int fastcall rt_down_read_trylock(struct rw_semaphore *rwsem)
{
unsigned long flags;
int ret;
/*
* Read locks within the self-held write lock succeed.
*/
spin_lock_irqsave(&rwsem->lock.wait_lock, flags);
if (rt_mutex_real_owner(&rwsem->lock) == current) {
spin_unlock_irqrestore(&rwsem->lock.wait_lock, flags);
rwsem->read_depth++;
/*
* NOTE: we handle it as a write-lock:
*/
rwsem_acquire(&rwsem->dep_map, 0, 1, _RET_IP_);
return 1;
}
spin_unlock_irqrestore(&rwsem->lock.wait_lock, flags);
ret = rt_mutex_trylock(&rwsem->lock);
if (ret)
rwsem_acquire(&rwsem->dep_map, 0, 1, _RET_IP_);
return ret;
}
int __lockfunc rt_read_trylock(rwlock_t *rwlock)
{
struct rt_mutex *lock = &rwlock->lock;
unsigned long flags;
int ret;
/*
* Read locks within the self-held write lock succeed.
*/
spin_lock_irqsave(&lock->wait_lock, flags);
if (rt_mutex_real_owner(lock) == current) {
spin_unlock_irqrestore(&lock->wait_lock, flags);
rwlock->read_depth++;
/*
* NOTE: we handle it as a write-lock:
*/
rwlock_acquire(&rwlock->dep_map, 0, 1, _RET_IP_);
return 1;
}
spin_unlock_irqrestore(&lock->wait_lock, flags);
ret = rt_mutex_trylock(lock);
if (ret)
rwlock_acquire(&rwlock->dep_map, 0, 1, _RET_IP_);
return ret;
}
int rt_down_write_trylock(struct rw_semaphore *rwsem)
{
int ret = rt_mutex_trylock(&rwsem->lock);
if (ret)
rwsem_acquire(&rwsem->dep_map, 0, 1, _RET_IP_);
return ret;
}
int __lockfunc rt_spin_trylock(spinlock_t *lock)
{
int ret = rt_mutex_trylock(&lock->lock);
if (ret)
spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);
return ret;
}
/*
* rwlock_t functions
*/
int __lockfunc rt_write_trylock(rwlock_t *rwlock)
{
int ret = rt_mutex_trylock(&rwlock->lock);
if (ret)
rwlock_acquire(&rwlock->dep_map, 0, 1, _RET_IP_);
return ret;
}
int __lockfunc _mutex_trylock(struct mutex *lock)
{
int ret = rt_mutex_trylock(&lock->lock);
if (ret)
mutex_acquire(&lock->dep_map, 0, 1, _RET_IP_);
return ret;
}
int __lockfunc rt_spin_trylock_irqsave(spinlock_t *lock, unsigned long *flags)
{
int ret;
*flags = 0;
ret = rt_mutex_trylock(&lock->lock);
if (ret)
spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);
return ret;
}
static int i2c_parent_trylock_bus(struct i2c_adapter *adapter,
unsigned int flags)
{
struct i2c_mux_priv *priv = adapter->algo_data;
struct i2c_adapter *parent = priv->muxc->parent;
if (!rt_mutex_trylock(&parent->mux_lock))
return 0; /* mux_lock not locked, failure */
if (i2c_trylock_bus(parent, flags))
return 1; /* parent locked too, success */
rt_mutex_unlock(&parent->mux_lock);
return 0; /* parent not locked, failure */
}
/*
* try to down the semaphore, 0 on success and 1 on failure. (inverted)
*/
int rt_down_trylock(struct semaphore *sem)
{
/*
* Here we are a tiny bit different from ordinary Linux semaphores,
* because we can get 'transient' locking-failures when say a
* process decreases the count from 9 to 8 and locks/releases the
* embedded mutex internally. It would be quite complex to remove
* these transient failures so lets try it the simple way first:
*/
if (rt_mutex_trylock(&sem->lock)) {
__down_complete(sem);
return 0;
}
return 1;
}
int rt_down_read_trylock(struct rw_semaphore *rwsem)
{
struct rt_mutex *lock = &rwsem->lock;
int ret = 1;
/*
* recursive read locks succeed when current owns the rwsem,
* but not when read_depth == 0 which means that the rwsem is
* write locked.
*/
if (rt_mutex_real_owner(lock) != current)
ret = rt_mutex_trylock(&rwsem->lock);
else if (!rwsem->read_depth)
ret = 0;
if (ret) {
rwsem->read_depth++;
rwsem_acquire(&rwsem->dep_map, 0, 1, _RET_IP_);
}
return ret;
}
/*************I2C functions*******************/
static int ds2482_get_i2c_bus(struct i2c_client *client)
{
struct i2c_adapter *adap = client->adapter;
int ret;
if (adap->algo->master_xfer) {
if (in_atomic() || irqs_disabled()) {
ret = rt_mutex_trylock(&adap->bus_lock);
if (!ret)
/* I2C activity is ongoing. */
return -EAGAIN;
} else {
rt_mutex_lock(&adap->bus_lock);
}
return 0;
} else {
dev_err(&client->dev, "I2C level transfers not supported\n");
return -EOPNOTSUPP;
}
}
int __lockfunc rt_read_trylock(rwlock_t *rwlock)
{
struct rt_mutex *lock = &rwlock->lock;
int ret = 1;
/*
* recursive read locks succeed when current owns the lock,
* but not when read_depth == 0 which means that the lock is
* write locked.
*/
if (rt_mutex_real_owner(lock) != current)
ret = rt_mutex_trylock(lock);
else if (!rwlock->read_depth)
ret = 0;
if (ret) {
rwlock->read_depth++;
rwlock_acquire_read(&rwlock->dep_map, 0, 1, _RET_IP_);
}
return ret;
}