cad7b38972
The include/linux/rcupdate.h file contains a number of definitions that are used only to communicate between rcutorture, rcuperf, and the RCU code itself. There is no point in having these definitions exposed globally throughout the kernel, so this commit moves them to kernel/rcu/rcu.h. This change has the added benefit of shrinking rcupdate.h. Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
97 lines
2.9 KiB
C
97 lines
2.9 KiB
C
/*
|
|
* Sleepable Read-Copy Update mechanism for mutual exclusion,
|
|
* tiny variant.
|
|
*
|
|
* 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) IBM Corporation, 2017
|
|
*
|
|
* Author: Paul McKenney <paulmck@us.ibm.com>
|
|
*/
|
|
|
|
#ifndef _LINUX_SRCU_TINY_H
|
|
#define _LINUX_SRCU_TINY_H
|
|
|
|
#include <linux/swait.h>
|
|
|
|
struct srcu_struct {
|
|
short srcu_lock_nesting[2]; /* srcu_read_lock() nesting depth. */
|
|
short srcu_idx; /* Current reader array element. */
|
|
u8 srcu_gp_running; /* GP workqueue running? */
|
|
u8 srcu_gp_waiting; /* GP waiting for readers? */
|
|
struct swait_queue_head srcu_wq;
|
|
/* Last srcu_read_unlock() wakes GP. */
|
|
unsigned long srcu_gp_seq; /* GP seq # for callback tagging. */
|
|
struct rcu_segcblist srcu_cblist;
|
|
/* Pending SRCU callbacks. */
|
|
struct work_struct srcu_work; /* For driving grace periods. */
|
|
#ifdef CONFIG_DEBUG_LOCK_ALLOC
|
|
struct lockdep_map dep_map;
|
|
#endif /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */
|
|
};
|
|
|
|
void srcu_drive_gp(struct work_struct *wp);
|
|
|
|
#define __SRCU_STRUCT_INIT(name) \
|
|
{ \
|
|
.srcu_wq = __SWAIT_QUEUE_HEAD_INITIALIZER(name.srcu_wq), \
|
|
.srcu_cblist = RCU_SEGCBLIST_INITIALIZER(name.srcu_cblist), \
|
|
.srcu_work = __WORK_INITIALIZER(name.srcu_work, srcu_drive_gp), \
|
|
__SRCU_DEP_MAP_INIT(name) \
|
|
}
|
|
|
|
/*
|
|
* This odd _STATIC_ arrangement is needed for API compatibility with
|
|
* Tree SRCU, which needs some per-CPU data.
|
|
*/
|
|
#define DEFINE_SRCU(name) \
|
|
struct srcu_struct name = __SRCU_STRUCT_INIT(name)
|
|
#define DEFINE_STATIC_SRCU(name) \
|
|
static struct srcu_struct name = __SRCU_STRUCT_INIT(name)
|
|
|
|
void synchronize_srcu(struct srcu_struct *sp);
|
|
|
|
/*
|
|
* Counts the new reader in the appropriate per-CPU element of the
|
|
* srcu_struct. Can be invoked from irq/bh handlers, but the matching
|
|
* __srcu_read_unlock() must be in the same handler instance. Returns an
|
|
* index that must be passed to the matching srcu_read_unlock().
|
|
*/
|
|
static inline int __srcu_read_lock(struct srcu_struct *sp)
|
|
{
|
|
int idx;
|
|
|
|
idx = READ_ONCE(sp->srcu_idx);
|
|
WRITE_ONCE(sp->srcu_lock_nesting[idx], sp->srcu_lock_nesting[idx] + 1);
|
|
return idx;
|
|
}
|
|
|
|
static inline void synchronize_srcu_expedited(struct srcu_struct *sp)
|
|
{
|
|
synchronize_srcu(sp);
|
|
}
|
|
|
|
static inline void srcu_barrier(struct srcu_struct *sp)
|
|
{
|
|
synchronize_srcu(sp);
|
|
}
|
|
|
|
static inline unsigned long srcu_batches_completed(struct srcu_struct *sp)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
#endif
|