ktime_add
res = ktime_add(res, amdgpu_ctx_fence_time(centity->fences[i]));
res = ktime_add(res, amdgpu_ctx_fence_time(entity->fences[i]));
usage[hw_ip] = ktime_add(usage[hw_ip], spend);
*vblanktime = ktime_add(*vblanktime, ns_to_ktime(vblank_start));
stats->total = ktime_add(stats->total,
total = ktime_add(total, ktime_sub(*now, stats->start));
total = ktime_add(total,
ktime_add(gt->stats.total,
vgpu_data->pri_time = ktime_add(now,
vgpu_data->sched_time = ktime_add(vgpu_data->sched_time, delta_ts);