1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _ASM_X86_NMI_H
3#define _ASM_X86_NMI_H
4
5#include <linux/irq_work.h>
6#include <linux/pm.h>
7#include <asm/irq.h>
8#include <asm/io.h>
9
10#ifdef CONFIG_X86_LOCAL_APIC
11
12extern int reserve_perfctr_nmi(unsigned int);
13extern void release_perfctr_nmi(unsigned int);
14extern int reserve_evntsel_nmi(unsigned int);
15extern void release_evntsel_nmi(unsigned int);
16
17#endif /* CONFIG_X86_LOCAL_APIC */
18
19extern int unknown_nmi_panic;
20extern int panic_on_unrecovered_nmi;
21extern int panic_on_io_nmi;
22
23/* NMI handler flags */
24#define NMI_FLAG_FIRST 1
25
26/**
27 * enum - NMI types.
28 * @NMI_LOCAL: Local NMI, CPU-specific NMI generated by the Local APIC.
29 * @NMI_UNKNOWN: Unknown NMI, the source of the NMI may not be identified.
30 * @NMI_SERR: System Error NMI, typically triggered by PCI errors.
31 * @NMI_IO_CHECK: I/O Check NMI, related to I/O errors.
32 * @NMI_MAX: Maximum value for NMI types.
33 *
34 * NMI types are used to categorize NMIs and to dispatch them to the
35 * appropriate handler.
36 */
37enum {
38 NMI_LOCAL=0,
39 NMI_UNKNOWN,
40 NMI_SERR,
41 NMI_IO_CHECK,
42 NMI_MAX
43};
44
45/* NMI handler return values */
46#define NMI_DONE 0
47#define NMI_HANDLED 1
48
49typedef int (*nmi_handler_t)(unsigned int, struct pt_regs *);
50
51struct nmiaction {
52 struct list_head list;
53 nmi_handler_t handler;
54 u64 max_duration;
55 unsigned long flags;
56 const char *name;
57};
58
59/**
60 * register_nmi_handler - Register a handler for a specific NMI type
61 * @t: NMI type (e.g. NMI_LOCAL)
62 * @fn: The NMI handler
63 * @fg: Flags associated with the NMI handler
64 * @n: Name of the NMI handler
65 * @init: Optional __init* attributes for struct nmiaction
66 *
67 * Adds the provided handler to the list of handlers for the specified
68 * NMI type. Handlers flagged with NMI_FLAG_FIRST would be executed first.
69 *
70 * Sometimes the source of an NMI can't be reliably determined which
71 * results in an NMI being tagged as "unknown". Register an additional
72 * handler using the NMI type - NMI_UNKNOWN to handle such cases. The
73 * caller would get one last chance to assume responsibility for the
74 * NMI.
75 *
76 * Return: 0 on success, or an error code on failure.
77 */
78#define register_nmi_handler(t, fn, fg, n, init...) \
79({ \
80 static struct nmiaction init fn##_na = { \
81 .list = LIST_HEAD_INIT(fn##_na.list), \
82 .handler = (fn), \
83 .name = (n), \
84 .flags = (fg), \
85 }; \
86 __register_nmi_handler((t), &fn##_na); \
87})
88
89int __register_nmi_handler(unsigned int, struct nmiaction *);
90
91/**
92 * unregister_nmi_handler - Unregister a handler for a specific NMI type
93 * @type: NMI type (e.g. NMI_LOCAL)
94 * @name: Name of the NMI handler used during registration
95 *
96 * Removes the handler associated with the specified NMI type from the
97 * NMI handler list. The "name" is used as a lookup key to identify the
98 * handler.
99 */
100void unregister_nmi_handler(unsigned int type, const char *name);
101
102void set_emergency_nmi_handler(unsigned int type, nmi_handler_t handler);
103
104void stop_nmi(void);
105void restart_nmi(void);
106void local_touch_nmi(void);
107
108#endif /* _ASM_X86_NMI_H */
109

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