1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * ipmi_watchdog.c 4 * 5 * A watchdog timer based upon the IPMI interface. 6 * 7 * Author: MontaVista Software, Inc. 8 * Corey Minyard <minyard@mvista.com> 9 * source@mvista.com 10 * 11 * Copyright 2002 MontaVista Software Inc. 12 */ 13 14 #define pr_fmt(fmt) "IPMI Watchdog: " fmt 15 16 #include <linux/module.h> 17 #include <linux/moduleparam.h> 18 #include <linux/ipmi.h> 19 #include <linux/ipmi_smi.h> 20 #include <linux/mutex.h> 21 #include <linux/watchdog.h> 22 #include <linux/miscdevice.h> 23 #include <linux/init.h> 24 #include <linux/completion.h> 25 #include <linux/kdebug.h> 26 #include <linux/rwsem.h> 27 #include <linux/errno.h> 28 #include <linux/uaccess.h> 29 #include <linux/notifier.h> 30 #include <linux/nmi.h> 31 #include <linux/reboot.h> 32 #include <linux/wait.h> 33 #include <linux/poll.h> 34 #include <linux/string.h> 35 #include <linux/ctype.h> 36 #include <linux/delay.h> 37 #include <linux/atomic.h> 38 #include <linux/sched/signal.h> 39 40 #ifdef CONFIG_X86 41 /* 42 * This is ugly, but I've determined that x86 is the only architecture 43 * that can reasonably support the IPMI NMI watchdog timeout at this 44 * time. If another architecture adds this capability somehow, it 45 * will have to be a somewhat different mechanism and I have no idea 46 * how it will work. So in the unlikely event that another 47 * architecture supports this, we can figure out a good generic 48 * mechanism for it at that time. 49 */ 50 #include <asm/kdebug.h> 51 #include <asm/nmi.h> 52 #define HAVE_DIE_NMI 53 #endif 54 55 /* 56 * The IPMI command/response information for the watchdog timer. 57 */ 58 59 /* values for byte 1 of the set command, byte 2 of the get response. */ 60 #define WDOG_DONT_LOG (1 << 7) 61 #define WDOG_DONT_STOP_ON_SET (1 << 6) 62 #define WDOG_SET_TIMER_USE(byte, use) \ 63 byte = ((byte) & 0xf8) | ((use) & 0x7) 64 #define WDOG_GET_TIMER_USE(byte) ((byte) & 0x7) 65 #define WDOG_TIMER_USE_BIOS_FRB2 1 66 #define WDOG_TIMER_USE_BIOS_POST 2 67 #define WDOG_TIMER_USE_OS_LOAD 3 68 #define WDOG_TIMER_USE_SMS_OS 4 69 #define WDOG_TIMER_USE_OEM 5 70 71 /* values for byte 2 of the set command, byte 3 of the get response. */ 72 #define WDOG_SET_PRETIMEOUT_ACT(byte, use) \ 73 byte = ((byte) & 0x8f) | (((use) & 0x7) << 4) 74 #define WDOG_GET_PRETIMEOUT_ACT(byte) (((byte) >> 4) & 0x7) 75 #define WDOG_PRETIMEOUT_NONE 0 76 #define WDOG_PRETIMEOUT_SMI 1 77 #define WDOG_PRETIMEOUT_NMI 2 78 #define WDOG_PRETIMEOUT_MSG_INT 3 79 80 /* Operations that can be performed on a pretimout. */ 81 #define WDOG_PREOP_NONE 0 82 #define WDOG_PREOP_PANIC 1 83 /* Cause data to be available to read. Doesn't work in NMI mode. */ 84 #define WDOG_PREOP_GIVE_DATA 2 85 86 /* Actions to perform on a full timeout. */ 87 #define WDOG_SET_TIMEOUT_ACT(byte, use) \ 88 byte = ((byte) & 0xf8) | ((use) & 0x7) 89 #define WDOG_GET_TIMEOUT_ACT(byte) ((byte) & 0x7) 90 #define WDOG_TIMEOUT_NONE 0 91 #define WDOG_TIMEOUT_RESET 1 92 #define WDOG_TIMEOUT_POWER_DOWN 2 93 #define WDOG_TIMEOUT_POWER_CYCLE 3 94 95 /* 96 * Byte 3 of the get command, byte 4 of the get response is the 97 * pre-timeout in seconds. 98 */ 99 100 /* Bits for setting byte 4 of the set command, byte 5 of the get response. */ 101 #define WDOG_EXPIRE_CLEAR_BIOS_FRB2 (1 << 1) 102 #define WDOG_EXPIRE_CLEAR_BIOS_POST (1 << 2) 103 #define WDOG_EXPIRE_CLEAR_OS_LOAD (1 << 3) 104 #define WDOG_EXPIRE_CLEAR_SMS_OS (1 << 4) 105 #define WDOG_EXPIRE_CLEAR_OEM (1 << 5) 106 107 /* 108 * Setting/getting the watchdog timer value. This is for bytes 5 and 109 * 6 (the timeout time) of the set command, and bytes 6 and 7 (the 110 * timeout time) and 8 and 9 (the current countdown value) of the 111 * response. The timeout value is given in seconds (in the command it 112 * is 100ms intervals). 113 */ 114 #define WDOG_SET_TIMEOUT(byte1, byte2, val) \ 115 (byte1) = (((val) * 10) & 0xff), (byte2) = (((val) * 10) >> 8) 116 #define WDOG_GET_TIMEOUT(byte1, byte2) \ 117 (((byte1) | ((byte2) << 8)) / 10) 118 119 #define IPMI_WDOG_RESET_TIMER 0x22 120 #define IPMI_WDOG_SET_TIMER 0x24 121 #define IPMI_WDOG_GET_TIMER 0x25 122 123 #define IPMI_WDOG_TIMER_NOT_INIT_RESP 0x80 124 125 static DEFINE_MUTEX(ipmi_watchdog_mutex); 126 static bool nowayout = WATCHDOG_NOWAYOUT; 127 128 static struct ipmi_user *watchdog_user; 129 static int watchdog_ifnum; 130 131 /* Default the timeout to 10 seconds. */ 132 static int timeout = 10; 133 134 /* The pre-timeout is disabled by default. */ 135 static int pretimeout; 136 137 /* Default timeout to set on panic */ 138 static int panic_wdt_timeout = 255; 139 140 /* Default action is to reset the board on a timeout. */ 141 static unsigned char action_val = WDOG_TIMEOUT_RESET; 142 143 static char action[16] = "reset"; 144 145 static unsigned char preaction_val = WDOG_PRETIMEOUT_NONE; 146 147 static char preaction[16] = "pre_none"; 148 149 static unsigned char preop_val = WDOG_PREOP_NONE; 150 151 static char preop[16] = "preop_none"; 152 static DEFINE_SPINLOCK(ipmi_read_lock); 153 static char data_to_read; 154 static DECLARE_WAIT_QUEUE_HEAD(read_q); 155 static struct fasync_struct *fasync_q; 156 static atomic_t pretimeout_since_last_heartbeat; 157 static char expect_close; 158 159 static int ifnum_to_use = -1; 160 161 /* Parameters to ipmi_set_timeout */ 162 #define IPMI_SET_TIMEOUT_NO_HB 0 163 #define IPMI_SET_TIMEOUT_HB_IF_NECESSARY 1 164 #define IPMI_SET_TIMEOUT_FORCE_HB 2 165 166 static int ipmi_set_timeout(int do_heartbeat); 167 static void ipmi_register_watchdog(int ipmi_intf); 168 static void ipmi_unregister_watchdog(int ipmi_intf); 169 170 /* 171 * If true, the driver will start running as soon as it is configured 172 * and ready. 173 */ 174 static int start_now; 175 176 static int set_param_timeout(const char *val, const struct kernel_param *kp) 177 { 178 char *endp; 179 int l; 180 int rv = 0; 181 182 if (!val) 183 return -EINVAL; 184 l = simple_strtoul(val, &endp, 0); 185 if (endp == val) 186 return -EINVAL; 187 188 *((int *)kp->arg) = l; 189 if (watchdog_user) 190 rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY); 191 192 return rv; 193 } 194 195 static const struct kernel_param_ops param_ops_timeout = { 196 .set = set_param_timeout, 197 .get = param_get_int, 198 }; 199 #define param_check_timeout param_check_int 200 201 typedef int (*action_fn)(const char *intval, char *outval); 202 203 static int action_op(const char *inval, char *outval); 204 static int preaction_op(const char *inval, char *outval); 205 static int preop_op(const char *inval, char *outval); 206 static void check_parms(void); 207 208 static int set_param_str(const char *val, const struct kernel_param *kp) 209 { 210 action_fn fn = (action_fn) kp->arg; 211 int rv = 0; 212 char valcp[16]; 213 char *s; 214 215 strncpy(valcp, val, 15); 216 valcp[15] = '\0'; 217 218 s = strstrip(valcp); 219 220 rv = fn(s, NULL); 221 if (rv) 222 goto out; 223 224 check_parms(); 225 if (watchdog_user) 226 rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY); 227 228 out: 229 return rv; 230 } 231 232 static int get_param_str(char *buffer, const struct kernel_param *kp) 233 { 234 action_fn fn = (action_fn) kp->arg; 235 int rv, len; 236 237 rv = fn(NULL, buffer); 238 if (rv) 239 return rv; 240 241 len = strlen(buffer); 242 buffer[len++] = '\n'; 243 buffer[len] = 0; 244 245 return len; 246 } 247 248 249 static int set_param_wdog_ifnum(const char *val, const struct kernel_param *kp) 250 { 251 int rv = param_set_int(val, kp); 252 if (rv) 253 return rv; 254 if ((ifnum_to_use < 0) || (ifnum_to_use == watchdog_ifnum)) 255 return 0; 256 257 ipmi_unregister_watchdog(watchdog_ifnum); 258 ipmi_register_watchdog(ifnum_to_use); 259 return 0; 260 } 261 262 static const struct kernel_param_ops param_ops_wdog_ifnum = { 263 .set = set_param_wdog_ifnum, 264 .get = param_get_int, 265 }; 266 267 #define param_check_wdog_ifnum param_check_int 268 269 static const struct kernel_param_ops param_ops_str = { 270 .set = set_param_str, 271 .get = get_param_str, 272 }; 273 274 module_param(ifnum_to_use, wdog_ifnum, 0644); 275 MODULE_PARM_DESC(ifnum_to_use, "The interface number to use for the watchdog " 276 "timer. Setting to -1 defaults to the first registered " 277 "interface"); 278 279 module_param(timeout, timeout, 0644); 280 MODULE_PARM_DESC(timeout, "Timeout value in seconds."); 281 282 module_param(pretimeout, timeout, 0644); 283 MODULE_PARM_DESC(pretimeout, "Pretimeout value in seconds."); 284 285 module_param(panic_wdt_timeout, timeout, 0644); 286 MODULE_PARM_DESC(panic_wdt_timeout, "Timeout value on kernel panic in seconds."); 287 288 module_param_cb(action, ¶m_ops_str, action_op, 0644); 289 MODULE_PARM_DESC(action, "Timeout action. One of: " 290 "reset, none, power_cycle, power_off."); 291 292 module_param_cb(preaction, ¶m_ops_str, preaction_op, 0644); 293 MODULE_PARM_DESC(preaction, "Pretimeout action. One of: " 294 "pre_none, pre_smi, pre_nmi, pre_int."); 295 296 module_param_cb(preop, ¶m_ops_str, preop_op, 0644); 297 MODULE_PARM_DESC(preop, "Pretimeout driver operation. One of: " 298 "preop_none, preop_panic, preop_give_data."); 299 300 module_param(start_now, int, 0444); 301 MODULE_PARM_DESC(start_now, "Set to 1 to start the watchdog as" 302 "soon as the driver is loaded."); 303 304 module_param(nowayout, bool, 0644); 305 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started " 306 "(default=CONFIG_WATCHDOG_NOWAYOUT)"); 307 308 /* Default state of the timer. */ 309 static unsigned char ipmi_watchdog_state = WDOG_TIMEOUT_NONE; 310 311 /* Is someone using the watchdog? Only one user is allowed. */ 312 static unsigned long ipmi_wdog_open; 313 314 /* 315 * If set to 1, the heartbeat command will set the state to reset and 316 * start the timer. The timer doesn't normally run when the driver is 317 * first opened until the heartbeat is set the first time, this 318 * variable is used to accomplish this. 319 */ 320 static int ipmi_start_timer_on_heartbeat; 321 322 /* IPMI version of the BMC. */ 323 static unsigned char ipmi_version_major; 324 static unsigned char ipmi_version_minor; 325 326 /* If a pretimeout occurs, this is used to allow only one panic to happen. */ 327 static atomic_t preop_panic_excl = ATOMIC_INIT(-1); 328 329 #ifdef HAVE_DIE_NMI 330 static int testing_nmi; 331 static int nmi_handler_registered; 332 #endif 333 334 static int __ipmi_heartbeat(void); 335 336 /* 337 * We use a mutex to make sure that only one thing can send a set a 338 * message at one time. The mutex is claimed when a message is sent 339 * and freed when both the send and receive messages are free. 340 */ 341 static atomic_t msg_tofree = ATOMIC_INIT(0); 342 static DECLARE_COMPLETION(msg_wait); 343 static void msg_free_smi(struct ipmi_smi_msg *msg) 344 { 345 if (atomic_dec_and_test(&msg_tofree)) 346 complete(&msg_wait); 347 } 348 static void msg_free_recv(struct ipmi_recv_msg *msg) 349 { 350 if (atomic_dec_and_test(&msg_tofree)) 351 complete(&msg_wait); 352 } 353 static struct ipmi_smi_msg smi_msg = { 354 .done = msg_free_smi 355 }; 356 static struct ipmi_recv_msg recv_msg = { 357 .done = msg_free_recv 358 }; 359 360 static int __ipmi_set_timeout(struct ipmi_smi_msg *smi_msg, 361 struct ipmi_recv_msg *recv_msg, 362 int *send_heartbeat_now) 363 { 364 struct kernel_ipmi_msg msg; 365 unsigned char data[6]; 366 int rv; 367 struct ipmi_system_interface_addr addr; 368 int hbnow = 0; 369 370 371 data[0] = 0; 372 WDOG_SET_TIMER_USE(data[0], WDOG_TIMER_USE_SMS_OS); 373 374 if (ipmi_watchdog_state != WDOG_TIMEOUT_NONE) { 375 if ((ipmi_version_major > 1) || 376 ((ipmi_version_major == 1) && (ipmi_version_minor >= 5))) { 377 /* This is an IPMI 1.5-only feature. */ 378 data[0] |= WDOG_DONT_STOP_ON_SET; 379 } else { 380 /* 381 * In ipmi 1.0, setting the timer stops the watchdog, we 382 * need to start it back up again. 383 */ 384 hbnow = 1; 385 } 386 } 387 388 data[1] = 0; 389 WDOG_SET_TIMEOUT_ACT(data[1], ipmi_watchdog_state); 390 if ((pretimeout > 0) && (ipmi_watchdog_state != WDOG_TIMEOUT_NONE)) { 391 WDOG_SET_PRETIMEOUT_ACT(data[1], preaction_val); 392 data[2] = pretimeout; 393 } else { 394 WDOG_SET_PRETIMEOUT_ACT(data[1], WDOG_PRETIMEOUT_NONE); 395 data[2] = 0; /* No pretimeout. */ 396 } 397 data[3] = 0; 398 WDOG_SET_TIMEOUT(data[4], data[5], timeout); 399 400 addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE; 401 addr.channel = IPMI_BMC_CHANNEL; 402 addr.lun = 0; 403 404 msg.netfn = 0x06; 405 msg.cmd = IPMI_WDOG_SET_TIMER; 406 msg.data = data; 407 msg.data_len = sizeof(data); 408 rv = ipmi_request_supply_msgs(watchdog_user, 409 (struct ipmi_addr *) &addr, 410 0, 411 &msg, 412 NULL, 413 smi_msg, 414 recv_msg, 415 1); 416 if (rv) 417 pr_warn("set timeout error: %d\n", rv); 418 else if (send_heartbeat_now) 419 *send_heartbeat_now = hbnow; 420 421 return rv; 422 } 423 424 static int _ipmi_set_timeout(int do_heartbeat) 425 { 426 int send_heartbeat_now; 427 int rv; 428 429 if (!watchdog_user) 430 return -ENODEV; 431 432 atomic_set(&msg_tofree, 2); 433 434 rv = __ipmi_set_timeout(&smi_msg, 435 &recv_msg, 436 &send_heartbeat_now); 437 if (rv) 438 return rv; 439 440 wait_for_completion(&msg_wait); 441 442 if ((do_heartbeat == IPMI_SET_TIMEOUT_FORCE_HB) 443 || ((send_heartbeat_now) 444 && (do_heartbeat == IPMI_SET_TIMEOUT_HB_IF_NECESSARY))) 445 rv = __ipmi_heartbeat(); 446 447 return rv; 448 } 449 450 static int ipmi_set_timeout(int do_heartbeat) 451 { 452 int rv; 453 454 mutex_lock(&ipmi_watchdog_mutex); 455 rv = _ipmi_set_timeout(do_heartbeat); 456 mutex_unlock(&ipmi_watchdog_mutex); 457 458 return rv; 459 } 460 461 static atomic_t panic_done_count = ATOMIC_INIT(0); 462 463 static void panic_smi_free(struct ipmi_smi_msg *msg) 464 { 465 atomic_dec(&panic_done_count); 466 } 467 static void panic_recv_free(struct ipmi_recv_msg *msg) 468 { 469 atomic_dec(&panic_done_count); 470 } 471 472 static struct ipmi_smi_msg panic_halt_heartbeat_smi_msg = { 473 .done = panic_smi_free 474 }; 475 static struct ipmi_recv_msg panic_halt_heartbeat_recv_msg = { 476 .done = panic_recv_free 477 }; 478 479 static void panic_halt_ipmi_heartbeat(void) 480 { 481 struct kernel_ipmi_msg msg; 482 struct ipmi_system_interface_addr addr; 483 int rv; 484 485 /* 486 * Don't reset the timer if we have the timer turned off, that 487 * re-enables the watchdog. 488 */ 489 if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE) 490 return; 491 492 addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE; 493 addr.channel = IPMI_BMC_CHANNEL; 494 addr.lun = 0; 495 496 msg.netfn = 0x06; 497 msg.cmd = IPMI_WDOG_RESET_TIMER; 498 msg.data = NULL; 499 msg.data_len = 0; 500 atomic_inc(&panic_done_count); 501 rv = ipmi_request_supply_msgs(watchdog_user, 502 (struct ipmi_addr *) &addr, 503 0, 504 &msg, 505 NULL, 506 &panic_halt_heartbeat_smi_msg, 507 &panic_halt_heartbeat_recv_msg, 508 1); 509 if (rv) 510 atomic_dec(&panic_done_count); 511 } 512 513 static struct ipmi_smi_msg panic_halt_smi_msg = { 514 .done = panic_smi_free 515 }; 516 static struct ipmi_recv_msg panic_halt_recv_msg = { 517 .done = panic_recv_free 518 }; 519 520 /* 521 * Special call, doesn't claim any locks. This is only to be called 522 * at panic or halt time, in run-to-completion mode, when the caller 523 * is the only CPU and the only thing that will be going is these IPMI 524 * calls. 525 */ 526 static void panic_halt_ipmi_set_timeout(void) 527 { 528 int send_heartbeat_now; 529 int rv; 530 531 /* Wait for the messages to be free. */ 532 while (atomic_read(&panic_done_count) != 0) 533 ipmi_poll_interface(watchdog_user); 534 atomic_inc(&panic_done_count); 535 rv = __ipmi_set_timeout(&panic_halt_smi_msg, 536 &panic_halt_recv_msg, 537 &send_heartbeat_now); 538 if (rv) { 539 atomic_dec(&panic_done_count); 540 pr_warn("Unable to extend the watchdog timeout\n"); 541 } else { 542 if (send_heartbeat_now) 543 panic_halt_ipmi_heartbeat(); 544 } 545 while (atomic_read(&panic_done_count) != 0) 546 ipmi_poll_interface(watchdog_user); 547 } 548 549 static int __ipmi_heartbeat(void) 550 { 551 struct kernel_ipmi_msg msg; 552 int rv; 553 struct ipmi_system_interface_addr addr; 554 int timeout_retries = 0; 555 556 restart: 557 /* 558 * Don't reset the timer if we have the timer turned off, that 559 * re-enables the watchdog. 560 */ 561 if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE) 562 return 0; 563 564 atomic_set(&msg_tofree, 2); 565 566 addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE; 567 addr.channel = IPMI_BMC_CHANNEL; 568 addr.lun = 0; 569 570 msg.netfn = 0x06; 571 msg.cmd = IPMI_WDOG_RESET_TIMER; 572 msg.data = NULL; 573 msg.data_len = 0; 574 rv = ipmi_request_supply_msgs(watchdog_user, 575 (struct ipmi_addr *) &addr, 576 0, 577 &msg, 578 NULL, 579 &smi_msg, 580 &recv_msg, 581 1); 582 if (rv) { 583 pr_warn("heartbeat send failure: %d\n", rv); 584 return rv; 585 } 586 587 /* Wait for the heartbeat to be sent. */ 588 wait_for_completion(&msg_wait); 589 590 if (recv_msg.msg.data[0] == IPMI_WDOG_TIMER_NOT_INIT_RESP) { 591 timeout_retries++; 592 if (timeout_retries > 3) { 593 pr_err("Unable to restore the IPMI watchdog's settings, giving up\n"); 594 rv = -EIO; 595 goto out; 596 } 597 598 /* 599 * The timer was not initialized, that means the BMC was 600 * probably reset and lost the watchdog information. Attempt 601 * to restore the timer's info. Note that we still hold 602 * the heartbeat lock, to keep a heartbeat from happening 603 * in this process, so must say no heartbeat to avoid a 604 * deadlock on this mutex 605 */ 606 rv = _ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB); 607 if (rv) { 608 pr_err("Unable to send the command to set the watchdog's settings, giving up\n"); 609 goto out; 610 } 611 612 /* Might need a heartbeat send, go ahead and do it. */ 613 goto restart; 614 } else if (recv_msg.msg.data[0] != 0) { 615 /* 616 * Got an error in the heartbeat response. It was already 617 * reported in ipmi_wdog_msg_handler, but we should return 618 * an error here. 619 */ 620 rv = -EINVAL; 621 } 622 623 out: 624 return rv; 625 } 626 627 static int _ipmi_heartbeat(void) 628 { 629 int rv; 630 631 if (!watchdog_user) 632 return -ENODEV; 633 634 if (ipmi_start_timer_on_heartbeat) { 635 ipmi_start_timer_on_heartbeat = 0; 636 ipmi_watchdog_state = action_val; 637 rv = _ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB); 638 } else if (atomic_cmpxchg(&pretimeout_since_last_heartbeat, 1, 0)) { 639 /* 640 * A pretimeout occurred, make sure we set the timeout. 641 * We don't want to set the action, though, we want to 642 * leave that alone (thus it can't be combined with the 643 * above operation. 644 */ 645 rv = _ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY); 646 } else { 647 rv = __ipmi_heartbeat(); 648 } 649 650 return rv; 651 } 652 653 static int ipmi_heartbeat(void) 654 { 655 int rv; 656 657 mutex_lock(&ipmi_watchdog_mutex); 658 rv = _ipmi_heartbeat(); 659 mutex_unlock(&ipmi_watchdog_mutex); 660 661 return rv; 662 } 663 664 static struct watchdog_info ident = { 665 .options = 0, /* WDIOF_SETTIMEOUT, */ 666 .firmware_version = 1, 667 .identity = "IPMI" 668 }; 669 670 static int ipmi_ioctl(struct file *file, 671 unsigned int cmd, unsigned long arg) 672 { 673 void __user *argp = (void __user *)arg; 674 int i; 675 int val; 676 677 switch (cmd) { 678 case WDIOC_GETSUPPORT: 679 i = copy_to_user(argp, &ident, sizeof(ident)); 680 return i ? -EFAULT : 0; 681 682 case WDIOC_SETTIMEOUT: 683 i = copy_from_user(&val, argp, sizeof(int)); 684 if (i) 685 return -EFAULT; 686 timeout = val; 687 return _ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY); 688 689 case WDIOC_GETTIMEOUT: 690 i = copy_to_user(argp, &timeout, sizeof(timeout)); 691 if (i) 692 return -EFAULT; 693 return 0; 694 695 case WDIOC_SETPRETIMEOUT: 696 i = copy_from_user(&val, argp, sizeof(int)); 697 if (i) 698 return -EFAULT; 699 pretimeout = val; 700 return _ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY); 701 702 case WDIOC_GETPRETIMEOUT: 703 i = copy_to_user(argp, &pretimeout, sizeof(pretimeout)); 704 if (i) 705 return -EFAULT; 706 return 0; 707 708 case WDIOC_KEEPALIVE: 709 return _ipmi_heartbeat(); 710 711 case WDIOC_SETOPTIONS: 712 i = copy_from_user(&val, argp, sizeof(int)); 713 if (i) 714 return -EFAULT; 715 if (val & WDIOS_DISABLECARD) { 716 ipmi_watchdog_state = WDOG_TIMEOUT_NONE; 717 _ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB); 718 ipmi_start_timer_on_heartbeat = 0; 719 } 720 721 if (val & WDIOS_ENABLECARD) { 722 ipmi_watchdog_state = action_val; 723 _ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB); 724 } 725 return 0; 726 727 case WDIOC_GETSTATUS: 728 val = 0; 729 i = copy_to_user(argp, &val, sizeof(val)); 730 if (i) 731 return -EFAULT; 732 return 0; 733 734 default: 735 return -ENOIOCTLCMD; 736 } 737 } 738 739 static long ipmi_unlocked_ioctl(struct file *file, 740 unsigned int cmd, 741 unsigned long arg) 742 { 743 int ret; 744 745 mutex_lock(&ipmi_watchdog_mutex); 746 ret = ipmi_ioctl(file, cmd, arg); 747 mutex_unlock(&ipmi_watchdog_mutex); 748 749 return ret; 750 } 751 752 static ssize_t ipmi_write(struct file *file, 753 const char __user *buf, 754 size_t len, 755 loff_t *ppos) 756 { 757 int rv; 758 759 if (len) { 760 if (!nowayout) { 761 size_t i; 762 763 /* In case it was set long ago */ 764 expect_close = 0; 765 766 for (i = 0; i != len; i++) { 767 char c; 768 769 if (get_user(c, buf + i)) 770 return -EFAULT; 771 if (c == 'V') 772 expect_close = 42; 773 } 774 } 775 rv = ipmi_heartbeat(); 776 if (rv) 777 return rv; 778 } 779 return len; 780 } 781 782 static ssize_t ipmi_read(struct file *file, 783 char __user *buf, 784 size_t count, 785 loff_t *ppos) 786 { 787 int rv = 0; 788 wait_queue_entry_t wait; 789 790 if (count <= 0) 791 return 0; 792 793 /* 794 * Reading returns if the pretimeout has gone off, and it only does 795 * it once per pretimeout. 796 */ 797 spin_lock_irq(&ipmi_read_lock); 798 if (!data_to_read) { 799 if (file->f_flags & O_NONBLOCK) { 800 rv = -EAGAIN; 801 goto out; 802 } 803 804 init_waitqueue_entry(&wait, current); 805 add_wait_queue(&read_q, &wait); 806 while (!data_to_read) { 807 set_current_state(TASK_INTERRUPTIBLE); 808 spin_unlock_irq(&ipmi_read_lock); 809 schedule(); 810 spin_lock_irq(&ipmi_read_lock); 811 } 812 remove_wait_queue(&read_q, &wait); 813 814 if (signal_pending(current)) { 815 rv = -ERESTARTSYS; 816 goto out; 817 } 818 } 819 data_to_read = 0; 820 821 out: 822 spin_unlock_irq(&ipmi_read_lock); 823 824 if (rv == 0) { 825 if (copy_to_user(buf, &data_to_read, 1)) 826 rv = -EFAULT; 827 else 828 rv = 1; 829 } 830 831 return rv; 832 } 833 834 static int ipmi_open(struct inode *ino, struct file *filep) 835 { 836 switch (iminor(ino)) { 837 case WATCHDOG_MINOR: 838 if (test_and_set_bit(0, &ipmi_wdog_open)) 839 return -EBUSY; 840 841 842 /* 843 * Don't start the timer now, let it start on the 844 * first heartbeat. 845 */ 846 ipmi_start_timer_on_heartbeat = 1; 847 return stream_open(ino, filep); 848 849 default: 850 return (-ENODEV); 851 } 852 } 853 854 static __poll_t ipmi_poll(struct file *file, poll_table *wait) 855 { 856 __poll_t mask = 0; 857 858 poll_wait(file, &read_q, wait); 859 860 spin_lock_irq(&ipmi_read_lock); 861 if (data_to_read) 862 mask |= (EPOLLIN | EPOLLRDNORM); 863 spin_unlock_irq(&ipmi_read_lock); 864 865 return mask; 866 } 867 868 static int ipmi_fasync(int fd, struct file *file, int on) 869 { 870 int result; 871 872 result = fasync_helper(fd, file, on, &fasync_q); 873 874 return (result); 875 } 876 877 static int ipmi_close(struct inode *ino, struct file *filep) 878 { 879 if (iminor(ino) == WATCHDOG_MINOR) { 880 if (expect_close == 42) { 881 mutex_lock(&ipmi_watchdog_mutex); 882 ipmi_watchdog_state = WDOG_TIMEOUT_NONE; 883 _ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB); 884 mutex_unlock(&ipmi_watchdog_mutex); 885 } else { 886 pr_crit("Unexpected close, not stopping watchdog!\n"); 887 ipmi_heartbeat(); 888 } 889 clear_bit(0, &ipmi_wdog_open); 890 } 891 892 expect_close = 0; 893 894 return 0; 895 } 896 897 static const struct file_operations ipmi_wdog_fops = { 898 .owner = THIS_MODULE, 899 .read = ipmi_read, 900 .poll = ipmi_poll, 901 .write = ipmi_write, 902 .unlocked_ioctl = ipmi_unlocked_ioctl, 903 .compat_ioctl = compat_ptr_ioctl, 904 .open = ipmi_open, 905 .release = ipmi_close, 906 .fasync = ipmi_fasync, 907 .llseek = no_llseek, 908 }; 909 910 static struct miscdevice ipmi_wdog_miscdev = { 911 .minor = WATCHDOG_MINOR, 912 .name = "watchdog", 913 .fops = &ipmi_wdog_fops 914 }; 915 916 static void ipmi_wdog_msg_handler(struct ipmi_recv_msg *msg, 917 void *handler_data) 918 { 919 if (msg->msg.cmd == IPMI_WDOG_RESET_TIMER && 920 msg->msg.data[0] == IPMI_WDOG_TIMER_NOT_INIT_RESP) 921 pr_info("response: The IPMI controller appears to have been reset, will attempt to reinitialize the watchdog timer\n"); 922 else if (msg->msg.data[0] != 0) 923 pr_err("response: Error %x on cmd %x\n", 924 msg->msg.data[0], 925 msg->msg.cmd); 926 927 ipmi_free_recv_msg(msg); 928 } 929 930 static void ipmi_wdog_pretimeout_handler(void *handler_data) 931 { 932 if (preaction_val != WDOG_PRETIMEOUT_NONE) { 933 if (preop_val == WDOG_PREOP_PANIC) { 934 if (atomic_inc_and_test(&preop_panic_excl)) 935 panic("Watchdog pre-timeout"); 936 } else if (preop_val == WDOG_PREOP_GIVE_DATA) { 937 unsigned long flags; 938 939 spin_lock_irqsave(&ipmi_read_lock, flags); 940 data_to_read = 1; 941 wake_up_interruptible(&read_q); 942 kill_fasync(&fasync_q, SIGIO, POLL_IN); 943 spin_unlock_irqrestore(&ipmi_read_lock, flags); 944 } 945 } 946 947 /* 948 * On some machines, the heartbeat will give an error and not 949 * work unless we re-enable the timer. So do so. 950 */ 951 atomic_set(&pretimeout_since_last_heartbeat, 1); 952 } 953 954 static void ipmi_wdog_panic_handler(void *user_data) 955 { 956 static int panic_event_handled; 957 958 /* 959 * On a panic, if we have a panic timeout, make sure to extend 960 * the watchdog timer to a reasonable value to complete the 961 * panic, if the watchdog timer is running. Plus the 962 * pretimeout is meaningless at panic time. 963 */ 964 if (watchdog_user && !panic_event_handled && 965 ipmi_watchdog_state != WDOG_TIMEOUT_NONE) { 966 /* Make sure we do this only once. */ 967 panic_event_handled = 1; 968 969 timeout = panic_wdt_timeout; 970 pretimeout = 0; 971 panic_halt_ipmi_set_timeout(); 972 } 973 } 974 975 static const struct ipmi_user_hndl ipmi_hndlrs = { 976 .ipmi_recv_hndl = ipmi_wdog_msg_handler, 977 .ipmi_watchdog_pretimeout = ipmi_wdog_pretimeout_handler, 978 .ipmi_panic_handler = ipmi_wdog_panic_handler 979 }; 980 981 static void ipmi_register_watchdog(int ipmi_intf) 982 { 983 int rv = -EBUSY; 984 985 if (watchdog_user) 986 goto out; 987 988 if ((ifnum_to_use >= 0) && (ifnum_to_use != ipmi_intf)) 989 goto out; 990 991 watchdog_ifnum = ipmi_intf; 992 993 rv = ipmi_create_user(ipmi_intf, &ipmi_hndlrs, NULL, &watchdog_user); 994 if (rv < 0) { 995 pr_crit("Unable to register with ipmi\n"); 996 goto out; 997 } 998 999 rv = ipmi_get_version(watchdog_user, 1000 &ipmi_version_major, 1001 &ipmi_version_minor); 1002 if (rv) { 1003 pr_warn("Unable to get IPMI version, assuming 1.0\n"); 1004 ipmi_version_major = 1; 1005 ipmi_version_minor = 0; 1006 } 1007 1008 rv = misc_register(&ipmi_wdog_miscdev); 1009 if (rv < 0) { 1010 ipmi_destroy_user(watchdog_user); 1011 watchdog_user = NULL; 1012 pr_crit("Unable to register misc device\n"); 1013 } 1014 1015 #ifdef HAVE_DIE_NMI 1016 if (nmi_handler_registered) { 1017 int old_pretimeout = pretimeout; 1018 int old_timeout = timeout; 1019 int old_preop_val = preop_val; 1020 1021 /* 1022 * Set the pretimeout to go off in a second and give 1023 * ourselves plenty of time to stop the timer. 1024 */ 1025 ipmi_watchdog_state = WDOG_TIMEOUT_RESET; 1026 preop_val = WDOG_PREOP_NONE; /* Make sure nothing happens */ 1027 pretimeout = 99; 1028 timeout = 100; 1029 1030 testing_nmi = 1; 1031 1032 rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB); 1033 if (rv) { 1034 pr_warn("Error starting timer to test NMI: 0x%x. The NMI pretimeout will likely not work\n", 1035 rv); 1036 rv = 0; 1037 goto out_restore; 1038 } 1039 1040 msleep(1500); 1041 1042 if (testing_nmi != 2) { 1043 pr_warn("IPMI NMI didn't seem to occur. The NMI pretimeout will likely not work\n"); 1044 } 1045 out_restore: 1046 testing_nmi = 0; 1047 preop_val = old_preop_val; 1048 pretimeout = old_pretimeout; 1049 timeout = old_timeout; 1050 } 1051 #endif 1052 1053 out: 1054 if ((start_now) && (rv == 0)) { 1055 /* Run from startup, so start the timer now. */ 1056 start_now = 0; /* Disable this function after first startup. */ 1057 ipmi_watchdog_state = action_val; 1058 ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB); 1059 pr_info("Starting now!\n"); 1060 } else { 1061 /* Stop the timer now. */ 1062 ipmi_watchdog_state = WDOG_TIMEOUT_NONE; 1063 ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB); 1064 } 1065 } 1066 1067 static void ipmi_unregister_watchdog(int ipmi_intf) 1068 { 1069 int rv; 1070 struct ipmi_user *loc_user = watchdog_user; 1071 1072 if (!loc_user) 1073 return; 1074 1075 if (watchdog_ifnum != ipmi_intf) 1076 return; 1077 1078 /* Make sure no one can call us any more. */ 1079 misc_deregister(&ipmi_wdog_miscdev); 1080 1081 watchdog_user = NULL; 1082 1083 /* 1084 * Wait to make sure the message makes it out. The lower layer has 1085 * pointers to our buffers, we want to make sure they are done before 1086 * we release our memory. 1087 */ 1088 while (atomic_read(&msg_tofree)) 1089 msg_free_smi(NULL); 1090 1091 mutex_lock(&ipmi_watchdog_mutex); 1092 1093 /* Disconnect from IPMI. */ 1094 rv = ipmi_destroy_user(loc_user); 1095 if (rv) 1096 pr_warn("error unlinking from IPMI: %d\n", rv); 1097 1098 /* If it comes back, restart it properly. */ 1099 ipmi_start_timer_on_heartbeat = 1; 1100 1101 mutex_unlock(&ipmi_watchdog_mutex); 1102 } 1103 1104 #ifdef HAVE_DIE_NMI 1105 static int 1106 ipmi_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 atomic_set(&pretimeout_since_last_heartbeat, 1); 1136 if (atomic_inc_and_test(&preop_panic_excl)) 1137 nmi_panic(regs, "pre-timeout"); 1138 } 1139 1140 return NMI_HANDLED; 1141 } 1142 #endif 1143 1144 static 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 happen or 1160 reset if it hangs, but only if the watchdog 1161 timer was already running. */ 1162 if (timeout < 120) 1163 timeout = 120; 1164 pretimeout = 0; 1165 ipmi_watchdog_state = WDOG_TIMEOUT_RESET; 1166 ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB); 1167 } 1168 } 1169 return NOTIFY_OK; 1170 } 1171 1172 static struct notifier_block wdog_reboot_notifier = { 1173 .notifier_call = wdog_reboot_handler, 1174 .next = NULL, 1175 .priority = 0 1176 }; 1177 1178 static void ipmi_new_smi(int if_num, struct device *device) 1179 { 1180 ipmi_register_watchdog(if_num); 1181 } 1182 1183 static void ipmi_smi_gone(int if_num) 1184 { 1185 ipmi_unregister_watchdog(if_num); 1186 } 1187 1188 static struct ipmi_smi_watcher smi_watcher = { 1189 .owner = THIS_MODULE, 1190 .new_smi = ipmi_new_smi, 1191 .smi_gone = ipmi_smi_gone 1192 }; 1193 1194 static int action_op(const char *inval, char *outval) 1195 { 1196 if (outval) 1197 strcpy(outval, action); 1198 1199 if (!inval) 1200 return 0; 1201 1202 if (strcmp(inval, "reset") == 0) 1203 action_val = WDOG_TIMEOUT_RESET; 1204 else if (strcmp(inval, "none") == 0) 1205 action_val = WDOG_TIMEOUT_NONE; 1206 else if (strcmp(inval, "power_cycle") == 0) 1207 action_val = WDOG_TIMEOUT_POWER_CYCLE; 1208 else if (strcmp(inval, "power_off") == 0) 1209 action_val = WDOG_TIMEOUT_POWER_DOWN; 1210 else 1211 return -EINVAL; 1212 strcpy(action, inval); 1213 return 0; 1214 } 1215 1216 static int preaction_op(const char *inval, char *outval) 1217 { 1218 if (outval) 1219 strcpy(outval, preaction); 1220 1221 if (!inval) 1222 return 0; 1223 1224 if (strcmp(inval, "pre_none") == 0) 1225 preaction_val = WDOG_PRETIMEOUT_NONE; 1226 else if (strcmp(inval, "pre_smi") == 0) 1227 preaction_val = WDOG_PRETIMEOUT_SMI; 1228 #ifdef HAVE_DIE_NMI 1229 else if (strcmp(inval, "pre_nmi") == 0) 1230 preaction_val = WDOG_PRETIMEOUT_NMI; 1231 #endif 1232 else if (strcmp(inval, "pre_int") == 0) 1233 preaction_val = WDOG_PRETIMEOUT_MSG_INT; 1234 else 1235 return -EINVAL; 1236 strcpy(preaction, inval); 1237 return 0; 1238 } 1239 1240 static int preop_op(const char *inval, char *outval) 1241 { 1242 if (outval) 1243 strcpy(outval, preop); 1244 1245 if (!inval) 1246 return 0; 1247 1248 if (strcmp(inval, "preop_none") == 0) 1249 preop_val = WDOG_PREOP_NONE; 1250 else if (strcmp(inval, "preop_panic") == 0) 1251 preop_val = WDOG_PREOP_PANIC; 1252 else if (strcmp(inval, "preop_give_data") == 0) 1253 preop_val = WDOG_PREOP_GIVE_DATA; 1254 else 1255 return -EINVAL; 1256 strcpy(preop, inval); 1257 return 0; 1258 } 1259 1260 static void check_parms(void) 1261 { 1262 #ifdef HAVE_DIE_NMI 1263 int do_nmi = 0; 1264 int rv; 1265 1266 if (preaction_val == WDOG_PRETIMEOUT_NMI) { 1267 do_nmi = 1; 1268 if (preop_val == WDOG_PREOP_GIVE_DATA) { 1269 pr_warn("Pretimeout op is to give data but NMI pretimeout is enabled, setting pretimeout op to none\n"); 1270 preop_op("preop_none", NULL); 1271 do_nmi = 0; 1272 } 1273 } 1274 if (do_nmi && !nmi_handler_registered) { 1275 rv = register_nmi_handler(NMI_UNKNOWN, ipmi_nmi, 0, 1276 "ipmi"); 1277 if (rv) { 1278 pr_warn("Can't register nmi handler\n"); 1279 return; 1280 } else 1281 nmi_handler_registered = 1; 1282 } else if (!do_nmi && nmi_handler_registered) { 1283 unregister_nmi_handler(NMI_UNKNOWN, "ipmi"); 1284 nmi_handler_registered = 0; 1285 } 1286 #endif 1287 } 1288 1289 static int __init ipmi_wdog_init(void) 1290 { 1291 int rv; 1292 1293 if (action_op(action, NULL)) { 1294 action_op("reset", NULL); 1295 pr_info("Unknown action '%s', defaulting to reset\n", action); 1296 } 1297 1298 if (preaction_op(preaction, NULL)) { 1299 preaction_op("pre_none", NULL); 1300 pr_info("Unknown preaction '%s', defaulting to none\n", 1301 preaction); 1302 } 1303 1304 if (preop_op(preop, NULL)) { 1305 preop_op("preop_none", NULL); 1306 pr_info("Unknown preop '%s', defaulting to none\n", preop); 1307 } 1308 1309 check_parms(); 1310 1311 register_reboot_notifier(&wdog_reboot_notifier); 1312 1313 rv = ipmi_smi_watcher_register(&smi_watcher); 1314 if (rv) { 1315 #ifdef HAVE_DIE_NMI 1316 if (nmi_handler_registered) 1317 unregister_nmi_handler(NMI_UNKNOWN, "ipmi"); 1318 #endif 1319 unregister_reboot_notifier(&wdog_reboot_notifier); 1320 pr_warn("can't register smi watcher\n"); 1321 return rv; 1322 } 1323 1324 pr_info("driver initialized\n"); 1325 1326 return 0; 1327 } 1328 1329 static void __exit ipmi_wdog_exit(void) 1330 { 1331 ipmi_smi_watcher_unregister(&smi_watcher); 1332 ipmi_unregister_watchdog(watchdog_ifnum); 1333 1334 #ifdef HAVE_DIE_NMI 1335 if (nmi_handler_registered) 1336 unregister_nmi_handler(NMI_UNKNOWN, "ipmi"); 1337 #endif 1338 1339 unregister_reboot_notifier(&wdog_reboot_notifier); 1340 } 1341 module_exit(ipmi_wdog_exit); 1342 module_init(ipmi_wdog_init); 1343 MODULE_LICENSE("GPL"); 1344 MODULE_AUTHOR("Corey Minyard <minyard@mvista.com>"); 1345 MODULE_DESCRIPTION("watchdog timer based upon the IPMI interface."); 1346