arch/x86_64/mm/k8topology.c

   1 /*
   2  * AMD K8 NUMA support.
   3  * Discover the memory map and associated nodes.
   4  *
   5  * This version reads it directly from the K8 northbridge.
   6  *
   7  * Copyright 2002,2003 Andi Kleen, SuSE Labs.
   8  */
   9 #include <linux/kernel.h>
  10 #include <linux/init.h>
  11 #include <linux/string.h>
  12 #include <linux/module.h>
  13 #include <linux/nodemask.h>
  14 #include <asm/io.h>
  15 #include <linux/pci_ids.h>
  16 #include <asm/types.h>
  17 #include <asm/mmzone.h>
  18 #include <asm/proto.h>
  19 #include <asm/e820.h>
  20 #include <asm/pci-direct.h>
  21 #include <asm/numa.h>
  22
  23 static __init int find_northbridge(void)
  24 {
  25         int num;
  26
  27         for (num = 0; num < 32; num++) {
  28                 u32 header;
  29
  30                 header = read_pci_config(0, num, 0, 0x00);
  31                 if (header != (PCI_VENDOR_ID_AMD | (0x1100<<16)))
  32                         continue;
  33
  34                 header = read_pci_config(0, num, 1, 0x00);
  35                 if (header != (PCI_VENDOR_ID_AMD | (0x1101<<16)))
  36                         continue;
  37                 return num;
  38         }
  39
  40         return -1;
  41 }
  42
  43 int __init k8_scan_nodes(unsigned long start, unsigned long end)
  44 {
  45         unsigned long prevbase;
  46         struct node nodes[8];
  47         int nodeid, i, nb;
  48         unsigned char nodeids[8];
  49         int found = 0;
  50         u32 reg;
  51         unsigned numnodes;
  52         nodemask_t nodes_parsed;
  53         unsigned dualcore = 0;
  54
  55         nodes_clear(nodes_parsed);
  56
  57         nb = find_northbridge();
  58         if (nb < 0)
  59                 return nb;
  60
  61         printk(KERN_INFO "Scanning NUMA topology in Northbridge %d\n", nb);
  62
  63         reg = read_pci_config(0, nb, 0, 0x60);
  64         numnodes = ((reg >> 4) & 0xF) + 1;
  65
  66         printk(KERN_INFO "Number of nodes %d\n", numnodes);
  67
  68         memset(&nodes,0,sizeof(nodes));
  69         prevbase = 0;
  70         for (i = 0; i < 8; i++) {
  71                 unsigned long base,limit;
  72                 u32 nodeid;
  73
  74                 /* Undefined before E stepping, but hopefully 0 */
  75                 dualcore |= ((read_pci_config(0, nb, 3, 0xe8) >> 12) & 3) == 1;
  76                 base = read_pci_config(0, nb, 1, 0x40 + i*8);
  77                 limit = read_pci_config(0, nb, 1, 0x44 + i*8);
  78
  79                 nodeid = limit & 7;
  80                 nodeids[i] = nodeid;
  81                 if ((base & 3) == 0) {
  82                         if (i < numnodes)
  83                                 printk("Skipping disabled node %d\n", i);
  84                         continue;
  85                 }
  86                 if (nodeid >= numnodes) {
  87                         printk("Ignoring excess node %d (%lx:%lx)\n", nodeid,
  88                                base, limit);
  89                         continue;
  90                 }
  91
  92                 if (!limit) {
  93                         printk(KERN_INFO "Skipping node entry %d (base %lx)\n", i,
  94                                base);
  95                         continue;
  96                 }
  97                 if ((base >> 8) & 3 || (limit >> 8) & 3) {
  98                         printk(KERN_ERR "Node %d using interleaving mode %lx/%lx\n",
  99                                nodeid, (base>>8)&3, (limit>>8) & 3);
 100                         return -1;
 101                 }
 102                 if (node_isset(nodeid, nodes_parsed)) {
 103                         printk(KERN_INFO "Node %d already present. Skipping\n",
 104                                nodeid);
 105                         continue;
 106                 }
 107
 108                 limit >>= 16;
 109                 limit <<= 24;
 110                 limit |= (1<<24)-1;
 111                 limit++;
 112
 113                 if (limit > end_pfn << PAGE_SHIFT)
 114                         limit = end_pfn << PAGE_SHIFT;
 115                 if (limit <= base)
 116                         continue;
 117
 118                 base >>= 16;
 119                 base <<= 24;
 120
 121                 if (base < start)
 122                         base = start;
 123                 if (limit > end)
 124                         limit = end;
 125                 if (limit == base) {
 126                         printk(KERN_ERR "Empty node %d\n", nodeid);
 127                         continue;
 128                 }
 129                 if (limit < base) {
 130                         printk(KERN_ERR "Node %d bogus settings %lx-%lx.\n",
 131                                nodeid, base, limit);
 132                         continue;
 133                 }
 134
 135                 /* Could sort here, but pun for now. Should not happen anyroads. */
 136                 if (prevbase > base) {
 137                         printk(KERN_ERR "Node map not sorted %lx,%lx\n",
 138                                prevbase,base);
 139                         return -1;
 140                 }
 141
 142                 printk(KERN_INFO "Node %d MemBase %016lx Limit %016lx\n",
 143                        nodeid, base, limit);
 144
 145                 found++;
 146
 147                 nodes[nodeid].start = base;
 148                 nodes[nodeid].end = limit;
 149
 150                 prevbase = base;
 151
 152                 node_set(nodeid, nodes_parsed);
 153         }
 154
 155         if (!found)
 156                 return -1;
 157
 158         memnode_shift = compute_hash_shift(nodes, numnodes);
 159         if (memnode_shift < 0) {
 160                 printk(KERN_ERR "No NUMA node hash function found. Contact maintainer\n");
 161                 return -1;
 162         }
 163         printk(KERN_INFO "Using node hash shift of %d\n", memnode_shift);
 164
 165         for (i = 0; i < 8; i++) {
 166                 if (nodes[i].start != nodes[i].end) {
 167                         nodeid = nodeids[i];
 168                         apicid_to_node[nodeid << dualcore] = i;
 169                         apicid_to_node[(nodeid << dualcore) + dualcore] = i;
 170                         setup_node_bootmem(i, nodes[i].start, nodes[i].end);
 171                 }
 172         }
 173
 174         numa_init_array();
 175         return 0;
 176 }