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 #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(int hrtimer_interrupts); 124 #else 125 static inline void watchdog_buddy_check_hardlockup(int 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 touch_softlockup_watchdog(); 150 } 151 152 /* 153 * Create trigger_all_cpu_backtrace() out of the arch-provided 154 * base function. Return whether such support was available, 155 * to allow calling code to fall back to some other mechanism: 156 */ 157 #ifdef arch_trigger_cpumask_backtrace 158 static inline bool trigger_all_cpu_backtrace(void) 159 { 160 arch_trigger_cpumask_backtrace(cpu_online_mask, false); 161 return true; 162 } 163 164 static inline bool trigger_allbutself_cpu_backtrace(void) 165 { 166 arch_trigger_cpumask_backtrace(cpu_online_mask, true); 167 return true; 168 } 169 170 static inline bool trigger_cpumask_backtrace(struct cpumask *mask) 171 { 172 arch_trigger_cpumask_backtrace(mask, false); 173 return true; 174 } 175 176 static inline bool trigger_single_cpu_backtrace(int cpu) 177 { 178 arch_trigger_cpumask_backtrace(cpumask_of(cpu), false); 179 return true; 180 } 181 182 /* generic implementation */ 183 void nmi_trigger_cpumask_backtrace(const cpumask_t *mask, 184 bool exclude_self, 185 void (*raise)(cpumask_t *mask)); 186 bool nmi_cpu_backtrace(struct pt_regs *regs); 187 188 #else 189 static inline bool trigger_all_cpu_backtrace(void) 190 { 191 return false; 192 } 193 static inline bool trigger_allbutself_cpu_backtrace(void) 194 { 195 return false; 196 } 197 static inline bool trigger_cpumask_backtrace(struct cpumask *mask) 198 { 199 return false; 200 } 201 static inline bool trigger_single_cpu_backtrace(int cpu) 202 { 203 return false; 204 } 205 #endif 206 207 #ifdef CONFIG_HARDLOCKUP_DETECTOR_PERF 208 u64 hw_nmi_get_sample_period(int watchdog_thresh); 209 bool arch_perf_nmi_is_available(void); 210 #endif 211 212 #if defined(CONFIG_HARDLOCKUP_CHECK_TIMESTAMP) && \ 213 defined(CONFIG_HARDLOCKUP_DETECTOR_PERF) 214 void watchdog_update_hrtimer_threshold(u64 period); 215 #else 216 static inline void watchdog_update_hrtimer_threshold(u64 period) { } 217 #endif 218 219 struct ctl_table; 220 int proc_watchdog(struct ctl_table *, int, void *, size_t *, loff_t *); 221 int proc_nmi_watchdog(struct ctl_table *, int , void *, size_t *, loff_t *); 222 int proc_soft_watchdog(struct ctl_table *, int , void *, size_t *, loff_t *); 223 int proc_watchdog_thresh(struct ctl_table *, int , void *, size_t *, loff_t *); 224 int proc_watchdog_cpumask(struct ctl_table *, int, void *, size_t *, loff_t *); 225 226 #ifdef CONFIG_HAVE_ACPI_APEI_NMI 227 #include <asm/nmi.h> 228 #endif 229 230 #ifdef CONFIG_NMI_CHECK_CPU 231 void nmi_backtrace_stall_snap(const struct cpumask *btp); 232 void nmi_backtrace_stall_check(const struct cpumask *btp); 233 #else 234 static inline void nmi_backtrace_stall_snap(const struct cpumask *btp) {} 235 static inline void nmi_backtrace_stall_check(const struct cpumask *btp) {} 236 #endif 237 238 #endif 239