[linux-block.git] / drivers / gpu / drm / scheduler / sched_entity.c

/*
 * 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;
	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;
}

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);
	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);
	int r;

	dma_fence_put(f);

	/* Wait for all dependencies to avoid data corruptions */
	while (!xa_empty(&job->dependencies)) {
		f = xa_erase(&job->dependencies, job->last_dependency++);
		r = dma_fence_add_callback(f, &job->finish_cb,
					   drm_sched_entity_kill_jobs_cb);
		if (!r)
			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);

	prev = dma_fence_get(entity->last_scheduled);
	while ((job = to_drm_sched_job(spsc_queue_pop(&entity->job_queue)))) {
		struct drm_sched_fence *s_fence = job->s_fence;

		dma_fence_set_error(&s_fence->finished, -ESRCH);

		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(entity->last_scheduled);
	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(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 (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)
{
	if (!xa_empty(&job->dependencies))
		return xa_erase(&job->dependencies, job->last_dependency++);

	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(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);

	/*
	 * 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);
	}

	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 = entity->last_scheduled;

	/* 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(entity->rq->sched);
	}
}
EXPORT_SYMBOL(drm_sched_entity_push_job);
Commit	Line	Data
620e762f CK	1	/*
	2	* Copyright 2015 Advanced Micro Devices, Inc.
	3	*
	4	* Permission is hereby granted, free of charge, to any person obtaining a
	5	* copy of this software and associated documentation files (the "Software"),
	6	* to deal in the Software without restriction, including without limitation
	7	* the rights to use, copy, modify, merge, publish, distribute, sublicense,
	8	* and/or sell copies of the Software, and to permit persons to whom the
	9	* Software is furnished to do so, subject to the following conditions:
	10	*
	11	* The above copyright notice and this permission notice shall be included in
	12	* all copies or substantial portions of the Software.
	13	*
	14	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	15	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	16	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	17	* THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
	18	* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
	19	* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
	20	* OTHER DEALINGS IN THE SOFTWARE.
	21	*
	22	*/
	23
	24	#include <linux/kthread.h>
7c1be93c	25	#include <linux/slab.h>
83a7772b	26	#include <linux/completion.h>
7c1be93c SR	27
7c1be93c SR	28	#include <drm/drm_print.h>
620e762f CK	29	#include <drm/gpu_scheduler.h>
	30
	31	#include "gpu_scheduler_trace.h"
	32
	33	#define to_drm_sched_job(sched_job) \
	34	container_of((sched_job), struct drm_sched_job, queue_node)
	35
	36	/**
	37	* drm_sched_entity_init - Init a context entity used by scheduler when
	38	* submit to HW ring.
	39	*
	40	* @entity: scheduler entity to init
b3ac1766 ND	41	* @priority: priority of the entity
b3ac1766 ND	42	* @sched_list: the list of drm scheds on which jobs from this
620e762f	43	* entity can be submitted
b3ac1766	44	* @num_sched_list: number of drm sched in sched_list
620e762f CK	45	* @guilty: atomic_t set to 1 when a job on this queue
	46	* is found to be guilty causing a timeout
	47	*
981b04d9 DV	48	* Note that the &sched_list must have at least one element to schedule the entity.
	49	*
	50	* For changing @priority later on at runtime see
	51	* drm_sched_entity_set_priority(). For changing the set of schedulers
	52	* @sched_list at runtime see drm_sched_entity_modify_sched().
	53	*
	54	* An entity is cleaned up by callind drm_sched_entity_fini(). See also
	55	* drm_sched_entity_destroy().
620e762f CK	56	*
620e762f CK	57	* Returns 0 on success or a negative error code on failure.
7b10574e	58	*/
620e762f	59	int drm_sched_entity_init(struct drm_sched_entity *entity,
b3ac1766 ND	60	enum drm_sched_priority priority,
	61	struct drm_gpu_scheduler **sched_list,
	62	unsigned int num_sched_list,
620e762f CK	63	atomic_t *guilty)
620e762f CK	64	{
b3ac1766	65	if (!(entity && sched_list && (num_sched_list == 0 \|\| sched_list[0])))
620e762f CK	66	return -EINVAL;
	67
	68	memset(entity, 0, sizeof(struct drm_sched_entity));
	69	INIT_LIST_HEAD(&entity->list);
1decbf6b	70	entity->rq = NULL;
620e762f	71	entity->guilty = guilty;
b3ac1766 ND	72	entity->num_sched_list = num_sched_list;
b3ac1766 ND	73	entity->priority = priority;
8c23056b ND	74	entity->sched_list = num_sched_list > 1 ? sched_list : NULL;
8c23056b ND	75	entity->last_scheduled = NULL;
08fb97de	76	RB_CLEAR_NODE(&entity->rb_tree_node);
b3ac1766	77
8c23056b ND	78	if(num_sched_list)
8c23056b ND	79	entity->rq = &sched_list[0]->sched_rq[entity->priority];
620e762f	80
83a7772b AG	81	init_completion(&entity->entity_idle);
83a7772b AG	82
170fb58e	83	/* We start in an idle state. */
03dec92c	84	complete_all(&entity->entity_idle);
170fb58e	85
620e762f CK	86	spin_lock_init(&entity->rq_lock);
	87	spsc_queue_init(&entity->job_queue);
	88
	89	atomic_set(&entity->fence_seq, 0);
	90	entity->fence_context = dma_fence_context_alloc(2);
	91
	92	return 0;
	93	}
	94	EXPORT_SYMBOL(drm_sched_entity_init);
	95
b37aced3 ND	96	/**
	97	* drm_sched_entity_modify_sched - Modify sched of an entity
	98	* @entity: scheduler entity to init
	99	* @sched_list: the list of new drm scheds which will replace
	100	* existing entity->sched_list
	101	* @num_sched_list: number of drm sched in sched_list
981b04d9 DV	102	*
	103	* Note that this must be called under the same common lock for @entity as
	104	* drm_sched_job_arm() and drm_sched_entity_push_job(), or the driver needs to
	105	* guarantee through some other means that this is never called while new jobs
	106	* can be pushed to @entity.
b37aced3 ND	107	*/
	108	void drm_sched_entity_modify_sched(struct drm_sched_entity *entity,
	109	struct drm_gpu_scheduler **sched_list,
	110	unsigned int num_sched_list)
	111	{
	112	WARN_ON(!num_sched_list \|\| !sched_list);
	113
	114	entity->sched_list = sched_list;
	115	entity->num_sched_list = num_sched_list;
	116	}
	117	EXPORT_SYMBOL(drm_sched_entity_modify_sched);
	118
620e762f CK	119	static bool drm_sched_entity_is_idle(struct drm_sched_entity *entity)
620e762f CK	120	{
7b10574e	121	rmb(); /* for list_empty to work without lock */
620e762f CK	122
620e762f CK	123	if (list_empty(&entity->list) \|\|
c61cdbdb AG	124	spsc_queue_count(&entity->job_queue) == 0 \|\|
c61cdbdb AG	125	entity->stopped)
620e762f CK	126	return true;
	127
	128	return false;
	129	}
	130
981b04d9	131	/* Return true if entity could provide a job. */
620e762f CK	132	bool drm_sched_entity_is_ready(struct drm_sched_entity *entity)
	133	{
	134	if (spsc_queue_peek(&entity->job_queue) == NULL)
	135	return false;
	136
	137	if (READ_ONCE(entity->dependency))
	138	return false;
	139
	140	return true;
	141	}
	142
2fdb8a8f CK	143	static void drm_sched_entity_kill_jobs_work(struct work_struct *wrk)
	144	{
	145	struct drm_sched_job job = container_of(wrk, typeof(job), work);
	146
	147	drm_sched_fence_finished(job->s_fence);
	148	WARN_ON(job->s_fence->parent);
	149	job->sched->ops->free_job(job);
	150	}
	151
	152	/* Signal the scheduler finished fence when the entity in question is killed. */
	153	static void drm_sched_entity_kill_jobs_cb(struct dma_fence *f,
	154	struct dma_fence_cb *cb)
	155	{
	156	struct drm_sched_job *job = container_of(cb, struct drm_sched_job,
	157	finish_cb);
	158	int r;
	159
	160	dma_fence_put(f);
	161
	162	/* Wait for all dependencies to avoid data corruptions */
	163	while (!xa_empty(&job->dependencies)) {
	164	f = xa_erase(&job->dependencies, job->last_dependency++);
	165	r = dma_fence_add_callback(f, &job->finish_cb,
	166	drm_sched_entity_kill_jobs_cb);
	167	if (!r)
	168	return;
	169
	170	dma_fence_put(f);
	171	}
	172
	173	INIT_WORK(&job->work, drm_sched_entity_kill_jobs_work);
	174	schedule_work(&job->work);
	175	}
	176
	177	/* Remove the entity from the scheduler and kill all pending jobs */
	178	static void drm_sched_entity_kill(struct drm_sched_entity *entity)
	179	{
	180	struct drm_sched_job *job;
	181	struct dma_fence *prev;
	182
	183	if (!entity->rq)
	184	return;
	185
	186	spin_lock(&entity->rq_lock);
	187	entity->stopped = true;
	188	drm_sched_rq_remove_entity(entity->rq, entity);
	189	spin_unlock(&entity->rq_lock);
	190
	191	/* Make sure this entity is not used by the scheduler at the moment */
	192	wait_for_completion(&entity->entity_idle);
	193
	194	prev = dma_fence_get(entity->last_scheduled);
	195	while ((job = to_drm_sched_job(spsc_queue_pop(&entity->job_queue)))) {
	196	struct drm_sched_fence *s_fence = job->s_fence;
	197
	198	dma_fence_set_error(&s_fence->finished, -ESRCH);
	199
	200	dma_fence_get(&s_fence->finished);
	201	if (!prev \|\| dma_fence_add_callback(prev, &job->finish_cb,
	202	drm_sched_entity_kill_jobs_cb))
	203	drm_sched_entity_kill_jobs_cb(NULL, &job->finish_cb);
	204
	205	prev = &s_fence->finished;
	206	}
207	dma_fence_put(prev);
208	}
209
620e762f CK	210	/**
	211	* drm_sched_entity_flush - Flush a context entity
	212	*
	213	* @entity: scheduler entity
	214	* @timeout: time to wait in for Q to become empty in jiffies.
	215	*
7b10574e CK	216	* Splitting drm_sched_entity_fini() into two functions, The first one does the
	217	* waiting, removes the entity from the runqueue and returns an error when the
	218	* process was killed.
620e762f CK	219	*
	220	* Returns the remaining time in jiffies left from the input timeout
	221	*/
	222	long drm_sched_entity_flush(struct drm_sched_entity *entity, long timeout)
	223	{
	224	struct drm_gpu_scheduler *sched;
	225	struct task_struct *last_user;
	226	long ret = timeout;
	227
1decbf6b BN	228	if (!entity->rq)
	229	return 0;
	230
620e762f CK	231	sched = entity->rq->sched;
	232	/**
	233	* The client will not queue more IBs during this fini, consume existing
	234	* queued IBs or discard them on SIGKILL
7b10574e	235	*/
620e762f CK	236	if (current->flags & PF_EXITING) {
	237	if (timeout)
	238	ret = wait_event_timeout(
	239	sched->job_scheduled,
	240	drm_sched_entity_is_idle(entity),
	241	timeout);
	242	} else {
	243	wait_event_killable(sched->job_scheduled,
	244	drm_sched_entity_is_idle(entity));
	245	}
	246
	247	/* For killed process disable any more IBs enqueue right now */
	248	last_user = cmpxchg(&entity->last_user, current->group_leader, NULL);
	249	if ((!last_user \|\| last_user == current->group_leader) &&
2fdb8a8f CK	250	(current->flags & PF_EXITING) && (current->exit_code == SIGKILL))
2fdb8a8f CK	251	drm_sched_entity_kill(entity);
620e762f CK	252
	253	return ret;
	254	}
	255	EXPORT_SYMBOL(drm_sched_entity_flush);
	256
	257	/**
04be0c5b	258	* drm_sched_entity_fini - Destroy a context entity
620e762f CK	259	*
	260	* @entity: scheduler entity
	261	*
981b04d9	262	* Cleanups up @entity which has been initialized by drm_sched_entity_init().
620e762f	263	*
981b04d9 DV	264	* If there are potentially job still in flight or getting newly queued
	265	* drm_sched_entity_flush() must be called first. This function then goes over
	266	* the entity and signals all jobs with an error code if the process was killed.
620e762f CK	267	*/
	268	void drm_sched_entity_fini(struct drm_sched_entity *entity)
	269	{
2fdb8a8f CK	270	/*
	271	* If consumption of existing IBs wasn't completed. Forcefully remove
	272	* them here. Also makes sure that the scheduler won't touch this entity
	273	* any more.
620e762f	274	*/
2fdb8a8f CK	275	drm_sched_entity_kill(entity);
	276
	277	if (entity->dependency) {
	278	dma_fence_remove_callback(entity->dependency, &entity->cb);
	279	dma_fence_put(entity->dependency);
	280	entity->dependency = NULL;
620e762f CK	281	}
	282
	283	dma_fence_put(entity->last_scheduled);
	284	entity->last_scheduled = NULL;
620e762f CK	285	}
	286	EXPORT_SYMBOL(drm_sched_entity_fini);
	287
	288	/**
04be0c5b	289	* drm_sched_entity_destroy - Destroy a context entity
620e762f CK	290	* @entity: scheduler entity
620e762f CK	291	*
981b04d9 DV	292	* Calls drm_sched_entity_flush() and drm_sched_entity_fini() as a
981b04d9 DV	293	* convenience wrapper.
620e762f CK	294	*/
	295	void drm_sched_entity_destroy(struct drm_sched_entity *entity)
	296	{
	297	drm_sched_entity_flush(entity, MAX_WAIT_SCHED_ENTITY_Q_EMPTY);
	298	drm_sched_entity_fini(entity);
	299	}
	300	EXPORT_SYMBOL(drm_sched_entity_destroy);
	301
981b04d9	302	/* drm_sched_entity_clear_dep - callback to clear the entities dependency */
7b10574e CK	303	static void drm_sched_entity_clear_dep(struct dma_fence *f,
7b10574e CK	304	struct dma_fence_cb *cb)
620e762f CK	305	{
	306	struct drm_sched_entity *entity =
	307	container_of(cb, struct drm_sched_entity, cb);
7b10574e	308
620e762f CK	309	entity->dependency = NULL;
620e762f CK	310	dma_fence_put(f);
620e762f CK	311	}
620e762f CK	312
00d44b96	313	/*
7b10574e CK	314	* drm_sched_entity_clear_dep - callback to clear the entities dependency and
	315	* wake up scheduler
	316	*/
	317	static void drm_sched_entity_wakeup(struct dma_fence *f,
	318	struct dma_fence_cb *cb)
620e762f CK	319	{
	320	struct drm_sched_entity *entity =
	321	container_of(cb, struct drm_sched_entity, cb);
7b10574e CK	322
	323	drm_sched_entity_clear_dep(f, cb);
	324	drm_sched_wakeup(entity->rq->sched);
620e762f CK	325	}
620e762f CK	326
620e762f CK	327	/**
	328	* drm_sched_entity_set_priority - Sets priority of the entity
	329	*
	330	* @entity: scheduler entity
	331	* @priority: scheduler priority
	332	*
	333	* Update the priority of runqueus used for the entity.
	334	*/
	335	void drm_sched_entity_set_priority(struct drm_sched_entity *entity,
	336	enum drm_sched_priority priority)
	337	{
620e762f	338	spin_lock(&entity->rq_lock);
b3ac1766	339	entity->priority = priority;
620e762f CK	340	spin_unlock(&entity->rq_lock);
	341	}
	342	EXPORT_SYMBOL(drm_sched_entity_set_priority);
	343
981b04d9	344	/*
7b10574e CK	345	* Add a callback to the current dependency of the entity to wake up the
	346	* scheduler when the entity becomes available.
	347	*/
620e762f CK	348	static bool drm_sched_entity_add_dependency_cb(struct drm_sched_entity *entity)
	349	{
	350	struct drm_gpu_scheduler *sched = entity->rq->sched;
7b10574e	351	struct dma_fence *fence = entity->dependency;
620e762f CK	352	struct drm_sched_fence *s_fence;
	353
	354	if (fence->context == entity->fence_context \|\|
7b10574e CK	355	fence->context == entity->fence_context + 1) {
	356	/*
	357	* Fence is a scheduled/finished fence from a job
	358	* which belongs to the same entity, we can ignore
	359	* fences from ourself
	360	*/
620e762f CK	361	dma_fence_put(entity->dependency);
	362	return false;
	363	}
	364
	365	s_fence = to_drm_sched_fence(fence);
7b476aff CK	366	if (s_fence && s_fence->sched == sched &&
7b476aff CK	367	!test_bit(DRM_SCHED_FENCE_DONT_PIPELINE, &fence->flags)) {
620e762f CK	368
	369	/*
	370	* Fence is from the same scheduler, only need to wait for
	371	* it to be scheduled
	372	*/
	373	fence = dma_fence_get(&s_fence->scheduled);
	374	dma_fence_put(entity->dependency);
	375	entity->dependency = fence;
	376	if (!dma_fence_add_callback(fence, &entity->cb,
	377	drm_sched_entity_clear_dep))
	378	return true;
	379
	380	/* Ignore it when it is already scheduled */
	381	dma_fence_put(fence);
	382	return false;
	383	}
	384
	385	if (!dma_fence_add_callback(entity->dependency, &entity->cb,
	386	drm_sched_entity_wakeup))
	387	return true;
	388
	389	dma_fence_put(entity->dependency);
	390	return false;
	391	}
	392
2fdb8a8f CK	393	static struct dma_fence *
	394	drm_sched_job_dependency(struct drm_sched_job *job,
	395	struct drm_sched_entity *entity)
	396	{
	397	if (!xa_empty(&job->dependencies))
	398	return xa_erase(&job->dependencies, job->last_dependency++);
	399
a82f30b0 CK	400	if (job->sched->ops->prepare_job)
a82f30b0 CK	401	return job->sched->ops->prepare_job(job, entity);
2fdb8a8f CK	402
	403	return NULL;
	404	}
	405
620e762f CK	406	struct drm_sched_job drm_sched_entity_pop_job(struct drm_sched_entity entity)
620e762f CK	407	{
7b10574e	408	struct drm_sched_job *sched_job;
620e762f	409
7b10574e	410	sched_job = to_drm_sched_job(spsc_queue_peek(&entity->job_queue));
620e762f CK	411	if (!sched_job)
	412	return NULL;
	413
7b10574e	414	while ((entity->dependency =
ebd5f742	415	drm_sched_job_dependency(sched_job, entity))) {
82abf337	416	trace_drm_sched_job_wait_dep(sched_job, entity->dependency);
7b10574e	417
82abf337	418	if (drm_sched_entity_add_dependency_cb(entity))
620e762f	419	return NULL;
620e762f CK	420	}
	421
	422	/* skip jobs from entity that marked guilty */
	423	if (entity->guilty && atomic_read(entity->guilty))
	424	dma_fence_set_error(&sched_job->s_fence->finished, -ECANCELED);
	425
	426	dma_fence_put(entity->last_scheduled);
b0a5303d	427
620e762f CK	428	entity->last_scheduled = dma_fence_get(&sched_job->s_fence->finished);
620e762f CK	429
b0a5303d DV	430	/*
	431	* If the queue is empty we allow drm_sched_entity_select_rq() to
	432	* locklessly access ->last_scheduled. This only works if we set the
	433	* pointer before we dequeue and if we a write barrier here.
	434	*/
	435	smp_wmb();
	436
620e762f	437	spsc_queue_pop(&entity->job_queue);
08fb97de AG	438
	439	/*
	440	* Update the entity's location in the min heap according to
	441	* the timestamp of the next job, if any.
	442	*/
	443	if (drm_sched_policy == DRM_SCHED_POLICY_FIFO) {
	444	struct drm_sched_job *next;
	445
	446	next = to_drm_sched_job(spsc_queue_peek(&entity->job_queue));
	447	if (next)
	448	drm_sched_rq_update_fifo(entity, next->submit_ts);
	449	}
	450
620e762f CK	451	return sched_job;
	452	}
	453
620e762f CK	454	void drm_sched_entity_select_rq(struct drm_sched_entity *entity)
	455	{
	456	struct dma_fence *fence;
ec2edcc2	457	struct drm_gpu_scheduler *sched;
620e762f CK	458	struct drm_sched_rq *rq;
620e762f CK	459
b0a5303d DV	460	/* single possible engine and already selected */
	461	if (!entity->sched_list)
	462	return;
	463
	464	/* queue non-empty, stay on the same engine */
	465	if (spsc_queue_count(&entity->job_queue))
620e762f CK	466	return;
620e762f CK	467
b0a5303d DV	468	/*
	469	* Only when the queue is empty are we guaranteed that the scheduler
	470	* thread cannot change ->last_scheduled. To enforce ordering we need
	471	* a read barrier here. See drm_sched_entity_pop_job() for the other
	472	* side.
	473	*/
	474	smp_rmb();
	475
	476	fence = entity->last_scheduled;
	477
	478	/* stay on the same engine if the previous job hasn't finished */
620e762f CK	479	if (fence && !dma_fence_is_signaled(fence))
	480	return;
	481
b3ac1766	482	spin_lock(&entity->rq_lock);
ec2edcc2 ND	483	sched = drm_sched_pick_best(entity->sched_list, entity->num_sched_list);
ec2edcc2 ND	484	rq = sched ? &sched->sched_rq[entity->priority] : NULL;
b3ac1766 ND	485	if (rq != entity->rq) {
	486	drm_sched_rq_remove_entity(entity->rq, entity);
	487	entity->rq = rq;
	488	}
620e762f	489	spin_unlock(&entity->rq_lock);
ac4eb83a CK	490
	491	if (entity->num_sched_list == 1)
	492	entity->sched_list = NULL;
620e762f CK	493	}
	494
	495	/**
	496	* drm_sched_entity_push_job - Submit a job to the entity's job queue
620e762f	497	* @sched_job: job to submit
620e762f	498	*
dbe48d03 DV	499	* Note: To guarantee that the order of insertion to queue matches the job's
dbe48d03 DV	500	* fence sequence number this function should be called with drm_sched_job_arm()
981b04d9 DV	501	* under common lock for the struct drm_sched_entity that was set up for
981b04d9 DV	502	* @sched_job in drm_sched_job_init().
620e762f CK	503	*
	504	* Returns 0 for success, negative error code otherwise.
	505	*/
0e10e9a1	506	void drm_sched_entity_push_job(struct drm_sched_job *sched_job)
620e762f	507	{
0e10e9a1	508	struct drm_sched_entity *entity = sched_job->entity;
620e762f	509	bool first;
1e1d3574	510	ktime_t submit_ts;
620e762f CK	511
620e762f CK	512	trace_drm_sched_job(sched_job, entity);
f2f12eb9	513	atomic_inc(entity->rq->sched->score);
620e762f	514	WRITE_ONCE(entity->last_user, current->group_leader);
1e1d3574 AL	515
	516	/*
	517	* After the sched_job is pushed into the entity queue, it may be
	518	* completed and freed up at any time. We can no longer access it.
	519	* Make sure to set the submit_ts first, to avoid a race.
	520	*/
	521	sched_job->submit_ts = submit_ts = ktime_get();
620e762f CK	522	first = spsc_queue_push(&entity->job_queue, &sched_job->queue_node);
	523
	524	/* first job wakes up scheduler */
	525	if (first) {
	526	/* Add the entity to the run queue */
	527	spin_lock(&entity->rq_lock);
62347a33 AG	528	if (entity->stopped) {
	529	spin_unlock(&entity->rq_lock);
	530
	531	DRM_ERROR("Trying to push to a killed entity\n");
	532	return;
	533	}
08fb97de	534
620e762f CK	535	drm_sched_rq_add_entity(entity->rq, entity);
620e762f CK	536	spin_unlock(&entity->rq_lock);
08fb97de AG	537
08fb97de AG	538	if (drm_sched_policy == DRM_SCHED_POLICY_FIFO)
1e1d3574	539	drm_sched_rq_update_fifo(entity, submit_ts);
08fb97de	540
620e762f CK	541	drm_sched_wakeup(entity->rq->sched);
	542	}
	543	}
	544	EXPORT_SYMBOL(drm_sched_entity_push_job);