Re: [PATCH 1/2] PCI: pcibus address to resource converting take bus instead of dev

[Bjorn Helgaas <bhelgaas@google.com>]

On Sun, Dec 8, 2013 at 4:54 PM, Yinghai Lu <yinghai@kernel.org> wrote:
> For allocating resource under bus path, we do not have dev to pass along,
> and we only have bus to use instead.
>
> -v2: drop pcibios_bus_addr_to_resource().
>
> Signed-off-by: Yinghai Lu <yinghai@kernel.org>
> Cc: stable@vger.kernel.org
> ---
>  drivers/pci/host-bridge.c | 34 +++++++++++++++++++++-------------
>  include/linux/pci.h       |  5 +++++
>  2 files changed, 26 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/pci/host-bridge.c b/drivers/pci/host-bridge.c
> index a68dc61..c988a30 100644
> --- a/drivers/pci/host-bridge.c
> +++ b/drivers/pci/host-bridge.c
> @@ -9,22 +9,19 @@
>
>  #include "pci.h"
>
> -static struct pci_bus *find_pci_root_bus(struct pci_dev *dev)
> +static struct pci_bus *find_pci_root_bus(struct pci_bus *bus)
>  {
> -       struct pci_bus *bus;
> -
> -       bus = dev->bus;
>         while (bus->parent)
>                 bus = bus->parent;
>
>         return bus;
>  }
>
> -static struct pci_host_bridge *find_pci_host_bridge(struct pci_dev *dev)
> +static struct pci_host_bridge *find_pci_host_bridge(struct pci_bus *bus)
>  {
> -       struct pci_bus *bus = find_pci_root_bus(dev);
> +       struct pci_bus *root_bus = find_pci_root_bus(bus);
>
> -       return to_pci_host_bridge(bus->bridge);
> +       return to_pci_host_bridge(root_bus->bridge);
>  }
>
>  void pci_set_host_bridge_release(struct pci_host_bridge *bridge,
> @@ -40,10 +37,11 @@ static bool resource_contains(struct resource *res1, struct resource *res2)
>         return res1->start <= res2->start && res1->end >= res2->end;
>  }
>
> -void pcibios_resource_to_bus(struct pci_dev *dev, struct pci_bus_region *region,
> -                            struct resource *res)
> +void __pcibios_resource_to_bus(struct pci_bus *bus,
> +                                     struct pci_bus_region *region,
> +                                     struct resource *res)
>  {
> -       struct pci_host_bridge *bridge = find_pci_host_bridge(dev);
> +       struct pci_host_bridge *bridge = find_pci_host_bridge(bus);
>         struct pci_host_bridge_window *window;
>         resource_size_t offset = 0;
>
> @@ -60,6 +58,11 @@ void pcibios_resource_to_bus(struct pci_dev *dev, struct pci_bus_region *region,
>         region->start = res->start - offset;
>         region->end = res->end - offset;
>  }
> +void pcibios_resource_to_bus(struct pci_dev *dev, struct pci_bus_region *region,
> +                            struct resource *res)
> +{
> +       __pcibios_resource_to_bus(dev->bus, region, res);
> +}
>  EXPORT_SYMBOL(pcibios_resource_to_bus);
>
>  static bool region_contains(struct pci_bus_region *region1,
> @@ -68,10 +71,10 @@ static bool region_contains(struct pci_bus_region *region1,
>         return region1->start <= region2->start && region1->end >= region2->end;
>  }
>
> -void pcibios_bus_to_resource(struct pci_dev *dev, struct resource *res,
> -                            struct pci_bus_region *region)
> +void __pcibios_bus_to_resource(struct pci_bus *bus, struct resource *res,
> +                                     struct pci_bus_region *region)
>  {
> -       struct pci_host_bridge *bridge = find_pci_host_bridge(dev);
> +       struct pci_host_bridge *bridge = find_pci_host_bridge(bus);
>         struct pci_host_bridge_window *window;
>         resource_size_t offset = 0;
>
> @@ -93,4 +96,9 @@ void pcibios_bus_to_resource(struct pci_dev *dev, struct resource *res,
>         res->start = region->start + offset;
>         res->end = region->end + offset;
>  }
> +void pcibios_bus_to_resource(struct pci_dev *dev, struct resource *res,
> +                            struct pci_bus_region *region)
> +{
> +       __pcibios_bus_to_resource(dev->bus, res, region);
> +}
>  EXPORT_SYMBOL(pcibios_bus_to_resource);
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 1084a15..5c2cf8e 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -737,8 +737,13 @@ void pci_fixup_cardbus(struct pci_bus *);
>
>  /* Generic PCI functions used internally */
>
> +void __pcibios_resource_to_bus(struct pci_bus *bus,
> +                              struct pci_bus_region *region,
> +                              struct resource *res);
>  void pcibios_resource_to_bus(struct pci_dev *dev, struct pci_bus_region *region,
>                              struct resource *res);
> +void __pcibios_bus_to_resource(struct pci_bus *bus, struct resource *res,
> +                                     struct pci_bus_region *region);
>  void pcibios_bus_to_resource(struct pci_dev *dev, struct resource *res,
>                              struct pci_bus_region *region);
>  void pcibios_scan_specific_bus(int busn);

Ugh.  Why would we add new functions with "__" prefixes?  There are
only a handful of callers to pcibios_bus_to_resource() and
pcibios_resource_to_bus().  We can just change them to supply a
"struct pci_bus *" directly.  That's a better match for how the
hardware works anyway.

Bjorn