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

Claudio Imbrenda
2021-08-06T09:35:09Z

On Fri, 6 Aug 2021 09:26:11 +0200
David Hildenbrand <david@redhat.com> wrote:

> 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.

maybe there will be in the future.

I wanted to split away this generic change from the patch that uses it,
to improve readability

> 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".
>