Re: [RFC PATCH 1/3] pci, acpi: Match PCI config space accessors against platfrom specific ECAM quirks.

[Tomasz Nowicki]

On 02.06.2016 13:42, Arnd Bergmann wrote:
> On Thursday, June 2, 2016 10:41:01 AM CEST Tomasz Nowicki wrote:
> > +struct pci_ecam_ops *pci_mcfg_get_ops(struct acpi_pci_root *root)
> > +{
> > +       int bus_num = root->secondary.start;
> > +       int domain = root->segment;
> > +       struct pci_cfg_fixup *f;
> > +
> > +       if (!mcfg_table)
> > +               return &pci_generic_ecam_ops;
> > +
> > +       /*
> > +        * Match against platform specific quirks and return corresponding
> > +        * CAM ops.
> > +        *
> > +        * First match against PCI topology <domain:bus> then use OEM ID and
> > +        * OEM revision from MCFG table standard header.
> > +        */
> > +       for (f = __start_acpi_mcfg_fixups; f < __end_acpi_mcfg_fixups; f++) {
> > +               if ((f->domain == domain || f->domain == PCI_MCFG_DOMAIN_ANY) &&
> > +                   (f->bus_num == bus_num || f->bus_num == PCI_MCFG_BUS_ANY) &&
> > +                   (!strncmp(f->oem_id, mcfg_table->header.oem_id,
> > +                             ACPI_OEM_ID_SIZE)) &&
> > +                   (f->oem_revision == mcfg_table->header.oem_revision))
> > +                       return f->ops;
> > +       }
> > +       /* No quirks, use ECAM */
> > +       return &pci_generic_ecam_ops;
> > +}
> > +
> >   int pci_mcfg_lookup(struct acpi_pci_root *root)
>
> Can you explain the use of pci_ecam_ops instead of pci_ops here?

I wanted to get associated bus_shift and use it to setup configuration 
region properly before calling pci_ecam_create. Please see next patch.

Thanks,
Tomasz