linux/arch/x86/mm/numa.c
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   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/nodemask.h>
  11#include <linux/sched.h>
  12#include <linux/topology.h>
  13
  14#include <asm/e820.h>
  15#include <asm/proto.h>
  16#include <asm/dma.h>
  17#include <asm/acpi.h>
  18#include <asm/amd_nb.h>
  19
  20#include "numa_internal.h"
  21
  22int __initdata numa_off;
  23nodemask_t numa_nodes_parsed __initdata;
  24
  25struct pglist_data *node_data[MAX_NUMNODES] __read_mostly;
  26EXPORT_SYMBOL(node_data);
  27
  28static struct numa_meminfo numa_meminfo
  29#ifndef CONFIG_MEMORY_HOTPLUG
  30__initdata
  31#endif
  32;
  33
  34static int numa_distance_cnt;
  35static u8 *numa_distance;
  36
  37static __init int numa_setup(char *opt)
  38{
  39        if (!opt)
  40                return -EINVAL;
  41        if (!strncmp(opt, "off", 3))
  42                numa_off = 1;
  43#ifdef CONFIG_NUMA_EMU
  44        if (!strncmp(opt, "fake=", 5))
  45                numa_emu_cmdline(opt + 5);
  46#endif
  47#ifdef CONFIG_ACPI_NUMA
  48        if (!strncmp(opt, "noacpi", 6))
  49                acpi_numa = -1;
  50#endif
  51        return 0;
  52}
  53early_param("numa", numa_setup);
  54
  55/*
  56 * apicid, cpu, node mappings
  57 */
  58s16 __apicid_to_node[MAX_LOCAL_APIC] = {
  59        [0 ... MAX_LOCAL_APIC-1] = NUMA_NO_NODE
  60};
  61
  62int numa_cpu_node(int cpu)
  63{
  64        int apicid = early_per_cpu(x86_cpu_to_apicid, cpu);
  65
  66        if (apicid != BAD_APICID)
  67                return __apicid_to_node[apicid];
  68        return NUMA_NO_NODE;
  69}
  70
  71cpumask_var_t node_to_cpumask_map[MAX_NUMNODES];
  72EXPORT_SYMBOL(node_to_cpumask_map);
  73
  74/*
  75 * Map cpu index to node index
  76 */
  77DEFINE_EARLY_PER_CPU(int, x86_cpu_to_node_map, NUMA_NO_NODE);
  78EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_node_map);
  79
  80void numa_set_node(int cpu, int node)
  81{
  82        int *cpu_to_node_map = early_per_cpu_ptr(x86_cpu_to_node_map);
  83
  84        /* early setting, no percpu area yet */
  85        if (cpu_to_node_map) {
  86                cpu_to_node_map[cpu] = node;
  87                return;
  88        }
  89
  90#ifdef CONFIG_DEBUG_PER_CPU_MAPS
  91        if (cpu >= nr_cpu_ids || !cpu_possible(cpu)) {
  92                printk(KERN_ERR "numa_set_node: invalid cpu# (%d)\n", cpu);
  93                dump_stack();
  94                return;
  95        }
  96#endif
  97        per_cpu(x86_cpu_to_node_map, cpu) = node;
  98
  99        set_cpu_numa_node(cpu, node);
 100}
 101
 102void numa_clear_node(int cpu)
 103{
 104        numa_set_node(cpu, NUMA_NO_NODE);
 105}
 106
 107/*
 108 * Allocate node_to_cpumask_map based on number of available nodes
 109 * Requires node_possible_map to be valid.
 110 *
 111 * Note: cpumask_of_node() is not valid until after this is done.
 112 * (Use CONFIG_DEBUG_PER_CPU_MAPS to check this.)
 113 */
 114void __init setup_node_to_cpumask_map(void)
 115{
 116        unsigned int node;
 117
 118        /* setup nr_node_ids if not done yet */
 119        if (nr_node_ids == MAX_NUMNODES)
 120                setup_nr_node_ids();
 121
 122        /* allocate the map */
 123        for (node = 0; node < nr_node_ids; node++)
 124                alloc_bootmem_cpumask_var(&node_to_cpumask_map[node]);
 125
 126        /* cpumask_of_node() will now work */
 127        pr_debug("Node to cpumask map for %d nodes\n", nr_node_ids);
 128}
 129
 130static int __init numa_add_memblk_to(int nid, u64 start, u64 end,
 131                                     struct numa_meminfo *mi)
 132{
 133        /* ignore zero length blks */
 134        if (start == end)
 135                return 0;
 136
 137        /* whine about and ignore invalid blks */
 138        if (start > end || nid < 0 || nid >= MAX_NUMNODES) {
 139                pr_warning("NUMA: Warning: invalid memblk node %d [mem %#010Lx-%#010Lx]\n",
 140                           nid, start, end - 1);
 141                return 0;
 142        }
 143
 144        if (mi->nr_blks >= NR_NODE_MEMBLKS) {
 145                pr_err("NUMA: too many memblk ranges\n");
 146                return -EINVAL;
 147        }
 148
 149        mi->blk[mi->nr_blks].start = start;
 150        mi->blk[mi->nr_blks].end = end;
 151        mi->blk[mi->nr_blks].nid = nid;
 152        mi->nr_blks++;
 153        return 0;
 154}
 155
 156/**
 157 * numa_remove_memblk_from - Remove one numa_memblk from a numa_meminfo
 158 * @idx: Index of memblk to remove
 159 * @mi: numa_meminfo to remove memblk from
 160 *
 161 * Remove @idx'th numa_memblk from @mi by shifting @mi->blk[] and
 162 * decrementing @mi->nr_blks.
 163 */
 164void __init numa_remove_memblk_from(int idx, struct numa_meminfo *mi)
 165{
 166        mi->nr_blks--;
 167        memmove(&mi->blk[idx], &mi->blk[idx + 1],
 168                (mi->nr_blks - idx) * sizeof(mi->blk[0]));
 169}
 170
 171/**
 172 * numa_add_memblk - Add one numa_memblk to numa_meminfo
 173 * @nid: NUMA node ID of the new memblk
 174 * @start: Start address of the new memblk
 175 * @end: End address of the new memblk
 176 *
 177 * Add a new memblk to the default numa_meminfo.
 178 *
 179 * RETURNS:
 180 * 0 on success, -errno on failure.
 181 */
 182int __init numa_add_memblk(int nid, u64 start, u64 end)
 183{
 184        return numa_add_memblk_to(nid, start, end, &numa_meminfo);
 185}
 186
 187/* Allocate NODE_DATA for a node on the local memory */
 188static void __init alloc_node_data(int nid)
 189{
 190        const size_t nd_size = roundup(sizeof(pg_data_t), PAGE_SIZE);
 191        u64 nd_pa;
 192        void *nd;
 193        int tnid;
 194
 195        /*
 196         * Allocate node data.  Try node-local memory and then any node.
 197         * Never allocate in DMA zone.
 198         */
 199        nd_pa = memblock_alloc_try_nid(nd_size, SMP_CACHE_BYTES, nid);
 200        if (!nd_pa) {
 201                pr_err("Cannot find %zu bytes in any node\n", nd_size);
 202                return;
 203        }
 204        nd = __va(nd_pa);
 205
 206        /* report and initialize */
 207        printk(KERN_INFO "NODE_DATA(%d) allocated [mem %#010Lx-%#010Lx]\n", nid,
 208               nd_pa, nd_pa + nd_size - 1);
 209        tnid = early_pfn_to_nid(nd_pa >> PAGE_SHIFT);
 210        if (tnid != nid)
 211                printk(KERN_INFO "    NODE_DATA(%d) on node %d\n", nid, tnid);
 212
 213        node_data[nid] = nd;
 214        memset(NODE_DATA(nid), 0, sizeof(pg_data_t));
 215
 216        node_set_online(nid);
 217}
 218
 219/**
 220 * numa_cleanup_meminfo - Cleanup a numa_meminfo
 221 * @mi: numa_meminfo to clean up
 222 *
 223 * Sanitize @mi by merging and removing unncessary memblks.  Also check for
 224 * conflicts and clear unused memblks.
 225 *
 226 * RETURNS:
 227 * 0 on success, -errno on failure.
 228 */
 229int __init numa_cleanup_meminfo(struct numa_meminfo *mi)
 230{
 231        const u64 low = 0;
 232        const u64 high = PFN_PHYS(max_pfn);
 233        int i, j, k;
 234
 235        /* first, trim all entries */
 236        for (i = 0; i < mi->nr_blks; i++) {
 237                struct numa_memblk *bi = &mi->blk[i];
 238
 239                /* make sure all blocks are inside the limits */
 240                bi->start = max(bi->start, low);
 241                bi->end = min(bi->end, high);
 242
 243                /* and there's no empty or non-exist block */
 244                if (bi->start >= bi->end ||
 245                    !memblock_overlaps_region(&memblock.memory,
 246                        bi->start, bi->end - bi->start))
 247                        numa_remove_memblk_from(i--, mi);
 248        }
 249
 250        /* merge neighboring / overlapping entries */
 251        for (i = 0; i < mi->nr_blks; i++) {
 252                struct numa_memblk *bi = &mi->blk[i];
 253
 254                for (j = i + 1; j < mi->nr_blks; j++) {
 255                        struct numa_memblk *bj = &mi->blk[j];
 256                        u64 start, end;
 257
 258                        /*
 259                         * See whether there are overlapping blocks.  Whine
 260                         * about but allow overlaps of the same nid.  They
 261                         * will be merged below.
 262                         */
 263                        if (bi->end > bj->start && bi->start < bj->end) {
 264                                if (bi->nid != bj->nid) {
 265                                        pr_err("NUMA: node %d [mem %#010Lx-%#010Lx] overlaps with node %d [mem %#010Lx-%#010Lx]\n",
 266                                               bi->nid, bi->start, bi->end - 1,
 267                                               bj->nid, bj->start, bj->end - 1);
 268                                        return -EINVAL;
 269                                }
 270                                pr_warning("NUMA: Warning: node %d [mem %#010Lx-%#010Lx] overlaps with itself [mem %#010Lx-%#010Lx]\n",
 271                                           bi->nid, bi->start, bi->end - 1,
 272                                           bj->start, bj->end - 1);
 273                        }
 274
 275                        /*
 276                         * Join together blocks on the same node, holes
 277                         * between which don't overlap with memory on other
 278                         * nodes.
 279                         */
 280                        if (bi->nid != bj->nid)
 281                                continue;
 282                        start = min(bi->start, bj->start);
 283                        end = max(bi->end, bj->end);
 284                        for (k = 0; k < mi->nr_blks; k++) {
 285                                struct numa_memblk *bk = &mi->blk[k];
 286
 287                                if (bi->nid == bk->nid)
 288                                        continue;
 289                                if (start < bk->end && end > bk->start)
 290                                        break;
 291                        }
 292                        if (k < mi->nr_blks)
 293                                continue;
 294                        printk(KERN_INFO "NUMA: Node %d [mem %#010Lx-%#010Lx] + [mem %#010Lx-%#010Lx] -> [mem %#010Lx-%#010Lx]\n",
 295                               bi->nid, bi->start, bi->end - 1, bj->start,
 296                               bj->end - 1, start, end - 1);
 297                        bi->start = start;
 298                        bi->end = end;
 299                        numa_remove_memblk_from(j--, mi);
 300                }
 301        }
 302
 303        /* clear unused ones */
 304        for (i = mi->nr_blks; i < ARRAY_SIZE(mi->blk); i++) {
 305                mi->blk[i].start = mi->blk[i].end = 0;
 306                mi->blk[i].nid = NUMA_NO_NODE;
 307        }
 308
 309        return 0;
 310}
 311
 312/*
 313 * Set nodes, which have memory in @mi, in *@nodemask.
 314 */
 315static void __init numa_nodemask_from_meminfo(nodemask_t *nodemask,
 316                                              const struct numa_meminfo *mi)
 317{
 318        int i;
 319
 320        for (i = 0; i < ARRAY_SIZE(mi->blk); i++)
 321                if (mi->blk[i].start != mi->blk[i].end &&
 322                    mi->blk[i].nid != NUMA_NO_NODE)
 323                        node_set(mi->blk[i].nid, *nodemask);
 324}
 325
 326/**
 327 * numa_reset_distance - Reset NUMA distance table
 328 *
 329 * The current table is freed.  The next numa_set_distance() call will
 330 * create a new one.
 331 */
 332void __init numa_reset_distance(void)
 333{
 334        size_t size = numa_distance_cnt * numa_distance_cnt * sizeof(numa_distance[0]);
 335
 336        /* numa_distance could be 1LU marking allocation failure, test cnt */
 337        if (numa_distance_cnt)
 338                memblock_free(__pa(numa_distance), size);
 339        numa_distance_cnt = 0;
 340        numa_distance = NULL;   /* enable table creation */
 341}
 342
 343static int __init numa_alloc_distance(void)
 344{
 345        nodemask_t nodes_parsed;
 346        size_t size;
 347        int i, j, cnt = 0;
 348        u64 phys;
 349
 350        /* size the new table and allocate it */
 351        nodes_parsed = numa_nodes_parsed;
 352        numa_nodemask_from_meminfo(&nodes_parsed, &numa_meminfo);
 353
 354        for_each_node_mask(i, nodes_parsed)
 355                cnt = i;
 356        cnt++;
 357        size = cnt * cnt * sizeof(numa_distance[0]);
 358
 359        phys = memblock_find_in_range(0, PFN_PHYS(max_pfn_mapped),
 360                                      size, PAGE_SIZE);
 361        if (!phys) {
 362                pr_warning("NUMA: Warning: can't allocate distance table!\n");
 363                /* don't retry until explicitly reset */
 364                numa_distance = (void *)1LU;
 365                return -ENOMEM;
 366        }
 367        memblock_reserve(phys, size);
 368
 369        numa_distance = __va(phys);
 370        numa_distance_cnt = cnt;
 371
 372        /* fill with the default distances */
 373        for (i = 0; i < cnt; i++)
 374                for (j = 0; j < cnt; j++)
 375                        numa_distance[i * cnt + j] = i == j ?
 376                                LOCAL_DISTANCE : REMOTE_DISTANCE;
 377        printk(KERN_DEBUG "NUMA: Initialized distance table, cnt=%d\n", cnt);
 378
 379        return 0;
 380}
 381
 382/**
 383 * numa_set_distance - Set NUMA distance from one NUMA to another
 384 * @from: the 'from' node to set distance
 385 * @to: the 'to'  node to set distance
 386 * @distance: NUMA distance
 387 *
 388 * Set the distance from node @from to @to to @distance.  If distance table
 389 * doesn't exist, one which is large enough to accommodate all the currently
 390 * known nodes will be created.
 391 *
 392 * If such table cannot be allocated, a warning is printed and further
 393 * calls are ignored until the distance table is reset with
 394 * numa_reset_distance().
 395 *
 396 * If @from or @to is higher than the highest known node or lower than zero
 397 * at the time of table creation or @distance doesn't make sense, the call
 398 * is ignored.
 399 * This is to allow simplification of specific NUMA config implementations.
 400 */
 401void __init numa_set_distance(int from, int to, int distance)
 402{
 403        if (!numa_distance && numa_alloc_distance() < 0)
 404                return;
 405
 406        if (from >= numa_distance_cnt || to >= numa_distance_cnt ||
 407                        from < 0 || to < 0) {
 408                pr_warn_once("NUMA: Warning: node ids are out of bound, from=%d to=%d distance=%d\n",
 409                            from, to, distance);
 410                return;
 411        }
 412
 413        if ((u8)distance != distance ||
 414            (from == to && distance != LOCAL_DISTANCE)) {
 415                pr_warn_once("NUMA: Warning: invalid distance parameter, from=%d to=%d distance=%d\n",
 416                             from, to, distance);
 417                return;
 418        }
 419
 420        numa_distance[from * numa_distance_cnt + to] = distance;
 421}
 422
 423int __node_distance(int from, int to)
 424{
 425        if (from >= numa_distance_cnt || to >= numa_distance_cnt)
 426                return from == to ? LOCAL_DISTANCE : REMOTE_DISTANCE;
 427        return numa_distance[from * numa_distance_cnt + to];
 428}
 429EXPORT_SYMBOL(__node_distance);
 430
 431/*
 432 * Sanity check to catch more bad NUMA configurations (they are amazingly
 433 * common).  Make sure the nodes cover all memory.
 434 */
 435static bool __init numa_meminfo_cover_memory(const struct numa_meminfo *mi)
 436{
 437        u64 numaram, e820ram;
 438        int i;
 439
 440        numaram = 0;
 441        for (i = 0; i < mi->nr_blks; i++) {
 442                u64 s = mi->blk[i].start >> PAGE_SHIFT;
 443                u64 e = mi->blk[i].end >> PAGE_SHIFT;
 444                numaram += e - s;
 445                numaram -= __absent_pages_in_range(mi->blk[i].nid, s, e);
 446                if ((s64)numaram < 0)
 447                        numaram = 0;
 448        }
 449
 450        e820ram = max_pfn - absent_pages_in_range(0, max_pfn);
 451
 452        /* We seem to lose 3 pages somewhere. Allow 1M of slack. */
 453        if ((s64)(e820ram - numaram) >= (1 << (20 - PAGE_SHIFT))) {
 454                printk(KERN_ERR "NUMA: nodes only cover %LuMB of your %LuMB e820 RAM. Not used.\n",
 455                       (numaram << PAGE_SHIFT) >> 20,
 456                       (e820ram << PAGE_SHIFT) >> 20);
 457                return false;
 458        }
 459        return true;
 460}
 461
 462static void __init numa_clear_kernel_node_hotplug(void)
 463{
 464        int i, nid;
 465        nodemask_t numa_kernel_nodes = NODE_MASK_NONE;
 466        unsigned long start, end;
 467        struct memblock_region *r;
 468
 469        /*
 470         * At this time, all memory regions reserved by memblock are
 471         * used by the kernel. Set the nid in memblock.reserved will
 472         * mark out all the nodes the kernel resides in.
 473         */
 474        for (i = 0; i < numa_meminfo.nr_blks; i++) {
 475                struct numa_memblk *mb = &numa_meminfo.blk[i];
 476
 477                memblock_set_node(mb->start, mb->end - mb->start,
 478                                  &memblock.reserved, mb->nid);
 479        }
 480
 481        /*
 482         * Mark all kernel nodes.
 483         *
 484         * When booting with mem=nn[kMG] or in a kdump kernel, numa_meminfo
 485         * may not include all the memblock.reserved memory ranges because
 486         * trim_snb_memory() reserves specific pages for Sandy Bridge graphics.
 487         */
 488        for_each_memblock(reserved, r)
 489                if (r->nid != MAX_NUMNODES)
 490                        node_set(r->nid, numa_kernel_nodes);
 491
 492        /* Clear MEMBLOCK_HOTPLUG flag for memory in kernel nodes. */
 493        for (i = 0; i < numa_meminfo.nr_blks; i++) {
 494                nid = numa_meminfo.blk[i].nid;
 495                if (!node_isset(nid, numa_kernel_nodes))
 496                        continue;
 497
 498                start = numa_meminfo.blk[i].start;
 499                end = numa_meminfo.blk[i].end;
 500
 501                memblock_clear_hotplug(start, end - start);
 502        }
 503}
 504
 505static int __init numa_register_memblks(struct numa_meminfo *mi)
 506{
 507        unsigned long uninitialized_var(pfn_align);
 508        int i, nid;
 509
 510        /* Account for nodes with cpus and no memory */
 511        node_possible_map = numa_nodes_parsed;
 512        numa_nodemask_from_meminfo(&node_possible_map, mi);
 513        if (WARN_ON(nodes_empty(node_possible_map)))
 514                return -EINVAL;
 515
 516        for (i = 0; i < mi->nr_blks; i++) {
 517                struct numa_memblk *mb = &mi->blk[i];
 518                memblock_set_node(mb->start, mb->end - mb->start,
 519                                  &memblock.memory, mb->nid);
 520        }
 521
 522        /*
 523         * At very early time, the kernel have to use some memory such as
 524         * loading the kernel image. We cannot prevent this anyway. So any
 525         * node the kernel resides in should be un-hotpluggable.
 526         *
 527         * And when we come here, alloc node data won't fail.
 528         */
 529        numa_clear_kernel_node_hotplug();
 530
 531        /*
 532         * If sections array is gonna be used for pfn -> nid mapping, check
 533         * whether its granularity is fine enough.
 534         */
 535#ifdef NODE_NOT_IN_PAGE_FLAGS
 536        pfn_align = node_map_pfn_alignment();
 537        if (pfn_align && pfn_align < PAGES_PER_SECTION) {
 538                printk(KERN_WARNING "Node alignment %LuMB < min %LuMB, rejecting NUMA config\n",
 539                       PFN_PHYS(pfn_align) >> 20,
 540                       PFN_PHYS(PAGES_PER_SECTION) >> 20);
 541                return -EINVAL;
 542        }
 543#endif
 544        if (!numa_meminfo_cover_memory(mi))
 545                return -EINVAL;
 546
 547        /* Finally register nodes. */
 548        for_each_node_mask(nid, node_possible_map) {
 549                u64 start = PFN_PHYS(max_pfn);
 550                u64 end = 0;
 551
 552                for (i = 0; i < mi->nr_blks; i++) {
 553                        if (nid != mi->blk[i].nid)
 554                                continue;
 555                        start = min(mi->blk[i].start, start);
 556                        end = max(mi->blk[i].end, end);
 557                }
 558
 559                if (start >= end)
 560                        continue;
 561
 562                /*
 563                 * Don't confuse VM with a node that doesn't have the
 564                 * minimum amount of memory:
 565                 */
 566                if (end && (end - start) < NODE_MIN_SIZE)
 567                        continue;
 568
 569                alloc_node_data(nid);
 570        }
 571
 572        /* Dump memblock with node info and return. */
 573        memblock_dump_all();
 574        return 0;
 575}
 576
 577/*
 578 * There are unfortunately some poorly designed mainboards around that
 579 * only connect memory to a single CPU. This breaks the 1:1 cpu->node
 580 * mapping. To avoid this fill in the mapping for all possible CPUs,
 581 * as the number of CPUs is not known yet. We round robin the existing
 582 * nodes.
 583 */
 584static void __init numa_init_array(void)
 585{
 586        int rr, i;
 587
 588        rr = first_node(node_online_map);
 589        for (i = 0; i < nr_cpu_ids; i++) {
 590                if (early_cpu_to_node(i) != NUMA_NO_NODE)
 591                        continue;
 592                numa_set_node(i, rr);
 593                rr = next_node(rr, node_online_map);
 594                if (rr == MAX_NUMNODES)
 595                        rr = first_node(node_online_map);
 596        }
 597}
 598
 599static int __init numa_init(int (*init_func)(void))
 600{
 601        int i;
 602        int ret;
 603
 604        for (i = 0; i < MAX_LOCAL_APIC; i++)
 605                set_apicid_to_node(i, NUMA_NO_NODE);
 606
 607        nodes_clear(numa_nodes_parsed);
 608        nodes_clear(node_possible_map);
 609        nodes_clear(node_online_map);
 610        memset(&numa_meminfo, 0, sizeof(numa_meminfo));
 611        WARN_ON(memblock_set_node(0, ULLONG_MAX, &memblock.memory,
 612                                  MAX_NUMNODES));
 613        WARN_ON(memblock_set_node(0, ULLONG_MAX, &memblock.reserved,
 614                                  MAX_NUMNODES));
 615        /* In case that parsing SRAT failed. */
 616        WARN_ON(memblock_clear_hotplug(0, ULLONG_MAX));
 617        numa_reset_distance();
 618
 619        ret = init_func();
 620        if (ret < 0)
 621                return ret;
 622
 623        /*
 624         * We reset memblock back to the top-down direction
 625         * here because if we configured ACPI_NUMA, we have
 626         * parsed SRAT in init_func(). It is ok to have the
 627         * reset here even if we did't configure ACPI_NUMA
 628         * or acpi numa init fails and fallbacks to dummy
 629         * numa init.
 630         */
 631        memblock_set_bottom_up(false);
 632
 633        ret = numa_cleanup_meminfo(&numa_meminfo);
 634        if (ret < 0)
 635                return ret;
 636
 637        numa_emulation(&numa_meminfo, numa_distance_cnt);
 638
 639        ret = numa_register_memblks(&numa_meminfo);
 640        if (ret < 0)
 641                return ret;
 642
 643        for (i = 0; i < nr_cpu_ids; i++) {
 644                int nid = early_cpu_to_node(i);
 645
 646                if (nid == NUMA_NO_NODE)
 647                        continue;
 648                if (!node_online(nid))
 649                        numa_clear_node(i);
 650        }
 651        numa_init_array();
 652
 653        return 0;
 654}
 655
 656/**
 657 * dummy_numa_init - Fallback dummy NUMA init
 658 *
 659 * Used if there's no underlying NUMA architecture, NUMA initialization
 660 * fails, or NUMA is disabled on the command line.
 661 *
 662 * Must online at least one node and add memory blocks that cover all
 663 * allowed memory.  This function must not fail.
 664 */
 665static int __init dummy_numa_init(void)
 666{
 667        printk(KERN_INFO "%s\n",
 668               numa_off ? "NUMA turned off" : "No NUMA configuration found");
 669        printk(KERN_INFO "Faking a node at [mem %#018Lx-%#018Lx]\n",
 670               0LLU, PFN_PHYS(max_pfn) - 1);
 671
 672        node_set(0, numa_nodes_parsed);
 673        numa_add_memblk(0, 0, PFN_PHYS(max_pfn));
 674
 675        return 0;
 676}
 677
 678/**
 679 * x86_numa_init - Initialize NUMA
 680 *
 681 * Try each configured NUMA initialization method until one succeeds.  The
 682 * last fallback is dummy single node config encomapssing whole memory and
 683 * never fails.
 684 */
 685void __init x86_numa_init(void)
 686{
 687        if (!numa_off) {
 688#ifdef CONFIG_X86_NUMAQ
 689                if (!numa_init(numaq_numa_init))
 690                        return;
 691#endif
 692#ifdef CONFIG_ACPI_NUMA
 693                if (!numa_init(x86_acpi_numa_init))
 694                        return;
 695#endif
 696#ifdef CONFIG_AMD_NUMA
 697                if (!numa_init(amd_numa_init))
 698                        return;
 699#endif
 700        }
 701
 702        numa_init(dummy_numa_init);
 703}
 704
 705static void __init init_memory_less_node(int nid)
 706{
 707        unsigned long zones_size[MAX_NR_ZONES] = {0};
 708        unsigned long zholes_size[MAX_NR_ZONES] = {0};
 709
 710        /* Allocate and initialize node data. Memory-less node is now online.*/
 711        alloc_node_data(nid);
 712        free_area_init_node(nid, zones_size, 0, zholes_size);
 713
 714        /*
 715         * All zonelists will be built later in start_kernel() after per cpu
 716         * areas are initialized.
 717         */
 718}
 719
 720/*
 721 * Setup early cpu_to_node.
 722 *
 723 * Populate cpu_to_node[] only if x86_cpu_to_apicid[],
 724 * and apicid_to_node[] tables have valid entries for a CPU.
 725 * This means we skip cpu_to_node[] initialisation for NUMA
 726 * emulation and faking node case (when running a kernel compiled
 727 * for NUMA on a non NUMA box), which is OK as cpu_to_node[]
 728 * is already initialized in a round robin manner at numa_init_array,
 729 * prior to this call, and this initialization is good enough
 730 * for the fake NUMA cases.
 731 *
 732 * Called before the per_cpu areas are setup.
 733 */
 734void __init init_cpu_to_node(void)
 735{
 736        int cpu;
 737        u16 *cpu_to_apicid = early_per_cpu_ptr(x86_cpu_to_apicid);
 738
 739        BUG_ON(cpu_to_apicid == NULL);
 740
 741        for_each_possible_cpu(cpu) {
 742                int node = numa_cpu_node(cpu);
 743
 744                if (node == NUMA_NO_NODE)
 745                        continue;
 746
 747                if (!node_online(node))
 748                        init_memory_less_node(node);
 749
 750                numa_set_node(cpu, node);
 751        }
 752}
 753
 754#ifndef CONFIG_DEBUG_PER_CPU_MAPS
 755
 756# ifndef CONFIG_NUMA_EMU
 757void numa_add_cpu(int cpu)
 758{
 759        cpumask_set_cpu(cpu, node_to_cpumask_map[early_cpu_to_node(cpu)]);
 760}
 761
 762void numa_remove_cpu(int cpu)
 763{
 764        cpumask_clear_cpu(cpu, node_to_cpumask_map[early_cpu_to_node(cpu)]);
 765}
 766# endif /* !CONFIG_NUMA_EMU */
 767
 768#else   /* !CONFIG_DEBUG_PER_CPU_MAPS */
 769
 770int __cpu_to_node(int cpu)
 771{
 772        if (early_per_cpu_ptr(x86_cpu_to_node_map)) {
 773                printk(KERN_WARNING
 774                        "cpu_to_node(%d): usage too early!\n", cpu);
 775                dump_stack();
 776                return early_per_cpu_ptr(x86_cpu_to_node_map)[cpu];
 777        }
 778        return per_cpu(x86_cpu_to_node_map, cpu);
 779}
 780EXPORT_SYMBOL(__cpu_to_node);
 781
 782/*
 783 * Same function as cpu_to_node() but used if called before the
 784 * per_cpu areas are setup.
 785 */
 786int early_cpu_to_node(int cpu)
 787{
 788        if (early_per_cpu_ptr(x86_cpu_to_node_map))
 789                return early_per_cpu_ptr(x86_cpu_to_node_map)[cpu];
 790
 791        if (!cpu_possible(cpu)) {
 792                printk(KERN_WARNING
 793                        "early_cpu_to_node(%d): no per_cpu area!\n", cpu);
 794                dump_stack();
 795                return NUMA_NO_NODE;
 796        }
 797        return per_cpu(x86_cpu_to_node_map, cpu);
 798}
 799
 800void debug_cpumask_set_cpu(int cpu, int node, bool enable)
 801{
 802        struct cpumask *mask;
 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        printk(KERN_DEBUG "%s cpu %d node %d: mask now %pc\n",
 821                enable ? "numa_add_cpu" : "numa_remove_cpu",
 822                cpu, node, mask);
 823        return;
 824}
 825
 826# ifndef CONFIG_NUMA_EMU
 827static void numa_set_cpumask(int cpu, bool enable)
 828{
 829        debug_cpumask_set_cpu(cpu, early_cpu_to_node(cpu), enable);
 830}
 831
 832void numa_add_cpu(int cpu)
 833{
 834        numa_set_cpumask(cpu, true);
 835}
 836
 837void numa_remove_cpu(int cpu)
 838{
 839        numa_set_cpumask(cpu, false);
 840}
 841# endif /* !CONFIG_NUMA_EMU */
 842
 843/*
 844 * Returns a pointer to the bitmask of CPUs on Node 'node'.
 845 */
 846const struct cpumask *cpumask_of_node(int node)
 847{
 848        if (node >= nr_node_ids) {
 849                printk(KERN_WARNING
 850                        "cpumask_of_node(%d): node > nr_node_ids(%d)\n",
 851                        node, nr_node_ids);
 852                dump_stack();
 853                return cpu_none_mask;
 854        }
 855        if (node_to_cpumask_map[node] == NULL) {
 856                printk(KERN_WARNING
 857                        "cpumask_of_node(%d): no node_to_cpumask_map!\n",
 858                        node);
 859                dump_stack();
 860                return cpu_online_mask;
 861        }
 862        return node_to_cpumask_map[node];
 863}
 864EXPORT_SYMBOL(cpumask_of_node);
 865
 866#endif  /* !CONFIG_DEBUG_PER_CPU_MAPS */
 867
 868#ifdef CONFIG_MEMORY_HOTPLUG
 869int memory_add_physaddr_to_nid(u64 start)
 870{
 871        struct numa_meminfo *mi = &numa_meminfo;
 872        int nid = mi->blk[0].nid;
 873        int i;
 874
 875        for (i = 0; i < mi->nr_blks; i++)
 876                if (mi->blk[i].start <= start && mi->blk[i].end > start)
 877                        nid = mi->blk[i].nid;
 878        return nid;
 879}
 880EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
 881#endif
 882