arch/sh/kernel/nmi_debug.c

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