drivers/char/ipmi/ipmi

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

DEFINITIONS
