Finding an IRQ mapping in APIC

Alan Garfield alan at fromorbit.com
Tue Apr 10 05:30:25 UTC 2007


On Tue, 2007-04-10 at 12:20 +1000, Alan Garfield wrote:
> Hello all!
> 
> I'm wondering if someone can point me in the direction of a solution to
> my little problem.
> 
> I've been porting a Linux driver across to FreeBSD and I've come against
> this lovely little hack in it's code.
> 
> I've tried to bus_alloc_resource() the IOAPIC_DEFAULT_ADDR and
> IOAPIC_WINDOW but I never seem get allocated. Plus to my
> knowing-little-about-kernels eye this seems like a really horrid hack to
> figure out the IRQ.
> 
> Any suggestions?

Further to this I've done the following :-

---------------------------
static void
jnet_identify(driver_t *driver, device_t parent)
{
        uint32_t pci_intline;
        device_t dev;

        dev = pci_find_bsf(PCI_BUS, PCI_DEV, PCI_FUN);

        if(dev == NULL) {
                return;
        }

        device_printf(parent, "Looking for IRQ....\n");

        pci_intline = pci_read_config(dev, PCIR_INTLINE, 1);
        printf("%x\n", pci_intline);

        return;
}
---------------------------

which just output the IRQ for the given bus,device,function. I can
locate the IRQ's for all devices I care to throw at it, but the 0:7:3
device is found, but the PCIR_INTLINE is always 0xFF.

Looking at the linux code I should get back 0x19.

Am I totally missing something?

Thanks in advance,
Alan.




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