On Wed, 2017-10-25 at 19:51 -0700, Guenter Roeck wrote:
> Fix the following build error, seen when building sparc32:allmodconfig.
>
> drivers/net/ethernet/intel/i40e/i40e_ethtool.c:
> In function 'i40e_set_priv_flags':
> drivers/net/ethernet/intel/i40e/i40e_ethtool.c:4150:2: error:
> implicit declaration of function 'cmpxchg64'
>
> Signed-off-by: Guenter Roeck <[email protected]>
> ---
> v2: Actually implement cmpxchg64 with code snippet provided by Dave Miller
> Note: I am aware that this doesn't pass checkpatch; I found it more
> important to be in line with __cmpxchg_u32().
>
> arch/sparc/include/asm/cmpxchg_32.h | 2 ++
> arch/sparc/lib/atomic32.c | 14 ++++++++++++++
> 2 files changed, 16 insertions(+)
>
> diff --git a/arch/sparc/include/asm/cmpxchg_32.h
> b/arch/sparc/include/asm/cmpxchg_32.h
> index 83ffb83c5397..7f95d3ca20e2 100644
> --- a/arch/sparc/include/asm/cmpxchg_32.h
> +++ b/arch/sparc/include/asm/cmpxchg_32.h
> @@ -62,6 +62,8 @@ __cmpxchg(volatile void *ptr, unsigned long old, unsigned
> long new_, int size)
> (unsigned long)_n_, sizeof(*(ptr))); \
> })
>
> +extern u64 cmpxchg64(u64 *ptr, u64 old, u64 new);
This extern is unusual style for sparc function declarations.
> +
> #include <asm-generic/cmpxchg-local.h>
>
> /*
> diff --git a/arch/sparc/lib/atomic32.c b/arch/sparc/lib/atomic32.c
> index 2c373329d5cb..41601eb540e7 100644
> --- a/arch/sparc/lib/atomic32.c
> +++ b/arch/sparc/lib/atomic32.c
> @@ -172,6 +172,20 @@ unsigned long __cmpxchg_u32(volatile u32 *ptr, u32 old,
> u32 new)
> }
> EXPORT_SYMBOL(__cmpxchg_u32);
>
> +u64 cmpxchg64(u64 *ptr, u64 old, u64 new)
> +{
> + unsigned long flags;
> + u64 prev;
> +
> + spin_lock_irqsave(ATOMIC_HASH(ptr), flags);
> + if ((prev = *ptr) == old)
> + *ptr = new;
> + spin_unlock_irqrestore(ATOMIC_HASH(ptr), flags);
> +
> + return prev;
> +}
> +EXPORT_SYMBOL(cmpxchg64);
> +
> unsigned long __xchg_u32(volatile u32 *ptr, u32 new)
> {
> unsigned long flags;
