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Date:   Thu, 22 Mar 2018 13:43:50 +0000
From:   James Hogan <jhogan@kernel.org>
To:     Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc:     chenhc@lemote.com, linux-mips@linux-mips.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] MIPS: Introduce has_cpu_mips*_user in cpu-features.h
Message-ID: <20180322134349.GH13126@saruman>
References: <20180321145304.4639-1-jiaxun.yang@flygoat.com>
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On Wed, Mar 21, 2018 at 10:53:03PM +0800, Jiaxun Yang wrote:
> Some processors support user mode instructions ISA level witch is

nit: s/witch/which/ here, below, and in the comment.

Otherwise it doesn't look unreasonable.

Cheers
James

> different with the ISA level it should be treated in kernel, such
> as Loongson 3A1000 3B1000 3A1500 3B1500 support all mips64r2 user
> mode instructions however, they should be treated as mips64r1 in
> kernel.
>=20
> So we introduce has_cpu_mips*_user to decide witch level should be
> displayed in cpuinfo to prevent misleading userspace programs.
>=20
> Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
> ---
>  arch/mips/include/asm/cpu-features.h | 39 ++++++++++++++++++++++++++++++=
++++++
>  arch/mips/kernel/proc.c              | 22 ++++++++++----------
>  2 files changed, 50 insertions(+), 11 deletions(-)
>=20
> diff --git a/arch/mips/include/asm/cpu-features.h b/arch/mips/include/asm=
/cpu-features.h
> index 721b698bfe3c..0eff1956e229 100644
> --- a/arch/mips/include/asm/cpu-features.h
> +++ b/arch/mips/include/asm/cpu-features.h
> @@ -251,6 +251,45 @@
>  # define cpu_has_mips64r6	(cpu_data[0].isa_level & MIPS_CPU_ISA_M64R6)
>  #endif
> =20
> +/*
> + * For the CPU that has a user mode instructions ISA level witch is diff=
erent
> + * from the ISA level it should be treated in kernel, this ISA level will
> + * be displayed in cpuinfo as a reference for userspace programs.
> + */
> +#ifndef cpu_has_mips_1_user
> +# define cpu_has_mips_1_user		(cpu_has_mips_1)
> +#endif
> +#ifndef cpu_has_mips_2_user
> +# define cpu_has_mips_2_user		(cpu_has_mips_2)
> +#endif
> +#ifndef cpu_has_mips_3_user
> +# define cpu_has_mips_3_user		(cpu_has_mips_3)
> +#endif
> +#ifndef cpu_has_mips_4_user
> +# define cpu_has_mips_4_user		(cpu_has_mips_4)
> +#endif
> +#ifndef cpu_has_mips_5_user
> +# define cpu_has_mips_5_user		(cpu_has_mips_5)
> +#endif
> +#ifndef cpu_has_mips32r1_user
> +# define cpu_has_mips32r1_user	(cpu_has_mips32r1)
> +#endif
> +#ifndef cpu_has_mips32r2_user
> +# define cpu_has_mips32r2_user	(cpu_has_mips32r2)
> +#endif
> +#ifndef cpu_has_mips32r6_user
> +# define cpu_has_mips32r6_user	(cpu_has_mips32r6)
> +#endif
> +#ifndef cpu_has_mips64r1_user
> +# define cpu_has_mips64r1_user	(cpu_has_mips64r1)
> +#endif
> +#ifndef cpu_has_mips64r2_user
> +# define cpu_has_mips64r2_user	(cpu_has_mips64r2)
> +#endif
> +#ifndef cpu_has_mips64r6_user
> +# define cpu_has_mips64r6_user	(cpu_has_mips64r6)
> +#endif
> +
>  /*
>   * Shortcuts ...
>   */
> diff --git a/arch/mips/kernel/proc.c b/arch/mips/kernel/proc.c
> index b2de408a259e..65a9a695af3c 100644
> --- a/arch/mips/kernel/proc.c
> +++ b/arch/mips/kernel/proc.c
> @@ -84,27 +84,27 @@ static int show_cpuinfo(struct seq_file *m, void *v)
>  	}
> =20
>  	seq_printf(m, "isa\t\t\t:");=20
> -	if (cpu_has_mips_1)
> +	if (cpu_has_mips_1_user)
>  		seq_printf(m, " mips1");
> -	if (cpu_has_mips_2)
> +	if (cpu_has_mips_2_user)
>  		seq_printf(m, "%s", " mips2");
> -	if (cpu_has_mips_3)
> +	if (cpu_has_mips_3_user)
>  		seq_printf(m, "%s", " mips3");
> -	if (cpu_has_mips_4)
> +	if (cpu_has_mips_4_user)
>  		seq_printf(m, "%s", " mips4");
> -	if (cpu_has_mips_5)
> +	if (cpu_has_mips_5_user)
>  		seq_printf(m, "%s", " mips5");
> -	if (cpu_has_mips32r1)
> +	if (cpu_has_mips32r1_user)
>  		seq_printf(m, "%s", " mips32r1");
> -	if (cpu_has_mips32r2)
> +	if (cpu_has_mips32r2_user)
>  		seq_printf(m, "%s", " mips32r2");
> -	if (cpu_has_mips32r6)
> +	if (cpu_has_mips32r6_user)
>  		seq_printf(m, "%s", " mips32r6");
> -	if (cpu_has_mips64r1)
> +	if (cpu_has_mips64r1_user)
>  		seq_printf(m, "%s", " mips64r1");
> -	if (cpu_has_mips64r2)
> +	if (cpu_has_mips64r2_user)
>  		seq_printf(m, "%s", " mips64r2");
> -	if (cpu_has_mips64r6)
> +	if (cpu_has_mips64r6_user)
>  		seq_printf(m, "%s", " mips64r6");
>  	seq_printf(m, "\n");
> =20
> --=20
> 2.16.2
>=20

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