Re: [PATCH 1/3] loongarch: Call arch_mem_init() before platform_init() in the init sequence

[Huacai Chen <chenhuacai@kernel.org>]

Hi, Oreoluwa,

On Sat, Feb 10, 2024 at 8:29 AM Oreoluwa Babatunde
<quic_obabatun@quicinc.com> wrote:
>
> The platform_init() function which is called during device bootup
> contains a few calls to memblock_alloc().
> This is an issue because these allocations are done before reserved
> memory regions are set aside in arch_mem_init().
> This means that there is a possibility for memblock to allocate memory
> from any of the reserved memory regions.
>
> Hence, move the call to arch_mem_init() to be earlier in the init
> sequence so that all reserved memory is set aside before any allocations
> are made with memblock.
>
> Signed-off-by: Oreoluwa Babatunde <quic_obabatun@quicinc.com>
> ---
>  arch/loongarch/kernel/setup.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/loongarch/kernel/setup.c b/arch/loongarch/kernel/setup.c
> index edf2bba..66c307c 100644
> --- a/arch/loongarch/kernel/setup.c
> +++ b/arch/loongarch/kernel/setup.c
> @@ -597,8 +597,8 @@ void __init setup_arch(char **cmdline_p)
>         parse_early_param();
>         reserve_initrd_mem();
>
> -       platform_init();
>         arch_mem_init(cmdline_p);
> +       platform_init();
Thank you for your patch, but I think we cannot simply exchange their
order. If I'm right, you try to move all memblock_reserve() as early
as possible, but both arch_mem_init() and platform_init() call
memblock_reserve(), we should do a complete refactor for this. And
since it works with the existing order, we can simply keep it as is
now.

Huacai

>
>         resource_init();
>  #ifdef CONFIG_SMP
> --