[RFC/RFT PATCH 0/6] Unify NUMA implementation between ARM64 & RISC-V

[Atish Patra]

This series attempts to move the ARM64 numa implementation to common
code so that RISC-V can leverage that as well instead of reimplementing
it again.

RISC-V specific bits are based on initial work done by Greentime Hu [1] but
modified to reuse the common implementation to avoid duplication.

[1] https://lkml.org/lkml/2020/1/10/233

This series has been tested on qemu with numa enabled for both RISC-V & ARM64.
It would be great if somebody can test it on numa capable ARM64 hardware platforms.
This patch series doesn't modify the maintainers list for the common code (arch_numa)
as I am not sure if somebody from ARM64 community or Greg should take up the
maintainership. Ganapatrao was the original author of the arm64 version.
I would be happy to update that in the next revision once it is decided.

# numactl --hardware
available: 2 nodes (0-1)
node 0 cpus: 0 1 2 3
node 0 size: 486 MB
node 0 free: 470 MB
node 1 cpus: 4 5 6 7
node 1 size: 424 MB
node 1 free: 408 MB
node distances:
node   0   1 
  0:  10  20 
  1:  20  10 
# numactl -show
policy: default
preferred node: current
physcpubind: 0 1 2 3 4 5 6 7 
cpubind: 0 1 
nodebind: 0 1 
membind: 0 1 

For RISC-V, the following qemu series is a pre-requisite to test the patches in Qemu.

https://patchwork.kernel.org/project/qemu-devel/list/?series=303313

The patches are also available at

https://github.com/atishp04/linux/tree/5.10_numa_unified

There may be some minor conflicts with Mike's cleanup series [2] depending on the
order in which these two series are being accepted. I can rebase on top his series
if required.

[2] https://lkml.org/lkml/2020/7/28/39

Atish Patra (5):
numa: Move numa implementation to common code
arm64, numa: Change the numa init function name to be generic
arm64, numa: Move pcibus_to_node definition to generic numa code
riscv: Separate memory init from paging init
riscv: Add numa support for riscv64 platform

Greentime Hu (1):
riscv: Add support pte_protnone and pmd_protnone if
CONFIG_NUMA_BALANCING

arch/arm64/Kconfig                            |  1 +
arch/arm64/include/asm/numa.h                 | 45 +---------------
arch/arm64/kernel/pci.c                       | 10 ----
arch/arm64/mm/Makefile                        |  1 -
arch/arm64/mm/init.c                          |  4 +-
arch/riscv/Kconfig                            | 31 ++++++++++-
arch/riscv/include/asm/mmzone.h               | 13 +++++
arch/riscv/include/asm/numa.h                 |  8 +++
arch/riscv/include/asm/pci.h                  | 10 ++++
arch/riscv/include/asm/pgtable.h              | 21 ++++++++
arch/riscv/kernel/setup.c                     | 12 ++++-
arch/riscv/kernel/smpboot.c                   | 12 ++++-
arch/riscv/mm/init.c                          | 10 +++-
drivers/base/Kconfig                          |  6 +++
drivers/base/Makefile                         |  1 +
.../mm/numa.c => drivers/base/arch_numa.c     | 19 ++++++-
include/asm-generic/numa.h                    | 51 +++++++++++++++++++
17 files changed, 190 insertions(+), 65 deletions(-)
create mode 100644 arch/riscv/include/asm/mmzone.h
create mode 100644 arch/riscv/include/asm/numa.h
rename arch/arm64/mm/numa.c => drivers/base/arch_numa.c (97%)
create mode 100644 include/asm-generic/numa.h

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2.24.0