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

   1 /*
   2  * Copyright 2014 Advanced Micro Devices, Inc.
   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  *    Christian König <christian.koenig@amd.com>
  29  */
  30
  31 #include <drm/drmP.h>
  32 #include "amdgpu.h"
  33 #include "amdgpu_trace.h"
  34
  35 /**
  36  * amdgpu_sync_create - zero init sync object
  37  *
  38  * @sync: sync object to initialize
  39  *
  40  * Just clear the sync object for now.
  41  */
  42 void amdgpu_sync_create(struct amdgpu_sync *sync)
  43 {
  44         unsigned i;
  45
  46         for (i = 0; i < AMDGPU_NUM_SYNCS; ++i)
  47                 sync->semaphores[i] = NULL;
  48
  49         for (i = 0; i < AMDGPU_MAX_RINGS; ++i)
  50                 sync->sync_to[i] = NULL;
  51
  52         sync->last_vm_update = NULL;
  53 }
  54
  55 /**
  56  * amdgpu_sync_fence - use the semaphore to sync to a fence
  57  *
  58  * @sync: sync object to add fence to
  59  * @fence: fence to sync to
  60  *
  61  * Sync to the fence using the semaphore objects
  62  */
  63 void amdgpu_sync_fence(struct amdgpu_sync *sync,
  64                        struct amdgpu_fence *fence)
  65 {
  66         struct amdgpu_fence *other;
  67
  68         if (!fence)
  69                 return;
  70
  71         other = sync->sync_to[fence->ring->idx];
  72         sync->sync_to[fence->ring->idx] = amdgpu_fence_ref(
  73                 amdgpu_fence_later(fence, other));
  74         amdgpu_fence_unref(&other);
  75
  76         if (fence->owner == AMDGPU_FENCE_OWNER_VM) {
  77                 other = sync->last_vm_update;
  78                 sync->last_vm_update = amdgpu_fence_ref(
  79                         amdgpu_fence_later(fence, other));
  80                 amdgpu_fence_unref(&other);
  81         }
  82 }
  83
  84 /**
  85  * amdgpu_sync_resv - use the semaphores to sync to a reservation object
  86  *
  87  * @sync: sync object to add fences from reservation object to
  88  * @resv: reservation object with embedded fence
  89  * @shared: true if we should only sync to the exclusive fence
  90  *
  91  * Sync to the fence using the semaphore objects
  92  */
  93 int amdgpu_sync_resv(struct amdgpu_device *adev,
  94                      struct amdgpu_sync *sync,
  95                      struct reservation_object *resv,
  96                      void *owner)
  97 {
  98         struct reservation_object_list *flist;
  99         struct fence *f;
 100         struct amdgpu_fence *fence;
 101         unsigned i;
 102         int r = 0;
 103
 104         if (resv == NULL)
 105                 return -EINVAL;
 106
 107         /* always sync to the exclusive fence */
 108         f = reservation_object_get_excl(resv);
 109         fence = f ? to_amdgpu_fence(f) : NULL;
 110         if (fence && fence->ring->adev == adev)
 111                 amdgpu_sync_fence(sync, fence);
 112         else if (f)
 113                 r = fence_wait(f, true);
 114
 115         flist = reservation_object_get_list(resv);
 116         if (!flist || r)
 117                 return r;
 118
 119         for (i = 0; i < flist->shared_count; ++i) {
 120                 f = rcu_dereference_protected(flist->shared[i],
 121                                               reservation_object_held(resv));
 122                 fence = f ? to_amdgpu_fence(f) : NULL;
 123                 if (fence && fence->ring->adev == adev) {
 124                         if (fence->owner != owner ||
 125                             fence->owner == AMDGPU_FENCE_OWNER_UNDEFINED)
 126                                 amdgpu_sync_fence(sync, fence);
 127                 } else if (f) {
 128                         r = fence_wait(f, true);
 129                         if (r)
 130                                 break;
 131                 }
 132         }
 133         return r;
 134 }
 135
 136 /**
 137  * amdgpu_sync_rings - sync ring to all registered fences
 138  *
 139  * @sync: sync object to use
 140  * @ring: ring that needs sync
 141  *
 142  * Ensure that all registered fences are signaled before letting
 143  * the ring continue. The caller must hold the ring lock.
 144  */
 145 int amdgpu_sync_rings(struct amdgpu_sync *sync,
 146                       struct amdgpu_ring *ring)
 147 {
 148         struct amdgpu_device *adev = ring->adev;
 149         unsigned count = 0;
 150         int i, r;
 151
 152         for (i = 0; i < AMDGPU_MAX_RINGS; ++i) {
 153                 struct amdgpu_fence *fence = sync->sync_to[i];
 154                 struct amdgpu_semaphore *semaphore;
 155                 struct amdgpu_ring *other = adev->rings[i];
 156
 157                 /* check if we really need to sync */
 158                 if (!amdgpu_fence_need_sync(fence, ring))
 159                         continue;
 160
 161                 /* prevent GPU deadlocks */
 162                 if (!other->ready) {
 163                         dev_err(adev->dev, "Syncing to a disabled ring!");
 164                         return -EINVAL;
 165                 }
 166
 167                 if (count >= AMDGPU_NUM_SYNCS) {
 168                         /* not enough room, wait manually */
 169                         r = amdgpu_fence_wait(fence, false);
 170                         if (r)
 171                                 return r;
 172                         continue;
 173                 }
 174                 r = amdgpu_semaphore_create(adev, &semaphore);
 175                 if (r)
 176                         return r;
 177
 178                 sync->semaphores[count++] = semaphore;
 179
 180                 /* allocate enough space for sync command */
 181                 r = amdgpu_ring_alloc(other, 16);
 182                 if (r)
 183                         return r;
 184
 185                 /* emit the signal semaphore */
 186                 if (!amdgpu_semaphore_emit_signal(other, semaphore)) {
 187                         /* signaling wasn't successful wait manually */
 188                         amdgpu_ring_undo(other);
 189                         r = amdgpu_fence_wait(fence, false);
 190                         if (r)
 191                                 return r;
 192                         continue;
 193                 }
 194
 195                 /* we assume caller has already allocated space on waiters ring */
 196                 if (!amdgpu_semaphore_emit_wait(ring, semaphore)) {
 197                         /* waiting wasn't successful wait manually */
 198                         amdgpu_ring_undo(other);
 199                         r = amdgpu_fence_wait(fence, false);
 200                         if (r)
 201                                 return r;
 202                         continue;
 203                 }
 204
 205                 amdgpu_ring_commit(other);
 206                 amdgpu_fence_note_sync(fence, ring);
 207         }
 208
 209         return 0;
 210 }
 211
 212 /**
 213  * amdgpu_sync_free - free the sync object
 214  *
 215  * @adev: amdgpu_device pointer
 216  * @sync: sync object to use
 217  * @fence: fence to use for the free
 218  *
 219  * Free the sync object by freeing all semaphores in it.
 220  */
 221 void amdgpu_sync_free(struct amdgpu_device *adev,
 222                       struct amdgpu_sync *sync,
 223                       struct amdgpu_fence *fence)
 224 {
 225         unsigned i;
 226
 227         for (i = 0; i < AMDGPU_NUM_SYNCS; ++i)
 228                 amdgpu_semaphore_free(adev, &sync->semaphores[i], fence);
 229
 230         for (i = 0; i < AMDGPU_MAX_RINGS; ++i)
 231                 amdgpu_fence_unref(&sync->sync_to[i]);
 232
 233         amdgpu_fence_unref(&sync->last_vm_update);
 234 }