xref: /linux/arch/x86/include/asm/mach_traps.h (revision 498495dba268b20e8eadd7fe93c140c68b6cc9d2)
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 
default_get_nmi_reason(void)21 static inline unsigned char default_get_nmi_reason(void)
22 {
23 	return inb(NMI_REASON_PORT);
24 }
25 
reassert_nmi(void)26 static 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(0x8f, 0x70);
35 	inb(0x71);		/* dummy */
36 	outb(0x0f, 0x70);
37 	inb(0x71);		/* dummy */
38 	if (old_reg >= 0)
39 		outb(old_reg, 0x70);
40 	else
41 		unlock_cmos();
42 }
43 
44 #endif /* _ASM_X86_MACH_DEFAULT_MACH_TRAPS_H */
45