xref: /openbsd-src/sys/dev/pci/drm/include/drm/gpu_scheduler.h (revision 46035553bfdd96e63c94e32da0210227ec2e3cf1)
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 schedulers (drm_gpu_schedulers).
56  *              Jobs from this entity can be scheduled on any scheduler
57  *              on this list.
58  * @num_sched_list: number of drm_gpu_schedulers in the sched_list.
59  * @rq_lock: lock to modify the runqueue to which this entity belongs.
60  * @job_queue: the list of jobs of this entity.
61  * @fence_seq: a linearly increasing seqno incremented with each
62  *             new &drm_sched_fence which is part of the entity.
63  * @fence_context: a unique context for all the fences which belong
64  *                 to this entity.
65  *                 The &drm_sched_fence.scheduled uses the
66  *                 fence_context but &drm_sched_fence.finished uses
67  *                 fence_context + 1.
68  * @dependency: the dependency fence of the job which is on the top
69  *              of the job queue.
70  * @cb: callback for the dependency fence above.
71  * @guilty: points to ctx's guilty.
72  * @fini_status: contains the exit status in case the process was signalled.
73  * @last_scheduled: points to the finished fence of the last scheduled job.
74  * @last_user: last group leader pushing a job into the entity.
75  * @stopped: Marks the enity as removed from rq and destined for termination.
76  * @entity_idle: Signals when enityt is not in use
77  *
78  * Entities will emit jobs in order to their corresponding hardware
79  * ring, and the scheduler will alternate between entities based on
80  * scheduling policy.
81  */
82 struct drm_sched_entity {
83 	struct list_head		list;
84 	struct drm_sched_rq		*rq;
85 	struct drm_gpu_scheduler        **sched_list;
86 	unsigned int                    num_sched_list;
87 	enum drm_sched_priority         priority;
88 	spinlock_t			rq_lock;
89 
90 	struct spsc_queue		job_queue;
91 
92 	atomic_t			fence_seq;
93 	uint64_t			fence_context;
94 
95 	struct dma_fence		*dependency;
96 	struct dma_fence_cb		cb;
97 	atomic_t			*guilty;
98 	struct dma_fence                *last_scheduled;
99 #ifdef __linux__
100 	struct task_struct		*last_user;
101 #else
102 	struct process			*last_user;
103 #endif
104 	bool 				stopped;
105 	struct completion		entity_idle;
106 };
107 
108 /**
109  * struct drm_sched_rq - queue of entities to be scheduled.
110  *
111  * @lock: to modify the entities list.
112  * @sched: the scheduler to which this rq belongs to.
113  * @entities: list of the entities to be scheduled.
114  * @current_entity: the entity which is to be scheduled.
115  *
116  * Run queue is a set of entities scheduling command submissions for
117  * one specific ring. It implements the scheduling policy that selects
118  * the next entity to emit commands from.
119  */
120 struct drm_sched_rq {
121 	spinlock_t			lock;
122 	struct drm_gpu_scheduler	*sched;
123 	struct list_head		entities;
124 	struct drm_sched_entity		*current_entity;
125 };
126 
127 /**
128  * struct drm_sched_fence - fences corresponding to the scheduling of a job.
129  */
130 struct drm_sched_fence {
131         /**
132          * @scheduled: this fence is what will be signaled by the scheduler
133          * when the job is scheduled.
134          */
135 	struct dma_fence		scheduled;
136 
137         /**
138          * @finished: this fence is what will be signaled by the scheduler
139          * when the job is completed.
140          *
141          * When setting up an out fence for the job, you should use
142          * this, since it's available immediately upon
143          * drm_sched_job_init(), and the fence returned by the driver
144          * from run_job() won't be created until the dependencies have
145          * resolved.
146          */
147 	struct dma_fence		finished;
148 
149         /**
150          * @parent: the fence returned by &drm_sched_backend_ops.run_job
151          * when scheduling the job on hardware. We signal the
152          * &drm_sched_fence.finished fence once parent is signalled.
153          */
154 	struct dma_fence		*parent;
155         /**
156          * @sched: the scheduler instance to which the job having this struct
157          * belongs to.
158          */
159 	struct drm_gpu_scheduler	*sched;
160         /**
161          * @lock: the lock used by the scheduled and the finished fences.
162          */
163 	spinlock_t			lock;
164         /**
165          * @owner: job owner for debugging
166          */
167 	void				*owner;
168 };
169 
170 struct drm_sched_fence *to_drm_sched_fence(struct dma_fence *f);
171 
172 /**
173  * struct drm_sched_job - A job to be run by an entity.
174  *
175  * @queue_node: used to append this struct to the queue of jobs in an entity.
176  * @sched: the scheduler instance on which this job is scheduled.
177  * @s_fence: contains the fences for the scheduling of job.
178  * @finish_cb: the callback for the finished fence.
179  * @node: used to append this struct to the @drm_gpu_scheduler.ring_mirror_list.
180  * @id: a unique id assigned to each job scheduled on the scheduler.
181  * @karma: increment on every hang caused by this job. If this exceeds the hang
182  *         limit of the scheduler then the job is marked guilty and will not
183  *         be scheduled further.
184  * @s_priority: the priority of the job.
185  * @entity: the entity to which this job belongs.
186  * @cb: the callback for the parent fence in s_fence.
187  *
188  * A job is created by the driver using drm_sched_job_init(), and
189  * should call drm_sched_entity_push_job() once it wants the scheduler
190  * to schedule the job.
191  */
192 struct drm_sched_job {
193 	struct spsc_node		queue_node;
194 	struct drm_gpu_scheduler	*sched;
195 	struct drm_sched_fence		*s_fence;
196 	struct dma_fence_cb		finish_cb;
197 	struct list_head		node;
198 	uint64_t			id;
199 	atomic_t			karma;
200 	enum drm_sched_priority		s_priority;
201 	struct drm_sched_entity  *entity;
202 	struct dma_fence_cb		cb;
203 };
204 
205 static inline bool drm_sched_invalidate_job(struct drm_sched_job *s_job,
206 					    int threshold)
207 {
208 	return (s_job && atomic_inc_return(&s_job->karma) > threshold);
209 }
210 
211 /**
212  * struct drm_sched_backend_ops
213  *
214  * Define the backend operations called by the scheduler,
215  * these functions should be implemented in driver side.
216  */
217 struct drm_sched_backend_ops {
218 	/**
219          * @dependency: Called when the scheduler is considering scheduling
220          * this job next, to get another struct dma_fence for this job to
221 	 * block on.  Once it returns NULL, run_job() may be called.
222 	 */
223 	struct dma_fence *(*dependency)(struct drm_sched_job *sched_job,
224 					struct drm_sched_entity *s_entity);
225 
226 	/**
227          * @run_job: Called to execute the job once all of the dependencies
228          * have been resolved.  This may be called multiple times, if
229 	 * timedout_job() has happened and drm_sched_job_recovery()
230 	 * decides to try it again.
231 	 */
232 	struct dma_fence *(*run_job)(struct drm_sched_job *sched_job);
233 
234 	/**
235          * @timedout_job: Called when a job has taken too long to execute,
236          * to trigger GPU recovery.
237 	 */
238 	void (*timedout_job)(struct drm_sched_job *sched_job);
239 
240 	/**
241          * @free_job: Called once the job's finished fence has been signaled
242          * and it's time to clean it up.
243 	 */
244 	void (*free_job)(struct drm_sched_job *sched_job);
245 };
246 
247 /**
248  * struct drm_gpu_scheduler
249  *
250  * @ops: backend operations provided by the driver.
251  * @hw_submission_limit: the max size of the hardware queue.
252  * @timeout: the time after which a job is removed from the scheduler.
253  * @name: name of the ring for which this scheduler is being used.
254  * @sched_rq: priority wise array of run queues.
255  * @wake_up_worker: the wait queue on which the scheduler sleeps until a job
256  *                  is ready to be scheduled.
257  * @job_scheduled: once @drm_sched_entity_do_release is called the scheduler
258  *                 waits on this wait queue until all the scheduled jobs are
259  *                 finished.
260  * @hw_rq_count: the number of jobs currently in the hardware queue.
261  * @job_id_count: used to assign unique id to the each job.
262  * @work_tdr: schedules a delayed call to @drm_sched_job_timedout after the
263  *            timeout interval is over.
264  * @thread: the kthread on which the scheduler which run.
265  * @ring_mirror_list: the list of jobs which are currently in the job queue.
266  * @job_list_lock: lock to protect the ring_mirror_list.
267  * @hang_limit: once the hangs by a job crosses this limit then it is marked
268  *              guilty and it will be considered for scheduling further.
269  * @num_jobs: the number of jobs in queue in the scheduler
270  * @ready: marks if the underlying HW is ready to work
271  * @free_guilty: A hit to time out handler to free the guilty job.
272  *
273  * One scheduler is implemented for each hardware ring.
274  */
275 struct drm_gpu_scheduler {
276 	const struct drm_sched_backend_ops	*ops;
277 	uint32_t			hw_submission_limit;
278 	long				timeout;
279 	const char			*name;
280 	struct drm_sched_rq		sched_rq[DRM_SCHED_PRIORITY_MAX];
281 	wait_queue_head_t		wake_up_worker;
282 	wait_queue_head_t		job_scheduled;
283 	atomic_t			hw_rq_count;
284 	atomic64_t			job_id_count;
285 	struct delayed_work		work_tdr;
286 #ifdef __linux__
287 	struct task_struct		*thread;
288 #else
289 	struct proc			*thread;
290 #endif
291 	struct list_head		ring_mirror_list;
292 	spinlock_t			job_list_lock;
293 	int				hang_limit;
294 	atomic_t                        num_jobs;
295 	bool			ready;
296 	bool				free_guilty;
297 };
298 
299 int drm_sched_init(struct drm_gpu_scheduler *sched,
300 		   const struct drm_sched_backend_ops *ops,
301 		   uint32_t hw_submission, unsigned hang_limit, long timeout,
302 		   const char *name);
303 
304 void drm_sched_fini(struct drm_gpu_scheduler *sched);
305 int drm_sched_job_init(struct drm_sched_job *job,
306 		       struct drm_sched_entity *entity,
307 		       void *owner);
308 void drm_sched_entity_modify_sched(struct drm_sched_entity *entity,
309 				    struct drm_gpu_scheduler **sched_list,
310                                    unsigned int num_sched_list);
311 
312 void drm_sched_job_cleanup(struct drm_sched_job *job);
313 void drm_sched_wakeup(struct drm_gpu_scheduler *sched);
314 void drm_sched_stop(struct drm_gpu_scheduler *sched, struct drm_sched_job *bad);
315 void drm_sched_start(struct drm_gpu_scheduler *sched, bool full_recovery);
316 void drm_sched_resubmit_jobs(struct drm_gpu_scheduler *sched);
317 void drm_sched_increase_karma(struct drm_sched_job *bad);
318 bool drm_sched_dependency_optimized(struct dma_fence* fence,
319 				    struct drm_sched_entity *entity);
320 void drm_sched_fault(struct drm_gpu_scheduler *sched);
321 void drm_sched_job_kickout(struct drm_sched_job *s_job);
322 
323 void drm_sched_rq_add_entity(struct drm_sched_rq *rq,
324 			     struct drm_sched_entity *entity);
325 void drm_sched_rq_remove_entity(struct drm_sched_rq *rq,
326 				struct drm_sched_entity *entity);
327 
328 int drm_sched_entity_init(struct drm_sched_entity *entity,
329 			  enum drm_sched_priority priority,
330 			  struct drm_gpu_scheduler **sched_list,
331 			  unsigned int num_sched_list,
332 			  atomic_t *guilty);
333 long drm_sched_entity_flush(struct drm_sched_entity *entity, long timeout);
334 void drm_sched_entity_fini(struct drm_sched_entity *entity);
335 void drm_sched_entity_destroy(struct drm_sched_entity *entity);
336 void drm_sched_entity_select_rq(struct drm_sched_entity *entity);
337 struct drm_sched_job *drm_sched_entity_pop_job(struct drm_sched_entity *entity);
338 void drm_sched_entity_push_job(struct drm_sched_job *sched_job,
339 			       struct drm_sched_entity *entity);
340 void drm_sched_entity_set_priority(struct drm_sched_entity *entity,
341 				   enum drm_sched_priority priority);
342 bool drm_sched_entity_is_ready(struct drm_sched_entity *entity);
343 
344 struct drm_sched_fence *drm_sched_fence_create(
345 	struct drm_sched_entity *s_entity, void *owner);
346 void drm_sched_fence_scheduled(struct drm_sched_fence *fence);
347 void drm_sched_fence_finished(struct drm_sched_fence *fence);
348 
349 unsigned long drm_sched_suspend_timeout(struct drm_gpu_scheduler *sched);
350 void drm_sched_resume_timeout(struct drm_gpu_scheduler *sched,
351 		                unsigned long remaining);
352 struct drm_gpu_scheduler *
353 drm_sched_pick_best(struct drm_gpu_scheduler **sched_list,
354 		     unsigned int num_sched_list);
355 
356 #endif
357