Fix the handling of memory controller detection to index the array
of detected Northbridges, allowing memory controllers over multiple
PCI domains in federated systems eg using Numascale's NumaConnect/
NumaChip.

v4: Generate linear Northbridge ID by indexing detected Northbridges
v5: Reorder functions to prevent extra function declaration; merge 4th
    patch; simplify Fam15h code; add detail to warning

Signed-off-by: Daniel J Blueman <daniel@numascale-asia.com>
---
 arch/x86/include/asm/amd_nb.h |   13 +++++++++++
 drivers/edac/amd64_edac.c     |   49 ++++++++++++++++++++++-------------------
 drivers/edac/amd64_edac.h     |    6 -----
 3 files changed, 39 insertions(+), 29 deletions(-)

diff --git a/arch/x86/include/asm/amd_nb.h b/arch/x86/include/asm/amd_nb.h
index b3341e9..9f5532a 100644
--- a/arch/x86/include/asm/amd_nb.h
+++ b/arch/x86/include/asm/amd_nb.h
@@ -81,6 +81,19 @@ 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)
+{
+	int i;
+
+	for (i = 0; i != amd_nb_num(); i++)
+		if (pci_domain_nr(node_to_amd_nb(i)->misc->bus) == pci_domain_nr(pdev->bus) &&
+		    PCI_SLOT(node_to_amd_nb(i)->misc->devfn) == PCI_SLOT(pdev->devfn))
+			return i;
+
+	WARN(1, "Unable to find AMD Northbridge identifier for %s\n", pci_name(pdev));
+	return 0;
+}
+
 #else
 
 #define amd_nb_num(x)		0
diff --git a/drivers/edac/amd64_edac.c b/drivers/edac/amd64_edac.c
index cc8e7c7..852f1cd 100644
--- a/drivers/edac/amd64_edac.c
+++ b/drivers/edac/amd64_edac.c
@@ -982,6 +982,24 @@ 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;
+
+	dev = pci_get_device(vendor, device, dev);
+	while (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;
+		dev = pci_get_device(vendor, device, dev);
+	}
+
+	return dev;
+}
+
 static void read_dram_base_limit_regs(struct amd64_pvt *pvt, unsigned range)
 {
 	struct cpuinfo_x86 *c = &boot_cpu_data;
@@ -1001,11 +1019,13 @@ static void read_dram_base_limit_regs(struct amd64_pvt *pvt, unsigned range)
 
 	/* 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);
+		struct pci_dev *misc, *f1 = NULL;
+		struct amd64_family_type *fam_type;
+		u16 nid = dram_dst_node(pvt, range);
 		u32 llim;
 
-		f1 = pci_get_domain_bus_and_slot(0, 0, PCI_DEVFN(0x18 + nid, 1));
+		misc = node_to_amd_nb(nid)->misc;
+		f1 = pci_get_related_function(misc->vendor, PCI_DEVICE_ID_AMD_15H_NB_F1, misc);
 		if (WARN_ON(!f1))
 			return;
 
@@ -1712,23 +1732,6 @@ 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
@@ -2546,7 +2549,7 @@ 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);
+	u8 nid = amd_get_node_id(F2);
 
 	ret = -ENOMEM;
 	pvt = kzalloc(sizeof(struct amd64_pvt), GFP_KERNEL);
@@ -2637,7 +2640,7 @@ err_ret:
 static int __devinit amd64_probe_one_instance(struct pci_dev *pdev,
 					     const struct pci_device_id *mc_type)
 {
-	u8 nid = get_node_id(pdev);
+	u8 nid = amd_get_node_id(pdev);
 	struct pci_dev *F3 = node_to_amd_nb(nid)->misc;
 	struct ecc_settings *s;
 	int ret = 0;
@@ -2687,7 +2690,7 @@ static void __devexit amd64_remove_one_instance(struct pci_dev *pdev)
 {
 	struct mem_ctl_info *mci;
 	struct amd64_pvt *pvt;
-	u8 nid = get_node_id(pdev);
+	u8 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 8d48047..90cae61 100644
--- a/drivers/edac/amd64_edac.h
+++ b/drivers/edac/amd64_edac.h
@@ -290,12 +290,6 @@
 /* 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,
-- 
1.7.10.4