[RFC 10/15] sparc/PCI: simplify pci_scan_one_pbm

From: Arnd Bergmann
Date: Fri Aug 17 2018 - 06:28:28 EST


We no longer need a separate pci_create_root_bus() function, and
merging it into pci_scan_one_pbm() makes the implementation easier
to understand.

A possible future cleanup would move the allocation of the
pci_host_bridge structure into the callers of pci_scan_one_pbm,
and avoid duplication between pci_host_bridge and pci_pbm_info
fields.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
arch/sparc/kernel/pci.c | 62 ++++++++++++++---------------------------
1 file changed, 21 insertions(+), 41 deletions(-)

diff --git a/arch/sparc/kernel/pci.c b/arch/sparc/kernel/pci.c
index afbce59d9231..0d34fb2ac55b 100644
--- a/arch/sparc/kernel/pci.c
+++ b/arch/sparc/kernel/pci.c
@@ -691,70 +691,50 @@ static void pci_claim_bus_resources(struct pci_bus *bus)
pci_claim_bus_resources(child_bus);
}

-static struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
- struct pci_ops *ops, void *sysdata, struct list_head *resources)
+struct pci_bus *pci_scan_one_pbm(struct pci_pbm_info *pbm,
+ struct device *parent)
{
- int error;
+ struct device_node *node = pbm->op->dev.of_node;
struct pci_host_bridge *bridge;
+ int ret;

bridge = pci_alloc_host_bridge(0);
if (!bridge)
return NULL;

bridge->dev.parent = parent;
+ bridge->sysdata = pbm;
+ bridge->busnr = pbm->pci_first_busno;
+ bridge->ops = pbm->pci_ops;

- list_splice_init(resources, &bridge->windows);
- bridge->sysdata = sysdata;
- bridge->busnr = bus;
- bridge->ops = ops;
-
- error = pci_register_host_bridge(bridge);
- if (error < 0)
- goto err_out;
-
- return bridge->bus;
-
-err_out:
- kfree(bridge);
- return NULL;
-}
-
-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;
-
- printk("PCI: Scanning PBM %s\n", node->full_name);
-
- pci_add_resource_offset(&resources, &pbm->io_space,
+ pci_add_resource_offset(&bridge->windows, &pbm->io_space,
pbm->io_offset);
- pci_add_resource_offset(&resources, &pbm->mem_space,
+ pci_add_resource_offset(&bridge->windows, &pbm->mem_space,
pbm->mem_offset);
if (pbm->mem64_space.flags)
- pci_add_resource_offset(&resources, &pbm->mem64_space,
+ pci_add_resource_offset(&bridge->windows, &pbm->mem64_space,
pbm->mem64_offset);
pbm->busn.start = pbm->pci_first_busno;
pbm->busn.end = pbm->pci_last_busno;
pbm->busn.flags = IORESOURCE_BUS;
- pci_add_resource(&resources, &pbm->busn);
- bus = pci_create_root_bus(parent, pbm->pci_first_busno, pbm->pci_ops,
- pbm, &resources);
- if (!bus) {
+ pci_add_resource(&bridge->windows, &pbm->busn);
+
+ printk("PCI: Scanning PBM %s\n", node->full_name);
+ ret = pci_register_host_bridge(bridge);
+ if (!ret) {
printk(KERN_ERR "Failed to create bus for %s\n",
node->full_name);
- pci_free_resource_list(&resources);
+ pci_free_host_bridge(bridge);
return NULL;
}

- pci_of_scan_bus(pbm, node, bus);
- pci_bus_register_of_sysfs(bus);
+ pci_of_scan_bus(pbm, node, bridge->bus);
+ pci_bus_register_of_sysfs(bridge->bus);

- pci_claim_bus_resources(bus);
+ pci_claim_bus_resources(bridge->bus);

- pci_bus_add_devices(bus);
- return bus;
+ pci_bus_add_devices(bridge->bus);
+ return bridge->bus;
}

int pcibios_enable_device(struct pci_dev *dev, int mask)
--
2.18.0