diff --git a/arch/x86/include/asm/amd_nb.h b/arch/x86/include/asm/amd_nb.h
index b3341e9cd8fd..a54ee1d054d9 100644
--- a/arch/x86/include/asm/amd_nb.h
+++ b/arch/x86/include/asm/amd_nb.h
@@ -81,6 +81,23 @@ static inline struct amd_northbridge *node_to_amd_nb(int node)
 	return (node < amd_northbridges.num) ? &amd_northbridges.nb[node] : NULL;
 }
 
+static inline u16 amd_get_node_id(struct pci_dev *pdev)
+{
+	struct pci_dev *misc;
+	int i;
+
+	for (i = 0; i != amd_nb_num(); i++) {
+		misc = node_to_amd_nb(i)->misc;
+
+		if (pci_domain_nr(misc->bus) == pci_domain_nr(pdev->bus) &&
+		    PCI_SLOT(misc->devfn) == PCI_SLOT(pdev->devfn))
+			return i;
+	}
+
+	WARN(1, "Unable to find AMD Northbridge id for %s\n", pci_name(pdev));
+	return 0;
+}
+
 #else
 
 #define amd_nb_num(x)		0
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 888184b2fc85..cf500543f6ff 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -943,7 +943,7 @@ extern void start_thread(struct pt_regs *regs, unsigned long new_ip,
 extern int get_tsc_mode(unsigned long adr);
 extern int set_tsc_mode(unsigned int val);
 
-extern int amd_get_nb_id(int cpu);
+extern u16 amd_get_nb_id(int cpu);
 
 struct aperfmperf {
 	u64 aperf, mperf;
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 15239fffd6fe..782c456eaa01 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -364,9 +364,9 @@ static void __cpuinit amd_detect_cmp(struct cpuinfo_x86 *c)
 #endif
 }
 
-int amd_get_nb_id(int cpu)
+u16 amd_get_nb_id(int cpu)
 {
-	int id = 0;
+	u16 id = 0;
 #ifdef CONFIG_SMP
 	id = per_cpu(cpu_llc_id, cpu);
 #endif
diff --git a/drivers/edac/amd64_edac.c b/drivers/edac/amd64_edac.c
index ad8bf2aa629d..2d3f8825e8b8 100644
--- a/drivers/edac/amd64_edac.c
+++ b/drivers/edac/amd64_edac.c
@@ -31,7 +31,7 @@ static struct ecc_settings **ecc_stngs;
  *
  *FIXME: Produce a better mapping/linearisation.
  */
-struct scrubrate {
+static const struct scrubrate {
        u32 scrubval;           /* bit pattern for scrub rate */
        u32 bandwidth;          /* bandwidth consumed (bytes/sec) */
 } scrubrates[] = {
@@ -239,7 +239,7 @@ static int amd64_get_scrub_rate(struct mem_ctl_info *mci)
  * DRAM base/limit associated with node_id
  */
 static bool amd64_base_limit_match(struct amd64_pvt *pvt, u64 sys_addr,
-				   unsigned nid)
+				   u8 nid)
 {
 	u64 addr;
 
@@ -265,7 +265,7 @@ static struct mem_ctl_info *find_mc_by_sys_addr(struct mem_ctl_info *mci,
 						u64 sys_addr)
 {
 	struct amd64_pvt *pvt;
-	unsigned node_id;
+	u8 node_id;
 	u32 intlv_en, bits;
 
 	/*
@@ -939,7 +939,8 @@ static u64 get_error_address(struct mce *m)
 		struct amd64_pvt *pvt;
 		u64 cc6_base, tmp_addr;
 		u32 tmp;
-		u8 mce_nid, intlv_en;
+		u16 mce_nid;
+		u8 intlv_en;
 
 		if ((addr & GENMASK(24, 47)) >> 24 != 0x00fdf7)
 			return addr;
@@ -979,10 +980,29 @@ static u64 get_error_address(struct mce *m)
 	return addr;
 }
 
+static struct pci_dev *pci_get_related_function(unsigned int vendor,
+						unsigned int device,
+						struct pci_dev *related)
+{
+	struct pci_dev *dev = NULL;
+
+	while ((dev = pci_get_device(vendor, device, dev))) {
+		if (pci_domain_nr(dev->bus) == pci_domain_nr(related->bus) &&
+		    (dev->bus->number == related->bus->number) &&
+		    (PCI_SLOT(dev->devfn) == PCI_SLOT(related->devfn)))
+			break;
+	}
+
+	return dev;
+}
+
 static void read_dram_base_limit_regs(struct amd64_pvt *pvt, unsigned range)
 {
+	struct amd_northbridge *nb;
+	struct pci_dev *misc, *f1 = NULL;
 	struct cpuinfo_x86 *c = &boot_cpu_data;
 	int off = range << 3;
+	u32 llim;
 
 	amd64_read_pci_cfg(pvt->F1, DRAM_BASE_LO + off,  &pvt->ranges[range].base.lo);
 	amd64_read_pci_cfg(pvt->F1, DRAM_LIMIT_LO + off, &pvt->ranges[range].lim.lo);
@@ -996,30 +1016,32 @@ static void read_dram_base_limit_regs(struct amd64_pvt *pvt, unsigned range)
 	amd64_read_pci_cfg(pvt->F1, DRAM_BASE_HI + off,  &pvt->ranges[range].base.hi);
 	amd64_read_pci_cfg(pvt->F1, DRAM_LIMIT_HI + off, &pvt->ranges[range].lim.hi);
 
-	/* Factor in CC6 save area by reading dst node's limit reg */
-	if (c->x86 == 0x15) {
-		struct pci_dev *f1 = NULL;
-		u8 nid = dram_dst_node(pvt, range);
-		u32 llim;
+	/* F15h: factor in CC6 save area by reading dst node's limit reg */
+	if (c->x86 != 0x15)
+		return;
 
-		f1 = pci_get_domain_bus_and_slot(0, 0, PCI_DEVFN(0x18 + nid, 1));
-		if (WARN_ON(!f1))
-			return;
+	nb = node_to_amd_nb(dram_dst_node(pvt, range));
+	if (WARN_ON(!nb))
+		return;
 
-		amd64_read_pci_cfg(f1, DRAM_LOCAL_NODE_LIM, &llim);
+	misc = nb->misc;
+	f1 = pci_get_related_function(misc->vendor, PCI_DEVICE_ID_AMD_15H_NB_F1, misc);
+	if (WARN_ON(!f1))
+		return;
 
-		pvt->ranges[range].lim.lo &= GENMASK(0, 15);
+	amd64_read_pci_cfg(f1, DRAM_LOCAL_NODE_LIM, &llim);
 
-					    /* {[39:27],111b} */
-		pvt->ranges[range].lim.lo |= ((llim & 0x1fff) << 3 | 0x7) << 16;
+	pvt->ranges[range].lim.lo &= GENMASK(0, 15);
 
-		pvt->ranges[range].lim.hi &= GENMASK(0, 7);
+				    /* {[39:27],111b} */
+	pvt->ranges[range].lim.lo |= ((llim & 0x1fff) << 3 | 0x7) << 16;
 
-					    /* [47:40] */
-		pvt->ranges[range].lim.hi |= llim >> 13;
+	pvt->ranges[range].lim.hi &= GENMASK(0, 7);
 
-		pci_dev_put(f1);
-	}
+				    /* [47:40] */
+	pvt->ranges[range].lim.hi |= llim >> 13;
+
+	pci_dev_put(f1);
 }
 
 static void k8_map_sysaddr_to_csrow(struct mem_ctl_info *mci, u64 sys_addr,
@@ -1305,7 +1327,7 @@ static u8 f1x_determine_channel(struct amd64_pvt *pvt, u64 sys_addr,
 }
 
 /* Convert the sys_addr to the normalized DCT address */
-static u64 f1x_get_norm_dct_addr(struct amd64_pvt *pvt, unsigned range,
+static u64 f1x_get_norm_dct_addr(struct amd64_pvt *pvt, u8 range,
 				 u64 sys_addr, bool hi_rng,
 				 u32 dct_sel_base_addr)
 {
@@ -1381,7 +1403,7 @@ static int f10_process_possible_spare(struct amd64_pvt *pvt, u8 dct, int csrow)
  *	-EINVAL:  NOT FOUND
  *	0..csrow = Chip-Select Row
  */
-static int f1x_lookup_addr_in_dct(u64 in_addr, u32 nid, u8 dct)
+static int f1x_lookup_addr_in_dct(u64 in_addr, u8 nid, u8 dct)
 {
 	struct mem_ctl_info *mci;
 	struct amd64_pvt *pvt;
@@ -1672,23 +1694,6 @@ static struct amd64_family_type amd64_family_types[] = {
 	},
 };
 
-static struct pci_dev *pci_get_related_function(unsigned int vendor,
-						unsigned int device,
-						struct pci_dev *related)
-{
-	struct pci_dev *dev = NULL;
-
-	dev = pci_get_device(vendor, device, dev);
-	while (dev) {
-		if ((dev->bus->number == related->bus->number) &&
-		    (PCI_SLOT(dev->devfn) == PCI_SLOT(related->devfn)))
-			break;
-		dev = pci_get_device(vendor, device, dev);
-	}
-
-	return dev;
-}
-
 /*
  * These are tables of eigenvectors (one per line) which can be used for the
  * construction of the syndrome tables. The modified syndrome search algorithm
@@ -1696,7 +1701,7 @@ static struct pci_dev *pci_get_related_function(unsigned int vendor,
  *
  * Algorithm courtesy of Ross LaFetra from AMD.
  */
-static u16 x4_vectors[] = {
+static const u16 x4_vectors[] = {
 	0x2f57, 0x1afe, 0x66cc, 0xdd88,
 	0x11eb, 0x3396, 0x7f4c, 0xeac8,
 	0x0001, 0x0002, 0x0004, 0x0008,
@@ -1735,7 +1740,7 @@ static u16 x4_vectors[] = {
 	0x19a9, 0x2efe, 0xb5cc, 0x6f88,
 };
 
-static u16 x8_vectors[] = {
+static const u16 x8_vectors[] = {
 	0x0145, 0x028a, 0x2374, 0x43c8, 0xa1f0, 0x0520, 0x0a40, 0x1480,
 	0x0211, 0x0422, 0x0844, 0x1088, 0x01b0, 0x44e0, 0x23c0, 0xed80,
 	0x1011, 0x0116, 0x022c, 0x0458, 0x08b0, 0x8c60, 0x2740, 0x4e80,
@@ -1757,7 +1762,7 @@ static u16 x8_vectors[] = {
 	0x0100, 0x0200, 0x0400, 0x0800, 0x1000, 0x2000, 0x4000, 0x8000,
 };
 
-static int decode_syndrome(u16 syndrome, u16 *vectors, unsigned num_vecs,
+static int decode_syndrome(u16 syndrome, const u16 *vectors, unsigned num_vecs,
 			   unsigned v_dim)
 {
 	unsigned int i, err_sym;
@@ -2181,7 +2186,7 @@ static int init_csrows(struct mem_ctl_info *mci)
 }
 
 /* get all cores on this DCT */
-static void get_cpus_on_this_dct_cpumask(struct cpumask *mask, unsigned nid)
+static void get_cpus_on_this_dct_cpumask(struct cpumask *mask, u16 nid)
 {
 	int cpu;
 
@@ -2191,7 +2196,7 @@ static void get_cpus_on_this_dct_cpumask(struct cpumask *mask, unsigned nid)
 }
 
 /* check MCG_CTL on all the cpus on this node */
-static bool amd64_nb_mce_bank_enabled_on_node(unsigned nid)
+static bool amd64_nb_mce_bank_enabled_on_node(u16 nid)
 {
 	cpumask_var_t mask;
 	int cpu, nbe;
@@ -2224,7 +2229,7 @@ out:
 	return ret;
 }
 
-static int toggle_ecc_err_reporting(struct ecc_settings *s, u8 nid, bool on)
+static int toggle_ecc_err_reporting(struct ecc_settings *s, u16 nid, bool on)
 {
 	cpumask_var_t cmask;
 	int cpu;
@@ -2262,7 +2267,7 @@ static int toggle_ecc_err_reporting(struct ecc_settings *s, u8 nid, bool on)
 	return 0;
 }
 
-static bool enable_ecc_error_reporting(struct ecc_settings *s, u8 nid,
+static bool enable_ecc_error_reporting(struct ecc_settings *s, u16 nid,
 				       struct pci_dev *F3)
 {
 	bool ret = true;
@@ -2314,7 +2319,7 @@ static bool enable_ecc_error_reporting(struct ecc_settings *s, u8 nid,
 	return ret;
 }
 
-static void restore_ecc_error_reporting(struct ecc_settings *s, u8 nid,
+static void restore_ecc_error_reporting(struct ecc_settings *s, u16 nid,
 					struct pci_dev *F3)
 {
 	u32 value, mask = 0x3;		/* UECC/CECC enable */
@@ -2353,7 +2358,7 @@ static const char *ecc_msg =
 	"'ecc_enable_override'.\n"
 	" (Note that use of the override may cause unknown side effects.)\n";
 
-static bool ecc_enabled(struct pci_dev *F3, u8 nid)
+static bool ecc_enabled(struct pci_dev *F3, u16 nid)
 {
 	u32 value;
 	u8 ecc_en = 0;
@@ -2474,7 +2479,7 @@ static int amd64_init_one_instance(struct pci_dev *F2)
 	struct mem_ctl_info *mci = NULL;
 	struct edac_mc_layer layers[2];
 	int err = 0, ret;
-	u8 nid = get_node_id(F2);
+	u16 nid = amd_get_node_id(F2);
 
 	ret = -ENOMEM;
 	pvt = kzalloc(sizeof(struct amd64_pvt), GFP_KERNEL);
@@ -2566,7 +2571,7 @@ err_ret:
 static int amd64_probe_one_instance(struct pci_dev *pdev,
 				    const struct pci_device_id *mc_type)
 {
-	u8 nid = get_node_id(pdev);
+	u16 nid = amd_get_node_id(pdev);
 	struct pci_dev *F3 = node_to_amd_nb(nid)->misc;
 	struct ecc_settings *s;
 	int ret = 0;
@@ -2616,7 +2621,7 @@ static void amd64_remove_one_instance(struct pci_dev *pdev)
 {
 	struct mem_ctl_info *mci;
 	struct amd64_pvt *pvt;
-	u8 nid = get_node_id(pdev);
+	u16 nid = amd_get_node_id(pdev);
 	struct pci_dev *F3 = node_to_amd_nb(nid)->misc;
 	struct ecc_settings *s = ecc_stngs[nid];
 
diff --git a/drivers/edac/amd64_edac.h b/drivers/edac/amd64_edac.h
index e864f407806c..35637d83f235 100644
--- a/drivers/edac/amd64_edac.h
+++ b/drivers/edac/amd64_edac.h
@@ -292,12 +292,6 @@
 /* MSRs */
 #define MSR_MCGCTL_NBE			BIT(4)
 
-/* AMD sets the first MC device at device ID 0x18. */
-static inline u8 get_node_id(struct pci_dev *pdev)
-{
-	return PCI_SLOT(pdev->devfn) - 0x18;
-}
-
 enum amd_families {
 	K8_CPUS = 0,
 	F10_CPUS,
@@ -340,7 +334,7 @@ struct amd64_pvt {
 	/* pci_device handles which we utilize */
 	struct pci_dev *F1, *F2, *F3;
 
-	unsigned mc_node_id;	/* MC index of this MC node */
+	u16 mc_node_id;		/* MC index of this MC node */
 	int ext_model;		/* extended model value of this node */
 	int channel_count;
 
@@ -393,7 +387,7 @@ struct err_info {
 	u32 offset;
 };
 
-static inline u64 get_dram_base(struct amd64_pvt *pvt, unsigned i)
+static inline u64 get_dram_base(struct amd64_pvt *pvt, u8 i)
 {
 	u64 addr = ((u64)pvt->ranges[i].base.lo & 0xffff0000) << 8;
 
@@ -403,7 +397,7 @@ static inline u64 get_dram_base(struct amd64_pvt *pvt, unsigned i)
 	return (((u64)pvt->ranges[i].base.hi & 0x000000ff) << 40) | addr;
 }
 
-static inline u64 get_dram_limit(struct amd64_pvt *pvt, unsigned i)
+static inline u64 get_dram_limit(struct amd64_pvt *pvt, u8 i)
 {
 	u64 lim = (((u64)pvt->ranges[i].lim.lo & 0xffff0000) << 8) | 0x00ffffff;