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/if0020.h>
  33
  34 #include "nouveau_drv.h"
  35 #include "nouveau_dma.h"
  36 #include "nouveau_fence.h"
  37
  38 static const struct dma_fence_ops nouveau_fence_ops_uevent;
  39 static const struct dma_fence_ops nouveau_fence_ops_legacy;
  40
  41 static inline struct nouveau_fence *
  42 from_fence(struct dma_fence *fence)
  43 {
  44         return container_of(fence, struct nouveau_fence, base);
  45 }
  46
  47 static inline struct nouveau_fence_chan *
  48 nouveau_fctx(struct nouveau_fence *fence)
  49 {
  50         return container_of(fence->base.lock, struct nouveau_fence_chan, lock);
  51 }
  52
  53 static int
  54 nouveau_fence_signal(struct nouveau_fence *fence)
  55 {
  56         int drop = 0;
  57
  58         dma_fence_signal_locked(&fence->base);
  59         list_del(&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->base);
  70         return drop;
  71 }
  72
  73 static struct nouveau_fence *
  74 nouveau_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
  83 void
  84 nouveau_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(&fctx->pending)) {
  91                 fence = list_entry(fctx->pending.next, typeof(*fence), head);
  92
  93                 if (error)
  94                         dma_fence_set_error(&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(&fctx->lock, flags);
 101 }
 102
 103 void
 104 nouveau_fence_context_del(struct nouveau_fence_chan *fctx)
 105 {
 106         cancel_work_sync(&fctx->uevent_work);
 107         nouveau_fence_context_kill(fctx, 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
 118 static void
 119 nouveau_fence_context_put(struct kref *fence_ref)
 120 {
 121         kfree(container_of(fence_ref, struct nouveau_fence_chan, fence_ref));
 122 }
 123
 124 void
 125 nouveau_fence_context_free(struct nouveau_fence_chan *fctx)
 126 {
 127         kref_put(&fctx->fence_ref, nouveau_fence_context_put);
 128 }
 129
 130 static int
 131 nouveau_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(&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
 149 static void
 150 nouveau_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(&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(&fctx->lock, flags);
 171 }
 172
 173 static int
 174 nouveau_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(&fctx->uevent_work);
 178         return NVIF_EVENT_KEEP;
 179 }
 180
 181 void
 182 nouveau_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(&fctx->flip);
 194         INIT_LIST_HEAD(&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(fctx->name, "copy engine channel");
 200         else if (chan == chan->drm->channel)
 201                 strcpy(fctx->name, "generic kernel channel");
 202         else
 203                 strcpy(fctx->name, nvxx_client(&cli->base)->name);
 204
 205         kref_init(&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
 219 int
 220 nouveau_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->base, &nouveau_fence_ops_uevent,
 231                                &fctx->lock, fctx->context, ++fctx->sequence);
 232         else
 233                 dma_fence_init(&fence->base, &nouveau_fence_ops_legacy,
 234                                &fctx->lock, fctx->context, ++fctx->sequence);
 235         kref_get(&fctx->fence_ref);
 236
 237         ret = fctx->emit(fence);
 238         if (!ret) {
 239                 dma_fence_get(&fence->base);
 240                 spin_lock_irq(&fctx->lock);
 241
 242                 if (unlikely(fctx->killed)) {
 243                         spin_unlock_irq(&fctx->lock);
 244                         dma_fence_put(&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(&fence->head, &fctx->pending);
 252                 spin_unlock_irq(&fctx->lock);
 253         }
 254
 255         return ret;
 256 }
 257
 258 bool
 259 nouveau_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(&fctx->lock, flags);
 275         }
 276         return dma_fence_is_signaled(&fence->base);
 277 }
 278
 279 static long
 280 nouveau_fence_wait_legacy(struct dma_fence *f, bool intr, long wait)
 281 {
 282         struct nouveau_fence *fence = from_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(&kt, 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
 314 static int
 315 nouveau_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
 339 int
 340 nouveau_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, 15 * HZ);
 348         if (ret < 0)
 349                 return ret;
 350         else if (!ret)
 351                 return -EBUSY;
 352         else
 353                 return 0;
 354 }
 355
 356 int
 357 nouveau_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(resv, 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);
 382                         if (i == 0 && usage == DMA_RESV_USAGE_WRITE)
 383                                 continue;
 384
 385                         f = nouveau_local_fence(fence, 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
 409 void
 410 nouveau_fence_unref(struct nouveau_fence **pfence)
 411 {
 412         if (*pfence)
 413                 dma_fence_put(&(*pfence)->base);
 414         *pfence = NULL;
 415 }
 416
 417 int
 418 nouveau_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(sizeof(*fence), GFP_KERNEL);
 427         if (!fence)
 428                 return -ENOMEM;
 429
 430         fence->channel = chan;
 431
 432         *pfence = fence;
 433         return 0;
 434 }
 435
 436 int
 437 nouveau_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(*pfence);
 447         if (ret)
 448                 nouveau_fence_unref(pfence);
 449
 450         return ret;
 451 }
 452
 453 static const char *nouveau_fence_get_get_driver_name(struct dma_fence *fence)
 454 {
 455         return "nouveau";
 456 }
 457
 458 static const char *nouveau_fence_get_timeline_name(struct dma_fence *f)
 459 {
 460         struct nouveau_fence *fence = from_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  */
 472 static bool nouveau_fence_is_signaled(struct dma_fence *f)
 473 {
 474         struct nouveau_fence *fence = from_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
 488 static bool nouveau_fence_no_signaling(struct dma_fence *f)
 489 {
 490         struct nouveau_fence *fence = from_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(&fence->head);
 505
 506                 dma_fence_put(&fence->base);
 507                 return false;
 508         }
 509
 510         return true;
 511 }
 512
 513 static void nouveau_fence_release(struct dma_fence *f)
 514 {
 515         struct nouveau_fence *fence = from_fence(f);
 516         struct nouveau_fence_chan *fctx = nouveau_fctx(fence);
 517
 518         kref_put(&fctx->fence_ref, nouveau_fence_context_put);
 519         dma_fence_free(&fence->base);
 520 }
 521
 522 static 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
 531 static bool nouveau_fence_enable_signaling(struct dma_fence *f)
 532 {
 533         struct nouveau_fence *fence = from_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(DMA_FENCE_FLAG_USER_BITS, &fence->base.flags);
 543         else if (!--fctx->notify_ref)
 544                 nvif_event_block(&fctx->event);
 545
 546         return ret;
 547 }
 548
 549 static 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 };