1 files changed, 638 insertions, 0 deletions

diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c
new file mode 100644
index 000000000000..44fe587aaef9
--- /dev/null
+++ b/drivers/gpu/drm/scheduler/sched_main.c
@@ -0,0 +1,638 @@
+/*
+ * 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.
+ *
+ */
+
+/**
+ * DOC: Overview
+ *
+ * The GPU scheduler provides entities which allow userspace to push jobs
+ * into software queues which are then scheduled on a hardware run queue.
+ * The software queues have a priority among them. The scheduler selects the entities
+ * from the run queue using a FIFO. The scheduler provides dependency handling
+ * features among jobs. The driver is supposed to provide callback functions for
+ * backend operations to the scheduler like submitting a job to hardware run queue,
+ * returning the dependencies of a job etc.
+ *
+ * The organisation of the scheduler is the following:
+ *
+ * 1. Each hw run queue has one scheduler
+ * 2. Each scheduler has multiple run queues with different priorities
+ *    (e.g., HIGH_HW,HIGH_SW, KERNEL, NORMAL)
+ * 3. Each scheduler run queue has a queue of entities to schedule
+ * 4. Entities themselves maintain a queue of jobs that will be scheduled on
+ *    the hardware.
+ *
+ * The jobs in a entity are always scheduled in the order that they were pushed.
+ */
+
+#include <linux/kthread.h>
+#include <linux/wait.h>
+#include <linux/sched.h>
+#include <uapi/linux/sched/types.h>
+#include <drm/drmP.h>
+#include <drm/gpu_scheduler.h>
+#include <drm/spsc_queue.h>
+
+#define CREATE_TRACE_POINTS
+#include "gpu_scheduler_trace.h"
+
+#define to_drm_sched_job(sched_job)		\
+		container_of((sched_job), struct drm_sched_job, queue_node)
+
+static void drm_sched_process_job(struct dma_fence *f, struct dma_fence_cb *cb);
+
+/**
+ * drm_sched_rq_init - initialize a given run queue struct
+ *
+ * @rq: scheduler run queue
+ *
+ * Initializes a scheduler runqueue.
+ */
+static void drm_sched_rq_init(struct drm_gpu_scheduler *sched,
+			      struct drm_sched_rq *rq)
+{
+	spin_lock_init(&rq->lock);
+	INIT_LIST_HEAD(&rq->entities);
+	rq->current_entity = NULL;
+	rq->sched = sched;
+}
+
+/**
+ * drm_sched_rq_add_entity - add an entity
+ *
+ * @rq: scheduler run queue
+ * @entity: scheduler entity
+ *
+ * Adds a scheduler entity to the run queue.
+ */
+void drm_sched_rq_add_entity(struct drm_sched_rq *rq,
+			     struct drm_sched_entity *entity)
+{
+	if (!list_empty(&entity->list))
+		return;
+	spin_lock(&rq->lock);
+	list_add_tail(&entity->list, &rq->entities);
+	spin_unlock(&rq->lock);
+}
+
+/**
+ * drm_sched_rq_remove_entity - remove an entity
+ *
+ * @rq: scheduler run queue
+ * @entity: scheduler entity
+ *
+ * Removes a scheduler entity from the run queue.
+ */
+void drm_sched_rq_remove_entity(struct drm_sched_rq *rq,
+				struct drm_sched_entity *entity)
+{
+	if (list_empty(&entity->list))
+		return;
+	spin_lock(&rq->lock);
+	list_del_init(&entity->list);
+	if (rq->current_entity == entity)
+		rq->current_entity = NULL;
+	spin_unlock(&rq->lock);
+}
+
+/**
+ * drm_sched_rq_select_entity - Select an entity which could provide a job to run
+ *
+ * @rq: scheduler run queue to check.
+ *
+ * Try to find a ready entity, returns NULL if none found.
+ */
+static struct drm_sched_entity *
+drm_sched_rq_select_entity(struct drm_sched_rq *rq)
+{
+	struct drm_sched_entity *entity;
+
+	spin_lock(&rq->lock);
+
+	entity = rq->current_entity;
+	if (entity) {
+		list_for_each_entry_continue(entity, &rq->entities, list) {
+			if (drm_sched_entity_is_ready(entity)) {
+				rq->current_entity = entity;
+				spin_unlock(&rq->lock);
+				return entity;
+			}
+		}
+	}
+
+	list_for_each_entry(entity, &rq->entities, list) {
+
+		if (drm_sched_entity_is_ready(entity)) {
+			rq->current_entity = entity;
+			spin_unlock(&rq->lock);
+			return entity;
+		}
+
+		if (entity == rq->current_entity)
+			break;
+	}
+
+	spin_unlock(&rq->lock);
+
+	return NULL;
+}
+
+/**
+ * drm_sched_dependency_optimized
+ *
+ * @fence: the dependency fence
+ * @entity: the entity which depends on the above fence
+ *
+ * Returns true if the dependency can be optimized and false otherwise
+ */
+bool drm_sched_dependency_optimized(struct dma_fence* fence,
+				    struct drm_sched_entity *entity)
+{
+	struct drm_gpu_scheduler *sched = entity->rq->sched;
+	struct drm_sched_fence *s_fence;
+
+	if (!fence || dma_fence_is_signaled(fence))
+		return false;
+	if (fence->context == entity->fence_context)
+		return true;
+	s_fence = to_drm_sched_fence(fence);
+	if (s_fence && s_fence->sched == sched)
+		return true;
+
+	return false;
+}
+EXPORT_SYMBOL(drm_sched_dependency_optimized);
+
+/**
+ * drm_sched_start_timeout - start timeout for reset worker
+ *
+ * @sched: scheduler instance to start the worker for
+ *
+ * Start the timeout for the given scheduler.
+ */
+static void drm_sched_start_timeout(struct drm_gpu_scheduler *sched)
+{
+	if (sched->timeout != MAX_SCHEDULE_TIMEOUT &&
+	    !list_empty(&sched->ring_mirror_list))
+		schedule_delayed_work(&sched->work_tdr, sched->timeout);
+}
+
+/* job_finish is called after hw fence signaled
+ */
+static void drm_sched_job_finish(struct work_struct *work)
+{
+	struct drm_sched_job *s_job = container_of(work, struct drm_sched_job,
+						   finish_work);
+	struct drm_gpu_scheduler *sched = s_job->sched;
+
+	/*
+	 * Canceling the timeout without removing our job from the ring mirror
+	 * list is safe, as we will only end up in this worker if our jobs
+	 * finished fence has been signaled. So even if some another worker
+	 * manages to find this job as the next job in the list, the fence
+	 * signaled check below will prevent the timeout to be restarted.
+	 */
+	cancel_delayed_work_sync(&sched->work_tdr);
+
+	spin_lock(&sched->job_list_lock);
+	/* remove job from ring_mirror_list */
+	list_del(&s_job->node);
+	/* queue TDR for next job */
+	drm_sched_start_timeout(sched);
+	spin_unlock(&sched->job_list_lock);
+
+	dma_fence_put(&s_job->s_fence->finished);
+	sched->ops->free_job(s_job);
+}
+
+static void drm_sched_job_finish_cb(struct dma_fence *f,
+				    struct dma_fence_cb *cb)
+{
+	struct drm_sched_job *job = container_of(cb, struct drm_sched_job,
+						 finish_cb);
+	schedule_work(&job->finish_work);
+}
+
+static void drm_sched_job_begin(struct drm_sched_job *s_job)
+{
+	struct drm_gpu_scheduler *sched = s_job->sched;
+
+	dma_fence_add_callback(&s_job->s_fence->finished, &s_job->finish_cb,
+			       drm_sched_job_finish_cb);
+
+	spin_lock(&sched->job_list_lock);
+	list_add_tail(&s_job->node, &sched->ring_mirror_list);
+	drm_sched_start_timeout(sched);
+	spin_unlock(&sched->job_list_lock);
+}
+
+static void drm_sched_job_timedout(struct work_struct *work)
+{
+	struct drm_gpu_scheduler *sched;
+	struct drm_sched_job *job;
+	int r;
+
+	sched = container_of(work, struct drm_gpu_scheduler, work_tdr.work);
+
+	spin_lock(&sched->job_list_lock);
+	list_for_each_entry_reverse(job, &sched->ring_mirror_list, node) {
+		struct drm_sched_fence *fence = job->s_fence;
+
+		if (!dma_fence_remove_callback(fence->parent, &fence->cb))
+			goto already_signaled;
+	}
+
+	job = list_first_entry_or_null(&sched->ring_mirror_list,
+				       struct drm_sched_job, node);
+	spin_unlock(&sched->job_list_lock);
+
+	if (job)
+		sched->ops->timedout_job(job);
+
+	spin_lock(&sched->job_list_lock);
+	list_for_each_entry(job, &sched->ring_mirror_list, node) {
+		struct drm_sched_fence *fence = job->s_fence;
+
+		if (!fence->parent || !list_empty(&fence->cb.node))
+			continue;
+
+		r = dma_fence_add_callback(fence->parent, &fence->cb,
+					   drm_sched_process_job);
+		if (r)
+			drm_sched_process_job(fence->parent, &fence->cb);
+
+already_signaled:
+		;
+	}
+	spin_unlock(&sched->job_list_lock);
+}
+
+/**
+ * drm_sched_hw_job_reset - stop the scheduler if it contains the bad job
+ *
+ * @sched: scheduler instance
+ * @bad: bad scheduler job
+ *
+ */
+void drm_sched_hw_job_reset(struct drm_gpu_scheduler *sched, struct drm_sched_job *bad)
+{
+	struct drm_sched_job *s_job;
+	struct drm_sched_entity *entity, *tmp;
+	int i;
+
+	spin_lock(&sched->job_list_lock);
+	list_for_each_entry_reverse(s_job, &sched->ring_mirror_list, node) {
+		if (s_job->s_fence->parent &&
+		    dma_fence_remove_callback(s_job->s_fence->parent,
+					      &s_job->s_fence->cb)) {
+			dma_fence_put(s_job->s_fence->parent);
+			s_job->s_fence->parent = NULL;
+			atomic_dec(&sched->hw_rq_count);
+		}
+	}
+	spin_unlock(&sched->job_list_lock);
+
+	if (bad && bad->s_priority != DRM_SCHED_PRIORITY_KERNEL) {
+		atomic_inc(&bad->karma);
+		/* don't increase @bad's karma if it's from KERNEL RQ,
+		 * becuase sometimes GPU hang would cause kernel jobs (like VM updating jobs)
+		 * corrupt but keep in mind that kernel jobs always considered good.
+		 */
+		for (i = DRM_SCHED_PRIORITY_MIN; i < DRM_SCHED_PRIORITY_KERNEL; i++ ) {
+			struct drm_sched_rq *rq = &sched->sched_rq[i];
+
+			spin_lock(&rq->lock);
+			list_for_each_entry_safe(entity, tmp, &rq->entities, list) {
+				if (bad->s_fence->scheduled.context == entity->fence_context) {
+				    if (atomic_read(&bad->karma) > bad->sched->hang_limit)
+						if (entity->guilty)
+							atomic_set(entity->guilty, 1);
+					break;
+				}
+			}
+			spin_unlock(&rq->lock);
+			if (&entity->list != &rq->entities)
+				break;
+		}
+	}
+}
+EXPORT_SYMBOL(drm_sched_hw_job_reset);
+
+/**
+ * drm_sched_job_recovery - recover jobs after a reset
+ *
+ * @sched: scheduler instance
+ *
+ */
+void drm_sched_job_recovery(struct drm_gpu_scheduler *sched)
+{
+	struct drm_sched_job *s_job, *tmp;
+	bool found_guilty = false;
+	int r;
+
+	spin_lock(&sched->job_list_lock);
+	list_for_each_entry_safe(s_job, tmp, &sched->ring_mirror_list, node) {
+		struct drm_sched_fence *s_fence = s_job->s_fence;
+		struct dma_fence *fence;
+		uint64_t guilty_context;
+
+		if (!found_guilty && atomic_read(&s_job->karma) > sched->hang_limit) {
+			found_guilty = true;
+			guilty_context = s_job->s_fence->scheduled.context;
+		}
+
+		if (found_guilty && s_job->s_fence->scheduled.context == guilty_context)
+			dma_fence_set_error(&s_fence->finished, -ECANCELED);
+
+		spin_unlock(&sched->job_list_lock);
+		fence = sched->ops->run_job(s_job);
+		atomic_inc(&sched->hw_rq_count);
+
+		if (fence) {
+			s_fence->parent = dma_fence_get(fence);
+			r = dma_fence_add_callback(fence, &s_fence->cb,
+						   drm_sched_process_job);
+			if (r == -ENOENT)
+				drm_sched_process_job(fence, &s_fence->cb);
+			else if (r)
+				DRM_ERROR("fence add callback failed (%d)\n",
+					  r);
+			dma_fence_put(fence);
+		} else {
+			drm_sched_process_job(NULL, &s_fence->cb);
+		}
+		spin_lock(&sched->job_list_lock);
+	}
+	drm_sched_start_timeout(sched);
+	spin_unlock(&sched->job_list_lock);
+}
+EXPORT_SYMBOL(drm_sched_job_recovery);
+
+/**
+ * drm_sched_job_init - init a scheduler job
+ *
+ * @job: scheduler job to init
+ * @entity: scheduler entity to use
+ * @owner: job owner for debugging
+ *
+ * Refer to drm_sched_entity_push_job() documentation
+ * for locking considerations.
+ *
+ * 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);
+	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);
+	if (!job->s_fence)
+		return -ENOMEM;
+	job->id = atomic64_inc_return(&sched->job_id_count);
+
+	INIT_WORK(&job->finish_work, drm_sched_job_finish);
+	INIT_LIST_HEAD(&job->node);
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_sched_job_init);
+
+/**
+ * drm_sched_ready - is the scheduler ready
+ *
+ * @sched: scheduler instance
+ *
+ * Return true if we can push more jobs to the hw, otherwise false.
+ */
+static bool drm_sched_ready(struct drm_gpu_scheduler *sched)
+{
+	return atomic_read(&sched->hw_rq_count) <
+		sched->hw_submission_limit;
+}
+
+/**
+ * drm_sched_wakeup - Wake up the scheduler when it is ready
+ *
+ * @sched: scheduler instance
+ *
+ */
+void drm_sched_wakeup(struct drm_gpu_scheduler *sched)
+{
+	if (drm_sched_ready(sched))
+		wake_up_interruptible(&sched->wake_up_worker);
+}
+
+/**
+ * drm_sched_select_entity - Select next entity to process
+ *
+ * @sched: scheduler instance
+ *
+ * Returns the entity to process or NULL if none are found.
+ */
+static struct drm_sched_entity *
+drm_sched_select_entity(struct drm_gpu_scheduler *sched)
+{
+	struct drm_sched_entity *entity;
+	int i;
+
+	if (!drm_sched_ready(sched))
+		return NULL;
+
+	/* Kernel run queue has higher priority than normal run queue*/
+	for (i = DRM_SCHED_PRIORITY_MAX - 1; i >= DRM_SCHED_PRIORITY_MIN; i--) {
+		entity = drm_sched_rq_select_entity(&sched->sched_rq[i]);
+		if (entity)
+			break;
+	}
+
+	return entity;
+}
+
+/**
+ * drm_sched_process_job - process a job
+ *
+ * @f: fence
+ * @cb: fence callbacks
+ *
+ * Called after job has finished execution.
+ */
+static void drm_sched_process_job(struct dma_fence *f, struct dma_fence_cb *cb)
+{
+	struct drm_sched_fence *s_fence =
+		container_of(cb, struct drm_sched_fence, cb);
+	struct drm_gpu_scheduler *sched = s_fence->sched;
+
+	dma_fence_get(&s_fence->finished);
+	atomic_dec(&sched->hw_rq_count);
+	atomic_dec(&sched->num_jobs);
+	drm_sched_fence_finished(s_fence);
+
+	trace_drm_sched_process_job(s_fence);
+	dma_fence_put(&s_fence->finished);
+	wake_up_interruptible(&sched->wake_up_worker);
+}
+
+/**
+ * drm_sched_blocked - check if the scheduler is blocked
+ *
+ * @sched: scheduler instance
+ *
+ * Returns true if blocked, otherwise false.
+ */
+static bool drm_sched_blocked(struct drm_gpu_scheduler *sched)
+{
+	if (kthread_should_park()) {
+		kthread_parkme();
+		return true;
+	}
+
+	return false;
+}
+
+/**
+ * drm_sched_main - main scheduler thread
+ *
+ * @param: scheduler instance
+ *
+ * Returns 0.
+ */
+static int drm_sched_main(void *param)
+{
+	struct sched_param sparam = {.sched_priority = 1};
+	struct drm_gpu_scheduler *sched = (struct drm_gpu_scheduler *)param;
+	int r;
+
+	sched_setscheduler(current, SCHED_FIFO, &sparam);
+
+	while (!kthread_should_stop()) {
+		struct drm_sched_entity *entity = NULL;
+		struct drm_sched_fence *s_fence;
+		struct drm_sched_job *sched_job;
+		struct dma_fence *fence;
+
+		wait_event_interruptible(sched->wake_up_worker,
+					 (!drm_sched_blocked(sched) &&
+					  (entity = drm_sched_select_entity(sched))) ||
+					 kthread_should_stop());
+
+		if (!entity)
+			continue;
+
+		sched_job = drm_sched_entity_pop_job(entity);
+		if (!sched_job)
+			continue;
+
+		s_fence = sched_job->s_fence;
+
+		atomic_inc(&sched->hw_rq_count);
+		drm_sched_job_begin(sched_job);
+
+		fence = sched->ops->run_job(sched_job);
+		drm_sched_fence_scheduled(s_fence);
+
+		if (fence) {
+			s_fence->parent = dma_fence_get(fence);
+			r = dma_fence_add_callback(fence, &s_fence->cb,
+						   drm_sched_process_job);
+			if (r == -ENOENT)
+				drm_sched_process_job(fence, &s_fence->cb);
+			else if (r)
+				DRM_ERROR("fence add callback failed (%d)\n",
+					  r);
+			dma_fence_put(fence);
+		} else {
+			drm_sched_process_job(NULL, &s_fence->cb);
+		}
+
+		wake_up(&sched->job_scheduled);
+	}
+	return 0;
+}
+
+/**
+ * drm_sched_init - Init a gpu scheduler instance
+ *
+ * @sched: scheduler instance
+ * @ops: backend operations for this scheduler
+ * @hw_submission: number of hw submissions that can be in flight
+ * @hang_limit: number of times to allow a job to hang before dropping it
+ * @timeout: timeout value in jiffies for the scheduler
+ * @name: name used for debugging
+ *
+ * Return 0 on success, otherwise error code.
+ */
+int drm_sched_init(struct drm_gpu_scheduler *sched,
+		   const struct drm_sched_backend_ops *ops,
+		   unsigned hw_submission,
+		   unsigned hang_limit,
+		   long timeout,
+		   const char *name)
+{
+	int i;
+	sched->ops = ops;
+	sched->hw_submission_limit = hw_submission;
+	sched->name = name;
+	sched->timeout = timeout;
+	sched->hang_limit = hang_limit;
+	for (i = DRM_SCHED_PRIORITY_MIN; i < DRM_SCHED_PRIORITY_MAX; i++)
+		drm_sched_rq_init(sched, &sched->sched_rq[i]);
+
+	init_waitqueue_head(&sched->wake_up_worker);
+	init_waitqueue_head(&sched->job_scheduled);
+	INIT_LIST_HEAD(&sched->ring_mirror_list);
+	spin_lock_init(&sched->job_list_lock);
+	atomic_set(&sched->hw_rq_count, 0);
+	INIT_DELAYED_WORK(&sched->work_tdr, drm_sched_job_timedout);
+	atomic_set(&sched->num_jobs, 0);
+	atomic64_set(&sched->job_id_count, 0);
+
+	/* Each scheduler will run on a seperate kernel thread */
+	sched->thread = kthread_run(drm_sched_main, sched, sched->name);
+	if (IS_ERR(sched->thread)) {
+		DRM_ERROR("Failed to create scheduler for %s.\n", name);
+		return PTR_ERR(sched->thread);
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_sched_init);
+
+/**
+ * drm_sched_fini - Destroy a gpu scheduler
+ *
+ * @sched: scheduler instance
+ *
+ * Tears down and cleans up the scheduler.
+ */
+void drm_sched_fini(struct drm_gpu_scheduler *sched)
+{
+	if (sched->thread)
+		kthread_stop(sched->thread);
+}
+EXPORT_SYMBOL(drm_sched_fini);