Re: [kvm-unit-tests PATCH v1 4/5] s390x: sclp: add service call instruction wrapper

[Thomas Huth <thuth@redhat.com>]

On 22/10/2019 12.53, Claudio Imbrenda wrote:
> Add a wrapper for the service call instruction, and use it for SCLP
> interactions instead of using inline assembly everywhere.
> 
> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
> ---
>  lib/s390x/asm/arch_def.h | 13 +++++++++++++
>  lib/s390x/sclp.c         |  7 +------
>  2 files changed, 14 insertions(+), 6 deletions(-)
> 
> diff --git a/lib/s390x/asm/arch_def.h b/lib/s390x/asm/arch_def.h
> index 96cca2e..b3caff6 100644
> --- a/lib/s390x/asm/arch_def.h
> +++ b/lib/s390x/asm/arch_def.h
> @@ -269,4 +269,17 @@ static inline int stsi(void *addr, int fc, int sel1, int sel2)
>  	return cc;
>  }
>  
> +static inline int servc(uint32_t command, unsigned long sccb)
> +{
> +	int cc;
> +
> +	asm volatile(
> +		"       .insn   rre,0xb2200000,%1,%2\n"  /* servc %1,%2 */
> +		"       ipm     %0\n"
> +		"       srl     %0,28"
> +		: "=&d" (cc) : "d" (command), "a" (sccb)
> +		: "cc", "memory");
> +	return cc;
> +}
> +
>  #endif
> diff --git a/lib/s390x/sclp.c b/lib/s390x/sclp.c
> index a57096c..376040e 100644
> --- a/lib/s390x/sclp.c
> +++ b/lib/s390x/sclp.c
> @@ -116,12 +116,7 @@ int sclp_service_call(unsigned int command, void *sccb)
>  	int cc;
>  
>  	sclp_setup_int();
> -	asm volatile(
> -		"       .insn   rre,0xb2200000,%1,%2\n"  /* servc %1,%2 */
> -		"       ipm     %0\n"
> -		"       srl     %0,28"
> -		: "=&d" (cc) : "d" (command), "a" (__pa(sccb))
> -		: "cc", "memory");
> +	cc = servc(command, __pa(sccb));
>  	sclp_wait_busy();
>  	if (cc == 3)
>  		return -1;
> 

Reviewed-by: Thomas Huth <thuth@redhat.com>