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/dma_fence.h>
  32
  33 #include <nvif/cl826e.h>
  34 #include <nvif/notify.h>
  35 #include <nvif/event.h>
  36
  37 #include "nouveau_drv.h"
  38 #include "nouveau_dma.h"
  39 #include "nouveau_fence.h"
  40
  41 static const struct dma_fence_ops nouveau_fence_ops_uevent;
  42 static const struct dma_fence_ops nouveau_fence_ops_legacy;
  43
  44 static inline struct nouveau_fence *
  45 from_fence(struct dma_fence *fence)
  46 {
  47         return container_of(fence, struct nouveau_fence, base);
  48 }
  49
  50 static inline struct nouveau_fence_chan *
  51 nouveau_fctx(struct nouveau_fence *fence)
  52 {
  53         return container_of(fence->base.lock, struct nouveau_fence_chan, lock);
  54 }
  55
  56 static int
  57 nouveau_fence_signal(struct nouveau_fence *fence)
  58 {
  59         int drop = 0;
  60
  61         dma_fence_signal_locked(&fence->base);
  62         list_del(&fence->head);
  63         rcu_assign_pointer(fence->channel, NULL);
  64
  65         if (test_bit(DMA_FENCE_FLAG_USER_BITS, &fence->base.flags)) {
  66                 struct nouveau_fence_chan *fctx = nouveau_fctx(fence);
  67
  68                 if (!--fctx->notify_ref)
  69                         drop = 1;
  70         }
  71
  72         dma_fence_put(&fence->base);
  73         return drop;
  74 }
  75
  76 static struct nouveau_fence *
  77 nouveau_local_fence(struct dma_fence *fence, struct nouveau_drm *drm) {
  78         struct nouveau_fence_priv *priv = (void*)drm->fence;
  79
  80         if (fence->ops != &nouveau_fence_ops_legacy &&
  81             fence->ops != &nouveau_fence_ops_uevent)
  82                 return NULL;
  83
  84         if (fence->context < priv->context_base ||
  85             fence->context >= priv->context_base + priv->contexts)
  86                 return NULL;
  87
  88         return from_fence(fence);
  89 }
  90
  91 void
  92 nouveau_fence_context_del(struct nouveau_fence_chan *fctx)
  93 {
  94         struct nouveau_fence *fence;
  95
  96         spin_lock_irq(&fctx->lock);
  97         while (!list_empty(&fctx->pending)) {
  98                 fence = list_entry(fctx->pending.next, typeof(*fence), head);
  99
 100                 if (nouveau_fence_signal(fence))
 101                         nvif_notify_put(&fctx->notify);
 102         }
 103         spin_unlock_irq(&fctx->lock);
 104
 105         nvif_notify_fini(&fctx->notify);
 106         fctx->dead = 1;
 107
 108         /*
 109          * Ensure that all accesses to fence->channel complete before freeing
 110          * the channel.
 111          */
 112         synchronize_rcu();
 113 }
 114
 115 static void
 116 nouveau_fence_context_put(struct kref *fence_ref)
 117 {
 118         kfree(container_of(fence_ref, struct nouveau_fence_chan, fence_ref));
 119 }
 120
 121 void
 122 nouveau_fence_context_free(struct nouveau_fence_chan *fctx)
 123 {
 124         kref_put(&fctx->fence_ref, nouveau_fence_context_put);
 125 }
 126
 127 static int
 128 nouveau_fence_update(struct nouveau_channel *chan, struct nouveau_fence_chan *fctx)
 129 {
 130         struct nouveau_fence *fence;
 131         int drop = 0;
 132         u32 seq = fctx->read(chan);
 133
 134         while (!list_empty(&fctx->pending)) {
 135                 fence = list_entry(fctx->pending.next, typeof(*fence), head);
 136
 137                 if ((int)(seq - fence->base.seqno) < 0)
 138                         break;
 139
 140                 drop |= nouveau_fence_signal(fence);
 141         }
 142
 143         return drop;
 144 }
 145
 146 static int
 147 nouveau_fence_wait_uevent_handler(struct nvif_notify *notify)
 148 {
 149         struct nouveau_fence_chan *fctx =
 150                 container_of(notify, typeof(*fctx), notify);
 151         unsigned long flags;
 152         int ret = NVIF_NOTIFY_KEEP;
 153
 154         spin_lock_irqsave(&fctx->lock, flags);
 155         if (!list_empty(&fctx->pending)) {
 156                 struct nouveau_fence *fence;
 157                 struct nouveau_channel *chan;
 158
 159                 fence = list_entry(fctx->pending.next, typeof(*fence), head);
 160                 chan = rcu_dereference_protected(fence->channel, lockdep_is_held(&fctx->lock));
 161                 if (nouveau_fence_update(fence->channel, fctx))
 162                         ret = NVIF_NOTIFY_DROP;
 163         }
 164         spin_unlock_irqrestore(&fctx->lock, flags);
 165
 166         return ret;
 167 }
 168
 169 void
 170 nouveau_fence_context_new(struct nouveau_channel *chan, struct nouveau_fence_chan *fctx)
 171 {
 172         struct nouveau_fence_priv *priv = (void*)chan->drm->fence;
 173         struct nouveau_cli *cli = (void *)chan->user.client;
 174         int ret;
 175
 176         INIT_LIST_HEAD(&fctx->flip);
 177         INIT_LIST_HEAD(&fctx->pending);
 178         spin_lock_init(&fctx->lock);
 179         fctx->context = priv->context_base + chan->chid;
 180
 181         if (chan == chan->drm->cechan)
 182                 strcpy(fctx->name, "copy engine channel");
 183         else if (chan == chan->drm->channel)
 184                 strcpy(fctx->name, "generic kernel channel");
 185         else
 186                 strcpy(fctx->name, nvxx_client(&cli->base)->name);
 187
 188         kref_init(&fctx->fence_ref);
 189         if (!priv->uevent)
 190                 return;
 191
 192         ret = nvif_notify_init(&chan->user, nouveau_fence_wait_uevent_handler,
 193                                false, NV826E_V0_NTFY_NON_STALL_INTERRUPT,
 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 int
 203 nouveau_fence_emit(struct nouveau_fence *fence, struct nouveau_channel *chan)
 204 {
 205         struct nouveau_fence_chan *fctx = chan->fence;
 206         struct nouveau_fence_priv *priv = (void*)chan->drm->fence;
 207         int ret;
 208
 209         fence->channel  = chan;
 210         fence->timeout  = jiffies + (15 * HZ);
 211
 212         if (priv->uevent)
 213                 dma_fence_init(&fence->base, &nouveau_fence_ops_uevent,
 214                                &fctx->lock, fctx->context, ++fctx->sequence);
 215         else
 216                 dma_fence_init(&fence->base, &nouveau_fence_ops_legacy,
 217                                &fctx->lock, fctx->context, ++fctx->sequence);
 218         kref_get(&fctx->fence_ref);
 219
 220         trace_dma_fence_emit(&fence->base);
 221         ret = fctx->emit(fence);
 222         if (!ret) {
 223                 dma_fence_get(&fence->base);
 224                 spin_lock_irq(&fctx->lock);
 225
 226                 if (nouveau_fence_update(chan, fctx))
 227                         nvif_notify_put(&fctx->notify);
 228
 229                 list_add_tail(&fence->head, &fctx->pending);
 230                 spin_unlock_irq(&fctx->lock);
 231         }
 232
 233         return ret;
 234 }
 235
 236 bool
 237 nouveau_fence_done(struct nouveau_fence *fence)
 238 {
 239         if (fence->base.ops == &nouveau_fence_ops_legacy ||
 240             fence->base.ops == &nouveau_fence_ops_uevent) {
 241                 struct nouveau_fence_chan *fctx = nouveau_fctx(fence);
 242                 struct nouveau_channel *chan;
 243                 unsigned long flags;
 244
 245                 if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->base.flags))
 246                         return true;
 247
 248                 spin_lock_irqsave(&fctx->lock, flags);
 249                 chan = rcu_dereference_protected(fence->channel, lockdep_is_held(&fctx->lock));
 250                 if (chan && nouveau_fence_update(chan, fctx))
 251                         nvif_notify_put(&fctx->notify);
 252                 spin_unlock_irqrestore(&fctx->lock, flags);
 253         }
 254         return dma_fence_is_signaled(&fence->base);
 255 }
 256
 257 static long
 258 nouveau_fence_wait_legacy(struct dma_fence *f, bool intr, long wait)
 259 {
 260         struct nouveau_fence *fence = from_fence(f);
 261         unsigned long sleep_time = NSEC_PER_MSEC / 1000;
 262         unsigned long t = jiffies, timeout = t + wait;
 263
 264         while (!nouveau_fence_done(fence)) {
 265                 ktime_t kt;
 266
 267                 t = jiffies;
 268
 269                 if (wait != MAX_SCHEDULE_TIMEOUT && time_after_eq(t, timeout)) {
 270                         __set_current_state(TASK_RUNNING);
 271                         return 0;
 272                 }
 273
 274                 __set_current_state(intr ? TASK_INTERRUPTIBLE :
 275                                            TASK_UNINTERRUPTIBLE);
 276
 277                 kt = sleep_time;
 278                 schedule_hrtimeout(&kt, HRTIMER_MODE_REL);
 279                 sleep_time *= 2;
 280                 if (sleep_time > NSEC_PER_MSEC)
 281                         sleep_time = NSEC_PER_MSEC;
 282
 283                 if (intr && signal_pending(current))
 284                         return -ERESTARTSYS;
 285         }
 286
 287         __set_current_state(TASK_RUNNING);
 288
 289         return timeout - t;
 290 }
 291
 292 static int
 293 nouveau_fence_wait_busy(struct nouveau_fence *fence, bool intr)
 294 {
 295         int ret = 0;
 296
 297         while (!nouveau_fence_done(fence)) {
 298                 if (time_after_eq(jiffies, fence->timeout)) {
 299                         ret = -EBUSY;
 300                         break;
 301                 }
 302
 303                 __set_current_state(intr ?
 304                                     TASK_INTERRUPTIBLE :
 305                                     TASK_UNINTERRUPTIBLE);
 306
 307                 if (intr && signal_pending(current)) {
 308                         ret = -ERESTARTSYS;
 309                         break;
 310                 }
 311         }
 312
 313         __set_current_state(TASK_RUNNING);
 314         return ret;
 315 }
 316
 317 int
 318 nouveau_fence_wait(struct nouveau_fence *fence, bool lazy, bool intr)
 319 {
 320         long ret;
 321
 322         if (!lazy)
 323                 return nouveau_fence_wait_busy(fence, intr);
 324
 325         ret = dma_fence_wait_timeout(&fence->base, intr, 15 * HZ);
 326         if (ret < 0)
 327                 return ret;
 328         else if (!ret)
 329                 return -EBUSY;
 330         else
 331                 return 0;
 332 }
 333
 334 int
 335 nouveau_fence_sync(struct nouveau_bo *nvbo, struct nouveau_channel *chan, bool exclusive, bool intr)
 336 {
 337         struct nouveau_fence_chan *fctx = chan->fence;
 338         struct dma_fence *fence;
 339         struct reservation_object *resv = nvbo->bo.resv;
 340         struct reservation_object_list *fobj;
 341         struct nouveau_fence *f;
 342         int ret = 0, i;
 343
 344         if (!exclusive) {
 345                 ret = reservation_object_reserve_shared(resv);
 346
 347                 if (ret)
 348                         return ret;
 349         }
 350
 351         fobj = reservation_object_get_list(resv);
 352         fence = reservation_object_get_excl(resv);
 353
 354         if (fence && (!exclusive || !fobj || !fobj->shared_count)) {
 355                 struct nouveau_channel *prev = NULL;
 356                 bool must_wait = true;
 357
 358                 f = nouveau_local_fence(fence, chan->drm);
 359                 if (f) {
 360                         rcu_read_lock();
 361                         prev = rcu_dereference(f->channel);
 362                         if (prev && (prev == chan || fctx->sync(f, prev, chan) == 0))
 363                                 must_wait = false;
 364                         rcu_read_unlock();
 365                 }
 366
 367                 if (must_wait)
 368                         ret = dma_fence_wait(fence, intr);
 369
 370                 return ret;
 371         }
 372
 373         if (!exclusive || !fobj)
 374                 return ret;
 375
 376         for (i = 0; i < fobj->shared_count && !ret; ++i) {
 377                 struct nouveau_channel *prev = NULL;
 378                 bool must_wait = true;
 379
 380                 fence = rcu_dereference_protected(fobj->shared[i],
 381                                                 reservation_object_held(resv));
 382
 383                 f = nouveau_local_fence(fence, chan->drm);
 384                 if (f) {
 385                         rcu_read_lock();
 386                         prev = rcu_dereference(f->channel);
 387                         if (prev && (prev == chan || fctx->sync(f, prev, chan) == 0))
 388                                 must_wait = false;
 389                         rcu_read_unlock();
 390                 }
 391
 392                 if (must_wait)
 393                         ret = dma_fence_wait(fence, intr);
 394         }
 395
 396         return ret;
 397 }
 398
 399 void
 400 nouveau_fence_unref(struct nouveau_fence **pfence)
 401 {
 402         if (*pfence)
 403                 dma_fence_put(&(*pfence)->base);
 404         *pfence = NULL;
 405 }
 406
 407 int
 408 nouveau_fence_new(struct nouveau_channel *chan, bool sysmem,
 409                   struct nouveau_fence **pfence)
 410 {
 411         struct nouveau_fence *fence;
 412         int ret = 0;
 413
 414         if (unlikely(!chan->fence))
 415                 return -ENODEV;
 416
 417         fence = kzalloc(sizeof(*fence), GFP_KERNEL);
 418         if (!fence)
 419                 return -ENOMEM;
 420
 421         ret = nouveau_fence_emit(fence, chan);
 422         if (ret)
 423                 nouveau_fence_unref(&fence);
 424
 425         *pfence = fence;
 426         return ret;
 427 }
 428
 429 static const char *nouveau_fence_get_get_driver_name(struct dma_fence *fence)
 430 {
 431         return "nouveau";
 432 }
 433
 434 static const char *nouveau_fence_get_timeline_name(struct dma_fence *f)
 435 {
 436         struct nouveau_fence *fence = from_fence(f);
 437         struct nouveau_fence_chan *fctx = nouveau_fctx(fence);
 438
 439         return !fctx->dead ? fctx->name : "dead channel";
 440 }
 441
 442 /*
 443  * In an ideal world, read would not assume the channel context is still alive.
 444  * This function may be called from another device, running into free memory as a
 445  * result. The drm node should still be there, so we can derive the index from
 446  * the fence context.
 447  */
 448 static bool nouveau_fence_is_signaled(struct dma_fence *f)
 449 {
 450         struct nouveau_fence *fence = from_fence(f);
 451         struct nouveau_fence_chan *fctx = nouveau_fctx(fence);
 452         struct nouveau_channel *chan;
 453         bool ret = false;
 454
 455         rcu_read_lock();
 456         chan = rcu_dereference(fence->channel);
 457         if (chan)
 458                 ret = (int)(fctx->read(chan) - fence->base.seqno) >= 0;
 459         rcu_read_unlock();
 460
 461         return ret;
 462 }
 463
 464 static bool nouveau_fence_no_signaling(struct dma_fence *f)
 465 {
 466         struct nouveau_fence *fence = from_fence(f);
 467
 468         /*
 469          * caller should have a reference on the fence,
 470          * else fence could get freed here
 471          */
 472         WARN_ON(kref_read(&fence->base.refcount) <= 1);
 473
 474         /*
 475          * This needs uevents to work correctly, but dma_fence_add_callback relies on
 476          * being able to enable signaling. It will still get signaled eventually,
 477          * just not right away.
 478          */
 479         if (nouveau_fence_is_signaled(f)) {
 480                 list_del(&fence->head);
 481
 482                 dma_fence_put(&fence->base);
 483                 return false;
 484         }
 485
 486         return true;
 487 }
 488
 489 static void nouveau_fence_release(struct dma_fence *f)
 490 {
 491         struct nouveau_fence *fence = from_fence(f);
 492         struct nouveau_fence_chan *fctx = nouveau_fctx(fence);
 493
 494         kref_put(&fctx->fence_ref, nouveau_fence_context_put);
 495         dma_fence_free(&fence->base);
 496 }
 497
 498 static const struct dma_fence_ops nouveau_fence_ops_legacy = {
 499         .get_driver_name = nouveau_fence_get_get_driver_name,
 500         .get_timeline_name = nouveau_fence_get_timeline_name,
 501         .enable_signaling = nouveau_fence_no_signaling,
 502         .signaled = nouveau_fence_is_signaled,
 503         .wait = nouveau_fence_wait_legacy,
 504         .release = nouveau_fence_release
 505 };
 506
 507 static bool nouveau_fence_enable_signaling(struct dma_fence *f)
 508 {
 509         struct nouveau_fence *fence = from_fence(f);
 510         struct nouveau_fence_chan *fctx = nouveau_fctx(fence);
 511         bool ret;
 512
 513         if (!fctx->notify_ref++)
 514                 nvif_notify_get(&fctx->notify);
 515
 516         ret = nouveau_fence_no_signaling(f);
 517         if (ret)
 518                 set_bit(DMA_FENCE_FLAG_USER_BITS, &fence->base.flags);
 519         else if (!--fctx->notify_ref)
 520                 nvif_notify_put(&fctx->notify);
 521
 522         return ret;
 523 }
 524
 525 static const struct dma_fence_ops nouveau_fence_ops_uevent = {
 526         .get_driver_name = nouveau_fence_get_get_driver_name,
 527         .get_timeline_name = nouveau_fence_get_timeline_name,
 528         .enable_signaling = nouveau_fence_enable_signaling,
 529         .signaled = nouveau_fence_is_signaled,
 530         .wait = dma_fence_default_wait,
 531         .release = nouveau_fence_release
 532 };