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/sched/debug.h>
  13 #include <linux/hardirq.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
  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
  48 static 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);