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 */
22struct drm_mock_sched_entity *
23drm_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, size: sizeof(*entity), GFP_KERNEL);
32 KUNIT_ASSERT_NOT_NULL(test, entity);
33
34 drm_sched = &sched->base;
35 ret = drm_sched_entity_init(entity: &entity->base,
36 priority,
37 sched_list: &drm_sched, num_sched_list: 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 */
53void drm_mock_sched_entity_free(struct drm_mock_sched_entity *entity)
54{
55 drm_sched_entity_destroy(entity: &entity->base);
56}
57
58static 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(sched: job->base.sched);
62
63 lockdep_assert_held(&sched->lock);
64
65 job->flags |= DRM_MOCK_SCHED_JOB_DONE;
66 list_del(entry: &job->link);
67 dma_fence_signal_locked(fence: &job->hw_fence);
68 complete(&job->done);
69}
70
71static enum hrtimer_restart
72drm_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(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(cmp1: now, cmp2: 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(lock: &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 */
107struct drm_mock_sched_job *
108drm_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, size: sizeof(*job), GFP_KERNEL);
115 KUNIT_ASSERT_NOT_NULL(test, job);
116
117 ret = drm_sched_job_init(job: &job->base,
118 entity: &entity->base,
119 credits: 1,
120 NULL,
121 drm_client_id: 1);
122 KUNIT_ASSERT_EQ(test, ret, 0);
123
124 job->test = test;
125
126 init_completion(x: &job->done);
127 INIT_LIST_HEAD(list: &job->link);
128 hrtimer_setup(timer: &job->timer, function: drm_mock_sched_job_signal_timer,
129 CLOCK_MONOTONIC, mode: HRTIMER_MODE_ABS);
130
131 return job;
132}
133
134static const char *drm_mock_sched_hw_fence_driver_name(struct dma_fence *fence)
135{
136 return "drm_mock_sched";
137}
138
139static const char *
140drm_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
148static 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(timer: &job->timer);
154
155 /* Containing job is freed by the kunit framework */
156}
157
158static 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
164static 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: sched_job->sched);
168 struct drm_mock_sched_job *job = drm_sched_job_to_mock_job(sched_job);
169
170 dma_fence_init(fence: &job->hw_fence,
171 ops: &drm_mock_sched_hw_fence_ops,
172 lock: &sched->lock,
173 context: sched->hw_timeline.context,
174 seqno: atomic_inc_return(v: &sched->hw_timeline.next_seqno));
175
176 dma_fence_get(fence: &job->hw_fence); /* Reference for the job_list */
177
178 spin_lock_irq(lock: &sched->lock);
179 if (job->duration_us) {
180 ktime_t prev_finish_at = 0;
181
182 if (!list_empty(head: &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(kt: prev_finish_at, usec: job->duration_us);
194 }
195 list_add_tail(new: &job->link, head: &sched->job_list);
196 if (job->finish_at)
197 hrtimer_start(timer: &job->timer, tim: job->finish_at, mode: HRTIMER_MODE_ABS);
198 spin_unlock_irq(lock: &sched->lock);
199
200 return &job->hw_fence;
201}
202
203/*
204 * Normally, drivers would take appropriate measures in this callback, such as
205 * killing the entity the faulty job is associated with, resetting the hardware
206 * and / or resubmitting non-faulty jobs.
207 *
208 * For the mock scheduler, there are no hardware rings to be resetted nor jobs
209 * to be resubmitted. Thus, this function merely ensures that
210 * a) timedout fences get signaled properly and removed from the pending list
211 * b) the mock scheduler framework gets informed about the timeout via a flag
212 * c) The drm_sched_job, not longer needed, gets freed
213 */
214static enum drm_gpu_sched_stat
215mock_sched_timedout_job(struct drm_sched_job *sched_job)
216{
217 struct drm_mock_scheduler *sched = drm_sched_to_mock_sched(sched: sched_job->sched);
218 struct drm_mock_sched_job *job = drm_sched_job_to_mock_job(sched_job);
219 unsigned long flags;
220
221 if (job->flags & DRM_MOCK_SCHED_JOB_DONT_RESET) {
222 job->flags |= DRM_MOCK_SCHED_JOB_RESET_SKIPPED;
223 return DRM_GPU_SCHED_STAT_NO_HANG;
224 }
225
226 spin_lock_irqsave(&sched->lock, flags);
227 if (!dma_fence_is_signaled_locked(fence: &job->hw_fence)) {
228 list_del(entry: &job->link);
229 job->flags |= DRM_MOCK_SCHED_JOB_TIMEDOUT;
230 dma_fence_set_error(fence: &job->hw_fence, error: -ETIMEDOUT);
231 dma_fence_signal_locked(fence: &job->hw_fence);
232 }
233 spin_unlock_irqrestore(lock: &sched->lock, flags);
234
235 dma_fence_put(fence: &job->hw_fence);
236 drm_sched_job_cleanup(job: sched_job);
237 /* Mock job itself is freed by the kunit framework. */
238
239 return DRM_GPU_SCHED_STAT_RESET;
240}
241
242static void mock_sched_free_job(struct drm_sched_job *sched_job)
243{
244 struct drm_mock_sched_job *job = drm_sched_job_to_mock_job(sched_job);
245
246 dma_fence_put(fence: &job->hw_fence);
247 drm_sched_job_cleanup(job: sched_job);
248
249 /* Mock job itself is freed by the kunit framework. */
250}
251
252static void mock_sched_cancel_job(struct drm_sched_job *sched_job)
253{
254 struct drm_mock_scheduler *sched = drm_sched_to_mock_sched(sched: sched_job->sched);
255 struct drm_mock_sched_job *job = drm_sched_job_to_mock_job(sched_job);
256 unsigned long flags;
257
258 hrtimer_cancel(timer: &job->timer);
259
260 spin_lock_irqsave(&sched->lock, flags);
261 if (!dma_fence_is_signaled_locked(fence: &job->hw_fence)) {
262 list_del(entry: &job->link);
263 dma_fence_set_error(fence: &job->hw_fence, error: -ECANCELED);
264 dma_fence_signal_locked(fence: &job->hw_fence);
265 }
266 spin_unlock_irqrestore(lock: &sched->lock, flags);
267
268 /*
269 * The GPU Scheduler will call drm_sched_backend_ops.free_job(), still.
270 * Mock job itself is freed by the kunit framework.
271 */
272}
273
274static const struct drm_sched_backend_ops drm_mock_scheduler_ops = {
275 .run_job = mock_sched_run_job,
276 .timedout_job = mock_sched_timedout_job,
277 .free_job = mock_sched_free_job,
278 .cancel_job = mock_sched_cancel_job,
279};
280
281/**
282 * drm_mock_sched_new - Create a new mock scheduler
283 *
284 * @test: KUnit test owning the job
285 * @timeout: Job timeout to set
286 *
287 * Returns: New mock scheduler with allocation managed by the test
288 */
289struct drm_mock_scheduler *drm_mock_sched_new(struct kunit *test, long timeout)
290{
291 struct drm_sched_init_args args = {
292 .ops = &drm_mock_scheduler_ops,
293 .num_rqs = DRM_SCHED_PRIORITY_COUNT,
294 .credit_limit = U32_MAX,
295 .hang_limit = 1,
296 .timeout = timeout,
297 .name = "drm-mock-scheduler",
298 };
299 struct drm_mock_scheduler *sched;
300 int ret;
301
302 sched = kunit_kzalloc(test, size: sizeof(*sched), GFP_KERNEL);
303 KUNIT_ASSERT_NOT_NULL(test, sched);
304
305 ret = drm_sched_init(sched: &sched->base, args: &args);
306 KUNIT_ASSERT_EQ(test, ret, 0);
307
308 sched->test = test;
309 sched->hw_timeline.context = dma_fence_context_alloc(num: 1);
310 atomic_set(v: &sched->hw_timeline.next_seqno, i: 0);
311 INIT_LIST_HEAD(list: &sched->job_list);
312 spin_lock_init(&sched->lock);
313
314 return sched;
315}
316
317/**
318 * drm_mock_sched_fini - Destroys a mock scheduler
319 *
320 * @sched: Scheduler to destroy
321 *
322 * To be used from the test cases once done with the scheduler.
323 */
324void drm_mock_sched_fini(struct drm_mock_scheduler *sched)
325{
326 drm_sched_fini(sched: &sched->base);
327}
328
329/**
330 * drm_mock_sched_advance - Advances the mock scheduler timeline
331 *
332 * @sched: Scheduler timeline to advance
333 * @num: By how many jobs to advance
334 *
335 * Advancing the scheduler timeline by a number of seqnos will trigger
336 * signalling of the hardware fences and unlinking the jobs from the internal
337 * scheduler tracking.
338 *
339 * This can be used from test cases which want complete control of the simulated
340 * job execution timing. For example submitting one job with no set duration
341 * would never complete it before test cases advances the timeline by one.
342 */
343unsigned int drm_mock_sched_advance(struct drm_mock_scheduler *sched,
344 unsigned int num)
345{
346 struct drm_mock_sched_job *job, *next;
347 unsigned int found = 0;
348 unsigned long flags;
349 LIST_HEAD(signal);
350
351 spin_lock_irqsave(&sched->lock, flags);
352 if (WARN_ON_ONCE(sched->hw_timeline.cur_seqno + num <
353 sched->hw_timeline.cur_seqno))
354 goto unlock;
355 sched->hw_timeline.cur_seqno += num;
356 list_for_each_entry_safe(job, next, &sched->job_list, link) {
357 if (sched->hw_timeline.cur_seqno < job->hw_fence.seqno)
358 break;
359
360 drm_mock_sched_job_complete(job);
361 found++;
362 }
363unlock:
364 spin_unlock_irqrestore(lock: &sched->lock, flags);
365
366 return found;
367}
368
369MODULE_DESCRIPTION("DRM mock scheduler and tests");
370MODULE_LICENSE("GPL");
371

source code of linux/drivers/gpu/drm/scheduler/tests/mock_scheduler.c