xref: /openbmc/linux/include/linux/nmi.h (revision 98ddec80)
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 */
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 */
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 #else
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) { }
53 #endif
54 
55 #ifdef CONFIG_DETECT_HUNG_TASK
56 void reset_hung_task_detector(void);
57 #else
58 static inline void reset_hung_task_detector(void) { }
59 #endif
60 
61 /*
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.
65  *
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.
72  */
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)
77 
78 #if defined(CONFIG_HARDLOCKUP_DETECTOR)
79 extern void hardlockup_detector_disable(void);
80 extern unsigned int hardlockup_panic;
81 #else
82 static inline void hardlockup_detector_disable(void) {}
83 #endif
84 
85 #if defined(CONFIG_HAVE_NMI_WATCHDOG) || defined(CONFIG_HARDLOCKUP_DETECTOR)
86 # define NMI_WATCHDOG_SYSCTL_PERM	0644
87 #else
88 # define NMI_WATCHDOG_SYSCTL_PERM	0444
89 #endif
90 
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);
99 #else
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) {}
108 # else
109 static inline int hardlockup_detector_perf_init(void) { return 0; }
110 # endif
111 #endif
112 
113 void watchdog_nmi_stop(void);
114 void watchdog_nmi_start(void);
115 int watchdog_nmi_probe(void);
116 
117 /**
118  * touch_nmi_watchdog - restart NMI watchdog timeout.
119  *
120  * If the architecture supports the NMI watchdog, touch_nmi_watchdog()
121  * may be used to reset the timeout - for code which intentionally
122  * disables interrupts for a long time. This call is stateless.
123  */
124 static inline void touch_nmi_watchdog(void)
125 {
126 	arch_touch_nmi_watchdog();
127 	touch_softlockup_watchdog();
128 }
129 
130 /*
131  * Create trigger_all_cpu_backtrace() out of the arch-provided
132  * base function. Return whether such support was available,
133  * to allow calling code to fall back to some other mechanism:
134  */
135 #ifdef arch_trigger_cpumask_backtrace
136 static inline bool trigger_all_cpu_backtrace(void)
137 {
138 	arch_trigger_cpumask_backtrace(cpu_online_mask, false);
139 	return true;
140 }
141 
142 static inline bool trigger_allbutself_cpu_backtrace(void)
143 {
144 	arch_trigger_cpumask_backtrace(cpu_online_mask, true);
145 	return true;
146 }
147 
148 static inline bool trigger_cpumask_backtrace(struct cpumask *mask)
149 {
150 	arch_trigger_cpumask_backtrace(mask, false);
151 	return true;
152 }
153 
154 static inline bool trigger_single_cpu_backtrace(int cpu)
155 {
156 	arch_trigger_cpumask_backtrace(cpumask_of(cpu), false);
157 	return true;
158 }
159 
160 /* generic implementation */
161 void nmi_trigger_cpumask_backtrace(const cpumask_t *mask,
162 				   bool exclude_self,
163 				   void (*raise)(cpumask_t *mask));
164 bool nmi_cpu_backtrace(struct pt_regs *regs);
165 
166 #else
167 static inline bool trigger_all_cpu_backtrace(void)
168 {
169 	return false;
170 }
171 static inline bool trigger_allbutself_cpu_backtrace(void)
172 {
173 	return false;
174 }
175 static inline bool trigger_cpumask_backtrace(struct cpumask *mask)
176 {
177 	return false;
178 }
179 static inline bool trigger_single_cpu_backtrace(int cpu)
180 {
181 	return false;
182 }
183 #endif
184 
185 #ifdef CONFIG_HARDLOCKUP_DETECTOR_PERF
186 u64 hw_nmi_get_sample_period(int watchdog_thresh);
187 #endif
188 
189 #if defined(CONFIG_HARDLOCKUP_CHECK_TIMESTAMP) && \
190     defined(CONFIG_HARDLOCKUP_DETECTOR)
191 void watchdog_update_hrtimer_threshold(u64 period);
192 #else
193 static inline void watchdog_update_hrtimer_threshold(u64 period) { }
194 #endif
195 
196 struct ctl_table;
197 extern int proc_watchdog(struct ctl_table *, int ,
198 			 void __user *, size_t *, loff_t *);
199 extern int proc_nmi_watchdog(struct ctl_table *, int ,
200 			     void __user *, size_t *, loff_t *);
201 extern int proc_soft_watchdog(struct ctl_table *, int ,
202 			      void __user *, size_t *, loff_t *);
203 extern int proc_watchdog_thresh(struct ctl_table *, int ,
204 				void __user *, size_t *, loff_t *);
205 extern int proc_watchdog_cpumask(struct ctl_table *, int,
206 				 void __user *, size_t *, loff_t *);
207 
208 #ifdef CONFIG_HAVE_ACPI_APEI_NMI
209 #include <asm/nmi.h>
210 #endif
211 
212 #endif
213