Sandipan Das reported that, "The Power ISA mandates that all writes to the Authority Mask Register (AMR) must always be preceded as well as succeeded by a context-synchronizing instruction. This applies to both the privileged and unprivileged variants of the Move To AMR instruction. This [requirement] is from Table 6 of Chapter 11 in page 1134 of Power ISA 3.0B. The document can be found here: <https://ibm.ent.box.com/s/1hzcwkwf8rbju5h9iyf44wm94amnlcrv> " See this kernel patch submission: <https://lore.kernel.org/linuxppc-dev/5f65cf37be993760de8112a88da194e3ccbb2bf8.1588959697.git.sandipan@linux.ibm.com/>
