arch/sh/kernel/nmi_debug.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2007 Atmel Corporation
   4  */
   5 #include <linux/delay.h>
   6 #include <linux/kdebug.h>
   7 #include <linux/notifier.h>
   8 #include <linux/sched.h>
   9 #include <linux/sched/debug.h>
  10 #include <linux/hardirq.h>
  11
  12 enum nmi_action {
  13         NMI_SHOW_STATE  = 1 << 0,
  14         NMI_SHOW_REGS   = 1 << 1,
  15         NMI_DIE         = 1 << 2,
  16         NMI_DEBOUNCE    = 1 << 3,
  17 };
  18
  19 static unsigned long nmi_actions;
  20
  21 static int nmi_debug_notify(struct notifier_block *self,
  22                 unsigned long val, void *data)
  23 {
  24         struct die_args *args = data;
  25
  26         if (likely(val != DIE_NMI))
  27                 return NOTIFY_DONE;
  28
  29         if (nmi_actions & NMI_SHOW_STATE)
  30                 show_state();
  31         if (nmi_actions & NMI_SHOW_REGS)
  32                 show_regs(args->regs);
  33         if (nmi_actions & NMI_DEBOUNCE)
  34                 mdelay(10);
  35         if (nmi_actions & NMI_DIE)
  36                 return NOTIFY_BAD;
  37
  38         return NOTIFY_OK;
  39 }
  40
  41 static struct notifier_block nmi_debug_nb = {
  42         .notifier_call = nmi_debug_notify,
  43 };
  44
  45 static int __init nmi_debug_setup(char *str)
  46 {
  47         char *p, *sep;
  48
  49         register_die_notifier(&nmi_debug_nb);
  50
  51         if (*str != '=')
  52                 return 0;
  53
  54         for (p = str + 1; *p; p = sep + 1) {
  55                 sep = strchr(p, ',');
  56                 if (sep)
  57                         *sep = 0;
  58                 if (strcmp(p, "state") == 0)
  59                         nmi_actions |= NMI_SHOW_STATE;
  60                 else if (strcmp(p, "regs") == 0)
  61                         nmi_actions |= NMI_SHOW_REGS;
  62                 else if (strcmp(p, "debounce") == 0)
  63                         nmi_actions |= NMI_DEBOUNCE;
  64                 else if (strcmp(p, "die") == 0)
  65                         nmi_actions |= NMI_DIE;
  66                 else
  67                         printk(KERN_WARNING "NMI: Unrecognized action `%s'\n",
  68                                 p);
  69                 if (!sep)
  70                         break;
  71         }
  72
  73         return 0;
  74 }
  75 __setup("nmi_debug", nmi_debug_setup);