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