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Diffstat (limited to 'include/linux/rcutiny.h')
| -rw-r--r-- | include/linux/rcutiny.h | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h new file mode 100644 index 000000000..768196a5f --- /dev/null +++ b/include/linux/rcutiny.h @@ -0,0 +1,180 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Read-Copy Update mechanism for mutual exclusion, the Bloatwatch edition. + * + * Copyright IBM Corporation, 2008 + * + * Author: Paul E. McKenney <paulmck@linux.ibm.com> + * + * For detailed explanation of Read-Copy Update mechanism see - + * Documentation/RCU + */ +#ifndef __LINUX_TINY_H +#define __LINUX_TINY_H + +#include <asm/param.h> /* for HZ */ + +struct rcu_gp_oldstate { + unsigned long rgos_norm; +}; + +// Maximum number of rcu_gp_oldstate values corresponding to +// not-yet-completed RCU grace periods. +#define NUM_ACTIVE_RCU_POLL_FULL_OLDSTATE 2 + +/* + * Are the two oldstate values the same? See the Tree RCU version for + * docbook header. + */ +static inline bool same_state_synchronize_rcu_full(struct rcu_gp_oldstate *rgosp1, + struct rcu_gp_oldstate *rgosp2) +{ + return rgosp1->rgos_norm == rgosp2->rgos_norm; +} + +unsigned long get_state_synchronize_rcu(void); + +static inline void get_state_synchronize_rcu_full(struct rcu_gp_oldstate *rgosp) +{ + rgosp->rgos_norm = get_state_synchronize_rcu(); +} + +unsigned long start_poll_synchronize_rcu(void); + +static inline void start_poll_synchronize_rcu_full(struct rcu_gp_oldstate *rgosp) +{ + rgosp->rgos_norm = start_poll_synchronize_rcu(); +} + +bool poll_state_synchronize_rcu(unsigned long oldstate); + +static inline bool poll_state_synchronize_rcu_full(struct rcu_gp_oldstate *rgosp) +{ + return poll_state_synchronize_rcu(rgosp->rgos_norm); +} + +static inline void cond_synchronize_rcu(unsigned long oldstate) +{ + might_sleep(); +} + +static inline void cond_synchronize_rcu_full(struct rcu_gp_oldstate *rgosp) +{ + cond_synchronize_rcu(rgosp->rgos_norm); +} + +static inline unsigned long start_poll_synchronize_rcu_expedited(void) +{ + return start_poll_synchronize_rcu(); +} + +static inline void start_poll_synchronize_rcu_expedited_full(struct rcu_gp_oldstate *rgosp) +{ + rgosp->rgos_norm = start_poll_synchronize_rcu_expedited(); +} + +static inline void cond_synchronize_rcu_expedited(unsigned long oldstate) +{ + cond_synchronize_rcu(oldstate); +} + +static inline void cond_synchronize_rcu_expedited_full(struct rcu_gp_oldstate *rgosp) +{ + cond_synchronize_rcu_expedited(rgosp->rgos_norm); +} + +extern void rcu_barrier(void); + +static inline void synchronize_rcu_expedited(void) +{ + synchronize_rcu(); +} + +/* + * Add one more declaration of kvfree() here. It is + * not so straight forward to just include <linux/mm.h> + * where it is defined due to getting many compile + * errors caused by that include. + */ +extern void kvfree(const void *addr); + +static inline void __kvfree_call_rcu(struct rcu_head *head, rcu_callback_t func) +{ + if (head) { + call_rcu(head, func); + return; + } + + // kvfree_rcu(one_arg) call. + might_sleep(); + synchronize_rcu(); + kvfree((void *) func); +} + +#ifdef CONFIG_KASAN_GENERIC +void kvfree_call_rcu(struct rcu_head *head, rcu_callback_t func); +#else +static inline void kvfree_call_rcu(struct rcu_head *head, rcu_callback_t func) +{ + __kvfree_call_rcu(head, func); +} +#endif + +void rcu_qs(void); + +static inline void rcu_softirq_qs(void) +{ + rcu_qs(); +} + +#define rcu_note_context_switch(preempt) \ + do { \ + rcu_qs(); \ + rcu_tasks_qs(current, (preempt)); \ + } while (0) + +static inline int rcu_needs_cpu(void) +{ + return 0; +} + +/* + * Take advantage of the fact that there is only one CPU, which + * allows us to ignore virtualization-based context switches. + */ +static inline void rcu_virt_note_context_switch(int cpu) { } +static inline void rcu_cpu_stall_reset(void) { } +static inline int rcu_jiffies_till_stall_check(void) { return 21 * HZ; } +static inline void rcu_irq_exit_check_preempt(void) { } +#define rcu_is_idle_cpu(cpu) \ + (is_idle_task(current) && !in_nmi() && !in_hardirq() && !in_serving_softirq()) +static inline void exit_rcu(void) { } +static inline bool rcu_preempt_need_deferred_qs(struct task_struct *t) +{ + return false; +} +static inline void rcu_preempt_deferred_qs(struct task_struct *t) { } +#ifdef CONFIG_SRCU +void rcu_scheduler_starting(void); +#else /* #ifndef CONFIG_SRCU */ +static inline void rcu_scheduler_starting(void) { } +#endif /* #else #ifndef CONFIG_SRCU */ +static inline void rcu_end_inkernel_boot(void) { } +static inline bool rcu_inkernel_boot_has_ended(void) { return true; } +static inline bool rcu_is_watching(void) { return true; } +static inline void rcu_momentary_dyntick_idle(void) { } +static inline void kfree_rcu_scheduler_running(void) { } +static inline bool rcu_gp_might_be_stalled(void) { return false; } + +/* Avoid RCU read-side critical sections leaking across. */ +static inline void rcu_all_qs(void) { barrier(); } + +/* RCUtree hotplug events */ +#define rcutree_prepare_cpu NULL +#define rcutree_online_cpu NULL +#define rcutree_offline_cpu NULL +#define rcutree_dead_cpu NULL +#define rcutree_dying_cpu NULL +static inline void rcu_cpu_starting(unsigned int cpu) { } + +#endif /* __LINUX_RCUTINY_H */ |