Re: [PATCH v1 4/9] RISC-V: repurpose riscv_isa_ext array in riscv_fill_hwcap()

[Andrew Jones]

On Mon, Jun 26, 2023 at 12:19:42PM +0100, Conor Dooley wrote:
> In riscv_fill_hwcap() riscv_isa_ext array can be looped over, rather
> than duplicating the list of extensions with individual
> SET_ISA_EXT_MAP() usage. While at it, drop the statement-of-the-obvious
> comments from the struct, rename uprop to something more suitable for
> its new use & constify the members.
> 
> Signed-off-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
> ---
>  arch/riscv/include/asm/hwcap.h |  6 ++----
>  arch/riscv/kernel/cpu.c        |  5 +++--
>  arch/riscv/kernel/cpufeature.c | 26 +++++++-------------------
>  3 files changed, 12 insertions(+), 25 deletions(-)
> 
> diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h
> index 7a57e6109aef..36f46dfd2b87 100644
> --- a/arch/riscv/include/asm/hwcap.h
> +++ b/arch/riscv/include/asm/hwcap.h
> @@ -70,10 +70,8 @@
>  unsigned long riscv_get_elf_hwcap(void);
>  
>  struct riscv_isa_ext_data {
> -	/* Name of the extension displayed to userspace via /proc/cpuinfo */
> -	char uprop[RISCV_ISA_EXT_NAME_LEN_MAX];

The RISCV_ISA_EXT_NAME_LEN_MAX define can now also be deleted.

> -	/* The logical ISA extension ID */
> -	unsigned int isa_ext_id;
> +	const unsigned int id;
> +	const char *name;
>  };
>  
>  extern const struct riscv_isa_ext_data riscv_isa_ext[];
> diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
> index 61fb92e7d524..beb8b16bbf87 100644
> --- a/arch/riscv/kernel/cpu.c
> +++ b/arch/riscv/kernel/cpu.c
> @@ -164,9 +164,10 @@ static void print_isa_ext(struct seq_file *f)
>  {
>  	for (int i = 0; i < riscv_isa_ext_count; i++) {
>  		const struct riscv_isa_ext_data *edata = &riscv_isa_ext[i];
> -		if (!__riscv_isa_extension_available(NULL, edata->isa_ext_id))
> +		if (!__riscv_isa_extension_available(NULL, edata->id))
>  			continue;
> -		seq_printf(f, "_%s", edata->uprop);
> +
> +		seq_printf(f, "_%s", edata->name);
>  	}
>  }
>  
> diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
> index f0ae310006de..b5e23506c4f0 100644
> --- a/arch/riscv/kernel/cpufeature.c
> +++ b/arch/riscv/kernel/cpufeature.c
> @@ -99,11 +99,10 @@ static bool riscv_isa_extension_check(int id)
>  	return true;
>  }
>  
> -#define __RISCV_ISA_EXT_DATA(UPROP, EXTID) \
> -	{							\
> -		.uprop = #UPROP,				\
> -		.isa_ext_id = EXTID,				\
> -	}
> +#define __RISCV_ISA_EXT_DATA(_name, _id) {	\
> +	.name = #_name,				\
> +	.id = _id,				\
> +}
>  
>  /*
>   * The canonical order of ISA extension names in the ISA string is defined in
> @@ -367,20 +366,9 @@ void __init riscv_fill_hwcap(void)
>  					set_bit(nr, isainfo->isa);
>  				}
>  			} else {
> -				/* sorted alphabetically */
> -				SET_ISA_EXT_MAP("smaia", RISCV_ISA_EXT_SMAIA);
> -				SET_ISA_EXT_MAP("ssaia", RISCV_ISA_EXT_SSAIA);
> -				SET_ISA_EXT_MAP("sscofpmf", RISCV_ISA_EXT_SSCOFPMF);
> -				SET_ISA_EXT_MAP("sstc", RISCV_ISA_EXT_SSTC);
> -				SET_ISA_EXT_MAP("svinval", RISCV_ISA_EXT_SVINVAL);
> -				SET_ISA_EXT_MAP("svnapot", RISCV_ISA_EXT_SVNAPOT);
> -				SET_ISA_EXT_MAP("svpbmt", RISCV_ISA_EXT_SVPBMT);
> -				SET_ISA_EXT_MAP("zba", RISCV_ISA_EXT_ZBA);
> -				SET_ISA_EXT_MAP("zbb", RISCV_ISA_EXT_ZBB);
> -				SET_ISA_EXT_MAP("zbs", RISCV_ISA_EXT_ZBS);
> -				SET_ISA_EXT_MAP("zicbom", RISCV_ISA_EXT_ZICBOM);
> -				SET_ISA_EXT_MAP("zicboz", RISCV_ISA_EXT_ZICBOZ);
> -				SET_ISA_EXT_MAP("zihintpause", RISCV_ISA_EXT_ZIHINTPAUSE);
> +				for (int i = 0; i < riscv_isa_ext_count; i++)
> +					SET_ISA_EXT_MAP(riscv_isa_ext[i].name,
> +							riscv_isa_ext[i].id);

Three cheers for removing one list that needed to be maintained!

>  			}
>  #undef SET_ISA_EXT_MAP
>  		}
> -- 
> 2.40.1
>

Other than also dropping the define,

Reviewed-by: Andrew Jones <ajones@xxxxxxxxxxxxxxxx>

Thanks,
drew