On Fri, Aug 17, 2018 at 12:32 PM Arnd Bergmann <arnd@xxxxxxxx> wrote:
>
> pcibios_scan_root() is now just a wrapper around pci_scan_root_bus(),
> and merging the two into one makes it shorter and more readable.
>
> We can also take advantage of pci_alloc_host_bridge() doing the
> allocation of the sysdata for us, which helps if we ever want to
> allow hot-unplugging the host bridge itself.
>
> We might be able to simplify it further using pci_host_probe(),
> but I wasn't sure about the resource registration there.
>
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> ---
> arch/x86/pci/common.c | 53 ++++++++++++++-----------------------------
> 1 file changed, 17 insertions(+), 36 deletions(-)
>
> diff --git a/arch/x86/pci/common.c b/arch/x86/pci/common.c
> index e740d9aa4024..920d0885434c 100644
> --- a/arch/x86/pci/common.c
> +++ b/arch/x86/pci/common.c
> @@ -453,54 +453,35 @@ void __init dmi_check_pciprobe(void)
> dmi_check_system(pciprobe_dmi_table);
> }
>
> -static struct pci_bus *pci_scan_root_bus(struct device *parent, int bus,
> - struct pci_ops *ops, void *sysdata, struct list_head *resources)
> +void pcibios_scan_root(int busnum)
> {
> + struct pci_sysdata *sd;
> struct pci_host_bridge *bridge;
> int error;
>
> - bridge = pci_alloc_host_bridge(0);
> - if (!bridge)
> - return NULL;
> + bridge = pci_alloc_host_bridge(sizeof(sd));
> + if (!bridge) {
> + printk(KERN_ERR "PCI: OOM, skipping PCI bus %02x\n", busnum);
> + return;
> + }
> + sd = pci_host_bridge_priv(bridge);
This looks fishy, as bridge->private is not set at this point AFAICS,
unless one of the previous patches changes that.
>
> - list_splice_init(resources, &bridge->windows);
> - bridge->dev.parent = parent;
> - bridge->sysdata = sysdata;
> - bridge->busnr = bus;
> - bridge->ops = ops;
> + sd->node = x86_pci_root_bus_node(busnum);
> + x86_pci_root_bus_resources(busnum, &bridge->windows);
> + bridge->sysdata = sd;
> + bridge->busnr = busnum;
> + bridge->ops = &pci_root_ops;
>
> + printk(KERN_DEBUG "PCI: Probing PCI hardware (bus %02x)\n", busnum);
> error = pci_scan_root_bus_bridge(bridge);
> if (error < 0)
> goto err_out;
>
> - return bridge->bus;
> + pci_bus_add_devices(bridge->bus);
> + return;
>
> err_out:
> - kfree(bridge);
> - return NULL;
> -}
> -
> -void pcibios_scan_root(int busnum)
> -{
> - struct pci_bus *bus;
> - struct pci_sysdata *sd;
> - LIST_HEAD(resources);
> -
> - sd = kzalloc(sizeof(*sd), GFP_KERNEL);
> - if (!sd) {
> - printk(KERN_ERR "PCI: OOM, skipping PCI bus %02x\n", busnum);
> - return;
> - }
> - sd->node = x86_pci_root_bus_node(busnum);
> - x86_pci_root_bus_resources(busnum, &resources);
> - printk(KERN_DEBUG "PCI: Probing PCI hardware (bus %02x)\n", busnum);
> - bus = pci_scan_root_bus(NULL, busnum, &pci_root_ops, sd, &resources);
> - if (!bus) {
> - pci_free_resource_list(&resources);
> - kfree(sd);
> - return;
> - }
> - pci_bus_add_devices(bus);
> + pci_free_host_bridge(bridge);
> }
>
> void __init pcibios_set_cache_line_size(void)
> --
> 2.18.0
>
