drm/amdgpu: add a fence after the VM flush

This way we can track when the flush is done.

Signed-off-by: Christian König <christian.koenig@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Chunming Zhou <david1.zhou@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 148e2c6..66e51f9 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -880,6 +880,7 @@
 	struct list_head	list;
 	struct fence		*first;
 	struct amdgpu_sync	active;
+	struct fence		*last_flush;
 	atomic_long_t		owner;
 
 	uint64_t		pd_gpu_addr;
@@ -926,11 +927,11 @@
 int amdgpu_vm_grab_id(struct amdgpu_vm *vm, struct amdgpu_ring *ring,
 		      struct amdgpu_sync *sync, struct fence *fence,
 		      unsigned *vm_id, uint64_t *vm_pd_addr);
-void amdgpu_vm_flush(struct amdgpu_ring *ring,
-		     unsigned vm_id, uint64_t pd_addr,
-		     uint32_t gds_base, uint32_t gds_size,
-		     uint32_t gws_base, uint32_t gws_size,
-		     uint32_t oa_base, uint32_t oa_size);
+int amdgpu_vm_flush(struct amdgpu_ring *ring,
+		    unsigned vm_id, uint64_t pd_addr,
+		    uint32_t gds_base, uint32_t gds_size,
+		    uint32_t gws_base, uint32_t gws_size,
+		    uint32_t oa_base, uint32_t oa_size);
 void amdgpu_vm_reset_id(struct amdgpu_device *adev, unsigned vm_id);
 uint64_t amdgpu_vm_map_gart(const dma_addr_t *pages_addr, uint64_t addr);
 int amdgpu_vm_update_page_directory(struct amdgpu_device *adev,