On Mon, 2018-05-28 at 15:47 +0300, Mika Westerberg wrote:
> There is a special case where there is only single bridge on the bus.
> In
> that case we just assign all resources to it. Currently this is done
> as
> a part of the resource distribution loop but it does not have to be
> there, and moving it outside actually improves readability because we
> can then save one indent level in the loop.
>
> While there we can add hotplug_bridges == 1 && normal_bridges == 0 to
> the same block because they are dealt the same way.
>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> Suggested-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> ---
> drivers/pci/setup-bus.c | 82 ++++++++++++++++++++------------------
> ---
> 1 file changed, 41 insertions(+), 41 deletions(-)
>
> diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
> index 072784f55ea5..79b1824e83b4 100644
> --- a/drivers/pci/setup-bus.c
> +++ b/drivers/pci/setup-bus.c
> @@ -1942,57 +1942,57 @@ static void
> pci_bus_distribute_available_resources(struct pci_bus *bus,
> remaining_mmio_pref -= resource_size(res);
> }
>
> + /*
> + * There is only one bridge on the bus so it gets all
> available
> + * resources which it can then distribute to the possible
> + * hotplug bridges below.
> + */
> + if (hotplug_bridges + normal_bridges == 1) {
> + dev = list_first_entry(&bus->devices, struct pci_dev,
> bus_list);
> + if (dev->subordinate) {
> + pci_bus_distribute_available_resources(dev-
> >subordinate,
> + add_list, available_io,
> available_mmio,
> + available_mmio_pref);
> + }
> + return;
> + }
> +
> /*
> * Go over devices on this bus and distribute the remaining
> * resource space between hotplug bridges.
> */
> for_each_pci_bridge(dev, bus) {
> + resource_size_t align, io, mmio, mmio_pref;
> struct pci_bus *b;
>
> b = dev->subordinate;
> - if (!b)
> + if (!b || !dev->is_hotplug_bridge)
> continue;
>
> - if (!hotplug_bridges && normal_bridges == 1) {
> - /*
> - * There is only one bridge on the bus
> (upstream
> - * port) so it gets all available resources
> - * which it can then distribute to the
> possible
> - * hotplug bridges below.
> - */
> - pci_bus_distribute_available_resources(b,
> add_list,
> - available_io, available_mmio,
> - available_mmio_pref);
> - } else if (dev->is_hotplug_bridge) {
> - resource_size_t align, io, mmio, mmio_pref;
> -
> - /*
> - * Distribute available extra resources
> equally
> - * between hotplug-capable downstream ports
> - * taking alignment into account.
> - *
> - * Here hotplug_bridges is always != 0.
> - */
> - align = pci_resource_alignment(bridge,
> io_res);
> - io = div64_ul(available_io, hotplug_bridges);
> - io = min(ALIGN(io, align), remaining_io);
> - remaining_io -= io;
> -
> - align = pci_resource_alignment(bridge,
> mmio_res);
> - mmio = div64_ul(available_mmio,
> hotplug_bridges);
> - mmio = min(ALIGN(mmio, align),
> remaining_mmio);
> - remaining_mmio -= mmio;
> -
> - align = pci_resource_alignment(bridge,
> mmio_pref_res);
> - mmio_pref = div64_ul(available_mmio_pref,
> - hotplug_bridges);
> - mmio_pref = min(ALIGN(mmio_pref, align),
> - remaining_mmio_pref);
> - remaining_mmio_pref -= mmio_pref;
> -
> - pci_bus_distribute_available_resources(b,
> add_list, io,
> - mmio,
> mmio_pref);
> - }
> + /*
> + * Distribute available extra resources equally
> between
> + * hotplug-capable downstream ports taking alignment
> into
> + * account.
> + *
> + * Here hotplug_bridges is always != 0.
> + */
> + align = pci_resource_alignment(bridge, io_res);
> + io = div64_ul(available_io, hotplug_bridges);
> + io = min(ALIGN(io, align), remaining_io);
> + remaining_io -= io;
> +
> + align = pci_resource_alignment(bridge, mmio_res);
> + mmio = div64_ul(available_mmio, hotplug_bridges);
> + mmio = min(ALIGN(mmio, align), remaining_mmio);
> + remaining_mmio -= mmio;
> +
> + align = pci_resource_alignment(bridge,
> mmio_pref_res);
> + mmio_pref = div64_ul(available_mmio_pref,
> hotplug_bridges);
> + mmio_pref = min(ALIGN(mmio_pref, align),
> remaining_mmio_pref);
> + remaining_mmio_pref -= mmio_pref;
> +
> + pci_bus_distribute_available_resources(b, add_list,
> io, mmio,
> + mmio_pref);
> }
> }
>
--
Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Intel Finland Oy
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