drivers/gpu/drm/nouveau/nouveau_fence.c

   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 <drm/drmP.h>
  28
  29 #include <linux/ktime.h>
  30 #include <linux/hrtimer.h>
  31 #include <trace/events/fence.h>
  32
  33 #include <nvif/notify.h>
  34 #include <nvif/event.h>
  35
  36 #include "nouveau_drm.h"
  37 #include "nouveau_dma.h"
  38 #include "nouveau_fence.h"
  39
  40 static const struct fence_ops nouveau_fence_ops_uevent;
  41 static const struct fence_ops nouveau_fence_ops_legacy;
  42
  43 static inline struct nouveau_fence *
  44 from_fence(struct fence *fence)
  45 {
  46         return container_of(fence, struct nouveau_fence, base);
  47 }
  48
  49 static inline struct nouveau_fence_chan *
  50 nouveau_fctx(struct nouveau_fence *fence)
  51 {
  52         return container_of(fence->base.lock, struct nouveau_fence_chan, lock);
  53 }
  54
  55 static int
  56 nouveau_fence_signal(struct nouveau_fence *fence)
  57 {
  58         int drop = 0;
  59
  60         fence_signal_locked(&fence->base);
  61         list_del(&fence->head);
  62         rcu_assign_pointer(fence->channel, NULL);
  63
  64         if (test_bit(FENCE_FLAG_USER_BITS, &fence->base.flags)) {
  65                 struct nouveau_fence_chan *fctx = nouveau_fctx(fence);
  66
  67                 if (!--fctx->notify_ref)
  68                         drop = 1;
  69         }
  70
  71         fence_put(&fence->base);
  72         return drop;
  73 }
  74
  75 static struct nouveau_fence *
  76 nouveau_local_fence(struct fence *fence, struct nouveau_drm *drm) {
  77         struct nouveau_fence_priv *priv = (void*)drm->fence;
  78
  79         if (fence->ops != &nouveau_fence_ops_legacy &&
  80             fence->ops != &nouveau_fence_ops_uevent)
  81                 return NULL;
  82
  83         if (fence->context < priv->context_base ||
  84             fence->context >= priv->context_base + priv->contexts)
  85                 return NULL;
  86
  87         return from_fence(fence);
  88 }
  89
  90 void
  91 nouveau_fence_context_del(struct nouveau_fence_chan *fctx)
  92 {
  93         struct nouveau_fence *fence;
  94
  95         spin_lock_irq(&fctx->lock);
  96         while (!list_empty(&fctx->pending)) {
  97                 fence = list_entry(fctx->pending.next, typeof(*fence), head);
  98
  99                 if (nouveau_fence_signal(fence))
 100                         nvif_notify_put(&fctx->notify);
 101         }
 102         spin_unlock_irq(&fctx->lock);
 103
 104         nvif_notify_fini(&fctx->notify);
 105         fctx->dead = 1;
 106
 107         /*
 108          * Ensure that all accesses to fence->channel complete before freeing
 109          * the channel.
 110          */
 111         synchronize_rcu();
 112 }
 113
 114 static void
 115 nouveau_fence_context_put(struct kref *fence_ref)
 116 {
 117         kfree(container_of(fence_ref, struct nouveau_fence_chan, fence_ref));
 118 }
 119
 120 void
 121 nouveau_fence_context_free(struct nouveau_fence_chan *fctx)
 122 {
 123         kref_put(&fctx->fence_ref, nouveau_fence_context_put);
 124 }
 125
 126 static int
 127 nouveau_fence_update(struct nouveau_channel *chan, struct nouveau_fence_chan *fctx)
 128 {
 129         struct nouveau_fence *fence;
 130         int drop = 0;
 131         u32 seq = fctx->read(chan);
 132
 133         while (!list_empty(&fctx->pending)) {
 134                 fence = list_entry(fctx->pending.next, typeof(*fence), head);
 135
 136                 if ((int)(seq - fence->base.seqno) < 0)
 137                         break;
 138
 139                 drop |= nouveau_fence_signal(fence);
 140         }
 141
 142         return drop;
 143 }
 144
 145 static int
 146 nouveau_fence_wait_uevent_handler(struct nvif_notify *notify)
 147 {
 148         struct nouveau_fence_chan *fctx =
 149                 container_of(notify, typeof(*fctx), notify);
 150         unsigned long flags;
 151         int ret = NVIF_NOTIFY_KEEP;
 152
 153         spin_lock_irqsave(&fctx->lock, flags);
 154         if (!list_empty(&fctx->pending)) {
 155                 struct nouveau_fence *fence;
 156                 struct nouveau_channel *chan;
 157
 158                 fence = list_entry(fctx->pending.next, typeof(*fence), head);
 159                 chan = rcu_dereference_protected(fence->channel, lockdep_is_held(&fctx->lock));
 160                 if (nouveau_fence_update(fence->channel, fctx))
 161                         ret = NVIF_NOTIFY_DROP;
 162         }
 163         spin_unlock_irqrestore(&fctx->lock, flags);
 164
 165         return ret;
 166 }
 167
 168 void
 169 nouveau_fence_context_new(struct nouveau_channel *chan, struct nouveau_fence_chan *fctx)
 170 {
 171         struct nouveau_fence_priv *priv = (void*)chan->drm->fence;
 172         struct nouveau_cli *cli = (void *)chan->user.client;
 173         int ret;
 174
 175         INIT_LIST_HEAD(&fctx->flip);
 176         INIT_LIST_HEAD(&fctx->pending);
 177         spin_lock_init(&fctx->lock);
 178         fctx->context = priv->context_base + chan->chid;
 179
 180         if (chan == chan->drm->cechan)
 181                 strcpy(fctx->name, "copy engine channel");
 182         else if (chan == chan->drm->channel)
 183                 strcpy(fctx->name, "generic kernel channel");
 184         else
 185                 strcpy(fctx->name, nvxx_client(&cli->base)->name);
 186
 187         kref_init(&fctx->fence_ref);
 188         if (!priv->uevent)
 189                 return;
 190
 191         ret = nvif_notify_init(&chan->user, nouveau_fence_wait_uevent_handler,
 192                                false, G82_CHANNEL_DMA_V0_NTFY_UEVENT,
 193                                &(struct nvif_notify_uevent_req) { },
 194                                sizeof(struct nvif_notify_uevent_req),
 195                                sizeof(struct nvif_notify_uevent_rep),
 196                                &fctx->notify);
 197
 198         WARN_ON(ret);
 199 }
 200
 201 struct nouveau_fence_work {
 202         struct work_struct work;
 203         struct fence_cb cb;
 204         void (*func)(void *);
 205         void *data;
 206 };
 207
 208 static void
 209 nouveau_fence_work_handler(struct work_struct *kwork)
 210 {
 211         struct nouveau_fence_work *work = container_of(kwork, typeof(*work), work);
 212         work->func(work->data);
 213         kfree(work);
 214 }
 215
 216 static void nouveau_fence_work_cb(struct fence *fence, struct fence_cb *cb)
 217 {
 218         struct nouveau_fence_work *work = container_of(cb, typeof(*work), cb);
 219
 220         schedule_work(&work->work);
 221 }
 222
 223 void
 224 nouveau_fence_work(struct fence *fence,
 225                    void (*func)(void *), void *data)
 226 {
 227         struct nouveau_fence_work *work;
 228
 229         if (fence_is_signaled(fence))
 230                 goto err;
 231
 232         work = kmalloc(sizeof(*work), GFP_KERNEL);
 233         if (!work) {
 234                 /*
 235                  * this might not be a nouveau fence any more,
 236                  * so force a lazy wait here
 237                  */
 238                 WARN_ON(nouveau_fence_wait((struct nouveau_fence *)fence,
 239                                            true, false));
 240                 goto err;
 241         }
 242
 243         INIT_WORK(&work->work, nouveau_fence_work_handler);
 244         work->func = func;
 245         work->data = data;
 246
 247         if (fence_add_callback(fence, &work->cb, nouveau_fence_work_cb) < 0)
 248                 goto err_free;
 249         return;
 250
 251 err_free:
 252         kfree(work);
 253 err:
 254         func(data);
 255 }
 256
 257 int
 258 nouveau_fence_emit(struct nouveau_fence *fence, struct nouveau_channel *chan)
 259 {
 260         struct nouveau_fence_chan *fctx = chan->fence;
 261         struct nouveau_fence_priv *priv = (void*)chan->drm->fence;
 262         int ret;
 263
 264         fence->channel  = chan;
 265         fence->timeout  = jiffies + (15 * HZ);
 266
 267         if (priv->uevent)
 268                 fence_init(&fence->base, &nouveau_fence_ops_uevent,
 269                            &fctx->lock, fctx->context, ++fctx->sequence);
 270         else
 271                 fence_init(&fence->base, &nouveau_fence_ops_legacy,
 272                            &fctx->lock, fctx->context, ++fctx->sequence);
 273         kref_get(&fctx->fence_ref);
 274
 275         trace_fence_emit(&fence->base);
 276         ret = fctx->emit(fence);
 277         if (!ret) {
 278                 fence_get(&fence->base);
 279                 spin_lock_irq(&fctx->lock);
 280
 281                 if (nouveau_fence_update(chan, fctx))
 282                         nvif_notify_put(&fctx->notify);
 283
 284                 list_add_tail(&fence->head, &fctx->pending);
 285                 spin_unlock_irq(&fctx->lock);
 286         }
 287
 288         return ret;
 289 }
 290
 291 bool
 292 nouveau_fence_done(struct nouveau_fence *fence)
 293 {
 294         if (fence->base.ops == &nouveau_fence_ops_legacy ||
 295             fence->base.ops == &nouveau_fence_ops_uevent) {
 296                 struct nouveau_fence_chan *fctx = nouveau_fctx(fence);
 297                 struct nouveau_channel *chan;
 298                 unsigned long flags;
 299
 300                 if (test_bit(FENCE_FLAG_SIGNALED_BIT, &fence->base.flags))
 301                         return true;
 302
 303                 spin_lock_irqsave(&fctx->lock, flags);
 304                 chan = rcu_dereference_protected(fence->channel, lockdep_is_held(&fctx->lock));
 305                 if (chan && nouveau_fence_update(chan, fctx))
 306                         nvif_notify_put(&fctx->notify);
 307                 spin_unlock_irqrestore(&fctx->lock, flags);
 308         }
 309         return fence_is_signaled(&fence->base);
 310 }
 311
 312 static long
 313 nouveau_fence_wait_legacy(struct fence *f, bool intr, long wait)
 314 {
 315         struct nouveau_fence *fence = from_fence(f);
 316         unsigned long sleep_time = NSEC_PER_MSEC / 1000;
 317         unsigned long t = jiffies, timeout = t + wait;
 318
 319         while (!nouveau_fence_done(fence)) {
 320                 ktime_t kt;
 321
 322                 t = jiffies;
 323
 324                 if (wait != MAX_SCHEDULE_TIMEOUT && time_after_eq(t, timeout)) {
 325                         __set_current_state(TASK_RUNNING);
 326                         return 0;
 327                 }
 328
 329                 __set_current_state(intr ? TASK_INTERRUPTIBLE :
 330                                            TASK_UNINTERRUPTIBLE);
 331
 332                 kt = ktime_set(0, sleep_time);
 333                 schedule_hrtimeout(&kt, HRTIMER_MODE_REL);
 334                 sleep_time *= 2;
 335                 if (sleep_time > NSEC_PER_MSEC)
 336                         sleep_time = NSEC_PER_MSEC;
 337
 338                 if (intr && signal_pending(current))
 339                         return -ERESTARTSYS;
 340         }
 341
 342         __set_current_state(TASK_RUNNING);
 343
 344         return timeout - t;
 345 }
 346
 347 static int
 348 nouveau_fence_wait_busy(struct nouveau_fence *fence, bool intr)
 349 {
 350         int ret = 0;
 351
 352         while (!nouveau_fence_done(fence)) {
 353                 if (time_after_eq(jiffies, fence->timeout)) {
 354                         ret = -EBUSY;
 355                         break;
 356                 }
 357
 358                 __set_current_state(intr ?
 359                                     TASK_INTERRUPTIBLE :
 360                                     TASK_UNINTERRUPTIBLE);
 361
 362                 if (intr && signal_pending(current)) {
 363                         ret = -ERESTARTSYS;
 364                         break;
 365                 }
 366         }
 367
 368         __set_current_state(TASK_RUNNING);
 369         return ret;
 370 }
 371
 372 int
 373 nouveau_fence_wait(struct nouveau_fence *fence, bool lazy, bool intr)
 374 {
 375         long ret;
 376
 377         if (!lazy)
 378                 return nouveau_fence_wait_busy(fence, intr);
 379
 380         ret = fence_wait_timeout(&fence->base, intr, 15 * HZ);
 381         if (ret < 0)
 382                 return ret;
 383         else if (!ret)
 384                 return -EBUSY;
 385         else
 386                 return 0;
 387 }
 388
 389 int
 390 nouveau_fence_sync(struct nouveau_bo *nvbo, struct nouveau_channel *chan, bool exclusive, bool intr)
 391 {
 392         struct nouveau_fence_chan *fctx = chan->fence;
 393         struct fence *fence;
 394         struct reservation_object *resv = nvbo->bo.resv;
 395         struct reservation_object_list *fobj;
 396         struct nouveau_fence *f;
 397         int ret = 0, i;
 398
 399         if (!exclusive) {
 400                 ret = reservation_object_reserve_shared(resv);
 401
 402                 if (ret)
 403                         return ret;
 404         }
 405
 406         fobj = reservation_object_get_list(resv);
 407         fence = reservation_object_get_excl(resv);
 408
 409         if (fence && (!exclusive || !fobj || !fobj->shared_count)) {
 410                 struct nouveau_channel *prev = NULL;
 411                 bool must_wait = true;
 412
 413                 f = nouveau_local_fence(fence, chan->drm);
 414                 if (f) {
 415                         rcu_read_lock();
 416                         prev = rcu_dereference(f->channel);
 417                         if (prev && (prev == chan || fctx->sync(f, prev, chan) == 0))
 418                                 must_wait = false;
 419                         rcu_read_unlock();
 420                 }
 421
 422                 if (must_wait)
 423                         ret = fence_wait(fence, intr);
 424
 425                 return ret;
 426         }
 427
 428         if (!exclusive || !fobj)
 429                 return ret;
 430
 431         for (i = 0; i < fobj->shared_count && !ret; ++i) {
 432                 struct nouveau_channel *prev = NULL;
 433                 bool must_wait = true;
 434
 435                 fence = rcu_dereference_protected(fobj->shared[i],
 436                                                 reservation_object_held(resv));
 437
 438                 f = nouveau_local_fence(fence, chan->drm);
 439                 if (f) {
 440                         rcu_read_lock();
 441                         prev = rcu_dereference(f->channel);
 442                         if (prev && (prev == chan || fctx->sync(f, prev, chan) == 0))
 443                                 must_wait = false;
 444                         rcu_read_unlock();
 445                 }
 446
 447                 if (must_wait)
 448                         ret = fence_wait(fence, intr);
 449         }
 450
 451         return ret;
 452 }
 453
 454 void
 455 nouveau_fence_unref(struct nouveau_fence **pfence)
 456 {
 457         if (*pfence)
 458                 fence_put(&(*pfence)->base);
 459         *pfence = NULL;
 460 }
 461
 462 int
 463 nouveau_fence_new(struct nouveau_channel *chan, bool sysmem,
 464                   struct nouveau_fence **pfence)
 465 {
 466         struct nouveau_fence *fence;
 467         int ret = 0;
 468
 469         if (unlikely(!chan->fence))
 470                 return -ENODEV;
 471
 472         fence = kzalloc(sizeof(*fence), GFP_KERNEL);
 473         if (!fence)
 474                 return -ENOMEM;
 475
 476         fence->sysmem = sysmem;
 477
 478         ret = nouveau_fence_emit(fence, chan);
 479         if (ret)
 480                 nouveau_fence_unref(&fence);
 481
 482         *pfence = fence;
 483         return ret;
 484 }
 485
 486 static const char *nouveau_fence_get_get_driver_name(struct fence *fence)
 487 {
 488         return "nouveau";
 489 }
 490
 491 static const char *nouveau_fence_get_timeline_name(struct fence *f)
 492 {
 493         struct nouveau_fence *fence = from_fence(f);
 494         struct nouveau_fence_chan *fctx = nouveau_fctx(fence);
 495
 496         return !fctx->dead ? fctx->name : "dead channel";
 497 }
 498
 499 /*
 500  * In an ideal world, read would not assume the channel context is still alive.
 501  * This function may be called from another device, running into free memory as a
 502  * result. The drm node should still be there, so we can derive the index from
 503  * the fence context.
 504  */
 505 static bool nouveau_fence_is_signaled(struct fence *f)
 506 {
 507         struct nouveau_fence *fence = from_fence(f);
 508         struct nouveau_fence_chan *fctx = nouveau_fctx(fence);
 509         struct nouveau_channel *chan;
 510         bool ret = false;
 511
 512         rcu_read_lock();
 513         chan = rcu_dereference(fence->channel);
 514         if (chan)
 515                 ret = (int)(fctx->read(chan) - fence->base.seqno) >= 0;
 516         rcu_read_unlock();
 517
 518         return ret;
 519 }
 520
 521 static bool nouveau_fence_no_signaling(struct fence *f)
 522 {
 523         struct nouveau_fence *fence = from_fence(f);
 524
 525         /*
 526          * caller should have a reference on the fence,
 527          * else fence could get freed here
 528          */
 529         WARN_ON(atomic_read(&fence->base.refcount.refcount) <= 1);
 530
 531         /*
 532          * This needs uevents to work correctly, but fence_add_callback relies on
 533          * being able to enable signaling. It will still get signaled eventually,
 534          * just not right away.
 535          */
 536         if (nouveau_fence_is_signaled(f)) {
 537                 list_del(&fence->head);
 538
 539                 fence_put(&fence->base);
 540                 return false;
 541         }
 542
 543         return true;
 544 }
 545
 546 static void nouveau_fence_release(struct fence *f)
 547 {
 548         struct nouveau_fence *fence = from_fence(f);
 549         struct nouveau_fence_chan *fctx = nouveau_fctx(fence);
 550
 551         kref_put(&fctx->fence_ref, nouveau_fence_context_put);
 552         fence_free(&fence->base);
 553 }
 554
 555 static const struct fence_ops nouveau_fence_ops_legacy = {
 556         .get_driver_name = nouveau_fence_get_get_driver_name,
 557         .get_timeline_name = nouveau_fence_get_timeline_name,
 558         .enable_signaling = nouveau_fence_no_signaling,
 559         .signaled = nouveau_fence_is_signaled,
 560         .wait = nouveau_fence_wait_legacy,
 561         .release = nouveau_fence_release
 562 };
 563
 564 static bool nouveau_fence_enable_signaling(struct fence *f)
 565 {
 566         struct nouveau_fence *fence = from_fence(f);
 567         struct nouveau_fence_chan *fctx = nouveau_fctx(fence);
 568         bool ret;
 569
 570         if (!fctx->notify_ref++)
 571                 nvif_notify_get(&fctx->notify);
 572
 573         ret = nouveau_fence_no_signaling(f);
 574         if (ret)
 575                 set_bit(FENCE_FLAG_USER_BITS, &fence->base.flags);
 576         else if (!--fctx->notify_ref)
 577                 nvif_notify_put(&fctx->notify);
 578
 579         return ret;
 580 }
 581
 582 static const struct fence_ops nouveau_fence_ops_uevent = {
 583         .get_driver_name = nouveau_fence_get_get_driver_name,
 584         .get_timeline_name = nouveau_fence_get_timeline_name,
 585         .enable_signaling = nouveau_fence_enable_signaling,
 586         .signaled = nouveau_fence_is_signaled,
 587         .wait = fence_default_wait,
 588         .release = NULL
 589 };