[PATCH v2] platform: Uses hart count as the default size of tlb info

[Anup Patel]

On Thu, Oct 12, 2023 at 2:04 PM Inochi Amaoto <inochiama at outlook.com> wrote:
>
> For platform with high number of harts, it is better to auto detect a
> suitable number of entries in tlb fifo. Since allocating tlb entry for
> all online harts can reduce the wait time significantly, using the
> number of the online harts can make most platforms happy. This auto
> detection can avoid most duplicate code for setting tlb fifo size.
>
> Signed-off-by: Inochi Amaoto <inochiama at outlook.com>

Looks good to me.

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

Applied this patch to the riscv/opensbi repo.

Thanks,
Anup

> ---
> Changed from v1:
> 1. replace SBI_PLATFORM_TLB_FIFO_NUM_ENTRIES with hart count in all cases.
>
> ---
>  include/sbi/sbi_platform.h  | 3 +--
>  platform/generic/platform.c | 2 +-
>  2 files changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/include/sbi/sbi_platform.h b/include/sbi/sbi_platform.h
> index 389203b..58b9069 100644
> --- a/include/sbi/sbi_platform.h
> +++ b/include/sbi/sbi_platform.h
> @@ -41,7 +41,6 @@
>  #define SBI_PLATFORM_HART_INDEX2ID_OFFSET (0x60 + (__SIZEOF_POINTER__ * 2))
>
>  #define SBI_PLATFORM_TLB_RANGE_FLUSH_LIMIT_DEFAULT             (1UL << 12)
> -#define SBI_PLATFORM_TLB_FIFO_NUM_ENTRIES                              8
>
>  #ifndef __ASSEMBLER__
>
> @@ -330,7 +329,7 @@ static inline u32 sbi_platform_tlb_fifo_num_entries(const struct sbi_platform *p
>  {
>         if (plat && sbi_platform_ops(plat)->get_tlb_num_entries)
>                 return sbi_platform_ops(plat)->get_tlb_num_entries();
> -       return SBI_PLATFORM_TLB_FIFO_NUM_ENTRIES;
> +       return sbi_scratch_last_hartindex() + 1;
>  }
>
>  /**
> diff --git a/platform/generic/platform.c b/platform/generic/platform.c
> index 66a0b77..4246efd 100644
> --- a/platform/generic/platform.c
> +++ b/platform/generic/platform.c
> @@ -260,7 +260,7 @@ static u32 generic_tlb_num_entries(void)
>  {
>         if (generic_plat && generic_plat->tlb_num_entries)
>                 return generic_plat->tlb_num_entries(generic_plat_match);
> -       return SBI_PLATFORM_TLB_FIFO_NUM_ENTRIES;
> +       return sbi_scratch_last_hartindex() + 1;
>  }
>
>  static int generic_pmu_init(void)
> --
> 2.42.0
>
>
> --
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