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         int found = 0;
  49         u32 reg;
  50         unsigned numnodes;
  51         nodemask_t nodes_parsed;
  52
  53         nodes_clear(nodes_parsed);
  54
  55         nb = find_northbridge();
  56         if (nb < 0)
  57                 return nb;
  58
  59         printk(KERN_INFO "Scanning NUMA topology in Northbridge %d\n", nb);
  60
  61         reg = read_pci_config(0, nb, 0, 0x60);
  62         numnodes = ((reg >> 4) & 0xF) + 1;
  63
  64         printk(KERN_INFO "Number of nodes %d\n", numnodes);
  65
  66         memset(&nodes,0,sizeof(nodes));
  67         prevbase = 0;
  68         for (i = 0; i < 8; i++) {
  69                 unsigned long base,limit;
  70
  71                 base = read_pci_config(0, nb, 1, 0x40 + i*8);
  72                 limit = read_pci_config(0, nb, 1, 0x44 + i*8);
  73
  74                 nodeid = limit & 7;
  75                 if ((base & 3) == 0) {
  76                         if (i < numnodes)
  77                                 printk("Skipping disabled node %d\n", i);
  78                         continue;
  79                 }
  80                 if (nodeid >= numnodes) {
  81                         printk("Ignoring excess node %d (%lx:%lx)\n", nodeid,
  82                                base, limit);
  83                         continue;
  84                 }
  85
  86                 if (!limit) {
  87                         printk(KERN_INFO "Skipping node entry %d (base %lx)\n", i,
  88                                base);
  89                         continue;
  90                 }
  91                 if ((base >> 8) & 3 || (limit >> 8) & 3) {
  92                         printk(KERN_ERR "Node %d using interleaving mode %lx/%lx\n",
  93                                nodeid, (base>>8)&3, (limit>>8) & 3);
  94                         return -1;
  95                 }
  96                 if (node_isset(nodeid, nodes_parsed)) {
  97                         printk(KERN_INFO "Node %d already present. Skipping\n",
  98                                nodeid);
  99                         continue;
 100                 }
 101
 102                 limit >>= 16;
 103                 limit <<= 24;
 104                 limit |= (1<<24)-1;
 105
 106                 if (limit > end_pfn << PAGE_SHIFT)
 107                         limit = end_pfn << PAGE_SHIFT;
 108                 if (limit <= base)
 109                         continue;
 110
 111                 base >>= 16;
 112                 base <<= 24;
 113
 114                 if (base < start)
 115                         base = start;
 116                 if (limit > end)
 117                         limit = end;
 118                 if (limit == base) {
 119                         printk(KERN_ERR "Empty node %d\n", nodeid);
 120                         continue;
 121                 }
 122                 if (limit < base) {
 123                         printk(KERN_ERR "Node %d bogus settings %lx-%lx.\n",
 124                                nodeid, base, limit);
 125                         continue;
 126                 }
 127
 128                 /* Could sort here, but pun for now. Should not happen anyroads. */
 129                 if (prevbase > base) {
 130                         printk(KERN_ERR "Node map not sorted %lx,%lx\n",
 131                                prevbase,base);
 132                         return -1;
 133                 }
 134
 135                 printk(KERN_INFO "Node %d MemBase %016lx Limit %016lx\n",
 136                        nodeid, base, limit);
 137
 138                 found++;
 139
 140                 nodes[nodeid].start = base;
 141                 nodes[nodeid].end = limit;
 142
 143                 prevbase = base;
 144
 145                 node_set(nodeid, nodes_parsed);
 146         }
 147
 148         if (!found)
 149                 return -1;
 150
 151         memnode_shift = compute_hash_shift(nodes, numnodes);
 152         if (memnode_shift < 0) {
 153                 printk(KERN_ERR "No NUMA node hash function found. Contact maintainer\n");
 154                 return -1;
 155         }
 156         printk(KERN_INFO "Using node hash shift of %d\n", memnode_shift);
 157
 158         for (i = 0; i < 8; i++) {
 159                 if (nodes[i].start != nodes[i].end) {
 160                         /* assume 1:1 NODE:CPU */
 161                         cpu_to_node[i] = i;
 162                         setup_node_bootmem(i, nodes[i].start, nodes[i].end);
 163                 }
 164         }
 165
 166         numa_init_array();
 167         return 0;
 168 }