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 */ 36 static inline void lockup_detector_init(void) { } 37 static inline void lockup_detector_retry_init(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 */ 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 /* Sparc64 has special implemetantion that is always enabled. */ 91 #if defined(CONFIG_HARDLOCKUP_DETECTOR) || defined(CONFIG_HARDLOCKUP_DETECTOR_SPARC64) 92 void arch_touch_nmi_watchdog(void); 93 #else 94 static inline void arch_touch_nmi_watchdog(void) { } 95 #endif 96 97 #if defined(CONFIG_HARDLOCKUP_DETECTOR_COUNTS_HRTIMER) 98 void watchdog_hardlockup_touch_cpu(unsigned int cpu); 99 void watchdog_hardlockup_check(unsigned int cpu, struct pt_regs *regs); 100 #endif 101 102 #if defined(CONFIG_HARDLOCKUP_DETECTOR_PERF) 103 extern void hardlockup_detector_perf_stop(void); 104 extern void hardlockup_detector_perf_restart(void); 105 extern void hardlockup_config_perf_event(const char *str); 106 #else 107 static inline void hardlockup_detector_perf_stop(void) { } 108 static inline void hardlockup_detector_perf_restart(void) { } 109 static inline void hardlockup_config_perf_event(const char *str) { } 110 #endif 111 112 void watchdog_hardlockup_stop(void); 113 void watchdog_hardlockup_start(void); 114 int watchdog_hardlockup_probe(void); 115 void watchdog_hardlockup_enable(unsigned int cpu); 116 void watchdog_hardlockup_disable(unsigned int cpu); 117 118 void lockup_detector_reconfigure(void); 119 120 #ifdef CONFIG_HARDLOCKUP_DETECTOR_BUDDY 121 void watchdog_buddy_check_hardlockup(int hrtimer_interrupts); 122 #else 123 static inline void watchdog_buddy_check_hardlockup(int hrtimer_interrupts) {} 124 #endif 125 126 /** 127 * touch_nmi_watchdog - manually reset the hardlockup watchdog timeout. 128 * 129 * If we support detecting hardlockups, touch_nmi_watchdog() may be 130 * used to pet the watchdog (reset the timeout) - for code which 131 * intentionally disables interrupts for a long time. This call is stateless. 132 * 133 * Though this function has "nmi" in the name, the hardlockup watchdog might 134 * not be backed by NMIs. This function will likely be renamed to 135 * touch_hardlockup_watchdog() in the future. 136 */ 137 static inline void touch_nmi_watchdog(void) 138 { 139 /* 140 * Pass on to the hardlockup detector selected via CONFIG_. Note that 141 * the hardlockup detector may not be arch-specific nor using NMIs 142 * and the arch_touch_nmi_watchdog() function will likely be renamed 143 * in the future. 144 */ 145 arch_touch_nmi_watchdog(); 146 147 touch_softlockup_watchdog(); 148 } 149 150 /* 151 * Create trigger_all_cpu_backtrace() out of the arch-provided 152 * base function. Return whether such support was available, 153 * to allow calling code to fall back to some other mechanism: 154 */ 155 #ifdef arch_trigger_cpumask_backtrace 156 static inline bool trigger_all_cpu_backtrace(void) 157 { 158 arch_trigger_cpumask_backtrace(cpu_online_mask, -1); 159 return true; 160 } 161 162 static inline bool trigger_allbutcpu_cpu_backtrace(int exclude_cpu) 163 { 164 arch_trigger_cpumask_backtrace(cpu_online_mask, exclude_cpu); 165 return true; 166 } 167 168 static inline bool trigger_cpumask_backtrace(struct cpumask *mask) 169 { 170 arch_trigger_cpumask_backtrace(mask, -1); 171 return true; 172 } 173 174 static inline bool trigger_single_cpu_backtrace(int cpu) 175 { 176 arch_trigger_cpumask_backtrace(cpumask_of(cpu), -1); 177 return true; 178 } 179 180 /* generic implementation */ 181 void nmi_trigger_cpumask_backtrace(const cpumask_t *mask, 182 int exclude_cpu, 183 void (*raise)(cpumask_t *mask)); 184 bool nmi_cpu_backtrace(struct pt_regs *regs); 185 186 #else 187 static inline bool trigger_all_cpu_backtrace(void) 188 { 189 return false; 190 } 191 static inline bool trigger_allbutcpu_cpu_backtrace(int exclude_cpu) 192 { 193 return false; 194 } 195 static inline bool trigger_cpumask_backtrace(struct cpumask *mask) 196 { 197 return false; 198 } 199 static inline bool trigger_single_cpu_backtrace(int cpu) 200 { 201 return false; 202 } 203 #endif 204 205 #ifdef CONFIG_HARDLOCKUP_DETECTOR_PERF 206 u64 hw_nmi_get_sample_period(int watchdog_thresh); 207 bool arch_perf_nmi_is_available(void); 208 #endif 209 210 #if defined(CONFIG_HARDLOCKUP_CHECK_TIMESTAMP) && \ 211 defined(CONFIG_HARDLOCKUP_DETECTOR_PERF) 212 void watchdog_update_hrtimer_threshold(u64 period); 213 #else 214 static inline void watchdog_update_hrtimer_threshold(u64 period) { } 215 #endif 216 217 #ifdef CONFIG_HAVE_ACPI_APEI_NMI 218 #include <asm/nmi.h> 219 #endif 220 221 #ifdef CONFIG_NMI_CHECK_CPU 222 void nmi_backtrace_stall_snap(const struct cpumask *btp); 223 void nmi_backtrace_stall_check(const struct cpumask *btp); 224 #else 225 static inline void nmi_backtrace_stall_snap(const struct cpumask *btp) {} 226 static inline void nmi_backtrace_stall_check(const struct cpumask *btp) {} 227 #endif 228 229 #endif 230