2015-08-21 17:42:44 +00:00
|
|
|
/*
|
|
|
|
|
* RCU-based infrastructure for lightweight reader-writer locking
|
|
|
|
|
*
|
|
|
|
|
* This program is free software; you can redistribute it and/or modify
|
|
|
|
|
* it under the terms of the GNU General Public License as published by
|
|
|
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
|
|
|
* (at your option) any later version.
|
|
|
|
|
*
|
|
|
|
|
* This program is distributed in the hope that it will be useful,
|
|
|
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
|
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
|
|
|
* GNU General Public License for more details.
|
|
|
|
|
*
|
|
|
|
|
* You should have received a copy of the GNU General Public License
|
|
|
|
|
* along with this program; if not, you can access it online at
|
|
|
|
|
* http://www.gnu.org/licenses/gpl-2.0.html.
|
|
|
|
|
*
|
|
|
|
|
* Copyright (c) 2015, Red Hat, Inc.
|
|
|
|
|
*
|
|
|
|
|
* Author: Oleg Nesterov <oleg@redhat.com>
|
|
|
|
|
*/
|
|
|
|
|
|
|
|
|
|
#ifndef _LINUX_RCU_SYNC_H_
|
|
|
|
|
#define _LINUX_RCU_SYNC_H_
|
|
|
|
|
|
|
|
|
|
#include <linux/wait.h>
|
|
|
|
|
#include <linux/rcupdate.h>
|
|
|
|
|
|
2015-08-21 17:42:47 +00:00
|
|
|
enum rcu_sync_type { RCU_SYNC, RCU_SCHED_SYNC, RCU_BH_SYNC };
|
|
|
|
|
|
2015-08-21 17:42:44 +00:00
|
|
|
/* Structure to mediate between updaters and fastpath-using readers. */
|
|
|
|
|
struct rcu_sync {
|
|
|
|
|
int gp_state;
|
|
|
|
|
int gp_count;
|
|
|
|
|
wait_queue_head_t gp_wait;
|
|
|
|
|
|
|
|
|
|
int cb_state;
|
|
|
|
|
struct rcu_head cb_head;
|
|
|
|
|
|
2015-08-21 17:42:47 +00:00
|
|
|
enum rcu_sync_type gp_type;
|
2015-08-21 17:42:44 +00:00
|
|
|
};
|
|
|
|
|
|
2015-09-11 15:59:18 +00:00
|
|
|
extern void rcu_sync_lockdep_assert(struct rcu_sync *);
|
2015-08-21 17:42:50 +00:00
|
|
|
|
2015-08-21 17:42:44 +00:00
|
|
|
/**
|
|
|
|
|
* rcu_sync_is_idle() - Are readers permitted to use their fastpaths?
|
|
|
|
|
* @rsp: Pointer to rcu_sync structure to use for synchronization
|
|
|
|
|
*
|
|
|
|
|
* Returns true if readers are permitted to use their fastpaths.
|
|
|
|
|
* Must be invoked within an RCU read-side critical section whose
|
|
|
|
|
* flavor matches that of the rcu_sync struture.
|
|
|
|
|
*/
|
|
|
|
|
static inline bool rcu_sync_is_idle(struct rcu_sync *rsp)
|
|
|
|
|
{
|
2015-08-21 17:42:50 +00:00
|
|
|
#ifdef CONFIG_PROVE_RCU
|
2015-09-11 15:59:18 +00:00
|
|
|
rcu_sync_lockdep_assert(rsp);
|
2015-08-21 17:42:50 +00:00
|
|
|
#endif
|
2015-09-11 15:59:18 +00:00
|
|
|
return !rsp->gp_state; /* GP_IDLE */
|
2015-08-21 17:42:44 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
extern void rcu_sync_init(struct rcu_sync *, enum rcu_sync_type);
|
2016-08-11 16:54:13 +00:00
|
|
|
extern void rcu_sync_enter_start(struct rcu_sync *);
|
2015-08-21 17:42:44 +00:00
|
|
|
extern void rcu_sync_enter(struct rcu_sync *);
|
|
|
|
|
extern void rcu_sync_exit(struct rcu_sync *);
|
2015-08-21 17:42:52 +00:00
|
|
|
extern void rcu_sync_dtor(struct rcu_sync *);
|
2015-08-21 17:42:44 +00:00
|
|
|
|
2015-08-21 17:42:47 +00:00
|
|
|
#define __RCU_SYNC_INITIALIZER(name, type) { \
|
|
|
|
|
.gp_state = 0, \
|
|
|
|
|
.gp_count = 0, \
|
|
|
|
|
.gp_wait = __WAIT_QUEUE_HEAD_INITIALIZER(name.gp_wait), \
|
|
|
|
|
.cb_state = 0, \
|
|
|
|
|
.gp_type = type, \
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
#define __DEFINE_RCU_SYNC(name, type) \
|
|
|
|
|
struct rcu_sync_struct name = __RCU_SYNC_INITIALIZER(name, type)
|
|
|
|
|
|
|
|
|
|
#define DEFINE_RCU_SYNC(name) \
|
|
|
|
|
__DEFINE_RCU_SYNC(name, RCU_SYNC)
|
|
|
|
|
|
|
|
|
|
#define DEFINE_RCU_SCHED_SYNC(name) \
|
|
|
|
|
__DEFINE_RCU_SYNC(name, RCU_SCHED_SYNC)
|
|
|
|
|
|
|
|
|
|
#define DEFINE_RCU_BH_SYNC(name) \
|
|
|
|
|
__DEFINE_RCU_SYNC(name, RCU_BH_SYNC)
|
|
|
|
|
|
2015-08-21 17:42:44 +00:00
|
|
|
#endif /* _LINUX_RCU_SYNC_H_ */
|
