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-rw-r--r--kernel/rcupdate.c278
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diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c
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--- a/kernel/rcupdate.c
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@@ -1,278 +0,0 @@
-/*
- * Read-Copy Update mechanism for mutual exclusion
- *
- * 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, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
- *
- * Copyright IBM Corporation, 2001
- *
- * Authors: Dipankar Sarma <dipankar@in.ibm.com>
- * Manfred Spraul <manfred@colorfullife.com>
- *
- * Based on the original work by Paul McKenney <paulmck@us.ibm.com>
- * 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
- *
- */
-#include <linux/types.h>
-#include <linux/kernel.h>
-#include <linux/init.h>
-#include <linux/spinlock.h>
-#include <linux/smp.h>
-#include <linux/interrupt.h>
-#include <linux/sched.h>
-#include <asm/atomic.h>
-#include <linux/bitops.h>
-#include <linux/percpu.h>
-#include <linux/notifier.h>
-#include <linux/cpu.h>
-#include <linux/mutex.h>
-#include <linux/module.h>
-#include <linux/hardirq.h>
-
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-static struct lock_class_key rcu_lock_key;
-struct lockdep_map rcu_lock_map =
- STATIC_LOCKDEP_MAP_INIT("rcu_read_lock", &rcu_lock_key);
-EXPORT_SYMBOL_GPL(rcu_lock_map);
-
-static struct lock_class_key rcu_bh_lock_key;
-struct lockdep_map rcu_bh_lock_map =
- STATIC_LOCKDEP_MAP_INIT("rcu_read_lock_bh", &rcu_bh_lock_key);
-EXPORT_SYMBOL_GPL(rcu_bh_lock_map);
-
-static struct lock_class_key rcu_sched_lock_key;
-struct lockdep_map rcu_sched_lock_map =
- STATIC_LOCKDEP_MAP_INIT("rcu_read_lock_sched", &rcu_sched_lock_key);
-EXPORT_SYMBOL_GPL(rcu_sched_lock_map);
-#endif
-
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-
-int debug_lockdep_rcu_enabled(void)
-{
- return rcu_scheduler_active && debug_locks &&
- current->lockdep_recursion == 0;
-}
-EXPORT_SYMBOL_GPL(debug_lockdep_rcu_enabled);
-
-/**
- * rcu_read_lock_bh_held() - might we be in RCU-bh read-side critical section?
- *
- * Check for bottom half being disabled, which covers both the
- * CONFIG_PROVE_RCU and not cases. Note that if someone uses
- * rcu_read_lock_bh(), but then later enables BH, lockdep (if enabled)
- * will show the situation. This is useful for debug checks in functions
- * that require that they be called within an RCU read-side critical
- * section.
- *
- * Check debug_lockdep_rcu_enabled() to prevent false positives during boot.
- */
-int rcu_read_lock_bh_held(void)
-{
- if (!debug_lockdep_rcu_enabled())
- return 1;
- return in_softirq() || irqs_disabled();
-}
-EXPORT_SYMBOL_GPL(rcu_read_lock_bh_held);
-
-#endif /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */
-
-/*
- * Awaken the corresponding synchronize_rcu() instance now that a
- * grace period has elapsed.
- */
-void wakeme_after_rcu(struct rcu_head *head)
-{
- struct rcu_synchronize *rcu;
-
- rcu = container_of(head, struct rcu_synchronize, head);
- complete(&rcu->completion);
-}
-
-#ifdef CONFIG_PROVE_RCU
-/*
- * wrapper function to avoid #include problems.
- */
-int rcu_my_thread_group_empty(void)
-{
- return thread_group_empty(current);
-}
-EXPORT_SYMBOL_GPL(rcu_my_thread_group_empty);
-#endif /* #ifdef CONFIG_PROVE_RCU */
-
-#ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
-static inline void debug_init_rcu_head(struct rcu_head *head)
-{
- debug_object_init(head, &rcuhead_debug_descr);
-}
-
-static inline void debug_rcu_head_free(struct rcu_head *head)
-{
- debug_object_free(head, &rcuhead_debug_descr);
-}
-
-/*
- * fixup_init is called when:
- * - an active object is initialized
- */
-static int rcuhead_fixup_init(void *addr, enum debug_obj_state state)
-{
- struct rcu_head *head = addr;
-
- switch (state) {
- case ODEBUG_STATE_ACTIVE:
- /*
- * Ensure that queued callbacks are all executed.
- * If we detect that we are nested in a RCU read-side critical
- * section, we should simply fail, otherwise we would deadlock.
- */
- if (rcu_preempt_depth() != 0 || preempt_count() != 0 ||
- irqs_disabled()) {
- WARN_ON(1);
- return 0;
- }
- rcu_barrier();
- rcu_barrier_sched();
- rcu_barrier_bh();
- debug_object_init(head, &rcuhead_debug_descr);
- return 1;
- default:
- return 0;
- }
-}
-
-/*
- * fixup_activate is called when:
- * - an active object is activated
- * - an unknown object is activated (might be a statically initialized object)
- * Activation is performed internally by call_rcu().
- */
-static int rcuhead_fixup_activate(void *addr, enum debug_obj_state state)
-{
- struct rcu_head *head = addr;
-
- switch (state) {
-
- case ODEBUG_STATE_NOTAVAILABLE:
- /*
- * This is not really a fixup. We just make sure that it is
- * tracked in the object tracker.
- */
- debug_object_init(head, &rcuhead_debug_descr);
- debug_object_activate(head, &rcuhead_debug_descr);
- return 0;
-
- case ODEBUG_STATE_ACTIVE:
- /*
- * Ensure that queued callbacks are all executed.
- * If we detect that we are nested in a RCU read-side critical
- * section, we should simply fail, otherwise we would deadlock.
- */
- if (rcu_preempt_depth() != 0 || preempt_count() != 0 ||
- irqs_disabled()) {
- WARN_ON(1);
- return 0;
- }
- rcu_barrier();
- rcu_barrier_sched();
- rcu_barrier_bh();
- debug_object_activate(head, &rcuhead_debug_descr);
- return 1;
- default:
- return 0;
- }
-}
-
-/*
- * fixup_free is called when:
- * - an active object is freed
- */
-static int rcuhead_fixup_free(void *addr, enum debug_obj_state state)
-{
- struct rcu_head *head = addr;
-
- switch (state) {
- case ODEBUG_STATE_ACTIVE:
- /*
- * Ensure that queued callbacks are all executed.
- * If we detect that we are nested in a RCU read-side critical
- * section, we should simply fail, otherwise we would deadlock.
- */
-#ifndef CONFIG_PREEMPT
- WARN_ON(1);
- return 0;
-#else
- if (rcu_preempt_depth() != 0 || preempt_count() != 0 ||
- irqs_disabled()) {
- WARN_ON(1);
- return 0;
- }
- rcu_barrier();
- rcu_barrier_sched();
- rcu_barrier_bh();
- debug_object_free(head, &rcuhead_debug_descr);
- return 1;
-#endif
- default:
- return 0;
- }
-}
-
-/**
- * init_rcu_head_on_stack() - initialize on-stack rcu_head for debugobjects
- * @head: pointer to rcu_head structure to be initialized
- *
- * This function informs debugobjects of a new rcu_head structure that
- * has been allocated as an auto variable on the stack. This function
- * is not required for rcu_head structures that are statically defined or
- * that are dynamically allocated on the heap. This function has no
- * effect for !CONFIG_DEBUG_OBJECTS_RCU_HEAD kernel builds.
- */
-void init_rcu_head_on_stack(struct rcu_head *head)
-{
- debug_object_init_on_stack(head, &rcuhead_debug_descr);
-}
-EXPORT_SYMBOL_GPL(init_rcu_head_on_stack);
-
-/**
- * destroy_rcu_head_on_stack() - destroy on-stack rcu_head for debugobjects
- * @head: pointer to rcu_head structure to be initialized
- *
- * This function informs debugobjects that an on-stack rcu_head structure
- * is about to go out of scope. As with init_rcu_head_on_stack(), this
- * function is not required for rcu_head structures that are statically
- * defined or that are dynamically allocated on the heap. Also as with
- * init_rcu_head_on_stack(), this function has no effect for
- * !CONFIG_DEBUG_OBJECTS_RCU_HEAD kernel builds.
- */
-void destroy_rcu_head_on_stack(struct rcu_head *head)
-{
- debug_object_free(head, &rcuhead_debug_descr);
-}
-EXPORT_SYMBOL_GPL(destroy_rcu_head_on_stack);
-
-struct debug_obj_descr rcuhead_debug_descr = {
- .name = "rcu_head",
- .fixup_init = rcuhead_fixup_init,
- .fixup_activate = rcuhead_fixup_activate,
- .fixup_free = rcuhead_fixup_free,
-};
-EXPORT_SYMBOL_GPL(rcuhead_debug_descr);
-#endif /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */