[PATCH 03/11] drm/panfrost: Use xarray and helpers for depedency tracking
Daniel Vetter
daniel at ffwll.ch
Wed Jun 2 18:51:05 UTC 2021
On Wed, Jun 02, 2021 at 03:06:50PM +0100, Steven Price wrote:
> 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.
Thanks for taking a look.
> > ---
> > 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.
Indeed, will fix for the next version.
>
> >
> > 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);
I copypasted this from other drivers, imo consistency is better than
looking pretty. I think eventually we should stuff this as optional
helpers into drm/scheduler.
Also yours walks the xa twice.
-Daniel
>
> 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;
> >
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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