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 <linux/thread_info.h>
13 #include <asm/apic.h>
14 #include <asm/nmi.h>
15
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>
23
24 #include "local.h"
25
26 #ifdef CONFIG_HARDLOCKUP_DETECTOR_PERF
27 u64 hw_nmi_get_sample_period(int watchdog_thresh)
28 {
29 return (u64)(cpu_khz) * 1000 * watchdog_thresh;
30 }
31 #endif
32
33 #ifdef arch_trigger_cpumask_backtrace
34 static void nmi_raise_cpu_backtrace(cpumask_t *mask)
35 {
36 __apic_send_IPI_mask(mask, NMI_VECTOR);
37 }
38
39 void arch_trigger_cpumask_backtrace(const cpumask_t *mask, int exclude_cpu)
40 {
41 nmi_trigger_cpumask_backtrace(mask, exclude_cpu,
42 nmi_raise_cpu_backtrace);
43 }
44
45 static int nmi_cpu_backtrace_handler(unsigned int cmd, struct pt_regs *regs)
46 {
47 if (nmi_cpu_backtrace(regs))
48 return NMI_HANDLED;
49
50 return NMI_DONE;
51 }
52 NOKPROBE_SYMBOL(nmi_cpu_backtrace_handler);
53
54 static int __init register_nmi_cpu_backtrace_handler(void)
55 {
56 register_nmi_handler(NMI_LOCAL, nmi_cpu_backtrace_handler,
57 0, "arch_bt");
58 return 0;
59 }
60 early_initcall(register_nmi_cpu_backtrace_handler);
61 #endif
62
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