OSCL-LXR linux-6.0.1/​drivers/​gpu/​drm/​scheduler/​sched_entity.c	Source navigation Diff markup Identifier search General search
	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 /*
  * 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;
 
     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(&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_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)) {
         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);
 
 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);
 
     INIT_WORK(&job->work, drm_sched_entity_kill_jobs_work);
     schedule_work(&job->work);
 }
 
 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;
 }
 
 static void drm_sched_entity_kill_jobs(struct drm_sched_entity *entity)
 {
     struct drm_sched_job *job;
     struct dma_fence *f;
     int r;
 
     while ((job = to_drm_sched_job(spsc_queue_pop(&entity->job_queue)))) {
         struct drm_sched_fence *s_fence = job->s_fence;
 
         /* Wait for all dependencies to avoid data corruptions */
         while ((f = drm_sched_job_dependency(job, entity)))
             dma_fence_wait(f, false);
 
         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_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)
 {
     struct drm_gpu_scheduler *sched = NULL;
 
     if (entity->rq) {
         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_count(&entity->job_queue)) {
         if (sched) {
             /*
              * Wait for thread to idle to make sure it isn't processing
              * this entity.
              */
             wait_for_completion(&entity->entity_idle);
 
         }
         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;
 }
 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) {
 
         /*
          * 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;
 }
 
 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);
     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;
 
     trace_drm_sched_job(sched_job, entity);
     atomic_inc(entity->rq->sched->score);
     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);

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