Re: [Qemu-devel] [PATCH v3 2/7] s390x/css: IO instr handler ending control

[Cornelia Huck <cohuck@redhat.com>]

On Wed, 18 Oct 2017 10:45:28 +0200
Thomas Huth <thuth@redhat.com> wrote:

> On 17.10.2017 16:04, Halil Pasic wrote:
> > CSS code needs to tell the IO instruction handlers located in how should  
> 
> locate in? ... sorry, I've got trouble to parse this sentence ...

"located in ioinst.c", I guess.

And maybe also move "should" a bit later in the sentence.

> 
> > the emulated instruction be ended. Currently this is done by returning
> > generic (POSIX) error codes, and mapping them to outcomes like condition
> > codes. This makes bugs easy to create and hard to recognise.
> > 
> > As a preparation for moving a way form (mis)using generic error codes for  
> 
> s/a way/away/ ?

I can fix that up as well.

> 
> > flow control let us introduce a type which tells the instruction
> > handler function how to end the instruction, in a more straight-forward
> > and less ambiguous way.
> > 
> > Signed-off-by: Halil Pasic <pasic@linux.vnet.ibm.com>
> > ---
> >  include/hw/s390x/css.h | 16 ++++++++++++++++
> >  1 file changed, 16 insertions(+)
> > 
> > diff --git a/include/hw/s390x/css.h b/include/hw/s390x/css.h
> > index 69b374730e..7e0dbd162f 100644
> > --- a/include/hw/s390x/css.h
> > +++ b/include/hw/s390x/css.h
> > @@ -99,6 +99,22 @@ typedef struct CcwDataStream {
> >      hwaddr cda;
> >  } CcwDataStream;
> >  
> > +/*
> > + * IO instructions conclude according this. Currently we have only  
> 
> Maybe rather "terminate like this" or "finish like this"? I'm not a
> native speaker, but "conclude" sounds a little bit strange to me here.

I do remember reading "conclude" in various places in s390
documentation, so I think I'll keep this.

> 
> > + * cc codes. Valid values are 0,1,2,3 and the generic semantic for
> > + * IO instructions is described briefly. For more details consult the PoP.
> > + */
> > +typedef enum IOInstEnding {
> > +    /* produced expected result */
> > +    IOINST_CC_EXPECTED = 0,
> > +    /* status conditions were present or produced alternate result */
> > +    IOINST_CC_STATUS_PRESENT = 1,
> > +    /* inst. ineffective because busy with previously initiated function */
> > +    IOINST_CC_BUSY = 2,
> > +    /* inst. ineffective because not operational */
> > +    IOINST_CC_NOT_OPERATIONAL = 3
> > +} IOInstEnding;
> > +
> >  typedef struct SubchDev SubchDev;
> >  struct SubchDev {
> >      /* channel-subsystem related things: */
> >   
> 
> With the patch description fixed:
> 
> Reviewed-by: Thomas Huth <thuth@redhat.com>