fedora core 6 1.2949 + vserver 2.2.0
[linux-2.6.git] / drivers / char / ipmi / ipmi_watchdog.c
index fd70938..6b634e8 100644 (file)
@@ -31,7 +31,6 @@
  *  675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
-#include <linux/config.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/ipmi.h>
@@ -39,6 +38,7 @@
 #include <linux/watchdog.h>
 #include <linux/miscdevice.h>
 #include <linux/init.h>
+#include <linux/completion.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>
+#include <linux/string.h>
+#include <linux/ctype.h>
+#include <asm/atomic.h>
 #ifdef CONFIG_X86_LOCAL_APIC
 #include <asm/apic.h>
 #endif
 
 #define        PFX "IPMI Watchdog: "
 
-#define IPMI_WATCHDOG_VERSION "v33"
-
 /*
  * The IPMI command/response information for the watchdog timer.
  */
 #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 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;
@@ -158,74 +156,187 @@ 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;
 
+static int ifnum_to_use = -1;
+
+static DECLARE_RWSEM(register_sem);
+
+/* 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 = 0;
+static int start_now;
+
+static int set_param_int(const char *val, 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;
+
+       down_read(&register_sem);
+       *((int *)kp->arg) = l;
+       if (watchdog_user)
+               rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
+       up_read(&register_sem);
+
+       return rv;
+}
+
+static int get_param_int(char *buffer, struct kernel_param *kp)
+{
+       return sprintf(buffer, "%i", *((int *)kp->arg));
+}
+
+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, 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);
 
-module_param(timeout, int, 0);
+       down_read(&register_sem);
+       rv = fn(s, NULL);
+       if (rv)
+               goto out_unlock;
+
+       check_parms();
+       if (watchdog_user)
+               rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
+
+ out_unlock:
+       up_read(&register_sem);
+       return rv;
+}
+
+static int get_param_str(char *buffer, 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, 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;
+}
+
+module_param_call(ifnum_to_use, set_param_wdog_ifnum, get_param_int,
+                 &ifnum_to_use, 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_call(timeout, set_param_int, get_param_int, &timeout, 0644);
 MODULE_PARM_DESC(timeout, "Timeout value in seconds.");
-module_param(pretimeout, int, 0);
+
+module_param_call(pretimeout, set_param_int, get_param_int, &pretimeout, 0644);
 MODULE_PARM_DESC(pretimeout, "Pretimeout value in seconds.");
-module_param_string(action, action, sizeof(action), 0);
+
+module_param_call(action, set_param_str, get_param_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_call(preaction, set_param_str, get_param_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_call(preop, set_param_str, get_param_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;
+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);
 
 
-/* We use a semaphore to make sure that only one thing can send a set
+/* 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 semaphore is claimed when the set_timeout is sent and freed
+   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 =
 {
@@ -263,7 +374,7 @@ static int i_ipmi_set_timeout(struct ipmi_smi_msg  *smi_msg,
 
        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 +411,6 @@ 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 +418,7 @@ 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);
 
@@ -320,16 +426,21 @@ 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);
+
+       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);
 
+out:
        return rv;
 }
 
@@ -371,17 +482,17 @@ static void panic_halt_ipmi_set_timeout(void)
    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 =
 {
@@ -424,14 +535,14 @@ static int ipmi_heartbeat(void)
                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. */
        if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE) {
-               up(&heartbeat_lock);
+               mutex_unlock(&heartbeat_lock);
                return 0;
        }
 
@@ -452,14 +563,14 @@ 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
@@ -468,7 +579,7 @@ static int ipmi_heartbeat(void)
            rv = -EINVAL;
        }
 
-       up(&heartbeat_lock);
+       mutex_unlock(&heartbeat_lock);
 
        return rv;
 }
@@ -502,7 +613,7 @@ static void panic_halt_ipmi_heartbeat(void)
                                 1);
 }
 
-static struct watchdog_info ident=
+static struct watchdog_info ident =
 {
        .options        = 0,    /* WDIOF_SETTIMEOUT, */
        .firmware_version = 1,
@@ -663,19 +774,18 @@ 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))
+        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);
+               /* 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);
+       default:
+               return (-ENODEV);
         }
 }
 
@@ -704,16 +814,16 @@ 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);
-                       clear_bit(0, &ipmi_wdog_open);
                } 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);
@@ -722,7 +832,7 @@ static int ipmi_close(struct inode *ino, struct file *filep)
        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,
@@ -739,8 +849,6 @@ 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)
 {
@@ -756,9 +864,10 @@ static void ipmi_wdog_msg_handler(struct ipmi_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);
@@ -788,6 +897,11 @@ static void ipmi_register_watchdog(int ipmi_intf)
        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");
@@ -817,19 +931,57 @@ static void ipmi_register_watchdog(int ipmi_intf)
        }
 }
 
+static void ipmi_unregister_watchdog(int ipmi_intf)
+{
+       int rv;
+
+       down_write(&register_sem);
+
+       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;
+
+ out:
+       up_write(&register_sem);
+}
+
 #ifdef HAVE_NMI_HANDLER
 static int
-ipmi_nmi(void *dev_id, struct pt_regs *regs, int cpu, int handled)
+ipmi_nmi(void *dev_id, int cpu, int handled)
 {
+        /* If we are not expecting a timeout, ignore it. */
+       if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE)
+               return NOTIFY_DONE;
+
        /* 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;
+       if ((!handled) && (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_DONE;
 }
@@ -842,6 +994,7 @@ static struct nmi_handler ipmi_nmi_handler =
        .handler  = ipmi_nmi,
        .priority = 0, /* Call us last. */
 };
+int nmi_handler_registered;
 #endif
 
 static int wdog_reboot_handler(struct notifier_block *this,
@@ -858,9 +1011,10 @@ static int wdog_reboot_handler(struct notifier_block *this,
                        /* 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;
@@ -882,16 +1036,17 @@ static int wdog_panic_handler(struct notifier_block *this,
 {
        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. */
+       /* 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();
        }
 
@@ -905,16 +1060,14 @@ 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 =
@@ -924,62 +1077,86 @@ static struct ipmi_smi_watcher smi_watcher =
        .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) {
+       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 (strcmp(preop, "preop_none") == 0) {
+       if (!inval)
+               return 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_NMI_HANDLER
+       int do_nmi = 0;
+       int rv;
+
        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) {
@@ -989,18 +1166,52 @@ static int __init ipmi_wdog_init(void)
                               " Disabling IPMI nmi pretimeout.\n",
                               nmi_watchdog);
                        preaction_val = WDOG_PRETIMEOUT_NONE;
-               } else {
+                       do_nmi = 0;
+               }
 #endif
+       }
+       if (do_nmi && !nmi_handler_registered) {
                rv = request_nmi(&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) {
+               release_nmi(&ipmi_nmi_handler);
+               nmi_handler_registered = 0;
        }
 #endif
+}
+
+static int __init ipmi_wdog_init(void)
+{
+       int rv;
+
+       if (action_op(action, NULL)) {
+               action_op("reset", NULL);
+               printk(KERN_INFO PFX "Unknown action '%s', defaulting to"
+                      " reset\n", action);
+       }
+
+       if (preaction_op(preaction, NULL)) {
+               preaction_op("pre_none", NULL);
+               printk(KERN_INFO PFX "Unknown preaction '%s', defaulting to"
+                      " none\n", preaction);
+       }
+
+       if (preop_op(preop, NULL)) {
+               preop_op("preop_none", NULL);
+               printk(KERN_INFO PFX "Unknown preop '%s', defaulting to"
+                      " none\n", preop);
+       }
+
+       check_parms();
+
+       register_reboot_notifier(&wdog_reboot_notifier);
+       atomic_notifier_chain_register(&panic_notifier_list,
+                       &wdog_panic_notifier);
 
        rv = ipmi_smi_watcher_register(&smi_watcher);
        if (rv) {
@@ -1008,61 +1219,34 @@ static int __init ipmi_wdog_init(void)
                if (preaction_val == WDOG_PRETIMEOUT_NMI)
                        release_nmi(&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;
        }
 
-       register_reboot_notifier(&wdog_reboot_notifier);
-       notifier_chain_register(&panic_notifier_list, &wdog_panic_notifier);
+       printk(KERN_INFO PFX "driver initialized\n");
 
        return 0;
 }
 
-static __exit void ipmi_unregister_watchdog(void)
+static void __exit ipmi_wdog_exit(void)
 {
-       int rv;
-
-       down_write(&register_sem);
+       ipmi_smi_watcher_unregister(&smi_watcher);
+       ipmi_unregister_watchdog(watchdog_ifnum);
 
 #ifdef HAVE_NMI_HANDLER
-       if (preaction_val == WDOG_PRETIMEOUT_NMI)
+       if (nmi_handler_registered)
                release_nmi(&ipmi_nmi_handler);
 #endif
 
-       notifier_chain_unregister(&panic_notifier_list, &wdog_panic_notifier);
+       atomic_notifier_chain_unregister(&panic_notifier_list,
+                                        &wdog_panic_notifier);
        unregister_reboot_notifier(&wdog_reboot_notifier);
-
-       if (! watchdog_user)
-               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)) {
-               set_current_state(TASK_UNINTERRUPTIBLE);
-               schedule_timeout(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;
-
- out:
-       up_write(&register_sem);
-}
-
-static void __exit ipmi_wdog_exit(void)
-{
-       ipmi_smi_watcher_unregister(&smi_watcher);
-       ipmi_unregister_watchdog();
 }
 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.");