Re: [Qemu-ppc] [Qemu-devel] [PATCH v5 for-2.3 23/28] hw/pxb: add map_irq func

[Marcel Apfelbaum]

On 03/10/2015 06:43 PM, Michael S. Tsirkin wrote:
> On Tue, Mar 10, 2015 at 05:32:09PM +0200, Marcel Apfelbaum wrote:
> > The bios does not index the pxb slot number when
> > it computes the IRQ because it resides on bus 0
> > and not on the current bus.
> > However Qemu routes the irq through bus 0 and adds
> > the pxb slot to the IRQ computation.
> >
> > Synchronize between bios and Qemu by canceling
> > pxb's effect.
> >
> > Signed-off-by: Marcel Apfelbaum <address@hidden>
> > ---
> >   hw/pci-bridge/pci_expander_bridge.c | 20 +++++++++++++++++++-
> >   1 file changed, 19 insertions(+), 1 deletion(-)
> >
> > diff --git a/hw/pci-bridge/pci_expander_bridge.c 
> > b/hw/pci-bridge/pci_expander_bridge.c
> > index 941f3c8..87515c1 100644
> > --- a/hw/pci-bridge/pci_expander_bridge.c
> > +++ b/hw/pci-bridge/pci_expander_bridge.c
> > @@ -92,6 +92,24 @@ static const TypeInfo pxb_host_info = {
> >       .class_init    = pxb_host_class_init,
> >   };
> >
> > +
> > +static int pxb_map_irq_fn(PCIDevice *pci_dev, int pin)
> > +{
> > +    PCIDevice *pxb = pci_dev->bus->parent_dev;
> > +
> > +    /*
> > +     * The bios does not index the pxb slot number when
> > +     * it computes the IRQ because it resides on bus 0
> > +     * and not on the current bus.
> > +     * However QEMU routes the irq through bus 0 and adds
> > +     * the pxb slot to the IRQ computation.
>
> I know it's QEMU but which function exactly?
PXB device with is a PCI host-bridge device.

Thanks,
Marcel

> > +     *
> > +     * Synchronize between bios and QEMU by canceling
> > +     * pxb's effect.
> > +     */
> > +    return pin - PCI_SLOT(pxb->devfn);
> > +}
> > +
> >   static int pxb_dev_initfn(PCIDevice *dev)
> >   {
> >       PXBDev *pxb = PXB_DEV(dev);
> > @@ -118,7 +136,7 @@ static int pxb_dev_initfn(PCIDevice *dev)
> >       bus->parent_dev = dev;
> >       bus->address_space_mem = dev->bus->address_space_mem;
> >       bus->address_space_io = dev->bus->address_space_io;
> > -    bus->map_irq = pci_swizzle_map_irq_fn;
> > +    bus->map_irq = pxb_map_irq_fn;
> >
> >       bds = qdev_create(BUS(bus), "pci-bridge");
> >       bds->id = dev_name;
> > --
> > 2.1.0