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
21 extern int watchdog_user_enabled;
22 extern int watchdog_thresh;
23 extern unsigned long watchdog_enabled;
24
25 extern struct cpumask watchdog_cpumask;
26 extern unsigned long *watchdog_cpumask_bits;
27 #ifdef CONFIG_SMP
28 extern int sysctl_softlockup_all_cpu_backtrace;
29 extern int sysctl_hardlockup_all_cpu_backtrace;
30 #else
31 #define sysctl_softlockup_all_cpu_backtrace 0
32 #define sysctl_hardlockup_all_cpu_backtrace 0
33 #endif /* !CONFIG_SMP */
34
35 #else /* CONFIG_LOCKUP_DETECTOR */
lockup_detector_init(void)36 static inline void lockup_detector_init(void) { }
lockup_detector_retry_init(void)37 static inline void lockup_detector_retry_init(void) { }
lockup_detector_soft_poweroff(void)38 static inline void lockup_detector_soft_poweroff(void) { }
39 #endif /* !CONFIG_LOCKUP_DETECTOR */
40
41 #ifdef CONFIG_SOFTLOCKUP_DETECTOR
42 extern void touch_softlockup_watchdog_sched(void);
43 extern void touch_softlockup_watchdog(void);
44 extern void touch_softlockup_watchdog_sync(void);
45 extern void touch_all_softlockup_watchdogs(void);
46 extern unsigned int softlockup_panic;
47
48 extern int lockup_detector_online_cpu(unsigned int cpu);
49 extern int lockup_detector_offline_cpu(unsigned int cpu);
50 #else /* CONFIG_SOFTLOCKUP_DETECTOR */
touch_softlockup_watchdog_sched(void)51 static inline void touch_softlockup_watchdog_sched(void) { }
touch_softlockup_watchdog(void)52 static inline void touch_softlockup_watchdog(void) { }
touch_softlockup_watchdog_sync(void)53 static inline void touch_softlockup_watchdog_sync(void) { }
touch_all_softlockup_watchdogs(void)54 static inline void touch_all_softlockup_watchdogs(void) { }
55
56 #define lockup_detector_online_cpu NULL
57 #define lockup_detector_offline_cpu NULL
58 #endif /* CONFIG_SOFTLOCKUP_DETECTOR */
59
60 #ifdef CONFIG_DETECT_HUNG_TASK
61 void reset_hung_task_detector(void);
62 #else
reset_hung_task_detector(void)63 static inline void reset_hung_task_detector(void) { }
64 #endif
65
66 /*
67 * The run state of the lockup detectors is controlled by the content of the
68 * 'watchdog_enabled' variable. Each lockup detector has its dedicated bit -
69 * bit 0 for the hard lockup detector and bit 1 for the soft lockup detector.
70 *
71 * 'watchdog_user_enabled', 'watchdog_hardlockup_user_enabled' and
72 * 'watchdog_softlockup_user_enabled' are variables that are only used as an
73 * 'interface' between the parameters in /proc/sys/kernel and the internal
74 * state bits in 'watchdog_enabled'. The 'watchdog_thresh' variable is
75 * handled differently because its value is not boolean, and the lockup
76 * detectors are 'suspended' while 'watchdog_thresh' is equal zero.
77 */
78 #define WATCHDOG_HARDLOCKUP_ENABLED_BIT 0
79 #define WATCHDOG_SOFTOCKUP_ENABLED_BIT 1
80 #define WATCHDOG_HARDLOCKUP_ENABLED (1 << WATCHDOG_HARDLOCKUP_ENABLED_BIT)
81 #define WATCHDOG_SOFTOCKUP_ENABLED (1 << WATCHDOG_SOFTOCKUP_ENABLED_BIT)
82
83 #if defined(CONFIG_HARDLOCKUP_DETECTOR)
84 extern void hardlockup_detector_disable(void);
85 extern unsigned int hardlockup_panic;
86 #else
hardlockup_detector_disable(void)87 static inline void hardlockup_detector_disable(void) {}
88 #endif
89
90 /* Sparc64 has special implemetantion that is always enabled. */
91 #if defined(CONFIG_HARDLOCKUP_DETECTOR) || defined(CONFIG_HARDLOCKUP_DETECTOR_SPARC64)
92 void arch_touch_nmi_watchdog(void);
93 #else
arch_touch_nmi_watchdog(void)94 static inline void arch_touch_nmi_watchdog(void) { }
95 #endif
96
97 #if defined(CONFIG_HARDLOCKUP_DETECTOR_COUNTS_HRTIMER)
98 void watchdog_hardlockup_touch_cpu(unsigned int cpu);
99 void watchdog_hardlockup_check(unsigned int cpu, struct pt_regs *regs);
100 #endif
101
102 #if defined(CONFIG_HARDLOCKUP_DETECTOR_PERF)
103 extern void hardlockup_detector_perf_stop(void);
104 extern void hardlockup_detector_perf_restart(void);
105 extern void hardlockup_config_perf_event(const char *str);
106 extern void hardlockup_detector_perf_adjust_period(u64 period);
107 #else
hardlockup_detector_perf_stop(void)108 static inline void hardlockup_detector_perf_stop(void) { }
hardlockup_detector_perf_restart(void)109 static inline void hardlockup_detector_perf_restart(void) { }
hardlockup_config_perf_event(const char * str)110 static inline void hardlockup_config_perf_event(const char *str) { }
hardlockup_detector_perf_adjust_period(u64 period)111 static inline void hardlockup_detector_perf_adjust_period(u64 period) { }
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 #ifdef CONFIG_HAVE_ACPI_APEI_NMI
220 #include <asm/nmi.h>
221 #endif
222
223 #ifdef CONFIG_NMI_CHECK_CPU
224 void nmi_backtrace_stall_snap(const struct cpumask *btp);
225 void nmi_backtrace_stall_check(const struct cpumask *btp);
226 #else
nmi_backtrace_stall_snap(const struct cpumask * btp)227 static inline void nmi_backtrace_stall_snap(const struct cpumask *btp) {}
nmi_backtrace_stall_check(const struct cpumask * btp)228 static inline void nmi_backtrace_stall_check(const struct cpumask *btp) {}
229 #endif
230
231 #endif
232