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 #if defined(CONFIG_HAVE_NMI_WATCHDOG) 11 #include <asm/nmi.h> 12 #endif 13 14 #ifdef CONFIG_LOCKUP_DETECTOR 15 void lockup_detector_init(void); 16 void lockup_detector_soft_poweroff(void); 17 void lockup_detector_cleanup(void); 18 bool is_hardlockup(void); 19 20 extern int watchdog_user_enabled; 21 extern int nmi_watchdog_user_enabled; 22 extern int soft_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_soft_poweroff(void) { } 39 static inline void lockup_detector_cleanup(void) { } 40 #endif /* !CONFIG_LOCKUP_DETECTOR */ 41 42 #ifdef CONFIG_SOFTLOCKUP_DETECTOR 43 extern void touch_softlockup_watchdog_sched(void); 44 extern void touch_softlockup_watchdog(void); 45 extern void touch_softlockup_watchdog_sync(void); 46 extern void touch_all_softlockup_watchdogs(void); 47 extern unsigned int softlockup_panic; 48 49 extern int lockup_detector_online_cpu(unsigned int cpu); 50 extern int lockup_detector_offline_cpu(unsigned int cpu); 51 #else /* CONFIG_SOFTLOCKUP_DETECTOR */ 52 static inline void touch_softlockup_watchdog_sched(void) { } 53 static inline void touch_softlockup_watchdog(void) { } 54 static inline void touch_softlockup_watchdog_sync(void) { } 55 static inline void touch_all_softlockup_watchdogs(void) { } 56 57 #define lockup_detector_online_cpu NULL 58 #define lockup_detector_offline_cpu NULL 59 #endif /* CONFIG_SOFTLOCKUP_DETECTOR */ 60 61 #ifdef CONFIG_DETECT_HUNG_TASK 62 void reset_hung_task_detector(void); 63 #else 64 static inline void reset_hung_task_detector(void) { } 65 #endif 66 67 /* 68 * The run state of the lockup detectors is controlled by the content of the 69 * 'watchdog_enabled' variable. Each lockup detector has its dedicated bit - 70 * bit 0 for the hard lockup detector and bit 1 for the soft lockup detector. 71 * 72 * 'watchdog_user_enabled', 'nmi_watchdog_user_enabled' and 73 * 'soft_watchdog_user_enabled' are variables that are only used as an 74 * 'interface' between the parameters in /proc/sys/kernel and the internal 75 * state bits in 'watchdog_enabled'. The 'watchdog_thresh' variable is 76 * handled differently because its value is not boolean, and the lockup 77 * detectors are 'suspended' while 'watchdog_thresh' is equal zero. 78 */ 79 #define NMI_WATCHDOG_ENABLED_BIT 0 80 #define SOFT_WATCHDOG_ENABLED_BIT 1 81 #define NMI_WATCHDOG_ENABLED (1 << NMI_WATCHDOG_ENABLED_BIT) 82 #define SOFT_WATCHDOG_ENABLED (1 << SOFT_WATCHDOG_ENABLED_BIT) 83 84 #if defined(CONFIG_HARDLOCKUP_DETECTOR) 85 extern void hardlockup_detector_disable(void); 86 extern unsigned int hardlockup_panic; 87 #else 88 static inline void hardlockup_detector_disable(void) {} 89 #endif 90 91 #if defined(CONFIG_HAVE_NMI_WATCHDOG) || defined(CONFIG_HARDLOCKUP_DETECTOR) 92 # define NMI_WATCHDOG_SYSCTL_PERM 0644 93 #else 94 # define NMI_WATCHDOG_SYSCTL_PERM 0444 95 #endif 96 97 #if defined(CONFIG_HARDLOCKUP_DETECTOR_PERF) 98 extern void arch_touch_nmi_watchdog(void); 99 extern void hardlockup_detector_perf_stop(void); 100 extern void hardlockup_detector_perf_restart(void); 101 extern void hardlockup_detector_perf_disable(void); 102 extern void hardlockup_detector_perf_enable(void); 103 extern void hardlockup_detector_perf_cleanup(void); 104 extern int hardlockup_detector_perf_init(void); 105 #else 106 static inline void hardlockup_detector_perf_stop(void) { } 107 static inline void hardlockup_detector_perf_restart(void) { } 108 static inline void hardlockup_detector_perf_disable(void) { } 109 static inline void hardlockup_detector_perf_enable(void) { } 110 static inline void hardlockup_detector_perf_cleanup(void) { } 111 # if !defined(CONFIG_HAVE_NMI_WATCHDOG) 112 static inline int hardlockup_detector_perf_init(void) { return -ENODEV; } 113 static inline void arch_touch_nmi_watchdog(void) {} 114 # else 115 static inline int hardlockup_detector_perf_init(void) { return 0; } 116 # endif 117 #endif 118 119 void watchdog_nmi_stop(void); 120 void watchdog_nmi_start(void); 121 int watchdog_nmi_probe(void); 122 int watchdog_nmi_enable(unsigned int cpu); 123 void watchdog_nmi_disable(unsigned int cpu); 124 125 void lockup_detector_reconfigure(void); 126 127 /** 128 * touch_nmi_watchdog - restart NMI watchdog timeout. 129 * 130 * If the architecture supports the NMI watchdog, touch_nmi_watchdog() 131 * may be used to reset the timeout - for code which intentionally 132 * disables interrupts for a long time. This call is stateless. 133 */ 134 static inline void touch_nmi_watchdog(void) 135 { 136 arch_touch_nmi_watchdog(); 137 touch_softlockup_watchdog(); 138 } 139 140 /* 141 * Create trigger_all_cpu_backtrace() out of the arch-provided 142 * base function. Return whether such support was available, 143 * to allow calling code to fall back to some other mechanism: 144 */ 145 #ifdef arch_trigger_cpumask_backtrace 146 static inline bool trigger_all_cpu_backtrace(void) 147 { 148 arch_trigger_cpumask_backtrace(cpu_online_mask, false); 149 return true; 150 } 151 152 static inline bool trigger_allbutself_cpu_backtrace(void) 153 { 154 arch_trigger_cpumask_backtrace(cpu_online_mask, true); 155 return true; 156 } 157 158 static inline bool trigger_cpumask_backtrace(struct cpumask *mask) 159 { 160 arch_trigger_cpumask_backtrace(mask, false); 161 return true; 162 } 163 164 static inline bool trigger_single_cpu_backtrace(int cpu) 165 { 166 arch_trigger_cpumask_backtrace(cpumask_of(cpu), false); 167 return true; 168 } 169 170 /* generic implementation */ 171 void nmi_trigger_cpumask_backtrace(const cpumask_t *mask, 172 bool exclude_self, 173 void (*raise)(cpumask_t *mask)); 174 bool nmi_cpu_backtrace(struct pt_regs *regs); 175 176 #else 177 static inline bool trigger_all_cpu_backtrace(void) 178 { 179 return false; 180 } 181 static inline bool trigger_allbutself_cpu_backtrace(void) 182 { 183 return false; 184 } 185 static inline bool trigger_cpumask_backtrace(struct cpumask *mask) 186 { 187 return false; 188 } 189 static inline bool trigger_single_cpu_backtrace(int cpu) 190 { 191 return false; 192 } 193 #endif 194 195 #ifdef CONFIG_HARDLOCKUP_DETECTOR_PERF 196 u64 hw_nmi_get_sample_period(int watchdog_thresh); 197 #endif 198 199 #if defined(CONFIG_HARDLOCKUP_CHECK_TIMESTAMP) && \ 200 defined(CONFIG_HARDLOCKUP_DETECTOR) 201 void watchdog_update_hrtimer_threshold(u64 period); 202 #else 203 static inline void watchdog_update_hrtimer_threshold(u64 period) { } 204 #endif 205 206 struct ctl_table; 207 int proc_watchdog(struct ctl_table *, int, void *, size_t *, loff_t *); 208 int proc_nmi_watchdog(struct ctl_table *, int , void *, size_t *, loff_t *); 209 int proc_soft_watchdog(struct ctl_table *, int , void *, size_t *, loff_t *); 210 int proc_watchdog_thresh(struct ctl_table *, int , void *, size_t *, loff_t *); 211 int proc_watchdog_cpumask(struct ctl_table *, int, void *, size_t *, loff_t *); 212 213 #ifdef CONFIG_HAVE_ACPI_APEI_NMI 214 #include <asm/nmi.h> 215 #endif 216 217 #ifdef CONFIG_NMI_CHECK_CPU 218 void nmi_backtrace_stall_snap(const struct cpumask *btp); 219 void nmi_backtrace_stall_check(const struct cpumask *btp); 220 #else 221 static inline void nmi_backtrace_stall_snap(const struct cpumask *btp) {} 222 static inline void nmi_backtrace_stall_check(const struct cpumask *btp) {} 223 #endif 224 225 #endif 226