arch/x86/mm/numa_64.c

   1 /*
   2  * Generic VM initialization for x86-64 NUMA setups.
   3  * Copyright 2002,2003 Andi Kleen, SuSE Labs.
   4  */
   5 #include <linux/kernel.h>
   6 #include <linux/mm.h>
   7 #include <linux/string.h>
   8 #include <linux/init.h>
   9 #include <linux/bootmem.h>
  10 #include <linux/mmzone.h>
  11 #include <linux/ctype.h>
  12 #include <linux/module.h>
  13 #include <linux/nodemask.h>
  14 #include <linux/sched.h>
  15
  16 #include <asm/e820.h>
  17 #include <asm/proto.h>
  18 #include <asm/dma.h>
  19 #include <asm/numa.h>
  20 #include <asm/acpi.h>
  21 #include <asm/k8.h>
  22
  23 #ifndef Dprintk
  24 #define Dprintk(x...)
  25 #endif
  26
  27 struct pglist_data *node_data[MAX_NUMNODES] __read_mostly;
  28 EXPORT_SYMBOL(node_data);
  29
  30 bootmem_data_t plat_node_bdata[MAX_NUMNODES];
  31
  32 struct memnode memnode;
  33
  34 u16 x86_cpu_to_node_map_init[NR_CPUS] __initdata = {
  35         [0 ... NR_CPUS-1] = NUMA_NO_NODE
  36 };
  37 void *x86_cpu_to_node_map_early_ptr;
  38 EXPORT_SYMBOL(x86_cpu_to_node_map_init);
  39 EXPORT_SYMBOL(x86_cpu_to_node_map_early_ptr);
  40 DEFINE_PER_CPU(u16, x86_cpu_to_node_map) = NUMA_NO_NODE;
  41 EXPORT_PER_CPU_SYMBOL(x86_cpu_to_node_map);
  42
  43 u16 apicid_to_node[MAX_LOCAL_APIC] __cpuinitdata = {
  44         [0 ... MAX_LOCAL_APIC-1] = NUMA_NO_NODE
  45 };
  46
  47 cpumask_t node_to_cpumask_map[MAX_NUMNODES] __read_mostly;
  48 EXPORT_SYMBOL(node_to_cpumask_map);
  49
  50 int numa_off __initdata;
  51 unsigned long __initdata nodemap_addr;
  52 unsigned long __initdata nodemap_size;
  53
  54 /*
  55  * Given a shift value, try to populate memnodemap[]
  56  * Returns :
  57  * 1 if OK
  58  * 0 if memnodmap[] too small (of shift too small)
  59  * -1 if node overlap or lost ram (shift too big)
  60  */
  61 static int __init populate_memnodemap(const struct bootnode *nodes,
  62                                       int numnodes, int shift)
  63 {
  64         unsigned long addr, end;
  65         int i, res = -1;
  66
  67         memset(memnodemap, 0xff, memnodemapsize);
  68         for (i = 0; i < numnodes; i++) {
  69                 addr = nodes[i].start;
  70                 end = nodes[i].end;
  71                 if (addr >= end)
  72                         continue;
  73                 if ((end >> shift) >= memnodemapsize)
  74                         return 0;
  75                 do {
  76                         if (memnodemap[addr >> shift] != 0xff)
  77                                 return -1;
  78                         memnodemap[addr >> shift] = i;
  79                         addr += (1UL << shift);
  80                 } while (addr < end);
  81                 res = 1;
  82         }
  83         return res;
  84 }
  85
  86 static int __init allocate_cachealigned_memnodemap(void)
  87 {
  88         unsigned long pad, pad_addr;
  89
  90         memnodemap = memnode.embedded_map;
  91         if (memnodemapsize <= 48)
  92                 return 0;
  93
  94         pad = L1_CACHE_BYTES - 1;
  95         pad_addr = 0x8000;
  96         nodemap_size = pad + memnodemapsize;
  97         nodemap_addr = find_e820_area(pad_addr, end_pfn<<PAGE_SHIFT,
  98                                       nodemap_size);
  99         if (nodemap_addr == -1UL) {
 100                 printk(KERN_ERR
 101                        "NUMA: Unable to allocate Memory to Node hash map\n");
 102                 nodemap_addr = nodemap_size = 0;
 103                 return -1;
 104         }
 105         pad_addr = (nodemap_addr + pad) & ~pad;
 106         memnodemap = phys_to_virt(pad_addr);
 107
 108         printk(KERN_DEBUG "NUMA: Allocated memnodemap from %lx - %lx\n",
 109                nodemap_addr, nodemap_addr + nodemap_size);
 110         return 0;
 111 }
 112
 113 /*
 114  * The LSB of all start and end addresses in the node map is the value of the
 115  * maximum possible shift.
 116  */
 117 static int __init extract_lsb_from_nodes(const struct bootnode *nodes,
 118                                          int numnodes)
 119 {
 120         int i, nodes_used = 0;
 121         unsigned long start, end;
 122         unsigned long bitfield = 0, memtop = 0;
 123
 124         for (i = 0; i < numnodes; i++) {
 125                 start = nodes[i].start;
 126                 end = nodes[i].end;
 127                 if (start >= end)
 128                         continue;
 129                 bitfield |= start;
 130                 nodes_used++;
 131                 if (end > memtop)
 132                         memtop = end;
 133         }
 134         if (nodes_used <= 1)
 135                 i = 63;
 136         else
 137                 i = find_first_bit(&bitfield, sizeof(unsigned long)*8);
 138         memnodemapsize = (memtop >> i)+1;
 139         return i;
 140 }
 141
 142 int __init compute_hash_shift(struct bootnode *nodes, int numnodes)
 143 {
 144         int shift;
 145
 146         shift = extract_lsb_from_nodes(nodes, numnodes);
 147         if (allocate_cachealigned_memnodemap())
 148                 return -1;
 149         printk(KERN_DEBUG "NUMA: Using %d for the hash shift.\n",
 150                 shift);
 151
 152         if (populate_memnodemap(nodes, numnodes, shift) != 1) {
 153                 printk(KERN_INFO "Your memory is not aligned you need to "
 154                        "rebuild your kernel with a bigger NODEMAPSIZE "
 155                        "shift=%d\n", shift);
 156                 return -1;
 157         }
 158         return shift;
 159 }
 160
 161 int early_pfn_to_nid(unsigned long pfn)
 162 {
 163         return phys_to_nid(pfn << PAGE_SHIFT);
 164 }
 165
 166 static void * __init early_node_mem(int nodeid, unsigned long start,
 167                                     unsigned long end, unsigned long size)
 168 {
 169         unsigned long mem = find_e820_area(start, end, size);
 170         void *ptr;
 171
 172         if (mem != -1L)
 173                 return __va(mem);
 174         ptr = __alloc_bootmem_nopanic(size,
 175                                 SMP_CACHE_BYTES, __pa(MAX_DMA_ADDRESS));
 176         if (ptr == NULL) {
 177                 printk(KERN_ERR "Cannot find %lu bytes in node %d\n",
 178                        size, nodeid);
 179                 return NULL;
 180         }
 181         return ptr;
 182 }
 183
 184 /* Initialize bootmem allocator for a node */
 185 void __init setup_node_bootmem(int nodeid, unsigned long start,
 186                                unsigned long end)
 187 {
 188         unsigned long start_pfn, end_pfn, bootmap_pages, bootmap_size;
 189         unsigned long bootmap_start, nodedata_phys;
 190         void *bootmap;
 191         const int pgdat_size = round_up(sizeof(pg_data_t), PAGE_SIZE);
 192
 193         start = round_up(start, ZONE_ALIGN);
 194
 195         printk(KERN_INFO "Bootmem setup node %d %016lx-%016lx\n", nodeid,
 196                start, end);
 197
 198         start_pfn = start >> PAGE_SHIFT;
 199         end_pfn = end >> PAGE_SHIFT;
 200
 201         node_data[nodeid] = early_node_mem(nodeid, start, end, pgdat_size);
 202         if (node_data[nodeid] == NULL)
 203                 return;
 204         nodedata_phys = __pa(node_data[nodeid]);
 205
 206         memset(NODE_DATA(nodeid), 0, sizeof(pg_data_t));
 207         NODE_DATA(nodeid)->bdata = &plat_node_bdata[nodeid];
 208         NODE_DATA(nodeid)->node_start_pfn = start_pfn;
 209         NODE_DATA(nodeid)->node_spanned_pages = end_pfn - start_pfn;
 210
 211         /* Find a place for the bootmem map */
 212         bootmap_pages = bootmem_bootmap_pages(end_pfn - start_pfn);
 213         bootmap_start = round_up(nodedata_phys + pgdat_size, PAGE_SIZE);
 214         bootmap = early_node_mem(nodeid, bootmap_start, end,
 215                                         bootmap_pages<<PAGE_SHIFT);
 216         if (bootmap == NULL)  {
 217                 if (nodedata_phys < start || nodedata_phys >= end)
 218                         free_bootmem((unsigned long)node_data[nodeid],
 219                                      pgdat_size);
 220                 node_data[nodeid] = NULL;
 221                 return;
 222         }
 223         bootmap_start = __pa(bootmap);
 224         Dprintk("bootmap start %lu pages %lu\n", bootmap_start, bootmap_pages);
 225
 226         bootmap_size = init_bootmem_node(NODE_DATA(nodeid),
 227                                          bootmap_start >> PAGE_SHIFT,
 228                                          start_pfn, end_pfn);
 229
 230         free_bootmem_with_active_regions(nodeid, end);
 231
 232         reserve_bootmem_node(NODE_DATA(nodeid), nodedata_phys, pgdat_size);
 233         reserve_bootmem_node(NODE_DATA(nodeid), bootmap_start,
 234                              bootmap_pages<<PAGE_SHIFT);
 235 #ifdef CONFIG_ACPI_NUMA
 236         srat_reserve_add_area(nodeid);
 237 #endif
 238         node_set_online(nodeid);
 239 }
 240
 241 #ifdef CONFIG_FLAT_NODE_MEM_MAP
 242 /* Initialize final allocator for a zone */
 243 static void __init flat_setup_node_zones(int nodeid)
 244 {
 245         unsigned long start_pfn, end_pfn, memmapsize, limit;
 246
 247         start_pfn = node_start_pfn(nodeid);
 248         end_pfn = node_end_pfn(nodeid);
 249
 250         Dprintk(KERN_INFO "Setting up memmap for node %d %lx-%lx\n",
 251                 nodeid, start_pfn, end_pfn);
 252
 253         /*
 254          * Try to allocate mem_map at end to not fill up precious <4GB
 255          * memory.
 256          */
 257         memmapsize = sizeof(struct page) * (end_pfn-start_pfn);
 258         limit = end_pfn << PAGE_SHIFT;
 259
 260         NODE_DATA(nodeid)->node_mem_map =
 261                 __alloc_bootmem_core(NODE_DATA(nodeid)->bdata,
 262                                      memmapsize, SMP_CACHE_BYTES,
 263                                      round_down(limit - memmapsize, PAGE_SIZE),
 264                                      limit);
 265 }
 266 #else
 267 #define flat_setup_node_zones(i) do {} while (0)
 268 #endif
 269
 270 /*
 271  * There are unfortunately some poorly designed mainboards around that
 272  * only connect memory to a single CPU. This breaks the 1:1 cpu->node
 273  * mapping. To avoid this fill in the mapping for all possible CPUs,
 274  * as the number of CPUs is not known yet. We round robin the existing
 275  * nodes.
 276  */
 277 void __init numa_init_array(void)
 278 {
 279         int rr, i;
 280
 281         rr = first_node(node_online_map);
 282         for (i = 0; i < NR_CPUS; i++) {
 283                 if (cpu_to_node(i) != NUMA_NO_NODE)
 284                         continue;
 285                 numa_set_node(i, rr);
 286                 rr = next_node(rr, node_online_map);
 287                 if (rr == MAX_NUMNODES)
 288                         rr = first_node(node_online_map);
 289         }
 290 }
 291
 292 #ifdef CONFIG_NUMA_EMU
 293 /* Numa emulation */
 294 char *cmdline __initdata;
 295
 296 /*
 297  * Setups up nid to range from addr to addr + size.  If the end
 298  * boundary is greater than max_addr, then max_addr is used instead.
 299  * The return value is 0 if there is additional memory left for
 300  * allocation past addr and -1 otherwise.  addr is adjusted to be at
 301  * the end of the node.
 302  */
 303 static int __init setup_node_range(int nid, struct bootnode *nodes, u64 *addr,
 304                                    u64 size, u64 max_addr)
 305 {
 306         int ret = 0;
 307
 308         nodes[nid].start = *addr;
 309         *addr += size;
 310         if (*addr >= max_addr) {
 311                 *addr = max_addr;
 312                 ret = -1;
 313         }
 314         nodes[nid].end = *addr;
 315         node_set(nid, node_possible_map);
 316         printk(KERN_INFO "Faking node %d at %016Lx-%016Lx (%LuMB)\n", nid,
 317                nodes[nid].start, nodes[nid].end,
 318                (nodes[nid].end - nodes[nid].start) >> 20);
 319         return ret;
 320 }
 321
 322 /*
 323  * Splits num_nodes nodes up equally starting at node_start.  The return value
 324  * is the number of nodes split up and addr is adjusted to be at the end of the
 325  * last node allocated.
 326  */
 327 static int __init split_nodes_equally(struct bootnode *nodes, u64 *addr,
 328                                       u64 max_addr, int node_start,
 329                                       int num_nodes)
 330 {
 331         unsigned int big;
 332         u64 size;
 333         int i;
 334
 335         if (num_nodes <= 0)
 336                 return -1;
 337         if (num_nodes > MAX_NUMNODES)
 338                 num_nodes = MAX_NUMNODES;
 339         size = (max_addr - *addr - e820_hole_size(*addr, max_addr)) /
 340                num_nodes;
 341         /*
 342          * Calculate the number of big nodes that can be allocated as a result
 343          * of consolidating the leftovers.
 344          */
 345         big = ((size & ~FAKE_NODE_MIN_HASH_MASK) * num_nodes) /
 346               FAKE_NODE_MIN_SIZE;
 347
 348         /* Round down to nearest FAKE_NODE_MIN_SIZE. */
 349         size &= FAKE_NODE_MIN_HASH_MASK;
 350         if (!size) {
 351                 printk(KERN_ERR "Not enough memory for each node.  "
 352                        "NUMA emulation disabled.\n");
 353                 return -1;
 354         }
 355
 356         for (i = node_start; i < num_nodes + node_start; i++) {
 357                 u64 end = *addr + size;
 358
 359                 if (i < big)
 360                         end += FAKE_NODE_MIN_SIZE;
 361                 /*
 362                  * The final node can have the remaining system RAM.  Other
 363                  * nodes receive roughly the same amount of available pages.
 364                  */
 365                 if (i == num_nodes + node_start - 1)
 366                         end = max_addr;
 367                 else
 368                         while (end - *addr - e820_hole_size(*addr, end) <
 369                                size) {
 370                                 end += FAKE_NODE_MIN_SIZE;
 371                                 if (end > max_addr) {
 372                                         end = max_addr;
 373                                         break;
 374                                 }
 375                         }
 376                 if (setup_node_range(i, nodes, addr, end - *addr, max_addr) < 0)
 377                         break;
 378         }
 379         return i - node_start + 1;
 380 }
 381
 382 /*
 383  * Splits the remaining system RAM into chunks of size.  The remaining memory is
 384  * always assigned to a final node and can be asymmetric.  Returns the number of
 385  * nodes split.
 386  */
 387 static int __init split_nodes_by_size(struct bootnode *nodes, u64 *addr,
 388                                       u64 max_addr, int node_start, u64 size)
 389 {
 390         int i = node_start;
 391         size = (size << 20) & FAKE_NODE_MIN_HASH_MASK;
 392         while (!setup_node_range(i++, nodes, addr, size, max_addr))
 393                 ;
 394         return i - node_start;
 395 }
 396
 397 /*
 398  * Sets up the system RAM area from start_pfn to end_pfn according to the
 399  * numa=fake command-line option.
 400  */
 401 static int __init numa_emulation(unsigned long start_pfn, unsigned long end_pfn)
 402 {
 403         struct bootnode nodes[MAX_NUMNODES];
 404         u64 size, addr = start_pfn << PAGE_SHIFT;
 405         u64 max_addr = end_pfn << PAGE_SHIFT;
 406         int num_nodes = 0, num = 0, coeff_flag, coeff = -1, i;
 407
 408         memset(&nodes, 0, sizeof(nodes));
 409         /*
 410          * If the numa=fake command-line is just a single number N, split the
 411          * system RAM into N fake nodes.
 412          */
 413         if (!strchr(cmdline, '*') && !strchr(cmdline, ',')) {
 414                 long n = simple_strtol(cmdline, NULL, 0);
 415
 416                 num_nodes = split_nodes_equally(nodes, &addr, max_addr, 0, n);
 417                 if (num_nodes < 0)
 418                         return num_nodes;
 419                 goto out;
 420         }
 421
 422         /* Parse the command line. */
 423         for (coeff_flag = 0; ; cmdline++) {
 424                 if (*cmdline && isdigit(*cmdline)) {
 425                         num = num * 10 + *cmdline - '0';
 426                         continue;
 427                 }
 428                 if (*cmdline == '*') {
 429                         if (num > 0)
 430                                 coeff = num;
 431                         coeff_flag = 1;
 432                 }
 433                 if (!*cmdline || *cmdline == ',') {
 434                         if (!coeff_flag)
 435                                 coeff = 1;
 436                         /*
 437                          * Round down to the nearest FAKE_NODE_MIN_SIZE.
 438                          * Command-line coefficients are in megabytes.
 439                          */
 440                         size = ((u64)num << 20) & FAKE_NODE_MIN_HASH_MASK;
 441                         if (size)
 442                                 for (i = 0; i < coeff; i++, num_nodes++)
 443                                         if (setup_node_range(num_nodes, nodes,
 444                                                 &addr, size, max_addr) < 0)
 445                                                 goto done;
 446                         if (!*cmdline)
 447                                 break;
 448                         coeff_flag = 0;
 449                         coeff = -1;
 450                 }
 451                 num = 0;
 452         }
 453 done:
 454         if (!num_nodes)
 455                 return -1;
 456         /* Fill remainder of system RAM, if appropriate. */
 457         if (addr < max_addr) {
 458                 if (coeff_flag && coeff < 0) {
 459                         /* Split remaining nodes into num-sized chunks */
 460                         num_nodes += split_nodes_by_size(nodes, &addr, max_addr,
 461                                                          num_nodes, num);
 462                         goto out;
 463                 }
 464                 switch (*(cmdline - 1)) {
 465                 case '*':
 466                         /* Split remaining nodes into coeff chunks */
 467                         if (coeff <= 0)
 468                                 break;
 469                         num_nodes += split_nodes_equally(nodes, &addr, max_addr,
 470                                                          num_nodes, coeff);
 471                         break;
 472                 case ',':
 473                         /* Do not allocate remaining system RAM */
 474                         break;
 475                 default:
 476                         /* Give one final node */
 477                         setup_node_range(num_nodes, nodes, &addr,
 478                                          max_addr - addr, max_addr);
 479                         num_nodes++;
 480                 }
 481         }
 482 out:
 483         memnode_shift = compute_hash_shift(nodes, num_nodes);
 484         if (memnode_shift < 0) {
 485                 memnode_shift = 0;
 486                 printk(KERN_ERR "No NUMA hash function found.  NUMA emulation "
 487                        "disabled.\n");
 488                 return -1;
 489         }
 490
 491         /*
 492          * We need to vacate all active ranges that may have been registered by
 493          * SRAT and set acpi_numa to -1 so that srat_disabled() always returns
 494          * true.  NUMA emulation has succeeded so we will not scan ACPI nodes.
 495          */
 496         remove_all_active_ranges();
 497 #ifdef CONFIG_ACPI_NUMA
 498         acpi_numa = -1;
 499 #endif
 500         for_each_node_mask(i, node_possible_map) {
 501                 e820_register_active_regions(i, nodes[i].start >> PAGE_SHIFT,
 502                                                 nodes[i].end >> PAGE_SHIFT);
 503                 setup_node_bootmem(i, nodes[i].start, nodes[i].end);
 504         }
 505         acpi_fake_nodes(nodes, num_nodes);
 506         numa_init_array();
 507         return 0;
 508 }
 509 #endif /* CONFIG_NUMA_EMU */
 510
 511 void __init numa_initmem_init(unsigned long start_pfn, unsigned long end_pfn)
 512 {
 513         int i;
 514
 515         nodes_clear(node_possible_map);
 516
 517 #ifdef CONFIG_NUMA_EMU
 518         if (cmdline && !numa_emulation(start_pfn, end_pfn))
 519                 return;
 520         nodes_clear(node_possible_map);
 521 #endif
 522
 523 #ifdef CONFIG_ACPI_NUMA
 524         if (!numa_off && !acpi_scan_nodes(start_pfn << PAGE_SHIFT,
 525                                           end_pfn << PAGE_SHIFT))
 526                 return;
 527         nodes_clear(node_possible_map);
 528 #endif
 529
 530 #ifdef CONFIG_K8_NUMA
 531         if (!numa_off && !k8_scan_nodes(start_pfn<<PAGE_SHIFT,
 532                                         end_pfn<<PAGE_SHIFT))
 533                 return;
 534         nodes_clear(node_possible_map);
 535 #endif
 536         printk(KERN_INFO "%s\n",
 537                numa_off ? "NUMA turned off" : "No NUMA configuration found");
 538
 539         printk(KERN_INFO "Faking a node at %016lx-%016lx\n",
 540                start_pfn << PAGE_SHIFT,
 541                end_pfn << PAGE_SHIFT);
 542         /* setup dummy node covering all memory */
 543         memnode_shift = 63;
 544         memnodemap = memnode.embedded_map;
 545         memnodemap[0] = 0;
 546         nodes_clear(node_online_map);
 547         node_set_online(0);
 548         node_set(0, node_possible_map);
 549         for (i = 0; i < NR_CPUS; i++)
 550                 numa_set_node(i, 0);
 551         /* cpumask_of_cpu() may not be available during early startup */
 552         memset(&node_to_cpumask_map[0], 0, sizeof(node_to_cpumask_map[0]));
 553         cpu_set(0, node_to_cpumask_map[0]);
 554         e820_register_active_regions(0, start_pfn, end_pfn);
 555         setup_node_bootmem(0, start_pfn << PAGE_SHIFT, end_pfn << PAGE_SHIFT);
 556 }
 557
 558 __cpuinit void numa_add_cpu(int cpu)
 559 {
 560         set_bit(cpu, (unsigned long *)&node_to_cpumask_map[cpu_to_node(cpu)]);
 561 }
 562
 563 void __cpuinit numa_set_node(int cpu, int node)
 564 {
 565         u16 *cpu_to_node_map = (u16 *)x86_cpu_to_node_map_early_ptr;
 566
 567         cpu_pda(cpu)->nodenumber = node;
 568
 569         if(cpu_to_node_map)
 570                 cpu_to_node_map[cpu] = node;
 571         else if(per_cpu_offset(cpu))
 572                 per_cpu(x86_cpu_to_node_map, cpu) = node;
 573         else
 574                 Dprintk(KERN_INFO "Setting node for non-present cpu %d\n", cpu);
 575 }
 576
 577 unsigned long __init numa_free_all_bootmem(void)
 578 {
 579         unsigned long pages = 0;
 580         int i;
 581
 582         for_each_online_node(i)
 583                 pages += free_all_bootmem_node(NODE_DATA(i));
 584
 585         return pages;
 586 }
 587
 588 void __init paging_init(void)
 589 {
 590         unsigned long max_zone_pfns[MAX_NR_ZONES];
 591         int i;
 592
 593         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 594         max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
 595         max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
 596         max_zone_pfns[ZONE_NORMAL] = end_pfn;
 597
 598         sparse_memory_present_with_active_regions(MAX_NUMNODES);
 599         sparse_init();
 600
 601         for_each_online_node(i)
 602                 flat_setup_node_zones(i);
 603
 604         free_area_init_nodes(max_zone_pfns);
 605 }
 606
 607 static __init int numa_setup(char *opt)
 608 {
 609         if (!opt)
 610                 return -EINVAL;
 611         if (!strncmp(opt, "off", 3))
 612                 numa_off = 1;
 613 #ifdef CONFIG_NUMA_EMU
 614         if (!strncmp(opt, "fake=", 5))
 615                 cmdline = opt + 5;
 616 #endif
 617 #ifdef CONFIG_ACPI_NUMA
 618         if (!strncmp(opt, "noacpi", 6))
 619                 acpi_numa = -1;
 620         if (!strncmp(opt, "hotadd=", 7))
 621                 hotadd_percent = simple_strtoul(opt+7, NULL, 10);
 622 #endif
 623         return 0;
 624 }
 625 early_param("numa", numa_setup);
 626
 627 /*
 628  * Setup early cpu_to_node.
 629  *
 630  * Populate cpu_to_node[] only if x86_cpu_to_apicid[],
 631  * and apicid_to_node[] tables have valid entries for a CPU.
 632  * This means we skip cpu_to_node[] initialisation for NUMA
 633  * emulation and faking node case (when running a kernel compiled
 634  * for NUMA on a non NUMA box), which is OK as cpu_to_node[]
 635  * is already initialized in a round robin manner at numa_init_array,
 636  * prior to this call, and this initialization is good enough
 637  * for the fake NUMA cases.
 638  */
 639 void __init init_cpu_to_node(void)
 640 {
 641         int i;
 642
 643         for (i = 0; i < NR_CPUS; i++) {
 644                 u16 apicid = x86_cpu_to_apicid_init[i];
 645
 646                 if (apicid == BAD_APICID)
 647                         continue;
 648                 if (apicid_to_node[apicid] == NUMA_NO_NODE)
 649                         continue;
 650                 numa_set_node(i, apicid_to_node[apicid]);
 651         }
 652 }
 653
 654