x86: nmi_32/64.c - merge down nmi_32.c and nmi_64.c to nmi.c

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: hpa@zytor.com
Cc: mingo@redhat.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

3 files changed, 65 insertions, 515 deletions

diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 5e618c3b4720..d5dd6668225f 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -53,7 +53,7 @@ obj-$(CONFIG_X86_32_SMP)	+= smpcommon.o
 obj-$(CONFIG_X86_64_SMP)	+= tsc_sync.o smpcommon.o
 obj-$(CONFIG_X86_TRAMPOLINE)	+= trampoline_$(BITS).o
 obj-$(CONFIG_X86_MPPARSE)	+= mpparse.o
-obj-$(CONFIG_X86_LOCAL_APIC)	+= apic_$(BITS).o nmi_$(BITS).o
+obj-$(CONFIG_X86_LOCAL_APIC)	+= apic_$(BITS).o nmi.o
 obj-$(CONFIG_X86_IO_APIC)	+= io_apic_$(BITS).o
 obj-$(CONFIG_X86_REBOOTFIXUPS)	+= reboot_fixups_32.o
 obj-$(CONFIG_KEXEC)		+= machine_kexec_$(BITS).o
diff --git a/arch/x86/kernel/nmi_32.c b/arch/x86/kernel/nmi.c
index a94dbedf2b74..69a839fc1eb0 100644
--- a/arch/x86/kernel/nmi_32.c
+++ b/arch/x86/kernel/nmi.c
@@ -11,10 +11,11 @@
  *  Mikael Pettersson	: PM converted to driver model. Disable/enable API.
  */
 
+#include <linux/nmi.h>
+#include <linux/mm.h>
 #include <linux/delay.h>
 #include <linux/interrupt.h>
 #include <linux/module.h>
-#include <linux/nmi.h>
 #include <linux/sysdev.h>
 #include <linux/sysctl.h>
 #include <linux/percpu.h>
@@ -22,13 +23,15 @@
 #include <linux/cpumask.h>
 #include <linux/kernel_stat.h>
 #include <linux/kdebug.h>
-#include <linux/slab.h>
 
 #include <asm/smp.h>
 #include <asm/nmi.h>
+#include <asm/proto.h>
 #include <asm/timer.h>
 
-#include "mach_traps.h"
+#include <asm/mce.h>
+
+#include <mach_traps.h>
 
 int unknown_nmi_panic;
 int nmi_watchdog_enabled;
@@ -45,19 +48,25 @@ atomic_t nmi_active = ATOMIC_INIT(0);		/* oprofile uses this */
 static int panic_on_timeout;
 
 unsigned int nmi_watchdog = NMI_DEFAULT;
-static unsigned int nmi_hz = HZ;
 
+static unsigned int nmi_hz = HZ;
 static DEFINE_PER_CPU(short, wd_enabled);
-
 static int endflag __initdata = 0;
 
 static inline unsigned int get_nmi_count(int cpu)
 {
+#ifdef CONFIG_X86_64
+	return cpu_pda(cpu)->__nmi_count;
+#else
 	return nmi_count(cpu);
+#endif
 }
 
 static inline int mce_in_progress(void)
 {
+#if defined(CONFIX_X86_64) && defined(CONFIG_X86_MCE)
+	return atomic_read(&mce_entry) > 0;
+#endif
 	return 0;
 }
 
@@ -67,8 +76,12 @@ static inline int mce_in_progress(void)
  */
 static inline unsigned int get_timer_irqs(int cpu)
 {
+#ifdef CONFIG_X86_64
+	return read_pda(apic_timer_irqs) + read_pda(irq0_irqs);
+#else
 	return per_cpu(irq_stat, cpu).apic_timer_irqs +
 		per_cpu(irq_stat, cpu).irq0_irqs;
+#endif
 }
 
 /* Run after command line and cpu_init init, but before all other checks */
@@ -76,26 +89,33 @@ void nmi_watchdog_default(void)
 {
 	if (nmi_watchdog != NMI_DEFAULT)
 		return;
+#ifdef CONFIG_X86_64
+	nmi_watchdog = NMI_NONE;
+#else
 	if (lapic_watchdog_ok())
 		nmi_watchdog = NMI_LOCAL_APIC;
 	else
 		nmi_watchdog = NMI_IO_APIC;
+#endif
 }
 
 #ifdef CONFIG_SMP
-/* The performance counters used by NMI_LOCAL_APIC don't trigger when
+/*
+ * The performance counters used by NMI_LOCAL_APIC don't trigger when
  * the CPU is idle. To make sure the NMI watchdog really ticks on all
  * CPUs during the test make them busy.
  */
 static __init void nmi_cpu_busy(void *data)
 {
 	local_irq_enable_in_hardirq();
-	/* Intentionally don't use cpu_relax here. This is
-	   to make sure that the performance counter really ticks,
-	   even if there is a simulator or similar that catches the
-	   pause instruction. On a real HT machine this is fine because
-	   all other CPUs are busy with "useless" delay loops and don't
-	   care if they get somewhat less cycles. */
+	/*
+	 * Intentionally don't use cpu_relax here. This is
+	 * to make sure that the performance counter really ticks,
+	 * even if there is a simulator or similar that catches the
+	 * pause instruction. On a real HT machine this is fine because
+	 * all other CPUs are busy with "useless" delay loops and don't
+	 * care if they get somewhat less cycles.
+	 */
 	while (endflag == 0)
 		mb();
 }
@@ -106,7 +126,7 @@ int __init check_nmi_watchdog(void)
 	unsigned int *prev_nmi_count;
 	int cpu;
 
-	if ((nmi_watchdog == NMI_NONE) || (nmi_watchdog == NMI_DISABLED))
+	if (nmi_watchdog == NMI_NONE || nmi_watchdog == NMI_DISABLED)
 		return 0;
 
 	if (!atomic_read(&nmi_active))
@@ -126,7 +146,7 @@ int __init check_nmi_watchdog(void)
 	for_each_possible_cpu(cpu)
 		prev_nmi_count[cpu] = get_nmi_count(cpu);
 	local_irq_enable();
-	mdelay((20*1000)/nmi_hz); // wait 20 ticks
+	mdelay((20 * 1000) / nmi_hz); /* wait 20 ticks */
 
 	for_each_online_cpu(cpu) {
 		if (!per_cpu(wd_enabled, cpu))
@@ -149,16 +169,20 @@ int __init check_nmi_watchdog(void)
 	}
 	printk("OK.\n");
 
-	/* now that we know it works we can reduce NMI frequency to
-	   something more reasonable; makes a difference in some configs */
+	/*
+	 * now that we know it works we can reduce NMI frequency to
+	 * something more reasonable; makes a difference in some configs
+	 */
 	if (nmi_watchdog == NMI_LOCAL_APIC)
 		nmi_hz = lapic_adjust_nmi_hz(1);
 
 	kfree(prev_nmi_count);
 	return 0;
+
 error:
+#ifdef CONFIG_X86_32
 	timer_ack = !cpu_has_tsc;
-
+#endif
 	return -1;
 }
 
@@ -176,18 +200,17 @@ static int __init setup_nmi_watchdog(char *str)
 
 	get_option(&str, &nmi);
 
-	if ((nmi >= NMI_INVALID) || (nmi < NMI_NONE))
+	if (nmi >= NMI_INVALID || nmi < NMI_NONE)
 		return 0;
 
 	nmi_watchdog = nmi;
 	return 1;
 }
-
 __setup("nmi_watchdog=", setup_nmi_watchdog);
 
-
-/* Suspend/resume support */
-
+/*
+ * Suspend/resume support
+ */
 #ifdef CONFIG_PM
 
 static int nmi_pm_active; /* nmi_active before suspend */
@@ -211,7 +234,6 @@ static int lapic_nmi_resume(struct sys_device *dev)
 	return 0;
 }
 
-
 static struct sysdev_class nmi_sysclass = {
 	.name		= "lapic_nmi",
 	.resume		= lapic_nmi_resume,
@@ -227,7 +249,8 @@ static int __init init_lapic_nmi_sysfs(void)
 {
 	int error;
 
-	/* should really be a BUG_ON but b/c this is an
+	/*
+	 * should really be a BUG_ON but b/c this is an
 	 * init call, it just doesn't work.  -dcz
 	 */
 	if (nmi_watchdog != NMI_LOCAL_APIC)
@@ -241,6 +264,7 @@ static int __init init_lapic_nmi_sysfs(void)
 		error = sysdev_register(&device_lapic_nmi);
 	return error;
 }
+
 /* must come after the local APIC's device_initcall() */
 late_initcall(init_lapic_nmi_sysfs);
 
@@ -281,12 +305,13 @@ void setup_apic_nmi_watchdog(void *unused)
 
 	/* cheap hack to support suspend/resume */
 	/* if cpu0 is not active neither should the other cpus */
-	if ((smp_processor_id() != 0) && (atomic_read(&nmi_active) <= 0))
+	if (smp_processor_id() != 0 && atomic_read(&nmi_active) <= 0)
 		return;
 
 	switch (nmi_watchdog) {
 	case NMI_LOCAL_APIC:
-		__get_cpu_var(wd_enabled) = 1; /* enable it before to avoid race with handler */
+		 /* enable it before to avoid race with handler */
+		__get_cpu_var(wd_enabled) = 1;
 		if (lapic_watchdog_init(nmi_hz) < 0) {
 			__get_cpu_var(wd_enabled) = 0;
 			return;
@@ -301,9 +326,9 @@ void setup_apic_nmi_watchdog(void *unused)
 void stop_apic_nmi_watchdog(void *unused)
 {
 	/* only support LOCAL and IO APICs for now */
-	if ((nmi_watchdog != NMI_LOCAL_APIC) &&
-	    (nmi_watchdog != NMI_IO_APIC))
-	    	return;
+	if (nmi_watchdog != NMI_LOCAL_APIC &&
+	    nmi_watchdog != NMI_IO_APIC)
+		return;
 	if (__get_cpu_var(wd_enabled) == 0)
 		return;
 	if (nmi_watchdog == NMI_LOCAL_APIC)
@@ -323,8 +348,7 @@ void stop_apic_nmi_watchdog(void *unused)
  * since NMIs don't listen to _any_ locks, we have to be extremely
  * careful not to rely on unsafe variables. The printk might lock
  * up though, so we have to break up any console locks first ...
- * [when there will be more tty-related locks, break them up
- *  here too!]
+ * [when there will be more tty-related locks, break them up here too!]
  */
 
 static DEFINE_PER_CPU(unsigned, last_irq_sum);
@@ -357,7 +381,6 @@ EXPORT_SYMBOL(touch_nmi_watchdog);
 notrace __kprobes int
 nmi_watchdog_tick(struct pt_regs *regs, unsigned reason)
 {
-
 	/*
 	 * Since current_thread_info()-> is always on the stack, and we
 	 * always switch the stack NMI-atomically, it's safe to use
@@ -403,7 +426,7 @@ nmi_watchdog_tick(struct pt_regs *regs, unsigned reason)
 		 * wait a few IRQs (5 seconds) before doing the oops ...
 		 */
 		local_inc(&__get_cpu_var(alert_counter));
-		if (local_read(&__get_cpu_var(alert_counter)) == 5*nmi_hz)
+		if (local_read(&__get_cpu_var(alert_counter)) == 5 * nmi_hz)
 			/*
 			 * die_nmi will return ONLY if NOTIFY_STOP happens..
 			 */
@@ -413,6 +436,7 @@ nmi_watchdog_tick(struct pt_regs *regs, unsigned reason)
 		__get_cpu_var(last_irq_sum) = sum;
 		local_set(&__get_cpu_var(alert_counter), 0);
 	}
+
 	/* see if the nmi watchdog went off */
 	if (!__get_cpu_var(wd_enabled))
 		return rc;
@@ -421,7 +445,8 @@ nmi_watchdog_tick(struct pt_regs *regs, unsigned reason)
 		rc |= lapic_wd_event(nmi_hz);
 		break;
 	case NMI_IO_APIC:
-		/* don't know how to accurately check for this.
+		/*
+		 * don't know how to accurately check for this.
 		 * just assume it was a watchdog timer interrupt
 		 * This matches the old behaviour.
 		 */
@@ -458,7 +483,8 @@ int proc_nmi_enabled(struct ctl_table *table, int write, struct file *file,
 		return 0;
 
 	if (atomic_read(&nmi_active) < 0 || nmi_watchdog == NMI_DISABLED) {
-		printk( KERN_WARNING "NMI watchdog is permanently disabled\n");
+		printk(KERN_WARNING
+			"NMI watchdog is permanently disabled\n");
 		return -EIO;
 	}
 
@@ -471,14 +497,14 @@ int proc_nmi_enabled(struct ctl_table *table, int write, struct file *file,
 		else
 			disable_lapic_nmi_watchdog();
 	} else {
-		printk( KERN_WARNING
+		printk(KERN_WARNING
 			"NMI watchdog doesn't know what hardware to touch\n");
 		return -EIO;
 	}
 	return 0;
 }
 
-#endif
+#endif /* CONFIG_SYSCTL */
 
 int do_nmi_callback(struct pt_regs *regs, int cpu)
 {
@@ -504,3 +530,4 @@ void __trigger_all_cpu_backtrace(void)
 
 EXPORT_SYMBOL(nmi_active);
 EXPORT_SYMBOL(nmi_watchdog);
+
diff --git a/arch/x86/kernel/nmi_64.c b/arch/x86/kernel/nmi_64.c
deleted file mode 100644
index c6802447262c..000000000000
--- a/arch/x86/kernel/nmi_64.c
+++ /dev/null
@@ -1,477 +0,0 @@
-/*
- *  NMI watchdog support on APIC systems
- *
- *  Started by Ingo Molnar <mingo@redhat.com>
- *
- *  Fixes:
- *  Mikael Pettersson	: AMD K7 support for local APIC NMI watchdog.
- *  Mikael Pettersson	: Power Management for local APIC NMI watchdog.
- *  Pavel Machek and
- *  Mikael Pettersson	: PM converted to driver model. Disable/enable API.
- */
-
-#include <linux/nmi.h>
-#include <linux/mm.h>
-#include <linux/delay.h>
-#include <linux/interrupt.h>
-#include <linux/module.h>
-#include <linux/sysdev.h>
-#include <linux/sysctl.h>
-#include <linux/kprobes.h>
-#include <linux/cpumask.h>
-#include <linux/kdebug.h>
-
-#include <asm/smp.h>
-#include <asm/nmi.h>
-#include <asm/proto.h>
-#include <asm/mce.h>
-
-#include <mach_traps.h>
-
-int unknown_nmi_panic;
-int nmi_watchdog_enabled;
-
-static cpumask_t backtrace_mask = CPU_MASK_NONE;
-
-/* nmi_active:
- * >0: the lapic NMI watchdog is active, but can be disabled
- * <0: the lapic NMI watchdog has not been set up, and cannot
- *     be enabled
- *  0: the lapic NMI watchdog is disabled, but can be enabled
- */
-atomic_t nmi_active = ATOMIC_INIT(0);		/* oprofile uses this */
-static int panic_on_timeout;
-
-unsigned int nmi_watchdog = NMI_DEFAULT;
-static unsigned int nmi_hz = HZ;
-
-static DEFINE_PER_CPU(short, wd_enabled);
-
-static int endflag __initdata = 0;
-
-static inline unsigned int get_nmi_count(int cpu)
-{
-	return cpu_pda(cpu)->__nmi_count;
-}
-
-static inline int mce_in_progress(void)
-{
-#ifdef CONFIG_X86_MCE
-	return atomic_read(&mce_entry) > 0;
-#endif
-	return 0;
-}
-
-/*
- * Take the local apic timer and PIT/HPET into account. We don't
- * know which one is active, when we have highres/dyntick on
- */
-static inline unsigned int get_timer_irqs(int cpu)
-{
-	return read_pda(apic_timer_irqs) + read_pda(irq0_irqs);
-}
-
-/* Run after command line and cpu_init init, but before all other checks */
-void nmi_watchdog_default(void)
-{
-	if (nmi_watchdog != NMI_DEFAULT)
-		return;
-	nmi_watchdog = NMI_NONE;
-}
-
-#ifdef CONFIG_SMP
-/* The performance counters used by NMI_LOCAL_APIC don't trigger when
- * the CPU is idle. To make sure the NMI watchdog really ticks on all
- * CPUs during the test make them busy.
- */
-static __init void nmi_cpu_busy(void *data)
-{
-	local_irq_enable_in_hardirq();
-	/* Intentionally don't use cpu_relax here. This is
-	   to make sure that the performance counter really ticks,
-	   even if there is a simulator or similar that catches the
-	   pause instruction. On a real HT machine this is fine because
-	   all other CPUs are busy with "useless" delay loops and don't
-	   care if they get somewhat less cycles. */
-	while (endflag == 0)
-		mb();
-}
-#endif
-
-int __init check_nmi_watchdog(void)
-{
-	unsigned int *prev_nmi_count;
-	int cpu;
-
-	if ((nmi_watchdog == NMI_NONE) || (nmi_watchdog == NMI_DISABLED))
-		return 0;
-
-	if (!atomic_read(&nmi_active))
-		return 0;
-
-	prev_nmi_count = kmalloc(NR_CPUS * sizeof(int), GFP_KERNEL);
-	if (!prev_nmi_count)
-		return -1;
-
-	printk(KERN_INFO "Testing NMI watchdog ... ");
-
-#ifdef CONFIG_SMP
-	if (nmi_watchdog == NMI_LOCAL_APIC)
-		smp_call_function(nmi_cpu_busy, (void *)&endflag, 0, 0);
-#endif
-
-	for_each_possible_cpu(cpu)
-		prev_nmi_count[cpu] = get_nmi_count(cpu);
-	local_irq_enable();
-	mdelay((20*1000)/nmi_hz); // wait 20 ticks
-
-	for_each_online_cpu(cpu) {
-		if (!per_cpu(wd_enabled, cpu))
-			continue;
-		if (get_nmi_count(cpu) - prev_nmi_count[cpu] <= 5) {
-			printk(KERN_WARNING "WARNING: CPU#%d: NMI "
-			       "appears to be stuck (%d->%d)!\n",
-				cpu,
-				prev_nmi_count[cpu],
-				get_nmi_count(cpu));
-			per_cpu(wd_enabled, cpu) = 0;
-			atomic_dec(&nmi_active);
-		}
-	}
-	endflag = 1;
-	if (!atomic_read(&nmi_active)) {
-		kfree(prev_nmi_count);
-		atomic_set(&nmi_active, -1);
-		return -1;
-	}
-	printk("OK.\n");
-
-	/* now that we know it works we can reduce NMI frequency to
-	   something more reasonable; makes a difference in some configs */
-	if (nmi_watchdog == NMI_LOCAL_APIC)
-		nmi_hz = lapic_adjust_nmi_hz(1);
-
-	kfree(prev_nmi_count);
-	return 0;
-}
-
-static int __init setup_nmi_watchdog(char *str)
-{
-	int nmi;
-
-	if (!strncmp(str,"panic",5)) {
-		panic_on_timeout = 1;
-		str = strchr(str, ',');
-		if (!str)
-			return 1;
-		++str;
-	}
-
-	get_option(&str, &nmi);
-
-	if ((nmi >= NMI_INVALID) || (nmi < NMI_NONE))
-		return 0;
-
-	nmi_watchdog = nmi;
-	return 1;
-}
-
-__setup("nmi_watchdog=", setup_nmi_watchdog);
-
-#ifdef CONFIG_PM
-
-static int nmi_pm_active; /* nmi_active before suspend */
-
-static int lapic_nmi_suspend(struct sys_device *dev, pm_message_t state)
-{
-	/* only CPU0 goes here, other CPUs should be offline */
-	nmi_pm_active = atomic_read(&nmi_active);
-	stop_apic_nmi_watchdog(NULL);
-	BUG_ON(atomic_read(&nmi_active) != 0);
-	return 0;
-}
-
-static int lapic_nmi_resume(struct sys_device *dev)
-{
-	/* only CPU0 goes here, other CPUs should be offline */
-	if (nmi_pm_active > 0) {
-		setup_apic_nmi_watchdog(NULL);
-		touch_nmi_watchdog();
-	}
-	return 0;
-}
-
-static struct sysdev_class nmi_sysclass = {
-	.name		= "lapic_nmi",
-	.resume		= lapic_nmi_resume,
-	.suspend	= lapic_nmi_suspend,
-};
-
-static struct sys_device device_lapic_nmi = {
-	.id	= 0,
-	.cls	= &nmi_sysclass,
-};
-
-static int __init init_lapic_nmi_sysfs(void)
-{
-	int error;
-
-	/* should really be a BUG_ON but b/c this is an
-	 * init call, it just doesn't work.  -dcz
-	 */
-	if (nmi_watchdog != NMI_LOCAL_APIC)
-		return 0;
-
-	if (atomic_read(&nmi_active) < 0)
-		return 0;
-
-	error = sysdev_class_register(&nmi_sysclass);
-	if (!error)
-		error = sysdev_register(&device_lapic_nmi);
-	return error;
-}
-/* must come after the local APIC's device_initcall() */
-late_initcall(init_lapic_nmi_sysfs);
-
-#endif	/* CONFIG_PM */
-
-static void __acpi_nmi_enable(void *__unused)
-{
-	apic_write_around(APIC_LVT0, APIC_DM_NMI);
-}
-
-/*
- * Enable timer based NMIs on all CPUs:
- */
-void acpi_nmi_enable(void)
-{
-	if (atomic_read(&nmi_active) && nmi_watchdog == NMI_IO_APIC)
-		on_each_cpu(__acpi_nmi_enable, NULL, 0, 1);
-}
-
-static void __acpi_nmi_disable(void *__unused)
-{
-	apic_write_around(APIC_LVT0, APIC_DM_NMI | APIC_LVT_MASKED);
-}
-
-/*
- * Disable timer based NMIs on all CPUs:
- */
-void acpi_nmi_disable(void)
-{
-	if (atomic_read(&nmi_active) && nmi_watchdog == NMI_IO_APIC)
-		on_each_cpu(__acpi_nmi_disable, NULL, 0, 1);
-}
-
-void setup_apic_nmi_watchdog(void *unused)
-{
-	if (__get_cpu_var(wd_enabled))
-		return;
-
-	/* cheap hack to support suspend/resume */
-	/* if cpu0 is not active neither should the other cpus */
-	if ((smp_processor_id() != 0) && (atomic_read(&nmi_active) <= 0))
-		return;
-
-	switch (nmi_watchdog) {
-	case NMI_LOCAL_APIC:
-		__get_cpu_var(wd_enabled) = 1;
-		if (lapic_watchdog_init(nmi_hz) < 0) {
-			__get_cpu_var(wd_enabled) = 0;
-			return;
-		}
-		/* FALL THROUGH */
-	case NMI_IO_APIC:
-		__get_cpu_var(wd_enabled) = 1;
-		atomic_inc(&nmi_active);
-	}
-}
-
-void stop_apic_nmi_watchdog(void *unused)
-{
-	/* only support LOCAL and IO APICs for now */
-	if ((nmi_watchdog != NMI_LOCAL_APIC) &&
-	    (nmi_watchdog != NMI_IO_APIC))
-	    	return;
-	if (__get_cpu_var(wd_enabled) == 0)
-		return;
-	if (nmi_watchdog == NMI_LOCAL_APIC)
-		lapic_watchdog_stop();
-	__get_cpu_var(wd_enabled) = 0;
-	atomic_dec(&nmi_active);
-}
-
-/*
- * the best way to detect whether a CPU has a 'hard lockup' problem
- * is to check it's local APIC timer IRQ counts. If they are not
- * changing then that CPU has some problem.
- *
- * as these watchdog NMI IRQs are generated on every CPU, we only
- * have to check the current processor.
- */
-
-static DEFINE_PER_CPU(unsigned, last_irq_sum);
-static DEFINE_PER_CPU(local_t, alert_counter);
-static DEFINE_PER_CPU(int, nmi_touch);
-
-void touch_nmi_watchdog(void)
-{
-	if (nmi_watchdog > 0) {
-		unsigned cpu;
-
-		/*
- 		 * Tell other CPUs to reset their alert counters. We cannot
-		 * do it ourselves because the alert count increase is not
-		 * atomic.
-		 */
-		for_each_present_cpu(cpu) {
-			if (per_cpu(nmi_touch, cpu) != 1)
-				per_cpu(nmi_touch, cpu) = 1;
-		}
-	}
-
-	touch_softlockup_watchdog();
-}
-EXPORT_SYMBOL(touch_nmi_watchdog);
-
-notrace __kprobes int
-nmi_watchdog_tick(struct pt_regs *regs, unsigned reason)
-{
-	unsigned int sum;
-	int touched = 0;
-	int cpu = smp_processor_id();
-	int rc = 0;
-
-	/* check for other users first */
-	if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT)
-			== NOTIFY_STOP) {
-		rc = 1;
-		touched = 1;
-	}
-
-	sum = get_timer_irqs(cpu);
-
-	if (__get_cpu_var(nmi_touch)) {
-		__get_cpu_var(nmi_touch) = 0;
-		touched = 1;
-	}
-
-	if (cpu_isset(cpu, backtrace_mask)) {
-		static DEFINE_SPINLOCK(lock);	/* Serialise the printks */
-
-		spin_lock(&lock);
-		printk("NMI backtrace for cpu %d\n", cpu);
-		dump_stack();
-		spin_unlock(&lock);
-		cpu_clear(cpu, backtrace_mask);
-	}
-
-	if (mce_in_progress())
-		touched = 1;
-
-	/* if the apic timer isn't firing, this cpu isn't doing much */
-	if (!touched && __get_cpu_var(last_irq_sum) == sum) {
-		/*
-		 * Ayiee, looks like this CPU is stuck ...
-		 * wait a few IRQs (5 seconds) before doing the oops ...
-		 */
-		local_inc(&__get_cpu_var(alert_counter));
-		if (local_read(&__get_cpu_var(alert_counter)) == 5*nmi_hz)
-			die_nmi("NMI Watchdog detected LOCKUP",
-				regs, panic_on_timeout);
-	} else {
-		__get_cpu_var(last_irq_sum) = sum;
-		local_set(&__get_cpu_var(alert_counter), 0);
-	}
-
-	/* see if the nmi watchdog went off */
-	if (!__get_cpu_var(wd_enabled))
-		return rc;
-	switch (nmi_watchdog) {
-	case NMI_LOCAL_APIC:
-		rc |= lapic_wd_event(nmi_hz);
-		break;
-	case NMI_IO_APIC:
-		/* don't know how to accurately check for this.
-		 * just assume it was a watchdog timer interrupt
-		 * This matches the old behaviour.
-		 */
-		rc = 1;
-		break;
-	}
-	return rc;
-}
-
-#ifdef CONFIG_SYSCTL
-
-static int unknown_nmi_panic_callback(struct pt_regs *regs, int cpu)
-{
-	unsigned char reason = get_nmi_reason();
-	char buf[64];
-
-	sprintf(buf, "NMI received for unknown reason %02x\n", reason);
-	die_nmi(buf, regs, 1);	/* Always panic here */
-	return 0;
-}
-
-/*
- * proc handler for /proc/sys/kernel/nmi
- */
-int proc_nmi_enabled(struct ctl_table *table, int write, struct file *file,
-			void __user *buffer, size_t *length, loff_t *ppos)
-{
-	int old_state;
-
-	nmi_watchdog_enabled = (atomic_read(&nmi_active) > 0) ? 1 : 0;
-	old_state = nmi_watchdog_enabled;
-	proc_dointvec(table, write, file, buffer, length, ppos);
-	if (!!old_state == !!nmi_watchdog_enabled)
-		return 0;
-
-	if (atomic_read(&nmi_active) < 0 || nmi_watchdog == NMI_DISABLED) {
-		printk( KERN_WARNING "NMI watchdog is permanently disabled\n");
-		return -EIO;
-	}
-
-	/* if nmi_watchdog is not set yet, then set it */
-	nmi_watchdog_default();
-
-	if (nmi_watchdog == NMI_LOCAL_APIC) {
-		if (nmi_watchdog_enabled)
-			enable_lapic_nmi_watchdog();
-		else
-			disable_lapic_nmi_watchdog();
-	} else {
-		printk( KERN_WARNING
-			"NMI watchdog doesn't know what hardware to touch\n");
-		return -EIO;
-	}
-	return 0;
-}
-
-#endif
-
-int do_nmi_callback(struct pt_regs *regs, int cpu)
-{
-#ifdef CONFIG_SYSCTL
-	if (unknown_nmi_panic)
-		return unknown_nmi_panic_callback(regs, cpu);
-#endif
-	return 0;
-}
-
-void __trigger_all_cpu_backtrace(void)
-{
-	int i;
-
-	backtrace_mask = cpu_online_map;
-	/* Wait for up to 10 seconds for all CPUs to do the backtrace */
-	for (i = 0; i < 10 * 1000; i++) {
-		if (cpus_empty(backtrace_mask))
-			break;
-		mdelay(1);
-	}
-}
-
-EXPORT_SYMBOL(nmi_active);
-EXPORT_SYMBOL(nmi_watchdog);