diff --git a/arch/x86/pci/amd_bus.c b/arch/x86/pci/amd_bus.c
index e88f4c5..7c251c2 100644
--- a/arch/x86/pci/amd_bus.c
+++ b/arch/x86/pci/amd_bus.c
@@ -11,27 +11,33 @@
 
 #include "bus_numa.h"
 
-/*
- * This discovers the pcibus <-> node mapping on AMD K8.
- * also get peer root bus resource for io,mmio
- */
+#define AMD_NB_F0_NODE_ID			0x60
+#define AMD_NB_F0_UNIT_ID			0x64
+#define AMD_NB_F1_CONFIG_MAP_REG		0xe0
 
-struct pci_hostbridge_probe {
+#define RANGE_NUM				16
+#define AMD_NB_F1_CONFIG_MAP_RANGES		4
+
+struct amd_hostbridge {
 	u32 bus;
 	u32 slot;
-	u32 vendor;
 	u32 device;
 };
 
-static struct pci_hostbridge_probe pci_probes[] __initdata = {
-	{ 0, 0x18, PCI_VENDOR_ID_AMD, 0x1100 },
-	{ 0, 0x18, PCI_VENDOR_ID_AMD, 0x1200 },
-	{ 0xff, 0, PCI_VENDOR_ID_AMD, 0x1200 },
-	{ 0, 0x18, PCI_VENDOR_ID_AMD, 0x1300 },
+/*
+ * IMPORTANT NOTE:
+ * hb_probes[] and early_root_info_init() is in maintenance mode.
+ * It only supports K8, Fam10h, Fam11h, and Fam15h_00h-0fh .
+ * Future processor will rely on information in ACPI.
+ */
+static struct amd_hostbridge hb_probes[] __initdata = {
+	{ 0, 0x18, 0x1100 }, /* K8 */
+	{ 0, 0x18, 0x1200 }, /* Family10h */
+	{ 0xff, 0, 0x1200 }, /* Family10h */
+	{ 0, 0x18, 0x1300 }, /* Family11h */
+	{ 0, 0x18, 0x1600 }, /* Family15h */
 };
 
-#define RANGE_NUM 16
-
 static struct pci_root_info __init *find_pci_root_info(int node, int link)
 {
 	struct pci_root_info *info;
@@ -45,12 +51,12 @@ static struct pci_root_info __init *find_pci_root_info(int node, int link)
 }
 
 /**
- * early_fill_mp_bus_to_node()
+ * early_root_info_init()
  * called before pcibios_scan_root and pci_scan_bus
- * fills the mp_bus_to_cpumask array based according to the LDT Bus Number
- * Registers found in the K8 northbridge
+ * fills the mp_bus_to_cpumask array based according
+ * to the LDT Bus Number Registers found in the northbridge.
  */
-static int __init early_fill_mp_bus_info(void)
+static int __init early_root_info_init(void)
 {
 	int i;
 	unsigned bus;
@@ -75,19 +81,21 @@ static int __init early_fill_mp_bus_info(void)
 		return -1;
 
 	found = false;
-	for (i = 0; i < ARRAY_SIZE(pci_probes); i++) {
+	for (i = 0; i < ARRAY_SIZE(hb_probes); i++) {
 		u32 id;
 		u16 device;
 		u16 vendor;
 
-		bus = pci_probes[i].bus;
-		slot = pci_probes[i].slot;
+		bus = hb_probes[i].bus;
+		slot = hb_probes[i].slot;
 		id = read_pci_config(bus, slot, 0, PCI_VENDOR_ID);
-
 		vendor = id & 0xffff;
 		device = (id>>16) & 0xffff;
-		if (pci_probes[i].vendor == vendor &&
-		    pci_probes[i].device == device) {
+
+		if (vendor != PCI_VENDOR_ID_AMD)
+			continue;
+
+		if (hb_probes[i].device == device) {
 			found = true;
 			break;
 		}
@@ -96,10 +104,11 @@ static int __init early_fill_mp_bus_info(void)
 	if (!found)
 		return 0;
 
-	for (i = 0; i < 4; i++) {
+	for (i = 0; i < AMD_NB_F1_CONFIG_MAP_RANGES; i++) {
 		int min_bus;
 		int max_bus;
-		reg = read_pci_config(bus, slot, 1, 0xe0 + (i << 2));
+		reg = read_pci_config(bus, slot, 1,
+				AMD_NB_F1_CONFIG_MAP_REG + (i << 2));
 
 		/* Check if that register is enabled for bus range */
 		if ((reg & 7) != 3)
@@ -113,10 +122,17 @@ static int __init early_fill_mp_bus_info(void)
 		info = alloc_pci_root_info(min_bus, max_bus, node, link);
 	}
 
+	/*
+	 * The following code is only supported until Fam11h.
+	 * Newer processors will depend on ACPI MCFG table instead.
+	 */
+	if (boot_cpu_data.x86 > 0x11)
+		return 0;
+
 	/* get the default node and link for left over res */
-	reg = read_pci_config(bus, slot, 0, 0x60);
+	reg = read_pci_config(bus, slot, 0, AMD_NB_F0_NODE_ID);
 	def_node = (reg >> 8) & 0x07;
-	reg = read_pci_config(bus, slot, 0, 0x64);
+	reg = read_pci_config(bus, slot, 0, AMD_NB_F0_UNIT_ID);
 	def_link = (reg >> 8) & 0x03;
 
 	memset(range, 0, sizeof(range));
@@ -363,7 +379,7 @@ static int __init pci_io_ecs_init(void)
 	int cpu;
 
 	/* assume all cpus from fam10h have IO ECS */
-        if (boot_cpu_data.x86 < 0x10)
+	if (boot_cpu_data.x86 < 0x10)
 		return 0;
 
 	/* Try the PCI method first. */
@@ -387,7 +403,8 @@ static int __init amd_postcore_init(void)
 	if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
 		return 0;
 
-	early_fill_mp_bus_info();
+	early_root_info_init();
+
 	pci_io_ecs_init();
 
 	return 0;
