Re: [PATCH 5/6] hw/isa/piix4: Factor out SM bus initialization from create() function

[Mark Cave-Ayland]

On 13/05/2022 18:54, Bernhard Beschow wrote:

> Initialize the SM bus just like is done for piix3 which modernizes the
> code.
>
> Signed-off-by: Bernhard Beschow <shentey@gmail.com>
> ---
>   hw/isa/piix4.c                | 15 +++------------
>   hw/mips/malta.c               |  7 ++++++-
>   include/hw/southbridge/piix.h |  2 +-
>   3 files changed, 10 insertions(+), 14 deletions(-)
>
> diff --git a/hw/isa/piix4.c b/hw/isa/piix4.c
> index 4968c69da9..852e5c4db1 100644
> --- a/hw/isa/piix4.c
> +++ b/hw/isa/piix4.c
> @@ -301,21 +301,12 @@ static void piix4_register_types(void)
>   
>   type_init(piix4_register_types)
>   
> -DeviceState *piix4_create(PCIBus *pci_bus, I2CBus **smbus)
> +PCIDevice *piix4_create(PCIBus *pci_bus)
>   {
>       PCIDevice *pci;
> -    DeviceState *dev;
> -    int devfn = PCI_DEVFN(10, 0);
>   
> -    pci = pci_create_simple_multifunction(pci_bus, devfn,  true,
> +    pci = pci_create_simple_multifunction(pci_bus, PCI_DEVFN(10, 0), true,
>                                             TYPE_PIIX4_PCI_DEVICE);
> -    dev = DEVICE(pci);
>   
> -    if (smbus) {
> -        *smbus = piix4_pm_init(pci_bus, devfn + 3, 0x1100,
> -                               qdev_get_gpio_in_named(dev, "isa", 9),
> -                               NULL, 0, NULL);
> -    }
> -
> -    return dev;
> +    return pci;
>   }

I don't think it makes sense to return PCIDevice here: when returning a QOM object 
from a function, the general expectation is that for a device you would return a 
DeviceState since then it can natively be used by the qdev API. So please keep the 
original return type above.

> diff --git a/hw/mips/malta.c b/hw/mips/malta.c
> index e446b25ad0..d4bd3549d0 100644
> --- a/hw/mips/malta.c
> +++ b/hw/mips/malta.c
> @@ -1238,6 +1238,7 @@ void mips_malta_init(MachineState *machine)
>       int be;
>       MaltaState *s;
>       DeviceState *dev;
> +    PCIDevice *piix4;
>   
>       s = MIPS_MALTA(qdev_new(TYPE_MIPS_MALTA));
>       sysbus_realize_and_unref(SYS_BUS_DEVICE(s), &error_fatal);
> @@ -1399,8 +1400,12 @@ void mips_malta_init(MachineState *machine)
>       empty_slot_init("GT64120", 0, 0x20000000);
>   
>       /* Southbridge */
> -    dev = piix4_create(pci_bus, &smbus);
> +    piix4 = piix4_create(pci_bus);
> +    dev = DEVICE(piix4);
>       isa_bus = ISA_BUS(qdev_get_child_bus(dev, "isa.0"));
> +    smbus = piix4_pm_init(pci_bus, piix4->devfn + 3, 0x1100,
> +                          qdev_get_gpio_in_named(dev, "isa", 9),
> +                          NULL, 0, NULL);

... then here you can do either "piix4 = PCI_DEVICE(dev)" or perhaps even inline it 
directly as PCI_DEVICE(dev)->devfn if it isn't used elsewhere.

>       /* Interrupt controller */
>       qdev_connect_gpio_out_named(dev, "intr", 0, i8259_irq);
> diff --git a/include/hw/southbridge/piix.h b/include/hw/southbridge/piix.h
> index b768109f30..bea3b44551 100644
> --- a/include/hw/southbridge/piix.h
> +++ b/include/hw/southbridge/piix.h
> @@ -74,6 +74,6 @@ DECLARE_INSTANCE_CHECKER(PIIX3State, PIIX3_PCI_DEVICE,
>   
>   PIIX3State *piix3_create(PCIBus *pci_bus);
>   
> -DeviceState *piix4_create(PCIBus *pci_bus, I2CBus **smbus);
> +PCIDevice *piix4_create(PCIBus *pci_bus);
>   
>   #endif


ATB,

Mark.