Re: [PATCH] riscv: RISCV_ISA_SV48 and RISCV_ISA_SV57 should depend on MMU

From: Jisheng Zhang

Date: Wed Oct 14 2026 - 19:48:14 EST


On Wed, Oct 14, 2026 at 12:20:39PM +0200, Geert Uytterhoeven wrote:
> These options are irreleant for nommu systems.
>
> Fixes: 36de74049ec8cb1a ("riscv: introduce RISCV_ISA_SV48 and RISCV_ISA_SV57")
> Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> ---
> arch/riscv/Kconfig | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> index 15f6e67c60410a87..15beeb4690aebcc4 100644
> --- a/arch/riscv/Kconfig
> +++ b/arch/riscv/Kconfig
> @@ -605,7 +605,7 @@ config RISCV_ISA_SSQOSID
>
> config RISCV_ISA_SV48
> bool "Page-Based 48-bit Virtual-Memory System"
> - depends on 64BIT
> + depends on 64BIT && MMU
> default y
> help
> Add support for the Page-Based 48-bit Virtual-Memory System.
> @@ -617,7 +617,7 @@ config RISCV_ISA_SV48
>
> config RISCV_ISA_SV57
> bool "Page-Based 57-bit Virtual-Memory System"
> - depends on 64BIT
> + depends on 64BIT && MMU

hmm, I think we also need to make RISCV_ISA_SV57 depend on
RISCV_ISA_SV48. Otherwise, there's a case: RISCV_ISA_SV57 &&
!RISCV_ISA_SV48. Human won't make this wrong combination, but
the random config can.

with that change,
Reviewed-by: Jisheng Zhang <jszhang@xxxxxxxxxx>

> default y
> help
> Add support for the Page-Based 57-bit Virtual-Memory System.
> --
> 2.43.0
>