1 /*
2 * Copyright (C) 2007 Atmel Corporation
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 */
8 #include <linux/delay.h>
9 #include <linux/kdebug.h>
10 #include <linux/notifier.h>
11 #include <linux/sched.h>
12
13 #include <asm/irq.h>
14
15 enum 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
22 static unsigned long nmi_actions;
23
nmi_debug_notify(struct notifier_block * self,unsigned long val,void * data)24 static 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
44 static struct notifier_block nmi_debug_nb = {
45 .notifier_call = nmi_debug_notify,
46 };
47
nmi_debug_setup(char * str)48 static int __init nmi_debug_setup(char *str)
49 {
50 char *p, *sep;
51
52 register_die_notifier(&nmi_debug_nb);
53 if (nmi_enable()) {
54 printk(KERN_WARNING "Unable to enable NMI.\n");
55 return 0;
56 }
57
58 if (*str != '=')
59 return 0;
60
61 for (p = str + 1; *p; p = sep + 1) {
62 sep = strchr(p, ',');
63 if (sep)
64 *sep = 0;
65 if (strcmp(p, "state") == 0)
66 nmi_actions |= NMI_SHOW_STATE;
67 else if (strcmp(p, "regs") == 0)
68 nmi_actions |= NMI_SHOW_REGS;
69 else if (strcmp(p, "debounce") == 0)
70 nmi_actions |= NMI_DEBOUNCE;
71 else if (strcmp(p, "die") == 0)
72 nmi_actions |= NMI_DIE;
73 else
74 printk(KERN_WARNING "NMI: Unrecognized action `%s'\n",
75 p);
76 if (!sep)
77 break;
78 }
79
80 return 0;
81 }
82 __setup("nmi_debug", nmi_debug_setup);
83