xref: /linux/drivers/gpu/drm/scheduler/tests/mock_scheduler.c (revision 7b1166dee847d5018c1f3cc781218e806078f752)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2025 Valve Corporation */
3 
4 #include "sched_tests.h"
5 
6 /*
7  * Here we implement the mock "GPU" (or the scheduler backend) which is used by
8  * the DRM scheduler unit tests in order to exercise the core functionality.
9  *
10  * Test cases are implemented in a separate file.
11  */
12 
13 /**
14  * drm_mock_sched_entity_new - Create a new mock scheduler entity
15  *
16  * @test: KUnit test owning the entity
17  * @priority: Scheduling priority
18  * @sched: Mock scheduler on which the entity can be scheduled
19  *
20  * Returns: New mock scheduler entity with allocation managed by the test
21  */
22 struct drm_mock_sched_entity *
23 drm_mock_sched_entity_new(struct kunit *test,
24 			  enum drm_sched_priority priority,
25 			  struct drm_mock_scheduler *sched)
26 {
27 	struct drm_mock_sched_entity *entity;
28 	struct drm_gpu_scheduler *drm_sched;
29 	int ret;
30 
31 	entity = kunit_kzalloc(test, sizeof(*entity), GFP_KERNEL);
32 	KUNIT_ASSERT_NOT_NULL(test, entity);
33 
34 	drm_sched = &sched->base;
35 	ret = drm_sched_entity_init(&entity->base,
36 				    priority,
37 				    &drm_sched, 1,
38 				    NULL);
39 	KUNIT_ASSERT_EQ(test, ret, 0);
40 
41 	entity->test = test;
42 
43 	return entity;
44 }
45 
46 /**
47  * drm_mock_sched_entity_free - Destroys a mock scheduler entity
48  *
49  * @entity: Entity to destroy
50  *
51  * To be used from the test cases once done with the entity.
52  */
53 void drm_mock_sched_entity_free(struct drm_mock_sched_entity *entity)
54 {
55 	drm_sched_entity_destroy(&entity->base);
56 }
57 
58 static void drm_mock_sched_job_complete(struct drm_mock_sched_job *job)
59 {
60 	struct drm_mock_scheduler *sched =
61 		drm_sched_to_mock_sched(job->base.sched);
62 
63 	lockdep_assert_held(&sched->lock);
64 
65 	job->flags |= DRM_MOCK_SCHED_JOB_DONE;
66 	list_move_tail(&job->link, &sched->done_list);
67 	dma_fence_signal_locked(&job->hw_fence);
68 	complete(&job->done);
69 }
70 
71 static enum hrtimer_restart
72 drm_mock_sched_job_signal_timer(struct hrtimer *hrtimer)
73 {
74 	struct drm_mock_sched_job *job =
75 		container_of(hrtimer, typeof(*job), timer);
76 	struct drm_mock_scheduler *sched =
77 		drm_sched_to_mock_sched(job->base.sched);
78 	struct drm_mock_sched_job *next;
79 	ktime_t now = ktime_get();
80 	unsigned long flags;
81 	LIST_HEAD(signal);
82 
83 	spin_lock_irqsave(&sched->lock, flags);
84 	list_for_each_entry_safe(job, next, &sched->job_list, link) {
85 		if (!job->duration_us)
86 			break;
87 
88 		if (ktime_before(now, job->finish_at))
89 			break;
90 
91 		sched->hw_timeline.cur_seqno = job->hw_fence.seqno;
92 		drm_mock_sched_job_complete(job);
93 	}
94 	spin_unlock_irqrestore(&sched->lock, flags);
95 
96 	return HRTIMER_NORESTART;
97 }
98 
99 /**
100  * drm_mock_sched_job_new - Create a new mock scheduler job
101  *
102  * @test: KUnit test owning the job
103  * @entity: Scheduler entity of the job
104  *
105  * Returns: New mock scheduler job with allocation managed by the test
106  */
107 struct drm_mock_sched_job *
108 drm_mock_sched_job_new(struct kunit *test,
109 		       struct drm_mock_sched_entity *entity)
110 {
111 	struct drm_mock_sched_job *job;
112 	int ret;
113 
114 	job = kunit_kzalloc(test, sizeof(*job), GFP_KERNEL);
115 	KUNIT_ASSERT_NOT_NULL(test, job);
116 
117 	ret = drm_sched_job_init(&job->base,
118 				 &entity->base,
119 				 1,
120 				 NULL,
121 				 1);
122 	KUNIT_ASSERT_EQ(test, ret, 0);
123 
124 	job->test = test;
125 
126 	init_completion(&job->done);
127 	INIT_LIST_HEAD(&job->link);
128 	hrtimer_setup(&job->timer, drm_mock_sched_job_signal_timer,
129 		      CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
130 
131 	return job;
132 }
133 
134 static const char *drm_mock_sched_hw_fence_driver_name(struct dma_fence *fence)
135 {
136 	return "drm_mock_sched";
137 }
138 
139 static const char *
140 drm_mock_sched_hw_fence_timeline_name(struct dma_fence *fence)
141 {
142 	struct drm_mock_sched_job *job =
143 		container_of(fence, typeof(*job), hw_fence);
144 
145 	return (const char *)job->base.sched->name;
146 }
147 
148 static void drm_mock_sched_hw_fence_release(struct dma_fence *fence)
149 {
150 	struct drm_mock_sched_job *job =
151 		container_of(fence, typeof(*job), hw_fence);
152 
153 	hrtimer_cancel(&job->timer);
154 
155 	/* Containing job is freed by the kunit framework */
156 }
157 
158 static const struct dma_fence_ops drm_mock_sched_hw_fence_ops = {
159 	.get_driver_name = drm_mock_sched_hw_fence_driver_name,
160 	.get_timeline_name = drm_mock_sched_hw_fence_timeline_name,
161 	.release = drm_mock_sched_hw_fence_release,
162 };
163 
164 static struct dma_fence *mock_sched_run_job(struct drm_sched_job *sched_job)
165 {
166 	struct drm_mock_scheduler *sched =
167 		drm_sched_to_mock_sched(sched_job->sched);
168 	struct drm_mock_sched_job *job = drm_sched_job_to_mock_job(sched_job);
169 
170 	dma_fence_init(&job->hw_fence,
171 		       &drm_mock_sched_hw_fence_ops,
172 		       &sched->lock,
173 		       sched->hw_timeline.context,
174 		       atomic_inc_return(&sched->hw_timeline.next_seqno));
175 
176 	dma_fence_get(&job->hw_fence); /* Reference for the job_list */
177 
178 	spin_lock_irq(&sched->lock);
179 	if (job->duration_us) {
180 		ktime_t prev_finish_at = 0;
181 
182 		if (!list_empty(&sched->job_list)) {
183 			struct drm_mock_sched_job *prev =
184 				list_last_entry(&sched->job_list, typeof(*prev),
185 						link);
186 
187 			prev_finish_at = prev->finish_at;
188 		}
189 
190 		if (!prev_finish_at)
191 			prev_finish_at = ktime_get();
192 
193 		job->finish_at = ktime_add_us(prev_finish_at, job->duration_us);
194 	}
195 	list_add_tail(&job->link, &sched->job_list);
196 	if (job->finish_at)
197 		hrtimer_start(&job->timer, job->finish_at, HRTIMER_MODE_ABS);
198 	spin_unlock_irq(&sched->lock);
199 
200 	return &job->hw_fence;
201 }
202 
203 static enum drm_gpu_sched_stat
204 mock_sched_timedout_job(struct drm_sched_job *sched_job)
205 {
206 	struct drm_mock_sched_job *job = drm_sched_job_to_mock_job(sched_job);
207 
208 	job->flags |= DRM_MOCK_SCHED_JOB_TIMEDOUT;
209 
210 	return DRM_GPU_SCHED_STAT_NOMINAL;
211 }
212 
213 static void mock_sched_free_job(struct drm_sched_job *sched_job)
214 {
215 	struct drm_mock_scheduler *sched =
216 			drm_sched_to_mock_sched(sched_job->sched);
217 	struct drm_mock_sched_job *job = drm_sched_job_to_mock_job(sched_job);
218 	unsigned long flags;
219 
220 	/* Remove from the scheduler done list. */
221 	spin_lock_irqsave(&sched->lock, flags);
222 	list_del(&job->link);
223 	spin_unlock_irqrestore(&sched->lock, flags);
224 	dma_fence_put(&job->hw_fence);
225 
226 	drm_sched_job_cleanup(sched_job);
227 
228 	/* Mock job itself is freed by the kunit framework. */
229 }
230 
231 static const struct drm_sched_backend_ops drm_mock_scheduler_ops = {
232 	.run_job = mock_sched_run_job,
233 	.timedout_job = mock_sched_timedout_job,
234 	.free_job = mock_sched_free_job
235 };
236 
237 /**
238  * drm_mock_sched_new - Create a new mock scheduler
239  *
240  * @test: KUnit test owning the job
241  * @timeout: Job timeout to set
242  *
243  * Returns: New mock scheduler with allocation managed by the test
244  */
245 struct drm_mock_scheduler *drm_mock_sched_new(struct kunit *test, long timeout)
246 {
247 	struct drm_sched_init_args args = {
248 		.ops		= &drm_mock_scheduler_ops,
249 		.num_rqs	= DRM_SCHED_PRIORITY_COUNT,
250 		.credit_limit	= U32_MAX,
251 		.hang_limit	= 1,
252 		.timeout	= timeout,
253 		.name		= "drm-mock-scheduler",
254 	};
255 	struct drm_mock_scheduler *sched;
256 	int ret;
257 
258 	sched = kunit_kzalloc(test, sizeof(*sched), GFP_KERNEL);
259 	KUNIT_ASSERT_NOT_NULL(test, sched);
260 
261 	ret = drm_sched_init(&sched->base, &args);
262 	KUNIT_ASSERT_EQ(test, ret, 0);
263 
264 	sched->test = test;
265 	sched->hw_timeline.context = dma_fence_context_alloc(1);
266 	atomic_set(&sched->hw_timeline.next_seqno, 0);
267 	INIT_LIST_HEAD(&sched->job_list);
268 	INIT_LIST_HEAD(&sched->done_list);
269 	spin_lock_init(&sched->lock);
270 
271 	return sched;
272 }
273 
274 /**
275  * drm_mock_sched_fini - Destroys a mock scheduler
276  *
277  * @sched: Scheduler to destroy
278  *
279  * To be used from the test cases once done with the scheduler.
280  */
281 void drm_mock_sched_fini(struct drm_mock_scheduler *sched)
282 {
283 	struct drm_mock_sched_job *job, *next;
284 	unsigned long flags;
285 	LIST_HEAD(list);
286 
287 	drm_sched_wqueue_stop(&sched->base);
288 
289 	/* Force complete all unfinished jobs. */
290 	spin_lock_irqsave(&sched->lock, flags);
291 	list_for_each_entry_safe(job, next, &sched->job_list, link)
292 		list_move_tail(&job->link, &list);
293 	spin_unlock_irqrestore(&sched->lock, flags);
294 
295 	list_for_each_entry(job, &list, link)
296 		hrtimer_cancel(&job->timer);
297 
298 	spin_lock_irqsave(&sched->lock, flags);
299 	list_for_each_entry_safe(job, next, &list, link)
300 		drm_mock_sched_job_complete(job);
301 	spin_unlock_irqrestore(&sched->lock, flags);
302 
303 	/*
304 	 * Free completed jobs and jobs not yet processed by the DRM scheduler
305 	 * free worker.
306 	 */
307 	spin_lock_irqsave(&sched->lock, flags);
308 	list_for_each_entry_safe(job, next, &sched->done_list, link)
309 		list_move_tail(&job->link, &list);
310 	spin_unlock_irqrestore(&sched->lock, flags);
311 
312 	list_for_each_entry_safe(job, next, &list, link)
313 		mock_sched_free_job(&job->base);
314 
315 	drm_sched_fini(&sched->base);
316 }
317 
318 /**
319  * drm_mock_sched_advance - Advances the mock scheduler timeline
320  *
321  * @sched: Scheduler timeline to advance
322  * @num: By how many jobs to advance
323  *
324  * Advancing the scheduler timeline by a number of seqnos will trigger
325  * signalling of the hardware fences and unlinking the jobs from the internal
326  * scheduler tracking.
327  *
328  * This can be used from test cases which want complete control of the simulated
329  * job execution timing. For example submitting one job with no set duration
330  * would never complete it before test cases advances the timeline by one.
331  */
332 unsigned int drm_mock_sched_advance(struct drm_mock_scheduler *sched,
333 				    unsigned int num)
334 {
335 	struct drm_mock_sched_job *job, *next;
336 	unsigned int found = 0;
337 	unsigned long flags;
338 	LIST_HEAD(signal);
339 
340 	spin_lock_irqsave(&sched->lock, flags);
341 	if (WARN_ON_ONCE(sched->hw_timeline.cur_seqno + num <
342 			 sched->hw_timeline.cur_seqno))
343 		goto unlock;
344 	sched->hw_timeline.cur_seqno += num;
345 	list_for_each_entry_safe(job, next, &sched->job_list, link) {
346 		if (sched->hw_timeline.cur_seqno < job->hw_fence.seqno)
347 			break;
348 
349 		drm_mock_sched_job_complete(job);
350 		found++;
351 	}
352 unlock:
353 	spin_unlock_irqrestore(&sched->lock, flags);
354 
355 	return found;
356 }
357 
358 MODULE_DESCRIPTION("DRM mock scheduler and tests");
359 MODULE_LICENSE("GPL");
360