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

Tomasz Nowicki
2016-06-02T12:07:51Z

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