This is a very confusingly named function, because not just does it init an object, it arms it and provides a point of no return for pushing a job into the scheduler. It would be nice if that's a bit clearer in the interface.

But the real reason is that I want to push the dependency tracking helpers into the scheduler code, and that means drm_sched_job_init must be called a lot earlier, without arming the job.

v2: - don't change .gitignore (Steven) - don't forget v3d (Emma)

v3: Emma noticed that I leak the memory allocated in drm_sched_job_init if we bail out before the point of no return in subsequent driver patches. To be able to fix this change drm_sched_job_cleanup() so it can handle being called both before and after drm_sched_job_arm().

Also improve the kerneldoc for this.

v4: - Fix the drm_sched_job_cleanup logic, I inverted the booleans, as usual (Melissa)

- Christian pointed out that drm_sched_entity_select_rq() also needs to be moved into drm_sched_job_arm, which made me realize that the job->id definitely needs to be moved too.

Shuffle things to fit between job_init and job_arm.

v5: Reshuffle the split between init/arm once more, amdgpu abuses drm_sched.ready to signal gpu reset failures. Also document this somewhat. (Christian)

Cc: Melissa Wen melissa.srw@gmail.com Acked-by: Steven Price steven.price@arm.com (v2) Signed-off-by: Daniel Vetter daniel.vetter@intel.com Cc: Lucas Stach l.stach@pengutronix.de Cc: Russell King linux+etnaviv@armlinux.org.uk Cc: Christian Gmeiner christian.gmeiner@gmail.com Cc: Qiang Yu yuq825@gmail.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: David Airlie airlied@linux.ie Cc: Daniel Vetter daniel@ffwll.ch Cc: Sumit Semwal sumit.semwal@linaro.org Cc: "Christian König" christian.koenig@amd.com Cc: Masahiro Yamada masahiroy@kernel.org Cc: Kees Cook keescook@chromium.org Cc: Adam Borowski kilobyte@angband.pl Cc: Nick Terrell terrelln@fb.com Cc: Mauro Carvalho Chehab mchehab+huawei@kernel.org Cc: Paul Menzel pmenzel@molgen.mpg.de Cc: Sami Tolvanen samitolvanen@google.com Cc: Viresh Kumar viresh.kumar@linaro.org Cc: Alex Deucher alexander.deucher@amd.com Cc: Dave Airlie airlied@redhat.com Cc: Nirmoy Das nirmoy.das@amd.com Cc: Deepak R Varma mh12gx2825@gmail.com Cc: Lee Jones lee.jones@linaro.org Cc: Kevin Wang kevin1.wang@amd.com Cc: Chen Li chenli@uniontech.com Cc: Luben Tuikov luben.tuikov@amd.com Cc: "Marek Olšák" marek.olsak@amd.com Cc: Dennis Li Dennis.Li@amd.com Cc: Maarten Lankhorst maarten.lankhorst@linux.intel.com Cc: Andrey Grodzovsky andrey.grodzovsky@amd.com Cc: Sonny Jiang sonny.jiang@amd.com Cc: Boris Brezillon boris.brezillon@collabora.com Cc: Tian Tao tiantao6@hisilicon.com Cc: etnaviv@lists.freedesktop.org Cc: lima@lists.freedesktop.org Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org Cc: Emma Anholt emma@anholt.net --- drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c | 2 + drivers/gpu/drm/amd/amdgpu/amdgpu_job.c | 2 + drivers/gpu/drm/etnaviv/etnaviv_sched.c | 2 + drivers/gpu/drm/lima/lima_sched.c | 2 + drivers/gpu/drm/panfrost/panfrost_job.c | 2 + drivers/gpu/drm/scheduler/sched_entity.c | 6 +-- drivers/gpu/drm/scheduler/sched_fence.c | 19 ++++--- drivers/gpu/drm/scheduler/sched_main.c | 69 ++++++++++++++++++++---- drivers/gpu/drm/v3d/v3d_gem.c | 2 + include/drm/gpu_scheduler.h | 7 ++- 10 files changed, 91 insertions(+), 22 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c index c5386d13eb4a..a4ec092af9a7 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c @@ -1226,6 +1226,8 @@ static int amdgpu_cs_submit(struct amdgpu_cs_parser *p, if (r) goto error_unlock;

+ drm_sched_job_arm(&job->base); + /* No memory allocation is allowed while holding the notifier lock. * The lock is held until amdgpu_cs_submit is finished and fence is * added to BOs. diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c index d33e6d97cc89..5ddb955d2315 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c @@ -170,6 +170,8 @@ int amdgpu_job_submit(struct amdgpu_job *job, struct drm_sched_entity *entity, if (r) return r;

+ drm_sched_job_arm(&job->base); + *f = dma_fence_get(&job->base.s_fence->finished); amdgpu_job_free_resources(job); drm_sched_entity_push_job(&job->base, entity); diff --git a/drivers/gpu/drm/etnaviv/etnaviv_sched.c b/drivers/gpu/drm/etnaviv/etnaviv_sched.c index feb6da1b6ceb..05f412204118 100644 --- a/drivers/gpu/drm/etnaviv/etnaviv_sched.c +++ b/drivers/gpu/drm/etnaviv/etnaviv_sched.c @@ -163,6 +163,8 @@ int etnaviv_sched_push_job(struct drm_sched_entity *sched_entity, if (ret) goto out_unlock;

+ drm_sched_job_arm(&submit->sched_job); + submit->out_fence = dma_fence_get(&submit->sched_job.s_fence->finished); submit->out_fence_id = idr_alloc_cyclic(&submit->gpu->fence_idr, submit->out_fence, 0, diff --git a/drivers/gpu/drm/lima/lima_sched.c b/drivers/gpu/drm/lima/lima_sched.c index dba8329937a3..38f755580507 100644 --- a/drivers/gpu/drm/lima/lima_sched.c +++ b/drivers/gpu/drm/lima/lima_sched.c @@ -129,6 +129,8 @@ int lima_sched_task_init(struct lima_sched_task *task, return err; }

+ drm_sched_job_arm(&task->base); + task->num_bos = num_bos; task->vm = lima_vm_get(vm);

diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panfrost/panfrost_job.c index 71a72fb50e6b..2992dc85325f 100644 --- a/drivers/gpu/drm/panfrost/panfrost_job.c +++ b/drivers/gpu/drm/panfrost/panfrost_job.c @@ -288,6 +288,8 @@ int panfrost_job_push(struct panfrost_job *job) 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, diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c index 79554aa4dbb1..f7347c284886 100644 --- a/drivers/gpu/drm/scheduler/sched_entity.c +++ b/drivers/gpu/drm/scheduler/sched_entity.c @@ -485,9 +485,9 @@ void drm_sched_entity_select_rq(struct drm_sched_entity *entity) * @sched_job: job to submit * @entity: scheduler entity * - * Note: To guarantee that the order of insertion to queue matches - * the job's fence sequence number this function should be - * called with drm_sched_job_init under common lock. + * Note: To guarantee that the order of insertion to queue matches the job's + * fence sequence number this function should be called with drm_sched_job_arm() + * under common lock. * * Returns 0 for success, negative error code otherwise. */ diff --git a/drivers/gpu/drm/scheduler/sched_fence.c b/drivers/gpu/drm/scheduler/sched_fence.c index 69de2c76731f..bcea035cf4c6 100644 --- a/drivers/gpu/drm/scheduler/sched_fence.c +++ b/drivers/gpu/drm/scheduler/sched_fence.c @@ -90,7 +90,7 @@ static const char *drm_sched_fence_get_timeline_name(struct dma_fence *f) * * Free up the fence memory after the RCU grace period. */ -static void drm_sched_fence_free(struct rcu_head *rcu) +void drm_sched_fence_free(struct rcu_head *rcu) { struct dma_fence *f = container_of(rcu, struct dma_fence, rcu); struct drm_sched_fence *fence = to_drm_sched_fence(f); @@ -152,27 +152,32 @@ struct drm_sched_fence *to_drm_sched_fence(struct dma_fence *f) } EXPORT_SYMBOL(to_drm_sched_fence);

-struct drm_sched_fence *drm_sched_fence_create(struct drm_sched_entity *entity, - void *owner) +struct drm_sched_fence *drm_sched_fence_alloc(struct drm_sched_entity *entity, + void *owner) { struct drm_sched_fence *fence = NULL; - unsigned seq;

fence = kmem_cache_zalloc(sched_fence_slab, GFP_KERNEL); if (fence == NULL) return NULL;

fence->owner = owner; - fence->sched = entity->rq->sched; spin_lock_init(&fence->lock);

+ return fence; +} + +void drm_sched_fence_init(struct drm_sched_fence *fence, + struct drm_sched_entity *entity) +{ + unsigned seq; + + fence->sched = entity->rq->sched; seq = atomic_inc_return(&entity->fence_seq); dma_fence_init(&fence->scheduled, &drm_sched_fence_ops_scheduled, &fence->lock, entity->fence_context, seq); dma_fence_init(&fence->finished, &drm_sched_fence_ops_finished, &fence->lock, entity->fence_context + 1, seq); - - return fence; }

module_init(drm_sched_fence_slab_init); diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c index 33c414d55fab..454cb6164bdc 100644 --- a/drivers/gpu/drm/scheduler/sched_main.c +++ b/drivers/gpu/drm/scheduler/sched_main.c @@ -48,9 +48,11 @@ #include <linux/wait.h> #include <linux/sched.h> #include <linux/completion.h> +#include <linux/dma-resv.h> #include <uapi/linux/sched/types.h>

#include <drm/drm_print.h> +#include <drm/drm_gem.h> #include <drm/gpu_scheduler.h> #include <drm/spsc_queue.h>

@@ -569,7 +571,6 @@ EXPORT_SYMBOL(drm_sched_resubmit_jobs_ext);

/** * drm_sched_job_init - init a scheduler job - * * @job: scheduler job to init * @entity: scheduler entity to use * @owner: job owner for debugging @@ -577,27 +578,28 @@ EXPORT_SYMBOL(drm_sched_resubmit_jobs_ext); * Refer to drm_sched_entity_push_job() documentation * for locking considerations. * + * Drivers must make sure drm_sched_job_cleanup() if this function returns + * successfully, even when @job is aborted before drm_sched_job_arm() is called. + * + * WARNING: amdgpu abuses &drm_sched.ready to signal when the hardware + * has died, which can mean that there's no valid runqueue for a @entity. + * This function returns -ENOENT in this case (which probably should be -EIO as + * a more meanigful return value). + * * Returns 0 for success, negative error code otherwise. */ int drm_sched_job_init(struct drm_sched_job *job, struct drm_sched_entity *entity, void *owner) { - struct drm_gpu_scheduler *sched; - drm_sched_entity_select_rq(entity); if (!entity->rq) return -ENOENT;

- sched = entity->rq->sched; - - job->sched = sched; job->entity = entity; - job->s_priority = entity->rq - sched->sched_rq; - job->s_fence = drm_sched_fence_create(entity, owner); + job->s_fence = drm_sched_fence_alloc(entity, owner); if (!job->s_fence) return -ENOMEM; - job->id = atomic64_inc_return(&sched->job_id_count);

INIT_LIST_HEAD(&job->list);

@@ -606,13 +608,58 @@ int drm_sched_job_init(struct drm_sched_job *job, EXPORT_SYMBOL(drm_sched_job_init);

/** - * drm_sched_job_cleanup - clean up scheduler job resources + * drm_sched_job_arm - arm a scheduler job for execution + * @job: scheduler job to arm + * + * This arms a scheduler job for execution. Specifically it initializes the + * &drm_sched_job.s_fence of @job, so that it can be attached to struct dma_resv + * or other places that need to track the completion of this job. + * + * Refer to drm_sched_entity_push_job() documentation for locking + * considerations. * + * This can only be called if drm_sched_job_init() succeeded. + */ +void drm_sched_job_arm(struct drm_sched_job *job) +{ + struct drm_gpu_scheduler *sched; + struct drm_sched_entity *entity = job->entity; + + BUG_ON(!entity); + + sched = entity->rq->sched; + + job->sched = sched; + job->s_priority = entity->rq - sched->sched_rq; + job->id = atomic64_inc_return(&sched->job_id_count); + + drm_sched_fence_init(job->s_fence, job->entity); +} +EXPORT_SYMBOL(drm_sched_job_arm); + +/** + * drm_sched_job_cleanup - clean up scheduler job resources * @job: scheduler job to clean up + * + * Cleans up the resources allocated with drm_sched_job_init(). + * + * Drivers should call this from their error unwind code if @job is aborted + * before drm_sched_job_arm() is called. + * + * After that point of no return @job is committed to be executed by the + * scheduler, and this function should be called from the + * &drm_sched_backend_ops.free_job callback. */ void drm_sched_job_cleanup(struct drm_sched_job *job) { - dma_fence_put(&job->s_fence->finished); + if (kref_read(&job->s_fence->finished.refcount)) { + /* drm_sched_job_arm() has been called */ + dma_fence_put(&job->s_fence->finished); + } else { + /* aborted job before committing to run it */ + drm_sched_fence_free(&job->s_fence->finished.rcu); + } + job->s_fence = NULL; } EXPORT_SYMBOL(drm_sched_job_cleanup); diff --git a/drivers/gpu/drm/v3d/v3d_gem.c b/drivers/gpu/drm/v3d/v3d_gem.c index 4eb354226972..5c3a99027ecd 100644 --- a/drivers/gpu/drm/v3d/v3d_gem.c +++ b/drivers/gpu/drm/v3d/v3d_gem.c @@ -475,6 +475,8 @@ v3d_push_job(struct v3d_file_priv *v3d_priv, if (ret) return ret;

+ drm_sched_job_arm(&job->base); + job->done_fence = dma_fence_get(&job->base.s_fence->finished);

/* put by scheduler job completion */ diff --git a/include/drm/gpu_scheduler.h b/include/drm/gpu_scheduler.h index 88ae7f331bb1..83afc3aa8e2f 100644 --- a/include/drm/gpu_scheduler.h +++ b/include/drm/gpu_scheduler.h @@ -348,6 +348,7 @@ void drm_sched_fini(struct drm_gpu_scheduler *sched); int drm_sched_job_init(struct drm_sched_job *job, struct drm_sched_entity *entity, void *owner); +void drm_sched_job_arm(struct drm_sched_job *job); void drm_sched_entity_modify_sched(struct drm_sched_entity *entity, struct drm_gpu_scheduler **sched_list, unsigned int num_sched_list); @@ -387,8 +388,12 @@ void drm_sched_entity_set_priority(struct drm_sched_entity *entity, enum drm_sched_priority priority); bool drm_sched_entity_is_ready(struct drm_sched_entity *entity);

-struct drm_sched_fence *drm_sched_fence_create( +struct drm_sched_fence *drm_sched_fence_alloc( struct drm_sched_entity *s_entity, void *owner); +void drm_sched_fence_init(struct drm_sched_fence *fence, + struct drm_sched_entity *entity); +void drm_sched_fence_free(struct rcu_head *rcu); + void drm_sched_fence_scheduled(struct drm_sched_fence *fence); void drm_sched_fence_finished(struct drm_sched_fence *fence);

It might be good enough on x86 with just READ_ONCE, but the write side should then at least be WRITE_ONCE because x86 has total store order.

It's definitely not enough on arm.

Fix this proplery, which means - explain the need for the barrier in both places - point at the other side in each comment

Also pull out the !sched_list case as the first check, so that the code flow is clearer.

While at it sprinkle some comments around because it was very non-obvious to me what's actually going on here and why.

Note that we really need full barriers here, at first I thought store-release and load-acquire on ->last_scheduled would be enough, but we actually requiring ordering between that and the queue state.

v2: Put smp_rmp() in the right place and fix up comment (Andrey)

Signed-off-by: Daniel Vetter daniel.vetter@intel.com Cc: "Christian König" christian.koenig@amd.com Cc: Steven Price steven.price@arm.com Cc: Daniel Vetter daniel.vetter@ffwll.ch Cc: Andrey Grodzovsky andrey.grodzovsky@amd.com Cc: Lee Jones lee.jones@linaro.org Cc: Boris Brezillon boris.brezillon@collabora.com --- drivers/gpu/drm/scheduler/sched_entity.c | 27 ++++++++++++++++++++++-- 1 file changed, 25 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c index f7347c284886..89e3f6eaf519 100644 --- a/drivers/gpu/drm/scheduler/sched_entity.c +++ b/drivers/gpu/drm/scheduler/sched_entity.c @@ -439,8 +439,16 @@ struct drm_sched_job *drm_sched_entity_pop_job(struct drm_sched_entity *entity) dma_fence_set_error(&sched_job->s_fence->finished, -ECANCELED);

dma_fence_put(entity->last_scheduled); + entity->last_scheduled = dma_fence_get(&sched_job->s_fence->finished);

+ /* + * If the queue is empty we allow drm_sched_entity_select_rq() to + * locklessly access ->last_scheduled. This only works if we set the + * pointer before we dequeue and if we a write barrier here. + */ + smp_wmb(); + spsc_queue_pop(&entity->job_queue); return sched_job; } @@ -459,10 +467,25 @@ void drm_sched_entity_select_rq(struct drm_sched_entity *entity) struct drm_gpu_scheduler *sched; struct drm_sched_rq *rq;

- if (spsc_queue_count(&entity->job_queue) || !entity->sched_list) + /* single possible engine and already selected */ + if (!entity->sched_list) + return; + + /* queue non-empty, stay on the same engine */ + if (spsc_queue_count(&entity->job_queue)) return;

- fence = READ_ONCE(entity->last_scheduled); + /* + * Only when the queue is empty are we guaranteed that the scheduler + * thread cannot change ->last_scheduled. To enforce ordering we need + * a read barrier here. See drm_sched_entity_pop_job() for the other + * side. + */ + smp_rmb(); + + fence = entity->last_scheduled; + + /* stay on the same engine if the previous job hasn't finished */ if (fence && !dma_fence_is_signaled(fence)) return;

Instead of just a callback we can just glue in the gem helpers that panfrost, v3d and lima currently use. There's really not that many ways to skin this cat.

On the naming bikeshed: The idea for using _await_ to denote adding dependencies to a job comes from i915, where that's used quite extensively all over the place, in lots of datastructures.

v2/3: Rebased.

Reviewed-by: Steven Price steven.price@arm.com (v1) Signed-off-by: Daniel Vetter daniel.vetter@intel.com Cc: David Airlie airlied@linux.ie Cc: Daniel Vetter daniel@ffwll.ch Cc: Sumit Semwal sumit.semwal@linaro.org Cc: "Christian König" christian.koenig@amd.com Cc: Andrey Grodzovsky andrey.grodzovsky@amd.com Cc: Lee Jones lee.jones@linaro.org Cc: Nirmoy Das nirmoy.aiemd@gmail.com Cc: Boris Brezillon boris.brezillon@collabora.com Cc: Luben Tuikov luben.tuikov@amd.com Cc: Alex Deucher alexander.deucher@amd.com Cc: Jack Zhang Jack.Zhang1@amd.com Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org --- drivers/gpu/drm/scheduler/sched_entity.c | 18 +++- drivers/gpu/drm/scheduler/sched_main.c | 103 +++++++++++++++++++++++ include/drm/gpu_scheduler.h | 31 ++++++- 3 files changed, 146 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c index 89e3f6eaf519..381fbf462ea7 100644 --- a/drivers/gpu/drm/scheduler/sched_entity.c +++ b/drivers/gpu/drm/scheduler/sched_entity.c @@ -211,6 +211,19 @@ static void drm_sched_entity_kill_jobs_cb(struct dma_fence *f, job->sched->ops->free_job(job); }

+static struct dma_fence * +drm_sched_job_dependency(struct drm_sched_job *job, + struct drm_sched_entity *entity) +{ + if (!xa_empty(&job->dependencies)) + return xa_erase(&job->dependencies, job->last_dependency++); + + if (job->sched->ops->dependency) + return job->sched->ops->dependency(job, entity); + + return NULL; +} + /** * drm_sched_entity_kill_jobs - Make sure all remaining jobs are killed * @@ -229,7 +242,7 @@ static void drm_sched_entity_kill_jobs(struct drm_sched_entity *entity) struct drm_sched_fence *s_fence = job->s_fence;

/* Wait for all dependencies to avoid data corruptions */ - while ((f = job->sched->ops->dependency(job, entity))) + while ((f = drm_sched_job_dependency(job, entity))) dma_fence_wait(f, false);

drm_sched_fence_scheduled(s_fence); @@ -419,7 +432,6 @@ static bool drm_sched_entity_add_dependency_cb(struct drm_sched_entity *entity) */ struct drm_sched_job *drm_sched_entity_pop_job(struct drm_sched_entity *entity) { - struct drm_gpu_scheduler *sched = entity->rq->sched; struct drm_sched_job *sched_job;

sched_job = to_drm_sched_job(spsc_queue_peek(&entity->job_queue)); @@ -427,7 +439,7 @@ struct drm_sched_job *drm_sched_entity_pop_job(struct drm_sched_entity *entity) return NULL;

while ((entity->dependency = - sched->ops->dependency(sched_job, entity))) { + drm_sched_job_dependency(sched_job, entity))) { trace_drm_sched_job_wait_dep(sched_job, entity->dependency);

if (drm_sched_entity_add_dependency_cb(entity)) diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c index 454cb6164bdc..84c30badb78e 100644 --- a/drivers/gpu/drm/scheduler/sched_main.c +++ b/drivers/gpu/drm/scheduler/sched_main.c @@ -603,6 +603,8 @@ int drm_sched_job_init(struct drm_sched_job *job,

INIT_LIST_HEAD(&job->list);

+ xa_init_flags(&job->dependencies, XA_FLAGS_ALLOC); + return 0; } EXPORT_SYMBOL(drm_sched_job_init); @@ -637,6 +639,98 @@ void drm_sched_job_arm(struct drm_sched_job *job) } EXPORT_SYMBOL(drm_sched_job_arm);

+/** + * drm_sched_job_await_fence - adds the fence as a job dependency + * @job: scheduler job to add the dependencies to + * @fence: the dma_fence to add to the list of dependencies. + * + * Note that @fence is consumed in both the success and error cases. + * + * Returns: + * 0 on success, or an error on failing to expand the array. + */ +int drm_sched_job_await_fence(struct drm_sched_job *job, + struct dma_fence *fence) +{ + struct dma_fence *entry; + unsigned long index; + u32 id = 0; + int ret; + + if (!fence) + return 0; + + /* Deduplicate if we already depend on a fence from the same context. + * This lets the size of the array of deps scale with the number of + * engines involved, rather than the number of BOs. + */ + xa_for_each(&job->dependencies, index, entry) { + if (entry->context != fence->context) + continue; + + if (dma_fence_is_later(fence, entry)) { + dma_fence_put(entry); + xa_store(&job->dependencies, index, fence, GFP_KERNEL); + } else { + dma_fence_put(fence); + } + return 0; + } + + ret = xa_alloc(&job->dependencies, &id, fence, xa_limit_32b, GFP_KERNEL); + if (ret != 0) + dma_fence_put(fence); + + return ret; +} +EXPORT_SYMBOL(drm_sched_job_await_fence); + +/** + * drm_sched_job_await_implicit - adds implicit dependencies as job dependencies + * @job: scheduler job to add the dependencies to + * @obj: the gem object to add new dependencies from. + * @write: whether the job might write the object (so we need to depend on + * shared fences in the reservation object). + * + * This should be called after drm_gem_lock_reservations() on your array of + * GEM objects used in the job but before updating the reservations with your + * own fences. + * + * Returns: + * 0 on success, or an error on failing to expand the array. + */ +int drm_sched_job_await_implicit(struct drm_sched_job *job, + struct drm_gem_object *obj, + bool write) +{ + int ret; + struct dma_fence **fences; + unsigned int i, fence_count; + + if (!write) { + struct dma_fence *fence = dma_resv_get_excl_unlocked(obj->resv); + + return drm_sched_job_await_fence(job, fence); + } + + ret = dma_resv_get_fences(obj->resv, NULL, &fence_count, &fences); + if (ret || !fence_count) + return ret; + + for (i = 0; i < fence_count; i++) { + ret = drm_sched_job_await_fence(job, fences[i]); + if (ret) + break; + } + + for (; i < fence_count; i++) + dma_fence_put(fences[i]); + kfree(fences); + return ret; +} +EXPORT_SYMBOL(drm_sched_job_await_implicit); + + /** * drm_sched_job_cleanup - clean up scheduler job resources * @job: scheduler job to clean up @@ -652,6 +746,9 @@ EXPORT_SYMBOL(drm_sched_job_arm); */ void drm_sched_job_cleanup(struct drm_sched_job *job) { + struct dma_fence *fence; + unsigned long index; + if (kref_read(&job->s_fence->finished.refcount)) { /* drm_sched_job_arm() has been called */ dma_fence_put(&job->s_fence->finished); @@ -661,6 +758,12 @@ void drm_sched_job_cleanup(struct drm_sched_job *job) }

job->s_fence = NULL; + + xa_for_each(&job->dependencies, index, fence) { + dma_fence_put(fence); + } + xa_destroy(&job->dependencies); + } EXPORT_SYMBOL(drm_sched_job_cleanup);

diff --git a/include/drm/gpu_scheduler.h b/include/drm/gpu_scheduler.h index 83afc3aa8e2f..74fb321dbc44 100644 --- a/include/drm/gpu_scheduler.h +++ b/include/drm/gpu_scheduler.h @@ -27,9 +27,12 @@ #include <drm/spsc_queue.h> #include <linux/dma-fence.h> #include <linux/completion.h> +#include <linux/xarray.h>

#define MAX_WAIT_SCHED_ENTITY_Q_EMPTY msecs_to_jiffies(1000)

+struct drm_gem_object; + struct drm_gpu_scheduler; struct drm_sched_rq;

@@ -198,6 +201,16 @@ struct drm_sched_job { enum drm_sched_priority s_priority; struct drm_sched_entity *entity; struct dma_fence_cb cb; + /** + * @dependencies: + * + * Contains the dependencies as struct dma_fence for this job, see + * drm_sched_job_await_fence() and drm_sched_job_await_implicit(). + */ + struct xarray dependencies; + + /** @last_dependency: tracks @dependencies as they signal */ + unsigned long last_dependency; };

static inline bool drm_sched_invalidate_job(struct drm_sched_job *s_job, @@ -220,9 +233,14 @@ enum drm_gpu_sched_stat { */ struct drm_sched_backend_ops { /** - * @dependency: Called when the scheduler is considering scheduling - * this job next, to get another struct dma_fence for this job to - * block on. Once it returns NULL, run_job() may be called. + * @dependency: + * + * Called when the scheduler is considering scheduling this job next, to + * get another struct dma_fence for this job to block on. Once it + * returns NULL, run_job() may be called. + * + * If a driver exclusively uses drm_sched_job_await_fence() and + * drm_sched_job_await_implicit() this can be ommitted and left as NULL. */ struct dma_fence *(*dependency)(struct drm_sched_job *sched_job, struct drm_sched_entity *s_entity); @@ -349,6 +367,13 @@ int drm_sched_job_init(struct drm_sched_job *job, struct drm_sched_entity *entity, void *owner); void drm_sched_job_arm(struct drm_sched_job *job); +int drm_sched_job_await_fence(struct drm_sched_job *job, + struct dma_fence *fence); +int drm_sched_job_await_implicit(struct drm_sched_job *job, + struct drm_gem_object *obj, + bool write); + + void drm_sched_entity_modify_sched(struct drm_sched_entity *entity, struct drm_gpu_scheduler **sched_list, unsigned int num_sched_list);

Originally a job was only bound to the queue when we pushed this, but now that's done in drm_sched_job_init, making that parameter entirely redundant.

Remove it.

The same applies to the context parameter in lima_sched_context_queue_task, simplify that too.

Reviewed-by: Steven Price steven.price@arm.com (v1) Signed-off-by: Daniel Vetter daniel.vetter@intel.com Cc: Lucas Stach l.stach@pengutronix.de Cc: Russell King linux+etnaviv@armlinux.org.uk Cc: Christian Gmeiner christian.gmeiner@gmail.com Cc: Qiang Yu yuq825@gmail.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: Emma Anholt emma@anholt.net Cc: David Airlie airlied@linux.ie Cc: Daniel Vetter daniel@ffwll.ch Cc: Sumit Semwal sumit.semwal@linaro.org Cc: "Christian König" christian.koenig@amd.com Cc: Alex Deucher alexander.deucher@amd.com Cc: Nirmoy Das nirmoy.das@amd.com Cc: Dave Airlie airlied@redhat.com Cc: Chen Li chenli@uniontech.com Cc: Lee Jones lee.jones@linaro.org Cc: Deepak R Varma mh12gx2825@gmail.com Cc: Kevin Wang kevin1.wang@amd.com Cc: Luben Tuikov luben.tuikov@amd.com Cc: "Marek Olšák" marek.olsak@amd.com Cc: Maarten Lankhorst maarten.lankhorst@linux.intel.com Cc: Andrey Grodzovsky andrey.grodzovsky@amd.com Cc: Dennis Li Dennis.Li@amd.com Cc: Boris Brezillon boris.brezillon@collabora.com Cc: etnaviv@lists.freedesktop.org Cc: lima@lists.freedesktop.org Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org --- drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c | 2 +- drivers/gpu/drm/amd/amdgpu/amdgpu_job.c | 2 +- drivers/gpu/drm/etnaviv/etnaviv_sched.c | 2 +- drivers/gpu/drm/lima/lima_gem.c | 3 +-- drivers/gpu/drm/lima/lima_sched.c | 5 ++--- drivers/gpu/drm/lima/lima_sched.h | 3 +-- drivers/gpu/drm/panfrost/panfrost_job.c | 2 +- drivers/gpu/drm/scheduler/sched_entity.c | 6 ++---- drivers/gpu/drm/v3d/v3d_gem.c | 2 +- include/drm/gpu_scheduler.h | 3 +-- 10 files changed, 12 insertions(+), 18 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c index a4ec092af9a7..18f63567fb69 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c @@ -1267,7 +1267,7 @@ static int amdgpu_cs_submit(struct amdgpu_cs_parser *p,

trace_amdgpu_cs_ioctl(job); amdgpu_vm_bo_trace_cs(&fpriv->vm, &p->ticket); - drm_sched_entity_push_job(&job->base, entity); + drm_sched_entity_push_job(&job->base);

amdgpu_vm_move_to_lru_tail(p->adev, &fpriv->vm);

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c index 5ddb955d2315..b8609cccc9c1 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c @@ -174,7 +174,7 @@ int amdgpu_job_submit(struct amdgpu_job *job, struct drm_sched_entity *entity,

*f = dma_fence_get(&job->base.s_fence->finished); amdgpu_job_free_resources(job); - drm_sched_entity_push_job(&job->base, entity); + drm_sched_entity_push_job(&job->base);

return 0; } diff --git a/drivers/gpu/drm/etnaviv/etnaviv_sched.c b/drivers/gpu/drm/etnaviv/etnaviv_sched.c index 05f412204118..180bb633d5c5 100644 --- a/drivers/gpu/drm/etnaviv/etnaviv_sched.c +++ b/drivers/gpu/drm/etnaviv/etnaviv_sched.c @@ -178,7 +178,7 @@ int etnaviv_sched_push_job(struct drm_sched_entity *sched_entity, /* the scheduler holds on to the job now */ kref_get(&submit->refcount);

- drm_sched_entity_push_job(&submit->sched_job, sched_entity); + drm_sched_entity_push_job(&submit->sched_job);

out_unlock: mutex_unlock(&submit->gpu->fence_lock); diff --git a/drivers/gpu/drm/lima/lima_gem.c b/drivers/gpu/drm/lima/lima_gem.c index de62966243cd..c528f40981bb 100644 --- a/drivers/gpu/drm/lima/lima_gem.c +++ b/drivers/gpu/drm/lima/lima_gem.c @@ -359,8 +359,7 @@ int lima_gem_submit(struct drm_file *file, struct lima_submit *submit) goto err_out2; }

- fence = lima_sched_context_queue_task( - submit->ctx->context + submit->pipe, submit->task); + fence = lima_sched_context_queue_task(submit->task);

for (i = 0; i < submit->nr_bos; i++) { if (submit->bos[i].flags & LIMA_SUBMIT_BO_WRITE) diff --git a/drivers/gpu/drm/lima/lima_sched.c b/drivers/gpu/drm/lima/lima_sched.c index 38f755580507..e968b5a8f0b0 100644 --- a/drivers/gpu/drm/lima/lima_sched.c +++ b/drivers/gpu/drm/lima/lima_sched.c @@ -177,13 +177,12 @@ void lima_sched_context_fini(struct lima_sched_pipe *pipe, drm_sched_entity_fini(&context->base); }

-struct dma_fence *lima_sched_context_queue_task(struct lima_sched_context *context, - struct lima_sched_task *task) +struct dma_fence *lima_sched_context_queue_task(struct lima_sched_task *task) { struct dma_fence *fence = dma_fence_get(&task->base.s_fence->finished);

trace_lima_task_submit(task); - drm_sched_entity_push_job(&task->base, &context->base); + drm_sched_entity_push_job(&task->base); return fence; }

diff --git a/drivers/gpu/drm/lima/lima_sched.h b/drivers/gpu/drm/lima/lima_sched.h index 90f03c48ef4a..ac70006b0e26 100644 --- a/drivers/gpu/drm/lima/lima_sched.h +++ b/drivers/gpu/drm/lima/lima_sched.h @@ -98,8 +98,7 @@ int lima_sched_context_init(struct lima_sched_pipe *pipe, atomic_t *guilty); void lima_sched_context_fini(struct lima_sched_pipe *pipe, struct lima_sched_context *context); -struct dma_fence *lima_sched_context_queue_task(struct lima_sched_context *context, - struct lima_sched_task *task); +struct dma_fence *lima_sched_context_queue_task(struct lima_sched_task *task);

int lima_sched_pipe_init(struct lima_sched_pipe *pipe, const char *name); void lima_sched_pipe_fini(struct lima_sched_pipe *pipe); diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panfrost/panfrost_job.c index 2992dc85325f..4bc962763e1f 100644 --- a/drivers/gpu/drm/panfrost/panfrost_job.c +++ b/drivers/gpu/drm/panfrost/panfrost_job.c @@ -301,7 +301,7 @@ int panfrost_job_push(struct panfrost_job *job)

kref_get(&job->refcount); /* put by scheduler job completion */

- drm_sched_entity_push_job(&job->base, entity); + drm_sched_entity_push_job(&job->base);

mutex_unlock(&pfdev->sched_lock);

diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c index 381fbf462ea7..e4d33db1eb45 100644 --- a/drivers/gpu/drm/scheduler/sched_entity.c +++ b/drivers/gpu/drm/scheduler/sched_entity.c @@ -516,9 +516,7 @@ void drm_sched_entity_select_rq(struct drm_sched_entity *entity)

/** * drm_sched_entity_push_job - Submit a job to the entity's job queue - * * @sched_job: job to submit - * @entity: scheduler entity * * Note: To guarantee that the order of insertion to queue matches the job's * fence sequence number this function should be called with drm_sched_job_arm() @@ -526,9 +524,9 @@ void drm_sched_entity_select_rq(struct drm_sched_entity *entity) * * Returns 0 for success, negative error code otherwise. */ -void drm_sched_entity_push_job(struct drm_sched_job *sched_job, - struct drm_sched_entity *entity) +void drm_sched_entity_push_job(struct drm_sched_job *sched_job) { + struct drm_sched_entity *entity = sched_job->entity; bool first;

trace_drm_sched_job(sched_job, entity); diff --git a/drivers/gpu/drm/v3d/v3d_gem.c b/drivers/gpu/drm/v3d/v3d_gem.c index 5c3a99027ecd..69ac20e11b09 100644 --- a/drivers/gpu/drm/v3d/v3d_gem.c +++ b/drivers/gpu/drm/v3d/v3d_gem.c @@ -482,7 +482,7 @@ v3d_push_job(struct v3d_file_priv *v3d_priv, /* put by scheduler job completion */ kref_get(&job->refcount);

- drm_sched_entity_push_job(&job->base, &v3d_priv->sched_entity[queue]); + drm_sched_entity_push_job(&job->base);

return 0; } diff --git a/include/drm/gpu_scheduler.h b/include/drm/gpu_scheduler.h index 74fb321dbc44..2bb1869f2352 100644 --- a/include/drm/gpu_scheduler.h +++ b/include/drm/gpu_scheduler.h @@ -407,8 +407,7 @@ void drm_sched_entity_fini(struct drm_sched_entity *entity); void drm_sched_entity_destroy(struct drm_sched_entity *entity); void drm_sched_entity_select_rq(struct drm_sched_entity *entity); struct drm_sched_job *drm_sched_entity_pop_job(struct drm_sched_entity *entity); -void drm_sched_entity_push_job(struct drm_sched_job *sched_job, - struct drm_sched_entity *entity); +void drm_sched_entity_push_job(struct drm_sched_job *sched_job); void drm_sched_entity_set_priority(struct drm_sched_entity *entity, enum drm_sched_priority priority); bool drm_sched_entity_is_ready(struct drm_sched_entity *entity);

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.

v2: Correctly clean up the partially set up job, now that job_init() and job_arm() are apart (Emma).

Reviewed-by: Steven Price steven.price@arm.com 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 | 16 ++++++++--- drivers/gpu/drm/panfrost/panfrost_job.c | 37 +++---------------------- drivers/gpu/drm/panfrost/panfrost_job.h | 5 +--- 3 files changed, 17 insertions(+), 41 deletions(-)

diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c index 1ffaef5ec5ff..9f53bea07d61 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_put; + ret = panfrost_copy_in_sync(dev, file, args, job); if (ret) goto fail_job; @@ -283,6 +289,8 @@ static int panfrost_ioctl_submit(struct drm_device *dev, void *data, drm_syncobj_replace_fence(sync_out, job->render_done_fence);

fail_job: + drm_sched_job_cleanup(&job->base); +fail_job_put: panfrost_job_put(job); fail_out_sync: if (sync_out) diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panfrost/panfrost_job.c index 4bc962763e1f..86c843d8822e 100644 --- a/drivers/gpu/drm/panfrost/panfrost_job.c +++ b/drivers/gpu/drm/panfrost/panfrost_job.c @@ -102,7 +102,7 @@ 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 @@ -242,13 +242,13 @@ 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; } @@ -269,31 +269,21 @@ 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; @@ -318,15 +308,8 @@ 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);

@@ -365,17 +348,6 @@ 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); @@ -765,7 +737,6 @@ static void panfrost_reset_work(struct work_struct *work) }

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);

Prep work for using the scheduler dependency handling. We need to call drm_sched_job_init earlier so we can use the new drm_sched_job_await* functions for dependency handling here.

v2: Slightly better commit message and rebase to include the drm_sched_job_arm() call (Emma).

v3: Cleanup jobs under construction correctly (Emma)

Cc: Melissa Wen melissa.srw@gmail.com Signed-off-by: Daniel Vetter daniel.vetter@intel.com Cc: Emma Anholt emma@anholt.net --- drivers/gpu/drm/v3d/v3d_drv.h | 1 + drivers/gpu/drm/v3d/v3d_gem.c | 88 ++++++++++++++------------------- drivers/gpu/drm/v3d/v3d_sched.c | 15 +++--- 3 files changed, 44 insertions(+), 60 deletions(-)

diff --git a/drivers/gpu/drm/v3d/v3d_drv.h b/drivers/gpu/drm/v3d/v3d_drv.h index 8a390738d65b..1d870261eaac 100644 --- a/drivers/gpu/drm/v3d/v3d_drv.h +++ b/drivers/gpu/drm/v3d/v3d_drv.h @@ -332,6 +332,7 @@ int v3d_submit_csd_ioctl(struct drm_device *dev, void *data, struct drm_file *file_priv); int v3d_wait_bo_ioctl(struct drm_device *dev, void *data, struct drm_file *file_priv); +void v3d_job_cleanup(struct v3d_job *job); void v3d_job_put(struct v3d_job *job); void v3d_reset(struct v3d_dev *v3d); void v3d_invalidate_caches(struct v3d_dev *v3d); diff --git a/drivers/gpu/drm/v3d/v3d_gem.c b/drivers/gpu/drm/v3d/v3d_gem.c index 69ac20e11b09..5eccd3658938 100644 --- a/drivers/gpu/drm/v3d/v3d_gem.c +++ b/drivers/gpu/drm/v3d/v3d_gem.c @@ -392,6 +392,12 @@ v3d_render_job_free(struct kref *ref) v3d_job_free(ref); }

+void v3d_job_cleanup(struct v3d_job *job) +{ + drm_sched_job_cleanup(&job->base); + v3d_job_put(job); +} + void v3d_job_put(struct v3d_job *job) { kref_put(&job->refcount, job->free); @@ -433,9 +439,10 @@ v3d_wait_bo_ioctl(struct drm_device *dev, void *data, static int v3d_job_init(struct v3d_dev *v3d, struct drm_file *file_priv, struct v3d_job *job, void (*free)(struct kref *ref), - u32 in_sync) + u32 in_sync, enum v3d_queue queue) { struct dma_fence *in_fence = NULL; + struct v3d_file_priv *v3d_priv = file_priv->driver_priv; int ret;

job->v3d = v3d; @@ -446,35 +453,33 @@ v3d_job_init(struct v3d_dev *v3d, struct drm_file *file_priv, return ret;

xa_init_flags(&job->deps, XA_FLAGS_ALLOC); + ret = drm_sched_job_init(&job->base, &v3d_priv->sched_entity[queue], + v3d_priv); + if (ret) + goto fail;

ret = drm_syncobj_find_fence(file_priv, in_sync, 0, 0, &in_fence); if (ret == -EINVAL) - goto fail; + goto fail_job;

ret = drm_gem_fence_array_add(&job->deps, in_fence); if (ret) - goto fail; + goto fail_job;

kref_init(&job->refcount);

return 0; +fail_job: + drm_sched_job_cleanup(&job->base); fail: xa_destroy(&job->deps); pm_runtime_put_autosuspend(v3d->drm.dev); return ret; }

-static int -v3d_push_job(struct v3d_file_priv *v3d_priv, - struct v3d_job *job, enum v3d_queue queue) +static void +v3d_push_job(struct v3d_job *job) { - int ret; - - ret = drm_sched_job_init(&job->base, &v3d_priv->sched_entity[queue], - v3d_priv); - if (ret) - return ret; - drm_sched_job_arm(&job->base);

job->done_fence = dma_fence_get(&job->base.s_fence->finished); @@ -483,8 +488,6 @@ v3d_push_job(struct v3d_file_priv *v3d_priv, kref_get(&job->refcount);

drm_sched_entity_push_job(&job->base); - - return 0; }

static void @@ -530,7 +533,6 @@ v3d_submit_cl_ioctl(struct drm_device *dev, void *data, struct drm_file *file_priv) { struct v3d_dev *v3d = to_v3d_dev(dev); - struct v3d_file_priv *v3d_priv = file_priv->driver_priv; struct drm_v3d_submit_cl *args = data; struct v3d_bin_job *bin = NULL; struct v3d_render_job *render; @@ -556,7 +558,7 @@ v3d_submit_cl_ioctl(struct drm_device *dev, void *data, INIT_LIST_HEAD(&render->unref_list);

ret = v3d_job_init(v3d, file_priv, &render->base, - v3d_render_job_free, args->in_sync_rcl); + v3d_render_job_free, args->in_sync_rcl, V3D_RENDER); if (ret) { kfree(render); return ret; @@ -570,7 +572,7 @@ v3d_submit_cl_ioctl(struct drm_device *dev, void *data, }

ret = v3d_job_init(v3d, file_priv, &bin->base, - v3d_job_free, args->in_sync_bcl); + v3d_job_free, args->in_sync_bcl, V3D_BIN); if (ret) { v3d_job_put(&render->base); kfree(bin); @@ -592,7 +594,7 @@ v3d_submit_cl_ioctl(struct drm_device *dev, void *data, goto fail; }

- ret = v3d_job_init(v3d, file_priv, clean_job, v3d_job_free, 0); + ret = v3d_job_init(v3d, file_priv, clean_job, v3d_job_free, 0, V3D_CACHE_CLEAN); if (ret) { kfree(clean_job); clean_job = NULL; @@ -615,9 +617,7 @@ v3d_submit_cl_ioctl(struct drm_device *dev, void *data,

mutex_lock(&v3d->sched_lock); if (bin) { - ret = v3d_push_job(v3d_priv, &bin->base, V3D_BIN); - if (ret) - goto fail_unreserve; + v3d_push_job(&bin->base);

ret = drm_gem_fence_array_add(&render->base.deps, dma_fence_get(bin->base.done_fence)); @@ -625,9 +625,7 @@ v3d_submit_cl_ioctl(struct drm_device *dev, void *data, goto fail_unreserve; }

- ret = v3d_push_job(v3d_priv, &render->base, V3D_RENDER); - if (ret) - goto fail_unreserve; + v3d_push_job(&render->base);

if (clean_job) { struct dma_fence *render_fence = @@ -635,9 +633,7 @@ v3d_submit_cl_ioctl(struct drm_device *dev, void *data, ret = drm_gem_fence_array_add(&clean_job->deps, render_fence); if (ret) goto fail_unreserve; - ret = v3d_push_job(v3d_priv, clean_job, V3D_CACHE_CLEAN); - if (ret) - goto fail_unreserve; + v3d_push_job(clean_job); }

mutex_unlock(&v3d->sched_lock); @@ -662,10 +658,10 @@ v3d_submit_cl_ioctl(struct drm_device *dev, void *data, last_job->bo_count, &acquire_ctx); fail: if (bin) - v3d_job_put(&bin->base); - v3d_job_put(&render->base); + v3d_job_cleanup(&bin->base); + v3d_job_cleanup(&render->base); if (clean_job) - v3d_job_put(clean_job); + v3d_job_cleanup(clean_job);

return ret; } @@ -684,7 +680,6 @@ v3d_submit_tfu_ioctl(struct drm_device *dev, void *data, struct drm_file *file_priv) { struct v3d_dev *v3d = to_v3d_dev(dev); - struct v3d_file_priv *v3d_priv = file_priv->driver_priv; struct drm_v3d_submit_tfu *args = data; struct v3d_tfu_job *job; struct ww_acquire_ctx acquire_ctx; @@ -697,7 +692,7 @@ v3d_submit_tfu_ioctl(struct drm_device *dev, void *data, return -ENOMEM;

ret = v3d_job_init(v3d, file_priv, &job->base, - v3d_job_free, args->in_sync); + v3d_job_free, args->in_sync, V3D_TFU); if (ret) { kfree(job); return ret; @@ -741,9 +736,7 @@ v3d_submit_tfu_ioctl(struct drm_device *dev, void *data, goto fail;

mutex_lock(&v3d->sched_lock); - ret = v3d_push_job(v3d_priv, &job->base, V3D_TFU); - if (ret) - goto fail_unreserve; + v3d_push_job(&job->base); mutex_unlock(&v3d->sched_lock);

v3d_attach_fences_and_unlock_reservation(file_priv, @@ -755,12 +748,8 @@ v3d_submit_tfu_ioctl(struct drm_device *dev, void *data,

return 0;

-fail_unreserve: - mutex_unlock(&v3d->sched_lock); - drm_gem_unlock_reservations(job->base.bo, job->base.bo_count, - &acquire_ctx); fail: - v3d_job_put(&job->base); + v3d_job_cleanup(&job->base);

return ret; } @@ -779,7 +768,6 @@ v3d_submit_csd_ioctl(struct drm_device *dev, void *data, struct drm_file *file_priv) { struct v3d_dev *v3d = to_v3d_dev(dev); - struct v3d_file_priv *v3d_priv = file_priv->driver_priv; struct drm_v3d_submit_csd *args = data; struct v3d_csd_job *job; struct v3d_job *clean_job; @@ -798,7 +786,7 @@ v3d_submit_csd_ioctl(struct drm_device *dev, void *data, return -ENOMEM;

ret = v3d_job_init(v3d, file_priv, &job->base, - v3d_job_free, args->in_sync); + v3d_job_free, args->in_sync, V3D_CSD); if (ret) { kfree(job); return ret; @@ -811,7 +799,7 @@ v3d_submit_csd_ioctl(struct drm_device *dev, void *data, return -ENOMEM; }

- ret = v3d_job_init(v3d, file_priv, clean_job, v3d_job_free, 0); + ret = v3d_job_init(v3d, file_priv, clean_job, v3d_job_free, 0, V3D_CACHE_CLEAN); if (ret) { v3d_job_put(&job->base); kfree(clean_job); @@ -830,18 +818,14 @@ v3d_submit_csd_ioctl(struct drm_device *dev, void *data, goto fail;

mutex_lock(&v3d->sched_lock); - ret = v3d_push_job(v3d_priv, &job->base, V3D_CSD); - if (ret) - goto fail_unreserve; + v3d_push_job(&job->base);

ret = drm_gem_fence_array_add(&clean_job->deps, dma_fence_get(job->base.done_fence)); if (ret) goto fail_unreserve;

- ret = v3d_push_job(v3d_priv, clean_job, V3D_CACHE_CLEAN); - if (ret) - goto fail_unreserve; + v3d_push_job(clean_job); mutex_unlock(&v3d->sched_lock);

v3d_attach_fences_and_unlock_reservation(file_priv, @@ -860,8 +844,8 @@ v3d_submit_csd_ioctl(struct drm_device *dev, void *data, drm_gem_unlock_reservations(clean_job->bo, clean_job->bo_count, &acquire_ctx); fail: - v3d_job_put(&job->base); - v3d_job_put(clean_job); + v3d_job_cleanup(&job->base); + v3d_job_cleanup(clean_job);

return ret; } diff --git a/drivers/gpu/drm/v3d/v3d_sched.c b/drivers/gpu/drm/v3d/v3d_sched.c index a39bdd5cfc4f..3f352d73af9c 100644 --- a/drivers/gpu/drm/v3d/v3d_sched.c +++ b/drivers/gpu/drm/v3d/v3d_sched.c @@ -55,12 +55,11 @@ to_csd_job(struct drm_sched_job *sched_job) }

static void -v3d_job_free(struct drm_sched_job *sched_job) +v3d_sched_job_free(struct drm_sched_job *sched_job) { struct v3d_job *job = to_v3d_job(sched_job);

- drm_sched_job_cleanup(sched_job); - v3d_job_put(job); + v3d_job_cleanup(job); }

/* @@ -360,35 +359,35 @@ static const struct drm_sched_backend_ops v3d_bin_sched_ops = { .dependency = v3d_job_dependency, .run_job = v3d_bin_job_run, .timedout_job = v3d_bin_job_timedout, - .free_job = v3d_job_free, + .free_job = v3d_sched_job_free, };

static const struct drm_sched_backend_ops v3d_render_sched_ops = { .dependency = v3d_job_dependency, .run_job = v3d_render_job_run, .timedout_job = v3d_render_job_timedout, - .free_job = v3d_job_free, + .free_job = v3d_sched_job_free, };

static const struct drm_sched_backend_ops v3d_tfu_sched_ops = { .dependency = v3d_job_dependency, .run_job = v3d_tfu_job_run, .timedout_job = v3d_generic_job_timedout, - .free_job = v3d_job_free, + .free_job = v3d_sched_job_free, };

static const struct drm_sched_backend_ops v3d_csd_sched_ops = { .dependency = v3d_job_dependency, .run_job = v3d_csd_job_run, .timedout_job = v3d_csd_job_timedout, - .free_job = v3d_job_free + .free_job = v3d_sched_job_free };

static const struct drm_sched_backend_ops v3d_cache_clean_sched_ops = { .dependency = v3d_job_dependency, .run_job = v3d_cache_clean_job_run, .timedout_job = v3d_generic_job_timedout, - .free_job = v3d_job_free + .free_job = v3d_sched_job_free };

int

With the prep work out of the way this isn't tricky anymore.

Aside: The chaining of the various jobs is a bit awkward, with the possibility of failure in bad places. I think with the drm_sched_job_init/arm split and maybe preloading the job->dependencies xarray this should be fixable.

Cc: Melissa Wen melissa.srw@gmail.com Signed-off-by: Daniel Vetter daniel.vetter@intel.com Cc: Cc: Emma Anholt emma@anholt.net --- drivers/gpu/drm/v3d/v3d_drv.h | 5 ----- drivers/gpu/drm/v3d/v3d_gem.c | 25 ++++++++----------------- drivers/gpu/drm/v3d/v3d_sched.c | 29 +---------------------------- 3 files changed, 9 insertions(+), 50 deletions(-)

diff --git a/drivers/gpu/drm/v3d/v3d_drv.h b/drivers/gpu/drm/v3d/v3d_drv.h index 1d870261eaac..f80f4ff1f7aa 100644 --- a/drivers/gpu/drm/v3d/v3d_drv.h +++ b/drivers/gpu/drm/v3d/v3d_drv.h @@ -192,11 +192,6 @@ struct v3d_job { struct drm_gem_object **bo; u32 bo_count;

- /* Array of struct dma_fence * to block on before submitting this job. - */ - struct xarray deps; - unsigned long last_dep; - /* v3d fence to be signaled by IRQ handler when the job is complete. */ struct dma_fence *irq_fence;

diff --git a/drivers/gpu/drm/v3d/v3d_gem.c b/drivers/gpu/drm/v3d/v3d_gem.c index 5eccd3658938..42b07ffbea5e 100644 --- a/drivers/gpu/drm/v3d/v3d_gem.c +++ b/drivers/gpu/drm/v3d/v3d_gem.c @@ -257,8 +257,8 @@ v3d_lock_bo_reservations(struct v3d_job *job, return ret;

for (i = 0; i < job->bo_count; i++) { - ret = drm_gem_fence_array_add_implicit(&job->deps, - job->bo[i], true); + ret = drm_sched_job_await_implicit(&job->base, + job->bo[i], true); if (ret) { drm_gem_unlock_reservations(job->bo, job->bo_count, acquire_ctx); @@ -354,8 +354,6 @@ static void v3d_job_free(struct kref *ref) { struct v3d_job *job = container_of(ref, struct v3d_job, refcount); - unsigned long index; - struct dma_fence *fence; int i;

for (i = 0; i < job->bo_count; i++) { @@ -364,11 +362,6 @@ v3d_job_free(struct kref *ref) } kvfree(job->bo);

- xa_for_each(&job->deps, index, fence) { - dma_fence_put(fence); - } - xa_destroy(&job->deps); - dma_fence_put(job->irq_fence); dma_fence_put(job->done_fence);

@@ -452,7 +445,6 @@ v3d_job_init(struct v3d_dev *v3d, struct drm_file *file_priv, if (ret < 0) return ret;

- xa_init_flags(&job->deps, XA_FLAGS_ALLOC); ret = drm_sched_job_init(&job->base, &v3d_priv->sched_entity[queue], v3d_priv); if (ret) @@ -462,7 +454,7 @@ v3d_job_init(struct v3d_dev *v3d, struct drm_file *file_priv, if (ret == -EINVAL) goto fail_job;

- ret = drm_gem_fence_array_add(&job->deps, in_fence); + ret = drm_sched_job_await_fence(&job->base, in_fence); if (ret) goto fail_job;

@@ -472,7 +464,6 @@ v3d_job_init(struct v3d_dev *v3d, struct drm_file *file_priv, fail_job: drm_sched_job_cleanup(&job->base); fail: - xa_destroy(&job->deps); pm_runtime_put_autosuspend(v3d->drm.dev); return ret; } @@ -619,8 +610,8 @@ v3d_submit_cl_ioctl(struct drm_device *dev, void *data, if (bin) { v3d_push_job(&bin->base);

- ret = drm_gem_fence_array_add(&render->base.deps, - dma_fence_get(bin->base.done_fence)); + ret = drm_sched_job_await_fence(&render->base.base, + dma_fence_get(bin->base.done_fence)); if (ret) goto fail_unreserve; } @@ -630,7 +621,7 @@ v3d_submit_cl_ioctl(struct drm_device *dev, void *data, if (clean_job) { struct dma_fence *render_fence = dma_fence_get(render->base.done_fence); - ret = drm_gem_fence_array_add(&clean_job->deps, render_fence); + ret = drm_sched_job_await_fence(&clean_job->base, render_fence); if (ret) goto fail_unreserve; v3d_push_job(clean_job); @@ -820,8 +811,8 @@ v3d_submit_csd_ioctl(struct drm_device *dev, void *data, mutex_lock(&v3d->sched_lock); v3d_push_job(&job->base);

- ret = drm_gem_fence_array_add(&clean_job->deps, - dma_fence_get(job->base.done_fence)); + ret = drm_sched_job_await_fence(&clean_job->base, + dma_fence_get(job->base.done_fence)); if (ret) goto fail_unreserve;

diff --git a/drivers/gpu/drm/v3d/v3d_sched.c b/drivers/gpu/drm/v3d/v3d_sched.c index 3f352d73af9c..f0de584f452c 100644 --- a/drivers/gpu/drm/v3d/v3d_sched.c +++ b/drivers/gpu/drm/v3d/v3d_sched.c @@ -13,7 +13,7 @@ * jobs when bulk background jobs are queued up, we submit a new job * to the HW only when it has completed the last one, instead of * filling up the CT[01]Q FIFOs with jobs. Similarly, we use - * v3d_job_dependency() to manage the dependency between bin and + * drm_sched_job_await_fence() to manage the dependency between bin and * render, instead of having the clients submit jobs using the HW's * semaphores to interlock between them. */ @@ -62,28 +62,6 @@ v3d_sched_job_free(struct drm_sched_job *sched_job) v3d_job_cleanup(job); }

-/* - * Returns the fences that the job depends on, one by one. - * - * If placed in the scheduler's .dependency method, the corresponding - * .run_job won't be called until all of them have been signaled. - */ -static struct dma_fence * -v3d_job_dependency(struct drm_sched_job *sched_job, - struct drm_sched_entity *s_entity) -{ - struct v3d_job *job = to_v3d_job(sched_job); - - /* XXX: Wait on a fence for switching the GMP if necessary, - * and then do so. - */ - - if (!xa_empty(&job->deps)) - return xa_erase(&job->deps, job->last_dep++); - - return NULL; -} - static struct dma_fence *v3d_bin_job_run(struct drm_sched_job *sched_job) { struct v3d_bin_job *job = to_bin_job(sched_job); @@ -356,35 +334,30 @@ v3d_csd_job_timedout(struct drm_sched_job *sched_job) }

static const struct drm_sched_backend_ops v3d_bin_sched_ops = { - .dependency = v3d_job_dependency, .run_job = v3d_bin_job_run, .timedout_job = v3d_bin_job_timedout, .free_job = v3d_sched_job_free, };

static const struct drm_sched_backend_ops v3d_render_sched_ops = { - .dependency = v3d_job_dependency, .run_job = v3d_render_job_run, .timedout_job = v3d_render_job_timedout, .free_job = v3d_sched_job_free, };

static const struct drm_sched_backend_ops v3d_tfu_sched_ops = { - .dependency = v3d_job_dependency, .run_job = v3d_tfu_job_run, .timedout_job = v3d_generic_job_timedout, .free_job = v3d_sched_job_free, };

static const struct drm_sched_backend_ops v3d_csd_sched_ops = { - .dependency = v3d_job_dependency, .run_job = v3d_csd_job_run, .timedout_job = v3d_csd_job_timedout, .free_job = v3d_sched_job_free };

static const struct drm_sched_backend_ops v3d_cache_clean_sched_ops = { - .dependency = v3d_job_dependency, .run_job = v3d_cache_clean_job_run, .timedout_job = v3d_generic_job_timedout, .free_job = v3d_sched_job_free

We need to pull the drm_sched_job_init much earlier, but that's very minor surgery.

v2: Actually fix up cleanup paths by calling drm_sched_job_init, which I wanted to to in the previous round (and did, for all other drivers). Spotted by Lucas.

Signed-off-by: Daniel Vetter daniel.vetter@intel.com Cc: Lucas Stach l.stach@pengutronix.de Cc: Russell King linux+etnaviv@armlinux.org.uk Cc: Christian Gmeiner christian.gmeiner@gmail.com Cc: Sumit Semwal sumit.semwal@linaro.org Cc: "Christian König" christian.koenig@amd.com Cc: etnaviv@lists.freedesktop.org Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org --- drivers/gpu/drm/etnaviv/etnaviv_gem.h | 5 +- drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c | 58 +++++++++--------- drivers/gpu/drm/etnaviv/etnaviv_sched.c | 63 +------------------- drivers/gpu/drm/etnaviv/etnaviv_sched.h | 3 +- 4 files changed, 35 insertions(+), 94 deletions(-)

diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem.h b/drivers/gpu/drm/etnaviv/etnaviv_gem.h index 98e60df882b6..63688e6e4580 100644 --- a/drivers/gpu/drm/etnaviv/etnaviv_gem.h +++ b/drivers/gpu/drm/etnaviv/etnaviv_gem.h @@ -80,9 +80,6 @@ struct etnaviv_gem_submit_bo { u64 va; struct etnaviv_gem_object *obj; struct etnaviv_vram_mapping *mapping; - struct dma_fence *excl; - unsigned int nr_shared; - struct dma_fence **shared; };

/* Created per submit-ioctl, to track bo's and cmdstream bufs, etc, @@ -95,7 +92,7 @@ struct etnaviv_gem_submit { struct etnaviv_file_private *ctx; struct etnaviv_gpu *gpu; struct etnaviv_iommu_context *mmu_context, *prev_mmu_context; - struct dma_fence *out_fence, *in_fence; + struct dma_fence *out_fence; int out_fence_id; struct list_head node; /* GPU active submit list */ struct etnaviv_cmdbuf cmdbuf; diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c b/drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c index 4dd7d9d541c0..5b97ce1299ad 100644 --- a/drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c +++ b/drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c @@ -188,16 +188,10 @@ static int submit_fence_sync(struct etnaviv_gem_submit *submit) if (submit->flags & ETNA_SUBMIT_NO_IMPLICIT) continue;

- if (bo->flags & ETNA_SUBMIT_BO_WRITE) { - ret = dma_resv_get_fences(robj, &bo->excl, - &bo->nr_shared, - &bo->shared); - if (ret) - return ret; - } else { - bo->excl = dma_resv_get_excl_unlocked(robj); - } - + ret = drm_sched_job_await_implicit(&submit->sched_job, &bo->obj->base, + bo->flags & ETNA_SUBMIT_BO_WRITE); + if (ret) + return ret; }

return ret; @@ -403,8 +397,6 @@ static void submit_cleanup(struct kref *kref)

wake_up_all(&submit->gpu->fence_event);

- if (submit->in_fence) - dma_fence_put(submit->in_fence); if (submit->out_fence) { /* first remove from IDR, so fence can not be found anymore */ mutex_lock(&submit->gpu->fence_lock); @@ -529,7 +521,7 @@ int etnaviv_ioctl_gem_submit(struct drm_device *dev, void *data, ret = etnaviv_cmdbuf_init(priv->cmdbuf_suballoc, &submit->cmdbuf, ALIGN(args->stream_size, 8) + 8); if (ret) - goto err_submit_objects; + goto err_submit_put;

submit->ctx = file->driver_priv; etnaviv_iommu_context_get(submit->ctx->mmu); @@ -537,51 +529,61 @@ int etnaviv_ioctl_gem_submit(struct drm_device *dev, void *data, submit->exec_state = args->exec_state; submit->flags = args->flags;

+ ret = drm_sched_job_init(&submit->sched_job, + &ctx->sched_entity[args->pipe], + submit->ctx); + if (ret) + goto err_submit_put; + ret = submit_lookup_objects(submit, file, bos, args->nr_bos); if (ret) - goto err_submit_objects; + goto err_submit_job;

if ((priv->mmu_global->version != ETNAVIV_IOMMU_V2) && !etnaviv_cmd_validate_one(gpu, stream, args->stream_size / 4, relocs, args->nr_relocs)) { ret = -EINVAL; - goto err_submit_objects; + goto err_submit_job; }

if (args->flags & ETNA_SUBMIT_FENCE_FD_IN) { - submit->in_fence = sync_file_get_fence(args->fence_fd); - if (!submit->in_fence) { + struct dma_fence *in_fence = sync_file_get_fence(args->fence_fd); + if (!in_fence) { ret = -EINVAL; - goto err_submit_objects; + goto err_submit_job; } + + ret = drm_sched_job_await_fence(&submit->sched_job, in_fence); + if (ret) + goto err_submit_job; }

ret = submit_pin_objects(submit); if (ret) - goto err_submit_objects; + goto err_submit_job;

ret = submit_reloc(submit, stream, args->stream_size / 4, relocs, args->nr_relocs); if (ret) - goto err_submit_objects; + goto err_submit_job;

ret = submit_perfmon_validate(submit, args->exec_state, pmrs); if (ret) - goto err_submit_objects; + goto err_submit_job;

memcpy(submit->cmdbuf.vaddr, stream, args->stream_size);

ret = submit_lock_objects(submit, &ticket); if (ret) - goto err_submit_objects; + goto err_submit_job;

ret = submit_fence_sync(submit); if (ret) - goto err_submit_objects; + goto err_submit_job;

- ret = etnaviv_sched_push_job(&ctx->sched_entity[args->pipe], submit); + ret = etnaviv_sched_push_job(submit); if (ret) - goto err_submit_objects; + goto err_submit_job;

submit_attach_object_fences(submit);

@@ -595,7 +597,7 @@ int etnaviv_ioctl_gem_submit(struct drm_device *dev, void *data, sync_file = sync_file_create(submit->out_fence); if (!sync_file) { ret = -ENOMEM; - goto err_submit_objects; + goto err_submit_job; } fd_install(out_fence_fd, sync_file->file); } @@ -603,7 +605,9 @@ int etnaviv_ioctl_gem_submit(struct drm_device *dev, void *data, args->fence_fd = out_fence_fd; args->fence = submit->out_fence_id;

-err_submit_objects: +err_submit_job: + drm_sched_job_cleanup(&submit->sched_job); +err_submit_put: etnaviv_submit_put(submit);

err_submit_ww_acquire: diff --git a/drivers/gpu/drm/etnaviv/etnaviv_sched.c b/drivers/gpu/drm/etnaviv/etnaviv_sched.c index 180bb633d5c5..2bbbd6ccc95e 100644 --- a/drivers/gpu/drm/etnaviv/etnaviv_sched.c +++ b/drivers/gpu/drm/etnaviv/etnaviv_sched.c @@ -17,58 +17,6 @@ module_param_named(job_hang_limit, etnaviv_job_hang_limit, int , 0444); static int etnaviv_hw_jobs_limit = 4; module_param_named(hw_job_limit, etnaviv_hw_jobs_limit, int , 0444);

-static struct dma_fence * -etnaviv_sched_dependency(struct drm_sched_job *sched_job, - struct drm_sched_entity *entity) -{ - struct etnaviv_gem_submit *submit = to_etnaviv_submit(sched_job); - struct dma_fence *fence; - int i; - - if (unlikely(submit->in_fence)) { - fence = submit->in_fence; - submit->in_fence = NULL; - - if (!dma_fence_is_signaled(fence)) - return fence; - - dma_fence_put(fence); - } - - for (i = 0; i < submit->nr_bos; i++) { - struct etnaviv_gem_submit_bo *bo = &submit->bos[i]; - int j; - - if (bo->excl) { - fence = bo->excl; - bo->excl = NULL; - - if (!dma_fence_is_signaled(fence)) - return fence; - - dma_fence_put(fence); - } - - for (j = 0; j < bo->nr_shared; j++) { - if (!bo->shared[j]) - continue; - - fence = bo->shared[j]; - bo->shared[j] = NULL; - - if (!dma_fence_is_signaled(fence)) - return fence; - - dma_fence_put(fence); - } - kfree(bo->shared); - bo->nr_shared = 0; - bo->shared = NULL; - } - - return NULL; -} - static struct dma_fence *etnaviv_sched_run_job(struct drm_sched_job *sched_job) { struct etnaviv_gem_submit *submit = to_etnaviv_submit(sched_job); @@ -140,29 +88,22 @@ static void etnaviv_sched_free_job(struct drm_sched_job *sched_job) }

static const struct drm_sched_backend_ops etnaviv_sched_ops = { - .dependency = etnaviv_sched_dependency, .run_job = etnaviv_sched_run_job, .timedout_job = etnaviv_sched_timedout_job, .free_job = etnaviv_sched_free_job, };

-int etnaviv_sched_push_job(struct drm_sched_entity *sched_entity, - struct etnaviv_gem_submit *submit) +int etnaviv_sched_push_job(struct etnaviv_gem_submit *submit) { int ret = 0;

/* * Hold the fence lock across the whole operation to avoid jobs being * pushed out of order with regard to their sched fence seqnos as - * allocated in drm_sched_job_init. + * allocated in drm_sched_job_arm. */ mutex_lock(&submit->gpu->fence_lock);

- ret = drm_sched_job_init(&submit->sched_job, sched_entity, - submit->ctx); - if (ret) - goto out_unlock; - drm_sched_job_arm(&submit->sched_job);

submit->out_fence = dma_fence_get(&submit->sched_job.s_fence->finished); diff --git a/drivers/gpu/drm/etnaviv/etnaviv_sched.h b/drivers/gpu/drm/etnaviv/etnaviv_sched.h index c0a6796e22c9..baebfa069afc 100644 --- a/drivers/gpu/drm/etnaviv/etnaviv_sched.h +++ b/drivers/gpu/drm/etnaviv/etnaviv_sched.h @@ -18,7 +18,6 @@ struct etnaviv_gem_submit *to_etnaviv_submit(struct drm_sched_job *sched_job)

int etnaviv_sched_init(struct etnaviv_gpu *gpu); void etnaviv_sched_fini(struct etnaviv_gpu *gpu); -int etnaviv_sched_push_job(struct drm_sched_entity *sched_entity, - struct etnaviv_gem_submit *submit); +int etnaviv_sched_push_job(struct etnaviv_gem_submit *submit);

#endif /* __ETNAVIV_SCHED_H__ */

This is essentially part of drm_sched_dependency_optimized(), which only amdgpu seems to make use of. Use it a bit more.

This would mean that as-is amdgpu can't use the dependency helpers, at least not with the current approach amdgpu has for deciding whether a vm_flush is needed. Since amdgpu also has very special rules around implicit fencing it can't use those helpers either, and adding a drm_sched_job_await_fence_always or similar for amdgpu wouldn't be too onerous. That way the special case handling for amdgpu sticks even more out and we have higher chances that reviewers that go across all drivers wont miss it.

Reviewed-by: Lucas Stach l.stach@pengutronix.de Signed-off-by: Daniel Vetter daniel.vetter@intel.com Cc: "Christian König" christian.koenig@amd.com Cc: Daniel Vetter daniel.vetter@ffwll.ch Cc: Luben Tuikov luben.tuikov@amd.com Cc: Andrey Grodzovsky andrey.grodzovsky@amd.com Cc: Alex Deucher alexander.deucher@amd.com Cc: Jack Zhang Jack.Zhang1@amd.com --- drivers/gpu/drm/scheduler/sched_main.c | 7 +++++++ 1 file changed, 7 insertions(+)

diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c index 84c30badb78e..fd52db906b90 100644 --- a/drivers/gpu/drm/scheduler/sched_main.c +++ b/drivers/gpu/drm/scheduler/sched_main.c @@ -660,6 +660,13 @@ int drm_sched_job_await_fence(struct drm_sched_job *job, if (!fence) return 0;

+ /* if it's a fence from us it's guaranteed to be earlier */ + if (fence->context == job->entity->fence_context || + fence->context == job->entity->fence_context + 1) { + dma_fence_put(fence); + return 0; + } + /* Deduplicate if we already depend on a fence from the same context. * This lets the size of the array of deps scale with the number of * engines involved, rather than the number of BOs.

There's only one exclusive slot, and we must not break the ordering.

Adding a new exclusive fence drops all previous fences from the dma_resv. To avoid violating the signalling order we err on the side of over-synchronizing by waiting for the existing fences, even if userspace asked us to ignore them.

A better fix would be to us a dma_fence_chain or _array like e.g. amdgpu now uses, but - msm has a synchronous dma_fence_wait for anything from another context, so doesn't seem to care much, - and it probably makes sense to lift this into dma-resv.c code as a proper concept, so that drivers don't have to hack up their own solution each on their own.

v2: Improve commit message per Lucas' suggestion.

Cc: Lucas Stach l.stach@pengutronix.de Signed-off-by: Daniel Vetter daniel.vetter@intel.com Cc: Rob Clark robdclark@gmail.com Cc: Sean Paul sean@poorly.run Cc: linux-arm-msm@vger.kernel.org Cc: freedreno@lists.freedesktop.org --- drivers/gpu/drm/msm/msm_gem_submit.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/msm/msm_gem_submit.c b/drivers/gpu/drm/msm/msm_gem_submit.c index b71da71a3dd8..edd0051d849f 100644 --- a/drivers/gpu/drm/msm/msm_gem_submit.c +++ b/drivers/gpu/drm/msm/msm_gem_submit.c @@ -306,7 +306,8 @@ static int submit_fence_sync(struct msm_gem_submit *submit, bool no_implicit) return ret; }

- if (no_implicit) + /* exclusive fences must be ordered */ + if (no_implicit && !write) continue;

ret = msm_gem_sync_object(&msm_obj->base, submit->ring->fctx,

No longer used, the last user disappeared with

commit d07f0e59b2c762584478920cd2d11fba2980a94a Author: Chris Wilson chris@chris-wilson.co.uk Date: Fri Oct 28 13:58:44 2016 +0100

drm/i915: Move GEM activity tracking into a common struct reservation_object

Signed-off-by: Daniel Vetter daniel.vetter@intel.com Cc: Maarten Lankhorst maarten.lankhorst@linux.intel.com Cc: "Thomas Hellström" thomas.hellstrom@linux.intel.com Cc: Jason Ekstrand jason@jlekstrand.net --- drivers/gpu/drm/i915/display/intel_display.c | 4 ++-- drivers/gpu/drm/i915/gem/i915_gem_clflush.c | 2 +- drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c | 2 +- drivers/gpu/drm/i915/i915_sw_fence.c | 6 +----- drivers/gpu/drm/i915/i915_sw_fence.h | 1 - 5 files changed, 5 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c index 98e0f4ed7e4a..678c7839034e 100644 --- a/drivers/gpu/drm/i915/display/intel_display.c +++ b/drivers/gpu/drm/i915/display/intel_display.c @@ -11119,7 +11119,7 @@ intel_prepare_plane_fb(struct drm_plane *_plane, */ if (intel_crtc_needs_modeset(crtc_state)) { ret = i915_sw_fence_await_reservation(&state->commit_ready, - old_obj->base.resv, NULL, + old_obj->base.resv, false, 0, GFP_KERNEL); if (ret < 0) @@ -11153,7 +11153,7 @@ intel_prepare_plane_fb(struct drm_plane *_plane, struct dma_fence *fence;

ret = i915_sw_fence_await_reservation(&state->commit_ready, - obj->base.resv, NULL, + obj->base.resv, false, i915_fence_timeout(dev_priv), GFP_KERNEL); diff --git a/drivers/gpu/drm/i915/gem/i915_gem_clflush.c b/drivers/gpu/drm/i915/gem/i915_gem_clflush.c index daf9284ef1f5..93439d2c7a58 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_clflush.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_clflush.c @@ -106,7 +106,7 @@ bool i915_gem_clflush_object(struct drm_i915_gem_object *obj, clflush = clflush_work_create(obj); if (clflush) { i915_sw_fence_await_reservation(&clflush->base.chain, - obj->base.resv, NULL, true, + obj->base.resv, true, i915_fence_timeout(to_i915(obj->base.dev)), I915_FENCE_GFP); dma_resv_add_excl_fence(obj->base.resv, &clflush->base.dma); diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c index b95c8927d465..b4a77eba8631 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c @@ -2087,7 +2087,7 @@ static int eb_parse_pipeline(struct i915_execbuffer *eb,

/* Wait for all writes (and relocs) into the batch to complete */ err = i915_sw_fence_await_reservation(&pw->base.chain, - pw->batch->resv, NULL, false, + pw->batch->resv, false, 0, I915_FENCE_GFP); if (err < 0) goto err_commit; diff --git a/drivers/gpu/drm/i915/i915_sw_fence.c b/drivers/gpu/drm/i915/i915_sw_fence.c index c589a681da77..91711a46b1c7 100644 --- a/drivers/gpu/drm/i915/i915_sw_fence.c +++ b/drivers/gpu/drm/i915/i915_sw_fence.c @@ -567,7 +567,6 @@ int __i915_sw_fence_await_dma_fence(struct i915_sw_fence *fence,

int i915_sw_fence_await_reservation(struct i915_sw_fence *fence, struct dma_resv *resv, - const struct dma_fence_ops *exclude, bool write, unsigned long timeout, gfp_t gfp) @@ -587,9 +586,6 @@ int i915_sw_fence_await_reservation(struct i915_sw_fence *fence, return ret;

for (i = 0; i < count; i++) { - if (shared[i]->ops == exclude) - continue; - pending = i915_sw_fence_await_dma_fence(fence, shared[i], timeout, @@ -609,7 +605,7 @@ int i915_sw_fence_await_reservation(struct i915_sw_fence *fence, excl = dma_resv_get_excl_unlocked(resv); }

- if (ret >= 0 && excl && excl->ops != exclude) { + if (ret >= 0 && excl) { pending = i915_sw_fence_await_dma_fence(fence, excl, timeout, diff --git a/drivers/gpu/drm/i915/i915_sw_fence.h b/drivers/gpu/drm/i915/i915_sw_fence.h index 30a863353ee6..6572f01668e4 100644 --- a/drivers/gpu/drm/i915/i915_sw_fence.h +++ b/drivers/gpu/drm/i915/i915_sw_fence.h @@ -86,7 +86,6 @@ int i915_sw_fence_await_dma_fence(struct i915_sw_fence *fence,

int i915_sw_fence_await_reservation(struct i915_sw_fence *fence, struct dma_resv *resv, - const struct dma_fence_ops *exclude, bool write, unsigned long timeout, gfp_t gfp);

Specifically document the new/clarified rules around how the shared fences do not have any ordering requirements against the exclusive fence.

But also document all the things a bit better, given how central struct dma_resv to dynamic buffer management the docs have been very inadequat.

- Lots more links to other pieces of the puzzle. Unfortunately ttm_buffer_object has no docs, so no links :-(

- Explain/complain a bit about dma_resv_locking_ctx(). I still don't like that one, but fixing the ttm call chains is going to be horrible. Plus we want to plug in real slowpath locking when we do that anyway.

- Main part of the patch is some actual docs for struct dma_resv.

Overall I think we still have a lot of bad naming in this area (e.g. dma_resv.fence is singular, but contains the multiple shared fences), but I think that's more indicative of how the semantics and rules are just not great.

Another thing that's real awkard is how chaining exclusive fences right now means direct dma_resv.exclusive_fence pointer access with an rcu_assign_pointer. Not so great either.

v2: - Fix a pile of typos (Matt, Jason) - Hammer it in that breaking the rules leads to use-after-free issues around dma-buf sharing (Christian)

Reviewed-by: Christian König christian.koenig@amd.com Cc: Jason Ekstrand jason@jlekstrand.net Cc: Matthew Auld matthew.auld@intel.com Reviewed-by: Matthew Auld matthew.auld@intel.com Signed-off-by: Daniel Vetter daniel.vetter@intel.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/dma-buf/dma-resv.c | 24 ++++++--- include/linux/dma-buf.h | 7 +++ include/linux/dma-resv.h | 104 +++++++++++++++++++++++++++++++++++-- 3 files changed, 124 insertions(+), 11 deletions(-)

diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c index e744fd87c63c..84fbe60629e3 100644 --- a/drivers/dma-buf/dma-resv.c +++ b/drivers/dma-buf/dma-resv.c @@ -48,6 +48,8 @@ * write operations) or N shared fences (read operations). The RCU * mechanism is used to protect read access to fences from locked * write-side updates. + * + * See struct dma_resv for more details. */

DEFINE_WD_CLASS(reservation_ww_class); @@ -137,7 +139,11 @@ EXPORT_SYMBOL(dma_resv_fini); * @num_fences: number of fences we want to add * * Should be called before dma_resv_add_shared_fence(). Must - * be called with obj->lock held. + * be called with @obj locked through dma_resv_lock(). + * + * Note that the preallocated slots need to be re-reserved if @obj is unlocked + * at any time before calling dma_resv_add_shared_fence(). This is validated + * when CONFIG_DEBUG_MUTEXES is enabled. * * RETURNS * Zero for success, or -errno @@ -234,8 +240,10 @@ EXPORT_SYMBOL(dma_resv_reset_shared_max); * @obj: the reservation object * @fence: the shared fence to add * - * Add a fence to a shared slot, obj->lock must be held, and + * Add a fence to a shared slot, @obj must be locked with dma_resv_lock(), and * dma_resv_reserve_shared() has been called. + * + * See also &dma_resv.fence for a discussion of the semantics. */ void dma_resv_add_shared_fence(struct dma_resv *obj, struct dma_fence *fence) { @@ -278,9 +286,11 @@ EXPORT_SYMBOL(dma_resv_add_shared_fence); /** * dma_resv_add_excl_fence - Add an exclusive fence. * @obj: the reservation object - * @fence: the shared fence to add + * @fence: the exclusive fence to add * - * Add a fence to the exclusive slot. The obj->lock must be held. + * Add a fence to the exclusive slot. @obj must be locked with dma_resv_lock(). + * Note that this function replaces all fences attached to @obj, see also + * &dma_resv.fence_excl for a discussion of the semantics. */ void dma_resv_add_excl_fence(struct dma_resv *obj, struct dma_fence *fence) { @@ -609,9 +619,11 @@ static inline int dma_resv_test_signaled_single(struct dma_fence *passed_fence) * fence * * Callers are not required to hold specific locks, but maybe hold - * dma_resv_lock() already + * dma_resv_lock() already. + * * RETURNS - * true if all fences signaled, else false + * + * True if all fences signaled, else false. */ bool dma_resv_test_signaled(struct dma_resv *obj, bool test_all) { diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h index 2b814fde0d11..8cc0c55877a6 100644 --- a/include/linux/dma-buf.h +++ b/include/linux/dma-buf.h @@ -420,6 +420,13 @@ struct dma_buf { * - Dynamic importers should set fences for any access that they can't * disable immediately from their &dma_buf_attach_ops.move_notify * callback. + * + * IMPORTANT: + * + * All drivers must obey the struct dma_resv rules, specifically the + * rules for updating fences, see &dma_resv.fence_excl and + * &dma_resv.fence. If these dependency rules are broken access tracking + * can be lost resulting in use after free issues. */ struct dma_resv *resv;

diff --git a/include/linux/dma-resv.h b/include/linux/dma-resv.h index e1ca2080a1ff..9100dd3dc21f 100644 --- a/include/linux/dma-resv.h +++ b/include/linux/dma-resv.h @@ -62,16 +62,90 @@ struct dma_resv_list {

/** * struct dma_resv - a reservation object manages fences for a buffer - * @lock: update side lock - * @seq: sequence count for managing RCU read-side synchronization - * @fence_excl: the exclusive fence, if there is one currently - * @fence: list of current shared fences + * + * There are multiple uses for this, with sometimes slightly different rules in + * how the fence slots are used. + * + * One use is to synchronize cross-driver access to a struct dma_buf, either for + * dynamic buffer management or just to handle implicit synchronization between + * different users of the buffer in userspace. See &dma_buf.resv for a more + * in-depth discussion. + * + * The other major use is to manage access and locking within a driver in a + * buffer based memory manager. struct ttm_buffer_object is the canonical + * example here, since this is where reservation objects originated from. But + * use in drivers is spreading and some drivers also manage struct + * drm_gem_object with the same scheme. */ struct dma_resv { + /** + * @lock: + * + * Update side lock. Don't use directly, instead use the wrapper + * functions like dma_resv_lock() and dma_resv_unlock(). + * + * Drivers which use the reservation object to manage memory dynamically + * also use this lock to protect buffer object state like placement, + * allocation policies or throughout command submission. + */ struct ww_mutex lock; + + /** + * @seq: + * + * Sequence count for managing RCU read-side synchronization, allows + * read-only access to @fence_excl and @fence while ensuring we take a + * consistent snapshot. + */ seqcount_ww_mutex_t seq;

+ /** + * @fence_excl: + * + * The exclusive fence, if there is one currently. + * + * There are two ways to update this fence: + * + * - First by calling dma_resv_add_excl_fence(), which replaces all + * fences attached to the reservation object. To guarantee that no + * fences are lost, this new fence must signal only after all previous + * fences, both shared and exclusive, have signalled. In some cases it + * is convenient to achieve that by attaching a struct dma_fence_array + * with all the new and old fences. + * + * - Alternatively the fence can be set directly, which leaves the + * shared fences unchanged. To guarantee that no fences are lost, this + * new fence must signal only after the previous exclusive fence has + * signalled. Since the shared fences are staying intact, it is not + * necessary to maintain any ordering against those. If semantically + * only a new access is added without actually treating the previous + * one as a dependency the exclusive fences can be strung together + * using struct dma_fence_chain. + * + * Note that actual semantics of what an exclusive or shared fence mean + * is defined by the user, for reservation objects shared across drivers + * see &dma_buf.resv. + */ struct dma_fence __rcu *fence_excl; + + /** + * @fence: + * + * List of current shared fences. + * + * There are no ordering constraints of shared fences against the + * exclusive fence slot. If a waiter needs to wait for all access, it + * has to wait for both sets of fences to signal. + * + * A new fence is added by calling dma_resv_add_shared_fence(). Since + * this often needs to be done past the point of no return in command + * submission it cannot fail, and therefore sufficient slots need to be + * reserved by calling dma_resv_reserve_shared(). + * + * Note that actual semantics of what an exclusive or shared fence mean + * is defined by the user, for reservation objects shared across drivers + * see &dma_buf.resv. + */ struct dma_resv_list __rcu *fence; };

@@ -98,6 +172,13 @@ static inline void dma_resv_reset_shared_max(struct dma_resv *obj) {} * undefined order, a #ww_acquire_ctx is passed to unwind if a cycle * is detected. See ww_mutex_lock() and ww_acquire_init(). A reservation * object may be locked by itself by passing NULL as @ctx. + * + * When a die situation is indicated by returning -EDEADLK all locks held by + * @ctx must be unlocked and then dma_resv_lock_slow() called on @obj. + * + * Unlocked by calling dma_resv_unlock(). + * + * See also dma_resv_lock_interruptible() for the interruptible variant. */ static inline int dma_resv_lock(struct dma_resv *obj, struct ww_acquire_ctx *ctx) @@ -119,6 +200,12 @@ static inline int dma_resv_lock(struct dma_resv *obj, * undefined order, a #ww_acquire_ctx is passed to unwind if a cycle * is detected. See ww_mutex_lock() and ww_acquire_init(). A reservation * object may be locked by itself by passing NULL as @ctx. + * + * When a die situation is indicated by returning -EDEADLK all locks held by + * @ctx must be unlocked and then dma_resv_lock_slow_interruptible() called on + * @obj. + * + * Unlocked by calling dma_resv_unlock(). */ static inline int dma_resv_lock_interruptible(struct dma_resv *obj, struct ww_acquire_ctx *ctx) @@ -134,6 +221,8 @@ static inline int dma_resv_lock_interruptible(struct dma_resv *obj, * Acquires the reservation object after a die case. This function * will sleep until the lock becomes available. See dma_resv_lock() as * well. + * + * See also dma_resv_lock_slow_interruptible() for the interruptible variant. */ static inline void dma_resv_lock_slow(struct dma_resv *obj, struct ww_acquire_ctx *ctx) @@ -167,7 +256,7 @@ static inline int dma_resv_lock_slow_interruptible(struct dma_resv *obj, * if they overlap with a writer. * * Also note that since no context is provided, no deadlock protection is - * possible. + * possible, which is also not needed for a trylock. * * Returns true if the lock was acquired, false otherwise. */ @@ -193,6 +282,11 @@ static inline bool dma_resv_is_locked(struct dma_resv *obj) * * Returns the context used to lock a reservation object or NULL if no context * was used or the object is not locked at all. + * + * WARNING: This interface is pretty horrible, but TTM needs it because it + * doesn't pass the struct ww_acquire_ctx around in some very long callchains. + * Everyone else just uses it to check whether they're holding a reservation or + * not. */ static inline struct ww_acquire_ctx *dma_resv_locking_ctx(struct dma_resv *obj) {