Re: [PATCH 1/8] sparc32: make __cmpxchg_u32() return u32

From: Paul E. McKenney
Date: Tue Apr 02 2024 - 16:03:19 EST


On Tue, Apr 02, 2024 at 12:28:28AM -0400, Al Viro wrote:
> Conversion between u32 and unsigned long is tautological there,
> and the only use of return value is to return it from
> __cmpxchg() (which return unsigned long).
>
> Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>

I have pulled these in as replacements for my patches in the meantime.

Thank you!

Thanx, Paul

> ---
> arch/sparc/include/asm/cmpxchg_32.h | 2 +-
> arch/sparc/lib/atomic32.c | 4 ++--
> 2 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/arch/sparc/include/asm/cmpxchg_32.h b/arch/sparc/include/asm/cmpxchg_32.h
> index d0af82c240b7..112bfaa28729 100644
> --- a/arch/sparc/include/asm/cmpxchg_32.h
> +++ b/arch/sparc/include/asm/cmpxchg_32.h
> @@ -39,7 +39,7 @@ static __always_inline unsigned long __arch_xchg(unsigned long x, __volatile__ v
> /* bug catcher for when unsupported size is used - won't link */
> void __cmpxchg_called_with_bad_pointer(void);
> /* we only need to support cmpxchg of a u32 on sparc */
> -unsigned long __cmpxchg_u32(volatile u32 *m, u32 old, u32 new_);
> +u32 __cmpxchg_u32(volatile u32 *m, u32 old, u32 new_);
>
> /* don't worry...optimizer will get rid of most of this */
> static inline unsigned long
> diff --git a/arch/sparc/lib/atomic32.c b/arch/sparc/lib/atomic32.c
> index cf80d1ae352b..d90d756123d8 100644
> --- a/arch/sparc/lib/atomic32.c
> +++ b/arch/sparc/lib/atomic32.c
> @@ -159,7 +159,7 @@ unsigned long sp32___change_bit(unsigned long *addr, unsigned long mask)
> }
> EXPORT_SYMBOL(sp32___change_bit);
>
> -unsigned long __cmpxchg_u32(volatile u32 *ptr, u32 old, u32 new)
> +u32 __cmpxchg_u32(volatile u32 *ptr, u32 old, u32 new)
> {
> unsigned long flags;
> u32 prev;
> @@ -169,7 +169,7 @@ unsigned long __cmpxchg_u32(volatile u32 *ptr, u32 old, u32 new)
> *ptr = new;
> spin_unlock_irqrestore(ATOMIC_HASH(ptr), flags);
>
> - return (unsigned long)prev;
> + return prev;
> }
> EXPORT_SYMBOL(__cmpxchg_u32);
>
> --
> 2.39.2
>