- struct write_fence args = {
- .dev = obj->base.dev,
- .fence = fence_number(dev_priv, fence),
- .obj = enable ? obj : NULL,
- };
-
- /* In order to fully serialize access to the fenced region and
- * the update to the fence register we need to take extreme
- * measures on SNB+. In theory, the write to the fence register
- * flushes all memory transactions before, and coupled with the
- * mb() placed around the register write we serialise all memory
- * operations with respect to the changes in the tiler. Yet, on
- * SNB+ we need to take a step further and emit an explicit wbinvd()
- * on each processor in order to manually flush all memory
- * transactions before updating the fence register.
- *
- * However, Valleyview complicates matter. There the wbinvd is
- * insufficient and unlike SNB/IVB requires the serialising
- * register write. (Note that that register write by itself is
- * conversely not sufficient for SNB+.) To compromise, we do both.
- */
- if (INTEL_INFO(args.dev)->gen >= 6)
- on_each_cpu(i915_gem_write_fence__ipi, &args, 1);
- else
- i915_gem_write_fence(args.dev, args.fence, args.obj);