xref: /openbmc/linux/include/drm/gpu_scheduler.h (revision f519cd13)
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 enum drm_sched_priority {
37 	DRM_SCHED_PRIORITY_MIN,
38 	DRM_SCHED_PRIORITY_LOW = DRM_SCHED_PRIORITY_MIN,
39 	DRM_SCHED_PRIORITY_NORMAL,
40 	DRM_SCHED_PRIORITY_HIGH_SW,
41 	DRM_SCHED_PRIORITY_HIGH_HW,
42 	DRM_SCHED_PRIORITY_KERNEL,
43 	DRM_SCHED_PRIORITY_MAX,
44 	DRM_SCHED_PRIORITY_INVALID = -1,
45 	DRM_SCHED_PRIORITY_UNSET = -2
46 };
47 
48 /**
49  * struct drm_sched_entity - A wrapper around a job queue (typically
50  * attached to the DRM file_priv).
51  *
52  * @list: used to append this struct to the list of entities in the
53  *        runqueue.
54  * @rq: runqueue on which this entity is currently scheduled.
55  * @sched_list: a list of drm_gpu_schedulers on which jobs from this entity can
56  *              be scheduled
57  * @num_sched_list: number of drm_gpu_schedulers in the sched_list.
58  * @rq_lock: lock to modify the runqueue to which this entity belongs.
59  * @job_queue: the list of jobs of this entity.
60  * @fence_seq: a linearly increasing seqno incremented with each
61  *             new &drm_sched_fence which is part of the entity.
62  * @fence_context: a unique context for all the fences which belong
63  *                 to this entity.
64  *                 The &drm_sched_fence.scheduled uses the
65  *                 fence_context but &drm_sched_fence.finished uses
66  *                 fence_context + 1.
67  * @dependency: the dependency fence of the job which is on the top
68  *              of the job queue.
69  * @cb: callback for the dependency fence above.
70  * @guilty: points to ctx's guilty.
71  * @fini_status: contains the exit status in case the process was signalled.
72  * @last_scheduled: points to the finished fence of the last scheduled job.
73  * @last_user: last group leader pushing a job into the entity.
74  * @stopped: Marks the enity as removed from rq and destined for termination.
75  * @entity_idle: Signals when enityt is not in use
76  *
77  * Entities will emit jobs in order to their corresponding hardware
78  * ring, and the scheduler will alternate between entities based on
79  * scheduling policy.
80  */
81 struct drm_sched_entity {
82 	struct list_head		list;
83 	struct drm_sched_rq		*rq;
84 	struct drm_gpu_scheduler        **sched_list;
85 	unsigned int                    num_sched_list;
86 	enum drm_sched_priority         priority;
87 	spinlock_t			rq_lock;
88 
89 	struct spsc_queue		job_queue;
90 
91 	atomic_t			fence_seq;
92 	uint64_t			fence_context;
93 
94 	struct dma_fence		*dependency;
95 	struct dma_fence_cb		cb;
96 	atomic_t			*guilty;
97 	struct dma_fence                *last_scheduled;
98 	struct task_struct		*last_user;
99 	bool 				stopped;
100 	struct completion		entity_idle;
101 };
102 
103 /**
104  * struct drm_sched_rq - queue of entities to be scheduled.
105  *
106  * @lock: to modify the entities list.
107  * @sched: the scheduler to which this rq belongs to.
108  * @entities: list of the entities to be scheduled.
109  * @current_entity: the entity which is to be scheduled.
110  *
111  * Run queue is a set of entities scheduling command submissions for
112  * one specific ring. It implements the scheduling policy that selects
113  * the next entity to emit commands from.
114  */
115 struct drm_sched_rq {
116 	spinlock_t			lock;
117 	struct drm_gpu_scheduler	*sched;
118 	struct list_head		entities;
119 	struct drm_sched_entity		*current_entity;
120 };
121 
122 /**
123  * struct drm_sched_fence - fences corresponding to the scheduling of a job.
124  */
125 struct drm_sched_fence {
126         /**
127          * @scheduled: this fence is what will be signaled by the scheduler
128          * when the job is scheduled.
129          */
130 	struct dma_fence		scheduled;
131 
132         /**
133          * @finished: this fence is what will be signaled by the scheduler
134          * when the job is completed.
135          *
136          * When setting up an out fence for the job, you should use
137          * this, since it's available immediately upon
138          * drm_sched_job_init(), and the fence returned by the driver
139          * from run_job() won't be created until the dependencies have
140          * resolved.
141          */
142 	struct dma_fence		finished;
143 
144         /**
145          * @parent: the fence returned by &drm_sched_backend_ops.run_job
146          * when scheduling the job on hardware. We signal the
147          * &drm_sched_fence.finished fence once parent is signalled.
148          */
149 	struct dma_fence		*parent;
150         /**
151          * @sched: the scheduler instance to which the job having this struct
152          * belongs to.
153          */
154 	struct drm_gpu_scheduler	*sched;
155         /**
156          * @lock: the lock used by the scheduled and the finished fences.
157          */
158 	spinlock_t			lock;
159         /**
160          * @owner: job owner for debugging
161          */
162 	void				*owner;
163 };
164 
165 struct drm_sched_fence *to_drm_sched_fence(struct dma_fence *f);
166 
167 /**
168  * struct drm_sched_job - A job to be run by an entity.
169  *
170  * @queue_node: used to append this struct to the queue of jobs in an entity.
171  * @sched: the scheduler instance on which this job is scheduled.
172  * @s_fence: contains the fences for the scheduling of job.
173  * @finish_cb: the callback for the finished fence.
174  * @node: used to append this struct to the @drm_gpu_scheduler.ring_mirror_list.
175  * @id: a unique id assigned to each job scheduled on the scheduler.
176  * @karma: increment on every hang caused by this job. If this exceeds the hang
177  *         limit of the scheduler then the job is marked guilty and will not
178  *         be scheduled further.
179  * @s_priority: the priority of the job.
180  * @entity: the entity to which this job belongs.
181  * @cb: the callback for the parent fence in s_fence.
182  *
183  * A job is created by the driver using drm_sched_job_init(), and
184  * should call drm_sched_entity_push_job() once it wants the scheduler
185  * to schedule the job.
186  */
187 struct drm_sched_job {
188 	struct spsc_node		queue_node;
189 	struct drm_gpu_scheduler	*sched;
190 	struct drm_sched_fence		*s_fence;
191 	struct dma_fence_cb		finish_cb;
192 	struct list_head		node;
193 	uint64_t			id;
194 	atomic_t			karma;
195 	enum drm_sched_priority		s_priority;
196 	struct drm_sched_entity  *entity;
197 	struct dma_fence_cb		cb;
198 };
199 
200 static inline bool drm_sched_invalidate_job(struct drm_sched_job *s_job,
201 					    int threshold)
202 {
203 	return (s_job && atomic_inc_return(&s_job->karma) > threshold);
204 }
205 
206 /**
207  * struct drm_sched_backend_ops
208  *
209  * Define the backend operations called by the scheduler,
210  * these functions should be implemented in driver side.
211  */
212 struct drm_sched_backend_ops {
213 	/**
214          * @dependency: Called when the scheduler is considering scheduling
215          * this job next, to get another struct dma_fence for this job to
216 	 * block on.  Once it returns NULL, run_job() may be called.
217 	 */
218 	struct dma_fence *(*dependency)(struct drm_sched_job *sched_job,
219 					struct drm_sched_entity *s_entity);
220 
221 	/**
222          * @run_job: Called to execute the job once all of the dependencies
223          * have been resolved.  This may be called multiple times, if
224 	 * timedout_job() has happened and drm_sched_job_recovery()
225 	 * decides to try it again.
226 	 */
227 	struct dma_fence *(*run_job)(struct drm_sched_job *sched_job);
228 
229 	/**
230          * @timedout_job: Called when a job has taken too long to execute,
231          * to trigger GPU recovery.
232 	 */
233 	void (*timedout_job)(struct drm_sched_job *sched_job);
234 
235 	/**
236          * @free_job: Called once the job's finished fence has been signaled
237          * and it's time to clean it up.
238 	 */
239 	void (*free_job)(struct drm_sched_job *sched_job);
240 };
241 
242 /**
243  * struct drm_gpu_scheduler
244  *
245  * @ops: backend operations provided by the driver.
246  * @hw_submission_limit: the max size of the hardware queue.
247  * @timeout: the time after which a job is removed from the scheduler.
248  * @name: name of the ring for which this scheduler is being used.
249  * @sched_rq: priority wise array of run queues.
250  * @wake_up_worker: the wait queue on which the scheduler sleeps until a job
251  *                  is ready to be scheduled.
252  * @job_scheduled: once @drm_sched_entity_do_release is called the scheduler
253  *                 waits on this wait queue until all the scheduled jobs are
254  *                 finished.
255  * @hw_rq_count: the number of jobs currently in the hardware queue.
256  * @job_id_count: used to assign unique id to the each job.
257  * @work_tdr: schedules a delayed call to @drm_sched_job_timedout after the
258  *            timeout interval is over.
259  * @thread: the kthread on which the scheduler which run.
260  * @ring_mirror_list: the list of jobs which are currently in the job queue.
261  * @job_list_lock: lock to protect the ring_mirror_list.
262  * @hang_limit: once the hangs by a job crosses this limit then it is marked
263  *              guilty and it will be considered for scheduling further.
264  * @score: score to help loadbalancer pick a idle sched
265  * @ready: marks if the underlying HW is ready to work
266  * @free_guilty: A hit to time out handler to free the guilty job.
267  *
268  * One scheduler is implemented for each hardware ring.
269  */
270 struct drm_gpu_scheduler {
271 	const struct drm_sched_backend_ops	*ops;
272 	uint32_t			hw_submission_limit;
273 	long				timeout;
274 	const char			*name;
275 	struct drm_sched_rq		sched_rq[DRM_SCHED_PRIORITY_MAX];
276 	wait_queue_head_t		wake_up_worker;
277 	wait_queue_head_t		job_scheduled;
278 	atomic_t			hw_rq_count;
279 	atomic64_t			job_id_count;
280 	struct delayed_work		work_tdr;
281 	struct task_struct		*thread;
282 	struct list_head		ring_mirror_list;
283 	spinlock_t			job_list_lock;
284 	int				hang_limit;
285 	atomic_t                        score;
286 	bool				ready;
287 	bool				free_guilty;
288 };
289 
290 int drm_sched_init(struct drm_gpu_scheduler *sched,
291 		   const struct drm_sched_backend_ops *ops,
292 		   uint32_t hw_submission, unsigned hang_limit, long timeout,
293 		   const char *name);
294 
295 void drm_sched_fini(struct drm_gpu_scheduler *sched);
296 int drm_sched_job_init(struct drm_sched_job *job,
297 		       struct drm_sched_entity *entity,
298 		       void *owner);
299 void drm_sched_job_cleanup(struct drm_sched_job *job);
300 void drm_sched_wakeup(struct drm_gpu_scheduler *sched);
301 void drm_sched_stop(struct drm_gpu_scheduler *sched, struct drm_sched_job *bad);
302 void drm_sched_start(struct drm_gpu_scheduler *sched, bool full_recovery);
303 void drm_sched_resubmit_jobs(struct drm_gpu_scheduler *sched);
304 void drm_sched_increase_karma(struct drm_sched_job *bad);
305 bool drm_sched_dependency_optimized(struct dma_fence* fence,
306 				    struct drm_sched_entity *entity);
307 void drm_sched_fault(struct drm_gpu_scheduler *sched);
308 void drm_sched_job_kickout(struct drm_sched_job *s_job);
309 
310 void drm_sched_rq_add_entity(struct drm_sched_rq *rq,
311 			     struct drm_sched_entity *entity);
312 void drm_sched_rq_remove_entity(struct drm_sched_rq *rq,
313 				struct drm_sched_entity *entity);
314 
315 int drm_sched_entity_init(struct drm_sched_entity *entity,
316 			  enum drm_sched_priority priority,
317 			  struct drm_gpu_scheduler **sched_list,
318 			  unsigned int num_sched_list,
319 			  atomic_t *guilty);
320 long drm_sched_entity_flush(struct drm_sched_entity *entity, long timeout);
321 void drm_sched_entity_fini(struct drm_sched_entity *entity);
322 void drm_sched_entity_destroy(struct drm_sched_entity *entity);
323 void drm_sched_entity_select_rq(struct drm_sched_entity *entity);
324 struct drm_sched_job *drm_sched_entity_pop_job(struct drm_sched_entity *entity);
325 void drm_sched_entity_push_job(struct drm_sched_job *sched_job,
326 			       struct drm_sched_entity *entity);
327 void drm_sched_entity_set_priority(struct drm_sched_entity *entity,
328 				   enum drm_sched_priority priority);
329 bool drm_sched_entity_is_ready(struct drm_sched_entity *entity);
330 
331 struct drm_sched_fence *drm_sched_fence_create(
332 	struct drm_sched_entity *s_entity, void *owner);
333 void drm_sched_fence_scheduled(struct drm_sched_fence *fence);
334 void drm_sched_fence_finished(struct drm_sched_fence *fence);
335 
336 unsigned long drm_sched_suspend_timeout(struct drm_gpu_scheduler *sched);
337 void drm_sched_resume_timeout(struct drm_gpu_scheduler *sched,
338 		                unsigned long remaining);
339 
340 #endif
341