Re: [PATCH 05/12] MIPS: Switch to arch_topology

[Sudeep Holla <sudeep.holla@arm.com>]

On Wed, Apr 08, 2020 at 07:34:15PM +0800, Jiaxun Yang wrote:
> Previously, MIPS is using self-defined "globalnumber" in struct
> mips_cpuinfo to store topology information. However, it's not friendly
> to DeviceTree based systems and lack of cpu_capacity related feature
> which can take advantage of multi-cluster system.
>
> Here, we enabled arch_topology for MIPS and adapted some functions
> to fit arch_topology structure.
> Also, we implmented smp_store_cpu_info to probe CPU's topology information
> by "globalnumber" registers in VP ASE or Ebase.CPUNum for legacy systems.
>
> Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
> ---
>  arch/mips/Kconfig                |  1 +
>  arch/mips/include/asm/cpu-info.h | 49 ----------------------------
>  arch/mips/include/asm/smp.h      |  2 --
>  arch/mips/include/asm/topology.h | 48 +++++++++++++++++++++++++---
>  arch/mips/kernel/cpu-probe.c     | 43 -------------------------
>  arch/mips/kernel/setup.c         |  1 +
>  arch/mips/kernel/smp.c           | 55 ++++----------------------------
>  arch/mips/kernel/topology.c      | 42 ++++++++++++++++++++++++
>  8 files changed, 93 insertions(+), 148 deletions(-)
>

[...]

> diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
> index 8a418783a6bb..b9fefc5dc702 100644
> --- a/arch/mips/kernel/setup.c
> +++ b/arch/mips/kernel/setup.c
> @@ -784,6 +784,7 @@ void __init setup_arch(char **cmdline_p)
>  	dmi_setup();
>
>  	resource_init();
> +	init_cpu_topology();
>  	plat_smp_setup();
>

Continuing my reply on previous patch, I see possible_cpu_mask being
set up in plat_smp_setup. Why not reverse the order above. Further I see
that the logical->physical CPU mapping is done in plat_smp_setup which
is required to store/save any topology information.

--
Regards,
Sudeep