Re: [PATCH 04/11] drm/panfrost: use scheduler dependency tracking

[Steven Price <steven.price@arm.com>]

On 24/06/2021 15:00, Daniel Vetter wrote:
> Just deletes some code that's now more shared.
> 
> Note that thanks to the split into drm_sched_job_init/arm we can now
> easily pull the _init() part from under the submission lock way ahead
> where we're adding the sync file in-fences as dependencies.
> 
> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
> Cc: Rob Herring <robh@kernel.org>
> Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com>
> Cc: Steven Price <steven.price@arm.com>
> Cc: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
> Cc: Sumit Semwal <sumit.semwal@linaro.org>
> Cc: "Christian König" <christian.koenig@amd.com>
> Cc: linux-media@vger.kernel.org
> Cc: linaro-mm-sig@lists.linaro.org
> ---
>  drivers/gpu/drm/panfrost/panfrost_drv.c | 14 +++++++---
>  drivers/gpu/drm/panfrost/panfrost_job.c | 37 +++----------------------
>  drivers/gpu/drm/panfrost/panfrost_job.h |  5 +---
>  3 files changed, 15 insertions(+), 41 deletions(-)

Nice!

Reviewed-by: Steven Price <steven.price@arm.com>

> 
> diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c
> index 1ffaef5ec5ff..79904f55c19f 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_drv.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_drv.c
> @@ -218,7 +218,7 @@ panfrost_copy_in_sync(struct drm_device *dev,
>  		if (ret)
>  			goto fail;
>  
> -		ret = drm_gem_fence_array_add(&job->deps, fence);
> +		ret = drm_sched_job_await_fence(&job->base, fence);
>  
>  		if (ret)
>  			goto fail;
> @@ -236,7 +236,7 @@ static int panfrost_ioctl_submit(struct drm_device *dev, void *data,
>  	struct drm_panfrost_submit *args = data;
>  	struct drm_syncobj *sync_out = NULL;
>  	struct panfrost_job *job;
> -	int ret = 0;
> +	int ret = 0, slot;
>  
>  	if (!args->jc)
>  		return -EINVAL;
> @@ -258,14 +258,20 @@ static int panfrost_ioctl_submit(struct drm_device *dev, void *data,
>  
>  	kref_init(&job->refcount);
>  
> -	xa_init_flags(&job->deps, XA_FLAGS_ALLOC);
> -
>  	job->pfdev = pfdev;
>  	job->jc = args->jc;
>  	job->requirements = args->requirements;
>  	job->flush_id = panfrost_gpu_get_latest_flush_id(pfdev);
>  	job->file_priv = file->driver_priv;
>  
> +	slot = panfrost_job_get_slot(job);
> +
> +	ret = drm_sched_job_init(&job->base,
> +				 &job->file_priv->sched_entity[slot],
> +				 NULL);
> +	if (ret)
> +		goto fail_job;
> +
>  	ret = panfrost_copy_in_sync(dev, file, args, job);
>  	if (ret)
>  		goto fail_job;
> diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panfrost/panfrost_job.c
> index 2d01a670a4e8..d097e52f8caa 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_job.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_job.c
> @@ -109,7 +109,7 @@ static struct dma_fence *panfrost_fence_create(struct panfrost_device *pfdev, in
>  	return &fence->base;
>  }
>  
> -static int panfrost_job_get_slot(struct panfrost_job *job)
> +int panfrost_job_get_slot(struct panfrost_job *job)
>  {
>  	/* JS0: fragment jobs.
>  	 * JS1: vertex/tiler jobs
> @@ -198,13 +198,13 @@ static void panfrost_job_hw_submit(struct panfrost_job *job, int js)
>  
>  static int panfrost_acquire_object_fences(struct drm_gem_object **bos,
>  					  int bo_count,
> -					  struct xarray *deps)
> +					  struct drm_sched_job *job)
>  {
>  	int i, ret;
>  
>  	for (i = 0; i < bo_count; i++) {
>  		/* panfrost always uses write mode in its current uapi */
> -		ret = drm_gem_fence_array_add_implicit(deps, bos[i], true);
> +		ret = drm_sched_job_await_implicit(job, bos[i], true);
>  		if (ret)
>  			return ret;
>  	}
> @@ -225,31 +225,21 @@ static void panfrost_attach_object_fences(struct drm_gem_object **bos,
>  int panfrost_job_push(struct panfrost_job *job)
>  {
>  	struct panfrost_device *pfdev = job->pfdev;
> -	int slot = panfrost_job_get_slot(job);
> -	struct drm_sched_entity *entity = &job->file_priv->sched_entity[slot];
>  	struct ww_acquire_ctx acquire_ctx;
>  	int ret = 0;
>  
> -
>  	ret = drm_gem_lock_reservations(job->bos, job->bo_count,
>  					    &acquire_ctx);
>  	if (ret)
>  		return ret;
>  
>  	mutex_lock(&pfdev->sched_lock);
> -
> -	ret = drm_sched_job_init(&job->base, entity, NULL);
> -	if (ret) {
> -		mutex_unlock(&pfdev->sched_lock);
> -		goto unlock;
> -	}
> -
>  	drm_sched_job_arm(&job->base);
>  
>  	job->render_done_fence = dma_fence_get(&job->base.s_fence->finished);
>  
>  	ret = panfrost_acquire_object_fences(job->bos, job->bo_count,
> -					     &job->deps);
> +					     &job->base);
>  	if (ret) {
>  		mutex_unlock(&pfdev->sched_lock);
>  		goto unlock;
> @@ -274,15 +264,8 @@ static void panfrost_job_cleanup(struct kref *ref)
>  {
>  	struct panfrost_job *job = container_of(ref, struct panfrost_job,
>  						refcount);
> -	struct dma_fence *fence;
> -	unsigned long index;
>  	unsigned int i;
>  
> -	xa_for_each(&job->deps, index, fence) {
> -		dma_fence_put(fence);
> -	}
> -	xa_destroy(&job->deps);
> -
>  	dma_fence_put(job->done_fence);
>  	dma_fence_put(job->render_done_fence);
>  
> @@ -321,17 +304,6 @@ static void panfrost_job_free(struct drm_sched_job *sched_job)
>  	panfrost_job_put(job);
>  }
>  
> -static struct dma_fence *panfrost_job_dependency(struct drm_sched_job *sched_job,
> -						 struct drm_sched_entity *s_entity)
> -{
> -	struct panfrost_job *job = to_panfrost_job(sched_job);
> -
> -	if (!xa_empty(&job->deps))
> -		return xa_erase(&job->deps, job->last_dep++);
> -
> -	return NULL;
> -}
> -
>  static struct dma_fence *panfrost_job_run(struct drm_sched_job *sched_job)
>  {
>  	struct panfrost_job *job = to_panfrost_job(sched_job);
> @@ -457,7 +429,6 @@ static enum drm_gpu_sched_stat panfrost_job_timedout(struct drm_sched_job
>  }
>  
>  static const struct drm_sched_backend_ops panfrost_sched_ops = {
> -	.dependency = panfrost_job_dependency,
>  	.run_job = panfrost_job_run,
>  	.timedout_job = panfrost_job_timedout,
>  	.free_job = panfrost_job_free
> diff --git a/drivers/gpu/drm/panfrost/panfrost_job.h b/drivers/gpu/drm/panfrost/panfrost_job.h
> index 82306a03b57e..77e6d0e6f612 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_job.h
> +++ b/drivers/gpu/drm/panfrost/panfrost_job.h
> @@ -19,10 +19,6 @@ struct panfrost_job {
>  	struct panfrost_device *pfdev;
>  	struct panfrost_file_priv *file_priv;
>  
> -	/* Contains both explicit and implicit fences */
> -	struct xarray deps;
> -	unsigned long last_dep;
> -
>  	/* Fence to be signaled by IRQ handler when the job is complete. */
>  	struct dma_fence *done_fence;
>  
> @@ -42,6 +38,7 @@ int panfrost_job_init(struct panfrost_device *pfdev);
>  void panfrost_job_fini(struct panfrost_device *pfdev);
>  int panfrost_job_open(struct panfrost_file_priv *panfrost_priv);
>  void panfrost_job_close(struct panfrost_file_priv *panfrost_priv);
> +int panfrost_job_get_slot(struct panfrost_job *job);
>  int panfrost_job_push(struct panfrost_job *job);
>  void panfrost_job_put(struct panfrost_job *job);
>  void panfrost_job_enable_interrupts(struct panfrost_device *pfdev);
>