1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * linux/include/linux/nmi.h
4 */
5 #ifndef LINUX_NMI_H
6 #define LINUX_NMI_H
7
8 #include <linux/sched.h>
9 #include <asm/irq.h>
10 #if defined(CONFIG_HAVE_NMI_WATCHDOG)
11 #include <asm/nmi.h>
12 #endif
13
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);
19
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;
25
26 extern struct cpumask watchdog_cpumask;
27 extern unsigned long *watchdog_cpumask_bits;
28 #ifdef CONFIG_SMP
29 extern int sysctl_softlockup_all_cpu_backtrace;
30 extern int sysctl_hardlockup_all_cpu_backtrace;
31 #else
32 #define sysctl_softlockup_all_cpu_backtrace 0
33 #define sysctl_hardlockup_all_cpu_backtrace 0
34 #endif /* !CONFIG_SMP */
35
36 #else /* CONFIG_LOCKUP_DETECTOR */
lockup_detector_init(void)37 static inline void lockup_detector_init(void) { }
lockup_detector_soft_poweroff(void)38 static inline void lockup_detector_soft_poweroff(void) { }
lockup_detector_cleanup(void)39 static inline void lockup_detector_cleanup(void) { }
40 #endif /* !CONFIG_LOCKUP_DETECTOR */
41
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;
48
49 extern int lockup_detector_online_cpu(unsigned int cpu);
50 extern int lockup_detector_offline_cpu(unsigned int cpu);
51 #else /* CONFIG_SOFTLOCKUP_DETECTOR */
touch_softlockup_watchdog_sched(void)52 static inline void touch_softlockup_watchdog_sched(void) { }
touch_softlockup_watchdog(void)53 static inline void touch_softlockup_watchdog(void) { }
touch_softlockup_watchdog_sync(void)54 static inline void touch_softlockup_watchdog_sync(void) { }
touch_all_softlockup_watchdogs(void)55 static inline void touch_all_softlockup_watchdogs(void) { }
56
57 #define lockup_detector_online_cpu NULL
58 #define lockup_detector_offline_cpu NULL
59 #endif /* CONFIG_SOFTLOCKUP_DETECTOR */
60
61 #ifdef CONFIG_DETECT_HUNG_TASK
62 void reset_hung_task_detector(void);
63 #else
reset_hung_task_detector(void)64 static inline void reset_hung_task_detector(void) { }
65 #endif
66
67 /*
68 * The run state of the lockup detectors is controlled by the content of the
69 * 'watchdog_enabled' variable. Each lockup detector has its dedicated bit -
70 * bit 0 for the hard lockup detector and bit 1 for the soft lockup detector.
71 *
72 * 'watchdog_user_enabled', 'nmi_watchdog_user_enabled' and
73 * 'soft_watchdog_user_enabled' are variables that are only used as an
74 * 'interface' between the parameters in /proc/sys/kernel and the internal
75 * state bits in 'watchdog_enabled'. The 'watchdog_thresh' variable is
76 * handled differently because its value is not boolean, and the lockup
77 * detectors are 'suspended' while 'watchdog_thresh' is equal zero.
78 */
79 #define NMI_WATCHDOG_ENABLED_BIT 0
80 #define SOFT_WATCHDOG_ENABLED_BIT 1
81 #define NMI_WATCHDOG_ENABLED (1 << NMI_WATCHDOG_ENABLED_BIT)
82 #define SOFT_WATCHDOG_ENABLED (1 << SOFT_WATCHDOG_ENABLED_BIT)
83
84 #if defined(CONFIG_HARDLOCKUP_DETECTOR)
85 extern void hardlockup_detector_disable(void);
86 extern unsigned int hardlockup_panic;
87 #else
hardlockup_detector_disable(void)88 static inline void hardlockup_detector_disable(void) {}
89 #endif
90
91 #if defined(CONFIG_HAVE_NMI_WATCHDOG) || defined(CONFIG_HARDLOCKUP_DETECTOR)
92 # define NMI_WATCHDOG_SYSCTL_PERM 0644
93 #else
94 # define NMI_WATCHDOG_SYSCTL_PERM 0444
95 #endif
96
97 #if defined(CONFIG_HARDLOCKUP_DETECTOR_PERF)
98 extern void arch_touch_nmi_watchdog(void);
99 extern void hardlockup_detector_perf_stop(void);
100 extern void hardlockup_detector_perf_restart(void);
101 extern void hardlockup_detector_perf_disable(void);
102 extern void hardlockup_detector_perf_enable(void);
103 extern void hardlockup_detector_perf_cleanup(void);
104 extern int hardlockup_detector_perf_init(void);
105 #else
hardlockup_detector_perf_stop(void)106 static inline void hardlockup_detector_perf_stop(void) { }
hardlockup_detector_perf_restart(void)107 static inline void hardlockup_detector_perf_restart(void) { }
hardlockup_detector_perf_disable(void)108 static inline void hardlockup_detector_perf_disable(void) { }
hardlockup_detector_perf_enable(void)109 static inline void hardlockup_detector_perf_enable(void) { }
hardlockup_detector_perf_cleanup(void)110 static inline void hardlockup_detector_perf_cleanup(void) { }
111 # if !defined(CONFIG_HAVE_NMI_WATCHDOG)
hardlockup_detector_perf_init(void)112 static inline int hardlockup_detector_perf_init(void) { return -ENODEV; }
arch_touch_nmi_watchdog(void)113 static inline void arch_touch_nmi_watchdog(void) {}
114 # else
hardlockup_detector_perf_init(void)115 static inline int hardlockup_detector_perf_init(void) { return 0; }
116 # endif
117 #endif
118
119 void watchdog_nmi_stop(void);
120 void watchdog_nmi_start(void);
121 int watchdog_nmi_probe(void);
122 int watchdog_nmi_enable(unsigned int cpu);
123 void watchdog_nmi_disable(unsigned int cpu);
124
125 /**
126 * touch_nmi_watchdog - restart NMI watchdog timeout.
127 *
128 * If the architecture supports the NMI watchdog, touch_nmi_watchdog()
129 * may be used to reset the timeout - for code which intentionally
130 * disables interrupts for a long time. This call is stateless.
131 */
touch_nmi_watchdog(void)132 static inline void touch_nmi_watchdog(void)
133 {
134 arch_touch_nmi_watchdog();
135 touch_softlockup_watchdog();
136 }
137
138 /*
139 * Create trigger_all_cpu_backtrace() out of the arch-provided
140 * base function. Return whether such support was available,
141 * to allow calling code to fall back to some other mechanism:
142 */
143 #ifdef arch_trigger_cpumask_backtrace
trigger_all_cpu_backtrace(void)144 static inline bool trigger_all_cpu_backtrace(void)
145 {
146 arch_trigger_cpumask_backtrace(cpu_online_mask, false);
147 return true;
148 }
149
trigger_allbutself_cpu_backtrace(void)150 static inline bool trigger_allbutself_cpu_backtrace(void)
151 {
152 arch_trigger_cpumask_backtrace(cpu_online_mask, true);
153 return true;
154 }
155
trigger_cpumask_backtrace(struct cpumask * mask)156 static inline bool trigger_cpumask_backtrace(struct cpumask *mask)
157 {
158 arch_trigger_cpumask_backtrace(mask, false);
159 return true;
160 }
161
trigger_single_cpu_backtrace(int cpu)162 static inline bool trigger_single_cpu_backtrace(int cpu)
163 {
164 arch_trigger_cpumask_backtrace(cpumask_of(cpu), false);
165 return true;
166 }
167
168 /* generic implementation */
169 void nmi_trigger_cpumask_backtrace(const cpumask_t *mask,
170 bool exclude_self,
171 void (*raise)(cpumask_t *mask));
172 bool nmi_cpu_backtrace(struct pt_regs *regs);
173
174 #else
trigger_all_cpu_backtrace(void)175 static inline bool trigger_all_cpu_backtrace(void)
176 {
177 return false;
178 }
trigger_allbutself_cpu_backtrace(void)179 static inline bool trigger_allbutself_cpu_backtrace(void)
180 {
181 return false;
182 }
trigger_cpumask_backtrace(struct cpumask * mask)183 static inline bool trigger_cpumask_backtrace(struct cpumask *mask)
184 {
185 return false;
186 }
trigger_single_cpu_backtrace(int cpu)187 static inline bool trigger_single_cpu_backtrace(int cpu)
188 {
189 return false;
190 }
191 #endif
192
193 #ifdef CONFIG_HARDLOCKUP_DETECTOR_PERF
194 u64 hw_nmi_get_sample_period(int watchdog_thresh);
195 #endif
196
197 #if defined(CONFIG_HARDLOCKUP_CHECK_TIMESTAMP) && \
198 defined(CONFIG_HARDLOCKUP_DETECTOR)
199 void watchdog_update_hrtimer_threshold(u64 period);
200 #else
watchdog_update_hrtimer_threshold(u64 period)201 static inline void watchdog_update_hrtimer_threshold(u64 period) { }
202 #endif
203
204 struct ctl_table;
205 extern int proc_watchdog(struct ctl_table *, int ,
206 void __user *, size_t *, loff_t *);
207 extern int proc_nmi_watchdog(struct ctl_table *, int ,
208 void __user *, size_t *, loff_t *);
209 extern int proc_soft_watchdog(struct ctl_table *, int ,
210 void __user *, size_t *, loff_t *);
211 extern int proc_watchdog_thresh(struct ctl_table *, int ,
212 void __user *, size_t *, loff_t *);
213 extern int proc_watchdog_cpumask(struct ctl_table *, int,
214 void __user *, size_t *, loff_t *);
215
216 #ifdef CONFIG_HAVE_ACPI_APEI_NMI
217 #include <asm/nmi.h>
218 #endif
219
220 #endif
221
