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/module.h>
  13 #include <linux/nodemask.h>
  14 #include <linux/memblock.h>
  15 #include <linux/bootmem.h>
  16
  17 #include <asm/io.h>
  18 #include <linux/pci_ids.h>
  19 #include <linux/acpi.h>
  20 #include <asm/types.h>
  21 #include <asm/mmzone.h>
  22 #include <asm/proto.h>
  23 #include <asm/e820.h>
  24 #include <asm/pci-direct.h>
  25 #include <asm/numa.h>
  26 #include <asm/mpspec.h>
  27 #include <asm/apic.h>
  28 #include <asm/amd_nb.h>
  29
  30 static unsigned char __initdata nodeids[8];
  31
  32 static __init int find_northbridge(void)
  33 {
  34         int num;
  35
  36         for (num = 0; num < 32; num++) {
  37                 u32 header;
  38
  39                 header = read_pci_config(0, num, 0, 0x00);
  40                 if (header != (PCI_VENDOR_ID_AMD | (0x1100<<16)) &&
  41                         header != (PCI_VENDOR_ID_AMD | (0x1200<<16)) &&
  42                         header != (PCI_VENDOR_ID_AMD | (0x1300<<16)))
  43                         continue;
  44
  45                 header = read_pci_config(0, num, 1, 0x00);
  46                 if (header != (PCI_VENDOR_ID_AMD | (0x1101<<16)) &&
  47                         header != (PCI_VENDOR_ID_AMD | (0x1201<<16)) &&
  48                         header != (PCI_VENDOR_ID_AMD | (0x1301<<16)))
  49                         continue;
  50                 return num;
  51         }
  52
  53         return -ENOENT;
  54 }
  55
  56 static __init void early_get_boot_cpu_id(void)
  57 {
  58         /*
  59          * need to get the APIC ID of the BSP so can use that to
  60          * create apicid_to_node in amd_scan_nodes()
  61          */
  62 #ifdef CONFIG_X86_MPPARSE
  63         /*
  64          * get boot-time SMP configuration:
  65          */
  66         if (smp_found_config)
  67                 early_get_smp_config();
  68 #endif
  69 }
  70
  71 int __init amd_numa_init(void)
  72 {
  73         u64 start = PFN_PHYS(0);
  74         u64 end = PFN_PHYS(max_pfn);
  75         unsigned numnodes;
  76         u64 prevbase;
  77         int i, j, nb;
  78         u32 nodeid, reg;
  79         unsigned int bits, cores, apicid_base;
  80
  81         if (!early_pci_allowed())
  82                 return -EINVAL;
  83
  84         nb = find_northbridge();
  85         if (nb < 0)
  86                 return nb;
  87
  88         pr_info("Scanning NUMA topology in Northbridge %d\n", nb);
  89
  90         reg = read_pci_config(0, nb, 0, 0x60);
  91         numnodes = ((reg >> 4) & 0xF) + 1;
  92         if (numnodes <= 1)
  93                 return -ENOENT;
  94
  95         pr_info("Number of physical nodes %d\n", numnodes);
  96
  97         prevbase = 0;
  98         for (i = 0; i < 8; i++) {
  99                 u64 base, limit;
 100
 101                 base = read_pci_config(0, nb, 1, 0x40 + i*8);
 102                 limit = read_pci_config(0, nb, 1, 0x44 + i*8);
 103
 104                 nodeids[i] = nodeid = limit & 7;
 105                 if ((base & 3) == 0) {
 106                         if (i < numnodes)
 107                                 pr_info("Skipping disabled node %d\n", i);
 108                         continue;
 109                 }
 110                 if (nodeid >= numnodes) {
 111                         pr_info("Ignoring excess node %d (%Lx:%Lx)\n", nodeid,
 112                                 base, limit);
 113                         continue;
 114                 }
 115
 116                 if (!limit) {
 117                         pr_info("Skipping node entry %d (base %Lx)\n",
 118                                 i, base);
 119                         continue;
 120                 }
 121                 if ((base >> 8) & 3 || (limit >> 8) & 3) {
 122                         pr_err("Node %d using interleaving mode %Lx/%Lx\n",
 123                                nodeid, (base >> 8) & 3, (limit >> 8) & 3);
 124                         return -EINVAL;
 125                 }
 126                 if (node_isset(nodeid, numa_nodes_parsed)) {
 127                         pr_info("Node %d already present, skipping\n",
 128                                 nodeid);
 129                         continue;
 130                 }
 131
 132                 limit >>= 16;
 133                 limit <<= 24;
 134                 limit |= (1<<24)-1;
 135                 limit++;
 136
 137                 if (limit > end)
 138                         limit = end;
 139                 if (limit <= base)
 140                         continue;
 141
 142                 base >>= 16;
 143                 base <<= 24;
 144
 145                 if (base < start)
 146                         base = start;
 147                 if (limit > end)
 148                         limit = end;
 149                 if (limit == base) {
 150                         pr_err("Empty node %d\n", nodeid);
 151                         continue;
 152                 }
 153                 if (limit < base) {
 154                         pr_err("Node %d bogus settings %Lx-%Lx.\n",
 155                                nodeid, base, limit);
 156                         continue;
 157                 }
 158
 159                 /* Could sort here, but pun for now. Should not happen anyroads. */
 160                 if (prevbase > base) {
 161                         pr_err("Node map not sorted %Lx,%Lx\n",
 162                                prevbase, base);
 163                         return -EINVAL;
 164                 }
 165
 166                 pr_info("Node %d MemBase %016Lx Limit %016Lx\n",
 167                         nodeid, base, limit);
 168
 169                 prevbase = base;
 170                 numa_add_memblk(nodeid, base, limit);
 171                 node_set(nodeid, numa_nodes_parsed);
 172         }
 173
 174         if (!nodes_weight(numa_nodes_parsed))
 175                 return -ENOENT;
 176
 177         /*
 178          * We seem to have valid NUMA configuration.  Map apicids to nodes
 179          * using the coreid bits from early_identify_cpu.
 180          */
 181         bits = boot_cpu_data.x86_coreid_bits;
 182         cores = 1 << bits;
 183         apicid_base = 0;
 184
 185         /* get the APIC ID of the BSP early for systems with apicid lifting */
 186         early_get_boot_cpu_id();
 187         if (boot_cpu_physical_apicid > 0) {
 188                 pr_info("BSP APIC ID: %02x\n", boot_cpu_physical_apicid);
 189                 apicid_base = boot_cpu_physical_apicid;
 190         }
 191
 192         for_each_node_mask(i, numa_nodes_parsed)
 193                 for (j = apicid_base; j < cores + apicid_base; j++)
 194                         set_apicid_to_node((i << bits) + j, i);
 195
 196         return 0;
 197 }