1 files changed, 524 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 000000000000..3e22a54a99c2
--- /dev/null
+++ b/drivers/gpu/drm/scheduler/sched_entity.c
@@ -0,0 +1,524 @@
+/*
+ * 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 <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
+ * @rq_list: the list of run queue on which jobs from this
+ *           entity can be submitted
+ * @num_rq_list: number of run queue in rq_list
+ * @guilty: atomic_t set to 1 when a job on this queue
+ *          is found to be guilty causing a timeout
+ *
+ * Note: the rq_list should have atleast one element to schedule
+ *       the entity
+ *
+ * Returns 0 on success or a negative error code on failure.
+ */
+int drm_sched_entity_init(struct drm_sched_entity *entity,
+			  struct drm_sched_rq **rq_list,
+			  unsigned int num_rq_list,
+			  atomic_t *guilty)
+{
+	int i;
+
+	if (!(entity && rq_list && num_rq_list > 0 && rq_list[0]))
+		return -EINVAL;
+
+	memset(entity, 0, sizeof(struct drm_sched_entity));
+	INIT_LIST_HEAD(&entity->list);
+	entity->rq = rq_list[0];
+	entity->guilty = guilty;
+	entity->num_rq_list = num_rq_list;
+	entity->rq_list = kcalloc(num_rq_list, sizeof(struct drm_sched_rq *),
+				GFP_KERNEL);
+	if (!entity->rq_list)
+		return -ENOMEM;
+
+	for (i = 0; i < num_rq_list; ++i)
+		entity->rq_list[i] = rq_list[i];
+	entity->last_scheduled = NULL;
+
+	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_is_idle - Check if entity is idle
+ *
+ * @entity: scheduler entity
+ *
+ * Returns true if the entity does not have any unscheduled jobs.
+ */
+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_peek(&entity->job_queue) == NULL)
+		return true;
+
+	return false;
+}
+
+/**
+ * drm_sched_entity_is_ready - Check if entity is ready
+ *
+ * @entity: scheduler entity
+ *
+ * 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_get_free_sched - Get the rq from rq_list with least load
+ *
+ * @entity: scheduler entity
+ *
+ * Return the pointer to the rq with least load.
+ */
+static struct drm_sched_rq *
+drm_sched_entity_get_free_sched(struct drm_sched_entity *entity)
+{
+	struct drm_sched_rq *rq = NULL;
+	unsigned int min_jobs = UINT_MAX, num_jobs;
+	int i;
+
+	for (i = 0; i < entity->num_rq_list; ++i) {
+		num_jobs = atomic_read(&entity->rq_list[i]->sched->num_jobs);
+		if (num_jobs < min_jobs) {
+			min_jobs = num_jobs;
+			rq = entity->rq_list[i];
+		}
+	}
+
+	return rq;
+}
+
+/**
+ * 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;
+
+	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)) {
+		spin_lock(&entity->rq_lock);
+		entity->stopped = true;
+		drm_sched_rq_remove_entity(entity->rq, entity);
+		spin_unlock(&entity->rq_lock);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL(drm_sched_entity_flush);
+
+/**
+ * drm_sched_entity_kill_jobs - helper for drm_sched_entity_kill_jobs
+ *
+ * @f: signaled fence
+ * @cb: our callback structure
+ *
+ * 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);
+
+	drm_sched_fence_finished(job->s_fence);
+	WARN_ON(job->s_fence->parent);
+	dma_fence_put(&job->s_fence->finished);
+	job->sched->ops->free_job(job);
+}
+
+/**
+ * drm_sched_entity_kill_jobs - Make sure all remaining jobs are killed
+ *
+ * @entity: entity which is cleaned up
+ *
+ * Makes sure that all remaining jobs in an entity are killed before it is
+ * destroyed.
+ */
+static void drm_sched_entity_kill_jobs(struct drm_sched_entity *entity)
+{
+	struct drm_sched_job *job;
+	int r;
+
+	while ((job = to_drm_sched_job(spsc_queue_pop(&entity->job_queue)))) {
+		struct drm_sched_fence *s_fence = job->s_fence;
+
+		drm_sched_fence_scheduled(s_fence);
+		dma_fence_set_error(&s_fence->finished, -ESRCH);
+
+		/*
+		 * When pipe is hanged by older entity, new entity might
+		 * not even have chance to submit it's first job to HW
+		 * and so entity->last_scheduled will remain NULL
+		 */
+		if (!entity->last_scheduled) {
+			drm_sched_entity_kill_jobs_cb(NULL, &job->finish_cb);
+			continue;
+		}
+
+		r = dma_fence_add_callback(entity->last_scheduled,
+					   &job->finish_cb,
+					   drm_sched_entity_kill_jobs_cb);
+		if (r == -ENOENT)
+			drm_sched_entity_kill_jobs_cb(NULL, &job->finish_cb);
+		else if (r)
+			DRM_ERROR("fence add callback failed (%d)\n", r);
+	}
+}
+
+/**
+ * drm_sched_entity_cleanup - Destroy a context entity
+ *
+ * @entity: scheduler entity
+ *
+ * This should be called after @drm_sched_entity_do_release. It 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)
+{
+	struct drm_gpu_scheduler *sched;
+
+	sched = entity->rq->sched;
+	drm_sched_rq_remove_entity(entity->rq, entity);
+
+	/* Consumption of existing IBs wasn't completed. Forcefully
+	 * remove them here.
+	 */
+	if (spsc_queue_peek(&entity->job_queue)) {
+		/* Park the kernel for a moment to make sure it isn't processing
+		 * our enity.
+		 */
+		kthread_park(sched->thread);
+		kthread_unpark(sched->thread);
+		if (entity->dependency) {
+			dma_fence_remove_callback(entity->dependency,
+						  &entity->cb);
+			dma_fence_put(entity->dependency);
+			entity->dependency = NULL;
+		}
+
+		drm_sched_entity_kill_jobs(entity);
+	}
+
+	dma_fence_put(entity->last_scheduled);
+	entity->last_scheduled = NULL;
+	kfree(entity->rq_list);
+}
+EXPORT_SYMBOL(drm_sched_entity_fini);
+
+/**
+ * drm_sched_entity_fini - Destroy a context entity
+ *
+ * @entity: scheduler entity
+ *
+ * Calls drm_sched_entity_do_release() and drm_sched_entity_cleanup()
+ */
+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(entity->rq->sched);
+}
+
+/**
+ * drm_sched_entity_set_rq_priority - helper for drm_sched_entity_set_priority
+ */
+static void drm_sched_entity_set_rq_priority(struct drm_sched_rq **rq,
+					     enum drm_sched_priority priority)
+{
+	*rq = &(*rq)->sched->sched_rq[priority];
+}
+
+/**
+ * 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)
+{
+	unsigned int i;
+
+	spin_lock(&entity->rq_lock);
+
+	for (i = 0; i < entity->num_rq_list; ++i)
+		drm_sched_entity_set_rq_priority(&entity->rq_list[i], priority);
+
+	drm_sched_rq_remove_entity(entity->rq, entity);
+	drm_sched_entity_set_rq_priority(&entity->rq, priority);
+	drm_sched_rq_add_entity(entity->rq, entity);
+
+	spin_unlock(&entity->rq_lock);
+}
+EXPORT_SYMBOL(drm_sched_entity_set_priority);
+
+/**
+ * drm_sched_entity_add_dependency_cb - add callback for the entities dependency
+ *
+ * @entity: entity with dependency
+ *
+ * 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 (s_fence && s_fence->sched == sched) {
+
+		/*
+		 * 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;
+}
+
+/**
+ * drm_sched_entity_pop_job - get a ready to be scheduled job from the entity
+ *
+ * @entity: entity to get the job from
+ *
+ * Process all dependencies and try to get one job from the entities queue.
+ */
+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));
+	if (!sched_job)
+		return NULL;
+
+	while ((entity->dependency =
+			sched->ops->dependency(sched_job, entity))) {
+
+		if (drm_sched_entity_add_dependency_cb(entity)) {
+
+			trace_drm_sched_job_wait_dep(sched_job,
+						     entity->dependency);
+			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(entity->last_scheduled);
+	entity->last_scheduled = dma_fence_get(&sched_job->s_fence->finished);
+
+	spsc_queue_pop(&entity->job_queue);
+	return sched_job;
+}
+
+/**
+ * drm_sched_entity_select_rq - select a new rq for the entity
+ *
+ * @entity: scheduler entity
+ *
+ * Check all prerequisites and select a new rq for the entity for load
+ * balancing.
+ */
+void drm_sched_entity_select_rq(struct drm_sched_entity *entity)
+{
+	struct dma_fence *fence;
+	struct drm_sched_rq *rq;
+
+	if (spsc_queue_count(&entity->job_queue) || entity->num_rq_list <= 1)
+		return;
+
+	fence = READ_ONCE(entity->last_scheduled);
+	if (fence && !dma_fence_is_signaled(fence))
+		return;
+
+	rq = drm_sched_entity_get_free_sched(entity);
+	if (rq == entity->rq)
+		return;
+
+	spin_lock(&entity->rq_lock);
+	drm_sched_rq_remove_entity(entity->rq, entity);
+	entity->rq = rq;
+	spin_unlock(&entity->rq_lock);
+}
+
+/**
+ * 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_init under common lock.
+ *
+ * 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)
+{
+	bool first;
+
+	trace_drm_sched_job(sched_job, entity);
+	atomic_inc(&entity->rq->sched->num_jobs);
+	WRITE_ONCE(entity->last_user, current->group_leader);
+	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);
+		drm_sched_wakeup(entity->rq->sched);
+	}
+}
+EXPORT_SYMBOL(drm_sched_entity_push_job);