Add generic schedule message interface which sends messages to backend from the drm_gpu_scheduler main submission thread. The idea is some of these messages modify some state in drm_sched_entity which is also modified during submission. By scheduling these messages and submission in the same thread their is not race changing states in drm_sched_entity. This interface will be used in Xe, new Intel GPU driver, to cleanup, suspend, resume, and change scheduling properties of a drm_sched_entity. The interface is designed to be generic and extendable with only the backend understanding the messages. v2: - (Christian) We dedicated work item Signed-off-by: Matthew Brost <matthew.brost@xxxxxxxxx> --- drivers/gpu/drm/scheduler/sched_main.c | 98 ++++++++++++++++++++++++++ include/drm/gpu_scheduler.h | 34 ++++++++- 2 files changed, 131 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c index b67469eac179..fbd99f7e5b4a 100644 --- a/drivers/gpu/drm/scheduler/sched_main.c +++ b/drivers/gpu/drm/scheduler/sched_main.c @@ -340,6 +340,35 @@ static void drm_sched_free_job_queue_if_ready(struct drm_gpu_scheduler *sched) spin_unlock(&sched->job_list_lock); } +/** + * drm_sched_process_msg_queue - queue process msg worker + * + * @sched: scheduler instance to queue process_msg worker + */ +static void drm_sched_process_msg_queue(struct drm_gpu_scheduler *sched) +{ + if (!READ_ONCE(sched->pause_submit)) + queue_work(sched->submit_wq, &sched->work_process_msg); +} + +/** + * drm_sched_process_msg_queue_if_ready - queue process msg worker if ready + * + * @sched: scheduler instance to queue process_msg worker + */ +static void +drm_sched_process_msg_queue_if_ready(struct drm_gpu_scheduler *sched) +{ + struct drm_sched_msg *msg; + + spin_lock(&sched->job_list_lock); + msg = list_first_entry_or_null(&sched->msgs, + struct drm_sched_msg, link); + if (msg) + drm_sched_process_msg_queue(sched); + spin_unlock(&sched->job_list_lock); +} + /** * drm_sched_job_done - complete a job * @s_job: pointer to the job which is done @@ -1075,6 +1104,71 @@ drm_sched_pick_best(struct drm_gpu_scheduler **sched_list, } EXPORT_SYMBOL(drm_sched_pick_best); +/** + * drm_sched_add_msg - add scheduler message + * + * @sched: scheduler instance + * @msg: message to be added + * + * Can and will pass an jobs waiting on dependencies or in a runnable queue. + * Messages processing will stop if schedule run wq is stopped and resume when + * run wq is started. + */ +void drm_sched_add_msg(struct drm_gpu_scheduler *sched, + struct drm_sched_msg *msg) +{ + spin_lock(&sched->job_list_lock); + list_add_tail(&msg->link, &sched->msgs); + spin_unlock(&sched->job_list_lock); + + drm_sched_process_msg_queue(sched); +} +EXPORT_SYMBOL(drm_sched_add_msg); + +/** + * drm_sched_get_msg - get scheduler message + * + * @sched: scheduler instance + * + * Returns NULL or message + */ +static struct drm_sched_msg * +drm_sched_get_msg(struct drm_gpu_scheduler *sched) +{ + struct drm_sched_msg *msg; + + spin_lock(&sched->job_list_lock); + msg = list_first_entry_or_null(&sched->msgs, + struct drm_sched_msg, link); + if (msg) + list_del(&msg->link); + spin_unlock(&sched->job_list_lock); + + return msg; +} + +/** + * drm_sched_process_msg_work - worker to call process_msg + * + * @w: process msg work + */ +static void drm_sched_process_msg_work(struct work_struct *w) +{ + struct drm_gpu_scheduler *sched = + container_of(w, struct drm_gpu_scheduler, work_process_msg); + struct drm_sched_msg *msg; + + if (READ_ONCE(sched->pause_submit)) + return; + + msg = drm_sched_get_msg(sched); + if (msg) { + sched->ops->process_msg(msg); + + drm_sched_process_msg_queue_if_ready(sched); + } +} + /** * drm_sched_free_job_work - worker to call free_job * @@ -1209,11 +1303,13 @@ int drm_sched_init(struct drm_gpu_scheduler *sched, init_waitqueue_head(&sched->job_scheduled); INIT_LIST_HEAD(&sched->pending_list); + INIT_LIST_HEAD(&sched->msgs); spin_lock_init(&sched->job_list_lock); atomic_set(&sched->hw_rq_count, 0); INIT_DELAYED_WORK(&sched->work_tdr, drm_sched_job_timedout); INIT_WORK(&sched->work_run_job, drm_sched_run_job_work); INIT_WORK(&sched->work_free_job, drm_sched_free_job_work); + INIT_WORK(&sched->work_process_msg, drm_sched_process_msg_work); atomic_set(&sched->_score, 0); atomic64_set(&sched->job_id_count, 0); sched->pause_submit = false; @@ -1340,6 +1436,7 @@ void drm_sched_submit_stop(struct drm_gpu_scheduler *sched) WRITE_ONCE(sched->pause_submit, true); cancel_work_sync(&sched->work_run_job); cancel_work_sync(&sched->work_free_job); + cancel_work_sync(&sched->work_process_msg); } EXPORT_SYMBOL(drm_sched_submit_stop); @@ -1353,5 +1450,6 @@ void drm_sched_submit_start(struct drm_gpu_scheduler *sched) WRITE_ONCE(sched->pause_submit, false); queue_work(sched->submit_wq, &sched->work_run_job); queue_work(sched->submit_wq, &sched->work_free_job); + queue_work(sched->submit_wq, &sched->work_process_msg); } EXPORT_SYMBOL(drm_sched_submit_start); diff --git a/include/drm/gpu_scheduler.h b/include/drm/gpu_scheduler.h index fbc083a92757..5d753ecb5d71 100644 --- a/include/drm/gpu_scheduler.h +++ b/include/drm/gpu_scheduler.h @@ -394,6 +394,23 @@ enum drm_gpu_sched_stat { DRM_GPU_SCHED_STAT_ENODEV, }; +/** + * struct drm_sched_msg - an in-band (relative to GPU scheduler run queue) + * message + * + * Generic enough for backend defined messages, backend can expand if needed. + */ +struct drm_sched_msg { + /** @link: list link into the gpu scheduler list of messages */ + struct list_head link; + /** + * @private_data: opaque pointer to message private data (backend defined) + */ + void *private_data; + /** @opcode: opcode of message (backend defined) */ + unsigned int opcode; +}; + /** * struct drm_sched_backend_ops - Define the backend operations * called by the scheduler @@ -471,6 +488,12 @@ struct drm_sched_backend_ops { * and it's time to clean it up. */ void (*free_job)(struct drm_sched_job *sched_job); + + /** + * @process_msg: Process a message. Allowed to block, it is this + * function's responsibility to free message if dynamically allocated. + */ + void (*process_msg)(struct drm_sched_msg *msg); }; /** @@ -482,15 +505,18 @@ struct drm_sched_backend_ops { * @timeout: the time after which a job is removed from the scheduler. * @name: name of the ring for which this scheduler is being used. * @sched_rq: priority wise array of run queues. + * @msgs: list of messages to be processed in @work_process_msg * @job_scheduled: once @drm_sched_entity_do_release is called the scheduler * waits on this wait queue until all the scheduled jobs are * finished. * @hw_rq_count: the number of jobs currently in the hardware queue. * @job_id_count: used to assign unique id to the each job. - * @submit_wq: workqueue used to queue @work_run_job and @work_free_job + * @submit_wq: workqueue used to queue @work_run_job, @work_free_job, and + * @work_process_msg * @timeout_wq: workqueue used to queue @work_tdr * @work_run_job: schedules jobs * @work_free_job: cleans up jobs + * @work_process_msg: processes messages * @work_tdr: schedules a delayed call to @drm_sched_job_timedout after the * timeout interval is over. * @pending_list: the list of jobs which are currently in the job queue. @@ -502,6 +528,8 @@ struct drm_sched_backend_ops { * @sched_policy: Schedule policy for scheduler * @ready: marks if the underlying HW is ready to work * @free_guilty: A hit to time out handler to free the guilty job. + * @pause_submit: pause queuing of @work_run_job, @work_free_job, and + * @work_process_msg on @submit_wq * @pause_submit: pause queuing of @work_submit on @submit_wq * @dev: system &struct device * @@ -514,6 +542,7 @@ struct drm_gpu_scheduler { long timeout; const char *name; struct drm_sched_rq sched_rq[DRM_SCHED_PRIORITY_COUNT]; + struct list_head msgs; wait_queue_head_t job_scheduled; atomic_t hw_rq_count; atomic64_t job_id_count; @@ -521,6 +550,7 @@ struct drm_gpu_scheduler { struct workqueue_struct *timeout_wq; struct work_struct work_run_job; struct work_struct work_free_job; + struct work_struct work_process_msg; struct delayed_work work_tdr; struct list_head pending_list; spinlock_t job_list_lock; @@ -568,6 +598,8 @@ void drm_sched_entity_modify_sched(struct drm_sched_entity *entity, void drm_sched_job_cleanup(struct drm_sched_job *job); void drm_sched_wakeup_if_can_queue(struct drm_gpu_scheduler *sched); +void drm_sched_add_msg(struct drm_gpu_scheduler *sched, + struct drm_sched_msg *msg); bool drm_sched_submit_ready(struct drm_gpu_scheduler *sched); void drm_sched_submit_stop(struct drm_gpu_scheduler *sched); void drm_sched_submit_start(struct drm_gpu_scheduler *sched); -- 2.34.1