drm/amdgpu: introduce AMDGPU_GEM_CREATE_EXPLICIT_SYNC v2

Introduce a flag to signal that access to a BO will be synchronized
through an external mechanism.

Currently all buffers shared between contexts are subject to implicit
synchronization. However, this is only required for protocols that
currently don't support an explicit synchronization mechanism (DRI2/3).

This patch introduces the AMDGPU_GEM_CREATE_EXPLICIT_SYNC, so that
users can specify when it is safe to disable implicit sync.

v2: only disable explicit sync in amdgpu_cs_ioctl

Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Andres Rodriguez <andresx7@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index 10952c3e5eb6..a2282bacf960 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -1489,7 +1489,8 @@ int amdgpu_copy_buffer(struct amdgpu_ring *ring, uint64_t src_offset,
         job->vm_needs_flush = vm_needs_flush;
         if (resv) {
                 r = amdgpu_sync_resv(adev, &job->sync, resv,
-                                     AMDGPU_FENCE_OWNER_UNDEFINED);
+                                     AMDGPU_FENCE_OWNER_UNDEFINED,
+                                     false);
                 if (r) {
                         DRM_ERROR("sync failed (%d).\n", r);
                         goto error_free;
@@ -1581,7 +1582,7 @@ int amdgpu_fill_buffer(struct amdgpu_bo *bo,
 
         if (resv) {
                 r = amdgpu_sync_resv(adev, &job->sync, resv,
-                                     AMDGPU_FENCE_OWNER_UNDEFINED);
+                                     AMDGPU_FENCE_OWNER_UNDEFINED, false);
                 if (r) {
                         DRM_ERROR("sync failed (%d).\n", r);
                         goto error_free;