diff options
Diffstat (limited to 'include/linux/nmi.h')
| -rw-r--r-- | include/linux/nmi.h | 238 |
1 files changed, 238 insertions, 0 deletions
diff --git a/include/linux/nmi.h b/include/linux/nmi.h new file mode 100644 index 000000000..e92e378df --- /dev/null +++ b/include/linux/nmi.h @@ -0,0 +1,238 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * linux/include/linux/nmi.h + */ +#ifndef LINUX_NMI_H +#define LINUX_NMI_H + +#include <linux/sched.h> +#include <asm/irq.h> + +/* Arch specific watchdogs might need to share extra watchdog-related APIs. */ +#if defined(CONFIG_HARDLOCKUP_DETECTOR_ARCH) || defined(CONFIG_HARDLOCKUP_DETECTOR_SPARC64) +#include <asm/nmi.h> +#endif + +#ifdef CONFIG_LOCKUP_DETECTOR +void lockup_detector_init(void); +void lockup_detector_retry_init(void); +void lockup_detector_soft_poweroff(void); +void lockup_detector_cleanup(void); + +extern int watchdog_user_enabled; +extern int watchdog_thresh; +extern unsigned long watchdog_enabled; + +extern struct cpumask watchdog_cpumask; +extern unsigned long *watchdog_cpumask_bits; +#ifdef CONFIG_SMP +extern int sysctl_softlockup_all_cpu_backtrace; +extern int sysctl_hardlockup_all_cpu_backtrace; +#else +#define sysctl_softlockup_all_cpu_backtrace 0 +#define sysctl_hardlockup_all_cpu_backtrace 0 +#endif /* !CONFIG_SMP */ + +#else /* CONFIG_LOCKUP_DETECTOR */ +static inline void lockup_detector_init(void) { } +static inline void lockup_detector_retry_init(void) { } +static inline void lockup_detector_soft_poweroff(void) { } +static inline void lockup_detector_cleanup(void) { } +#endif /* !CONFIG_LOCKUP_DETECTOR */ + +#ifdef CONFIG_SOFTLOCKUP_DETECTOR +extern void touch_softlockup_watchdog_sched(void); +extern void touch_softlockup_watchdog(void); +extern void touch_softlockup_watchdog_sync(void); +extern void touch_all_softlockup_watchdogs(void); +extern unsigned int softlockup_panic; + +extern int lockup_detector_online_cpu(unsigned int cpu); +extern int lockup_detector_offline_cpu(unsigned int cpu); +#else /* CONFIG_SOFTLOCKUP_DETECTOR */ +static inline void touch_softlockup_watchdog_sched(void) { } +static inline void touch_softlockup_watchdog(void) { } +static inline void touch_softlockup_watchdog_sync(void) { } +static inline void touch_all_softlockup_watchdogs(void) { } + +#define lockup_detector_online_cpu NULL +#define lockup_detector_offline_cpu NULL +#endif /* CONFIG_SOFTLOCKUP_DETECTOR */ + +#ifdef CONFIG_DETECT_HUNG_TASK +void reset_hung_task_detector(void); +#else +static inline void reset_hung_task_detector(void) { } +#endif + +/* + * The run state of the lockup detectors is controlled by the content of the + * 'watchdog_enabled' variable. Each lockup detector has its dedicated bit - + * bit 0 for the hard lockup detector and bit 1 for the soft lockup detector. + * + * 'watchdog_user_enabled', 'watchdog_hardlockup_user_enabled' and + * 'watchdog_softlockup_user_enabled' are variables that are only used as an + * 'interface' between the parameters in /proc/sys/kernel and the internal + * state bits in 'watchdog_enabled'. The 'watchdog_thresh' variable is + * handled differently because its value is not boolean, and the lockup + * detectors are 'suspended' while 'watchdog_thresh' is equal zero. + */ +#define WATCHDOG_HARDLOCKUP_ENABLED_BIT 0 +#define WATCHDOG_SOFTOCKUP_ENABLED_BIT 1 +#define WATCHDOG_HARDLOCKUP_ENABLED (1 << WATCHDOG_HARDLOCKUP_ENABLED_BIT) +#define WATCHDOG_SOFTOCKUP_ENABLED (1 << WATCHDOG_SOFTOCKUP_ENABLED_BIT) + +#if defined(CONFIG_HARDLOCKUP_DETECTOR) +extern void hardlockup_detector_disable(void); +extern unsigned int hardlockup_panic; +#else +static inline void hardlockup_detector_disable(void) {} +#endif + +/* Sparc64 has special implemetantion that is always enabled. */ +#if defined(CONFIG_HARDLOCKUP_DETECTOR) || defined(CONFIG_HARDLOCKUP_DETECTOR_SPARC64) +void arch_touch_nmi_watchdog(void); +#else +static inline void arch_touch_nmi_watchdog(void) { } +#endif + +#if defined(CONFIG_HARDLOCKUP_DETECTOR_COUNTS_HRTIMER) +void watchdog_hardlockup_touch_cpu(unsigned int cpu); +void watchdog_hardlockup_check(unsigned int cpu, struct pt_regs *regs); +#endif + +#if defined(CONFIG_HARDLOCKUP_DETECTOR_PERF) +extern void hardlockup_detector_perf_stop(void); +extern void hardlockup_detector_perf_restart(void); +extern void hardlockup_detector_perf_cleanup(void); +#else +static inline void hardlockup_detector_perf_stop(void) { } +static inline void hardlockup_detector_perf_restart(void) { } +static inline void hardlockup_detector_perf_cleanup(void) { } +#endif + +void watchdog_hardlockup_stop(void); +void watchdog_hardlockup_start(void); +int watchdog_hardlockup_probe(void); +void watchdog_hardlockup_enable(unsigned int cpu); +void watchdog_hardlockup_disable(unsigned int cpu); + +void lockup_detector_reconfigure(void); + +#ifdef CONFIG_HARDLOCKUP_DETECTOR_BUDDY +void watchdog_buddy_check_hardlockup(int hrtimer_interrupts); +#else +static inline void watchdog_buddy_check_hardlockup(int hrtimer_interrupts) {} +#endif + +/** + * touch_nmi_watchdog - manually reset the hardlockup watchdog timeout. + * + * If we support detecting hardlockups, touch_nmi_watchdog() may be + * used to pet the watchdog (reset the timeout) - for code which + * intentionally disables interrupts for a long time. This call is stateless. + * + * Though this function has "nmi" in the name, the hardlockup watchdog might + * not be backed by NMIs. This function will likely be renamed to + * touch_hardlockup_watchdog() in the future. + */ +static inline void touch_nmi_watchdog(void) +{ + /* + * Pass on to the hardlockup detector selected via CONFIG_. Note that + * the hardlockup detector may not be arch-specific nor using NMIs + * and the arch_touch_nmi_watchdog() function will likely be renamed + * in the future. + */ + arch_touch_nmi_watchdog(); + + touch_softlockup_watchdog(); +} + +/* + * Create trigger_all_cpu_backtrace() out of the arch-provided + * base function. Return whether such support was available, + * to allow calling code to fall back to some other mechanism: + */ +#ifdef arch_trigger_cpumask_backtrace +static inline bool trigger_all_cpu_backtrace(void) +{ + arch_trigger_cpumask_backtrace(cpu_online_mask, -1); + return true; +} + +static inline bool trigger_allbutcpu_cpu_backtrace(int exclude_cpu) +{ + arch_trigger_cpumask_backtrace(cpu_online_mask, exclude_cpu); + return true; +} + +static inline bool trigger_cpumask_backtrace(struct cpumask *mask) +{ + arch_trigger_cpumask_backtrace(mask, -1); + return true; +} + +static inline bool trigger_single_cpu_backtrace(int cpu) +{ + arch_trigger_cpumask_backtrace(cpumask_of(cpu), -1); + return true; +} + +/* generic implementation */ +void nmi_trigger_cpumask_backtrace(const cpumask_t *mask, + int exclude_cpu, + void (*raise)(cpumask_t *mask)); +bool nmi_cpu_backtrace(struct pt_regs *regs); + +#else +static inline bool trigger_all_cpu_backtrace(void) +{ + return false; +} +static inline bool trigger_allbutcpu_cpu_backtrace(int exclude_cpu) +{ + return false; +} +static inline bool trigger_cpumask_backtrace(struct cpumask *mask) +{ + return false; +} +static inline bool trigger_single_cpu_backtrace(int cpu) +{ + return false; +} +#endif + +#ifdef CONFIG_HARDLOCKUP_DETECTOR_PERF +u64 hw_nmi_get_sample_period(int watchdog_thresh); +bool arch_perf_nmi_is_available(void); +#endif + +#if defined(CONFIG_HARDLOCKUP_CHECK_TIMESTAMP) && \ + defined(CONFIG_HARDLOCKUP_DETECTOR_PERF) +void watchdog_update_hrtimer_threshold(u64 period); +#else +static inline void watchdog_update_hrtimer_threshold(u64 period) { } +#endif + +struct ctl_table; +int proc_watchdog(struct ctl_table *, int, void *, size_t *, loff_t *); +int proc_nmi_watchdog(struct ctl_table *, int , void *, size_t *, loff_t *); +int proc_soft_watchdog(struct ctl_table *, int , void *, size_t *, loff_t *); +int proc_watchdog_thresh(struct ctl_table *, int , void *, size_t *, loff_t *); +int proc_watchdog_cpumask(struct ctl_table *, int, void *, size_t *, loff_t *); + +#ifdef CONFIG_HAVE_ACPI_APEI_NMI +#include <asm/nmi.h> +#endif + +#ifdef CONFIG_NMI_CHECK_CPU +void nmi_backtrace_stall_snap(const struct cpumask *btp); +void nmi_backtrace_stall_check(const struct cpumask *btp); +#else +static inline void nmi_backtrace_stall_snap(const struct cpumask *btp) {} +static inline void nmi_backtrace_stall_check(const struct cpumask *btp) {} +#endif + +#endif |