1 files changed, 167 insertions, 101 deletions

diff --git a/drivers/char/ipmi/ipmi_watchdog.c b/drivers/char/ipmi/ipmi_watchdog.c
index 41f78e2c158..e686fc92516 100644
--- a/drivers/char/ipmi/ipmi_watchdog.c
+++ b/drivers/char/ipmi/ipmi_watchdog.c
@@ -50,10 +50,19 @@
 #include <linux/poll.h>
 #include <linux/string.h>
 #include <linux/ctype.h>
+#include <linux/delay.h>
 #include <asm/atomic.h>
 
-#ifdef CONFIG_X86_LOCAL_APIC
-#include <asm/apic.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: "
@@ -166,8 +175,6 @@ 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
@@ -193,11 +200,9 @@ static int set_param_int(const char *val, struct kernel_param *kp)
         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;
 }
@@ -226,17 +231,15 @@ static int set_param_str(const char *val, struct kernel_param *kp)
 
         s = strstrip(valcp);
 
-        down_read(&register_sem);
         rv = fn(s, NULL);
         if (rv)
-                goto out_unlock;
+                goto out;
 
         check_parms();
         if (watchdog_user)
                 rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
 
- out_unlock:
-        up_read(&register_sem);
+ out:
         return rv;
 }
 
@@ -319,9 +322,12 @@ 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 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.
@@ -360,6 +366,9 @@ 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);
 
@@ -434,31 +443,75 @@ static int ipmi_set_timeout(int do_heartbeat)
 
         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();
-        }
-        mutex_unlock(&set_timeout_lock);
 
 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_heartbeat_smi_msg =
+{
+        .done = panic_smi_free
+};
+static struct ipmi_recv_msg panic_halt_heartbeat_recv_msg =
+{
+        .done = panic_recv_free
+};
+
+static void panic_halt_ipmi_heartbeat(void)
+{
+        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 = dummy_smi_free
+        .done = panic_smi_free
 };
 static struct ipmi_recv_msg panic_halt_recv_msg =
 {
-        .done = dummy_recv_free
+        .done = panic_recv_free
 };
 
 /* Special call, doesn't claim any locks.  This is only to be called
@@ -470,13 +523,21 @@ 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
@@ -505,24 +566,14 @@ 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;
@@ -533,7 +584,6 @@ static int ipmi_heartbeat(void)
                    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;
                 return ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
         }
 
@@ -586,35 +636,6 @@ static int ipmi_heartbeat(void)
         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 =
 {
         .options        = 0,    /* WDIOF_SETTIMEOUT, */
@@ -895,7 +916,6 @@ static void ipmi_register_watchdog(int ipmi_intf)
 {
         int rv = -EBUSY;
 
-        down_write(&register_sem);
         if (watchdog_user)
                 goto out;
 
@@ -921,15 +941,56 @@ 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);
         }
 }
 
@@ -937,8 +998,6 @@ static void ipmi_unregister_watchdog(int ipmi_intf)
 {
         int rv;
 
-        down_write(&register_sem);
-
         if (!watchdog_user)
                 goto out;
 
@@ -963,20 +1022,44 @@ static void ipmi_unregister_watchdog(int ipmi_intf)
         watchdog_user = NULL;
 
  out:
-        up_write(&register_sem);
+        return;
 }
 
-#ifdef HAVE_NMI_HANDLER
+#ifdef HAVE_DIE_NMI
 static int
-ipmi_nmi(void *dev_id, int cpu, int handled)
+ipmi_nmi(struct notifier_block *self, unsigned long val, void *data)
 {
+        struct die_args *args = data;
+
+        if (val != DIE_NMI)
+                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_DONE;
+                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 ((!handled) && (preop_val == WDOG_PREOP_PANIC)) {
+        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. */
@@ -985,18 +1068,12 @@ ipmi_nmi(void *dev_id, int cpu, int handled)
                         panic(PFX "pre-timeout");
         }
 
-        return NOTIFY_DONE;
+        return NOTIFY_STOP;
 }
 
-static struct nmi_handler ipmi_nmi_handler =
-{
-        .link     = LIST_HEAD_INIT(ipmi_nmi_handler.link),
-        .dev_name = "ipmi_watchdog",
-        .dev_id   = NULL,
-        .handler  = ipmi_nmi,
-        .priority = 0, /* Call us last. */
+static struct notifier_block ipmi_nmi_handler = {
+        .notifier_call = ipmi_nmi
 };
-int nmi_handler_registered;
 #endif
 
 static int wdog_reboot_handler(struct notifier_block *this,
@@ -1009,7 +1086,7 @@ static int wdog_reboot_handler(struct notifier_block *this,
                 /* 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();
@@ -1113,7 +1190,7 @@ static int preaction_op(const char *inval, char *outval)
                 preaction_val = WDOG_PRETIMEOUT_NONE;
         else if (strcmp(inval, "pre_smi") == 0)
                 preaction_val = WDOG_PRETIMEOUT_SMI;
-#ifdef HAVE_NMI_HANDLER
+#ifdef HAVE_DIE_NMI
         else if (strcmp(inval, "pre_nmi") == 0)
                 preaction_val = WDOG_PRETIMEOUT_NMI;
 #endif
@@ -1147,7 +1224,7 @@ static int preop_op(const char *inval, char *outval)
 
 static void check_parms(void)
 {
-#ifdef HAVE_NMI_HANDLER
+#ifdef HAVE_DIE_NMI
         int do_nmi = 0;
         int rv;
 
@@ -1160,20 +1237,9 @@ static void check_parms(void)
                         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;
-                        do_nmi = 0;
-                }
-#endif
         }
         if (do_nmi && !nmi_handler_registered) {
-                rv = request_nmi(&ipmi_nmi_handler);
+                rv = register_die_notifier(&ipmi_nmi_handler);
                 if (rv) {
                         printk(KERN_WARNING PFX
                                "Can't register nmi handler\n");
@@ -1181,7 +1247,7 @@ static void check_parms(void)
                 } else
                         nmi_handler_registered = 1;
         } else if (!do_nmi && nmi_handler_registered) {
-                release_nmi(&ipmi_nmi_handler);
+                unregister_die_notifier(&ipmi_nmi_handler);
                 nmi_handler_registered = 0;
         }
 #endif
@@ -1217,9 +1283,9 @@ static int __init ipmi_wdog_init(void)
 
         rv = ipmi_smi_watcher_register(&smi_watcher);
         if (rv) {
-#ifdef HAVE_NMI_HANDLER
-                if (preaction_val == WDOG_PRETIMEOUT_NMI)
-                        release_nmi(&ipmi_nmi_handler);
+#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);
@@ -1238,9 +1304,9 @@ static void __exit ipmi_wdog_exit(void)
         ipmi_smi_watcher_unregister(&smi_watcher);
         ipmi_unregister_watchdog(watchdog_ifnum);
 
-#ifdef HAVE_NMI_HANDLER
+#ifdef HAVE_DIE_NMI
         if (nmi_handler_registered)
-                release_nmi(&ipmi_nmi_handler);
+                unregister_die_notifier(&ipmi_nmi_handler);
 #endif
 
         atomic_notifier_chain_unregister(&panic_notifier_list,