I was under the impression that the sanctions worked the other way around, i.e. Loongson can't buy a lot of things from American companies.

> Entities on the Entity List are prohibited from purchasing or licensing American technologies, even indirectly. For example, Loongson can't have its CPUs manufactured by American equipment, ruling out most foundries with modern nodes.

According to https://www.techspot.com/news/97817-us-blacklists-china-loon...