[PATCH V7 08/11] pci, acpi: Support for ACPI based generic PCI host controller

[Rafael J. Wysocki]

On Tue, May 10, 2016 at 5:19 PM, Tomasz Nowicki <tn at semihalf.com> wrote:
> This patch is going to implement generic PCI host controller for
> ACPI world, similar to what pci-host-generic.c driver does for DT world.
>
> All such drivers, which we have seen so far, were implemented within
> arch/ directory since they had some arch assumptions (x86 and ia64).
> However, they all are doing similar thing, so it makes sense to find
> some common code and abstract it into the generic driver.
>
> In order to handle PCI config space regions properly, we define new
> MCFG interface which does sanity checks on MCFG table and keeps its
> root pointer. User is able to lookup MCFG regions based on that root
> pointer and specified domain:bus_start:bus_end touple. We are using
> pci_mmcfg_late_init old prototype to avoid another function name.
>
> The implementation of pci_acpi_scan_root() looks up the MCFG entries
> and sets up a new mapping (regions are not mapped until host controller ask
> for it). Generic PCI functions are used for accessing config space.
> Driver selects PCI_ECAM and uses functions from drivers/pci/ecam.h
> to create and access ECAM mappings.
>
> As mentioned in Kconfig help section, ACPI_PCI_HOST_GENERIC choice
> should be made on a per-architecture basis.
>
> Signed-off-by: Tomasz Nowicki <tn at semihalf.com>
> Signed-off-by: Jayachandran C <jchandra at broadcom.com>
> ---
>  drivers/acpi/Kconfig            |   8 +++
>  drivers/acpi/Makefile           |   1 +
>  drivers/acpi/pci_mcfg.c         |  97 ++++++++++++++++++++++++++
>  drivers/acpi/pci_root_generic.c | 149 ++++++++++++++++++++++++++++++++++++++++

Why do we need a new file?  Would there be any problem with adding
that code to pci_root.c?