Re: [Qemu-devel] [PATCH v2 2/7] s390x/pci: rework PCI STORE

[Pierre Morel]

On 22/11/2017 14:25, Cornelia Huck wrote:
> On Tue, 21 Nov 2017 19:03:17 +0100
> Pierre Morel <address@hidden> wrote:
>
> > On 21/11/2017 15:25, Cornelia Huck wrote:
> > > On Tue, 21 Nov 2017 11:38:45 +0100
> > > Cornelia Huck <address@hidden> wrote:
> > >    
> > > > On Thu, 16 Nov 2017 18:51:50 +0100
> > > > Pierre Morel <address@hidden> wrote:
> > >    
> > > > > @@ -493,9 +494,13 @@ int pcistg_service_call(S390CPU *cpu, uint8_t r1, uint8_t 
> > > > > r2)
> > > > >            break;
> > > > >        }
> > > > >    
> > > > > -    data = env->regs[r1];
> > > > > -    if (pcias < 6) {
> > > > > -        if ((8 - (offset & 0x7)) < len) {
> > > > > +    /* Test that the pcias is valid and do the appropriates operations */
> > > > > +    switch (pcias) {
> > > > > +    case 0 ... 5:
> > > >
> > > > Make this
> > > > case 0...5:
> > > > ?
> > >
> > > ...only that it confuses the compiler when using numbers. We can either
> >
> > I did not see this as I replied to the previous email, sorry.
> >
> > > keep the slightly ugly version, or introduce #defines.
> > > ZPCI_PCIAS_IOREGION_{MIN,MAX} (and maybe ZPCI_PCIAS_CONFIG for 15)?
> >
> >
> > I agree something is missing.
> > But I am not sure that a #define brings clarity.
> > I would prefer to add a comment.
> >         /* A ZPCI PCI card may use any BAR from BAR 0 to BAR 5 */
> >
> > ?
>
> It's more a speaking value vs. magic numbers thing. A comment does not
> hurt either, though :)
>
> (And we get rid of the spacing as well.)

OK, thanks.

> > > > > +         * A length of 0 is invalid and length should not cross a double word
> > > > > +         */
> > > > > +        if (!len || (len > (8 - (offset & 0x7)))) {
> > > > >                program_interrupt(env, PGM_OPERAND, 4);
> > > > >                return 0;
> > > > >            }
> > > > > @@ -513,21 +518,21 @@ int pcistg_service_call(S390CPU *cpu, uint8_t r1, uint8_t 
> > > > > r2)
> > > > >                program_interrupt(env, PGM_OPERAND, 4);
> > > > >                return 0;
> > > > >            }
> > > > > -    } else if (pcias == 15) {
> > > > > -        if ((4 - (offset & 0x3)) < len) {
> > > > > -            program_interrupt(env, PGM_OPERAND, 4);
> > > > > -            return 0;
> > > > > -        }
> > > > > -
> > > > > -        if (zpci_endian_swap(&data, len)) {
> > > > > +        break;
> > > > > +    case 15:
> > > > > +        /* ZPCI uses the pseudo BAR number 15 as configuration space */
> > > > > +        /* possible access lengths are 1,2,4 and must not cross a word */
> > > > > +        if (!len || (len > (4 - (offset & 0x3))) || len == 3) {
> > > > >                program_interrupt(env, PGM_OPERAND, 4);
> > > > >                return 0;
> > > > >            }
> > > > > -
> > > > > +        /* len = 1,2,4 so we do not need to test */
> > > > > +        zpci_endian_swap(&data, len);
> > > > >            pci_host_config_write_common(pbdev->pdev, offset,
> > > > >                                         pci_config_size(pbdev->pdev),
> > > > >                                         data, len);
> > > > > -    } else {
> > > > > +        break;
> > > > > +    default:
> > > > >            DPRINTF("pcistg invalid space\n");
> > > > >            setcc(cpu, ZPCI_PCI_LS_ERR);
> > > > >            s390_set_status_code(env, r2, ZPCI_PCI_ST_INVAL_AS);
> > > >
> > > > Other than the nits, looks good.
> > >    


--
Pierre Morel
Linux/KVM/QEMU in Böblingen - Germany