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