If configuration options SOFTIRQ_ON_OWN_STACK and PREEMPT_RT 
are enabled simultaneously under RISC-V architecture,
it will result in a compilation failure:

arch/riscv/kernel/irq.c:64:6: error: redefinition of 'do_softirq_own_stack'
   64 | void do_softirq_own_stack(void)
      |      ^~~~~~~~~~~~~~~~~~~~
In file included from ./arch/riscv/include/generated/asm/softirq_stack.h:1,
                 from arch/riscv/kernel/irq.c:15:
./include/asm-generic/softirq_stack.h:8:20: note: previous definition of 'do_softirq_own_stack' was here
    8 | static inline void do_softirq_own_stack(void)
      |                    ^~~~~~~~~~~~~~~~~~~~
      
After changing CONFIG_HAVE_SOFTIRQ_ON_OWN_STACK to CONFIG_SOFTIRQ_ON_OWN_STACK,
compilation can be successful.

Fixes: dd69d07a5a6c ("riscv: stack: Support HAVE_SOFTIRQ_ON_OWN_STACK")
Reviewed-by: Guo Ren <guoren@kernel.org>
Signed-off-by: Jiexun Wang <wangjiexun@tinylab.org>
---
Changes in v3:
- changed to a more suitable subject line
- fix the #endif comment at the bottom of the function

Changes in v2:
- changed to a more suitable subject line
- add a Fixes tag

---
 arch/riscv/kernel/irq.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/riscv/kernel/irq.c b/arch/riscv/kernel/irq.c
index a8efa053c4a5..9cc0a7669271 100644
--- a/arch/riscv/kernel/irq.c
+++ b/arch/riscv/kernel/irq.c
@@ -60,7 +60,7 @@ static void init_irq_stacks(void)
 }
 #endif /* CONFIG_VMAP_STACK */
 
-#ifdef CONFIG_HAVE_SOFTIRQ_ON_OWN_STACK
+#ifdef CONFIG_SOFTIRQ_ON_OWN_STACK
 void do_softirq_own_stack(void)
 {
 #ifdef CONFIG_IRQ_STACKS
@@ -92,7 +92,7 @@ void do_softirq_own_stack(void)
 #endif
 		__do_softirq();
 }
-#endif /* CONFIG_HAVE_SOFTIRQ_ON_OWN_STACK */
+#endif /* CONFIG_SOFTIRQ_ON_OWN_STACK */
 
 #else
 static void init_irq_stacks(void) {}
-- 
2.34.1

Hello:

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

On Wed, 13 Sep 2023 13:29:40 +0800 you wrote:
> If configuration options SOFTIRQ_ON_OWN_STACK and PREEMPT_RT
> are enabled simultaneously under RISC-V architecture,
> it will result in a compilation failure:
> 
> arch/riscv/kernel/irq.c:64:6: error: redefinition of 'do_softirq_own_stack'
>    64 | void do_softirq_own_stack(void)
>       |      ^~~~~~~~~~~~~~~~~~~~
> In file included from ./arch/riscv/include/generated/asm/softirq_stack.h:1,
>                  from arch/riscv/kernel/irq.c:15:
> ./include/asm-generic/softirq_stack.h:8:20: note: previous definition of 'do_softirq_own_stack' was here
>     8 | static inline void do_softirq_own_stack(void)
>       |                    ^~~~~~~~~~~~~~~~~~~~
> 
> [...]

Here is the summary with links:
  - [v3] RISC-V: Fix wrong use of CONFIG_HAVE_SOFTIRQ_ON_OWN_STACK
    https://git.kernel.org/riscv/c/07a27665754b

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

On 9/13/23 00:29, Jiexun Wang wrote:
> If configuration options SOFTIRQ_ON_OWN_STACK and PREEMPT_RT 
> are enabled simultaneously under RISC-V architecture,
> it will result in a compilation failure:
> 
> arch/riscv/kernel/irq.c:64:6: error: redefinition of 'do_softirq_own_stack'
>    64 | void do_softirq_own_stack(void)
>       |      ^~~~~~~~~~~~~~~~~~~~
> In file included from ./arch/riscv/include/generated/asm/softirq_stack.h:1,
>                  from arch/riscv/kernel/irq.c:15:
> ./include/asm-generic/softirq_stack.h:8:20: note: previous definition of 'do_softirq_own_stack' was here
>     8 | static inline void do_softirq_own_stack(void)
>       |                    ^~~~~~~~~~~~~~~~~~~~
>       
> After changing CONFIG_HAVE_SOFTIRQ_ON_OWN_STACK to CONFIG_SOFTIRQ_ON_OWN_STACK,
> compilation can be successful.
> 
> Fixes: dd69d07a5a6c ("riscv: stack: Support HAVE_SOFTIRQ_ON_OWN_STACK")
> Reviewed-by: Guo Ren <guoren@kernel.org>
> Signed-off-by: Jiexun Wang <wangjiexun@tinylab.org>
> ---
> Changes in v3:
> - changed to a more suitable subject line
> - fix the #endif comment at the bottom of the function
> 
> Changes in v2:
> - changed to a more suitable subject line
> - add a Fixes tag
> 
> ---
>  arch/riscv/kernel/irq.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

Reviewed-by: Samuel Holland <samuel@sholland.org>