obj-$(CONFIG_SMP) += smpcommon.o
obj-$(CONFIG_X86_TRAMPOLINE) += trampoline.o
obj-$(CONFIG_X86_MPPARSE) += mpparse.o
-obj-$(CONFIG_X86_LOCAL_APIC) += apic_32.o nmi.o
+obj-$(CONFIG_X86_LOCAL_APIC) += apic_32.o nmi_32.o
obj-$(CONFIG_X86_IO_APIC) += io_apic_32.o
obj-$(CONFIG_X86_REBOOTFIXUPS) += reboot_fixups.o
obj-$(CONFIG_KEXEC) += machine_kexec.o relocate_kernel_32.o crash_32.o
+++ /dev/null
-/*
- * 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);
--- /dev/null
+/*
+ * 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);
projects / deliverable / linux.git / commitdiff
