1 /* SPDX-License-Identifier: GPL-2.0 */
3 * linux/include/linux/nmi.h
8 #include <linux/sched.h>
10 #if defined(CONFIG_HAVE_NMI_WATCHDOG)
14 #ifdef CONFIG_LOCKUP_DETECTOR
15 void lockup_detector_init(void);
16 void lockup_detector_soft_poweroff(void);
17 void lockup_detector_cleanup(void);
18 bool is_hardlockup(void);
20 extern int watchdog_user_enabled;
21 extern int nmi_watchdog_user_enabled;
22 extern int soft_watchdog_user_enabled;
23 extern int watchdog_thresh;
24 extern unsigned long watchdog_enabled;
26 extern struct cpumask watchdog_cpumask;
27 extern unsigned long *watchdog_cpumask_bits;
29 extern int sysctl_softlockup_all_cpu_backtrace;
30 extern int sysctl_hardlockup_all_cpu_backtrace;
32 #define sysctl_softlockup_all_cpu_backtrace 0
33 #define sysctl_hardlockup_all_cpu_backtrace 0
34 #endif /* !CONFIG_SMP */
36 #else /* CONFIG_LOCKUP_DETECTOR */
37 static inline void lockup_detector_init(void) { }
38 static inline void lockup_detector_soft_poweroff(void) { }
39 static inline void lockup_detector_cleanup(void) { }
40 #endif /* !CONFIG_LOCKUP_DETECTOR */
42 #ifdef CONFIG_SOFTLOCKUP_DETECTOR
43 extern void touch_softlockup_watchdog_sched(void);
44 extern void touch_softlockup_watchdog(void);
45 extern void touch_softlockup_watchdog_sync(void);
46 extern void touch_all_softlockup_watchdogs(void);
47 extern unsigned int softlockup_panic;
49 static inline void touch_softlockup_watchdog_sched(void) { }
50 static inline void touch_softlockup_watchdog(void) { }
51 static inline void touch_softlockup_watchdog_sync(void) { }
52 static inline void touch_all_softlockup_watchdogs(void) { }
55 #ifdef CONFIG_DETECT_HUNG_TASK
56 void reset_hung_task_detector(void);
58 static inline void reset_hung_task_detector(void) { }
62 * The run state of the lockup detectors is controlled by the content of the
63 * 'watchdog_enabled' variable. Each lockup detector has its dedicated bit -
64 * bit 0 for the hard lockup detector and bit 1 for the soft lockup detector.
66 * 'watchdog_user_enabled', 'nmi_watchdog_user_enabled' and
67 * 'soft_watchdog_user_enabled' are variables that are only used as an
68 * 'interface' between the parameters in /proc/sys/kernel and the internal
69 * state bits in 'watchdog_enabled'. The 'watchdog_thresh' variable is
70 * handled differently because its value is not boolean, and the lockup
71 * detectors are 'suspended' while 'watchdog_thresh' is equal zero.
73 #define NMI_WATCHDOG_ENABLED_BIT 0
74 #define SOFT_WATCHDOG_ENABLED_BIT 1
75 #define NMI_WATCHDOG_ENABLED (1 << NMI_WATCHDOG_ENABLED_BIT)
76 #define SOFT_WATCHDOG_ENABLED (1 << SOFT_WATCHDOG_ENABLED_BIT)
78 #if defined(CONFIG_HARDLOCKUP_DETECTOR)
79 extern void hardlockup_detector_disable(void);
80 extern unsigned int hardlockup_panic;
82 static inline void hardlockup_detector_disable(void) {}
85 #if defined(CONFIG_HAVE_NMI_WATCHDOG) || defined(CONFIG_HARDLOCKUP_DETECTOR)
86 # define NMI_WATCHDOG_SYSCTL_PERM 0644
88 # define NMI_WATCHDOG_SYSCTL_PERM 0444
91 #if defined(CONFIG_HARDLOCKUP_DETECTOR_PERF)
92 extern void arch_touch_nmi_watchdog(void);
93 extern void hardlockup_detector_perf_stop(void);
94 extern void hardlockup_detector_perf_restart(void);
95 extern void hardlockup_detector_perf_disable(void);
96 extern void hardlockup_detector_perf_enable(void);
97 extern void hardlockup_detector_perf_cleanup(void);
98 extern int hardlockup_detector_perf_init(void);
100 static inline void hardlockup_detector_perf_stop(void) { }
101 static inline void hardlockup_detector_perf_restart(void) { }
102 static inline void hardlockup_detector_perf_disable(void) { }
103 static inline void hardlockup_detector_perf_enable(void) { }
104 static inline void hardlockup_detector_perf_cleanup(void) { }
105 # if !defined(CONFIG_HAVE_NMI_WATCHDOG)
106 static inline int hardlockup_detector_perf_init(void) { return -ENODEV; }
107 static inline void arch_touch_nmi_watchdog(void) {}
109 static inline int hardlockup_detector_perf_init(void) { return 0; }
113 void watchdog_nmi_stop(void);
114 void watchdog_nmi_start(void);
115 int watchdog_nmi_probe(void);
116 int watchdog_nmi_enable(unsigned int cpu);
117 void watchdog_nmi_disable(unsigned int cpu);
120 * touch_nmi_watchdog - restart NMI watchdog timeout.
122 * If the architecture supports the NMI watchdog, touch_nmi_watchdog()
123 * may be used to reset the timeout - for code which intentionally
124 * disables interrupts for a long time. This call is stateless.
126 static inline void touch_nmi_watchdog(void)
128 arch_touch_nmi_watchdog();
129 touch_softlockup_watchdog();
133 * Create trigger_all_cpu_backtrace() out of the arch-provided
134 * base function. Return whether such support was available,
135 * to allow calling code to fall back to some other mechanism:
137 #ifdef arch_trigger_cpumask_backtrace
138 static inline bool trigger_all_cpu_backtrace(void)
140 arch_trigger_cpumask_backtrace(cpu_online_mask, false);
144 static inline bool trigger_allbutself_cpu_backtrace(void)
146 arch_trigger_cpumask_backtrace(cpu_online_mask, true);
150 static inline bool trigger_cpumask_backtrace(struct cpumask *mask)
152 arch_trigger_cpumask_backtrace(mask, false);
156 static inline bool trigger_single_cpu_backtrace(int cpu)
158 arch_trigger_cpumask_backtrace(cpumask_of(cpu), false);
162 /* generic implementation */
163 void nmi_trigger_cpumask_backtrace(const cpumask_t *mask,
165 void (*raise)(cpumask_t *mask));
166 bool nmi_cpu_backtrace(struct pt_regs *regs);
169 static inline bool trigger_all_cpu_backtrace(void)
173 static inline bool trigger_allbutself_cpu_backtrace(void)
177 static inline bool trigger_cpumask_backtrace(struct cpumask *mask)
181 static inline bool trigger_single_cpu_backtrace(int cpu)
187 #ifdef CONFIG_HARDLOCKUP_DETECTOR_PERF
188 u64 hw_nmi_get_sample_period(int watchdog_thresh);
191 #if defined(CONFIG_HARDLOCKUP_CHECK_TIMESTAMP) && \
192 defined(CONFIG_HARDLOCKUP_DETECTOR)
193 void watchdog_update_hrtimer_threshold(u64 period);
195 static inline void watchdog_update_hrtimer_threshold(u64 period) { }
199 extern int proc_watchdog(struct ctl_table *, int ,
200 void __user *, size_t *, loff_t *);
201 extern int proc_nmi_watchdog(struct ctl_table *, int ,
202 void __user *, size_t *, loff_t *);
203 extern int proc_soft_watchdog(struct ctl_table *, int ,
204 void __user *, size_t *, loff_t *);
205 extern int proc_watchdog_thresh(struct ctl_table *, int ,
206 void __user *, size_t *, loff_t *);
207 extern int proc_watchdog_cpumask(struct ctl_table *, int,
208 void __user *, size_t *, loff_t *);
210 #ifdef CONFIG_HAVE_ACPI_APEI_NMI