5 files changed, 103 insertions, 42 deletions

diff --git a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c
index f21b41e7770c..58c8e015e77e 100644
--- a/arch/i386/kernel/traps.c
+++ b/arch/i386/kernel/traps.c
@@ -747,6 +747,11 @@ static __kprobes void default_do_nmi(struct pt_regs * regs)
                  */
                 if (nmi_watchdog_tick(regs, reason))
                         return;
+#endif
+                if (notify_die(DIE_NMI_POST, "nmi_post", regs, reason, 2, 0)
+                                                        == NOTIFY_STOP)
+                        return;
+#ifdef CONFIG_X86_LOCAL_APIC
                 if (!do_nmi_callback(regs, smp_processor_id()))
 #endif
                         unknown_nmi_error(reason, regs);
diff --git a/arch/x86_64/kernel/traps.c b/arch/x86_64/kernel/traps.c
index d76fc32d4599..0484a2ceac87 100644
--- a/arch/x86_64/kernel/traps.c
+++ b/arch/x86_64/kernel/traps.c
@@ -792,6 +792,8 @@ asmlinkage __kprobes void default_do_nmi(struct pt_regs *regs)
                  */
                 if (nmi_watchdog_tick(regs,reason))
                         return;
+                if (notify_die(DIE_NMI_POST, "nmi_post", regs, reason, 2, 0)
+                                                                == NOTIFY_STOP)
                 if (!do_nmi_callback(regs,cpu))
                         unknown_nmi_error(reason, regs);
 
diff --git a/drivers/char/ipmi/ipmi_watchdog.c b/drivers/char/ipmi/ipmi_watchdog.c
index 6b634e8d9519..9e9c5de2e549 100644
--- a/drivers/char/ipmi/ipmi_watchdog.c
+++ b/drivers/char/ipmi/ipmi_watchdog.c
@@ -49,9 +49,19 @@
 #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_POST
 #endif
 
 #define PFX "IPMI Watchdog: "
@@ -317,6 +327,11 @@ 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);
 
+#ifdef HAVE_DIE_NMI_POST
+static int testing_nmi;
+static int nmi_handler_registered;
+#endif
+
 static int ipmi_heartbeat(void);
 static void panic_halt_ipmi_heartbeat(void);
 
@@ -358,6 +373,10 @@ 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. */
+        ipmi_start_timer_on_heartbeat = 0;
+        pretimeout_since_last_heartbeat = 0;
+
         data[0] = 0;
         WDOG_SET_TIMER_USE(data[0], WDOG_TIMER_USE_SMS_OS);
 
@@ -432,13 +451,12 @@ 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;
@@ -518,12 +536,10 @@ static int ipmi_heartbeat(void)
         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) {
@@ -531,7 +547,6 @@ 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);
         }
 
@@ -919,6 +934,45 @@ static void ipmi_register_watchdog(int ipmi_intf)
                 printk(KERN_CRIT PFX "Unable to register misc device\n");
         }
 
+#ifdef HAVE_DIE_NMI_POST
+        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:
         up_write(&register_sem);
 
@@ -928,6 +982,10 @@ static void ipmi_register_watchdog(int ipmi_intf)
                 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);
         }
 }
 
@@ -964,17 +1022,28 @@ static void ipmi_unregister_watchdog(int ipmi_intf)
         up_write(&register_sem);
 }
 
-#ifdef HAVE_NMI_HANDLER
+#ifdef HAVE_DIE_NMI_POST
 static int
-ipmi_nmi(void *dev_id, int cpu, int handled)
+ipmi_nmi(struct notifier_block *self, unsigned long val, void *data)
 {
+        if (val != DIE_NMI_POST)
+                return NOTIFY_OK;
+
+        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. */
@@ -983,18 +1052,12 @@ 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,
@@ -1111,7 +1174,7 @@ 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_POST
         else if (strcmp(inval, "pre_nmi") == 0)
                 preaction_val = WDOG_PRETIMEOUT_NMI;
 #endif
@@ -1145,7 +1208,7 @@ static int preop_op(const char *inval, char *outval)
 
 static void check_parms(void)
 {
-#ifdef HAVE_NMI_HANDLER
+#ifdef HAVE_DIE_NMI_POST
         int do_nmi = 0;
         int rv;
 
@@ -1158,20 +1221,9 @@ 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");
@@ -1179,7 +1231,7 @@ 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
@@ -1215,9 +1267,9 @@ 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_POST
+                if (nmi_handler_registered)
+                        unregister_die_notifier(&ipmi_nmi_handler);
 #endif
                 atomic_notifier_chain_unregister(&panic_notifier_list,
                                                  &wdog_panic_notifier);
@@ -1236,9 +1288,9 @@ 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_POST
         if (nmi_handler_registered)
-                release_nmi(&ipmi_nmi_handler);
+                unregister_die_notifier(&ipmi_nmi_handler);
 #endif
 
         atomic_notifier_chain_unregister(&panic_notifier_list,
diff --git a/include/asm-i386/kdebug.h b/include/asm-i386/kdebug.h
index d18cdb9fc9a6..6e1c8e1b5e2b 100644
--- a/include/asm-i386/kdebug.h
+++ b/include/asm-i386/kdebug.h
@@ -38,6 +38,7 @@ enum die_val {
         DIE_GPF,
         DIE_CALL,
         DIE_NMI_IPI,
+        DIE_NMI_POST,
         DIE_PAGE_FAULT,
 };
 
diff --git a/include/asm-x86_64/kdebug.h b/include/asm-x86_64/kdebug.h
index 2b0c088e2957..e9ce163b1550 100644
--- a/include/asm-x86_64/kdebug.h
+++ b/include/asm-x86_64/kdebug.h
@@ -33,6 +33,7 @@ enum die_val {
         DIE_GPF,
         DIE_CALL,
         DIE_NMI_IPI,
+        DIE_NMI_POST,
         DIE_PAGE_FAULT,
 };