Re: [PATCH 3/3] arch/tile: tilegx PCI root complex support

[Arnd Bergmann <arnd@arndb.de>]

On Tuesday 10 April 2012, Bjorn Helgaas wrote:
> > +       if ((header_type & 0x7F) == PCI_HEADER_TYPE_BRIDGE) {
> > +               /*
> > +                * For bridges, we enable both memory and I/O decoding
> > +                * in call cases.
> > +                */
> > +               cmd |= PCI_COMMAND_IO;
> > +               cmd |= PCI_COMMAND_MEMORY;
> > +       } else {
> > +               /*
> > +                * For endpoints, we enable memory and/or I/O decoding
> > +                * only if they have a memory resource of that type.
> > +                */
> > +               for (i = 0; i < 6; i++) {
> > +                       r = &dev->resource[i];
> > +                       if (r->flags & IORESOURCE_UNSET) {
> > +                               pr_err("PCI: Device %s not available "
> > +                                      "because of resource collisions\n",
> > +                                      pci_name(dev));
> > +                               return -EINVAL;
> > +                       }
> > +                       if (r->flags & IORESOURCE_IO)
> > +                               cmd |= PCI_COMMAND_IO;
> > +                       if (r->flags & IORESOURCE_MEM)
> > +                               cmd |= PCI_COMMAND_MEMORY;
> > +               }
> 
> It would be nice if you could use pci_enable_resources() here, though
> you use IORESOURCE_UNSET here, while pci_enable_resources() does not.
> But you could at least use PCI_NUM_RESOURCES and "mask."  There's
> nothing fundamentally architecture-dependent here, so I'd like to move
> toward a generic implementation.

Note that if tile does not support I/O space as indicated, it should
never enable PCI_COMMAND_IO.

	Arnd