LXR linux/include/linux/nmi.h

   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
  15void lockup_detector_init(void);
  16void lockup_detector_soft_poweroff(void);
  17void lockup_detector_cleanup(void);
  18bool is_hardlockup(void);
  19
  20extern int watchdog_user_enabled;
  21extern int nmi_watchdog_user_enabled;
  22extern int soft_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_soft_poweroff(void) { }
  39static inline void lockup_detector_cleanup(void) { }
  40#endif /* !CONFIG_LOCKUP_DETECTOR */
  41
  42#ifdef CONFIG_SOFTLOCKUP_DETECTOR
  43extern void touch_softlockup_watchdog_sched(void);
  44extern void touch_softlockup_watchdog(void);
  45extern void touch_softlockup_watchdog_sync(void);
  46extern void touch_all_softlockup_watchdogs(void);
  47extern unsigned int  softlockup_panic;
  48
  49extern int lockup_detector_online_cpu(unsigned int cpu);
  50extern int lockup_detector_offline_cpu(unsigned int cpu);
  51#else /* CONFIG_SOFTLOCKUP_DETECTOR */
  52static inline void touch_softlockup_watchdog_sched(void) { }
  53static inline void touch_softlockup_watchdog(void) { }
  54static inline void touch_softlockup_watchdog_sync(void) { }
  55static inline void touch_all_softlockup_watchdogs(void) { }
  56
  57#define lockup_detector_online_cpu      NULL
  58#define lockup_detector_offline_cpu     NULL
  59#endif /* CONFIG_SOFTLOCKUP_DETECTOR */
  60
  61#ifdef CONFIG_DETECT_HUNG_TASK
  62void reset_hung_task_detector(void);
  63#else
  64static inline void reset_hung_task_detector(void) { }
  65#endif
  66
  67/*
  68 * The run state of the lockup detectors is controlled by the content of the
  69 * 'watchdog_enabled' variable. Each lockup detector has its dedicated bit -
  70 * bit 0 for the hard lockup detector and bit 1 for the soft lockup detector.
  71 *
  72 * 'watchdog_user_enabled', 'nmi_watchdog_user_enabled' and
  73 * 'soft_watchdog_user_enabled' are variables that are only used as an
  74 * 'interface' between the parameters in /proc/sys/kernel and the internal
  75 * state bits in 'watchdog_enabled'. The 'watchdog_thresh' variable is
  76 * handled differently because its value is not boolean, and the lockup
  77 * detectors are 'suspended' while 'watchdog_thresh' is equal zero.
  78 */
  79#define NMI_WATCHDOG_ENABLED_BIT   0
  80#define SOFT_WATCHDOG_ENABLED_BIT  1
  81#define NMI_WATCHDOG_ENABLED      (1 << NMI_WATCHDOG_ENABLED_BIT)
  82#define SOFT_WATCHDOG_ENABLED     (1 << SOFT_WATCHDOG_ENABLED_BIT)
  83
  84#if defined(CONFIG_HARDLOCKUP_DETECTOR)
  85extern void hardlockup_detector_disable(void);
  86extern unsigned int hardlockup_panic;
  87#else
  88static inline void hardlockup_detector_disable(void) {}
  89#endif
  90
  91#if defined(CONFIG_HAVE_NMI_WATCHDOG) || defined(CONFIG_HARDLOCKUP_DETECTOR)
  92# define NMI_WATCHDOG_SYSCTL_PERM       0644
  93#else
  94# define NMI_WATCHDOG_SYSCTL_PERM       0444
  95#endif
  96
  97#if defined(CONFIG_HARDLOCKUP_DETECTOR_PERF)
  98extern void arch_touch_nmi_watchdog(void);
  99extern void hardlockup_detector_perf_stop(void);
 100extern void hardlockup_detector_perf_restart(void);
 101extern void hardlockup_detector_perf_disable(void);
 102extern void hardlockup_detector_perf_enable(void);
 103extern void hardlockup_detector_perf_cleanup(void);
 104extern int hardlockup_detector_perf_init(void);
 105#else
 106static inline void hardlockup_detector_perf_stop(void) { }
 107static inline void hardlockup_detector_perf_restart(void) { }
 108static inline void hardlockup_detector_perf_disable(void) { }
 109static inline void hardlockup_detector_perf_enable(void) { }
 110static inline void hardlockup_detector_perf_cleanup(void) { }
 111# if !defined(CONFIG_HAVE_NMI_WATCHDOG)
 112static inline int hardlockup_detector_perf_init(void) { return -ENODEV; }
 113static inline void arch_touch_nmi_watchdog(void) {}
 114# else
 115static inline int hardlockup_detector_perf_init(void) { return 0; }
 116# endif
 117#endif
 118
 119void watchdog_nmi_stop(void);
 120void watchdog_nmi_start(void);
 121int watchdog_nmi_probe(void);
 122
 123/**
 124 * touch_nmi_watchdog - restart NMI watchdog timeout.
 125 *
 126 * If the architecture supports the NMI watchdog, touch_nmi_watchdog()
 127 * may be used to reset the timeout - for code which intentionally
 128 * disables interrupts for a long time. This call is stateless.
 129 */
 130static inline void touch_nmi_watchdog(void)
 131{
 132        arch_touch_nmi_watchdog();
 133        touch_softlockup_watchdog();
 134}
 135
 136/*
 137 * Create trigger_all_cpu_backtrace() out of the arch-provided
 138 * base function. Return whether such support was available,
 139 * to allow calling code to fall back to some other mechanism:
 140 */
 141#ifdef arch_trigger_cpumask_backtrace
 142static inline bool trigger_all_cpu_backtrace(void)
 143{
 144        arch_trigger_cpumask_backtrace(cpu_online_mask, false);
 145        return true;
 146}
 147
 148static inline bool trigger_allbutself_cpu_backtrace(void)
 149{
 150        arch_trigger_cpumask_backtrace(cpu_online_mask, true);
 151        return true;
 152}
 153
 154static inline bool trigger_cpumask_backtrace(struct cpumask *mask)
 155{
 156        arch_trigger_cpumask_backtrace(mask, false);
 157        return true;
 158}
 159
 160static inline bool trigger_single_cpu_backtrace(int cpu)
 161{
 162        arch_trigger_cpumask_backtrace(cpumask_of(cpu), false);
 163        return true;
 164}
 165
 166/* generic implementation */
 167void nmi_trigger_cpumask_backtrace(const cpumask_t *mask,
 168                                   bool exclude_self,
 169                                   void (*raise)(cpumask_t *mask));
 170bool nmi_cpu_backtrace(struct pt_regs *regs);
 171
 172#else
 173static inline bool trigger_all_cpu_backtrace(void)
 174{
 175        return false;
 176}
 177static inline bool trigger_allbutself_cpu_backtrace(void)
 178{
 179        return false;
 180}
 181static inline bool trigger_cpumask_backtrace(struct cpumask *mask)
 182{
 183        return false;
 184}
 185static inline bool trigger_single_cpu_backtrace(int cpu)
 186{
 187        return false;
 188}
 189#endif
 190
 191#ifdef CONFIG_HARDLOCKUP_DETECTOR_PERF
 192u64 hw_nmi_get_sample_period(int watchdog_thresh);
 193#endif
 194
 195#if defined(CONFIG_HARDLOCKUP_CHECK_TIMESTAMP) && \
 196    defined(CONFIG_HARDLOCKUP_DETECTOR)
 197void watchdog_update_hrtimer_threshold(u64 period);
 198#else
 199static inline void watchdog_update_hrtimer_threshold(u64 period) { }
 200#endif
 201
 202struct ctl_table;
 203extern int proc_watchdog(struct ctl_table *, int ,
 204                         void __user *, size_t *, loff_t *);
 205extern int proc_nmi_watchdog(struct ctl_table *, int ,
 206                             void __user *, size_t *, loff_t *);
 207extern int proc_soft_watchdog(struct ctl_table *, int ,
 208                              void __user *, size_t *, loff_t *);
 209extern int proc_watchdog_thresh(struct ctl_table *, int ,
 210                                void __user *, size_t *, loff_t *);
 211extern int proc_watchdog_cpumask(struct ctl_table *, int,
 212                                 void __user *, size_t *, loff_t *);
 213
 214#ifdef CONFIG_HAVE_ACPI_APEI_NMI
 215#include <asm/nmi.h>
 216#endif
 217
 218#endif
 219