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/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
  23int __initdata numa_off;
  24nodemask_t numa_nodes_parsed __initdata;
  25
  26struct pglist_data *node_data[MAX_NUMNODES] __read_mostly;
  27EXPORT_SYMBOL(node_data);
  28
  29static struct numa_meminfo numa_meminfo
  30#ifndef CONFIG_MEMORY_HOTPLUG
  31__initdata
  32#endif
  33;
  34
  35static int numa_distance_cnt;
  36static u8 *numa_distance;
  37
  38static __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}
  54early_param("numa", numa_setup);
  55
  56/*
  57 * apicid, cpu, node mappings
  58 */
  59s16 __apicid_to_node[MAX_LOCAL_APIC] = {
  60        [0 ... MAX_LOCAL_APIC-1] = NUMA_NO_NODE
  61};
  62
  63int 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
  72cpumask_var_t node_to_cpumask_map[MAX_NUMNODES];
  73EXPORT_SYMBOL(node_to_cpumask_map);
  74
  75/*
  76 * Map cpu index to node index
  77 */
  78DEFINE_EARLY_PER_CPU(int, x86_cpu_to_node_map, NUMA_NO_NODE);
  79EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_node_map);
  80
  81void 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
 103void 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 */
 115void __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
 131static 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 */
 165void __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 */
 183int __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 */
 189static 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                pr_err("Cannot find %zu bytes in node %d\n",
 215                       nd_size, nid);
 216                return;
 217        }
 218        nd = __va(nd_pa);
 219
 220        /* report and initialize */
 221        printk(KERN_INFO "  NODE_DATA [mem %#010Lx-%#010Lx]\n",
 222               nd_pa, nd_pa + nd_size - 1);
 223        tnid = early_pfn_to_nid(nd_pa >> PAGE_SHIFT);
 224        if (tnid != nid)
 225                printk(KERN_INFO "    NODE_DATA(%d) on node %d\n", nid, tnid);
 226
 227        node_data[nid] = nd;
 228        memset(NODE_DATA(nid), 0, sizeof(pg_data_t));
 229        NODE_DATA(nid)->node_id = nid;
 230        NODE_DATA(nid)->node_start_pfn = start >> PAGE_SHIFT;
 231        NODE_DATA(nid)->node_spanned_pages = (end - start) >> PAGE_SHIFT;
 232
 233        node_set_online(nid);
 234}
 235
 236/**
 237 * numa_cleanup_meminfo - Cleanup a numa_meminfo
 238 * @mi: numa_meminfo to clean up
 239 *
 240 * Sanitize @mi by merging and removing unncessary memblks.  Also check for
 241 * conflicts and clear unused memblks.
 242 *
 243 * RETURNS:
 244 * 0 on success, -errno on failure.
 245 */
 246int __init numa_cleanup_meminfo(struct numa_meminfo *mi)
 247{
 248        const u64 low = 0;
 249        const u64 high = PFN_PHYS(max_pfn);
 250        int i, j, k;
 251
 252        /* first, trim all entries */
 253        for (i = 0; i < mi->nr_blks; i++) {
 254                struct numa_memblk *bi = &mi->blk[i];
 255
 256                /* make sure all blocks are inside the limits */
 257                bi->start = max(bi->start, low);
 258                bi->end = min(bi->end, high);
 259
 260                /* and there's no empty block */
 261                if (bi->start >= bi->end)
 262                        numa_remove_memblk_from(i--, mi);
 263        }
 264
 265        /* merge neighboring / overlapping entries */
 266        for (i = 0; i < mi->nr_blks; i++) {
 267                struct numa_memblk *bi = &mi->blk[i];
 268
 269                for (j = i + 1; j < mi->nr_blks; j++) {
 270                        struct numa_memblk *bj = &mi->blk[j];
 271                        u64 start, end;
 272
 273                        /*
 274                         * See whether there are overlapping blocks.  Whine
 275                         * about but allow overlaps of the same nid.  They
 276                         * will be merged below.
 277                         */
 278                        if (bi->end > bj->start && bi->start < bj->end) {
 279                                if (bi->nid != bj->nid) {
 280                                        pr_err("NUMA: node %d [mem %#010Lx-%#010Lx] overlaps with node %d [mem %#010Lx-%#010Lx]\n",
 281                                               bi->nid, bi->start, bi->end - 1,
 282                                               bj->nid, bj->start, bj->end - 1);
 283                                        return -EINVAL;
 284                                }
 285                                pr_warning("NUMA: Warning: node %d [mem %#010Lx-%#010Lx] overlaps with itself [mem %#010Lx-%#010Lx]\n",
 286                                           bi->nid, bi->start, bi->end - 1,
 287                                           bj->start, bj->end - 1);
 288                        }
 289
 290                        /*
 291                         * Join together blocks on the same node, holes
 292                         * between which don't overlap with memory on other
 293                         * nodes.
 294                         */
 295                        if (bi->nid != bj->nid)
 296                                continue;
 297                        start = min(bi->start, bj->start);
 298                        end = max(bi->end, bj->end);
 299                        for (k = 0; k < mi->nr_blks; k++) {
 300                                struct numa_memblk *bk = &mi->blk[k];
 301
 302                                if (bi->nid == bk->nid)
 303                                        continue;
 304                                if (start < bk->end && end > bk->start)
 305                                        break;
 306                        }
 307                        if (k < mi->nr_blks)
 308                                continue;
 309                        printk(KERN_INFO "NUMA: Node %d [mem %#010Lx-%#010Lx] + [mem %#010Lx-%#010Lx] -> [mem %#010Lx-%#010Lx]\n",
 310                               bi->nid, bi->start, bi->end - 1, bj->start,
 311                               bj->end - 1, start, end - 1);
 312                        bi->start = start;
 313                        bi->end = end;
 314                        numa_remove_memblk_from(j--, mi);
 315                }
 316        }
 317
 318        /* clear unused ones */
 319        for (i = mi->nr_blks; i < ARRAY_SIZE(mi->blk); i++) {
 320                mi->blk[i].start = mi->blk[i].end = 0;
 321                mi->blk[i].nid = NUMA_NO_NODE;
 322        }
 323
 324        return 0;
 325}
 326
 327/*
 328 * Set nodes, which have memory in @mi, in *@nodemask.
 329 */
 330static void __init numa_nodemask_from_meminfo(nodemask_t *nodemask,
 331                                              const struct numa_meminfo *mi)
 332{
 333        int i;
 334
 335        for (i = 0; i < ARRAY_SIZE(mi->blk); i++)
 336                if (mi->blk[i].start != mi->blk[i].end &&
 337                    mi->blk[i].nid != NUMA_NO_NODE)
 338                        node_set(mi->blk[i].nid, *nodemask);
 339}
 340
 341/**
 342 * numa_reset_distance - Reset NUMA distance table
 343 *
 344 * The current table is freed.  The next numa_set_distance() call will
 345 * create a new one.
 346 */
 347void __init numa_reset_distance(void)
 348{
 349        size_t size = numa_distance_cnt * numa_distance_cnt * sizeof(numa_distance[0]);
 350
 351        /* numa_distance could be 1LU marking allocation failure, test cnt */
 352        if (numa_distance_cnt)
 353                memblock_free(__pa(numa_distance), size);
 354        numa_distance_cnt = 0;
 355        numa_distance = NULL;   /* enable table creation */
 356}
 357
 358static int __init numa_alloc_distance(void)
 359{
 360        nodemask_t nodes_parsed;
 361        size_t size;
 362        int i, j, cnt = 0;
 363        u64 phys;
 364
 365        /* size the new table and allocate it */
 366        nodes_parsed = numa_nodes_parsed;
 367        numa_nodemask_from_meminfo(&nodes_parsed, &numa_meminfo);
 368
 369        for_each_node_mask(i, nodes_parsed)
 370                cnt = i;
 371        cnt++;
 372        size = cnt * cnt * sizeof(numa_distance[0]);
 373
 374        phys = memblock_find_in_range(0, PFN_PHYS(max_pfn_mapped),
 375                                      size, PAGE_SIZE);
 376        if (!phys) {
 377                pr_warning("NUMA: Warning: can't allocate distance table!\n");
 378                /* don't retry until explicitly reset */
 379                numa_distance = (void *)1LU;
 380                return -ENOMEM;
 381        }
 382        memblock_reserve(phys, size);
 383
 384        numa_distance = __va(phys);
 385        numa_distance_cnt = cnt;
 386
 387        /* fill with the default distances */
 388        for (i = 0; i < cnt; i++)
 389                for (j = 0; j < cnt; j++)
 390                        numa_distance[i * cnt + j] = i == j ?
 391                                LOCAL_DISTANCE : REMOTE_DISTANCE;
 392        printk(KERN_DEBUG "NUMA: Initialized distance table, cnt=%d\n", cnt);
 393
 394        return 0;
 395}
 396
 397/**
 398 * numa_set_distance - Set NUMA distance from one NUMA to another
 399 * @from: the 'from' node to set distance
 400 * @to: the 'to'  node to set distance
 401 * @distance: NUMA distance
 402 *
 403 * Set the distance from node @from to @to to @distance.  If distance table
 404 * doesn't exist, one which is large enough to accommodate all the currently
 405 * known nodes will be created.
 406 *
 407 * If such table cannot be allocated, a warning is printed and further
 408 * calls are ignored until the distance table is reset with
 409 * numa_reset_distance().
 410 *
 411 * If @from or @to is higher than the highest known node or lower than zero
 412 * at the time of table creation or @distance doesn't make sense, the call
 413 * is ignored.
 414 * This is to allow simplification of specific NUMA config implementations.
 415 */
 416void __init numa_set_distance(int from, int to, int distance)
 417{
 418        if (!numa_distance && numa_alloc_distance() < 0)
 419                return;
 420
 421        if (from >= numa_distance_cnt || to >= numa_distance_cnt ||
 422                        from < 0 || to < 0) {
 423                pr_warn_once("NUMA: Warning: node ids are out of bound, from=%d to=%d distance=%d\n",
 424                            from, to, distance);
 425                return;
 426        }
 427
 428        if ((u8)distance != distance ||
 429            (from == to && distance != LOCAL_DISTANCE)) {
 430                pr_warn_once("NUMA: Warning: invalid distance parameter, from=%d to=%d distance=%d\n",
 431                             from, to, distance);
 432                return;
 433        }
 434
 435        numa_distance[from * numa_distance_cnt + to] = distance;
 436}
 437
 438int __node_distance(int from, int to)
 439{
 440        if (from >= numa_distance_cnt || to >= numa_distance_cnt)
 441                return from == to ? LOCAL_DISTANCE : REMOTE_DISTANCE;
 442        return numa_distance[from * numa_distance_cnt + to];
 443}
 444EXPORT_SYMBOL(__node_distance);
 445
 446/*
 447 * Sanity check to catch more bad NUMA configurations (they are amazingly
 448 * common).  Make sure the nodes cover all memory.
 449 */
 450static bool __init numa_meminfo_cover_memory(const struct numa_meminfo *mi)
 451{
 452        u64 numaram, e820ram;
 453        int i;
 454
 455        numaram = 0;
 456        for (i = 0; i < mi->nr_blks; i++) {
 457                u64 s = mi->blk[i].start >> PAGE_SHIFT;
 458                u64 e = mi->blk[i].end >> PAGE_SHIFT;
 459                numaram += e - s;
 460                numaram -= __absent_pages_in_range(mi->blk[i].nid, s, e);
 461                if ((s64)numaram < 0)
 462                        numaram = 0;
 463        }
 464
 465        e820ram = max_pfn - absent_pages_in_range(0, max_pfn);
 466
 467        /* We seem to lose 3 pages somewhere. Allow 1M of slack. */
 468        if ((s64)(e820ram - numaram) >= (1 << (20 - PAGE_SHIFT))) {
 469                printk(KERN_ERR "NUMA: nodes only cover %LuMB of your %LuMB e820 RAM. Not used.\n",
 470                       (numaram << PAGE_SHIFT) >> 20,
 471                       (e820ram << PAGE_SHIFT) >> 20);
 472                return false;
 473        }
 474        return true;
 475}
 476
 477static int __init numa_register_memblks(struct numa_meminfo *mi)
 478{
 479        unsigned long uninitialized_var(pfn_align);
 480        int i, nid;
 481
 482        /* Account for nodes with cpus and no memory */
 483        node_possible_map = numa_nodes_parsed;
 484        numa_nodemask_from_meminfo(&node_possible_map, mi);
 485        if (WARN_ON(nodes_empty(node_possible_map)))
 486                return -EINVAL;
 487
 488        for (i = 0; i < mi->nr_blks; i++) {
 489                struct numa_memblk *mb = &mi->blk[i];
 490                memblock_set_node(mb->start, mb->end - mb->start, mb->nid);
 491        }
 492
 493        /*
 494         * If sections array is gonna be used for pfn -> nid mapping, check
 495         * whether its granularity is fine enough.
 496         */
 497#ifdef NODE_NOT_IN_PAGE_FLAGS
 498        pfn_align = node_map_pfn_alignment();
 499        if (pfn_align && pfn_align < PAGES_PER_SECTION) {
 500                printk(KERN_WARNING "Node alignment %LuMB < min %LuMB, rejecting NUMA config\n",
 501                       PFN_PHYS(pfn_align) >> 20,
 502                       PFN_PHYS(PAGES_PER_SECTION) >> 20);
 503                return -EINVAL;
 504        }
 505#endif
 506        if (!numa_meminfo_cover_memory(mi))
 507                return -EINVAL;
 508
 509        /* Finally register nodes. */
 510        for_each_node_mask(nid, node_possible_map) {
 511                u64 start = PFN_PHYS(max_pfn);
 512                u64 end = 0;
 513
 514                for (i = 0; i < mi->nr_blks; i++) {
 515                        if (nid != mi->blk[i].nid)
 516                                continue;
 517                        start = min(mi->blk[i].start, start);
 518                        end = max(mi->blk[i].end, end);
 519                }
 520
 521                if (start < end)
 522                        setup_node_data(nid, start, end);
 523        }
 524
 525        /* Dump memblock with node info and return. */
 526        memblock_dump_all();
 527        return 0;
 528}
 529
 530/*
 531 * There are unfortunately some poorly designed mainboards around that
 532 * only connect memory to a single CPU. This breaks the 1:1 cpu->node
 533 * mapping. To avoid this fill in the mapping for all possible CPUs,
 534 * as the number of CPUs is not known yet. We round robin the existing
 535 * nodes.
 536 */
 537static void __init numa_init_array(void)
 538{
 539        int rr, i;
 540
 541        rr = first_node(node_online_map);
 542        for (i = 0; i < nr_cpu_ids; i++) {
 543                if (early_cpu_to_node(i) != NUMA_NO_NODE)
 544                        continue;
 545                numa_set_node(i, rr);
 546                rr = next_node(rr, node_online_map);
 547                if (rr == MAX_NUMNODES)
 548                        rr = first_node(node_online_map);
 549        }
 550}
 551
 552static int __init numa_init(int (*init_func)(void))
 553{
 554        int i;
 555        int ret;
 556
 557        for (i = 0; i < MAX_LOCAL_APIC; i++)
 558                set_apicid_to_node(i, NUMA_NO_NODE);
 559
 560        nodes_clear(numa_nodes_parsed);
 561        nodes_clear(node_possible_map);
 562        nodes_clear(node_online_map);
 563        memset(&numa_meminfo, 0, sizeof(numa_meminfo));
 564        WARN_ON(memblock_set_node(0, ULLONG_MAX, MAX_NUMNODES));
 565        numa_reset_distance();
 566
 567        ret = init_func();
 568        if (ret < 0)
 569                return ret;
 570        ret = numa_cleanup_meminfo(&numa_meminfo);
 571        if (ret < 0)
 572                return ret;
 573
 574        numa_emulation(&numa_meminfo, numa_distance_cnt);
 575
 576        ret = numa_register_memblks(&numa_meminfo);
 577        if (ret < 0)
 578                return ret;
 579
 580        for (i = 0; i < nr_cpu_ids; i++) {
 581                int nid = early_cpu_to_node(i);
 582
 583                if (nid == NUMA_NO_NODE)
 584                        continue;
 585                if (!node_online(nid))
 586                        numa_clear_node(i);
 587        }
 588        numa_init_array();
 589        return 0;
 590}
 591
 592/**
 593 * dummy_numa_init - Fallback dummy NUMA init
 594 *
 595 * Used if there's no underlying NUMA architecture, NUMA initialization
 596 * fails, or NUMA is disabled on the command line.
 597 *
 598 * Must online at least one node and add memory blocks that cover all
 599 * allowed memory.  This function must not fail.
 600 */
 601static int __init dummy_numa_init(void)
 602{
 603        printk(KERN_INFO "%s\n",
 604               numa_off ? "NUMA turned off" : "No NUMA configuration found");
 605        printk(KERN_INFO "Faking a node at [mem %#018Lx-%#018Lx]\n",
 606               0LLU, PFN_PHYS(max_pfn) - 1);
 607
 608        node_set(0, numa_nodes_parsed);
 609        numa_add_memblk(0, 0, PFN_PHYS(max_pfn));
 610
 611        return 0;
 612}
 613
 614/**
 615 * x86_numa_init - Initialize NUMA
 616 *
 617 * Try each configured NUMA initialization method until one succeeds.  The
 618 * last fallback is dummy single node config encomapssing whole memory and
 619 * never fails.
 620 */
 621void __init x86_numa_init(void)
 622{
 623        if (!numa_off) {
 624#ifdef CONFIG_X86_NUMAQ
 625                if (!numa_init(numaq_numa_init))
 626                        return;
 627#endif
 628#ifdef CONFIG_ACPI_NUMA
 629                if (!numa_init(x86_acpi_numa_init))
 630                        return;
 631#endif
 632#ifdef CONFIG_AMD_NUMA
 633                if (!numa_init(amd_numa_init))
 634                        return;
 635#endif
 636        }
 637
 638        numa_init(dummy_numa_init);
 639}
 640
 641static __init int find_near_online_node(int node)
 642{
 643        int n, val;
 644        int min_val = INT_MAX;
 645        int best_node = -1;
 646
 647        for_each_online_node(n) {
 648                val = node_distance(node, n);
 649
 650                if (val < min_val) {
 651                        min_val = val;
 652                        best_node = n;
 653                }
 654        }
 655
 656        return best_node;
 657}
 658
 659/*
 660 * Setup early cpu_to_node.
 661 *
 662 * Populate cpu_to_node[] only if x86_cpu_to_apicid[],
 663 * and apicid_to_node[] tables have valid entries for a CPU.
 664 * This means we skip cpu_to_node[] initialisation for NUMA
 665 * emulation and faking node case (when running a kernel compiled
 666 * for NUMA on a non NUMA box), which is OK as cpu_to_node[]
 667 * is already initialized in a round robin manner at numa_init_array,
 668 * prior to this call, and this initialization is good enough
 669 * for the fake NUMA cases.
 670 *
 671 * Called before the per_cpu areas are setup.
 672 */
 673void __init init_cpu_to_node(void)
 674{
 675        int cpu;
 676        u16 *cpu_to_apicid = early_per_cpu_ptr(x86_cpu_to_apicid);
 677
 678        BUG_ON(cpu_to_apicid == NULL);
 679
 680        for_each_possible_cpu(cpu) {
 681                int node = numa_cpu_node(cpu);
 682
 683                if (node == NUMA_NO_NODE)
 684                        continue;
 685                if (!node_online(node))
 686                        node = find_near_online_node(node);
 687                numa_set_node(cpu, node);
 688        }
 689}
 690
 691#ifndef CONFIG_DEBUG_PER_CPU_MAPS
 692
 693# ifndef CONFIG_NUMA_EMU
 694void numa_add_cpu(int cpu)
 695{
 696        cpumask_set_cpu(cpu, node_to_cpumask_map[early_cpu_to_node(cpu)]);
 697}
 698
 699void numa_remove_cpu(int cpu)
 700{
 701        cpumask_clear_cpu(cpu, node_to_cpumask_map[early_cpu_to_node(cpu)]);
 702}
 703# endif /* !CONFIG_NUMA_EMU */
 704
 705#else   /* !CONFIG_DEBUG_PER_CPU_MAPS */
 706
 707int __cpu_to_node(int cpu)
 708{
 709        if (early_per_cpu_ptr(x86_cpu_to_node_map)) {
 710                printk(KERN_WARNING
 711                        "cpu_to_node(%d): usage too early!\n", cpu);
 712                dump_stack();
 713                return early_per_cpu_ptr(x86_cpu_to_node_map)[cpu];
 714        }
 715        return per_cpu(x86_cpu_to_node_map, cpu);
 716}
 717EXPORT_SYMBOL(__cpu_to_node);
 718
 719/*
 720 * Same function as cpu_to_node() but used if called before the
 721 * per_cpu areas are setup.
 722 */
 723int early_cpu_to_node(int cpu)
 724{
 725        if (early_per_cpu_ptr(x86_cpu_to_node_map))
 726                return early_per_cpu_ptr(x86_cpu_to_node_map)[cpu];
 727
 728        if (!cpu_possible(cpu)) {
 729                printk(KERN_WARNING
 730                        "early_cpu_to_node(%d): no per_cpu area!\n", cpu);
 731                dump_stack();
 732                return NUMA_NO_NODE;
 733        }
 734        return per_cpu(x86_cpu_to_node_map, cpu);
 735}
 736
 737void debug_cpumask_set_cpu(int cpu, int node, bool enable)
 738{
 739        struct cpumask *mask;
 740        char buf[64];
 741
 742        if (node == NUMA_NO_NODE) {
 743                /* early_cpu_to_node() already emits a warning and trace */
 744                return;
 745        }
 746        mask = node_to_cpumask_map[node];
 747        if (!mask) {
 748                pr_err("node_to_cpumask_map[%i] NULL\n", node);
 749                dump_stack();
 750                return;
 751        }
 752
 753        if (enable)
 754                cpumask_set_cpu(cpu, mask);
 755        else
 756                cpumask_clear_cpu(cpu, mask);
 757
 758        cpulist_scnprintf(buf, sizeof(buf), mask);
 759        printk(KERN_DEBUG "%s cpu %d node %d: mask now %s\n",
 760                enable ? "numa_add_cpu" : "numa_remove_cpu",
 761                cpu, node, buf);
 762        return;
 763}
 764
 765# ifndef CONFIG_NUMA_EMU
 766static void numa_set_cpumask(int cpu, bool enable)
 767{
 768        debug_cpumask_set_cpu(cpu, early_cpu_to_node(cpu), enable);
 769}
 770
 771void numa_add_cpu(int cpu)
 772{
 773        numa_set_cpumask(cpu, true);
 774}
 775
 776void numa_remove_cpu(int cpu)
 777{
 778        numa_set_cpumask(cpu, false);
 779}
 780# endif /* !CONFIG_NUMA_EMU */
 781
 782/*
 783 * Returns a pointer to the bitmask of CPUs on Node 'node'.
 784 */
 785const struct cpumask *cpumask_of_node(int node)
 786{
 787        if (node >= nr_node_ids) {
 788                printk(KERN_WARNING
 789                        "cpumask_of_node(%d): node > nr_node_ids(%d)\n",
 790                        node, nr_node_ids);
 791                dump_stack();
 792                return cpu_none_mask;
 793        }
 794        if (node_to_cpumask_map[node] == NULL) {
 795                printk(KERN_WARNING
 796                        "cpumask_of_node(%d): no node_to_cpumask_map!\n",
 797                        node);
 798                dump_stack();
 799                return cpu_online_mask;
 800        }
 801        return node_to_cpumask_map[node];
 802}
 803EXPORT_SYMBOL(cpumask_of_node);
 804
 805#endif  /* !CONFIG_DEBUG_PER_CPU_MAPS */
 806
 807#ifdef CONFIG_MEMORY_HOTPLUG
 808int memory_add_physaddr_to_nid(u64 start)
 809{
 810        struct numa_meminfo *mi = &numa_meminfo;
 811        int nid = mi->blk[0].nid;
 812        int i;
 813
 814        for (i = 0; i < mi->nr_blks; i++)
 815                if (mi->blk[i].start <= start && mi->blk[i].end > start)
 816                        nid = mi->blk[i].nid;
 817        return nid;
 818}
 819EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
 820#endif
 821