/*
* Process operation work.
*
* For incoming requests, call the protocol request handler. The operation
* result should be -EINPROGRESS at this point.
*
* For outgoing requests, the operation result value should have
* been set before queueing this. The operation callback function
* allows the original requester to know the request has completed
* and its result is available.
*/
static void gb_operation_work(struct work_struct *work)
{
struct gb_operation *operation;
operation = container_of(work, struct gb_operation, work);
if (gb_operation_is_incoming(operation))
gb_operation_request_handle(operation);
else
operation->callback(operation);
gb_operation_put_active(operation);
gb_operation_put(operation);
}
/*
* Cancel an outgoing operation synchronously, and record the given error to
* indicate why.
*/
void gb_operation_cancel(struct gb_operation *operation, int errno)
{
if (WARN_ON(gb_operation_is_incoming(operation)))
return;
if (gb_operation_result_set(operation, errno)) {
gb_message_cancel(operation->request);
queue_work(gb_operation_completion_wq, &operation->work);
}
trace_gb_message_cancel_outgoing(operation->request);
atomic_inc(&operation->waiters);
wait_event(gb_operation_cancellation_queue,
!gb_operation_is_active(operation));
atomic_dec(&operation->waiters);
}
/*
* Looks up an outgoing operation on a connection and returns a refcounted
* pointer if found, or NULL otherwise.
*/
static struct gb_operation *
gb_operation_find_outgoing(struct gb_connection *connection, u16 operation_id)
{
struct gb_operation *operation;
unsigned long flags;
bool found = false;
spin_lock_irqsave(&connection->lock, flags);
list_for_each_entry(operation, &connection->operations, links)
if (operation->id == operation_id &&
!gb_operation_is_incoming(operation)) {
gb_operation_get(operation);
found = true;
break;
}
spin_unlock_irqrestore(&connection->lock, flags);
return found ? operation : NULL;
}
/*
* Increment operation active count and add to connection list unless the
* connection is going away.
*
* Caller holds operation reference.
*/
static int gb_operation_get_active(struct gb_operation *operation)
{
struct gb_connection *connection = operation->connection;
unsigned long flags;
spin_lock_irqsave(&connection->lock, flags);
if (connection->state != GB_CONNECTION_STATE_ENABLED &&
connection->state != GB_CONNECTION_STATE_ENABLED_TX &&
!gb_operation_is_incoming(operation)) {
spin_unlock_irqrestore(&connection->lock, flags);
return -ENOTCONN;
}
if (operation->active++ == 0)
list_add_tail(&operation->links, &connection->operations);
spin_unlock_irqrestore(&connection->lock, flags);
return 0;
}
/*
* Cancel an incoming operation synchronously. Called during connection tear
* down.
*/
void gb_operation_cancel_incoming(struct gb_operation *operation, int errno)
{
if (WARN_ON(!gb_operation_is_incoming(operation)))
return;
if (!gb_operation_is_unidirectional(operation)) {
/*
* Make sure the request handler has submitted the response
* before cancelling it.
*/
flush_work(&operation->work);
if (!gb_operation_result_set(operation, errno))
gb_message_cancel(operation->response);
}
trace_gb_message_cancel_incoming(operation->response);
atomic_inc(&operation->waiters);
wait_event(gb_operation_cancellation_queue,
!gb_operation_is_active(operation));
atomic_dec(&operation->waiters);
}
/*
* Cancel all active operations on a connection.
*
* Should only be called during connection tear down.
*/
static void gb_connection_cancel_operations(struct gb_connection *connection,
int errno)
{
struct gb_operation *operation;
spin_lock_irq(&connection->lock);
while (!list_empty(&connection->operations)) {
operation = list_last_entry(&connection->operations,
struct gb_operation, links);
gb_operation_get(operation);
spin_unlock_irq(&connection->lock);
if (gb_operation_is_incoming(operation))
gb_operation_cancel_incoming(operation, errno);
else
gb_operation_cancel(operation, errno);
gb_operation_put(operation);
spin_lock_irq(&connection->lock);
}
spin_unlock_irq(&connection->lock);
}