Hi Jiaxun,
Nice catch! Only one minor nit. Otherwise:
Reviewed-by: WANG Xuerui <git@xxxxxxxxxx>
On 2020/7/31 12:10, Jiaxun Yang wrote:
> Requested by downstream distros, a Kconfig option for default
> IEEE754 conformance mode allows them to set their mode to
> relaxed by default.
>
> Signed-off-by: Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx>
> ---
> arch/mips/Kconfig | 21 +++++++++++++++++++++
> arch/mips/kernel/cpu-probe.c | 12 +++++++++++-
> 2 files changed, 32 insertions(+), 1 deletion(-)
>
> diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
> index f6bb446d30f0..ef5b2a177b1b 100644
> --- a/arch/mips/Kconfig
> +++ b/arch/mips/Kconfig
> @@ -2877,6 +2877,27 @@ config MIPS_NR_CPU_NR_MAP
> default 1024 if MIPS_NR_CPU_NR_MAP_1024
> default NR_CPUS if !MIPS_NR_CPU_NR_MAP_1024
>
> +choice
> + prompt "Default IEEE Std 754 conformance mode"
> + default IEEE754_DEFAULT_STRICT
> + help
> + Default IEEE Std 754 conformance mode, see ieee754= kernel parameter
> + for detail.
Here and the title, "IEEE Std 754" can be just "IEEE 754". I don't
remember seeing the "IEEE Std 754" phrase anywhere.
I suggest the following help message:
"Sets the default IEEE 754 conformance mode, same as overriding the
default value for the ieee754= kernel parameter. See the kernel
parameter for details."
> +
> + config IEEE754_DEFAULT_STRICT
> + bool "Strict"
> +
> + config IEEE754_DEFAULT_LEGACY
> + bool "Legacy"
> +
> + config IEEE754_DEFAULT_STD2008
> + bool "2008"
> +
> + config IEEE754_DEFAULT_RELAXED
> + bool "Relaxed"
> +
> +endchoice
> +
> #
> # Timer Interrupt Frequency Configuration
> #
> diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
> index d9e8d39a7289..03adeed58efb 100644
> --- a/arch/mips/kernel/cpu-probe.c
> +++ b/arch/mips/kernel/cpu-probe.c
> @@ -157,7 +157,17 @@ static void cpu_set_fpu_2008(struct cpuinfo_mips *c)
> * IEEE 754 conformance mode to use. Affects the NaN encoding and the
> * ABS.fmt/NEG.fmt execution mode.
> */
> -static enum { STRICT, LEGACY, STD2008, RELAXED } ieee754 = STRICT;
> +enum ieee754_mode { STRICT, LEGACY, STD2008, RELAXED };
> +
> +#if defined(CONFIG_IEEE754_DEFAULT_STRICT)
> +static enum ieee754_mode ieee754 = STRICT;
> +#elif defined(CONFIG_IEEE754_DEFAULT_LEGACY)
> +static enum ieee754_mode ieee754 = LEGACY;
> +#elif defined(CONFIG_IEEE754_DEFAULT_STD2008)
> +static enum ieee754_mode ieee754 = STD2008;
> +#elif defined(CONFIG_IEEE754_DEFAULT_RELAXED)
> +static enum ieee754_mode ieee754 = RELAXED;
> +#endif
>
> /*
> * Set the IEEE 754 NaN encodings and the ABS.fmt/NEG.fmt execution modes
