On 2012-06-07 16:32, Michael S. Tsirkin wrote: > On Mon, Jun 04, 2012 at 10:52:13AM +0200, Jan Kiszka wrote: >> @@ -1089,6 +1093,14 @@ static void pci_set_irq(void *opaque, int irq_num, >> int level) >> pci_change_irq_level(pci_dev, irq_num, change); >> } >> >> +PCIINTxRoute pci_device_route_intx_to_irq(PCIDevice *dev, int pin) >> +{ >> + PCIBus *bus = dev->host_bus; >> + >> + assert(bus->route_intx_to_irq); >> + return bus->route_intx_to_irq(bus->irq_opaque, dev->host_intx_pin[pin]); >> +} >> + >> /***********************************************************/ >> /* monitor info on PCI */ >> > > Just an idea: can devices cache this result, bypassing the > intx to irq lookup on data path?
That lookup is part of set_irq which we don't bypass so far and where this is generally trivial. If we want to cache the effects of set_irq as well, I guess things would become pretty complex (e.g. due to vmstate compatibility), and I'm unsure if it would buy us much. > >> diff --git a/hw/pci.h b/hw/pci.h >> index 5b54e2d..bbba01e 100644 >> --- a/hw/pci.h >> +++ b/hw/pci.h >> @@ -141,6 +141,15 @@ enum { >> #define PCI_DEVICE_GET_CLASS(obj) \ >> OBJECT_GET_CLASS(PCIDeviceClass, (obj), TYPE_PCI_DEVICE) >> >> +typedef struct PCIINTxRoute { >> + enum { >> + PCI_INTX_ENABLED, >> + PCI_INTX_INVERTED, >> + PCI_INTX_DISABLED, >> + } mode; >> + int irq; >> +} PCIINTxRoute; > > Is this INTX route or IRQ route? > Is the INTX enabled/disabled/inverted or the IRQ? > > I have the impression it's the IRQ, in the apic. > PCI INTX are never inverted they are always active low. This should be considered as "the route *of* an INTx", not "to some IRQ". I could call it PCIINTxToIRQRoute if you prefer, but it's a bit lengthy. Jan
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