arch/x86/mm/amdtopology.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * AMD NUMA support.
   4  * Discover the memory map and associated nodes.
   5  *
   6  * This version reads it directly from the AMD northbridge.
   7  *
   8  * Copyright 2002,2003 Andi Kleen, SuSE Labs.
   9  */
  10 #include <linux/kernel.h>
  11 #include <linux/init.h>
  12 #include <linux/string.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/api.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 int __init amd_numa_init(void)
  57 {
  58         u64 start = PFN_PHYS(0);
  59         u64 end = PFN_PHYS(max_pfn);
  60         unsigned numnodes;
  61         u64 prevbase;
  62         int i, j, nb;
  63         u32 nodeid, reg;
  64         unsigned int bits, cores, apicid_base;
  65
  66         if (!early_pci_allowed())
  67                 return -EINVAL;
  68
  69         nb = find_northbridge();
  70         if (nb < 0)
  71                 return nb;
  72
  73         pr_info("Scanning NUMA topology in Northbridge %d\n", nb);
  74
  75         reg = read_pci_config(0, nb, 0, 0x60);
  76         numnodes = ((reg >> 4) & 0xF) + 1;
  77         if (numnodes <= 1)
  78                 return -ENOENT;
  79
  80         pr_info("Number of physical nodes %d\n", numnodes);
  81
  82         prevbase = 0;
  83         for (i = 0; i < 8; i++) {
  84                 u64 base, limit;
  85
  86                 base = read_pci_config(0, nb, 1, 0x40 + i*8);
  87                 limit = read_pci_config(0, nb, 1, 0x44 + i*8);
  88
  89                 nodeids[i] = nodeid = limit & 7;
  90                 if ((base & 3) == 0) {
  91                         if (i < numnodes)
  92                                 pr_info("Skipping disabled node %d\n", i);
  93                         continue;
  94                 }
  95                 if (nodeid >= numnodes) {
  96                         pr_info("Ignoring excess node %d (%Lx:%Lx)\n", nodeid,
  97                                 base, limit);
  98                         continue;
  99                 }
 100
 101                 if (!limit) {
 102                         pr_info("Skipping node entry %d (base %Lx)\n",
 103                                 i, base);
 104                         continue;
 105                 }
 106                 if ((base >> 8) & 3 || (limit >> 8) & 3) {
 107                         pr_err("Node %d using interleaving mode %Lx/%Lx\n",
 108                                nodeid, (base >> 8) & 3, (limit >> 8) & 3);
 109                         return -EINVAL;
 110                 }
 111                 if (node_isset(nodeid, numa_nodes_parsed)) {
 112                         pr_info("Node %d already present, skipping\n",
 113                                 nodeid);
 114                         continue;
 115                 }
 116
 117                 limit >>= 16;
 118                 limit++;
 119                 limit <<= 24;
 120
 121                 if (limit > end)
 122                         limit = end;
 123                 if (limit <= base)
 124                         continue;
 125
 126                 base >>= 16;
 127                 base <<= 24;
 128
 129                 if (base < start)
 130                         base = start;
 131                 if (limit > end)
 132                         limit = end;
 133                 if (limit == base) {
 134                         pr_err("Empty node %d\n", nodeid);
 135                         continue;
 136                 }
 137                 if (limit < base) {
 138                         pr_err("Node %d bogus settings %Lx-%Lx.\n",
 139                                nodeid, base, limit);
 140                         continue;
 141                 }
 142
 143                 /* Could sort here, but pun for now. Should not happen anyroads. */
 144                 if (prevbase > base) {
 145                         pr_err("Node map not sorted %Lx,%Lx\n",
 146                                prevbase, base);
 147                         return -EINVAL;
 148                 }
 149
 150                 pr_info("Node %d MemBase %016Lx Limit %016Lx\n",
 151                         nodeid, base, limit);
 152
 153                 prevbase = base;
 154                 numa_add_memblk(nodeid, base, limit);
 155                 node_set(nodeid, numa_nodes_parsed);
 156         }
 157
 158         if (!nodes_weight(numa_nodes_parsed))
 159                 return -ENOENT;
 160
 161         /*
 162          * We seem to have valid NUMA configuration.  Map apicids to nodes
 163          * using the coreid bits from early_identify_cpu.
 164          */
 165         bits = boot_cpu_data.x86_coreid_bits;
 166         cores = 1 << bits;
 167         apicid_base = 0;
 168
 169         /*
 170          * get boot-time SMP configuration:
 171          */
 172         early_get_smp_config();
 173
 174         if (boot_cpu_physical_apicid > 0) {
 175                 pr_info("BSP APIC ID: %02x\n", boot_cpu_physical_apicid);
 176                 apicid_base = boot_cpu_physical_apicid;
 177         }
 178
 179         for_each_node_mask(i, numa_nodes_parsed)
 180                 for (j = apicid_base; j < cores + apicid_base; j++)
 181                         set_apicid_to_node((i << bits) + j, i);
 182
 183         return 0;
 184 }