[PATCH] firmware: fw_base.S: fix multi-core boot bug.

[Anup Patel]

On Fri, Sep 13, 2024 at 10:07 AM Xiang W <wxjstz at 126.com> wrote:
>
> From: "dong.yang" <dong.yang at sophgo.com>
>
> In a multi-core startup scenario, if both _try_lottery and
> _wait_for_boot_hart use the data in the _boot_status address, when
> a CPU enters OpenSBI later than boot hart set the _boot_status to
> BOOT_STATUS_BOOT_HART_DONE, the CPU will modify _boot_status to 1
> by amoswap.w and will never be awakened in _wait_for_boot_hart.
> So let _try_lottery and _boot_status use data from two addresses.
>
> Signed-off-by: dong.yang <dong.yang at sophgo.com>
> Reviewed-by: Xing Xiaoguang <xiaoguang.xing at sophgo.com>
> Reviewed-by: Xiang W <wxjstz at 126.com>

First of all, we need a Fixes tag in the commit description.

> ---
>  firmware/fw_base.S | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/firmware/fw_base.S b/firmware/fw_base.S
> index b950c0b..0971612 100644
> --- a/firmware/fw_base.S
> +++ b/firmware/fw_base.S
> @@ -47,7 +47,7 @@ _start:
>         bne     a0, a6, _wait_for_boot_hart
>  _try_lottery:
>         /* Jump to relocation wait loop if we don't get relocation lottery */
> -       lla     a6, _boot_status
> +       lla     a6, _relocate_lottery

The _relocate_lottery should be named _boot_lottery.

>         li      a7, BOOT_STATUS_LOTTERY_DONE

This macro needs to be renamed as well.

>         amoswap.w a6, a7, (a6)
>         bnez    a6, _wait_for_boot_hart
> @@ -371,6 +371,8 @@ _skip_trap_handler_hyp:
>
>         .data
>         .align 3
> +_relocate_lottery:
> +       RISCV_PTR   0
>  _boot_status:
>         RISCV_PTR       0
>
> --
> 2.45.2
>

I have taken care of the above comments at the time of merging this patch.

Reviewed-by: Anup Patel <anup at brainfault.org>

Applied this patch to the riscv/opensbi repo.

Thanks,
Anup