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/init.h>
  20 #include <linux/delay.h>
  21
  22 #ifdef CONFIG_HARDLOCKUP_DETECTOR
  23 u64 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 static void nmi_raise_cpu_backtrace(cpumask_t *mask)
  31 {
  32         apic->send_IPI_mask(mask, NMI_VECTOR);
  33 }
  34
  35 void arch_trigger_all_cpu_backtrace(bool include_self)
  36 {
  37         nmi_trigger_all_cpu_backtrace(include_self, nmi_raise_cpu_backtrace);
  38 }
  39
  40 static int
  41 arch_trigger_all_cpu_backtrace_handler(unsigned int cmd, struct pt_regs *regs)
  42 {
  43         if (nmi_cpu_backtrace(regs))
  44                 return NMI_HANDLED;
  45
  46         return NMI_DONE;
  47 }
  48 NOKPROBE_SYMBOL(arch_trigger_all_cpu_backtrace_handler);
  49
  50 static int __init register_trigger_all_cpu_backtrace(void)
  51 {
  52         register_nmi_handler(NMI_LOCAL, arch_trigger_all_cpu_backtrace_handler,
  53                                 0, "arch_bt");
  54         return 0;
  55 }
  56 early_initcall(register_trigger_all_cpu_backtrace);
  57 #endif