blob: b50a7c7c47f8984b45329d07447a5b9cbb1447d3 [file] [log] [blame]
#include <linux/init.h>
#include <linux/pci.h>
#include <asm/mpspec.h>
#include <linux/cpumask.h>
#include <asm/k8.h>
/*
* This discovers the pcibus <-> node mapping on AMD K8.
*
* RED-PEN need to call this again on PCI hotplug
* RED-PEN empty cpus get reported wrong
*/
#define NODE_ID_REGISTER 0x60
#define NODE_ID(dword) (dword & 0x07)
#define LDT_BUS_NUMBER_REGISTER_0 0x94
#define LDT_BUS_NUMBER_REGISTER_1 0xB4
#define LDT_BUS_NUMBER_REGISTER_2 0xD4
#define NR_LDT_BUS_NUMBER_REGISTERS 3
#define SECONDARY_LDT_BUS_NUMBER(dword) ((dword >> 8) & 0xFF)
#define SUBORDINATE_LDT_BUS_NUMBER(dword) ((dword >> 16) & 0xFF)
/**
* fill_mp_bus_to_cpumask()
* fills the mp_bus_to_cpumask array based according to the LDT Bus Number
* Registers found in the K8 northbridge
*/
__init static int
fill_mp_bus_to_cpumask(void)
{
int i, j, k;
u32 ldtbus, nid;
static int lbnr[3] = {
LDT_BUS_NUMBER_REGISTER_0,
LDT_BUS_NUMBER_REGISTER_1,
LDT_BUS_NUMBER_REGISTER_2
};
cache_k8_northbridges();
for (k = 0; k < num_k8_northbridges; k++) {
struct pci_dev *nb_dev = k8_northbridges[k];
pci_read_config_dword(nb_dev, NODE_ID_REGISTER, &nid);
for (i = 0; i < NR_LDT_BUS_NUMBER_REGISTERS; i++) {
pci_read_config_dword(nb_dev, lbnr[i], &ldtbus);
/*
* if there are no busses hanging off of the current
* ldt link then both the secondary and subordinate
* bus number fields are set to 0.
*
* RED-PEN
* This is slightly broken because it assumes
* HT node IDs == Linux node ids, which is not always
* true. However it is probably mostly true.
*/
if (!(SECONDARY_LDT_BUS_NUMBER(ldtbus) == 0
&& SUBORDINATE_LDT_BUS_NUMBER(ldtbus) == 0)) {
for (j = SECONDARY_LDT_BUS_NUMBER(ldtbus);
j <= SUBORDINATE_LDT_BUS_NUMBER(ldtbus);
j++) {
struct pci_bus *bus;
long node = NODE_ID(nid);
/* Algorithm a bit dumb, but
it shouldn't matter here */
bus = pci_find_bus(0, j);
if (!bus)
continue;
if (!node_online(node))
node = 0;
bus->sysdata = (void *)node;
}
}
}
}
return 0;
}
fs_initcall(fill_mp_bus_to_cpumask);