PCI subsystem: Drop parameter max from scan_bus

Change-Id: Ib33d3363c8d42fa54ac07c11a7ab2bc7ee4ae8bf
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/8539
Tested-by: build bot (Jenkins)
Tested-by: Raptor Engineering Automated Test Stand <noreply@raptorengineeringinc.com>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>

src/device/hypertransport.c

@@ -488,11 +488,9 @@ end_of_chain:
  * @param bus TODO
  * @param min_devfn TODO
  * @param max_devfn TODO
- * @param max The highest bus number assigned up to now.
- * @return The maximum bus number found, after scanning all subordinate busses.
  */
-static unsigned int hypertransport_scan_chain_x(struct bus *bus,
+static void hypertransport_scan_chain_x(struct bus *bus,
-	unsigned int min_devfn, unsigned int max_devfn, unsigned int max)
+	unsigned int min_devfn, unsigned int max_devfn)
 {
 	unsigned int ht_unitid_base[4];
 	unsigned int offset_unitid = 1;
@@ -501,8 +499,7 @@ static unsigned int hypertransport_scan_chain_x(struct bus *bus,
 					 ht_unitid_base, offset_unitid);
 
 	/* Now that nothing is overlapping it is safe to scan the children. */
-	bus->subordinate = pci_scan_bus(bus, 0x00, ((next_unitid - 1) << 3) | 7, bus->secondary);
+	pci_scan_bus(bus, 0x00, ((next_unitid - 1) << 3) | 7);
-	return bus->subordinate;
 }
 
 unsigned int ht_scan_bridge(struct device *dev, unsigned int max)

src/device/pci_device.c

@@ -1074,17 +1074,12 @@ unsigned int pci_match_simple_dev(device_t dev, pci_devfn_t sdev)
  * Determine the existence of devices and bridges on a PCI bus. If there are
  * bridges on the bus, recursively scan the buses behind the bridges.
  *
- * This function is the default scan_bus() method for the root device
- * 'dev_root'.
- *
  * @param bus Pointer to the bus structure.
  * @param min_devfn Minimum devfn to look at in the scan, usually 0x00.
  * @param max_devfn Maximum devfn to look at in the scan, usually 0xff.
- * @param max Current bus number.
- * @return The maximum bus number found, after scanning all subordinate busses.
  */
-unsigned int pci_scan_bus(struct bus *bus, unsigned min_devfn,
+void pci_scan_bus(struct bus *bus, unsigned min_devfn,
-			  unsigned max_devfn, unsigned int max)
+			  unsigned max_devfn)
 {
 	unsigned int devfn;
 	struct device *old_devices;
@@ -1149,17 +1144,19 @@ unsigned int pci_scan_bus(struct bus *bus, unsigned min_devfn,
 	 * For all children that implement scan_bus() (i.e. bridges)
 	 * scan the bus behind that child.
 	 */
+	unsigned int max = bus->secondary;
+
 	for (child = bus->children; child; child = child->sibling)
 		max = scan_bus(child, max);
 
+	bus->subordinate = max;
+
 	/*
 	 * We've scanned the bus and so we know all about what's on the other
 	 * side of any bridges that may be on this bus plus any devices.
 	 * Return how far we've got finding sub-buses.
 	 */
-	printk(BIOS_DEBUG, "PCI: pci_scan_bus returning with max=%03x\n", max);
 	post_code(0x55);
-	return max;
 }
 
 typedef enum {
@@ -1228,10 +1225,9 @@ static void pci_bridge_route(struct bus *link, scan_state state)
  * @return The maximum bus number found, after scanning all subordinate buses.
  */
 unsigned int do_pci_scan_bridge(struct device *dev, unsigned int max,
-				unsigned int (*do_scan_bus) (struct bus * bus,
+				void (*do_scan_bus) (struct bus * bus,
 							     unsigned min_devfn,
-							     unsigned max_devfn,
+							     unsigned max_devfn))
-							     unsigned int max))
 {
 	struct bus *bus;
 
@@ -1251,7 +1247,7 @@ unsigned int do_pci_scan_bridge(struct device *dev, unsigned int max,
 
 	pci_bridge_route(bus, PCI_ROUTE_SCAN);
 
-	bus->subordinate = do_scan_bus(bus, 0x00, 0xff, bus->secondary);
+	do_scan_bus(bus, 0x00, 0xff);
 
 	pci_bridge_route(bus, PCI_ROUTE_FINAL);
 
@@ -1287,7 +1283,7 @@ unsigned int pci_scan_bridge(struct device *dev, unsigned int max)
 unsigned int pci_domain_scan_bus(device_t dev, unsigned int unused)
 {
 	struct bus *link = dev->link_list;
-	link->subordinate = pci_scan_bus(link, PCI_DEVFN(0, 0), 0xff, link->secondary);
+	pci_scan_bus(link, PCI_DEVFN(0, 0), 0xff);
 	return unused;
 }
 

src/device/pciexp_device.c

@@ -416,12 +416,12 @@ static void pciexp_tune_dev(device_t dev)
 #endif
 }
 
-unsigned int pciexp_scan_bus(struct bus *bus, unsigned int min_devfn,
+void pciexp_scan_bus(struct bus *bus, unsigned int min_devfn,
-			     unsigned int max_devfn, unsigned int max)
+			     unsigned int max_devfn)
 {
 	device_t child;
 
-	max = pci_scan_bus(bus, min_devfn, max_devfn, max);
+	pci_scan_bus(bus, min_devfn, max_devfn);
 
 	for (child = bus->children; child; child = child->sibling) {
 		if ((child->path.pci.devfn < min_devfn) ||
@@ -430,7 +430,6 @@ unsigned int pciexp_scan_bus(struct bus *bus, unsigned int min_devfn,
 		}
 		pciexp_tune_dev(child);
 	}
-	return max;
 }
 
 unsigned int pciexp_scan_bridge(device_t dev, unsigned int max)

src/include/device/pci.h

@@ -70,11 +70,14 @@ void pci_dev_enable_resources(device_t dev);
 void pci_bus_enable_resources(device_t dev);
 void pci_bus_reset(struct bus *bus);
 device_t pci_probe_dev(device_t dev, struct bus *bus, unsigned devfn);
+
 unsigned int do_pci_scan_bridge(device_t bus, unsigned int max,
-	unsigned int (*do_scan_bus)(struct bus *bus,
+	void (*do_scan_bus)(struct bus *bus,
-		unsigned min_devfn, unsigned max_devfn, unsigned int max));
+		unsigned min_devfn, unsigned max_devfn));
 unsigned int pci_scan_bridge(device_t bus, unsigned int max);
-unsigned int pci_scan_bus(struct bus *bus, unsigned min_devfn, unsigned max_devfn, unsigned int max);
+
+void pci_scan_bus(struct bus *bus, unsigned min_devfn, unsigned max_devfn);
+
 uint8_t pci_moving_config8(struct device *dev, unsigned reg);
 uint16_t pci_moving_config16(struct device *dev, unsigned reg);
 uint32_t pci_moving_config32(struct device *dev, unsigned reg);

src/include/device/pciexp.h

@@ -9,8 +9,9 @@ enum aspm_type {
 	PCIE_ASPM_BOTH = 3,
 };
 
-unsigned int pciexp_scan_bus(struct bus *bus, unsigned int min_devfn,
+void pciexp_scan_bus(struct bus *bus, unsigned int min_devfn,
-			     unsigned int max_devfn, unsigned int max);
+			     unsigned int max_devfn);
+
 unsigned int pciexp_scan_bridge(device_t dev, unsigned int max);
 
 extern struct device_operations default_pciexp_ops_bus;

src/include/device/pcix.h

@@ -2,8 +2,6 @@
 #define DEVICE_PCIX_H
 /* (c) 2005 Linux Networx GPL see COPYING for details */
 
-unsigned int pcix_scan_bus(struct bus *bus, unsigned int min_devfn,
-			   unsigned int max_devfn, unsigned int max);
 unsigned int pcix_scan_bridge(device_t dev, unsigned int max);
 const char *pcix_speed(u16 sstatus);
 

src/northbridge/amd/agesa/family10/northbridge.c

@@ -565,6 +565,7 @@ static unsigned amdfam10_scan_chains(device_t dev, unsigned unused)
 
 	nodeid = amdfam10_nodeid(dev);
 	if (nodeid == 0) {
+		ASSERT(dev->bus->secondary == 0);
 		for (link = dev->link_list; link; link = link->next) {
 			if (link->link_num == sblink) { /* devicetree put IO Hub on link_lsit[3] */
 				io_hub = link->children;
@@ -572,9 +573,10 @@ static unsigned amdfam10_scan_chains(device_t dev, unsigned unused)
 					die("I can't find the IO Hub, or IO Hub not enabled, please check the device tree.\n");
 				}
 				/* Now that nothing is overlapping it is safe to scan the children. */
-				max = pci_scan_bus(link, 0x00, ((next_unitid - 1) << 3) | 7, 0);
+				pci_scan_bus(link, 0x00, ((next_unitid - 1) << 3) | 7);
 			}
 		}
+		max = dev->bus->subordinate;
 	}
 
 	dev->bus->subordinate = max;
@@ -917,7 +919,7 @@ static u32 amdfam10_domain_scan_bus(device_t dev, u32 unused)
 
 	for (link = dev->link_list; link; link = link->next) {
 		link->secondary = dev->bus->subordinate;
-		link->subordinate = pci_scan_bus(link, PCI_DEVFN(CONFIG_CDB, 0), 0xff, link->secondary);
+		pci_scan_bus(link, PCI_DEVFN(CONFIG_CDB, 0), 0xff);
 		dev->bus->subordinate = link->subordinate;
 	}
 

src/northbridge/amd/agesa/family15/northbridge.c

@@ -469,6 +469,7 @@ static unsigned scan_chains(device_t dev, unsigned unused)
 
 	nodeid = amdfam15_nodeid(dev);
 	if (nodeid == 0) {
+		ASSERT(dev->bus->secondary == 0);
 		for (link = dev->link_list; link; link = link->next) {
 			//if (link->link_num == sblink) { /* devicetree put IO Hub on link_lsit[sblink] */
 			if (link->link_num == 0) { /* devicetree put IO Hub on link_lsit[0] */
@@ -477,9 +478,10 @@ static unsigned scan_chains(device_t dev, unsigned unused)
 					die("I can't find the IO Hub, or IO Hub not enabled, please check the device tree.\n");
 				}
 				/* Now that nothing is overlapping it is safe to scan the children. */
-				max = pci_scan_bus(link, 0x00, ((next_unitid - 1) << 3) | 7, 0);
+				pci_scan_bus(link, 0x00, ((next_unitid - 1) << 3) | 7);
 			}
 		}
+		max = dev->bus->subordinate;
 	}
 
 	dev->bus->subordinate = max;
@@ -954,7 +956,7 @@ static void domain_set_resources(device_t dev)
 static unsigned int f15_pci_domain_scan_bus(device_t dev, unsigned int unused)
 {
 	struct bus *link = dev->link_list;
-	link->subordinate = pci_scan_bus(link, PCI_DEVFN(0x18, 0), 0xff, link->secondary);
+	pci_scan_bus(link, PCI_DEVFN(0x18, 0), 0xff);
 	return unused;
 }
 

src/northbridge/amd/amdfam10/northbridge.c

@@ -263,7 +263,7 @@ static u32 amdfam10_scan_chain(device_t dev, u32 nodeid, struct bus *link, bool
 		next_unitid = hypertransport_scan_chain(link, 0, max_devfn, ht_unitid_base, offset_unit_id(is_sblink));
 
 		/* Now that nothing is overlapping it is safe to scan the children. */
-		link->subordinate = pci_scan_bus(link, 0x00, ((next_unitid - 1) << 3) | 7, link->secondary);
+		pci_scan_bus(link, 0x00, ((next_unitid - 1) << 3) | 7);
 
 		/* We know the number of busses behind this bridge.  Set the
 		 * subordinate bus number to it's real value
@@ -924,7 +924,7 @@ static u32 amdfam10_domain_scan_bus(device_t dev, u32 unused)
 
 	for(link = dev->link_list; link; link = link->next) {
 		link->secondary = dev->bus->subordinate;
-		link->subordinate = pci_scan_bus(link, PCI_DEVFN(CONFIG_CDB, 0), 0xff, link->secondary);
+		pci_scan_bus(link, PCI_DEVFN(CONFIG_CDB, 0), 0xff);
 		dev->bus->subordinate = link->subordinate;
 	}
 

src/northbridge/amd/amdk8/northbridge.c

@@ -213,7 +213,7 @@ static u32 amdk8_scan_chain(device_t dev, u32 nodeid, struct bus *link, bool is_
 		next_unitid = hypertransport_scan_chain(link, 0, max_devfn, ht_unitid_base, offset_unit_id(is_sblink));
 
 		/* Now that nothing is overlapping it is safe to scan the children. */
-		link->subordinate = pci_scan_bus(link, 0x00, ((next_unitid - 1) << 3) | 7, link->secondary);
+		pci_scan_bus(link, 0x00, ((next_unitid - 1) << 3) | 7);
 
 		/* We know the number of busses behind this bridge.  Set the
 		 * subordinate bus number to it's real value
@@ -1107,7 +1107,7 @@ static u32 amdk8_domain_scan_bus(device_t dev, u32 unused)
 	}
 
 	link->secondary = dev->bus->subordinate;
-	link->subordinate = pci_scan_bus(link, PCI_DEVFN(0x18, 0), 0xff, link->secondary);
+	pci_scan_bus(link, PCI_DEVFN(0x18, 0), 0xff);
 	dev->bus->subordinate = link->subordinate;
 
 	/* Tune the hypertransport transaction for best performance.

src/southbridge/amd/amd8131/bridge.c

@@ -192,16 +192,15 @@ static void amd8131_pcix_tune_dev(device_t dev, void *ptr)
 		pci_write_config16(dev, cap + PCI_X_CMD, cmd);
 	}
 }
-static unsigned int amd8131_scan_bus(struct bus *bus,
+static void amd8131_scan_bus(struct bus *bus,
-	unsigned min_devfn, unsigned max_devfn, unsigned int max)
+	unsigned min_devfn, unsigned max_devfn)
 {
 	struct amd8131_bus_info info;
 	struct bus *pbus;
 	unsigned pos;
 
-
 	/* Find the children on the bus */
-	max = pci_scan_bus(bus, min_devfn, max_devfn, max);
+	pci_scan_bus(bus, min_devfn, max_devfn);
 
 	/* Find the revision of the 8131 */
 	info.rev = pci_read_config8(bus->dev, PCI_CLASS_REVISION);
@@ -243,13 +242,13 @@ static unsigned int amd8131_scan_bus(struct bus *bus,
 		pcix_misc &= ~(0x1f << 16);
 		pci_write_config32(bus->dev, 0x40, pcix_misc);
 
-		return max;
+		return;
 	}
 
 	/* If we are in conventional PCI mode nothing more is necessary.
 	 */
 	if (PCI_X_SSTATUS_MFREQ(info.sstatus) == PCI_X_SSTATUS_CONVENTIONAL_PCI) {
-		return max;
+		return;
 	}
 
 
@@ -264,7 +263,6 @@ static unsigned int amd8131_scan_bus(struct bus *bus,
 			bus_path(pbus));
 		pbus->disable_relaxed_ordering = 1;
 	}
-	return max;
 }
 
 static unsigned int amd8131_scan_bridge(device_t dev, unsigned int max)

src/southbridge/amd/amd8132/bridge.c

@@ -138,15 +138,14 @@ static void amd8132_pcix_tune_dev(device_t dev, void *ptr)
 
 
 }
-static unsigned int amd8132_scan_bus(struct bus *bus,
+static void amd8132_scan_bus(struct bus *bus,
-	unsigned min_devfn, unsigned max_devfn, unsigned int max)
+	unsigned min_devfn, unsigned max_devfn)
 {
 	struct amd8132_bus_info info;
 	unsigned pos;
 
-
 	/* Find the children on the bus */
-	max = pci_scan_bus(bus, min_devfn, max_devfn, max);
+	pci_scan_bus(bus, min_devfn, max_devfn);
 
 	/* Find the revision of the 8132 */
 	info.rev = pci_read_config8(bus->dev, PCI_CLASS_REVISION);
@@ -181,20 +180,18 @@ static unsigned int amd8132_scan_bus(struct bus *bus,
 		pcix_misc &= ~(0x1f << 16);
 		pci_write_config32(bus->dev, 0x40, pcix_misc);
 
-		return max;
+		return;
 	}
 #endif
 
 	/* If we are in conventional PCI mode nothing more is necessary.
 	 */
 	if (PCI_X_SSTATUS_MFREQ(info.sstatus) == PCI_X_SSTATUS_CONVENTIONAL_PCI) {
-		return max;
+		return;
 	}
 
 	/* Tune the devices on the bus */
 	amd8132_walk_children(bus, amd8132_pcix_tune_dev, &info);
-
-	return max;
 }
 
 static unsigned int amd8132_scan_bridge(device_t dev, unsigned int max)