i386: prepare shared kernel/nmi.c

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 0 insertions, 468 deletions

diff --git a/arch/i386/kernel/nmi.c b/arch/i386/kernel/nmi.c
deleted file mode 100644
index c7227e2..0000000
--- a/arch/i386/kernel/nmi.c
+++ /dev/null
@@ -1,468 +0,0 @@
-/*
- *  linux/arch/i386/nmi.c
- *
- *  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.
- *  Mikael Pettersson	: Pentium 4 support for local APIC NMI watchdog.
- *  Pavel Machek and
- *  Mikael Pettersson	: PM converted to driver model. Disable/enable API.
- */
-
-#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>
-#include <linux/kprobes.h>
-#include <linux/cpumask.h>
-#include <linux/kernel_stat.h>
-#include <linux/kdebug.h>
-
-#include <asm/smp.h>
-#include <asm/nmi.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 */
-
-unsigned int nmi_watchdog = NMI_DEFAULT;
-static unsigned int nmi_hz = HZ;
-
-static DEFINE_PER_CPU(short, wd_enabled);
-
-/* local prototypes */
-static int unknown_nmi_panic_callback(struct pt_regs *regs, int cpu);
-
-static int endflag __initdata = 0;
-
-#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
-
-static 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 ... ");
-
-	if (nmi_watchdog == NMI_LOCAL_APIC)
-		smp_call_function(nmi_cpu_busy, (void *)&endflag, 0, 0);
-
-	for_each_possible_cpu(cpu)
-		prev_nmi_count[cpu] = per_cpu(irq_stat, cpu).__nmi_count;
-	local_irq_enable();
-	mdelay((20*1000)/nmi_hz); // wait 20 ticks
-
-	for_each_possible_cpu(cpu) {
-#ifdef CONFIG_SMP
-		/* Check cpu_callin_map here because that is set
-		   after the timer is started. */
-		if (!cpu_isset(cpu, cpu_callin_map))
-			continue;
-#endif
-		if (!per_cpu(wd_enabled, cpu))
-			continue;
-		if (nmi_count(cpu) - prev_nmi_count[cpu] <= 5) {
-			printk("CPU#%d: NMI appears to be stuck (%d->%d)!\n",
-				cpu,
-				prev_nmi_count[cpu],
-				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;
-}
-/* This needs to happen later in boot so counters are working */
-late_initcall(check_nmi_watchdog);
-
-static int __init setup_nmi_watchdog(char *str)
-{
-	int nmi;
-
-	get_option(&str, &nmi);
-
-	if ((nmi >= NMI_INVALID) || (nmi < NMI_NONE))
-		return 0;
-
-	nmi_watchdog = nmi;
-	return 1;
-}
-
-__setup("nmi_watchdog=", setup_nmi_watchdog);
-
-
-/* Suspend/resume support */
-
-#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 = {
-	set_kset_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(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; /* enable it before to avoid race with handler */
-		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.
- *
- * 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!]
- */
-
-static unsigned int
-	last_irq_sums [NR_CPUS],
-	alert_counter [NR_CPUS];
-
-void touch_nmi_watchdog(void)
-{
-	if (nmi_watchdog > 0) {
-		unsigned cpu;
-
-		/*
-		 * Just reset the alert counters, (other CPUs might be
-		 * spinning on locks we hold):
-		 */
-		for_each_present_cpu(cpu) {
-			if (alert_counter[cpu])
-				alert_counter[cpu] = 0;
-		}
-	}
-
-	/*
-	 * Tickle the softlockup detector too:
-	 */
-	touch_softlockup_watchdog();
-}
-EXPORT_SYMBOL(touch_nmi_watchdog);
-
-extern void die_nmi(struct pt_regs *, const char *msg);
-
-__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
-	 * smp_processor_id().
-	 */
-	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;
-	}
-
-	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);
-	}
-
-	/*
-	 * Take the local apic timer and PIT/HPET into account. We don't
-	 * know which one is active, when we have highres/dyntick on
-	 */
-	sum = per_cpu(irq_stat, cpu).apic_timer_irqs + kstat_cpu(cpu).irqs[0];
-
-	/* if the none of the timers isn't firing, this cpu isn't doing much */
-	if (!touched && last_irq_sums[cpu] == sum) {
-		/*
-		 * Ayiee, looks like this CPU is stuck ...
-		 * wait a few IRQs (5 seconds) before doing the oops ...
-		 */
-		alert_counter[cpu]++;
-		if (alert_counter[cpu] == 5*nmi_hz)
-			/*
-			 * die_nmi will return ONLY if NOTIFY_STOP happens..
-			 */
-			die_nmi(regs, "BUG: NMI Watchdog detected LOCKUP");
-	} else {
-		last_irq_sums[cpu] = sum;
-		alert_counter[cpu] = 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;
-}
-
-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;
-}
-
-#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(regs, buf);
-	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 == NMI_DEFAULT) {
-		if (lapic_watchdog_ok())
-			nmi_watchdog = NMI_LOCAL_APIC;
-		else
-			nmi_watchdog = NMI_IO_APIC;
-	}
-
-	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
-
-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);