Re: [PATCH 2/7] RISC-V: Detect AIA CSRs from ISA string

[Andrew Jones]

On Thu, Jan 12, 2023 at 07:32:59PM +0530, Anup Patel wrote:
> We have two extension names for AIA ISA support: Smaia (M-mode AIA CSRs)
> and Ssaia (S-mode AIA CSRs).
> 
> We extend the ISA string parsing to detect Smaia and Ssaia extensions.
> 
> Signed-off-by: Anup Patel <apatel@xxxxxxxxxxxxxxxx>
> ---
>  arch/riscv/include/asm/hwcap.h | 8 ++++++++
>  arch/riscv/kernel/cpu.c        | 2 ++
>  arch/riscv/kernel/cpufeature.c | 2 ++
>  3 files changed, 12 insertions(+)
> 
> diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h
> index 86328e3acb02..c649e85ed7bb 100644
> --- a/arch/riscv/include/asm/hwcap.h
> +++ b/arch/riscv/include/asm/hwcap.h
> @@ -59,10 +59,18 @@ enum riscv_isa_ext_id {
>  	RISCV_ISA_EXT_ZIHINTPAUSE,
>  	RISCV_ISA_EXT_SSTC,
>  	RISCV_ISA_EXT_SVINVAL,
> +	RISCV_ISA_EXT_SSAIA,
> +	RISCV_ISA_EXT_SMAIA,

These will change a couple different ways due other other patches in
flight, but let's put the pair in alphabetical order now so they get
moved together that way.

>  	RISCV_ISA_EXT_ID_MAX
>  };
>  static_assert(RISCV_ISA_EXT_ID_MAX <= RISCV_ISA_EXT_MAX);
>  
> +#ifdef CONFIG_RISCV_M_MODE
> +#define RISCV_ISA_EXT_SxAIA		RISCV_ISA_EXT_SMAIA
> +#else
> +#define RISCV_ISA_EXT_SxAIA		RISCV_ISA_EXT_SSAIA
> +#endif

This isn't used in this patch, so should probably be introduced in a later
patch when it is.

> +
>  /*
>   * This enum represents the logical ID for each RISC-V ISA extension static
>   * keys. We can use static key to optimize code path if some ISA extensions
> diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
> index 1b9a5a66e55a..a215ec929160 100644
> --- a/arch/riscv/kernel/cpu.c
> +++ b/arch/riscv/kernel/cpu.c
> @@ -162,6 +162,8 @@ arch_initcall(riscv_cpuinfo_init);
>   *    extensions by an underscore.
>   */
>  static struct riscv_isa_ext_data isa_ext_arr[] = {
> +	__RISCV_ISA_EXT_DATA(smaia, RISCV_ISA_EXT_SMAIA),
> +	__RISCV_ISA_EXT_DATA(ssaia, RISCV_ISA_EXT_SSAIA),
>  	__RISCV_ISA_EXT_DATA(sscofpmf, RISCV_ISA_EXT_SSCOFPMF),
>  	__RISCV_ISA_EXT_DATA(sstc, RISCV_ISA_EXT_SSTC),
>  	__RISCV_ISA_EXT_DATA(svinval, RISCV_ISA_EXT_SVINVAL),
> diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
> index 93e45560af30..3c5b51f519d5 100644
> --- a/arch/riscv/kernel/cpufeature.c
> +++ b/arch/riscv/kernel/cpufeature.c
> @@ -228,6 +228,8 @@ void __init riscv_fill_hwcap(void)
>  				SET_ISA_EXT_MAP("zihintpause", RISCV_ISA_EXT_ZIHINTPAUSE);
>  				SET_ISA_EXT_MAP("sstc", RISCV_ISA_EXT_SSTC);
>  				SET_ISA_EXT_MAP("svinval", RISCV_ISA_EXT_SVINVAL);
> +				SET_ISA_EXT_MAP("smaia", RISCV_ISA_EXT_SMAIA);
> +				SET_ISA_EXT_MAP("ssaia", RISCV_ISA_EXT_SSAIA);
>  			}
>  #undef SET_ISA_EXT_MAP
>  		}
> -- 
> 2.34.1
>

Otherwise,

Reviewed-by: Andrew Jones <ajones@xxxxxxxxxxxxxxxx>

Thanks,
drew