staging: greybus: operation: add generic timeout support

Add a struct timer_list to struct gb_operation and use that to implement
generic operation timeouts.

This simplifies the synchronous operation handling somewhat while also
providing a generic timeout mechanism that drivers can use for
asynchronous operations.

Signed-off-by: Johan Hovold <johan@kernel.org>
Acked-by: Bryan O'Donoghue <pure.logic@nexus-software.ie>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Johan Hovold 2017-01-23 13:04:14 +01:00 committed by Greg Kroah-Hartman
parent a769f30c7b
commit dbec27298b
3 changed files with 39 additions and 14 deletions

View file

@ -629,6 +629,7 @@ static int gb_loopback_async_operation(struct gb_loopback *gb, int type,
mutex_lock(&gb->mutex);
ret = gb_operation_request_send(operation,
gb_loopback_async_operation_callback,
0,
GFP_KERNEL);
if (ret)
goto error;

View file

@ -273,18 +273,40 @@ static void gb_operation_request_handle(struct gb_operation *operation)
static void gb_operation_work(struct work_struct *work)
{
struct gb_operation *operation;
int ret;
operation = container_of(work, struct gb_operation, work);
if (gb_operation_is_incoming(operation))
if (gb_operation_is_incoming(operation)) {
gb_operation_request_handle(operation);
else
} else {
ret = del_timer_sync(&operation->timer);
if (!ret) {
/* Cancel request message if scheduled by timeout. */
if (gb_operation_result(operation) == -ETIMEDOUT)
gb_message_cancel(operation->request);
}
operation->callback(operation);
}
gb_operation_put_active(operation);
gb_operation_put(operation);
}
static void gb_operation_timeout(unsigned long arg)
{
struct gb_operation *operation = (void *)arg;
if (gb_operation_result_set(operation, -ETIMEDOUT)) {
/*
* A stuck request message will be cancelled from the
* workqueue.
*/
queue_work(gb_operation_completion_wq, &operation->work);
}
}
static void gb_operation_message_init(struct gb_host_device *hd,
struct gb_message *message, u16 operation_id,
size_t payload_size, u8 type)
@ -518,6 +540,9 @@ gb_operation_create_common(struct gb_connection *connection, u8 type,
gfp_flags)) {
goto err_request;
}
setup_timer(&operation->timer, gb_operation_timeout,
(unsigned long)operation);
}
operation->flags = op_flags;
@ -679,6 +704,7 @@ static void gb_operation_sync_callback(struct gb_operation *operation)
* gb_operation_request_send() - send an operation request message
* @operation: the operation to initiate
* @callback: the operation completion callback
* @timeout: operation timeout in milliseconds, or zero for no timeout
* @gfp: the memory flags to use for any allocations
*
* The caller has filled in any payload so the request message is ready to go.
@ -693,6 +719,7 @@ static void gb_operation_sync_callback(struct gb_operation *operation)
*/
int gb_operation_request_send(struct gb_operation *operation,
gb_operation_callback callback,
unsigned int timeout,
gfp_t gfp)
{
struct gb_connection *connection = operation->connection;
@ -742,6 +769,11 @@ int gb_operation_request_send(struct gb_operation *operation,
if (ret)
goto err_put_active;
if (timeout) {
operation->timer.expires = jiffies + msecs_to_jiffies(timeout);
add_timer(&operation->timer);
}
return 0;
err_put_active:
@ -763,26 +795,16 @@ int gb_operation_request_send_sync_timeout(struct gb_operation *operation,
unsigned int timeout)
{
int ret;
unsigned long timeout_jiffies;
ret = gb_operation_request_send(operation, gb_operation_sync_callback,
GFP_KERNEL);
timeout, GFP_KERNEL);
if (ret)
return ret;
if (timeout)
timeout_jiffies = msecs_to_jiffies(timeout);
else
timeout_jiffies = MAX_SCHEDULE_TIMEOUT;
ret = wait_for_completion_interruptible_timeout(&operation->completion,
timeout_jiffies);
ret = wait_for_completion_interruptible(&operation->completion);
if (ret < 0) {
/* Cancel the operation if interrupted */
gb_operation_cancel(operation, -ECANCELED);
} else if (ret == 0) {
/* Cancel the operation if op timed out */
gb_operation_cancel(operation, -ETIMEDOUT);
}
return gb_operation_result(operation);

View file

@ -98,6 +98,7 @@ struct gb_operation {
struct work_struct work;
gb_operation_callback callback;
struct completion completion;
struct timer_list timer;
struct kref kref;
atomic_t waiters;
@ -164,6 +165,7 @@ bool gb_operation_response_alloc(struct gb_operation *operation,
int gb_operation_request_send(struct gb_operation *operation,
gb_operation_callback callback,
unsigned int timeout,
gfp_t gfp);
int gb_operation_request_send_sync_timeout(struct gb_operation *operation,
unsigned int timeout);