- greybus-dev - lists.linaro.org

[PATCH v3 4/4] staging: greybus: loopback: convert loopback to use generic async operations

by Bryan O'Donoghue

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(a)nexus-software.ie> Cc: Johan Hovold <johan(a)kernel.org> Cc: Alex Elder <elder(a)kernel.org> Cc: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Cc: Kees Cook <keescook(a)chromium.org> Cc: Mitch Tasman <tasman(a)leaflabs.com> Cc: greybus-dev(a)lists.linaro.org Cc: devel(a)driverdev.osuosl.org Cc: linux-kernel(a)vger.kernel.org --- drivers/staging/greybus/loopback.c | 168 +++++++------------------------------ 1 file changed, 29 insertions(+), 139 deletions(-) diff --git a/drivers/staging/greybus/loopback.c b/drivers/staging/greybus/loopback.c index 9c5980c..6d51998 100644 --- a/drivers/staging/greybus/loopback.c +++ b/drivers/staging/greybus/loopback.c @@ -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 @@ static int gb_loopback_operation_sync(struct gb_loopback *gb, int type, 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++; } - mutex_unlock(&gb->mutex); - - dev_dbg(&gb->connection->bundle->dev, "complete operation %d\n", - operation->id); - - gb_loopback_async_operation_put(op_async); -} - -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; + gb->iteration_count++; + gb_loopback_calculate_stats(gb, result); - 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", + dev_dbg(&gb->connection->bundle->dev, "complete 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; + /* Wake up waiters */ + atomic_dec(&op_async->gb->outstanding_operations); + wake_up(&gb->wq_completion); - 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; } -- 2.7.4

6 years, 6 months

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[PATCH v3 2/4] staging: greybus: loopback: Fix iteration count on async path

by Bryan O'Donoghue

Commit 12927835d211 ("greybus: loopback: Add asynchronous bi-directional support") does what it says on the tin - namely, adds support for asynchronous bi-directional loopback operations. What it neglects to do though is increment the per-connection gb->iteration_count on an asynchronous operation error. This patch fixes that omission. Fixes: 12927835d211 ("greybus: loopback: Add asynchronous bi-directional support") Signed-off-by: Bryan O'Donoghue <pure.logic(a)nexus-software.ie> Reported-by: Mitch Tasman <tasman(a)leaflabs.com> Cc: Johan Hovold <johan(a)kernel.org> Cc: Alex Elder <elder(a)kernel.org> Cc: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Cc: Mitch Tasman <tasman(a)leaflabs.com> Cc: greybus-dev(a)lists.linaro.org Cc: devel(a)driverdev.osuosl.org Cc: linux-kernel(a)vger.kernel.org --- drivers/staging/greybus/loopback.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/staging/greybus/loopback.c b/drivers/staging/greybus/loopback.c index 20d1b45..9c5980c 100644 --- a/drivers/staging/greybus/loopback.c +++ b/drivers/staging/greybus/loopback.c @@ -1021,8 +1021,10 @@ static int gb_loopback_fn(void *data) else if (type == GB_LOOPBACK_TYPE_SINK) error = gb_loopback_async_sink(gb, size); - if (error) + if (error) { gb->error++; + gb->iteration_count++; + } } else { /* We are effectively single threaded here */ if (type == GB_LOOPBACK_TYPE_PING) -- 2.7.4

6 years, 6 months

2
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[PATCH v3 1/4] staging: greybus: loopback: Hold per-connection mutex across operations

by Bryan O'Donoghue

Commit d9fb3754ecf8 ("greybus: loopback: Relax locking during loopback operations") changes the holding of the per-connection mutex to be less restrictive because at the time of that commit per-connection mutexes were encapsulated by a per-driver level gb_dev.mutex. Commit 8e1d6c336d74 ("greybus: loopback: drop bus aggregate calculation") on the other hand subtracts the driver level gb_dev.mutex but neglects to move the mutex back to the place it was prior to commit d9fb3754ecf8 ("greybus: loopback: Relax locking during loopback operations"), as a result several members of the per connection struct gb_loopback are racy. The solution is restoring the old location of mutex_unlock(&gb->mutex) as it was in commit d9fb3754ecf8 ("greybus: loopback: Relax locking during loopback operations"). Fixes: 8e1d6c336d74 ("greybus: loopback: drop bus aggregate calculation") Signed-off-by: Bryan O'Donoghue <pure.logic(a)nexus-software.ie> Cc: Johan Hovold <johan(a)kernel.org> Cc: Alex Elder <elder(a)kernel.org> Cc: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Cc: Mitch Tasman <tasman(a)leaflabs.com> Cc: greybus-dev(a)lists.linaro.org Cc: devel(a)driverdev.osuosl.org Cc: linux-kernel(a)vger.kernel.org --- drivers/staging/greybus/loopback.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/drivers/staging/greybus/loopback.c b/drivers/staging/greybus/loopback.c index 3d92638..20d1b45 100644 --- a/drivers/staging/greybus/loopback.c +++ b/drivers/staging/greybus/loopback.c @@ -605,7 +605,6 @@ static int gb_loopback_async_operation(struct gb_loopback *gb, int type, op_async->ts = ktime_get(); op_async->pending = true; atomic_inc(&gb->outstanding_operations); - mutex_lock(&gb->mutex); ret = gb_operation_request_send(operation, gb_loopback_async_operation_callback, 0, @@ -622,7 +621,6 @@ static int gb_loopback_async_operation(struct gb_loopback *gb, int type, error: gb_loopback_async_operation_put(op_async); done: - mutex_unlock(&gb->mutex); return ret; } @@ -1013,7 +1011,6 @@ static int gb_loopback_fn(void *data) type = gb->type; if (ktime_to_ns(gb->ts) == 0) gb->ts = ktime_get(); - mutex_unlock(&gb->mutex); /* Else operations to perform */ if (gb->async) { @@ -1041,6 +1038,7 @@ static int gb_loopback_fn(void *data) gb_loopback_calculate_stats(gb, !!error); } gb->send_count++; + mutex_unlock(&gb->mutex); if (us_wait) { if (us_wait < 20000) -- 2.7.4

6 years, 6 months

2
1
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[PATCH v3 3/4] staging: greybus: operation: add private data with get/set accessors

by Bryan O'Donoghue

Asynchronous operation completion handler's lives are made easier if there is a generic pointer that can store private data associated with the operation. This patch adds a pointer field to struct gb_operation and get/set methods to access that pointer. Signed-off-by: Bryan O'Donoghue <pure.logic(a)nexus-software.ie> Cc: Johan Hovold <johan(a)kernel.org> Cc: Alex Elder <elder(a)kernel.org> Cc: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Cc: Mitch Tasman <tasman(a)leaflabs.com> Cc: greybus-dev(a)lists.linaro.org Cc: devel(a)driverdev.osuosl.org Cc: linux-kernel(a)vger.kernel.org Reviewed-by: Johan Hovold <johan(a)kernel.org> --- drivers/staging/greybus/operation.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/staging/greybus/operation.h b/drivers/staging/greybus/operation.h index 7529f01..bfec1e9 100644 --- a/drivers/staging/greybus/operation.h +++ b/drivers/staging/greybus/operation.h @@ -105,6 +105,8 @@ struct gb_operation { int active; struct list_head links; /* connection->operations */ + + void *private; }; static inline bool @@ -206,6 +208,17 @@ static inline int gb_operation_unidirectional(struct gb_connection *connection, request, request_size, GB_OPERATION_TIMEOUT_DEFAULT); } +static inline void *gb_operation_get_data(struct gb_operation *operation) +{ + return operation->private; +} + +static inline void gb_operation_set_data(struct gb_operation *operation, + void *data) +{ + operation->private = data; +} + int gb_operation_init(void); void gb_operation_exit(void); -- 2.7.4

6 years, 6 months

1
0
0 0

[PATCH v2 4/4] staging: greybus: loopback: convert loopback to use generic async operations

by Bryan O'Donoghue

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(a)nexus-software.ie> Cc: Johan Hovold <johan(a)kernel.org> Cc: Alex Elder <elder(a)kernel.org> Cc: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Cc: Kees Cook <keescook(a)chromium.org> Cc: Mitch Tasman <tasman(a)leaflabs.com> Cc: greybus-dev(a)lists.linaro.org Cc: devel(a)driverdev.osuosl.org Cc: linux-kernel(a)vger.kernel.org --- drivers/staging/greybus/loopback.c | 168 +++++++------------------------------ 1 file changed, 29 insertions(+), 139 deletions(-) diff --git a/drivers/staging/greybus/loopback.c b/drivers/staging/greybus/loopback.c index 9c5980c..6d51998 100644 --- a/drivers/staging/greybus/loopback.c +++ b/drivers/staging/greybus/loopback.c @@ -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 @@ static int gb_loopback_operation_sync(struct gb_loopback *gb, int type, 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++; } - mutex_unlock(&gb->mutex); - - dev_dbg(&gb->connection->bundle->dev, "complete operation %d\n", - operation->id); - - gb_loopback_async_operation_put(op_async); -} - -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; + gb->iteration_count++; + gb_loopback_calculate_stats(gb, result); - 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", + dev_dbg(&gb->connection->bundle->dev, "complete 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; + /* Wake up waiters */ + atomic_dec(&op_async->gb->outstanding_operations); + wake_up(&gb->wq_completion); - 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; } -- 2.7.4

6 years, 6 months

1
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[PATCH v2 3/4] staging: greybus: operation: add private data with get/set accessors

by Bryan O'Donoghue

Asynchronous operation completion handler's lives are made easier if there is a generic pointer that can store private data associated with the operation. This patch adds a pointer field to struct gb_operation and get/set methods to access that pointer. Signed-off-by: Bryan O'Donoghue <pure.logic(a)nexus-software.ie> Cc: Johan Hovold <johan(a)kernel.org> Cc: Alex Elder <elder(a)kernel.org> Cc: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Cc: Mitch Tasman <tasman(a)leaflabs.com> Cc: greybus-dev(a)lists.linaro.org Cc: devel(a)driverdev.osuosl.org Cc: linux-kernel(a)vger.kernel.org Reviewed-by: Johan Hovold <johan(a)kernel.org> --- drivers/staging/greybus/operation.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/staging/greybus/operation.h b/drivers/staging/greybus/operation.h index 7529f01..bfec1e9 100644 --- a/drivers/staging/greybus/operation.h +++ b/drivers/staging/greybus/operation.h @@ -105,6 +105,8 @@ struct gb_operation { int active; struct list_head links; /* connection->operations */ + + void *private; }; static inline bool @@ -206,6 +208,17 @@ static inline int gb_operation_unidirectional(struct gb_connection *connection, request, request_size, GB_OPERATION_TIMEOUT_DEFAULT); } +static inline void *gb_operation_get_data(struct gb_operation *operation) +{ + return operation->private; +} + +static inline void gb_operation_set_data(struct gb_operation *operation, + void *data) +{ + operation->private = data; +} + int gb_operation_init(void); void gb_operation_exit(void); -- 2.7.4

6 years, 6 months

1
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[PATCH v2 2/4] staging: greybus: loopback: Fix iteration count on async path

by Bryan O'Donoghue

Commit 12927835d211 ("greybus: loopback: Add asynchronous bi-directional support") does what it says on the tin - namely, adds support for asynchronous bi-directional loopback operations. What it neglects to do though is increment the per-connection gb->iteration_count on an asynchronous operation error. This patch fixes that omission. Fixes: 12927835d211 ("greybus: loopback: Add asynchronous bi-directional support") Signed-off-by: Bryan O'Donoghue <pure.logic(a)nexus-software.ie> Reported-by: Mitch Tasman <tasman(a)leaflabs.com> Cc: Johan Hovold <johan(a)kernel.org> Cc: Alex Elder <elder(a)kernel.org> Cc: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Cc: Mitch Tasman <tasman(a)leaflabs.com> Cc: greybus-dev(a)lists.linaro.org Cc: devel(a)driverdev.osuosl.org Cc: linux-kernel(a)vger.kernel.org --- drivers/staging/greybus/loopback.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/staging/greybus/loopback.c b/drivers/staging/greybus/loopback.c index 20d1b45..9c5980c 100644 --- a/drivers/staging/greybus/loopback.c +++ b/drivers/staging/greybus/loopback.c @@ -1021,8 +1021,10 @@ static int gb_loopback_fn(void *data) else if (type == GB_LOOPBACK_TYPE_SINK) error = gb_loopback_async_sink(gb, size); - if (error) + if (error) { gb->error++; + gb->iteration_count++; + } } else { /* We are effectively single threaded here */ if (type == GB_LOOPBACK_TYPE_PING) -- 2.7.4

6 years, 6 months

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[PATCH v2 1/4] staging: greybus: loopback: Hold per-connection mutex across operations

by Bryan O'Donoghue

Commit d9fb3754ecf8 ("greybus: loopback: Relax locking during loopback operations") changes the holding of the per-connection mutex to be less restrictive because at the time of that commit per-connection mutexes were encapsulated by a per-driver level gb_dev.mutex. Commit 8e1d6c336d74 ("greybus: loopback: drop bus aggregate calculation") on the other hand subtracts the driver level gb_dev.mutex but neglects to move the mutex back to the place it was prior to commit d9fb3754ecf8 ("greybus: loopback: Relax locking during loopback operations"), as a result several members of the per connection struct gb_loopback are racy. The solution is restoring the old location of mutex_unlock(&gb->mutex) as it was in commit d9fb3754ecf8 ("greybus: loopback: Relax locking during loopback operations"). Fixes: 8e1d6c336d74 ("greybus: loopback: drop bus aggregate calculation") Signed-off-by: Bryan O'Donoghue <pure.logic(a)nexus-software.ie> Cc: Johan Hovold <johan(a)kernel.org> Cc: Alex Elder <elder(a)kernel.org> Cc: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Cc: Mitch Tasman <tasman(a)leaflabs.com> Cc: greybus-dev(a)lists.linaro.org Cc: devel(a)driverdev.osuosl.org Cc: linux-kernel(a)vger.kernel.or --- drivers/staging/greybus/loopback.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/drivers/staging/greybus/loopback.c b/drivers/staging/greybus/loopback.c index 3d92638..20d1b45 100644 --- a/drivers/staging/greybus/loopback.c +++ b/drivers/staging/greybus/loopback.c @@ -605,7 +605,6 @@ static int gb_loopback_async_operation(struct gb_loopback *gb, int type, op_async->ts = ktime_get(); op_async->pending = true; atomic_inc(&gb->outstanding_operations); - mutex_lock(&gb->mutex); ret = gb_operation_request_send(operation, gb_loopback_async_operation_callback, 0, @@ -622,7 +621,6 @@ static int gb_loopback_async_operation(struct gb_loopback *gb, int type, error: gb_loopback_async_operation_put(op_async); done: - mutex_unlock(&gb->mutex); return ret; } @@ -1013,7 +1011,6 @@ static int gb_loopback_fn(void *data) type = gb->type; if (ktime_to_ns(gb->ts) == 0) gb->ts = ktime_get(); - mutex_unlock(&gb->mutex); /* Else operations to perform */ if (gb->async) { @@ -1041,6 +1038,7 @@ static int gb_loopback_fn(void *data) gb_loopback_calculate_stats(gb, !!error); } gb->send_count++; + mutex_unlock(&gb->mutex); if (us_wait) { if (us_wait < 20000) -- 2.7.4

6 years, 6 months

1
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[PATCH 2/2] staging: greybus: loopback: convert loopback to use generic async operations

by Bryan O'Donoghue

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(a)nexus-software.ie> Cc: Johan Hovold <johan(a)kernel.org> Cc: Alex Elder <elder(a)kernel.org> Cc: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Cc: Kees Cook <keescook(a)chromium.org> Cc: greybus-dev(a)lists.linaro.org Cc: devel(a)driverdev.osuosl.org Cc: linux-kernel(a)vger.kernel.org --- drivers/staging/greybus/loopback.c | 165 +++++++------------------------------ 1 file changed, 31 insertions(+), 134 deletions(-) diff --git a/drivers/staging/greybus/loopback.c b/drivers/staging/greybus/loopback.c index 3d92638..48599ed 100644 --- a/drivers/staging/greybus/loopback.c +++ b/drivers/staging/greybus/loopback.c @@ -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 @@ static int gb_loopback_operation_sync(struct gb_loopback *gb, int type, 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++; } - mutex_unlock(&gb->mutex); - - dev_dbg(&gb->connection->bundle->dev, "complete operation %d\n", - operation->id); - - gb_loopback_async_operation_put(op_async); -} - -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; + gb->iteration_count++; + gb_loopback_calculate_stats(gb, result); - 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", + dev_dbg(&gb->connection->bundle->dev, "complete 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; + /* Wake up waiters */ + atomic_dec(&op_async->gb->outstanding_operations); + wake_up(&gb->wq_completion); - 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 +493,29 @@ 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); + mutex_lock(&gb->mutex); 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); + atomic_dec(&gb->outstanding_operations); + gb_operation_put(operation); + kfree(op_async); done: mutex_unlock(&gb->mutex); return ret; @@ -1024,8 +919,10 @@ static int gb_loopback_fn(void *data) else if (type == GB_LOOPBACK_TYPE_SINK) error = gb_loopback_async_sink(gb, size); - if (error) + if (error) { gb->error++; + gb->iteration_count++; + } } else { /* We are effectively single threaded here */ if (type == GB_LOOPBACK_TYPE_PING) -- 2.7.4

6 years, 6 months

2
2
0 0

[PATCH 1/2] staging: greybus: operation: add private data with get/set accessors

by Bryan O'Donoghue

Asynchronous operation completion handler's lives are made easier if there is a generic pointer that can store private data associated with the operation. This patch adds a pointer field to operation.h and get/set methods to access that pointer. Signed-off-by: Bryan O'Donoghue <pure.logic(a)nexus-software.ie> Cc: Johan Hovold <johan(a)kernel.org> Cc: Alex Elder <elder(a)kernel.org> Cc: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Cc: greybus-dev(a)lists.linaro.org Cc: devel(a)driverdev.osuosl.org Cc: linux-kernel(a)vger.kernel.org --- drivers/staging/greybus/operation.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/staging/greybus/operation.h b/drivers/staging/greybus/operation.h index 7529f01..bfec1e9 100644 --- a/drivers/staging/greybus/operation.h +++ b/drivers/staging/greybus/operation.h @@ -105,6 +105,8 @@ struct gb_operation { int active; struct list_head links; /* connection->operations */ + + void *private; }; static inline bool @@ -206,6 +208,17 @@ static inline int gb_operation_unidirectional(struct gb_connection *connection, request, request_size, GB_OPERATION_TIMEOUT_DEFAULT); } +static inline void *gb_operation_get_data(struct gb_operation *operation) +{ + return operation->private; +} + +static inline void gb_operation_set_data(struct gb_operation *operation, + void *data) +{ + operation->private = data; +} + int gb_operation_init(void); void gb_operation_exit(void); -- 2.7.4

6 years, 6 months

2
1
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