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- /* SPDX-License-Identifier: GPL-2.0+ */
- /*
- * Read-Copy Update mechanism for mutual exclusion (tree-based version)
- *
- * Copyright IBM Corporation, 2008
- *
- * Author: Dipankar Sarma <[email protected]>
- * Paul E. McKenney <[email protected]> Hierarchical algorithm
- *
- * Based on the original work by Paul McKenney <[email protected]>
- * and inputs from Rusty Russell, Andrea Arcangeli and Andi Kleen.
- *
- * For detailed explanation of Read-Copy Update mechanism see -
- * Documentation/RCU
- */
- #ifndef __LINUX_RCUTREE_H
- #define __LINUX_RCUTREE_H
- void rcu_softirq_qs(void);
- void rcu_note_context_switch(bool preempt);
- int rcu_needs_cpu(void);
- void rcu_cpu_stall_reset(void);
- /*
- * Note a virtualization-based context switch. This is simply a
- * wrapper around rcu_note_context_switch(), which allows TINY_RCU
- * to save a few bytes. The caller must have disabled interrupts.
- */
- static inline void rcu_virt_note_context_switch(int cpu)
- {
- rcu_note_context_switch(false);
- }
- void synchronize_rcu_expedited(void);
- void kvfree_call_rcu(struct rcu_head *head, rcu_callback_t func);
- void rcu_barrier(void);
- bool rcu_eqs_special_set(int cpu);
- void rcu_momentary_dyntick_idle(void);
- void kfree_rcu_scheduler_running(void);
- bool rcu_gp_might_be_stalled(void);
- struct rcu_gp_oldstate {
- unsigned long rgos_norm;
- unsigned long rgos_exp;
- };
- // Maximum number of rcu_gp_oldstate values corresponding to
- // not-yet-completed RCU grace periods.
- #define NUM_ACTIVE_RCU_POLL_FULL_OLDSTATE 4
- /**
- * same_state_synchronize_rcu_full - Are two old-state values identical?
- * @rgosp1: First old-state value.
- * @rgosp2: Second old-state value.
- *
- * The two old-state values must have been obtained from either
- * get_state_synchronize_rcu_full(), start_poll_synchronize_rcu_full(),
- * or get_completed_synchronize_rcu_full(). Returns @true if the two
- * values are identical and @false otherwise. This allows structures
- * whose lifetimes are tracked by old-state values to push these values
- * to a list header, allowing those structures to be slightly smaller.
- *
- * Note that equality is judged on a bitwise basis, so that an
- * @rcu_gp_oldstate structure with an already-completed state in one field
- * will compare not-equal to a structure with an already-completed state
- * in the other field. After all, the @rcu_gp_oldstate structure is opaque
- * so how did such a situation come to pass in the first place?
- */
- 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 && rgosp1->rgos_exp == rgosp2->rgos_exp;
- }
- unsigned long start_poll_synchronize_rcu_expedited(void);
- void start_poll_synchronize_rcu_expedited_full(struct rcu_gp_oldstate *rgosp);
- void cond_synchronize_rcu_expedited(unsigned long oldstate);
- void cond_synchronize_rcu_expedited_full(struct rcu_gp_oldstate *rgosp);
- unsigned long get_state_synchronize_rcu(void);
- void get_state_synchronize_rcu_full(struct rcu_gp_oldstate *rgosp);
- unsigned long start_poll_synchronize_rcu(void);
- void start_poll_synchronize_rcu_full(struct rcu_gp_oldstate *rgosp);
- bool poll_state_synchronize_rcu(unsigned long oldstate);
- bool poll_state_synchronize_rcu_full(struct rcu_gp_oldstate *rgosp);
- void cond_synchronize_rcu(unsigned long oldstate);
- void cond_synchronize_rcu_full(struct rcu_gp_oldstate *rgosp);
- bool rcu_is_idle_cpu(int cpu);
- #ifdef CONFIG_PROVE_RCU
- void rcu_irq_exit_check_preempt(void);
- #else
- static inline void rcu_irq_exit_check_preempt(void) { }
- #endif
- struct task_struct;
- void rcu_preempt_deferred_qs(struct task_struct *t);
- void exit_rcu(void);
- void rcu_scheduler_starting(void);
- extern int rcu_scheduler_active;
- void rcu_end_inkernel_boot(void);
- bool rcu_inkernel_boot_has_ended(void);
- bool rcu_is_watching(void);
- #ifndef CONFIG_PREEMPTION
- void rcu_all_qs(void);
- #endif
- /* RCUtree hotplug events */
- int rcutree_prepare_cpu(unsigned int cpu);
- int rcutree_online_cpu(unsigned int cpu);
- int rcutree_offline_cpu(unsigned int cpu);
- int rcutree_dead_cpu(unsigned int cpu);
- int rcutree_dying_cpu(unsigned int cpu);
- void rcu_cpu_starting(unsigned int cpu);
- #endif /* __LINUX_RCUTREE_H */
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