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 <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/cl826e.h>
  33 #include <nvif/notify.h>
  34 #include <nvif/event.h>
  35
  36 #include "nouveau_drv.h"
  37 #include "nouveau_dma.h"
  38 #include "nouveau_fence.h"
  39
  40 static const struct dma_fence_ops nouveau_fence_ops_uevent;
  41 static const struct dma_fence_ops nouveau_fence_ops_legacy;
  42
  43 static inline struct nouveau_fence *
  44 from_fence(struct dma_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         dma_fence_signal_locked(&fence->base);
  61         list_del(&fence->head);
  62         rcu_assign_pointer(fence->channel, NULL);
  63
  64         if (test_bit(DMA_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         dma_fence_put(&fence->base);
  72         return drop;
  73 }
  74
  75 static struct nouveau_fence *
  76 nouveau_local_fence(struct dma_fence *fence, struct nouveau_drm *drm)
  77 {
  78         if (fence->ops != &nouveau_fence_ops_legacy &&
  79             fence->ops != &nouveau_fence_ops_uevent)
  80                 return NULL;
  81
  82         if (fence->context < drm->chan.context_base ||
  83             fence->context >= drm->chan.context_base + drm->chan.nr)
  84                 return NULL;
  85
  86         return from_fence(fence);
  87 }
  88
  89 void
  90 nouveau_fence_context_del(struct nouveau_fence_chan *fctx)
  91 {
  92         struct nouveau_fence *fence;
  93
  94         spin_lock_irq(&fctx->lock);
  95         while (!list_empty(&fctx->pending)) {
  96                 fence = list_entry(fctx->pending.next, typeof(*fence), head);
  97
  98                 if (nouveau_fence_signal(fence))
  99                         nvif_notify_put(&fctx->notify);
 100         }
 101         spin_unlock_irq(&fctx->lock);
 102
 103         nvif_notify_fini(&fctx->notify);
 104         fctx->dead = 1;
 105
 106         /*
 107          * Ensure that all accesses to fence->channel complete before freeing
 108          * the channel.
 109          */
 110         synchronize_rcu();
 111 }
 112
 113 static void
 114 nouveau_fence_context_put(struct kref *fence_ref)
 115 {
 116         kfree(container_of(fence_ref, struct nouveau_fence_chan, fence_ref));
 117 }
 118
 119 void
 120 nouveau_fence_context_free(struct nouveau_fence_chan *fctx)
 121 {
 122         kref_put(&fctx->fence_ref, nouveau_fence_context_put);
 123 }
 124
 125 static int
 126 nouveau_fence_update(struct nouveau_channel *chan, struct nouveau_fence_chan *fctx)
 127 {
 128         struct nouveau_fence *fence;
 129         int drop = 0;
 130         u32 seq = fctx->read(chan);
 131
 132         while (!list_empty(&fctx->pending)) {
 133                 fence = list_entry(fctx->pending.next, typeof(*fence), head);
 134
 135                 if ((int)(seq - fence->base.seqno) < 0)
 136                         break;
 137
 138                 drop |= nouveau_fence_signal(fence);
 139         }
 140
 141         return drop;
 142 }
 143
 144 static int
 145 nouveau_fence_wait_uevent_handler(struct nvif_notify *notify)
 146 {
 147         struct nouveau_fence_chan *fctx =
 148                 container_of(notify, typeof(*fctx), notify);
 149         unsigned long flags;
 150         int ret = NVIF_NOTIFY_KEEP;
 151
 152         spin_lock_irqsave(&fctx->lock, flags);
 153         if (!list_empty(&fctx->pending)) {
 154                 struct nouveau_fence *fence;
 155                 struct nouveau_channel *chan;
 156
 157                 fence = list_entry(fctx->pending.next, typeof(*fence), head);
 158                 chan = rcu_dereference_protected(fence->channel, lockdep_is_held(&fctx->lock));
 159                 if (nouveau_fence_update(fence->channel, fctx))
 160                         ret = NVIF_NOTIFY_DROP;
 161         }
 162         spin_unlock_irqrestore(&fctx->lock, flags);
 163
 164         return ret;
 165 }
 166
 167 void
 168 nouveau_fence_context_new(struct nouveau_channel *chan, struct nouveau_fence_chan *fctx)
 169 {
 170         struct nouveau_fence_priv *priv = (void*)chan->drm->fence;
 171         struct nouveau_cli *cli = (void *)chan->user.client;
 172         int ret;
 173
 174         INIT_LIST_HEAD(&fctx->flip);
 175         INIT_LIST_HEAD(&fctx->pending);
 176         spin_lock_init(&fctx->lock);
 177         fctx->context = chan->drm->chan.context_base + chan->chid;
 178
 179         if (chan == chan->drm->cechan)
 180                 strcpy(fctx->name, "copy engine channel");
 181         else if (chan == chan->drm->channel)
 182                 strcpy(fctx->name, "generic kernel channel");
 183         else
 184                 strcpy(fctx->name, nvxx_client(&cli->base)->name);
 185
 186         kref_init(&fctx->fence_ref);
 187         if (!priv->uevent)
 188                 return;
 189
 190         ret = nvif_notify_init(&chan->user, nouveau_fence_wait_uevent_handler,
 191                                false, NV826E_V0_NTFY_NON_STALL_INTERRUPT,
 192                                &(struct nvif_notify_uevent_req) { },
 193                                sizeof(struct nvif_notify_uevent_req),
 194                                sizeof(struct nvif_notify_uevent_rep),
 195                                &fctx->notify);
 196
 197         WARN_ON(ret);
 198 }
 199
 200 int
 201 nouveau_fence_emit(struct nouveau_fence *fence, struct nouveau_channel *chan)
 202 {
 203         struct nouveau_fence_chan *fctx = chan->fence;
 204         struct nouveau_fence_priv *priv = (void*)chan->drm->fence;
 205         int ret;
 206
 207         fence->channel  = chan;
 208         fence->timeout  = jiffies + (15 * HZ);
 209
 210         if (priv->uevent)
 211                 dma_fence_init(&fence->base, &nouveau_fence_ops_uevent,
 212                                &fctx->lock, fctx->context, ++fctx->sequence);
 213         else
 214                 dma_fence_init(&fence->base, &nouveau_fence_ops_legacy,
 215                                &fctx->lock, fctx->context, ++fctx->sequence);
 216         kref_get(&fctx->fence_ref);
 217
 218         trace_dma_fence_emit(&fence->base);
 219         ret = fctx->emit(fence);
 220         if (!ret) {
 221                 dma_fence_get(&fence->base);
 222                 spin_lock_irq(&fctx->lock);
 223
 224                 if (nouveau_fence_update(chan, fctx))
 225                         nvif_notify_put(&fctx->notify);
 226
 227                 list_add_tail(&fence->head, &fctx->pending);
 228                 spin_unlock_irq(&fctx->lock);
 229         }
 230
 231         return ret;
 232 }
 233
 234 bool
 235 nouveau_fence_done(struct nouveau_fence *fence)
 236 {
 237         if (fence->base.ops == &nouveau_fence_ops_legacy ||
 238             fence->base.ops == &nouveau_fence_ops_uevent) {
 239                 struct nouveau_fence_chan *fctx = nouveau_fctx(fence);
 240                 struct nouveau_channel *chan;
 241                 unsigned long flags;
 242
 243                 if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->base.flags))
 244                         return true;
 245
 246                 spin_lock_irqsave(&fctx->lock, flags);
 247                 chan = rcu_dereference_protected(fence->channel, lockdep_is_held(&fctx->lock));
 248                 if (chan && nouveau_fence_update(chan, fctx))
 249                         nvif_notify_put(&fctx->notify);
 250                 spin_unlock_irqrestore(&fctx->lock, flags);
 251         }
 252         return dma_fence_is_signaled(&fence->base);
 253 }
 254
 255 static long
 256 nouveau_fence_wait_legacy(struct dma_fence *f, bool intr, long wait)
 257 {
 258         struct nouveau_fence *fence = from_fence(f);
 259         unsigned long sleep_time = NSEC_PER_MSEC / 1000;
 260         unsigned long t = jiffies, timeout = t + wait;
 261
 262         while (!nouveau_fence_done(fence)) {
 263                 ktime_t kt;
 264
 265                 t = jiffies;
 266
 267                 if (wait != MAX_SCHEDULE_TIMEOUT && time_after_eq(t, timeout)) {
 268                         __set_current_state(TASK_RUNNING);
 269                         return 0;
 270                 }
 271
 272                 __set_current_state(intr ? TASK_INTERRUPTIBLE :
 273                                            TASK_UNINTERRUPTIBLE);
 274
 275                 kt = sleep_time;
 276                 schedule_hrtimeout(&kt, HRTIMER_MODE_REL);
 277                 sleep_time *= 2;
 278                 if (sleep_time > NSEC_PER_MSEC)
 279                         sleep_time = NSEC_PER_MSEC;
 280
 281                 if (intr && signal_pending(current))
 282                         return -ERESTARTSYS;
 283         }
 284
 285         __set_current_state(TASK_RUNNING);
 286
 287         return timeout - t;
 288 }
 289
 290 static int
 291 nouveau_fence_wait_busy(struct nouveau_fence *fence, bool intr)
 292 {
 293         int ret = 0;
 294
 295         while (!nouveau_fence_done(fence)) {
 296                 if (time_after_eq(jiffies, fence->timeout)) {
 297                         ret = -EBUSY;
 298                         break;
 299                 }
 300
 301                 __set_current_state(intr ?
 302                                     TASK_INTERRUPTIBLE :
 303                                     TASK_UNINTERRUPTIBLE);
 304
 305                 if (intr && signal_pending(current)) {
 306                         ret = -ERESTARTSYS;
 307                         break;
 308                 }
 309         }
 310
 311         __set_current_state(TASK_RUNNING);
 312         return ret;
 313 }
 314
 315 int
 316 nouveau_fence_wait(struct nouveau_fence *fence, bool lazy, bool intr)
 317 {
 318         long ret;
 319
 320         if (!lazy)
 321                 return nouveau_fence_wait_busy(fence, intr);
 322
 323         ret = dma_fence_wait_timeout(&fence->base, intr, 15 * HZ);
 324         if (ret < 0)
 325                 return ret;
 326         else if (!ret)
 327                 return -EBUSY;
 328         else
 329                 return 0;
 330 }
 331
 332 int
 333 nouveau_fence_sync(struct nouveau_bo *nvbo, struct nouveau_channel *chan, bool exclusive, bool intr)
 334 {
 335         struct nouveau_fence_chan *fctx = chan->fence;
 336         struct dma_fence *fence;
 337         struct dma_resv *resv = nvbo->bo.base.resv;
 338         struct dma_resv_list *fobj;
 339         struct nouveau_fence *f;
 340         int ret = 0, i;
 341
 342         if (!exclusive) {
 343                 ret = dma_resv_reserve_shared(resv, 1);
 344
 345                 if (ret)
 346                         return ret;
 347         }
 348
 349         fobj = dma_resv_get_list(resv);
 350         fence = dma_resv_get_excl(resv);
 351
 352         if (fence && (!exclusive || !fobj || !fobj->shared_count)) {
 353                 struct nouveau_channel *prev = NULL;
 354                 bool must_wait = true;
 355
 356                 f = nouveau_local_fence(fence, chan->drm);
 357                 if (f) {
 358                         rcu_read_lock();
 359                         prev = rcu_dereference(f->channel);
 360                         if (prev && (prev == chan || fctx->sync(f, prev, chan) == 0))
 361                                 must_wait = false;
 362                         rcu_read_unlock();
 363                 }
 364
 365                 if (must_wait)
 366                         ret = dma_fence_wait(fence, intr);
 367
 368                 return ret;
 369         }
 370
 371         if (!exclusive || !fobj)
 372                 return ret;
 373
 374         for (i = 0; i < fobj->shared_count && !ret; ++i) {
 375                 struct nouveau_channel *prev = NULL;
 376                 bool must_wait = true;
 377
 378                 fence = rcu_dereference_protected(fobj->shared[i],
 379                                                 dma_resv_held(resv));
 380
 381                 f = nouveau_local_fence(fence, chan->drm);
 382                 if (f) {
 383                         rcu_read_lock();
 384                         prev = rcu_dereference(f->channel);
 385                         if (prev && (prev == chan || fctx->sync(f, prev, chan) == 0))
 386                                 must_wait = false;
 387                         rcu_read_unlock();
 388                 }
 389
 390                 if (must_wait)
 391                         ret = dma_fence_wait(fence, intr);
 392         }
 393
 394         return ret;
 395 }
 396
 397 void
 398 nouveau_fence_unref(struct nouveau_fence **pfence)
 399 {
 400         if (*pfence)
 401                 dma_fence_put(&(*pfence)->base);
 402         *pfence = NULL;
 403 }
 404
 405 int
 406 nouveau_fence_new(struct nouveau_channel *chan, bool sysmem,
 407                   struct nouveau_fence **pfence)
 408 {
 409         struct nouveau_fence *fence;
 410         int ret = 0;
 411
 412         if (unlikely(!chan->fence))
 413                 return -ENODEV;
 414
 415         fence = kzalloc(sizeof(*fence), GFP_KERNEL);
 416         if (!fence)
 417                 return -ENOMEM;
 418
 419         ret = nouveau_fence_emit(fence, chan);
 420         if (ret)
 421                 nouveau_fence_unref(&fence);
 422
 423         *pfence = fence;
 424         return ret;
 425 }
 426
 427 static const char *nouveau_fence_get_get_driver_name(struct dma_fence *fence)
 428 {
 429         return "nouveau";
 430 }
 431
 432 static const char *nouveau_fence_get_timeline_name(struct dma_fence *f)
 433 {
 434         struct nouveau_fence *fence = from_fence(f);
 435         struct nouveau_fence_chan *fctx = nouveau_fctx(fence);
 436
 437         return !fctx->dead ? fctx->name : "dead channel";
 438 }
 439
 440 /*
 441  * In an ideal world, read would not assume the channel context is still alive.
 442  * This function may be called from another device, running into free memory as a
 443  * result. The drm node should still be there, so we can derive the index from
 444  * the fence context.
 445  */
 446 static bool nouveau_fence_is_signaled(struct dma_fence *f)
 447 {
 448         struct nouveau_fence *fence = from_fence(f);
 449         struct nouveau_fence_chan *fctx = nouveau_fctx(fence);
 450         struct nouveau_channel *chan;
 451         bool ret = false;
 452
 453         rcu_read_lock();
 454         chan = rcu_dereference(fence->channel);
 455         if (chan)
 456                 ret = (int)(fctx->read(chan) - fence->base.seqno) >= 0;
 457         rcu_read_unlock();
 458
 459         return ret;
 460 }
 461
 462 static bool nouveau_fence_no_signaling(struct dma_fence *f)
 463 {
 464         struct nouveau_fence *fence = from_fence(f);
 465
 466         /*
 467          * caller should have a reference on the fence,
 468          * else fence could get freed here
 469          */
 470         WARN_ON(kref_read(&fence->base.refcount) <= 1);
 471
 472         /*
 473          * This needs uevents to work correctly, but dma_fence_add_callback relies on
 474          * being able to enable signaling. It will still get signaled eventually,
 475          * just not right away.
 476          */
 477         if (nouveau_fence_is_signaled(f)) {
 478                 list_del(&fence->head);
 479
 480                 dma_fence_put(&fence->base);
 481                 return false;
 482         }
 483
 484         return true;
 485 }
 486
 487 static void nouveau_fence_release(struct dma_fence *f)
 488 {
 489         struct nouveau_fence *fence = from_fence(f);
 490         struct nouveau_fence_chan *fctx = nouveau_fctx(fence);
 491
 492         kref_put(&fctx->fence_ref, nouveau_fence_context_put);
 493         dma_fence_free(&fence->base);
 494 }
 495
 496 static const struct dma_fence_ops nouveau_fence_ops_legacy = {
 497         .get_driver_name = nouveau_fence_get_get_driver_name,
 498         .get_timeline_name = nouveau_fence_get_timeline_name,
 499         .enable_signaling = nouveau_fence_no_signaling,
 500         .signaled = nouveau_fence_is_signaled,
 501         .wait = nouveau_fence_wait_legacy,
 502         .release = nouveau_fence_release
 503 };
 504
 505 static bool nouveau_fence_enable_signaling(struct dma_fence *f)
 506 {
 507         struct nouveau_fence *fence = from_fence(f);
 508         struct nouveau_fence_chan *fctx = nouveau_fctx(fence);
 509         bool ret;
 510
 511         if (!fctx->notify_ref++)
 512                 nvif_notify_get(&fctx->notify);
 513
 514         ret = nouveau_fence_no_signaling(f);
 515         if (ret)
 516                 set_bit(DMA_FENCE_FLAG_USER_BITS, &fence->base.flags);
 517         else if (!--fctx->notify_ref)
 518                 nvif_notify_put(&fctx->notify);
 519
 520         return ret;
 521 }
 522
 523 static const struct dma_fence_ops nouveau_fence_ops_uevent = {
 524         .get_driver_name = nouveau_fence_get_get_driver_name,
 525         .get_timeline_name = nouveau_fence_get_timeline_name,
 526         .enable_signaling = nouveau_fence_enable_signaling,
 527         .signaled = nouveau_fence_is_signaled,
 528         .release = nouveau_fence_release
 529 };