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