In message <xofr9r7v6fu.fsf@blubb.pdc.kth.se>  Johan Danielsson wrote:
> 
> Let's say I have a PCI device with more than one function, and the
> device has some I/O map register that is shared between the two
> functions (that is the register points to the same io address).
> 
> How can this be handled when attaching the device? I would like to get
> a pointer (or something) to the first function when attaching the
> second.
> 
> The same problem arises with registers that `should be written only
> through function 0'.
> 
> Is there some code that does something like this in the tree?

No code in the tree, but you can write a driver which probes the 
additional function as it likes (and just maps registers once, or
takes care of useing function 0 for certain things).

Basic code to do it :

In match return 1; only for fucntion 0 (or ignore the others in 
...attach).

in ...attach:
	struct pci_attach_args *pa = aux,tpa[NDEVS];
	pci_chipset_tag_t pc = pa->pa_pc;

	for (i = 0 ;i <NDEVS ; i++) {
	    int bus,dev;
	    tpa[i] = *pa;

	    if (i) {

		pci_decompose_tag(pc,pa->pa_tag,&bus,&dev,NULL);

		tpa[i].pa_tag[i] = pci_make_tag(pc,bus,dev,i);

		tpa[i].pa_function = i;
	    }

	    ....
	}

Now you can all pci_mapreg_map(&tpa[i], ... ), and 
have valid tags etc.A

Stefan

> 
> /Johan

--
Stefan Grefen                                Tandem Computers Europe Inc.
grefen@hprc.tandem.com                       High Performance Research Center
 --- Hacking's just another word for nothing left to kludge. ---