drivers/char/ipmi/ipmi_watchdog.c

   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/kstrtox.h>
  27 #include <linux/rwsem.h>
  28 #include <linux/errno.h>
  29 #include <linux/uaccess.h>
  30 #include <linux/notifier.h>
  31 #include <linux/nmi.h>
  32 #include <linux/reboot.h>
  33 #include <linux/wait.h>
  34 #include <linux/poll.h>
  35 #include <linux/string.h>
  36 #include <linux/ctype.h>
  37 #include <linux/delay.h>
  38 #include <linux/atomic.h>
  39 #include <linux/sched/signal.h>
  40
  41 #ifdef CONFIG_X86
  42 /*
  43  * This is ugly, but I've determined that x86 is the only architecture
  44  * that can reasonably support the IPMI NMI watchdog timeout at this
  45  * time.  If another architecture adds this capability somehow, it
  46  * will have to be a somewhat different mechanism and I have no idea
  47  * how it will work.  So in the unlikely event that another
  48  * architecture supports this, we can figure out a good generic
  49  * mechanism for it at that time.
  50  */
  51 #include <asm/kdebug.h>
  52 #include <asm/nmi.h>
  53 #define HAVE_DIE_NMI
  54 #endif
  55
  56 /*
  57  * The IPMI command/response information for the watchdog timer.
  58  */
  59
  60 /* values for byte 1 of the set command, byte 2 of the get response. */
  61 #define WDOG_DONT_LOG           (1 << 7)
  62 #define WDOG_DONT_STOP_ON_SET   (1 << 6)
  63 #define WDOG_SET_TIMER_USE(byte, use) \
  64         byte = ((byte) & 0xf8) | ((use) & 0x7)
  65 #define WDOG_GET_TIMER_USE(byte) ((byte) & 0x7)
  66 #define WDOG_TIMER_USE_BIOS_FRB2        1
  67 #define WDOG_TIMER_USE_BIOS_POST        2
  68 #define WDOG_TIMER_USE_OS_LOAD          3
  69 #define WDOG_TIMER_USE_SMS_OS           4
  70 #define WDOG_TIMER_USE_OEM              5
  71
  72 /* values for byte 2 of the set command, byte 3 of the get response. */
  73 #define WDOG_SET_PRETIMEOUT_ACT(byte, use) \
  74         byte = ((byte) & 0x8f) | (((use) & 0x7) << 4)
  75 #define WDOG_GET_PRETIMEOUT_ACT(byte) (((byte) >> 4) & 0x7)
  76 #define WDOG_PRETIMEOUT_NONE            0
  77 #define WDOG_PRETIMEOUT_SMI             1
  78 #define WDOG_PRETIMEOUT_NMI             2
  79 #define WDOG_PRETIMEOUT_MSG_INT         3
  80
  81 /* Operations that can be performed on a pretimout. */
  82 #define WDOG_PREOP_NONE         0
  83 #define WDOG_PREOP_PANIC        1
  84 /* Cause data to be available to read.  Doesn't work in NMI mode. */
  85 #define WDOG_PREOP_GIVE_DATA    2
  86
  87 /* Actions to perform on a full timeout. */
  88 #define WDOG_SET_TIMEOUT_ACT(byte, use) \
  89         byte = ((byte) & 0xf8) | ((use) & 0x7)
  90 #define WDOG_GET_TIMEOUT_ACT(byte) ((byte) & 0x7)
  91 #define WDOG_TIMEOUT_NONE               0
  92 #define WDOG_TIMEOUT_RESET              1
  93 #define WDOG_TIMEOUT_POWER_DOWN         2
  94 #define WDOG_TIMEOUT_POWER_CYCLE        3
  95
  96 /*
  97  * Byte 3 of the get command, byte 4 of the get response is the
  98  * pre-timeout in seconds.
  99  */
 100
 101 /* Bits for setting byte 4 of the set command, byte 5 of the get response. */
 102 #define WDOG_EXPIRE_CLEAR_BIOS_FRB2     (1 << 1)
 103 #define WDOG_EXPIRE_CLEAR_BIOS_POST     (1 << 2)
 104 #define WDOG_EXPIRE_CLEAR_OS_LOAD       (1 << 3)
 105 #define WDOG_EXPIRE_CLEAR_SMS_OS        (1 << 4)
 106 #define WDOG_EXPIRE_CLEAR_OEM           (1 << 5)
 107
 108 /*
 109  * Setting/getting the watchdog timer value.  This is for bytes 5 and
 110  * 6 (the timeout time) of the set command, and bytes 6 and 7 (the
 111  * timeout time) and 8 and 9 (the current countdown value) of the
 112  * response.  The timeout value is given in seconds (in the command it
 113  * is 100ms intervals).
 114  */
 115 #define WDOG_SET_TIMEOUT(byte1, byte2, val) \
 116         (byte1) = (((val) * 10) & 0xff), (byte2) = (((val) * 10) >> 8)
 117 #define WDOG_GET_TIMEOUT(byte1, byte2) \
 118         (((byte1) | ((byte2) << 8)) / 10)
 119
 120 #define IPMI_WDOG_RESET_TIMER           0x22
 121 #define IPMI_WDOG_SET_TIMER             0x24
 122 #define IPMI_WDOG_GET_TIMER             0x25
 123
 124 #define IPMI_WDOG_TIMER_NOT_INIT_RESP   0x80
 125
 126 static DEFINE_MUTEX(ipmi_watchdog_mutex);
 127 static bool nowayout = WATCHDOG_NOWAYOUT;
 128
 129 static struct ipmi_user *watchdog_user;
 130 static int watchdog_ifnum;
 131
 132 /* Default the timeout to 10 seconds. */
 133 static int timeout = 10;
 134
 135 /* The pre-timeout is disabled by default. */
 136 static int pretimeout;
 137
 138 /* Default timeout to set on panic */
 139 static int panic_wdt_timeout = 255;
 140
 141 /* Default action is to reset the board on a timeout. */
 142 static unsigned char action_val = WDOG_TIMEOUT_RESET;
 143
 144 static char action[16] = "reset";
 145
 146 static unsigned char preaction_val = WDOG_PRETIMEOUT_NONE;
 147
 148 static char preaction[16] = "pre_none";
 149
 150 static unsigned char preop_val = WDOG_PREOP_NONE;
 151
 152 static char preop[16] = "preop_none";
 153 static DEFINE_SPINLOCK(ipmi_read_lock);
 154 static char data_to_read;
 155 static DECLARE_WAIT_QUEUE_HEAD(read_q);
 156 static struct fasync_struct *fasync_q;
 157 static atomic_t pretimeout_since_last_heartbeat;
 158 static char expect_close;
 159
 160 static int ifnum_to_use = -1;
 161
 162 /* Parameters to ipmi_set_timeout */
 163 #define IPMI_SET_TIMEOUT_NO_HB                  0
 164 #define IPMI_SET_TIMEOUT_HB_IF_NECESSARY        1
 165 #define IPMI_SET_TIMEOUT_FORCE_HB               2
 166
 167 static int ipmi_set_timeout(int do_heartbeat);
 168 static void ipmi_register_watchdog(int ipmi_intf);
 169 static void ipmi_unregister_watchdog(int ipmi_intf);
 170
 171 /*
 172  * If true, the driver will start running as soon as it is configured
 173  * and ready.
 174  */
 175 static int start_now;
 176
 177 static int set_param_timeout(const char *val, const struct kernel_param *kp)
 178 {
 179         char *endp;
 180         int  l;
 181         int  rv = 0;
 182
 183         if (!val)
 184                 return -EINVAL;
 185         l = simple_strtoul(val, &endp, 0);
 186         if (endp == val)
 187                 return -EINVAL;
 188
 189         *((int *)kp->arg) = l;
 190         if (watchdog_user)
 191                 rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
 192
 193         return rv;
 194 }
 195
 196 static const struct kernel_param_ops param_ops_timeout = {
 197         .set = set_param_timeout,
 198         .get = param_get_int,
 199 };
 200 #define param_check_timeout param_check_int
 201
 202 typedef int (*action_fn)(const char *intval, char *outval);
 203
 204 static int action_op(const char *inval, char *outval);
 205 static int preaction_op(const char *inval, char *outval);
 206 static int preop_op(const char *inval, char *outval);
 207 static void check_parms(void);
 208
 209 static int set_param_str(const char *val, const struct kernel_param *kp)
 210 {
 211         action_fn  fn = (action_fn) kp->arg;
 212         int        rv = 0;
 213         char       valcp[16];
 214         char       *s;
 215
 216         strscpy(valcp, val, 16);
 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, &param_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, &param_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, &param_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                 if (!oops_in_progress)
 347                         complete(&msg_wait);
 348         }
 349 }
 350 static void msg_free_recv(struct ipmi_recv_msg *msg)
 351 {
 352         if (atomic_dec_and_test(&msg_tofree)) {
 353                 if (!oops_in_progress)
 354                         complete(&msg_wait);
 355         }
 356 }
 357 static struct ipmi_smi_msg smi_msg = INIT_IPMI_SMI_MSG(msg_free_smi);
 358 static struct ipmi_recv_msg recv_msg = INIT_IPMI_RECV_MSG(msg_free_recv);
 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                 atomic_set(&msg_tofree, 0);
 439                 return rv;
 440         }
 441
 442         wait_for_completion(&msg_wait);
 443
 444         if ((do_heartbeat == IPMI_SET_TIMEOUT_FORCE_HB)
 445                 || ((send_heartbeat_now)
 446                     && (do_heartbeat == IPMI_SET_TIMEOUT_HB_IF_NECESSARY)))
 447                 rv = __ipmi_heartbeat();
 448
 449         return rv;
 450 }
 451
 452 static int ipmi_set_timeout(int do_heartbeat)
 453 {
 454         int rv;
 455
 456         mutex_lock(&ipmi_watchdog_mutex);
 457         rv = _ipmi_set_timeout(do_heartbeat);
 458         mutex_unlock(&ipmi_watchdog_mutex);
 459
 460         return rv;
 461 }
 462
 463 static atomic_t panic_done_count = ATOMIC_INIT(0);
 464
 465 static void panic_smi_free(struct ipmi_smi_msg *msg)
 466 {
 467         atomic_dec(&panic_done_count);
 468 }
 469 static void panic_recv_free(struct ipmi_recv_msg *msg)
 470 {
 471         atomic_dec(&panic_done_count);
 472 }
 473
 474 static struct ipmi_smi_msg panic_halt_heartbeat_smi_msg =
 475         INIT_IPMI_SMI_MSG(panic_smi_free);
 476 static struct ipmi_recv_msg panic_halt_heartbeat_recv_msg =
 477         INIT_IPMI_RECV_MSG(panic_recv_free);
 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_add(2, &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_sub(2, &panic_done_count);
 511 }
 512
 513 static struct ipmi_smi_msg panic_halt_smi_msg =
 514         INIT_IPMI_SMI_MSG(panic_smi_free);
 515 static struct ipmi_recv_msg panic_halt_recv_msg =
 516         INIT_IPMI_RECV_MSG(panic_recv_free);
 517
 518 /*
 519  * Special call, doesn't claim any locks.  This is only to be called
 520  * at panic or halt time, in run-to-completion mode, when the caller
 521  * is the only CPU and the only thing that will be going is these IPMI
 522  * calls.
 523  */
 524 static void panic_halt_ipmi_set_timeout(void)
 525 {
 526         int send_heartbeat_now;
 527         int rv;
 528
 529         /* Wait for the messages to be free. */
 530         while (atomic_read(&panic_done_count) != 0)
 531                 ipmi_poll_interface(watchdog_user);
 532         atomic_add(2, &panic_done_count);
 533         rv = __ipmi_set_timeout(&panic_halt_smi_msg,
 534                                 &panic_halt_recv_msg,
 535                                 &send_heartbeat_now);
 536         if (rv) {
 537                 atomic_sub(2, &panic_done_count);
 538                 pr_warn("Unable to extend the watchdog timeout\n");
 539         } else {
 540                 if (send_heartbeat_now)
 541                         panic_halt_ipmi_heartbeat();
 542         }
 543         while (atomic_read(&panic_done_count) != 0)
 544                 ipmi_poll_interface(watchdog_user);
 545 }
 546
 547 static int __ipmi_heartbeat(void)
 548 {
 549         struct kernel_ipmi_msg msg;
 550         int rv;
 551         struct ipmi_system_interface_addr addr;
 552         int timeout_retries = 0;
 553
 554 restart:
 555         /*
 556          * Don't reset the timer if we have the timer turned off, that
 557          * re-enables the watchdog.
 558          */
 559         if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE)
 560                 return 0;
 561
 562         atomic_set(&msg_tofree, 2);
 563
 564         addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
 565         addr.channel = IPMI_BMC_CHANNEL;
 566         addr.lun = 0;
 567
 568         msg.netfn = 0x06;
 569         msg.cmd = IPMI_WDOG_RESET_TIMER;
 570         msg.data = NULL;
 571         msg.data_len = 0;
 572         rv = ipmi_request_supply_msgs(watchdog_user,
 573                                       (struct ipmi_addr *) &addr,
 574                                       0,
 575                                       &msg,
 576                                       NULL,
 577                                       &smi_msg,
 578                                       &recv_msg,
 579                                       1);
 580         if (rv) {
 581                 atomic_set(&msg_tofree, 0);
 582                 pr_warn("heartbeat send failure: %d\n", rv);
 583                 return rv;
 584         }
 585
 586         /* Wait for the heartbeat to be sent. */
 587         wait_for_completion(&msg_wait);
 588
 589         if (recv_msg.msg.data[0] == IPMI_WDOG_TIMER_NOT_INIT_RESP)  {
 590                 timeout_retries++;
 591                 if (timeout_retries > 3) {
 592                         pr_err("Unable to restore the IPMI watchdog's settings, giving up\n");
 593                         rv = -EIO;
 594                         goto out;
 595                 }
 596
 597                 /*
 598                  * The timer was not initialized, that means the BMC was
 599                  * probably reset and lost the watchdog information.  Attempt
 600                  * to restore the timer's info.  Note that we still hold
 601                  * the heartbeat lock, to keep a heartbeat from happening
 602                  * in this process, so must say no heartbeat to avoid a
 603                  * deadlock on this mutex
 604                  */
 605                 rv = _ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB);
 606                 if (rv) {
 607                         pr_err("Unable to send the command to set the watchdog's settings, giving up\n");
 608                         goto out;
 609                 }
 610
 611                 /* Might need a heartbeat send, go ahead and do it. */
 612                 goto restart;
 613         } else if (recv_msg.msg.data[0] != 0) {
 614                 /*
 615                  * Got an error in the heartbeat response.  It was already
 616                  * reported in ipmi_wdog_msg_handler, but we should return
 617                  * an error here.
 618                  */
 619                 rv = -EINVAL;
 620         }
 621
 622 out:
 623         return rv;
 624 }
 625
 626 static int _ipmi_heartbeat(void)
 627 {
 628         int rv;
 629
 630         if (!watchdog_user)
 631                 return -ENODEV;
 632
 633         if (ipmi_start_timer_on_heartbeat) {
 634                 ipmi_start_timer_on_heartbeat = 0;
 635                 ipmi_watchdog_state = action_val;
 636                 rv = _ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB);
 637         } else if (atomic_cmpxchg(&pretimeout_since_last_heartbeat, 1, 0)) {
 638                 /*
 639                  * A pretimeout occurred, make sure we set the timeout.
 640                  * We don't want to set the action, though, we want to
 641                  * leave that alone (thus it can't be combined with the
 642                  * above operation.
 643                  */
 644                 rv = _ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
 645         } else {
 646                 rv = __ipmi_heartbeat();
 647         }
 648
 649         return rv;
 650 }
 651
 652 static int ipmi_heartbeat(void)
 653 {
 654         int rv;
 655
 656         mutex_lock(&ipmi_watchdog_mutex);
 657         rv = _ipmi_heartbeat();
 658         mutex_unlock(&ipmi_watchdog_mutex);
 659
 660         return rv;
 661 }
 662
 663 static const struct watchdog_info ident = {
 664         .options        = 0,    /* WDIOF_SETTIMEOUT, */
 665         .firmware_version = 1,
 666         .identity       = "IPMI"
 667 };
 668
 669 static int ipmi_ioctl(struct file *file,
 670                       unsigned int cmd, unsigned long arg)
 671 {
 672         void __user *argp = (void __user *)arg;
 673         int i;
 674         int val;
 675
 676         switch (cmd) {
 677         case WDIOC_GETSUPPORT:
 678                 i = copy_to_user(argp, &ident, sizeof(ident));
 679                 return i ? -EFAULT : 0;
 680
 681         case WDIOC_SETTIMEOUT:
 682                 i = copy_from_user(&val, argp, sizeof(int));
 683                 if (i)
 684                         return -EFAULT;
 685                 timeout = val;
 686                 return _ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
 687
 688         case WDIOC_GETTIMEOUT:
 689                 i = copy_to_user(argp, &timeout, sizeof(timeout));
 690                 if (i)
 691                         return -EFAULT;
 692                 return 0;
 693
 694         case WDIOC_SETPRETIMEOUT:
 695                 i = copy_from_user(&val, argp, sizeof(int));
 696                 if (i)
 697                         return -EFAULT;
 698                 pretimeout = val;
 699                 return _ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
 700
 701         case WDIOC_GETPRETIMEOUT:
 702                 i = copy_to_user(argp, &pretimeout, sizeof(pretimeout));
 703                 if (i)
 704                         return -EFAULT;
 705                 return 0;
 706
 707         case WDIOC_KEEPALIVE:
 708                 return _ipmi_heartbeat();
 709
 710         case WDIOC_SETOPTIONS:
 711                 i = copy_from_user(&val, argp, sizeof(int));
 712                 if (i)
 713                         return -EFAULT;
 714                 if (val & WDIOS_DISABLECARD) {
 715                         ipmi_watchdog_state = WDOG_TIMEOUT_NONE;
 716                         _ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB);
 717                         ipmi_start_timer_on_heartbeat = 0;
 718                 }
 719
 720                 if (val & WDIOS_ENABLECARD) {
 721                         ipmi_watchdog_state = action_val;
 722                         _ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB);
 723                 }
 724                 return 0;
 725
 726         case WDIOC_GETSTATUS:
 727                 val = 0;
 728                 i = copy_to_user(argp, &val, sizeof(val));
 729                 if (i)
 730                         return -EFAULT;
 731                 return 0;
 732
 733         default:
 734                 return -ENOIOCTLCMD;
 735         }
 736 }
 737
 738 static long ipmi_unlocked_ioctl(struct file *file,
 739                                 unsigned int cmd,
 740                                 unsigned long arg)
 741 {
 742         int ret;
 743
 744         mutex_lock(&ipmi_watchdog_mutex);
 745         ret = ipmi_ioctl(file, cmd, arg);
 746         mutex_unlock(&ipmi_watchdog_mutex);
 747
 748         return ret;
 749 }
 750
 751 static ssize_t ipmi_write(struct file *file,
 752                           const char  __user *buf,
 753                           size_t      len,
 754                           loff_t      *ppos)
 755 {
 756         int rv;
 757
 758         if (len) {
 759                 if (!nowayout) {
 760                         size_t i;
 761
 762                         /* In case it was set long ago */
 763                         expect_close = 0;
 764
 765                         for (i = 0; i != len; i++) {
 766                                 char c;
 767
 768                                 if (get_user(c, buf + i))
 769                                         return -EFAULT;
 770                                 if (c == 'V')
 771                                         expect_close = 42;
 772                         }
 773                 }
 774                 rv = ipmi_heartbeat();
 775                 if (rv)
 776                         return rv;
 777         }
 778         return len;
 779 }
 780
 781 static ssize_t ipmi_read(struct file *file,
 782                          char        __user *buf,
 783                          size_t      count,
 784                          loff_t      *ppos)
 785 {
 786         int          rv = 0;
 787         wait_queue_entry_t wait;
 788
 789         if (count <= 0)
 790                 return 0;
 791
 792         /*
 793          * Reading returns if the pretimeout has gone off, and it only does
 794          * it once per pretimeout.
 795          */
 796         spin_lock_irq(&ipmi_read_lock);
 797         if (!data_to_read) {
 798                 if (file->f_flags & O_NONBLOCK) {
 799                         rv = -EAGAIN;
 800                         goto out;
 801                 }
 802
 803                 init_waitqueue_entry(&wait, current);
 804                 add_wait_queue(&read_q, &wait);
 805                 while (!data_to_read && !signal_pending(current)) {
 806                         set_current_state(TASK_INTERRUPTIBLE);
 807                         spin_unlock_irq(&ipmi_read_lock);
 808                         schedule();
 809                         spin_lock_irq(&ipmi_read_lock);
 810                 }
 811                 remove_wait_queue(&read_q, &wait);
 812
 813                 if (signal_pending(current)) {
 814                         rv = -ERESTARTSYS;
 815                         goto out;
 816                 }
 817         }
 818         data_to_read = 0;
 819
 820  out:
 821         spin_unlock_irq(&ipmi_read_lock);
 822
 823         if (rv == 0) {
 824                 if (copy_to_user(buf, &data_to_read, 1))
 825                         rv = -EFAULT;
 826                 else
 827                         rv = 1;
 828         }
 829
 830         return rv;
 831 }
 832
 833 static int ipmi_open(struct inode *ino, struct file *filep)
 834 {
 835         switch (iminor(ino)) {
 836         case WATCHDOG_MINOR:
 837                 if (test_and_set_bit(0, &ipmi_wdog_open))
 838                         return -EBUSY;
 839
 840
 841                 /*
 842                  * Don't start the timer now, let it start on the
 843                  * first heartbeat.
 844                  */
 845                 ipmi_start_timer_on_heartbeat = 1;
 846                 return stream_open(ino, filep);
 847
 848         default:
 849                 return (-ENODEV);
 850         }
 851 }
 852
 853 static __poll_t ipmi_poll(struct file *file, poll_table *wait)
 854 {
 855         __poll_t mask = 0;
 856
 857         poll_wait(file, &read_q, wait);
 858
 859         spin_lock_irq(&ipmi_read_lock);
 860         if (data_to_read)
 861                 mask |= (EPOLLIN | EPOLLRDNORM);
 862         spin_unlock_irq(&ipmi_read_lock);
 863
 864         return mask;
 865 }
 866
 867 static int ipmi_fasync(int fd, struct file *file, int on)
 868 {
 869         int result;
 870
 871         result = fasync_helper(fd, file, on, &fasync_q);
 872
 873         return (result);
 874 }
 875
 876 static int ipmi_close(struct inode *ino, struct file *filep)
 877 {
 878         if (iminor(ino) == WATCHDOG_MINOR) {
 879                 if (expect_close == 42) {
 880                         mutex_lock(&ipmi_watchdog_mutex);
 881                         ipmi_watchdog_state = WDOG_TIMEOUT_NONE;
 882                         _ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB);
 883                         mutex_unlock(&ipmi_watchdog_mutex);
 884                 } else {
 885                         pr_crit("Unexpected close, not stopping watchdog!\n");
 886                         ipmi_heartbeat();
 887                 }
 888                 clear_bit(0, &ipmi_wdog_open);
 889         }
 890
 891         expect_close = 0;
 892
 893         return 0;
 894 }
 895
 896 static const struct file_operations ipmi_wdog_fops = {
 897         .owner   = THIS_MODULE,
 898         .read    = ipmi_read,
 899         .poll    = ipmi_poll,
 900         .write   = ipmi_write,
 901         .unlocked_ioctl = ipmi_unlocked_ioctl,
 902         .compat_ioctl   = compat_ptr_ioctl,
 903         .open    = ipmi_open,
 904         .release = ipmi_close,
 905         .fasync  = ipmi_fasync,
 906         .llseek  = no_llseek,
 907 };
 908
 909 static struct miscdevice ipmi_wdog_miscdev = {
 910         .minor          = WATCHDOG_MINOR,
 911         .name           = "watchdog",
 912         .fops           = &ipmi_wdog_fops
 913 };
 914
 915 static void ipmi_wdog_msg_handler(struct ipmi_recv_msg *msg,
 916                                   void                 *handler_data)
 917 {
 918         if (msg->msg.cmd == IPMI_WDOG_RESET_TIMER &&
 919                         msg->msg.data[0] == IPMI_WDOG_TIMER_NOT_INIT_RESP)
 920                 pr_info("response: The IPMI controller appears to have been reset, will attempt to reinitialize the watchdog timer\n");
 921         else if (msg->msg.data[0] != 0)
 922                 pr_err("response: Error %x on cmd %x\n",
 923                        msg->msg.data[0],
 924                        msg->msg.cmd);
 925
 926         ipmi_free_recv_msg(msg);
 927 }
 928
 929 static void ipmi_wdog_pretimeout_handler(void *handler_data)
 930 {
 931         if (preaction_val != WDOG_PRETIMEOUT_NONE) {
 932                 if (preop_val == WDOG_PREOP_PANIC) {
 933                         if (atomic_inc_and_test(&preop_panic_excl))
 934                                 panic("Watchdog pre-timeout");
 935                 } else if (preop_val == WDOG_PREOP_GIVE_DATA) {
 936                         unsigned long flags;
 937
 938                         spin_lock_irqsave(&ipmi_read_lock, flags);
 939                         data_to_read = 1;
 940                         wake_up_interruptible(&read_q);
 941                         kill_fasync(&fasync_q, SIGIO, POLL_IN);
 942                         spin_unlock_irqrestore(&ipmi_read_lock, flags);
 943                 }
 944         }
 945
 946         /*
 947          * On some machines, the heartbeat will give an error and not
 948          * work unless we re-enable the timer.  So do so.
 949          */
 950         atomic_set(&pretimeout_since_last_heartbeat, 1);
 951 }
 952
 953 static void ipmi_wdog_panic_handler(void *user_data)
 954 {
 955         static int panic_event_handled;
 956
 957         /*
 958          * On a panic, if we have a panic timeout, make sure to extend
 959          * the watchdog timer to a reasonable value to complete the
 960          * panic, if the watchdog timer is running.  Plus the
 961          * pretimeout is meaningless at panic time.
 962          */
 963         if (watchdog_user && !panic_event_handled &&
 964             ipmi_watchdog_state != WDOG_TIMEOUT_NONE) {
 965                 /* Make sure we do this only once. */
 966                 panic_event_handled = 1;
 967
 968                 timeout = panic_wdt_timeout;
 969                 pretimeout = 0;
 970                 panic_halt_ipmi_set_timeout();
 971         }
 972 }
 973
 974 static const struct ipmi_user_hndl ipmi_hndlrs = {
 975         .ipmi_recv_hndl           = ipmi_wdog_msg_handler,
 976         .ipmi_watchdog_pretimeout = ipmi_wdog_pretimeout_handler,
 977         .ipmi_panic_handler       = ipmi_wdog_panic_handler
 978 };
 979
 980 static void ipmi_register_watchdog(int ipmi_intf)
 981 {
 982         int rv = -EBUSY;
 983
 984         if (watchdog_user)
 985                 goto out;
 986
 987         if ((ifnum_to_use >= 0) && (ifnum_to_use != ipmi_intf))
 988                 goto out;
 989
 990         watchdog_ifnum = ipmi_intf;
 991
 992         rv = ipmi_create_user(ipmi_intf, &ipmi_hndlrs, NULL, &watchdog_user);
 993         if (rv < 0) {
 994                 pr_crit("Unable to register with ipmi\n");
 995                 goto out;
 996         }
 997
 998         rv = ipmi_get_version(watchdog_user,
 999                               &ipmi_version_major,
1000                               &ipmi_version_minor);
1001         if (rv) {
1002                 pr_warn("Unable to get IPMI version, assuming 1.0\n");
1003                 ipmi_version_major = 1;
1004                 ipmi_version_minor = 0;
1005         }
1006
1007         rv = misc_register(&ipmi_wdog_miscdev);
1008         if (rv < 0) {
1009                 ipmi_destroy_user(watchdog_user);
1010                 watchdog_user = NULL;
1011                 pr_crit("Unable to register misc device\n");
1012         }
1013
1014 #ifdef HAVE_DIE_NMI
1015         if (nmi_handler_registered) {
1016                 int old_pretimeout = pretimeout;
1017                 int old_timeout = timeout;
1018                 int old_preop_val = preop_val;
1019
1020                 /*
1021                  * Set the pretimeout to go off in a second and give
1022                  * ourselves plenty of time to stop the timer.
1023                  */
1024                 ipmi_watchdog_state = WDOG_TIMEOUT_RESET;
1025                 preop_val = WDOG_PREOP_NONE; /* Make sure nothing happens */
1026                 pretimeout = 99;
1027                 timeout = 100;
1028
1029                 testing_nmi = 1;
1030
1031                 rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB);
1032                 if (rv) {
1033                         pr_warn("Error starting timer to test NMI: 0x%x.  The NMI pretimeout will likely not work\n",
1034                                 rv);
1035                         rv = 0;
1036                         goto out_restore;
1037                 }
1038
1039                 msleep(1500);
1040
1041                 if (testing_nmi != 2) {
1042                         pr_warn("IPMI NMI didn't seem to occur.  The NMI pretimeout will likely not work\n");
1043                 }
1044  out_restore:
1045                 testing_nmi = 0;
1046                 preop_val = old_preop_val;
1047                 pretimeout = old_pretimeout;
1048                 timeout = old_timeout;
1049         }
1050 #endif
1051
1052  out:
1053         if ((start_now) && (rv == 0)) {
1054                 /* Run from startup, so start the timer now. */
1055                 start_now = 0; /* Disable this function after first startup. */
1056                 ipmi_watchdog_state = action_val;
1057                 ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB);
1058                 pr_info("Starting now!\n");
1059         } else {
1060                 /* Stop the timer now. */
1061                 ipmi_watchdog_state = WDOG_TIMEOUT_NONE;
1062                 ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB);
1063         }
1064 }
1065
1066 static void ipmi_unregister_watchdog(int ipmi_intf)
1067 {
1068         int rv;
1069         struct ipmi_user *loc_user = watchdog_user;
1070
1071         if (!loc_user)
1072                 return;
1073
1074         if (watchdog_ifnum != ipmi_intf)
1075                 return;
1076
1077         /* Make sure no one can call us any more. */
1078         misc_deregister(&ipmi_wdog_miscdev);
1079
1080         watchdog_user = NULL;
1081
1082         /*
1083          * Wait to make sure the message makes it out.  The lower layer has
1084          * pointers to our buffers, we want to make sure they are done before
1085          * we release our memory.
1086          */
1087         while (atomic_read(&msg_tofree))
1088                 msg_free_smi(NULL);
1089
1090         mutex_lock(&ipmi_watchdog_mutex);
1091
1092         /* Disconnect from IPMI. */
1093         rv = ipmi_destroy_user(loc_user);
1094         if (rv)
1095                 pr_warn("error unlinking from IPMI: %d\n",  rv);
1096
1097         /* If it comes back, restart it properly. */
1098         ipmi_start_timer_on_heartbeat = 1;
1099
1100         mutex_unlock(&ipmi_watchdog_mutex);
1101 }
1102
1103 #ifdef HAVE_DIE_NMI
1104 static int
1105 ipmi_nmi(unsigned int val, struct pt_regs *regs)
1106 {
1107         /*
1108          * If we get here, it's an NMI that's not a memory or I/O
1109          * error.  We can't truly tell if it's from IPMI or not
1110          * without sending a message, and sending a message is almost
1111          * impossible because of locking.
1112          */
1113
1114         if (testing_nmi) {
1115                 testing_nmi = 2;
1116                 return NMI_HANDLED;
1117         }
1118
1119         /* If we are not expecting a timeout, ignore it. */
1120         if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE)
1121                 return NMI_DONE;
1122
1123         if (preaction_val != WDOG_PRETIMEOUT_NMI)
1124                 return NMI_DONE;
1125
1126         /*
1127          * If no one else handled the NMI, we assume it was the IPMI
1128          * watchdog.
1129          */
1130         if (preop_val == WDOG_PREOP_PANIC) {
1131                 /* On some machines, the heartbeat will give
1132                    an error and not work unless we re-enable
1133                    the timer.   So do so. */
1134                 atomic_set(&pretimeout_since_last_heartbeat, 1);
1135                 if (atomic_inc_and_test(&preop_panic_excl))
1136                         nmi_panic(regs, "pre-timeout");
1137         }
1138
1139         return NMI_HANDLED;
1140 }
1141 #endif
1142
1143 static int wdog_reboot_handler(struct notifier_block *this,
1144                                unsigned long         code,
1145                                void                  *unused)
1146 {
1147         static int reboot_event_handled;
1148
1149         if ((watchdog_user) && (!reboot_event_handled)) {
1150                 /* Make sure we only do this once. */
1151                 reboot_event_handled = 1;
1152
1153                 if (code == SYS_POWER_OFF || code == SYS_HALT) {
1154                         /* Disable the WDT if we are shutting down. */
1155                         ipmi_watchdog_state = WDOG_TIMEOUT_NONE;
1156                         ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB);
1157                 } else if (ipmi_watchdog_state != WDOG_TIMEOUT_NONE) {
1158                         /* Set a long timer to let the reboot happen or
1159                            reset if it hangs, but only if the watchdog
1160                            timer was already running. */
1161                         if (timeout < 120)
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
1171 static struct notifier_block wdog_reboot_notifier = {
1172         .notifier_call  = wdog_reboot_handler,
1173         .next           = NULL,
1174         .priority       = 0
1175 };
1176
1177 static void ipmi_new_smi(int if_num, struct device *device)
1178 {
1179         ipmi_register_watchdog(if_num);
1180 }
1181
1182 static void ipmi_smi_gone(int if_num)
1183 {
1184         ipmi_unregister_watchdog(if_num);
1185 }
1186
1187 static struct ipmi_smi_watcher smi_watcher = {
1188         .owner    = THIS_MODULE,
1189         .new_smi  = ipmi_new_smi,
1190         .smi_gone = ipmi_smi_gone
1191 };
1192
1193 static int action_op(const char *inval, char *outval)
1194 {
1195         if (outval)
1196                 strcpy(outval, action);
1197
1198         if (!inval)
1199                 return 0;
1200
1201         if (strcmp(inval, "reset") == 0)
1202                 action_val = WDOG_TIMEOUT_RESET;
1203         else if (strcmp(inval, "none") == 0)
1204                 action_val = WDOG_TIMEOUT_NONE;
1205         else if (strcmp(inval, "power_cycle") == 0)
1206                 action_val = WDOG_TIMEOUT_POWER_CYCLE;
1207         else if (strcmp(inval, "power_off") == 0)
1208                 action_val = WDOG_TIMEOUT_POWER_DOWN;
1209         else
1210                 return -EINVAL;
1211         strcpy(action, inval);
1212         return 0;
1213 }
1214
1215 static int preaction_op(const char *inval, char *outval)
1216 {
1217         if (outval)
1218                 strcpy(outval, preaction);
1219
1220         if (!inval)
1221                 return 0;
1222
1223         if (strcmp(inval, "pre_none") == 0)
1224                 preaction_val = WDOG_PRETIMEOUT_NONE;
1225         else if (strcmp(inval, "pre_smi") == 0)
1226                 preaction_val = WDOG_PRETIMEOUT_SMI;
1227 #ifdef HAVE_DIE_NMI
1228         else if (strcmp(inval, "pre_nmi") == 0)
1229                 preaction_val = WDOG_PRETIMEOUT_NMI;
1230 #endif
1231         else if (strcmp(inval, "pre_int") == 0)
1232                 preaction_val = WDOG_PRETIMEOUT_MSG_INT;
1233         else
1234                 return -EINVAL;
1235         strcpy(preaction, inval);
1236         return 0;
1237 }
1238
1239 static int preop_op(const char *inval, char *outval)
1240 {
1241         if (outval)
1242                 strcpy(outval, preop);
1243
1244         if (!inval)
1245                 return 0;
1246
1247         if (strcmp(inval, "preop_none") == 0)
1248                 preop_val = WDOG_PREOP_NONE;
1249         else if (strcmp(inval, "preop_panic") == 0)
1250                 preop_val = WDOG_PREOP_PANIC;
1251         else if (strcmp(inval, "preop_give_data") == 0)
1252                 preop_val = WDOG_PREOP_GIVE_DATA;
1253         else
1254                 return -EINVAL;
1255         strcpy(preop, inval);
1256         return 0;
1257 }
1258
1259 static void check_parms(void)
1260 {
1261 #ifdef HAVE_DIE_NMI
1262         int do_nmi = 0;
1263         int rv;
1264
1265         if (preaction_val == WDOG_PRETIMEOUT_NMI) {
1266                 do_nmi = 1;
1267                 if (preop_val == WDOG_PREOP_GIVE_DATA) {
1268                         pr_warn("Pretimeout op is to give data but NMI pretimeout is enabled, setting pretimeout op to none\n");
1269                         preop_op("preop_none", NULL);
1270                         do_nmi = 0;
1271                 }
1272         }
1273         if (do_nmi && !nmi_handler_registered) {
1274                 rv = register_nmi_handler(NMI_UNKNOWN, ipmi_nmi, 0,
1275                                                 "ipmi");
1276                 if (rv) {
1277                         pr_warn("Can't register nmi handler\n");
1278                         return;
1279                 } else
1280                         nmi_handler_registered = 1;
1281         } else if (!do_nmi && nmi_handler_registered) {
1282                 unregister_nmi_handler(NMI_UNKNOWN, "ipmi");
1283                 nmi_handler_registered = 0;
1284         }
1285 #endif
1286 }
1287
1288 static int __init ipmi_wdog_init(void)
1289 {
1290         int rv;
1291
1292         if (action_op(action, NULL)) {
1293                 action_op("reset", NULL);
1294                 pr_info("Unknown action '%s', defaulting to reset\n", action);
1295         }
1296
1297         if (preaction_op(preaction, NULL)) {
1298                 preaction_op("pre_none", NULL);
1299                 pr_info("Unknown preaction '%s', defaulting to none\n",
1300                         preaction);
1301         }
1302
1303         if (preop_op(preop, NULL)) {
1304                 preop_op("preop_none", NULL);
1305                 pr_info("Unknown preop '%s', defaulting to none\n", preop);
1306         }
1307
1308         check_parms();
1309
1310         register_reboot_notifier(&wdog_reboot_notifier);
1311
1312         rv = ipmi_smi_watcher_register(&smi_watcher);
1313         if (rv) {
1314 #ifdef HAVE_DIE_NMI
1315                 if (nmi_handler_registered)
1316                         unregister_nmi_handler(NMI_UNKNOWN, "ipmi");
1317 #endif
1318                 unregister_reboot_notifier(&wdog_reboot_notifier);
1319                 pr_warn("can't register smi watcher\n");
1320                 return rv;
1321         }
1322
1323         pr_info("driver initialized\n");
1324
1325         return 0;
1326 }
1327
1328 static void __exit ipmi_wdog_exit(void)
1329 {
1330         ipmi_smi_watcher_unregister(&smi_watcher);
1331         ipmi_unregister_watchdog(watchdog_ifnum);
1332
1333 #ifdef HAVE_DIE_NMI
1334         if (nmi_handler_registered)
1335                 unregister_nmi_handler(NMI_UNKNOWN, "ipmi");
1336 #endif
1337
1338         unregister_reboot_notifier(&wdog_reboot_notifier);
1339 }
1340 module_exit(ipmi_wdog_exit);
1341 module_init(ipmi_wdog_init);
1342 MODULE_LICENSE("GPL");
1343 MODULE_AUTHOR("Corey Minyard <minyard@mvista.com>");
1344 MODULE_DESCRIPTION("watchdog timer based upon the IPMI interface.");