[PATCH] lockdep: clean up rwsems

#define RWSEM_ACTIVE_WRITE_BIAS		(RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS)

	spinlock_t		wait_lock;

	struct list_head	wait_list;

#if RWSEM_DEBUG

	int			debug;

#endif

};

/*

 * initialisation

 */

#if RWSEM_DEBUG

#define __RWSEM_DEBUG_INIT      , 0

#else

#define __RWSEM_DEBUG_INIT	/* */

#endif

#define __RWSEM_INITIALIZER(name) \

{ RWSEM_UNLOCKED_VALUE, SPIN_LOCK_UNLOCKED, LIST_HEAD_INIT((name).wait_list) \

	__RWSEM_DEBUG_INIT }

	}

#define DECLARE_RWSEM(name) \

	struct rw_semaphore name = __RWSEM_INITIALIZER(name)

	sem->count = RWSEM_UNLOCKED_VALUE;

	spin_lock_init(&sem->wait_lock);

	INIT_LIST_HEAD(&sem->wait_list);

#if RWSEM_DEBUG

	sem->debug = 0;

#endif

}

/*

	__s32			activity;

	spinlock_t		wait_lock;

	struct list_head	wait_list;

#if RWSEM_DEBUG

	int			debug;

#endif

};

/*

 * initialisation

 */

#if RWSEM_DEBUG

#define __RWSEM_DEBUG_INIT      , 0

#else

#define __RWSEM_DEBUG_INIT	/* */

#endif

#define __RWSEM_INITIALIZER(name) \

{ 0, SPIN_LOCK_UNLOCKED, LIST_HEAD_INIT((name).wait_list) __RWSEM_DEBUG_INIT }

{ 0, SPIN_LOCK_UNLOCKED, LIST_HEAD_INIT((name).wait_list) }

#define DECLARE_RWSEM(name) \

	struct rw_semaphore name = __RWSEM_INITIALIZER(name)

#include <linux/linkage.h>

#define RWSEM_DEBUG 0

#ifdef __KERNEL__

#include <linux/types.h>

#include <asm/rwsem.h> /* use an arch-specific implementation */

#endif

#ifndef rwsemtrace

#if RWSEM_DEBUG

extern void FASTCALL(rwsemtrace(struct rw_semaphore *sem, const char *str));

#else

#define rwsemtrace(SEM,FMT)

#endif

#endif

/*

 * lock for reading

 */

static inline void down_read(struct rw_semaphore *sem)

{

	might_sleep();

	rwsemtrace(sem,"Entering down_read");

	__down_read(sem);

	rwsemtrace(sem,"Leaving down_read");

}

/*

static inline int down_read_trylock(struct rw_semaphore *sem)

{

	int ret;

	rwsemtrace(sem,"Entering down_read_trylock");

	ret = __down_read_trylock(sem);

	rwsemtrace(sem,"Leaving down_read_trylock");

	return ret;

}

static inline void down_write(struct rw_semaphore *sem)

{

	might_sleep();

	rwsemtrace(sem,"Entering down_write");

	__down_write(sem);

	rwsemtrace(sem,"Leaving down_write");

}

/*

static inline int down_write_trylock(struct rw_semaphore *sem)

{

	int ret;

	rwsemtrace(sem,"Entering down_write_trylock");

	ret = __down_write_trylock(sem);

	rwsemtrace(sem,"Leaving down_write_trylock");

	return ret;

}

 */

static inline void up_read(struct rw_semaphore *sem)

{

	rwsemtrace(sem,"Entering up_read");

	__up_read(sem);

	rwsemtrace(sem,"Leaving up_read");

}

/*

 */

static inline void up_write(struct rw_semaphore *sem)

{

	rwsemtrace(sem,"Entering up_write");

	__up_write(sem);

	rwsemtrace(sem,"Leaving up_write");

}

/*

 */

static inline void downgrade_write(struct rw_semaphore *sem)

{

	rwsemtrace(sem,"Entering downgrade_write");

	__downgrade_write(sem);

	rwsemtrace(sem,"Leaving downgrade_write");

}

#endif /* __KERNEL__ */

/* kernel/rwsem.c: R/W semaphores, public implementation

 *

 * Written by David Howells (dhowells@redhat.com).

 * Derived from asm-i386/semaphore.h

 */

#include <linux/types.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/rwsem.h>

#include <asm/system.h>

#include <asm/atomic.h>

/*

 * lock for reading

 */

void down_read(struct rw_semaphore *sem)

{

	might_sleep();

	rwsem_acquire_read(&sem->dep_map, 0, 0, _RET_IP_);

	__down_read(sem);

}

EXPORT_SYMBOL(down_read);

/*

 * trylock for reading -- returns 1 if successful, 0 if contention

 */

int down_read_trylock(struct rw_semaphore *sem)

{

	int ret = __down_read_trylock(sem);

	if (ret == 1)

		rwsem_acquire_read(&sem->dep_map, 0, 1, _RET_IP_);

	return ret;

}

EXPORT_SYMBOL(down_read_trylock);

/*

 * lock for writing

 */

void down_write(struct rw_semaphore *sem)

{

	might_sleep();

	rwsem_acquire(&sem->dep_map, 0, 0, _RET_IP_);

	__down_write(sem);

}

EXPORT_SYMBOL(down_write);

/*

 * trylock for writing -- returns 1 if successful, 0 if contention

 */

int down_write_trylock(struct rw_semaphore *sem)

{

	int ret = __down_write_trylock(sem);

	if (ret == 1)

		rwsem_acquire(&sem->dep_map, 0, 0, _RET_IP_);

	return ret;

}

EXPORT_SYMBOL(down_write_trylock);

/*

 * release a read lock

 */

void up_read(struct rw_semaphore *sem)

{

	rwsem_release(&sem->dep_map, 1, _RET_IP_);

	__up_read(sem);

}

EXPORT_SYMBOL(up_read);

/*

 * release a write lock

 */

void up_write(struct rw_semaphore *sem)

{

	rwsem_release(&sem->dep_map, 1, _RET_IP_);

	__up_write(sem);

}

EXPORT_SYMBOL(up_write);

/*

 * downgrade write lock to read lock

 */

void downgrade_write(struct rw_semaphore *sem)

{

	/*

	 * lockdep: a downgraded write will live on as a write

	 * dependency.

	 */

	__downgrade_write(sem);

}

EXPORT_SYMBOL(downgrade_write);

#define RWSEM_WAITING_FOR_WRITE	0x00000002

};

#if RWSEM_DEBUG

void rwsemtrace(struct rw_semaphore *sem, const char *str)

{

	if (sem->debug)

		printk("[%d] %s({%d,%d})\n",

		       current->pid, str, sem->activity,

		       list_empty(&sem->wait_list) ? 0 : 1);

}

#endif

/*

 * initialise the semaphore

 */

	sem->activity = 0;

	spin_lock_init(&sem->wait_lock);

	INIT_LIST_HEAD(&sem->wait_list);

#if RWSEM_DEBUG

	sem->debug = 0;

#endif

}

/*

	struct task_struct *tsk;

	int woken;

	rwsemtrace(sem, "Entering __rwsem_do_wake");

	waiter = list_entry(sem->wait_list.next, struct rwsem_waiter, list);

	if (!wakewrite) {

	sem->activity += woken;

 out:

	rwsemtrace(sem, "Leaving __rwsem_do_wake");

	return sem;

}

	struct rwsem_waiter waiter;

	struct task_struct *tsk;

	rwsemtrace(sem, "Entering __down_read");

	spin_lock_irq(&sem->wait_lock);

	if (sem->activity >= 0 && list_empty(&sem->wait_list)) {

	}

	tsk->state = TASK_RUNNING;

 out:

	rwsemtrace(sem, "Leaving __down_read");

	;

}

/*

	unsigned long flags;

	int ret = 0;

	rwsemtrace(sem, "Entering __down_read_trylock");

	spin_lock_irqsave(&sem->wait_lock, flags);

	spin_unlock_irqrestore(&sem->wait_lock, flags);

	rwsemtrace(sem, "Leaving __down_read_trylock");

	return ret;

}

	struct rwsem_waiter waiter;

	struct task_struct *tsk;

	rwsemtrace(sem, "Entering __down_write");

	spin_lock_irq(&sem->wait_lock);

	if (sem->activity == 0 && list_empty(&sem->wait_list)) {

	}

	tsk->state = TASK_RUNNING;

 out:

	rwsemtrace(sem, "Leaving __down_write");

	;

}

/*

	unsigned long flags;

	int ret = 0;

	rwsemtrace(sem, "Entering __down_write_trylock");

	spin_lock_irqsave(&sem->wait_lock, flags);

	if (sem->activity == 0 && list_empty(&sem->wait_list)) {

	spin_unlock_irqrestore(&sem->wait_lock, flags);

	rwsemtrace(sem, "Leaving __down_write_trylock");

	return ret;

}

{

	unsigned long flags;

	rwsemtrace(sem, "Entering __up_read");

	spin_lock_irqsave(&sem->wait_lock, flags);

	if (--sem->activity == 0 && !list_empty(&sem->wait_list))

		sem = __rwsem_wake_one_writer(sem);

	spin_unlock_irqrestore(&sem->wait_lock, flags);

	rwsemtrace(sem, "Leaving __up_read");

}

/*

{

	unsigned long flags;

	rwsemtrace(sem, "Entering __up_write");

	spin_lock_irqsave(&sem->wait_lock, flags);

	sem->activity = 0;

		sem = __rwsem_do_wake(sem, 1);

	spin_unlock_irqrestore(&sem->wait_lock, flags);

	rwsemtrace(sem, "Leaving __up_write");

}

/*

{

	unsigned long flags;

	rwsemtrace(sem, "Entering __downgrade_write");

	spin_lock_irqsave(&sem->wait_lock, flags);

	sem->activity = 1;

		sem = __rwsem_do_wake(sem, 0);

	spin_unlock_irqrestore(&sem->wait_lock, flags);

	rwsemtrace(sem, "Leaving __downgrade_write");

}

EXPORT_SYMBOL(init_rwsem);

EXPORT_SYMBOL(__up_read);

EXPORT_SYMBOL(__up_write);

EXPORT_SYMBOL(__downgrade_write);

#if RWSEM_DEBUG

EXPORT_SYMBOL(rwsemtrace);

#endif