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 <[email protected]>
  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                       unsigned flags)
 136 {
 137         struct amdgpu_device *adev = ring->adev;
 138         struct amdgpu_fence *fence;
 139         struct dma_fence __rcu **ptr;
 140         uint32_t seq;
 141         int r;
 142
 143         fence = kmem_cache_alloc(amdgpu_fence_slab, GFP_KERNEL);
 144         if (fence == NULL)
 145                 return -ENOMEM;
 146
 147         seq = ++ring->fence_drv.sync_seq;
 148         fence->ring = ring;
 149         dma_fence_init(&fence->base, &amdgpu_fence_ops,
 150                        &ring->fence_drv.lock,
 151                        adev->fence_context + ring->idx,
 152                        seq);
 153         amdgpu_ring_emit_fence(ring, ring->fence_drv.gpu_addr,
 154                                seq, flags | AMDGPU_FENCE_FLAG_INT);
 155
 156         ptr = &ring->fence_drv.fences[seq & ring->fence_drv.num_fences_mask];
 157         if (unlikely(rcu_dereference_protected(*ptr, 1))) {
 158                 struct dma_fence *old;
 159
 160                 rcu_read_lock();
 161                 old = dma_fence_get_rcu_safe(ptr);
 162                 rcu_read_unlock();
 163
 164                 if (old) {
 165                         r = dma_fence_wait(old, false);
 166                         dma_fence_put(old);
 167                         if (r)
 168                                 return r;
 169                 }
 170         }
 171
 172         /* This function can't be called concurrently anyway, otherwise
 173          * emitting the fence would mess up the hardware ring buffer.
 174          */
 175         rcu_assign_pointer(*ptr, dma_fence_get(&fence->base));
 176
 177         *f = &fence->base;
 178
 179         return 0;
 180 }
 181
 182 /**
 183  * amdgpu_fence_emit_polling - emit a fence on the requeste ring
 184  *
 185  * @ring: ring the fence is associated with
 186  * @s: resulting sequence number
 187  *
 188  * Emits a fence command on the requested ring (all asics).
 189  * Used For polling fence.
 190  * Returns 0 on success, -ENOMEM on failure.
 191  */
 192 int amdgpu_fence_emit_polling(struct amdgpu_ring *ring, uint32_t *s)
 193 {
 194         uint32_t seq;
 195
 196         if (!s)
 197                 return -EINVAL;
 198
 199         seq = ++ring->fence_drv.sync_seq;
 200         amdgpu_ring_emit_fence(ring, ring->fence_drv.gpu_addr,
 201                                seq, 0);
 202
 203         *s = seq;
 204
 205         return 0;
 206 }
 207
 208 /**
 209  * amdgpu_fence_schedule_fallback - schedule fallback check
 210  *
 211  * @ring: pointer to struct amdgpu_ring
 212  *
 213  * Start a timer as fallback to our interrupts.
 214  */
 215 static void amdgpu_fence_schedule_fallback(struct amdgpu_ring *ring)
 216 {
 217         mod_timer(&ring->fence_drv.fallback_timer,
 218                   jiffies + AMDGPU_FENCE_JIFFIES_TIMEOUT);
 219 }
 220
 221 /**
 222  * amdgpu_fence_process - check for fence activity
 223  *
 224  * @ring: pointer to struct amdgpu_ring
 225  *
 226  * Checks the current fence value and calculates the last
 227  * signalled fence value. Wakes the fence queue if the
 228  * sequence number has increased.
 229  *
 230  * Returns true if fence was processed
 231  */
 232 bool amdgpu_fence_process(struct amdgpu_ring *ring)
 233 {
 234         struct amdgpu_fence_driver *drv = &ring->fence_drv;
 235         uint32_t seq, last_seq;
 236         int r;
 237
 238         do {
 239                 last_seq = atomic_read(&ring->fence_drv.last_seq);
 240                 seq = amdgpu_fence_read(ring);
 241
 242         } while (atomic_cmpxchg(&drv->last_seq, last_seq, seq) != last_seq);
 243
 244         if (del_timer(&ring->fence_drv.fallback_timer) &&
 245             seq != ring->fence_drv.sync_seq)
 246                 amdgpu_fence_schedule_fallback(ring);
 247
 248         if (unlikely(seq == last_seq))
 249                 return false;
 250
 251         last_seq &= drv->num_fences_mask;
 252         seq &= drv->num_fences_mask;
 253
 254         do {
 255                 struct dma_fence *fence, **ptr;
 256
 257                 ++last_seq;
 258                 last_seq &= drv->num_fences_mask;
 259                 ptr = &drv->fences[last_seq];
 260
 261                 /* There is always exactly one thread signaling this fence slot */
 262                 fence = rcu_dereference_protected(*ptr, 1);
 263                 RCU_INIT_POINTER(*ptr, NULL);
 264
 265                 if (!fence)
 266                         continue;
 267
 268                 r = dma_fence_signal(fence);
 269                 if (!r)
 270                         DMA_FENCE_TRACE(fence, "signaled from irq context\n");
 271                 else
 272                         BUG();
 273
 274                 dma_fence_put(fence);
 275         } while (last_seq != seq);
 276
 277         return true;
 278 }
 279
 280 /**
 281  * amdgpu_fence_fallback - fallback for hardware interrupts
 282  *
 283  * @work: delayed work item
 284  *
 285  * Checks for fence activity.
 286  */
 287 static void amdgpu_fence_fallback(struct timer_list *t)
 288 {
 289         struct amdgpu_ring *ring = from_timer(ring, t,
 290                                               fence_drv.fallback_timer);
 291
 292         if (amdgpu_fence_process(ring))
 293                 DRM_WARN("Fence fallback timer expired on ring %s\n", ring->name);
 294 }
 295
 296 /**
 297  * amdgpu_fence_wait_empty - wait for all fences to signal
 298  *
 299  * @adev: amdgpu device pointer
 300  * @ring: ring index the fence is associated with
 301  *
 302  * Wait for all fences on the requested ring to signal (all asics).
 303  * Returns 0 if the fences have passed, error for all other cases.
 304  */
 305 int amdgpu_fence_wait_empty(struct amdgpu_ring *ring)
 306 {
 307         uint64_t seq = READ_ONCE(ring->fence_drv.sync_seq);
 308         struct dma_fence *fence, **ptr;
 309         int r;
 310
 311         if (!seq)
 312                 return 0;
 313
 314         ptr = &ring->fence_drv.fences[seq & ring->fence_drv.num_fences_mask];
 315         rcu_read_lock();
 316         fence = rcu_dereference(*ptr);
 317         if (!fence || !dma_fence_get_rcu(fence)) {
 318                 rcu_read_unlock();
 319                 return 0;
 320         }
 321         rcu_read_unlock();
 322
 323         r = dma_fence_wait(fence, false);
 324         dma_fence_put(fence);
 325         return r;
 326 }
 327
 328 /**
 329  * amdgpu_fence_wait_polling - busy wait for givn sequence number
 330  *
 331  * @ring: ring index the fence is associated with
 332  * @wait_seq: sequence number to wait
 333  * @timeout: the timeout for waiting in usecs
 334  *
 335  * Wait for all fences on the requested ring to signal (all asics).
 336  * Returns left time if no timeout, 0 or minus if timeout.
 337  */
 338 signed long amdgpu_fence_wait_polling(struct amdgpu_ring *ring,
 339                                       uint32_t wait_seq,
 340                                       signed long timeout)
 341 {
 342         uint32_t seq;
 343
 344         do {
 345                 seq = amdgpu_fence_read(ring);
 346                 udelay(5);
 347                 timeout -= 5;
 348         } while ((int32_t)(wait_seq - seq) > 0 && timeout > 0);
 349
 350         return timeout > 0 ? timeout : 0;
 351 }
 352 /**
 353  * amdgpu_fence_count_emitted - get the count of emitted fences
 354  *
 355  * @ring: ring the fence is associated with
 356  *
 357  * Get the number of fences emitted on the requested ring (all asics).
 358  * Returns the number of emitted fences on the ring.  Used by the
 359  * dynpm code to ring track activity.
 360  */
 361 unsigned amdgpu_fence_count_emitted(struct amdgpu_ring *ring)
 362 {
 363         uint64_t emitted;
 364
 365         /* We are not protected by ring lock when reading the last sequence
 366          * but it's ok to report slightly wrong fence count here.
 367          */
 368         amdgpu_fence_process(ring);
 369         emitted = 0x100000000ull;
 370         emitted -= atomic_read(&ring->fence_drv.last_seq);
 371         emitted += READ_ONCE(ring->fence_drv.sync_seq);
 372         return lower_32_bits(emitted);
 373 }
 374
 375 /**
 376  * amdgpu_fence_driver_start_ring - make the fence driver
 377  * ready for use on the requested ring.
 378  *
 379  * @ring: ring to start the fence driver on
 380  * @irq_src: interrupt source to use for this ring
 381  * @irq_type: interrupt type to use for this ring
 382  *
 383  * Make the fence driver ready for processing (all asics).
 384  * Not all asics have all rings, so each asic will only
 385  * start the fence driver on the rings it has.
 386  * Returns 0 for success, errors for failure.
 387  */
 388 int amdgpu_fence_driver_start_ring(struct amdgpu_ring *ring,
 389                                    struct amdgpu_irq_src *irq_src,
 390                                    unsigned irq_type)
 391 {
 392         struct amdgpu_device *adev = ring->adev;
 393         uint64_t index;
 394
 395         if (ring->funcs->type != AMDGPU_RING_TYPE_UVD) {
 396                 ring->fence_drv.cpu_addr = &adev->wb.wb[ring->fence_offs];
 397                 ring->fence_drv.gpu_addr = adev->wb.gpu_addr + (ring->fence_offs * 4);
 398         } else {
 399                 /* put fence directly behind firmware */
 400                 index = ALIGN(adev->uvd.fw->size, 8);
 401                 ring->fence_drv.cpu_addr = adev->uvd.inst[ring->me].cpu_addr + index;
 402                 ring->fence_drv.gpu_addr = adev->uvd.inst[ring->me].gpu_addr + index;
 403         }
 404         amdgpu_fence_write(ring, atomic_read(&ring->fence_drv.last_seq));
 405         amdgpu_irq_get(adev, irq_src, irq_type);
 406
 407         ring->fence_drv.irq_src = irq_src;
 408         ring->fence_drv.irq_type = irq_type;
 409         ring->fence_drv.initialized = true;
 410
 411         DRM_DEV_DEBUG(adev->dev, "fence driver on ring %s use gpu addr "
 412                       "0x%016llx, cpu addr 0x%p\n", ring->name,
 413                       ring->fence_drv.gpu_addr, ring->fence_drv.cpu_addr);
 414         return 0;
 415 }
 416
 417 /**
 418  * amdgpu_fence_driver_init_ring - init the fence driver
 419  * for the requested ring.
 420  *
 421  * @ring: ring to init the fence driver on
 422  * @num_hw_submission: number of entries on the hardware queue
 423  *
 424  * Init the fence driver for the requested ring (all asics).
 425  * Helper function for amdgpu_fence_driver_init().
 426  */
 427 int amdgpu_fence_driver_init_ring(struct amdgpu_ring *ring,
 428                                   unsigned num_hw_submission)
 429 {
 430         long timeout;
 431         int r;
 432
 433         /* Check that num_hw_submission is a power of two */
 434         if ((num_hw_submission & (num_hw_submission - 1)) != 0)
 435                 return -EINVAL;
 436
 437         ring->fence_drv.cpu_addr = NULL;
 438         ring->fence_drv.gpu_addr = 0;
 439         ring->fence_drv.sync_seq = 0;
 440         atomic_set(&ring->fence_drv.last_seq, 0);
 441         ring->fence_drv.initialized = false;
 442
 443         timer_setup(&ring->fence_drv.fallback_timer, amdgpu_fence_fallback, 0);
 444
 445         ring->fence_drv.num_fences_mask = num_hw_submission * 2 - 1;
 446         spin_lock_init(&ring->fence_drv.lock);
 447         ring->fence_drv.fences = kcalloc(num_hw_submission * 2, sizeof(void *),
 448                                          GFP_KERNEL);
 449         if (!ring->fence_drv.fences)
 450                 return -ENOMEM;
 451
 452         /* No need to setup the GPU scheduler for KIQ ring */
 453         if (ring->funcs->type != AMDGPU_RING_TYPE_KIQ) {
 454                 /* for non-sriov case, no timeout enforce on compute ring */
 455                 if ((ring->funcs->type == AMDGPU_RING_TYPE_COMPUTE)
 456                                 && !amdgpu_sriov_vf(ring->adev))
 457                         timeout = MAX_SCHEDULE_TIMEOUT;
 458                 else
 459                         timeout = msecs_to_jiffies(amdgpu_lockup_timeout);
 460
 461                 r = drm_sched_init(&ring->sched, &amdgpu_sched_ops,
 462                                    num_hw_submission, amdgpu_job_hang_limit,
 463                                    timeout, ring->name);
 464                 if (r) {
 465                         DRM_ERROR("Failed to create scheduler on ring %s.\n",
 466                                   ring->name);
 467                         return r;
 468                 }
 469         }
 470
 471         return 0;
 472 }
 473
 474 /**
 475  * amdgpu_fence_driver_init - init the fence driver
 476  * for all possible rings.
 477  *
 478  * @adev: amdgpu device pointer
 479  *
 480  * Init the fence driver for all possible rings (all asics).
 481  * Not all asics have all rings, so each asic will only
 482  * start the fence driver on the rings it has using
 483  * amdgpu_fence_driver_start_ring().
 484  * Returns 0 for success.
 485  */
 486 int amdgpu_fence_driver_init(struct amdgpu_device *adev)
 487 {
 488         if (amdgpu_debugfs_fence_init(adev))
 489                 dev_err(adev->dev, "fence debugfs file creation failed\n");
 490
 491         return 0;
 492 }
 493
 494 /**
 495  * amdgpu_fence_driver_fini - tear down the fence driver
 496  * for all possible rings.
 497  *
 498  * @adev: amdgpu device pointer
 499  *
 500  * Tear down the fence driver for all possible rings (all asics).
 501  */
 502 void amdgpu_fence_driver_fini(struct amdgpu_device *adev)
 503 {
 504         unsigned i, j;
 505         int r;
 506
 507         for (i = 0; i < AMDGPU_MAX_RINGS; i++) {
 508                 struct amdgpu_ring *ring = adev->rings[i];
 509
 510                 if (!ring || !ring->fence_drv.initialized)
 511                         continue;
 512                 r = amdgpu_fence_wait_empty(ring);
 513                 if (r) {
 514                         /* no need to trigger GPU reset as we are unloading */
 515                         amdgpu_fence_driver_force_completion(ring);
 516                 }
 517                 amdgpu_irq_put(adev, ring->fence_drv.irq_src,
 518                                ring->fence_drv.irq_type);
 519                 drm_sched_fini(&ring->sched);
 520                 del_timer_sync(&ring->fence_drv.fallback_timer);
 521                 for (j = 0; j <= ring->fence_drv.num_fences_mask; ++j)
 522                         dma_fence_put(ring->fence_drv.fences[j]);
 523                 kfree(ring->fence_drv.fences);
 524                 ring->fence_drv.fences = NULL;
 525                 ring->fence_drv.initialized = false;
 526         }
 527 }
 528
 529 /**
 530  * amdgpu_fence_driver_suspend - suspend the fence driver
 531  * for all possible rings.
 532  *
 533  * @adev: amdgpu device pointer
 534  *
 535  * Suspend the fence driver for all possible rings (all asics).
 536  */
 537 void amdgpu_fence_driver_suspend(struct amdgpu_device *adev)
 538 {
 539         int i, r;
 540
 541         for (i = 0; i < AMDGPU_MAX_RINGS; i++) {
 542                 struct amdgpu_ring *ring = adev->rings[i];
 543                 if (!ring || !ring->fence_drv.initialized)
 544                         continue;
 545
 546                 /* wait for gpu to finish processing current batch */
 547                 r = amdgpu_fence_wait_empty(ring);
 548                 if (r) {
 549                         /* delay GPU reset to resume */
 550                         amdgpu_fence_driver_force_completion(ring);
 551                 }
 552
 553                 /* disable the interrupt */
 554                 amdgpu_irq_put(adev, ring->fence_drv.irq_src,
 555                                ring->fence_drv.irq_type);
 556         }
 557 }
 558
 559 /**
 560  * amdgpu_fence_driver_resume - resume the fence driver
 561  * for all possible rings.
 562  *
 563  * @adev: amdgpu device pointer
 564  *
 565  * Resume the fence driver for all possible rings (all asics).
 566  * Not all asics have all rings, so each asic will only
 567  * start the fence driver on the rings it has using
 568  * amdgpu_fence_driver_start_ring().
 569  * Returns 0 for success.
 570  */
 571 void amdgpu_fence_driver_resume(struct amdgpu_device *adev)
 572 {
 573         int i;
 574
 575         for (i = 0; i < AMDGPU_MAX_RINGS; i++) {
 576                 struct amdgpu_ring *ring = adev->rings[i];
 577                 if (!ring || !ring->fence_drv.initialized)
 578                         continue;
 579
 580                 /* enable the interrupt */
 581                 amdgpu_irq_get(adev, ring->fence_drv.irq_src,
 582                                ring->fence_drv.irq_type);
 583         }
 584 }
 585
 586 /**
 587  * amdgpu_fence_driver_force_completion - force signal latest fence of ring
 588  *
 589  * @ring: fence of the ring to signal
 590  *
 591  */
 592 void amdgpu_fence_driver_force_completion(struct amdgpu_ring *ring)
 593 {
 594         amdgpu_fence_write(ring, ring->fence_drv.sync_seq);
 595         amdgpu_fence_process(ring);
 596 }
 597
 598 /*
 599  * Common fence implementation
 600  */
 601
 602 static const char *amdgpu_fence_get_driver_name(struct dma_fence *fence)
 603 {
 604         return "amdgpu";
 605 }
 606
 607 static const char *amdgpu_fence_get_timeline_name(struct dma_fence *f)
 608 {
 609         struct amdgpu_fence *fence = to_amdgpu_fence(f);
 610         return (const char *)fence->ring->name;
 611 }
 612
 613 /**
 614  * amdgpu_fence_enable_signaling - enable signalling on fence
 615  * @fence: fence
 616  *
 617  * This function is called with fence_queue lock held, and adds a callback
 618  * to fence_queue that checks if this fence is signaled, and if so it
 619  * signals the fence and removes itself.
 620  */
 621 static bool amdgpu_fence_enable_signaling(struct dma_fence *f)
 622 {
 623         struct amdgpu_fence *fence = to_amdgpu_fence(f);
 624         struct amdgpu_ring *ring = fence->ring;
 625
 626         if (!timer_pending(&ring->fence_drv.fallback_timer))
 627                 amdgpu_fence_schedule_fallback(ring);
 628
 629         DMA_FENCE_TRACE(&fence->base, "armed on ring %i!\n", ring->idx);
 630
 631         return true;
 632 }
 633
 634 /**
 635  * amdgpu_fence_free - free up the fence memory
 636  *
 637  * @rcu: RCU callback head
 638  *
 639  * Free up the fence memory after the RCU grace period.
 640  */
 641 static void amdgpu_fence_free(struct rcu_head *rcu)
 642 {
 643         struct dma_fence *f = container_of(rcu, struct dma_fence, rcu);
 644         struct amdgpu_fence *fence = to_amdgpu_fence(f);
 645         kmem_cache_free(amdgpu_fence_slab, fence);
 646 }
 647
 648 /**
 649  * amdgpu_fence_release - callback that fence can be freed
 650  *
 651  * @fence: fence
 652  *
 653  * This function is called when the reference count becomes zero.
 654  * It just RCU schedules freeing up the fence.
 655  */
 656 static void amdgpu_fence_release(struct dma_fence *f)
 657 {
 658         call_rcu(&f->rcu, amdgpu_fence_free);
 659 }
 660
 661 static const struct dma_fence_ops amdgpu_fence_ops = {
 662         .get_driver_name = amdgpu_fence_get_driver_name,
 663         .get_timeline_name = amdgpu_fence_get_timeline_name,
 664         .enable_signaling = amdgpu_fence_enable_signaling,
 665         .release = amdgpu_fence_release,
 666 };
 667
 668 /*
 669  * Fence debugfs
 670  */
 671 #if defined(CONFIG_DEBUG_FS)
 672 static int amdgpu_debugfs_fence_info(struct seq_file *m, void *data)
 673 {
 674         struct drm_info_node *node = (struct drm_info_node *)m->private;
 675         struct drm_device *dev = node->minor->dev;
 676         struct amdgpu_device *adev = dev->dev_private;
 677         int i;
 678
 679         for (i = 0; i < AMDGPU_MAX_RINGS; ++i) {
 680                 struct amdgpu_ring *ring = adev->rings[i];
 681                 if (!ring || !ring->fence_drv.initialized)
 682                         continue;
 683
 684                 amdgpu_fence_process(ring);
 685
 686                 seq_printf(m, "--- ring %d (%s) ---\n", i, ring->name);
 687                 seq_printf(m, "Last signaled fence 0x%08x\n",
 688                            atomic_read(&ring->fence_drv.last_seq));
 689                 seq_printf(m, "Last emitted        0x%08x\n",
 690                            ring->fence_drv.sync_seq);
 691
 692                 if (ring->funcs->type != AMDGPU_RING_TYPE_GFX)
 693                         continue;
 694
 695                 /* set in CP_VMID_PREEMPT and preemption occurred */
 696                 seq_printf(m, "Last preempted      0x%08x\n",
 697                            le32_to_cpu(*(ring->fence_drv.cpu_addr + 2)));
 698                 /* set in CP_VMID_RESET and reset occurred */
 699                 seq_printf(m, "Last reset          0x%08x\n",
 700                            le32_to_cpu(*(ring->fence_drv.cpu_addr + 4)));
 701                 /* Both preemption and reset occurred */
 702                 seq_printf(m, "Last both           0x%08x\n",
 703                            le32_to_cpu(*(ring->fence_drv.cpu_addr + 6)));
 704         }
 705         return 0;
 706 }
 707
 708 /**
 709  * amdgpu_debugfs_gpu_recover - manually trigger a gpu reset & recover
 710  *
 711  * Manually trigger a gpu reset at the next fence wait.
 712  */
 713 static int amdgpu_debugfs_gpu_recover(struct seq_file *m, void *data)
 714 {
 715         struct drm_info_node *node = (struct drm_info_node *) m->private;
 716         struct drm_device *dev = node->minor->dev;
 717         struct amdgpu_device *adev = dev->dev_private;
 718
 719         seq_printf(m, "gpu recover\n");
 720         amdgpu_device_gpu_recover(adev, NULL);
 721
 722         return 0;
 723 }
 724
 725 static const struct drm_info_list amdgpu_debugfs_fence_list[] = {
 726         {"amdgpu_fence_info", &amdgpu_debugfs_fence_info, 0, NULL},
 727         {"amdgpu_gpu_recover", &amdgpu_debugfs_gpu_recover, 0, NULL}
 728 };
 729
 730 static const struct drm_info_list amdgpu_debugfs_fence_list_sriov[] = {
 731         {"amdgpu_fence_info", &amdgpu_debugfs_fence_info, 0, NULL},
 732 };
 733 #endif
 734
 735 int amdgpu_debugfs_fence_init(struct amdgpu_device *adev)
 736 {
 737 #if defined(CONFIG_DEBUG_FS)
 738         if (amdgpu_sriov_vf(adev))
 739                 return amdgpu_debugfs_add_files(adev, amdgpu_debugfs_fence_list_sriov, 1);
 740         return amdgpu_debugfs_add_files(adev, amdgpu_debugfs_fence_list, 2);
 741 #else
 742         return 0;
 743 #endif
 744 }
 745