92 строки
3.0 KiB
C
92 строки
3.0 KiB
C
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/*
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* Sleepable Read-Copy Update mechanism for mutual exclusion,
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* tree variant.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, you can access it online at
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* http://www.gnu.org/licenses/gpl-2.0.html.
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*
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* Copyright (C) IBM Corporation, 2017
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*
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* Author: Paul McKenney <paulmck@us.ibm.com>
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*/
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#ifndef _LINUX_SRCU_TREE_H
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#define _LINUX_SRCU_TREE_H
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struct srcu_array {
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unsigned long lock_count[2];
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unsigned long unlock_count[2];
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};
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struct srcu_struct {
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unsigned long completed;
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unsigned long srcu_gp_seq;
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atomic_t srcu_exp_cnt;
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struct srcu_array __percpu *per_cpu_ref;
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spinlock_t queue_lock; /* protect ->srcu_cblist */
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struct rcu_segcblist srcu_cblist;
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struct delayed_work work;
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#ifdef CONFIG_DEBUG_LOCK_ALLOC
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struct lockdep_map dep_map;
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#endif /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */
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};
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/* Values for -> state variable. */
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#define SRCU_STATE_IDLE 0
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#define SRCU_STATE_SCAN1 1
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#define SRCU_STATE_SCAN2 2
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void process_srcu(struct work_struct *work);
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#define __SRCU_STRUCT_INIT(name) \
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{ \
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.completed = -300, \
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.per_cpu_ref = &name##_srcu_array, \
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.queue_lock = __SPIN_LOCK_UNLOCKED(name.queue_lock), \
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.srcu_cblist = RCU_SEGCBLIST_INITIALIZER(name.srcu_cblist),\
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.work = __DELAYED_WORK_INITIALIZER(name.work, process_srcu, 0),\
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__SRCU_DEP_MAP_INIT(name) \
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}
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/*
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* Define and initialize a srcu struct at build time.
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* Do -not- call init_srcu_struct() nor cleanup_srcu_struct() on it.
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*
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* Note that although DEFINE_STATIC_SRCU() hides the name from other
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* files, the per-CPU variable rules nevertheless require that the
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* chosen name be globally unique. These rules also prohibit use of
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* DEFINE_STATIC_SRCU() within a function. If these rules are too
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* restrictive, declare the srcu_struct manually. For example, in
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* each file:
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*
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* static struct srcu_struct my_srcu;
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*
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* Then, before the first use of each my_srcu, manually initialize it:
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*
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* init_srcu_struct(&my_srcu);
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*
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* See include/linux/percpu-defs.h for the rules on per-CPU variables.
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*/
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#define __DEFINE_SRCU(name, is_static) \
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static DEFINE_PER_CPU(struct srcu_array, name##_srcu_array);\
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is_static struct srcu_struct name = __SRCU_STRUCT_INIT(name)
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#define DEFINE_SRCU(name) __DEFINE_SRCU(name, /* not static */)
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#define DEFINE_STATIC_SRCU(name) __DEFINE_SRCU(name, static)
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void synchronize_srcu_expedited(struct srcu_struct *sp);
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void srcu_barrier(struct srcu_struct *sp);
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unsigned long srcu_batches_completed(struct srcu_struct *sp);
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#endif
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