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: &fence->base);
59 list_del(entry: &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: &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(head: &fctx->pending)) {
91 fence = list_entry(fctx->pending.next, typeof(*fence), head);
92
93 if (error)
94 dma_fence_set_error(fence: &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(lock: &fctx->lock, flags);
101}
102
103void
104nouveau_fence_context_del(struct nouveau_fence_chan *fctx)
105{
106 cancel_work_sync(work: &fctx->uevent_work);
107 nouveau_fence_context_kill(fctx, error: 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(kref: &fctx->fence_ref, release: 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(head: &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(head: &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(lock: &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(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(list: &fctx->flip);
194 INIT_LIST_HEAD(list: &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(p: fctx->name, q: "copy engine channel");
200 else if (chan == chan->drm->channel)
201 strcpy(p: fctx->name, q: "generic kernel channel");
202 else
203 strcpy(fctx->name, nvxx_client(&cli->base)->name);
204
205 kref_init(kref: &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: &fence->base, ops: &nouveau_fence_ops_uevent,
231 lock: &fctx->lock, context: fctx->context, seqno: ++fctx->sequence);
232 else
233 dma_fence_init(fence: &fence->base, ops: &nouveau_fence_ops_legacy,
234 lock: &fctx->lock, context: fctx->context, seqno: ++fctx->sequence);
235 kref_get(kref: &fctx->fence_ref);
236
237 ret = fctx->emit(fence);
238 if (!ret) {
239 dma_fence_get(fence: &fence->base);
240 spin_lock_irq(lock: &fctx->lock);
241
242 if (unlikely(fctx->killed)) {
243 spin_unlock_irq(lock: &fctx->lock);
244 dma_fence_put(fence: &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(new: &fence->head, head: &fctx->pending);
252 spin_unlock_irq(lock: &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(lock: &fctx->lock, flags);
275 }
276 return dma_fence_is_signaled(fence: &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(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(expires: &kt, mode: 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, timeout: 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(obj: resv, num_fences: 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: &cursor);
382 if (i == 0 && usage == DMA_RESV_USAGE_WRITE)
383 continue;
384
385 f = nouveau_local_fence(fence, drm: 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(fence: &(*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(size: 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(fence: *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(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(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(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(entry: &fence->head);
505
506 dma_fence_put(fence: &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(fence: f);
516 struct nouveau_fence_chan *fctx = nouveau_fctx(fence);
517
518 kref_put(kref: &fctx->fence_ref, release: nouveau_fence_context_put);
519 dma_fence_free(fence: &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(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(nr: DMA_FENCE_FLAG_USER_BITS, addr: &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

source code of linux/drivers/gpu/drm/nouveau/nouveau_fence.c