Re: [PATCH v2 1/2] arm64: topology: move store_cpu_topology() to shared code

From: Sudeep Holla
Date: Mon Jul 11 2022 - 06:58:40 EST

On Sat, Jul 09, 2022 at 12:58:57PM +0000, Conor.Dooley@xxxxxxxxxxxxx wrote:
> Looking at the arm32 implementation - it appears to be mostly the sort of MPIDR
> stuff that was removed from the arm64 implementation in 3102bc0e6ac7 ("arm64:
> topology: Stop using MPIDR for topology information"). Could arm32 benefit from
> the same shared implemenation too, or is usage of MPIDR only invalid for arm64?

I don't recall all the details but IIRC there are parts if arch_topology
that are ARM64/RISC-V only. ARM32 doesn't use it as it may break old
platforms. Some of the functions that still arm32 specific are retained
in arch/arm

> The other difference is a call to update_cpu_capacity() in the arm32
> implementation. Could that be moved to smp_store_cpu_info() which is the only
> callsite of store_cpu_topology()?

No please, leave arm32 as is. It was done for a reason like that and it
help to not break some of the old 32-by platforms.

> Either way, will respin a v3 that doesn't break the arm32 build when