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path: root/drivers/gpu/drm/scheduler/sched_entity.c
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Diffstat (limited to 'drivers/gpu/drm/scheduler/sched_entity.c')
-rw-r--r--drivers/gpu/drm/scheduler/sched_entity.c596
1 files changed, 596 insertions, 0 deletions
diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c
new file mode 100644
index 000000000..a42763e14
--- /dev/null
+++ b/drivers/gpu/drm/scheduler/sched_entity.c
@@ -0,0 +1,596 @@
+/*
+ * Copyright 2015 Advanced Micro Devices, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ */
+
+#include <linux/kthread.h>
+#include <linux/slab.h>
+#include <linux/completion.h>
+
+#include <drm/drm_print.h>
+#include <drm/gpu_scheduler.h>
+
+#include "gpu_scheduler_trace.h"
+
+#define to_drm_sched_job(sched_job) \
+ container_of((sched_job), struct drm_sched_job, queue_node)
+
+/**
+ * drm_sched_entity_init - Init a context entity used by scheduler when
+ * submit to HW ring.
+ *
+ * @entity: scheduler entity to init
+ * @priority: priority of the entity
+ * @sched_list: the list of drm scheds on which jobs from this
+ * entity can be submitted
+ * @num_sched_list: number of drm sched in sched_list
+ * @guilty: atomic_t set to 1 when a job on this queue
+ * is found to be guilty causing a timeout
+ *
+ * Note that the &sched_list must have at least one element to schedule the entity.
+ *
+ * For changing @priority later on at runtime see
+ * drm_sched_entity_set_priority(). For changing the set of schedulers
+ * @sched_list at runtime see drm_sched_entity_modify_sched().
+ *
+ * An entity is cleaned up by callind drm_sched_entity_fini(). See also
+ * drm_sched_entity_destroy().
+ *
+ * Returns 0 on success or a negative error code on failure.
+ */
+int drm_sched_entity_init(struct drm_sched_entity *entity,
+ enum drm_sched_priority priority,
+ struct drm_gpu_scheduler **sched_list,
+ unsigned int num_sched_list,
+ atomic_t *guilty)
+{
+ if (!(entity && sched_list && (num_sched_list == 0 || sched_list[0])))
+ return -EINVAL;
+
+ memset(entity, 0, sizeof(struct drm_sched_entity));
+ INIT_LIST_HEAD(&entity->list);
+ entity->rq = NULL;
+ entity->guilty = guilty;
+ entity->num_sched_list = num_sched_list;
+ entity->priority = priority;
+ entity->sched_list = num_sched_list > 1 ? sched_list : NULL;
+ RCU_INIT_POINTER(entity->last_scheduled, NULL);
+ RB_CLEAR_NODE(&entity->rb_tree_node);
+
+ if(num_sched_list)
+ entity->rq = &sched_list[0]->sched_rq[entity->priority];
+
+ init_completion(&entity->entity_idle);
+
+ /* We start in an idle state. */
+ complete_all(&entity->entity_idle);
+
+ spin_lock_init(&entity->rq_lock);
+ spsc_queue_init(&entity->job_queue);
+
+ atomic_set(&entity->fence_seq, 0);
+ entity->fence_context = dma_fence_context_alloc(2);
+
+ return 0;
+}
+EXPORT_SYMBOL(drm_sched_entity_init);
+
+/**
+ * drm_sched_entity_modify_sched - Modify sched of an entity
+ * @entity: scheduler entity to init
+ * @sched_list: the list of new drm scheds which will replace
+ * existing entity->sched_list
+ * @num_sched_list: number of drm sched in sched_list
+ *
+ * Note that this must be called under the same common lock for @entity as
+ * drm_sched_job_arm() and drm_sched_entity_push_job(), or the driver needs to
+ * guarantee through some other means that this is never called while new jobs
+ * can be pushed to @entity.
+ */
+void drm_sched_entity_modify_sched(struct drm_sched_entity *entity,
+ struct drm_gpu_scheduler **sched_list,
+ unsigned int num_sched_list)
+{
+ WARN_ON(!num_sched_list || !sched_list);
+
+ entity->sched_list = sched_list;
+ entity->num_sched_list = num_sched_list;
+}
+EXPORT_SYMBOL(drm_sched_entity_modify_sched);
+
+static bool drm_sched_entity_is_idle(struct drm_sched_entity *entity)
+{
+ rmb(); /* for list_empty to work without lock */
+
+ if (list_empty(&entity->list) ||
+ spsc_queue_count(&entity->job_queue) == 0 ||
+ entity->stopped)
+ return true;
+
+ return false;
+}
+
+/* Return true if entity could provide a job. */
+bool drm_sched_entity_is_ready(struct drm_sched_entity *entity)
+{
+ if (spsc_queue_peek(&entity->job_queue) == NULL)
+ return false;
+
+ if (READ_ONCE(entity->dependency))
+ return false;
+
+ return true;
+}
+
+/**
+ * drm_sched_entity_error - return error of last scheduled job
+ * @entity: scheduler entity to check
+ *
+ * Opportunistically return the error of the last scheduled job. Result can
+ * change any time when new jobs are pushed to the hw.
+ */
+int drm_sched_entity_error(struct drm_sched_entity *entity)
+{
+ struct dma_fence *fence;
+ int r;
+
+ rcu_read_lock();
+ fence = rcu_dereference(entity->last_scheduled);
+ r = fence ? fence->error : 0;
+ rcu_read_unlock();
+
+ return r;
+}
+EXPORT_SYMBOL(drm_sched_entity_error);
+
+static void drm_sched_entity_kill_jobs_work(struct work_struct *wrk)
+{
+ struct drm_sched_job *job = container_of(wrk, typeof(*job), work);
+
+ drm_sched_fence_finished(job->s_fence, -ESRCH);
+ WARN_ON(job->s_fence->parent);
+ job->sched->ops->free_job(job);
+}
+
+/* Signal the scheduler finished fence when the entity in question is killed. */
+static void drm_sched_entity_kill_jobs_cb(struct dma_fence *f,
+ struct dma_fence_cb *cb)
+{
+ struct drm_sched_job *job = container_of(cb, struct drm_sched_job,
+ finish_cb);
+ unsigned long index;
+
+ dma_fence_put(f);
+
+ /* Wait for all dependencies to avoid data corruptions */
+ xa_for_each(&job->dependencies, index, f) {
+ struct drm_sched_fence *s_fence = to_drm_sched_fence(f);
+
+ if (s_fence && f == &s_fence->scheduled) {
+ /* The dependencies array had a reference on the scheduled
+ * fence, and the finished fence refcount might have
+ * dropped to zero. Use dma_fence_get_rcu() so we get
+ * a NULL fence in that case.
+ */
+ f = dma_fence_get_rcu(&s_fence->finished);
+
+ /* Now that we have a reference on the finished fence,
+ * we can release the reference the dependencies array
+ * had on the scheduled fence.
+ */
+ dma_fence_put(&s_fence->scheduled);
+ }
+
+ xa_erase(&job->dependencies, index);
+ if (f && !dma_fence_add_callback(f, &job->finish_cb,
+ drm_sched_entity_kill_jobs_cb))
+ return;
+
+ dma_fence_put(f);
+ }
+
+ INIT_WORK(&job->work, drm_sched_entity_kill_jobs_work);
+ schedule_work(&job->work);
+}
+
+/* Remove the entity from the scheduler and kill all pending jobs */
+static void drm_sched_entity_kill(struct drm_sched_entity *entity)
+{
+ struct drm_sched_job *job;
+ struct dma_fence *prev;
+
+ if (!entity->rq)
+ return;
+
+ spin_lock(&entity->rq_lock);
+ entity->stopped = true;
+ drm_sched_rq_remove_entity(entity->rq, entity);
+ spin_unlock(&entity->rq_lock);
+
+ /* Make sure this entity is not used by the scheduler at the moment */
+ wait_for_completion(&entity->entity_idle);
+
+ /* The entity is guaranteed to not be used by the scheduler */
+ prev = rcu_dereference_check(entity->last_scheduled, true);
+ dma_fence_get(prev);
+ while ((job = to_drm_sched_job(spsc_queue_pop(&entity->job_queue)))) {
+ struct drm_sched_fence *s_fence = job->s_fence;
+
+ dma_fence_get(&s_fence->finished);
+ if (!prev || dma_fence_add_callback(prev, &job->finish_cb,
+ drm_sched_entity_kill_jobs_cb))
+ drm_sched_entity_kill_jobs_cb(NULL, &job->finish_cb);
+
+ prev = &s_fence->finished;
+ }
+ dma_fence_put(prev);
+}
+
+/**
+ * drm_sched_entity_flush - Flush a context entity
+ *
+ * @entity: scheduler entity
+ * @timeout: time to wait in for Q to become empty in jiffies.
+ *
+ * Splitting drm_sched_entity_fini() into two functions, The first one does the
+ * waiting, removes the entity from the runqueue and returns an error when the
+ * process was killed.
+ *
+ * Returns the remaining time in jiffies left from the input timeout
+ */
+long drm_sched_entity_flush(struct drm_sched_entity *entity, long timeout)
+{
+ struct drm_gpu_scheduler *sched;
+ struct task_struct *last_user;
+ long ret = timeout;
+
+ if (!entity->rq)
+ return 0;
+
+ sched = entity->rq->sched;
+ /**
+ * The client will not queue more IBs during this fini, consume existing
+ * queued IBs or discard them on SIGKILL
+ */
+ if (current->flags & PF_EXITING) {
+ if (timeout)
+ ret = wait_event_timeout(
+ sched->job_scheduled,
+ drm_sched_entity_is_idle(entity),
+ timeout);
+ } else {
+ wait_event_killable(sched->job_scheduled,
+ drm_sched_entity_is_idle(entity));
+ }
+
+ /* For killed process disable any more IBs enqueue right now */
+ last_user = cmpxchg(&entity->last_user, current->group_leader, NULL);
+ if ((!last_user || last_user == current->group_leader) &&
+ (current->flags & PF_EXITING) && (current->exit_code == SIGKILL))
+ drm_sched_entity_kill(entity);
+
+ return ret;
+}
+EXPORT_SYMBOL(drm_sched_entity_flush);
+
+/**
+ * drm_sched_entity_fini - Destroy a context entity
+ *
+ * @entity: scheduler entity
+ *
+ * Cleanups up @entity which has been initialized by drm_sched_entity_init().
+ *
+ * If there are potentially job still in flight or getting newly queued
+ * drm_sched_entity_flush() must be called first. This function then goes over
+ * the entity and signals all jobs with an error code if the process was killed.
+ */
+void drm_sched_entity_fini(struct drm_sched_entity *entity)
+{
+ /*
+ * If consumption of existing IBs wasn't completed. Forcefully remove
+ * them here. Also makes sure that the scheduler won't touch this entity
+ * any more.
+ */
+ drm_sched_entity_kill(entity);
+
+ if (entity->dependency) {
+ dma_fence_remove_callback(entity->dependency, &entity->cb);
+ dma_fence_put(entity->dependency);
+ entity->dependency = NULL;
+ }
+
+ dma_fence_put(rcu_dereference_check(entity->last_scheduled, true));
+ RCU_INIT_POINTER(entity->last_scheduled, NULL);
+}
+EXPORT_SYMBOL(drm_sched_entity_fini);
+
+/**
+ * drm_sched_entity_destroy - Destroy a context entity
+ * @entity: scheduler entity
+ *
+ * Calls drm_sched_entity_flush() and drm_sched_entity_fini() as a
+ * convenience wrapper.
+ */
+void drm_sched_entity_destroy(struct drm_sched_entity *entity)
+{
+ drm_sched_entity_flush(entity, MAX_WAIT_SCHED_ENTITY_Q_EMPTY);
+ drm_sched_entity_fini(entity);
+}
+EXPORT_SYMBOL(drm_sched_entity_destroy);
+
+/* drm_sched_entity_clear_dep - callback to clear the entities dependency */
+static void drm_sched_entity_clear_dep(struct dma_fence *f,
+ struct dma_fence_cb *cb)
+{
+ struct drm_sched_entity *entity =
+ container_of(cb, struct drm_sched_entity, cb);
+
+ entity->dependency = NULL;
+ dma_fence_put(f);
+}
+
+/*
+ * drm_sched_entity_clear_dep - callback to clear the entities dependency and
+ * wake up scheduler
+ */
+static void drm_sched_entity_wakeup(struct dma_fence *f,
+ struct dma_fence_cb *cb)
+{
+ struct drm_sched_entity *entity =
+ container_of(cb, struct drm_sched_entity, cb);
+
+ drm_sched_entity_clear_dep(f, cb);
+ drm_sched_wakeup_if_can_queue(entity->rq->sched);
+}
+
+/**
+ * drm_sched_entity_set_priority - Sets priority of the entity
+ *
+ * @entity: scheduler entity
+ * @priority: scheduler priority
+ *
+ * Update the priority of runqueus used for the entity.
+ */
+void drm_sched_entity_set_priority(struct drm_sched_entity *entity,
+ enum drm_sched_priority priority)
+{
+ spin_lock(&entity->rq_lock);
+ entity->priority = priority;
+ spin_unlock(&entity->rq_lock);
+}
+EXPORT_SYMBOL(drm_sched_entity_set_priority);
+
+/*
+ * Add a callback to the current dependency of the entity to wake up the
+ * scheduler when the entity becomes available.
+ */
+static bool drm_sched_entity_add_dependency_cb(struct drm_sched_entity *entity)
+{
+ struct drm_gpu_scheduler *sched = entity->rq->sched;
+ struct dma_fence *fence = entity->dependency;
+ struct drm_sched_fence *s_fence;
+
+ if (fence->context == entity->fence_context ||
+ fence->context == entity->fence_context + 1) {
+ /*
+ * Fence is a scheduled/finished fence from a job
+ * which belongs to the same entity, we can ignore
+ * fences from ourself
+ */
+ dma_fence_put(entity->dependency);
+ return false;
+ }
+
+ s_fence = to_drm_sched_fence(fence);
+ if (!fence->error && s_fence && s_fence->sched == sched &&
+ !test_bit(DRM_SCHED_FENCE_DONT_PIPELINE, &fence->flags)) {
+
+ /*
+ * Fence is from the same scheduler, only need to wait for
+ * it to be scheduled
+ */
+ fence = dma_fence_get(&s_fence->scheduled);
+ dma_fence_put(entity->dependency);
+ entity->dependency = fence;
+ if (!dma_fence_add_callback(fence, &entity->cb,
+ drm_sched_entity_clear_dep))
+ return true;
+
+ /* Ignore it when it is already scheduled */
+ dma_fence_put(fence);
+ return false;
+ }
+
+ if (!dma_fence_add_callback(entity->dependency, &entity->cb,
+ drm_sched_entity_wakeup))
+ return true;
+
+ dma_fence_put(entity->dependency);
+ return false;
+}
+
+static struct dma_fence *
+drm_sched_job_dependency(struct drm_sched_job *job,
+ struct drm_sched_entity *entity)
+{
+ struct dma_fence *f;
+
+ /* We keep the fence around, so we can iterate over all dependencies
+ * in drm_sched_entity_kill_jobs_cb() to ensure all deps are signaled
+ * before killing the job.
+ */
+ f = xa_load(&job->dependencies, job->last_dependency);
+ if (f) {
+ job->last_dependency++;
+ return dma_fence_get(f);
+ }
+
+ if (job->sched->ops->prepare_job)
+ return job->sched->ops->prepare_job(job, entity);
+
+ return NULL;
+}
+
+struct drm_sched_job *drm_sched_entity_pop_job(struct drm_sched_entity *entity)
+{
+ struct drm_sched_job *sched_job;
+
+ sched_job = to_drm_sched_job(spsc_queue_peek(&entity->job_queue));
+ if (!sched_job)
+ return NULL;
+
+ while ((entity->dependency =
+ 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))
+ return NULL;
+ }
+
+ /* skip jobs from entity that marked guilty */
+ if (entity->guilty && atomic_read(entity->guilty))
+ dma_fence_set_error(&sched_job->s_fence->finished, -ECANCELED);
+
+ dma_fence_put(rcu_dereference_check(entity->last_scheduled, true));
+ rcu_assign_pointer(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);
+
+ /*
+ * Update the entity's location in the min heap according to
+ * the timestamp of the next job, if any.
+ */
+ if (drm_sched_policy == DRM_SCHED_POLICY_FIFO) {
+ struct drm_sched_job *next;
+
+ next = to_drm_sched_job(spsc_queue_peek(&entity->job_queue));
+ if (next)
+ drm_sched_rq_update_fifo(entity, next->submit_ts);
+ }
+
+ /* Jobs and entities might have different lifecycles. Since we're
+ * removing the job from the entities queue, set the jobs entity pointer
+ * to NULL to prevent any future access of the entity through this job.
+ */
+ sched_job->entity = NULL;
+
+ return sched_job;
+}
+
+void drm_sched_entity_select_rq(struct drm_sched_entity *entity)
+{
+ struct dma_fence *fence;
+ struct drm_gpu_scheduler *sched;
+ struct drm_sched_rq *rq;
+
+ /* 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;
+
+ /*
+ * 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 = rcu_dereference_check(entity->last_scheduled, true);
+
+ /* stay on the same engine if the previous job hasn't finished */
+ if (fence && !dma_fence_is_signaled(fence))
+ return;
+
+ spin_lock(&entity->rq_lock);
+ sched = drm_sched_pick_best(entity->sched_list, entity->num_sched_list);
+ rq = sched ? &sched->sched_rq[entity->priority] : NULL;
+ if (rq != entity->rq) {
+ drm_sched_rq_remove_entity(entity->rq, entity);
+ entity->rq = rq;
+ }
+ spin_unlock(&entity->rq_lock);
+
+ if (entity->num_sched_list == 1)
+ entity->sched_list = NULL;
+}
+
+/**
+ * drm_sched_entity_push_job - Submit a job to the entity's job queue
+ * @sched_job: job to submit
+ *
+ * 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 for the struct drm_sched_entity that was set up for
+ * @sched_job in drm_sched_job_init().
+ *
+ * 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 = sched_job->entity;
+ bool first;
+ ktime_t submit_ts;
+
+ trace_drm_sched_job(sched_job, entity);
+ atomic_inc(entity->rq->sched->score);
+ WRITE_ONCE(entity->last_user, current->group_leader);
+
+ /*
+ * After the sched_job is pushed into the entity queue, it may be
+ * completed and freed up at any time. We can no longer access it.
+ * Make sure to set the submit_ts first, to avoid a race.
+ */
+ sched_job->submit_ts = submit_ts = ktime_get();
+ first = spsc_queue_push(&entity->job_queue, &sched_job->queue_node);
+
+ /* first job wakes up scheduler */
+ if (first) {
+ /* Add the entity to the run queue */
+ spin_lock(&entity->rq_lock);
+ if (entity->stopped) {
+ spin_unlock(&entity->rq_lock);
+
+ DRM_ERROR("Trying to push to a killed entity\n");
+ return;
+ }
+
+ drm_sched_rq_add_entity(entity->rq, entity);
+ spin_unlock(&entity->rq_lock);
+
+ if (drm_sched_policy == DRM_SCHED_POLICY_FIFO)
+ drm_sched_rq_update_fifo(entity, submit_ts);
+
+ drm_sched_wakeup_if_can_queue(entity->rq->sched);
+ }
+}
+EXPORT_SYMBOL(drm_sched_entity_push_job);
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-23 04:50:21 +0000