Re: [Qemu-devel] [PATCH v3 2/8] usb/ehci: Use class_data to init PCI variations

[Peter Crosthwaite]

On Oct 29, 2012 7:35 PM, "Andreas Färber" <address@hidden> wrote:
>
> Am 29.10.2012 02:34, schrieb Peter Crosthwaite:
> > Got rid of the duplication of the class init functions for the two PCI EHCI
> > variants. The PCI specifics are passed in as as class_data and set by a common
> > class_init function.
> >
> > Premeptively defined a new Class "EHCICLass" for the upcomming addition of new
>
> "Preemptively", "upcoming"
>
> > fields. The class_data is an instance of EHCICLass that forms a template for the
> > class to generate.
>
> Using "EHCI[PCI]Class" to template itself seems a bit awkward, Anthony
> do you have any thoughts on this? The usual way would be to have a
> dedicated EHCIInfo struct or so.

Why? The class struct defines the exactly all information needed. Seems redundant and error prone to have to maintain two structs with the same fields?

> >
> > Signed-off-by: Peter Crosthwaite <address@hidden>
> > ---
> > Got rid of union for sharing EHCIClassDefinition - made PCI specific
> > Simplified literal class_data arrays in ehci_info accordingly
> > removed null sentinel from ehci_info and used ARRAY_SIZE for type_regsiter loop
> >       bound instead
> >
> >  hw/usb/hcd-ehci.c |   76 ++++++++++++++++++++++++++++------------------------
> >  1 files changed, 41 insertions(+), 35 deletions(-)
> >
> > diff --git a/hw/usb/hcd-ehci.c b/hw/usb/hcd-ehci.c
> > index 6c65a73..274225b 100644
> > --- a/hw/usb/hcd-ehci.c
> > +++ b/hw/usb/hcd-ehci.c
> > @@ -2641,46 +2641,49 @@ static Property ehci_properties[] = {
> >      DEFINE_PROP_END_OF_LIST(),
> >  };
> >
> > -static void ehci_class_init(ObjectClass *klass, void *data)
> > -{
> > -    DeviceClass *dc = DEVICE_CLASS(klass);
> > -    PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
> > -
> > -    k->init = usb_ehci_initfn;
> > -    k->vendor_id = PCI_VENDOR_ID_INTEL;
> > -    k->device_id = PCI_DEVICE_ID_INTEL_82801D; /* ich4 */
> > -    k->revision = 0x10;
> > -    k->class_id = PCI_CLASS_SERIAL_USB;
> > -    dc->vmsd = &vmstate_ehci;
> > -    dc->props = ehci_properties;
> > -}
> > +typedef struct EHCIPCIClass {
> > +    PCIDeviceClass pci;
> > +} EHCIPCIClass;
> >
> > -static TypeInfo ehci_info = {
> > -    .name          = "usb-ehci",
> > -    .parent        = TYPE_PCI_DEVICE,
> > -    .instance_size = sizeof(EHCIState),
> > -    .class_init    = ehci_class_init,
> > -};
> > -
> > -static void ich9_ehci_class_init(ObjectClass *klass, void *data)
> > +static void ehci_class_init(ObjectClass *klass, void *data)
> >  {
> >      DeviceClass *dc = DEVICE_CLASS(klass);
> > -    PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
> > -
> > -    k->init = usb_ehci_initfn;
> > -    k->vendor_id = PCI_VENDOR_ID_INTEL;
> > -    k->device_id = PCI_DEVICE_ID_INTEL_82801I_EHCI1;
> > -    k->revision = 0x03;
> > -    k->class_id = PCI_CLASS_SERIAL_USB;
> > +    EHCIPCIClass *k = (EHCIPCIClass *)klass;
>
> Please use a proper QOM cast macro: EHCI_PCI_CLASS(klass)
>

How is this possible whe TYPE_EHCI_PCI doesn't exist ? The FOO_CLASS macros require the name of the class but that does not exist as its a dynamic class.

> In this case however, please keep using PCIDeviceClass rather than
> trying to access it through a named member. If we need to access any
> dedicated EHCIPCIClass fields later in the series we can add additional
> variables the QOM way.

What do you mean the Qom way? Don't we just add fields to the class and class_info and class_init copies them across ?

> > +    EHCIPCIClass *template = data;
> > +
> > +    k->pci.init = usb_ehci_initfn;
> > +    k->pci.vendor_id = template->pci.vendor_id;
> > +    k->pci.device_id = template->pci.device_id; /* ich4 */
> > +    k->pci.revision = template->pci.revision;
> > +    k->pci.class_id = PCI_CLASS_SERIAL_USB;
> >      dc->vmsd = &vmstate_ehci;
> >      dc->props = ehci_properties;
> >  }
> >
> > -static TypeInfo ich9_ehci_info = {
> > -    .name          = "ich9-usb-ehci1",
> > -    .parent        = TYPE_PCI_DEVICE,
> > -    .instance_size = sizeof(EHCIState),
> > -    .class_init    = ich9_ehci_class_init,
> > +static TypeInfo ehci_info[] = {
>
> Can this still be made const despite the embedded class_data?
>
> > +    {
> > +        .name          = "usb-ehci",
> > +        .parent        = TYPE_PCI_DEVICE,
> > +        .instance_size = sizeof(EHCIState),
> > +        .class_init    = ehci_class_init,
> > +        .class_size    = sizeof(EHCIPCIClass),
> > +        .class_data    = (EHCIPCIClass[]) {{
> > +            .pci.vendor_id = PCI_VENDOR_ID_INTEL,
> > +            .pci.device_id = PCI_DEVICE_ID_INTEL_82801D,
> > +            .pci.revision  = 0x10,
> > +        } }
> > +    }, {
> > +        .name          = "ich9-usb-ehci1",
>
> Do we have a suitable header to introduce TYPE_* constants for these
> while at it? That would benefit q35.
>

No because there are no TYPE_ constants. The classes are private to hcd-ehci.c.

Regards
Peter

> Andreas
>
> > +        .parent        = TYPE_PCI_DEVICE,
> > +        .instance_size = sizeof(EHCIState),
> > +        .class_init    = ehci_class_init,
> > +        .class_size    = sizeof(EHCIPCIClass),
> > +        .class_data    = (EHCIPCIClass[]) {{
> > +            .pci.vendor_id = PCI_VENDOR_ID_INTEL,
> > +            .pci.device_id = PCI_DEVICE_ID_INTEL_82801I_EHCI1,
> > +            .pci.revision  = 0x03,
> > +        } }
> > +    },
> >  };
> >
> >  static int usb_ehci_initfn(PCIDevice *dev)
> > @@ -2769,8 +2772,11 @@ static int usb_ehci_initfn(PCIDevice *dev)
> >
> >  static void ehci_register_types(void)
> >  {
> > -    type_register_static(&ehci_info);
> > -    type_register_static(&ich9_ehci_info);
> > +    int i;
> > +
> > +    for (i = 0; i < ARRAY_SIZE(ehci_info); i++) {
> > +        type_register_static(&ehci_info[i]);
> > +    }
> >  }
> >
> >  type_init(ehci_register_types)
> >
>
>
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