RE: RFC: bare pci configuration access functions ?

[Lee, Jung-Ik]

Minor fix to the code.
A patch to a flying patch ;-)

Thanks,
J.I.
=====================================================
static struct pci_bus *get_pci_bus(s, b, d, f)
{
	struct pci_bus *bus;
	struct pci_dev *dev = pci_find_slot(s, b, d+f);

	if (dev && dev->bus)
		bus = dev->bus;
	else	// dup pci_bus w/ root & set bus->number=b
		bus = get_fake_pci_bus(b);

	return bus;
}

int pci_config_{read|write}(
#ifdef WANT_PCI_BUS_PARAM
		pci_bus, 
#endif
			s, b, d, f, w, size, v)
{
	struct pci_bus *bus;
#ifdef WANT_PCI_BUS_PARAM
	if (valid(pci_bus))
		bus = pci_bus;
	else
#endif
	bus = get_pci_bus(s, b, d, f);
	if (!bus)
		return error;

	switch (size) {
	case byte:
		ret = pci_bus_{read|write}_##size (bus, d+f, w, v);
		break;
	...
	}
	return ret;
}

EXPORT_SYMBOL(pci_config_{read|write});
> > 
> > > OK, if simple and pure pci config access is not possible in 
> > Linux land,
> > > let pci driver fake itself, not everyone else :)
> > > Just export the two APIs like 
> pci_config_{read|write}(s,b,d,f,s,v),
> > > or the ones in acpi driver. Hide the fake pci_bus 
> > manipulation in them. 
> > > This way is way better than having everyone fake pci driver ;-)
> > 
> > I agree.  But can we do this for all archs?  I don't know, and look
> > forward to your patch proving this will work.  Without all 
> > arch support
> > of this, I can't justify only exporting the functions for 
> > i386 and ia64.
> 
> How about the followings ?
> It's for all architecture.
> 
> thanks,
> J.I.
> 
> static struct pci_bus *get_pci_bus(s, b, d, f)
> {
> 	struct pci_bus *bus;
> 	struct pci_dev *dev = pci_find_slot(s, b, d+f);
> 
> 	if (dev && dev->bus)
> 		bus = dev->bus;
> 	else	// dup pci_bus w/ root & set bus->number=b
> 		bus = get_fake_pci_bus(b);
> 
> 	return bus;
> }
> 
> int pci_config_{read|write}(
> #ifdef WANT_PCI_BUS_PARAM
> 		pci_bus, 
> #endif
> 			s, b, d, f, w, size, v)
> {
> 	struct pci_bus *bus;
> #ifdef WANT_PCI_BUS_PARAM
> 	if (!valid(pci_bus))	// null or invalid
> #endif
> 	bus = get_pci_bus(s, b, d, f);
> 	if (!bus)
> 		return error;
> 
> 	switch (size) {
> 	case byte:
> 		ret = pci_bus_{read|write}_##size (bus, d+f, w, v);
> 		break;
> 	...
> 	}
> 
> 	return ret;
> }
> 
> EXPORT_SYMBOL(pci_config_{read|write});
>