "reset"; 169 170 static unsigned char preaction_val = WDOG_PRETIMEOUT_NONE; 171 172 static char preaction[16] = "pre_none"; 173 174 static unsigned char preop_val = WDOG_PREOP_NONE; 175 176 static char preop[16] = "preop_none"; 177 static DEFINE_SPINLOCK(ipmi_read_lock); 178 static char data_to_read; 179 static DECLARE_WAIT_QUEUE_HEAD(read_q); 180 static struct fasync_struct *fasync_q; 181 static char pretimeout_since_last_heartbeat; 182 static char expect_close; 183 184 static int ifnum_to_use = -1; 185 186 /* Parameters to ipmi_set_timeout */ 187 #define IPMI_SET_TIMEOUT_NO_HB 0 188 #define IPMI_SET_TIMEOUT_HB_IF_NECESSARY 1 189 #define IPMI_SET_TIMEOUT_FORCE_HB 2 190 191 static int ipmi_set_timeout(int do_heartbeat); 192 static void ipmi_register_watchdog(int ipmi_intf); 193 static void ipmi_unregister_watchdog(int ipmi_intf); 194 195 /* 196 * If true, the driver will start running as soon as it is configured 197 * and ready. 198 */ 199 static int start_now; 200 201 static int set_param_timeout(const char *val, const struct kernel_param *kp) 202 { 203 char *endp; 204 int l; 205 int rv = 0; 206 207 if (!val) 208 return -EINVAL; 209 l = simple_strtoul(val, &endp, 0); 210 if (endp == val) 211 return -EINVAL; 212 213 *((int *)kp->arg) = l; 214 if (watchdog_user) 215 rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY); 216 217 return rv; 218 } 219 220 static struct kernel_param_ops param_ops_timeout = { 221 .set = set_param_timeout, 222 .get = param_get_int, 223 }; 224 #define param_check_timeout param_check_int 225 226 typedef int (*action_fn)(const char *intval, char *outval); 227 228 static int action_op(const char *inval, char *outval); 229 static int preaction_op(const char *inval, char *outval); 230 static int preop_op(const char *inval, char *outval); 231 static void check_parms(void); 232 233 static int set_param_str(const char *val, const struct kernel_param *kp) 234 { 235 action_fn fn = (action_fn) kp->arg; 236 int rv = 0; 237 char valcp[16]; 238 char *s; 239 240 strncpy(valcp, val, 16); 241 valcp[15] = '\0'; 242 243 s = strstrip(valcp); 244 245 rv = fn(s, NULL); 246 if (rv) 247 goto out; 248 249 check_parms(); 250 if (watchdog_user) 251 rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY); 252 253 out: 254 return rv; 255 } 256 257 static int get_param_str(char *buffer, const struct kernel_param *kp) 258 { 259 action_fn fn = (action_fn) kp->arg; 260 int rv; 261 262 rv = fn(NULL, buffer); 263 if (rv) 264 return rv; 265 return strlen(buffer); 266 } 267 268 269 static int set_param_wdog_ifnum(const char *val, const struct kernel_param *kp) 270 { 271 int rv = param_set_int(val, kp); 272 if (rv) 273 return rv; 274 if ((ifnum_to_use < 0) || (ifnum_to_use == watchdog_ifnum)) 275 return 0; 276 277 ipmi_unregister_watchdog(watchdog_ifnum); 278 ipmi_register_watchdog(ifnum_to_use); 279 return 0; 280 } 281 282 static struct kernel_param_ops param_ops_wdog_ifnum = { 283 .set = set_param_wdog_ifnum, 284 .get = param_get_int, 285 }; 286 287 #define param_check_wdog_ifnum param_check_int 288 289 static struct kernel_param_ops param_ops_str = { 290 .set = set_param_str, 291 .get = get_param_str, 292 }; 293 294 module_param(ifnum_to_use, wdog_ifnum, 0644); 295 MODULE_PARM_DESC(ifnum_to_use, "The interface number to use for the watchdog " 296 "timer. Setting to -1 defaults to the first registered " 297 "interface"); 298 299 module_param(timeout, timeout, 0644); 300 MODULE_PARM_DESC(timeout, "Timeout value in seconds."); 301 302 module_param(pretimeout, timeout, 0644); 303 MODULE_PARM_DESC(pretimeout, "Pretimeout value in seconds."); 304 305 module_param_cb(action, ¶m_ops_str, action_op, 0644); 306 MODULE_PARM_DESC(action, "Timeout action. One of: " 307 "reset, none, power_cycle, power_off."); 308 309 module_param_cb(preaction, ¶m_ops_str, preaction_op, 0644); 310 MODULE_PARM_DESC(preaction, "Pretimeout action. One of: " 311 "pre_none, pre_smi, pre_nmi, pre_int."); 312 313 module_param_cb(preop, ¶m_ops_str, preop_op, 0644); 314 MODULE_PARM_DESC(preop, "Pretimeout driver operation. One of: " 315 "preop_none, preop_panic, preop_give_data."); 316 317 module_param(start_now, int, 0444); 318 MODULE_PARM_DESC(start_now, "Set to 1 to start the watchdog as" 319 "soon as the driver is loaded."); 320 321 module_param(nowayout, int, 0644); 322 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started " 323 "(default=CONFIG_WATCHDOG_NOWAYOUT)"); 324 325 /* Default state of the timer. */ 326 static unsigned char ipmi_watchdog_state = WDOG_TIMEOUT_NONE; 327 328 /* If shutting down via IPMI, we ignore the heartbeat. */ 329 static int ipmi_ignore_heartbeat; 330 331 /* Is someone using the watchdog? Only one user is allowed. */ 332 static unsigned long ipmi_wdog_open; 333 334 /* 335 * If set to 1, the heartbeat command will set the state to reset and 336 * start the timer. The timer doesn't normally run when the driver is 337 * first opened until the heartbeat is set the first time, this 338 * variable is used to accomplish this. 339 */ 340 static int ipmi_start_timer_on_heartbeat; 341 342 /* IPMI version of the BMC. */ 343 static unsigned char ipmi_version_major; 344 static unsigned char ipmi_version_minor; 345 346 /* If a pretimeout occurs, this is used to allow only one panic to happen. */ 347 static atomic_t preop_panic_excl = ATOMIC_INIT(-1); 348 349 #ifdef HAVE_DIE_NMI 350 static int testing_nmi; 351 static int nmi_handler_registered; 352 #endif 353 354 static int ipmi_heartbeat(void); 355 356 /* 357 * We use a mutex to make sure that only one thing can send a set 358 * timeout at one time, because we only have one copy of the data. 359 * The mutex is claimed when the set_timeout is sent and freed 360 * when both messages are free. 361 */ 362 static atomic_t set_timeout_tofree = ATOMIC_INIT(0); 363 static DEFINE_MUTEX(set_timeout_lock); 364 static DECLARE_COMPLETION(set_timeout_wait); 365 static void set_timeout_free_smi(struct ipmi_smi_msg *msg) 366 { 367 if (atomic_dec_and_test(&set_timeout_tofree)) 368 complete(&set_timeout_wait); 369 } 370 static void set_timeout_free_recv(struct ipmi_recv_msg *msg) 371 { 372 if (atomic_dec_and_test(&set_timeout_tofree)) 373 complete(&set_timeout_wait); 374 } 375 static struct ipmi_smi_msg set_timeout_smi_msg = { 376 .done = set_timeout_free_smi 377 }; 378 static struct ipmi_recv_msg set_timeout_recv_msg = { 379 .done = set_timeout_free_recv 380 }; 381 382 static int i_ipmi_set_timeout(struct ipmi_smi_msg *smi_msg, 383 struct ipmi_recv_msg *recv_msg, 384 int *send_heartbeat_now) 385 { 386 struct kernel_ipmi_msg msg; 387 unsigned char data[6]; 388 int rv; 389 struct ipmi_system_interface_addr addr; 390 int hbnow = 0; 391 392 393 /* These can be cleared as we are setting the timeout. */ 394 pretimeout_since_last_heartbeat = 0; 395 396 data[0] = 0; 397 WDOG_SET_TIMER_USE(data[0], WDOG_TIMER_USE_SMS_OS); 398 399 if ((ipmi_version_major > 1) 400 || ((ipmi_version_major == 1) && (ipmi_version_minor >= 5))) { 401 /* This is an IPMI 1.5-only feature. */ 402 data[0] |= WDOG_DONT_STOP_ON_SET; 403 } else if (ipmi_watchdog_state != WDOG_TIMEOUT_NONE) { 404 /* 405 * In ipmi 1.0, setting the timer stops the watchdog, we 406 * need to start it back up again. 407 */ 408 hbnow = 1; 409 } 410 411 data[1] = 0; 412 WDOG_SET_TIMEOUT_ACT(data[1], ipmi_watchdog_state); 413 if ((pretimeout > 0) && (ipmi_watchdog_state != WDOG_TIMEOUT_NONE)) { 414 WDOG_SET_PRETIMEOUT_ACT(data[1], preaction_val); 415 data[2] = pretimeout; 416 } else { 417 WDOG_SET_PRETIMEOUT_ACT(data[1], WDOG_PRETIMEOUT_NONE); 418 data[2] = 0; /* No pretimeout. */ 419 } 420 data[3] = 0; 421 WDOG_SET_TIMEOUT(data[4], data[5], timeout); 422 423 addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE; 424 addr.channel = IPMI_BMC_CHANNEL; 425 addr.lun = 0; 426 427 msg.netfn = 0x06; 428 msg.cmd = IPMI_WDOG_SET_TIMER; 429 msg.data = data; 430 msg.data_len = sizeof(data); 431 rv = ipmi_request_supply_msgs(watchdog_user, 432 (struct ipmi_addr *) &addr, 433 0, 434 &msg, 435 NULL, 436 smi_msg, 437 recv_msg, 438 1); 439 if (rv) { 440 printk(KERN_WARNING PFX "set timeout error: %d\n", 441 rv); 442 } 443 444 if (send_heartbeat_now) 445 *send_heartbeat_now = hbnow; 446 447 return rv; 448 } 449 450 static int ipmi_set_timeout(int do_heartbeat) 451 { 452 int send_heartbeat_now; 453 int rv; 454 455 456 /* We can only send one of these at a time. */ 457 mutex_lock(&set_timeout_lock); 458 459 atomic_set(&set_timeout_tofree, 2); 460 461 rv = i_ipmi_set_timeout(&set_timeout_smi_msg, 462 &set_timeout_recv_msg, 463 &send_heartbeat_now); 464 if (rv) { 465 mutex_unlock(&set_timeout_lock); 466 goto out; 467 } 468 469 wait_for_completion(&set_timeout_wait); 470 471 mutex_unlock(&set_timeout_lock); 472 473 if ((do_heartbeat == IPMI_SET_TIMEOUT_FORCE_HB) 474 || ((send_heartbeat_now) 475 && (do_heartbeat == IPMI_SET_TIMEOUT_HB_IF_NECESSARY))) 476 rv = ipmi_heartbeat(); 477 478 out: 479 return rv; 480 } 481 482 static atomic_t panic_done_count = ATOMIC_INIT(0); 483 484 static void panic_smi_free(struct ipmi_smi_msg *msg) 485 { 486 atomic_dec(&panic_done_count); 487 } 488 static void panic_recv_free(struct ipmi_recv_msg *msg) 489 { 490 atomic_dec(&panic_done_count); 491 } 492 493 static struct ipmi_smi_msg panic_halt_heartbeat_smi_msg = { 494 .done = panic_smi_free 495 }; 496 static struct ipmi_recv_msg panic_halt_heartbeat_recv_msg = { 497 .done = panic_recv_free 498 }; 499 500 static void panic_halt_ipmi_heartbeat(void) 501 { 502 struct kernel_ipmi_msg msg; 503 struct ipmi_system_interface_addr addr; 504 int rv; 505 506 /* 507 * Don't reset the timer if we have the timer turned off, that 508 * re-enables the watchdog. 509 */ 510 if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE) 511 return; 512 513 addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE; 514 addr.channel = IPMI_BMC_CHANNEL; 515 addr.lun = 0; 516 517 msg.netfn = 0x06; 518 msg.cmd = IPMI_WDOG_RESET_TIMER; 519 msg.data = NULL; 520 msg.data_len = 0; 521 rv = ipmi_request_supply_msgs(watchdog_user, 522 (struct ipmi_addr *) &addr, 523 0, 524 &msg, 525 NULL, 526 &panic_halt_heartbeat_smi_msg, 527 &panic_halt_heartbeat_recv_msg, 528 1); 529 if (!rv) 530 atomic_add(2, &panic_done_count); 531 } 532 533 static struct ipmi_smi_msg panic_halt_smi_msg = { 534 .done = panic_smi_free 535 }; 536 static struct ipmi_recv_msg panic_halt_recv_msg = { 537 .done = panic_recv_free 538 }; 539 540 /* 541 * Special call, doesn't claim any locks. This is only to be called 542 * at panic or halt time, in run-to-completion mode, when the caller 543 * is the only CPU and the only thing that will be going is these IPMI 544 * calls. 545 */ 546 static void panic_halt_ipmi_set_timeout(void) 547 { 548 int send_heartbeat_now; 549 int rv; 550 551 /* Wait for the messages to be free. */ 552 while (atomic_read(&panic_done_count) != 0) 553 ipmi_poll_interface(watchdog_user); 554 rv = i_ipmi_set_timeout(&panic_halt_smi_msg, 555 &panic_halt_recv_msg, 556 &send_heartbeat_now); 557 if (!rv) { 558 atomic_add(2, &panic_done_count); 559 if (send_heartbeat_now) 560 panic_halt_ipmi_heartbeat(); 561 } else 562 printk(KERN_WARNING PFX 563 "Unable to extend the watchdog timeout."); 564 while (atomic_read(&panic_done_count) != 0) 565 ipmi_poll_interface(watchdog_user); 566 } 567 568 /* 569 * We use a mutex to make sure that only one thing can send a 570 * heartbeat at one time, because we only have one copy of the data. 571 * The semaphore is claimed when the set_timeout is sent and freed 572 * when both messages are free. 573 */ 574 static atomic_t heartbeat_tofree = ATOMIC_INIT(0); 575 static DEFINE_MUTEX(heartbeat_lock); 576 static DECLARE_COMPLETION(heartbeat_wait); 577 static void heartbeat_free_smi(struct ipmi_smi_msg *msg) 578 { 579 if (atomic_dec_and_test(&heartbeat_tofree)) 580 complete(&heartbeat_wait); 581 } 582 static void heartbeat_free_recv(struct ipmi_recv_msg *msg) 583 { 584 if (atomic_dec_and_test(&heartbeat_tofree)) 585 complete(&heartbeat_wait); 586 } 587 static struct ipmi_smi_msg heartbeat_smi_msg = { 588 .done = heartbeat_free_smi 589 }; 590 static struct ipmi_recv_msg heartbeat_recv_msg = { 591 .done = heartbeat_free_recv 592 }; 593 594 static int ipmi_heartbeat(void) 595 { 596 struct kernel_ipmi_msg msg; 597 int rv; 598 struct ipmi_system_interface_addr addr; 599 600 if (ipmi_ignore_heartbeat) 601 return 0; 602 603 if (ipmi_start_timer_on_heartbeat) { 604 ipmi_start_timer_on_heartbeat = 0; 605 ipmi_watchdog_state = action_val; 606 return ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB); 607 } else if (pretimeout_since_last_heartbeat) { 608 /* 609 * A pretimeout occurred, make sure we set the timeout. 610 * We don't want to set the action, though, we want to 611 * leave that alone (thus it can't be combined with the 612 * above operation. 613 */ 614 return ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY); 615 } 616 617 mutex_lock(&heartbeat_lock); 618 619 atomic_set(&heartbeat_tofree, 2); 620 621 /* 622 * Don't reset the timer if we have the timer turned off, that 623 * re-enables the watchdog. 624 */ 625 if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE) { 626 mutex_unlock(&heartbeat_lock); 627 return 0; 628 } 629 630 addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE; 631 addr.channel = IPMI_BMC_CHANNEL; 632 addr.lun = 0; 633 634 msg.netfn = 0x06; 635 msg.cmd = IPMI_WDOG_RESET_TIMER; 636 msg.data = NULL; 637 msg.data_len = 0; 638 rv = ipmi_request_supply_msgs(watchdog_user, 639 (struct ipmi_addr *) &addr, 640 0, 641 &msg, 642 NULL, 643 &heartbeat_smi_msg, 644 &heartbeat_recv_msg, 645 1); 646 if (rv) { 647 mutex_unlock(&heartbeat_lock); 648 printk(KERN_WARNING PFX "heartbeat failure: %d\n", 649 rv); 650 return rv; 651 } 652 653 /* Wait for the heartbeat to be sent. */ 654 wait_for_completion(&heartbeat_wait); 655 656 if (heartbeat_recv_msg.msg.data[0] != 0) { 657 /* 658 * Got an error in the heartbeat response. It was already 659 * reported in ipmi_wdog_msg_handler, but we should return 660 * an error here. 661 */ 662 rv = -EINVAL; 663 } 664 665 mutex_unlock(&heartbeat_lock); 666 667 return rv; 668 } 669 670 static struct watchdog_info ident = { 671 .options = 0, /* WDIOF_SETTIMEOUT, */ 672 .firmware_version = 1, 673 .identity = "IPMI" 674 }; 675 676 static int ipmi_ioctl(struct file *file, 677 unsigned int cmd, unsigned long arg) 678 { 679 void __user *argp = (void __user *)arg; 680 int i; 681 int val; 682 683 switch (cmd) { 684 case WDIOC_GETSUPPORT: 685 i = copy_to_user(argp, &ident, sizeof(ident)); 686 return i ? -EFAULT : 0; 687 688 case WDIOC_SETTIMEOUT: 689 i = copy_from_user(&val, argp, sizeof(int)); 690 if (i) 691 return -EFAULT; 692 timeout = val; 693 return ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY); 694 695 case WDIOC_GETTIMEOUT: 696 i = copy_to_user(argp, &timeout, sizeof(timeout)); 697 if (i) 698 return -EFAULT; 699 return 0; 700 701 case WDIOC_SET_PRETIMEOUT: 702 case WDIOC_SETPRETIMEOUT: 703 i = copy_from_user(&val, argp, sizeof(int)); 704 if (i) 705 return -EFAULT; 706 pretimeout = val; 707 return ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY); 708 709 case WDIOC_GET_PRETIMEOUT: 710 case WDIOC_GETPRETIMEOUT: 711 i = copy_to_user(argp, &pretimeout, sizeof(pretimeout)); 712 if (i) 713 return -EFAULT; 714 return 0; 715 716 case WDIOC_KEEPALIVE: 717 return ipmi_heartbeat(); 718 719 case WDIOC_SETOPTIONS: 720 i = copy_from_user(&val, argp, sizeof(int)); 721 if (i) 722 return -EFAULT; 723 if (val & WDIOS_DISABLECARD) { 724 ipmi_watchdog_state = WDOG_TIMEOUT_NONE; 725 ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB); 726 ipmi_start_timer_on_heartbeat = 0; 727 } 728 729 if (val & WDIOS_ENABLECARD) { 730 ipmi_watchdog_state = action_val; 731 ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB); 732 } 733 return 0; 734 735 case WDIOC_GETSTATUS: 736 val = 0; 737 i = copy_to_user(argp, &val, sizeof(val)); 738 if (i) 739 return -EFAULT; 740 return 0; 741 742 default: 743 return -ENOIOCTLCMD; 744 } 745 } 746 747 static long ipmi_unlocked_ioctl(struct file *file, 748 unsigned int cmd, 749 unsigned long arg) 750 { 751 int ret; 752 753 mutex_lock(&ipmi_watchdog_mutex); 754 ret = ipmi_ioctl(file, cmd, arg); 755 mutex_unlock(&ipmi_watchdog_mutex); 756 757 return ret; 758 } 759 760 static ssize_t ipmi_write(struct file *file, 761 const char __user *buf, 762 size_t len, 763 loff_t *ppos) 764 { 765 int rv; 766 767 if (len) { 768 if (!nowayout) { 769 size_t i; 770 771 /* In case it was set long ago */ 772 expect_close = 0; 773 774 for (i = 0; i != len; i++) { 775 char c; 776 777 if (get_user(c, buf + i)) 778 return -EFAULT; 779 if (c == 'V') 780 expect_close = 42; 781 } 782 } 783 rv = ipmi_heartbeat(); 784 if (rv) 785 return rv; 786 } 787 return len; 788 } 789 790 static ssize_t ipmi_read(struct file *file, 791 char __user *buf, 792 size_t count, 793 loff_t *ppos) 794 { 795 int rv = 0; 796 wait_queue_t wait; 797 798 if (count <= 0) 799 return 0; 800 801 /* 802 * Reading returns if the pretimeout has gone off, and it only does 803 * it once per pretimeout. 804 */ 805 spin_lock(&ipmi_read_lock); 806 if (!data_to_read) { 807 if (file->f_flags & O_NONBLOCK) { 808 rv = -EAGAIN; 809 goto out; 810 } 811 812 init_waitqueue_entry(&wait, current); 813 add_wait_queue(&read_q, &wait); 814 while (!data_to_read) { 815 set_current_state(TASK_INTERRUPTIBLE); 816 spin_unlock(&ipmi_read_lock); 817 schedule(); 818 spin_lock(&ipmi_read_lock); 819 } 820 remove_wait_queue(&read_q, &wait); 821 822 if (signal_pending(current)) { 823 rv = -ERESTARTSYS; 824 goto out; 825 } 826 } 827 data_to_read = 0; 828 829 out: 830 spin_unlock(&ipmi_read_lock); 831 832 if (rv == 0) { 833 if (copy_to_user(buf, &data_to_read, 1)) 834 rv = -EFAULT; 835 else 836 rv = 1; 837 } 838 839 return rv; 840 } 841 842 static int ipmi_open(struct inode *ino, struct file *filep) 843 { 844 switch (iminor(ino)) { 845 case WATCHDOG_MINOR: 846 if (test_and_set_bit(0, &ipmi_wdog_open)) 847 return -EBUSY; 848 849 850 /* 851 * Don't start the timer now, let it start on the 852 * first heartbeat. 853 */ 854 ipmi_start_timer_on_heartbeat = 1; 855 return nonseekable_open(ino, filep); 856 857 default: 858 return (-ENODEV); 859 } 860 } 861 862 static unsigned int ipmi_poll(struct file *file, poll_table *wait) 863 { 864 unsigned int mask = 0; 865 866 poll_wait(file, &read_q, wait); 867 868 spin_lock(&ipmi_read_lock); 869 if (data_to_read) 870 mask |= (POLLIN | POLLRDNORM); 871 spin_unlock(&ipmi_read_lock); 872 873 return mask; 874 } 875 876 static int ipmi_fasync(int fd, struct file *file, int on) 877 { 878 int result; 879 880 result = fasync_helper(fd, file, on, &fasync_q); 881 882 return (result); 883 } 884 885 static int ipmi_close(struct inode *ino, struct file *filep) 886 { 887 if (iminor(ino) == WATCHDOG_MINOR) { 888 if (expect_close == 42) { 889 ipmi_watchdog_state = WDOG_TIMEOUT_NONE; 890 ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB); 891 } else { 892 printk(KERN_CRIT PFX 893 "Unexpected close, not stopping watchdog!\n"); 894 ipmi_heartbeat(); 895 } 896 clear_bit(0, &ipmi_wdog_open); 897 } 898 899 expect_close = 0; 900 901 return 0; 902 } 903 904 static const struct file_operations ipmi_wdog_fops = { 905 .owner = THIS_MODULE, 906 .read = ipmi_read, 907 .poll = ipmi_poll, 908 .write = ipmi_write, 909 .unlocked_ioctl = ipmi_unlocked_ioctl, 910 .open = ipmi_open, 911 .release = ipmi_close, 912 .fasync = ipmi_fasync, 913 .llseek = no_llseek, 914 }; 915 916 static struct miscdevice ipmi_wdog_miscdev = { 917 .minor = WATCHDOG_MINOR, 918 .name = "watchdog", 919 .fops = &ipmi_wdog_fops 920 }; 921 922 static void ipmi_wdog_msg_handler(struct ipmi_recv_msg *msg, 923 void *handler_data) 924 { 925 if (msg->msg.data[0] != 0) { 926 printk(KERN_ERR PFX "response: Error %x on cmd %x\n", 927 msg->msg.data[0], 928 msg->msg.cmd); 929 } 930 931 ipmi_free_recv_msg(msg); 932 } 933 934 static void ipmi_wdog_pretimeout_handler(void *handler_data) 935 { 936 if (preaction_val != WDOG_PRETIMEOUT_NONE) { 937 if (preop_val == WDOG_PREOP_PANIC) { 938 if (atomic_inc_and_test(&preop_panic_excl)) 939 panic("Watchdog pre-timeout"); 940 } else if (preop_val == WDOG_PREOP_GIVE_DATA) { 941 spin_lock(&ipmi_read_lock); 942 data_to_read = 1; 943 wake_up_interruptible(&read_q); 944 kill_fasync(&fasync_q, SIGIO, POLL_IN); 945 946 spin_unlock(&ipmi_read_lock); 947 } 948 } 949 950 /* 951 * On some machines, the heartbeat will give an error and not 952 * work unless we re-enable the timer. So do so. 953 */ 954 pretimeout_since_last_heartbeat = 1; 955 } 956 957 static struct ipmi_user_hndl ipmi_hndlrs = { 958 .ipmi_recv_hndl = ipmi_wdog_msg_handler, 959 .ipmi_watchdog_pretimeout = ipmi_wdog_pretimeout_handler 960 }; 961 962 static void ipmi_register_watchdog(int ipmi_intf) 963 { 964 int rv = -EBUSY; 965 966 if (watchdog_user) 967 goto out; 968 969 if ((ifnum_to_use >= 0) && (ifnum_to_use != ipmi_intf)) 970 goto out; 971 972 watchdog_ifnum = ipmi_intf; 973 974 rv = ipmi_create_user(ipmi_intf, &ipmi_hndlrs, NULL, &watchdog_user); 975 if (rv < 0) { 976 printk(KERN_CRIT PFX "Unable to register with ipmi\n"); 977 goto out; 978 } 979 980 ipmi_get_version(watchdog_user, 981 &ipmi_version_major, 982 &ipmi_version_minor); 983 984 rv = misc_register(&ipmi_wdog_miscdev); 985 if (rv < 0) { 986 ipmi_destroy_user(watchdog_user); 987 watchdog_user = NULL; 988 printk(KERN_CRIT PFX "Unable to register misc device\n"); 989 } 990 991 #ifdef HAVE_DIE_NMI 992 if (nmi_handler_registered) { 993 int old_pretimeout = pretimeout; 994 int old_timeout = timeout; 995 int old_preop_val = preop_val; 996 997 /* 998 * Set the pretimeout to go off in a second and give 999 * ourselves plenty of time to stop the timer. 1000 */ 1001 ipmi_watchdog_state = WDOG_TIMEOUT_RESET; 1002 preop_val = WDOG_PREOP_NONE; /* Make sure nothing happens */ 1003 pretimeout = 99; 1004 timeout = 100; 1005 1006 testing_nmi = 1; 1007 1008 rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB); 1009 if (rv) { 1010 printk(KERN_WARNING PFX "Error starting timer to" 1011 " test NMI: 0x%x. The NMI pretimeout will" 1012 " likely not work\n", rv); 1013 rv = 0; 1014 goto out_restore; 1015 } 1016 1017 msleep(1500); 1018 1019 if (testing_nmi != 2) { 1020 printk(KERN_WARNING PFX "IPMI NMI didn't seem to" 1021 " occur. The NMI pretimeout will" 1022 " likely not work\n"); 1023 } 1024 out_restore: 1025 testing_nmi = 0; 1026 preop_val = old_preop_val; 1027 pretimeout = old_pretimeout; 1028 timeout = old_timeout; 1029 } 1030 #endif 1031 1032 out: 1033 if ((start_now) && (rv == 0)) { 1034 /* Run from startup, so start the timer now. */ 1035 start_now = 0; /* Disable this function after first startup. */ 1036 ipmi_watchdog_state = action_val; 1037 ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB); 1038 printk(KERN_INFO PFX "Starting now!\n"); 1039 } else { 1040 /* Stop the timer now. */ 1041 ipmi_watchdog_state = WDOG_TIMEOUT_NONE; 1042 ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB); 1043 } 1044 } 1045 1046 static void ipmi_unregister_watchdog(int ipmi_intf) 1047 { 1048 int rv; 1049 1050 if (!watchdog_user) 1051 goto out; 1052 1053 if (watchdog_ifnum != ipmi_intf) 1054 goto out; 1055 1056 /* Make sure no one can call us any more. */ 1057 misc_deregister(&ipmi_wdog_miscdev); 1058 1059 /* 1060 * Wait to make sure the message makes it out. The lower layer has 1061 * pointers to our buffers, we want to make sure they are done before 1062 * we release our memory. 1063 */ 1064 while (atomic_read(&set_timeout_tofree)) 1065 schedule_timeout_uninterruptible(1); 1066 1067 /* Disconnect from IPMI. */ 1068 rv = ipmi_destroy_user(watchdog_user); 1069 if (rv) { 1070 printk(KERN_WARNING PFX "error unlinking from IPMI: %d\n", 1071 rv); 1072 } 1073 watchdog_user = NULL; 1074 1075 out: 1076 return; 1077 } 1078 1079 #ifdef HAVE_DIE_NMI 1080 static int 1081 ipmi_nmi(unsigned int val, struct pt_regs *regs) 1082 { 1083 /* 1084 * If we get here, it's an NMI that's not a memory or I/O 1085 * error. We can't truly tell if it's from IPMI or not 1086 * without sending a message, and sending a message is almost 1087 * impossible because of locking. 1088 */ 1089 1090 if (testing_nmi) { 1091 testing_nmi = 2; 1092 return NMI_HANDLED; 1093 } 1094 1095 /* If we are not expecting a timeout, ignore it. */ 1096 if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE) 1097 return NMI_DONE; 1098 1099 if (preaction_val != WDOG_PRETIMEOUT_NMI) 1100 return NMI_DONE; 1101 1102 /* 1103 * If no one else handled the NMI, we assume it was the IPMI 1104 * watchdog. 1105 */ 1106 if (preop_val == WDOG_PREOP_PANIC) { 1107 /* On some machines, the heartbeat will give 1108 an error and not work unless we re-enable 1109 the timer. So do so. */ 1110 pretimeout_since_last_heartbeat = 1; 1111 if (atomic_inc_and_test(&preop_panic_excl)) 1112 panic(PFX "pre-timeout"); 1113 } 1114 1115 return NMI_HANDLED; 1116 } 1117 #endif 1118 1119 static int wdog_reboot_handler(struct notifier_block *this, 1120 unsigned long code, 1121 void *unused) 1122 { 1123 static int reboot_event_handled; 1124 1125 if ((watchdog_user) && (!reboot_event_handled)) { 1126 /* Make sure we only do this once. */ 1127 reboot_event_handled = 1; 1128 1129 if (code == SYS_POWER_OFF || code == SYS_HALT) { 1130 /* Disable the WDT if we are shutting down. */ 1131 ipmi_watchdog_state = WDOG_TIMEOUT_NONE; 1132 panic_halt_ipmi_set_timeout(); 1133 } else if (ipmi_watchdog_state != WDOG_TIMEOUT_NONE) { 1134 /* Set a long timer to let the reboot happens, but 1135 reboot if it hangs, but only if the watchdog 1136 timer was already running. */ 1137 timeout = 120; 1138 pretimeout = 0; 1139 ipmi_watchdog_state = WDOG_TIMEOUT_RESET; 1140 panic_halt_ipmi_set_timeout(); 1141 } 1142 } 1143 return NOTIFY_OK; 1144 } 1145 1146 static struct notifier_block wdog_reboot_notifier = { 1147 .notifier_call = wdog_reboot_handler, 1148 .next = NULL, 1149 .priority = 0 1150 }; 1151 1152 static int wdog_panic_handler(struct notifier_block *this, 1153 unsigned long event, 1154 void *unused) 1155 { 1156 static int panic_event_handled; 1157 1158 /* On a panic, if we have a panic timeout, make sure to extend 1159 the watchdog timer to a reasonable value to complete the 1160 panic, if the watchdog timer is running. Plus the 1161 pretimeout is meaningless at panic time. */ 1162 if (watchdog_user && !panic_event_handled && 1163 ipmi_watchdog_state != WDOG_TIMEOUT_NONE) { 1164 /* Make sure we do this only once. */ 1165 panic_event_handled = 1; 1166 1167 timeout = 255; 1168 pretimeout = 0; 1169 panic_halt_ipmi_set_timeout(); 1170 } 1171 1172 return NOTIFY_OK; 1173 } 1174 1175 static struct notifier_block wdog_panic_notifier = { 1176 .notifier_call = wdog_panic_handler, 1177 .next = NULL, 1178 .priority = 150 /* priority: INT_MAX >= x >= 0 */ 1179 }; 1180 1181 1182 static void ipmi_new_smi(int if_num, struct device *device) 1183 { 1184 ipmi_register_watchdog(if_num); 1185 } 1186 1187 static void ipmi_smi_gone(int if_num) 1188 { 1189 ipmi_unregister_watchdog(if_num); 1190 } 1191 1192 static struct ipmi_smi_watcher smi_watcher = { 1193 .owner = THIS_MODULE, 1194 .new_smi = ipmi_new_smi, 1195 .smi_gone = ipmi_smi_gone 1196 }; 1197 1198 static int action_op(const char *inval, char *outval) 1199 { 1200 if (outval) 1201 strcpy(outval, action); 1202 1203 if (!inval) 1204 return 0; 1205 1206 if (strcmp(inval, "reset") == 0) 1207 action_val = WDOG_TIMEOUT_RESET; 1208 else if (strcmp(inval, "none") == 0) 1209 action_val = WDOG_TIMEOUT_NONE; 1210 else if (strcmp(inval, "power_cycle") == 0) 1211 action_val = WDOG_TIMEOUT_POWER_CYCLE; 1212 else if (strcmp(inval, "power_off") == 0) 1213 action_val = WDOG_TIMEOUT_POWER_DOWN; 1214 else 1215 return -EINVAL; 1216 strcpy(action, inval); 1217 return 0; 1218 } 1219 1220 static int preaction_op(const char *inval, char *outval) 1221 { 1222 if (outval) 1223 strcpy(outval, preaction); 1224 1225 if (!inval) 1226 return 0; 1227 1228 if (strcmp(inval, "pre_none") == 0) 1229 preaction_val = WDOG_PRETIMEOUT_NONE; 1230 else if (strcmp(inval, "pre_smi") == 0) 1231 preaction_val = WDOG_PRETIMEOUT_SMI; 1232 #ifdef HAVE_DIE_NMI 1233 else if (strcmp(inval, "pre_nmi") == 0) 1234 preaction_val = WDOG_PRETIMEOUT_NMI; 1235 #endif 1236 else if (strcmp(inval, "pre_int") == 0) 1237 preaction_val = WDOG_PRETIMEOUT_MSG_INT; 1238 else 1239 return -EINVAL; 1240 strcpy(preaction, inval); 1241 return 0; 1242 } 1243 1244 static int preop_op(const char *inval, char *outval) 1245 { 1246 if (outval) 1247 strcpy(outval, preop); 1248 1249 if (!inval) 1250 return 0; 1251 1252 if (strcmp(inval, "preop_none") == 0) 1253 preop_val = WDOG_PREOP_NONE; 1254 else if (strcmp(inval, "preop_panic") == 0) 1255 preop_val = WDOG_PREOP_PANIC; 1256 else if (strcmp(inval, "preop_give_data") == 0) 1257 preop_val = WDOG_PREOP_GIVE_DATA; 1258 else 1259 return -EINVAL; 1260 strcpy(preop, inval); 1261 return 0; 1262 } 1263 1264 static void check_parms(void) 1265 { 1266 #ifdef HAVE_DIE_NMI 1267 int do_nmi = 0; 1268 int rv; 1269 1270 if (preaction_val == WDOG_PRETIMEOUT_NMI) { 1271 do_nmi = 1; 1272 if (preop_val == WDOG_PREOP_GIVE_DATA) { 1273 printk(KERN_WARNING PFX "Pretimeout op is to give data" 1274 " but NMI pretimeout is enabled, setting" 1275 " pretimeout op to none\n"); 1276 preop_op("preop_none", NULL); 1277 do_nmi = 0; 1278 } 1279 } 1280 if (do_nmi && !nmi_handler_registered) { 1281 rv = register_nmi_handler(NMI_UNKNOWN, ipmi_nmi, 0, 1282 "ipmi"); 1283 if (rv) { 1284 printk(KERN_WARNING PFX 1285 "Can't register nmi handler\n"); 1286 return; 1287 } else 1288 nmi_handler_registered = 1; 1289 } else if (!do_nmi && nmi_handler_registered) { 1290 unregister_nmi_handler(NMI_UNKNOWN, "ipmi"); 1291 nmi_handler_registered = 0; 1292 } 1293 #endif 1294 } 1295 1296 static int __init ipmi_wdog_init(void) 1297 { 1298 int rv; 1299 1300 if (action_op(action, NULL)) { 1301 action_op("reset", NULL); 1302 printk(KERN_INFO PFX "Unknown action '%s', defaulting to" 1303 " reset\n", action); 1304 } 1305 1306 if (preaction_op(preaction, NULL)) { 1307 preaction_op("pre_none", NULL); 1308 printk(KERN_INFO PFX "Unknown preaction '%s', defaulting to" 1309 " none\n", preaction); 1310 } 1311 1312 if (preop_op(preop, NULL)) { 1313 preop_op("preop_none", NULL); 1314 printk(KERN_INFO PFX "Unknown preop '%s', defaulting to" 1315 " none\n", preop); 1316 } 1317 1318 check_parms(); 1319 1320 register_reboot_notifier(&wdog_reboot_notifier); 1321 atomic_notifier_chain_register(&panic_notifier_list, 1322 &wdog_panic_notifier); 1323 1324 rv = ipmi_smi_watcher_register(&smi_watcher); 1325 if (rv) { 1326 #ifdef HAVE_DIE_NMI 1327 if (nmi_handler_registered) 1328 unregister_nmi_handler(NMI_UNKNOWN, "ipmi"); 1329 #endif 1330 atomic_notifier_chain_unregister(&panic_notifier_list, 1331 &wdog_panic_notifier); 1332 unregister_reboot_notifier(&wdog_reboot_notifier); 1333 printk(KERN_WARNING PFX "can't register smi watcher\n"); 1334 return rv; 1335 } 1336 1337 printk(KERN_INFO PFX "driver initialized\n"); 1338 1339 return 0; 1340 } 1341 1342 static void __exit ipmi_wdog_exit(void) 1343 { 1344 ipmi_smi_watcher_unregister(&smi_watcher); 1345 ipmi_unregister_watchdog(watchdog_ifnum); 1346 1347 #ifdef HAVE_DIE_NMI 1348 if (nmi_handler_registered) 1349 unregister_nmi_handler(NMI_UNKNOWN, "ipmi"); 1350 #endif 1351 1352 atomic_notifier_chain_unregister(&panic_notifier_list, 1353 &wdog_panic_notifier); 1354 unregister_reboot_notifier(&wdog_reboot_notifier); 1355 } 1356 module_exit(ipmi_wdog_exit); 1357 module_init(ipmi_wdog_init); 1358 MODULE_LICENSE("GPL"); 1359 MODULE_AUTHOR("Corey Minyard <minyard@mvista.com>"); 1360 MODULE_DESCRIPTION("watchdog timer based upon the IPMI interface."); 1361