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