1 // SPDX-License-Identifier: GPL-2.0
3 * HW NMI watchdog support
5 * started by Don Zickus, Copyright (C) 2010 Red Hat, Inc.
7 * Arch specific calls to support NMI watchdog
9 * Bits copied from original nmi.c file
12 #include <linux/thread_info.h>
16 #include <linux/cpumask.h>
17 #include <linux/kdebug.h>
18 #include <linux/notifier.h>
19 #include <linux/kprobes.h>
20 #include <linux/nmi.h>
21 #include <linux/init.h>
22 #include <linux/delay.h>
24 #ifdef CONFIG_HARDLOCKUP_DETECTOR_PERF
25 u64 hw_nmi_get_sample_period(int watchdog_thresh)
27 return (u64)(cpu_khz) * 1000 * watchdog_thresh;
31 #ifdef arch_trigger_cpumask_backtrace
32 static void nmi_raise_cpu_backtrace(cpumask_t *mask)
34 apic->send_IPI_mask(mask, NMI_VECTOR);
37 void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)
39 nmi_trigger_cpumask_backtrace(mask, exclude_self,
40 nmi_raise_cpu_backtrace);
43 static int nmi_cpu_backtrace_handler(unsigned int cmd, struct pt_regs *regs)
45 if (nmi_cpu_backtrace(regs))
50 NOKPROBE_SYMBOL(nmi_cpu_backtrace_handler);
52 static int __init register_nmi_cpu_backtrace_handler(void)
54 register_nmi_handler(NMI_LOCAL, nmi_cpu_backtrace_handler,
58 early_initcall(register_nmi_cpu_backtrace_handler);