[PATCH] riscv: Skip riscv_cpu_setup() when CPU driver is disabled

[Yao Zi]

On Thu, Apr 30, 2026 at 01:57:51PM +0200, Michal Simek wrote:
> Building on commit c64fc632a86a ("riscv: cpu: Use CONFIG_IS_ENABLED(CPU)
> instead of plain ifdef"), add an early return in riscv_cpu_setup() when
> CONFIG_CPU is not enabled. This allows platforms to save code space in
> SPL by disabling CONFIG_SPL_CPU.
> 
> The compiler's dead-code elimination combined with --gc-sections
> removes the unreachable code and all associated static data,
> achieving significant size reduction without preprocessor guards:
> 
>   spl/u-boot-spl:all -4332 spl/u-boot-spl:rodata -2872
>   spl/u-boot-spl:text -1460
> 
> Signed-off-by: Michal Simek <michal.simek at amd.com>
> ---
> 
>  arch/riscv/cpu/cpu.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/arch/riscv/cpu/cpu.c b/arch/riscv/cpu/cpu.c
> index bbadd0c9a469..3bec7c7cb6d0 100644
> --- a/arch/riscv/cpu/cpu.c
> +++ b/arch/riscv/cpu/cpu.c
> @@ -638,6 +638,9 @@ int riscv_cpu_setup(void)
>  	const char *isa, **exts;
>  	struct udevice *dev;
>  
> +	if (!CONFIG_IS_ENABLED(CPU))
> +		return 0;

Should we return zero here, or -ENOENT like the original behavior when
no UCLASS_CPU device is found?

Otherwise the patch looks good to me.

Reviewed-by: Yao Zi <me at ziyao.cc>

> +
>  	uclass_find_first_device(UCLASS_CPU, &dev);
>  	if (!dev) {
>  		debug("unable to find the RISC-V cpu device\n");
> -- 
> 2.43.0
> 
> base-commit: ab9f3cb4de54c65bde394e31469c75ec89b18d5b