[PATCH v2 1/4] dma-fence: add dma_fence_match_context helper

[Christian König]

Am 17.03.2017 um 17:34 schrieb Philipp Zabel:
> Add a helper to check if all fences in a fence array are from a given
> context. For convenience, the function can also handle being given a
> non-array fence.
>
> Signed-off-by: Philipp Zabel <p.zabel at pengutronix.de>

Reviewed-by: Christian König <christian.koenig at amd.com>

> ---
>   drivers/dma-buf/dma-fence-array.c | 26 ++++++++++++++++++++++++++
>   include/linux/dma-fence-array.h   |  2 ++
>   2 files changed, 28 insertions(+)
>
> diff --git a/drivers/dma-buf/dma-fence-array.c b/drivers/dma-buf/dma-fence-array.c
> index 67eb7c8fb88c3..0350829ba62e7 100644
> --- a/drivers/dma-buf/dma-fence-array.c
> +++ b/drivers/dma-buf/dma-fence-array.c
> @@ -144,3 +144,29 @@ struct dma_fence_array *dma_fence_array_create(int num_fences,
>   	return array;
>   }
>   EXPORT_SYMBOL(dma_fence_array_create);
> +
> +/**
> + * dma_fence_match_context - Check if all fences are from the given context
> + * @fence:		[in]	fence or fence array
> + * @context:		[in]	fence context to check all fences against
> + *
> + * Checks the provided fence or, for a fence array, all fences in the array
> + * against the given context. Returns false if any fence is from a different
> + * context.
> + */
> +bool dma_fence_match_context(struct dma_fence *fence, u64 context)
> +{
> +	struct dma_fence_array *array = to_dma_fence_array(fence);
> +	unsigned i;
> +
> +	if (!dma_fence_is_array(fence))
> +		return fence->context == context;
> +
> +	for (i = 0; i < array->num_fences; i++) {
> +		if (array->fences[i]->context != context)
> +			return false;
> +	}
> +
> +	return true;
> +}
> +EXPORT_SYMBOL(dma_fence_match_context);
> diff --git a/include/linux/dma-fence-array.h b/include/linux/dma-fence-array.h
> index 5900945f962dd..332a5420243c4 100644
> --- a/include/linux/dma-fence-array.h
> +++ b/include/linux/dma-fence-array.h
> @@ -83,4 +83,6 @@ struct dma_fence_array *dma_fence_array_create(int num_fences,
>   					       u64 context, unsigned seqno,
>   					       bool signal_on_any);
>   
> +bool dma_fence_match_context(struct dma_fence *fence, u64 context);
> +
>   #endif /* __LINUX_DMA_FENCE_ARRAY_H */