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); 76