[PATCH v4 0/2] Fix and enable pmem as RAM device on arm64

[Jia He]

This fixies a few issues when I tried to enable pmem as RAM device on arm64.

To use memory_add_physaddr_to_nid as a fallback nid, it would be better
implement a general version (__weak) in mm/memory_hotplug. After that, arm64/
sh/s390 can simply use the general version, and PowerPC/ia64/x86 will use
arch specific version.

Tested on ThunderX2 host/qemu "-M virt" guest with a nvdimm device. The
memblocks from the dax pmem device can be either hot-added or hot-removed
on arm64 guest. Also passed the compilation test on x86.

Changes:
v4: - remove "device-dax: use fallback nid when numa_node is invalid", wait
      for Dan Williams' phys_addr_to_target_node() patch
    - folder v3 patch1-4 into single one, no functional changes
v3: https://lkml.org/lkml/2020/7/8/1541
    - introduce general version memory_add_physaddr_to_nid, refine the arch
      specific one
    - fix an uninitialization bug in v2 device-dax patch
v2: https://lkml.org/lkml/2020/7/7/71
    - Drop unnecessary patch to harden try_offline_node
    - Use new solution(by David) to fix dev->target_node=-1 during probing
    - Refine the mem_hotplug_begin/done patch

v1: https://lkml.org/lkml/2020/7/5/381

Jia He (2):
  mm/memory_hotplug: introduce default dummy
    memory_add_physaddr_to_nid()
  mm/memory_hotplug: fix unpaired mem_hotplug_begin/done

 arch/arm64/mm/numa.c | 10 ----------
 arch/ia64/mm/numa.c  |  2 --
 arch/sh/mm/init.c    |  9 ---------
 arch/x86/mm/numa.c   |  1 -
 mm/memory_hotplug.c  | 15 ++++++++++++---
 5 files changed, 12 insertions(+), 25 deletions(-)

-- 
2.17.1