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
  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/api.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 int __init amd_numa_init(void)
  56 {
  57         u64 start = PFN_PHYS(0);
  58         u64 end = PFN_PHYS(max_pfn);
  59         unsigned numnodes;
  60         u64 prevbase;
  61         int i, j, nb;
  62         u32 nodeid, reg;
  63         unsigned int bits, cores, apicid_base;
  64
  65         if (!early_pci_allowed())
  66                 return -EINVAL;
  67
  68         nb = find_northbridge();
  69         if (nb < 0)
  70                 return nb;
  71
  72         pr_info("Scanning NUMA topology in Northbridge %d\n", nb);
  73
  74         reg = read_pci_config(0, nb, 0, 0x60);
  75         numnodes = ((reg >> 4) & 0xF) + 1;
  76         if (numnodes <= 1)
  77                 return -ENOENT;
  78
  79         pr_info("Number of physical nodes %d\n", numnodes);
  80
  81         prevbase = 0;
  82         for (i = 0; i < 8; i++) {
  83                 u64 base, limit;
  84
  85                 base = read_pci_config(0, nb, 1, 0x40 + i*8);
  86                 limit = read_pci_config(0, nb, 1, 0x44 + i*8);
  87
  88                 nodeids[i] = nodeid = limit & 7;
  89                 if ((base & 3) == 0) {
  90                         if (i < numnodes)
  91                                 pr_info("Skipping disabled node %d\n", i);
  92                         continue;
  93                 }
  94                 if (nodeid >= numnodes) {
  95                         pr_info("Ignoring excess node %d (%Lx:%Lx)\n", nodeid,
  96                                 base, limit);
  97                         continue;
  98                 }
  99
 100                 if (!limit) {
 101                         pr_info("Skipping node entry %d (base %Lx)\n",
 102                                 i, base);
 103                         continue;
 104                 }
 105                 if ((base >> 8) & 3 || (limit >> 8) & 3) {
 106                         pr_err("Node %d using interleaving mode %Lx/%Lx\n",
 107                                nodeid, (base >> 8) & 3, (limit >> 8) & 3);
 108                         return -EINVAL;
 109                 }
 110                 if (node_isset(nodeid, numa_nodes_parsed)) {
 111                         pr_info("Node %d already present, skipping\n",
 112                                 nodeid);
 113                         continue;
 114                 }
 115
 116                 limit >>= 16;
 117                 limit++;
 118                 limit <<= 24;
 119
 120                 if (limit > end)
 121                         limit = end;
 122                 if (limit <= base)
 123                         continue;
 124
 125                 base >>= 16;
 126                 base <<= 24;
 127
 128                 if (base < start)
 129                         base = start;
 130                 if (limit > end)
 131                         limit = end;
 132                 if (limit == base) {
 133                         pr_err("Empty node %d\n", nodeid);
 134                         continue;
 135                 }
 136                 if (limit < base) {
 137                         pr_err("Node %d bogus settings %Lx-%Lx.\n",
 138                                nodeid, base, limit);
 139                         continue;
 140                 }
 141
 142                 /* Could sort here, but pun for now. Should not happen anyroads. */
 143                 if (prevbase > base) {
 144                         pr_err("Node map not sorted %Lx,%Lx\n",
 145                                prevbase, base);
 146                         return -EINVAL;
 147                 }
 148
 149                 pr_info("Node %d MemBase %016Lx Limit %016Lx\n",
 150                         nodeid, base, limit);
 151
 152                 prevbase = base;
 153                 numa_add_memblk(nodeid, base, limit);
 154                 node_set(nodeid, numa_nodes_parsed);
 155         }
 156
 157         if (!nodes_weight(numa_nodes_parsed))
 158                 return -ENOENT;
 159
 160         /*
 161          * We seem to have valid NUMA configuration.  Map apicids to nodes
 162          * using the coreid bits from early_identify_cpu.
 163          */
 164         bits = boot_cpu_data.x86_coreid_bits;
 165         cores = 1 << bits;
 166         apicid_base = 0;
 167
 168         /*
 169          * get boot-time SMP configuration:
 170          */
 171         early_get_smp_config();
 172
 173         if (boot_cpu_physical_apicid > 0) {
 174                 pr_info("BSP APIC ID: %02x\n", boot_cpu_physical_apicid);
 175                 apicid_base = boot_cpu_physical_apicid;
 176         }
 177
 178         for_each_node_mask(i, numa_nodes_parsed)
 179                 for (j = apicid_base; j < cores + apicid_base; j++)
 180                         set_apicid_to_node((i << bits) + j, i);
 181
 182         return 0;
 183 }