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 | raise: 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 | |