atomic: use <linux/atomic.h>
[linux-2.6.git] / drivers / char / ipmi / ipmi_watchdog.c
index fcd1c02..3302586 100644 (file)
  *  675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
-#include <linux/config.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/ipmi.h>
 #include <linux/ipmi_smi.h>
+#include <linux/mutex.h>
 #include <linux/watchdog.h>
 #include <linux/miscdevice.h>
 #include <linux/init.h>
+#include <linux/completion.h>
+#include <linux/kdebug.h>
 #include <linux/rwsem.h>
 #include <linux/errno.h>
 #include <asm/uaccess.h>
 #include <linux/reboot.h>
 #include <linux/wait.h>
 #include <linux/poll.h>
-#ifdef CONFIG_X86_LOCAL_APIC
-#include <asm/apic.h>
+#include <linux/string.h>
+#include <linux/ctype.h>
+#include <linux/delay.h>
+#include <linux/atomic.h>
+
+#ifdef CONFIG_X86
+/*
+ * This is ugly, but I've determined that x86 is the only architecture
+ * that can reasonably support the IPMI NMI watchdog timeout at this
+ * time.  If another architecture adds this capability somehow, it
+ * will have to be a somewhat different mechanism and I have no idea
+ * how it will work.  So in the unlikely event that another
+ * architecture supports this, we can figure out a good generic
+ * mechanism for it at that time.
+ */
+#include <asm/kdebug.h>
+#define HAVE_DIE_NMI
 #endif
 
 #define        PFX "IPMI Watchdog: "
 
-#define IPMI_WATCHDOG_VERSION "v33"
-
 /*
  * The IPMI command/response information for the watchdog timer.
  */
@@ -83,9 +98,8 @@
 /* Operations that can be performed on a pretimout. */
 #define WDOG_PREOP_NONE                0
 #define WDOG_PREOP_PANIC       1
-#define WDOG_PREOP_GIVE_DATA   2 /* Cause data to be available to
-                                     read.  Doesn't work in NMI
-                                     mode. */
+/* Cause data to be available to read.  Doesn't work in NMI mode. */
+#define WDOG_PREOP_GIVE_DATA   2
 
 /* Actions to perform on a full timeout. */
 #define WDOG_SET_TIMEOUT_ACT(byte, use) \
 #define WDOG_TIMEOUT_POWER_DOWN                2
 #define WDOG_TIMEOUT_POWER_CYCLE       3
 
-/* Byte 3 of the get command, byte 4 of the get response is the
-   pre-timeout in seconds. */
+/*
+ * Byte 3 of the get command, byte 4 of the get response is the
+ * pre-timeout in seconds.
+ */
 
 /* Bits for setting byte 4 of the set command, byte 5 of the get response. */
 #define WDOG_EXPIRE_CLEAR_BIOS_FRB2    (1 << 1)
 #define WDOG_EXPIRE_CLEAR_SMS_OS       (1 << 4)
 #define WDOG_EXPIRE_CLEAR_OEM          (1 << 5)
 
-/* Setting/getting the watchdog timer value.  This is for bytes 5 and
-   6 (the timeout time) of the set command, and bytes 6 and 7 (the
-   timeout time) and 8 and 9 (the current countdown value) of the
-   response.  The timeout value is given in seconds (in the command it
-   is 100ms intervals). */
+/*
+ * Setting/getting the watchdog timer value.  This is for bytes 5 and
+ * 6 (the timeout time) of the set command, and bytes 6 and 7 (the
+ * timeout time) and 8 and 9 (the current countdown value) of the
+ * response.  The timeout value is given in seconds (in the command it
+ * is 100ms intervals).
+ */
 #define WDOG_SET_TIMEOUT(byte1, byte2, val) \
        (byte1) = (((val) * 10) & 0xff), (byte2) = (((val) * 10) >> 8)
 #define WDOG_GET_TIMEOUT(byte1, byte2) \
 #define        WDIOC_GET_PRETIMEOUT     _IOW(WATCHDOG_IOCTL_BASE, 22, int)
 #endif
 
-#ifdef CONFIG_WATCHDOG_NOWAYOUT
-static int nowayout = 1;
-#else
-static int nowayout;
-#endif
+static DEFINE_MUTEX(ipmi_watchdog_mutex);
+static int nowayout = WATCHDOG_NOWAYOUT;
 
-static ipmi_user_t watchdog_user = NULL;
+static ipmi_user_t watchdog_user;
+static int watchdog_ifnum;
 
 /* Default the timeout to 10 seconds. */
 static int timeout = 10;
 
 /* The pre-timeout is disabled by default. */
-static int pretimeout = 0;
+static int pretimeout;
 
 /* Default action is to reset the board on a timeout. */
 static unsigned char action_val = WDOG_TIMEOUT_RESET;
@@ -158,84 +174,210 @@ static unsigned char preop_val = WDOG_PREOP_NONE;
 
 static char preop[16] = "preop_none";
 static DEFINE_SPINLOCK(ipmi_read_lock);
-static char data_to_read = 0;
+static char data_to_read;
 static DECLARE_WAIT_QUEUE_HEAD(read_q);
-static struct fasync_struct *fasync_q = NULL;
-static char pretimeout_since_last_heartbeat = 0;
+static struct fasync_struct *fasync_q;
+static char pretimeout_since_last_heartbeat;
 static char expect_close;
 
-/* If true, the driver will start running as soon as it is configured
-   and ready. */
-static int start_now = 0;
+static int ifnum_to_use = -1;
+
+/* Parameters to ipmi_set_timeout */
+#define IPMI_SET_TIMEOUT_NO_HB                 0
+#define IPMI_SET_TIMEOUT_HB_IF_NECESSARY       1
+#define IPMI_SET_TIMEOUT_FORCE_HB              2
+
+static int ipmi_set_timeout(int do_heartbeat);
+static void ipmi_register_watchdog(int ipmi_intf);
+static void ipmi_unregister_watchdog(int ipmi_intf);
+
+/*
+ * If true, the driver will start running as soon as it is configured
+ * and ready.
+ */
+static int start_now;
+
+static int set_param_timeout(const char *val, const struct kernel_param *kp)
+{
+       char *endp;
+       int  l;
+       int  rv = 0;
+
+       if (!val)
+               return -EINVAL;
+       l = simple_strtoul(val, &endp, 0);
+       if (endp == val)
+               return -EINVAL;
+
+       *((int *)kp->arg) = l;
+       if (watchdog_user)
+               rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
+
+       return rv;
+}
+
+static struct kernel_param_ops param_ops_timeout = {
+       .set = set_param_timeout,
+       .get = param_get_int,
+};
+#define param_check_timeout param_check_int
+
+typedef int (*action_fn)(const char *intval, char *outval);
+
+static int action_op(const char *inval, char *outval);
+static int preaction_op(const char *inval, char *outval);
+static int preop_op(const char *inval, char *outval);
+static void check_parms(void);
+
+static int set_param_str(const char *val, const struct kernel_param *kp)
+{
+       action_fn  fn = (action_fn) kp->arg;
+       int        rv = 0;
+       char       valcp[16];
+       char       *s;
+
+       strncpy(valcp, val, 16);
+       valcp[15] = '\0';
+
+       s = strstrip(valcp);
+
+       rv = fn(s, NULL);
+       if (rv)
+               goto out;
+
+       check_parms();
+       if (watchdog_user)
+               rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
+
+ out:
+       return rv;
+}
+
+static int get_param_str(char *buffer, const struct kernel_param *kp)
+{
+       action_fn fn = (action_fn) kp->arg;
+       int       rv;
+
+       rv = fn(NULL, buffer);
+       if (rv)
+               return rv;
+       return strlen(buffer);
+}
+
+
+static int set_param_wdog_ifnum(const char *val, const struct kernel_param *kp)
+{
+       int rv = param_set_int(val, kp);
+       if (rv)
+               return rv;
+       if ((ifnum_to_use < 0) || (ifnum_to_use == watchdog_ifnum))
+               return 0;
+
+       ipmi_unregister_watchdog(watchdog_ifnum);
+       ipmi_register_watchdog(ifnum_to_use);
+       return 0;
+}
+
+static struct kernel_param_ops param_ops_wdog_ifnum = {
+       .set = set_param_wdog_ifnum,
+       .get = param_get_int,
+};
 
-module_param(timeout, int, 0);
+#define param_check_wdog_ifnum param_check_int
+
+static struct kernel_param_ops param_ops_str = {
+       .set = set_param_str,
+       .get = get_param_str,
+};
+
+module_param(ifnum_to_use, wdog_ifnum, 0644);
+MODULE_PARM_DESC(ifnum_to_use, "The interface number to use for the watchdog "
+                "timer.  Setting to -1 defaults to the first registered "
+                "interface");
+
+module_param(timeout, timeout, 0644);
 MODULE_PARM_DESC(timeout, "Timeout value in seconds.");
-module_param(pretimeout, int, 0);
+
+module_param(pretimeout, timeout, 0644);
 MODULE_PARM_DESC(pretimeout, "Pretimeout value in seconds.");
-module_param_string(action, action, sizeof(action), 0);
+
+module_param_cb(action, &param_ops_str, action_op, 0644);
 MODULE_PARM_DESC(action, "Timeout action. One of: "
                 "reset, none, power_cycle, power_off.");
-module_param_string(preaction, preaction, sizeof(preaction), 0);
+
+module_param_cb(preaction, &param_ops_str, preaction_op, 0644);
 MODULE_PARM_DESC(preaction, "Pretimeout action.  One of: "
                 "pre_none, pre_smi, pre_nmi, pre_int.");
-module_param_string(preop, preop, sizeof(preop), 0);
+
+module_param_cb(preop, &param_ops_str, preop_op, 0644);
 MODULE_PARM_DESC(preop, "Pretimeout driver operation.  One of: "
                 "preop_none, preop_panic, preop_give_data.");
-module_param(start_now, int, 0);
+
+module_param(start_now, int, 0444);
 MODULE_PARM_DESC(start_now, "Set to 1 to start the watchdog as"
                 "soon as the driver is loaded.");
-module_param(nowayout, int, 0);
-MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
+
+module_param(nowayout, int, 0644);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
+                "(default=CONFIG_WATCHDOG_NOWAYOUT)");
 
 /* Default state of the timer. */
 static unsigned char ipmi_watchdog_state = WDOG_TIMEOUT_NONE;
 
 /* If shutting down via IPMI, we ignore the heartbeat. */
-static int ipmi_ignore_heartbeat = 0;
+static int ipmi_ignore_heartbeat;
 
 /* Is someone using the watchdog?  Only one user is allowed. */
-static unsigned long ipmi_wdog_open = 0;
+static unsigned long ipmi_wdog_open;
 
-/* If set to 1, the heartbeat command will set the state to reset and
-   start the timer.  The timer doesn't normally run when the driver is
-   first opened until the heartbeat is set the first time, this
-   variable is used to accomplish this. */
-static int ipmi_start_timer_on_heartbeat = 0;
+/*
+ * If set to 1, the heartbeat command will set the state to reset and
+ * start the timer.  The timer doesn't normally run when the driver is
+ * first opened until the heartbeat is set the first time, this
+ * variable is used to accomplish this.
+ */
+static int ipmi_start_timer_on_heartbeat;
 
 /* IPMI version of the BMC. */
 static unsigned char ipmi_version_major;
 static unsigned char ipmi_version_minor;
 
+/* If a pretimeout occurs, this is used to allow only one panic to happen. */
+static atomic_t preop_panic_excl = ATOMIC_INIT(-1);
 
-static int ipmi_heartbeat(void);
-static void panic_halt_ipmi_heartbeat(void);
+#ifdef HAVE_DIE_NMI
+static int testing_nmi;
+static int nmi_handler_registered;
+#endif
 
+static int ipmi_heartbeat(void);
 
-/* We use a semaphore to make sure that only one thing can send a set
-   timeout at one time, because we only have one copy of the data.
-   The semaphore is claimed when the set_timeout is sent and freed
-   when both messages are free. */
+/*
+ * We use a mutex to make sure that only one thing can send a set
+ * timeout at one time, because we only have one copy of the data.
+ * The mutex is claimed when the set_timeout is sent and freed
+ * when both messages are free.
+ */
 static atomic_t set_timeout_tofree = ATOMIC_INIT(0);
-static DECLARE_MUTEX(set_timeout_lock);
+static DEFINE_MUTEX(set_timeout_lock);
+static DECLARE_COMPLETION(set_timeout_wait);
 static void set_timeout_free_smi(struct ipmi_smi_msg *msg)
 {
     if (atomic_dec_and_test(&set_timeout_tofree))
-           up(&set_timeout_lock);
+           complete(&set_timeout_wait);
 }
 static void set_timeout_free_recv(struct ipmi_recv_msg *msg)
 {
     if (atomic_dec_and_test(&set_timeout_tofree))
-           up(&set_timeout_lock);
+           complete(&set_timeout_wait);
 }
-static struct ipmi_smi_msg set_timeout_smi_msg =
-{
+static struct ipmi_smi_msg set_timeout_smi_msg = {
        .done = set_timeout_free_smi
 };
-static struct ipmi_recv_msg set_timeout_recv_msg =
-{
+static struct ipmi_recv_msg set_timeout_recv_msg = {
        .done = set_timeout_free_recv
 };
+
 static int i_ipmi_set_timeout(struct ipmi_smi_msg  *smi_msg,
                              struct ipmi_recv_msg *recv_msg,
                              int                  *send_heartbeat_now)
@@ -247,23 +389,27 @@ static int i_ipmi_set_timeout(struct ipmi_smi_msg  *smi_msg,
        int                               hbnow = 0;
 
 
+       /* These can be cleared as we are setting the timeout. */
+       pretimeout_since_last_heartbeat = 0;
+
        data[0] = 0;
        WDOG_SET_TIMER_USE(data[0], WDOG_TIMER_USE_SMS_OS);
 
        if ((ipmi_version_major > 1)
-           || ((ipmi_version_major == 1) && (ipmi_version_minor >= 5)))
-       {
+           || ((ipmi_version_major == 1) && (ipmi_version_minor >= 5))) {
                /* This is an IPMI 1.5-only feature. */
                data[0] |= WDOG_DONT_STOP_ON_SET;
        } else if (ipmi_watchdog_state != WDOG_TIMEOUT_NONE) {
-               /* In ipmi 1.0, setting the timer stops the watchdog, we
-                  need to start it back up again. */
+               /*
+                * In ipmi 1.0, setting the timer stops the watchdog, we
+                * need to start it back up again.
+                */
                hbnow = 1;
        }
 
        data[1] = 0;
        WDOG_SET_TIMEOUT_ACT(data[1], ipmi_watchdog_state);
-       if (pretimeout > 0) {
+       if ((pretimeout > 0) && (ipmi_watchdog_state != WDOG_TIMEOUT_NONE)) {
            WDOG_SET_PRETIMEOUT_ACT(data[1], preaction_val);
            data[2] = pretimeout;
        } else {
@@ -300,11 +446,6 @@ static int i_ipmi_set_timeout(struct ipmi_smi_msg  *smi_msg,
        return rv;
 }
 
-/* Parameters to ipmi_set_timeout */
-#define IPMI_SET_TIMEOUT_NO_HB                 0
-#define IPMI_SET_TIMEOUT_HB_IF_NECESSARY       1
-#define IPMI_SET_TIMEOUT_FORCE_HB              2
-
 static int ipmi_set_timeout(int do_heartbeat)
 {
        int send_heartbeat_now;
@@ -312,7 +453,7 @@ static int ipmi_set_timeout(int do_heartbeat)
 
 
        /* We can only send one of these at a time. */
-       down(&set_timeout_lock);
+       mutex_lock(&set_timeout_lock);
 
        atomic_set(&set_timeout_tofree, 2);
 
@@ -320,118 +461,168 @@ static int ipmi_set_timeout(int do_heartbeat)
                                &set_timeout_recv_msg,
                                &send_heartbeat_now);
        if (rv) {
-               up(&set_timeout_lock);
-       } else {
-               if ((do_heartbeat == IPMI_SET_TIMEOUT_FORCE_HB)
-                   || ((send_heartbeat_now)
-                       && (do_heartbeat == IPMI_SET_TIMEOUT_HB_IF_NECESSARY)))
-               {
-                       rv = ipmi_heartbeat();
-               }
+               mutex_unlock(&set_timeout_lock);
+               goto out;
        }
 
+       wait_for_completion(&set_timeout_wait);
+
+       mutex_unlock(&set_timeout_lock);
+
+       if ((do_heartbeat == IPMI_SET_TIMEOUT_FORCE_HB)
+           || ((send_heartbeat_now)
+               && (do_heartbeat == IPMI_SET_TIMEOUT_HB_IF_NECESSARY)))
+               rv = ipmi_heartbeat();
+
+out:
        return rv;
 }
 
-static void dummy_smi_free(struct ipmi_smi_msg *msg)
+static atomic_t panic_done_count = ATOMIC_INIT(0);
+
+static void panic_smi_free(struct ipmi_smi_msg *msg)
 {
+       atomic_dec(&panic_done_count);
 }
-static void dummy_recv_free(struct ipmi_recv_msg *msg)
+static void panic_recv_free(struct ipmi_recv_msg *msg)
 {
+       atomic_dec(&panic_done_count);
 }
-static struct ipmi_smi_msg panic_halt_smi_msg =
-{
-       .done = dummy_smi_free
+
+static struct ipmi_smi_msg panic_halt_heartbeat_smi_msg = {
+       .done = panic_smi_free
 };
-static struct ipmi_recv_msg panic_halt_recv_msg =
+static struct ipmi_recv_msg panic_halt_heartbeat_recv_msg = {
+       .done = panic_recv_free
+};
+
+static void panic_halt_ipmi_heartbeat(void)
 {
-       .done = dummy_recv_free
+       struct kernel_ipmi_msg             msg;
+       struct ipmi_system_interface_addr addr;
+       int rv;
+
+       /*
+        * Don't reset the timer if we have the timer turned off, that
+        * re-enables the watchdog.
+        */
+       if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE)
+               return;
+
+       addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
+       addr.channel = IPMI_BMC_CHANNEL;
+       addr.lun = 0;
+
+       msg.netfn = 0x06;
+       msg.cmd = IPMI_WDOG_RESET_TIMER;
+       msg.data = NULL;
+       msg.data_len = 0;
+       rv = ipmi_request_supply_msgs(watchdog_user,
+                                     (struct ipmi_addr *) &addr,
+                                     0,
+                                     &msg,
+                                     NULL,
+                                     &panic_halt_heartbeat_smi_msg,
+                                     &panic_halt_heartbeat_recv_msg,
+                                     1);
+       if (!rv)
+               atomic_add(2, &panic_done_count);
+}
+
+static struct ipmi_smi_msg panic_halt_smi_msg = {
+       .done = panic_smi_free
+};
+static struct ipmi_recv_msg panic_halt_recv_msg = {
+       .done = panic_recv_free
 };
 
-/* Special call, doesn't claim any locks.  This is only to be called
-   at panic or halt time, in run-to-completion mode, when the caller
-   is the only CPU and the only thing that will be going is these IPMI
-   calls. */
+/*
+ * Special call, doesn't claim any locks.  This is only to be called
+ * at panic or halt time, in run-to-completion mode, when the caller
+ * is the only CPU and the only thing that will be going is these IPMI
+ * calls.
+ */
 static void panic_halt_ipmi_set_timeout(void)
 {
        int send_heartbeat_now;
        int rv;
 
+       /* Wait for the messages to be free. */
+       while (atomic_read(&panic_done_count) != 0)
+               ipmi_poll_interface(watchdog_user);
        rv = i_ipmi_set_timeout(&panic_halt_smi_msg,
                                &panic_halt_recv_msg,
                                &send_heartbeat_now);
        if (!rv) {
+               atomic_add(2, &panic_done_count);
                if (send_heartbeat_now)
                        panic_halt_ipmi_heartbeat();
-       }
+       } else
+               printk(KERN_WARNING PFX
+                      "Unable to extend the watchdog timeout.");
+       while (atomic_read(&panic_done_count) != 0)
+               ipmi_poll_interface(watchdog_user);
 }
 
-/* We use a semaphore to make sure that only one thing can send a
-   heartbeat at one time, because we only have one copy of the data.
-   The semaphore is claimed when the set_timeout is sent and freed
-   when both messages are free. */
+/*
+ * We use a mutex to make sure that only one thing can send a
+ * heartbeat at one time, because we only have one copy of the data.
+ * The semaphore is claimed when the set_timeout is sent and freed
+ * when both messages are free.
+ */
 static atomic_t heartbeat_tofree = ATOMIC_INIT(0);
-static DECLARE_MUTEX(heartbeat_lock);
-static DECLARE_MUTEX_LOCKED(heartbeat_wait_lock);
+static DEFINE_MUTEX(heartbeat_lock);
+static DECLARE_COMPLETION(heartbeat_wait);
 static void heartbeat_free_smi(struct ipmi_smi_msg *msg)
 {
     if (atomic_dec_and_test(&heartbeat_tofree))
-           up(&heartbeat_wait_lock);
+           complete(&heartbeat_wait);
 }
 static void heartbeat_free_recv(struct ipmi_recv_msg *msg)
 {
     if (atomic_dec_and_test(&heartbeat_tofree))
-           up(&heartbeat_wait_lock);
+           complete(&heartbeat_wait);
 }
-static struct ipmi_smi_msg heartbeat_smi_msg =
-{
+static struct ipmi_smi_msg heartbeat_smi_msg = {
        .done = heartbeat_free_smi
 };
-static struct ipmi_recv_msg heartbeat_recv_msg =
-{
+static struct ipmi_recv_msg heartbeat_recv_msg = {
        .done = heartbeat_free_recv
 };
-static struct ipmi_smi_msg panic_halt_heartbeat_smi_msg =
-{
-       .done = dummy_smi_free
-};
-static struct ipmi_recv_msg panic_halt_heartbeat_recv_msg =
-{
-       .done = dummy_recv_free
-};
+
 static int ipmi_heartbeat(void)
 {
        struct kernel_ipmi_msg            msg;
        int                               rv;
        struct ipmi_system_interface_addr addr;
 
-       if (ipmi_ignore_heartbeat) {
+       if (ipmi_ignore_heartbeat)
                return 0;
-       }
 
        if (ipmi_start_timer_on_heartbeat) {
                ipmi_start_timer_on_heartbeat = 0;
                ipmi_watchdog_state = action_val;
                return ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB);
        } else if (pretimeout_since_last_heartbeat) {
-               /* A pretimeout occurred, make sure we set the timeout.
-                  We don't want to set the action, though, we want to
-                  leave that alone (thus it can't be combined with the
-                  above operation. */
-               pretimeout_since_last_heartbeat = 0;
+               /*
+                * A pretimeout occurred, make sure we set the timeout.
+                * We don't want to set the action, though, we want to
+                * leave that alone (thus it can't be combined with the
+                * above operation.
+                */
                return ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
        }
 
-       down(&heartbeat_lock);
+       mutex_lock(&heartbeat_lock);
 
        atomic_set(&heartbeat_tofree, 2);
 
-       /* Don't reset the timer if we have the timer turned off, that
-           re-enables the watchdog. */
+       /*
+        * Don't reset the timer if we have the timer turned off, that
+        * re-enables the watchdog.
+        */
        if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE) {
-               up(&heartbeat_lock);
+               mutex_unlock(&heartbeat_lock);
                return 0;
        }
 
@@ -452,71 +643,43 @@ static int ipmi_heartbeat(void)
                                      &heartbeat_recv_msg,
                                      1);
        if (rv) {
-               up(&heartbeat_lock);
+               mutex_unlock(&heartbeat_lock);
                printk(KERN_WARNING PFX "heartbeat failure: %d\n",
                       rv);
                return rv;
        }
 
        /* Wait for the heartbeat to be sent. */
-       down(&heartbeat_wait_lock);
+       wait_for_completion(&heartbeat_wait);
 
        if (heartbeat_recv_msg.msg.data[0] != 0) {
-           /* Got an error in the heartbeat response.  It was already
-              reported in ipmi_wdog_msg_handler, but we should return
-              an error here. */
-           rv = -EINVAL;
+               /*
+                * Got an error in the heartbeat response.  It was already
+                * reported in ipmi_wdog_msg_handler, but we should return
+                * an error here.
+                */
+               rv = -EINVAL;
        }
 
-       up(&heartbeat_lock);
+       mutex_unlock(&heartbeat_lock);
 
        return rv;
 }
 
-static void panic_halt_ipmi_heartbeat(void)
-{
-       struct kernel_ipmi_msg             msg;
-       struct ipmi_system_interface_addr addr;
-
-
-       /* Don't reset the timer if we have the timer turned off, that
-           re-enables the watchdog. */
-       if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE)
-               return;
-
-       addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
-       addr.channel = IPMI_BMC_CHANNEL;
-       addr.lun = 0;
-
-       msg.netfn = 0x06;
-       msg.cmd = IPMI_WDOG_RESET_TIMER;
-       msg.data = NULL;
-       msg.data_len = 0;
-       ipmi_request_supply_msgs(watchdog_user,
-                                (struct ipmi_addr *) &addr,
-                                0,
-                                &msg,
-                                NULL,
-                                &panic_halt_heartbeat_smi_msg,
-                                &panic_halt_heartbeat_recv_msg,
-                                1);
-}
-
-static struct watchdog_info ident=
-{
+static struct watchdog_info ident = {
        .options        = 0,    /* WDIOF_SETTIMEOUT, */
        .firmware_version = 1,
        .identity       = "IPMI"
 };
 
-static int ipmi_ioctl(struct inode *inode, struct file *file,
+static int ipmi_ioctl(struct file *file,
                      unsigned int cmd, unsigned long arg)
 {
        void __user *argp = (void __user *)arg;
        int i;
        int val;
 
-       switch(cmd) {
+       switch (cmd) {
        case WDIOC_GETSUPPORT:
                i = copy_to_user(argp, &ident, sizeof(ident));
                return i ? -EFAULT : 0;
@@ -535,6 +698,7 @@ static int ipmi_ioctl(struct inode *inode, struct file *file,
                return 0;
 
        case WDIOC_SET_PRETIMEOUT:
+       case WDIOC_SETPRETIMEOUT:
                i = copy_from_user(&val, argp, sizeof(int));
                if (i)
                        return -EFAULT;
@@ -542,6 +706,7 @@ static int ipmi_ioctl(struct inode *inode, struct file *file,
                return ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
 
        case WDIOC_GET_PRETIMEOUT:
+       case WDIOC_GETPRETIMEOUT:
                i = copy_to_user(argp, &pretimeout, sizeof(pretimeout));
                if (i)
                        return -EFAULT;
@@ -554,15 +719,13 @@ static int ipmi_ioctl(struct inode *inode, struct file *file,
                i = copy_from_user(&val, argp, sizeof(int));
                if (i)
                        return -EFAULT;
-               if (val & WDIOS_DISABLECARD)
-               {
+               if (val & WDIOS_DISABLECARD) {
                        ipmi_watchdog_state = WDOG_TIMEOUT_NONE;
                        ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB);
                        ipmi_start_timer_on_heartbeat = 0;
                }
 
-               if (val & WDIOS_ENABLECARD)
-               {
+               if (val & WDIOS_ENABLECARD) {
                        ipmi_watchdog_state = action_val;
                        ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB);
                }
@@ -580,6 +743,19 @@ static int ipmi_ioctl(struct inode *inode, struct file *file,
        }
 }
 
+static long ipmi_unlocked_ioctl(struct file *file,
+                               unsigned int cmd,
+                               unsigned long arg)
+{
+       int ret;
+
+       mutex_lock(&ipmi_watchdog_mutex);
+       ret = ipmi_ioctl(file, cmd, arg);
+       mutex_unlock(&ipmi_watchdog_mutex);
+
+       return ret;
+}
+
 static ssize_t ipmi_write(struct file *file,
                          const char  __user *buf,
                          size_t      len,
@@ -588,13 +764,13 @@ static ssize_t ipmi_write(struct file *file,
        int rv;
 
        if (len) {
-               if (!nowayout) {
-                       size_t i;
+               if (!nowayout) {
+                       size_t i;
 
                        /* In case it was set long ago */
                        expect_close = 0;
 
-                       for (i = 0; i != len; i++) {
+                       for (i = 0; i != len; i++) {
                                char c;
 
                                if (get_user(c, buf + i))
@@ -606,9 +782,8 @@ static ssize_t ipmi_write(struct file *file,
                rv = ipmi_heartbeat();
                if (rv)
                        return rv;
-               return 1;
        }
-       return 0;
+       return len;
 }
 
 static ssize_t ipmi_read(struct file *file,
@@ -622,15 +797,17 @@ static ssize_t ipmi_read(struct file *file,
        if (count <= 0)
                return 0;
 
-       /* Reading returns if the pretimeout has gone off, and it only does
-          it once per pretimeout. */
+       /*
+        * Reading returns if the pretimeout has gone off, and it only does
+        * it once per pretimeout.
+        */
        spin_lock(&ipmi_read_lock);
        if (!data_to_read) {
                if (file->f_flags & O_NONBLOCK) {
                        rv = -EAGAIN;
                        goto out;
                }
-               
+
                init_waitqueue_entry(&wait, current);
                add_wait_queue(&read_q, &wait);
                while (!data_to_read) {
@@ -640,7 +817,7 @@ static ssize_t ipmi_read(struct file *file,
                        spin_lock(&ipmi_read_lock);
                }
                remove_wait_queue(&read_q, &wait);
-           
+
                if (signal_pending(current)) {
                        rv = -ERESTARTSYS;
                        goto out;
@@ -663,26 +840,28 @@ static ssize_t ipmi_read(struct file *file,
 
 static int ipmi_open(struct inode *ino, struct file *filep)
 {
-        switch (iminor(ino))
-        {
-                case WATCHDOG_MINOR:
-                   if(test_and_set_bit(0, &ipmi_wdog_open))
-                        return -EBUSY;
-
-                   /* Don't start the timer now, let it start on the
-                      first heartbeat. */
-                   ipmi_start_timer_on_heartbeat = 1;
-                    return nonseekable_open(ino, filep);
-
-                default:
-                    return (-ENODEV);
-        }
+       switch (iminor(ino)) {
+       case WATCHDOG_MINOR:
+               if (test_and_set_bit(0, &ipmi_wdog_open))
+                       return -EBUSY;
+
+
+               /*
+                * Don't start the timer now, let it start on the
+                * first heartbeat.
+                */
+               ipmi_start_timer_on_heartbeat = 1;
+               return nonseekable_open(ino, filep);
+
+       default:
+               return (-ENODEV);
+       }
 }
 
 static unsigned int ipmi_poll(struct file *file, poll_table *wait)
 {
        unsigned int mask = 0;
-       
+
        poll_wait(file, &read_q, wait);
 
        spin_lock(&ipmi_read_lock);
@@ -704,33 +883,33 @@ static int ipmi_fasync(int fd, struct file *file, int on)
 
 static int ipmi_close(struct inode *ino, struct file *filep)
 {
-       if (iminor(ino)==WATCHDOG_MINOR)
-       {
+       if (iminor(ino) == WATCHDOG_MINOR) {
                if (expect_close == 42) {
                        ipmi_watchdog_state = WDOG_TIMEOUT_NONE;
                        ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB);
                } else {
-                       printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
+                       printk(KERN_CRIT PFX
+                              "Unexpected close, not stopping watchdog!\n");
                        ipmi_heartbeat();
                }
                clear_bit(0, &ipmi_wdog_open);
        }
 
-       ipmi_fasync (-1, filep, 0);
        expect_close = 0;
 
        return 0;
 }
 
-static struct file_operations ipmi_wdog_fops = {
+static const struct file_operations ipmi_wdog_fops = {
        .owner   = THIS_MODULE,
        .read    = ipmi_read,
        .poll    = ipmi_poll,
        .write   = ipmi_write,
-       .ioctl   = ipmi_ioctl,
+       .unlocked_ioctl = ipmi_unlocked_ioctl,
        .open    = ipmi_open,
        .release = ipmi_close,
        .fasync  = ipmi_fasync,
+       .llseek  = no_llseek,
 };
 
 static struct miscdevice ipmi_wdog_miscdev = {
@@ -739,8 +918,6 @@ static struct miscdevice ipmi_wdog_miscdev = {
        .fops           = &ipmi_wdog_fops
 };
 
-static DECLARE_RWSEM(register_sem);
-
 static void ipmi_wdog_msg_handler(struct ipmi_recv_msg *msg,
                                  void                 *handler_data)
 {
@@ -749,16 +926,17 @@ static void ipmi_wdog_msg_handler(struct ipmi_recv_msg *msg,
                       msg->msg.data[0],
                       msg->msg.cmd);
        }
-       
+
        ipmi_free_recv_msg(msg);
 }
 
 static void ipmi_wdog_pretimeout_handler(void *handler_data)
 {
        if (preaction_val != WDOG_PRETIMEOUT_NONE) {
-               if (preop_val == WDOG_PREOP_PANIC)
-                       panic("Watchdog pre-timeout");
-               else if (preop_val == WDOG_PREOP_GIVE_DATA) {
+               if (preop_val == WDOG_PREOP_PANIC) {
+                       if (atomic_inc_and_test(&preop_panic_excl))
+                               panic("Watchdog pre-timeout");
+               } else if (preop_val == WDOG_PREOP_GIVE_DATA) {
                        spin_lock(&ipmi_read_lock);
                        data_to_read = 1;
                        wake_up_interruptible(&read_q);
@@ -768,14 +946,14 @@ static void ipmi_wdog_pretimeout_handler(void *handler_data)
                }
        }
 
-       /* On some machines, the heartbeat will give
-          an error and not work unless we re-enable
-          the timer.   So do so. */
+       /*
+        * On some machines, the heartbeat will give an error and not
+        * work unless we re-enable the timer.  So do so.
+        */
        pretimeout_since_last_heartbeat = 1;
 }
 
-static struct ipmi_user_hndl ipmi_hndlrs =
-{
+static struct ipmi_user_hndl ipmi_hndlrs = {
        .ipmi_recv_hndl           = ipmi_wdog_msg_handler,
        .ipmi_watchdog_pretimeout = ipmi_wdog_pretimeout_handler
 };
@@ -784,10 +962,14 @@ static void ipmi_register_watchdog(int ipmi_intf)
 {
        int rv = -EBUSY;
 
-       down_write(&register_sem);
        if (watchdog_user)
                goto out;
 
+       if ((ifnum_to_use >= 0) && (ifnum_to_use != ipmi_intf))
+               goto out;
+
+       watchdog_ifnum = ipmi_intf;
+
        rv = ipmi_create_user(ipmi_intf, &ipmi_hndlrs, NULL, &watchdog_user);
        if (rv < 0) {
                printk(KERN_CRIT PFX "Unable to register with ipmi\n");
@@ -805,42 +987,144 @@ static void ipmi_register_watchdog(int ipmi_intf)
                printk(KERN_CRIT PFX "Unable to register misc device\n");
        }
 
- out:
-       up_write(&register_sem);
+#ifdef HAVE_DIE_NMI
+       if (nmi_handler_registered) {
+               int old_pretimeout = pretimeout;
+               int old_timeout = timeout;
+               int old_preop_val = preop_val;
+
+               /*
+                * Set the pretimeout to go off in a second and give
+                * ourselves plenty of time to stop the timer.
+                */
+               ipmi_watchdog_state = WDOG_TIMEOUT_RESET;
+               preop_val = WDOG_PREOP_NONE; /* Make sure nothing happens */
+               pretimeout = 99;
+               timeout = 100;
 
+               testing_nmi = 1;
+
+               rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB);
+               if (rv) {
+                       printk(KERN_WARNING PFX "Error starting timer to"
+                              " test NMI: 0x%x.  The NMI pretimeout will"
+                              " likely not work\n", rv);
+                       rv = 0;
+                       goto out_restore;
+               }
+
+               msleep(1500);
+
+               if (testing_nmi != 2) {
+                       printk(KERN_WARNING PFX "IPMI NMI didn't seem to"
+                              " occur.  The NMI pretimeout will"
+                              " likely not work\n");
+               }
+ out_restore:
+               testing_nmi = 0;
+               preop_val = old_preop_val;
+               pretimeout = old_pretimeout;
+               timeout = old_timeout;
+       }
+#endif
+
+ out:
        if ((start_now) && (rv == 0)) {
                /* Run from startup, so start the timer now. */
                start_now = 0; /* Disable this function after first startup. */
                ipmi_watchdog_state = action_val;
                ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB);
                printk(KERN_INFO PFX "Starting now!\n");
+       } else {
+               /* Stop the timer now. */
+               ipmi_watchdog_state = WDOG_TIMEOUT_NONE;
+               ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB);
        }
 }
 
-#ifdef HAVE_NMI_HANDLER
-static int
-ipmi_nmi(void *dev_id, struct pt_regs *regs, int cpu, int handled)
+static void ipmi_unregister_watchdog(int ipmi_intf)
 {
-       /* If no one else handled the NMI, we assume it was the IPMI
-           watchdog. */
-       if ((!handled) && (preop_val == WDOG_PREOP_PANIC))
-               panic(PFX "pre-timeout");
-
-       /* On some machines, the heartbeat will give
-          an error and not work unless we re-enable
-          the timer.   So do so. */
-       pretimeout_since_last_heartbeat = 1;
+       int rv;
+
+       if (!watchdog_user)
+               goto out;
+
+       if (watchdog_ifnum != ipmi_intf)
+               goto out;
+
+       /* Make sure no one can call us any more. */
+       misc_deregister(&ipmi_wdog_miscdev);
+
+       /*
+        * Wait to make sure the message makes it out.  The lower layer has
+        * pointers to our buffers, we want to make sure they are done before
+        * we release our memory.
+        */
+       while (atomic_read(&set_timeout_tofree))
+               schedule_timeout_uninterruptible(1);
+
+       /* Disconnect from IPMI. */
+       rv = ipmi_destroy_user(watchdog_user);
+       if (rv) {
+               printk(KERN_WARNING PFX "error unlinking from IPMI: %d\n",
+                      rv);
+       }
+       watchdog_user = NULL;
 
-       return NOTIFY_DONE;
+ out:
+       return;
 }
 
-static struct nmi_handler ipmi_nmi_handler =
+#ifdef HAVE_DIE_NMI
+static int
+ipmi_nmi(struct notifier_block *self, unsigned long val, void *data)
 {
-       .link     = LIST_HEAD_INIT(ipmi_nmi_handler.link),
-       .dev_name = "ipmi_watchdog",
-       .dev_id   = NULL,
-       .handler  = ipmi_nmi,
-       .priority = 0, /* Call us last. */
+       struct die_args *args = data;
+
+       if (val != DIE_NMIUNKNOWN)
+               return NOTIFY_OK;
+
+       /* Hack, if it's a memory or I/O error, ignore it. */
+       if (args->err & 0xc0)
+               return NOTIFY_OK;
+
+       /*
+        * If we get here, it's an NMI that's not a memory or I/O
+        * error.  We can't truly tell if it's from IPMI or not
+        * without sending a message, and sending a message is almost
+        * impossible because of locking.
+        */
+
+       if (testing_nmi) {
+               testing_nmi = 2;
+               return NOTIFY_STOP;
+       }
+
+       /* If we are not expecting a timeout, ignore it. */
+       if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE)
+               return NOTIFY_OK;
+
+       if (preaction_val != WDOG_PRETIMEOUT_NMI)
+               return NOTIFY_OK;
+
+       /*
+        * If no one else handled the NMI, we assume it was the IPMI
+        * watchdog.
+        */
+       if (preop_val == WDOG_PREOP_PANIC) {
+               /* On some machines, the heartbeat will give
+                  an error and not work unless we re-enable
+                  the timer.   So do so. */
+               pretimeout_since_last_heartbeat = 1;
+               if (atomic_inc_and_test(&preop_panic_excl))
+                       panic(PFX "pre-timeout");
+       }
+
+       return NOTIFY_STOP;
+}
+
+static struct notifier_block ipmi_nmi_handler = {
+       .notifier_call = ipmi_nmi
 };
 #endif
 
@@ -848,19 +1132,20 @@ static int wdog_reboot_handler(struct notifier_block *this,
                               unsigned long         code,
                               void                  *unused)
 {
-       static int reboot_event_handled = 0;
+       static int reboot_event_handled;
 
        if ((watchdog_user) && (!reboot_event_handled)) {
                /* Make sure we only do this once. */
                reboot_event_handled = 1;
 
-               if (code == SYS_DOWN || code == SYS_HALT) {
+               if (code == SYS_POWER_OFF || code == SYS_HALT) {
                        /* Disable the WDT if we are shutting down. */
                        ipmi_watchdog_state = WDOG_TIMEOUT_NONE;
                        panic_halt_ipmi_set_timeout();
-               } else {
+               } else if (ipmi_watchdog_state != WDOG_TIMEOUT_NONE) {
                        /* Set a long timer to let the reboot happens, but
-                          reboot if it hangs. */
+                          reboot if it hangs, but only if the watchdog
+                          timer was already running. */
                        timeout = 120;
                        pretimeout = 0;
                        ipmi_watchdog_state = WDOG_TIMEOUT_RESET;
@@ -880,18 +1165,19 @@ static int wdog_panic_handler(struct notifier_block *this,
                              unsigned long         event,
                              void                  *unused)
 {
-       static int panic_event_handled = 0;
-
-       /* On a panic, if we have a panic timeout, make sure that the thing
-          reboots, even if it hangs during that panic. */
-       if (watchdog_user && !panic_event_handled) {
-               /* Make sure the panic doesn't hang, and make sure we
-                  do this only once. */
+       static int panic_event_handled;
+
+       /* On a panic, if we have a panic timeout, make sure to extend
+          the watchdog timer to a reasonable value to complete the
+          panic, if the watchdog timer is running.  Plus the
+          pretimeout is meaningless at panic time. */
+       if (watchdog_user && !panic_event_handled &&
+           ipmi_watchdog_state != WDOG_TIMEOUT_NONE) {
+               /* Make sure we do this only once. */
                panic_event_handled = 1;
-           
+
                timeout = 255;
                pretimeout = 0;
-               ipmi_watchdog_state = WDOG_TIMEOUT_RESET;
                panic_halt_ipmi_set_timeout();
        }
 
@@ -905,164 +1191,181 @@ static struct notifier_block wdog_panic_notifier = {
 };
 
 
-static void ipmi_new_smi(int if_num)
+static void ipmi_new_smi(int if_num, struct device *device)
 {
        ipmi_register_watchdog(if_num);
 }
 
 static void ipmi_smi_gone(int if_num)
 {
-       /* This can never be called, because once the watchdog is
-          registered, the interface can't go away until the watchdog
-          is unregistered. */
+       ipmi_unregister_watchdog(if_num);
 }
 
-static struct ipmi_smi_watcher smi_watcher =
-{
+static struct ipmi_smi_watcher smi_watcher = {
        .owner    = THIS_MODULE,
        .new_smi  = ipmi_new_smi,
        .smi_gone = ipmi_smi_gone
 };
 
-static int __init ipmi_wdog_init(void)
+static int action_op(const char *inval, char *outval)
 {
-       int rv;
+       if (outval)
+               strcpy(outval, action);
 
-       printk(KERN_INFO PFX "driver version "
-              IPMI_WATCHDOG_VERSION "\n");
+       if (!inval)
+               return 0;
 
-       if (strcmp(action, "reset") == 0) {
+       if (strcmp(inval, "reset") == 0)
                action_val = WDOG_TIMEOUT_RESET;
-       } else if (strcmp(action, "none") == 0) {
+       else if (strcmp(inval, "none") == 0)
                action_val = WDOG_TIMEOUT_NONE;
-       } else if (strcmp(action, "power_cycle") == 0) {
+       else if (strcmp(inval, "power_cycle") == 0)
                action_val = WDOG_TIMEOUT_POWER_CYCLE;
-       } else if (strcmp(action, "power_off") == 0) {
+       else if (strcmp(inval, "power_off") == 0)
                action_val = WDOG_TIMEOUT_POWER_DOWN;
-       } else {
-               action_val = WDOG_TIMEOUT_RESET;
-               printk(KERN_INFO PFX "Unknown action '%s', defaulting to"
-                      " reset\n", action);
-       }
+       else
+               return -EINVAL;
+       strcpy(action, inval);
+       return 0;
+}
 
-       if (strcmp(preaction, "pre_none") == 0) {
+static int preaction_op(const char *inval, char *outval)
+{
+       if (outval)
+               strcpy(outval, preaction);
+
+       if (!inval)
+               return 0;
+
+       if (strcmp(inval, "pre_none") == 0)
                preaction_val = WDOG_PRETIMEOUT_NONE;
-       } else if (strcmp(preaction, "pre_smi") == 0) {
+       else if (strcmp(inval, "pre_smi") == 0)
                preaction_val = WDOG_PRETIMEOUT_SMI;
-#ifdef HAVE_NMI_HANDLER
-       } else if (strcmp(preaction, "pre_nmi") == 0) {
+#ifdef HAVE_DIE_NMI
+       else if (strcmp(inval, "pre_nmi") == 0)
                preaction_val = WDOG_PRETIMEOUT_NMI;
 #endif
-       } else if (strcmp(preaction, "pre_int") == 0) {
+       else if (strcmp(inval, "pre_int") == 0)
                preaction_val = WDOG_PRETIMEOUT_MSG_INT;
-       } else {
-               preaction_val = WDOG_PRETIMEOUT_NONE;
-               printk(KERN_INFO PFX "Unknown preaction '%s', defaulting to"
-                      " none\n", preaction);
-       }
+       else
+               return -EINVAL;
+       strcpy(preaction, inval);
+       return 0;
+}
+
+static int preop_op(const char *inval, char *outval)
+{
+       if (outval)
+               strcpy(outval, preop);
+
+       if (!inval)
+               return 0;
 
-       if (strcmp(preop, "preop_none") == 0) {
+       if (strcmp(inval, "preop_none") == 0)
                preop_val = WDOG_PREOP_NONE;
-       } else if (strcmp(preop, "preop_panic") == 0) {
+       else if (strcmp(inval, "preop_panic") == 0)
                preop_val = WDOG_PREOP_PANIC;
-       } else if (strcmp(preop, "preop_give_data") == 0) {
+       else if (strcmp(inval, "preop_give_data") == 0)
                preop_val = WDOG_PREOP_GIVE_DATA;
-       } else {
-               preop_val = WDOG_PREOP_NONE;
-               printk(KERN_INFO PFX "Unknown preop '%s', defaulting to"
-                      " none\n", preop);
-       }
+       else
+               return -EINVAL;
+       strcpy(preop, inval);
+       return 0;
+}
+
+static void check_parms(void)
+{
+#ifdef HAVE_DIE_NMI
+       int do_nmi = 0;
+       int rv;
 
-#ifdef HAVE_NMI_HANDLER
        if (preaction_val == WDOG_PRETIMEOUT_NMI) {
+               do_nmi = 1;
                if (preop_val == WDOG_PREOP_GIVE_DATA) {
                        printk(KERN_WARNING PFX "Pretimeout op is to give data"
                               " but NMI pretimeout is enabled, setting"
                               " pretimeout op to none\n");
-                       preop_val = WDOG_PREOP_NONE;
+                       preop_op("preop_none", NULL);
+                       do_nmi = 0;
                }
-#ifdef CONFIG_X86_LOCAL_APIC
-               if (nmi_watchdog == NMI_IO_APIC) {
-                       printk(KERN_WARNING PFX "nmi_watchdog is set to IO APIC"
-                              " mode (value is %d), that is incompatible"
-                              " with using NMI in the IPMI watchdog."
-                              " Disabling IPMI nmi pretimeout.\n",
-                              nmi_watchdog);
-                       preaction_val = WDOG_PRETIMEOUT_NONE;
-               } else {
-#endif
-               rv = request_nmi(&ipmi_nmi_handler);
+       }
+       if (do_nmi && !nmi_handler_registered) {
+               rv = register_die_notifier(&ipmi_nmi_handler);
                if (rv) {
-                       printk(KERN_WARNING PFX "Can't register nmi handler\n");
-                       return rv;
-               }
-#ifdef CONFIG_X86_LOCAL_APIC
-               }
-#endif
+                       printk(KERN_WARNING PFX
+                              "Can't register nmi handler\n");
+                       return;
+               } else
+                       nmi_handler_registered = 1;
+       } else if (!do_nmi && nmi_handler_registered) {
+               unregister_die_notifier(&ipmi_nmi_handler);
+               nmi_handler_registered = 0;
        }
 #endif
-
-       rv = ipmi_smi_watcher_register(&smi_watcher);
-       if (rv) {
-#ifdef HAVE_NMI_HANDLER
-               if (preaction_val == WDOG_PRETIMEOUT_NMI)
-                       release_nmi(&ipmi_nmi_handler);
-#endif
-               printk(KERN_WARNING PFX "can't register smi watcher\n");
-               return rv;
-       }
-
-       register_reboot_notifier(&wdog_reboot_notifier);
-       notifier_chain_register(&panic_notifier_list, &wdog_panic_notifier);
-
-       return 0;
 }
 
-static __exit void ipmi_unregister_watchdog(void)
+static int __init ipmi_wdog_init(void)
 {
        int rv;
 
-       down_write(&register_sem);
-
-#ifdef HAVE_NMI_HANDLER
-       if (preaction_val == WDOG_PRETIMEOUT_NMI)
-               release_nmi(&ipmi_nmi_handler);
-#endif
+       if (action_op(action, NULL)) {
+               action_op("reset", NULL);
+               printk(KERN_INFO PFX "Unknown action '%s', defaulting to"
+                      " reset\n", action);
+       }
 
-       notifier_chain_unregister(&panic_notifier_list, &wdog_panic_notifier);
-       unregister_reboot_notifier(&wdog_reboot_notifier);
+       if (preaction_op(preaction, NULL)) {
+               preaction_op("pre_none", NULL);
+               printk(KERN_INFO PFX "Unknown preaction '%s', defaulting to"
+                      " none\n", preaction);
+       }
 
-       if (! watchdog_user)
-               goto out;
+       if (preop_op(preop, NULL)) {
+               preop_op("preop_none", NULL);
+               printk(KERN_INFO PFX "Unknown preop '%s', defaulting to"
+                      " none\n", preop);
+       }
 
-       /* Make sure no one can call us any more. */
-       misc_deregister(&ipmi_wdog_miscdev);
+       check_parms();
 
-       /* Wait to make sure the message makes it out.  The lower layer has
-          pointers to our buffers, we want to make sure they are done before
-          we release our memory. */
-       while (atomic_read(&set_timeout_tofree)) {
-               set_current_state(TASK_UNINTERRUPTIBLE);
-               schedule_timeout(1);
-       }
+       register_reboot_notifier(&wdog_reboot_notifier);
+       atomic_notifier_chain_register(&panic_notifier_list,
+                       &wdog_panic_notifier);
 
-       /* Disconnect from IPMI. */
-       rv = ipmi_destroy_user(watchdog_user);
+       rv = ipmi_smi_watcher_register(&smi_watcher);
        if (rv) {
-               printk(KERN_WARNING PFX "error unlinking from IPMI: %d\n",
-                      rv);
+#ifdef HAVE_DIE_NMI
+               if (nmi_handler_registered)
+                       unregister_die_notifier(&ipmi_nmi_handler);
+#endif
+               atomic_notifier_chain_unregister(&panic_notifier_list,
+                                                &wdog_panic_notifier);
+               unregister_reboot_notifier(&wdog_reboot_notifier);
+               printk(KERN_WARNING PFX "can't register smi watcher\n");
+               return rv;
        }
-       watchdog_user = NULL;
 
- out:
-       up_write(&register_sem);
+       printk(KERN_INFO PFX "driver initialized\n");
+
+       return 0;
 }
 
 static void __exit ipmi_wdog_exit(void)
 {
        ipmi_smi_watcher_unregister(&smi_watcher);
-       ipmi_unregister_watchdog();
+       ipmi_unregister_watchdog(watchdog_ifnum);
+
+#ifdef HAVE_DIE_NMI
+       if (nmi_handler_registered)
+               unregister_die_notifier(&ipmi_nmi_handler);
+#endif
+
+       atomic_notifier_chain_unregister(&panic_notifier_list,
+                                        &wdog_panic_notifier);
+       unregister_reboot_notifier(&wdog_reboot_notifier);
 }
 module_exit(ipmi_wdog_exit);
 module_init(ipmi_wdog_init);
 MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Corey Minyard <minyard@mvista.com>");
+MODULE_DESCRIPTION("watchdog timer based upon the IPMI interface.");