[PATCH v2 16/16] powerpc/microwatt: Don't select the hash MMU code

[Joel Stanley]

On Thu, 21 Oct 2021 at 04:04, Nicholas Piggin <npiggin at gmail.com> wrote:
>
> Microwatt is radix-only, so it does not require hash MMU support.
>
> This saves 20kB compressed dtbImage and 56kB vmlinux size.
>
> Signed-off-by: Nicholas Piggin <npiggin at gmail.com>
> ---
>  arch/powerpc/configs/microwatt_defconfig | 1 -
>  arch/powerpc/platforms/microwatt/Kconfig | 1 -
>  2 files changed, 2 deletions(-)
>
> diff --git a/arch/powerpc/configs/microwatt_defconfig b/arch/powerpc/configs/microwatt_defconfig
> index 6e62966730d3..7c8eb29d8afe 100644
> --- a/arch/powerpc/configs/microwatt_defconfig
> +++ b/arch/powerpc/configs/microwatt_defconfig
> @@ -27,7 +27,6 @@ CONFIG_PPC_MICROWATT=y
>  # CONFIG_PPC_OF_BOOT_TRAMPOLINE is not set
>  CONFIG_CPU_FREQ=y
>  CONFIG_HZ_100=y
> -# CONFIG_PPC_MEM_KEYS is not set
>  # CONFIG_SECCOMP is not set
>  # CONFIG_MQ_IOSCHED_KYBER is not set
>  # CONFIG_COREDUMP is not set

We still end up with CONFIG_PPC_64S_HASH_MMU=y in the config as it
defaults to y.

We should disable in the defconfig it so your new changes are tested
by that defconfig:

+# CONFIG_PPC_64S_HASH_MMU is not set

I boot tested your series on Microwatt with microwatt_defconfig (with
and without that option set) and ppc64le_defconfig.

Cheers,

Joel

> diff --git a/arch/powerpc/platforms/microwatt/Kconfig b/arch/powerpc/platforms/microwatt/Kconfig
> index 823192e9d38a..5e320f49583a 100644
> --- a/arch/powerpc/platforms/microwatt/Kconfig
> +++ b/arch/powerpc/platforms/microwatt/Kconfig
> @@ -5,7 +5,6 @@ config PPC_MICROWATT
>         select PPC_XICS
>         select PPC_ICS_NATIVE
>         select PPC_ICP_NATIVE
> -       select PPC_HASH_MMU_NATIVE if PPC_64S_HASH_MMU
>         select PPC_UDBG_16550
>         select ARCH_RANDOM
>         help
> --
> 2.23.0
>