Date:   Tue, 14 Dec 2021 08:29:21 -0800 (PST)
Subject:     Re: [PATCH v9 03/17] riscv: Extending cpufeature.c to detect V-extension
In-Reply-To: <802edef897b4bd40f3ebc2cb47c02b8e2f61a666.1636362169.git.greentime.hu@sifive.com>
CC:     Paul Walmsley <paul.walmsley@sifive.com>,
        linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
        aou@eecs.berkeley.edu
From:   Palmer Dabbelt <palmer@dabbelt.com>
To:     greentime.hu@sifive.com
Message-ID: <mhng-37fab3bf-8fa6-4f02-a7ea-a19f775369a6@palmer-ri-x1c9>
Mime-Version: 1.0 (MHng)
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 8bit
Precedence: bulk

On Tue, 09 Nov 2021 01:48:15 PST (-0800), greentime.hu@sifive.com wrote:
> From: Guo Ren <ren_guo@c-sky.com>
>
> Current cpufeature.c doesn't support detecting V-extension, because
> "rv64" also contain a 'v' letter and we need to skip it.
>
> Signed-off-by: Guo Ren <ren_guo@c-sky.com>
> Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
> Reviewed-by: Anup Patel <anup@brainfault.org>
> Reviewed-by: Greentime Hu <greentime.hu@sifive.com>
> Signed-off-by: Greentime Hu <greentime.hu@sifive.com>
> ---
>  arch/riscv/include/uapi/asm/hwcap.h | 1 +
>  arch/riscv/kernel/cpufeature.c      | 1 +
>  2 files changed, 2 insertions(+)
>
> diff --git a/arch/riscv/include/uapi/asm/hwcap.h b/arch/riscv/include/uapi/asm/hwcap.h
> index 46dc3f5ee99f..c52bb7bbbabe 100644
> --- a/arch/riscv/include/uapi/asm/hwcap.h
> +++ b/arch/riscv/include/uapi/asm/hwcap.h
> @@ -21,5 +21,6 @@
>  #define COMPAT_HWCAP_ISA_F	(1 << ('F' - 'A'))
>  #define COMPAT_HWCAP_ISA_D	(1 << ('D' - 'A'))
>  #define COMPAT_HWCAP_ISA_C	(1 << ('C' - 'A'))
> +#define COMPAT_HWCAP_ISA_V	(1 << ('V' - 'A'))
>
>  #endif /* _UAPI_ASM_RISCV_HWCAP_H */
> diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
> index d959d207a40d..7069e55335d0 100644
> --- a/arch/riscv/kernel/cpufeature.c
> +++ b/arch/riscv/kernel/cpufeature.c
> @@ -73,6 +73,7 @@ void __init riscv_fill_hwcap(void)
>  	isa2hwcap['f'] = isa2hwcap['F'] = COMPAT_HWCAP_ISA_F;
>  	isa2hwcap['d'] = isa2hwcap['D'] = COMPAT_HWCAP_ISA_D;
>  	isa2hwcap['c'] = isa2hwcap['C'] = COMPAT_HWCAP_ISA_C;
> +	isa2hwcap['v'] = isa2hwcap['V'] = COMPAT_HWCAP_ISA_V;
>
>  	elf_hwcap = 0;

Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com>