arch/x86_64/pci/k8-bus.c

   1 #include <linux/init.h>
   2 #include <linux/pci.h>
   3 #include <asm/mpspec.h>
   4 #include <linux/cpumask.h>
   5 #include <asm/k8.h>
   6
   7 /*
   8  * This discovers the pcibus <-> node mapping on AMD K8.
   9  *
  10  * RED-PEN need to call this again on PCI hotplug
  11  * RED-PEN empty cpus get reported wrong
  12  */
  13
  14 #define NODE_ID_REGISTER 0x60
  15 #define NODE_ID(dword) (dword & 0x07)
  16 #define LDT_BUS_NUMBER_REGISTER_0 0x94
  17 #define LDT_BUS_NUMBER_REGISTER_1 0xB4
  18 #define LDT_BUS_NUMBER_REGISTER_2 0xD4
  19 #define NR_LDT_BUS_NUMBER_REGISTERS 3
  20 #define SECONDARY_LDT_BUS_NUMBER(dword) ((dword >> 8) & 0xFF)
  21 #define SUBORDINATE_LDT_BUS_NUMBER(dword) ((dword >> 16) & 0xFF)
  22
  23 /**
  24  * fill_mp_bus_to_cpumask()
  25  * fills the mp_bus_to_cpumask array based according to the LDT Bus Number
  26  * Registers found in the K8 northbridge
  27  */
  28 __init static int
  29 fill_mp_bus_to_cpumask(void)
  30 {
  31         int i, j, k;
  32         u32 ldtbus, nid;
  33         static int lbnr[3] = {
  34                 LDT_BUS_NUMBER_REGISTER_0,
  35                 LDT_BUS_NUMBER_REGISTER_1,
  36                 LDT_BUS_NUMBER_REGISTER_2
  37         };
  38
  39         cache_k8_northbridges();
  40         for (k = 0; k < num_k8_northbridges; k++) {
  41                 struct pci_dev *nb_dev = k8_northbridges[k];
  42                 pci_read_config_dword(nb_dev, NODE_ID_REGISTER, &nid);
  43
  44                 for (i = 0; i < NR_LDT_BUS_NUMBER_REGISTERS; i++) {
  45                         pci_read_config_dword(nb_dev, lbnr[i], &ldtbus);
  46                         /*
  47                          * if there are no busses hanging off of the current
  48                          * ldt link then both the secondary and subordinate
  49                          * bus number fields are set to 0.
  50                          *
  51                          * RED-PEN
  52                          * This is slightly broken because it assumes
  53                          * HT node IDs == Linux node ids, which is not always
  54                          * true. However it is probably mostly true.
  55                          */
  56                         if (!(SECONDARY_LDT_BUS_NUMBER(ldtbus) == 0
  57                                 && SUBORDINATE_LDT_BUS_NUMBER(ldtbus) == 0)) {
  58                                 for (j = SECONDARY_LDT_BUS_NUMBER(ldtbus);
  59                                      j <= SUBORDINATE_LDT_BUS_NUMBER(ldtbus);
  60                                      j++) {
  61                                         struct pci_bus *bus;
  62                                         long node = NODE_ID(nid);
  63                                         /* Algorithm a bit dumb, but
  64                                            it shouldn't matter here */
  65                                         bus = pci_find_bus(0, j);
  66                                         if (!bus)
  67                                                 continue;
  68                                         if (!node_online(node))
  69                                                 node = 0;
  70                                         bus->sysdata = (void *)node;
  71                                 }
  72                         }
  73                 }
  74         }
  75
  76         return 0;
  77 }
  78
  79 fs_initcall(fill_mp_bus_to_cpumask);