xref: /openbmc/linux/include/drm/gpu_scheduler.h (revision d9fd5a71)
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  * @list: a job participates in a "pending" and "done" lists.
175  * @sched: the scheduler instance on which this job is scheduled.
176  * @s_fence: contains the fences for the scheduling of job.
177  * @finish_cb: the callback for the finished fence.
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 list_head		list;
193 	struct drm_gpu_scheduler	*sched;
194 	struct drm_sched_fence		*s_fence;
195 	struct dma_fence_cb		finish_cb;
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  * @pending_list: the list of jobs which are currently in the job queue.
264  * @job_list_lock: lock to protect the pending_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		pending_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
351