[PATCH v3 4/4] lib: sbi: Detect extensions from the ISA string in DT

[Anup Patel]

On Tue, Dec 12, 2023 at 2:28 PM Yong-Xuan Wang <yongxuan.wang at sifive.com> wrote:
>
> Enable access to some extensions through menvcfg and show them in "Boot
> HART ISA Extensions" if they are present in the device tree.
>
> Signed-off-by: Yong-Xuan Wang <yongxuan.wang at sifive.com>
> ---
>  include/sbi/sbi_hart.h |  6 +++++
>  lib/sbi/sbi_hart.c     | 51 +++++++++++++-----------------------------
>  2 files changed, 22 insertions(+), 35 deletions(-)
>
> diff --git a/include/sbi/sbi_hart.h b/include/sbi/sbi_hart.h
> index 77138232..47be251d 100644
> --- a/include/sbi/sbi_hart.h
> +++ b/include/sbi/sbi_hart.h
> @@ -47,6 +47,12 @@ enum sbi_hart_extensions {
>         SBI_HART_EXT_SMCNTRPMF,
>         /** Hart has Xandespmu extension */
>         SBI_HART_EXT_XANDESPMU,
> +       /** Hart has Zicboz extension */
> +       SBI_HART_EXT_ZICBOZ,
> +       /** Hart has Zicbom extension */
> +       SBI_HART_EXT_ZICBOM,
> +       /** Hart has Svpbmt extension */
> +       SBI_HART_EXT_SVPBMT,
>
>         /** Maximum index of Hart extension */
>         SBI_HART_EXT_MAX,
> diff --git a/lib/sbi/sbi_hart.c b/lib/sbi/sbi_hart.c
> index 06b5f87e..6a9f6a71 100644
> --- a/lib/sbi/sbi_hart.c
> +++ b/lib/sbi/sbi_hart.c
> @@ -112,46 +112,24 @@ static void mstatus_init(struct sbi_scratch *scratch)
>                 menvcfg_val |= ((uint64_t)csr_read(CSR_MENVCFGH)) << 32;
>  #endif
>
> -               /*
> -                * Set menvcfg.CBZE == 1
> -                *
> -                * If Zicboz extension is not available then writes to
> -                * menvcfg.CBZE will be ignored because it is a WARL field.
> -                */
> -               menvcfg_val |= ENVCFG_CBZE;
> +#define __set_menvcfg_ext(__ext, __bit)                                        \
> +               if (sbi_hart_has_extension(scratch, __ext)) {           \
> +                       menvcfg_val |= __bit;                           \
> +               }
>
>                 /*
> -                * Set menvcfg.CBCFE == 1
> -                *
> -                * If Zicbom extension is not available then writes to
> -                * menvcfg.CBCFE will be ignored because it is a WARL field.
> +               * Enable access to extensions if they are present in the
> +                * hardware or in the device tree.
>                  */
> -               menvcfg_val |= ENVCFG_CBCFE;
>
> -               /*
> -                * Set menvcfg.CBIE == 3
> -                *
> -                * If Zicbom extension is not available then writes to
> -                * menvcfg.CBIE will be ignored because it is a WARL field.
> -                */
> -               menvcfg_val |= ENVCFG_CBIE_INV << ENVCFG_CBIE_SHIFT;
> +               __set_menvcfg_ext(SBI_HART_EXT_ZICBOZ, ENVCFG_CBZE);
> +               __set_menvcfg_ext(SBI_HART_EXT_ZICBOM, ENVCFG_CBCFE);
> +               __set_menvcfg_ext(SBI_HART_EXT_ZICBOM,
> +                                 ENVCFG_CBIE_INV << ENVCFG_CBIE_SHIFT);
> +               __set_menvcfg_ext(SBI_HART_EXT_SVPBMT, ENVCFG_PBMTE);

Same as PATCH2, we need a #if here since Svpbmt is not available on RV32.

> +               __set_menvcfg_ext(SBI_HART_EXT_SSTC, ENVCFG_STCE);
>
> -               /*
> -                * Set menvcfg.PBMTE == 1 for RV64 or RV128
> -                *
> -                * If Svpbmt extension is not available then menvcfg.PBMTE
> -                * will be read-only zero.
> -                */
> -               menvcfg_val |= ENVCFG_PBMTE;
> -
> -               /*
> -                * The spec doesn't explicitly describe the reset value of menvcfg.
> -                * Enable access to stimecmp if sstc extension is present in the
> -                * hardware.
> -                */
> -               if (sbi_hart_has_extension(scratch, SBI_HART_EXT_SSTC)) {
> -                       menvcfg_val |= ENVCFG_STCE;
> -               }
> +#undef __set_menvcfg_ext
>
>                 csr_write(CSR_MENVCFG, menvcfg_val);
>  #if __riscv_xlen == 32
> @@ -675,6 +653,9 @@ const struct sbi_hart_ext_data sbi_hart_ext[] = {
>         __SBI_HART_EXT_DATA(zkr, SBI_HART_EXT_ZKR),
>         __SBI_HART_EXT_DATA(smcntrpmf, SBI_HART_EXT_SMCNTRPMF),
>         __SBI_HART_EXT_DATA(xandespmu, SBI_HART_EXT_XANDESPMU),
> +       __SBI_HART_EXT_DATA(zicboz, SBI_HART_EXT_ZICBOZ),
> +       __SBI_HART_EXT_DATA(zicbom, SBI_HART_EXT_ZICBOM),
> +       __SBI_HART_EXT_DATA(svpbmt, SBI_HART_EXT_SVPBMT),
>  };
>
>  /**
> --
> 2.17.1
>
>
> --
> opensbi mailing list
> opensbi at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/opensbi

I have taken care of the above issue 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