Re: [dpdk-dev] [PATCH 1/3] eal: add 128-bit cmpset (x86-64 only)

[Andrew Rybchenko <arybchenko@solarflare.com>]

On 1/10/19 11:55 PM, Gage Eads wrote:
> This operation can be used for non-blocking algorithms, such as a
> non-blocking stack or ring.
>
> Signed-off-by: Gage Eads <gage.eads@intel.com>
> ---
>   .../common/include/arch/x86/rte_atomic_64.h        | 22 ++++++++++++++++++++++
>   1 file changed, 22 insertions(+)
>
> diff --git a/lib/librte_eal/common/include/arch/x86/rte_atomic_64.h b/lib/librte_eal/common/include/arch/x86/rte_atomic_64.h
> index fd2ec9c53..34c2addf8 100644
> --- a/lib/librte_eal/common/include/arch/x86/rte_atomic_64.h
> +++ b/lib/librte_eal/common/include/arch/x86/rte_atomic_64.h
> @@ -34,6 +34,7 @@
>   /*
>    * Inspired from FreeBSD src/sys/amd64/include/atomic.h
>    * Copyright (c) 1998 Doug Rabson
> + * Copyright (c) 2019 Intel Corporation
>    * All rights reserved.
>    */
>   
> @@ -208,4 +209,25 @@ static inline void rte_atomic64_clear(rte_atomic64_t *v)
>   }
>   #endif
>   
> +static inline int
> +rte_atomic128_cmpset(volatile uint64_t *dst, uint64_t *exp, uint64_t *src)
> +{
> +	uint8_t res;
> +
> +	asm volatile (
> +		      MPLOCKED
> +		      "cmpxchg16b %[dst];"
> +		      " sete %[res]"
> +		      : [dst] "=m" (*dst),
> +			[res] "=r" (res)
> +		      : "c" (src[1]),
> +			"b" (src[0]),
> +			"m" (*dst),
> +			"d" (exp[1]),
> +			"a" (exp[0])
> +		      : "memory");
> +
> +	return res;
> +}
> +
>   #endif /* _RTE_ATOMIC_X86_64_

Is it OK to add it to rte_atomic_64.h header which is for 64-bit integer 
ops?

Andrew.
> H_ */