[PATCH v3 1/2] dma-buf: Split out dma fence array create into alloc and arm functions
Christian König
christian.koenig at amd.com
Fri Aug 23 06:37:30 UTC 2024
Am 23.08.24 um 06:54 schrieb Matthew Brost:
> Useful to preallocate dma fence array and then arm in path of reclaim or
> a dma fence.
Exactly that was rejected before because it allows to create circle
dependencies.
You would need a really really good argument why that is necessary.
Regards,
Christian.
>
> Cc: Sumit Semwal <sumit.semwal at linaro.org>
> Cc: Christian König <christian.koenig at amd.com>
> Signed-off-by: Matthew Brost <matthew.brost at intel.com>
> ---
> drivers/dma-buf/dma-fence-array.c | 81 ++++++++++++++++++++++---------
> include/linux/dma-fence-array.h | 7 +++
> 2 files changed, 66 insertions(+), 22 deletions(-)
>
> diff --git a/drivers/dma-buf/dma-fence-array.c b/drivers/dma-buf/dma-fence-array.c
> index c74ac197d5fe..b03e0a87a5cd 100644
> --- a/drivers/dma-buf/dma-fence-array.c
> +++ b/drivers/dma-buf/dma-fence-array.c
> @@ -144,36 +144,38 @@ const struct dma_fence_ops dma_fence_array_ops = {
> EXPORT_SYMBOL(dma_fence_array_ops);
>
> /**
> - * dma_fence_array_create - Create a custom fence array
> + * dma_fence_array_alloc - Allocate a custom fence array
> + * @num_fences: [in] number of fences to add in the array
> + *
> + * Return dma fence array on success, NULL on failure
> + */
> +struct dma_fence_array *dma_fence_array_alloc(int num_fences)
> +{
> + struct dma_fence_array *array;
> +
> + return kzalloc(struct_size(array, callbacks, num_fences), GFP_KERNEL);
> +}
> +EXPORT_SYMBOL(dma_fence_array_alloc);
> +
> +/**
> + * dma_fence_array_arm - Arm a custom fence array
> + * @array: [in] dma fence array to arm
> * @num_fences: [in] number of fences to add in the array
> * @fences: [in] array containing the fences
> * @context: [in] fence context to use
> * @seqno: [in] sequence number to use
> * @signal_on_any: [in] signal on any fence in the array
> *
> - * Allocate a dma_fence_array object and initialize the base fence with
> - * dma_fence_init().
> - * In case of error it returns NULL.
> - *
> - * The caller should allocate the fences array with num_fences size
> - * and fill it with the fences it wants to add to the object. Ownership of this
> - * array is taken and dma_fence_put() is used on each fence on release.
> - *
> - * If @signal_on_any is true the fence array signals if any fence in the array
> - * signals, otherwise it signals when all fences in the array signal.
> + * Implementation of @dma_fence_array_create without allocation. Useful to arm a
> + * preallocated dma fence fence in the path of reclaim or dma fence signaling.
> */
> -struct dma_fence_array *dma_fence_array_create(int num_fences,
> - struct dma_fence **fences,
> - u64 context, unsigned seqno,
> - bool signal_on_any)
> +void dma_fence_array_arm(struct dma_fence_array *array,
> + int num_fences,
> + struct dma_fence **fences,
> + u64 context, unsigned seqno,
> + bool signal_on_any)
> {
> - struct dma_fence_array *array;
> -
> - WARN_ON(!num_fences || !fences);
> -
> - array = kzalloc(struct_size(array, callbacks, num_fences), GFP_KERNEL);
> - if (!array)
> - return NULL;
> + WARN_ON(!array || !num_fences || !fences);
>
> array->num_fences = num_fences;
>
> @@ -200,6 +202,41 @@ struct dma_fence_array *dma_fence_array_create(int num_fences,
> */
> while (num_fences--)
> WARN_ON(dma_fence_is_container(fences[num_fences]));
> +}
> +EXPORT_SYMBOL(dma_fence_array_arm);
> +
> +/**
> + * dma_fence_array_create - Create a custom fence array
> + * @num_fences: [in] number of fences to add in the array
> + * @fences: [in] array containing the fences
> + * @context: [in] fence context to use
> + * @seqno: [in] sequence number to use
> + * @signal_on_any: [in] signal on any fence in the array
> + *
> + * Allocate a dma_fence_array object and initialize the base fence with
> + * dma_fence_init().
> + * In case of error it returns NULL.
> + *
> + * The caller should allocate the fences array with num_fences size
> + * and fill it with the fences it wants to add to the object. Ownership of this
> + * array is taken and dma_fence_put() is used on each fence on release.
> + *
> + * If @signal_on_any is true the fence array signals if any fence in the array
> + * signals, otherwise it signals when all fences in the array signal.
> + */
> +struct dma_fence_array *dma_fence_array_create(int num_fences,
> + struct dma_fence **fences,
> + u64 context, unsigned seqno,
> + bool signal_on_any)
> +{
> + struct dma_fence_array *array;
> +
> + array = dma_fence_array_alloc(num_fences);
> + if (!array)
> + return NULL;
> +
> + dma_fence_array_arm(array, num_fences, fences,
> + context, seqno, signal_on_any);
>
> return array;
> }
> diff --git a/include/linux/dma-fence-array.h b/include/linux/dma-fence-array.h
> index 29c5650c1038..3466ffc4b803 100644
> --- a/include/linux/dma-fence-array.h
> +++ b/include/linux/dma-fence-array.h
> @@ -79,6 +79,13 @@ to_dma_fence_array(struct dma_fence *fence)
> for (index = 0, fence = dma_fence_array_first(head); fence; \
> ++(index), fence = dma_fence_array_next(head, index))
>
> +struct dma_fence_array *dma_fence_array_alloc(int num_fences);
> +void dma_fence_array_arm(struct dma_fence_array *array,
> + int num_fences,
> + struct dma_fence **fences,
> + u64 context, unsigned seqno,
> + bool signal_on_any);
> +
> struct dma_fence_array *dma_fence_array_create(int num_fences,
> struct dma_fence **fences,
> u64 context, unsigned seqno,
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