drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c

   1 /*
   2  * Copyright 2009 Jerome Glisse.
   3  * All Rights Reserved.
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a
   6  * 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, sub license, 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 SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  14  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  15  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
  16  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
  17  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  18  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  19  * USE OR OTHER DEALINGS IN THE SOFTWARE.
  20  *
  21  * The above copyright notice and this permission notice (including the
  22  * next paragraph) shall be included in all copies or substantial portions
  23  * of the Software.
  24  *
  25  */
  26 /*
  27  * Authors:
  28  *    Jerome Glisse <glisse@freedesktop.org>
  29  *    Dave Airlie
  30  */
  31 #include <linux/seq_file.h>
  32 #include <linux/atomic.h>
  33 #include <linux/wait.h>
  34 #include <linux/kref.h>
  35 #include <linux/slab.h>
  36 #include <linux/firmware.h>
  37 #include <drm/drmP.h>
  38 #include "amdgpu.h"
  39 #include "amdgpu_trace.h"
  40
  41 /*
  42  * Fences
  43  * Fences mark an event in the GPUs pipeline and are used
  44  * for GPU/CPU synchronization.  When the fence is written,
  45  * it is expected that all buffers associated with that fence
  46  * are no longer in use by the associated ring on the GPU and
  47  * that the the relevant GPU caches have been flushed.
  48  */
  49
  50 struct amdgpu_fence {
  51         struct dma_fence base;
  52
  53         /* RB, DMA, etc. */
  54         struct amdgpu_ring              *ring;
  55 };
  56
  57 static struct kmem_cache *amdgpu_fence_slab;
  58
  59 int amdgpu_fence_slab_init(void)
  60 {
  61         amdgpu_fence_slab = kmem_cache_create(
  62                 "amdgpu_fence", sizeof(struct amdgpu_fence), 0,
  63                 SLAB_HWCACHE_ALIGN, NULL);
  64         if (!amdgpu_fence_slab)
  65                 return -ENOMEM;
  66         return 0;
  67 }
  68
  69 void amdgpu_fence_slab_fini(void)
  70 {
  71         rcu_barrier();
  72         kmem_cache_destroy(amdgpu_fence_slab);
  73 }
  74 /*
  75  * Cast helper
  76  */
  77 static const struct dma_fence_ops amdgpu_fence_ops;
  78 static inline struct amdgpu_fence *to_amdgpu_fence(struct dma_fence *f)
  79 {
  80         struct amdgpu_fence *__f = container_of(f, struct amdgpu_fence, base);
  81
  82         if (__f->base.ops == &amdgpu_fence_ops)
  83                 return __f;
  84
  85         return NULL;
  86 }
  87
  88 /**
  89  * amdgpu_fence_write - write a fence value
  90  *
  91  * @ring: ring the fence is associated with
  92  * @seq: sequence number to write
  93  *
  94  * Writes a fence value to memory (all asics).
  95  */
  96 static void amdgpu_fence_write(struct amdgpu_ring *ring, u32 seq)
  97 {
  98         struct amdgpu_fence_driver *drv = &ring->fence_drv;
  99
 100         if (drv->cpu_addr)
 101                 *drv->cpu_addr = cpu_to_le32(seq);
 102 }
 103
 104 /**
 105  * amdgpu_fence_read - read a fence value
 106  *
 107  * @ring: ring the fence is associated with
 108  *
 109  * Reads a fence value from memory (all asics).
 110  * Returns the value of the fence read from memory.
 111  */
 112 static u32 amdgpu_fence_read(struct amdgpu_ring *ring)
 113 {
 114         struct amdgpu_fence_driver *drv = &ring->fence_drv;
 115         u32 seq = 0;
 116
 117         if (drv->cpu_addr)
 118                 seq = le32_to_cpu(*drv->cpu_addr);
 119         else
 120                 seq = atomic_read(&drv->last_seq);
 121
 122         return seq;
 123 }
 124
 125 /**
 126  * amdgpu_fence_emit - emit a fence on the requested ring
 127  *
 128  * @ring: ring the fence is associated with
 129  * @f: resulting fence object
 130  *
 131  * Emits a fence command on the requested ring (all asics).
 132  * Returns 0 on success, -ENOMEM on failure.
 133  */
 134 int amdgpu_fence_emit(struct amdgpu_ring *ring, struct dma_fence **f)
 135 {
 136         struct amdgpu_device *adev = ring->adev;
 137         struct amdgpu_fence *fence;
 138         struct dma_fence *old, **ptr;
 139         uint32_t seq;
 140
 141         fence = kmem_cache_alloc(amdgpu_fence_slab, GFP_KERNEL);
 142         if (fence == NULL)
 143                 return -ENOMEM;
 144
 145         seq = ++ring->fence_drv.sync_seq;
 146         fence->ring = ring;
 147         dma_fence_init(&fence->base, &amdgpu_fence_ops,
 148                        &ring->fence_drv.lock,
 149                        adev->fence_context + ring->idx,
 150                        seq);
 151         amdgpu_ring_emit_fence(ring, ring->fence_drv.gpu_addr,
 152                                seq, AMDGPU_FENCE_FLAG_INT);
 153
 154         ptr = &ring->fence_drv.fences[seq & ring->fence_drv.num_fences_mask];
 155         /* This function can't be called concurrently anyway, otherwise
 156          * emitting the fence would mess up the hardware ring buffer.
 157          */
 158         old = rcu_dereference_protected(*ptr, 1);
 159         if (old && !dma_fence_is_signaled(old)) {
 160                 DRM_INFO("rcu slot is busy\n");
 161                 dma_fence_wait(old, false);
 162         }
 163
 164         rcu_assign_pointer(*ptr, dma_fence_get(&fence->base));
 165
 166         *f = &fence->base;
 167
 168         return 0;
 169 }
 170
 171 /**
 172  * amdgpu_fence_emit_polling - emit a fence on the requeste ring
 173  *
 174  * @ring: ring the fence is associated with
 175  * @s: resulting sequence number
 176  *
 177  * Emits a fence command on the requested ring (all asics).
 178  * Used For polling fence.
 179  * Returns 0 on success, -ENOMEM on failure.
 180  */
 181 int amdgpu_fence_emit_polling(struct amdgpu_ring *ring, uint32_t *s)
 182 {
 183         uint32_t seq;
 184
 185         if (!s)
 186                 return -EINVAL;
 187
 188         seq = ++ring->fence_drv.sync_seq;
 189         amdgpu_ring_emit_fence(ring, ring->fence_drv.gpu_addr,
 190                                seq, AMDGPU_FENCE_FLAG_INT);
 191
 192         *s = seq;
 193
 194         return 0;
 195 }
 196
 197 /**
 198  * amdgpu_fence_schedule_fallback - schedule fallback check
 199  *
 200  * @ring: pointer to struct amdgpu_ring
 201  *
 202  * Start a timer as fallback to our interrupts.
 203  */
 204 static void amdgpu_fence_schedule_fallback(struct amdgpu_ring *ring)
 205 {
 206         mod_timer(&ring->fence_drv.fallback_timer,
 207                   jiffies + AMDGPU_FENCE_JIFFIES_TIMEOUT);
 208 }
 209
 210 /**
 211  * amdgpu_fence_process - check for fence activity
 212  *
 213  * @ring: pointer to struct amdgpu_ring
 214  *
 215  * Checks the current fence value and calculates the last
 216  * signalled fence value. Wakes the fence queue if the
 217  * sequence number has increased.
 218  */
 219 void amdgpu_fence_process(struct amdgpu_ring *ring)
 220 {
 221         struct amdgpu_fence_driver *drv = &ring->fence_drv;
 222         uint32_t seq, last_seq;
 223         int r;
 224
 225         do {
 226                 last_seq = atomic_read(&ring->fence_drv.last_seq);
 227                 seq = amdgpu_fence_read(ring);
 228
 229         } while (atomic_cmpxchg(&drv->last_seq, last_seq, seq) != last_seq);
 230
 231         if (seq != ring->fence_drv.sync_seq)
 232                 amdgpu_fence_schedule_fallback(ring);
 233
 234         if (unlikely(seq == last_seq))
 235                 return;
 236
 237         last_seq &= drv->num_fences_mask;
 238         seq &= drv->num_fences_mask;
 239
 240         do {
 241                 struct dma_fence *fence, **ptr;
 242
 243                 ++last_seq;
 244                 last_seq &= drv->num_fences_mask;
 245                 ptr = &drv->fences[last_seq];
 246
 247                 /* There is always exactly one thread signaling this fence slot */
 248                 fence = rcu_dereference_protected(*ptr, 1);
 249                 RCU_INIT_POINTER(*ptr, NULL);
 250
 251                 if (!fence)
 252                         continue;
 253
 254                 r = dma_fence_signal(fence);
 255                 if (!r)
 256                         DMA_FENCE_TRACE(fence, "signaled from irq context\n");
 257                 else
 258                         BUG();
 259
 260                 dma_fence_put(fence);
 261         } while (last_seq != seq);
 262 }
 263
 264 /**
 265  * amdgpu_fence_fallback - fallback for hardware interrupts
 266  *
 267  * @work: delayed work item
 268  *
 269  * Checks for fence activity.
 270  */
 271 static void amdgpu_fence_fallback(unsigned long arg)
 272 {
 273         struct amdgpu_ring *ring = (void *)arg;
 274
 275         amdgpu_fence_process(ring);
 276 }
 277
 278 /**
 279  * amdgpu_fence_wait_empty - wait for all fences to signal
 280  *
 281  * @adev: amdgpu device pointer
 282  * @ring: ring index the fence is associated with
 283  *
 284  * Wait for all fences on the requested ring to signal (all asics).
 285  * Returns 0 if the fences have passed, error for all other cases.
 286  */
 287 int amdgpu_fence_wait_empty(struct amdgpu_ring *ring)
 288 {
 289         uint64_t seq = ACCESS_ONCE(ring->fence_drv.sync_seq);
 290         struct dma_fence *fence, **ptr;
 291         int r;
 292
 293         if (!seq)
 294                 return 0;
 295
 296         ptr = &ring->fence_drv.fences[seq & ring->fence_drv.num_fences_mask];
 297         rcu_read_lock();
 298         fence = rcu_dereference(*ptr);
 299         if (!fence || !dma_fence_get_rcu(fence)) {
 300                 rcu_read_unlock();
 301                 return 0;
 302         }
 303         rcu_read_unlock();
 304
 305         r = dma_fence_wait(fence, false);
 306         dma_fence_put(fence);
 307         return r;
 308 }
 309
 310 /**
 311  * amdgpu_fence_wait_polling - busy wait for givn sequence number
 312  *
 313  * @ring: ring index the fence is associated with
 314  * @wait_seq: sequence number to wait
 315  * @timeout: the timeout for waiting in usecs
 316  *
 317  * Wait for all fences on the requested ring to signal (all asics).
 318  * Returns left time if no timeout, 0 or minus if timeout.
 319  */
 320 signed long amdgpu_fence_wait_polling(struct amdgpu_ring *ring,
 321                                       uint32_t wait_seq,
 322                                       signed long timeout)
 323 {
 324         uint32_t seq;
 325
 326         do {
 327                 seq = amdgpu_fence_read(ring);
 328                 udelay(5);
 329                 timeout -= 5;
 330         } while ((int32_t)(wait_seq - seq) > 0 && timeout > 0);
 331
 332         return timeout > 0 ? timeout : 0;
 333 }
 334 /**
 335  * amdgpu_fence_count_emitted - get the count of emitted fences
 336  *
 337  * @ring: ring the fence is associated with
 338  *
 339  * Get the number of fences emitted on the requested ring (all asics).
 340  * Returns the number of emitted fences on the ring.  Used by the
 341  * dynpm code to ring track activity.
 342  */
 343 unsigned amdgpu_fence_count_emitted(struct amdgpu_ring *ring)
 344 {
 345         uint64_t emitted;
 346
 347         /* We are not protected by ring lock when reading the last sequence
 348          * but it's ok to report slightly wrong fence count here.
 349          */
 350         amdgpu_fence_process(ring);
 351         emitted = 0x100000000ull;
 352         emitted -= atomic_read(&ring->fence_drv.last_seq);
 353         emitted += ACCESS_ONCE(ring->fence_drv.sync_seq);
 354         return lower_32_bits(emitted);
 355 }
 356
 357 /**
 358  * amdgpu_fence_driver_start_ring - make the fence driver
 359  * ready for use on the requested ring.
 360  *
 361  * @ring: ring to start the fence driver on
 362  * @irq_src: interrupt source to use for this ring
 363  * @irq_type: interrupt type to use for this ring
 364  *
 365  * Make the fence driver ready for processing (all asics).
 366  * Not all asics have all rings, so each asic will only
 367  * start the fence driver on the rings it has.
 368  * Returns 0 for success, errors for failure.
 369  */
 370 int amdgpu_fence_driver_start_ring(struct amdgpu_ring *ring,
 371                                    struct amdgpu_irq_src *irq_src,
 372                                    unsigned irq_type)
 373 {
 374         struct amdgpu_device *adev = ring->adev;
 375         uint64_t index;
 376
 377         if (ring != &adev->uvd.ring) {
 378                 ring->fence_drv.cpu_addr = &adev->wb.wb[ring->fence_offs];
 379                 ring->fence_drv.gpu_addr = adev->wb.gpu_addr + (ring->fence_offs * 4);
 380         } else {
 381                 /* put fence directly behind firmware */
 382                 index = ALIGN(adev->uvd.fw->size, 8);
 383                 ring->fence_drv.cpu_addr = adev->uvd.cpu_addr + index;
 384                 ring->fence_drv.gpu_addr = adev->uvd.gpu_addr + index;
 385         }
 386         amdgpu_fence_write(ring, atomic_read(&ring->fence_drv.last_seq));
 387         amdgpu_irq_get(adev, irq_src, irq_type);
 388
 389         ring->fence_drv.irq_src = irq_src;
 390         ring->fence_drv.irq_type = irq_type;
 391         ring->fence_drv.initialized = true;
 392
 393         dev_info(adev->dev, "fence driver on ring %d use gpu addr 0x%016llx, "
 394                  "cpu addr 0x%p\n", ring->idx,
 395                  ring->fence_drv.gpu_addr, ring->fence_drv.cpu_addr);
 396         return 0;
 397 }
 398
 399 /**
 400  * amdgpu_fence_driver_init_ring - init the fence driver
 401  * for the requested ring.
 402  *
 403  * @ring: ring to init the fence driver on
 404  * @num_hw_submission: number of entries on the hardware queue
 405  *
 406  * Init the fence driver for the requested ring (all asics).
 407  * Helper function for amdgpu_fence_driver_init().
 408  */
 409 int amdgpu_fence_driver_init_ring(struct amdgpu_ring *ring,
 410                                   unsigned num_hw_submission)
 411 {
 412         long timeout;
 413         int r;
 414
 415         /* Check that num_hw_submission is a power of two */
 416         if ((num_hw_submission & (num_hw_submission - 1)) != 0)
 417                 return -EINVAL;
 418
 419         ring->fence_drv.cpu_addr = NULL;
 420         ring->fence_drv.gpu_addr = 0;
 421         ring->fence_drv.sync_seq = 0;
 422         atomic_set(&ring->fence_drv.last_seq, 0);
 423         ring->fence_drv.initialized = false;
 424
 425         setup_timer(&ring->fence_drv.fallback_timer, amdgpu_fence_fallback,
 426                     (unsigned long)ring);
 427
 428         ring->fence_drv.num_fences_mask = num_hw_submission * 2 - 1;
 429         spin_lock_init(&ring->fence_drv.lock);
 430         ring->fence_drv.fences = kcalloc(num_hw_submission * 2, sizeof(void *),
 431                                          GFP_KERNEL);
 432         if (!ring->fence_drv.fences)
 433                 return -ENOMEM;
 434
 435         /* No need to setup the GPU scheduler for KIQ ring */
 436         if (ring->funcs->type != AMDGPU_RING_TYPE_KIQ) {
 437                 timeout = msecs_to_jiffies(amdgpu_lockup_timeout);
 438                 if (timeout == 0) {
 439                         /*
 440                          * FIXME:
 441                          * Delayed workqueue cannot use it directly,
 442                          * so the scheduler will not use delayed workqueue if
 443                          * MAX_SCHEDULE_TIMEOUT is set.
 444                          * Currently keep it simple and silly.
 445                          */
 446                         timeout = MAX_SCHEDULE_TIMEOUT;
 447                 }
 448                 r = amd_sched_init(&ring->sched, &amdgpu_sched_ops,
 449                                    num_hw_submission,
 450                                    timeout, ring->name);
 451                 if (r) {
 452                         DRM_ERROR("Failed to create scheduler on ring %s.\n",
 453                                   ring->name);
 454                         return r;
 455                 }
 456         }
 457
 458         return 0;
 459 }
 460
 461 /**
 462  * amdgpu_fence_driver_init - init the fence driver
 463  * for all possible rings.
 464  *
 465  * @adev: amdgpu device pointer
 466  *
 467  * Init the fence driver for all possible rings (all asics).
 468  * Not all asics have all rings, so each asic will only
 469  * start the fence driver on the rings it has using
 470  * amdgpu_fence_driver_start_ring().
 471  * Returns 0 for success.
 472  */
 473 int amdgpu_fence_driver_init(struct amdgpu_device *adev)
 474 {
 475         if (amdgpu_debugfs_fence_init(adev))
 476                 dev_err(adev->dev, "fence debugfs file creation failed\n");
 477
 478         return 0;
 479 }
 480
 481 /**
 482  * amdgpu_fence_driver_fini - tear down the fence driver
 483  * for all possible rings.
 484  *
 485  * @adev: amdgpu device pointer
 486  *
 487  * Tear down the fence driver for all possible rings (all asics).
 488  */
 489 void amdgpu_fence_driver_fini(struct amdgpu_device *adev)
 490 {
 491         unsigned i, j;
 492         int r;
 493
 494         for (i = 0; i < AMDGPU_MAX_RINGS; i++) {
 495                 struct amdgpu_ring *ring = adev->rings[i];
 496
 497                 if (!ring || !ring->fence_drv.initialized)
 498                         continue;
 499                 r = amdgpu_fence_wait_empty(ring);
 500                 if (r) {
 501                         /* no need to trigger GPU reset as we are unloading */
 502                         amdgpu_fence_driver_force_completion(adev);
 503                 }
 504                 amdgpu_irq_put(adev, ring->fence_drv.irq_src,
 505                                ring->fence_drv.irq_type);
 506                 amd_sched_fini(&ring->sched);
 507                 del_timer_sync(&ring->fence_drv.fallback_timer);
 508                 for (j = 0; j <= ring->fence_drv.num_fences_mask; ++j)
 509                         dma_fence_put(ring->fence_drv.fences[j]);
 510                 kfree(ring->fence_drv.fences);
 511                 ring->fence_drv.fences = NULL;
 512                 ring->fence_drv.initialized = false;
 513         }
 514 }
 515
 516 /**
 517  * amdgpu_fence_driver_suspend - suspend the fence driver
 518  * for all possible rings.
 519  *
 520  * @adev: amdgpu device pointer
 521  *
 522  * Suspend the fence driver for all possible rings (all asics).
 523  */
 524 void amdgpu_fence_driver_suspend(struct amdgpu_device *adev)
 525 {
 526         int i, r;
 527
 528         for (i = 0; i < AMDGPU_MAX_RINGS; i++) {
 529                 struct amdgpu_ring *ring = adev->rings[i];
 530                 if (!ring || !ring->fence_drv.initialized)
 531                         continue;
 532
 533                 /* wait for gpu to finish processing current batch */
 534                 r = amdgpu_fence_wait_empty(ring);
 535                 if (r) {
 536                         /* delay GPU reset to resume */
 537                         amdgpu_fence_driver_force_completion(adev);
 538                 }
 539
 540                 /* disable the interrupt */
 541                 amdgpu_irq_put(adev, ring->fence_drv.irq_src,
 542                                ring->fence_drv.irq_type);
 543         }
 544 }
 545
 546 /**
 547  * amdgpu_fence_driver_resume - resume the fence driver
 548  * for all possible rings.
 549  *
 550  * @adev: amdgpu device pointer
 551  *
 552  * Resume the fence driver for all possible rings (all asics).
 553  * Not all asics have all rings, so each asic will only
 554  * start the fence driver on the rings it has using
 555  * amdgpu_fence_driver_start_ring().
 556  * Returns 0 for success.
 557  */
 558 void amdgpu_fence_driver_resume(struct amdgpu_device *adev)
 559 {
 560         int i;
 561
 562         for (i = 0; i < AMDGPU_MAX_RINGS; i++) {
 563                 struct amdgpu_ring *ring = adev->rings[i];
 564                 if (!ring || !ring->fence_drv.initialized)
 565                         continue;
 566
 567                 /* enable the interrupt */
 568                 amdgpu_irq_get(adev, ring->fence_drv.irq_src,
 569                                ring->fence_drv.irq_type);
 570         }
 571 }
 572
 573 /**
 574  * amdgpu_fence_driver_force_completion - force all fence waiter to complete
 575  *
 576  * @adev: amdgpu device pointer
 577  *
 578  * In case of GPU reset failure make sure no process keep waiting on fence
 579  * that will never complete.
 580  */
 581 void amdgpu_fence_driver_force_completion(struct amdgpu_device *adev)
 582 {
 583         int i;
 584
 585         for (i = 0; i < AMDGPU_MAX_RINGS; i++) {
 586                 struct amdgpu_ring *ring = adev->rings[i];
 587                 if (!ring || !ring->fence_drv.initialized)
 588                         continue;
 589
 590                 amdgpu_fence_write(ring, ring->fence_drv.sync_seq);
 591         }
 592 }
 593
 594 void amdgpu_fence_driver_force_completion_ring(struct amdgpu_ring *ring)
 595 {
 596         if (ring)
 597                 amdgpu_fence_write(ring, ring->fence_drv.sync_seq);
 598 }
 599
 600 /*
 601  * Common fence implementation
 602  */
 603
 604 static const char *amdgpu_fence_get_driver_name(struct dma_fence *fence)
 605 {
 606         return "amdgpu";
 607 }
 608
 609 static const char *amdgpu_fence_get_timeline_name(struct dma_fence *f)
 610 {
 611         struct amdgpu_fence *fence = to_amdgpu_fence(f);
 612         return (const char *)fence->ring->name;
 613 }
 614
 615 /**
 616  * amdgpu_fence_enable_signaling - enable signalling on fence
 617  * @fence: fence
 618  *
 619  * This function is called with fence_queue lock held, and adds a callback
 620  * to fence_queue that checks if this fence is signaled, and if so it
 621  * signals the fence and removes itself.
 622  */
 623 static bool amdgpu_fence_enable_signaling(struct dma_fence *f)
 624 {
 625         struct amdgpu_fence *fence = to_amdgpu_fence(f);
 626         struct amdgpu_ring *ring = fence->ring;
 627
 628         if (!timer_pending(&ring->fence_drv.fallback_timer))
 629                 amdgpu_fence_schedule_fallback(ring);
 630
 631         DMA_FENCE_TRACE(&fence->base, "armed on ring %i!\n", ring->idx);
 632
 633         return true;
 634 }
 635
 636 /**
 637  * amdgpu_fence_free - free up the fence memory
 638  *
 639  * @rcu: RCU callback head
 640  *
 641  * Free up the fence memory after the RCU grace period.
 642  */
 643 static void amdgpu_fence_free(struct rcu_head *rcu)
 644 {
 645         struct dma_fence *f = container_of(rcu, struct dma_fence, rcu);
 646         struct amdgpu_fence *fence = to_amdgpu_fence(f);
 647         kmem_cache_free(amdgpu_fence_slab, fence);
 648 }
 649
 650 /**
 651  * amdgpu_fence_release - callback that fence can be freed
 652  *
 653  * @fence: fence
 654  *
 655  * This function is called when the reference count becomes zero.
 656  * It just RCU schedules freeing up the fence.
 657  */
 658 static void amdgpu_fence_release(struct dma_fence *f)
 659 {
 660         call_rcu(&f->rcu, amdgpu_fence_free);
 661 }
 662
 663 static const struct dma_fence_ops amdgpu_fence_ops = {
 664         .get_driver_name = amdgpu_fence_get_driver_name,
 665         .get_timeline_name = amdgpu_fence_get_timeline_name,
 666         .enable_signaling = amdgpu_fence_enable_signaling,
 667         .wait = dma_fence_default_wait,
 668         .release = amdgpu_fence_release,
 669 };
 670
 671 /*
 672  * Fence debugfs
 673  */
 674 #if defined(CONFIG_DEBUG_FS)
 675 static int amdgpu_debugfs_fence_info(struct seq_file *m, void *data)
 676 {
 677         struct drm_info_node *node = (struct drm_info_node *)m->private;
 678         struct drm_device *dev = node->minor->dev;
 679         struct amdgpu_device *adev = dev->dev_private;
 680         int i;
 681
 682         for (i = 0; i < AMDGPU_MAX_RINGS; ++i) {
 683                 struct amdgpu_ring *ring = adev->rings[i];
 684                 if (!ring || !ring->fence_drv.initialized)
 685                         continue;
 686
 687                 amdgpu_fence_process(ring);
 688
 689                 seq_printf(m, "--- ring %d (%s) ---\n", i, ring->name);
 690                 seq_printf(m, "Last signaled fence 0x%08x\n",
 691                            atomic_read(&ring->fence_drv.last_seq));
 692                 seq_printf(m, "Last emitted        0x%08x\n",
 693                            ring->fence_drv.sync_seq);
 694
 695                 if (ring->funcs->type != AMDGPU_RING_TYPE_GFX)
 696                         continue;
 697
 698                 /* set in CP_VMID_PREEMPT and preemption occurred */
 699                 seq_printf(m, "Last preempted      0x%08x\n",
 700                            le32_to_cpu(*(ring->fence_drv.cpu_addr + 2)));
 701                 /* set in CP_VMID_RESET and reset occurred */
 702                 seq_printf(m, "Last reset          0x%08x\n",
 703                            le32_to_cpu(*(ring->fence_drv.cpu_addr + 4)));
 704                 /* Both preemption and reset occurred */
 705                 seq_printf(m, "Last both           0x%08x\n",
 706                            le32_to_cpu(*(ring->fence_drv.cpu_addr + 6)));
 707         }
 708         return 0;
 709 }
 710
 711 /**
 712  * amdgpu_debugfs_gpu_reset - manually trigger a gpu reset
 713  *
 714  * Manually trigger a gpu reset at the next fence wait.
 715  */
 716 static int amdgpu_debugfs_gpu_reset(struct seq_file *m, void *data)
 717 {
 718         struct drm_info_node *node = (struct drm_info_node *) m->private;
 719         struct drm_device *dev = node->minor->dev;
 720         struct amdgpu_device *adev = dev->dev_private;
 721
 722         seq_printf(m, "gpu reset\n");
 723         amdgpu_gpu_reset(adev);
 724
 725         return 0;
 726 }
 727
 728 static const struct drm_info_list amdgpu_debugfs_fence_list[] = {
 729         {"amdgpu_fence_info", &amdgpu_debugfs_fence_info, 0, NULL},
 730         {"amdgpu_gpu_reset", &amdgpu_debugfs_gpu_reset, 0, NULL}
 731 };
 732
 733 static const struct drm_info_list amdgpu_debugfs_fence_list_sriov[] = {
 734         {"amdgpu_fence_info", &amdgpu_debugfs_fence_info, 0, NULL},
 735 };
 736 #endif
 737
 738 int amdgpu_debugfs_fence_init(struct amdgpu_device *adev)
 739 {
 740 #if defined(CONFIG_DEBUG_FS)
 741         if (amdgpu_sriov_vf(adev))
 742                 return amdgpu_debugfs_add_files(adev, amdgpu_debugfs_fence_list_sriov, 1);
 743         return amdgpu_debugfs_add_files(adev, amdgpu_debugfs_fence_list, 2);
 744 #else
 745         return 0;
 746 #endif
 747 }
 748