[PATCH v4 1/3] lib: sbi: Allow platform to influence cold boot HART selection

[Bin Meng]

On Tue, Dec 20, 2022 at 11:48 AM Wei Liang Lim
<weiliang.lim at starfivetech.com> wrote:
>
> From: Anup Patel <apatel at ventanamicro.com>
>
> We add an optional cold_boot_allowed() platform callback which allows
> platform support to decide which HARTs can do cold boot initialization.
>
> If this platform callback is not available then any HART can do cold
> boot initialization.
>
> Signed-off-by: Anup Patel <apatel at ventanamicro.com>
> ---
>  include/sbi/sbi_platform.h | 20 ++++++++++++++++++++
>  lib/sbi/sbi_init.c         |  7 +++++--
>  2 files changed, 25 insertions(+), 2 deletions(-)
>
> diff --git a/include/sbi/sbi_platform.h b/include/sbi/sbi_platform.h
> index 722f27a..566eee3 100644
> --- a/include/sbi/sbi_platform.h
> +++ b/include/sbi/sbi_platform.h
> @@ -65,6 +65,9 @@ enum sbi_platform_features {
>
>  /** Platform functions */
>  struct sbi_platform_operations {
> +       /* Check if specified HART is allowed to do cold boot */
> +       bool (*cold_boot_allowed)(u32 hartid);
> +
>         /* Platform nascent initialization */
>         int (*nascent_init)(void);
>
> @@ -356,6 +359,23 @@ static inline bool sbi_platform_hart_invalid(const struct sbi_platform *plat,
>         return FALSE;
>  }
>
> +/**
> + * Check whether given HART is allowed to do cold boot
> + *
> + * @param plat pointer to struct sbi_platform
> + * @param hartid HART ID
> + *
> + * @return TRUE if HART is allowed to do cold boot and FALSE otherwise

s/TRUE/true/g
s/FALSE/false/g

> + */
> +static inline bool sbi_platform_cold_boot_allowed(
> +                                       const struct sbi_platform *plat,
> +                                       u32 hartid)
> +{
> +       if (plat && sbi_platform_ops(plat)->cold_boot_allowed)
> +               return sbi_platform_ops(plat)->cold_boot_allowed(hartid);
> +       return TRUE;
> +}
> +
>  /**
>   * Nascent (very early) initialization for current HART
>   *
> diff --git a/lib/sbi/sbi_init.c b/lib/sbi/sbi_init.c
> index a8500e5..d4902d9 100644
> --- a/lib/sbi/sbi_init.c
> +++ b/lib/sbi/sbi_init.c
> @@ -498,8 +498,11 @@ void __noreturn sbi_init(struct sbi_scratch *scratch)
>          * HARTs which satisfy above condition.
>          */
>
> -       if (next_mode_supported && atomic_xchg(&coldboot_lottery, 1) == 0)
> -               coldboot = TRUE;
> +       if (sbi_platform_cold_boot_allowed(plat, hartid)) {
> +               if (next_mode_supported &&
> +                   atomic_xchg(&coldboot_lottery, 1) == 0)
> +                       coldboot = TRUE;
> +       }
>
>         /*
>          * Do platform specific nascent (very early) initialization so
> --
> 2.25.1

Otherwise,
Reviewed-by: Bin Meng <bmeng at tinylab.org>