Re: [PATCH v4 12/30] PCI: Introduce pci_host_bridge_ops to support host specific operations

From: Bjorn Helgaas
Date: Mon Mar 02 2015 - 22:03:18 EST


On Thu, Feb 26, 2015 at 04:12:06PM +0800, Yijing Wang wrote:
> Now we have weak functions like pcibios_root_bridge_prepare()
> to setup pci host bridge, We could introduce pci_host_bridge_ops
> which contain host bridge specific ops to setup pci_host_bridge.
> Then host bridge driver could add pci_host_bridge_ops hooks
> intead of weak function to setup pci_host_bridge.
> This patch add following pci_host_bridge_ops hooks:
>
> pci_host_bridge_ops {
> /* set root bus speed, some platform need this like powerpc */
> void (*phb_set_root_bus_speed)(struct pci_host_bridge *host);
> /* setup pci_host_bridge before pci_host_bridge be added to driver core */
> int (*phb_prepare)(struct pci_host_bridge *host);
> /* platform specific of scan hook to scan pci device */
> void (*phb_of_scan_bus)(struct pci_host_bridge *);
> }
> We could easily extend it to support different host bridge
> specific operations.
>
> Signed-off-by: Yijing Wang <wangyijing@xxxxxxxxxx>
> ...

> @@ -2050,10 +2052,13 @@ static struct pci_bus *__pci_scan_root_bus(
> pci_bus_insert_busn_res(b, b->number, 255);
> }
>
> - max = pci_scan_child_bus(b);
> -
> - if (!found)
> - pci_bus_update_busn_res_end(b, max);
> + if (host->ops && host->ops->phb_of_scan_bus) {
> + host->ops->phb_of_scan_bus(host);

The important thing here is not the use of OF (Open Firmware/Device Tree),
is it? Why would we want "_of_" in the function name? I assume the intent
is that this host bridge op performs the same function as
pci_scan_child_bus(), so I think the op should be called "scan_bus".

> + } else {
> + max = pci_scan_child_bus(b);
> + if (!found)
> + pci_bus_update_busn_res_end(b, max);
> + }
>
> return b;
> }
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/