x86: get mp_bus_to_node early

Currently, on an amd k8 system with multi ht chains, the numa_node of
pci devices under /sys/devices/pci0000:80/* is always 0, even if that
chain is on node 1 or 2 or 3.

Workaround: pcibus_to_node(bus) is used when we want to get the node that
pci_device is on.

In struct device, we already have numa_node member, and we could use
dev_to_node()/set_dev_node() to get and set numa_node in the device.
set_dev_node is called in pci_device_add() with pcibus_to_node(bus),
and pcibus_to_node uses bus->sysdata for nodeid.

The problem is when pci_add_device is called, bus->sysdata is not assigned
correct nodeid yet. The result is that numa_node will always be 0.

pcibios_scan_root and pci_scan_root could take sysdata. So we need to get
mp_bus_to_node mapping before these two are called, and thus
get_mp_bus_to_node could get correct node for sysdata in root bus.

In scanning of the root bus, all child busses will take parent bus sysdata.
So all pci_device->dev.numa_node will be assigned correctly and automatically.

Later we could use dev_to_node(&pci_dev->dev) to get numa_node, and we
could also could make other bus specific device get the correct numa_node
too.

This is an updated version of pci_sysdata and Jeff's pci_domain patch.

[ mingo@elte.hu: build fix ]

Signed-off-by: Yinghai Lu <yinghai.lu@sun.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
index 2664cb3..1a9c0c6 100644
--- a/arch/x86/pci/acpi.c
+++ b/arch/x86/pci/acpi.c
@@ -191,7 +191,10 @@
 {
 	struct pci_bus *bus;
 	struct pci_sysdata *sd;
+	int node;
+#ifdef CONFIG_ACPI_NUMA
 	int pxm;
+#endif
 
 	dmi_check_system(acpi_pciprobe_dmi_table);
 
@@ -201,6 +204,17 @@
 		return NULL;
 	}
 
+	node = -1;
+#ifdef CONFIG_ACPI_NUMA
+	pxm = acpi_get_pxm(device->handle);
+	if (pxm >= 0)
+		node = pxm_to_node(pxm);
+	if (node != -1)
+		set_mp_bus_to_node(busnum, node);
+	else
+		node = get_mp_bus_to_node(busnum);
+#endif
+
 	/* Allocate per-root-bus (not per bus) arch-specific data.
 	 * TODO: leak; this memory is never freed.
 	 * It's arguable whether it's worth the trouble to care.
@@ -212,13 +226,7 @@
 	}
 
 	sd->domain = domain;
-	sd->node = -1;
-
-	pxm = acpi_get_pxm(device->handle);
-#ifdef CONFIG_ACPI_NUMA
-	if (pxm >= 0)
-		sd->node = pxm_to_node(pxm);
-#endif
+	sd->node = node;
 	/*
 	 * Maybe the desired pci bus has been already scanned. In such case
 	 * it is unnecessary to scan the pci bus with the given domain,busnum.
@@ -238,9 +246,9 @@
 		kfree(sd);
 
 #ifdef CONFIG_ACPI_NUMA
-	if (bus != NULL) {
+	if (bus) {
 		if (pxm >= 0) {
-			printk("bus %d -> pxm %d -> node %d\n",
+			printk(KERN_DEBUG "bus %02x -> pxm %d -> node %d\n",
 				busnum, pxm, pxm_to_node(pxm));
 		}
 	}
@@ -248,7 +256,6 @@
 
 	if (bus && (pci_probe & PCI_USE__CRS))
 		get_current_resources(device, busnum, domain, bus);
-	
 	return bus;
 }