devicetree: Change scan_bus() prototype in device ops

The input/output value max is no longer used for tracking the
bus enumeration sequence, everything is handled in the context
of devicetree bus objects.

Change-Id: I545088bd8eaf205b1436d8c52d3bc7faf4cfb0f9
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/8541
Tested-by: build bot (Jenkins)
Tested-by: Raptor Engineering Automated Test Stand <noreply@raptorengineeringinc.com>
Reviewed-by: Timothy Pearson <tpearson@raptorengineeringinc.com>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>

src/device/device.c

@@ -913,16 +913,13 @@ int reset_bus(struct bus *bus)
  * required, reset the bus and scan it again.
  *
  * @param busdev Pointer to the bus device.
- * @param max Current bus number.
- * @return The maximum bus number found, after scanning all subordinate buses.
  */
-static unsigned int scan_bus(struct device *busdev, unsigned int max)
+static void scan_bus(struct device *busdev)
 {
-	unsigned int new_max;
 	int do_scan_bus;
 
 	if (!busdev->enabled)
-		return max;
+		return;
 
 	printk(BIOS_SPEW, "%s scanning...\n", dev_path(busdev));
 
@@ -931,7 +928,7 @@ static unsigned int scan_bus(struct device *busdev, unsigned int max)
 	do_scan_bus = 1;
 	while (do_scan_bus) {
 		struct bus *link;
-		new_max = busdev->ops->scan_bus(busdev, max);
+		busdev->ops->scan_bus(busdev);
 		do_scan_bus = 0;
 		for (link = busdev->link_list; link; link = link->next) {
 			if (link->reset_needed) {
@@ -942,20 +939,17 @@ static unsigned int scan_bus(struct device *busdev, unsigned int max)
 			}
 		}
 	}
-	return new_max;
 }
 
 void scan_bridges(struct bus *bus)
 {
 	struct device *child;
-	unsigned int max = bus->secondary;
 
 	for (child = bus->children; child; child = child->sibling) {
 		if (!child->ops || !child->ops->scan_bus)
 			continue;
-		max = scan_bus(child, max);
+		scan_bus(child);
 	}
-	bus->subordinate = max;
 }
 
 /**
@@ -999,7 +993,7 @@ void dev_enumerate(void)
 		printk(BIOS_ERR, "dev_root missing scan_bus operation");
 		return;
 	}
-	scan_bus(root, 0);
+	scan_bus(root);
 	post_log_clear();
 	printk(BIOS_INFO, "done\n");
 }

src/device/hypertransport.c

@@ -502,9 +502,9 @@ static void hypertransport_scan_chain_x(struct bus *bus,
 	pci_scan_bus(bus, 0x00, ((next_unitid - 1) << 3) | 7);
 }
 
-unsigned int ht_scan_bridge(struct device *dev, unsigned int max)
+void ht_scan_bridge(struct device *dev)
 {
-	return do_pci_scan_bridge(dev, max, hypertransport_scan_chain_x);
+	do_pci_scan_bridge(dev, hypertransport_scan_chain_x);
 }
 
 /** Default device operations for hypertransport bridges */

src/device/pci_device.c

@@ -1215,11 +1215,9 @@ static void pci_bridge_route(struct bus *link, scan_state state)
  * This function is the default scan_bus() method for PCI bridge devices.
  *
  * @param dev Pointer to the bridge device.
- * @param max The highest bus number assigned up to now.
  * @param do_scan_bus TODO
- * @return The maximum bus number found, after scanning all subordinate buses.
  */
-unsigned int do_pci_scan_bridge(struct device *dev, unsigned int max,
+void do_pci_scan_bridge(struct device *dev,
 				void (*do_scan_bus) (struct bus * bus,
 							     unsigned min_devfn,
 							     unsigned max_devfn))
@@ -1245,8 +1243,6 @@ unsigned int do_pci_scan_bridge(struct device *dev, unsigned int max,
 	do_scan_bus(bus, 0x00, 0xff);
 
 	pci_bridge_route(bus, PCI_ROUTE_FINAL);
-
-	return bus->subordinate;
 }
 
 /**
@@ -1258,12 +1254,10 @@ unsigned int do_pci_scan_bridge(struct device *dev, unsigned int max,
  * This function is the default scan_bus() method for PCI bridge devices.
  *
  * @param dev Pointer to the bridge device.
- * @param max The highest bus number assigned up to now.
- * @return The maximum bus number found, after scanning all subordinate buses.
  */
-unsigned int pci_scan_bridge(struct device *dev, unsigned int max)
+void pci_scan_bridge(struct device *dev)
 {
-	return do_pci_scan_bridge(dev, max, pci_scan_bus);
+	do_pci_scan_bridge(dev, pci_scan_bus);
 }
 
 /**
@@ -1272,14 +1266,11 @@ unsigned int pci_scan_bridge(struct device *dev, unsigned int max)
  * This function is the default scan_bus() method for PCI domains.
  *
  * @param dev Pointer to the domain.
- * @param max The highest bus number assigned up to now.
- * @return The maximum bus number found, after scanning all subordinate busses.
  */
-unsigned int pci_domain_scan_bus(device_t dev, unsigned int unused)
+void pci_domain_scan_bus(device_t dev)
 {
 	struct bus *link = dev->link_list;
 	pci_scan_bus(link, PCI_DEVFN(0, 0), 0xff);
-	return unused;
 }
 
 /**

src/device/pciexp_device.c

@@ -432,9 +432,9 @@ void pciexp_scan_bus(struct bus *bus, unsigned int min_devfn,
 	}
 }
 
-unsigned int pciexp_scan_bridge(device_t dev, unsigned int max)
+void pciexp_scan_bridge(device_t dev)
 {
-	return do_pci_scan_bridge(dev, max, pciexp_scan_bus);
+	do_pci_scan_bridge(dev, pciexp_scan_bus);
 }
 
 /** Default device operations for PCI Express bridges */

src/device/pcix_device.c

@@ -112,12 +112,12 @@ const char *pcix_speed(u16 sstatus)
 	return result;
 }
 
-unsigned int pcix_scan_bridge(device_t dev, unsigned int max)
+void pcix_scan_bridge(device_t dev)
 {
 	unsigned int pos;
 	u16 sstatus;
 
-	max = do_pci_scan_bridge(dev, max, pci_scan_bus);
+	do_pci_scan_bridge(dev, pci_scan_bus);
 
 	/* Find the PCI-X capability. */
 	pos = pci_find_capability(dev, PCI_CAP_ID_PCIX);
@@ -129,8 +129,6 @@ unsigned int pcix_scan_bridge(device_t dev, unsigned int max)
 	/* Print the PCI-X bus speed. */
 	printk(BIOS_DEBUG, "PCI: %02x: %s\n", dev->link_list->secondary,
 	       pcix_speed(sstatus));
-
-	return max;
 }
 
 /** Default device operations for PCI-X bridges */

src/device/root_device.c

@@ -45,11 +45,9 @@ const char mainboard_name[] = CONFIG_MAINBOARD_VENDOR " " CONFIG_MAINBOARD_PART_
  * file under some static bus in order to be enumerated at run time.
  *
  * @param bus Pointer to the device to which the static buses are attached to.
- * @param max Maximum bus number currently used before scanning.
- * @return The largest bus number used.
  */
 
-static unsigned int scan_static_bus(device_t bus, unsigned int passthru)
+static void scan_static_bus(device_t bus)
 {
 	device_t child;
 	struct bus *link;
@@ -67,22 +65,18 @@ static unsigned int scan_static_bus(device_t bus, unsigned int passthru)
 			       child->enabled ? "enabled" : "disabled");
 		}
 	}
-
-	return passthru;
 }
 
-unsigned int scan_lpc_bus(device_t bus, unsigned int passthru)
+void scan_lpc_bus(device_t bus)
 {
 	printk(BIOS_SPEW, "%s for %s\n", __func__, dev_path(bus));
 
-	scan_static_bus(bus, 0);
+	scan_static_bus(bus);
 
 	printk(BIOS_SPEW, "%s for %s done\n", __func__, dev_path(bus));
-
-	return passthru;
 }
 
-unsigned int scan_smbus(device_t bus, unsigned int passthru)
+void scan_smbus(device_t bus)
 {
 	device_t child;
 	struct bus *link;
@@ -111,8 +105,6 @@ unsigned int scan_smbus(device_t bus, unsigned int passthru)
 	}
 
 	printk(BIOS_SPEW, "%s for %s done\n", __func__, dev_path(bus));
-
-	return passthru;
 }
 
 /**
@@ -121,23 +113,19 @@ unsigned int scan_smbus(device_t bus, unsigned int passthru)
  * This function is the default scan_bus() method of the root device.
  *
  * @param root The root device structure.
- * @param max The current bus number scanned so far, usually 0x00.
- * @return The largest bus number used.
  */
-static unsigned int root_dev_scan_bus(device_t bus, unsigned int passthru)
+static void root_dev_scan_bus(device_t bus)
 {
 	struct bus *link;
 
 	printk(BIOS_SPEW, "%s for %s\n", __func__, dev_path(bus));
 
-	scan_static_bus(bus, 0);
+	scan_static_bus(bus);
 
 	for (link = bus->link_list; link; link = link->next)
 		scan_bridges(link);
 
 	printk(BIOS_SPEW, "%s for %s done\n", __func__, dev_path(bus));
-
-	return passthru;
 }
 
 static void root_dev_reset(struct bus *bus)