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 nouveau_fence_context_kill(fctx, error: 0);
107 nvif_event_dtor(&fctx->event);
108 fctx->dead = 1;
109
110 /*
111 * Ensure that all accesses to fence->channel complete before freeing
112 * the channel.
113 */
114 synchronize_rcu();
115}
116
117static void
118nouveau_fence_context_put(struct kref *fence_ref)
119{
120 kfree(container_of(fence_ref, struct nouveau_fence_chan, fence_ref));
121}
122
123void
124nouveau_fence_context_free(struct nouveau_fence_chan *fctx)
125{
126 kref_put(kref: &fctx->fence_ref, release: nouveau_fence_context_put);
127}
128
129static int
130nouveau_fence_update(struct nouveau_channel *chan, struct nouveau_fence_chan *fctx)
131{
132 struct nouveau_fence *fence;
133 int drop = 0;
134 u32 seq = fctx->read(chan);
135
136 while (!list_empty(head: &fctx->pending)) {
137 fence = list_entry(fctx->pending.next, typeof(*fence), head);
138
139 if ((int)(seq - fence->base.seqno) < 0)
140 break;
141
142 drop |= nouveau_fence_signal(fence);
143 }
144
145 return drop;
146}
147
148static int
149nouveau_fence_wait_uevent_handler(struct nvif_event *event, void *repv, u32 repc)
150{
151 struct nouveau_fence_chan *fctx = container_of(event, typeof(*fctx), event);
152 unsigned long flags;
153 int ret = NVIF_EVENT_KEEP;
154
155 spin_lock_irqsave(&fctx->lock, flags);
156 if (!list_empty(head: &fctx->pending)) {
157 struct nouveau_fence *fence;
158 struct nouveau_channel *chan;
159
160 fence = list_entry(fctx->pending.next, typeof(*fence), head);
161 chan = rcu_dereference_protected(fence->channel, lockdep_is_held(&fctx->lock));
162 if (nouveau_fence_update(chan, fctx))
163 ret = NVIF_EVENT_DROP;
164 }
165 spin_unlock_irqrestore(lock: &fctx->lock, flags);
166
167 return ret;
168}
169
170void
171nouveau_fence_context_new(struct nouveau_channel *chan, struct nouveau_fence_chan *fctx)
172{
173 struct nouveau_fence_priv *priv = (void*)chan->drm->fence;
174 struct nouveau_cli *cli = (void *)chan->user.client;
175 struct {
176 struct nvif_event_v0 base;
177 struct nvif_chan_event_v0 host;
178 } args;
179 int ret;
180
181 INIT_LIST_HEAD(list: &fctx->flip);
182 INIT_LIST_HEAD(list: &fctx->pending);
183 spin_lock_init(&fctx->lock);
184 fctx->context = chan->drm->runl[chan->runlist].context_base + chan->chid;
185
186 if (chan == chan->drm->cechan)
187 strcpy(p: fctx->name, q: "copy engine channel");
188 else if (chan == chan->drm->channel)
189 strcpy(p: fctx->name, q: "generic kernel channel");
190 else
191 strcpy(fctx->name, nvxx_client(&cli->base)->name);
192
193 kref_init(kref: &fctx->fence_ref);
194 if (!priv->uevent)
195 return;
196
197 args.host.version = 0;
198 args.host.type = NVIF_CHAN_EVENT_V0_NON_STALL_INTR;
199
200 ret = nvif_event_ctor(&chan->user, "fenceNonStallIntr", (chan->runlist << 16) | chan->chid,
201 nouveau_fence_wait_uevent_handler, false,
202 &args.base, sizeof(args), &fctx->event);
203
204 WARN_ON(ret);
205}
206
207int
208nouveau_fence_emit(struct nouveau_fence *fence)
209{
210 struct nouveau_channel *chan = unrcu_pointer(fence->channel);
211 struct nouveau_fence_chan *fctx = chan->fence;
212 struct nouveau_fence_priv *priv = (void*)chan->drm->fence;
213 int ret;
214
215 fence->timeout = jiffies + (15 * HZ);
216
217 if (priv->uevent)
218 dma_fence_init(fence: &fence->base, ops: &nouveau_fence_ops_uevent,
219 lock: &fctx->lock, context: fctx->context, seqno: ++fctx->sequence);
220 else
221 dma_fence_init(fence: &fence->base, ops: &nouveau_fence_ops_legacy,
222 lock: &fctx->lock, context: fctx->context, seqno: ++fctx->sequence);
223 kref_get(kref: &fctx->fence_ref);
224
225 ret = fctx->emit(fence);
226 if (!ret) {
227 dma_fence_get(fence: &fence->base);
228 spin_lock_irq(lock: &fctx->lock);
229
230 if (unlikely(fctx->killed)) {
231 spin_unlock_irq(lock: &fctx->lock);
232 dma_fence_put(fence: &fence->base);
233 return -ENODEV;
234 }
235
236 if (nouveau_fence_update(chan, fctx))
237 nvif_event_block(&fctx->event);
238
239 list_add_tail(new: &fence->head, head: &fctx->pending);
240 spin_unlock_irq(lock: &fctx->lock);
241 }
242
243 return ret;
244}
245
246bool
247nouveau_fence_done(struct nouveau_fence *fence)
248{
249 if (fence->base.ops == &nouveau_fence_ops_legacy ||
250 fence->base.ops == &nouveau_fence_ops_uevent) {
251 struct nouveau_fence_chan *fctx = nouveau_fctx(fence);
252 struct nouveau_channel *chan;
253 unsigned long flags;
254
255 if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->base.flags))
256 return true;
257
258 spin_lock_irqsave(&fctx->lock, flags);
259 chan = rcu_dereference_protected(fence->channel, lockdep_is_held(&fctx->lock));
260 if (chan && nouveau_fence_update(chan, fctx))
261 nvif_event_block(&fctx->event);
262 spin_unlock_irqrestore(lock: &fctx->lock, flags);
263 }
264 return dma_fence_is_signaled(fence: &fence->base);
265}
266
267static long
268nouveau_fence_wait_legacy(struct dma_fence *f, bool intr, long wait)
269{
270 struct nouveau_fence *fence = from_fence(fence: f);
271 unsigned long sleep_time = NSEC_PER_MSEC / 1000;
272 unsigned long t = jiffies, timeout = t + wait;
273
274 while (!nouveau_fence_done(fence)) {
275 ktime_t kt;
276
277 t = jiffies;
278
279 if (wait != MAX_SCHEDULE_TIMEOUT && time_after_eq(t, timeout)) {
280 __set_current_state(TASK_RUNNING);
281 return 0;
282 }
283
284 __set_current_state(intr ? TASK_INTERRUPTIBLE :
285 TASK_UNINTERRUPTIBLE);
286
287 kt = sleep_time;
288 schedule_hrtimeout(expires: &kt, mode: HRTIMER_MODE_REL);
289 sleep_time *= 2;
290 if (sleep_time > NSEC_PER_MSEC)
291 sleep_time = NSEC_PER_MSEC;
292
293 if (intr && signal_pending(current))
294 return -ERESTARTSYS;
295 }
296
297 __set_current_state(TASK_RUNNING);
298
299 return timeout - t;
300}
301
302static int
303nouveau_fence_wait_busy(struct nouveau_fence *fence, bool intr)
304{
305 int ret = 0;
306
307 while (!nouveau_fence_done(fence)) {
308 if (time_after_eq(jiffies, fence->timeout)) {
309 ret = -EBUSY;
310 break;
311 }
312
313 __set_current_state(intr ?
314 TASK_INTERRUPTIBLE :
315 TASK_UNINTERRUPTIBLE);
316
317 if (intr && signal_pending(current)) {
318 ret = -ERESTARTSYS;
319 break;
320 }
321 }
322
323 __set_current_state(TASK_RUNNING);
324 return ret;
325}
326
327int
328nouveau_fence_wait(struct nouveau_fence *fence, bool lazy, bool intr)
329{
330 long ret;
331
332 if (!lazy)
333 return nouveau_fence_wait_busy(fence, intr);
334
335 ret = dma_fence_wait_timeout(&fence->base, intr, timeout: 15 * HZ);
336 if (ret < 0)
337 return ret;
338 else if (!ret)
339 return -EBUSY;
340 else
341 return 0;
342}
343
344int
345nouveau_fence_sync(struct nouveau_bo *nvbo, struct nouveau_channel *chan,
346 bool exclusive, bool intr)
347{
348 struct nouveau_fence_chan *fctx = chan->fence;
349 struct dma_resv *resv = nvbo->bo.base.resv;
350 int i, ret;
351
352 ret = dma_resv_reserve_fences(obj: resv, num_fences: 1);
353 if (ret)
354 return ret;
355
356 /* Waiting for the writes first causes performance regressions
357 * under some circumstances. So manually wait for the reads first.
358 */
359 for (i = 0; i < 2; ++i) {
360 struct dma_resv_iter cursor;
361 struct dma_fence *fence;
362
363 dma_resv_for_each_fence(&cursor, resv,
364 dma_resv_usage_rw(exclusive),
365 fence) {
366 enum dma_resv_usage usage;
367 struct nouveau_fence *f;
368
369 usage = dma_resv_iter_usage(cursor: &cursor);
370 if (i == 0 && usage == DMA_RESV_USAGE_WRITE)
371 continue;
372
373 f = nouveau_local_fence(fence, drm: chan->drm);
374 if (f) {
375 struct nouveau_channel *prev;
376 bool must_wait = true;
377
378 rcu_read_lock();
379 prev = rcu_dereference(f->channel);
380 if (prev && (prev == chan ||
381 fctx->sync(f, prev, chan) == 0))
382 must_wait = false;
383 rcu_read_unlock();
384 if (!must_wait)
385 continue;
386 }
387
388 ret = dma_fence_wait(fence, intr);
389 if (ret)
390 return ret;
391 }
392 }
393
394 return 0;
395}
396
397void
398nouveau_fence_unref(struct nouveau_fence **pfence)
399{
400 if (*pfence)
401 dma_fence_put(fence: &(*pfence)->base);
402 *pfence = NULL;
403}
404
405int
406nouveau_fence_create(struct nouveau_fence **pfence,
407 struct nouveau_channel *chan)
408{
409 struct nouveau_fence *fence;
410
411 if (unlikely(!chan->fence))
412 return -ENODEV;
413
414 fence = kzalloc(size: sizeof(*fence), GFP_KERNEL);
415 if (!fence)
416 return -ENOMEM;
417
418 fence->channel = chan;
419
420 *pfence = fence;
421 return 0;
422}
423
424int
425nouveau_fence_new(struct nouveau_fence **pfence,
426 struct nouveau_channel *chan)
427{
428 int ret = 0;
429
430 ret = nouveau_fence_create(pfence, chan);
431 if (ret)
432 return ret;
433
434 ret = nouveau_fence_emit(fence: *pfence);
435 if (ret)
436 nouveau_fence_unref(pfence);
437
438 return ret;
439}
440
441static const char *nouveau_fence_get_get_driver_name(struct dma_fence *fence)
442{
443 return "nouveau";
444}
445
446static const char *nouveau_fence_get_timeline_name(struct dma_fence *f)
447{
448 struct nouveau_fence *fence = from_fence(fence: f);
449 struct nouveau_fence_chan *fctx = nouveau_fctx(fence);
450
451 return !fctx->dead ? fctx->name : "dead channel";
452}
453
454/*
455 * In an ideal world, read would not assume the channel context is still alive.
456 * This function may be called from another device, running into free memory as a
457 * result. The drm node should still be there, so we can derive the index from
458 * the fence context.
459 */
460static bool nouveau_fence_is_signaled(struct dma_fence *f)
461{
462 struct nouveau_fence *fence = from_fence(fence: f);
463 struct nouveau_fence_chan *fctx = nouveau_fctx(fence);
464 struct nouveau_channel *chan;
465 bool ret = false;
466
467 rcu_read_lock();
468 chan = rcu_dereference(fence->channel);
469 if (chan)
470 ret = (int)(fctx->read(chan) - fence->base.seqno) >= 0;
471 rcu_read_unlock();
472
473 return ret;
474}
475
476static bool nouveau_fence_no_signaling(struct dma_fence *f)
477{
478 struct nouveau_fence *fence = from_fence(fence: f);
479
480 /*
481 * caller should have a reference on the fence,
482 * else fence could get freed here
483 */
484 WARN_ON(kref_read(&fence->base.refcount) <= 1);
485
486 /*
487 * This needs uevents to work correctly, but dma_fence_add_callback relies on
488 * being able to enable signaling. It will still get signaled eventually,
489 * just not right away.
490 */
491 if (nouveau_fence_is_signaled(f)) {
492 list_del(entry: &fence->head);
493
494 dma_fence_put(fence: &fence->base);
495 return false;
496 }
497
498 return true;
499}
500
501static void nouveau_fence_release(struct dma_fence *f)
502{
503 struct nouveau_fence *fence = from_fence(fence: f);
504 struct nouveau_fence_chan *fctx = nouveau_fctx(fence);
505
506 kref_put(kref: &fctx->fence_ref, release: nouveau_fence_context_put);
507 dma_fence_free(fence: &fence->base);
508}
509
510static const struct dma_fence_ops nouveau_fence_ops_legacy = {
511 .get_driver_name = nouveau_fence_get_get_driver_name,
512 .get_timeline_name = nouveau_fence_get_timeline_name,
513 .enable_signaling = nouveau_fence_no_signaling,
514 .signaled = nouveau_fence_is_signaled,
515 .wait = nouveau_fence_wait_legacy,
516 .release = nouveau_fence_release
517};
518
519static bool nouveau_fence_enable_signaling(struct dma_fence *f)
520{
521 struct nouveau_fence *fence = from_fence(fence: f);
522 struct nouveau_fence_chan *fctx = nouveau_fctx(fence);
523 bool ret;
524
525 if (!fctx->notify_ref++)
526 nvif_event_allow(&fctx->event);
527
528 ret = nouveau_fence_no_signaling(f);
529 if (ret)
530 set_bit(nr: DMA_FENCE_FLAG_USER_BITS, addr: &fence->base.flags);
531 else if (!--fctx->notify_ref)
532 nvif_event_block(&fctx->event);
533
534 return ret;
535}
536
537static const struct dma_fence_ops nouveau_fence_ops_uevent = {
538 .get_driver_name = nouveau_fence_get_get_driver_name,
539 .get_timeline_name = nouveau_fence_get_timeline_name,
540 .enable_signaling = nouveau_fence_enable_signaling,
541 .signaled = nouveau_fence_is_signaled,
542 .release = nouveau_fence_release
543};
544

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