Since commit 80b6093b55e3 ("kbuild: add -Wundef to KBUILD_CPPFLAGS
for W=1 builds"), building with W=1 detects misuse of #if.

  $ make W=1 ARCH=riscv CROSS_COMPILE=riscv64-linux-gnu- arch/riscv/kernel/
    [snip]
    AS      arch/riscv/kernel/head.o
  arch/riscv/kernel/head.S:329:5: warning: "CONFIG_RISCV_BOOT_SPINWAIT" is not defined, evaluates to 0 [-Wundef]
    329 | #if CONFIG_RISCV_BOOT_SPINWAIT
        |     ^~~~~~~~~~~~~~~~~~~~~~~~~~

CONFIG_RISCV_BOOT_SPINWAIT is a bool option. #ifdef should be used.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---

 arch/riscv/kernel/head.S | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S
index b865046e4dbb..4bf6c449d78b 100644
--- a/arch/riscv/kernel/head.S
+++ b/arch/riscv/kernel/head.S
@@ -326,7 +326,7 @@ clear_bss_done:
 	call soc_early_init
 	tail start_kernel
 
-#if CONFIG_RISCV_BOOT_SPINWAIT
+#ifdef CONFIG_RISCV_BOOT_SPINWAIT
 .Lsecondary_start:
 	/* Set trap vector to spin forever to help debug */
 	la a3, .Lsecondary_park
-- 
2.34.1

Hello:

This patch was applied to riscv/linux.git (fixes)
by Palmer Dabbelt <palmer@rivosinc.com>:

On Sat,  7 Jan 2023 01:12:13 +0900 you wrote:
> Since commit 80b6093b55e3 ("kbuild: add -Wundef to KBUILD_CPPFLAGS
> for W=1 builds"), building with W=1 detects misuse of #if.
> 
>   $ make W=1 ARCH=riscv CROSS_COMPILE=riscv64-linux-gnu- arch/riscv/kernel/
>     [snip]
>     AS      arch/riscv/kernel/head.o
>   arch/riscv/kernel/head.S:329:5: warning: "CONFIG_RISCV_BOOT_SPINWAIT" is not defined, evaluates to 0 [-Wundef]
>     329 | #if CONFIG_RISCV_BOOT_SPINWAIT
>         |     ^~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> [...]

Here is the summary with links:
  - riscv: fix -Wundef warning for CONFIG_RISCV_BOOT_SPINWAIT
    https://git.kernel.org/riscv/c/5b89c6f9b2df

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html

On Sat, Jan 7, 2023 at 12:12 AM Masahiro Yamada <masahiroy@kernel.org> wrote:
>
> Since commit 80b6093b55e3 ("kbuild: add -Wundef to KBUILD_CPPFLAGS
> for W=1 builds"), building with W=1 detects misuse of #if.
>
>   $ make W=1 ARCH=riscv CROSS_COMPILE=riscv64-linux-gnu- arch/riscv/kernel/
>     [snip]
>     AS      arch/riscv/kernel/head.o
>   arch/riscv/kernel/head.S:329:5: warning: "CONFIG_RISCV_BOOT_SPINWAIT" is not defined, evaluates to 0 [-Wundef]
>     329 | #if CONFIG_RISCV_BOOT_SPINWAIT
>         |     ^~~~~~~~~~~~~~~~~~~~~~~~~~
>
> CONFIG_RISCV_BOOT_SPINWAIT is a bool option. #ifdef should be used.
Fixes: 2ffc48fc7071 ("RISC-V: Move spinwait booting method to its own config")

Right?

>
> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
> ---
>
>  arch/riscv/kernel/head.S | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S
> index b865046e4dbb..4bf6c449d78b 100644
> --- a/arch/riscv/kernel/head.S
> +++ b/arch/riscv/kernel/head.S
> @@ -326,7 +326,7 @@ clear_bss_done:
>         call soc_early_init
>         tail start_kernel
>
> -#if CONFIG_RISCV_BOOT_SPINWAIT
> +#ifdef CONFIG_RISCV_BOOT_SPINWAIT
>  .Lsecondary_start:
>         /* Set trap vector to spin forever to help debug */
>         la a3, .Lsecondary_park
> --
> 2.34.1
>


-- 
Best Regards
 Guo Ren