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1// SPDX-License-Identifier: GPL-2.0+2/*3 * ipmi_watchdog.c4 *5 * A watchdog timer based upon the IPMI interface.6 *7 * Author: MontaVista Software, Inc.8 * Corey Minyard <minyard@mvista.com>9 * source@mvista.com10 *11 * Copyright 2002 MontaVista Software Inc.12 */13 14#define pr_fmt(fmt) "IPMI Watchdog: " fmt15 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_X8642/*43 * This is ugly, but I've determined that x86 is the only architecture44 * that can reasonably support the IPMI NMI watchdog timeout at this45 * time. If another architecture adds this capability somehow, it46 * will have to be a somewhat different mechanism and I have no idea47 * how it will work. So in the unlikely event that another48 * architecture supports this, we can figure out a good generic49 * mechanism for it at that time.50 */51#include <asm/kdebug.h>52#include <asm/nmi.h>53#define HAVE_DIE_NMI54#endif55 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 167#define WDOG_TIMER_USE_BIOS_POST 268#define WDOG_TIMER_USE_OS_LOAD 369#define WDOG_TIMER_USE_SMS_OS 470#define WDOG_TIMER_USE_OEM 571 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 077#define WDOG_PRETIMEOUT_SMI 178#define WDOG_PRETIMEOUT_NMI 279#define WDOG_PRETIMEOUT_MSG_INT 380 81/* Operations that can be performed on a pretimout. */82#define WDOG_PREOP_NONE 083#define WDOG_PREOP_PANIC 184/* Cause data to be available to read. Doesn't work in NMI mode. */85#define WDOG_PREOP_GIVE_DATA 286 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 092#define WDOG_TIMEOUT_RESET 193#define WDOG_TIMEOUT_POWER_DOWN 294#define WDOG_TIMEOUT_POWER_CYCLE 395 96/*97 * Byte 3 of the get command, byte 4 of the get response is the98 * 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 and110 * 6 (the timeout time) of the set command, and bytes 6 and 7 (the111 * timeout time) and 8 and 9 (the current countdown value) of the112 * response. The timeout value is given in seconds (in the command it113 * 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 0x22121#define IPMI_WDOG_SET_TIMER 0x24122#define IPMI_WDOG_GET_TIMER 0x25123 124#define IPMI_WDOG_TIMER_NOT_INIT_RESP 0x80125 126static DEFINE_MUTEX(ipmi_watchdog_mutex);127static bool nowayout = WATCHDOG_NOWAYOUT;128 129static struct ipmi_user *watchdog_user;130static int watchdog_ifnum;131 132/* Default the timeout to 10 seconds. */133static int timeout = 10;134 135/* The pre-timeout is disabled by default. */136static int pretimeout;137 138/* Default timeout to set on panic */139static int panic_wdt_timeout = 255;140 141/* Default action is to reset the board on a timeout. */142static unsigned char action_val = WDOG_TIMEOUT_RESET;143 144static char action[16] = "reset";145 146static unsigned char preaction_val = WDOG_PRETIMEOUT_NONE;147 148static char preaction[16] = "pre_none";149 150static unsigned char preop_val = WDOG_PREOP_NONE;151 152static char preop[16] = "preop_none";153static DEFINE_SPINLOCK(ipmi_read_lock);154static char data_to_read;155static DECLARE_WAIT_QUEUE_HEAD(read_q);156static struct fasync_struct *fasync_q;157static atomic_t pretimeout_since_last_heartbeat;158static char expect_close;159 160static int ifnum_to_use = -1;161 162/* Parameters to ipmi_set_timeout */163#define IPMI_SET_TIMEOUT_NO_HB 0164#define IPMI_SET_TIMEOUT_HB_IF_NECESSARY 1165#define IPMI_SET_TIMEOUT_FORCE_HB 2166 167static int ipmi_set_timeout(int do_heartbeat);168static void ipmi_register_watchdog(int ipmi_intf);169static void ipmi_unregister_watchdog(int ipmi_intf);170 171/*172 * If true, the driver will start running as soon as it is configured173 * and ready.174 */175static int start_now;176 177static 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 196static 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_int201 202typedef int (*action_fn)(const char *intval, char *outval);203 204static int action_op(const char *inval, char *outval);205static int preaction_op(const char *inval, char *outval);206static int preop_op(const char *inval, char *outval);207static void check_parms(void);208 209static 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 232static 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 249static 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 262static 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_int268 269static const struct kernel_param_ops param_ops_str = {270 .set = set_param_str,271 .get = get_param_str,272};273 274module_param(ifnum_to_use, wdog_ifnum, 0644);275MODULE_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 279module_param(timeout, timeout, 0644);280MODULE_PARM_DESC(timeout, "Timeout value in seconds.");281 282module_param(pretimeout, timeout, 0644);283MODULE_PARM_DESC(pretimeout, "Pretimeout value in seconds.");284 285module_param(panic_wdt_timeout, timeout, 0644);286MODULE_PARM_DESC(panic_wdt_timeout, "Timeout value on kernel panic in seconds.");287 288module_param_cb(action, ¶m_ops_str, action_op, 0644);289MODULE_PARM_DESC(action, "Timeout action. One of: "290 "reset, none, power_cycle, power_off.");291 292module_param_cb(preaction, ¶m_ops_str, preaction_op, 0644);293MODULE_PARM_DESC(preaction, "Pretimeout action. One of: "294 "pre_none, pre_smi, pre_nmi, pre_int.");295 296module_param_cb(preop, ¶m_ops_str, preop_op, 0644);297MODULE_PARM_DESC(preop, "Pretimeout driver operation. One of: "298 "preop_none, preop_panic, preop_give_data.");299 300module_param(start_now, int, 0444);301MODULE_PARM_DESC(start_now, "Set to 1 to start the watchdog as"302 "soon as the driver is loaded.");303 304module_param(nowayout, bool, 0644);305MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "306 "(default=CONFIG_WATCHDOG_NOWAYOUT)");307 308/* Default state of the timer. */309static unsigned char ipmi_watchdog_state = WDOG_TIMEOUT_NONE;310 311/* Is someone using the watchdog? Only one user is allowed. */312static unsigned long ipmi_wdog_open;313 314/*315 * If set to 1, the heartbeat command will set the state to reset and316 * start the timer. The timer doesn't normally run when the driver is317 * first opened until the heartbeat is set the first time, this318 * variable is used to accomplish this.319 */320static int ipmi_start_timer_on_heartbeat;321 322/* IPMI version of the BMC. */323static unsigned char ipmi_version_major;324static unsigned char ipmi_version_minor;325 326/* If a pretimeout occurs, this is used to allow only one panic to happen. */327static atomic_t preop_panic_excl = ATOMIC_INIT(-1);328 329#ifdef HAVE_DIE_NMI330static int testing_nmi;331static int nmi_handler_registered;332#endif333 334static int __ipmi_heartbeat(void);335 336/*337 * We use a mutex to make sure that only one thing can send a set a338 * message at one time. The mutex is claimed when a message is sent339 * and freed when both the send and receive messages are free.340 */341static atomic_t msg_tofree = ATOMIC_INIT(0);342static DECLARE_COMPLETION(msg_wait);343static 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}350static 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}357static struct ipmi_smi_msg smi_msg = INIT_IPMI_SMI_MSG(msg_free_smi);358static struct ipmi_recv_msg recv_msg = INIT_IPMI_RECV_MSG(msg_free_recv);359 360static 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, we382 * 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 424static 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 452static 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 463static atomic_t panic_done_count = ATOMIC_INIT(0);464 465static void panic_smi_free(struct ipmi_smi_msg *msg)466{467 atomic_dec(&panic_done_count);468}469static void panic_recv_free(struct ipmi_recv_msg *msg)470{471 atomic_dec(&panic_done_count);472}473 474static struct ipmi_smi_msg panic_halt_heartbeat_smi_msg =475 INIT_IPMI_SMI_MSG(panic_smi_free);476static struct ipmi_recv_msg panic_halt_heartbeat_recv_msg =477 INIT_IPMI_RECV_MSG(panic_recv_free);478 479static 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, that487 * 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 513static struct ipmi_smi_msg panic_halt_smi_msg =514 INIT_IPMI_SMI_MSG(panic_smi_free);515static 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 called520 * at panic or halt time, in run-to-completion mode, when the caller521 * is the only CPU and the only thing that will be going is these IPMI522 * calls.523 */524static 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 547static 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 554restart:555 /*556 * Don't reset the timer if we have the timer turned off, that557 * 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 was599 * probably reset and lost the watchdog information. Attempt600 * to restore the timer's info. Note that we still hold601 * the heartbeat lock, to keep a heartbeat from happening602 * in this process, so must say no heartbeat to avoid a603 * deadlock on this mutex604 */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 already616 * reported in ipmi_wdog_msg_handler, but we should return617 * an error here.618 */619 rv = -EINVAL;620 }621 622out:623 return rv;624}625 626static 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 to641 * leave that alone (thus it can't be combined with the642 * 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 652static 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 663static const struct watchdog_info ident = {664 .options = 0, /* WDIOF_SETTIMEOUT, */665 .firmware_version = 1,666 .identity = "IPMI"667};668 669static 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 738static 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 751static 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 781static 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 does794 * 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 else827 rv = 1;828 }829 830 return rv;831}832 833static 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 the843 * 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 853static __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 867static 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 876static 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 896static 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};907 908static struct miscdevice ipmi_wdog_miscdev = {909 .minor = WATCHDOG_MINOR,910 .name = "watchdog",911 .fops = &ipmi_wdog_fops912};913 914static void ipmi_wdog_msg_handler(struct ipmi_recv_msg *msg,915 void *handler_data)916{917 if (msg->msg.cmd == IPMI_WDOG_RESET_TIMER &&918 msg->msg.data[0] == IPMI_WDOG_TIMER_NOT_INIT_RESP)919 pr_info("response: The IPMI controller appears to have been reset, will attempt to reinitialize the watchdog timer\n");920 else if (msg->msg.data[0] != 0)921 pr_err("response: Error %x on cmd %x\n",922 msg->msg.data[0],923 msg->msg.cmd);924 925 ipmi_free_recv_msg(msg);926}927 928static void ipmi_wdog_pretimeout_handler(void *handler_data)929{930 if (preaction_val != WDOG_PRETIMEOUT_NONE) {931 if (preop_val == WDOG_PREOP_PANIC) {932 if (atomic_inc_and_test(&preop_panic_excl))933 panic("Watchdog pre-timeout");934 } else if (preop_val == WDOG_PREOP_GIVE_DATA) {935 unsigned long flags;936 937 spin_lock_irqsave(&ipmi_read_lock, flags);938 data_to_read = 1;939 wake_up_interruptible(&read_q);940 kill_fasync(&fasync_q, SIGIO, POLL_IN);941 spin_unlock_irqrestore(&ipmi_read_lock, flags);942 }943 }944 945 /*946 * On some machines, the heartbeat will give an error and not947 * work unless we re-enable the timer. So do so.948 */949 atomic_set(&pretimeout_since_last_heartbeat, 1);950}951 952static void ipmi_wdog_panic_handler(void *user_data)953{954 static int panic_event_handled;955 956 /*957 * On a panic, if we have a panic timeout, make sure to extend958 * the watchdog timer to a reasonable value to complete the959 * panic, if the watchdog timer is running. Plus the960 * pretimeout is meaningless at panic time.961 */962 if (watchdog_user && !panic_event_handled &&963 ipmi_watchdog_state != WDOG_TIMEOUT_NONE) {964 /* Make sure we do this only once. */965 panic_event_handled = 1;966 967 timeout = panic_wdt_timeout;968 pretimeout = 0;969 panic_halt_ipmi_set_timeout();970 }971}972 973static const struct ipmi_user_hndl ipmi_hndlrs = {974 .ipmi_recv_hndl = ipmi_wdog_msg_handler,975 .ipmi_watchdog_pretimeout = ipmi_wdog_pretimeout_handler,976 .ipmi_panic_handler = ipmi_wdog_panic_handler977};978 979static void ipmi_register_watchdog(int ipmi_intf)980{981 int rv = -EBUSY;982 983 if (watchdog_user)984 goto out;985 986 if ((ifnum_to_use >= 0) && (ifnum_to_use != ipmi_intf))987 goto out;988 989 watchdog_ifnum = ipmi_intf;990 991 rv = ipmi_create_user(ipmi_intf, &ipmi_hndlrs, NULL, &watchdog_user);992 if (rv < 0) {993 pr_crit("Unable to register with ipmi\n");994 goto out;995 }996 997 rv = ipmi_get_version(watchdog_user,998 &ipmi_version_major,999 &ipmi_version_minor);1000 if (rv) {1001 pr_warn("Unable to get IPMI version, assuming 1.0\n");1002 ipmi_version_major = 1;1003 ipmi_version_minor = 0;1004 }1005 1006 rv = misc_register(&ipmi_wdog_miscdev);1007 if (rv < 0) {1008 ipmi_destroy_user(watchdog_user);1009 watchdog_user = NULL;1010 pr_crit("Unable to register misc device\n");1011 }1012 1013#ifdef HAVE_DIE_NMI1014 if (nmi_handler_registered) {1015 int old_pretimeout = pretimeout;1016 int old_timeout = timeout;1017 int old_preop_val = preop_val;1018 1019 /*1020 * Set the pretimeout to go off in a second and give1021 * ourselves plenty of time to stop the timer.1022 */1023 ipmi_watchdog_state = WDOG_TIMEOUT_RESET;1024 preop_val = WDOG_PREOP_NONE; /* Make sure nothing happens */1025 pretimeout = 99;1026 timeout = 100;1027 1028 testing_nmi = 1;1029 1030 rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB);1031 if (rv) {1032 pr_warn("Error starting timer to test NMI: 0x%x. The NMI pretimeout will likely not work\n",1033 rv);1034 rv = 0;1035 goto out_restore;1036 }1037 1038 msleep(1500);1039 1040 if (testing_nmi != 2) {1041 pr_warn("IPMI NMI didn't seem to occur. The NMI pretimeout will likely not work\n");1042 }1043 out_restore:1044 testing_nmi = 0;1045 preop_val = old_preop_val;1046 pretimeout = old_pretimeout;1047 timeout = old_timeout;1048 }1049#endif1050 1051 out:1052 if ((start_now) && (rv == 0)) {1053 /* Run from startup, so start the timer now. */1054 start_now = 0; /* Disable this function after first startup. */1055 ipmi_watchdog_state = action_val;1056 ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB);1057 pr_info("Starting now!\n");1058 } else {1059 /* Stop the timer now. */1060 ipmi_watchdog_state = WDOG_TIMEOUT_NONE;1061 ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB);1062 }1063}1064 1065static void ipmi_unregister_watchdog(int ipmi_intf)1066{1067 int rv;1068 struct ipmi_user *loc_user = watchdog_user;1069 1070 if (!loc_user)1071 return;1072 1073 if (watchdog_ifnum != ipmi_intf)1074 return;1075 1076 /* Make sure no one can call us any more. */1077 misc_deregister(&ipmi_wdog_miscdev);1078 1079 watchdog_user = NULL;1080 1081 /*1082 * Wait to make sure the message makes it out. The lower layer has1083 * pointers to our buffers, we want to make sure they are done before1084 * we release our memory.1085 */1086 while (atomic_read(&msg_tofree))1087 msg_free_smi(NULL);1088 1089 mutex_lock(&ipmi_watchdog_mutex);1090 1091 /* Disconnect from IPMI. */1092 rv = ipmi_destroy_user(loc_user);1093 if (rv)1094 pr_warn("error unlinking from IPMI: %d\n", rv);1095 1096 /* If it comes back, restart it properly. */1097 ipmi_start_timer_on_heartbeat = 1;1098 1099 mutex_unlock(&ipmi_watchdog_mutex);1100}1101 1102#ifdef HAVE_DIE_NMI1103static int1104ipmi_nmi(unsigned int val, struct pt_regs *regs)1105{1106 /*1107 * If we get here, it's an NMI that's not a memory or I/O1108 * error. We can't truly tell if it's from IPMI or not1109 * without sending a message, and sending a message is almost1110 * impossible because of locking.1111 */1112 1113 if (testing_nmi) {1114 testing_nmi = 2;1115 return NMI_HANDLED;1116 }1117 1118 /* If we are not expecting a timeout, ignore it. */1119 if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE)1120 return NMI_DONE;1121 1122 if (preaction_val != WDOG_PRETIMEOUT_NMI)1123 return NMI_DONE;1124 1125 /*1126 * If no one else handled the NMI, we assume it was the IPMI1127 * watchdog.1128 */1129 if (preop_val == WDOG_PREOP_PANIC) {1130 /* On some machines, the heartbeat will give1131 an error and not work unless we re-enable1132 the timer. So do so. */1133 atomic_set(&pretimeout_since_last_heartbeat, 1);1134 if (atomic_inc_and_test(&preop_panic_excl))1135 nmi_panic(regs, "pre-timeout");1136 }1137 1138 return NMI_HANDLED;1139}1140#endif1141 1142static int wdog_reboot_handler(struct notifier_block *this,1143 unsigned long code,1144 void *unused)1145{1146 static int reboot_event_handled;1147 1148 if ((watchdog_user) && (!reboot_event_handled)) {1149 /* Make sure we only do this once. */1150 reboot_event_handled = 1;1151 1152 if (code == SYS_POWER_OFF || code == SYS_HALT) {1153 /* Disable the WDT if we are shutting down. */1154 ipmi_watchdog_state = WDOG_TIMEOUT_NONE;1155 ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB);1156 } else if (ipmi_watchdog_state != WDOG_TIMEOUT_NONE) {1157 /* Set a long timer to let the reboot happen or1158 reset if it hangs, but only if the watchdog1159 timer was already running. */1160 if (timeout < 120)1161 timeout = 120;1162 pretimeout = 0;1163 ipmi_watchdog_state = WDOG_TIMEOUT_RESET;1164 ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB);1165 }1166 }1167 return NOTIFY_OK;1168}1169 1170static struct notifier_block wdog_reboot_notifier = {1171 .notifier_call = wdog_reboot_handler,1172 .next = NULL,1173 .priority = 01174};1175 1176static void ipmi_new_smi(int if_num, struct device *device)1177{1178 ipmi_register_watchdog(if_num);1179}1180 1181static void ipmi_smi_gone(int if_num)1182{1183 ipmi_unregister_watchdog(if_num);1184}1185 1186static struct ipmi_smi_watcher smi_watcher = {1187 .owner = THIS_MODULE,1188 .new_smi = ipmi_new_smi,1189 .smi_gone = ipmi_smi_gone1190};1191 1192static int action_op(const char *inval, char *outval)1193{1194 if (outval)1195 strcpy(outval, action);1196 1197 if (!inval)1198 return 0;1199 1200 if (strcmp(inval, "reset") == 0)1201 action_val = WDOG_TIMEOUT_RESET;1202 else if (strcmp(inval, "none") == 0)1203 action_val = WDOG_TIMEOUT_NONE;1204 else if (strcmp(inval, "power_cycle") == 0)1205 action_val = WDOG_TIMEOUT_POWER_CYCLE;1206 else if (strcmp(inval, "power_off") == 0)1207 action_val = WDOG_TIMEOUT_POWER_DOWN;1208 else1209 return -EINVAL;1210 strcpy(action, inval);1211 return 0;1212}1213 1214static int preaction_op(const char *inval, char *outval)1215{1216 if (outval)1217 strcpy(outval, preaction);1218 1219 if (!inval)1220 return 0;1221 1222 if (strcmp(inval, "pre_none") == 0)1223 preaction_val = WDOG_PRETIMEOUT_NONE;1224 else if (strcmp(inval, "pre_smi") == 0)1225 preaction_val = WDOG_PRETIMEOUT_SMI;1226#ifdef HAVE_DIE_NMI1227 else if (strcmp(inval, "pre_nmi") == 0)1228 preaction_val = WDOG_PRETIMEOUT_NMI;1229#endif1230 else if (strcmp(inval, "pre_int") == 0)1231 preaction_val = WDOG_PRETIMEOUT_MSG_INT;1232 else1233 return -EINVAL;1234 strcpy(preaction, inval);1235 return 0;1236}1237 1238static int preop_op(const char *inval, char *outval)1239{1240 if (outval)1241 strcpy(outval, preop);1242 1243 if (!inval)1244 return 0;1245 1246 if (strcmp(inval, "preop_none") == 0)1247 preop_val = WDOG_PREOP_NONE;1248 else if (strcmp(inval, "preop_panic") == 0)1249 preop_val = WDOG_PREOP_PANIC;1250 else if (strcmp(inval, "preop_give_data") == 0)1251 preop_val = WDOG_PREOP_GIVE_DATA;1252 else1253 return -EINVAL;1254 strcpy(preop, inval);1255 return 0;1256}1257 1258static void check_parms(void)1259{1260#ifdef HAVE_DIE_NMI1261 int do_nmi = 0;1262 int rv;1263 1264 if (preaction_val == WDOG_PRETIMEOUT_NMI) {1265 do_nmi = 1;1266 if (preop_val == WDOG_PREOP_GIVE_DATA) {1267 pr_warn("Pretimeout op is to give data but NMI pretimeout is enabled, setting pretimeout op to none\n");1268 preop_op("preop_none", NULL);1269 do_nmi = 0;1270 }1271 }1272 if (do_nmi && !nmi_handler_registered) {1273 rv = register_nmi_handler(NMI_UNKNOWN, ipmi_nmi, 0,1274 "ipmi");1275 if (rv) {1276 pr_warn("Can't register nmi handler\n");1277 return;1278 } else1279 nmi_handler_registered = 1;1280 } else if (!do_nmi && nmi_handler_registered) {1281 unregister_nmi_handler(NMI_UNKNOWN, "ipmi");1282 nmi_handler_registered = 0;1283 }1284#endif1285}1286 1287static int __init ipmi_wdog_init(void)1288{1289 int rv;1290 1291 if (action_op(action, NULL)) {1292 action_op("reset", NULL);1293 pr_info("Unknown action '%s', defaulting to reset\n", action);1294 }1295 1296 if (preaction_op(preaction, NULL)) {1297 preaction_op("pre_none", NULL);1298 pr_info("Unknown preaction '%s', defaulting to none\n",1299 preaction);1300 }1301 1302 if (preop_op(preop, NULL)) {1303 preop_op("preop_none", NULL);1304 pr_info("Unknown preop '%s', defaulting to none\n", preop);1305 }1306 1307 check_parms();1308 1309 register_reboot_notifier(&wdog_reboot_notifier);1310 1311 rv = ipmi_smi_watcher_register(&smi_watcher);1312 if (rv) {1313#ifdef HAVE_DIE_NMI1314 if (nmi_handler_registered)1315 unregister_nmi_handler(NMI_UNKNOWN, "ipmi");1316#endif1317 unregister_reboot_notifier(&wdog_reboot_notifier);1318 pr_warn("can't register smi watcher\n");1319 return rv;1320 }1321 1322 pr_info("driver initialized\n");1323 1324 return 0;1325}1326 1327static void __exit ipmi_wdog_exit(void)1328{1329 ipmi_smi_watcher_unregister(&smi_watcher);1330 ipmi_unregister_watchdog(watchdog_ifnum);1331 1332#ifdef HAVE_DIE_NMI1333 if (nmi_handler_registered)1334 unregister_nmi_handler(NMI_UNKNOWN, "ipmi");1335#endif1336 1337 unregister_reboot_notifier(&wdog_reboot_notifier);1338}1339module_exit(ipmi_wdog_exit);1340module_init(ipmi_wdog_init);1341MODULE_LICENSE("GPL");1342MODULE_AUTHOR("Corey Minyard <minyard@mvista.com>");1343MODULE_DESCRIPTION("watchdog timer based upon the IPMI interface.");1344