arch/x86_64/mm/srat.c

   1 /*
   2  * ACPI 3.0 based NUMA setup
   3  * Copyright 2004 Andi Kleen, SuSE Labs.
   4  *
   5  * Reads the ACPI SRAT table to figure out what memory belongs to which CPUs.
   6  *
   7  * Called from acpi_numa_init while reading the SRAT and SLIT tables.
   8  * Assumes all memory regions belonging to a single proximity domain
   9  * are in one chunk. Holes between them will be included in the node.
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/acpi.h>
  14 #include <linux/mmzone.h>
  15 #include <linux/bitmap.h>
  16 #include <linux/module.h>
  17 #include <linux/topology.h>
  18 #include <asm/proto.h>
  19 #include <asm/numa.h>
  20
  21 static struct acpi_table_slit *acpi_slit;
  22
  23 static nodemask_t nodes_parsed __initdata;
  24 static nodemask_t nodes_found __initdata;
  25 static struct node nodes[MAX_NUMNODES] __initdata;
  26 static __u8  pxm2node[256] = { [0 ... 255] = 0xff };
  27
  28 static int node_to_pxm(int n);
  29
  30 int pxm_to_node(int pxm)
  31 {
  32         if ((unsigned)pxm >= 256)
  33                 return 0;
  34         return pxm2node[pxm];
  35 }
  36
  37 static __init int setup_node(int pxm)
  38 {
  39         unsigned node = pxm2node[pxm];
  40         if (node == 0xff) {
  41                 if (nodes_weight(nodes_found) >= MAX_NUMNODES)
  42                         return -1;
  43                 node = first_unset_node(nodes_found);
  44                 node_set(node, nodes_found);
  45                 pxm2node[pxm] = node;
  46         }
  47         return pxm2node[pxm];
  48 }
  49
  50 static __init int conflicting_nodes(unsigned long start, unsigned long end)
  51 {
  52         int i;
  53         for_each_node_mask(i, nodes_parsed) {
  54                 struct node *nd = &nodes[i];
  55                 if (nd->start == nd->end)
  56                         continue;
  57                 if (nd->end > start && nd->start < end)
  58                         return i;
  59                 if (nd->end == end && nd->start == start)
  60                         return i;
  61         }
  62         return -1;
  63 }
  64
  65 static __init void cutoff_node(int i, unsigned long start, unsigned long end)
  66 {
  67         struct node *nd = &nodes[i];
  68         if (nd->start < start) {
  69                 nd->start = start;
  70                 if (nd->end < nd->start)
  71                         nd->start = nd->end;
  72         }
  73         if (nd->end > end) {
  74                 if (!(end & 0xfff))
  75                         end--;
  76                 nd->end = end;
  77                 if (nd->start > nd->end)
  78                         nd->start = nd->end;
  79         }
  80 }
  81
  82 static __init void bad_srat(void)
  83 {
  84         int i;
  85         printk(KERN_ERR "SRAT: SRAT not used.\n");
  86         acpi_numa = -1;
  87         for (i = 0; i < MAX_LOCAL_APIC; i++)
  88                 apicid_to_node[i] = NUMA_NO_NODE;
  89 }
  90
  91 static __init inline int srat_disabled(void)
  92 {
  93         return numa_off || acpi_numa < 0;
  94 }
  95
  96 /* Callback for SLIT parsing */
  97 void __init acpi_numa_slit_init(struct acpi_table_slit *slit)
  98 {
  99         acpi_slit = slit;
 100 }
 101
 102 /* Callback for Proximity Domain -> LAPIC mapping */
 103 void __init
 104 acpi_numa_processor_affinity_init(struct acpi_table_processor_affinity *pa)
 105 {
 106         int pxm, node;
 107         if (srat_disabled() || pa->flags.enabled == 0)
 108                 return;
 109         pxm = pa->proximity_domain;
 110         node = setup_node(pxm);
 111         if (node < 0) {
 112                 printk(KERN_ERR "SRAT: Too many proximity domains %x\n", pxm);
 113                 bad_srat();
 114                 return;
 115         }
 116         apicid_to_node[pa->apic_id] = node;
 117         acpi_numa = 1;
 118         printk(KERN_INFO "SRAT: PXM %u -> APIC %u -> Node %u\n",
 119                pxm, pa->apic_id, node);
 120 }
 121
 122 /* Callback for parsing of the Proximity Domain <-> Memory Area mappings */
 123 void __init
 124 acpi_numa_memory_affinity_init(struct acpi_table_memory_affinity *ma)
 125 {
 126         struct node *nd;
 127         unsigned long start, end;
 128         int node, pxm;
 129         int i;
 130
 131         if (srat_disabled() || ma->flags.enabled == 0)
 132                 return;
 133         pxm = ma->proximity_domain;
 134         node = setup_node(pxm);
 135         if (node < 0) {
 136                 printk(KERN_ERR "SRAT: Too many proximity domains.\n");
 137                 bad_srat();
 138                 return;
 139         }
 140         start = ma->base_addr_lo | ((u64)ma->base_addr_hi << 32);
 141         end = start + (ma->length_lo | ((u64)ma->length_hi << 32));
 142         /* It is fine to add this area to the nodes data it will be used later*/
 143         if (ma->flags.hot_pluggable == 1)
 144                 printk(KERN_INFO "SRAT: hot plug zone found %lx - %lx \n",
 145                                 start, end);
 146         i = conflicting_nodes(start, end);
 147         if (i == node) {
 148                 printk(KERN_WARNING
 149                 "SRAT: Warning: PXM %d (%lx-%lx) overlaps with itself (%Lx-%Lx)\n",
 150                         pxm, start, end, nodes[i].start, nodes[i].end);
 151         } else if (i >= 0) {
 152                 printk(KERN_ERR
 153                        "SRAT: PXM %d (%lx-%lx) overlaps with PXM %d (%Lx-%Lx)\n",
 154                        pxm, start, end, node_to_pxm(i),
 155                         nodes[i].start, nodes[i].end);
 156                 bad_srat();
 157                 return;
 158         }
 159         nd = &nodes[node];
 160         if (!node_test_and_set(node, nodes_parsed)) {
 161                 nd->start = start;
 162                 nd->end = end;
 163         } else {
 164                 if (start < nd->start)
 165                         nd->start = start;
 166                 if (nd->end < end)
 167                         nd->end = end;
 168         }
 169         if (!(nd->end & 0xfff))
 170                 nd->end--;
 171         printk(KERN_INFO "SRAT: Node %u PXM %u %Lx-%Lx\n", node, pxm,
 172                nd->start, nd->end);
 173 }
 174
 175 void __init acpi_numa_arch_fixup(void) {}
 176
 177 /* Use the information discovered above to actually set up the nodes. */
 178 int __init acpi_scan_nodes(unsigned long start, unsigned long end)
 179 {
 180         int i;
 181         if (acpi_numa <= 0)
 182                 return -1;
 183
 184         /* First clean up the node list */
 185         for_each_node_mask(i, nodes_parsed) {
 186                 cutoff_node(i, start, end);
 187                 if (nodes[i].start == nodes[i].end)
 188                         node_clear(i, nodes_parsed);
 189         }
 190
 191         memnode_shift = compute_hash_shift(nodes, nodes_weight(nodes_parsed));
 192         if (memnode_shift < 0) {
 193                 printk(KERN_ERR
 194                      "SRAT: No NUMA node hash function found. Contact maintainer\n");
 195                 bad_srat();
 196                 return -1;
 197         }
 198
 199         /* Finally register nodes */
 200         for_each_node_mask(i, nodes_parsed)
 201                 setup_node_bootmem(i, nodes[i].start, nodes[i].end);
 202         for (i = 0; i < NR_CPUS; i++) {
 203                 if (cpu_to_node[i] == NUMA_NO_NODE)
 204                         continue;
 205                 if (!node_isset(cpu_to_node[i], nodes_parsed))
 206                         numa_set_node(i, NUMA_NO_NODE);
 207         }
 208         numa_init_array();
 209         return 0;
 210 }
 211
 212 static int node_to_pxm(int n)
 213 {
 214        int i;
 215        if (pxm2node[n] == n)
 216                return n;
 217        for (i = 0; i < 256; i++)
 218                if (pxm2node[i] == n)
 219                        return i;
 220        return 0;
 221 }
 222
 223 int __node_distance(int a, int b)
 224 {
 225         int index;
 226
 227         if (!acpi_slit)
 228                 return a == b ? 10 : 20;
 229         index = acpi_slit->localities * node_to_pxm(a);
 230         return acpi_slit->entry[index + node_to_pxm(b)];
 231 }
 232
 233 EXPORT_SYMBOL(__node_distance);