1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright 2019 Linaro, Ltd, Rob Herring <robh@kernel.org> */
3 /* Copyright 2019 Collabora ltd. */
4 #include <linux/delay.h>
5 #include <linux/interrupt.h>
6 #include <linux/io.h>
7 #include <linux/iopoll.h>
8 #include <linux/platform_device.h>
9 #include <linux/pm_runtime.h>
10 #include <linux/dma-resv.h>
11 #include <drm/gpu_scheduler.h>
12 #include <drm/panfrost_drm.h>
13 
14 #include "panfrost_device.h"
15 #include "panfrost_devfreq.h"
16 #include "panfrost_job.h"
17 #include "panfrost_features.h"
18 #include "panfrost_issues.h"
19 #include "panfrost_gem.h"
20 #include "panfrost_regs.h"
21 #include "panfrost_gpu.h"
22 #include "panfrost_mmu.h"
23 
24 #define JOB_TIMEOUT_MS 500
25 
26 #define job_write(dev, reg, data) writel(data, dev->iomem + (reg))
27 #define job_read(dev, reg) readl(dev->iomem + (reg))
28 
29 struct panfrost_queue_state {
30 	struct drm_gpu_scheduler sched;
31 	u64 fence_context;
32 	u64 emit_seqno;
33 };
34 
35 struct panfrost_job_slot {
36 	struct panfrost_queue_state queue[NUM_JOB_SLOTS];
37 	spinlock_t job_lock;
38 	int irq;
39 };
40 
41 static struct panfrost_job *
42 to_panfrost_job(struct drm_sched_job *sched_job)
43 {
44 	return container_of(sched_job, struct panfrost_job, base);
45 }
46 
47 struct panfrost_fence {
48 	struct dma_fence base;
49 	struct drm_device *dev;
50 	/* panfrost seqno for signaled() test */
51 	u64 seqno;
52 	int queue;
53 };
54 
55 static inline struct panfrost_fence *
56 to_panfrost_fence(struct dma_fence *fence)
57 {
58 	return (struct panfrost_fence *)fence;
59 }
60 
61 static const char *panfrost_fence_get_driver_name(struct dma_fence *fence)
62 {
63 	return "panfrost";
64 }
65 
66 static const char *panfrost_fence_get_timeline_name(struct dma_fence *fence)
67 {
68 	struct panfrost_fence *f = to_panfrost_fence(fence);
69 
70 	switch (f->queue) {
71 	case 0:
72 		return "panfrost-js-0";
73 	case 1:
74 		return "panfrost-js-1";
75 	case 2:
76 		return "panfrost-js-2";
77 	default:
78 		return NULL;
79 	}
80 }
81 
82 static const struct dma_fence_ops panfrost_fence_ops = {
83 	.get_driver_name = panfrost_fence_get_driver_name,
84 	.get_timeline_name = panfrost_fence_get_timeline_name,
85 };
86 
87 static struct dma_fence *panfrost_fence_create(struct panfrost_device *pfdev, int js_num)
88 {
89 	struct panfrost_fence *fence;
90 	struct panfrost_job_slot *js = pfdev->js;
91 
92 	fence = kzalloc(sizeof(*fence), GFP_KERNEL);
93 	if (!fence)
94 		return ERR_PTR(-ENOMEM);
95 
96 	fence->dev = pfdev->ddev;
97 	fence->queue = js_num;
98 	fence->seqno = ++js->queue[js_num].emit_seqno;
99 	dma_fence_init(&fence->base, &panfrost_fence_ops, &js->job_lock,
100 		       js->queue[js_num].fence_context, fence->seqno);
101 
102 	return &fence->base;
103 }
104 
105 static int panfrost_job_get_slot(struct panfrost_job *job)
106 {
107 	/* JS0: fragment jobs.
108 	 * JS1: vertex/tiler jobs
109 	 * JS2: compute jobs
110 	 */
111 	if (job->requirements & PANFROST_JD_REQ_FS)
112 		return 0;
113 
114 /* Not exposed to userspace yet */
115 #if 0
116 	if (job->requirements & PANFROST_JD_REQ_ONLY_COMPUTE) {
117 		if ((job->requirements & PANFROST_JD_REQ_CORE_GRP_MASK) &&
118 		    (job->pfdev->features.nr_core_groups == 2))
119 			return 2;
120 		if (panfrost_has_hw_issue(job->pfdev, HW_ISSUE_8987))
121 			return 2;
122 	}
123 #endif
124 	return 1;
125 }
126 
127 static void panfrost_job_write_affinity(struct panfrost_device *pfdev,
128 					u32 requirements,
129 					int js)
130 {
131 	u64 affinity;
132 
133 	/*
134 	 * Use all cores for now.
135 	 * Eventually we may need to support tiler only jobs and h/w with
136 	 * multiple (2) coherent core groups
137 	 */
138 	affinity = pfdev->features.shader_present;
139 
140 	job_write(pfdev, JS_AFFINITY_NEXT_LO(js), affinity & 0xFFFFFFFF);
141 	job_write(pfdev, JS_AFFINITY_NEXT_HI(js), affinity >> 32);
142 }
143 
144 static u32
145 panfrost_get_job_chain_flag(const struct panfrost_job *job)
146 {
147 	struct panfrost_fence *f = to_panfrost_fence(job->done_fence);
148 
149 	if (!panfrost_has_hw_feature(job->pfdev, HW_FEATURE_JOBCHAIN_DISAMBIGUATION))
150 		return 0;
151 
152 	return (f->seqno & 1) ? JS_CONFIG_JOB_CHAIN_FLAG : 0;
153 }
154 
155 static struct panfrost_job *
156 panfrost_dequeue_job(struct panfrost_device *pfdev, int slot)
157 {
158 	struct panfrost_job *job = pfdev->jobs[slot][0];
159 
160 	WARN_ON(!job);
161 	pfdev->jobs[slot][0] = pfdev->jobs[slot][1];
162 	pfdev->jobs[slot][1] = NULL;
163 
164 	return job;
165 }
166 
167 static unsigned int
168 panfrost_enqueue_job(struct panfrost_device *pfdev, int slot,
169 		     struct panfrost_job *job)
170 {
171 	if (WARN_ON(!job))
172 		return 0;
173 
174 	if (!pfdev->jobs[slot][0]) {
175 		pfdev->jobs[slot][0] = job;
176 		return 0;
177 	}
178 
179 	WARN_ON(pfdev->jobs[slot][1]);
180 	pfdev->jobs[slot][1] = job;
181 	WARN_ON(panfrost_get_job_chain_flag(job) ==
182 		panfrost_get_job_chain_flag(pfdev->jobs[slot][0]));
183 	return 1;
184 }
185 
186 static void panfrost_job_hw_submit(struct panfrost_job *job, int js)
187 {
188 	struct panfrost_device *pfdev = job->pfdev;
189 	unsigned int subslot;
190 	u32 cfg;
191 	u64 jc_head = job->jc;
192 	int ret;
193 
194 	panfrost_devfreq_record_busy(&pfdev->pfdevfreq);
195 
196 	ret = pm_runtime_get_sync(pfdev->dev);
197 	if (ret < 0)
198 		return;
199 
200 	if (WARN_ON(job_read(pfdev, JS_COMMAND_NEXT(js)))) {
201 		return;
202 	}
203 
204 	cfg = panfrost_mmu_as_get(pfdev, job->file_priv->mmu);
205 
206 	job_write(pfdev, JS_HEAD_NEXT_LO(js), jc_head & 0xFFFFFFFF);
207 	job_write(pfdev, JS_HEAD_NEXT_HI(js), jc_head >> 32);
208 
209 	panfrost_job_write_affinity(pfdev, job->requirements, js);
210 
211 	/* start MMU, medium priority, cache clean/flush on end, clean/flush on
212 	 * start */
213 	cfg |= JS_CONFIG_THREAD_PRI(8) |
214 		JS_CONFIG_START_FLUSH_CLEAN_INVALIDATE |
215 		JS_CONFIG_END_FLUSH_CLEAN_INVALIDATE |
216 		panfrost_get_job_chain_flag(job);
217 
218 	if (panfrost_has_hw_feature(pfdev, HW_FEATURE_FLUSH_REDUCTION))
219 		cfg |= JS_CONFIG_ENABLE_FLUSH_REDUCTION;
220 
221 	if (panfrost_has_hw_issue(pfdev, HW_ISSUE_10649))
222 		cfg |= JS_CONFIG_START_MMU;
223 
224 	job_write(pfdev, JS_CONFIG_NEXT(js), cfg);
225 
226 	if (panfrost_has_hw_feature(pfdev, HW_FEATURE_FLUSH_REDUCTION))
227 		job_write(pfdev, JS_FLUSH_ID_NEXT(js), job->flush_id);
228 
229 	/* GO ! */
230 
231 	spin_lock(&pfdev->js->job_lock);
232 	subslot = panfrost_enqueue_job(pfdev, js, job);
233 	/* Don't queue the job if a reset is in progress */
234 	if (!atomic_read(&pfdev->reset.pending)) {
235 		job_write(pfdev, JS_COMMAND_NEXT(js), JS_COMMAND_START);
236 		dev_dbg(pfdev->dev,
237 			"JS: Submitting atom %p to js[%d][%d] with head=0x%llx AS %d",
238 			job, js, subslot, jc_head, cfg & 0xf);
239 	}
240 	spin_unlock(&pfdev->js->job_lock);
241 }
242 
243 static int panfrost_acquire_object_fences(struct drm_gem_object **bos,
244 					  int bo_count,
245 					  struct xarray *deps)
246 {
247 	int i, ret;
248 
249 	for (i = 0; i < bo_count; i++) {
250 		/* panfrost always uses write mode in its current uapi */
251 		ret = drm_gem_fence_array_add_implicit(deps, bos[i], true);
252 		if (ret)
253 			return ret;
254 	}
255 
256 	return 0;
257 }
258 
259 static void panfrost_attach_object_fences(struct drm_gem_object **bos,
260 					  int bo_count,
261 					  struct dma_fence *fence)
262 {
263 	int i;
264 
265 	for (i = 0; i < bo_count; i++)
266 		dma_resv_add_excl_fence(bos[i]->resv, fence);
267 }
268 
269 int panfrost_job_push(struct panfrost_job *job)
270 {
271 	struct panfrost_device *pfdev = job->pfdev;
272 	int slot = panfrost_job_get_slot(job);
273 	struct drm_sched_entity *entity = &job->file_priv->sched_entity[slot];
274 	struct ww_acquire_ctx acquire_ctx;
275 	int ret = 0;
276 
277 
278 	ret = drm_gem_lock_reservations(job->bos, job->bo_count,
279 					    &acquire_ctx);
280 	if (ret)
281 		return ret;
282 
283 	mutex_lock(&pfdev->sched_lock);
284 
285 	ret = drm_sched_job_init(&job->base, entity, NULL);
286 	if (ret) {
287 		mutex_unlock(&pfdev->sched_lock);
288 		goto unlock;
289 	}
290 
291 	job->render_done_fence = dma_fence_get(&job->base.s_fence->finished);
292 
293 	ret = panfrost_acquire_object_fences(job->bos, job->bo_count,
294 					     &job->deps);
295 	if (ret) {
296 		mutex_unlock(&pfdev->sched_lock);
297 		goto unlock;
298 	}
299 
300 	kref_get(&job->refcount); /* put by scheduler job completion */
301 
302 	drm_sched_entity_push_job(&job->base, entity);
303 
304 	mutex_unlock(&pfdev->sched_lock);
305 
306 	panfrost_attach_object_fences(job->bos, job->bo_count,
307 				      job->render_done_fence);
308 
309 unlock:
310 	drm_gem_unlock_reservations(job->bos, job->bo_count, &acquire_ctx);
311 
312 	return ret;
313 }
314 
315 static void panfrost_job_cleanup(struct kref *ref)
316 {
317 	struct panfrost_job *job = container_of(ref, struct panfrost_job,
318 						refcount);
319 	struct dma_fence *fence;
320 	unsigned long index;
321 	unsigned int i;
322 
323 	xa_for_each(&job->deps, index, fence) {
324 		dma_fence_put(fence);
325 	}
326 	xa_destroy(&job->deps);
327 
328 	dma_fence_put(job->done_fence);
329 	dma_fence_put(job->render_done_fence);
330 
331 	if (job->mappings) {
332 		for (i = 0; i < job->bo_count; i++) {
333 			if (!job->mappings[i])
334 				break;
335 
336 			atomic_dec(&job->mappings[i]->obj->gpu_usecount);
337 			panfrost_gem_mapping_put(job->mappings[i]);
338 		}
339 		kvfree(job->mappings);
340 	}
341 
342 	if (job->bos) {
343 		for (i = 0; i < job->bo_count; i++)
344 			drm_gem_object_put(job->bos[i]);
345 
346 		kvfree(job->bos);
347 	}
348 
349 	kfree(job);
350 }
351 
352 void panfrost_job_put(struct panfrost_job *job)
353 {
354 	kref_put(&job->refcount, panfrost_job_cleanup);
355 }
356 
357 static void panfrost_job_free(struct drm_sched_job *sched_job)
358 {
359 	struct panfrost_job *job = to_panfrost_job(sched_job);
360 
361 	drm_sched_job_cleanup(sched_job);
362 
363 	panfrost_job_put(job);
364 }
365 
366 static struct dma_fence *panfrost_job_dependency(struct drm_sched_job *sched_job,
367 						 struct drm_sched_entity *s_entity)
368 {
369 	struct panfrost_job *job = to_panfrost_job(sched_job);
370 
371 	if (!xa_empty(&job->deps))
372 		return xa_erase(&job->deps, job->last_dep++);
373 
374 	return NULL;
375 }
376 
377 static struct dma_fence *panfrost_job_run(struct drm_sched_job *sched_job)
378 {
379 	struct panfrost_job *job = to_panfrost_job(sched_job);
380 	struct panfrost_device *pfdev = job->pfdev;
381 	int slot = panfrost_job_get_slot(job);
382 	struct dma_fence *fence = NULL;
383 
384 	if (unlikely(job->base.s_fence->finished.error))
385 		return NULL;
386 
387 	/* Nothing to execute: can happen if the job has finished while
388 	 * we were resetting the GPU.
389 	 */
390 	if (!job->jc)
391 		return NULL;
392 
393 	fence = panfrost_fence_create(pfdev, slot);
394 	if (IS_ERR(fence))
395 		return fence;
396 
397 	if (job->done_fence)
398 		dma_fence_put(job->done_fence);
399 	job->done_fence = dma_fence_get(fence);
400 
401 	panfrost_job_hw_submit(job, slot);
402 
403 	return fence;
404 }
405 
406 void panfrost_job_enable_interrupts(struct panfrost_device *pfdev)
407 {
408 	int j;
409 	u32 irq_mask = 0;
410 
411 	for (j = 0; j < NUM_JOB_SLOTS; j++) {
412 		irq_mask |= MK_JS_MASK(j);
413 	}
414 
415 	job_write(pfdev, JOB_INT_CLEAR, irq_mask);
416 	job_write(pfdev, JOB_INT_MASK, irq_mask);
417 }
418 
419 static void panfrost_job_handle_err(struct panfrost_device *pfdev,
420 				    struct panfrost_job *job,
421 				    unsigned int js)
422 {
423 	u32 js_status = job_read(pfdev, JS_STATUS(js));
424 	const char *exception_name = panfrost_exception_name(js_status);
425 	bool signal_fence = true;
426 
427 	if (!panfrost_exception_is_fault(js_status)) {
428 		dev_dbg(pfdev->dev, "js event, js=%d, status=%s, head=0x%x, tail=0x%x",
429 			js, exception_name,
430 			job_read(pfdev, JS_HEAD_LO(js)),
431 			job_read(pfdev, JS_TAIL_LO(js)));
432 	} else {
433 		dev_err(pfdev->dev, "js fault, js=%d, status=%s, head=0x%x, tail=0x%x",
434 			js, exception_name,
435 			job_read(pfdev, JS_HEAD_LO(js)),
436 			job_read(pfdev, JS_TAIL_LO(js)));
437 	}
438 
439 	if (js_status == DRM_PANFROST_EXCEPTION_STOPPED) {
440 		/* Update the job head so we can resume */
441 		job->jc = job_read(pfdev, JS_TAIL_LO(js)) |
442 			  ((u64)job_read(pfdev, JS_TAIL_HI(js)) << 32);
443 
444 		/* The job will be resumed, don't signal the fence */
445 		signal_fence = false;
446 	} else if (js_status == DRM_PANFROST_EXCEPTION_TERMINATED) {
447 		/* Job has been hard-stopped, flag it as canceled */
448 		dma_fence_set_error(job->done_fence, -ECANCELED);
449 		job->jc = 0;
450 	} else if (panfrost_exception_is_fault(js_status)) {
451 		/* We might want to provide finer-grained error code based on
452 		 * the exception type, but unconditionally setting to EINVAL
453 		 * is good enough for now.
454 		 */
455 		dma_fence_set_error(job->done_fence, -EINVAL);
456 		job->jc = 0;
457 	}
458 
459 	panfrost_mmu_as_put(pfdev, job->file_priv->mmu);
460 	panfrost_devfreq_record_idle(&pfdev->pfdevfreq);
461 
462 	if (signal_fence)
463 		dma_fence_signal_locked(job->done_fence);
464 
465 	pm_runtime_put_autosuspend(pfdev->dev);
466 
467 	if (panfrost_exception_needs_reset(pfdev, js_status)) {
468 		atomic_set(&pfdev->reset.pending, 1);
469 		drm_sched_fault(&pfdev->js->queue[js].sched);
470 	}
471 }
472 
473 static void panfrost_job_handle_done(struct panfrost_device *pfdev,
474 				     struct panfrost_job *job)
475 {
476 	/* Set ->jc to 0 to avoid re-submitting an already finished job (can
477 	 * happen when we receive the DONE interrupt while doing a GPU reset).
478 	 */
479 	job->jc = 0;
480 	panfrost_mmu_as_put(pfdev, job->file_priv->mmu);
481 	panfrost_devfreq_record_idle(&pfdev->pfdevfreq);
482 
483 	dma_fence_signal_locked(job->done_fence);
484 	pm_runtime_put_autosuspend(pfdev->dev);
485 }
486 
487 static void panfrost_job_handle_irq(struct panfrost_device *pfdev, u32 status)
488 {
489 	struct panfrost_job *done[NUM_JOB_SLOTS][2] = {};
490 	struct panfrost_job *failed[NUM_JOB_SLOTS] = {};
491 	u32 js_state = 0, js_events = 0;
492 	unsigned int i, j;
493 
494 	/* First we collect all failed/done jobs. */
495 	while (status) {
496 		u32 js_state_mask = 0;
497 
498 		for (j = 0; j < NUM_JOB_SLOTS; j++) {
499 			if (status & MK_JS_MASK(j))
500 				js_state_mask |= MK_JS_MASK(j);
501 
502 			if (status & JOB_INT_MASK_DONE(j)) {
503 				if (done[j][0])
504 					done[j][1] = panfrost_dequeue_job(pfdev, j);
505 				else
506 					done[j][0] = panfrost_dequeue_job(pfdev, j);
507 			}
508 
509 			if (status & JOB_INT_MASK_ERR(j)) {
510 				/* Cancel the next submission. Will be submitted
511 				 * after we're done handling this failure if
512 				 * there's no reset pending.
513 				 */
514 				job_write(pfdev, JS_COMMAND_NEXT(j), JS_COMMAND_NOP);
515 				failed[j] = panfrost_dequeue_job(pfdev, j);
516 			}
517 		}
518 
519 		/* JS_STATE is sampled when JOB_INT_CLEAR is written.
520 		 * For each BIT(slot) or BIT(slot + 16) bit written to
521 		 * JOB_INT_CLEAR, the corresponding bits in JS_STATE
522 		 * (BIT(slot) and BIT(slot + 16)) are updated, but this
523 		 * is racy. If we only have one job done at the time we
524 		 * read JOB_INT_RAWSTAT but the second job fails before we
525 		 * clear the status, we end up with a status containing
526 		 * only the DONE bit and consider both jobs as DONE since
527 		 * JS_STATE reports both NEXT and CURRENT as inactive.
528 		 * To prevent that, let's repeat this clear+read steps
529 		 * until status is 0.
530 		 */
531 		job_write(pfdev, JOB_INT_CLEAR, status);
532 		js_state &= ~js_state_mask;
533 		js_state |= job_read(pfdev, JOB_INT_JS_STATE) & js_state_mask;
534 		js_events |= status;
535 		status = job_read(pfdev, JOB_INT_RAWSTAT);
536 	}
537 
538 	/* Then we handle the dequeued jobs. */
539 	for (j = 0; j < NUM_JOB_SLOTS; j++) {
540 		if (!(js_events & MK_JS_MASK(j)))
541 			continue;
542 
543 		if (failed[j]) {
544 			panfrost_job_handle_err(pfdev, failed[j], j);
545 		} else if (pfdev->jobs[j][0] && !(js_state & MK_JS_MASK(j))) {
546 			/* When the current job doesn't fail, the JM dequeues
547 			 * the next job without waiting for an ACK, this means
548 			 * we can have 2 jobs dequeued and only catch the
549 			 * interrupt when the second one is done. If both slots
550 			 * are inactive, but one job remains in pfdev->jobs[j],
551 			 * consider it done. Of course that doesn't apply if a
552 			 * failure happened since we cancelled execution of the
553 			 * job in _NEXT (see above).
554 			 */
555 			if (WARN_ON(!done[j][0]))
556 				done[j][0] = panfrost_dequeue_job(pfdev, j);
557 			else
558 				done[j][1] = panfrost_dequeue_job(pfdev, j);
559 		}
560 
561 		for (i = 0; i < ARRAY_SIZE(done[0]) && done[j][i]; i++)
562 			panfrost_job_handle_done(pfdev, done[j][i]);
563 	}
564 
565 	/* And finally we requeue jobs that were waiting in the second slot
566 	 * and have been stopped if we detected a failure on the first slot.
567 	 */
568 	for (j = 0; j < NUM_JOB_SLOTS; j++) {
569 		if (!(js_events & MK_JS_MASK(j)))
570 			continue;
571 
572 		if (!failed[j] || !pfdev->jobs[j][0])
573 			continue;
574 
575 		if (pfdev->jobs[j][0]->jc == 0) {
576 			/* The job was cancelled, signal the fence now */
577 			struct panfrost_job *canceled = panfrost_dequeue_job(pfdev, j);
578 
579 			dma_fence_set_error(canceled->done_fence, -ECANCELED);
580 			panfrost_job_handle_done(pfdev, canceled);
581 		} else if (!atomic_read(&pfdev->reset.pending)) {
582 			/* Requeue the job we removed if no reset is pending */
583 			job_write(pfdev, JS_COMMAND_NEXT(j), JS_COMMAND_START);
584 		}
585 	}
586 }
587 
588 static void panfrost_job_handle_irqs(struct panfrost_device *pfdev)
589 {
590 	u32 status = job_read(pfdev, JOB_INT_RAWSTAT);
591 
592 	while (status) {
593 		pm_runtime_mark_last_busy(pfdev->dev);
594 
595 		spin_lock(&pfdev->js->job_lock);
596 		panfrost_job_handle_irq(pfdev, status);
597 		spin_unlock(&pfdev->js->job_lock);
598 		status = job_read(pfdev, JOB_INT_RAWSTAT);
599 	}
600 }
601 
602 static u32 panfrost_active_slots(struct panfrost_device *pfdev,
603 				 u32 *js_state_mask, u32 js_state)
604 {
605 	u32 rawstat;
606 
607 	if (!(js_state & *js_state_mask))
608 		return 0;
609 
610 	rawstat = job_read(pfdev, JOB_INT_RAWSTAT);
611 	if (rawstat) {
612 		unsigned int i;
613 
614 		for (i = 0; i < NUM_JOB_SLOTS; i++) {
615 			if (rawstat & MK_JS_MASK(i))
616 				*js_state_mask &= ~MK_JS_MASK(i);
617 		}
618 	}
619 
620 	return js_state & *js_state_mask;
621 }
622 
623 static void
624 panfrost_reset(struct panfrost_device *pfdev,
625 	       struct drm_sched_job *bad)
626 {
627 	u32 js_state, js_state_mask = 0xffffffff;
628 	unsigned int i, j;
629 	bool cookie;
630 	int ret;
631 
632 	if (!atomic_read(&pfdev->reset.pending))
633 		return;
634 
635 	/* Stop the schedulers.
636 	 *
637 	 * FIXME: We temporarily get out of the dma_fence_signalling section
638 	 * because the cleanup path generate lockdep splats when taking locks
639 	 * to release job resources. We should rework the code to follow this
640 	 * pattern:
641 	 *
642 	 *	try_lock
643 	 *	if (locked)
644 	 *		release
645 	 *	else
646 	 *		schedule_work_to_release_later
647 	 */
648 	for (i = 0; i < NUM_JOB_SLOTS; i++)
649 		drm_sched_stop(&pfdev->js->queue[i].sched, bad);
650 
651 	cookie = dma_fence_begin_signalling();
652 
653 	if (bad)
654 		drm_sched_increase_karma(bad);
655 
656 	/* Mask job interrupts and synchronize to make sure we won't be
657 	 * interrupted during our reset.
658 	 */
659 	job_write(pfdev, JOB_INT_MASK, 0);
660 	synchronize_irq(pfdev->js->irq);
661 
662 	for (i = 0; i < NUM_JOB_SLOTS; i++) {
663 		/* Cancel the next job and soft-stop the running job. */
664 		job_write(pfdev, JS_COMMAND_NEXT(i), JS_COMMAND_NOP);
665 		job_write(pfdev, JS_COMMAND(i), JS_COMMAND_SOFT_STOP);
666 	}
667 
668 	/* Wait at most 10ms for soft-stops to complete */
669 	ret = readl_poll_timeout(pfdev->iomem + JOB_INT_JS_STATE, js_state,
670 				 !panfrost_active_slots(pfdev, &js_state_mask, js_state),
671 				 10, 10000);
672 
673 	if (ret)
674 		dev_err(pfdev->dev, "Soft-stop failed\n");
675 
676 	/* Handle the remaining interrupts before we reset. */
677 	panfrost_job_handle_irqs(pfdev);
678 
679 	/* Remaining interrupts have been handled, but we might still have
680 	 * stuck jobs. Let's make sure the PM counters stay balanced by
681 	 * manually calling pm_runtime_put_noidle() and
682 	 * panfrost_devfreq_record_idle() for each stuck job.
683 	 */
684 	spin_lock(&pfdev->js->job_lock);
685 	for (i = 0; i < NUM_JOB_SLOTS; i++) {
686 		for (j = 0; j < ARRAY_SIZE(pfdev->jobs[0]) && pfdev->jobs[i][j]; j++) {
687 			pm_runtime_put_noidle(pfdev->dev);
688 			panfrost_devfreq_record_idle(&pfdev->pfdevfreq);
689 		}
690 	}
691 	memset(pfdev->jobs, 0, sizeof(pfdev->jobs));
692 	spin_unlock(&pfdev->js->job_lock);
693 
694 	/* Proceed with reset now. */
695 	panfrost_device_reset(pfdev);
696 
697 	/* panfrost_device_reset() unmasks job interrupts, but we want to
698 	 * keep them masked a bit longer.
699 	 */
700 	job_write(pfdev, JOB_INT_MASK, 0);
701 
702 	/* GPU has been reset, we can clear the reset pending bit. */
703 	atomic_set(&pfdev->reset.pending, 0);
704 
705 	/* Now resubmit jobs that were previously queued but didn't have a
706 	 * chance to finish.
707 	 * FIXME: We temporarily get out of the DMA fence signalling section
708 	 * while resubmitting jobs because the job submission logic will
709 	 * allocate memory with the GFP_KERNEL flag which can trigger memory
710 	 * reclaim and exposes a lock ordering issue.
711 	 */
712 	dma_fence_end_signalling(cookie);
713 	for (i = 0; i < NUM_JOB_SLOTS; i++)
714 		drm_sched_resubmit_jobs(&pfdev->js->queue[i].sched);
715 	cookie = dma_fence_begin_signalling();
716 
717 	/* Restart the schedulers */
718 	for (i = 0; i < NUM_JOB_SLOTS; i++)
719 		drm_sched_start(&pfdev->js->queue[i].sched, true);
720 
721 	/* Re-enable job interrupts now that everything has been restarted. */
722 	job_write(pfdev, JOB_INT_MASK,
723 		  GENMASK(16 + NUM_JOB_SLOTS - 1, 16) |
724 		  GENMASK(NUM_JOB_SLOTS - 1, 0));
725 
726 	dma_fence_end_signalling(cookie);
727 }
728 
729 static enum drm_gpu_sched_stat panfrost_job_timedout(struct drm_sched_job
730 						     *sched_job)
731 {
732 	struct panfrost_job *job = to_panfrost_job(sched_job);
733 	struct panfrost_device *pfdev = job->pfdev;
734 	int js = panfrost_job_get_slot(job);
735 
736 	/*
737 	 * If the GPU managed to complete this jobs fence, the timeout is
738 	 * spurious. Bail out.
739 	 */
740 	if (dma_fence_is_signaled(job->done_fence))
741 		return DRM_GPU_SCHED_STAT_NOMINAL;
742 
743 	dev_err(pfdev->dev, "gpu sched timeout, js=%d, config=0x%x, status=0x%x, head=0x%x, tail=0x%x, sched_job=%p",
744 		js,
745 		job_read(pfdev, JS_CONFIG(js)),
746 		job_read(pfdev, JS_STATUS(js)),
747 		job_read(pfdev, JS_HEAD_LO(js)),
748 		job_read(pfdev, JS_TAIL_LO(js)),
749 		sched_job);
750 
751 	atomic_set(&pfdev->reset.pending, 1);
752 	panfrost_reset(pfdev, sched_job);
753 
754 	return DRM_GPU_SCHED_STAT_NOMINAL;
755 }
756 
757 static void panfrost_reset_work(struct work_struct *work)
758 {
759 	struct panfrost_device *pfdev;
760 
761 	pfdev = container_of(work, struct panfrost_device, reset.work);
762 	panfrost_reset(pfdev, NULL);
763 }
764 
765 static const struct drm_sched_backend_ops panfrost_sched_ops = {
766 	.dependency = panfrost_job_dependency,
767 	.run_job = panfrost_job_run,
768 	.timedout_job = panfrost_job_timedout,
769 	.free_job = panfrost_job_free
770 };
771 
772 static irqreturn_t panfrost_job_irq_handler_thread(int irq, void *data)
773 {
774 	struct panfrost_device *pfdev = data;
775 
776 	panfrost_job_handle_irqs(pfdev);
777 	job_write(pfdev, JOB_INT_MASK,
778 		  GENMASK(16 + NUM_JOB_SLOTS - 1, 16) |
779 		  GENMASK(NUM_JOB_SLOTS - 1, 0));
780 	return IRQ_HANDLED;
781 }
782 
783 static irqreturn_t panfrost_job_irq_handler(int irq, void *data)
784 {
785 	struct panfrost_device *pfdev = data;
786 	u32 status = job_read(pfdev, JOB_INT_STAT);
787 
788 	if (!status)
789 		return IRQ_NONE;
790 
791 	job_write(pfdev, JOB_INT_MASK, 0);
792 	return IRQ_WAKE_THREAD;
793 }
794 
795 int panfrost_job_init(struct panfrost_device *pfdev)
796 {
797 	struct panfrost_job_slot *js;
798 	unsigned int nentries = 2;
799 	int ret, j;
800 
801 	/* All GPUs have two entries per queue, but without jobchain
802 	 * disambiguation stopping the right job in the close path is tricky,
803 	 * so let's just advertise one entry in that case.
804 	 */
805 	if (!panfrost_has_hw_feature(pfdev, HW_FEATURE_JOBCHAIN_DISAMBIGUATION))
806 		nentries = 1;
807 
808 	pfdev->js = js = devm_kzalloc(pfdev->dev, sizeof(*js), GFP_KERNEL);
809 	if (!js)
810 		return -ENOMEM;
811 
812 	INIT_WORK(&pfdev->reset.work, panfrost_reset_work);
813 	spin_lock_init(&js->job_lock);
814 
815 	js->irq = platform_get_irq_byname(to_platform_device(pfdev->dev), "job");
816 	if (js->irq <= 0)
817 		return -ENODEV;
818 
819 	ret = devm_request_threaded_irq(pfdev->dev, js->irq,
820 					panfrost_job_irq_handler,
821 					panfrost_job_irq_handler_thread,
822 					IRQF_SHARED, KBUILD_MODNAME "-job",
823 					pfdev);
824 	if (ret) {
825 		dev_err(pfdev->dev, "failed to request job irq");
826 		return ret;
827 	}
828 
829 	pfdev->reset.wq = alloc_ordered_workqueue("panfrost-reset", 0);
830 	if (!pfdev->reset.wq)
831 		return -ENOMEM;
832 
833 	for (j = 0; j < NUM_JOB_SLOTS; j++) {
834 		js->queue[j].fence_context = dma_fence_context_alloc(1);
835 
836 		ret = drm_sched_init(&js->queue[j].sched,
837 				     &panfrost_sched_ops,
838 				     nentries, 0,
839 				     msecs_to_jiffies(JOB_TIMEOUT_MS),
840 				     pfdev->reset.wq,
841 				     NULL, "pan_js");
842 		if (ret) {
843 			dev_err(pfdev->dev, "Failed to create scheduler: %d.", ret);
844 			goto err_sched;
845 		}
846 	}
847 
848 	panfrost_job_enable_interrupts(pfdev);
849 
850 	return 0;
851 
852 err_sched:
853 	for (j--; j >= 0; j--)
854 		drm_sched_fini(&js->queue[j].sched);
855 
856 	destroy_workqueue(pfdev->reset.wq);
857 	return ret;
858 }
859 
860 void panfrost_job_fini(struct panfrost_device *pfdev)
861 {
862 	struct panfrost_job_slot *js = pfdev->js;
863 	int j;
864 
865 	job_write(pfdev, JOB_INT_MASK, 0);
866 
867 	for (j = 0; j < NUM_JOB_SLOTS; j++) {
868 		drm_sched_fini(&js->queue[j].sched);
869 	}
870 
871 	cancel_work_sync(&pfdev->reset.work);
872 	destroy_workqueue(pfdev->reset.wq);
873 }
874 
875 int panfrost_job_open(struct panfrost_file_priv *panfrost_priv)
876 {
877 	struct panfrost_device *pfdev = panfrost_priv->pfdev;
878 	struct panfrost_job_slot *js = pfdev->js;
879 	struct drm_gpu_scheduler *sched;
880 	int ret, i;
881 
882 	for (i = 0; i < NUM_JOB_SLOTS; i++) {
883 		sched = &js->queue[i].sched;
884 		ret = drm_sched_entity_init(&panfrost_priv->sched_entity[i],
885 					    DRM_SCHED_PRIORITY_NORMAL, &sched,
886 					    1, NULL);
887 		if (WARN_ON(ret))
888 			return ret;
889 	}
890 	return 0;
891 }
892 
893 void panfrost_job_close(struct panfrost_file_priv *panfrost_priv)
894 {
895 	struct panfrost_device *pfdev = panfrost_priv->pfdev;
896 	int i;
897 
898 	for (i = 0; i < NUM_JOB_SLOTS; i++)
899 		drm_sched_entity_destroy(&panfrost_priv->sched_entity[i]);
900 
901 	/* Kill in-flight jobs */
902 	spin_lock(&pfdev->js->job_lock);
903 	for (i = 0; i < NUM_JOB_SLOTS; i++) {
904 		struct drm_sched_entity *entity = &panfrost_priv->sched_entity[i];
905 		int j;
906 
907 		for (j = ARRAY_SIZE(pfdev->jobs[0]) - 1; j >= 0; j--) {
908 			struct panfrost_job *job = pfdev->jobs[i][j];
909 			u32 cmd;
910 
911 			if (!job || job->base.entity != entity)
912 				continue;
913 
914 			if (j == 1) {
915 				/* Try to cancel the job before it starts */
916 				job_write(pfdev, JS_COMMAND_NEXT(i), JS_COMMAND_NOP);
917 				/* Reset the job head so it doesn't get restarted if
918 				 * the job in the first slot failed.
919 				 */
920 				job->jc = 0;
921 			}
922 
923 			if (panfrost_has_hw_feature(pfdev, HW_FEATURE_JOBCHAIN_DISAMBIGUATION)) {
924 				cmd = panfrost_get_job_chain_flag(job) ?
925 				      JS_COMMAND_HARD_STOP_1 :
926 				      JS_COMMAND_HARD_STOP_0;
927 			} else {
928 				cmd = JS_COMMAND_HARD_STOP;
929 			}
930 
931 			job_write(pfdev, JS_COMMAND(i), cmd);
932 		}
933 	}
934 	spin_unlock(&pfdev->js->job_lock);
935 }
936 
937 int panfrost_job_is_idle(struct panfrost_device *pfdev)
938 {
939 	struct panfrost_job_slot *js = pfdev->js;
940 	int i;
941 
942 	for (i = 0; i < NUM_JOB_SLOTS; i++) {
943 		/* If there are any jobs in the HW queue, we're not idle */
944 		if (atomic_read(&js->queue[i].sched.hw_rq_count))
945 			return false;
946 	}
947 
948 	return true;
949 }
950