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 extern unsigned long hardlockup_si_mask;
87 #else
hardlockup_detector_disable(void)88 static inline void hardlockup_detector_disable(void) {}
89 #endif
90
91 /* Sparc64 has special implemetantion that is always enabled. */
92 #if defined(CONFIG_HARDLOCKUP_DETECTOR) || defined(CONFIG_HARDLOCKUP_DETECTOR_SPARC64)
93 void arch_touch_nmi_watchdog(void);
94 #else
arch_touch_nmi_watchdog(void)95 static inline void arch_touch_nmi_watchdog(void) { }
96 #endif
97
98 #if defined(CONFIG_HARDLOCKUP_DETECTOR_COUNTS_HRTIMER)
99 void watchdog_hardlockup_touch_cpu(unsigned int cpu);
100 void watchdog_hardlockup_check(unsigned int cpu, struct pt_regs *regs);
101 #endif
102
103 #if defined(CONFIG_HARDLOCKUP_DETECTOR_PERF)
104 extern void hardlockup_detector_perf_stop(void);
105 extern void hardlockup_detector_perf_restart(void);
106 extern void hardlockup_config_perf_event(const char *str);
107 extern void hardlockup_detector_perf_adjust_period(u64 period);
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_config_perf_event(const char * str)111 static inline void hardlockup_config_perf_event(const char *str) { }
hardlockup_detector_perf_adjust_period(u64 period)112 static inline void hardlockup_detector_perf_adjust_period(u64 period) { }
113 #endif
114
115 void watchdog_hardlockup_stop(void);
116 void watchdog_hardlockup_start(void);
117 int watchdog_hardlockup_probe(void);
118 void watchdog_hardlockup_enable(unsigned int cpu);
119 void watchdog_hardlockup_disable(unsigned int cpu);
120
121 void lockup_detector_reconfigure(void);
122
123 #ifdef CONFIG_HARDLOCKUP_DETECTOR_BUDDY
124 void watchdog_buddy_check_hardlockup(int hrtimer_interrupts);
125 #else
watchdog_buddy_check_hardlockup(int hrtimer_interrupts)126 static inline void watchdog_buddy_check_hardlockup(int hrtimer_interrupts) {}
127 #endif
128
129 /**
130 * touch_nmi_watchdog - manually reset the hardlockup watchdog timeout.
131 *
132 * If we support detecting hardlockups, touch_nmi_watchdog() may be
133 * used to pet the watchdog (reset the timeout) - for code which
134 * intentionally disables interrupts for a long time. This call is stateless.
135 *
136 * Though this function has "nmi" in the name, the hardlockup watchdog might
137 * not be backed by NMIs. This function will likely be renamed to
138 * touch_hardlockup_watchdog() in the future.
139 */
touch_nmi_watchdog(void)140 static inline void touch_nmi_watchdog(void)
141 {
142 /*
143 * Pass on to the hardlockup detector selected via CONFIG_. Note that
144 * the hardlockup detector may not be arch-specific nor using NMIs
145 * and the arch_touch_nmi_watchdog() function will likely be renamed
146 * in the future.
147 */
148 arch_touch_nmi_watchdog();
149
150 touch_softlockup_watchdog();
151 }
152
153 /*
154 * Create trigger_all_cpu_backtrace() out of the arch-provided
155 * base function. Return whether such support was available,
156 * to allow calling code to fall back to some other mechanism:
157 */
158 #ifdef arch_trigger_cpumask_backtrace
trigger_all_cpu_backtrace(void)159 static inline bool trigger_all_cpu_backtrace(void)
160 {
161 arch_trigger_cpumask_backtrace(cpu_online_mask, -1);
162 return true;
163 }
164
trigger_allbutcpu_cpu_backtrace(int exclude_cpu)165 static inline bool trigger_allbutcpu_cpu_backtrace(int exclude_cpu)
166 {
167 arch_trigger_cpumask_backtrace(cpu_online_mask, exclude_cpu);
168 return true;
169 }
170
trigger_cpumask_backtrace(struct cpumask * mask)171 static inline bool trigger_cpumask_backtrace(struct cpumask *mask)
172 {
173 arch_trigger_cpumask_backtrace(mask, -1);
174 return true;
175 }
176
trigger_single_cpu_backtrace(int cpu)177 static inline bool trigger_single_cpu_backtrace(int cpu)
178 {
179 arch_trigger_cpumask_backtrace(cpumask_of(cpu), -1);
180 return true;
181 }
182
183 /* generic implementation */
184 void nmi_trigger_cpumask_backtrace(const cpumask_t *mask,
185 int exclude_cpu,
186 void (*raise)(cpumask_t *mask));
187 bool nmi_cpu_backtrace(struct pt_regs *regs);
188
189 #else
trigger_all_cpu_backtrace(void)190 static inline bool trigger_all_cpu_backtrace(void)
191 {
192 return false;
193 }
trigger_allbutcpu_cpu_backtrace(int exclude_cpu)194 static inline bool trigger_allbutcpu_cpu_backtrace(int exclude_cpu)
195 {
196 return false;
197 }
trigger_cpumask_backtrace(struct cpumask * mask)198 static inline bool trigger_cpumask_backtrace(struct cpumask *mask)
199 {
200 return false;
201 }
trigger_single_cpu_backtrace(int cpu)202 static inline bool trigger_single_cpu_backtrace(int cpu)
203 {
204 return false;
205 }
206 #endif
207
208 #ifdef CONFIG_HARDLOCKUP_DETECTOR_PERF
209 u64 hw_nmi_get_sample_period(int watchdog_thresh);
210 bool arch_perf_nmi_is_available(void);
211 #endif
212
213 #if defined(CONFIG_HARDLOCKUP_CHECK_TIMESTAMP) && \
214 defined(CONFIG_HARDLOCKUP_DETECTOR_PERF)
215 void watchdog_update_hrtimer_threshold(u64 period);
216 #else
watchdog_update_hrtimer_threshold(u64 period)217 static inline void watchdog_update_hrtimer_threshold(u64 period) { }
218 #endif
219
220 #ifdef CONFIG_HAVE_ACPI_APEI_NMI
221 #include <asm/nmi.h>
222 #endif
223
224 #ifdef CONFIG_NMI_CHECK_CPU
225 void nmi_backtrace_stall_snap(const struct cpumask *btp);
226 void nmi_backtrace_stall_check(const struct cpumask *btp);
227 #else
nmi_backtrace_stall_snap(const struct cpumask * btp)228 static inline void nmi_backtrace_stall_snap(const struct cpumask *btp) {}
nmi_backtrace_stall_check(const struct cpumask * btp)229 static inline void nmi_backtrace_stall_check(const struct cpumask *btp) {}
230 #endif
231
232 #endif
233