Re: [PATCH 1/3] powerpc: make CPU selection logic generic in Makefile

From: Michael Ellerman
Date: Tue Aug 07 2018 - 03:18:36 EST


Christophe Leroy <christophe.leroy@xxxxxx> writes:

> At the time being, when adding a new CPU for selection, both
> Kconfig.cputype and Makefile have to be modified.
>
> This patch moves into Kconfig.cputype the name of the CPU to me
> passed to the -mcpu= argument.
>
> Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxx>
> ---
> arch/powerpc/Makefile | 8 +-------
> arch/powerpc/platforms/Kconfig.cputype | 15 +++++++++++++++
> 2 files changed, 16 insertions(+), 7 deletions(-)
>
> diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
> index 9704ab360d39..9a5642552abc 100644
> --- a/arch/powerpc/Makefile
> +++ b/arch/powerpc/Makefile
> @@ -175,13 +175,7 @@ ifdef CONFIG_MPROFILE_KERNEL
> endif
> endif
>
> -CFLAGS-$(CONFIG_CELL_CPU) += $(call cc-option,-mcpu=cell)
> -CFLAGS-$(CONFIG_POWER5_CPU) += $(call cc-option,-mcpu=power5)
> -CFLAGS-$(CONFIG_POWER6_CPU) += $(call cc-option,-mcpu=power6)
> -CFLAGS-$(CONFIG_POWER7_CPU) += $(call cc-option,-mcpu=power7)
> -CFLAGS-$(CONFIG_POWER8_CPU) += $(call cc-option,-mcpu=power8)
> -CFLAGS-$(CONFIG_POWER9_CPU) += $(call cc-option,-mcpu=power9)
> -CFLAGS-$(CONFIG_PPC_8xx) += $(call cc-option,-mcpu=860)
> +CFLAGS-$(CONFIG_SPECIAL_CPU_BOOL) += $(call cc-option,-mcpu=$(CONFIG_SPECIAL_CPU))

This looks good.

I'll rename it from "SPECIAL_CPU" to "TARGET_CPU" because that's the
terminology used in the GCC docs, eg:

-mcpu=name
Specify the name of the target processor, optionally suffixed by one or more feature modifiers.


cheers