1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Copyright (C) 2007 Atmel Corporation |
4 | */ |
5 | #include <linux/delay.h> |
6 | #include <linux/kdebug.h> |
7 | #include <linux/notifier.h> |
8 | #include <linux/sched.h> |
9 | #include <linux/sched/debug.h> |
10 | #include <linux/hardirq.h> |
11 | |
12 | enum nmi_action { |
13 | NMI_SHOW_STATE = 1 << 0, |
14 | NMI_SHOW_REGS = 1 << 1, |
15 | NMI_DIE = 1 << 2, |
16 | NMI_DEBOUNCE = 1 << 3, |
17 | }; |
18 | |
19 | static unsigned long nmi_actions; |
20 | |
21 | static int nmi_debug_notify(struct notifier_block *self, |
22 | unsigned long val, void *data) |
23 | { |
24 | struct die_args *args = data; |
25 | |
26 | if (likely(val != DIE_NMI)) |
27 | return NOTIFY_DONE; |
28 | |
29 | if (nmi_actions & NMI_SHOW_STATE) |
30 | show_state(); |
31 | if (nmi_actions & NMI_SHOW_REGS) |
32 | show_regs(args->regs); |
33 | if (nmi_actions & NMI_DEBOUNCE) |
34 | mdelay(10); |
35 | if (nmi_actions & NMI_DIE) |
36 | return NOTIFY_BAD; |
37 | |
38 | return NOTIFY_OK; |
39 | } |
40 | |
41 | static struct notifier_block nmi_debug_nb = { |
42 | .notifier_call = nmi_debug_notify, |
43 | }; |
44 | |
45 | static int __init nmi_debug_setup(char *str) |
46 | { |
47 | char *p, *sep; |
48 | |
49 | register_die_notifier(nb: &nmi_debug_nb); |
50 | |
51 | if (*str != '=') |
52 | return 1; |
53 | |
54 | for (p = str + 1; *p; p = sep + 1) { |
55 | sep = strchr(p, ','); |
56 | if (sep) |
57 | *sep = 0; |
58 | if (strcmp(p, "state" ) == 0) |
59 | nmi_actions |= NMI_SHOW_STATE; |
60 | else if (strcmp(p, "regs" ) == 0) |
61 | nmi_actions |= NMI_SHOW_REGS; |
62 | else if (strcmp(p, "debounce" ) == 0) |
63 | nmi_actions |= NMI_DEBOUNCE; |
64 | else if (strcmp(p, "die" ) == 0) |
65 | nmi_actions |= NMI_DIE; |
66 | else |
67 | printk(KERN_WARNING "NMI: Unrecognized action `%s'\n" , |
68 | p); |
69 | if (!sep) |
70 | break; |
71 | } |
72 | |
73 | return 1; |
74 | } |
75 | __setup("nmi_debug" , nmi_debug_setup); |
76 | |