[PATCH] RISC-V: Don't include Zicsr or Zifencei in I from ACPI

Sunil V L sunilvl at ventanamicro.com
Tue Jul 11 23:42:41 PDT 2023


On Tue, Jul 11, 2023 at 03:46:00PM -0700, Palmer Dabbelt wrote:
> ACPI ISA strings are based on a specification after Zicsr and Zifencei
> were split out of I, so we shouldn't be treating them as part of I.  We
> haven't release an ACPI-based kernel yet, so we don't need to worry
> about compatibility with the old ISA strings.
> 
> Fixes: 396c018332a1 ("RISC-V: cpufeature: Add ACPI support in riscv_fill_hwcap()")
> Signed-off-by: Palmer Dabbelt <palmer at rivosinc.com>
> ---
LGTM. I agree with Conor that Fixes tag should point to 07edc32779e3.

Reviewed-by: Sunil V L <sunilvl at ventanamicro.com>

Thanks,
Sunil
>  arch/riscv/kernel/cpufeature.c | 9 ++-------
>  1 file changed, 2 insertions(+), 7 deletions(-)
> 
> diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
> index bdcf460ea53d..a8f66c015229 100644
> --- a/arch/riscv/kernel/cpufeature.c
> +++ b/arch/riscv/kernel/cpufeature.c
> @@ -317,19 +317,14 @@ void __init riscv_fill_hwcap(void)
>  #undef SET_ISA_EXT_MAP
>  		}
>  
> -		/*
> -		 * Linux requires the following extensions, so we may as well
> -		 * always set them.
> -		 */
> -		set_bit(RISCV_ISA_EXT_ZICSR, isainfo->isa);
> -		set_bit(RISCV_ISA_EXT_ZIFENCEI, isainfo->isa);
> -
>  		/*
>  		 * These ones were as they were part of the base ISA when the
>  		 * port & dt-bindings were upstreamed, and so can be set
>  		 * unconditionally where `i` is in riscv,isa on DT systems.
>  		 */
>  		if (acpi_disabled) {
> +			set_bit(RISCV_ISA_EXT_ZICSR, isainfo->isa);
> +			set_bit(RISCV_ISA_EXT_ZIFENCEI, isainfo->isa);
>  			set_bit(RISCV_ISA_EXT_ZICNTR, isainfo->isa);
>  			set_bit(RISCV_ISA_EXT_ZIHPM, isainfo->isa);
>  		}
> -- 
> 2.40.1
> 



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