The arch/riscv/include/asm/bitops.h does not functionally require
including /linux/irqflags.h. Additionally, adding
arch/riscv/include/asm/percpu.h causes a circular inclusion:
kernel/bounds.c
->include/linux/log2.h
->include/linux/bitops.h
->arch/riscv/include/asm/bitops.h
->include/linux/irqflags.h
->include/linux/find.h
->return val ? __ffs(val) : size;
->arch/riscv/include/asm/bitops.h

The compilation log is as follows:
CC      kernel/bounds.s
In file included from ./include/linux/bitmap.h:11,
               from ./include/linux/cpumask.h:12,
               from ./arch/riscv/include/asm/processor.h:55,
               from ./arch/riscv/include/asm/thread_info.h:42,
               from ./include/linux/thread_info.h:60,
               from ./include/asm-generic/preempt.h:5,
               from ./arch/riscv/include/generated/asm/preempt.h:1,
               from ./include/linux/preempt.h:79,
               from ./arch/riscv/include/asm/percpu.h:8,
               from ./include/linux/irqflags.h:19,
               from ./arch/riscv/include/asm/bitops.h:14,
               from ./include/linux/bitops.h:68,
               from ./include/linux/log2.h:12,
               from kernel/bounds.c:13:
./include/linux/find.h: In function 'find_next_bit':
./include/linux/find.h:66:30: error: implicit declaration of function '__ffs' [-Wimplicit-function-declaration]
   66 |                 return val ? __ffs(val) : size;
      |                              ^~~~~

Signed-off-by: Yunhui Cui <cuiyunhui@bytedance.com>
---
 arch/riscv/include/asm/bitops.h | 1 -
 1 file changed, 1 deletion(-)

diff --git a/arch/riscv/include/asm/bitops.h b/arch/riscv/include/asm/bitops.h
index 238092125c118..3c1a15be54d80 100644
--- a/arch/riscv/include/asm/bitops.h
+++ b/arch/riscv/include/asm/bitops.h
@@ -11,7 +11,6 @@
 #endif /* _LINUX_BITOPS_H */
 
 #include <linux/compiler.h>
-#include <linux/irqflags.h>
 #include <asm/barrier.h>
 #include <asm/bitsperlong.h>
 
-- 
2.39.5

On Tue, Dec 16, 2025 at 09:47:19AM +0800, Yunhui Cui wrote:
> The arch/riscv/include/asm/bitops.h does not functionally require
> including /linux/irqflags.h. Additionally, adding
> arch/riscv/include/asm/percpu.h causes a circular inclusion:
> kernel/bounds.c
> ->include/linux/log2.h
> ->include/linux/bitops.h
> ->arch/riscv/include/asm/bitops.h
> ->include/linux/irqflags.h
> ->include/linux/find.h
> ->return val ? __ffs(val) : size;
> ->arch/riscv/include/asm/bitops.h
> 
> The compilation log is as follows:
> CC      kernel/bounds.s
> In file included from ./include/linux/bitmap.h:11,
>                from ./include/linux/cpumask.h:12,
>                from ./arch/riscv/include/asm/processor.h:55,
>                from ./arch/riscv/include/asm/thread_info.h:42,
>                from ./include/linux/thread_info.h:60,
>                from ./include/asm-generic/preempt.h:5,
>                from ./arch/riscv/include/generated/asm/preempt.h:1,
>                from ./include/linux/preempt.h:79,
>                from ./arch/riscv/include/asm/percpu.h:8,
>                from ./include/linux/irqflags.h:19,
>                from ./arch/riscv/include/asm/bitops.h:14,
>                from ./include/linux/bitops.h:68,
>                from ./include/linux/log2.h:12,
>                from kernel/bounds.c:13:
> ./include/linux/find.h: In function 'find_next_bit':
> ./include/linux/find.h:66:30: error: implicit declaration of function '__ffs' [-Wimplicit-function-declaration]
>    66 |                 return val ? __ffs(val) : size;
>       |                              ^~~~~
> 
> Signed-off-by: Yunhui Cui <cuiyunhui@bytedance.com>

Acked-by: Yury Norov (NVIDIA) <yury.norov@gmail.com>

> ---
>  arch/riscv/include/asm/bitops.h | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/arch/riscv/include/asm/bitops.h b/arch/riscv/include/asm/bitops.h
> index 238092125c118..3c1a15be54d80 100644
> --- a/arch/riscv/include/asm/bitops.h
> +++ b/arch/riscv/include/asm/bitops.h
> @@ -11,7 +11,6 @@
>  #endif /* _LINUX_BITOPS_H */
>  
>  #include <linux/compiler.h>
> -#include <linux/irqflags.h>
>  #include <asm/barrier.h>
>  #include <asm/bitsperlong.h>
>  
> -- 
> 2.39.5