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11#include <asm/apic.h>
12#include <asm/nmi.h>
13
14#include <linux/cpumask.h>
15#include <linux/kdebug.h>
16#include <linux/notifier.h>
17#include <linux/kprobes.h>
18#include <linux/nmi.h>
19#include <linux/module.h>
20#include <linux/delay.h>
21
22#ifdef CONFIG_HARDLOCKUP_DETECTOR
23u64 hw_nmi_get_sample_period(int watchdog_thresh)
24{
25 return (u64)(cpu_khz) * 1000 * watchdog_thresh;
26}
27#endif
28
29#ifdef arch_trigger_all_cpu_backtrace
30
31static DECLARE_BITMAP(backtrace_mask, NR_CPUS) __read_mostly;
32
33
34static unsigned long backtrace_flag;
35
36void arch_trigger_all_cpu_backtrace(void)
37{
38 int i;
39
40 if (test_and_set_bit(0, &backtrace_flag))
41
42
43
44
45 return;
46
47 cpumask_copy(to_cpumask(backtrace_mask), cpu_online_mask);
48
49 printk(KERN_INFO "sending NMI to all CPUs:\n");
50 apic->send_IPI_all(NMI_VECTOR);
51
52
53 for (i = 0; i < 10 * 1000; i++) {
54 if (cpumask_empty(to_cpumask(backtrace_mask)))
55 break;
56 mdelay(1);
57 }
58
59 clear_bit(0, &backtrace_flag);
60 smp_mb__after_clear_bit();
61}
62
63static int __kprobes
64arch_trigger_all_cpu_backtrace_handler(unsigned int cmd, struct pt_regs *regs)
65{
66 int cpu;
67
68 cpu = smp_processor_id();
69
70 if (cpumask_test_cpu(cpu, to_cpumask(backtrace_mask))) {
71 static arch_spinlock_t lock = __ARCH_SPIN_LOCK_UNLOCKED;
72
73 arch_spin_lock(&lock);
74 printk(KERN_WARNING "NMI backtrace for cpu %d\n", cpu);
75 show_regs(regs);
76 arch_spin_unlock(&lock);
77 cpumask_clear_cpu(cpu, to_cpumask(backtrace_mask));
78 return NMI_HANDLED;
79 }
80
81 return NMI_DONE;
82}
83
84static int __init register_trigger_all_cpu_backtrace(void)
85{
86 register_nmi_handler(NMI_LOCAL, arch_trigger_all_cpu_backtrace_handler,
87 0, "arch_bt");
88 return 0;
89}
90early_initcall(register_trigger_all_cpu_backtrace);
91#endif
92