linux/arch/x86/pci/mp_bus_to_node.c
Yinghai Lu 871d5f8dd0 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>
2008-04-26 23:41:04 +02:00

24 lines
430 B
C

#include <linux/pci.h>
#include <linux/init.h>
#include <linux/topology.h>
#define BUS_NR 256
static unsigned char mp_bus_to_node[BUS_NR];
void set_mp_bus_to_node(int busnum, int node)
{
if (busnum >= 0 && busnum < BUS_NR)
mp_bus_to_node[busnum] = (unsigned char) node;
}
int get_mp_bus_to_node(int busnum)
{
int node;
if (busnum < 0 || busnum > (BUS_NR - 1))
return 0;
node = mp_bus_to_node[busnum];
return node;
}