diff options
Diffstat (limited to 'kernel/rcupdate.c')
| -rw-r--r-- | kernel/rcupdate.c | 278 | 
1 files changed, 0 insertions, 278 deletions
diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c deleted file mode 100644 index a23a57a976d..00000000000 --- a/kernel/rcupdate.c +++ /dev/null @@ -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 */  | 
