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 void lockup_detector_cleanup(void); 21 22 extern int 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_retry_init(void) { } 39 static inline void lockup_detector_soft_poweroff(void) { } 40 static inline void lockup_detector_cleanup(void) { } 41 #endif /* !CONFIG_LOCKUP_DETECTOR */ 42 43 #ifdef CONFIG_SOFTLOCKUP_DETECTOR 44 extern void touch_softlockup_watchdog_sched(void); 45 extern void touch_softlockup_watchdog(void); 46 extern void touch_softlockup_watchdog_sync(void); 47 extern void touch_all_softlockup_watchdogs(void); 48 extern unsigned int softlockup_panic; 49 50 extern int lockup_detector_online_cpu(unsigned int cpu); 51 extern int lockup_detector_offline_cpu(unsigned int cpu); 52 #else /* CONFIG_SOFTLOCKUP_DETECTOR */ 53 static inline void touch_softlockup_watchdog_sched(void) { } 54 static inline void touch_softlockup_watchdog(void) { } 55 static inline void touch_softlockup_watchdog_sync(void) { } 56 static inline void touch_all_softlockup_watchdogs(void) { } 57 58 #define lockup_detector_online_cpu NULL 59 #define lockup_detector_offline_cpu NULL 60 #endif /* CONFIG_SOFTLOCKUP_DETECTOR */ 61 62 #ifdef CONFIG_DETECT_HUNG_TASK 63 void reset_hung_task_detector(void); 64 #else 65 static inline void reset_hung_task_detector(void) { } 66 #endif 67 68 /* 69 * The run state of the lockup detectors is controlled by the content of the 70 * 'watchdog_enabled' variable. Each lockup detector has its dedicated bit - 71 * bit 0 for the hard lockup detector and bit 1 for the soft lockup detector. 72 * 73 * 'watchdog_user_enabled', 'watchdog_hardlockup_user_enabled' and 74 * 'watchdog_softlockup_user_enabled' are variables that are only used as an 75 * 'interface' between the parameters in /proc/sys/kernel and the internal 76 * state bits in 'watchdog_enabled'. The 'watchdog_thresh' variable is 77 * handled differently because its value is not boolean, and the lockup 78 * detectors are 'suspended' while 'watchdog_thresh' is equal zero. 79 */ 80 #define WATCHDOG_HARDLOCKUP_ENABLED_BIT 0 81 #define WATCHDOG_SOFTOCKUP_ENABLED_BIT 1 82 #define WATCHDOG_HARDLOCKUP_ENABLED (1 << WATCHDOG_HARDLOCKUP_ENABLED_BIT) 83 #define WATCHDOG_SOFTOCKUP_ENABLED (1 << WATCHDOG_SOFTOCKUP_ENABLED_BIT) 84 85 #if defined(CONFIG_HARDLOCKUP_DETECTOR) 86 extern void hardlockup_detector_disable(void); 87 extern unsigned int hardlockup_panic; 88 #else 89 static inline void hardlockup_detector_disable(void) {} 90 #endif 91 92 /* Sparc64 has special implemetantion that is always enabled. */ 93 #if defined(CONFIG_HARDLOCKUP_DETECTOR) || defined(CONFIG_HARDLOCKUP_DETECTOR_SPARC64) 94 void arch_touch_nmi_watchdog(void); 95 #else 96 static inline void arch_touch_nmi_watchdog(void) { } 97 #endif 98 99 #if defined(CONFIG_HARDLOCKUP_DETECTOR_COUNTS_HRTIMER) 100 void watchdog_hardlockup_touch_cpu(unsigned int cpu); 101 void watchdog_hardlockup_check(unsigned int cpu, struct pt_regs *regs); 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 extern void hardlockup_config_perf_event(const char *str); 109 #else 110 static inline void hardlockup_detector_perf_stop(void) { } 111 static inline void hardlockup_detector_perf_restart(void) { } 112 static inline void hardlockup_detector_perf_cleanup(void) { } 113 static inline void hardlockup_config_perf_event(const char *str) { } 114 #endif 115 116 void watchdog_hardlockup_stop(void); 117 void watchdog_hardlockup_start(void); 118 int watchdog_hardlockup_probe(void); 119 void watchdog_hardlockup_enable(unsigned int cpu); 120 void watchdog_hardlockup_disable(unsigned int cpu); 121 122 void lockup_detector_reconfigure(void); 123 124 #ifdef CONFIG_HARDLOCKUP_DETECTOR_BUDDY 125 void watchdog_buddy_check_hardlockup(int hrtimer_interrupts); 126 #else 127 static inline void watchdog_buddy_check_hardlockup(int hrtimer_interrupts) {} 128 #endif 129 130 /** 131 * touch_nmi_watchdog - manually reset the hardlockup watchdog timeout. 132 * 133 * If we support detecting hardlockups, touch_nmi_watchdog() may be 134 * used to pet the watchdog (reset the timeout) - for code which 135 * intentionally disables interrupts for a long time. This call is stateless. 136 * 137 * Though this function has "nmi" in the name, the hardlockup watchdog might 138 * not be backed by NMIs. This function will likely be renamed to 139 * touch_hardlockup_watchdog() in the future. 140 */ 141 static inline void touch_nmi_watchdog(void) 142 { 143 /* 144 * Pass on to the hardlockup detector selected via CONFIG_. Note that 145 * the hardlockup detector may not be arch-specific nor using NMIs 146 * and the arch_touch_nmi_watchdog() function will likely be renamed 147 * in the future. 148 */ 149 arch_touch_nmi_watchdog(); 150 151 touch_softlockup_watchdog(); 152 } 153 154 /* 155 * Create trigger_all_cpu_backtrace() out of the arch-provided 156 * base function. Return whether such support was available, 157 * to allow calling code to fall back to some other mechanism: 158 */ 159 #ifdef arch_trigger_cpumask_backtrace 160 static inline bool trigger_all_cpu_backtrace(void) 161 { 162 arch_trigger_cpumask_backtrace(cpu_online_mask, -1); 163 return true; 164 } 165 166 static inline bool trigger_allbutcpu_cpu_backtrace(int exclude_cpu) 167 { 168 arch_trigger_cpumask_backtrace(cpu_online_mask, exclude_cpu); 169 return true; 170 } 171 172 static inline bool trigger_cpumask_backtrace(struct cpumask *mask) 173 { 174 arch_trigger_cpumask_backtrace(mask, -1); 175 return true; 176 } 177 178 static inline bool trigger_single_cpu_backtrace(int cpu) 179 { 180 arch_trigger_cpumask_backtrace(cpumask_of(cpu), -1); 181 return true; 182 } 183 184 /* generic implementation */ 185 void nmi_trigger_cpumask_backtrace(const cpumask_t *mask, 186 int exclude_cpu, 187 void (*raise)(cpumask_t *mask)); 188 bool nmi_cpu_backtrace(struct pt_regs *regs); 189 190 #else 191 static inline bool trigger_all_cpu_backtrace(void) 192 { 193 return false; 194 } 195 static inline bool trigger_allbutcpu_cpu_backtrace(int exclude_cpu) 196 { 197 return false; 198 } 199 static inline bool trigger_cpumask_backtrace(struct cpumask *mask) 200 { 201 return false; 202 } 203 static inline bool trigger_single_cpu_backtrace(int cpu) 204 { 205 return false; 206 } 207 #endif 208 209 #ifdef CONFIG_HARDLOCKUP_DETECTOR_PERF 210 u64 hw_nmi_get_sample_period(int watchdog_thresh); 211 bool arch_perf_nmi_is_available(void); 212 #endif 213 214 #if defined(CONFIG_HARDLOCKUP_CHECK_TIMESTAMP) && \ 215 defined(CONFIG_HARDLOCKUP_DETECTOR_PERF) 216 void watchdog_update_hrtimer_threshold(u64 period); 217 #else 218 static inline void watchdog_update_hrtimer_threshold(u64 period) { } 219 #endif 220 221 #ifdef CONFIG_HAVE_ACPI_APEI_NMI 222 #include <asm/nmi.h> 223 #endif 224 225 #ifdef CONFIG_NMI_CHECK_CPU 226 void nmi_backtrace_stall_snap(const struct cpumask *btp); 227 void nmi_backtrace_stall_check(const struct cpumask *btp); 228 #else 229 static inline void nmi_backtrace_stall_snap(const struct cpumask *btp) {} 230 static inline void nmi_backtrace_stall_check(const struct cpumask *btp) {} 231 #endif 232 233 #endif 234