Re: [Xen-devel] [PATCH v6 02/18] Add cmpxchg16b support for x86-64

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 25.08.15 at 03:57, <feng.wu@xxxxxxxxx> wrote:
> --- a/xen/include/asm-x86/x86_64/system.h
> +++ b/xen/include/asm-x86/x86_64/system.h
> @@ -6,6 +6,34 @@
>                                     (unsigned long)(n),sizeof(*(ptr))))
>  
>  /*
> + * Atomic 16 bytes compare and exchange.  Compare OLD with MEM, if
> + * identical, store NEW in MEM.  Return the initial value in MEM.
> + * Success is indicated by comparing RETURN with OLD.
> + *
> + * This function can only be called when cpu_has_cx16 is true.
> + */
> +
> +static always_inline __uint128_t __cmpxchg16b(
> +    volatile void *ptr, __uint128_t *old, __uint128_t *new)

Noted just now - the latter two should both be const.

Jan


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel