arch/x86/mm/amdtopology.c

   1 /*
   2  * AMD NUMA support.
   3  * Discover the memory map and associated nodes.
   4  *
   5  * This version reads it directly from the AMD 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/nodemask.h>
  13 #include <linux/memblock.h>
  14 #include <linux/bootmem.h>
  15
  16 #include <asm/io.h>
  17 #include <linux/pci_ids.h>
  18 #include <linux/acpi.h>
  19 #include <asm/types.h>
  20 #include <asm/mmzone.h>
  21 #include <asm/proto.h>
  22 #include <asm/e820.h>
  23 #include <asm/pci-direct.h>
  24 #include <asm/numa.h>
  25 #include <asm/mpspec.h>
  26 #include <asm/apic.h>
  27 #include <asm/amd_nb.h>
  28
  29 static unsigned char __initdata nodeids[8];
  30
  31 static __init int find_northbridge(void)
  32 {
  33         int num;
  34
  35         for (num = 0; num < 32; num++) {
  36                 u32 header;
  37
  38                 header = read_pci_config(0, num, 0, 0x00);
  39                 if (header != (PCI_VENDOR_ID_AMD | (0x1100<<16)) &&
  40                         header != (PCI_VENDOR_ID_AMD | (0x1200<<16)) &&
  41                         header != (PCI_VENDOR_ID_AMD | (0x1300<<16)))
  42                         continue;
  43
  44                 header = read_pci_config(0, num, 1, 0x00);
  45                 if (header != (PCI_VENDOR_ID_AMD | (0x1101<<16)) &&
  46                         header != (PCI_VENDOR_ID_AMD | (0x1201<<16)) &&
  47                         header != (PCI_VENDOR_ID_AMD | (0x1301<<16)))
  48                         continue;
  49                 return num;
  50         }
  51
  52         return -ENOENT;
  53 }
  54
  55 static __init void early_get_boot_cpu_id(void)
  56 {
  57         /*
  58          * need to get the APIC ID of the BSP so can use that to
  59          * create apicid_to_node in amd_scan_nodes()
  60          */
  61 #ifdef CONFIG_X86_MPPARSE
  62         /*
  63          * get boot-time SMP configuration:
  64          */
  65         if (smp_found_config)
  66                 early_get_smp_config();
  67 #endif
  68 }
  69
  70 int __init amd_numa_init(void)
  71 {
  72         u64 start = PFN_PHYS(0);
  73         u64 end = PFN_PHYS(max_pfn);
  74         unsigned numnodes;
  75         u64 prevbase;
  76         int i, j, nb;
  77         u32 nodeid, reg;
  78         unsigned int bits, cores, apicid_base;
  79
  80         if (!early_pci_allowed())
  81                 return -EINVAL;
  82
  83         nb = find_northbridge();
  84         if (nb < 0)
  85                 return nb;
  86
  87         pr_info("Scanning NUMA topology in Northbridge %d\n", nb);
  88
  89         reg = read_pci_config(0, nb, 0, 0x60);
  90         numnodes = ((reg >> 4) & 0xF) + 1;
  91         if (numnodes <= 1)
  92                 return -ENOENT;
  93
  94         pr_info("Number of physical nodes %d\n", numnodes);
  95
  96         prevbase = 0;
  97         for (i = 0; i < 8; i++) {
  98                 u64 base, limit;
  99
 100                 base = read_pci_config(0, nb, 1, 0x40 + i*8);
 101                 limit = read_pci_config(0, nb, 1, 0x44 + i*8);
 102
 103                 nodeids[i] = nodeid = limit & 7;
 104                 if ((base & 3) == 0) {
 105                         if (i < numnodes)
 106                                 pr_info("Skipping disabled node %d\n", i);
 107                         continue;
 108                 }
 109                 if (nodeid >= numnodes) {
 110                         pr_info("Ignoring excess node %d (%Lx:%Lx)\n", nodeid,
 111                                 base, limit);
 112                         continue;
 113                 }
 114
 115                 if (!limit) {
 116                         pr_info("Skipping node entry %d (base %Lx)\n",
 117                                 i, base);
 118                         continue;
 119                 }
 120                 if ((base >> 8) & 3 || (limit >> 8) & 3) {
 121                         pr_err("Node %d using interleaving mode %Lx/%Lx\n",
 122                                nodeid, (base >> 8) & 3, (limit >> 8) & 3);
 123                         return -EINVAL;
 124                 }
 125                 if (node_isset(nodeid, numa_nodes_parsed)) {
 126                         pr_info("Node %d already present, skipping\n",
 127                                 nodeid);
 128                         continue;
 129                 }
 130
 131                 limit >>= 16;
 132                 limit++;
 133                 limit <<= 24;
 134
 135                 if (limit > end)
 136                         limit = end;
 137                 if (limit <= base)
 138                         continue;
 139
 140                 base >>= 16;
 141                 base <<= 24;
 142
 143                 if (base < start)
 144                         base = start;
 145                 if (limit > end)
 146                         limit = end;
 147                 if (limit == base) {
 148                         pr_err("Empty node %d\n", nodeid);
 149                         continue;
 150                 }
 151                 if (limit < base) {
 152                         pr_err("Node %d bogus settings %Lx-%Lx.\n",
 153                                nodeid, base, limit);
 154                         continue;
 155                 }
 156
 157                 /* Could sort here, but pun for now. Should not happen anyroads. */
 158                 if (prevbase > base) {
 159                         pr_err("Node map not sorted %Lx,%Lx\n",
 160                                prevbase, base);
 161                         return -EINVAL;
 162                 }
 163
 164                 pr_info("Node %d MemBase %016Lx Limit %016Lx\n",
 165                         nodeid, base, limit);
 166
 167                 prevbase = base;
 168                 numa_add_memblk(nodeid, base, limit);
 169                 node_set(nodeid, numa_nodes_parsed);
 170         }
 171
 172         if (!nodes_weight(numa_nodes_parsed))
 173                 return -ENOENT;
 174
 175         /*
 176          * We seem to have valid NUMA configuration.  Map apicids to nodes
 177          * using the coreid bits from early_identify_cpu.
 178          */
 179         bits = boot_cpu_data.x86_coreid_bits;
 180         cores = 1 << bits;
 181         apicid_base = 0;
 182
 183         /* get the APIC ID of the BSP early for systems with apicid lifting */
 184         early_get_boot_cpu_id();
 185         if (boot_cpu_physical_apicid > 0) {
 186                 pr_info("BSP APIC ID: %02x\n", boot_cpu_physical_apicid);
 187                 apicid_base = boot_cpu_physical_apicid;
 188         }
 189
 190         for_each_node_mask(i, numa_nodes_parsed)
 191                 for (j = apicid_base; j < cores + apicid_base; j++)
 192                         set_apicid_to_node((i << bits) + j, i);
 193
 194         return 0;
 195 }