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
  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
  17 void lockup_detector_init(void);
  18 void lockup_detector_retry_init(void);
  19 void lockup_detector_soft_poweroff(void);
  20 void lockup_detector_cleanup(void);
  21
  22 extern int 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_retry_init(void) { }
  39 static inline void lockup_detector_soft_poweroff(void) { }
  40 static inline void lockup_detector_cleanup(void) { }
  41 #endif /* !CONFIG_LOCKUP_DETECTOR */
  42
  43 #ifdef CONFIG_SOFTLOCKUP_DETECTOR
  44 extern void touch_softlockup_watchdog_sched(void);
  45 extern void touch_softlockup_watchdog(void);
  46 extern void touch_softlockup_watchdog_sync(void);
  47 extern void touch_all_softlockup_watchdogs(void);
  48 extern unsigned int  softlockup_panic;
  49
  50 extern int lockup_detector_online_cpu(unsigned int cpu);
  51 extern int lockup_detector_offline_cpu(unsigned int cpu);
  52 #else /* CONFIG_SOFTLOCKUP_DETECTOR */
  53 static inline void touch_softlockup_watchdog_sched(void) { }
  54 static inline void touch_softlockup_watchdog(void) { }
  55 static inline void touch_softlockup_watchdog_sync(void) { }
  56 static 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
  63 void reset_hung_task_detector(void);
  64 #else
  65 static 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)
  86 extern void hardlockup_detector_disable(void);
  87 extern unsigned int hardlockup_panic;
  88 #else
  89 static 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)
  94 void arch_touch_nmi_watchdog(void);
  95 #else
  96 static inline void arch_touch_nmi_watchdog(void) { }
  97 #endif
  98
  99 #if defined(CONFIG_HARDLOCKUP_DETECTOR_COUNTS_HRTIMER)
 100 void watchdog_hardlockup_touch_cpu(unsigned int cpu);
 101 void watchdog_hardlockup_check(unsigned int cpu, struct pt_regs *regs);
 102 #endif
 103
 104 #if defined(CONFIG_HARDLOCKUP_DETECTOR_PERF)
 105 extern void hardlockup_detector_perf_stop(void);
 106 extern void hardlockup_detector_perf_restart(void);
 107 extern void hardlockup_detector_perf_cleanup(void);
 108 extern void hardlockup_config_perf_event(const char *str);
 109 #else
 110 static inline void hardlockup_detector_perf_stop(void) { }
 111 static inline void hardlockup_detector_perf_restart(void) { }
 112 static inline void hardlockup_detector_perf_cleanup(void) { }
 113 static inline void hardlockup_config_perf_event(const char *str) { }
 114 #endif
 115
 116 void watchdog_hardlockup_stop(void);
 117 void watchdog_hardlockup_start(void);
 118 int watchdog_hardlockup_probe(void);
 119 void watchdog_hardlockup_enable(unsigned int cpu);
 120 void watchdog_hardlockup_disable(unsigned int cpu);
 121
 122 void lockup_detector_reconfigure(void);
 123
 124 #ifdef CONFIG_HARDLOCKUP_DETECTOR_BUDDY
 125 void watchdog_buddy_check_hardlockup(int hrtimer_interrupts);
 126 #else
 127 static inline void watchdog_buddy_check_hardlockup(int hrtimer_interrupts) {}
 128 #endif
 129
 130 /**
 131  * touch_nmi_watchdog - manually reset the hardlockup watchdog timeout.
 132  *
 133  * If we support detecting hardlockups, touch_nmi_watchdog() may be
 134  * used to pet the watchdog (reset the timeout) - for code which
 135  * intentionally disables interrupts for a long time. This call is stateless.
 136  *
 137  * Though this function has "nmi" in the name, the hardlockup watchdog might
 138  * not be backed by NMIs. This function will likely be renamed to
 139  * touch_hardlockup_watchdog() in the future.
 140  */
 141 static inline void touch_nmi_watchdog(void)
 142 {
 143         /*
 144          * Pass on to the hardlockup detector selected via CONFIG_. Note that
 145          * the hardlockup detector may not be arch-specific nor using NMIs
 146          * and the arch_touch_nmi_watchdog() function will likely be renamed
 147          * in the future.
 148          */
 149         arch_touch_nmi_watchdog();
 150
 151         touch_softlockup_watchdog();
 152 }
 153
 154 /*
 155  * Create trigger_all_cpu_backtrace() out of the arch-provided
 156  * base function. Return whether such support was available,
 157  * to allow calling code to fall back to some other mechanism:
 158  */
 159 #ifdef arch_trigger_cpumask_backtrace
 160 static inline bool trigger_all_cpu_backtrace(void)
 161 {
 162         arch_trigger_cpumask_backtrace(cpu_online_mask, -1);
 163         return true;
 164 }
 165
 166 static inline bool trigger_allbutcpu_cpu_backtrace(int exclude_cpu)
 167 {
 168         arch_trigger_cpumask_backtrace(cpu_online_mask, exclude_cpu);
 169         return true;
 170 }
 171
 172 static inline bool trigger_cpumask_backtrace(struct cpumask *mask)
 173 {
 174         arch_trigger_cpumask_backtrace(mask, -1);
 175         return true;
 176 }
 177
 178 static inline bool trigger_single_cpu_backtrace(int cpu)
 179 {
 180         arch_trigger_cpumask_backtrace(cpumask_of(cpu), -1);
 181         return true;
 182 }
 183
 184 /* generic implementation */
 185 void nmi_trigger_cpumask_backtrace(const cpumask_t *mask,
 186                                    int exclude_cpu,
 187                                    void (*raise)(cpumask_t *mask));
 188 bool nmi_cpu_backtrace(struct pt_regs *regs);
 189
 190 #else
 191 static inline bool trigger_all_cpu_backtrace(void)
 192 {
 193         return false;
 194 }
 195 static inline bool trigger_allbutcpu_cpu_backtrace(int exclude_cpu)
 196 {
 197         return false;
 198 }
 199 static inline bool trigger_cpumask_backtrace(struct cpumask *mask)
 200 {
 201         return false;
 202 }
 203 static inline bool trigger_single_cpu_backtrace(int cpu)
 204 {
 205         return false;
 206 }
 207 #endif
 208
 209 #ifdef CONFIG_HARDLOCKUP_DETECTOR_PERF
 210 u64 hw_nmi_get_sample_period(int watchdog_thresh);
 211 bool arch_perf_nmi_is_available(void);
 212 #endif
 213
 214 #if defined(CONFIG_HARDLOCKUP_CHECK_TIMESTAMP) && \
 215     defined(CONFIG_HARDLOCKUP_DETECTOR_PERF)
 216 void watchdog_update_hrtimer_threshold(u64 period);
 217 #else
 218 static inline void watchdog_update_hrtimer_threshold(u64 period) { }
 219 #endif
 220
 221 #ifdef CONFIG_HAVE_ACPI_APEI_NMI
 222 #include <asm/nmi.h>
 223 #endif
 224
 225 #ifdef CONFIG_NMI_CHECK_CPU
 226 void nmi_backtrace_stall_snap(const struct cpumask *btp);
 227 void nmi_backtrace_stall_check(const struct cpumask *btp);
 228 #else
 229 static inline void nmi_backtrace_stall_snap(const struct cpumask *btp) {}
 230 static inline void nmi_backtrace_stall_check(const struct cpumask *btp) {}
 231 #endif
 232
 233 #endif