arch/avr32/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
  14 #include <asm/irq.h>
  15
  16 enum nmi_action {
  17         NMI_SHOW_STATE  = 1 << 0,
  18         NMI_SHOW_REGS   = 1 << 1,
  19         NMI_DIE         = 1 << 2,
  20         NMI_DEBOUNCE    = 1 << 3,
  21 };
  22
  23 static unsigned long nmi_actions;
  24
  25 static int nmi_debug_notify(struct notifier_block *self,
  26                 unsigned long val, void *data)
  27 {
  28         struct die_args *args = data;
  29
  30         if (likely(val != DIE_NMI))
  31                 return NOTIFY_DONE;
  32
  33         if (nmi_actions & NMI_SHOW_STATE)
  34                 show_state();
  35         if (nmi_actions & NMI_SHOW_REGS)
  36                 show_regs(args->regs);
  37         if (nmi_actions & NMI_DEBOUNCE)
  38                 mdelay(10);
  39         if (nmi_actions & NMI_DIE)
  40                 return NOTIFY_BAD;
  41
  42         return NOTIFY_OK;
  43 }
  44
  45 static struct notifier_block nmi_debug_nb = {
  46         .notifier_call = nmi_debug_notify,
  47 };
  48
  49 static int __init nmi_debug_setup(char *str)
  50 {
  51         char *p, *sep;
  52
  53         register_die_notifier(&nmi_debug_nb);
  54         if (nmi_enable()) {
  55                 printk(KERN_WARNING "Unable to enable NMI.\n");
  56                 return 0;
  57         }
  58
  59         if (*str != '=')
  60                 return 0;
  61
  62         for (p = str + 1; *p; p = sep + 1) {
  63                 sep = strchr(p, ',');
  64                 if (sep)
  65                         *sep = 0;
  66                 if (strcmp(p, "state") == 0)
  67                         nmi_actions |= NMI_SHOW_STATE;
  68                 else if (strcmp(p, "regs") == 0)
  69                         nmi_actions |= NMI_SHOW_REGS;
  70                 else if (strcmp(p, "debounce") == 0)
  71                         nmi_actions |= NMI_DEBOUNCE;
  72                 else if (strcmp(p, "die") == 0)
  73                         nmi_actions |= NMI_DIE;
  74                 else
  75                         printk(KERN_WARNING "NMI: Unrecognized action `%s'\n",
  76                                 p);
  77                 if (!sep)
  78                         break;
  79         }
  80
  81         return 0;
  82 }
  83 __setup("nmi_debug", nmi_debug_setup);