On Mon, 4 Jan 2021 at 23:23, BALATON Zoltan <[email protected]> wrote: > > The code mapping all PCI interrupts to a single CPU IRQ works but is > not trivial so document it in a comment. > > Signed-off-by: BALATON Zoltan <[email protected]> > --- > hw/ppc/ppc440_pcix.c | 11 +++++++++-- > 1 file changed, 9 insertions(+), 2 deletions(-) > > diff --git a/hw/ppc/ppc440_pcix.c b/hw/ppc/ppc440_pcix.c > index ee952314c8..eb1290ffc8 100644 > --- a/hw/ppc/ppc440_pcix.c > +++ b/hw/ppc/ppc440_pcix.c > @@ -415,8 +415,15 @@ static void ppc440_pcix_reset(DeviceState *dev) > s->sts = 0; > } > > -/* All pins from each slot are tied to a single board IRQ. > - * This may need further refactoring for other boards. */ > +/* > + * All four IRQ[ABCD] pins from all slots are tied to a single board > + * IRQ, so our mapping function here maps everything to IRQ 0. > + * The code in pci_change_irq_level() tracks the number of times > + * the mapped IRQ is asserted and deasserted, so if multiple devices > + * assert an IRQ at the same time the behaviour is correct. > + * > + * This may need further refactoring for boards that use multiple IRQ lines. > + */ > static int ppc440_pcix_map_irq(PCIDevice *pci_dev, int irq_num) > { > trace_ppc440_pcix_map_irq(pci_dev->devfn, irq_num, 0); > --
Reviewed-by: Peter Maydell <[email protected]> thanks -- PMM
