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