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Index of /anon_sym/anon/sys/module/nft_compat/notes
Index of /anon_sym/anon/sys/module/nft_compat/notes
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i/_I|+ ? /* SPDX-License-Identifier: GPL-2.0+ */
/*
* Read-Copy Update mechanism for mutual exclusion
*
* Copyright IBM Corporation, 2001
*
* Author: Dipankar Sarma
*
* Based on the original work by Paul McKenney
* and inputs from Rusty Russell, Andrea Arcangeli and Andi Kleen.
* Papers:
* http://www.rdrop.com/users/paulmck/paper/rclockpdcsproof.pdf
* http://lse.sourceforge.net/locking/rclock_OLS.2001.05.01c.sc.pdf (OLS2001)
*
* For detailed explanation of Read-Copy Update mechanism see -
* http://lse.sourceforge.net/locking/rcupdate.html
*
*/
#ifndef __LINUX_RCUPDATE_H
#define __LINUX_RCUPDATE_H
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#define ULONG_CMP_GE(a, b) (ULONG_MAX / 2 >= (a) - (b))
#define ULONG_CMP_LT(a, b) (ULONG_MAX / 2 < (a) - (b))
#define RCU_SEQ_CTR_SHIFT 2
#define RCU_SEQ_STATE_MASK ((1 << RCU_SEQ_CTR_SHIFT) - 1)
/* Exported common interfaces */
void call_rcu(struct rcu_head *head, rcu_callback_t func);
void rcu_barrier_tasks(void);
void rcu_barrier_tasks_rude(void);
void synchronize_rcu(void);
struct rcu_gp_oldstate;
unsigned long get_completed_synchronize_rcu(void);
void get_completed_synchronize_rcu_full(struct rcu_gp_oldstate *rgosp);
// Maximum number of unsigned long values corresponding to
// not-yet-completed RCU grace periods.
#define NUM_ACTIVE_RCU_POLL_OLDSTATE 2
/**
* same_state_synchronize_rcu - Are two old-state values identical?
* @oldstate1: First old-state value.
* @oldstate2: Second old-state value.
*
* The two old-state values must have been obtained from either
* get_state_synchronize_rcu(), start_poll_synchronize_rcu(), or
* get_completed_synchronize_rcu(). 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.
*/
static inline bool same_state_synchronize_rcu(unsigned long oldstate1, unsigned long oldstate2)
{
return oldstate1 == oldstate2;
}
#ifdef CONFIG_PREEMPT_RCU
void __rcu_read_lock(void);
void __rcu_read_unlock(void);
/*
* Defined as a macro as it is a very low level header included from
* areas that don't even know about current. This gives the rcu_read_lock()
* nesting depth, but makes sense only if CONFIG_PREEMPT_RCU -- in other
* types of kernel builds, the rcu_read_lock() nesting depth is unknowable.
*/
#define rcu_preempt_depth() READ_ONCE(current->rcu_read_lock_nesting)
#else /* #ifdef CONFIG_PREEMPT_RCU */
#ifdef CONFIG_TINY_RCU
#define rcu_read_unlock_strict() do { } while (0)
#else
void rcu_read_unlock_strict(void);
#endif
static inline void __rcu_read_lock(void)
{
preempt_disable();
}
static inline void __rcu_read_unlock(void)
{
preempt_enable();
if (IS_ENABLED(CONFIG_RCU_STRICT_GRACE_PERIOD))
rcu_read_unlock_strict();
}
static inline int rcu_preempt_depth(void)
{
return 0;
}
#endif /* #else #ifdef CONFIG_PREEMPT_RCU */
#ifdef CO