119 lines
4.1 KiB
C
119 lines
4.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0+ */
|
|
/*
|
|
* Read-Copy Update mechanism for mutual exclusion (tree-based version)
|
|
*
|
|
* Copyright IBM Corporation, 2008
|
|
*
|
|
* Author: Dipankar Sarma <dipankar@in.ibm.com>
|
|
* Paul E. McKenney <paulmck@linux.ibm.com> Hierarchical algorithm
|
|
*
|
|
* Based on the original work by Paul McKenney <paulmck@linux.ibm.com>
|
|
* 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(void)
|
|
{
|
|
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);
|
|
|
|
#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 */
|