[RFC 1/5] PCI: Introduce pci_create_root_bus_priv()

[Boqun Feng <boqun.feng@xxxxxxxxx>]

In order to allow root bus creation to populate the ->private of the
pci_host_bridge at the same, pci_create_root_bus_priv() is introduced.
The new function will be used to support passing the corresponding ACPI
device as the ->private field when creating the PCI root bus.

No functional change.

Signed-off-by: Boqun Feng <boqun.feng@xxxxxxxxx>
---
 drivers/pci/probe.c | 15 ++++++++++++---
 include/linux/pci.h |  3 +++
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index ea7f2a57e2f5..8f5fea2a7bd9 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -2991,13 +2991,14 @@ void __weak pcibios_remove_bus(struct pci_bus *bus)
 {
 }
 
-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_create_root_bus_priv(struct device *parent, int bus,
+		struct pci_ops *ops, void *sysdata, struct list_head *resources,
+		void *private, size_t priv_size)
 {
 	int error;
 	struct pci_host_bridge *bridge;
 
-	bridge = pci_alloc_host_bridge(0);
+	bridge = pci_alloc_host_bridge(priv_size);
 	if (!bridge)
 		return NULL;
 
@@ -3008,6 +3009,9 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
 	bridge->busnr = bus;
 	bridge->ops = ops;
 
+	if (priv_size)
+		memcpy(bridge->private, private, priv_size);
+
 	error = pci_register_host_bridge(bridge);
 	if (error < 0)
 		goto err_out;
@@ -3018,6 +3022,11 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
 	put_device(&bridge->dev);
 	return NULL;
 }
+struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
+		struct pci_ops *ops, void *sysdata, struct list_head *resources)
+{
+	return pci_create_root_bus_priv(parent, bus, ops, sysdata, resources, NULL, 0);
+}
 EXPORT_SYMBOL_GPL(pci_create_root_bus);
 
 int pci_host_probe(struct pci_host_bridge *bridge)
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 01aa201e1df0..119356312979 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1041,6 +1041,9 @@ void pcibios_scan_specific_bus(int busn);
 struct pci_bus *pci_find_bus(int domain, int busnr);
 void pci_bus_add_devices(const struct pci_bus *bus);
 struct pci_bus *pci_scan_bus(int bus, struct pci_ops *ops, void *sysdata);
+struct pci_bus *pci_create_root_bus_priv(struct device *parent, int bus,
+		struct pci_ops *ops, void *sysdata, struct list_head *resources,
+		void *private, size_t priv_size);
 struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
 				    struct pci_ops *ops, void *sysdata,
 				    struct list_head *resources);
-- 
2.32.0