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 */
37 static inline void lockup_detector_init(void) { }
38 static inline void lockup_detector_retry_init(void) { }
39 static inline void lockup_detector_soft_poweroff(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 */
53 static inline void touch_softlockup_watchdog_sched(void) { }
54 static inline void touch_softlockup_watchdog(void) { }
55 static inline void touch_softlockup_watchdog_sync(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
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
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
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 extern void hardlockup_config_perf_event(const char *str);
109 #else
110 static inline void hardlockup_detector_perf_stop(void) { }
111 static inline void hardlockup_detector_perf_restart(void) { }
112 static inline void hardlockup_detector_perf_cleanup(void) { }
113 static inline void hardlockup_config_perf_event(const char *str) { }
114 #endif
115
116 void watchdog_hardlockup_stop(void);
117 void watchdog_hardlockup_start(void);
118 int watchdog_hardlockup_probe(void);
119 void watchdog_hardlockup_enable(unsigned int cpu);
120 void watchdog_hardlockup_disable(unsigned int cpu);
121
122 void lockup_detector_reconfigure(void);
123
124 #ifdef CONFIG_HARDLOCKUP_DETECTOR_BUDDY
125 void watchdog_buddy_check_hardlockup(int hrtimer_interrupts);
126 #else
127 static inline void watchdog_buddy_check_hardlockup(int hrtimer_interrupts) {}
128 #endif
129
130 /**
131 * touch_nmi_watchdog - manually reset the hardlockup watchdog timeout.
132 *
133 * If we support detecting hardlockups, touch_nmi_watchdog() may be
134 * used to pet the watchdog (reset the timeout) - for code which
135 * intentionally disables interrupts for a long time. This call is stateless.
136 *
137 * Though this function has "nmi" in the name, the hardlockup watchdog might
138 * not be backed by NMIs. This function will likely be renamed to
139 * touch_hardlockup_watchdog() in the future.
140 */
141 static inline void touch_nmi_watchdog(void)
142 {
143 /*
144 * Pass on to the hardlockup detector selected via CONFIG_. Note that
145 * the hardlockup detector may not be arch-specific nor using NMIs
146 * and the arch_touch_nmi_watchdog() function will likely be renamed
147 * in the future.
148 */
149 arch_touch_nmi_watchdog();
150
151 touch_softlockup_watchdog();
152 }
153
154 /*
155 * Create trigger_all_cpu_backtrace() out of the arch-provided
156 * base function. Return whether such support was available,
157 * to allow calling code to fall back to some other mechanism:
158 */
159 #ifdef arch_trigger_cpumask_backtrace
160 static inline bool trigger_all_cpu_backtrace(void)
161 {
162 arch_trigger_cpumask_backtrace(cpu_online_mask, -1);
163 return true;
164 }
165
166 static inline bool trigger_allbutcpu_cpu_backtrace(int exclude_cpu)
167 {
168 arch_trigger_cpumask_backtrace(cpu_online_mask, exclude_cpu);
169 return true;
170 }
171
172 static inline bool trigger_cpumask_backtrace(struct cpumask *mask)
173 {
174 arch_trigger_cpumask_backtrace(mask, -1);
175 return true;
176 }
177
178 static inline bool trigger_single_cpu_backtrace(int cpu)
179 {
180 arch_trigger_cpumask_backtrace(cpumask_of(cpu), -1);
181 return true;
182 }
183
184 /* generic implementation */
185 void nmi_trigger_cpumask_backtrace(const cpumask_t *mask,
186 int exclude_cpu,
187 void (*raise)(cpumask_t *mask));
188 bool nmi_cpu_backtrace(struct pt_regs *regs);
189
190 #else
191 static inline bool trigger_all_cpu_backtrace(void)
192 {
193 return false;
194 }
195 static inline bool trigger_allbutcpu_cpu_backtrace(int exclude_cpu)
196 {
197 return false;
198 }
199 static inline bool trigger_cpumask_backtrace(struct cpumask *mask)
200 {
201 return false;
202 }
203 static inline bool trigger_single_cpu_backtrace(int cpu)
204 {
205 return false;
206 }
207 #endif
208
209 #ifdef CONFIG_HARDLOCKUP_DETECTOR_PERF
210 u64 hw_nmi_get_sample_period(int watchdog_thresh);
211 bool arch_perf_nmi_is_available(void);
212 #endif
213
214 #if defined(CONFIG_HARDLOCKUP_CHECK_TIMESTAMP) && \
215 defined(CONFIG_HARDLOCKUP_DETECTOR_PERF)
216 void watchdog_update_hrtimer_threshold(u64 period);
217 #else
218 static inline void watchdog_update_hrtimer_threshold(u64 period) { }
219 #endif
220
221 #ifdef CONFIG_HAVE_ACPI_APEI_NMI
222 #include <asm/nmi.h>
223 #endif
224
225 #ifdef CONFIG_NMI_CHECK_CPU
226 void nmi_backtrace_stall_snap(const struct cpumask *btp);
227 void nmi_backtrace_stall_check(const struct cpumask *btp);
228 #else
229 static inline void nmi_backtrace_stall_snap(const struct cpumask *btp) {}
230 static inline void nmi_backtrace_stall_check(const struct cpumask *btp) {}
231 #endif
232
233 #endif
234
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