Re: [Qemu-devel] [PATCH v2 26/74] pc: acpi: memhp: move MHPD._STA method into SSDT

[Igor Mammedov]

On Sun, 20 Dec 2015 15:41:22 +0200
"Michael S. Tsirkin" <address@hidden> wrote:

> On Wed, Dec 16, 2015 at 03:47:35PM +0100, Igor Mammedov wrote:
[...]
> > +        method = aml_method("_STA", 0, AML_NOTSERIALIZED);
> > +        ifctx = aml_if(aml_equal(a_slots_nr, a_zero));
> > +        {
> > +             aml_append(ifctx, aml_return(a_zero));
> > +        }
> > +        aml_append(method, ifctx);
> > +        /* present, functioning, decoding, not shown in UI */
> > +        aml_append(method, aml_return(aml_int(0xB)));
> > +        aml_append(ctrl_dev, method);
> 
> 
> Simple unserialized methods that return value depending on input
> being zero seem very common.  How about a helper for this case?
> 
> E.g.
> 
> aml_method_if_then_else(slots_nr, aml_int(0xB), aml_int(0));
I've looked through all _STA methods that exist in DSDT
and though this method for mem hotplug doesn't belong to common pattern,
I could use you suggestion for 4 ISA devices.

Or perhaps I can save 2-3 LOC by making common
  build_if_else(cond, truectx, false_ctx);
I'll try both but it looks like build_if_else() will be more useful.

And after this series is applied there is a plenty to optimize,
for example most of these _STA methods will be gone or replaced
by simple _STA = FOO expression.


> 
> >      }
> >      aml_append(pci_scope, ctrl_dev);
> >      aml_append(ctx, pci_scope);
> > diff --git a/hw/i386/acpi-dsdt-mem-hotplug.dsl 
> > b/hw/i386/acpi-dsdt-mem-hotplug.dsl
> > index c2bb6a1..b4eacc9 100644
> > --- a/hw/i386/acpi-dsdt-mem-hotplug.dsl
> > +++ b/hw/i386/acpi-dsdt-mem-hotplug.dsl
> > @@ -35,14 +35,6 @@
> >              External(MEMORY_SLOT_OST_EVENT, FieldUnitObj) // _OST event 
> > code, write only
> >              External(MEMORY_SLOT_OST_STATUS, FieldUnitObj) // _OST status 
> > code, write only
> >  
> > -            Method(_STA, 0) {
> > -                If (LEqual(MEMORY_SLOTS_NUMBER, Zero)) {
> > -                    Return(0x0)
> > -                }
> > -                /* present, functioning, decoding, not shown in UI */
> > -                Return(0xB)
> > -            }
> > -
> >              Mutex (MEMORY_SLOT_LOCK, 0)
> >  
> >              Method(MEMORY_SLOT_SCAN_METHOD, 0) {
> > -- 
> > 1.8.3.1