[PATCH v6 3/7] drm/xe: Add xe_exec_queue_last_fence_test_dep

[Matthew Auld]

On 26/06/2024 22:15, Matthew Brost wrote:
> Helpful to determine if a bind can immediately use CPU or needs to be
> deferred a drm scheduler job.
> 
> Signed-off-by: Matthew Brost <matthew.brost at intel.com>
> ---
>   drivers/gpu/drm/xe/xe_exec_queue.c | 23 +++++++++++++++++++++++
>   drivers/gpu/drm/xe/xe_exec_queue.h |  2 ++
>   2 files changed, 25 insertions(+)
> 
> diff --git a/drivers/gpu/drm/xe/xe_exec_queue.c b/drivers/gpu/drm/xe/xe_exec_queue.c
> index 0ba37835849b..65b4d1da6c93 100644
> --- a/drivers/gpu/drm/xe/xe_exec_queue.c
> +++ b/drivers/gpu/drm/xe/xe_exec_queue.c
> @@ -906,3 +906,26 @@ void xe_exec_queue_last_fence_set(struct xe_exec_queue *q, struct xe_vm *vm,
>   	xe_exec_queue_last_fence_put(q, vm);
>   	q->last_fence = dma_fence_get(fence);
>   }
> +
> +/**
> + * xe_exec_queue_last_fence_test_dep - Test last fence dependency of queue
> + * @q: The exec queue
> + * @vm: The VM the engine does a bind or exec for
> + *
> + * Returns:
> + * 0 on success on dependency, -ETIME on dependency

Could maybe improve the wording here?

"-ETIME if there exists an unsignalled last fence dependency, zero 
otherwise."

?

Reviewed-by: Matthew Auld <matthew.auld at intel.com>

> + */
> +int xe_exec_queue_last_fence_test_dep(struct xe_exec_queue *q, struct xe_vm *vm)
> +{
> +	struct dma_fence *fence;
> +	int err = 0;
> +
> +	fence = xe_exec_queue_last_fence_get(q, vm);
> +	if (fence) {
> +		err = test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags) ?
> +			0 : -ETIME;
> +		dma_fence_put(fence);
> +	}
> +
> +	return err;
> +}
> diff --git a/drivers/gpu/drm/xe/xe_exec_queue.h b/drivers/gpu/drm/xe/xe_exec_queue.h
> index 289a3a51d2a2..ded77b0f3b90 100644
> --- a/drivers/gpu/drm/xe/xe_exec_queue.h
> +++ b/drivers/gpu/drm/xe/xe_exec_queue.h
> @@ -75,6 +75,8 @@ struct dma_fence *xe_exec_queue_last_fence_get(struct xe_exec_queue *e,
>   					       struct xe_vm *vm);
>   void xe_exec_queue_last_fence_set(struct xe_exec_queue *e, struct xe_vm *vm,
>   				  struct dma_fence *fence);
> +int xe_exec_queue_last_fence_test_dep(struct xe_exec_queue *q,
> +				      struct xe_vm *vm);
>   void xe_exec_queue_update_run_ticks(struct xe_exec_queue *q);
>   
>   #endif