x86: get mp_bus_to_node early

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

workaround: pcibus_to_node(bus) is used when we want to get 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 use bus->sysdata for nodeid.

the problem is when pci_add_device is called, bus->sysdata is not assigned
correct nodeid yet. the result will be numa_node always is 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 get_mp_bus_to_node
could get correct node for sysdata in root bus.

in scanning of root bus, all child bus will take parent bus sysdata. So all
pci_device->dev.numa_node will be assigned correctly 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 one update version to pci_sysdata and jeff's pci_domain patch.

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>

1 files changed, 13 insertions, 0 deletions

diff --git a/include/asm-x86/topology.h b/include/asm-x86/topology.h
index 22073268b481..f0cac2cfa83f 100644
--- a/include/asm-x86/topology.h
+++ b/include/asm-x86/topology.h
@@ -198,4 +198,17 @@ extern cpumask_t cpu_coregroup_map(int cpu);
 #define smt_capable()			(smp_num_siblings > 1)
 #endif
 
+#ifdef CONFIG_NUMA
+int get_mp_bus_to_node(int busnum);
+void set_mp_bus_to_node(int busnum, int node);
+#else
+static inline int get_mp_bus_to_node(int busnum)
+{
+	return 0;
+}
+static inline void set_mp_bus_to_node(int busnum, int node)
+{
+}
+#endif
+
 #endif