summaryrefslogtreecommitdiffstats
path: root/include/linux/nmi.h
blob: 0a3fadc32693a9cf869693f4c406eee5d168e36b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
/*
 *  linux/include/linux/nmi.h
 */
#ifndef LINUX_NMI_H
#define LINUX_NMI_H

#include <linux/sched.h>
#include <asm/irq.h>

/*
 * The run state of the lockup detectors is controlled by the content of the
 * 'watchdog_enabled' variable. Each lockup detector has its dedicated bit -
 * bit 0 for the hard lockup detector and bit 1 for the soft lockup detector.
 *
 * 'watchdog_user_enabled', 'nmi_watchdog_enabled' and 'soft_watchdog_enabled'
 * are variables that are only used as an 'interface' between the parameters
 * in /proc/sys/kernel and the internal state bits in 'watchdog_enabled'. The
 * 'watchdog_thresh' variable is handled differently because its value is not
 * boolean, and the lockup detectors are 'suspended' while 'watchdog_thresh'
 * is equal zero.
 */
#define NMI_WATCHDOG_ENABLED_BIT   0
#define SOFT_WATCHDOG_ENABLED_BIT  1
#define NMI_WATCHDOG_ENABLED      (1 << NMI_WATCHDOG_ENABLED_BIT)
#define SOFT_WATCHDOG_ENABLED     (1 << SOFT_WATCHDOG_ENABLED_BIT)

/**
 * touch_nmi_watchdog - restart NMI watchdog timeout.
 * 
 * If the architecture supports the NMI watchdog, touch_nmi_watchdog()
 * may be used to reset the timeout - for code which intentionally
 * disables interrupts for a long time. This call is stateless.
 */
#if defined(CONFIG_HAVE_NMI_WATCHDOG) || defined(CONFIG_HARDLOCKUP_DETECTOR)
#include <asm/nmi.h>
extern void touch_nmi_watchdog(void);
#else
static inline void touch_nmi_watchdog(void)
{
	touch_softlockup_watchdog();
}
#endif

#if defined(CONFIG_HARDLOCKUP_DETECTOR)
extern void hardlockup_detector_disable(void);
#else
static inline void hardlockup_detector_disable(void) {}
#endif

/*
 * Create trigger_all_cpu_backtrace() out of the arch-provided
 * base function. Return whether such support was available,
 * to allow calling code to fall back to some other mechanism:
 */
#ifdef arch_trigger_cpumask_backtrace
static inline bool trigger_all_cpu_backtrace(void)
{
	arch_trigger_cpumask_backtrace(cpu_online_mask, false);
	return true;
}

static inline bool trigger_allbutself_cpu_backtrace(void)
{
	arch_trigger_cpumask_backtrace(cpu_online_mask, true);
	return true;
}

static inline bool trigger_cpumask_backtrace(struct cpumask *mask)
{
	arch_trigger_cpumask_backtrace(mask, false);
	return true;
}

static inline bool trigger_single_cpu_backtrace(int cpu)
{
	arch_trigger_cpumask_backtrace(cpumask_of(cpu), false);
	return true;
}

/* generic implementation */
void nmi_trigger_cpumask_backtrace(const cpumask_t *mask,
				   bool exclude_self,
				   void (*raise)(cpumask_t *mask));
bool nmi_cpu_backtrace(struct pt_regs *regs);

#else
static inline bool trigger_all_cpu_backtrace(void)
{
	return false;
}
static inline bool trigger_allbutself_cpu_backtrace(void)
{
	return false;
}
static inline bool trigger_cpumask_backtrace(struct cpumask *mask)
{
	return false;
}
static inline bool trigger_single_cpu_backtrace(int cpu)
{
	return false;
}
#endif

#ifdef CONFIG_LOCKUP_DETECTOR
u64 hw_nmi_get_sample_period(int watchdog_thresh);
extern int nmi_watchdog_enabled;
extern int soft_watchdog_enabled;
extern int watchdog_user_enabled;
extern int watchdog_thresh;
extern unsigned long watchdog_enabled;
extern unsigned long *watchdog_cpumask_bits;
extern atomic_t watchdog_park_in_progress;
#ifdef CONFIG_SMP
extern int sysctl_softlockup_all_cpu_backtrace;
extern int sysctl_hardlockup_all_cpu_backtrace;
#else
#define sysctl_softlockup_all_cpu_backtrace 0
#define sysctl_hardlockup_all_cpu_backtrace 0
#endif
extern bool is_hardlockup(void);
struct ctl_table;
extern int proc_watchdog(struct ctl_table *, int ,
			 void __user *, size_t *, loff_t *);
extern int proc_nmi_watchdog(struct ctl_table *, int ,
			     void __user *, size_t *, loff_t *);
extern int proc_soft_watchdog(struct ctl_table *, int ,
			      void __user *, size_t *, loff_t *);
extern int proc_watchdog_thresh(struct ctl_table *, int ,
				void __user *, size_t *, loff_t *);
extern int proc_watchdog_cpumask(struct ctl_table *, int,
				 void __user *, size_t *, loff_t *);
extern int lockup_detector_suspend(void);
extern void lockup_detector_resume(void);
#else
static inline int lockup_detector_suspend(void)
{
	return 0;
}

static inline void lockup_detector_resume(void)
{
}
#endif

#ifdef CONFIG_HAVE_ACPI_APEI_NMI
#include <asm/nmi.h>
#endif

#endif
OpenPOWER on IntegriCloud