include/drm/gpu_scheduler.h

   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 #ifndef _DRM_GPU_SCHEDULER_H_
  25 #define _DRM_GPU_SCHEDULER_H_
  26
  27 #include <drm/spsc_queue.h>
  28 #include <linux/dma-fence.h>
  29 #include <linux/completion.h>
  30
  31 #define MAX_WAIT_SCHED_ENTITY_Q_EMPTY msecs_to_jiffies(1000)
  32
  33 struct drm_gpu_scheduler;
  34 struct drm_sched_rq;
  35
  36 /* These are often used as an (initial) index
  37  * to an array, and as such should start at 0.
  38  */
  39 enum drm_sched_priority {
  40         DRM_SCHED_PRIORITY_MIN,
  41         DRM_SCHED_PRIORITY_NORMAL,
  42         DRM_SCHED_PRIORITY_HIGH,
  43         DRM_SCHED_PRIORITY_KERNEL,
  44
  45         DRM_SCHED_PRIORITY_COUNT,
  46         DRM_SCHED_PRIORITY_UNSET = -2
  47 };
  48
  49 /**
  50  * struct drm_sched_entity - A wrapper around a job queue (typically
  51  * attached to the DRM file_priv).
  52  *
  53  * @list: used to append this struct to the list of entities in the
  54  *        runqueue.
  55  * @rq: runqueue on which this entity is currently scheduled.
  56  * @sched_list: A list of schedulers (drm_gpu_schedulers).
  57  *              Jobs from this entity can be scheduled on any scheduler
  58  *              on this list.
  59  * @num_sched_list: number of drm_gpu_schedulers in the sched_list.
  60  * @priority: priority of the entity
  61  * @rq_lock: lock to modify the runqueue to which this entity belongs.
  62  * @job_queue: the list of jobs of this entity.
  63  * @fence_seq: a linearly increasing seqno incremented with each
  64  *             new &drm_sched_fence which is part of the entity.
  65  * @fence_context: a unique context for all the fences which belong
  66  *                 to this entity.
  67  *                 The &drm_sched_fence.scheduled uses the
  68  *                 fence_context but &drm_sched_fence.finished uses
  69  *                 fence_context + 1.
  70  * @dependency: the dependency fence of the job which is on the top
  71  *              of the job queue.
  72  * @cb: callback for the dependency fence above.
  73  * @guilty: points to ctx's guilty.
  74  * @fini_status: contains the exit status in case the process was signalled.
  75  * @last_scheduled: points to the finished fence of the last scheduled job.
  76  * @last_user: last group leader pushing a job into the entity.
  77  * @stopped: Marks the enity as removed from rq and destined for termination.
  78  * @entity_idle: Signals when enityt is not in use
  79  *
  80  * Entities will emit jobs in order to their corresponding hardware
  81  * ring, and the scheduler will alternate between entities based on
  82  * scheduling policy.
  83  */
  84 struct drm_sched_entity {
  85         struct list_head                list;
  86         struct drm_sched_rq             *rq;
  87         struct drm_gpu_scheduler        **sched_list;
  88         unsigned int                    num_sched_list;
  89         enum drm_sched_priority         priority;
  90         spinlock_t                      rq_lock;
  91
  92         struct spsc_queue               job_queue;
  93
  94         atomic_t                        fence_seq;
  95         uint64_t                        fence_context;
  96
  97         struct dma_fence                *dependency;
  98         struct dma_fence_cb             cb;
  99         atomic_t                        *guilty;
 100         struct dma_fence                *last_scheduled;
 101         struct task_struct              *last_user;
 102         bool                            stopped;
 103         struct completion               entity_idle;
 104 };
 105
 106 /**
 107  * struct drm_sched_rq - queue of entities to be scheduled.
 108  *
 109  * @lock: to modify the entities list.
 110  * @sched: the scheduler to which this rq belongs to.
 111  * @entities: list of the entities to be scheduled.
 112  * @current_entity: the entity which is to be scheduled.
 113  *
 114  * Run queue is a set of entities scheduling command submissions for
 115  * one specific ring. It implements the scheduling policy that selects
 116  * the next entity to emit commands from.
 117  */
 118 struct drm_sched_rq {
 119         spinlock_t                      lock;
 120         struct drm_gpu_scheduler        *sched;
 121         struct list_head                entities;
 122         struct drm_sched_entity         *current_entity;
 123 };
 124
 125 /**
 126  * struct drm_sched_fence - fences corresponding to the scheduling of a job.
 127  */
 128 struct drm_sched_fence {
 129         /**
 130          * @scheduled: this fence is what will be signaled by the scheduler
 131          * when the job is scheduled.
 132          */
 133         struct dma_fence                scheduled;
 134
 135         /**
 136          * @finished: this fence is what will be signaled by the scheduler
 137          * when the job is completed.
 138          *
 139          * When setting up an out fence for the job, you should use
 140          * this, since it's available immediately upon
 141          * drm_sched_job_init(), and the fence returned by the driver
 142          * from run_job() won't be created until the dependencies have
 143          * resolved.
 144          */
 145         struct dma_fence                finished;
 146
 147         /**
 148          * @parent: the fence returned by &drm_sched_backend_ops.run_job
 149          * when scheduling the job on hardware. We signal the
 150          * &drm_sched_fence.finished fence once parent is signalled.
 151          */
 152         struct dma_fence                *parent;
 153         /**
 154          * @sched: the scheduler instance to which the job having this struct
 155          * belongs to.
 156          */
 157         struct drm_gpu_scheduler        *sched;
 158         /**
 159          * @lock: the lock used by the scheduled and the finished fences.
 160          */
 161         spinlock_t                      lock;
 162         /**
 163          * @owner: job owner for debugging
 164          */
 165         void                            *owner;
 166 };
 167
 168 struct drm_sched_fence *to_drm_sched_fence(struct dma_fence *f);
 169
 170 /**
 171  * struct drm_sched_job - A job to be run by an entity.
 172  *
 173  * @queue_node: used to append this struct to the queue of jobs in an entity.
 174  * @sched: the scheduler instance on which this job is scheduled.
 175  * @s_fence: contains the fences for the scheduling of job.
 176  * @finish_cb: the callback for the finished fence.
 177  * @node: used to append this struct to the @drm_gpu_scheduler.ring_mirror_list.
 178  * @id: a unique id assigned to each job scheduled on the scheduler.
 179  * @karma: increment on every hang caused by this job. If this exceeds the hang
 180  *         limit of the scheduler then the job is marked guilty and will not
 181  *         be scheduled further.
 182  * @s_priority: the priority of the job.
 183  * @entity: the entity to which this job belongs.
 184  * @cb: the callback for the parent fence in s_fence.
 185  *
 186  * A job is created by the driver using drm_sched_job_init(), and
 187  * should call drm_sched_entity_push_job() once it wants the scheduler
 188  * to schedule the job.
 189  */
 190 struct drm_sched_job {
 191         struct spsc_node                queue_node;
 192         struct drm_gpu_scheduler        *sched;
 193         struct drm_sched_fence          *s_fence;
 194         struct dma_fence_cb             finish_cb;
 195         struct list_head                node;
 196         uint64_t                        id;
 197         atomic_t                        karma;
 198         enum drm_sched_priority         s_priority;
 199         struct drm_sched_entity  *entity;
 200         struct dma_fence_cb             cb;
 201 };
 202
 203 static inline bool drm_sched_invalidate_job(struct drm_sched_job *s_job,
 204                                             int threshold)
 205 {
 206         return (s_job && atomic_inc_return(&s_job->karma) > threshold);
 207 }
 208
 209 /**
 210  * struct drm_sched_backend_ops
 211  *
 212  * Define the backend operations called by the scheduler,
 213  * these functions should be implemented in driver side.
 214  */
 215 struct drm_sched_backend_ops {
 216         /**
 217          * @dependency: Called when the scheduler is considering scheduling
 218          * this job next, to get another struct dma_fence for this job to
 219          * block on.  Once it returns NULL, run_job() may be called.
 220          */
 221         struct dma_fence *(*dependency)(struct drm_sched_job *sched_job,
 222                                         struct drm_sched_entity *s_entity);
 223
 224         /**
 225          * @run_job: Called to execute the job once all of the dependencies
 226          * have been resolved.  This may be called multiple times, if
 227          * timedout_job() has happened and drm_sched_job_recovery()
 228          * decides to try it again.
 229          */
 230         struct dma_fence *(*run_job)(struct drm_sched_job *sched_job);
 231
 232         /**
 233          * @timedout_job: Called when a job has taken too long to execute,
 234          * to trigger GPU recovery.
 235          */
 236         void (*timedout_job)(struct drm_sched_job *sched_job);
 237
 238         /**
 239          * @free_job: Called once the job's finished fence has been signaled
 240          * and it's time to clean it up.
 241          */
 242         void (*free_job)(struct drm_sched_job *sched_job);
 243 };
 244
 245 /**
 246  * struct drm_gpu_scheduler
 247  *
 248  * @ops: backend operations provided by the driver.
 249  * @hw_submission_limit: the max size of the hardware queue.
 250  * @timeout: the time after which a job is removed from the scheduler.
 251  * @name: name of the ring for which this scheduler is being used.
 252  * @sched_rq: priority wise array of run queues.
 253  * @wake_up_worker: the wait queue on which the scheduler sleeps until a job
 254  *                  is ready to be scheduled.
 255  * @job_scheduled: once @drm_sched_entity_do_release is called the scheduler
 256  *                 waits on this wait queue until all the scheduled jobs are
 257  *                 finished.
 258  * @hw_rq_count: the number of jobs currently in the hardware queue.
 259  * @job_id_count: used to assign unique id to the each job.
 260  * @work_tdr: schedules a delayed call to @drm_sched_job_timedout after the
 261  *            timeout interval is over.
 262  * @thread: the kthread on which the scheduler which run.
 263  * @ring_mirror_list: the list of jobs which are currently in the job queue.
 264  * @job_list_lock: lock to protect the ring_mirror_list.
 265  * @hang_limit: once the hangs by a job crosses this limit then it is marked
 266  *              guilty and it will be considered for scheduling further.
 267  * @score: score to help loadbalancer pick a idle sched
 268  * @ready: marks if the underlying HW is ready to work
 269  * @free_guilty: A hit to time out handler to free the guilty job.
 270  *
 271  * One scheduler is implemented for each hardware ring.
 272  */
 273 struct drm_gpu_scheduler {
 274         const struct drm_sched_backend_ops      *ops;
 275         uint32_t                        hw_submission_limit;
 276         long                            timeout;
 277         const char                      *name;
 278         struct drm_sched_rq             sched_rq[DRM_SCHED_PRIORITY_COUNT];
 279         wait_queue_head_t               wake_up_worker;
 280         wait_queue_head_t               job_scheduled;
 281         atomic_t                        hw_rq_count;
 282         atomic64_t                      job_id_count;
 283         struct delayed_work             work_tdr;
 284         struct task_struct              *thread;
 285         struct list_head                ring_mirror_list;
 286         spinlock_t                      job_list_lock;
 287         int                             hang_limit;
 288         atomic_t                        score;
 289         bool                            ready;
 290         bool                            free_guilty;
 291 };
 292
 293 int drm_sched_init(struct drm_gpu_scheduler *sched,
 294                    const struct drm_sched_backend_ops *ops,
 295                    uint32_t hw_submission, unsigned hang_limit, long timeout,
 296                    const char *name);
 297
 298 void drm_sched_fini(struct drm_gpu_scheduler *sched);
 299 int drm_sched_job_init(struct drm_sched_job *job,
 300                        struct drm_sched_entity *entity,
 301                        void *owner);
 302 void drm_sched_entity_modify_sched(struct drm_sched_entity *entity,
 303                                     struct drm_gpu_scheduler **sched_list,
 304                                    unsigned int num_sched_list);
 305
 306 void drm_sched_job_cleanup(struct drm_sched_job *job);
 307 void drm_sched_wakeup(struct drm_gpu_scheduler *sched);
 308 void drm_sched_stop(struct drm_gpu_scheduler *sched, struct drm_sched_job *bad);
 309 void drm_sched_start(struct drm_gpu_scheduler *sched, bool full_recovery);
 310 void drm_sched_resubmit_jobs(struct drm_gpu_scheduler *sched);
 311 void drm_sched_increase_karma(struct drm_sched_job *bad);
 312 bool drm_sched_dependency_optimized(struct dma_fence* fence,
 313                                     struct drm_sched_entity *entity);
 314 void drm_sched_fault(struct drm_gpu_scheduler *sched);
 315 void drm_sched_job_kickout(struct drm_sched_job *s_job);
 316
 317 void drm_sched_rq_add_entity(struct drm_sched_rq *rq,
 318                              struct drm_sched_entity *entity);
 319 void drm_sched_rq_remove_entity(struct drm_sched_rq *rq,
 320                                 struct drm_sched_entity *entity);
 321
 322 int drm_sched_entity_init(struct drm_sched_entity *entity,
 323                           enum drm_sched_priority priority,
 324                           struct drm_gpu_scheduler **sched_list,
 325                           unsigned int num_sched_list,
 326                           atomic_t *guilty);
 327 long drm_sched_entity_flush(struct drm_sched_entity *entity, long timeout);
 328 void drm_sched_entity_fini(struct drm_sched_entity *entity);
 329 void drm_sched_entity_destroy(struct drm_sched_entity *entity);
 330 void drm_sched_entity_select_rq(struct drm_sched_entity *entity);
 331 struct drm_sched_job *drm_sched_entity_pop_job(struct drm_sched_entity *entity);
 332 void drm_sched_entity_push_job(struct drm_sched_job *sched_job,
 333                                struct drm_sched_entity *entity);
 334 void drm_sched_entity_set_priority(struct drm_sched_entity *entity,
 335                                    enum drm_sched_priority priority);
 336 bool drm_sched_entity_is_ready(struct drm_sched_entity *entity);
 337
 338 struct drm_sched_fence *drm_sched_fence_create(
 339         struct drm_sched_entity *s_entity, void *owner);
 340 void drm_sched_fence_scheduled(struct drm_sched_fence *fence);
 341 void drm_sched_fence_finished(struct drm_sched_fence *fence);
 342
 343 unsigned long drm_sched_suspend_timeout(struct drm_gpu_scheduler *sched);
 344 void drm_sched_resume_timeout(struct drm_gpu_scheduler *sched,
 345                                 unsigned long remaining);
 346 struct drm_gpu_scheduler *
 347 drm_sched_pick_best(struct drm_gpu_scheduler **sched_list,
 348                      unsigned int num_sched_list);
 349
 350 #endif