Re: [PATCH 1/4] arm64: pci: acpi: Use pci_assign_unassigned_root_bus_resources()

Bjorn Helgaas
2019-06-21T20:48:42Z

On Sat, Jun 15, 2019 at 10:23:56AM +1000, Benjamin Herrenschmidt wrote:
> Instead of the simpler
>
> pci_bus_size_bridges(bus);
> pci_bus_assign_resources(bus);
>
> Use pci_assign_unassigned_root_bus_resources(). This should have no effect
> as long as we are reassigning everything. Once we start honoring FW
> resource allocations, this will bring up the "reallocation" feature
> which can help making room for SR-IOV when necessary.
>
> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

I applied these to pci/resource, with my comments and acks from
Lorenzo and Ard. Let me know if I was too aggressive or got something
wrong; I consider these branches malleable until the merge window.

Thanks for the first step on this long journey :)

> ---
> arch/arm64/kernel/pci.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c
> index bb85e2f4603f..1419b1b4e9b9 100644
> --- a/arch/arm64/kernel/pci.c
> +++ b/arch/arm64/kernel/pci.c
> @@ -193,8 +193,7 @@ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
> if (!bus)
> return NULL;
>
> - pci_bus_size_bridges(bus);
> - pci_bus_assign_resources(bus);
> + pci_assign_unassigned_root_bus_resources(bus);
>
> list_for_each_entry(child, &bus->children, node)
> pcie_bus_configure_settings(child);
> --
> 2.17.1
>