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 
11 /* Arch specific watchdogs might need to share extra watchdog-related APIs. */
12 #if defined(CONFIG_HARDLOCKUP_DETECTOR_ARCH) || defined(CONFIG_HARDLOCKUP_DETECTOR_SPARC64)
13 #include <asm/nmi.h>
14 #endif
15 
16 #ifdef CONFIG_LOCKUP_DETECTOR
17 void lockup_detector_init(void);
18 void lockup_detector_retry_init(void);
19 void lockup_detector_soft_poweroff(void);
20 void lockup_detector_cleanup(void);
21 
22 extern int 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_retry_init(void)38 static inline void lockup_detector_retry_init(void) { }
lockup_detector_soft_poweroff(void)39 static inline void lockup_detector_soft_poweroff(void) { }
lockup_detector_cleanup(void)40 static inline void lockup_detector_cleanup(void) { }
41 #endif /* !CONFIG_LOCKUP_DETECTOR */
42 
43 #ifdef CONFIG_SOFTLOCKUP_DETECTOR
44 extern void touch_softlockup_watchdog_sched(void);
45 extern void touch_softlockup_watchdog(void);
46 extern void touch_softlockup_watchdog_sync(void);
47 extern void touch_all_softlockup_watchdogs(void);
48 extern unsigned int  softlockup_panic;
49 
50 extern int lockup_detector_online_cpu(unsigned int cpu);
51 extern int lockup_detector_offline_cpu(unsigned int cpu);
52 #else /* CONFIG_SOFTLOCKUP_DETECTOR */
touch_softlockup_watchdog_sched(void)53 static inline void touch_softlockup_watchdog_sched(void) { }
touch_softlockup_watchdog(void)54 static inline void touch_softlockup_watchdog(void) { }
touch_softlockup_watchdog_sync(void)55 static inline void touch_softlockup_watchdog_sync(void) { }
touch_all_softlockup_watchdogs(void)56 static inline void touch_all_softlockup_watchdogs(void) { }
57 
58 #define lockup_detector_online_cpu	NULL
59 #define lockup_detector_offline_cpu	NULL
60 #endif /* CONFIG_SOFTLOCKUP_DETECTOR */
61 
62 #ifdef CONFIG_DETECT_HUNG_TASK
63 void reset_hung_task_detector(void);
64 #else
reset_hung_task_detector(void)65 static inline void reset_hung_task_detector(void) { }
66 #endif
67 
68 /*
69  * The run state of the lockup detectors is controlled by the content of the
70  * 'watchdog_enabled' variable. Each lockup detector has its dedicated bit -
71  * bit 0 for the hard lockup detector and bit 1 for the soft lockup detector.
72  *
73  * 'watchdog_user_enabled', 'watchdog_hardlockup_user_enabled' and
74  * 'watchdog_softlockup_user_enabled' are variables that are only used as an
75  * 'interface' between the parameters in /proc/sys/kernel and the internal
76  * state bits in 'watchdog_enabled'. The 'watchdog_thresh' variable is
77  * handled differently because its value is not boolean, and the lockup
78  * detectors are 'suspended' while 'watchdog_thresh' is equal zero.
79  */
80 #define WATCHDOG_HARDLOCKUP_ENABLED_BIT  0
81 #define WATCHDOG_SOFTOCKUP_ENABLED_BIT   1
82 #define WATCHDOG_HARDLOCKUP_ENABLED     (1 << WATCHDOG_HARDLOCKUP_ENABLED_BIT)
83 #define WATCHDOG_SOFTOCKUP_ENABLED      (1 << WATCHDOG_SOFTOCKUP_ENABLED_BIT)
84 
85 #if defined(CONFIG_HARDLOCKUP_DETECTOR)
86 extern void hardlockup_detector_disable(void);
87 extern unsigned int hardlockup_panic;
88 #else
hardlockup_detector_disable(void)89 static inline void hardlockup_detector_disable(void) {}
90 #endif
91 
92 /* Sparc64 has special implemetantion that is always enabled. */
93 #if defined(CONFIG_HARDLOCKUP_DETECTOR) || defined(CONFIG_HARDLOCKUP_DETECTOR_SPARC64)
94 void arch_touch_nmi_watchdog(void);
95 #else
arch_touch_nmi_watchdog(void)96 static inline void arch_touch_nmi_watchdog(void) { }
97 #endif
98 
99 #if defined(CONFIG_HARDLOCKUP_DETECTOR_COUNTS_HRTIMER)
100 void watchdog_hardlockup_touch_cpu(unsigned int cpu);
101 void watchdog_hardlockup_check(unsigned int cpu, struct pt_regs *regs);
102 #endif
103 
104 #if defined(CONFIG_HARDLOCKUP_DETECTOR_PERF)
105 extern void hardlockup_detector_perf_stop(void);
106 extern void hardlockup_detector_perf_restart(void);
107 extern void hardlockup_detector_perf_cleanup(void);
108 #else
hardlockup_detector_perf_stop(void)109 static inline void hardlockup_detector_perf_stop(void) { }
hardlockup_detector_perf_restart(void)110 static inline void hardlockup_detector_perf_restart(void) { }
hardlockup_detector_perf_cleanup(void)111 static inline void hardlockup_detector_perf_cleanup(void) { }
112 #endif
113 
114 void watchdog_hardlockup_stop(void);
115 void watchdog_hardlockup_start(void);
116 int watchdog_hardlockup_probe(void);
117 void watchdog_hardlockup_enable(unsigned int cpu);
118 void watchdog_hardlockup_disable(unsigned int cpu);
119 
120 void lockup_detector_reconfigure(void);
121 
122 #ifdef CONFIG_HARDLOCKUP_DETECTOR_BUDDY
123 void watchdog_buddy_check_hardlockup(int hrtimer_interrupts);
124 #else
watchdog_buddy_check_hardlockup(int hrtimer_interrupts)125 static inline void watchdog_buddy_check_hardlockup(int hrtimer_interrupts) {}
126 #endif
127 
128 /**
129  * touch_nmi_watchdog - manually reset the hardlockup watchdog timeout.
130  *
131  * If we support detecting hardlockups, touch_nmi_watchdog() may be
132  * used to pet the watchdog (reset the timeout) - for code which
133  * intentionally disables interrupts for a long time. This call is stateless.
134  *
135  * Though this function has "nmi" in the name, the hardlockup watchdog might
136  * not be backed by NMIs. This function will likely be renamed to
137  * touch_hardlockup_watchdog() in the future.
138  */
touch_nmi_watchdog(void)139 static inline void touch_nmi_watchdog(void)
140 {
141 	/*
142 	 * Pass on to the hardlockup detector selected via CONFIG_. Note that
143 	 * the hardlockup detector may not be arch-specific nor using NMIs
144 	 * and the arch_touch_nmi_watchdog() function will likely be renamed
145 	 * in the future.
146 	 */
147 	arch_touch_nmi_watchdog();
148 
149 	touch_softlockup_watchdog();
150 }
151 
152 /*
153  * Create trigger_all_cpu_backtrace() out of the arch-provided
154  * base function. Return whether such support was available,
155  * to allow calling code to fall back to some other mechanism:
156  */
157 #ifdef arch_trigger_cpumask_backtrace
trigger_all_cpu_backtrace(void)158 static inline bool trigger_all_cpu_backtrace(void)
159 {
160 	arch_trigger_cpumask_backtrace(cpu_online_mask, -1);
161 	return true;
162 }
163 
trigger_allbutcpu_cpu_backtrace(int exclude_cpu)164 static inline bool trigger_allbutcpu_cpu_backtrace(int exclude_cpu)
165 {
166 	arch_trigger_cpumask_backtrace(cpu_online_mask, exclude_cpu);
167 	return true;
168 }
169 
trigger_cpumask_backtrace(struct cpumask * mask)170 static inline bool trigger_cpumask_backtrace(struct cpumask *mask)
171 {
172 	arch_trigger_cpumask_backtrace(mask, -1);
173 	return true;
174 }
175 
trigger_single_cpu_backtrace(int cpu)176 static inline bool trigger_single_cpu_backtrace(int cpu)
177 {
178 	arch_trigger_cpumask_backtrace(cpumask_of(cpu), -1);
179 	return true;
180 }
181 
182 /* generic implementation */
183 void nmi_trigger_cpumask_backtrace(const cpumask_t *mask,
184 				   int exclude_cpu,
185 				   void (*raise)(cpumask_t *mask));
186 bool nmi_cpu_backtrace(struct pt_regs *regs);
187 
188 #else
trigger_all_cpu_backtrace(void)189 static inline bool trigger_all_cpu_backtrace(void)
190 {
191 	return false;
192 }
trigger_allbutcpu_cpu_backtrace(int exclude_cpu)193 static inline bool trigger_allbutcpu_cpu_backtrace(int exclude_cpu)
194 {
195 	return false;
196 }
trigger_cpumask_backtrace(struct cpumask * mask)197 static inline bool trigger_cpumask_backtrace(struct cpumask *mask)
198 {
199 	return false;
200 }
trigger_single_cpu_backtrace(int cpu)201 static inline bool trigger_single_cpu_backtrace(int cpu)
202 {
203 	return false;
204 }
205 #endif
206 
207 #ifdef CONFIG_HARDLOCKUP_DETECTOR_PERF
208 u64 hw_nmi_get_sample_period(int watchdog_thresh);
209 bool arch_perf_nmi_is_available(void);
210 #endif
211 
212 #if defined(CONFIG_HARDLOCKUP_CHECK_TIMESTAMP) && \
213     defined(CONFIG_HARDLOCKUP_DETECTOR_PERF)
214 void watchdog_update_hrtimer_threshold(u64 period);
215 #else
watchdog_update_hrtimer_threshold(u64 period)216 static inline void watchdog_update_hrtimer_threshold(u64 period) { }
217 #endif
218 
219 struct ctl_table;
220 int proc_watchdog(struct ctl_table *, int, void *, size_t *, loff_t *);
221 int proc_nmi_watchdog(struct ctl_table *, int , void *, size_t *, loff_t *);
222 int proc_soft_watchdog(struct ctl_table *, int , void *, size_t *, loff_t *);
223 int proc_watchdog_thresh(struct ctl_table *, int , void *, size_t *, loff_t *);
224 int proc_watchdog_cpumask(struct ctl_table *, int, void *, size_t *, loff_t *);
225 
226 #ifdef CONFIG_HAVE_ACPI_APEI_NMI
227 #include <asm/nmi.h>
228 #endif
229 
230 #ifdef CONFIG_NMI_CHECK_CPU
231 void nmi_backtrace_stall_snap(const struct cpumask *btp);
232 void nmi_backtrace_stall_check(const struct cpumask *btp);
233 #else
nmi_backtrace_stall_snap(const struct cpumask * btp)234 static inline void nmi_backtrace_stall_snap(const struct cpumask *btp) {}
nmi_backtrace_stall_check(const struct cpumask * btp)235 static inline void nmi_backtrace_stall_check(const struct cpumask *btp) {}
236 #endif
237 
238 #endif
239