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
  15 void lockup_detector_init(void);
  16 void lockup_detector_soft_poweroff(void);
  17 void lockup_detector_cleanup(void);
  18 bool is_hardlockup(void);
  19
  20 extern int watchdog_user_enabled;
  21 extern int nmi_watchdog_user_enabled;
  22 extern int soft_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_soft_poweroff(void) { }
  39 static inline void lockup_detector_cleanup(void) { }
  40 #endif /* !CONFIG_LOCKUP_DETECTOR */
  41
  42 #ifdef CONFIG_SOFTLOCKUP_DETECTOR
  43 extern void touch_softlockup_watchdog_sched(void);
  44 extern void touch_softlockup_watchdog(void);
  45 extern void touch_softlockup_watchdog_sync(void);
  46 extern void touch_all_softlockup_watchdogs(void);
  47 extern unsigned int  softlockup_panic;
  48 #else
  49 static inline void touch_softlockup_watchdog_sched(void) { }
  50 static inline void touch_softlockup_watchdog(void) { }
  51 static inline void touch_softlockup_watchdog_sync(void) { }
  52 static inline void touch_all_softlockup_watchdogs(void) { }
  53 #endif
  54
  55 #ifdef CONFIG_DETECT_HUNG_TASK
  56 void reset_hung_task_detector(void);
  57 #else
  58 static 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)
  79 extern void hardlockup_detector_disable(void);
  80 extern unsigned int hardlockup_panic;
  81 #else
  82 static 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)
  92 extern void arch_touch_nmi_watchdog(void);
  93 extern void hardlockup_detector_perf_stop(void);
  94 extern void hardlockup_detector_perf_restart(void);
  95 extern void hardlockup_detector_perf_disable(void);
  96 extern void hardlockup_detector_perf_enable(void);
  97 extern void hardlockup_detector_perf_cleanup(void);
  98 extern int hardlockup_detector_perf_init(void);
  99 #else
 100 static inline void hardlockup_detector_perf_stop(void) { }
 101 static inline void hardlockup_detector_perf_restart(void) { }
 102 static inline void hardlockup_detector_perf_disable(void) { }
 103 static inline void hardlockup_detector_perf_enable(void) { }
 104 static inline void hardlockup_detector_perf_cleanup(void) { }
 105 # if !defined(CONFIG_HAVE_NMI_WATCHDOG)
 106 static inline int hardlockup_detector_perf_init(void) { return -ENODEV; }
 107 static inline void arch_touch_nmi_watchdog(void) {}
 108 # else
 109 static inline int hardlockup_detector_perf_init(void) { return 0; }
 110 # endif
 111 #endif
 112
 113 void watchdog_nmi_stop(void);
 114 void watchdog_nmi_start(void);
 115 int watchdog_nmi_probe(void);
 116 int watchdog_nmi_enable(unsigned int cpu);
 117 void watchdog_nmi_disable(unsigned int cpu);
 118
 119 /**
 120  * touch_nmi_watchdog - restart NMI watchdog timeout.
 121  *
 122  * If the architecture supports the NMI watchdog, touch_nmi_watchdog()
 123  * may be used to reset the timeout - for code which intentionally
 124  * disables interrupts for a long time. This call is stateless.
 125  */
 126 static inline void touch_nmi_watchdog(void)
 127 {
 128         arch_touch_nmi_watchdog();
 129         touch_softlockup_watchdog();
 130 }
 131
 132 /*
 133  * Create trigger_all_cpu_backtrace() out of the arch-provided
 134  * base function. Return whether such support was available,
 135  * to allow calling code to fall back to some other mechanism:
 136  */
 137 #ifdef arch_trigger_cpumask_backtrace
 138 static inline bool trigger_all_cpu_backtrace(void)
 139 {
 140         arch_trigger_cpumask_backtrace(cpu_online_mask, false);
 141         return true;
 142 }
 143
 144 static inline bool trigger_allbutself_cpu_backtrace(void)
 145 {
 146         arch_trigger_cpumask_backtrace(cpu_online_mask, true);
 147         return true;
 148 }
 149
 150 static inline bool trigger_cpumask_backtrace(struct cpumask *mask)
 151 {
 152         arch_trigger_cpumask_backtrace(mask, false);
 153         return true;
 154 }
 155
 156 static inline bool trigger_single_cpu_backtrace(int cpu)
 157 {
 158         arch_trigger_cpumask_backtrace(cpumask_of(cpu), false);
 159         return true;
 160 }
 161
 162 /* generic implementation */
 163 void nmi_trigger_cpumask_backtrace(const cpumask_t *mask,
 164                                    bool exclude_self,
 165                                    void (*raise)(cpumask_t *mask));
 166 bool nmi_cpu_backtrace(struct pt_regs *regs);
 167
 168 #else
 169 static inline bool trigger_all_cpu_backtrace(void)
 170 {
 171         return false;
 172 }
 173 static inline bool trigger_allbutself_cpu_backtrace(void)
 174 {
 175         return false;
 176 }
 177 static inline bool trigger_cpumask_backtrace(struct cpumask *mask)
 178 {
 179         return false;
 180 }
 181 static inline bool trigger_single_cpu_backtrace(int cpu)
 182 {
 183         return false;
 184 }
 185 #endif
 186
 187 #ifdef CONFIG_HARDLOCKUP_DETECTOR_PERF
 188 u64 hw_nmi_get_sample_period(int watchdog_thresh);
 189 #endif
 190
 191 #if defined(CONFIG_HARDLOCKUP_CHECK_TIMESTAMP) && \
 192     defined(CONFIG_HARDLOCKUP_DETECTOR)
 193 void watchdog_update_hrtimer_threshold(u64 period);
 194 #else
 195 static inline void watchdog_update_hrtimer_threshold(u64 period) { }
 196 #endif
 197
 198 struct ctl_table;
 199 extern int proc_watchdog(struct ctl_table *, int ,
 200                          void __user *, size_t *, loff_t *);
 201 extern int proc_nmi_watchdog(struct ctl_table *, int ,
 202                              void __user *, size_t *, loff_t *);
 203 extern int proc_soft_watchdog(struct ctl_table *, int ,
 204                               void __user *, size_t *, loff_t *);
 205 extern int proc_watchdog_thresh(struct ctl_table *, int ,
 206                                 void __user *, size_t *, loff_t *);
 207 extern int proc_watchdog_cpumask(struct ctl_table *, int,
 208                                  void __user *, size_t *, loff_t *);
 209
 210 #ifdef CONFIG_HAVE_ACPI_APEI_NMI
 211 #include <asm/nmi.h>
 212 #endif
 213
 214 #endif