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
   6 /*
   7  * This discovers the pcibus <-> node mapping on AMD K8.
   8  *
   9  * RED-PEN need to call this again on PCI hotplug
  10  * RED-PEN empty cpus get reported wrong
  11  */
  12
  13 #define NODE_ID_REGISTER 0x60
  14 #define NODE_ID(dword) (dword & 0x07)
  15 #define LDT_BUS_NUMBER_REGISTER_0 0x94
  16 #define LDT_BUS_NUMBER_REGISTER_1 0xB4
  17 #define LDT_BUS_NUMBER_REGISTER_2 0xD4
  18 #define NR_LDT_BUS_NUMBER_REGISTERS 3
  19 #define SECONDARY_LDT_BUS_NUMBER(dword) ((dword >> 8) & 0xFF)
  20 #define SUBORDINATE_LDT_BUS_NUMBER(dword) ((dword >> 16) & 0xFF)
  21 #define PCI_DEVICE_ID_K8HTCONFIG 0x1100
  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         struct pci_dev *nb_dev = NULL;
  32         int i, j, printed;
  33         u32 ldtbus, nid;
  34         static int lbnr[3] = {
  35                 LDT_BUS_NUMBER_REGISTER_0,
  36                 LDT_BUS_NUMBER_REGISTER_1,
  37                 LDT_BUS_NUMBER_REGISTER_2
  38         };
  39
  40         while ((nb_dev = pci_get_device(PCI_VENDOR_ID_AMD,
  41                         PCI_DEVICE_ID_K8HTCONFIG, nb_dev))) {
  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                         if (!(SECONDARY_LDT_BUS_NUMBER(ldtbus) == 0
  52                                 && SUBORDINATE_LDT_BUS_NUMBER(ldtbus) == 0)) {
  53                                 for (j = SECONDARY_LDT_BUS_NUMBER(ldtbus);
  54                                      j <= SUBORDINATE_LDT_BUS_NUMBER(ldtbus);
  55                                      j++)
  56                                         pci_bus_to_cpumask[j] =
  57                                                 node_to_cpumask(NODE_ID(nid));
  58                         }
  59                 }
  60         }
  61
  62         /* quick sanity check */
  63         printed = 0;
  64         for (i = 0; i < 256; i++) {
  65                 if (cpus_empty(pci_bus_to_cpumask[i])) {
  66                         pci_bus_to_cpumask[i] = CPU_MASK_ALL;
  67                         if (printed)
  68                                 continue;
  69                         printk(KERN_ERR
  70                                "k8-bus.c: some busses have empty cpu mask\n");
  71                         printed = 1;
  72                 }
  73         }
  74
  75         return 0;
  76 }
  77
  78 fs_initcall(fill_mp_bus_to_cpumask);