Subject: [PATCH v6 20/30] sparc/PCI: Use pci_scan_host_bridge() for simplicity

From: [email-masked] (Bjorn Helgaas)
Date: Wed, 11 Mar 2015 22:30:50 -0500

On Mon, Mar 09, 2015 at 10:34:17AM +0800, Yijing Wang wrote:
> Now we could use pci_scan_host_bridge() to scan
> pci buses, provide sparc specific pci_host_bridge_ops.
> 
> Signed-off-by: Yijing Wang <[email-masked]>
> CC: "David S. Miller" <[email-masked]>
> CC: sparclinux at vger.kernel.org
> Signed-off-by: Bjorn Helgaas <[email-masked]>
> ---
>  arch/sparc/kernel/pci.c |   32 ++++++++++++++++++++++----------
>  1 files changed, 22 insertions(+), 10 deletions(-)
> 
> diff --git a/arch/sparc/kernel/pci.c b/arch/sparc/kernel/pci.c
> index 21f804a..7e28f74 100644
> --- a/arch/sparc/kernel/pci.c
> +++ b/arch/sparc/kernel/pci.c
> @@ -650,12 +650,25 @@ static void pci_claim_bus_resources(struct pci_bus *bus)
>  		pci_claim_bus_resources(child_bus);
>  }
>  
> +static void pci_host_bridge_of_scan_bus(
> +		struct pci_host_bridge *host)
> +{
> +	struct pci_pbm_info *pbm = dev_get_drvdata(&host->dev);
> +	struct device_node *node = pbm->op->dev.of_node;
> +
> +	pci_of_scan_bus(pbm, node, host->bus);
> +}
> +
> +static struct pci_host_bridge_ops phb_ops = {
> +	.scan_bus = pci_host_bridge_of_scan_bus,
> +};
> +
>  struct pci_bus *pci_scan_one_pbm(struct pci_pbm_info *pbm,
>  				 struct device *parent)
>  {
>  	LIST_HEAD(resources);
>  	struct device_node *node = pbm->op->dev.of_node;
> -	struct pci_bus *bus;
> +	struct pci_host_bridge *host;
>  
>  	printk("PCI: Scanning PBM %s\n", node->full_name);
>  
> @@ -667,22 +680,21 @@ struct pci_bus *pci_scan_one_pbm(struct pci_pbm_info *pbm,
>  	pbm->busn.end	= pbm->pci_last_busno;
>  	pbm->busn.flags	= IORESOURCE_BUS;
>  	pci_add_resource(&resources, &pbm->busn);
> -	bus = pci_create_root_bus(parent,
> +	host = pci_scan_host_bridge(parent,
>  			PCI_DOMBUS(pbm->index, pbm->pci_first_busno),
> -			pbm->pci_ops, pbm, &resources);
> -	if (!bus) {
> -		printk(KERN_ERR "Failed to create bus for %s\n",
> +			pbm->pci_ops, pbm, &resources, &phb_ops);
> +	if (!host) {
> +		printk(KERN_ERR "Failed to create host bridge for %s\n",
>  		       node->full_name);
>  		pci_free_resource_list(&resources);
>  		return NULL;
>  	}
>  

I would keep "bus" and set it here:

	bus = host->bus;

That would remove some lines from your patch that really didn't change,
which makes it easier to see what actually *is* changing, namely, you're
removing the pci_of_scan_bus() call because it is now done inside
pci_scan_host_bridge().

> -	pci_of_scan_bus(pbm, node, bus);
> -	pci_bus_register_of_sysfs(bus);
> +	pci_bus_register_of_sysfs(host->bus);
>  
> -	pci_claim_bus_resources(bus);
> -	pci_bus_add_devices(bus);
> -	return bus;
> +	pci_claim_bus_resources(host->bus);
> +	pci_bus_add_devices(host->bus);
> +	return host->bus;
>  }
>  
>  void pcibios_fixup_bus(struct pci_bus *pbus)
> -- 
> 1.7.1
>