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8#include <linux/delay.h>
9#include <linux/kdebug.h>
10#include <linux/notifier.h>
11#include <linux/sched.h>
12#include <linux/sched/debug.h>
13#include <linux/hardirq.h>
14
15enum nmi_action {
16 NMI_SHOW_STATE = 1 << 0,
17 NMI_SHOW_REGS = 1 << 1,
18 NMI_DIE = 1 << 2,
19 NMI_DEBOUNCE = 1 << 3,
20};
21
22static unsigned long nmi_actions;
23
24static int nmi_debug_notify(struct notifier_block *self,
25 unsigned long val, void *data)
26{
27 struct die_args *args = data;
28
29 if (likely(val != DIE_NMI))
30 return NOTIFY_DONE;
31
32 if (nmi_actions & NMI_SHOW_STATE)
33 show_state();
34 if (nmi_actions & NMI_SHOW_REGS)
35 show_regs(args->regs);
36 if (nmi_actions & NMI_DEBOUNCE)
37 mdelay(10);
38 if (nmi_actions & NMI_DIE)
39 return NOTIFY_BAD;
40
41 return NOTIFY_OK;
42}
43
44static struct notifier_block nmi_debug_nb = {
45 .notifier_call = nmi_debug_notify,
46};
47
48static int __init nmi_debug_setup(char *str)
49{
50 char *p, *sep;
51
52 register_die_notifier(&nmi_debug_nb);
53
54 if (*str != '=')
55 return 0;
56
57 for (p = str + 1; *p; p = sep + 1) {
58 sep = strchr(p, ',');
59 if (sep)
60 *sep = 0;
61 if (strcmp(p, "state") == 0)
62 nmi_actions |= NMI_SHOW_STATE;
63 else if (strcmp(p, "regs") == 0)
64 nmi_actions |= NMI_SHOW_REGS;
65 else if (strcmp(p, "debounce") == 0)
66 nmi_actions |= NMI_DEBOUNCE;
67 else if (strcmp(p, "die") == 0)
68 nmi_actions |= NMI_DIE;
69 else
70 printk(KERN_WARNING "NMI: Unrecognized action `%s'\n",
71 p);
72 if (!sep)
73 break;
74 }
75
76 return 0;
77}
78__setup("nmi_debug", nmi_debug_setup);
79