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);
122int watchdog_nmi_enable(unsigned int cpu);
123void watchdog_nmi_disable(unsigned int cpu);
 
 
 
 
 
 
 
 
124
125/**
126 * touch_nmi_watchdog - restart NMI watchdog timeout.
127 *
128 * If the architecture supports the NMI watchdog, touch_nmi_watchdog()
129 * may be used to reset the timeout - for code which intentionally
130 * disables interrupts for a long time. This call is stateless.
 
 
 
 
131 */
132static inline void touch_nmi_watchdog(void)
133{
 
 
 
 
 
 
134	arch_touch_nmi_watchdog();
 
135	touch_softlockup_watchdog();
136}
137
138/*
139 * Create trigger_all_cpu_backtrace() out of the arch-provided
140 * base function. Return whether such support was available,
141 * to allow calling code to fall back to some other mechanism:
142 */
143#ifdef arch_trigger_cpumask_backtrace
144static inline bool trigger_all_cpu_backtrace(void)
145{
146	arch_trigger_cpumask_backtrace(cpu_online_mask, false);
147	return true;
148}
149
150static inline bool trigger_allbutself_cpu_backtrace(void)
151{
152	arch_trigger_cpumask_backtrace(cpu_online_mask, true);
153	return true;
154}
155
156static inline bool trigger_cpumask_backtrace(struct cpumask *mask)
157{
158	arch_trigger_cpumask_backtrace(mask, false);
159	return true;
160}
161
162static inline bool trigger_single_cpu_backtrace(int cpu)
163{
164	arch_trigger_cpumask_backtrace(cpumask_of(cpu), false);
165	return true;
166}
167
168/* generic implementation */
169void nmi_trigger_cpumask_backtrace(const cpumask_t *mask,
170				   bool exclude_self,
171				   void (*raise)(cpumask_t *mask));
172bool nmi_cpu_backtrace(struct pt_regs *regs);
173
174#else
175static inline bool trigger_all_cpu_backtrace(void)
176{
177	return false;
178}
179static inline bool trigger_allbutself_cpu_backtrace(void)
180{
181	return false;
182}
183static inline bool trigger_cpumask_backtrace(struct cpumask *mask)
184{
185	return false;
186}
187static inline bool trigger_single_cpu_backtrace(int cpu)
188{
189	return false;
190}
191#endif
192
193#ifdef CONFIG_HARDLOCKUP_DETECTOR_PERF
194u64 hw_nmi_get_sample_period(int watchdog_thresh);
 
195#endif
196
197#if defined(CONFIG_HARDLOCKUP_CHECK_TIMESTAMP) && \
198    defined(CONFIG_HARDLOCKUP_DETECTOR)
199void watchdog_update_hrtimer_threshold(u64 period);
200#else
201static inline void watchdog_update_hrtimer_threshold(u64 period) { }
202#endif
203
204struct ctl_table;
205int proc_watchdog(struct ctl_table *, int, void *, size_t *, loff_t *);
206int proc_nmi_watchdog(struct ctl_table *, int , void *, size_t *, loff_t *);
207int proc_soft_watchdog(struct ctl_table *, int , void *, size_t *, loff_t *);
208int proc_watchdog_thresh(struct ctl_table *, int , void *, size_t *, loff_t *);
209int proc_watchdog_cpumask(struct ctl_table *, int, void *, size_t *, loff_t *);
210
211#ifdef CONFIG_HAVE_ACPI_APEI_NMI
212#include <asm/nmi.h>
 
 
 
 
 
 
 
 
213#endif
214
215#endif

  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
 17void lockup_detector_init(void);
 18void lockup_detector_retry_init(void);
 19void lockup_detector_soft_poweroff(void);
 20void lockup_detector_cleanup(void);
 
 21
 22extern int 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_retry_init(void) { }
 39static inline void lockup_detector_soft_poweroff(void) { }
 40static inline void lockup_detector_cleanup(void) { }
 41#endif /* !CONFIG_LOCKUP_DETECTOR */
 42
 43#ifdef CONFIG_SOFTLOCKUP_DETECTOR
 44extern void touch_softlockup_watchdog_sched(void);
 45extern void touch_softlockup_watchdog(void);
 46extern void touch_softlockup_watchdog_sync(void);
 47extern void touch_all_softlockup_watchdogs(void);
 48extern unsigned int  softlockup_panic;
 49
 50extern int lockup_detector_online_cpu(unsigned int cpu);
 51extern int lockup_detector_offline_cpu(unsigned int cpu);
 52#else /* CONFIG_SOFTLOCKUP_DETECTOR */
 53static inline void touch_softlockup_watchdog_sched(void) { }
 54static inline void touch_softlockup_watchdog(void) { }
 55static inline void touch_softlockup_watchdog_sync(void) { }
 56static 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
 63void reset_hung_task_detector(void);
 64#else
 65static 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)
 86extern void hardlockup_detector_disable(void);
 87extern unsigned int hardlockup_panic;
 88#else
 89static 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)
 94void arch_touch_nmi_watchdog(void);
 95#else
 96static inline void arch_touch_nmi_watchdog(void) { }
 97#endif
 98
 99#if defined(CONFIG_HARDLOCKUP_DETECTOR_COUNTS_HRTIMER)
100void watchdog_hardlockup_touch_cpu(unsigned int cpu);
101void watchdog_hardlockup_check(unsigned int cpu, struct pt_regs *regs);
102#endif
103
104#if defined(CONFIG_HARDLOCKUP_DETECTOR_PERF)
 
105extern void hardlockup_detector_perf_stop(void);
106extern void hardlockup_detector_perf_restart(void);
 
 
107extern void hardlockup_detector_perf_cleanup(void);
108extern void hardlockup_config_perf_event(const char *str);
109#else
110static inline void hardlockup_detector_perf_stop(void) { }
111static inline void hardlockup_detector_perf_restart(void) { }
 
 
112static inline void hardlockup_detector_perf_cleanup(void) { }
113static inline void hardlockup_config_perf_event(const char *str) { }
 
 
 
 
 
114#endif
115
116void watchdog_hardlockup_stop(void);
117void watchdog_hardlockup_start(void);
118int watchdog_hardlockup_probe(void);
119void watchdog_hardlockup_enable(unsigned int cpu);
120void watchdog_hardlockup_disable(unsigned int cpu);
121
122void lockup_detector_reconfigure(void);
123
124#ifdef CONFIG_HARDLOCKUP_DETECTOR_BUDDY
125void watchdog_buddy_check_hardlockup(int hrtimer_interrupts);
126#else
127static 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 */
141static 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
160static inline bool trigger_all_cpu_backtrace(void)
161{
162	arch_trigger_cpumask_backtrace(cpu_online_mask, -1);
163	return true;
164}
165
166static 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
172static inline bool trigger_cpumask_backtrace(struct cpumask *mask)
173{
174	arch_trigger_cpumask_backtrace(mask, -1);
175	return true;
176}
177
178static 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 */
185void nmi_trigger_cpumask_backtrace(const cpumask_t *mask,
186				   int exclude_cpu,
187				   void (*raise)(cpumask_t *mask));
188bool nmi_cpu_backtrace(struct pt_regs *regs);
189
190#else
191static inline bool trigger_all_cpu_backtrace(void)
192{
193	return false;
194}
195static inline bool trigger_allbutcpu_cpu_backtrace(int exclude_cpu)
196{
197	return false;
198}
199static inline bool trigger_cpumask_backtrace(struct cpumask *mask)
200{
201	return false;
202}
203static inline bool trigger_single_cpu_backtrace(int cpu)
204{
205	return false;
206}
207#endif
208
209#ifdef CONFIG_HARDLOCKUP_DETECTOR_PERF
210u64 hw_nmi_get_sample_period(int watchdog_thresh);
211bool arch_perf_nmi_is_available(void);
212#endif
213
214#if defined(CONFIG_HARDLOCKUP_CHECK_TIMESTAMP) && \
215    defined(CONFIG_HARDLOCKUP_DETECTOR_PERF)
216void watchdog_update_hrtimer_threshold(u64 period);
217#else
218static 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
226void nmi_backtrace_stall_snap(const struct cpumask *btp);
227void nmi_backtrace_stall_check(const struct cpumask *btp);
228#else
229static inline void nmi_backtrace_stall_snap(const struct cpumask *btp) {}
230static inline void nmi_backtrace_stall_check(const struct cpumask *btp) {}
231#endif
232
233#endif