kernel/arch/x86/kernel/apic/hw_nmi.c

   1 /*
   2  *  HW NMI watchdog support
   3  *
   4  *  started by Don Zickus, Copyright (C) 2010 Red Hat, Inc.
   5  *
   6  *  Arch specific calls to support NMI watchdog
   7  *
   8  *  Bits copied from original nmi.c file
   9  *
  10  */
  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 #include <linux/seq_buf.h>
  22
  23 #ifdef CONFIG_HARDLOCKUP_DETECTOR
  24 u64 hw_nmi_get_sample_period(int watchdog_thresh)
  25 {
  26         return (u64)(cpu_khz) * 1000 * watchdog_thresh;
  27 }
  28 #endif
  29
  30 #ifdef arch_trigger_all_cpu_backtrace
  31 static void nmi_raise_cpu_backtrace(cpumask_t *mask)
  32 {
  33         apic->send_IPI_mask(mask, NMI_VECTOR);
  34 }
  35
  36 void arch_trigger_all_cpu_backtrace(bool include_self)
  37 {
  38         nmi_trigger_all_cpu_backtrace(include_self, nmi_raise_cpu_backtrace);
  39 }
  40
  41 static int
  42 arch_trigger_all_cpu_backtrace_handler(unsigned int cmd, struct pt_regs *regs)
  43 {
  44         if (nmi_cpu_backtrace(regs))
  45                 return NMI_HANDLED;
  46
  47         return NMI_DONE;
  48 }
  49 NOKPROBE_SYMBOL(arch_trigger_all_cpu_backtrace_handler);
  50
  51 static int __init register_trigger_all_cpu_backtrace(void)
  52 {
  53         register_nmi_handler(NMI_LOCAL, arch_trigger_all_cpu_backtrace_handler,
  54                                 0, "arch_bt");
  55         return 0;
  56 }
  57 early_initcall(register_trigger_all_cpu_backtrace);
  58 #endif