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

Arnd Bergmann
2016-06-02T11:43:34Z

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 was hoping we'd be able to fold all of pci-ecam code into the
generic PCI layer at some point and get rid of pci_ecam_ops in the
process.

Arnd