diff options
Diffstat (limited to 'drivers/gpu/drm/scheduler/gpu_scheduler.c')
| -rw-r--r-- | drivers/gpu/drm/scheduler/gpu_scheduler.c | 364 |
1 files changed, 296 insertions, 68 deletions
diff --git a/drivers/gpu/drm/scheduler/gpu_scheduler.c b/drivers/gpu/drm/scheduler/gpu_scheduler.c index 0d95888ccc3e..dac71e3b4514 100644 --- a/drivers/gpu/drm/scheduler/gpu_scheduler.c +++ b/drivers/gpu/drm/scheduler/gpu_scheduler.c @@ -21,6 +21,29 @@ * */ +/** + * 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> @@ -30,7 +53,7 @@ #include <drm/spsc_queue.h> #define CREATE_TRACE_POINTS -#include <drm/gpu_scheduler_trace.h> +#include "gpu_scheduler_trace.h" #define to_drm_sched_job(sched_job) \ container_of((sched_job), struct drm_sched_job, queue_node) @@ -39,14 +62,30 @@ static bool drm_sched_entity_is_ready(struct drm_sched_entity *entity); static void drm_sched_wakeup(struct drm_gpu_scheduler *sched); static void drm_sched_process_job(struct dma_fence *f, struct dma_fence_cb *cb); -/* Initialize a given run queue struct */ -static void drm_sched_rq_init(struct drm_sched_rq *rq) +/** + * 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. + */ static void drm_sched_rq_add_entity(struct drm_sched_rq *rq, struct drm_sched_entity *entity) { @@ -57,6 +96,14 @@ static void drm_sched_rq_add_entity(struct drm_sched_rq *rq, 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. + */ static void drm_sched_rq_remove_entity(struct drm_sched_rq *rq, struct drm_sched_entity *entity) { @@ -70,9 +117,9 @@ static void drm_sched_rq_remove_entity(struct drm_sched_rq *rq, } /** - * Select an entity which could provide a job to run + * drm_sched_rq_select_entity - Select an entity which could provide a job to run * - * @rq The run queue to check. + * @rq: scheduler run queue to check. * * Try to find a ready entity, returns NULL if none found. */ @@ -112,32 +159,37 @@ drm_sched_rq_select_entity(struct drm_sched_rq *rq) } /** - * Init a context entity used by scheduler when submit to HW ring. + * 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 * - * @sched The pointer to the scheduler - * @entity The pointer to a valid drm_sched_entity - * @rq The run queue this entity belongs - * @kernel If this is an entity for the kernel - * @jobs The max number of jobs in the job queue + * Note: the rq_list should have atleast one element to schedule + * the entity * - * return 0 if succeed. negative error code on failure + * Returns 0 on success or a negative error code on failure. */ -int drm_sched_entity_init(struct drm_gpu_scheduler *sched, - struct drm_sched_entity *entity, - struct drm_sched_rq *rq, - uint32_t jobs, atomic_t *guilty) +int drm_sched_entity_init(struct drm_sched_entity *entity, + struct drm_sched_rq **rq_list, + unsigned int num_rq_list, + atomic_t *guilty) { - if (!(sched && entity && rq)) + 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; - entity->sched = sched; + entity->rq = rq_list[0]; + entity->sched = rq_list[0]->sched; entity->guilty = guilty; + entity->last_scheduled = NULL; spin_lock_init(&entity->rq_lock); - spin_lock_init(&entity->queue_lock); spsc_queue_init(&entity->job_queue); atomic_set(&entity->fence_seq, 0); @@ -148,10 +200,10 @@ int drm_sched_entity_init(struct drm_gpu_scheduler *sched, EXPORT_SYMBOL(drm_sched_entity_init); /** - * Query if entity is initialized + * drm_sched_entity_is_initialized - Query if entity is initialized * - * @sched Pointer to scheduler instance - * @entity The pointer to a valid scheduler entity + * @sched: Pointer to scheduler instance + * @entity: The pointer to a valid scheduler entity * * return true if entity is initialized, false otherwise */ @@ -163,25 +215,26 @@ static bool drm_sched_entity_is_initialized(struct drm_gpu_scheduler *sched, } /** - * Check if entity is idle + * drm_sched_entity_is_idle - Check if entity is idle * - * @entity The pointer to a valid scheduler entity + * @entity: scheduler entity * - * Return true if entity don't has any unscheduled jobs. + * Returns true if the entity does not have any unscheduled jobs. */ static bool drm_sched_entity_is_idle(struct drm_sched_entity *entity) { rmb(); - if (spsc_queue_peek(&entity->job_queue) == NULL) + + if (!entity->rq || spsc_queue_peek(&entity->job_queue) == NULL) return true; return false; } /** - * Check if entity is ready + * drm_sched_entity_is_ready - Check if entity is ready * - * @entity The pointer to a valid scheduler entity + * @entity: scheduler entity * * Return true if entity could provide a job. */ @@ -196,33 +249,81 @@ static bool drm_sched_entity_is_ready(struct drm_sched_entity *entity) return true; } +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); +} + + /** - * Destroy a context entity + * drm_sched_entity_flush - Flush a context entity * - * @sched Pointer to scheduler instance - * @entity The pointer to a valid scheduler entity + * @sched: scheduler instance + * @entity: scheduler entity + * @timeout: time to wait in for Q to become empty in jiffies. * - * Cleanup and free the allocated resources. + * 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 */ -void drm_sched_entity_fini(struct drm_gpu_scheduler *sched, - struct drm_sched_entity *entity) +long drm_sched_entity_flush(struct drm_gpu_scheduler *sched, + struct drm_sched_entity *entity, long timeout) { - int r; + long ret = timeout; if (!drm_sched_entity_is_initialized(sched, entity)) - return; + return ret; /** * The client will not queue more IBs during this fini, consume existing * queued IBs or discard them on SIGKILL */ - if ((current->flags & PF_SIGNALED) && current->exit_code == SIGKILL) - r = -ERESTARTSYS; - else - r = wait_event_killable(sched->job_scheduled, - drm_sched_entity_is_idle(entity)); + 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 */ + if ((current->flags & PF_EXITING) && (current->exit_code == SIGKILL)) + drm_sched_entity_set_rq(entity, NULL); + + return ret; +} +EXPORT_SYMBOL(drm_sched_entity_flush); + +/** + * drm_sched_entity_cleanup - Destroy a context entity + * + * @sched: scheduler instance + * @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_gpu_scheduler *sched, + struct drm_sched_entity *entity) +{ + drm_sched_entity_set_rq(entity, NULL); - if (r) { + + /* Consumption of existing IBs wasn't completed. Forcefully + * remove them here. + */ + if (spsc_queue_peek(&entity->job_queue)) { struct drm_sched_job *job; + int r; /* Park the kernel for a moment to make sure it isn't processing * our enity. @@ -240,15 +341,46 @@ void drm_sched_entity_fini(struct drm_gpu_scheduler *sched, struct drm_sched_fence *s_fence = job->s_fence; drm_sched_fence_scheduled(s_fence); dma_fence_set_error(&s_fence->finished, -ESRCH); - drm_sched_fence_finished(s_fence); - WARN_ON(s_fence->parent); - dma_fence_put(&s_fence->finished); - sched->ops->free_job(job); + + /* + * 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); + } else { + 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); + } } } + + dma_fence_put(entity->last_scheduled); + entity->last_scheduled = NULL; } EXPORT_SYMBOL(drm_sched_entity_fini); +/** + * drm_sched_entity_fini - Destroy a context entity + * + * @sched: scheduler instance + * @entity: scheduler entity + * + * Calls drm_sched_entity_do_release() and drm_sched_entity_cleanup() + */ +void drm_sched_entity_destroy(struct drm_gpu_scheduler *sched, + struct drm_sched_entity *entity) +{ + drm_sched_entity_flush(sched, entity, MAX_WAIT_SCHED_ENTITY_Q_EMPTY); + drm_sched_entity_fini(sched, entity); +} +EXPORT_SYMBOL(drm_sched_entity_destroy); + static void drm_sched_entity_wakeup(struct dma_fence *f, struct dma_fence_cb *cb) { struct drm_sched_entity *entity = @@ -266,6 +398,15 @@ static void drm_sched_entity_clear_dep(struct dma_fence *f, struct dma_fence_cb dma_fence_put(f); } +/** + * drm_sched_entity_set_rq - Sets the run queue for an entity + * + * @entity: scheduler entity + * @rq: scheduler run queue + * + * Sets the run queue for an entity and removes the entity from the previous + * run queue in which was present. + */ void drm_sched_entity_set_rq(struct drm_sched_entity *entity, struct drm_sched_rq *rq) { @@ -285,6 +426,14 @@ void drm_sched_entity_set_rq(struct drm_sched_entity *entity, } EXPORT_SYMBOL(drm_sched_entity_set_rq); +/** + * 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) { @@ -309,8 +458,13 @@ static bool drm_sched_entity_add_dependency_cb(struct drm_sched_entity *entity) struct dma_fence * fence = entity->dependency; struct drm_sched_fence *s_fence; - if (fence->context == entity->fence_context) { - /* We can ignore fences from ourself */ + 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; } @@ -360,14 +514,22 @@ drm_sched_entity_pop_job(struct drm_sched_entity *entity) 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; } /** - * Submit a job to the job queue + * drm_sched_entity_push_job - Submit a job to the entity's job queue * - * @sched_job The pointer to job required to submit + * @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. */ @@ -379,15 +541,17 @@ void drm_sched_entity_push_job(struct drm_sched_job *sched_job, trace_drm_sched_job(sched_job, entity); - spin_lock(&entity->queue_lock); first = spsc_queue_push(&entity->job_queue, &sched_job->queue_node); - spin_unlock(&entity->queue_lock); - /* first job wakes up scheduler */ if (first) { /* Add the entity to the run queue */ spin_lock(&entity->rq_lock); + if (!entity->rq) { + DRM_ERROR("Trying to push to a killed entity\n"); + spin_unlock(&entity->rq_lock); + return; + } drm_sched_rq_add_entity(entity->rq, entity); spin_unlock(&entity->rq_lock); drm_sched_wakeup(sched); @@ -457,6 +621,13 @@ static void drm_sched_job_timedout(struct work_struct *work) job->sched->ops->timedout_job(job); } +/** + * 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; @@ -501,6 +672,12 @@ void drm_sched_hw_job_reset(struct drm_gpu_scheduler *sched, struct drm_sched_jo } 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; @@ -529,6 +706,7 @@ void drm_sched_job_recovery(struct drm_gpu_scheduler *sched) 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, @@ -548,13 +726,26 @@ void drm_sched_job_recovery(struct drm_gpu_scheduler *sched) } EXPORT_SYMBOL(drm_sched_job_recovery); -/* init a sched_job with basic field */ +/** + * drm_sched_job_init - init a scheduler job + * + * @job: scheduler job to init + * @sched: scheduler instance + * @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_gpu_scheduler *sched, struct drm_sched_entity *entity, void *owner) { 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) @@ -570,7 +761,11 @@ int drm_sched_job_init(struct drm_sched_job *job, EXPORT_SYMBOL(drm_sched_job_init); /** - * Return ture if we can push more jobs to the hw. + * 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) { @@ -579,7 +774,10 @@ static bool drm_sched_ready(struct drm_gpu_scheduler *sched) } /** - * Wake up the scheduler when it is ready + * drm_sched_wakeup - Wake up the scheduler when it is ready + * + * @sched: scheduler instance + * */ static void drm_sched_wakeup(struct drm_gpu_scheduler *sched) { @@ -588,8 +786,12 @@ static void drm_sched_wakeup(struct drm_gpu_scheduler *sched) } /** - * Select next entity to process -*/ + * 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) { @@ -609,6 +811,14 @@ drm_sched_select_entity(struct drm_gpu_scheduler *sched) 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 = @@ -624,6 +834,13 @@ static void drm_sched_process_job(struct dma_fence *f, struct dma_fence_cb *cb) 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()) { @@ -634,6 +851,13 @@ static bool drm_sched_blocked(struct drm_gpu_scheduler *sched) 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}; @@ -688,15 +912,17 @@ static int drm_sched_main(void *param) } /** - * Init a gpu scheduler instance + * drm_sched_init - Init a gpu scheduler instance * - * @sched The pointer to the scheduler - * @ops The backend operations for this scheduler. - * @hw_submissions Number of hw submissions to do. - * @name Name used for debugging + * @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, @@ -711,7 +937,7 @@ int drm_sched_init(struct drm_gpu_scheduler *sched, 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_rq[i]); + drm_sched_rq_init(sched, &sched->sched_rq[i]); init_waitqueue_head(&sched->wake_up_worker); init_waitqueue_head(&sched->job_scheduled); @@ -732,9 +958,11 @@ int drm_sched_init(struct drm_gpu_scheduler *sched, EXPORT_SYMBOL(drm_sched_init); /** - * Destroy a gpu scheduler + * drm_sched_fini - Destroy a gpu scheduler + * + * @sched: scheduler instance * - * @sched The pointer to the scheduler + * Tears down and cleans up the scheduler. */ void drm_sched_fini(struct drm_gpu_scheduler *sched) { |