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 17void lockup_detector_init(void); 18void lockup_detector_retry_init(void); 19void lockup_detector_soft_poweroff(void); 20void lockup_detector_cleanup(void); 21 22extern int watchdog_user_enabled; 23extern int watchdog_thresh; 24extern unsigned long watchdog_enabled; 25 26extern struct cpumask watchdog_cpumask; 27extern unsigned long *watchdog_cpumask_bits; 28#ifdef CONFIG_SMP 29extern int sysctl_softlockup_all_cpu_backtrace; 30extern 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 */ 37static inline void lockup_detector_init(void) { } 38static inline void lockup_detector_retry_init(void) { } 39static inline void lockup_detector_soft_poweroff(void) { } 40static inline void lockup_detector_cleanup(void) { } 41#endif /* !CONFIG_LOCKUP_DETECTOR */ 42 43#ifdef CONFIG_SOFTLOCKUP_DETECTOR 44extern void touch_softlockup_watchdog_sched(void); 45extern void touch_softlockup_watchdog(void); 46extern void touch_softlockup_watchdog_sync(void); 47extern void touch_all_softlockup_watchdogs(void); 48extern unsigned int softlockup_panic; 49 50extern int lockup_detector_online_cpu(unsigned int cpu); 51extern int lockup_detector_offline_cpu(unsigned int cpu); 52#else /* CONFIG_SOFTLOCKUP_DETECTOR */ 53static inline void touch_softlockup_watchdog_sched(void) { } 54static inline void touch_softlockup_watchdog(void) { } 55static inline void touch_softlockup_watchdog_sync(void) { } 56static 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 63void reset_hung_task_detector(void); 64#else 65static 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) 86extern void hardlockup_detector_disable(void); 87extern unsigned int hardlockup_panic; 88#else 89static 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) 94void arch_touch_nmi_watchdog(void); 95#else 96static inline void arch_touch_nmi_watchdog(void) { } 97#endif 98 99#if defined(CONFIG_HARDLOCKUP_DETECTOR_COUNTS_HRTIMER) 100void watchdog_hardlockup_touch_cpu(unsigned int cpu); 101void watchdog_hardlockup_check(unsigned int cpu, struct pt_regs *regs); 102#endif 103 104#if defined(CONFIG_HARDLOCKUP_DETECTOR_PERF) 105extern void hardlockup_detector_perf_stop(void); 106extern void hardlockup_detector_perf_restart(void); 107extern void hardlockup_detector_perf_cleanup(void); 108#else 109static inline void hardlockup_detector_perf_stop(void) { } 110static inline void hardlockup_detector_perf_restart(void) { } 111static inline void hardlockup_detector_perf_cleanup(void) { } 112#endif 113 114void watchdog_hardlockup_stop(void); 115void watchdog_hardlockup_start(void); 116int watchdog_hardlockup_probe(void); 117void watchdog_hardlockup_enable(unsigned int cpu); 118void watchdog_hardlockup_disable(unsigned int cpu); 119 120void lockup_detector_reconfigure(void); 121 122#ifdef CONFIG_HARDLOCKUP_DETECTOR_BUDDY 123void watchdog_buddy_check_hardlockup(int hrtimer_interrupts); 124#else 125static 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 */ 139static 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 158static inline bool trigger_all_cpu_backtrace(void) 159{ 160 arch_trigger_cpumask_backtrace(cpu_online_mask, -1); 161 return true; 162} 163 164static inline bool trigger_allbutcpu_cpu_backtrace(int exclude_cpu) 165{ 166 arch_trigger_cpumask_backtrace(cpu_online_mask, exclude_cpu); 167 return true; 168} 169 170static inline bool trigger_cpumask_backtrace(struct cpumask *mask) 171{ 172 arch_trigger_cpumask_backtrace(mask, -1); 173 return true; 174} 175 176static inline bool trigger_single_cpu_backtrace(int cpu) 177{ 178 arch_trigger_cpumask_backtrace(cpumask_of(cpu), -1); 179 return true; 180} 181 182/* generic implementation */ 183void nmi_trigger_cpumask_backtrace(const cpumask_t *mask, 184 int exclude_cpu, 185 void (*raise)(cpumask_t *mask)); 186bool nmi_cpu_backtrace(struct pt_regs *regs); 187 188#else 189static inline bool trigger_all_cpu_backtrace(void) 190{ 191 return false; 192} 193static inline bool trigger_allbutcpu_cpu_backtrace(int exclude_cpu) 194{ 195 return false; 196} 197static inline bool trigger_cpumask_backtrace(struct cpumask *mask) 198{ 199 return false; 200} 201static inline bool trigger_single_cpu_backtrace(int cpu) 202{ 203 return false; 204} 205#endif 206 207#ifdef CONFIG_HARDLOCKUP_DETECTOR_PERF 208u64 hw_nmi_get_sample_period(int watchdog_thresh); 209bool arch_perf_nmi_is_available(void); 210#endif 211 212#if defined(CONFIG_HARDLOCKUP_CHECK_TIMESTAMP) && \ 213 defined(CONFIG_HARDLOCKUP_DETECTOR_PERF) 214void watchdog_update_hrtimer_threshold(u64 period); 215#else 216static inline void watchdog_update_hrtimer_threshold(u64 period) { } 217#endif 218 219#ifdef CONFIG_HAVE_ACPI_APEI_NMI 220#include <asm/nmi.h> 221#endif 222 223#ifdef CONFIG_NMI_CHECK_CPU 224void nmi_backtrace_stall_snap(const struct cpumask *btp); 225void nmi_backtrace_stall_check(const struct cpumask *btp); 226#else 227static inline void nmi_backtrace_stall_snap(const struct cpumask *btp) {} 228static inline void nmi_backtrace_stall_check(const struct cpumask *btp) {} 229#endif 230 231#endif 232