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staging: greybus: loopback: convert loopback to use generic async operations 

Loopback has its own internal method for tracking and timing out
asynchronous operations however previous patches make it possible to use
functionality provided by operation.c to do this instead. Using the code in
operation.c means we can completely subtract the timer, the work-queue, the
kref and the cringe-worthy 'pending' flag. The completion callback
triggered by operation.c will provide an authoritative result code -
including -ETIMEDOUT for asynchronous operations.

Signed-off-by: Bryan O'Donoghue <pure.logic@nexus-software.ie>
Reviewed-by: Johan Hovold <johan@kernel.org>
Cc: Alex Elder <elder@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mitch Tasman <tasman@leaflabs.com>
Cc: greybus-dev@lists.linaro.org
Cc: devel@driverdev.osuosl.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Bryan O'Donoghue 2017-11-06 01:32:22 +00:00 committed by Greg Kroah-Hartman
parent 200543c1b9
commit 262edc359d
1 changed files with 30 additions and 140 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

170
drivers/staging/greybus/loopback.c
View File

@ -59,11 +59,6 @@ struct gb_loopback_async_operation {
struct gb_loopback *gb;
struct gb_operation *operation;
ktime_t ts;
struct timer_list timer;
struct list_head entry;
struct work_struct work;
struct kref kref;
bool pending;
int (*completion)(struct gb_loopback_async_operation *op_async);
};
@ -427,56 +422,6 @@ out_put_operation:
return ret;
}
static void __gb_loopback_async_operation_destroy(struct kref *kref)
{
struct gb_loopback_async_operation *op_async;
op_async = container_of(kref, struct gb_loopback_async_operation, kref);
list_del(&op_async->entry);
if (op_async->operation)
gb_operation_put(op_async->operation);
atomic_dec(&op_async->gb->outstanding_operations);
wake_up(&op_async->gb->wq_completion);
kfree(op_async);
}
static void gb_loopback_async_operation_get(struct gb_loopback_async_operation
*op_async)
{
kref_get(&op_async->kref);
}
static void gb_loopback_async_operation_put(struct gb_loopback_async_operation
*op_async)
{
unsigned long flags;
spin_lock_irqsave(&gb_dev.lock, flags);
kref_put(&op_async->kref, __gb_loopback_async_operation_destroy);
spin_unlock_irqrestore(&gb_dev.lock, flags);
}
static struct gb_loopback_async_operation *
gb_loopback_operation_find(u16 id)
{
struct gb_loopback_async_operation *op_async;
bool found = false;
unsigned long flags;
spin_lock_irqsave(&gb_dev.lock, flags);
list_for_each_entry(op_async, &gb_dev.list_op_async, entry) {
if (op_async->operation->id == id) {
gb_loopback_async_operation_get(op_async);
found = true;
break;
}
}
spin_unlock_irqrestore(&gb_dev.lock, flags);
return found ? op_async : NULL;
}
static void gb_loopback_async_wait_all(struct gb_loopback *gb)
{
wait_event(gb->wq_completion,
@ -488,83 +433,41 @@ static void gb_loopback_async_operation_callback(struct gb_operation *operation)
struct gb_loopback_async_operation *op_async;
struct gb_loopback *gb;
ktime_t te;
bool err = false;
int result;
te = ktime_get();
op_async = gb_loopback_operation_find(operation->id);
if (!op_async)
return;
result = gb_operation_result(operation);
op_async = gb_operation_get_data(operation);
gb = op_async->gb;
mutex_lock(&gb->mutex);
if (!op_async->pending || gb_operation_result(operation)) {
err = true;
} else {
if (op_async->completion)
if (op_async->completion(op_async))
err = true;
}
if (!result && op_async->completion)
result = op_async->completion(op_async);
if (!err)
if (!result) {
gb->elapsed_nsecs = gb_loopback_calc_latency(op_async->ts, te);
if (op_async->pending) {
if (err)
gb->error++;
gb->iteration_count++;
op_async->pending = false;
del_timer_sync(&op_async->timer);
gb_loopback_async_operation_put(op_async);
gb_loopback_calculate_stats(gb, err);
} else {
gb->error++;
if (result == -ETIMEDOUT)
gb->requests_timedout++;
}
gb->iteration_count++;
gb_loopback_calculate_stats(gb, result);
mutex_unlock(&gb->mutex);
dev_dbg(&gb->connection->bundle->dev, "complete operation %d\n",
operation->id);
gb_loopback_async_operation_put(op_async);
}
/* Wake up waiters */
atomic_dec(&op_async->gb->outstanding_operations);
wake_up(&gb->wq_completion);
static void gb_loopback_async_operation_work(struct work_struct *work)
{
struct gb_loopback *gb;
struct gb_operation *operation;
struct gb_loopback_async_operation *op_async;
op_async = container_of(work, struct gb_loopback_async_operation, work);
gb = op_async->gb;
operation = op_async->operation;
mutex_lock(&gb->mutex);
if (op_async->pending) {
gb->requests_timedout++;
gb->error++;
gb->iteration_count++;
op_async->pending = false;
gb_loopback_async_operation_put(op_async);
gb_loopback_calculate_stats(gb, true);
}
mutex_unlock(&gb->mutex);
dev_dbg(&gb->connection->bundle->dev, "timeout operation %d\n",
operation->id);
gb_operation_cancel(operation, -ETIMEDOUT);
gb_loopback_async_operation_put(op_async);
}
static void gb_loopback_async_operation_timeout(unsigned long data)
{
struct gb_loopback_async_operation *op_async;
u16 id = data;
op_async = gb_loopback_operation_find(id);
if (!op_async) {
pr_err("operation %d not found - time out ?\n", id);
return;
}
schedule_work(&op_async->work);
/* Release resources */
gb_operation_put(operation);
kfree(op_async);
}
static int gb_loopback_async_operation(struct gb_loopback *gb, int type,
@ -575,15 +478,11 @@ static int gb_loopback_async_operation(struct gb_loopback *gb, int type,
struct gb_loopback_async_operation *op_async;
struct gb_operation *operation;
int ret;
unsigned long flags;
op_async = kzalloc(sizeof(*op_async), GFP_KERNEL);
if (!op_async)
return -ENOMEM;
INIT_WORK(&op_async->work, gb_loopback_async_operation_work);
kref_init(&op_async->kref);
operation = gb_operation_create(gb->connection, type, request_size,
response_size, GFP_KERNEL);
if (!operation) {
@ -594,33 +493,24 @@ static int gb_loopback_async_operation(struct gb_loopback *gb, int type,
if (request_size)
memcpy(operation->request->payload, request, request_size);
gb_operation_set_data(operation, op_async);
op_async->gb = gb;
op_async->operation = operation;
op_async->completion = completion;
spin_lock_irqsave(&gb_dev.lock, flags);
list_add_tail(&op_async->entry, &gb_dev.list_op_async);
spin_unlock_irqrestore(&gb_dev.lock, flags);
op_async->ts = ktime_get();
op_async->pending = true;
atomic_inc(&gb->outstanding_operations);
ret = gb_operation_request_send(operation,
gb_loopback_async_operation_callback,
0,
jiffies_to_msecs(gb->jiffy_timeout),
GFP_KERNEL);
if (ret)
goto error;
setup_timer(&op_async->timer, gb_loopback_async_operation_timeout,
(unsigned long)operation->id);
op_async->timer.expires = jiffies + gb->jiffy_timeout;
add_timer(&op_async->timer);
goto done;
error:
gb_loopback_async_operation_put(op_async);
done:
if (ret) {
atomic_dec(&gb->outstanding_operations);
gb_operation_put(operation);
kfree(op_async);
}
return ret;
}