PCI: add busn_res operation functions

Will use them insert/update busn res in pci_bus struct.

[bhelgaas: print conflicting entry if insertion fails]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/probe.c

@@ -1714,6 +1714,74 @@ err_out:
 	return NULL;
 }
 
+int pci_bus_insert_busn_res(struct pci_bus *b, int bus, int bus_max)
+{
+	struct resource *res = &b->busn_res;
+	struct resource *parent_res, *conflict;
+
+	res->start = bus;
+	res->end = bus_max;
+	res->flags = IORESOURCE_BUS;
+
+	if (!pci_is_root_bus(b))
+		parent_res = &b->parent->busn_res;
+	else {
+		parent_res = get_pci_domain_busn_res(pci_domain_nr(b));
+		res->flags |= IORESOURCE_PCI_FIXED;
+	}
+
+	conflict = insert_resource_conflict(parent_res, res);
+
+	if (conflict)
+		dev_printk(KERN_DEBUG, &b->dev,
+			   "busn_res: can not insert %pR under %s%pR (conflicts with %s %pR)\n",
+			    res, pci_is_root_bus(b) ? "domain " : "",
+			    parent_res, conflict->name, conflict);
+	else
+		dev_printk(KERN_DEBUG, &b->dev,
+			   "busn_res: %pR is inserted under %s%pR\n",
+			   res, pci_is_root_bus(b) ? "domain " : "",
+			   parent_res);
+
+	return conflict == NULL;
+}
+
+int pci_bus_update_busn_res_end(struct pci_bus *b, int bus_max)
+{
+	struct resource *res = &b->busn_res;
+	struct resource old_res = *res;
+	resource_size_t size;
+	int ret;
+
+	if (res->start > bus_max)
+		return -EINVAL;
+
+	size = bus_max - res->start + 1;
+	ret = adjust_resource(res, res->start, size);
+	dev_printk(KERN_DEBUG, &b->dev,
+			"busn_res: %pR end %s updated to %02x\n",
+			&old_res, ret ? "can not be" : "is", bus_max);
+
+	if (!ret && !res->parent)
+		pci_bus_insert_busn_res(b, res->start, res->end);
+
+	return ret;
+}
+
+void pci_bus_release_busn_res(struct pci_bus *b)
+{
+	struct resource *res = &b->busn_res;
+	int ret;
+
+	if (!res->flags || !res->parent)
+		return;
+
+	ret = release_resource(res);
+	dev_printk(KERN_DEBUG, &b->dev,
+			"busn_res: %pR %s released\n",
+			res, ret ? "can not be" : "is");
+}
+
 struct pci_bus * __devinit pci_scan_root_bus(struct device *parent, int bus,
 		struct pci_ops *ops, void *sysdata, struct list_head *resources)
 {

include/linux/pci.h

@@ -667,6 +667,9 @@ struct pci_bus *pci_scan_bus(int bus, struct pci_ops *ops, void *sysdata);
 struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
 				    struct pci_ops *ops, void *sysdata,
 				    struct list_head *resources);
+int pci_bus_insert_busn_res(struct pci_bus *b, int bus, int busmax);
+int pci_bus_update_busn_res_end(struct pci_bus *b, int busmax);
+void pci_bus_release_busn_res(struct pci_bus *b);
 struct pci_bus * __devinit pci_scan_root_bus(struct device *parent, int bus,
 					     struct pci_ops *ops, void *sysdata,
 					     struct list_head *resources);