1/*
2 * Copyright (C) 2007 Ben Skeggs.
3 * All Rights Reserved.
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining
6 * a copy of this software and associated documentation files (the
7 * "Software"), to deal in the Software without restriction, including
8 * without limitation the rights to use, copy, modify, merge, publish,
9 * distribute, sublicense, and/or sell copies of the Software, and to
10 * permit persons to whom the Software is furnished to do so, subject to
11 * the following conditions:
12 *
13 * The above copyright notice and this permission notice (including the
14 * next paragraph) shall be included in all copies or substantial
15 * portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
18 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
19 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
20 * IN NO EVENT SHALL THE COPYRIGHT OWNER(S) AND/OR ITS SUPPLIERS BE
21 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
22 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
23 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
24 *
25 */
26
27#include <linux/ktime.h>
28#include <linux/hrtimer.h>
29#include <linux/sched/signal.h>
30#include <trace/events/dma_fence.h>
31
32#include <nvif/if0020.h>
33
34#include "nouveau_drv.h"
35#include "nouveau_dma.h"
36#include "nouveau_fence.h"
37
38static const struct dma_fence_ops nouveau_fence_ops_uevent;
39static const struct dma_fence_ops nouveau_fence_ops_legacy;
40
41static inline struct nouveau_fence *
42from_fence(struct dma_fence *fence)
43{
44	return container_of(fence, struct nouveau_fence, base);
45}
46
47static inline struct nouveau_fence_chan *
48nouveau_fctx(struct nouveau_fence *fence)
49{
50	return container_of(fence->base.lock, struct nouveau_fence_chan, lock);
51}
52
53static int
54nouveau_fence_signal(struct nouveau_fence *fence)
55{
56	int drop = 0;
57
58	dma_fence_signal_locked(&fence->base);
59	list_del(&fence->head);
60	rcu_assign_pointer(fence->channel, NULL);
61
62	if (test_bit(DMA_FENCE_FLAG_USER_BITS, &fence->base.flags)) {
63		struct nouveau_fence_chan *fctx = nouveau_fctx(fence);
64
65		if (!--fctx->notify_ref)
66			drop = 1;
67	}
68
69	dma_fence_put(&fence->base);
70	return drop;
71}
72
73static struct nouveau_fence *
74nouveau_local_fence(struct dma_fence *fence, struct nouveau_drm *drm)
75{
76	if (fence->ops != &nouveau_fence_ops_legacy &&
77	    fence->ops != &nouveau_fence_ops_uevent)
78		return NULL;
79
80	return from_fence(fence);
81}
82
83void
84nouveau_fence_context_kill(struct nouveau_fence_chan *fctx, int error)
85{
86	struct nouveau_fence *fence;
87	unsigned long flags;
88
89	spin_lock_irqsave(&fctx->lock, flags);
90	while (!list_empty(&fctx->pending)) {
91		fence = list_entry(fctx->pending.next, typeof(*fence), head);
92
93		if (error)
94			dma_fence_set_error(&fence->base, error);
95
96		if (nouveau_fence_signal(fence))
97			nvif_event_block(&fctx->event);
98	}
99	fctx->killed = 1;
100	spin_unlock_irqrestore(&fctx->lock, flags);
101}
102
103void
104nouveau_fence_context_del(struct nouveau_fence_chan *fctx)
105{
106	cancel_work_sync(&fctx->uevent_work);
107	nouveau_fence_context_kill(fctx, 0);
108	nvif_event_dtor(&fctx->event);
109	fctx->dead = 1;
110
111	/*
112	 * Ensure that all accesses to fence->channel complete before freeing
113	 * the channel.
114	 */
115	synchronize_rcu();
116}
117
118static void
119nouveau_fence_context_put(struct kref *fence_ref)
120{
121	kfree(container_of(fence_ref, struct nouveau_fence_chan, fence_ref));
122}
123
124void
125nouveau_fence_context_free(struct nouveau_fence_chan *fctx)
126{
127	kref_put(&fctx->fence_ref, nouveau_fence_context_put);
128}
129
130static int
131nouveau_fence_update(struct nouveau_channel *chan, struct nouveau_fence_chan *fctx)
132{
133	struct nouveau_fence *fence;
134	int drop = 0;
135	u32 seq = fctx->read(chan);
136
137	while (!list_empty(&fctx->pending)) {
138		fence = list_entry(fctx->pending.next, typeof(*fence), head);
139
140		if ((int)(seq - fence->base.seqno) < 0)
141			break;
142
143		drop |= nouveau_fence_signal(fence);
144	}
145
146	return drop;
147}
148
149static void
150nouveau_fence_uevent_work(struct work_struct *work)
151{
152	struct nouveau_fence_chan *fctx = container_of(work, struct nouveau_fence_chan,
153						       uevent_work);
154	unsigned long flags;
155	int drop = 0;
156
157	spin_lock_irqsave(&fctx->lock, flags);
158	if (!list_empty(&fctx->pending)) {
159		struct nouveau_fence *fence;
160		struct nouveau_channel *chan;
161
162		fence = list_entry(fctx->pending.next, typeof(*fence), head);
163		chan = rcu_dereference_protected(fence->channel, lockdep_is_held(&fctx->lock));
164		if (nouveau_fence_update(chan, fctx))
165			drop = 1;
166	}
167	if (drop)
168		nvif_event_block(&fctx->event);
169
170	spin_unlock_irqrestore(&fctx->lock, flags);
171}
172
173static int
174nouveau_fence_wait_uevent_handler(struct nvif_event *event, void *repv, u32 repc)
175{
176	struct nouveau_fence_chan *fctx = container_of(event, typeof(*fctx), event);
177	schedule_work(&fctx->uevent_work);
178	return NVIF_EVENT_KEEP;
179}
180
181void
182nouveau_fence_context_new(struct nouveau_channel *chan, struct nouveau_fence_chan *fctx)
183{
184	struct nouveau_fence_priv *priv = (void*)chan->drm->fence;
185	struct nouveau_cli *cli = (void *)chan->user.client;
186	struct {
187		struct nvif_event_v0 base;
188		struct nvif_chan_event_v0 host;
189	} args;
190	int ret;
191
192	INIT_WORK(&fctx->uevent_work, nouveau_fence_uevent_work);
193	INIT_LIST_HEAD(&fctx->flip);
194	INIT_LIST_HEAD(&fctx->pending);
195	spin_lock_init(&fctx->lock);
196	fctx->context = chan->drm->runl[chan->runlist].context_base + chan->chid;
197
198	if (chan == chan->drm->cechan)
199		strcpy(fctx->name, "copy engine channel");
200	else if (chan == chan->drm->channel)
201		strcpy(fctx->name, "generic kernel channel");
202	else
203		strcpy(fctx->name, nvxx_client(&cli->base)->name);
204
205	kref_init(&fctx->fence_ref);
206	if (!priv->uevent)
207		return;
208
209	args.host.version = 0;
210	args.host.type = NVIF_CHAN_EVENT_V0_NON_STALL_INTR;
211
212	ret = nvif_event_ctor(&chan->user, "fenceNonStallIntr", (chan->runlist << 16) | chan->chid,
213			      nouveau_fence_wait_uevent_handler, false,
214			      &args.base, sizeof(args), &fctx->event);
215
216	WARN_ON(ret);
217}
218
219int
220nouveau_fence_emit(struct nouveau_fence *fence)
221{
222	struct nouveau_channel *chan = unrcu_pointer(fence->channel);
223	struct nouveau_fence_chan *fctx = chan->fence;
224	struct nouveau_fence_priv *priv = (void*)chan->drm->fence;
225	int ret;
226
227	fence->timeout  = jiffies + (15 * HZ);
228
229	if (priv->uevent)
230		dma_fence_init(&fence->base, &nouveau_fence_ops_uevent,
231			       &fctx->lock, fctx->context, ++fctx->sequence);
232	else
233		dma_fence_init(&fence->base, &nouveau_fence_ops_legacy,
234			       &fctx->lock, fctx->context, ++fctx->sequence);
235	kref_get(&fctx->fence_ref);
236
237	ret = fctx->emit(fence);
238	if (!ret) {
239		dma_fence_get(&fence->base);
240		spin_lock_irq(&fctx->lock);
241
242		if (unlikely(fctx->killed)) {
243			spin_unlock_irq(&fctx->lock);
244			dma_fence_put(&fence->base);
245			return -ENODEV;
246		}
247
248		if (nouveau_fence_update(chan, fctx))
249			nvif_event_block(&fctx->event);
250
251		list_add_tail(&fence->head, &fctx->pending);
252		spin_unlock_irq(&fctx->lock);
253	}
254
255	return ret;
256}
257
258bool
259nouveau_fence_done(struct nouveau_fence *fence)
260{
261	if (fence->base.ops == &nouveau_fence_ops_legacy ||
262	    fence->base.ops == &nouveau_fence_ops_uevent) {
263		struct nouveau_fence_chan *fctx = nouveau_fctx(fence);
264		struct nouveau_channel *chan;
265		unsigned long flags;
266
267		if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->base.flags))
268			return true;
269
270		spin_lock_irqsave(&fctx->lock, flags);
271		chan = rcu_dereference_protected(fence->channel, lockdep_is_held(&fctx->lock));
272		if (chan && nouveau_fence_update(chan, fctx))
273			nvif_event_block(&fctx->event);
274		spin_unlock_irqrestore(&fctx->lock, flags);
275	}
276	return dma_fence_is_signaled(&fence->base);
277}
278
279static long
280nouveau_fence_wait_legacy(struct dma_fence *f, bool intr, long wait)
281{
282	struct nouveau_fence *fence = from_fence(f);
283	unsigned long sleep_time = NSEC_PER_MSEC / 1000;
284	unsigned long t = jiffies, timeout = t + wait;
285
286	while (!nouveau_fence_done(fence)) {
287		ktime_t kt;
288
289		t = jiffies;
290
291		if (wait != MAX_SCHEDULE_TIMEOUT && time_after_eq(t, timeout)) {
292			__set_current_state(TASK_RUNNING);
293			return 0;
294		}
295
296		__set_current_state(intr ? TASK_INTERRUPTIBLE :
297					   TASK_UNINTERRUPTIBLE);
298
299		kt = sleep_time;
300		schedule_hrtimeout(&kt, HRTIMER_MODE_REL);
301		sleep_time *= 2;
302		if (sleep_time > NSEC_PER_MSEC)
303			sleep_time = NSEC_PER_MSEC;
304
305		if (intr && signal_pending(current))
306			return -ERESTARTSYS;
307	}
308
309	__set_current_state(TASK_RUNNING);
310
311	return timeout - t;
312}
313
314static int
315nouveau_fence_wait_busy(struct nouveau_fence *fence, bool intr)
316{
317	int ret = 0;
318
319	while (!nouveau_fence_done(fence)) {
320		if (time_after_eq(jiffies, fence->timeout)) {
321			ret = -EBUSY;
322			break;
323		}
324
325		__set_current_state(intr ?
326				    TASK_INTERRUPTIBLE :
327				    TASK_UNINTERRUPTIBLE);
328
329		if (intr && signal_pending(current)) {
330			ret = -ERESTARTSYS;
331			break;
332		}
333	}
334
335	__set_current_state(TASK_RUNNING);
336	return ret;
337}
338
339int
340nouveau_fence_wait(struct nouveau_fence *fence, bool lazy, bool intr)
341{
342	long ret;
343
344	if (!lazy)
345		return nouveau_fence_wait_busy(fence, intr);
346
347	ret = dma_fence_wait_timeout(&fence->base, intr, 15 * HZ);
348	if (ret < 0)
349		return ret;
350	else if (!ret)
351		return -EBUSY;
352	else
353		return 0;
354}
355
356int
357nouveau_fence_sync(struct nouveau_bo *nvbo, struct nouveau_channel *chan,
358		   bool exclusive, bool intr)
359{
360	struct nouveau_fence_chan *fctx = chan->fence;
361	struct dma_resv *resv = nvbo->bo.base.resv;
362	int i, ret;
363
364	ret = dma_resv_reserve_fences(resv, 1);
365	if (ret)
366		return ret;
367
368	/* Waiting for the writes first causes performance regressions
369	 * under some circumstances. So manually wait for the reads first.
370	 */
371	for (i = 0; i < 2; ++i) {
372		struct dma_resv_iter cursor;
373		struct dma_fence *fence;
374
375		dma_resv_for_each_fence(&cursor, resv,
376					dma_resv_usage_rw(exclusive),
377					fence) {
378			enum dma_resv_usage usage;
379			struct nouveau_fence *f;
380
381			usage = dma_resv_iter_usage(&cursor);
382			if (i == 0 && usage == DMA_RESV_USAGE_WRITE)
383				continue;
384
385			f = nouveau_local_fence(fence, chan->drm);
386			if (f) {
387				struct nouveau_channel *prev;
388				bool must_wait = true;
389
390				rcu_read_lock();
391				prev = rcu_dereference(f->channel);
392				if (prev && (prev == chan ||
393					     fctx->sync(f, prev, chan) == 0))
394					must_wait = false;
395				rcu_read_unlock();
396				if (!must_wait)
397					continue;
398			}
399
400			ret = dma_fence_wait(fence, intr);
401			if (ret)
402				return ret;
403		}
404	}
405
406	return 0;
407}
408
409void
410nouveau_fence_unref(struct nouveau_fence **pfence)
411{
412	if (*pfence)
413		dma_fence_put(&(*pfence)->base);
414	*pfence = NULL;
415}
416
417int
418nouveau_fence_create(struct nouveau_fence **pfence,
419		     struct nouveau_channel *chan)
420{
421	struct nouveau_fence *fence;
422
423	if (unlikely(!chan->fence))
424		return -ENODEV;
425
426	fence = kzalloc(sizeof(*fence), GFP_KERNEL);
427	if (!fence)
428		return -ENOMEM;
429
430	fence->channel = chan;
431
432	*pfence = fence;
433	return 0;
434}
435
436int
437nouveau_fence_new(struct nouveau_fence **pfence,
438		  struct nouveau_channel *chan)
439{
440	int ret = 0;
441
442	ret = nouveau_fence_create(pfence, chan);
443	if (ret)
444		return ret;
445
446	ret = nouveau_fence_emit(*pfence);
447	if (ret)
448		nouveau_fence_unref(pfence);
449
450	return ret;
451}
452
453static const char *nouveau_fence_get_get_driver_name(struct dma_fence *fence)
454{
455	return "nouveau";
456}
457
458static const char *nouveau_fence_get_timeline_name(struct dma_fence *f)
459{
460	struct nouveau_fence *fence = from_fence(f);
461	struct nouveau_fence_chan *fctx = nouveau_fctx(fence);
462
463	return !fctx->dead ? fctx->name : "dead channel";
464}
465
466/*
467 * In an ideal world, read would not assume the channel context is still alive.
468 * This function may be called from another device, running into free memory as a
469 * result. The drm node should still be there, so we can derive the index from
470 * the fence context.
471 */
472static bool nouveau_fence_is_signaled(struct dma_fence *f)
473{
474	struct nouveau_fence *fence = from_fence(f);
475	struct nouveau_fence_chan *fctx = nouveau_fctx(fence);
476	struct nouveau_channel *chan;
477	bool ret = false;
478
479	rcu_read_lock();
480	chan = rcu_dereference(fence->channel);
481	if (chan)
482		ret = (int)(fctx->read(chan) - fence->base.seqno) >= 0;
483	rcu_read_unlock();
484
485	return ret;
486}
487
488static bool nouveau_fence_no_signaling(struct dma_fence *f)
489{
490	struct nouveau_fence *fence = from_fence(f);
491
492	/*
493	 * caller should have a reference on the fence,
494	 * else fence could get freed here
495	 */
496	WARN_ON(kref_read(&fence->base.refcount) <= 1);
497
498	/*
499	 * This needs uevents to work correctly, but dma_fence_add_callback relies on
500	 * being able to enable signaling. It will still get signaled eventually,
501	 * just not right away.
502	 */
503	if (nouveau_fence_is_signaled(f)) {
504		list_del(&fence->head);
505
506		dma_fence_put(&fence->base);
507		return false;
508	}
509
510	return true;
511}
512
513static void nouveau_fence_release(struct dma_fence *f)
514{
515	struct nouveau_fence *fence = from_fence(f);
516	struct nouveau_fence_chan *fctx = nouveau_fctx(fence);
517
518	kref_put(&fctx->fence_ref, nouveau_fence_context_put);
519	dma_fence_free(&fence->base);
520}
521
522static const struct dma_fence_ops nouveau_fence_ops_legacy = {
523	.get_driver_name = nouveau_fence_get_get_driver_name,
524	.get_timeline_name = nouveau_fence_get_timeline_name,
525	.enable_signaling = nouveau_fence_no_signaling,
526	.signaled = nouveau_fence_is_signaled,
527	.wait = nouveau_fence_wait_legacy,
528	.release = nouveau_fence_release
529};
530
531static bool nouveau_fence_enable_signaling(struct dma_fence *f)
532{
533	struct nouveau_fence *fence = from_fence(f);
534	struct nouveau_fence_chan *fctx = nouveau_fctx(fence);
535	bool ret;
536
537	if (!fctx->notify_ref++)
538		nvif_event_allow(&fctx->event);
539
540	ret = nouveau_fence_no_signaling(f);
541	if (ret)
542		set_bit(DMA_FENCE_FLAG_USER_BITS, &fence->base.flags);
543	else if (!--fctx->notify_ref)
544		nvif_event_block(&fctx->event);
545
546	return ret;
547}
548
549static const struct dma_fence_ops nouveau_fence_ops_uevent = {
550	.get_driver_name = nouveau_fence_get_get_driver_name,
551	.get_timeline_name = nouveau_fence_get_timeline_name,
552	.enable_signaling = nouveau_fence_enable_signaling,
553	.signaled = nouveau_fence_is_signaled,
554	.release = nouveau_fence_release
555};
556