drm/amdgpu: wait for VM to become idle during flush

Make sure that not only the entities are flush, but that
we also wait for the HW to finish all processing.
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Chunming Zhou <david1.zhou@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -558,13 +558,12 @@ void amdgpu_ctx_mgr_init(struct amdgpu_ctx_mgr *mgr)
 	idr_init(&mgr->ctx_handles);
 }
 
-void amdgpu_ctx_mgr_entity_flush(struct amdgpu_ctx_mgr *mgr)
+long amdgpu_ctx_mgr_entity_flush(struct amdgpu_ctx_mgr *mgr, long timeout)
 {
 	unsigned num_entities = amdgput_ctx_total_num_entities();
 	struct amdgpu_ctx *ctx;
 	struct idr *idp;
 	uint32_t id, i;
-	long max_wait = MAX_WAIT_SCHED_ENTITY_Q_EMPTY;
 
 	idp = &mgr->ctx_handles;
 
@@ -574,10 +573,11 @@ void amdgpu_ctx_mgr_entity_flush(struct amdgpu_ctx_mgr *mgr)
 			struct drm_sched_entity *entity;
 
 			entity = &ctx->entities[0][i].entity;
-			max_wait = drm_sched_entity_flush(entity, max_wait);
+			timeout = drm_sched_entity_flush(entity, timeout);
 		}
 	}
 	mutex_unlock(&mgr->lock);
+	return timeout;
 }
 
 void amdgpu_ctx_mgr_entity_fini(struct amdgpu_ctx_mgr *mgr)

drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.h

@@ -84,7 +84,7 @@ int amdgpu_ctx_wait_prev_fence(struct amdgpu_ctx *ctx,
 
 void amdgpu_ctx_mgr_init(struct amdgpu_ctx_mgr *mgr);
 void amdgpu_ctx_mgr_entity_fini(struct amdgpu_ctx_mgr *mgr);
-void amdgpu_ctx_mgr_entity_flush(struct amdgpu_ctx_mgr *mgr);
+long amdgpu_ctx_mgr_entity_flush(struct amdgpu_ctx_mgr *mgr, long timeout);
 void amdgpu_ctx_mgr_fini(struct amdgpu_ctx_mgr *mgr);
 
 #endif

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

@@ -1176,13 +1176,14 @@ static int amdgpu_flush(struct file *f, fl_owner_t id)
 {
 	struct drm_file *file_priv = f->private_data;
 	struct amdgpu_fpriv *fpriv = file_priv->driver_priv;
+	long timeout = MAX_WAIT_SCHED_ENTITY_Q_EMPTY;
 
-	amdgpu_ctx_mgr_entity_flush(&fpriv->ctx_mgr);
+	timeout = amdgpu_ctx_mgr_entity_flush(&fpriv->ctx_mgr, timeout);
+	timeout = amdgpu_vm_wait_idle(&fpriv->vm, timeout);
 
-	return 0;
+	return timeout >= 0 ? 0 : timeout;
 }
 
-
 static const struct file_operations amdgpu_driver_kms_fops = {
 	.owner = THIS_MODULE,
 	.open = drm_open,

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

@@ -2977,6 +2977,18 @@ void amdgpu_vm_adjust_size(struct amdgpu_device *adev, uint32_t min_vm_size,
 		 adev->vm_manager.fragment_size);
 }
 
+/**
+ * amdgpu_vm_wait_idle - wait for the VM to become idle
+ *
+ * @vm: VM object to wait for
+ * @timeout: timeout to wait for VM to become idle
+ */
+long amdgpu_vm_wait_idle(struct amdgpu_vm *vm, long timeout)
+{
+	return reservation_object_wait_timeout_rcu(vm->root.base.bo->tbo.resv,
+						   true, true, timeout);
+}
+
 /**
  * amdgpu_vm_init - initialize a vm instance
  *

drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h

@@ -281,6 +281,8 @@ struct amdgpu_vm_manager {
 
 void amdgpu_vm_manager_init(struct amdgpu_device *adev);
 void amdgpu_vm_manager_fini(struct amdgpu_device *adev);
+
+long amdgpu_vm_wait_idle(struct amdgpu_vm *vm, long timeout);
 int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm *vm,
 		   int vm_context, unsigned int pasid);
 int amdgpu_vm_make_compute(struct amdgpu_device *adev, struct amdgpu_vm *vm, unsigned int pasid);