[v3,0/2] Fix RISC-V's arch-topology reporting

Message

Conor Dooley July 9, 2022, 3:23 p.m. UTC

From: Conor Dooley <[e-mail]>

Hey all,
It's my first time messing around with arch/ code at all, let alone
more than one arch, so forgive me if I have screwed up how to do a
migration like this.

The goal here is the fix the incorrectly reported arch topology on
RISC-V which seems to have been broken since it was added.
cpu, package and thread IDs are all currently reported as -1, so tools
like lstopo think systems have multiple threads on the same core when
this is not true:
https://github.com/open-mpi/hwloc/issues/536

arm64's topology code basically applies to RISC-V too, so it has been
made generic along with the removal of MPIDR related code, which
appears to be redudant code since '3102bc0e6ac7 ("arm64: topology: Stop
using MPIDR for topology information")' replaced the code that actually
interacted with MPIDR with default values.

I only built tested for arm{,64} , so hopefully it is not broken when
used. Testing on both arm64 & !SMP RISC-V would really be appreciated!

For V2, I dropped the idea of doing a RISC-V specific implementation
followed by a move to the generic code & just went for the more straight
forward method of moving to the shared version first. I also dropped the
RFC.

V3 moves store_cpu_topology() down inside the arch check alongside the
init function so that boot on 32bit arm is not broken.

Thanks,
Conor

Conor Dooley (2):
  arm64: topology: move store_cpu_topology() to shared code
  riscv: topology: fix default topology reporting

 arch/arm64/kernel/topology.c | 40 ------------------------------------
 arch/riscv/Kconfig           |  2 +-
 arch/riscv/kernel/smpboot.c  |  4 +++-
 drivers/base/arch_topology.c | 19 +++++++++++++++++
 4 files changed, 23 insertions(+), 42 deletions(-)


base-commit: b6f1f2fa2bddd69ff46a190b8120bd440fd50563