Re: [PATCH v3 01/14] KVM: s390: pv: add macros for UVC CC values

David Hildenbrand
2021-08-06T07:26:30Z

On 04.08.21 17:40, Claudio Imbrenda wrote:
> Add macros to describe the 4 possible CC values returned by the UVC
> instruction.
>
> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
> ---
> arch/s390/include/asm/uv.h | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/arch/s390/include/asm/uv.h b/arch/s390/include/asm/uv.h
> index 12c5f006c136..b35add51b967 100644
> --- a/arch/s390/include/asm/uv.h
> +++ b/arch/s390/include/asm/uv.h
> @@ -18,6 +18,11 @@
> #include <asm/page.h>
> #include <asm/gmap.h>
>
> +#define UVC_CC_OK 0
> +#define UVC_CC_ERROR 1
> +#define UVC_CC_BUSY 2
> +#define UVC_CC_PARTIAL 3
> +
> #define UVC_RC_EXECUTED 0x0001
> #define UVC_RC_INV_CMD 0x0002
> #define UVC_RC_INV_STATE 0x0003
>

Do we have any users we could directly fix up? AFAIKs, most users don't
really care about the cc value, only about cc vs !cc.

The only instances I was able to spot quickly:

diff --git a/arch/s390/include/asm/uv.h b/arch/s390/include/asm/uv.h
index 12c5f006c136..dd72d325f9e8 100644
--- a/arch/s390/include/asm/uv.h
+++ b/arch/s390/include/asm/uv.h
@@ -233,7 +233,7 @@ static inline int uv_call(unsigned long r1, unsigned
long r2)

do {
cc = __uv_call(r1, r2);
- } while (cc > 1);
+ } while (cc >= UVC_CC_BUSY);
return cc;
}

@@ -245,7 +245,7 @@ static inline int uv_call_sched(unsigned long r1,
unsigned long r2)
do {
cc = __uv_call(r1, r2);
cond_resched();
- } while (cc > 1);
+ } while (cc >= UVC_CC_BUSY);
return cc;
}

Of course, we could replace all checks for cc vs !cc with "cc !=
UVC_CC_OK" vs "cc == UVC_CC_OK".

--
Thanks,

David / dhildenb