include/linux/nmi.h

   1 /*
   2  *  linux/include/linux/nmi.h
   3  */
   4 #ifndef LINUX_NMI_H
   5 #define LINUX_NMI_H
   6
   7 #include <linux/sched.h>
   8 #include <asm/irq.h>
   9 #if defined(CONFIG_HAVE_NMI_WATCHDOG)
  10 #include <asm/nmi.h>
  11 #endif
  12
  13 #ifdef CONFIG_LOCKUP_DETECTOR
  14 void lockup_detector_init(void);
  15 void lockup_detector_soft_poweroff(void);
  16 void lockup_detector_cleanup(void);
  17 bool is_hardlockup(void);
  18
  19 extern int watchdog_user_enabled;
  20 extern int nmi_watchdog_user_enabled;
  21 extern int soft_watchdog_user_enabled;
  22 extern int watchdog_thresh;
  23 extern unsigned long watchdog_enabled;
  24
  25 extern struct cpumask watchdog_cpumask;
  26 extern unsigned long *watchdog_cpumask_bits;
  27 #ifdef CONFIG_SMP
  28 extern int sysctl_softlockup_all_cpu_backtrace;
  29 extern int sysctl_hardlockup_all_cpu_backtrace;
  30 #else
  31 #define sysctl_softlockup_all_cpu_backtrace 0
  32 #define sysctl_hardlockup_all_cpu_backtrace 0
  33 #endif /* !CONFIG_SMP */
  34
  35 #else /* CONFIG_LOCKUP_DETECTOR */
  36 static inline void lockup_detector_init(void) { }
  37 static inline void lockup_detector_soft_poweroff(void) { }
  38 static inline void lockup_detector_cleanup(void) { }
  39 #endif /* !CONFIG_LOCKUP_DETECTOR */
  40
  41 #ifdef CONFIG_SOFTLOCKUP_DETECTOR
  42 extern void touch_softlockup_watchdog_sched(void);
  43 extern void touch_softlockup_watchdog(void);
  44 extern void touch_softlockup_watchdog_sync(void);
  45 extern void touch_all_softlockup_watchdogs(void);
  46 extern unsigned int  softlockup_panic;
  47 #else
  48 static inline void touch_softlockup_watchdog_sched(void) { }
  49 static inline void touch_softlockup_watchdog(void) { }
  50 static inline void touch_softlockup_watchdog_sync(void) { }
  51 static inline void touch_all_softlockup_watchdogs(void) { }
  52 #endif
  53
  54 #ifdef CONFIG_DETECT_HUNG_TASK
  55 void reset_hung_task_detector(void);
  56 #else
  57 static inline void reset_hung_task_detector(void) { }
  58 #endif
  59
  60 /*
  61  * The run state of the lockup detectors is controlled by the content of the
  62  * 'watchdog_enabled' variable. Each lockup detector has its dedicated bit -
  63  * bit 0 for the hard lockup detector and bit 1 for the soft lockup detector.
  64  *
  65  * 'watchdog_user_enabled', 'nmi_watchdog_user_enabled' and
  66  * 'soft_watchdog_user_enabled' are variables that are only used as an
  67  * 'interface' between the parameters in /proc/sys/kernel and the internal
  68  * state bits in 'watchdog_enabled'. The 'watchdog_thresh' variable is
  69  * handled differently because its value is not boolean, and the lockup
  70  * detectors are 'suspended' while 'watchdog_thresh' is equal zero.
  71  */
  72 #define NMI_WATCHDOG_ENABLED_BIT   0
  73 #define SOFT_WATCHDOG_ENABLED_BIT  1
  74 #define NMI_WATCHDOG_ENABLED      (1 << NMI_WATCHDOG_ENABLED_BIT)
  75 #define SOFT_WATCHDOG_ENABLED     (1 << SOFT_WATCHDOG_ENABLED_BIT)
  76
  77 #if defined(CONFIG_HARDLOCKUP_DETECTOR)
  78 extern void hardlockup_detector_disable(void);
  79 extern unsigned int hardlockup_panic;
  80 #else
  81 static inline void hardlockup_detector_disable(void) {}
  82 #endif
  83
  84 #if defined(CONFIG_HAVE_NMI_WATCHDOG) || defined(CONFIG_HARDLOCKUP_DETECTOR)
  85 # define NMI_WATCHDOG_SYSCTL_PERM       0644
  86 #else
  87 # define NMI_WATCHDOG_SYSCTL_PERM       0444
  88 #endif
  89
  90 #if defined(CONFIG_HARDLOCKUP_DETECTOR_PERF)
  91 extern void arch_touch_nmi_watchdog(void);
  92 extern void hardlockup_detector_perf_stop(void);
  93 extern void hardlockup_detector_perf_restart(void);
  94 extern void hardlockup_detector_perf_disable(void);
  95 extern void hardlockup_detector_perf_cleanup(void);
  96 #else
  97 static inline void hardlockup_detector_perf_stop(void) { }
  98 static inline void hardlockup_detector_perf_restart(void) { }
  99 static inline void hardlockup_detector_perf_disable(void) { }
 100 static inline void hardlockup_detector_perf_cleanup(void) { }
 101 #if !defined(CONFIG_HAVE_NMI_WATCHDOG)
 102 static inline void arch_touch_nmi_watchdog(void) {}
 103 #endif
 104 #endif
 105
 106 void watchdog_nmi_reconfigure(bool run);
 107
 108 /**
 109  * touch_nmi_watchdog - restart NMI watchdog timeout.
 110  *
 111  * If the architecture supports the NMI watchdog, touch_nmi_watchdog()
 112  * may be used to reset the timeout - for code which intentionally
 113  * disables interrupts for a long time. This call is stateless.
 114  */
 115 static inline void touch_nmi_watchdog(void)
 116 {
 117         arch_touch_nmi_watchdog();
 118         touch_softlockup_watchdog();
 119 }
 120
 121 /*
 122  * Create trigger_all_cpu_backtrace() out of the arch-provided
 123  * base function. Return whether such support was available,
 124  * to allow calling code to fall back to some other mechanism:
 125  */
 126 #ifdef arch_trigger_cpumask_backtrace
 127 static inline bool trigger_all_cpu_backtrace(void)
 128 {
 129         arch_trigger_cpumask_backtrace(cpu_online_mask, false);
 130         return true;
 131 }
 132
 133 static inline bool trigger_allbutself_cpu_backtrace(void)
 134 {
 135         arch_trigger_cpumask_backtrace(cpu_online_mask, true);
 136         return true;
 137 }
 138
 139 static inline bool trigger_cpumask_backtrace(struct cpumask *mask)
 140 {
 141         arch_trigger_cpumask_backtrace(mask, false);
 142         return true;
 143 }
 144
 145 static inline bool trigger_single_cpu_backtrace(int cpu)
 146 {
 147         arch_trigger_cpumask_backtrace(cpumask_of(cpu), false);
 148         return true;
 149 }
 150
 151 /* generic implementation */
 152 void nmi_trigger_cpumask_backtrace(const cpumask_t *mask,
 153                                    bool exclude_self,
 154                                    void (*raise)(cpumask_t *mask));
 155 bool nmi_cpu_backtrace(struct pt_regs *regs);
 156
 157 #else
 158 static inline bool trigger_all_cpu_backtrace(void)
 159 {
 160         return false;
 161 }
 162 static inline bool trigger_allbutself_cpu_backtrace(void)
 163 {
 164         return false;
 165 }
 166 static inline bool trigger_cpumask_backtrace(struct cpumask *mask)
 167 {
 168         return false;
 169 }
 170 static inline bool trigger_single_cpu_backtrace(int cpu)
 171 {
 172         return false;
 173 }
 174 #endif
 175
 176 #ifdef CONFIG_HARDLOCKUP_DETECTOR_PERF
 177 u64 hw_nmi_get_sample_period(int watchdog_thresh);
 178 #endif
 179
 180 #if defined(CONFIG_HARDLOCKUP_CHECK_TIMESTAMP) && \
 181     defined(CONFIG_HARDLOCKUP_DETECTOR)
 182 void watchdog_update_hrtimer_threshold(u64 period);
 183 #else
 184 static inline void watchdog_update_hrtimer_threshold(u64 period) { }
 185 #endif
 186
 187 struct ctl_table;
 188 extern int proc_watchdog(struct ctl_table *, int ,
 189                          void __user *, size_t *, loff_t *);
 190 extern int proc_nmi_watchdog(struct ctl_table *, int ,
 191                              void __user *, size_t *, loff_t *);
 192 extern int proc_soft_watchdog(struct ctl_table *, int ,
 193                               void __user *, size_t *, loff_t *);
 194 extern int proc_watchdog_thresh(struct ctl_table *, int ,
 195                                 void __user *, size_t *, loff_t *);
 196 extern int proc_watchdog_cpumask(struct ctl_table *, int,
 197                                  void __user *, size_t *, loff_t *);
 198
 199 #ifdef CONFIG_HAVE_ACPI_APEI_NMI
 200 #include <asm/nmi.h>
 201 #endif
 202
 203 #endif