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_retry_init(void); 17 void lockup_detector_soft_poweroff(void); 18 void lockup_detector_cleanup(void); 19 20 extern int watchdog_user_enabled; 21 extern int watchdog_thresh; 22 extern unsigned long watchdog_enabled; 23 24 extern struct cpumask watchdog_cpumask; 25 extern unsigned long *watchdog_cpumask_bits; 26 #ifdef CONFIG_SMP 27 extern int sysctl_softlockup_all_cpu_backtrace; 28 extern int sysctl_hardlockup_all_cpu_backtrace; 29 #else 30 #define sysctl_softlockup_all_cpu_backtrace 0 31 #define sysctl_hardlockup_all_cpu_backtrace 0 32 #endif /* !CONFIG_SMP */ 33 34 #else /* CONFIG_LOCKUP_DETECTOR */ 35 static inline void lockup_detector_init(void) { } 36 static inline void lockup_detector_retry_init(void) { } 37 static inline void lockup_detector_soft_poweroff(void) { } 38 static inline void lockup_detector_cleanup(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 */ 51 static inline void touch_softlockup_watchdog_sched(void) { } 52 static inline void touch_softlockup_watchdog(void) { } 53 static inline void touch_softlockup_watchdog_sync(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 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 87 static inline void hardlockup_detector_disable(void) {} 88 #endif 89 90 #if defined(CONFIG_HARDLOCKUP_DETECTOR_COUNTS_HRTIMER) 91 void arch_touch_nmi_watchdog(void); 92 void watchdog_hardlockup_touch_cpu(unsigned int cpu); 93 void watchdog_hardlockup_check(unsigned int cpu, struct pt_regs *regs); 94 #elif !defined(CONFIG_HAVE_NMI_WATCHDOG) 95 static inline void arch_touch_nmi_watchdog(void) { } 96 #endif 97 98 #if defined(CONFIG_HAVE_NMI_WATCHDOG) || defined(CONFIG_HARDLOCKUP_DETECTOR) 99 # define NMI_WATCHDOG_SYSCTL_PERM 0644 100 #else 101 # define NMI_WATCHDOG_SYSCTL_PERM 0444 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 #else 109 static inline void hardlockup_detector_perf_stop(void) { } 110 static inline void hardlockup_detector_perf_restart(void) { } 111 static inline void hardlockup_detector_perf_cleanup(void) { } 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(unsigned long hrtimer_interrupts); 124 #else 125 static inline void watchdog_buddy_check_hardlockup(unsigned long 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 */ 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 /* 150 * Touching the hardlock detector implicitly resets the 151 * softlockup detector too 152 */ 153 touch_softlockup_watchdog(); 154 } 155 156 /* 157 * Create trigger_all_cpu_backtrace() out of the arch-provided 158 * base function. Return whether such support was available, 159 * to allow calling code to fall back to some other mechanism: 160 */ 161 #ifdef arch_trigger_cpumask_backtrace 162 static inline bool trigger_all_cpu_backtrace(void) 163 { 164 arch_trigger_cpumask_backtrace(cpu_online_mask, false); 165 return true; 166 } 167 168 static inline bool trigger_allbutself_cpu_backtrace(void) 169 { 170 arch_trigger_cpumask_backtrace(cpu_online_mask, true); 171 return true; 172 } 173 174 static inline bool trigger_cpumask_backtrace(struct cpumask *mask) 175 { 176 arch_trigger_cpumask_backtrace(mask, false); 177 return true; 178 } 179 180 static inline bool trigger_single_cpu_backtrace(int cpu) 181 { 182 arch_trigger_cpumask_backtrace(cpumask_of(cpu), false); 183 return true; 184 } 185 186 /* generic implementation */ 187 void nmi_trigger_cpumask_backtrace(const cpumask_t *mask, 188 bool exclude_self, 189 void (*raise)(cpumask_t *mask)); 190 bool nmi_cpu_backtrace(struct pt_regs *regs); 191 192 #else 193 static inline bool trigger_all_cpu_backtrace(void) 194 { 195 return false; 196 } 197 static inline bool trigger_allbutself_cpu_backtrace(void) 198 { 199 return false; 200 } 201 static inline bool trigger_cpumask_backtrace(struct cpumask *mask) 202 { 203 return false; 204 } 205 static inline bool trigger_single_cpu_backtrace(int cpu) 206 { 207 return false; 208 } 209 #endif 210 211 #ifdef CONFIG_HARDLOCKUP_DETECTOR_PERF 212 u64 hw_nmi_get_sample_period(int watchdog_thresh); 213 bool arch_perf_nmi_is_available(void); 214 #endif 215 216 #if defined(CONFIG_HARDLOCKUP_CHECK_TIMESTAMP) && \ 217 defined(CONFIG_HARDLOCKUP_DETECTOR_PERF) 218 void watchdog_update_hrtimer_threshold(u64 period); 219 #else 220 static inline void watchdog_update_hrtimer_threshold(u64 period) { } 221 #endif 222 223 struct ctl_table; 224 int proc_watchdog(struct ctl_table *, int, void *, size_t *, loff_t *); 225 int proc_nmi_watchdog(struct ctl_table *, int , void *, size_t *, loff_t *); 226 int proc_soft_watchdog(struct ctl_table *, int , void *, size_t *, loff_t *); 227 int proc_watchdog_thresh(struct ctl_table *, int , void *, size_t *, loff_t *); 228 int proc_watchdog_cpumask(struct ctl_table *, int, void *, size_t *, loff_t *); 229 230 #ifdef CONFIG_HAVE_ACPI_APEI_NMI 231 #include <asm/nmi.h> 232 #endif 233 234 #ifdef CONFIG_NMI_CHECK_CPU 235 void nmi_backtrace_stall_snap(const struct cpumask *btp); 236 void nmi_backtrace_stall_check(const struct cpumask *btp); 237 #else 238 static inline void nmi_backtrace_stall_snap(const struct cpumask *btp) {} 239 static inline void nmi_backtrace_stall_check(const struct cpumask *btp) {} 240 #endif 241 242 #endif 243