Re: [PATCH] locking/arch: Move qrwlock.h include after qspinlock.h

Guenter Roeck
2021-02-10T15:06:27Z

On 2/10/21 6:45 AM, Waiman Long wrote:
> The queued rwlock code has a dependency on the current spinlock
> implementation (likely to be qspinlock), but not vice versa. Including
> qrwlock.h before qspinlock.h can be problematic when expanding qrwlock
> functionality.
>
> If both qspinlock.h and qrwlock.h are to be included, the qrwlock.h
> include should always be after qspinlock.h. Update the current set of
> asm/spinlock.h files to enforce that.
>
> Signed-off-by: Waiman Long <longman@redhat.com>

There should be a Fixes: tag here. If the SHA of the offending commit is not
stable, there should be a better reference than "The queued rwlock code".

This patch fixes the build problem I had observed on mips. I also tested
xtensa:defconfig and arm64:defconfig with no problems observed.

Tested-by: Guenter Roeck <linux@roeck-us.net>

Guenter

> ---
> arch/arm64/include/asm/spinlock.h | 2 +-
> arch/mips/include/asm/spinlock.h | 2 +-
> arch/xtensa/include/asm/spinlock.h | 2 +-
> 3 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/arch/arm64/include/asm/spinlock.h b/arch/arm64/include/asm/spinlock.h
> index 9083d6992603..0525c0b089ed 100644
> --- a/arch/arm64/include/asm/spinlock.h
> +++ b/arch/arm64/include/asm/spinlock.h
> @@ -5,8 +5,8 @@
> #ifndef __ASM_SPINLOCK_H
> #define __ASM_SPINLOCK_H
>
> -#include <asm/qrwlock.h>
> #include <asm/qspinlock.h>
> +#include <asm/qrwlock.h>
>
> /* See include/linux/spinlock.h */
> #define smp_mb__after_spinlock() smp_mb()
> diff --git a/arch/mips/include/asm/spinlock.h b/arch/mips/include/asm/spinlock.h
> index 8a88eb265516..6ce2117e49f6 100644
> --- a/arch/mips/include/asm/spinlock.h
> +++ b/arch/mips/include/asm/spinlock.h
> @@ -10,7 +10,6 @@
> #define _ASM_SPINLOCK_H
>
> #include <asm/processor.h>
> -#include <asm/qrwlock.h>
>
> #include <asm-generic/qspinlock_types.h>
>
> @@ -27,5 +26,6 @@ static inline void queued_spin_unlock(struct qspinlock *lock)
> }
>
> #include <asm/qspinlock.h>
> +#include <asm/qrwlock.h>
>
> #endif /* _ASM_SPINLOCK_H */
> diff --git a/arch/xtensa/include/asm/spinlock.h b/arch/xtensa/include/asm/spinlock.h
> index 584b0de6f2ca..41c449ece2d8 100644
> --- a/arch/xtensa/include/asm/spinlock.h
> +++ b/arch/xtensa/include/asm/spinlock.h
> @@ -12,8 +12,8 @@
> #define _XTENSA_SPINLOCK_H
>
> #include <asm/barrier.h>
> -#include <asm/qrwlock.h>
> #include <asm/qspinlock.h>
> +#include <asm/qrwlock.h>
>
> #define smp_mb__after_spinlock() smp_mb()
>
>