The first changes for implementing Meltdown and Spectre mitigation for Linux ARM64 were reported on: https://www.phoronix.com/scan.php?page=news_item&px=ARM64-Linux-4.16 Contrary to a news story indicating that Cavium had stated Meltdown affected ThunderX2 (Vulkan), it seems like that custom ARM is being whitelisted for not needing KPTI. Qualcomm's Falkor CPU may be in the reverse situation, where a workaround for TLB updates is partially removed because the old assumption about shared kernel and user mappings has changed with KPTI being on. There seems to be a desire to expand the whitelist for cores known not to need Meltdown mitigation, including a possible wrinkle with checking for more than one core and turning on KPTI if any core needs it (eg. bigLITTLE). Branch prediction hardening for ARM's standard cores and the custom cores in this pull as well.