kernel/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 *)nvif_client(chan->object);
 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->object, NULL,
 192                          nouveau_fence_wait_uevent_handler, false,
 193                          G82_CHANNEL_DMA_V0_NTFY_UEVENT,
 194                          &(struct nvif_notify_uevent_req) { },
 195                          sizeof(struct nvif_notify_uevent_req),
 196                          sizeof(struct nvif_notify_uevent_rep),
 197                          &fctx->notify);
 198
 199         WARN_ON(ret);
 200 }
 201
 202 struct nouveau_fence_work {
 203         struct work_struct work;
 204         struct fence_cb cb;
 205         void (*func)(void *);
 206         void *data;
 207 };
 208
 209 static void
 210 nouveau_fence_work_handler(struct work_struct *kwork)
 211 {
 212         struct nouveau_fence_work *work = container_of(kwork, typeof(*work), work);
 213         work->func(work->data);
 214         kfree(work);
 215 }
 216
 217 static void nouveau_fence_work_cb(struct fence *fence, struct fence_cb *cb)
 218 {
 219         struct nouveau_fence_work *work = container_of(cb, typeof(*work), cb);
 220
 221         schedule_work(&work->work);
 222 }
 223
 224 void
 225 nouveau_fence_work(struct fence *fence,
 226                    void (*func)(void *), void *data)
 227 {
 228         struct nouveau_fence_work *work;
 229
 230         if (fence_is_signaled(fence))
 231                 goto err;
 232
 233         work = kmalloc(sizeof(*work), GFP_KERNEL);
 234         if (!work) {
 235                 /*
 236                  * this might not be a nouveau fence any more,
 237                  * so force a lazy wait here
 238                  */
 239                 WARN_ON(nouveau_fence_wait((struct nouveau_fence *)fence,
 240                                            true, false));
 241                 goto err;
 242         }
 243
 244         INIT_WORK(&work->work, nouveau_fence_work_handler);
 245         work->func = func;
 246         work->data = data;
 247
 248         if (fence_add_callback(fence, &work->cb, nouveau_fence_work_cb) < 0)
 249                 goto err_free;
 250         return;
 251
 252 err_free:
 253         kfree(work);
 254 err:
 255         func(data);
 256 }
 257
 258 int
 259 nouveau_fence_emit(struct nouveau_fence *fence, struct nouveau_channel *chan)
 260 {
 261         struct nouveau_fence_chan *fctx = chan->fence;
 262         struct nouveau_fence_priv *priv = (void*)chan->drm->fence;
 263         int ret;
 264
 265         fence->channel  = chan;
 266         fence->timeout  = jiffies + (15 * HZ);
 267
 268         if (priv->uevent)
 269                 fence_init(&fence->base, &nouveau_fence_ops_uevent,
 270                            &fctx->lock, fctx->context, ++fctx->sequence);
 271         else
 272                 fence_init(&fence->base, &nouveau_fence_ops_legacy,
 273                            &fctx->lock, fctx->context, ++fctx->sequence);
 274         kref_get(&fctx->fence_ref);
 275
 276         trace_fence_emit(&fence->base);
 277         ret = fctx->emit(fence);
 278         if (!ret) {
 279                 fence_get(&fence->base);
 280                 spin_lock_irq(&fctx->lock);
 281
 282                 if (nouveau_fence_update(chan, fctx))
 283                         nvif_notify_put(&fctx->notify);
 284
 285                 list_add_tail(&fence->head, &fctx->pending);
 286                 spin_unlock_irq(&fctx->lock);
 287         }
 288
 289         return ret;
 290 }
 291
 292 bool
 293 nouveau_fence_done(struct nouveau_fence *fence)
 294 {
 295         if (fence->base.ops == &nouveau_fence_ops_legacy ||
 296             fence->base.ops == &nouveau_fence_ops_uevent) {
 297                 struct nouveau_fence_chan *fctx = nouveau_fctx(fence);
 298                 struct nouveau_channel *chan;
 299                 unsigned long flags;
 300
 301                 if (test_bit(FENCE_FLAG_SIGNALED_BIT, &fence->base.flags))
 302                         return true;
 303
 304                 spin_lock_irqsave(&fctx->lock, flags);
 305                 chan = rcu_dereference_protected(fence->channel, lockdep_is_held(&fctx->lock));
 306                 if (chan && nouveau_fence_update(chan, fctx))
 307                         nvif_notify_put(&fctx->notify);
 308                 spin_unlock_irqrestore(&fctx->lock, flags);
 309         }
 310         return fence_is_signaled(&fence->base);
 311 }
 312
 313 static long
 314 nouveau_fence_wait_legacy(struct fence *f, bool intr, long wait)
 315 {
 316         struct nouveau_fence *fence = from_fence(f);
 317         unsigned long sleep_time = NSEC_PER_MSEC / 1000;
 318         unsigned long t = jiffies, timeout = t + wait;
 319
 320         while (!nouveau_fence_done(fence)) {
 321                 ktime_t kt;
 322
 323                 t = jiffies;
 324
 325                 if (wait != MAX_SCHEDULE_TIMEOUT && time_after_eq(t, timeout)) {
 326                         __set_current_state(TASK_RUNNING);
 327                         return 0;
 328                 }
 329
 330                 __set_current_state(intr ? TASK_INTERRUPTIBLE :
 331                                            TASK_UNINTERRUPTIBLE);
 332
 333                 kt = ktime_set(0, sleep_time);
 334                 schedule_hrtimeout(&kt, HRTIMER_MODE_REL);
 335                 sleep_time *= 2;
 336                 if (sleep_time > NSEC_PER_MSEC)
 337                         sleep_time = NSEC_PER_MSEC;
 338
 339                 if (intr && signal_pending(current))
 340                         return -ERESTARTSYS;
 341         }
 342
 343         __set_current_state(TASK_RUNNING);
 344
 345         return timeout - t;
 346 }
 347
 348 static int
 349 nouveau_fence_wait_busy(struct nouveau_fence *fence, bool intr)
 350 {
 351         int ret = 0;
 352
 353         while (!nouveau_fence_done(fence)) {
 354                 if (time_after_eq(jiffies, fence->timeout)) {
 355                         ret = -EBUSY;
 356                         break;
 357                 }
 358
 359                 __set_current_state(intr ?
 360                                     TASK_INTERRUPTIBLE :
 361                                     TASK_UNINTERRUPTIBLE);
 362
 363                 if (intr && signal_pending(current)) {
 364                         ret = -ERESTARTSYS;
 365                         break;
 366                 }
 367         }
 368
 369         __set_current_state(TASK_RUNNING);
 370         return ret;
 371 }
 372
 373 int
 374 nouveau_fence_wait(struct nouveau_fence *fence, bool lazy, bool intr)
 375 {
 376         long ret;
 377
 378         if (!lazy)
 379                 return nouveau_fence_wait_busy(fence, intr);
 380
 381         ret = fence_wait_timeout(&fence->base, intr, 15 * HZ);
 382         if (ret < 0)
 383                 return ret;
 384         else if (!ret)
 385                 return -EBUSY;
 386         else
 387                 return 0;
 388 }
 389
 390 int
 391 nouveau_fence_sync(struct nouveau_bo *nvbo, struct nouveau_channel *chan, bool exclusive, bool intr)
 392 {
 393         struct nouveau_fence_chan *fctx = chan->fence;
 394         struct fence *fence;
 395         struct reservation_object *resv = nvbo->bo.resv;
 396         struct reservation_object_list *fobj;
 397         struct nouveau_fence *f;
 398         int ret = 0, i;
 399
 400         if (!exclusive) {
 401                 ret = reservation_object_reserve_shared(resv);
 402
 403                 if (ret)
 404                         return ret;
 405         }
 406
 407         fobj = reservation_object_get_list(resv);
 408         fence = reservation_object_get_excl(resv);
 409
 410         if (fence && (!exclusive || !fobj || !fobj->shared_count)) {
 411                 struct nouveau_channel *prev = NULL;
 412                 bool must_wait = true;
 413
 414                 f = nouveau_local_fence(fence, chan->drm);
 415                 if (f) {
 416                         rcu_read_lock();
 417                         prev = rcu_dereference(f->channel);
 418                         if (prev && (prev == chan || fctx->sync(f, prev, chan) == 0))
 419                                 must_wait = false;
 420                         rcu_read_unlock();
 421                 }
 422
 423                 if (must_wait)
 424                         ret = fence_wait(fence, intr);
 425
 426                 return ret;
 427         }
 428
 429         if (!exclusive || !fobj)
 430                 return ret;
 431
 432         for (i = 0; i < fobj->shared_count && !ret; ++i) {
 433                 struct nouveau_channel *prev = NULL;
 434                 bool must_wait = true;
 435
 436                 fence = rcu_dereference_protected(fobj->shared[i],
 437                                                 reservation_object_held(resv));
 438
 439                 f = nouveau_local_fence(fence, chan->drm);
 440                 if (f) {
 441                         rcu_read_lock();
 442                         prev = rcu_dereference(f->channel);
 443                         if (prev && (prev == chan || fctx->sync(f, prev, chan) == 0))
 444                                 must_wait = false;
 445                         rcu_read_unlock();
 446                 }
 447
 448                 if (must_wait)
 449                         ret = fence_wait(fence, intr);
 450         }
 451
 452         return ret;
 453 }
 454
 455 void
 456 nouveau_fence_unref(struct nouveau_fence **pfence)
 457 {
 458         if (*pfence)
 459                 fence_put(&(*pfence)->base);
 460         *pfence = NULL;
 461 }
 462
 463 int
 464 nouveau_fence_new(struct nouveau_channel *chan, bool sysmem,
 465                   struct nouveau_fence **pfence)
 466 {
 467         struct nouveau_fence *fence;
 468         int ret = 0;
 469
 470         if (unlikely(!chan->fence))
 471                 return -ENODEV;
 472
 473         fence = kzalloc(sizeof(*fence), GFP_KERNEL);
 474         if (!fence)
 475                 return -ENOMEM;
 476
 477         fence->sysmem = sysmem;
 478
 479         ret = nouveau_fence_emit(fence, chan);
 480         if (ret)
 481                 nouveau_fence_unref(&fence);
 482
 483         *pfence = fence;
 484         return ret;
 485 }
 486
 487 static const char *nouveau_fence_get_get_driver_name(struct fence *fence)
 488 {
 489         return "nouveau";
 490 }
 491
 492 static const char *nouveau_fence_get_timeline_name(struct fence *f)
 493 {
 494         struct nouveau_fence *fence = from_fence(f);
 495         struct nouveau_fence_chan *fctx = nouveau_fctx(fence);
 496
 497         return !fctx->dead ? fctx->name : "dead channel";
 498 }
 499
 500 /*
 501  * In an ideal world, read would not assume the channel context is still alive.
 502  * This function may be called from another device, running into free memory as a
 503  * result. The drm node should still be there, so we can derive the index from
 504  * the fence context.
 505  */
 506 static bool nouveau_fence_is_signaled(struct fence *f)
 507 {
 508         struct nouveau_fence *fence = from_fence(f);
 509         struct nouveau_fence_chan *fctx = nouveau_fctx(fence);
 510         struct nouveau_channel *chan;
 511         bool ret = false;
 512
 513         rcu_read_lock();
 514         chan = rcu_dereference(fence->channel);
 515         if (chan)
 516                 ret = (int)(fctx->read(chan) - fence->base.seqno) >= 0;
 517         rcu_read_unlock();
 518
 519         return ret;
 520 }
 521
 522 static bool nouveau_fence_no_signaling(struct fence *f)
 523 {
 524         struct nouveau_fence *fence = from_fence(f);
 525
 526         /*
 527          * caller should have a reference on the fence,
 528          * else fence could get freed here
 529          */
 530         WARN_ON(atomic_read(&fence->base.refcount.refcount) <= 1);
 531
 532         /*
 533          * This needs uevents to work correctly, but fence_add_callback relies on
 534          * being able to enable signaling. It will still get signaled eventually,
 535          * just not right away.
 536          */
 537         if (nouveau_fence_is_signaled(f)) {
 538                 list_del(&fence->head);
 539
 540                 fence_put(&fence->base);
 541                 return false;
 542         }
 543
 544         return true;
 545 }
 546
 547 static void nouveau_fence_release(struct fence *f)
 548 {
 549         struct nouveau_fence *fence = from_fence(f);
 550         struct nouveau_fence_chan *fctx = nouveau_fctx(fence);
 551
 552         kref_put(&fctx->fence_ref, nouveau_fence_context_put);
 553         fence_free(&fence->base);
 554 }
 555
 556 static const struct fence_ops nouveau_fence_ops_legacy = {
 557         .get_driver_name = nouveau_fence_get_get_driver_name,
 558         .get_timeline_name = nouveau_fence_get_timeline_name,
 559         .enable_signaling = nouveau_fence_no_signaling,
 560         .signaled = nouveau_fence_is_signaled,
 561         .wait = nouveau_fence_wait_legacy,
 562         .release = nouveau_fence_release
 563 };
 564
 565 static bool nouveau_fence_enable_signaling(struct fence *f)
 566 {
 567         struct nouveau_fence *fence = from_fence(f);
 568         struct nouveau_fence_chan *fctx = nouveau_fctx(fence);
 569         bool ret;
 570
 571         if (!fctx->notify_ref++)
 572                 nvif_notify_get(&fctx->notify);
 573
 574         ret = nouveau_fence_no_signaling(f);
 575         if (ret)
 576                 set_bit(FENCE_FLAG_USER_BITS, &fence->base.flags);
 577         else if (!--fctx->notify_ref)
 578                 nvif_notify_put(&fctx->notify);
 579
 580         return ret;
 581 }
 582
 583 static const struct fence_ops nouveau_fence_ops_uevent = {
 584         .get_driver_name = nouveau_fence_get_get_driver_name,
 585         .get_timeline_name = nouveau_fence_get_timeline_name,
 586         .enable_signaling = nouveau_fence_enable_signaling,
 587         .signaled = nouveau_fence_is_signaled,
 588         .wait = fence_default_wait,
 589         .release = NULL
 590 };