Several ARM64 Changes Queued For Linux 4.14, VMAP_STACK Support

There are a few noteworthy ARM64 (64-bit ARM) architecture updates worth noting for the ongoing Linux 4.14 merge window.

First up, ARM64 (AArch64) now supports VMAP_STACK to let kernel stacks be allocated in vmalloc space with a guard page for trapping possible stack overflows. It was back during Linux 4.9 that x86_64 picked up the vmap'ed stack support.

There is also support for contiguous PTE hugetlb support has been re-enabled, initial support for persistent memory on ARM, RAID6 improvements for ARM64 via algorithm optimizations and recovery routines using NEON, FP/SIMD code refactoring, and perf subsystem support for Cortex A35 and A73 processors.

There is also a number of lower-level code improvements and bug fixes via this ARM64 update.