xref: /openbmc/linux/drivers/gpu/drm/v3d/v3d_sched.c (revision a2818ee4)
1 // SPDX-License-Identifier: GPL-2.0+
2 /* Copyright (C) 2018 Broadcom */
3 
4 /**
5  * DOC: Broadcom V3D scheduling
6  *
7  * The shared DRM GPU scheduler is used to coordinate submitting jobs
8  * to the hardware.  Each DRM fd (roughly a client process) gets its
9  * own scheduler entity, which will process jobs in order.  The GPU
10  * scheduler will round-robin between clients to submit the next job.
11  *
12  * For simplicity, and in order to keep latency low for interactive
13  * jobs when bulk background jobs are queued up, we submit a new job
14  * to the HW only when it has completed the last one, instead of
15  * filling up the CT[01]Q FIFOs with jobs.  Similarly, we use
16  * v3d_job_dependency() to manage the dependency between bin and
17  * render, instead of having the clients submit jobs using the HW's
18  * semaphores to interlock between them.
19  */
20 
21 #include <linux/kthread.h>
22 
23 #include "v3d_drv.h"
24 #include "v3d_regs.h"
25 #include "v3d_trace.h"
26 
27 static struct v3d_job *
28 to_v3d_job(struct drm_sched_job *sched_job)
29 {
30 	return container_of(sched_job, struct v3d_job, base);
31 }
32 
33 static struct v3d_tfu_job *
34 to_tfu_job(struct drm_sched_job *sched_job)
35 {
36 	return container_of(sched_job, struct v3d_tfu_job, base);
37 }
38 
39 static void
40 v3d_job_free(struct drm_sched_job *sched_job)
41 {
42 	struct v3d_job *job = to_v3d_job(sched_job);
43 
44 	drm_sched_job_cleanup(sched_job);
45 
46 	v3d_exec_put(job->exec);
47 }
48 
49 static void
50 v3d_tfu_job_free(struct drm_sched_job *sched_job)
51 {
52 	struct v3d_tfu_job *job = to_tfu_job(sched_job);
53 
54 	drm_sched_job_cleanup(sched_job);
55 
56 	v3d_tfu_job_put(job);
57 }
58 
59 /**
60  * Returns the fences that the bin or render job depends on, one by one.
61  * v3d_job_run() won't be called until all of them have been signaled.
62  */
63 static struct dma_fence *
64 v3d_job_dependency(struct drm_sched_job *sched_job,
65 		   struct drm_sched_entity *s_entity)
66 {
67 	struct v3d_job *job = to_v3d_job(sched_job);
68 	struct v3d_exec_info *exec = job->exec;
69 	enum v3d_queue q = job == &exec->bin ? V3D_BIN : V3D_RENDER;
70 	struct dma_fence *fence;
71 
72 	fence = job->in_fence;
73 	if (fence) {
74 		job->in_fence = NULL;
75 		return fence;
76 	}
77 
78 	if (q == V3D_RENDER) {
79 		/* If we had a bin job, the render job definitely depends on
80 		 * it. We first have to wait for bin to be scheduled, so that
81 		 * its done_fence is created.
82 		 */
83 		fence = exec->bin_done_fence;
84 		if (fence) {
85 			exec->bin_done_fence = NULL;
86 			return fence;
87 		}
88 	}
89 
90 	/* XXX: Wait on a fence for switching the GMP if necessary,
91 	 * and then do so.
92 	 */
93 
94 	return fence;
95 }
96 
97 /**
98  * Returns the fences that the TFU job depends on, one by one.
99  * v3d_tfu_job_run() won't be called until all of them have been
100  * signaled.
101  */
102 static struct dma_fence *
103 v3d_tfu_job_dependency(struct drm_sched_job *sched_job,
104 		       struct drm_sched_entity *s_entity)
105 {
106 	struct v3d_tfu_job *job = to_tfu_job(sched_job);
107 	struct dma_fence *fence;
108 
109 	fence = job->in_fence;
110 	if (fence) {
111 		job->in_fence = NULL;
112 		return fence;
113 	}
114 
115 	return NULL;
116 }
117 
118 static struct dma_fence *v3d_job_run(struct drm_sched_job *sched_job)
119 {
120 	struct v3d_job *job = to_v3d_job(sched_job);
121 	struct v3d_exec_info *exec = job->exec;
122 	enum v3d_queue q = job == &exec->bin ? V3D_BIN : V3D_RENDER;
123 	struct v3d_dev *v3d = exec->v3d;
124 	struct drm_device *dev = &v3d->drm;
125 	struct dma_fence *fence;
126 	unsigned long irqflags;
127 
128 	if (unlikely(job->base.s_fence->finished.error))
129 		return NULL;
130 
131 	/* Lock required around bin_job update vs
132 	 * v3d_overflow_mem_work().
133 	 */
134 	spin_lock_irqsave(&v3d->job_lock, irqflags);
135 	if (q == V3D_BIN) {
136 		v3d->bin_job = job->exec;
137 
138 		/* Clear out the overflow allocation, so we don't
139 		 * reuse the overflow attached to a previous job.
140 		 */
141 		V3D_CORE_WRITE(0, V3D_PTB_BPOS, 0);
142 	} else {
143 		v3d->render_job = job->exec;
144 	}
145 	spin_unlock_irqrestore(&v3d->job_lock, irqflags);
146 
147 	/* Can we avoid this flush when q==RENDER?  We need to be
148 	 * careful of scheduling, though -- imagine job0 rendering to
149 	 * texture and job1 reading, and them being executed as bin0,
150 	 * bin1, render0, render1, so that render1's flush at bin time
151 	 * wasn't enough.
152 	 */
153 	v3d_invalidate_caches(v3d);
154 
155 	fence = v3d_fence_create(v3d, q);
156 	if (IS_ERR(fence))
157 		return NULL;
158 
159 	if (job->done_fence)
160 		dma_fence_put(job->done_fence);
161 	job->done_fence = dma_fence_get(fence);
162 
163 	trace_v3d_submit_cl(dev, q == V3D_RENDER, to_v3d_fence(fence)->seqno,
164 			    job->start, job->end);
165 
166 	if (q == V3D_BIN) {
167 		if (exec->qma) {
168 			V3D_CORE_WRITE(0, V3D_CLE_CT0QMA, exec->qma);
169 			V3D_CORE_WRITE(0, V3D_CLE_CT0QMS, exec->qms);
170 		}
171 		if (exec->qts) {
172 			V3D_CORE_WRITE(0, V3D_CLE_CT0QTS,
173 				       V3D_CLE_CT0QTS_ENABLE |
174 				       exec->qts);
175 		}
176 	} else {
177 		/* XXX: Set the QCFG */
178 	}
179 
180 	/* Set the current and end address of the control list.
181 	 * Writing the end register is what starts the job.
182 	 */
183 	V3D_CORE_WRITE(0, V3D_CLE_CTNQBA(q), job->start);
184 	V3D_CORE_WRITE(0, V3D_CLE_CTNQEA(q), job->end);
185 
186 	return fence;
187 }
188 
189 static struct dma_fence *
190 v3d_tfu_job_run(struct drm_sched_job *sched_job)
191 {
192 	struct v3d_tfu_job *job = to_tfu_job(sched_job);
193 	struct v3d_dev *v3d = job->v3d;
194 	struct drm_device *dev = &v3d->drm;
195 	struct dma_fence *fence;
196 
197 	fence = v3d_fence_create(v3d, V3D_TFU);
198 	if (IS_ERR(fence))
199 		return NULL;
200 
201 	v3d->tfu_job = job;
202 	if (job->done_fence)
203 		dma_fence_put(job->done_fence);
204 	job->done_fence = dma_fence_get(fence);
205 
206 	trace_v3d_submit_tfu(dev, to_v3d_fence(fence)->seqno);
207 
208 	V3D_WRITE(V3D_TFU_IIA, job->args.iia);
209 	V3D_WRITE(V3D_TFU_IIS, job->args.iis);
210 	V3D_WRITE(V3D_TFU_ICA, job->args.ica);
211 	V3D_WRITE(V3D_TFU_IUA, job->args.iua);
212 	V3D_WRITE(V3D_TFU_IOA, job->args.ioa);
213 	V3D_WRITE(V3D_TFU_IOS, job->args.ios);
214 	V3D_WRITE(V3D_TFU_COEF0, job->args.coef[0]);
215 	if (job->args.coef[0] & V3D_TFU_COEF0_USECOEF) {
216 		V3D_WRITE(V3D_TFU_COEF1, job->args.coef[1]);
217 		V3D_WRITE(V3D_TFU_COEF2, job->args.coef[2]);
218 		V3D_WRITE(V3D_TFU_COEF3, job->args.coef[3]);
219 	}
220 	/* ICFG kicks off the job. */
221 	V3D_WRITE(V3D_TFU_ICFG, job->args.icfg | V3D_TFU_ICFG_IOC);
222 
223 	return fence;
224 }
225 
226 static void
227 v3d_gpu_reset_for_timeout(struct v3d_dev *v3d, struct drm_sched_job *sched_job)
228 {
229 	enum v3d_queue q;
230 
231 	mutex_lock(&v3d->reset_lock);
232 
233 	/* block scheduler */
234 	for (q = 0; q < V3D_MAX_QUEUES; q++) {
235 		struct drm_gpu_scheduler *sched = &v3d->queue[q].sched;
236 
237 		kthread_park(sched->thread);
238 		drm_sched_hw_job_reset(sched, (sched_job->sched == sched ?
239 					       sched_job : NULL));
240 	}
241 
242 	/* get the GPU back into the init state */
243 	v3d_reset(v3d);
244 
245 	/* Unblock schedulers and restart their jobs. */
246 	for (q = 0; q < V3D_MAX_QUEUES; q++) {
247 		drm_sched_job_recovery(&v3d->queue[q].sched);
248 		kthread_unpark(v3d->queue[q].sched.thread);
249 	}
250 
251 	mutex_unlock(&v3d->reset_lock);
252 }
253 
254 static void
255 v3d_job_timedout(struct drm_sched_job *sched_job)
256 {
257 	struct v3d_job *job = to_v3d_job(sched_job);
258 	struct v3d_exec_info *exec = job->exec;
259 	struct v3d_dev *v3d = exec->v3d;
260 	enum v3d_queue job_q = job == &exec->bin ? V3D_BIN : V3D_RENDER;
261 	u32 ctca = V3D_CORE_READ(0, V3D_CLE_CTNCA(job_q));
262 	u32 ctra = V3D_CORE_READ(0, V3D_CLE_CTNRA(job_q));
263 
264 	/* If the current address or return address have changed, then
265 	 * the GPU has probably made progress and we should delay the
266 	 * reset.  This could fail if the GPU got in an infinite loop
267 	 * in the CL, but that is pretty unlikely outside of an i-g-t
268 	 * testcase.
269 	 */
270 	if (job->timedout_ctca != ctca || job->timedout_ctra != ctra) {
271 		job->timedout_ctca = ctca;
272 		job->timedout_ctra = ctra;
273 		return;
274 	}
275 
276 	v3d_gpu_reset_for_timeout(v3d, sched_job);
277 }
278 
279 static void
280 v3d_tfu_job_timedout(struct drm_sched_job *sched_job)
281 {
282 	struct v3d_tfu_job *job = to_tfu_job(sched_job);
283 
284 	v3d_gpu_reset_for_timeout(job->v3d, sched_job);
285 }
286 
287 static const struct drm_sched_backend_ops v3d_sched_ops = {
288 	.dependency = v3d_job_dependency,
289 	.run_job = v3d_job_run,
290 	.timedout_job = v3d_job_timedout,
291 	.free_job = v3d_job_free
292 };
293 
294 static const struct drm_sched_backend_ops v3d_tfu_sched_ops = {
295 	.dependency = v3d_tfu_job_dependency,
296 	.run_job = v3d_tfu_job_run,
297 	.timedout_job = v3d_tfu_job_timedout,
298 	.free_job = v3d_tfu_job_free
299 };
300 
301 int
302 v3d_sched_init(struct v3d_dev *v3d)
303 {
304 	int hw_jobs_limit = 1;
305 	int job_hang_limit = 0;
306 	int hang_limit_ms = 500;
307 	int ret;
308 
309 	ret = drm_sched_init(&v3d->queue[V3D_BIN].sched,
310 			     &v3d_sched_ops,
311 			     hw_jobs_limit, job_hang_limit,
312 			     msecs_to_jiffies(hang_limit_ms),
313 			     "v3d_bin");
314 	if (ret) {
315 		dev_err(v3d->dev, "Failed to create bin scheduler: %d.", ret);
316 		return ret;
317 	}
318 
319 	ret = drm_sched_init(&v3d->queue[V3D_RENDER].sched,
320 			     &v3d_sched_ops,
321 			     hw_jobs_limit, job_hang_limit,
322 			     msecs_to_jiffies(hang_limit_ms),
323 			     "v3d_render");
324 	if (ret) {
325 		dev_err(v3d->dev, "Failed to create render scheduler: %d.",
326 			ret);
327 		drm_sched_fini(&v3d->queue[V3D_BIN].sched);
328 		return ret;
329 	}
330 
331 	ret = drm_sched_init(&v3d->queue[V3D_TFU].sched,
332 			     &v3d_tfu_sched_ops,
333 			     hw_jobs_limit, job_hang_limit,
334 			     msecs_to_jiffies(hang_limit_ms),
335 			     "v3d_tfu");
336 	if (ret) {
337 		dev_err(v3d->dev, "Failed to create TFU scheduler: %d.",
338 			ret);
339 		drm_sched_fini(&v3d->queue[V3D_RENDER].sched);
340 		drm_sched_fini(&v3d->queue[V3D_BIN].sched);
341 		return ret;
342 	}
343 
344 	return 0;
345 }
346 
347 void
348 v3d_sched_fini(struct v3d_dev *v3d)
349 {
350 	enum v3d_queue q;
351 
352 	for (q = 0; q < V3D_MAX_QUEUES; q++)
353 		drm_sched_fini(&v3d->queue[q].sched);
354 }
355