1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Machine specific NMI handling for generic.
4 * Split out from traps.c by Osamu Tomita <tomita@cinet.co.jp>
5 */
6#ifndef _ASM_X86_MACH_DEFAULT_MACH_TRAPS_H
7#define _ASM_X86_MACH_DEFAULT_MACH_TRAPS_H
8
9#include <asm/mc146818rtc.h>
10
11#define NMI_REASON_PORT 0x61
12
13#define NMI_REASON_SERR 0x80
14#define NMI_REASON_IOCHK 0x40
15#define NMI_REASON_MASK (NMI_REASON_SERR | NMI_REASON_IOCHK)
16
17#define NMI_REASON_CLEAR_SERR 0x04
18#define NMI_REASON_CLEAR_IOCHK 0x08
19#define NMI_REASON_CLEAR_MASK 0x0f
20
21static inline unsigned char default_get_nmi_reason(void)
22{
23 return inb(NMI_REASON_PORT);
24}
25
26static inline void reassert_nmi(void)
27{
28 int old_reg = -1;
29
30 if (do_i_have_lock_cmos())
31 old_reg = current_lock_cmos_reg();
32 else
33 lock_cmos(0); /* register doesn't matter here */
34 outb(value: 0x8f, port: 0x70);
35 inb(port: 0x71); /* dummy */
36 outb(value: 0x0f, port: 0x70);
37 inb(port: 0x71); /* dummy */
38 if (old_reg >= 0)
39 outb(value: old_reg, port: 0x70);
40 else
41 unlock_cmos();
42}
43
44#endif /* _ASM_X86_MACH_DEFAULT_MACH_TRAPS_H */
45

source code of linux/arch/x86/include/asm/mach_traps.h