EDAC, skx_edac: Handle systems with segmented PCI busses

Large systems separate their PCI busses into segments since
the limit of only 256 PCI busses can be too restrictive.

Extend this driver to check whether <segment, bus-number> matches
when deciding how to group memory controller PCI devices to
CPU sockets.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Cc: Aristeu Rozanski <arozansk@redhat.com>
Cc: Charles Rose <charles.rose@dell.com>
Cc: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Cc: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/f58abfd10bf73c8bc5adc1fe4de7408128b00625.1506358467.git.tony.luck@intel.com
[ Make skx_dev.seg an int. ]
Signed-off-by: Borislav Petkov <bp@suse.de>

drivers/edac/skx_edac.c

@@ -67,6 +67,7 @@ static u64 skx_tolm, skx_tohm;
 struct skx_dev {
 	struct list_head	list;
 	u8			bus[4];
+	int			seg;
 	struct pci_dev	*sad_all;
 	struct pci_dev	*util_all;
 	u32	mcroute;
@@ -112,12 +113,12 @@ struct decoded_addr {
 	int	bank_group;
 };
 
-static struct skx_dev *get_skx_dev(u8 bus, u8 idx)
+static struct skx_dev *get_skx_dev(struct pci_bus *bus, u8 idx)
 {
 	struct skx_dev *d;
 
 	list_for_each_entry(d, &skx_edac_list, list) {
-		if (d->bus[idx] == bus)
+		if (d->seg == pci_domain_nr(bus) && d->bus[idx] == bus->number)
 			return d;
 	}
 
@@ -174,6 +175,7 @@ static int get_all_bus_mappings(void)
 			pci_dev_put(pdev);
 			return -ENOMEM;
 		}
+		d->seg = pci_domain_nr(pdev->bus);
 		pci_read_config_dword(pdev, 0xCC, &reg);
 		d->bus[0] =  GET_BITFIELD(reg, 0, 7);
 		d->bus[1] =  GET_BITFIELD(reg, 8, 15);
@@ -209,7 +211,7 @@ static int get_all_munits(const struct munit *m)
 			if (i == NUM_IMC)
 				goto fail;
 		}
-		d = get_skx_dev(pdev->bus->number, m->busidx);
+		d = get_skx_dev(pdev->bus, m->busidx);
 		if (!d)
 			goto fail;