[PATCH 03/11] drm/panfrost: Use xarray and helpers for depedency tracking
Steven Price
steven.price at arm.com
Wed Jun 2 14:06:50 UTC 2021
On 21/05/2021 10:09, Daniel Vetter wrote:
> More consistency and prep work for the next patch.
>
> Aside: I wonder whether we shouldn't just move this entire xarray
> business into the scheduler so that not everyone has to reinvent the
> same wheels. Cc'ing some scheduler people for this too.
>
> Cc: "Christian König" <christian.koenig at amd.com>
> Cc: Luben Tuikov <luben.tuikov at amd.com>
> Cc: Alex Deucher <alexander.deucher at amd.com>
> Cc: Lee Jones <lee.jones at linaro.org>
> Cc: Steven Price <steven.price at arm.com>
> Cc: Rob Herring <robh at kernel.org>
> Cc: Tomeu Vizoso <tomeu.vizoso at collabora.com>
> Cc: Alyssa Rosenzweig <alyssa.rosenzweig at collabora.com>
> Cc: Sumit Semwal <sumit.semwal at linaro.org>
> Cc: linux-media at vger.kernel.org
> Cc: linaro-mm-sig at lists.linaro.org
> Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
Two comments below, but otherwise looks like a nice cleanup.
> ---
> drivers/gpu/drm/panfrost/panfrost_drv.c | 41 ++++++++---------
> drivers/gpu/drm/panfrost/panfrost_job.c | 61 ++++++++++---------------
> drivers/gpu/drm/panfrost/panfrost_job.h | 8 ++--
> 3 files changed, 46 insertions(+), 64 deletions(-)
>
> diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c
> index ca07098a6141..7977b4752b5c 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_drv.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_drv.c
> @@ -137,12 +137,6 @@ panfrost_lookup_bos(struct drm_device *dev,
> if (!job->bo_count)
> return 0;
>
> - job->implicit_fences = kvmalloc_array(job->bo_count,
> - sizeof(struct dma_fence *),
> - GFP_KERNEL | __GFP_ZERO);
> - if (!job->implicit_fences)
> - return -ENOMEM;
> -
> ret = drm_gem_objects_lookup(file_priv,
> (void __user *)(uintptr_t)args->bo_handles,
> job->bo_count, &job->bos);
> @@ -173,7 +167,7 @@ panfrost_lookup_bos(struct drm_device *dev,
> }
>
> /**
> - * panfrost_copy_in_sync() - Sets up job->in_fences[] with the sync objects
> + * panfrost_copy_in_sync() - Sets up job->deps with the sync objects
> * referenced by the job.
> * @dev: DRM device
> * @file_priv: DRM file for this fd
> @@ -193,22 +187,14 @@ panfrost_copy_in_sync(struct drm_device *dev,
> {
> u32 *handles;
> int ret = 0;
> - int i;
> + int i, in_fence_count;
>
> - job->in_fence_count = args->in_sync_count;
> + in_fence_count = args->in_sync_count;
>
> - if (!job->in_fence_count)
> + if (!in_fence_count)
> return 0;
>
> - job->in_fences = kvmalloc_array(job->in_fence_count,
> - sizeof(struct dma_fence *),
> - GFP_KERNEL | __GFP_ZERO);
> - if (!job->in_fences) {
> - DRM_DEBUG("Failed to allocate job in fences\n");
> - return -ENOMEM;
> - }
> -
> - handles = kvmalloc_array(job->in_fence_count, sizeof(u32), GFP_KERNEL);
> + handles = kvmalloc_array(in_fence_count, sizeof(u32), GFP_KERNEL);
> if (!handles) {
> ret = -ENOMEM;
> DRM_DEBUG("Failed to allocate incoming syncobj handles\n");
> @@ -217,16 +203,23 @@ panfrost_copy_in_sync(struct drm_device *dev,
>
> if (copy_from_user(handles,
> (void __user *)(uintptr_t)args->in_syncs,
> - job->in_fence_count * sizeof(u32))) {
> + in_fence_count * sizeof(u32))) {
> ret = -EFAULT;
> DRM_DEBUG("Failed to copy in syncobj handles\n");
> goto fail;
> }
>
> - for (i = 0; i < job->in_fence_count; i++) {
> + for (i = 0; i < in_fence_count; i++) {
> + struct dma_fence *fence;
> +
> ret = drm_syncobj_find_fence(file_priv, handles[i], 0, 0,
> - &job->in_fences[i]);
> - if (ret == -EINVAL)
> + &fence);
> + if (ret)
> + goto fail;
> +
> + ret = drm_gem_fence_array_add(&job->deps, fence);
> +
> + if (ret)
> goto fail;
> }
>
> @@ -264,6 +257,8 @@ 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;
> diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panfrost/panfrost_job.c
> index f5d39ee14ab5..707d912ff64a 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_job.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_job.c
> @@ -196,14 +196,21 @@ static void panfrost_job_hw_submit(struct panfrost_job *job, int js)
> job_write(pfdev, JS_COMMAND_NEXT(js), JS_COMMAND_START);
> }
>
> -static void panfrost_acquire_object_fences(struct drm_gem_object **bos,
> - int bo_count,
> - struct dma_fence **implicit_fences)
> +static int panfrost_acquire_object_fences(struct drm_gem_object **bos,
> + int bo_count,
> + struct xarray *deps)
> {
> - int i;
> + int i, ret;
>
> - for (i = 0; i < bo_count; i++)
> - implicit_fences[i] = dma_resv_get_excl_rcu(bos[i]->resv);
> + for (i = 0; i < bo_count; i++) {
> + struct dma_fence *fence = dma_resv_get_excl_rcu(bos[i]->resv);
> +
> + ret = drm_gem_fence_array_add(deps, fence);
> + if (ret)
> + return ret;
> + }
> +
> + return 0;
> }
>
> static void panfrost_attach_object_fences(struct drm_gem_object **bos,
> @@ -236,8 +243,10 @@ int panfrost_job_push(struct panfrost_job *job)
>
> kref_get(&job->refcount); /* put by scheduler job completion */
>
> - panfrost_acquire_object_fences(job->bos, job->bo_count,
> - job->implicit_fences);
> + ret = panfrost_acquire_object_fences(job->bos, job->bo_count,
> + &job->deps);
> + if (ret)
> + goto unlock;
I think this needs to move above the kref_get() otherwise we'll leak the
job on failure.
>
> drm_sched_entity_push_job(&job->base, entity);
>
> @@ -254,18 +263,15 @@ 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;
>
> - if (job->in_fences) {
> - for (i = 0; i < job->in_fence_count; i++)
> - dma_fence_put(job->in_fences[i]);
> - kvfree(job->in_fences);
> - }
> - if (job->implicit_fences) {
> - for (i = 0; i < job->bo_count; i++)
> - dma_fence_put(job->implicit_fences[i]);
> - kvfree(job->implicit_fences);
> + 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);
>
> @@ -308,26 +314,9 @@ 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);
> - struct dma_fence *fence;
> - unsigned int i;
>
> - /* Explicit fences */
> - for (i = 0; i < job->in_fence_count; i++) {
> - if (job->in_fences[i]) {
> - fence = job->in_fences[i];
> - job->in_fences[i] = NULL;
> - return fence;
> - }
> - }
> -
> - /* Implicit fences, max. one per BO */
> - for (i = 0; i < job->bo_count; i++) {
> - if (job->implicit_fences[i]) {
> - fence = job->implicit_fences[i];
> - job->implicit_fences[i] = NULL;
> - return fence;
> - }
> - }
> + if (!xa_empty(&job->deps))
> + return xa_erase(&job->deps, job->last_dep++);
Rather than tracking last_dep separately this could be written using
xa_find():
if (xa_find(&job->deps, &i, ULONG_MAX, XA_PRESENT))
return xa_erase(&job->deps, &i);
Steve
>
> return NULL;
> }
> diff --git a/drivers/gpu/drm/panfrost/panfrost_job.h b/drivers/gpu/drm/panfrost/panfrost_job.h
> index bbd3ba97ff67..82306a03b57e 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_job.h
> +++ b/drivers/gpu/drm/panfrost/panfrost_job.h
> @@ -19,9 +19,9 @@ struct panfrost_job {
> struct panfrost_device *pfdev;
> struct panfrost_file_priv *file_priv;
>
> - /* Optional fences userspace can pass in for the job to depend on. */
> - struct dma_fence **in_fences;
> - u32 in_fence_count;
> + /* 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;
> @@ -30,8 +30,6 @@ struct panfrost_job {
> __u32 requirements;
> __u32 flush_id;
>
> - /* Exclusive fences we have taken from the BOs to wait for */
> - struct dma_fence **implicit_fences;
> struct panfrost_gem_mapping **mappings;
> struct drm_gem_object **bos;
> u32 bo_count;
>
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