arch/x86/mm/numa.c

   1 /* Common code for 32 and 64-bit NUMA */
   2 #include <linux/kernel.h>
   3 #include <linux/mm.h>
   4 #include <linux/string.h>
   5 #include <linux/init.h>
   6 #include <linux/bootmem.h>
   7 #include <linux/memblock.h>
   8 #include <linux/mmzone.h>
   9 #include <linux/ctype.h>
  10 #include <linux/module.h>
  11 #include <linux/nodemask.h>
  12 #include <linux/sched.h>
  13 #include <linux/topology.h>
  14
  15 #include <asm/e820.h>
  16 #include <asm/proto.h>
  17 #include <asm/dma.h>
  18 #include <asm/acpi.h>
  19 #include <asm/amd_nb.h>
  20
  21 #include "numa_internal.h"
  22
  23 int __initdata numa_off;
  24 nodemask_t numa_nodes_parsed __initdata;
  25
  26 struct pglist_data *node_data[MAX_NUMNODES] __read_mostly;
  27 EXPORT_SYMBOL(node_data);
  28
  29 static struct numa_meminfo numa_meminfo
  30 #ifndef CONFIG_MEMORY_HOTPLUG
  31 __initdata
  32 #endif
  33 ;
  34
  35 static int numa_distance_cnt;
  36 static u8 *numa_distance;
  37
  38 static __init int numa_setup(char *opt)
  39 {
  40         if (!opt)
  41                 return -EINVAL;
  42         if (!strncmp(opt, "off", 3))
  43                 numa_off = 1;
  44 #ifdef CONFIG_NUMA_EMU
  45         if (!strncmp(opt, "fake=", 5))
  46                 numa_emu_cmdline(opt + 5);
  47 #endif
  48 #ifdef CONFIG_ACPI_NUMA
  49         if (!strncmp(opt, "noacpi", 6))
  50                 acpi_numa = -1;
  51 #endif
  52         return 0;
  53 }
  54 early_param("numa", numa_setup);
  55
  56 /*
  57  * apicid, cpu, node mappings
  58  */
  59 s16 __apicid_to_node[MAX_LOCAL_APIC] = {
  60         [0 ... MAX_LOCAL_APIC-1] = NUMA_NO_NODE
  61 };
  62
  63 int numa_cpu_node(int cpu)
  64 {
  65         int apicid = early_per_cpu(x86_cpu_to_apicid, cpu);
  66
  67         if (apicid != BAD_APICID)
  68                 return __apicid_to_node[apicid];
  69         return NUMA_NO_NODE;
  70 }
  71
  72 cpumask_var_t node_to_cpumask_map[MAX_NUMNODES];
  73 EXPORT_SYMBOL(node_to_cpumask_map);
  74
  75 /*
  76  * Map cpu index to node index
  77  */
  78 DEFINE_EARLY_PER_CPU(int, x86_cpu_to_node_map, NUMA_NO_NODE);
  79 EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_node_map);
  80
  81 void numa_set_node(int cpu, int node)
  82 {
  83         int *cpu_to_node_map = early_per_cpu_ptr(x86_cpu_to_node_map);
  84
  85         /* early setting, no percpu area yet */
  86         if (cpu_to_node_map) {
  87                 cpu_to_node_map[cpu] = node;
  88                 return;
  89         }
  90
  91 #ifdef CONFIG_DEBUG_PER_CPU_MAPS
  92         if (cpu >= nr_cpu_ids || !cpu_possible(cpu)) {
  93                 printk(KERN_ERR "numa_set_node: invalid cpu# (%d)\n", cpu);
  94                 dump_stack();
  95                 return;
  96         }
  97 #endif
  98         per_cpu(x86_cpu_to_node_map, cpu) = node;
  99
 100         set_cpu_numa_node(cpu, node);
 101 }
 102
 103 void numa_clear_node(int cpu)
 104 {
 105         numa_set_node(cpu, NUMA_NO_NODE);
 106 }
 107
 108 /*
 109  * Allocate node_to_cpumask_map based on number of available nodes
 110  * Requires node_possible_map to be valid.
 111  *
 112  * Note: cpumask_of_node() is not valid until after this is done.
 113  * (Use CONFIG_DEBUG_PER_CPU_MAPS to check this.)
 114  */
 115 void __init setup_node_to_cpumask_map(void)
 116 {
 117         unsigned int node;
 118
 119         /* setup nr_node_ids if not done yet */
 120         if (nr_node_ids == MAX_NUMNODES)
 121                 setup_nr_node_ids();
 122
 123         /* allocate the map */
 124         for (node = 0; node < nr_node_ids; node++)
 125                 alloc_bootmem_cpumask_var(&node_to_cpumask_map[node]);
 126
 127         /* cpumask_of_node() will now work */
 128         pr_debug("Node to cpumask map for %d nodes\n", nr_node_ids);
 129 }
 130
 131 static int __init numa_add_memblk_to(int nid, u64 start, u64 end,
 132                                      struct numa_meminfo *mi)
 133 {
 134         /* ignore zero length blks */
 135         if (start == end)
 136                 return 0;
 137
 138         /* whine about and ignore invalid blks */
 139         if (start > end || nid < 0 || nid >= MAX_NUMNODES) {
 140                 pr_warning("NUMA: Warning: invalid memblk node %d [mem %#010Lx-%#010Lx]\n",
 141                            nid, start, end - 1);
 142                 return 0;
 143         }
 144
 145         if (mi->nr_blks >= NR_NODE_MEMBLKS) {
 146                 pr_err("NUMA: too many memblk ranges\n");
 147                 return -EINVAL;
 148         }
 149
 150         mi->blk[mi->nr_blks].start = start;
 151         mi->blk[mi->nr_blks].end = end;
 152         mi->blk[mi->nr_blks].nid = nid;
 153         mi->nr_blks++;
 154         return 0;
 155 }
 156
 157 /**
 158  * numa_remove_memblk_from - Remove one numa_memblk from a numa_meminfo
 159  * @idx: Index of memblk to remove
 160  * @mi: numa_meminfo to remove memblk from
 161  *
 162  * Remove @idx'th numa_memblk from @mi by shifting @mi->blk[] and
 163  * decrementing @mi->nr_blks.
 164  */
 165 void __init numa_remove_memblk_from(int idx, struct numa_meminfo *mi)
 166 {
 167         mi->nr_blks--;
 168         memmove(&mi->blk[idx], &mi->blk[idx + 1],
 169                 (mi->nr_blks - idx) * sizeof(mi->blk[0]));
 170 }
 171
 172 /**
 173  * numa_add_memblk - Add one numa_memblk to numa_meminfo
 174  * @nid: NUMA node ID of the new memblk
 175  * @start: Start address of the new memblk
 176  * @end: End address of the new memblk
 177  *
 178  * Add a new memblk to the default numa_meminfo.
 179  *
 180  * RETURNS:
 181  * 0 on success, -errno on failure.
 182  */
 183 int __init numa_add_memblk(int nid, u64 start, u64 end)
 184 {
 185         return numa_add_memblk_to(nid, start, end, &numa_meminfo);
 186 }
 187
 188 /* Initialize NODE_DATA for a node on the local memory */
 189 static void __init setup_node_data(int nid, u64 start, u64 end)
 190 {
 191         const size_t nd_size = roundup(sizeof(pg_data_t), PAGE_SIZE);
 192         u64 nd_pa;
 193         void *nd;
 194         int tnid;
 195
 196         /*
 197          * Don't confuse VM with a node that doesn't have the
 198          * minimum amount of memory:
 199          */
 200         if (end && (end - start) < NODE_MIN_SIZE)
 201                 return;
 202
 203         start = roundup(start, ZONE_ALIGN);
 204
 205         printk(KERN_INFO "Initmem setup node %d [mem %#010Lx-%#010Lx]\n",
 206                nid, start, end - 1);
 207
 208         /*
 209          * Allocate node data.  Try node-local memory and then any node.
 210          * Never allocate in DMA zone.
 211          */
 212         nd_pa = memblock_alloc_nid(nd_size, SMP_CACHE_BYTES, nid);
 213         if (!nd_pa) {
 214                 nd_pa = __memblock_alloc_base(nd_size, SMP_CACHE_BYTES,
 215                                               MEMBLOCK_ALLOC_ACCESSIBLE);
 216                 if (!nd_pa) {
 217                         pr_err("Cannot find %zu bytes in node %d\n",
 218                                nd_size, nid);
 219                         return;
 220                 }
 221         }
 222         nd = __va(nd_pa);
 223
 224         /* report and initialize */
 225         printk(KERN_INFO "  NODE_DATA [mem %#010Lx-%#010Lx]\n",
 226                nd_pa, nd_pa + nd_size - 1);
 227         tnid = early_pfn_to_nid(nd_pa >> PAGE_SHIFT);
 228         if (tnid != nid)
 229                 printk(KERN_INFO "    NODE_DATA(%d) on node %d\n", nid, tnid);
 230
 231         node_data[nid] = nd;
 232         memset(NODE_DATA(nid), 0, sizeof(pg_data_t));
 233         NODE_DATA(nid)->node_id = nid;
 234         NODE_DATA(nid)->node_start_pfn = start >> PAGE_SHIFT;
 235         NODE_DATA(nid)->node_spanned_pages = (end - start) >> PAGE_SHIFT;
 236
 237         node_set_online(nid);
 238 }
 239
 240 /**
 241  * numa_cleanup_meminfo - Cleanup a numa_meminfo
 242  * @mi: numa_meminfo to clean up
 243  *
 244  * Sanitize @mi by merging and removing unncessary memblks.  Also check for
 245  * conflicts and clear unused memblks.
 246  *
 247  * RETURNS:
 248  * 0 on success, -errno on failure.
 249  */
 250 int __init numa_cleanup_meminfo(struct numa_meminfo *mi)
 251 {
 252         const u64 low = 0;
 253         const u64 high = PFN_PHYS(max_pfn);
 254         int i, j, k;
 255
 256         /* first, trim all entries */
 257         for (i = 0; i < mi->nr_blks; i++) {
 258                 struct numa_memblk *bi = &mi->blk[i];
 259
 260                 /* make sure all blocks are inside the limits */
 261                 bi->start = max(bi->start, low);
 262                 bi->end = min(bi->end, high);
 263
 264                 /* and there's no empty block */
 265                 if (bi->start >= bi->end)
 266                         numa_remove_memblk_from(i--, mi);
 267         }
 268
 269         /* merge neighboring / overlapping entries */
 270         for (i = 0; i < mi->nr_blks; i++) {
 271                 struct numa_memblk *bi = &mi->blk[i];
 272
 273                 for (j = i + 1; j < mi->nr_blks; j++) {
 274                         struct numa_memblk *bj = &mi->blk[j];
 275                         u64 start, end;
 276
 277                         /*
 278                          * See whether there are overlapping blocks.  Whine
 279                          * about but allow overlaps of the same nid.  They
 280                          * will be merged below.
 281                          */
 282                         if (bi->end > bj->start && bi->start < bj->end) {
 283                                 if (bi->nid != bj->nid) {
 284                                         pr_err("NUMA: node %d [mem %#010Lx-%#010Lx] overlaps with node %d [mem %#010Lx-%#010Lx]\n",
 285                                                bi->nid, bi->start, bi->end - 1,
 286                                                bj->nid, bj->start, bj->end - 1);
 287                                         return -EINVAL;
 288                                 }
 289                                 pr_warning("NUMA: Warning: node %d [mem %#010Lx-%#010Lx] overlaps with itself [mem %#010Lx-%#010Lx]\n",
 290                                            bi->nid, bi->start, bi->end - 1,
 291                                            bj->start, bj->end - 1);
 292                         }
 293
 294                         /*
 295                          * Join together blocks on the same node, holes
 296                          * between which don't overlap with memory on other
 297                          * nodes.
 298                          */
 299                         if (bi->nid != bj->nid)
 300                                 continue;
 301                         start = min(bi->start, bj->start);
 302                         end = max(bi->end, bj->end);
 303                         for (k = 0; k < mi->nr_blks; k++) {
 304                                 struct numa_memblk *bk = &mi->blk[k];
 305
 306                                 if (bi->nid == bk->nid)
 307                                         continue;
 308                                 if (start < bk->end && end > bk->start)
 309                                         break;
 310                         }
 311                         if (k < mi->nr_blks)
 312                                 continue;
 313                         printk(KERN_INFO "NUMA: Node %d [mem %#010Lx-%#010Lx] + [mem %#010Lx-%#010Lx] -> [mem %#010Lx-%#010Lx]\n",
 314                                bi->nid, bi->start, bi->end - 1, bj->start,
 315                                bj->end - 1, start, end - 1);
 316                         bi->start = start;
 317                         bi->end = end;
 318                         numa_remove_memblk_from(j--, mi);
 319                 }
 320         }
 321
 322         /* clear unused ones */
 323         for (i = mi->nr_blks; i < ARRAY_SIZE(mi->blk); i++) {
 324                 mi->blk[i].start = mi->blk[i].end = 0;
 325                 mi->blk[i].nid = NUMA_NO_NODE;
 326         }
 327
 328         return 0;
 329 }
 330
 331 /*
 332  * Set nodes, which have memory in @mi, in *@nodemask.
 333  */
 334 static void __init numa_nodemask_from_meminfo(nodemask_t *nodemask,
 335                                               const struct numa_meminfo *mi)
 336 {
 337         int i;
 338
 339         for (i = 0; i < ARRAY_SIZE(mi->blk); i++)
 340                 if (mi->blk[i].start != mi->blk[i].end &&
 341                     mi->blk[i].nid != NUMA_NO_NODE)
 342                         node_set(mi->blk[i].nid, *nodemask);
 343 }
 344
 345 /**
 346  * numa_reset_distance - Reset NUMA distance table
 347  *
 348  * The current table is freed.  The next numa_set_distance() call will
 349  * create a new one.
 350  */
 351 void __init numa_reset_distance(void)
 352 {
 353         size_t size = numa_distance_cnt * numa_distance_cnt * sizeof(numa_distance[0]);
 354
 355         /* numa_distance could be 1LU marking allocation failure, test cnt */
 356         if (numa_distance_cnt)
 357                 memblock_free(__pa(numa_distance), size);
 358         numa_distance_cnt = 0;
 359         numa_distance = NULL;   /* enable table creation */
 360 }
 361
 362 static int __init numa_alloc_distance(void)
 363 {
 364         nodemask_t nodes_parsed;
 365         size_t size;
 366         int i, j, cnt = 0;
 367         u64 phys;
 368
 369         /* size the new table and allocate it */
 370         nodes_parsed = numa_nodes_parsed;
 371         numa_nodemask_from_meminfo(&nodes_parsed, &numa_meminfo);
 372
 373         for_each_node_mask(i, nodes_parsed)
 374                 cnt = i;
 375         cnt++;
 376         size = cnt * cnt * sizeof(numa_distance[0]);
 377
 378         phys = memblock_find_in_range(0, PFN_PHYS(max_pfn_mapped),
 379                                       size, PAGE_SIZE);
 380         if (!phys) {
 381                 pr_warning("NUMA: Warning: can't allocate distance table!\n");
 382                 /* don't retry until explicitly reset */
 383                 numa_distance = (void *)1LU;
 384                 return -ENOMEM;
 385         }
 386         memblock_reserve(phys, size);
 387
 388         numa_distance = __va(phys);
 389         numa_distance_cnt = cnt;
 390
 391         /* fill with the default distances */
 392         for (i = 0; i < cnt; i++)
 393                 for (j = 0; j < cnt; j++)
 394                         numa_distance[i * cnt + j] = i == j ?
 395                                 LOCAL_DISTANCE : REMOTE_DISTANCE;
 396         printk(KERN_DEBUG "NUMA: Initialized distance table, cnt=%d\n", cnt);
 397
 398         return 0;
 399 }
 400
 401 /**
 402  * numa_set_distance - Set NUMA distance from one NUMA to another
 403  * @from: the 'from' node to set distance
 404  * @to: the 'to'  node to set distance
 405  * @distance: NUMA distance
 406  *
 407  * Set the distance from node @from to @to to @distance.  If distance table
 408  * doesn't exist, one which is large enough to accommodate all the currently
 409  * known nodes will be created.
 410  *
 411  * If such table cannot be allocated, a warning is printed and further
 412  * calls are ignored until the distance table is reset with
 413  * numa_reset_distance().
 414  *
 415  * If @from or @to is higher than the highest known node or lower than zero
 416  * at the time of table creation or @distance doesn't make sense, the call
 417  * is ignored.
 418  * This is to allow simplification of specific NUMA config implementations.
 419  */
 420 void __init numa_set_distance(int from, int to, int distance)
 421 {
 422         if (!numa_distance && numa_alloc_distance() < 0)
 423                 return;
 424
 425         if (from >= numa_distance_cnt || to >= numa_distance_cnt ||
 426                         from < 0 || to < 0) {
 427                 pr_warn_once("NUMA: Warning: node ids are out of bound, from=%d to=%d distance=%d\n",
 428                             from, to, distance);
 429                 return;
 430         }
 431
 432         if ((u8)distance != distance ||
 433             (from == to && distance != LOCAL_DISTANCE)) {
 434                 pr_warn_once("NUMA: Warning: invalid distance parameter, from=%d to=%d distance=%d\n",
 435                              from, to, distance);
 436                 return;
 437         }
 438
 439         numa_distance[from * numa_distance_cnt + to] = distance;
 440 }
 441
 442 int __node_distance(int from, int to)
 443 {
 444         if (from >= numa_distance_cnt || to >= numa_distance_cnt)
 445                 return from == to ? LOCAL_DISTANCE : REMOTE_DISTANCE;
 446         return numa_distance[from * numa_distance_cnt + to];
 447 }
 448 EXPORT_SYMBOL(__node_distance);
 449
 450 /*
 451  * Sanity check to catch more bad NUMA configurations (they are amazingly
 452  * common).  Make sure the nodes cover all memory.
 453  */
 454 static bool __init numa_meminfo_cover_memory(const struct numa_meminfo *mi)
 455 {
 456         u64 numaram, e820ram;
 457         int i;
 458
 459         numaram = 0;
 460         for (i = 0; i < mi->nr_blks; i++) {
 461                 u64 s = mi->blk[i].start >> PAGE_SHIFT;
 462                 u64 e = mi->blk[i].end >> PAGE_SHIFT;
 463                 numaram += e - s;
 464                 numaram -= __absent_pages_in_range(mi->blk[i].nid, s, e);
 465                 if ((s64)numaram < 0)
 466                         numaram = 0;
 467         }
 468
 469         e820ram = max_pfn - absent_pages_in_range(0, max_pfn);
 470
 471         /* We seem to lose 3 pages somewhere. Allow 1M of slack. */
 472         if ((s64)(e820ram - numaram) >= (1 << (20 - PAGE_SHIFT))) {
 473                 printk(KERN_ERR "NUMA: nodes only cover %LuMB of your %LuMB e820 RAM. Not used.\n",
 474                        (numaram << PAGE_SHIFT) >> 20,
 475                        (e820ram << PAGE_SHIFT) >> 20);
 476                 return false;
 477         }
 478         return true;
 479 }
 480
 481 static int __init numa_register_memblks(struct numa_meminfo *mi)
 482 {
 483         unsigned long uninitialized_var(pfn_align);
 484         int i, nid;
 485
 486         /* Account for nodes with cpus and no memory */
 487         node_possible_map = numa_nodes_parsed;
 488         numa_nodemask_from_meminfo(&node_possible_map, mi);
 489         if (WARN_ON(nodes_empty(node_possible_map)))
 490                 return -EINVAL;
 491
 492         for (i = 0; i < mi->nr_blks; i++) {
 493                 struct numa_memblk *mb = &mi->blk[i];
 494                 memblock_set_node(mb->start, mb->end - mb->start,
 495                                   &memblock.memory, mb->nid);
 496         }
 497
 498         /*
 499          * If sections array is gonna be used for pfn -> nid mapping, check
 500          * whether its granularity is fine enough.
 501          */
 502 #ifdef NODE_NOT_IN_PAGE_FLAGS
 503         pfn_align = node_map_pfn_alignment();
 504         if (pfn_align && pfn_align < PAGES_PER_SECTION) {
 505                 printk(KERN_WARNING "Node alignment %LuMB < min %LuMB, rejecting NUMA config\n",
 506                        PFN_PHYS(pfn_align) >> 20,
 507                        PFN_PHYS(PAGES_PER_SECTION) >> 20);
 508                 return -EINVAL;
 509         }
 510 #endif
 511         if (!numa_meminfo_cover_memory(mi))
 512                 return -EINVAL;
 513
 514         /* Finally register nodes. */
 515         for_each_node_mask(nid, node_possible_map) {
 516                 u64 start = PFN_PHYS(max_pfn);
 517                 u64 end = 0;
 518
 519                 for (i = 0; i < mi->nr_blks; i++) {
 520                         if (nid != mi->blk[i].nid)
 521                                 continue;
 522                         start = min(mi->blk[i].start, start);
 523                         end = max(mi->blk[i].end, end);
 524                 }
 525
 526                 if (start < end)
 527                         setup_node_data(nid, start, end);
 528         }
 529
 530         /* Dump memblock with node info and return. */
 531         memblock_dump_all();
 532         return 0;
 533 }
 534
 535 /*
 536  * There are unfortunately some poorly designed mainboards around that
 537  * only connect memory to a single CPU. This breaks the 1:1 cpu->node
 538  * mapping. To avoid this fill in the mapping for all possible CPUs,
 539  * as the number of CPUs is not known yet. We round robin the existing
 540  * nodes.
 541  */
 542 static void __init numa_init_array(void)
 543 {
 544         int rr, i;
 545
 546         rr = first_node(node_online_map);
 547         for (i = 0; i < nr_cpu_ids; i++) {
 548                 if (early_cpu_to_node(i) != NUMA_NO_NODE)
 549                         continue;
 550                 numa_set_node(i, rr);
 551                 rr = next_node(rr, node_online_map);
 552                 if (rr == MAX_NUMNODES)
 553                         rr = first_node(node_online_map);
 554         }
 555 }
 556
 557 static void __init numa_clear_kernel_node_hotplug(void)
 558 {
 559         int i, nid;
 560         nodemask_t numa_kernel_nodes = NODE_MASK_NONE;
 561         unsigned long start, end;
 562         struct memblock_region *r;
 563
 564         /*
 565          * At this time, all memory regions reserved by memblock are
 566          * used by the kernel. Set the nid in memblock.reserved will
 567          * mark out all the nodes the kernel resides in.
 568          */
 569         for (i = 0; i < numa_meminfo.nr_blks; i++) {
 570                 struct numa_memblk *mb = &numa_meminfo.blk[i];
 571                 memblock_set_node(mb->start, mb->end - mb->start,
 572                                   &memblock.reserved, mb->nid);
 573         }
 574
 575         /* Mark all kernel nodes. */
 576         for_each_memblock(reserved, r)
 577                 node_set(r->nid, numa_kernel_nodes);
 578
 579         /* Clear MEMBLOCK_HOTPLUG flag for memory in kernel nodes. */
 580         for (i = 0; i < numa_meminfo.nr_blks; i++) {
 581                 nid = numa_meminfo.blk[i].nid;
 582                 if (!node_isset(nid, numa_kernel_nodes))
 583                         continue;
 584
 585                 start = numa_meminfo.blk[i].start;
 586                 end = numa_meminfo.blk[i].end;
 587
 588                 memblock_clear_hotplug(start, end - start);
 589         }
 590 }
 591
 592 static int __init numa_init(int (*init_func)(void))
 593 {
 594         int i;
 595         int ret;
 596
 597         for (i = 0; i < MAX_LOCAL_APIC; i++)
 598                 set_apicid_to_node(i, NUMA_NO_NODE);
 599
 600         nodes_clear(numa_nodes_parsed);
 601         nodes_clear(node_possible_map);
 602         nodes_clear(node_online_map);
 603         memset(&numa_meminfo, 0, sizeof(numa_meminfo));
 604         WARN_ON(memblock_set_node(0, ULLONG_MAX, &memblock.memory,
 605                                   MAX_NUMNODES));
 606         WARN_ON(memblock_set_node(0, ULLONG_MAX, &memblock.reserved,
 607                                   MAX_NUMNODES));
 608         /* In case that parsing SRAT failed. */
 609         WARN_ON(memblock_clear_hotplug(0, ULLONG_MAX));
 610         numa_reset_distance();
 611
 612         ret = init_func();
 613         if (ret < 0)
 614                 return ret;
 615
 616         /*
 617          * We reset memblock back to the top-down direction
 618          * here because if we configured ACPI_NUMA, we have
 619          * parsed SRAT in init_func(). It is ok to have the
 620          * reset here even if we did't configure ACPI_NUMA
 621          * or acpi numa init fails and fallbacks to dummy
 622          * numa init.
 623          */
 624         memblock_set_bottom_up(false);
 625
 626         ret = numa_cleanup_meminfo(&numa_meminfo);
 627         if (ret < 0)
 628                 return ret;
 629
 630         numa_emulation(&numa_meminfo, numa_distance_cnt);
 631
 632         ret = numa_register_memblks(&numa_meminfo);
 633         if (ret < 0)
 634                 return ret;
 635
 636         for (i = 0; i < nr_cpu_ids; i++) {
 637                 int nid = early_cpu_to_node(i);
 638
 639                 if (nid == NUMA_NO_NODE)
 640                         continue;
 641                 if (!node_online(nid))
 642                         numa_clear_node(i);
 643         }
 644         numa_init_array();
 645
 646         /*
 647          * At very early time, the kernel have to use some memory such as
 648          * loading the kernel image. We cannot prevent this anyway. So any
 649          * node the kernel resides in should be un-hotpluggable.
 650          *
 651          * And when we come here, numa_init() won't fail.
 652          */
 653         numa_clear_kernel_node_hotplug();
 654
 655         return 0;
 656 }
 657
 658 /**
 659  * dummy_numa_init - Fallback dummy NUMA init
 660  *
 661  * Used if there's no underlying NUMA architecture, NUMA initialization
 662  * fails, or NUMA is disabled on the command line.
 663  *
 664  * Must online at least one node and add memory blocks that cover all
 665  * allowed memory.  This function must not fail.
 666  */
 667 static int __init dummy_numa_init(void)
 668 {
 669         printk(KERN_INFO "%s\n",
 670                numa_off ? "NUMA turned off" : "No NUMA configuration found");
 671         printk(KERN_INFO "Faking a node at [mem %#018Lx-%#018Lx]\n",
 672                0LLU, PFN_PHYS(max_pfn) - 1);
 673
 674         node_set(0, numa_nodes_parsed);
 675         numa_add_memblk(0, 0, PFN_PHYS(max_pfn));
 676
 677         return 0;
 678 }
 679
 680 /**
 681  * x86_numa_init - Initialize NUMA
 682  *
 683  * Try each configured NUMA initialization method until one succeeds.  The
 684  * last fallback is dummy single node config encomapssing whole memory and
 685  * never fails.
 686  */
 687 void __init x86_numa_init(void)
 688 {
 689         if (!numa_off) {
 690 #ifdef CONFIG_ACPI_NUMA
 691                 if (!numa_init(x86_acpi_numa_init))
 692                         return;
 693 #endif
 694 #ifdef CONFIG_AMD_NUMA
 695                 if (!numa_init(amd_numa_init))
 696                         return;
 697 #endif
 698         }
 699
 700         numa_init(dummy_numa_init);
 701 }
 702
 703 static __init int find_near_online_node(int node)
 704 {
 705         int n, val;
 706         int min_val = INT_MAX;
 707         int best_node = -1;
 708
 709         for_each_online_node(n) {
 710                 val = node_distance(node, n);
 711
 712                 if (val < min_val) {
 713                         min_val = val;
 714                         best_node = n;
 715                 }
 716         }
 717
 718         return best_node;
 719 }
 720
 721 /*
 722  * Setup early cpu_to_node.
 723  *
 724  * Populate cpu_to_node[] only if x86_cpu_to_apicid[],
 725  * and apicid_to_node[] tables have valid entries for a CPU.
 726  * This means we skip cpu_to_node[] initialisation for NUMA
 727  * emulation and faking node case (when running a kernel compiled
 728  * for NUMA on a non NUMA box), which is OK as cpu_to_node[]
 729  * is already initialized in a round robin manner at numa_init_array,
 730  * prior to this call, and this initialization is good enough
 731  * for the fake NUMA cases.
 732  *
 733  * Called before the per_cpu areas are setup.
 734  */
 735 void __init init_cpu_to_node(void)
 736 {
 737         int cpu;
 738         u16 *cpu_to_apicid = early_per_cpu_ptr(x86_cpu_to_apicid);
 739
 740         BUG_ON(cpu_to_apicid == NULL);
 741
 742         for_each_possible_cpu(cpu) {
 743                 int node = numa_cpu_node(cpu);
 744
 745                 if (node == NUMA_NO_NODE)
 746                         continue;
 747                 if (!node_online(node))
 748                         node = find_near_online_node(node);
 749                 numa_set_node(cpu, node);
 750         }
 751 }
 752
 753 #ifndef CONFIG_DEBUG_PER_CPU_MAPS
 754
 755 # ifndef CONFIG_NUMA_EMU
 756 void numa_add_cpu(int cpu)
 757 {
 758         cpumask_set_cpu(cpu, node_to_cpumask_map[early_cpu_to_node(cpu)]);
 759 }
 760
 761 void numa_remove_cpu(int cpu)
 762 {
 763         cpumask_clear_cpu(cpu, node_to_cpumask_map[early_cpu_to_node(cpu)]);
 764 }
 765 # endif /* !CONFIG_NUMA_EMU */
 766
 767 #else   /* !CONFIG_DEBUG_PER_CPU_MAPS */
 768
 769 int __cpu_to_node(int cpu)
 770 {
 771         if (early_per_cpu_ptr(x86_cpu_to_node_map)) {
 772                 printk(KERN_WARNING
 773                         "cpu_to_node(%d): usage too early!\n", cpu);
 774                 dump_stack();
 775                 return early_per_cpu_ptr(x86_cpu_to_node_map)[cpu];
 776         }
 777         return per_cpu(x86_cpu_to_node_map, cpu);
 778 }
 779 EXPORT_SYMBOL(__cpu_to_node);
 780
 781 /*
 782  * Same function as cpu_to_node() but used if called before the
 783  * per_cpu areas are setup.
 784  */
 785 int early_cpu_to_node(int cpu)
 786 {
 787         if (early_per_cpu_ptr(x86_cpu_to_node_map))
 788                 return early_per_cpu_ptr(x86_cpu_to_node_map)[cpu];
 789
 790         if (!cpu_possible(cpu)) {
 791                 printk(KERN_WARNING
 792                         "early_cpu_to_node(%d): no per_cpu area!\n", cpu);
 793                 dump_stack();
 794                 return NUMA_NO_NODE;
 795         }
 796         return per_cpu(x86_cpu_to_node_map, cpu);
 797 }
 798
 799 void debug_cpumask_set_cpu(int cpu, int node, bool enable)
 800 {
 801         struct cpumask *mask;
 802         char buf[64];
 803
 804         if (node == NUMA_NO_NODE) {
 805                 /* early_cpu_to_node() already emits a warning and trace */
 806                 return;
 807         }
 808         mask = node_to_cpumask_map[node];
 809         if (!mask) {
 810                 pr_err("node_to_cpumask_map[%i] NULL\n", node);
 811                 dump_stack();
 812                 return;
 813         }
 814
 815         if (enable)
 816                 cpumask_set_cpu(cpu, mask);
 817         else
 818                 cpumask_clear_cpu(cpu, mask);
 819
 820         cpulist_scnprintf(buf, sizeof(buf), mask);
 821         printk(KERN_DEBUG "%s cpu %d node %d: mask now %s\n",
 822                 enable ? "numa_add_cpu" : "numa_remove_cpu",
 823                 cpu, node, buf);
 824         return;
 825 }
 826
 827 # ifndef CONFIG_NUMA_EMU
 828 static void numa_set_cpumask(int cpu, bool enable)
 829 {
 830         debug_cpumask_set_cpu(cpu, early_cpu_to_node(cpu), enable);
 831 }
 832
 833 void numa_add_cpu(int cpu)
 834 {
 835         numa_set_cpumask(cpu, true);
 836 }
 837
 838 void numa_remove_cpu(int cpu)
 839 {
 840         numa_set_cpumask(cpu, false);
 841 }
 842 # endif /* !CONFIG_NUMA_EMU */
 843
 844 /*
 845  * Returns a pointer to the bitmask of CPUs on Node 'node'.
 846  */
 847 const struct cpumask *cpumask_of_node(int node)
 848 {
 849         if (node >= nr_node_ids) {
 850                 printk(KERN_WARNING
 851                         "cpumask_of_node(%d): node > nr_node_ids(%d)\n",
 852                         node, nr_node_ids);
 853                 dump_stack();
 854                 return cpu_none_mask;
 855         }
 856         if (node_to_cpumask_map[node] == NULL) {
 857                 printk(KERN_WARNING
 858                         "cpumask_of_node(%d): no node_to_cpumask_map!\n",
 859                         node);
 860                 dump_stack();
 861                 return cpu_online_mask;
 862         }
 863         return node_to_cpumask_map[node];
 864 }
 865 EXPORT_SYMBOL(cpumask_of_node);
 866
 867 #endif  /* !CONFIG_DEBUG_PER_CPU_MAPS */
 868
 869 #ifdef CONFIG_MEMORY_HOTPLUG
 870 int memory_add_physaddr_to_nid(u64 start)
 871 {
 872         struct numa_meminfo *mi = &numa_meminfo;
 873         int nid = mi->blk[0].nid;
 874         int i;
 875
 876         for (i = 0; i < mi->nr_blks; i++)
 877                 if (mi->blk[i].start <= start && mi->blk[i].end > start)
 878                         nid = mi->blk[i].nid;
 879         return nid;
 880 }
 881 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
 882 #endif