linux-kernel - Re: [PATCH v2] riscv: to make sure the cores in .Lsecondary

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Date:   Wed, 8 Jan 2020 09:06:38 +0530
From:   Anup Patel <anup@...infault.org>
To:     Greentime Hu <greentime.hu@...ive.com>
Cc:     Greentime Hu <green.hu@...il.com>, greentime@...nel.org,
        Paul Walmsley <paul.walmsley@...ive.com>,
        Palmer Dabbelt <palmer@...belt.com>,
        linux-riscv <linux-riscv@...ts.infradead.org>,
        "linux-kernel@...r.kernel.org List" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2] riscv: to make sure the cores in .Lsecondary_park

On Wed, Jan 8, 2020 at 8:10 AM Greentime Hu <greentime.hu@...ive.com> wrote:
>
> The code in secondary_park is currently placed in the .init section.  The
> kernel reclaims and clears this code when it finishes booting.  That
> causes the cores parked in it to go to somewhere unpredictable, so we
> move this function out of init to make sure the cores stay looping there.
>
> Signed-off-by: Greentime Hu <greentime.hu@...ive.com>
> ---
>  arch/riscv/kernel/head.S | 12 +++++++-----
>  1 file changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S
> index f8f996916c5b..276b98f9d0bd 100644
> --- a/arch/riscv/kernel/head.S
> +++ b/arch/riscv/kernel/head.S
> @@ -217,11 +217,6 @@ relocate:
>         tail smp_callin
>  #endif
>
> -.align 2
> -.Lsecondary_park:
> -       /* We lack SMP support or have too many harts, so park this hart */
> -       wfi
> -       j .Lsecondary_park
>  END(_start)
>
>  #ifdef CONFIG_RISCV_M_MODE
> @@ -303,6 +298,13 @@ ENTRY(reset_regs)
>  END(reset_regs)
>  #endif /* CONFIG_RISCV_M_MODE */
>
> +.section ".text", "ax",@progbits
> +.align 2
> +.Lsecondary_park:
> +       /* We lack SMP support or have too many harts, so park this hart */
> +       wfi
> +       j .Lsecondary_park
> +
>  __PAGE_ALIGNED_BSS
>         /* Empty zero page */
>         .balign PAGE_SIZE
> --
> 2.17.1
>

LGTM.

Reviewed-by: Anup Patel <anup@...infault.org>

Regards,
Anup