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, 2 insertions, 1 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
index ab83dfcabb41..38027a00f8ab 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
@@ -705,7 +705,8 @@ static int amdgpu_cs_sync_rings(struct amdgpu_cs_parser *p)
 
         list_for_each_entry(e, &p->validated, tv.head) {
                 struct reservation_object *resv = e->robj->tbo.resv;
-                r = amdgpu_sync_resv(p->adev, &p->job->sync, resv, p->filp);
+                r = amdgpu_sync_resv(p->adev, &p->job->sync, resv, p->filp,
+                                     amdgpu_bo_explicit_sync(e->robj));
 
                 if (r)
                         return r;