drm/amdgpu: Move to gtt before cpu accesses dma buf.
To improve cpu read performance. This is implemented for APUs currently.
v2: Adapt to change https://lists.freedesktop.org/archives/amd-gfx/2017-October/015174.html
v3: Adapt to change "forward begin_cpu_access callback to drivers"
v4: Instead of v3, reuse drm_gem dmabuf_ops here. Also some minor fixes as suggested.
v5: only set dma_buf ops when it is valid (Samuel)
Signed-off-by: Samuel Li <Samuel.Li@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index 0059a06..2ca14d6 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -418,6 +418,8 @@ amdgpu_gem_prime_import_sg_table(struct drm_device *dev,
struct dma_buf *amdgpu_gem_prime_export(struct drm_device *dev,
struct drm_gem_object *gobj,
int flags);
+struct drm_gem_object *amdgpu_gem_prime_import(struct drm_device *dev,
+ struct dma_buf *dma_buf);
int amdgpu_gem_prime_pin(struct drm_gem_object *obj);
void amdgpu_gem_prime_unpin(struct drm_gem_object *obj);
struct reservation_object *amdgpu_gem_prime_res_obj(struct drm_gem_object *);