LXR linux/arch/x86/kernel/apic/hw

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 *  HW NMI watchdog support
   4 *
   5 *  started by Don Zickus, Copyright (C) 2010 Red Hat, Inc.
   6 *
   7 *  Arch specific calls to support NMI watchdog
   8 *
   9 *  Bits copied from original nmi.c file
  10 *
  11 */
  12#include <asm/apic.h>
  13#include <asm/nmi.h>
  14
  15#include <linux/cpumask.h>
  16#include <linux/kdebug.h>
  17#include <linux/notifier.h>
  18#include <linux/kprobes.h>
  19#include <linux/nmi.h>
  20#include <linux/init.h>
  21#include <linux/delay.h>
  22
  23#ifdef CONFIG_HARDLOCKUP_DETECTOR_PERF
  24u64 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_cpumask_backtrace
  31static void nmi_raise_cpu_backtrace(cpumask_t *mask)
  32{
  33        apic->send_IPI_mask(mask, NMI_VECTOR);
  34}
  35
  36void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)
  37{
  38        nmi_trigger_cpumask_backtrace(mask, exclude_self,
  39                                      nmi_raise_cpu_backtrace);
  40}
  41
  42static int nmi_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}
  49NOKPROBE_SYMBOL(nmi_cpu_backtrace_handler);
  50
  51static int __init register_nmi_cpu_backtrace_handler(void)
  52{
  53        register_nmi_handler(NMI_LOCAL, nmi_cpu_backtrace_handler,
  54                                0, "arch_bt");
  55        return 0;
  56}
  57early_initcall(register_nmi_cpu_backtrace_handler);
  58#endif
  59