Re: how to trace bus_* functions?

["Sepherosa Ziehau" <sepherosa@xxxxxxxxx>]

On 6/12/06, Chuck Tuffli <ctuffli@xxxxxxxxx> wrote:
> I'm trying to decipher the object hierarchy for bus_setup_intr() and
> am getting lost. Adding printf's to bus_setup_intr, pci_setup_intr,
> bus_generic_setup_intr, and nexus_setup_intr both cleared up and
> confused the situation a bit. Here is the calling chain as derived
> from the printf's:
>
> 1) bus_setup_intr(dev->desc="(null)")
> 2) pci_setup_intr(dev->desc="PCI bus", child->desc="(null)")
> 3) bus_generic_setup_intr(dev->desc="PCI to PCI bridge")
> 4) pci_setup_intr(dev->desc="PCI bus", child->desc="(null)")
> 5) bus_generic_setup_intr(dev->desc="Host to PCI bridge")
> 6) bus_generic_setup_intr(dev->desc="(null)")
> 7) nexus_setup_intr(bus->desc="(null)" child->desc="(null)")
>
> So does this mean the heirarchy is
>
>   nexus
       |
"legacypci"

>       |
>  host bus
>       |
> PCI - PCI bridge
>       |

"pci"
  |
>  PCI device
>
> Also, I think I understand the flow up through step 5 but don't
> understand how the BUS_SETUP_INTR() macro in bus_generic_setup_intr()

Take a look at sys/bus/pci/i386/pcibus.c, it will show you how
"pcib"(special one) "legacypci" and "nexus" are connected.

Best Regards,
sephe

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