xref: /openbmc/linux/include/linux/nmi.h (revision 48c926cd)
1 /*
2  *  linux/include/linux/nmi.h
3  */
4 #ifndef LINUX_NMI_H
5 #define LINUX_NMI_H
6 
7 #include <linux/sched.h>
8 #include <asm/irq.h>
9 #if defined(CONFIG_HAVE_NMI_WATCHDOG)
10 #include <asm/nmi.h>
11 #endif
12 
13 #ifdef CONFIG_LOCKUP_DETECTOR
14 void lockup_detector_init(void);
15 #else
16 static inline void lockup_detector_init(void)
17 {
18 }
19 #endif
20 
21 #ifdef CONFIG_SOFTLOCKUP_DETECTOR
22 extern void touch_softlockup_watchdog_sched(void);
23 extern void touch_softlockup_watchdog(void);
24 extern void touch_softlockup_watchdog_sync(void);
25 extern void touch_all_softlockup_watchdogs(void);
26 extern unsigned int  softlockup_panic;
27 extern int soft_watchdog_enabled;
28 extern atomic_t watchdog_park_in_progress;
29 #else
30 static inline void touch_softlockup_watchdog_sched(void)
31 {
32 }
33 static inline void touch_softlockup_watchdog(void)
34 {
35 }
36 static inline void touch_softlockup_watchdog_sync(void)
37 {
38 }
39 static inline void touch_all_softlockup_watchdogs(void)
40 {
41 }
42 #endif
43 
44 #ifdef CONFIG_DETECT_HUNG_TASK
45 void reset_hung_task_detector(void);
46 #else
47 static inline void reset_hung_task_detector(void)
48 {
49 }
50 #endif
51 
52 /*
53  * The run state of the lockup detectors is controlled by the content of the
54  * 'watchdog_enabled' variable. Each lockup detector has its dedicated bit -
55  * bit 0 for the hard lockup detector and bit 1 for the soft lockup detector.
56  *
57  * 'watchdog_user_enabled', 'nmi_watchdog_enabled' and 'soft_watchdog_enabled'
58  * are variables that are only used as an 'interface' between the parameters
59  * in /proc/sys/kernel and the internal state bits in 'watchdog_enabled'. The
60  * 'watchdog_thresh' variable is handled differently because its value is not
61  * boolean, and the lockup detectors are 'suspended' while 'watchdog_thresh'
62  * is equal zero.
63  */
64 #define NMI_WATCHDOG_ENABLED_BIT   0
65 #define SOFT_WATCHDOG_ENABLED_BIT  1
66 #define NMI_WATCHDOG_ENABLED      (1 << NMI_WATCHDOG_ENABLED_BIT)
67 #define SOFT_WATCHDOG_ENABLED     (1 << SOFT_WATCHDOG_ENABLED_BIT)
68 
69 #if defined(CONFIG_HARDLOCKUP_DETECTOR)
70 extern void hardlockup_detector_disable(void);
71 extern unsigned int hardlockup_panic;
72 #else
73 static inline void hardlockup_detector_disable(void) {}
74 #endif
75 
76 #if defined(CONFIG_HARDLOCKUP_DETECTOR_PERF)
77 extern void arch_touch_nmi_watchdog(void);
78 #else
79 #if !defined(CONFIG_HAVE_NMI_WATCHDOG)
80 static inline void arch_touch_nmi_watchdog(void) {}
81 #endif
82 #endif
83 
84 /**
85  * touch_nmi_watchdog - restart NMI watchdog timeout.
86  *
87  * If the architecture supports the NMI watchdog, touch_nmi_watchdog()
88  * may be used to reset the timeout - for code which intentionally
89  * disables interrupts for a long time. This call is stateless.
90  */
91 static inline void touch_nmi_watchdog(void)
92 {
93 	arch_touch_nmi_watchdog();
94 	touch_softlockup_watchdog();
95 }
96 
97 /*
98  * Create trigger_all_cpu_backtrace() out of the arch-provided
99  * base function. Return whether such support was available,
100  * to allow calling code to fall back to some other mechanism:
101  */
102 #ifdef arch_trigger_cpumask_backtrace
103 static inline bool trigger_all_cpu_backtrace(void)
104 {
105 	arch_trigger_cpumask_backtrace(cpu_online_mask, false);
106 	return true;
107 }
108 
109 static inline bool trigger_allbutself_cpu_backtrace(void)
110 {
111 	arch_trigger_cpumask_backtrace(cpu_online_mask, true);
112 	return true;
113 }
114 
115 static inline bool trigger_cpumask_backtrace(struct cpumask *mask)
116 {
117 	arch_trigger_cpumask_backtrace(mask, false);
118 	return true;
119 }
120 
121 static inline bool trigger_single_cpu_backtrace(int cpu)
122 {
123 	arch_trigger_cpumask_backtrace(cpumask_of(cpu), false);
124 	return true;
125 }
126 
127 /* generic implementation */
128 void nmi_trigger_cpumask_backtrace(const cpumask_t *mask,
129 				   bool exclude_self,
130 				   void (*raise)(cpumask_t *mask));
131 bool nmi_cpu_backtrace(struct pt_regs *regs);
132 
133 #else
134 static inline bool trigger_all_cpu_backtrace(void)
135 {
136 	return false;
137 }
138 static inline bool trigger_allbutself_cpu_backtrace(void)
139 {
140 	return false;
141 }
142 static inline bool trigger_cpumask_backtrace(struct cpumask *mask)
143 {
144 	return false;
145 }
146 static inline bool trigger_single_cpu_backtrace(int cpu)
147 {
148 	return false;
149 }
150 #endif
151 
152 #ifdef CONFIG_HARDLOCKUP_DETECTOR_PERF
153 u64 hw_nmi_get_sample_period(int watchdog_thresh);
154 #endif
155 
156 #ifdef CONFIG_LOCKUP_DETECTOR
157 extern int nmi_watchdog_enabled;
158 extern int watchdog_user_enabled;
159 extern int watchdog_thresh;
160 extern unsigned long watchdog_enabled;
161 extern struct cpumask watchdog_cpumask;
162 extern unsigned long *watchdog_cpumask_bits;
163 extern int __read_mostly watchdog_suspended;
164 #ifdef CONFIG_SMP
165 extern int sysctl_softlockup_all_cpu_backtrace;
166 extern int sysctl_hardlockup_all_cpu_backtrace;
167 #else
168 #define sysctl_softlockup_all_cpu_backtrace 0
169 #define sysctl_hardlockup_all_cpu_backtrace 0
170 #endif
171 
172 #if defined(CONFIG_HARDLOCKUP_CHECK_TIMESTAMP) && \
173     defined(CONFIG_HARDLOCKUP_DETECTOR)
174 void watchdog_update_hrtimer_threshold(u64 period);
175 #else
176 static inline void watchdog_update_hrtimer_threshold(u64 period) { }
177 #endif
178 
179 extern bool is_hardlockup(void);
180 struct ctl_table;
181 extern int proc_watchdog(struct ctl_table *, int ,
182 			 void __user *, size_t *, loff_t *);
183 extern int proc_nmi_watchdog(struct ctl_table *, int ,
184 			     void __user *, size_t *, loff_t *);
185 extern int proc_soft_watchdog(struct ctl_table *, int ,
186 			      void __user *, size_t *, loff_t *);
187 extern int proc_watchdog_thresh(struct ctl_table *, int ,
188 				void __user *, size_t *, loff_t *);
189 extern int proc_watchdog_cpumask(struct ctl_table *, int,
190 				 void __user *, size_t *, loff_t *);
191 extern int lockup_detector_suspend(void);
192 extern void lockup_detector_resume(void);
193 #else
194 static inline int lockup_detector_suspend(void)
195 {
196 	return 0;
197 }
198 
199 static inline void lockup_detector_resume(void)
200 {
201 }
202 #endif
203 
204 #ifdef CONFIG_HAVE_ACPI_APEI_NMI
205 #include <asm/nmi.h>
206 #endif
207 
208 #endif
209