[RFC 3/5] dma-buf/fence: add .get_fences() ops

[Daniel Vetter]

On Thu, Jun 23, 2016 at 12:29:48PM -0300, Gustavo Padovan wrote:
> From: Gustavo Padovan <gustavo.padovan at collabora.co.uk>
> 
> get_fences() should return a copy of all fences in the fence as some
> fence subclass (such as fence_array) can store more than one fence at
> time.
> 
> Signed-off-by: Gustavo Padovan <gustavo.padovan at collabora.co.uk>
> ---
>  drivers/dma-buf/fence.c | 14 ++++++++++++++
>  include/linux/fence.h   |  3 +++
>  2 files changed, 17 insertions(+)
> 
> diff --git a/drivers/dma-buf/fence.c b/drivers/dma-buf/fence.c
> index 4e61afb..f4094fd 100644
> --- a/drivers/dma-buf/fence.c
> +++ b/drivers/dma-buf/fence.c
> @@ -185,6 +185,20 @@ void fence_release(struct kref *kref)
>  }
>  EXPORT_SYMBOL(fence_release);
>  

kerneldoc missing.
-Daniel

> +struct fence **fence_get_fences(struct fence *fence)
> +{
> +	if (fence->ops->get_fences) {
> +		return fence->ops->get_fences(fence);
> +	} else {
> +		struct fence **fences = kmalloc(sizeof(**fences), GFP_KERNEL);
> +		if (!fences)
> +			return NULL;
> +		fences[0] = fence;
> +		return fences;
> +	}
> +}
> +EXPORT_SYMBOL(fence_get_fences);
> +
>  void fence_teardown(struct fence *fence)
>  {
>  	if (fence->ops->teardown)
> diff --git a/include/linux/fence.h b/include/linux/fence.h
> index 1d3b671..a7a2fbc 100644
> --- a/include/linux/fence.h
> +++ b/include/linux/fence.h
> @@ -111,6 +111,7 @@ struct fence_cb {
>   * struct fence_ops - operations implemented for fence
>   * @get_driver_name: returns the driver name.
>   * @get_timeline_name: return the name of the context this fence belongs to.
> + * @get_fences: return an array with a copy of all fences in the fence.
>   * @enable_signaling: enable software signaling of fence.
>   * @signaled: [optional] peek whether the fence is signaled, can be null.
>   * @wait: custom wait implementation, or fence_default_wait.
> @@ -175,6 +176,7 @@ struct fence_cb {
>  struct fence_ops {
>  	const char * (*get_driver_name)(struct fence *fence);
>  	const char * (*get_timeline_name)(struct fence *fence);
> +	struct fence ** (*get_fences)(struct fence *fence);
>  	bool (*enable_signaling)(struct fence *fence);
>  	bool (*signaled)(struct fence *fence);
>  	signed long (*wait)(struct fence *fence, bool intr, signed long timeout);
> @@ -189,6 +191,7 @@ struct fence_ops {
>  void fence_init(struct fence *fence, const struct fence_ops *ops,
>  		spinlock_t *lock, u64 context, unsigned seqno);
>  
> +struct fence **fence_get_fences(struct fence *fence);
>  void fence_release(struct kref *kref);
>  void fence_teardown(struct fence *fence);
>  void fence_free(struct fence *fence);
> -- 
> 2.5.5
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch